Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 18831-2010 Safety of machinery—Interlocking devices associated with guards—Principles for design and selection. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 18831-2010:
——26 terms such as "defeat", "holding force" and "actuator" are added, and 3 terms such as "positive mode actuation", "positive opening operation of contact elements" and "stop time" are deleted (see Clause 3 hereof, Clause 3 of Edition 2010);
——The sub-clause 5.7 is adjusted to Clause 7 (see Clause 7 hereof; 5.7 of Edition 2010);
——The control requirements are added (see Clause 8 hereof);
——The content in Clause 6 is adjusted into 8.7 (see 8.7 hereof; Clause 6 of Edition 2010);
——The requirements for information for use are added (see Clause 9 hereof);
——According to the newly defined interlocking device types, the contents of Annex A to Annex M are integrated and rearranged into Annex A to Annex E (see Annex A to Annex E hereof, Annex A to Annex M of Edition 2010);
——The informative annex F "Example of guard locking devices" is added (see Annex F hereof);
——The informative annex G "Application examples of interlocking devices used within a safety function" is added (see Annex G hereof);
——The informative annex H "Motivation to defeat interlocking device" is added (see Annex H hereof);
——The informative annex I "Examples for maximum static action forces" is added (see Annex I hereof).
This standard is, by means of translation, identical to ISO 14119: 2013 Safety of machinery—Interlocking devices associated with guards—Principles for design and selection (English edition).
The Chinese documents consistent and corresponding with the normative international documents in this standard are as follows:
——GB 5226.1-2008 Electrical safety of machinery—Electrical equipment of machines—Part 1: General requirements (IEC 60204-1: 2005, IDT)
——GB/T 14048.13-2006 Low-voltage switchgear and controlgear—Part 5-3: Control circuit devices and switching elements - Requirements for proximity devices with defined behaviour under fault conditions(PDF) (IEC 60947-5-3: 1999, IDT)
——GB 28526-2012 Electrical safety of machinery—Functional safety of safety-related electrical, electronic and programmable electronic control systems (IEC 62061: 2005, IDT)
This standard was proposed by and is under the jurisdiction of the National Technical Committee on Machinery Safety of Standardization Administration of China (SAC/TC 208).
The previous editions of this standard are as follows:
——GB/T 18831-2002, GB/T 18831-2010.
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Introduction
The structure of safety standards in the field of machinery is as follows:
——Type-A standards (basic safety standards) giving basic concepts, principles for design, and general aspects that can be applied to all machinery;
——Type-B standards (generic safety standards) dealing with one safety aspect or one type of safeguard that can be used across a wide range of machinery;
? Type-B1 standards on particular safety aspects (e.g. safety distances, surface temperature, noise);
? Type-B2 standards on safeguards (e.g. two-hand controls, interlocking devices, pressure sensitive devices, guards);
——Type-C standards (machine safety standards) dealing with detailed safety requirements for a particular machine or group of machines.
This document is a Type-B2 standard as stated in IGB/T 15706.
The requirements of this document may be supplemented or modified by a Type-C standard.
For machines which are covered by the scope of a Type-C standard and which have been designed and built according to the requirements of that standard, the requirements of that Type-C standard take precedence.
This standard has been prepared to give guidance to machinery designers and writers of product safety standards on how to design and select interlocking devices associated with guards.
Relevant clauses of this standard, used alone or in conjunction with provisions from other standards, may be used as a basis for verification procedures for the suitability of a device for interlocking duties.
The informative Annexes A to F describe the technology and the typical characteristics of the defined 4 types of interlocking devices. Other solutions may be adopted, provided that they comply with the principles of this standard. The informative Annexes G to I give information on particular aspects like interlocking devices used within safety functions, risk assessment considering the motivation to defeat and static action forces. ISO/TR 24119 is under preparation and will give information on the masking of faults in series connection of interlocking devices.
Safety of machinery—Interlocking devices associated with guards—
Principles for design and selection
1 Scope
This standard specifies principles for the design and selection—independent of the nature of the energy source—of interlocking devices associated with guards.
This standard covers the parts of guards which actuate interlocking devices.
Note: ISO 14120 specifies general requirements for the design and construction of guards provided primarily to protect persons from mechanical hazards. The processing of the signal from the interlocking device to stop and immobilize the machine is dealt with in GB/T 16855.1 or IEC 62061.
This standard does not necessarily provide all the specific requirements for trapped key systems.
This standard provides measures to minimize defeat of interlocking devices in a reasonably foreseeable manner:
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 15706-2012 Safety of machinery—General principles for design—Risk assessment and risk reduction (ISO 12100: 2010, IDT)
GB/T 16855.1-2008 Safety of machinery—Safety-related parts of control systems—Part 1: General principles for design (ISO 13849-1: 2006, IDT)
GB/T 16855.2-2015 Safety of machinery—Safety-related parts of control systems—Part 2: Validation (ISO 13849-2: 2012, IDT)
IEC 60947-5-3 Low-voltage switchgear and controlgear—Part 5-3: Control circuit devices and switching elements—Requirements for proximity devices with defined behaviour under fault conditions (PDF)
IEC 60204-1: 2009 Safety of machinery—Electrical equipment of machines—Part 1: General requirements
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IEC 62061: 2012 Safety of machinery—Functional safety of safety-related electrical, electronic and programmable electronic control systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 15706 and GB/T 16855.1 and the following apply.
3.1
interlocking device
interlock
mechanical, electrical or other type of device, the purpose of which is to prevent the operation of hazardous machine functions under specified conditions (generally as long as a guard is not closed)
Note: See Figure 1 and Table 1.
[GB/T 15706-2012, Definition 3.28.1]
Key:
1––—guard; 4——position switch;
2——interlocking device; 5——actuating system;
3——actuator; 6——output system.
a——direction of opening;
Figure 1 Example of an interlocking device
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3.2
interlocking guard
guard associated with an interlocking device so that, together with the control system of the machine, the following functions are performed:
——the hazardous machine functions “covered” by the guard cannot operate until the guard is closed;
——if the guard is opened while hazardous machine functions are operating, a stop command is given;
——when the guard is closed, the hazardous machine functions “covered” by the guard may operate (the closure of the guard does not by itself start the hazardous machine functions). An interlocking guard can contain/be equipped of one or more interlocking devices.
Note: An interlocking guard can contain/be equipped of one or more interlocking devices. These interlocking devices can also be of different types.
[GB/T 15706-2012, Definition 3.27.4]
3.3
interlocking guard with a start function
control guard
special form of interlocking guard which, once it has reached its closed position, gives a command to initiate the hazardous machine function(s) without the use of a separate start control
Note: GB/T 15706-2012, 6.3.3.2.5 gives detailed provisions regarding the condition of use.
[GB/T 15706-2012, Definition 3.27.6]
3.4
guard locking device
device intended to lock a guard in the closed position and linked to the control system
3.5
interlocking guard with guard locking
guard associated with an interlocking device and a guard locking device so that, together with the control system of the machine, the following functions are performed:
——the hazardous machine functions "covered" by the guard cannot operate until the guard is cIosed and Iocked;
——the guard remains closed and Iocked until the risk due to the hazardous machine functions "covered” by the guard has disappeared;
——when the guard is closed and locked, the hazardous machine functions "covered" by the guard can operate. The closure and locking of the guard do not by themselves start the hazardous machine functions
[GB/T 15706-2012, Definition 3.27.5]
3.6
safety-related part of a control system
SRP/CS
part of a control system that responds to safety-related input signals and generates safety-related output signals
Note 1: The combined safety-related parts of a control system start at the point where the safety-related input signals are initiated (including e.g. the actuating cam and the roller of the position switch) and end at the output of the power control elements (including, for example, the main contacts of a contactor).
Note 2: If monitoring systems are used for diagnostics, they are also considered as SRP/CS.
Note 3: It is revised from GB/T 16855.1-2008, Definition 3.1.1.
