Some standard content:
1 Subject content and scope of application
Machinery Industry Standard of the People's Republic of China
Guidelines for the assembly process of electric tools
JB/T7086—1993
This standard specifies the equipment and fixtures for the assembly of electric tools, the requirements for the quality of parts and the workplace, as well as the typical parts assembly process, finished product debugging, quality requirements and precautions. This standard applies to the assembly of commonly used electric tools. 2 Reference standards
GB2900.28 Electrical terms
Electric tools
GB3883.1 Safety of handheld electric tools Part 1 General requirements
GB3883.2~3883.12 Safety of handheld electric tools JB2571
GB4863
3 Equipment and tools
Technical conditions for packaging of electric tools
Basic terms of mechanical manufacturing process
3.1 Press (oil pressure, air pressure)
The pressure can be adjusted evenly, the upper and lower pressure heads can move flexibly and stably, the pressure head working speed can be easily adjusted, and the pressure is appropriate. 3.2 Motorized screwdriver
It has a certain release torque and can rotate in both directions. 3.3 Verification workbench
Equipped with ammeter and voltmeter, and can adjust the voltage evenly. 3.4 Assembly fixture.
3.5 Commonly used small tools, such as screwdrivers, wooden hammers, etc. 4 Process preparation before assembly
4.1 Assembly workplace and workstation equipment.
4.1.1 Assembly workplace
4.1.1.1 The assembly workplace should be spacious and bright, with proper lighting and reasonable operating space. 4.1.1.2 There should be a good environment and facilities for dissipating noise, and good ventilation. 4.1.1.3 The transmission of the assembly line should have an adjustable beat device, and the assembly line should be equipped with an appropriate number of presses. 4.1.1.4 There should be good sound insulation facilities for product factory testing. 4.1.1.5 The assembly work surface should be made of materials that are unlikely to damage the surface of the parts to be assembled. 4.1.1.6 The workplace should have safety measures such as prevention of electric shock. 4.1.2 Workstation tools
4.1.2.1 Workstation tools should be easy to use, flexible in turnover, and of appropriate weight. They should effectively prevent the magnetism of the parts to be installed and protect the surface of the parts from damage.
4.1.2.2 According to the different shapes of the parts, the workstation tools should have different types, and inappropriate workstation tools should not be used. The workstation tools should be cleaned frequently and kept clean. 4.1.2.3
Approved by the Ministry of Machinery Industry on October 8, 1993
Implemented on January 1, 1994
JB/T70861993
4.1.2.4 Workstation tools should be used correctly according to the specified scope of use and the number of parts to be placed. 4.1.2.5 Commonly used workstation tools
Armature:
Shafts;
Gears,
General plastic trays and boxes;
Special workstation tools.
4.2 Quality of parts to be installed
4.2.1 All parts to be installed (including outsourced and purchased parts) shall meet the design requirements and shall be inspected and qualified. 4.2.2 The surface of the parts after coating shall be free of damage. 4.2.3 The surface of plastic parts shall be free of damage and other unnecessary defects. 4.3 Assembly tooling
4.3.1 Design principles
4.3.1.1 In order to ensure the assembly quality of power tools, the necessary number of assembly process equipment (hereinafter referred to as tooling) shall be available during product assembly.
4.3.1.2 The tooling shall be able to maintain the accuracy of the parts during use and shall not damage the parts. 4.3.1.3 The tooling should be easy to operate and ensure the assembly quality of parts. 4.3.1.4
The tooling should be properly matched with equipment such as presses. 4.3.1.5
The tooling should have sufficient hardness and resistance to mold and be able to ensure its accuracy for a long time. 5 The tooling should be designed as a top-to-bottom center structure as much as possible. 4.3.1.6
4.3.1.7 The design of the assembly workbench should not damage the apparent quality of the parts during the product assembly process. 4.3.1.8 The fixture used for press assembly should use guide pins and guide sleeves as much as possible. 4.3.2 Necessary types of tooling:
Bearing press-in fixture for reduction gearbox;
Bearing press-in fixture for intermediate cover;
Assembly and bearing press-in fixture for intermediate cover of armature; Shaft press-in fixture;
Gear press-in fixture;
Brush holder press-in fixture.
