A method for manufacturing a shaft of a driving motor of an automobile

Abstract

The present invention provides a method for manufacturing a shaft of an automobile drive motor, and belongs to the technical field of automobile manufacturing. It solves the problem that the coaxiality of the spline gear in the existing braking method is not high. The manufacturing method of the shaft of the automobile drive motor comprises the following steps: A. Rough machining: turning the blank and then rough grinding the outer circle to make a semi-finished shaft; B. Heat treatment: continuously high-frequency quenching and tempering the first and second gears of the semi-finished shaft; C. Finishing: C.1. Grinding the center hole; C.2. Fine grinding the outer circle: clamping once with the center hole as the clamping reference, fine grinding the outer circle of the first gear, the outer circle of the second gear, the outer circle of the first bearing gear, the outer circle of the rotor assembly gear and the outer circle of the second bearing gear; C.3. Fine rubbing of splines: clamping once with the center hole as the clamping reference, using an integrated tooth rubbing plate to rub teeth at the outer circle of the first gear and the outer circle of the second gear at the same time and forming the first gear spline and the second gear spline respectively. The manufacturing method of the shaft of the automobile drive motor improves the coaxiality of the spline gear.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile manufacturing, and relates to a method for manufacturing an automobile drive motor shaft. Background Art

[0002] New energy vehicles output kinetic energy through drive motors. The motor shaft in the drive motor is a key component for power output, and its parts have high tolerance requirements. Coaxiality, commonly referred to as the degree of coaxiality, indicates the condition in which the measured axis on the part remains on the same straight line relative to the reference axis. The coaxiality tolerance is the allowable variation of the actual measured axis relative to the reference axis. The drive motor shaft includes two bearing gears, several spline gears and a rotor assembly gear. The two bearing gears are the assembly reference. When checking the coaxiality, the coaxiality of the spline gear is generally checked with the two bearing gears as the reference. The coaxiality of the spline gear generally refers to the coaxiality of the spline pitch circle.

[0003] For machining shaft parts with multi-stage external splines, a general method is disclosed in a Chinese patent literature [publication number: CN110116300A], which discloses a machining process for an automobile transmission shaft, comprising: S1: forging a workpiece blank into shape; S2: rough turning, rough turning the shape, and removing the oxide layer of the formed forging; S3: quenching and tempering, quenching the rough turned workpiece and then high temperature tempering; S4: semi-finishing turning, turning the quenched and tempered workpiece; S5: gear shaping, machining the splines on the periphery of the workpiece by a gear shaping machine; S6: quenching, quenching the periphery of the splines; S7: fine grinding, fine grinding the splines of the workpiece and the periphery of the shaft.

[0004] In the above processing method, the multi-speed spline is formed by inserting teeth first and then quenching is performed. The spline will be deformed during quenching, affecting the coaxiality of the spline pitch circle. In addition, only the outer circle of the spline and the outer circle of the shaft are fine-ground during fine grinding. Although the coaxiality of the spline outer circle and the shaft outer circle can be improved, the coaxiality of the spline pitch circle cannot be improved. In order to improve the coaxiality of the multi-speed external spline pitch circle, the conventional technical method is: after fine grinding the outer circle, clamp it with the same clamping reference and then fine grind the multi-speed spline teeth. Fine grinding the spline teeth can correct the spline tooth shape, thereby improving the coaxiality. However, fine grinding the tooth shape requires specific grinding gears, which is costly. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems in the prior art and propose a method for manufacturing a shaft of a vehicle drive motor. The technical problem to be solved is how to improve the coaxiality of the spline gear of the drive motor shaft.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A method for manufacturing a shaft of an automobile drive motor, characterized in that it comprises the following steps:

[0008] A. Rough machining: Drill center holes at both ends of the blank, turn the blank, and then roughly grind the outer circle to form a semi-finished shaft with several cylindrical sections. The semi-finished shaft at least includes the first gear, the second gear, the first bearing gear, the rotor assembly gear and the second bearing gear;