3.7
defeat
action that makes interlocking devices inoperative or bypasses them with the result that a machine is used in a manner not intended by the designer or without the necessary safety measures
3.8
defeat in a reasonably foreseeable manner
defeat of an interlocking device either manually or by using readily available objects
Note 1: This definition includes the removal of switches or actuators using tools that are needed for the intended use of the machine or that are readily available (screw drivers, wrenches, hexagon keys, pliers).
Note 2: Readily available objects for substitute actuation include:
——screws, needles and sheet-metal pieces;
——objects in daily use such as keys, coins, adhesive tape, string and wire;
——spare keys for the trapped-key interlocking devices;
——spare actuators.
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3.9
automatic monitoring
diagnostic function which initiates a fault reaction function if the ability of a component or an element to perform its function is diminished, or if the process conditions are changed in such a way that hazards are generated
3.10
direct mechanical action
positive mechanical action
movement of a mechanical component which arises inevitably from the movement of another mechanical component either by direct contact or via rigid elements
3.11
direct opening action
positive opening operation
achievement of contact separation as a direct result of a specified movement of the switch actuator through non-resilient members (for example not dependent upon springs)
Note: It is revised from IEC 60947-5-1: 2003, Definition K.2.2.
3.12
actuator
separate part of an interlocking device which transmits the state of the guard (closed or not closed) to the actuating system
Example: Guard-mounted cam, key, shaped tongue, reflector, magnet, RFID tag.
Note 1: See also Annexes A to E.
Note 2: Examples of actuators are shown in Figure 2.
3.13
coded actuator
actuator which is specially designed (e.g. by shape) to actuate a certain position switch
3.13.1
low level coded actuator
coded actuator for which 1 to 9 variations in code are available
3.13.2
medium level coded actuator
coded actuator for which 10 to 1,000 variations in code are available
3.13.3
high level coded actuator
coded actuator for which more than 1,000 variations are available
3.14
actuating system
part of the interlocking device which transmits the position of the actuator and changes the state of the output system
Example: Roller plunger, cam mechanism, optical, inductive or capacitive sensor.
Note: Examples of actuating systems are shown in Figure 2.
3.15
output system
part of the interlocking device that indicates the state of the guard to the control system
Example: Contact element (electromechanical), semiconductor output, valve.
3.16
type 1 interlocking device
interlocking device with mechanically actuated position switch with uncoded actuator
Example: Hinged interlocking devices.
Note: See Annex A for detailed examples.
3.17
type 2 interlocking device
interlocking device with mechanically actuated position switch with coded actuator
Example: Tongue-actuated position switches.
Note: See Annex B for detailed examples.
3.18
type 3 interlocking device
interlocking device with non-contact actuated position switch with uncoded actuator
Example: Proximity switches.
Note: See Annex C for detailed examples.
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3.19
type 4 interlocking device
interlocking device with non-contact actuated position switch with coded actuator
Example: RFID tag actuated position switches.
Note: See Annex D for detailed examples.
3.20
stop command
signal generated by the interlocking device that causes the hazardous machine function to disappear
3.21
overall system stopping performance
time interval between the stop command given by opening the guard and the termination of the hazardous machine function
Note: It is revised from GB/T 19876-2012, Definition 3.1.2.
3.22
access time
time taken by a person to reach the hazard zone after initiation of the stop command by the interlocking device, as calculated on the basis of an approach speed of the body or part of the body
Note: For the selection of the approach speed and the calculation of the access time, see GB/T 19876.
3.23
holding force
force that a guard locking device can withstand without being damaged so that its further use will not be impaired and the guard will not leave the closed position
3.24
prevention of inadvertent locking position
feature of a guard locking device which ensures that the locking means (e.g. a locking bolt) cannot take the locked position when the guard is not closed
3.25
emergency release of guard locking
possibility to release manually without aids the guard locking from outside the safeguarded area in case of an emergency
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Note: The guard locking with emergency release can be necessary for releasing trapped persons or fire-fighting, for example.
3.26
auxiliary release of guard locking
possibility to release manually by means of a tool or a key the guard locking from outside the safeguarded area in case of its failure
Note: The guard locking with auxiliary release is not suitable for emergency or escape release of guard locking.
3.27
escape release of guard locking
possibility to release manually without aids the guard locking from inside the safeguarded area to leave the area
3.28
guard locking for protection of a person
application of a guard locking device to protect a person against a hazard
3.29
guard locking for protection of the process
application of a guard locking device to protect the working process from being interrupted
3.30
tool
implement such as a key or wrench designed to operate a fastener
Note: An improvised implement such as a coin or a nail file cannot be considered as a tool.
[ISO 14120: 2002, Definition 3.9]
3.31
power interlocking
interlocking which directly interrupts the energy supply to the machine actuators or disconnects moving parts from the machine actuators
Note: Resumption of the energy supply is only possible with the guard in the closed and locked position. “Directly” means that, unlike control interlocking, the control system does not play any intermediate role in the interlocking function.
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3.32
safety function
function of a machine whose failure can result in an immediate increase of the risk(s)
[GB/T 15706-2012, Definition 3.30]
4 Operating principles and typical forms of interlocking devices associated with guards
4.1 General
Interlocking techniques involve a broad spectrum of technological aspects. Interlocking devices may be classified using a great variety of criteria, e.g. the nature of the link between guard and output system, or the technological type (electromechanical, pneumatic, electronic, etc.) of the output system.
Interlocking devices have a guard position monitoring function that senses whether the guard is closed or not and produce a stop command when the guard is not in the closed position. An interlocking device may also be used in the control of other functions e.g. application of a brake to stop hazardous machine functions before access is possible. Some interlocking devices also have a guard locking function to keep the guard locked while hazardous machine function is present. A guard locking device status monitoring function monitors whether the guard locking device is locked or unlocked and produces an appropriate output signal [see 4.3.1a) and b)].
Note 1: The guard locking device (see 3.4) may be an integral part of an interlocking device, or a separate unit.
Note 2: See also GB/T 15706-2012, 6.3.3.1 for additional information on guards.
Note 3: The four types of interlocking device are not shown in Table 1 and presented in a hierarchical order. The correct application of each type of interlocking device will be dependent on the risk assessment that shall be made for the specific machine.
Table 1 shows the actuation principles and actuators for the defined interlocking device types.
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Table 1 Overview of interlocking devices
Actuation principle examples Actuator examples Type Examples: see Annex a
Mechanical Physical contact/force Uncoded Rotating cam Type 1 A.1
Linear cam A.2, A.4
Hinge A.3
Coded Tongue (-shaped actuator) Type 2 B.1
Trapped-key B.2
Non-contact Inductive Uncoded Suitable ferric metal Type 3 C
Magnetic Magnet, solenoid
Capacitive Any suitable object
Ultrasonic Any suitable object
Optic Any suitable object
Magnetic Coded Coded magnet Type 4 D.1
RFID Coded RFID tag D.2
Optic Optically coded tag —
a Examples of other interlocking guards are given in Annex E.
Key:
1——movable guard; 4——position switch;
2——interlocking device; 5——actuating system;
3——actuator; 6——output system.
a Cam; c E.g. RFID, reflector, suitable surface;
b Tongue; d Movement direction.
Note: In some exceptional cases, the position switch can be installed on the movable guard and the actuator on the stationary part of the machine. In these cases, “1” is the stationary part of the machine.
Figure 2 Principle of types 1, 2, 3 and 4 interlocking devices
4.2 Principles of guard interlocking without guard locking
When guard interlocking function without guard locking is used, the guard can be opened at any time regardless of the function of the machine.
If the guard is not closed, the interlocking device shall generate a stop command.
Note 1: For interlocking with the machine control system, see Clause 8.
Note 2: Examples of interlocking devices without guard locking are shown in Annexes A, B, C and D.
Note 3: A functional diagram of interlocking devices without guard locking is shown in Figure 3.
Figure 3 Functional diagram of interlocking devices without guard locking
4.3 Principles of guard interlocking with guard locking
4.3.1 General
When interlocking with guard locking is applied, opening of the guard shall be prevented by a guard locking device (see 3.4) unless all hazardous machine functions covered by this guard have disappeared.