4.3.3 Use of tooling
4.3.3.i Before using the tooling, carefully check whether the tooling is intact. If there is any defect, it is strictly prohibited to use it. 4.3.3.2 Before officially using the tooling to assemble parts, 1 to 3 parts should be tested with the tooling. Only after confirming that the installed parts are qualified can they be used.
4.3.3.3 During the use of the tooling, according to the importance of the installed parts, an appropriate number of random inspections should be carried out to ensure the quality of the assembled parts.
4.3.3.4 After the use of the tooling, it should be properly kept. For the tooling that has not been used for a long time, anti-rust measures should be taken to avoid damage to the tooling. 4.4 Auxiliary work before assembly
4.4.1 Except for the fully enclosed bearings, the rolling bearings must be cleaned with clean gasoline before use. After drying, fill with grease according to the design requirements, and then properly put into the work station equipment and keep it clean. 4.4.2 The power cord should be prepared for connection according to the requirements of the drawings, and the specifications of the terminal connectors should not be used incorrectly. 4.4.3 The stator should be pre-connected with the connectors according to the requirements of the drawings. The brazed joints should be full and smooth, without leakage and cold welding. The sliding bearings should be cleaned with gasoline. And they can be used after being soaked in clean engine oil for 24 hours. 4.4.4
4.4.5 Check the quality requirements of auxiliary materials such as grease. 59
4.5 Assemblers
JB/T7086—1993
4.5.1 Assemblers must undergo on-the-job training and pass the examination before they can take up their posts. 4.5.2 Assemblers must firmly establish the awareness of "quality first", receive quality management training and assessment, and have a strong sense of responsibility. 4.5.3 Assemblers must have basic electrical knowledge and fitter operation skills. 4.5.4 Assemblers must receive certain safety education and have the necessary fire prevention and fire extinguishing knowledge. 4.5.5 Assemblers should be familiar with the quality requirements of each product and the contents of relevant process documents. 4.6 Process documents
4.6.1 Process documents required for product assembly work; process equipment list;
Assembly process card, process card;
Parts and product inspection specifications;
d, assembly operation instructions or process rules 4.6.2 Product assembly work shall be carried out strictly in accordance with the provisions of the process documents, and no changes or modifications shall be made. If necessary, changes may be made only after the consent of relevant personnel.
5 Assembly process
5.1 Before assembling new products, relevant process personnel shall first introduce the assembly process methods and precautions, and assemblers shall be familiar with the assembly process and its quality requirements in advance.
5.2 It is strictly forbidden to use unqualified parts. Unqualified parts found during the assembly process shall be removed. 5.3 Product assembly generally adopts the process method of first sub-assembly and then general assembly. If it is assembly on an assembly line, a reasonable rhythm needs to be selected. 5.4 Product sub-assembly
5.4.1 Middle cover sub-assembly| |tt||5.4.1.1 When pressing the sliding bearing or rolling bearing into the middle cover, a clamp must be used. 5.4.1.2 Select the pressing pressure to avoid damage to the bearing and the middle cover. 5.4.2 Armature assembly
5.4.2.1 The fan should be installed on the armature before the armature is balanced. 5.4.2.2 Press-fit the rotor bearing and middle cover assembly: a clamp with a limit device must be used to avoid deformation of the rotor; a.
The structure of the clamp can be changed, but the clamp that will cause bearing damage and rotor deformation cannot be used; b.
