Some standard content:
GB12557--2000
This standard is a revision of GB12557-1990 based on the draft European standard PrEN691:1992 "Common safety and health requirements for woodworking machine tools". The technical content is basically consistent with PrEN691. This standard replaces GB12557-1990 from the date of implementation. Appendix A of this standard is the standard appendix, and Appendix B is the reminder appendix. This standard is proposed by the State Machinery Industry Bureau. This standard is under the jurisdiction of Fuzhou Woodworking Machine Tool Research Institute. This standard is drafted by Fuzhou Woodworking Machine Tool Research Institute. The main drafters of this standard are Zheng Zongjian and Zheng Li. This standard was first issued in 1990.
1 Scope
National Standard of the People's Republic of China
Woodworking machines-Safety code
Woodworking machines-Safety code This standard specifies the safety technical requirements for woodworking machine tools. GB 12557—-2000
Replaces GB12557—1990bzxz.net
This standard applies to all woodworking machine tools (hereinafter referred to as machine tools) manufactured from the date of implementation of this standard, except for woodworking portable machines. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB2893—1982Safety colors
GB2894—1996Safety signs
GB/T3766—1983General technical requirements for hydraulic systemsGB/T3768-1996Acoustics-Determination of sound power level of noise source by sound pressure method-Simplified method using envelope measuring surface above reflecting surfaceGB/T3770-1983Determination of sound power level of woodworking machine tool noiseGB/T5226.1--1996Industrial machinery and electrical equipment-Part 1:General technical requirementsGB/T6881--1986Determination of sound power level of acoustic noise source-Precision method in reverberation room and engineering methodGB/T 68821986
GB/T 7932-1987
Determination of sound power level of acoustic noise source-Precision method in anechoic chamber and semi-anechoic chamberGeneral technical requirements for pneumatic systems
Balance quality of rigid rotor-Determination of allowable imbalanceGB/T 9239—1988
GB/T10961--1989 Graphic symbols for woodworking machine operating instructions GB12265.1—1997 Safety of machinery Safety distance to prevent upper limbs from touching dangerous areas General ergonomic requirements for manipulators
GB/T14775-1993
GB/T15706.1-1995 Basic concepts and general principles for mechanical safety Part 1: Basic terms and methodology GB/T15706.2-1995 Basic concepts and general principles for mechanical safety Part 2: Technical principles and specifications GB/T1537 9--1994 Basic terminology for woodworking machine tools GB16179-1996 Guidelines for the use of safety signs GB/T16404-1996 Acoustics Sound intensity method for determining the sound power level of noise sources Part 1: Measurement at discrete points GB16754-1997 Mechanical safety Emergency stop design principles GB/T16755-1997 Mechanical safety Drafting and presentation rules for safety standards GB/T16855.1-1997 Mechanical safety Control system related safety components Part 1: General design principles GB17888.1-1999 Mechanical safety Access to fixed facilities for machines and industrial equipment Part 1: Selection of fixed facilities for entering between two levels
GB17888.2—19992
Machinery safety - Fixed facilities for entering machines and industrial equipment - Part 2: Working platforms and passages
GB17888.3-1999Machinery safety - Fixed facilities for entering machines and industrial equipment - Part 3: Stairs and guardrails
Approved by the State Administration of Quality and Technical Supervision on February 18, 2000 428
Implemented on June 1, 2000
GB12557--2000
GB17888. 4-1999 Fixed facilities for access to machines and industrial equipment Part 4: Fixed ladders GB/T17889.2-1999 Safety of machinery Ladders Part 2: Requirements, tests and marking JB/T5720-1991 General technical requirements for electrical equipment of woodworking machine tools JB6113-1992 Safety technical requirements for tools used in woodworking machines JB/T9953-1999 Methods for measuring sound pressure levels of noise from woodworking machine tools EN1088-1995 General principles and provisions for the design of interlocking devices with or without guard locking 3 Definitions
3.1 Woodworking machines See GB/T15379-1994, Section 2.1.
3.2 Machine operator
See GB/T15706.1-1995, Section 3.21. 3.3 Hand feed
The manual stopping and/or conveying of workpieces or machine tool elements with tools. Manual feeding includes the use of manually operated knobs or movable worktables (manual positioning of workpieces or clamping of workpieces on slides or movable worktables) and the use of removable power feeds. 3.4 Removable power feeds Demountable power feedunite is a feeding mechanism mounted on a machine tool that can be moved out of the working position without the use of a wrench or similar auxiliary device. 3.5 Integrated feed
It is a feeding of workpieces whose mechanism is integrated with the machine tool and mechanically controls the workpieces during the machining operation. 3.6 Loading the machine Manually or automatically providing workpieces to a board, silo, lifting device, loading hopper, movable support, conveyor or providing workpieces to a mechanical feed device.