There are two alternatives for the design of the guard locking function (see Figure 4).
a) Unlocking of the guard can be initiated at any time by the operator. When unlocking is started, the guard locking device generates a stop command. This is called unconditional unlocking. The time necessary for the guard to be unlocked shall be greater than the time necessary for the hazardous machine function to disappear.
b) Unlocking of the guard is possible only when the hazardous machine functions have disappeared. This is called conditional unlocking.
Note: In conditional locking, the change from state 2 to state 3 or from state 3 to state 2 can happen without time delay.
Figure 4 Functional diagrams of interlocking devices with guard locking
Examples of guard locking devices are given in Annex F.
4.3.2 Interlocking device with mechanically operated guard locking
The mechanical part (e.g. bolt) which locks the interlocking guard may be:
——manually applied and manually released (see Figure F.5);
——spring (or similar) applied and power-ON released [see Figure 5a)];
——power-ON applied and spring (or similar) released [see Figure 5b)];
——power-ON applied and power-ON released [see Figure 5c)].
Mechanically operated guard locking shall use the principle of direct mechanical blocking due to form. Friction and force alone shall not be relied upon.
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a) Spring applied Locking
Power-ON released Unlocking
b) Power-ON applied Locking
Spring released Unlocking
c) Power-ON applied Locking
Power-ON released Unlocking
d) Power-ON applied Locking
Power-ON released Unlocking
Figure 5 Operating modes of guard locking device in power-actuated guard locking devices
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4.3.3 Interlocking device with electromagnetically operated guard locking
The guard is kept closed (locked) without any mechanical locking means by an electromagnetic force (see F.4).
The electromagnetic guard locking operates on the principle of power-ON applied and power-OFF released [see Figure 5d)].
5 Requirements for the design and the installation of interlocking devices with and without guard locking
5.1 General
Interlocking devices shall be installed in a suitable robust manner and in accordance with any instructions provided by the manufacturer (see Clause 9).
5.2 Arrangement and fastening of position switches
Position switches shall be arranged so that they are sufficiently protected against a change of their position. In order to achieve this, the following requirements shall be met:
a) fasteners of the position switches shall be reliable and loosening them shall require a tool;
b) type 1 position switches shall have provisions for permanently fixing the location after adjustment (e.g. by means of pins or dowels);
c) necessary means of access to position switches for maintenance and checking for correct operation shall be ensured. Prevention of defeat in a reasonably foreseeable manner shall also be considered when designing the access means;
d) self-loosening shall be prevented;
e) defeat of the position switch in a reasonably foreseeable manner shall be prevented (see Clause 7);
f) the position switch shall be located and, if necessary, protected so that damage from foreseeable external causes is avoided;
g) the movement produced by mechanical actuation or the gap of the proximity device actuating system shall remain within the specified operating range of the position switch or actuating system specified by the switch manufacturer to ensure correct operation and/or prevent overtravel;
h) a position switch shall not be used as a mechanical stop, unless this is the intended use of the position switch as declared by the manufacturer;
i) misalignment of the guard that creates a gap before the position switch changes its state shall not be sufficient as to impair the protective effect of the guard (for access to hazard zones, see ISO 13855 and ISO 13857);
j) the support and fastening for the position switches shall be sufficiently rigid to maintain correct operation of the position switch.
5.3 Arrangement and fastening of actuators
5.3.1 General
Actuators (see Figure 2) shall be so fastened to minimize the possibility that they come loose or change their intended position relative to the actuating system during the intended lifetime.
Note: A regular check can be necessary (see 9.3.2).
The following requirements shall be met:
a) fasteners of the actuators shall be reliable and loosening them shall require a tool;
b) self-loosening shall be prevented;
c) the position switch shall be located and, if necessary, protected so that damage from foreseeable external causes is avoided;
d) an actuator shall not be used as a mechanical stop, unless this is the intended use of the actuator as declared by the manufacturer;
e) the support and fastening for the actuators shall be sufficiently rigid to maintain correct operation of the actuator.
5.3.2 Cams
Rotary and linear cams for type 1 interlocking devices shall meet the following requirements:
a) they are fixed by fasteners requiring a tool for loosening them;
b) final fixing is achieved by form (e.g. spline or pin) or other methods that provide equivalent integrity of fixing;
c) they do not damage the position switch or impair its durability.
5.4 Actuation modes of interlocking devices
When a single type 1 or type 2 interlocking device is used to generate a stop command, it shall be actuated by direct mechanical action between guard, actuator and output system and the contact element shall have direct opening action (see 3.10, 3.11 and Table 2).
Non-direct mechanical action for a type 1 interlocking device shall be used only in conjunction with a type 1 or type 2 interlocking device with direct mechanical action between guard, actuator and output system. Combining one interlocking device with direct mechanical action with a second interlocking device with non-direct mechanical action avoids common cause failures (see 8.3).
Table 2 Direct and non-direct mechanical action of type 1 interlocking devices
Mechanical action Guard closed Guard not closed Working mode Example of behaviour in case of failure (see 8.3.2)
Direct Plunger held depressed by cam as long as guard is not closed.
When guard closed, output system changes, its state as result of action of return spring. Output system remains in safe state when guard is not closed even if spring breaks.
Non-direct The plunger is held depressed by a cam as long as the guard is closed.
When guard not closed, output system changes state as result of action of return spring. If spring breaks, output system can go to unsafe state even if guard not closed.
Interlocking devices shall be actuated appropriate to the actuation principle of the applied position switch.
If a type 3 or type 4 interlocking device is the only interlocking device, it shall meet the requirements of IEC 60947-5-3.
5.5 Interface to control systems
The output system of interlocking devices shall be suitable for inclusion in a control system designed in accordance with GB/T 16855.1 or IEC 62061.
5.6 Mechanical stop
If an interlocking device is declared by the manufacturer of the device to be suitable for use as a mechanical stop the maximum impact energy withstand value shall be given [see also 9.2.2 r)].
5.7 Additional requirements on guard locking devices
5.7.1 General
If the application of the guard locking function creates hazards, additional measures shall be considered (see 5.7.5 and GB/T 15706-2012, 6.3.5.3).
The locking element (e.g. bolt) intended to lock the guard shall be “spring applied – power-ON released” [see Figure 5a)] or “power-ON applied – power-ON released” [see Figure 5c)] unless the outcome of the risk assessment shows that this is not appropriate. If other systems [e.g. Figure 5b)] are used in a specific application, they shall provide an equivalent level of safety.
Note: When the loss of power results in the release of the locking element, the stopping time of the machine is often lengthened considerably and it can be possible to access to the hazard before the movements have been stopped (or other hazards disappeared).
The requirements of 5.7 apply when guard locking function is used for the protection of persons. While the requirements of 5.7 do not apply when guard locking function is used solely for the protection of a process. Nevertheless, if guard locking function and guard interlocking function are part of the same device the safety level of the guard interlocking function shall not be negatively affected by a non safety related guard locking function (i. e. guard locking function used solely for the protection of the process).
The requirements of 5.7 apply to both guard locking devices composed of separate components as well as to guard locking devices which form an integral part of an interlocking device with guard locking. They apply to all technologies.
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The guard locking device shall allow the locked position to be monitored by providing an output system compatible with a control system designed in accordance with GB/T 16855.1 or IEC 62061.
The guard locking device shall only allow hazardous functions of the machine when the guard is closed and locked.
5.7.2 Mechanical guard locking device
5.7.2.1 General
Mechanically operating guard locking shall result from the engagement of two rigid parts [form closure, see Figure 5a) to c)].
If it is foreseeable that access is necessary in case of emergency, for “spring applied – power-ON released” or “power-ON applied – power-ON released” systems [see Figure 5a) and c)], a guard locking device with emergency release (see 5.7.5.3) shall be provided.
Figure 6 shows the functionality of such a device.