The pressure of the bearing pressed into the rotor must be appropriate. 5.4.3 Fuselage assembly
5.4.3.1 The stator can be installed into the casing using a shrink fit. There are two methods: hot-sleeving or cold-sleeving. Usually, only plastic casings use the hot-sleeving method. The preheating temperature of plastic casings is determined by the material used and generally does not exceed 60°C, while aluminum casings are usually suitable for cold-sleeving. 5.4.3.2 When the stator is installed into the casing, it must not be tilted and must be assembled in place. 5.4.3.3 The riveting between the brush holder and the casing should be firm and reliable, and a clamp should be used to ensure that the brush holder seat will not deform, so that the brush can be installed smoothly. 5.4.3.4 A clamp should be used when the patterned brush is pressed into the casing to ensure the coaxiality of the two brush holders and the pressing size of the brush holder. 5.4.3.5 The switch must be checked when installed, and switches with poor contact or defects must not be used. 5.4.3.6 All types of leads should be arranged in place as specified in the drawings. 5.4.4 Gear assembly
The assembly of gears and shafts can be divided into two categories: keyed and keyless. 5.4.4.1 Gears and shafts use a keyless interference fit, and attention should be paid during assembly; a.
Use a special fixture;
Ensure the correct introduction of the gears and shafts;
JB/T 7086--1993
The dimensions of the shaft and gear fit must meet the requirements of the drawing; d.
Control the pressure of the press when the gears and shafts are pressed to ensure that they fit in place and prevent the shaft from bending and deforming. 5.4.4.2 Gears and shafts use a keyed fit, and attention should be paid during press fitting. The fit between the semicircular key and the keyway should be a transition fit, and there should be no looseness; a.
The keyway should be flat and in place, and should not affect the press fitting; during press fitting, the key installed on the shaft should be aligned with the center of the keyway of the gear. To prevent damage to parts; shaft retaining rings must be installed in place to prevent gears from sliding and shifting. 5.4.7 Product assembly
5. 4. 7.2
All parts and components shall be assembled in place according to the requirements of the drawings. No omissions or wrong installations shall be allowed. The assembly of all parts and components shall be carried out in the order specified in the assembly process card and shall not be adjusted automatically. All connecting screws shall be tightened, and the tightening torque shall be determined according to the thread diameter and strength grade, according to the shape of the connected parts and the distribution of screws and bolts 5.4.7.34
. Design the tightening sequence and tighten in batches (initial tightening and final tightening). 5.4.7.4 All parts and components shall be accurately in place during assembly, and there shall be no obvious defects such as misalignment. 5.4.7.5 It is generally not allowed to use wooden (rubber) hammers to hit parts and components during assembly to avoid damaging parts. It is strictly forbidden to use iron hammers to hit parts and components. 5.4.7.6 The assembly quality of each part shall be checked during assembly, and parts that do not meet the requirements shall not be put into assembly. 5.4.7.7 The final assembled product must pass the self-inspection before it can be sent for testing. 6 Debugging
6.1 During the final assembly of power tools, debugging methods that will damage the reasonable accuracy reserve of the product should not be used, such as grinding the gears with non-design requirements to reduce meshing noise.
6.2 The debugging of power tools during final assembly is shown in the table below. Table
Debugging content
Large no-load current
Stator and rotor combined
Large spark
Cause
1. Large mechanical loss (such as poor gear matching, inflexible bearing rotation, too tight size, etc.)
2. Motor quality (such as impurities in the commutator, etc.) 3. Mechanical friction (friction between the fan and the fuselage, etc.) 4. Stator and rotor rub against each other
1. The dynamic balancing accuracy of the rotor is too low
2. The bearing hole of the middle cover and the bearing hole of the casing do not meet the requirements of the drawing
3. The plastic bearing hole is damaged
4. The rotor shaft is bent
1. The dynamic balancing accuracy of the rotor is low|| tt||2. The commutator is not round or the surface is uneven
3. The brush spring pressure is low, and the brush and commutator are in poor contact. 4. The brush holder and the brush do not match well.