3.7 Combined machine for woodworking See GB/T15379-1994, Section 2.9.
3.8 Multi-purpose machine for woodworking The workpiece of this machine tool undergoes multiple processes in one feed and all the processes after the initial feed are carried out without further manual assistance.
3.9 Work device with protecting function Work device with protecting function is an additional auxiliary measure. It is not a part of the machine tool, but is used to help the operator feed the workpiece safely.
3.10 Ejection
The workpiece, part of the workpiece or part of the machine tool moves out of the machine tool unexpectedly during processing. 3.11 Kickback
It is a special form of ejection. It refers to the unexpected movement of the workpiece, part of the workpiece or part of the machine tool in the opposite direction of the feed direction during processing. 3.12 Anti-kickback fingers See GB/T15379-1994 Article 6.7.2.2. 3.13 Run-up time
The time from the start of the operation to the time when the spindle reaches the predetermined speed. 3.14 Run-down time The time from the stop of the operation to the time when the spindle stops. 3.15 Warranty.confirmation
Report, sales literature or other documents on which the manufacturer (or supplier) declares that either the performance or the material or product complies with the relevant standards.
4 Hazard list
This hazard list covers all hazards of machine tools: GB 12557--2000
For important hazards, by specifying safety requirements and/or measures or by indicating appropriate Class B standards. For unimportant hazards, such as general, subordinate or secondary hazards, by indicating appropriate Class A standards, especially GB/T15706-1995 Part 1 and Part 2. These hazards are proposed in accordance with GB/T16755. Table 1 Hazard list
Mechanical hazards, such as those caused by the following factors of machine parts or workpieces: shape;
relative position;
mass and stability (potential energy of each part); mass and speed (kinetic energy of each part); insufficient mechanical strength,
accumulation of potential energy caused by the following reasons;
elastic parts (springs) or liquids or gases under pressure or vacuum. Crushing hazard
Shearing hazard
Cutting or severing hazard
Entanglement hazard
Introduction or entanglement hazard
Impact hazard
Stabbing or stabbing hazard
Friction or wear hazard
High-pressure liquid injection hazard
(machinery or processed material or workpiece)Parts projection hazard (machinery or machine tool parts)Instability
Machine-related slip, tipping, falling hazardElectrical hazards, such as electrical contact (direct or indirect) caused by the following factors
Electrical phenomena
Heat radiation or other phenomena, such as injection of molten particles, short circuits, chemical effects, overloads External influences on electrical equipment
Heat hazards, caused by the following factors
Burns and scalds caused by flames or explosions that people can touch, radiation from heat sources
Health effects due to hot or cold working environments
Hazards caused by noise, leading to
Hearing loss, etc.
Interference with language communications, auditory signals, etc.
Hazards caused by vibration
Hazards caused by radiation (e.g. ionizing radiation sources)
Hazards caused by materials and substances processed, used or discharged by machinery, such as: Hazards caused by contact with or inhalation of harmful liquids, gases, fumes and dust
Fire or explosion hazards
Conform to the provisions of this standard
5. 3.7,5.3.12,
5.3.9,5.3.4
5,3.5,5.3.3,5.2.8
5.3.3,5.3.1,5.2.8
5.4.1,5.4.2
5.4.12,5.4.13
Biological and microbiological (virus or bacteria) hazards GB 12557-2000
Table 1 (end)
Hazards caused by ignoring ergonomics (the characteristics of the machine and the human and whether they can match) during design, examples of which are:
Unhealthy postures or excessive force
Inappropriate consideration of the structure of the human hand, arm or leg||Ignoring the use of personal protective equipment
Inappropriate work surface lighting
Excessive mental stress or lack of preparation, etc.