5.7.2.2 Locking monitoring
The locked position of the locking element shall be monitored in accordance with the requirements of 5.5.
The hazardous function of the machine shall only be possible when the monitoring detects the closed position of the guard and the locked position of the locking element (see Annex F).
For an effective monitoring of the guard locking device, one of the following methods shall be ensured:
——the locking element can only go in the locked position if the movable guard is in the closed position (see Figure 6), in that case the closed position and the locking of the guard can be checked by the monitoring of the locking element;
——in the other case, the monitoring of the locking element and additionally the monitoring of the guard position shall be used for interlocking.
Key:
a)——guard closed and locked; 1——actuator (tongue);
b)——guard closed and not locked; 2——locking element (bolt);
c)——guard not closed and not locked; 3——actuating system (internal rotating cam).
Note: In this kind of position switch, the actuator has two functions: to operate the contacts (not shown in the figure) and together with the internal rotating cam and the bolt to provide the guard locking function. The bolt may be operated by external means e.g. a solenoid or pneumatic cylinder.
Figure 6 Example of type 2 interlocking device with guard locking
5.7.3 Electromagnetic guard locking device
5.7.3.1 General
The force required for the locking of the guard is applied by the generation of an electromagnetic field [see Figure 5d)].
5.7.3.2 Locking monitoring
The holding force shall be monitored to determine if the specified holding force has been achieved and maintained (see 6.2.2 and Annex I).
The hazardous function of the machine shall only be possible when the monitoring detects the closed position of the guard and the achievement of the specified holding force.
5.7.3.3 Basic measures for minimizing defeat possibilities
If an electromagnetic guard locking device is opened by force, it shall be ensured that the process cannot be immediately continued.
Note: In contrast to a mechanical guard locking, an electromagnetic guard locking shows no damage after an opening by force.
The objective of the measure is that an opening by force results in a time expenditure which is similar to that of repair works (time delay) and comparable with the repair of a damage of an electromechanical guard locking.
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Terms and definitions
4 Operating principles and typical forms of interlocking devices associated with guards
4.1 General
4.2 Principles of guard interlocking without guard locking
4.3 Principles of guard interlocking with guard locking
5 Requirements for the design and the installation of interlocking devices with and without guard locking
5.1 General
5.2 Arrangement and fastening of position switches
5.3 Arrangement and fastening of actuators
5.5 Interface to control systems
5.6 Mechanical stop
5.7 Additional requirements on guard locking devices
6 Selection of an interlocking device
6.1 General
6.2 Selection of a guard locking device
6.3 Environmental conditions considerations
7 Design to minimize defeat possibilities of interlocking devices
7.1 General
7.2 Additional measures to minimize defeat possibilities of interlocking devices
8 Control requirements
8.1 General
8.2 Assessment of faults
8.3 Prevention of common cause failures
8.4 Release of guard locking device
8.5 Fault exclusion
8.6 Logical series connection of interlocking devices
8.7 Electrical and environmental conditions
9 Information for use
9.1 General
9.2 Information for use given by the manufacturer of interlocking devices
9.3 Information for use given by the manufacturer of the machine
Annex A (Informative) Type 1 interlocking device — Examples
Annex B (Informative) Type 2 interlocking device — Examples
