JB 4029-2000 This standard is a revision of JB 4029-85 "Technical requirements for safety protection of grinding wheel guards for grinding machines". The revision referred to ANSI B11.9-1975 "Safety requirements for manufacturing, maintenance and use of grinding machines" and other advanced foreign standards. The differences from the original standard are: the scope of application has been increased; the material selection requirements have been modified. 3.1.1, 3.1.4, 3.3, and 4.2 of this standard are recommended provisions, and the rest are mandatory provisions. This standard specifies the technical requirements for grinding wheel guards. This standard is applicable to grinding wheel guards for cylindrical grinders and surface grinders, and other grinders can also refer to it for implementation. This standard was first issued in May 1983. JB 4029-2000 Technical requirements for safety protection of grinding wheel guards for grinding machines JB4029-2000 Standard download decompression password: www.bzxz.net
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Mechanical Industry Standard of the People's Republic of China JB4029-2000 Grinding wheel guard Technical requirements for safety protection Specifications of grinding-wheel guard for safety2000-04-17 Issued National Machinery Industry Bureau 2000-09-01 Implementation JB4029-2000 3.1.1, 3.1.4, 3.3, 4.2 of this standard are all recommended provisions, and the rest are mandatory provisions. This standard is a revision of JB4029-85 "Technical requirements for safety protection of grinding wheel guards for grinding machines". The revision was made with reference to ANSIB11.9--1975 "Safety requirements for the manufacture, maintenance and use of grinding machines" and other advanced foreign standards. The main differences between this standard and JB4029-85 are: 1. The scope of application is changed to "This standard applies to grinding wheel guards for cylindrical grinders and surface grinders, and other grinders can also refer to it". 2. The wall thickness requirements of gray cast iron for the material selection of grinding wheel guards are modified. It is changed to "When gray cast iron with a tensile strength of not less than 150N/mm is selected, its wall thickness should not be less than the values listed in Table 3" and the content related to grinding wheel guards for grinding machines in the original standard is deleted. This standard replaces JB4029-85 from the date of implementation. This standard is proposed by the National Technical Committee for Standardization of Metal Cutting Machine Tools and is under the jurisdiction of the responsible drafting unit of this standard: Shanghai Grinding Machine Research Institute. This standard was first issued in May 1983. Machinery Industry Standard of the People's Republic of China Grinding wheel guards for safety Technical requirements for safety protection Specifications of grinding-wheel guard for safety This standard specifies the technical requirements for grinding wheel guards. This standard applies to grinding wheel guards for cylindrical grinders and surface grinders, and other grinders may also refer to it. 2 Referenced standards JB4029—2000 Replaces JB4029—85 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 the parties using this standard should explore the possibility of using the latest versions of the following standards. GB24941995 Abrasive tool safety rules GB2894—1996 Safety signs 3 Technical requirements 3.1 General requirements 3.1.1 The grinding wheels of cylindrical grinders and surface grinders should be equipped with protective covers (except for the grinding wheels on the inner circle of universal cylindrical grinders). The grinding wheel guard is generally composed of a peripheral plate and two side plates, one side of the two side plates is a fixed plate and the other side is a movable plate. The protective cover using the end face of the grinding wheel (belt-type grinding wheel guard) is composed of a movable circumferential plate. 3.1.2 When the grinding wheel guard is assembled or welded, there must be sufficient connection strength between the components, and the grinding wheel guard must be firmly and reliably fixed on the machine tool. 3.1.3 When a window must be opened on the grinding wheel guard for easy observation and dressing of the grinding wheel, the window should have sufficient strength and be able to prevent abrasive particles, sparks, and water mist from splashing out. 3.1.4 For the external cylindrical grinder machine tool whose operating position is in front of the grinding wheel guard, the circumferential plate of the guard should be equipped with a mechanism that can be adjusted as the grinding wheel becomes smaller. For example, it can be achieved by moving the grinding wheel guard (see Figure 1) or installing an adjustable guard plate (see Figure 2). The installation of the adjustable guard plate must be guaranteed to be firm and reliable. The distance between the grinding wheel circumference and the adjustable guard plate of the protective cover, or the distance between the grinding wheel circumference and the upper edge of the protective cover opening should generally be adjustable to less than 6mm. Approved by the State Bureau of Machinery Industry on April 17, 2000 and implemented on September 1, 2000 JB4029-2000 3.1.5 The endless belt type grinding wheel protective cover for vertical spindle surface grinders shall have a mechanism for adjusting the movement of the grinding wheel protective cover. The endless belt type grinding wheel protective cover must be made of rolled steel plate, with no opening in the middle (except for sand tiles), and the joints must be reliably connected. 