Human errors
Combination of various hazards
Hazards caused by energy failure, damage to machine parts or other functional failures, such as: energy failure (energy or control circuit)
Accidental ejection of machine parts or fluids
Failure or malfunction of the control system (accidental start, accidental overcurrent) Assembly Errors
Machinery overturning, accidental loss of stability
Hazards caused by suspension of protective measures (short-term) or incorrect setting of protective measures, such as: various types of protective devices
Various types of safety-related (protective) devices
Starting devices and stopping devices
Safety signals and signal devices
Various types of information and alarm devices
Energy cut-off devices
Emergency stop devices
Workpiece feeding/removal devices
Main equipment and accessories for safe adjustment and/or maintenance Exhaust equipment for gases, etc.
5 Safety requirements and/or measures
5.1 Safety technical principles
Safety technical principles shall comply with the provisions of Chapter 5 of GB/T15706.1--1995. 5.2 Control and command devices
5.2.1 Energy cut-off
Conform to the provisions of this standard
Not applicable
5.2.3,5.4.5.1
5.2.3,5.4.5.1
5.2.11,5.2.2
Appendix A,5.3,7,5.3.8
5.3.8,5.4.3,5.3.7
5.2.4,5.2.5
7.1,7.2,7.3
The machine tool must be equipped with technical measures to disconnect from the power source and measures to release residual energy. The device for cutting off the energy of the machine tool should be clearly identifiable. If reclosing the connection between the energy source and the machine tool will cause danger to the relevant personnel, the device should be lockable in the disconnected position. Other requirements should also comply with the requirements of Article 6.2.2 of GB/T15706.2-1995. Measures for cutting off the power supply of the machine tool should comply with the provisions of 5.3 of GB/T5226.1-1996. The discharge of residual energy must not be dangerous to the operator. As an exception to the above requirements: some circuits also need to be connected to the power source to clamp the workpiece, maintain information, internal lighting, etc. In this case, special measures must be taken to ensure the safety of the operator. 5.2.2 Safety and reliability of control devices Control devices must be able to work safely and reliably without any dangerous situations. They should comply with the requirements of Articles 3 and 7 of GB/T15706.2-1995, and in particular, they must ensure:
GB 12557-2000
-Can withstand the expected working stress and external influences;-Logical failures should not lead to dangerous situations. The safety level of the control system shall be selected in accordance with GB/T16855.1. If the safety performance level of the safety components of the control system is not specified in the specific machine tool safety standard, the following requirements shall generally be observed: 1. Safety principle: At least level 1 shall be adopted;
2. The minimum safety level of the following safety device is level 2. The device prevents danger in the danger zone during the adjustment, setting, installation, troubleshooting, cleaning or maintenance of the machine tool. The minimum safety level of the following safety device is level 3. The device prevents danger in the danger zone during manual loading and unloading. Note: The definition of safety protection device is shown in GB/T15706.1--1995. 5.2.3 General requirements for manipulators
5.2.3.1 The manipulator shall be designed and manufactured in accordance with the requirements of 3.6.6, 3.6.7 and 3.7.8e.f of GB/T15706.2--1995. 5.2.3.2 The manual manipulator shall be easy to use, shall not pinch the hand, and shall not cause the hand to collide with other parts during operation. The operating displacement mechanism shall be equipped with a reliable positioner to prevent it from moving on its own. 5.2.3.3 When the circumferential speed exceeds 50m/min or the rotation speed exceeds 20r/min, the handle or handwheel on the rotating shaft must be disengaged from the rotating shaft through a clutch.
5.2.3.4 The general ergonomic requirements of the manipulator shall also comply with the requirements of GB/T14755. 5.2.3.5 The operating function and adjustment direction of the manipulator shall comply with the provisions of Article 5.3.5 of GB/T14775-1993. The operating movement direction of the handwheel handle shall also comply with the following provisions: 5.2.3.5.1 Handle operation
a) The moving part makes a linear motion: the line connecting the two extreme positions of the handle is roughly parallel to the moving trajectory of the moving part, and the operating direction of the handle shall be consistent with the moving direction of the moving part;
b) The moving part makes a rotary motion: the rotary plane of the handle shall be parallel to the rotary plane of the moving part, and the operating direction of the handle shall be consistent with the rotary direction of the moving part.