Annex C (Informative) Type 3 interlocking device — Examples
Annex D (Informative) Type 4 interlocking device — Examples
Annex E (Informative) Examples of other interlocking devices
Annex F (Informative) Example of guard locking devices
Annex G (Informative) Application examples of interlocking devices used within a safety function
Annex H (Informative) Motivation to defeat interlocking device
Annex I (Informative) Examples for maximum static action forces
Bibliography
機(jī)械安全與防護(hù)裝置相關(guān)的聯(lián)鎖裝置
設(shè)計(jì)和選擇原則
1 范圍
本標(biāo)準(zhǔn)規(guī)定了與防護(hù)裝置相關(guān)的聯(lián)鎖裝置的設(shè)計(jì)和選擇原則，不管其使用何種能源類型。
本標(biāo)準(zhǔn)適用于防護(hù)裝置中驅(qū)動(dòng)聯(lián)鎖裝置的部件。
注：ISO 14120規(guī)定的防護(hù)裝置的設(shè)計(jì)和制造一般要求主要用于防止機(jī)械危險(xiǎn)。關(guān)于聯(lián)鎖裝置發(fā)出的，使機(jī)器停止并保持不動(dòng)的信號(hào)的處理，見GB/T 16855.1或IEC 62061。
本標(biāo)準(zhǔn)未規(guī)定截留鑰匙系統(tǒng)的所有具體要求。
本標(biāo)準(zhǔn)給出了盡可能防止以合理可預(yù)見的方式棄用聯(lián)鎖裝置的措施。
2 規(guī)范性引用文件
下列文件對(duì)于本文件的應(yīng)用是必不可少的。凡是注日期的引用文件，僅注日期的版本適用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改單)適用于本文件。
GB/T 15706—2012 機(jī)械安全 設(shè)計(jì)通則 風(fēng)險(xiǎn)評(píng)估與風(fēng)險(xiǎn)減小(ISO 12100：2010，IDT)
GB/T 16855.1—2008 機(jī)械安全 控制系統(tǒng)有關(guān)安全部件 第1部分：設(shè)計(jì)通則(ISO 13849-1：2006，IDT)
GB/T 16855.2—2015 機(jī)械安全 控制系統(tǒng)安全相關(guān)部件 第2部分：確認(rèn)(ISO 13849-2：2012，IDT)
IEC 60947-5-3 低壓開關(guān)設(shè)備和控制設(shè)備 第5-3部分：控制電路電器和開關(guān)元件 在故障條件下具有確定功能的接近開關(guān)(PDF)的要求[Low-voltage switchgear and controlgear—Part 5-3：Control circuit devices and switching elements—Requirements for proximity devices with defined behaviour under fault conditions(PDF)]
IEC 60204-1：2009 機(jī)械安全 機(jī)械電氣設(shè)備 第1部分：通用技術(shù)條件(Safety of machinery—Electrical equipment of machines—Part 1：General requirements)
IEC 62061：2012 機(jī)械安全 電氣、電子和可編程序電子控制系統(tǒng)的功能安全(Safety of machinery—Functional safety of safety-related electrical，electronic and programmable electronic control systems)
3 術(shù)語和定 義
GB/T 15706、GB/T 16855.1界定的以及下列術(shù)語和定義適用于本文件。
3.1
聯(lián)鎖裝置 Interlocking device
聯(lián)鎖 Interlock
用于防止危險(xiǎn)機(jī)器功能在特定條件下(通常是指只要防護(hù)裝置未關(guān)閉)運(yùn)行的機(jī)械、電氣或其他類型的裝置。
注：見圖1和表1。
[GB/T 15706—2012，定義3.28.1]
說明：
1——防護(hù)裝置； 4——位置開關(guān)；
2——聯(lián)鎖裝置； 5——執(zhí)行系統(tǒng)；
3——操動(dòng)件； 6——輸出系統(tǒng)。
a——打開方向；
圖1 聯(lián)鎖裝置示例
3.2
聯(lián)鎖防護(hù)裝置 interlocking guard
與聯(lián)鎖裝置聯(lián)用的防護(hù)裝置，同機(jī)器控制系統(tǒng)一起實(shí)現(xiàn)以下功能：
——在防護(hù)裝置關(guān)閉前，其“遮蔽”的危險(xiǎn)的機(jī)器功能不能執(zhí)行；
——在危險(xiǎn)機(jī)器功能運(yùn)行時(shí)，如果打開防護(hù)裝置.則發(fā)出停機(jī)指令；
——在防護(hù)裝置關(guān)閉后，防護(hù)裝置“遮蔽”的危險(xiǎn)的機(jī)器功能可以運(yùn)行。防護(hù)裝置本身的關(guān)閉不會(huì)啟動(dòng)危險(xiǎn)機(jī)器功能。
注：一個(gè)聯(lián)鎖防護(hù)裝置可包含/配備一個(gè)或多個(gè)聯(lián)鎖裝置，這些聯(lián)鎖裝置的類型也可不同。
[GB/T 15706—2012，定義3.27.4]
3.3
帶啟動(dòng)功能的聯(lián)鎖防護(hù)裝置 interlocking guard with a start function
帶控制功能的防護(hù)裝置 control guard
特殊聯(lián)鎖防護(hù)裝置，一旦其到達(dá)關(guān)閉位置，便發(fā)出觸發(fā)機(jī)器危險(xiǎn)功能的命令，無需使用單獨(dú)的啟動(dòng)控制。
注：GB/T 15706—2012，6.3.3.2.5給出了關(guān)于使用條件的詳細(xì)規(guī)定。
[GB/T 15706—2012，定 義3.27.6]
3.4
防護(hù)鎖定裝置 guard locking device
預(yù)定用于將防護(hù)裝置鎖定在關(guān)閉位置并與控制系統(tǒng)相連的裝置。
3.5
帶防護(hù)鎖定的聯(lián)鎖防護(hù)裝置 interlocking guard with guard locking
與聯(lián)鎖裝置、防護(hù)鎖定裝置聯(lián)用的防護(hù)裝置，同機(jī)器控制系統(tǒng)一起實(shí)現(xiàn)以下功能：
——在防護(hù)裝置關(guān)閉和鎖定前，其“遮蔽”的危險(xiǎn)機(jī)器功能不能夠執(zhí)行；
——在防護(hù)裝置“遮蔽”的危險(xiǎn)機(jī)器功能所產(chǎn)生的風(fēng)險(xiǎn)消失之前，防護(hù)裝置保持關(guān)閉和鎖定狀態(tài)；
——在防護(hù)裝置關(guān)閉和鎖定后，被防護(hù)裝置“遮蔽”的危險(xiǎn)機(jī)器功能可以運(yùn)行。防護(hù)裝置本身的關(guān)閉和鎖定不會(huì)啟動(dòng)危險(xiǎn)機(jī)器功能。
[GB/T 15706—2012，定義3.27.5]
3.6
控制系統(tǒng)安全相關(guān)部件 safety-related part of a control system
SRP/CS
控制系統(tǒng)中響應(yīng)安全相關(guān)輸入信號(hào)并產(chǎn)生安全相關(guān)輸出信號(hào)的部件。
注1：控制系統(tǒng)安全相關(guān)部件的組成，以安全相關(guān)的輸入信號(hào)被觸發(fā)為起始點(diǎn)(例如，驅(qū)動(dòng)凸輪和位置開關(guān)的滾輪等)，以控制元件的動(dòng)力輸出(例如，接觸器的主觸點(diǎn)等)為終止點(diǎn)。
注2：如果監(jiān)控系統(tǒng)用于診斷，也可認(rèn)為它們是SRP/CS。
注3：改寫GB/T 16855.1—2008，定義3.1.1。
3.7
棄用 defeat