[0009] B. Heat treatment: The first and second gears of the semi-finished shaft are subjected to continuous high-frequency quenching so that the quenching layer of the first gear is connected to the quenching layer of the second gear, and then the semi-finished shaft is tempered;

[0010] C. Finishing:

[0011] C.1. Grinding the center hole;

[0012] C.2. Fine grinding of outer circle: take the center hole as the clamping reference, clamp once, fine grind the outer circle of the first gear, the outer circle of the second gear, the outer circle of the first bearing gear, the outer circle of the rotor assembly gear and the outer circle of the second bearing gear;

[0013] C.3. Fine spline rolling: With the center hole as the clamping reference, clamp once, use an integrated tooth rolling plate to roll the teeth at the outer circle of the first gear and the outer circle of the second gear at the same time to form the first gear spline and the second gear spline respectively.

[0014] The first gear and the second gear are continuously subjected to high-frequency quenching to form a connected quenching layer, which can reduce the difference in quenching conditions between the first gear and the second gear, so that the difference in crystal structure and hardness formed between the first gear and the second gear is small, ensuring that the first gear and the second gear can form stable plastic deformation when the integrated gear rolling plate is used for gear rolling in the subsequent process, so as to improve the coaxiality of the first gear spline pitch circle and the second gear spline pitch circle. In addition, the hardness can be increased after quenching, thereby improving the processing accuracy during fine grinding.

[0015] Grinding the center hole improves the accuracy of the center hole, thereby improving the machining accuracy of the formed surface when the center hole is used as the clamping reference. After fine grinding the center hole, clamping is performed once with the center hole as the clamping reference, and fine grinding of the first gear outer circle, the second gear outer circle, the first bearing gear outer circle, the rotor assembly gear outer circle and the second bearing gear outer circle can improve the coaxiality of the first gear outer circle, the second gear outer circle, the first bearing gear outer circle, the rotor assembly gear outer circle and the second bearing gear outer circle, that is, improve the coaxiality of the first gear outer circle and the second gear outer circle when the rotor assembly gear is used as the positioning reference and the first bearing gear and the second bearing gear are used as the inspection reference, which also provides conditions for the subsequent use of an integrated tooth rolling plate to form the first gear spline and the second gear spline in one time. Afterwards, the center hole is used as the clamping reference for one-time clamping, and an integrated gear rolling plate is used to roll teeth at the outer circles of the first gear and the second gear at the same time to form the first gear spline and the second gear spline respectively. On the one hand, since the coaxiality of the first gear outer circle and the second gear outer circle is high after fine grinding of the outer circle, and the clamping reference during gear rolling is the same as the clamping reference during fine grinding of the outer circle, the rolling diameter error between the first gear outer circle and the second gear outer circle and the gear rolling plate can be reduced. On the other hand, the first gear spline and the second gear spline are formed at one time by the integrated gear rolling plate, which reduces the processing error caused by multiple gear rolling. In combination with the high coaxiality of the first gear outer circle and the second gear outer circle after fine grinding of the outer circle, the differences in the crystal phase structure and hardness of the first gear and the second gear after heat treatment are small. During the gear rolling process, the first gear and the second gear can form stable plastic deformation under the action of the same gear rolling force, thereby improving the coaxiality of the first gear spline pitch circle and the second gear spline pitch circle.

[0016] Therefore, the manufacturing method of the automobile drive motor shaft can improve the coaxiality of the spline gear through the mutual correlation and joint action between various steps.

[0017] In the above-mentioned method for manufacturing the automobile drive motor shaft, in step C.2, after fine grinding the outer circle, the outer circle of the second stage is fine ground into a drum shape with the center hole as the clamping reference.