5. The commutator is dirty or short-circuited
6. The rotor or stator is short-circuited
Debugging method
1. Reduce mechanical loss
2. Improve motor quality
3. Eliminate mechanical friction
4. Eliminate friction
1. Improve the dynamic balancing accuracy of the rotor
2. Improve the processing accuracy of the middle cover and the casing 3. Improve the raw materials and improve the mold accuracy
4. Strengthen the control of each process and periodicity of rotor processing.
1. Improve the dynamic balancing accuracy of the rotor
2. Repair the commutator
3. Adjust the pressure of the electric spring
4. Correct the size of the brush or brush holder
5. Clean the commutator or replace the rotor
6. Replace the rotor or stator
Debugging content
Failure to start
Abnormal speed
Excessive noise or noise
Excessive temperature rise of the reduction gearbox surface
Excessive temperature rise of the casing
Quality requirements
JB /T70861993
Causes
1. Low accuracy of rotor dynamic balance
2. Poor bearing quality
3. Insufficient accuracy of bearing chamber dimensions
4. Shaft bending
1. Power line disconnected
2. Broken switch or poor contact
3. Poor contact between brush and commutator
4. Stator and rotor disconnected
5. Mechanical failure
1. Product axial dimension is too tight
2. Rolling bearing quality Not good
3. Poor contact of switch
4. Poor contact between brush and commutator
5. Short circuit of stator winding
6. Short circuit of rotor winding
1. Damaged bearing or debris in the bearing
2. Damaged gear
3. Rubbing between stator and rotor
4. The dimensional accuracy of gear, rotor shaft gear, intermediate shaft, gearbox and intermediate cover does not meet the requirements
5. The fan is magnetized or loosened with the casing
6. There is no lubricating oil or foreign matter in the gearbox|| tt||7. Short circuit of stator and rotor windings
8. Improper assemblywwW.bzxz.Net
1. No lubricating oil or foreign matter in the reduction box
2. Damaged bearing
3. Gears are damaged or too tight
1. Short circuit of stator and rotor windings
2. Commutator is short circuited or dirty
3. Excessive voltage pressure
4. Stator and armature phase
5. Damaged bearing
6. Improper assembly
The electric tool should comply with the relevant standards after assembly. 7.1
Debugging method
1. Improve the accuracy level of rotor dynamic balance
2. Replace bearings
3. Improve the machining accuracy of bearing chamber
4. Replace rotor or calibrate rotor shaft
1. Replace or repair power cord
2. Replace and repair switch
3. Adjust the pressure between brush and commutator
4. Replace stator and rotor
5. Eliminate mechanical failure
1. Adjust the axial dimension of the product
2. Replace rolling bearings
3. Repair and replace the joint
4. Adjust the pressure to make good contact
5. Replace stator
6. Replace rotor
1. Replace or clean bearings
2. Replace gears
3. Refer to No. 2 in this table
4. Improve machining accuracy
5. Adjust the fan position and tighten it
6. Add lubricant or remove foreign matter
7. Replace stator or rotor
8. Reassemble
1. Add lubricant or remove foreign matter
2. Replace bearings
3. Replace gears and adjust the meshing condition between gears1. Replace stator and rotor
2. Clean commutator or replace rotor
3. Adjust brush pressure
4. Refer to No. 2 in this table
5. Replace bearings
6. Reassemble
After assembly, the power tool should meet the requirements of relevant technical conditions. Defective products shall not be shipped. 7.2
During the assembly process, it is strictly forbidden to use unqualified parts. 7.3
During the assembly process, components or standard parts, fasteners, etc. must not be installed incorrectly or missing. 7.43
The length of the stator lead wire should meet the requirements of the drawing. 7.5
7.6Unsmooth wiring troughs shall not be used for assembly, and the lead wires shall be correctly installed in the wiring troughs or holes according to relevant requirements. 62
JB/T7086—1993
7.71 The grounding wire and grounding terminal of Class 1 electric tools must be firmly and reliably connected, and the length of the grounding wire and switch lead wire shall be strictly cut according to the requirements of the drawing.