使聯(lián)鎖裝置不起作用或繞開聯(lián)鎖裝置，從而導(dǎo)致不是按照設(shè)計(jì)者預(yù)定的方式或在無必需的安全措施的條件下使用機(jī)器的行為。
3.8
以可合理預(yù)見的方式棄用 defeat in a reasonable foreseeable manner
用手或通過容易獲得的物體棄用聯(lián)鎖裝置。
注1：本定義包括采用機(jī)器預(yù)定使用所需的或容易獲得的工具(螺絲刀、扳手、六角形鑰匙、鉗子)移除開關(guān)或操動(dòng)件。
注2：容易獲得的用于替換操動(dòng)件的物體包括：
——螺釘、針、金屬片；
——日常所用的物品，如鑰匙、硬幣、膠帶、線和金屬絲；
——截留鑰匙聯(lián)鎖裝置的備用鑰匙；
——備用操動(dòng)件。
3.9
自動(dòng)監(jiān)控 automatic monitoring
如果元件或組件執(zhí)行其功能的能力減弱，或過程條件改變導(dǎo)致產(chǎn)生危險(xiǎn)時(shí)，觸發(fā)故障反應(yīng)功能的診斷功能。
3.10
直接機(jī)械動(dòng)作 direct mechanical action
強(qiáng)制機(jī)械動(dòng)作 positive mechanical action
其他機(jī)械元件的運(yùn)動(dòng)通過直接接觸或通過剛性組件不可避免地引起的機(jī)械元件的運(yùn)動(dòng)。
3.11
直接斷開動(dòng)作 direct opening action
強(qiáng)制斷開操作 positive opening operation
開關(guān)操動(dòng)件的規(guī)定動(dòng)作通過非彈性部件(如不依靠彈簧)直接實(shí)現(xiàn)觸點(diǎn)分離。
主：改寫IEC 60947-5-1：2003，定義K.2.2。
3.12
操動(dòng)件 actuator
聯(lián)鎖裝置中將防護(hù)裝置狀態(tài)(關(guān)閉或未關(guān)閉)傳輸至執(zhí)行系統(tǒng)的單獨(dú)部件。
示例：安裝在防護(hù)裝置上的凸輪、銷、卡舌、反射鏡、磁體、射頻識(shí)別(RFID)標(biāo)簽。
注1：也可參見附錄A～附錄E。
注2：見圖2給出的操動(dòng)件示例。
3.13
編碼操動(dòng)件 coded actuator
專門設(shè)計(jì)(如通過外形)的用于驅(qū)動(dòng)某一位置開關(guān)的操動(dòng)件。
3.13.1
初級(jí)編碼操動(dòng)件 low level coded actuator
編碼能力在1～9之間的編碼操動(dòng)件。
3.13.2
中級(jí)編碼操動(dòng)件 medium level coded actuator
編碼能力在10～1000之間的編碼操動(dòng)件。
3.13.3
高級(jí)編碼操動(dòng)件 high level coded actuator
編碼能力大于1000的編碼操動(dòng)件。
3.14
執(zhí)行系統(tǒng) actuating system
聯(lián)鎖裝置的一部分，用于傳輸操動(dòng)件的位置信息并改變輸出系統(tǒng)狀態(tài)。
示例：活塞滾輪、凸輪機(jī)構(gòu)或者光學(xué)式、感應(yīng)式或電容式傳感器。
注：見圖2給出的執(zhí)行系統(tǒng)示例。
3.15
輸出系統(tǒng) output system
聯(lián)鎖裝置的一部分，用于向控制系統(tǒng)反饋防護(hù)裝置狀態(tài)。
示例：接觸組件(機(jī)電式)、半導(dǎo)體輸出、閥門。
3.16
1型聯(lián)鎖裝置 type 1 interlocking device
帶有機(jī)械驅(qū)動(dòng)式位置開關(guān)，并且其操動(dòng)件是非編碼類型的聯(lián)鎖裝置。
示例：鉸鏈?zhǔn)铰?lián)鎖裝置。
注：詳細(xì)示例參見附錄A。
3.17
2型聯(lián)鎖裝置 type 2 interlocking device
帶有機(jī)械驅(qū)動(dòng)式位置開關(guān)，并且其操動(dòng)件是編碼類型的聯(lián)鎖裝置。
示例：卡舌驅(qū)動(dòng)式位置開關(guān)。
注：詳細(xì)示例參見附錄B。
3.18
3型聯(lián)鎖裝置 type 3 interlocking device
帶有非接觸式位置開關(guān)，并且其操動(dòng)件是非編碼類型的聯(lián)鎖裝置。
示例：接近開關(guān)。
注：詳細(xì)示例參見附錄C。
3.19
4型聯(lián)鎖裝置 type 4 interlocking device
帶有非接觸式位置開關(guān)，并且其操動(dòng)件是編碼類型的聯(lián)鎖裝置。
示例：RFID標(biāo)簽驅(qū)動(dòng)式位置開關(guān)。
注：詳細(xì)示例參見附錄D。
3.20
停機(jī)指令 stop command
聯(lián)鎖裝置產(chǎn)生的，使危險(xiǎn)機(jī)器功能終止的信號(hào)。
3.21
全系統(tǒng)停機(jī)性能 overall system stopping performance
打開防護(hù)裝置發(fā)出停機(jī)指令至危險(xiǎn)機(jī)器功能終止之間的時(shí)間間隔。
注：改寫GB/T 19876—2012，定義3.1.2。
3.22
進(jìn)入時(shí)間 access time
聯(lián)鎖裝置發(fā)出停機(jī)指令后，根據(jù)人體或人體部位接近速度計(jì)算出的人員到達(dá)危險(xiǎn)區(qū)所用的時(shí)間。
注：接近速度的選擇和進(jìn)入時(shí)間的計(jì)算，見GB/T 19876。
3.23
保持力 holding force
防護(hù)鎖定裝置在不被損壞的情況下能承受的力，從而不影響其進(jìn)一步使用且防護(hù)裝置不會(huì)改變關(guān)閉位置。
3.24
防誤鎖 prevention of inadvertent locking position
防護(hù)鎖定裝置確保鎖定器件(如防松螺栓)在防護(hù)裝置未關(guān)閉時(shí)不能到達(dá)鎖定位置的特征。
3.25
防護(hù)鎖定的緊急解鎖 emergency release of guard locking
緊急情況下，從安全防護(hù)區(qū)域外部無需借助其他工具就能手動(dòng)解鎖防護(hù)鎖定的可能性。
注：例如，出于解救被困人員或消防的目的，有必要采用帶緊急解鎖的防護(hù)鎖定。
3.26
防護(hù)鎖定的輔助解鎖 auxiliary release of guard locking
防護(hù)鎖定失效時(shí)，從安全防護(hù)區(qū)域外部通過工具或鑰匙就能手動(dòng)釋放防護(hù)鎖定的可能性。
注：帶輔助解鎖的防護(hù)鎖定不適用于防護(hù)鎖定的緊急或逃生解鎖。
3.27
防護(hù)鎖定的逃生解鎖 escape release of guard locking
為了離開安全防護(hù)區(qū)域，從其內(nèi)部無需借助其他工具就能手動(dòng)解鎖防護(hù)鎖定的可能性。
3.28
用于保護(hù)人員的防護(hù)鎖定 guard locking for protection of a person
防護(hù)鎖定裝置用于保護(hù)人員安全的用途。
3.29
用于保護(hù)過程的防護(hù)鎖定 guard locking for protection of the process
防護(hù)鎖定裝置用于防止工作過程被中斷的用途。
3.30
工具 tool
設(shè)計(jì)用于操作緊固件的器具，如鑰匙或扳手等。
注：臨時(shí)器具，如硬幣或指甲銼不能被視為工具。
[ISO 14120：2002，定義3.9]
3.31
動(dòng)力聯(lián)鎖 power interlocking
直接中斷機(jī)器執(zhí)行器的能量供應(yīng)或者直接將運(yùn)動(dòng)部件與機(jī)器執(zhí)行器斷開的聯(lián)鎖。
注：只有防護(hù)裝置關(guān)閉并處于鎖定位置，才有可能恢復(fù)能量供應(yīng)。“直接”意味著，與控制聯(lián)鎖不同，控制系統(tǒng)在聯(lián)鎖功能中不起任何中間作用。
3.32
安全功能 safety function
失效后會(huì)立即造成風(fēng)險(xiǎn)增加的機(jī)器功能。
[GB/T 15706—2012，定義3.30]
4 與防護(hù)裝置相關(guān)的聯(lián)鎖裝置的工作原理與典型形式
4.1 概述