[0018] After the second gear is finely ground into a drum shape, since the middle part of the outer circumference of the second gear is convex while the outer circumference of the first gear is still cylindrical, the integrated gear rolling plate generally contacts the middle part of the outer circumference of the second gear first during gear rolling. This can reduce the resistance in the initial state during gear rolling and make the gear rolling proceed smoothly. At the same time, it can also ensure the stability of positioning when the center hole is used as the clamping reference, and avoid the reduction of the coaxiality of the first gear spline and the second gear spline caused by the vibration of the workpiece.

[0019] In the above-mentioned manufacturing method of the automobile drive motor shaft, in step C.2, the drum protrusion of the second gear outer circle is 0.015mm-0.025mm, so that the drum protrusion can be achieved, the coaxiality can be ensured, and the tooth height requirement of the second gear spline can be met.

[0020] In the above-mentioned manufacturing method of the automobile drive motor shaft, in step C.3, the integrated gear rolling plate includes a first split plate and a second split plate which are fixedly connected and both are in the shape of long strips, the top surface of the first split plate is used to form a first gear spline, the top surface of the second split plate is used to form a second gear spline, a side surface of the second split plate in the length direction is a vertical positioning surface, the vertical positioning surface has a vertically protruding horizontal positioning platform, the bottom surface of the first split plate is abutted against the horizontal positioning platform and a side surface of the first split plate in the length direction is abutted against the vertical positioning surface; the integrated gear rolling plate is installed on the gear rolling machine with the horizontal positioning platform as the horizontal reference, and the semi-finished shaft is horizontally clamped in the gear rolling machine.

[0021] The horizontal positioning platform enables the first and second split plates to be accurately positioned in the upper and lower positions, and the vertical positioning surface enables the second and second split plates to be accurately positioned in the front and rear positions, so that the top surface of the first split plate and the top surface of the second split plate are accurately positioned, thereby improving the coaxiality of the first-gear spline and the second-gear spline formed at one time using the integrated gear rolling plate.

[0022] In the above-mentioned method for manufacturing the automobile drive motor shaft, in step C.3, the horizontal positioning platform is fixed with a plurality of positioning pins arranged in sequence along the length direction, and the positioning pins are all inserted into the first split plate. The positioning pins are used to position the left and right directions of the first split plate and the second split plate, so that the circumferential positions of the first gear spline and the second gear spline are accurately positioned.

[0023] In the above-mentioned manufacturing method of the automobile drive motor shaft, in step B, the surface hardness of the first-stage quenched layer and the second-stage quenched layer after tempering is 40HRC-45HRC. Such surface hardness can not only improve the machining accuracy during grinding, but also enable smooth forming of the gear rolling, and is also conducive to ensuring the coaxiality of the first-stage spline and the second-stage spline.

[0024] In the above-mentioned method for manufacturing the automobile drive motor shaft, in step B, the rotor assembly stage is also subjected to high-frequency quenching and tempering.

[0025] This can increase the surface hardness of the rotor assembly file to improve the processing accuracy during grinding, so that the positioning can be accurate when the outer circle of the rotor assembly file is used as the positioning reference during inspection, and the coaxiality detection can be accurate to improve the coaxiality of the spline file.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] First, the first gear and the second gear are high-frequency quenched and tempered to form a continuous quenching layer, and then the center hole is fine-ground. The first gear outer circle, the second gear outer circle, the first bearing gear outer circle, the rotor assembly gear outer circle and the second bearing gear outer circle are clamped and fine-ground with the center hole as the clamping reference at one time to improve the coaxiality of multiple gear outer circles. Then, the center hole is used as the clamping reference, and an integrated tooth rolling plate is used for one-time clamping to simultaneously and separately roll teeth in the first gear and the second gear to form the first gear spline and the second gear spline to improve the coaxiality of the first gear spline and the second gear spline. In this way, the steps are interrelated and work together to improve the coaxiality of multiple spline gears of the drive motor shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a front view of an automobile drive motor shaft produced by the manufacturing method.

[0029] Figure 2 The present invention is a flow chart of a method for manufacturing a shaft of a driving motor of an automobile.