7.8 The connection between the power cord and the switch must be firm and reliable. 7.9 The installation of the blade on the electric planer shaft must meet the requirements of the drawing, and the pressure plate should ensure that the blade is always in a tight state. 7.10 The grinding wheel cover of the angle grinder shall not be loose after the grinding wheel is assembled, and the grinding wheel cover and the grinding wheel are not allowed to rub against each other. 7.11 The rotation direction of the main shaft of the angle grinder grinding wheel must be consistent with the requirements of the drawing. It is strictly forbidden to use unqualified grinding wheels or grinding wheels that have exceeded the shelf life and have not been re-confirmed as qualified.
7.12 After the product is assembled, grease and other debris are not allowed to exist in the stator and rotor ends, commutator and bearings, steel fan and winding, brush box and bearings.
8 Precautions
8.1 When assembling products, the process regulations should be strictly followed. The assembly sequence or special tooling should not be changed without permission. 8.2 Use workstation tools correctly to prevent magnetism and damage to parts. 8.3 Select the rated voltage according to the drawings and process requirements. Overpressure debugging or testing is not allowed. 8.4 Assemblers should be familiar with the performance and use of various equipment and tools to prevent equipment and personal accidents. 8.5. Set up electromechanical safety protection devices, use necessary labor protection supplies, and strictly prevent mechanical injuries and electric shock accidents. 8.6 Strengthen the responsibility system, improve the sense of responsibility of assemblers, and the assembled products should have the marks of assemblers. 8.7 During assembly and commissioning, it is strictly forbidden to use hammers and other tools to hit the products to avoid damaging parts and appearance quality. 8.8 Keep the site clean and tidy, and place parts reasonably to avoid contaminating products and reducing the quality of assembly. 8.9 Adhere to civilized production and strictly prohibit barbaric operations. 9. Factory inspection and packaging
9.1 Factory inspection of products
9.1.1 Each product after assembly should be inspected before entering the warehouse. : In addition to all the inspection and test items of product standards, the factory inspection of products generally includes, 9.1.2
No-load current;
No-load speed;
Switch;
Tooth sound and noise;
Operation status;
tAlarm.
9.1.3 Impact drills and electric hammers should be tested for impact. Electric planers should be checked for no-load operation for no less than 5 minutes. 9.1.4
9.1.5 Angle grinders, grinding wheels and protective covers should be firm and reliable and should not collide during operation. 9.1.6 Products should meet the requirements of technical conditions. Unqualified products should be repaired and can only be packaged after they meet the requirements. 9.2 Regular product inspections
9.2.1 In addition to normal factory tests, products should also be regularly inspected according to the provisions of GB3883. 9.2.2 The instruments, meters and test methods used for regular product inspections should meet the requirements of relevant standards. 9.2.3 If it is found that some of the test items do not meet the relevant requirements during regular product inspections, double sampling inspections can be carried out. If they are still unqualified, it is necessary to analyze the reasons and determine measures to ensure the quality of product assembly. 9.2.4 Regular product inspections should be carried out by the superior competent unit or the enterprise. 9.2.5 The regular sampling inspection of products generally includes the following items, which can be increased or decreased according to the specific conditions of the enterprise and the relevant standards. Load test;
Temperature rise test;
Durability test;
Dielectric strength test;
Noise measurement;
Cable or soft wire tensile test.
9.3 Product packaging
JB/T 70861993
Products can only be packaged after they have passed the factory test. 9.3.1
The nameplate of the product should be installed firmly and should not be loose. 9.3.3
The surface of the product should be wiped clean before packing, and the product shell should not be allowed to have defects such as bumps and scratches. Parts that need to be rust-proof should be rust-proofed before packing. Accessories, spare parts, inspection certificates, operating instructions, etc. should not be omitted when packing products. 9.3.5
9.3.6 Certified products shall use the certification mark correctly as required. 9.3.7 Product packaging and packing shall comply with the provisions of JB2571. Additional notes:
This standard is proposed and managed by the National Electric Tool Standardization Technical Committee. This standard was drafted by the Shanghai Electric Tool Research Institute of the Ministry of Machinery Industry and Shanghai Hitachi Electric Tools Co., Ltd. The main drafters of this standard are Liu Maochun and Lu Tiemin. 64
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