聯(lián)鎖技術(shù)涉及的技術(shù)領(lǐng)域非常廣泛。聯(lián)鎖裝置可按照很多準(zhǔn)則進(jìn)行分類，如按照防護(hù)裝置與輸出系統(tǒng)之間連接的性質(zhì)分類，或者按照輸出系統(tǒng)采用的技術(shù)類型(機(jī)電、氣動(dòng)、電子等)分類。
聯(lián)鎖裝置具有監(jiān)控防護(hù)裝置位置的功能，從而感應(yīng)防護(hù)裝置是否關(guān)閉并在防護(hù)裝置沒有處于關(guān)閉位置時(shí)產(chǎn)生停機(jī)指令。聯(lián)鎖裝置也可用來控制其他功能，如在可能進(jìn)入危險(xiǎn)區(qū)之前控制制動(dòng)功能停止危險(xiǎn)的機(jī)器功能。某些聯(lián)鎖裝置還具有防護(hù)鎖定功能，以使防護(hù)裝置在出現(xiàn)危險(xiǎn)機(jī)器功能時(shí)保持鎖定。防護(hù)鎖定裝置的狀態(tài)監(jiān)控功能監(jiān)控防護(hù)鎖定裝置是否鎖定并且產(chǎn)生合適的輸出信號(hào)[見4.3.1a)和b)]。
注1：防護(hù)鎖定裝置(見3.4)可以是聯(lián)鎖裝置的組成部分，也可以是獨(dú)立單元。
注2：關(guān)于防護(hù)裝置的附加信息，也可見GB/T 15706—2012，6.3.3.1。
注3：表1并沒有按照聯(lián)鎖裝置的4種類型遞進(jìn)給出示例。每種類型的聯(lián)鎖裝置的正確應(yīng)用將取決于針對(duì)具體機(jī)器進(jìn)行的風(fēng)險(xiǎn)評(píng)估。
表1給出了特定類型聯(lián)鎖裝置的驅(qū)動(dòng)原理和操動(dòng)件示例。
表1 聯(lián)鎖裝置概況
操動(dòng)原理示例 操動(dòng)件示例 類型 示例：見附錄a
機(jī)械式 物理接觸/力 非編碼 旋轉(zhuǎn)凸輪 1型 A.1
線性凸輪 A.2、A.4
鉸鏈 A.3
編碼 卡舌(外形操動(dòng)件) 2型 B.1
鑰匙型 B.2
非接觸式 電感 非編碼 合適的鐵質(zhì)金屬 3型 C
磁力 磁鐵、電磁閥
電容 任何合適的物品
超聲波 任何合適的物品
光學(xué) 任何合適的物品
磁力 編碼 編碼磁鐵 4型 D.1
RFID 編碼RFID標(biāo)簽 D.2
光學(xué) 光學(xué)編碼帶 —
a 其他聯(lián)鎖防護(hù)裝置的示例在附錄E給出。
a) 1型聯(lián)鎖裝置(非編碼凸輪式，防護(hù)裝置關(guān)閉)
b) 2型聯(lián)鎖裝置(編碼卡舌式，防護(hù)裝置未關(guān)閉)
c) 3型或4型聯(lián)鎖裝置(非編碼或編碼非接觸式操動(dòng)，防護(hù)裝置關(guān)閉)
說明：
1——活動(dòng)式防護(hù)裝置； 4——位置開關(guān)；
2——聯(lián)鎖裝置； 5——執(zhí)行系統(tǒng)；
3——操動(dòng)件； 6——輸出系統(tǒng)。
a 凸輪； c 如RFID、反射鏡、合適的表面；
b 卡舌； d 運(yùn)動(dòng)方向。
注：在某些特殊情況下，位置開關(guān)可安裝在活動(dòng)式防護(hù)裝置上，并且操動(dòng)件安裝在機(jī)器的固定部件上。這種情況下，圖中的“1”是機(jī)器的固定部件。
圖2 1型、2型、3型和4型聯(lián)鎖裝置的原理
4.2 不帶防護(hù)鎖定的防護(hù)聯(lián)鎖原理
當(dāng)采用不帶防護(hù)鎖定的防護(hù)聯(lián)鎖功能時(shí)，防護(hù)裝置在任何時(shí)候都能打開，與機(jī)器的功能無關(guān)。
如果防護(hù)裝置未關(guān)閉，則聯(lián)鎖裝置應(yīng)產(chǎn)生停機(jī)指令。
注1：與機(jī)器控制系統(tǒng)的聯(lián)鎖，見第8章。
注2：不帶防護(hù)鎖定的聯(lián)鎖裝置的示例在附錄A、附錄B、附錄C和附錄D中給出。
注3：不帶防護(hù)鎖定的聯(lián)鎖裝置的功能圖在圖3中給出。
危險(xiǎn)機(jī)器功能可能運(yùn)行
危險(xiǎn)機(jī)器功能不能運(yùn)行
防護(hù)裝置關(guān)閉
防護(hù)裝置終止關(guān)閉
防護(hù)裝置開始打開
防護(hù)裝置未關(guān)閉
圖3 不帶防護(hù)鎖定的聯(lián)鎖裝置的功能圖
4.3 帶防護(hù)鎖定的防護(hù)聯(lián)鎖原理
4.3.1 概述
當(dāng)采用帶防護(hù)鎖定的聯(lián)鎖時(shí)，應(yīng)通過防護(hù)鎖定裝置(見3.4)防止防護(hù)裝置打開，除非該防護(hù)裝置防護(hù)的所有危險(xiǎn)機(jī)器功能都已終止。
防護(hù)鎖定功能有兩種可選的設(shè)計(jì)方案(見圖4)：
a) 觸發(fā)防護(hù)裝置的解鎖可由操作者在任何時(shí)候?qū)崿F(xiàn)。當(dāng)開始解鎖時(shí)，防護(hù)鎖定裝置產(chǎn)生停機(jī)指令。這稱之為無條件解鎖，防護(hù)裝置解鎖所必需的時(shí)間應(yīng)大于危險(xiǎn)機(jī)器功能終止所必需的時(shí)間。
b) 防護(hù)裝置的解鎖只有在危險(xiǎn)機(jī)器功能終止時(shí)才能實(shí)現(xiàn)。這稱之為條件解鎖。
防護(hù)裝置關(guān)閉并鎖定能解鎖
完成鎖定
完成解鎖*)
防護(hù)裝置關(guān)閉且已解鎖能打開防護(hù)裝置
防護(hù)裝置完成關(guān)閉
防護(hù)裝置開始打開
防護(hù)裝置未關(guān)閉
危險(xiǎn)機(jī)器功能可能運(yùn)行
危險(xiǎn)機(jī)器功能不能運(yùn)行
防護(hù)裝置關(guān)閉并鎖定不能解鎖
不能解鎖
固定的時(shí)間段后已探測(cè)到或確保危險(xiǎn)已消除(如機(jī)器停止)
防護(hù)裝置關(guān)閉并鎖定能解鎖
完成鎖定
完成解鎖
防護(hù)裝置關(guān)閉并鎖定能打開防護(hù)裝置
防護(hù)裝置終止關(guān)閉
防護(hù)裝置開始打開
防護(hù)裝置未關(guān)閉
*)完成解鎖是指：
——開始驅(qū)動(dòng)解鎖裝置的同時(shí)已觸發(fā)停機(jī)指令，并且是開始驅(qū)動(dòng)解鎖裝置的結(jié)果；
——防護(hù)裝置解鎖所必需的時(shí)間大于危險(xiǎn)消除所必需的時(shí)間。
無條件解鎖
條件解鎖
注：對(duì)于條件解鎖，可無時(shí)間延遲的從狀態(tài)2改變至狀態(tài)3或者從狀態(tài)3改變至狀態(tài)2。
圖4 帶防護(hù)鎖定的聯(lián)鎖裝置的功能圖
防護(hù)鎖定裝置的示例在附錄F中給出。
4.3.2 帶機(jī)械式防護(hù)鎖定的聯(lián)鎖裝置
鎖定聯(lián)鎖防護(hù)裝置的機(jī)械部件(如螺栓)可以是：
——手動(dòng)鎖定和手動(dòng)解鎖(見圖F.5)；
——通過彈簧(或類似的)鎖定和通過動(dòng)力接通解鎖[見圖5a)]；
——通過動(dòng)力接通鎖定和通過彈簧(或類似的)解鎖[見圖5b)]；
——通過動(dòng)力接通鎖定和通過動(dòng)力接通解鎖[見圖5c)]。
機(jī)械式防護(hù)鎖定由于其形態(tài)的原因應(yīng)采用直接機(jī)械阻擋的原理，不應(yīng)僅僅依靠摩擦或作用力。
a) 通過彈簧鎖定 鎖定
通過動(dòng)力接通解鎖 解鎖
b) 通過動(dòng)力接通鎖定 鎖定
通過彈簧解鎖 解鎖
c) 通過動(dòng)力接通鎖定 鎖定
通過動(dòng)力接通解鎖 解鎖
d) 通過動(dòng)力接通鎖定 鎖定
通過動(dòng)力斷開鎖定 解鎖
圖5 動(dòng)力驅(qū)動(dòng)的防護(hù)鎖定裝置的工作模式
4.3.3 帶電磁式防護(hù)鎖定的聯(lián)鎖裝置
防護(hù)裝置通過電磁力而不通過任何機(jī)械鎖定方式來保持關(guān)閉(鎖定)(見F.4)。
電磁式防護(hù)鎖定的工作原理是通過動(dòng)力接通鎖定和通過動(dòng)力斷開解鎖[見圖5d)]。
5 帶或不帶防護(hù)鎖定的聯(lián)鎖裝置的設(shè)計(jì)與安裝要求
5.1 一般要求
聯(lián)鎖裝置的安裝應(yīng)使其牢固可靠，并滿足制造商提供的說明書(見第9章)的要求。
5.2 位置開關(guān)的布置與緊固
位置開關(guān)的布置應(yīng)使其得到充分的保護(hù)，防止其位置的改變。為了達(dá)到此目標(biāo)，應(yīng)滿足以下要求：
a) 位置開關(guān)的緊固件應(yīng)可靠，且僅能通過工具松開。
b) 1型位置開關(guān)在調(diào)整后應(yīng)提供持久固定在其位置措施(如通過釘子或銷)。
c) 為保證位置開關(guān)的正確運(yùn)行，應(yīng)提供接近位置開關(guān)進(jìn)行維護(hù)和檢查所必需的設(shè)施。設(shè)計(jì)接近設(shè)施時(shí)，還應(yīng)考慮防止以可合理預(yù)見的方式棄用位置開關(guān)。