3.1.6 The safety requirements for the use of grinding wheels shall comply with the provisions of GB2494. 3.2 Wall thickness of protective cover 3.2.1 Grinding wheel protective cover shall preferably be made of rolled steel plate with tensile strength not less than 415N/mm2, and its wall thickness (see Figure 3 for circumferential plate thickness A and side plate thickness B) shall be not less than the values listed in Table 1: If Q235 rolled steel plate with good welding performance (tensile strength of 375~460N/mm2) is used, its wall thickness shall not be less than the values listed in Table 1; When cast steel with tensile strength not less than 415N/mm2 is used, its wall thickness shall not be less than the values listed in Table 2; When gray cast iron with tensile strength not less than 150N/mm2 is used, its wall thickness shall not be less than the values listed in Table 3: When malleable cast iron is used, its wall thickness shall not be less than twice the values listed in Table 1; When materials or parameters not specified in Table 1, Table 2 and Table 3 are used, they shall be proved to be safe and reliable through tests or other verification methods. Figure 3bzxZ.net Grinding wheel linear speed Grinding wheel linear speed Grinding wheel thickness >50~100 >100160 >50100 >100~160 >50-100 >100~160 >160-2 00 >200~250 >250400 >400~500 >50~100 >100~160 >160~200 >200~250 >250400 > 400~500 Grinding wheel thickness >50~100 >100~160 >50~100 >100~160 >160-200 >200-256 >250~400 >400-500 ≤150 ≤150 JB4029—2000 Grinding wheel linear speed Grinding wheel thickness >50~100 >100~150 >15 0~200 >200~250 >250~400 >400~500 JB4029-2000 Outer diameter of grinding wheel 3.2.2 For grinding machines using two or more grinding wheels, when selecting the wall thickness of the grinding wheel guard, the grinding wheel thickness H in Table 1 should be calculated according to the following provisions: a) When the grinding wheel is installed using the method shown in Figure 4, the grinding wheel thickness is equal to the maximum spacing between the outer sides of the grinding wheel (H=H+H,+S, see Figure 4); H b) When the grinding wheel is installed using the method shown in Figure 5, its grinding wheel thickness is equal to the sum of the thicknesses of each grinding wheel (H=H+H,+H, see Figure 5). H JB 4029—2000 The wall thickness of the endless belt type grinding wheel guard shall not be less than the values listed in Table 4. 3.2.3 Outer diameter of grinding wheel Minimum knee thickness 3.3 Spacing between protective cover and grinding wheel >200600 > 600~750 3.3.1 Spacing between protective cover and grinding wheel When installing the thickest grinding wheel, the spacing between the outer side of the grinding wheel chuck and the edge of the opening of the grinding wheel protective cover should be as small as possible, and it is recommended to be no more than 15mm. 3.3.2 The spacing between the inner wall of the endless belt type grinding wheel protective cover and the circumferential surface of the grinding wheel should be as small as possible, and it is recommended to be less than 15mm (see Figure 6 E). 3.4 Grinding wheel exposure For the belt-type grinding wheel protection cover used for vertical surface grinder, the maximum exposure of the grinding wheel shall not exceed the provisions of Table 5 (see C in Figure 6). Grinding wheel thickness H >13-25 >25-50 > 50~75 >75~100 3.5 Grinding area opening angle Maximum allowable exposure of grinding wheel C The opening angle of the grinding wheel guard for the grinding area should be the minimum and should comply with the provisions of Table 6 according to the machine tool category. When measuring the opening of the guard, the observation shield or other additional devices should not be counted as part of the guard (unless the device has the same strength as the guard) 4 Marking Grinding type External cylindrical grinding Surface grinding (Horizontal axis type) JB4029-2000 Maximum opening angle 4.1 A safety sign indicating the direction of rotation of the grinding wheel should be provided at a conspicuous position of the grinding wheel cover (generally placed on the movable plate), and the requirements for the safety sign shall comply with the provisions of GB2894. 2 The following safety information should be provided on the grinding wheel cover or in the instruction manual: a) The grinding wheel can only be started to rotate after the movable plate is tightened; b) It is strictly forbidden to open the movable plate when the grinding wheel is rotating; c) Technical parameters such as the maximum grinding wheel diameter, maximum grinding wheel thickness, and maximum grinding wheel linear speed. 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