[0030] Figure 3 The present invention is a schematic diagram of the local structure of the first and second gears of the driving motor shaft of the automobile after fine grinding into a drum shape.

[0031] Figure 4 The present invention is a schematic diagram of the top view structure of an integrated tooth rolling plate in the manufacturing method of the automobile drive motor shaft.

[0032] Figure 5 It is a schematic diagram of the cross-sectional structure of an integrated tooth rolling plate in the manufacturing method of the automobile drive motor shaft.

[0033] Figure 6 The invention is a structural schematic diagram of a detection auxiliary device in the manufacturing method of the automobile drive motor shaft.

[0034] Figure 7 It is a schematic diagram of zeroing of a detection auxiliary device in the manufacturing method of the automobile drive motor shaft.

[0035] Figure 8 It is a schematic diagram of the measurement of the detection auxiliary device in the manufacturing method of the automobile drive motor shaft.

[0036] In the figure, 1, driving motor shaft; 1a, center hole; 1b, first gear; 1c, second gear; 1d, first bearing gear; 1e, shaft shoulder gear; 1f, rotor assembly gear; 1g, transition gear; 1h, second bearing gear; 1j, tail end first gear; 1k, tail end second gear; 1m, quenching layer; 2, integrated tooth rolling plate; 2a, first dividing plate; 2b, second dividing plate; 2b1, vertical positioning surface; 2b2, horizontal positioning platform; 2 c. locating pin; 3. auxiliary detection device; 3a. base plate; 3a1. mounting hole; 3a2. countersunk hole; 3b. vertical plate; 3c. ball; 3d. spring; 3e. pad; 3e1. fixing hole; 3f. finger cylinder; 3f1. finger; 3g. adjusting bolt; 3h. dial indicator; 3h1. fixing rod; 3h2. measuring head; 3k. fixing bolt; 3m. connecting bolt; 4. calibration rod; 4a. locating hole. DETAILED DESCRIPTION

[0037] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0038] like Figure 1 The invention discloses a shaft of a vehicle driving motor, which is in a stepped shape and comprises a first gear 1b, a second gear 1c, a first bearing gear 1d, a shoulder gear 1e, a rotor assembly gear 1f, a transition gear 1g, a second bearing gear 1h, a first tail end gear 1j and a second tail end gear 1k, which are arranged in sequence along the axial direction, wherein the outer circle of the first gear 1b is provided with a straight tooth spline, and the outer circle of the second gear 1c is provided with a helical tooth spline, and a center hole 1a is also provided at the center of the end surface of both ends of the shaft 1 of the vehicle driving motor. Figure 1 The dotted lines at both ends represent the central hole 1a, and the dotted lines at both sides represent the boundary between the quenched layer 1m and the unquenched area.

[0039] like Figure 1 and Figure 2 As shown, a method for manufacturing a shaft of a vehicle driving motor comprises the following steps:

[0040] A. Rough machining:

[0041] A.1. Milling end faces: Milling the end faces of the blank bar.

[0042] A.2. Drilling center hole: Drill center holes 1a at both ends of the blank bar.

[0043] A.3. Rough turning of outer circle: Taking the center hole 1a as the clamping reference, rough turn the outer circle of the blank bar.

[0044] A.4. Turning the end faces and the outer circle: Turn the end faces of the blank at both ends with the outer circle of the blank as the clamping reference; turn the outer circle with the center hole 1a as the clamping reference, so that the blank bar material forms a preliminary formed shaft with multiple cylindrical segments. The preliminary formed shaft includes the first gear 1b, the second gear 1c, the first bearing gear 1d, the shoulder gear 1e, the rotor assembly gear 1f, the transition gear 1g, the second bearing gear 1h, the tail end first gear 1j and the tail end second gear 1k.

[0045] A.5. Rough grinding of outer circle: Taking the center hole 1a as the clamping reference, the outer circle of each gear of the initially formed shaft is roughly ground to form a semi-finished shaft; the semi-finished shaft includes the first gear 1b, the second gear 1c, the first bearing gear 1d, the shoulder gear 1e, the rotor assembly gear 1f, the transition gear 1g, the second bearing gear 1h, the tail end first gear 1j and the tail end second gear 1k.