d) 應(yīng)防止位置開關(guān)自松動(dòng)。
e) 應(yīng)防止以可合理預(yù)見的方式棄用位置開關(guān)(見第7章)。
f) 位置開關(guān)的定位應(yīng)避免可預(yù)見的外部原因造成損壞，必要時(shí)應(yīng)加以保護(hù)。
g) 機(jī)械式驅(qū)動(dòng)產(chǎn)生的運(yùn)動(dòng)或接近裝置執(zhí)行系統(tǒng)的間隙應(yīng)保持在開關(guān)制造商規(guī)定的位置開關(guān)或執(zhí)行系統(tǒng)的工作范圍內(nèi)，以確保正確運(yùn)行和/或防止超程。
h) 位置開關(guān)不應(yīng)用于機(jī)械式停機(jī)，除非制造商聲明其具有這種預(yù)定用途。
i) 防護(hù)裝置錯(cuò)位產(chǎn)生的間隙在位置開關(guān)改變其狀態(tài)之前不應(yīng)大到影響防護(hù)裝置的防護(hù)效果(對(duì)于進(jìn)入危險(xiǎn)區(qū)，參見ISO 13855和ISO 13857)。
j) 位置開關(guān)的支撐和緊固應(yīng)具有足夠的剛度，以保持位置開關(guān)的正確運(yùn)行。
5.3 操動(dòng)件的布置與緊固
5.3.1 一般要求
操動(dòng)件(見圖2)應(yīng)牢固固定，以盡可能防止其在生命周期內(nèi)松動(dòng)或改變其相對(duì)于執(zhí)行系統(tǒng)的位置。
注：有必要進(jìn)行定期檢查(見9.3.2)。
應(yīng)滿足以下要求：
a) 操動(dòng)件的緊固件應(yīng)可靠，且僅能通過工具松開；
b) 應(yīng)防止操動(dòng)件自松動(dòng)；
c) 位置開關(guān)的定位應(yīng)避免可預(yù)見的外部原因造成損壞，必要時(shí)應(yīng)加以保護(hù)；
d) 操動(dòng)件不應(yīng)用于機(jī)械式停機(jī)，除非制造商聲明其具有這種預(yù)定用途；
e) 操動(dòng)件的支撐和緊固應(yīng)具有足夠的剛度，以保持操動(dòng)件的正確運(yùn)行。
5.3.2 凸輪
1 型聯(lián)鎖裝置的旋轉(zhuǎn)或線性凸輪應(yīng)滿足以下要求：
a) 通過緊固件固定且僅能通過工具松開；
b) 通過外形(如：花鍵或銷子)或通過能提供同等固定程度的其他方法達(dá)到最終的固定；
c) 不能損壞位置開關(guān)或削弱位置開關(guān)的耐用性。
5.4 聯(lián)鎖裝置的驅(qū)動(dòng)模式
當(dāng)使用單個(gè)1型或2型聯(lián)鎖裝置產(chǎn)生停機(jī)指令時(shí)，防護(hù)裝置、操動(dòng)件和輸出系統(tǒng)之間的驅(qū)動(dòng)模式應(yīng)是直接機(jī)械動(dòng)作，接觸組件應(yīng)是直接打開動(dòng)作(見3.10、3.11和表2)。
只有與1型或2型聯(lián)鎖裝置聯(lián)用，且防護(hù)裝置、操動(dòng)件和執(zhí)行系統(tǒng)之間為直接機(jī)械動(dòng)作時(shí)，才能采用1型聯(lián)鎖裝置的間接機(jī)械動(dòng)作。一個(gè)直接機(jī)械動(dòng)作的聯(lián)鎖裝置和一個(gè)間接機(jī)械動(dòng)作的聯(lián)鎖裝置聯(lián)合使用，可避免共因失效(見8.3)。
表2 1型聯(lián)鎖裝置的直接機(jī)械動(dòng)作和間接機(jī)械動(dòng)作
機(jī)械動(dòng)作 防護(hù)裝置關(guān)閉 防護(hù)裝置未關(guān)閉 工作模式 失效時(shí)的工況示例(見8.3.2)
直接 只要防護(hù)裝置未關(guān)閉，凸輪就使活塞保持壓下狀態(tài)。
當(dāng)防護(hù)裝置關(guān)閉時(shí)，彈簧復(fù)位致使輸出系統(tǒng)改變其狀態(tài) 即使彈簧斷裂，防護(hù)裝置未關(guān)閉時(shí)輸出系統(tǒng)始終保持在安全狀態(tài)
間接 只要防護(hù)裝置關(guān)閉，凸輪就使活塞保持在壓下狀態(tài)。
當(dāng)防護(hù)裝置打開時(shí)，彈簧復(fù)位致使輸出系統(tǒng)改變其狀態(tài) 如果彈簧斷裂，即使防護(hù)裝置未關(guān)閉，輸出也能變成不安全狀態(tài)
聯(lián)鎖裝置的驅(qū)動(dòng)原理應(yīng)與所采用的位置開關(guān)的驅(qū)動(dòng)原理相適應(yīng)。
如果3型和4型聯(lián)鎖裝置只用作聯(lián)鎖裝置，則應(yīng)滿足IEC 60947-5-3的要求。
5.5 控制系統(tǒng)的接口
聯(lián)鎖裝置的輸出系統(tǒng)應(yīng)與按照GB/T 16855.1或IEC 62061設(shè)計(jì)的控制系統(tǒng)相適應(yīng)。
5.6 機(jī)械式停機(jī)
如果制造商聲明聯(lián)鎖裝置可用于機(jī)械式停機(jī)，則應(yīng)給出能承受的最大沖擊能量[也可見9.2.2r)]。
5.7 防護(hù)鎖定裝置的附加要求
5.7.1 一般要求
如果采用防護(hù)鎖定功能會(huì)產(chǎn)生危險(xiǎn)，則應(yīng)考慮附加措施(見5.7.5和GB/T 15706—2012中6.3.5.3)。
除非風(fēng)險(xiǎn)評(píng)估的結(jié)果表明不合適，否則預(yù)定用于鎖定防護(hù)裝置的鎖定組件(如螺栓)應(yīng)采用“通過彈簧鎖定一通過動(dòng)力接通解鎖”[見圖5a)]或“通過動(dòng)力接通鎖定一通過動(dòng)力接通解鎖”[見圖5c)]的工作模式。如果在特殊的應(yīng)用中采用了其他工作模式[如圖5b)]，則應(yīng)提供同等的安全水平。
注：當(dāng)失去能量而導(dǎo)致鎖定組件解鎖時(shí)，機(jī)器的停止時(shí)間通常大大加長，這就有可能在停止運(yùn)動(dòng)(或其他危險(xiǎn)消除)之前進(jìn)入危險(xiǎn)區(qū)。
當(dāng)防護(hù)鎖定功能用于人員保護(hù)時(shí)，則應(yīng)滿足5.7規(guī)定的要求。當(dāng)防護(hù)鎖定功能只用作保護(hù)過程時(shí)，則5.7規(guī)定的要求不適用。但是，如果防護(hù)鎖定功能和防護(hù)聯(lián)鎖功能是同一裝置的組成部分，則防護(hù)聯(lián)鎖功能的安全水平不應(yīng)被與安全不相關(guān)的防護(hù)鎖定功能(即防護(hù)鎖定功能只用作保護(hù)過程)削弱。
5.7規(guī)定的要求既適用于由獨(dú)立元件組成的防護(hù)鎖定裝置，也適用于作為帶防護(hù)鎖定的聯(lián)鎖裝置的組成部分的防護(hù)鎖定裝置。5.7規(guī)定的要求適用于所有技術(shù)。
應(yīng)提供與按照GB/T 16855.1或IEC 62061設(shè)計(jì)的控制系統(tǒng)兼容的輸出系統(tǒng)，以便監(jiān)控防護(hù)鎖定裝置的鎖定位置。
只有防護(hù)裝置關(guān)閉并鎖定時(shí)，防護(hù)鎖定裝置才應(yīng)允許機(jī)器的危險(xiǎn)功能運(yùn)行。
5.7.2 機(jī)械式防護(hù)鎖定裝置
5.7.2.1 一般要求
機(jī)械式防護(hù)鎖定應(yīng)由兩個(gè)剛性部件配合完成[形封閉，見圖5a)～圖5c)]。
如果可預(yù)見到在緊急情況下必需進(jìn)入，則對(duì)于“通過彈簧鎖定一通過動(dòng)力接通解鎖”或者“通過動(dòng)力接通鎖定一通過動(dòng)力接通解鎖”系統(tǒng)[見圖5a)和c)]，應(yīng)提供帶緊急解鎖的防護(hù)裝置鎖定裝置(見5.7.5.3)。
圖6說明了此類裝置的功能。
5.7.2.2 鎖定監(jiān)控
鎖定組件的鎖定位置應(yīng)按照5.5的要求進(jìn)行監(jiān)控。
只有監(jiān)控到防護(hù)裝置處于關(guān)閉位置且鎖定組件處于鎖定位置，機(jī)器的危險(xiǎn)功能才可能運(yùn)行(參見附錄F)。
為有效監(jiān)控防護(hù)鎖定裝置，應(yīng)采用以下方法的其中一種：
——只有活動(dòng)式防護(hù)裝置處于關(guān)閉位置，鎖定組件才能進(jìn)入鎖定位置(見圖6)，這種情況下，防護(hù)裝置的關(guān)閉和鎖定位置可通過鎖定組件的監(jiān)控來檢查；
——對(duì)于其他情況，鎖定組件的監(jiān)控和對(duì)防護(hù)裝置位置的監(jiān)控應(yīng)聯(lián)鎖。