5.2.3.5.2 Handwheel operation
a) When the moving part makes linear motion: when the handwheel is turned clockwise (the operator faces the end of the handwheel shaft), the moving part should move to the right, away (away from the operator) and upward;
b) When the moving part makes rotational motion: when the handwheel is turned clockwise (the operator faces the end of the handwheel shaft), the moving part should rotate clockwise; c) When the moving part makes radial motion: when the handwheel is turned clockwise (the operator faces the handwheel shaft or wrench), the moving part should move toward the center. 5.2.3.6 Except for table-type machine tools or machine tools operated by standing on a special pedal, the height of the operating handle from the ground (calculated based on the middle position of the handle and handwheel) is recommended in Table 2.
Usage
>25 times/shift
>5～25 times/shift
≤5 times/shift
Height of operating handle and handwheel from the ground
0.5～1.6
5.2.3.7 For machine tools with the operating handle higher than 2m, an operating table, foot pedal, etc. should be provided. 5.2.3.8 The operating force of the operating handwheel and handle should not exceed the requirements of Table 3, and the operating force of the hydraulic system should comply with the requirements of GB/T3766.
Usage
>25 times/shift
>5～25 times/shift
≤5 times/shift
GB12557-2000
Operating force
1 For special requirements such as clamping, locking, jacking and increasing damping, the operating force of the handwheel and handle shall comply with the design requirements. 2 The operating force of the handwheel and handle of the modified machine tool shall comply with the basic model requirements. 5.2.3.9 The surface of the operating pedal shall be meshed or rough, and its recommended width shall be not less than 80mm, and the travel range shall be 45~～70mm. The operating force of the pedal of the starter machine tool shall not exceed 40N, and protective measures must be taken to prevent accidental stepping and action. 5.2.3.10 The recommended installation height for reading mechanisms that are frequently observed is 0.5~1.7m; the recommended installation height for reading mechanisms that are not frequently observed is 0.3~2.5m (except for desktop machine tools). 5.2.3.11 The recommended height of the buttons of the electrical control panel from the ground or operating table is: no less than 0.6m for the lower row of buttons; no more than 1.6m for the upper row of buttons. For control panels with lower row buttons lower than 0.9m, it is recommended that they should be placed with an inclination greater than 120° relative to the horizontal plane. Control panels with no more than 7 buttons are allowed to be placed vertically with no limit on the placement height. 5.2.3.12 The operating mechanism should be equipped with a sign indicating the function and purpose. The visual symbols of the operating instructions on the sign should comply with the requirements of GB/T10961 and should ensure that they can be read within a distance of 500mm. 5.2.3.13 The operating mechanism of moving parts that are not allowed to act simultaneously should be interlocked. If interlocking is not possible under special circumstances, a description sign should be fixed near the operating mechanism and explained in the machine tool manual. 5.2.3.14 The operating mechanism that allows switching only when the low speed or moving parts are stopped should be equipped with an interlocking device. If the interlocking device cannot be installed, a warning sign should be fixed near the operating mechanism. 5.2.3.15 Automatic machine tools and program-controlled machine tools must be equipped with auxiliary manual operating parts. Inspection method: Check the corresponding drawings and/or circuit diagrams, and perform corresponding functional tests on the machine tool. 5.2.4 Starting
5.2.4.1 Starting the machine tool should be able to be achieved by intentionally operating the corresponding starting operator. The foot-operated starting operator must comply with the provisions of 5.2.3.9. This also applies to:
-Restarting after stopping, regardless of the cause and state of stopping;-Essential changes in the operating state (such as speed, pressure, etc.). Unless this restart or change in operating state will not cause any danger to people. This basic requirement does not apply to restarting during normal command procedures in automatic operation. 5.2.4.2 The startup of the machine tool shall comply with the provisions of 9.2 and 5.2 of GB/T5226.1-1996. 5.2.4.3 The startup of the main motion of the machine tool shall be connected no later than the feed motion. The standard of the specific machine tool shall specify the startup sequence of each part of the machine tool and take corresponding measures to ensure that it is carried out in sequence. 5.2.4.4 On a machine tool with multiple starting manipulators, if the operations may be mutually dangerous, additional devices must be provided so that when one starting manipulator is in effect, the other starting manipulators will not be in effect to eliminate the danger. 5.2.4.5 Automatic equipment in automatic operation should be able to restart easily after being disconnected and safe operation is achieved. 5.2.4.6 Inspection method: Check the corresponding drawings and/or circuit diagrams and carry out corresponding functional tests on the machine tool. 5.2.5 Normal stop
5.2.5.1 The machine tool shall be equipped with a stop control device that can stop all the transmissions of the machine tool normally. 5.2.5.2 The normal stop of the machine tool shall be selected according to the specific situation and in accordance with 9.2.2 and 9.2.5.3 of GB/T5226.1--1996 and meet its requirements.
GB 12557-2000
5.2.5.3 The operation of the machine tool stop device shall be carried out at a stage in the machine tool cycle that will not cause danger. The order of normal stop of a specific machine tool shall be determined according to the specific situation, and measures shall be taken to ensure this order. The feed motion of the machine tool shall be disconnected no later than the main motion. 5.2.5.4 The energy supply of the transmission must be cut off after the machine tool or its dangerous parts are stopped. 5.2.5.5 Each operating position of the machine tool shall be equipped with a stop control device that can stop the corresponding dangerous moving parts of the machine tool. If there are other provisions in the specific machine tool standards, the provisions of the specific machine tool standards shall be followed. 5.2.6 Emergency stop
5.2.6.1 The specific machine tool should be equipped with an emergency stop device according to the requirements of the hazard analysis and GB167541997. 5.2.6.2 The emergency stop device should also comply with the requirements of 9.2.5.4 in GB/T5226.1-1996. 5.2.6.3 The specific machine tool should determine the cut-off sequence when operating the emergency stop device according to the specific situation. 5.2.7 Working mode selector
The working mode selector should comply with the requirements of 3.7.9, 3.7.10 and 3.7.8d in GB/T15706.2-1995. The machine tool should not start when the working mode is changed from one mode to another. 5.2.8 Speed change
If the machine tool can use different tools and there is a risk of exceeding the maximum permissible speed of the tool, a device for changing the tool speed must be given priority;
If the machine tool can operate at more than one tool speed, the structure of the device for changing the tool speed should ensure that the speed can be selected safely. When the speed can be changed during transmission and there is a possibility of exceeding the permissible speed of the tool, the machine tool with a device for changing the tool speed should only be switched on at the lowest speed. For special cases, see 5.2.3.14. On machines with a device for changing the tool speed or tool turning, it must be possible to prevent accidental switching on in a dangerous state. Once the speed is selected, it must be clearly displayed and readable at the operating position before switching on or changing. A machine tool with a continuously variable speed should be able to display special dangers, such as speed loss. 5.2.9 Mechanical feed
If the workpiece is fed to the tool by mechanical feed, the start and stop sequence of the feed motion and the start and stop sequence of the main motion shall be in accordance with the provisions of 5.2.4.3 and 5.2.5.3.
5.2.10 Double command device
If there are multiple sets of operating devices on a machine tool, for example, one set is inside the soundproof enclosure and the other set is outside the soundproof enclosure, it should be ensured that when one set of operating devices is in effect, the other set (except the emergency stop operating device) is ineffective. There should be several devices for a complete cut-off on the main control panel, through which all other operating devices are ineffective. 5.2.11 Power source failure or control circuit failure Appropriate protection should be provided for dangerous situations caused by power source interruption, fluctuation or control power failure. The protection for recovery of power interruption or voltage drop should be in accordance with the provisions of 7.5 of GB/T5226.1-1996. Inspection method: Check the corresponding drawings and circuit diagrams. Check on the machine tool. 5.3 Protection measures against mechanical hazards
5.3.1 Stability
Detailed provisions shall be in accordance with 6.2.5 of GB/T15706.2-1995. Inspection method: Check the corresponding drawings.
5.3.2 Risk of fracture during movement
In accordance with 3.3 of GB/T15706.2-1995.
Inspection method: Check the corresponding drawings and design calculation documents, etc., and check on the machine tool. 5.3.3 Tool holders and tools
Tools and tool spindles with connectors and fasteners must be made of materials suitable for their use, that is, they must be able to withstand the stress of the maximum allowable speed, cutting stress and stress during braking. Rotating tools, except drill bits, should be marked with the maximum allowable operating speed. 434
GB 12557-2000
Rotating tools should be statically or dynamically balanced according to the requirements of product safety standards, and the balance quality should be selected and evaluated according to GB/T9239. The tool, tool holder and tool body and their fixing on the machine tool should ensure that they will not loosen during starting, running and braking. On manually fed machines, the extension of the blade from the tool body should be limited. Special requirements are in accordance with JB6113 and specific machine tool standards. When installing and adjusting the tool, the tool spindle may rotate and cause injury; the manufacturer must specify safety measures to protect against this. Inspection method: Check the corresponding drawings and conduct inspection on the machine tool. 5.3.4 Braking system
5.3.4.1 General requirements
If the inertial movement of the tool spindle after stopping poses a risk of contact between people and the tool, the machine tool should be equipped with an automatic brake to stop the tool spindle in a sufficiently short time. Sufficiently short time means: a) less than 10s;
b) less than the start-up time, but not more than the time specified in the specific machine tool standard (for tool spindles with a start-up time greater than 10s). If the standard of the specific machine tool does not specify the conditions and methods of the test, the provisions of 5.3.4.2 and 5.3.4.3 shall be followed. 5.3.4.2 Test conditions
The spindle components shall be adjusted according to the manufacturer's instructions (e.g. belt tension). When selecting the speed and tool, the speed and tool that represent the maximum capacity shall be selected. Before inspection, the machine tool shall be run idly for at least 15 minutes to allow the spindle components to warm up. It shall be verified that the actual spindle speed deviation does not exceed 10% of the rated speed. When testing a machine with a manual star-delta starter, the machine tool builder's instructions for starting should be read. The accuracy of the speed measuring instrument should be ±1% of full reading. The accuracy of the time measuring instrument should be ±0.1 s. 5.3.4.3 Tests
5.3.4.3.1 Unbraked Coasting Time The unbraked coasting time is measured as follows: a) Cut off the power to the spindle drive motor and measure the unbraked coasting time; b) Restart the spindle and allow it to reach normal speed; c) Repeat steps a) and b) twice more.
The unbraked coasting time of the machine is the average of the above three measurements. 5.3.4.3.2 Starting Time
The starting time is measured as follows:
a) Cut off the spindle drive motor and allow the spindle to come to a complete stop; b) Restart the spindle drive motor and measure the starting time; c) Repeat steps a) and b) twice more.
The arithmetic mean of the above three measurements is the braking time of the machine tool. 5.3.4.3.3 Braking time
The braking time is tested 10 times as follows: a) Cut off the spindle transmission; the braking time starts from the operation of the cut-off manipulator and ends when the spindle stops; b) The spindle transmission restarts after (5)
)\min (P is the rated power of the drive motor), and the time taken to restart should be no less than 1min;
c) The spindle runs idle for ()
)min, and the idle time should be no less than 1min. The arithmetic mean of the 10 measurements is the measurement result. 5.3.5 Devices to minimize the possibility and effects of workpiece ejection On machine tools where there is a risk of workpiece ejection, appropriate safety protection devices must be installed, such as: the use of backstops on planers and multi-blade circular saws; 435
- the use of dividing knives on circular saws;
GB 12557--2000
- the use of cross-feed stops for slotting on single-axis milling machines. These devices must:
ensure that the entire workpiece channel (height, width) of the machine tool can be protected;
be able to withstand the force of the material hitting it;
when it contains moving parts, such as claws, it must be able to move freely within the working range and be easy to maintain. Note: These devices require special maintenance, and the manufacturer must consider these issues in the instruction manual. Inspection method: Check the corresponding drawings and inspect according to the requirements of the specific product standards. 5.3.6 Support and guidance of workpieces
For machine tools with hand-pushed workpiece feeding, the workpieces must be supported and held by the worktable and guide plate. The processing capacity and intended use of the machine tool must be considered.
Note: For intended use, see 3.12 of GB/T15706.1-1995. The worktable must be able to ensure the safe feeding of the workpiece. The specific machine tool safety standards should specify the dimensions and other relevant technical requirements to ensure safe feeding.
Machine tools with hand-pushed workpiece feeding should be equipped with guide plates. The guide plates should be able to ensure the correct position of the workpiece during feeding and should meet the dimensional requirements and other relevant technical requirements specified in the specific machine tool safety standards. In order to avoid interruption of the workpiece guidance, the worktable and guide plate must have a smooth surface with as few defects and pits as possible, and the surface flatness should be in accordance with the requirements of the specific machine tool accuracy standards. Measures must be taken to prevent the hand-pushed mobile worktable from falling off. Inspection method: Check the corresponding drawings and conduct inspection on the machine tool. 5.3.7 Obstructions to the moving parts of machine tools When there are no safety standards for specific machine tools, the following general rules can be used as an aid and guide for the installation of such safety protection devices for specific machine tools.
The definitions and requirements of various types of safety protection devices are shown in GB/T15706.1 and GB/T15706.2. 5.3.7.1 Protective devices to prevent contact with the tool on manual feed machine tools The cutting range of the tool must be safe. The more suitable safety protection devices are: - Adjustable protective devices (see 6.7.1.2 in GB/T15379-1994); - Self-adjusting protective devices (see 6.7.1.3 in GB/T15379-1994); - Automatic stop devices (see 3.23.5 in GB/T15706.1-1995). If the operator does not enter the non-cutting area of the tool, a fixed protective device should be used to ensure safety. If the risk analysis concludes that a movable interlocking guard cannot prevent the danger of entering the moving tool, an interlocking movable guard with a guard lock must be used.
During the risk analysis, it should be noted that the opening of the movable interlocking guard is not an appropriate method for stopping the machine tool, and it should be possible to connect the dust collector without the need for manual access to the tool.
Removable feed device:
The risk of contact with the tool on a machine tool with hand-pushed workpiece feed can be reduced and eliminated by using an additional feed device. Where such a device is used, measures should be taken to secure the device. 5.3.7.2 Safety measures on machine tools with mechanical feed The tool and feed mechanisms such as feed rollers, conveyor chains, slides, etc. must be safe. The safety protection device can be one of the following or various combinations: fixed protection device;
movable protection device;
- adjustable protection device or self-adjusting protection device; 436
GB 12557-2000
-——automatic stopping device (such as photoelectric system, pressure sensitive system, etc.); a fully enclosed protection, or fence type protection device. When using fully enclosed or fence type protection devices and the operator must go into the closed cover or fence, additional safety measures must be specified. They are: for example, a closed cover with an interlocking device or a suitable protection device mentioned above. The motorized workpiece loading feed device and the motorized tool feed device must be equipped with limit devices such as limit switches, fixed bumpers, clutches, and buffer devices when necessary.
5.3.7.3 Transmission (tool, spindle, feed, etc.) safety transmission devices (such as belts and pulleys, chains and sprockets, speed change gears, etc.) should be protected by fixed protective devices if they are not installed in the machine body (protected by the machine shell); if the operator needs to reach into this range, a movable protective device should be used for protection. For doors covering moving parts that are often opened, if there is a certain danger when opening, the inside of the door should be painted yellow, and a warning sign should be made on the outside of the door according to Figure 2-1 of GB2894-1996. If there is a greater danger when opening the door or movable protective device covering the moving parts, the protective device should be interlocked with the machine tool working cycle and equipped with a protective lock. The adoption of the above protective measures should be determined by risk analysis. In the risk analysis, it should be noted that the opening of a movable or interlocked protective device cannot be used as a suitable method to stop the machine tool. Inspection method: Check the corresponding drawings, conduct inspections on the machine tool and corresponding functional tests. 5.3.8 Requirements for safety protection devices
5.3.8.1 Requirements for the design and installation of protection devices The design and installation of protection devices shall comply with the requirements of 4.2.2 of GB/T15706.2-1995 and the requirements of Appendix A of this standard as well as the requirements of specific machine tool safety standards.
If the inertia running time of the tool spindle after the power is disconnected is greater than 30s, the interlocking device with a protection lock cannot be used to replace the braking system. The self-adjusting protection device must ensure that the danger zone can be automatically closed before and after the workpiece is processed. It is opened when the workpiece is fed, which is controlled by the workpiece or the workpiece fixture. During processing, the danger zone can be closed by the protection device and the workpiece or simply by the workpiece. When the workpiece is output, the protection device is automatically closed.
5.3.8.2 Requirements for interlocking devices.
The interlocking device shall comply with the requirements of EN1088.
5.3.8.3 Inspection method
Check the relevant drawings and circuit diagrams, and conduct the corresponding functional tests on the machine tool; conduct inspections according to the requirements of the specific machine tool standards. 5.3.9 Mechanization and Automation
Automation, especially feed systems, must be used where appropriate and conducive to safety. Where possible, feeding and retrieving devices such as manipulators, silos, conveying devices and similar devices may be used. Additional hazards caused by conveying devices, etc. must also be protected. For situations where it is necessary to enter this danger zone, measures such as interlocking protective devices shall be adopted in accordance with 5.3.7.1. In addition, automatic shutdown devices may also be used. If the operator must enter the danger zone within a fixed-distance protective device, the position of the operating parts and the structure of the control device for the protective device must be such that
- Before entering the danger zone, the movement that causes the danger is stopped. The machine tool can only be restarted after operating the additional device outside the fixed-distance protective device (such as the switch conversion system, etc.). This additional device should be operable from inside the danger zone to the outside. Inspection method: Check the corresponding drawings and circuit diagrams and perform corresponding functional tests on the machine tool and its auxiliary equipment. 5.3.10 Clamping device
Where necessary, protective measures must be taken for the clamping of the workpiece, such as mechanical clamping (including vacuum clamping). Mechanical clamping devices should ensure that the clamping state can be maintained in the event of energy supply failure. The control system on mechanically fed machine tools must ensure that the energy is maintained in the clamping device. The processing part of the machine tool can only start to operate when the workpiece is clamped.
The risk of extrusion must be reduced, for example, by: 437
A secondary clamping device with pressure reduction; GB 12557---2000
-The distance between the clamping part and the workpiece is reduced to 6mm or less; the clamping speed limit is 10mm/s or less, the clamping parts are protected and an appropriate control system is used (see GB/T15706.2). Inspection method: Check the corresponding drawings and perform corresponding functional tests on the machine tool. 5.3.11 Multi-process machine tools
Mechanical feed and programmable automatic motion tools must ensure safety. See 5.3.7.2 for the safety requirements of mechanical feeding. 5.3.12 Working devices with protective functions
If all possible protective measures are taken by the designer/manufacturer of the machine tool to eliminate or reduce the danger, the ultimate safety for the operator depends on the acceptance of safe working methods and the provision and use of working devices with protective functions where permitted. Examples of working devices with protective functions (safety feeding accessories): such as pushers used on manual feed woodworking circular saws, push blocks used on woodworking planers, and feed clamps used on single-axis woodworking milling machines. Feed pushers and push blocks should be made of hard miscellaneous wood, and the longitudinal wood grain should be straight, and must be able to withstand the force required for feeding. The ends of the pushers should not be curved.
The feed clamp should be able to clamp the workpiece reliably and keep the operator's hands at a safe distance from the tool. The clamp should have a hand-held operating part (such as a handle) that is firmly fixed and strong enough. Information on the provision and use of these working devices should be noted in specific machine tool standards. Safe working methods are included in the standard for each specific machine tool. 5.4 Protection against non-mechanical hazards
Hazards corresponding to the specific machine tool are precisely specified in the standard for the specific machine tool. 5.4.1 Fire and explosion
If accumulation of processing materials and dust occurs, there is a risk of fire and explosion. Precautions to prevent and reduce such risks should be: prevent or reduce the accumulation of dust and wood chips on the machine tool or in the machine cover; use electrical devices that comply with the provisions of 5.4.4; use appropriate containers for flammable fluids; avoid hot surfaces.
5.4.2 Noise
5.4.2.1 General requirements
The construction of the machine tool should be so that the noise risk is reduced to the minimum limit by using noise reduction methods, especially at the sound source, taking into account technical progress and availability. Recommended noise reduction methods are given in Appendix B. 5.4.2.2 Limits and measurements of noise sound pressure levels 5.4.2.2.1 Limits of machine tool noise sound pressure levels Under idling conditions, the maximum noise sound pressure level of a machine tool shall not exceed the provisions of Table 5 and the safety standards for various types of woodworking machines. The standards for specific machine tools shall further specify their noise limits in accordance with the provisions of this standard. For machine tools that exceed the noise limits specified in Table 5, if they are consistent with international products of the same type, it is permitted to specify noise limits exceeding those specified in Table 5 in the standards for such machine tools. However, the following information shall be attached:
a) The results of noise measurements of representative machine tools in accordance with JB/T9953; b) The noise values of representative similar machine tools produced abroad; 438
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