[0046] B. Heat treatment:

[0047] B.1. High-frequency quenching: With the center hole 1a as the clamping reference, the first gear 1b of the semi-finished shaft is vertically installed upward in the high-frequency quenching machine. The induction coil is sleeved on the outer side of the top of the semi-finished shaft, and moves continuously from top to bottom to heat the first gear 1b, the second gear 1c and the upper part of the first bearing gear 1d. After passing through the shoulder gear 1e, the induction coil moves continuously from top to bottom to heat the rotor assembly gear 1f. After passing through the upper part of the transition gear 1g, it moves continuously from top to bottom to heat the lower part of the transition gear 1g and the second bearing gear 1h. After the induction heating is completed, the induction coil moves upward to separate from the semi-finished shaft, and then sprays the quenching liquid to complete the high-frequency quenching. After quenching, three quenching layers 1m are formed on the semi-finished shaft, among which the first gear 1b and the second gear 1c are subjected to continuous high-frequency heating to connect the quenching layer 1m of the first gear 1b and the quenching layer 1m of the second gear 1c, that is, the first quenching layer is formed on the upper part of the first gear 1b, the second gear 1c and the first bearing gear 1d, the second quenching layer is formed on the rotor assembly gear 1f, and the third quenching layer is formed on the transition gear 1g and the second bearing gear 1h.

[0048] B.2. Tempering: Put the quenched semi-finished shaft into the tempering furnace for 2-4 hours, and the tempering temperature is 200℃-250℃. After tempering, the surface hardness of the first gear 1b quenching layer 1m, the second gear 1c quenching layer 1m, the rotor assembly gear 1f quenching layer 1m and the second bearing gear 1h quenching layer 1m is 40HRC-45HRC. Due to the differences in the composition of each batch of raw materials, the surface hardness after quenching is different. Therefore, the tempering time and tempering temperature need to be adjusted appropriately according to the surface hardness after quenching. Generally, the higher the surface hardness after quenching, the higher the tempering temperature and the longer the tempering time. Generally, you can choose to temper for 3 hours at a tempering temperature of 220℃.

[0049] B.3. Magnetic particle inspection: After tempering, cool to room temperature, perform magnetic particle inspection on a magnetic particle inspection machine, and then demagnetize on a demagnetization machine. Magnetic particle inspection is used to check whether there are quenching cracks. Products without cracks can flow to the next process.

[0050] C. Finishing:

[0051] C.1. Grinding center holes: Grind two center holes 1a using the rotor assembly file 1f as the clamping reference.

[0052] C.2. Fine grinding of outer circle, fine grinding of drum shape and fine turning of end face:

[0053] C.2.1. Fine grinding of outer circle: take the center hole 1a as the clamping reference, clamp once, fine grind the outer circle of the first gear 1b, the outer circle of the second gear 1c, the outer circle of the first bearing gear 1d, the outer circle of the rotor assembly gear 1f and the outer circle of the second bearing gear 1h;

[0054] C.2.2, Fine grinding drum shape: Figure 3 As shown, the outer circle of the second gear 1c finely ground with the center hole 1a as the clamping reference is drum-shaped, and the drum-shaped protrusion is 0.015mm-0.025mm; preferably, the drum-shaped protrusion does not exceed 0.020mm.

[0055] C.2.2. Finish turning of end faces: Use the rotor assembly file 1f as the clamping reference to finish turn the two end faces.

[0056] C.3. Fine spline rolling: With the center hole 1a as the clamping reference, clamp once, use the integrated tooth rolling plate 2 to roll the teeth at the outer circle of the first gear 1b and the outer circle of the second gear 1c at the same time, and form the first gear 1b spline and the second gear 1c spline respectively. The first gear 1b spline is a straight tooth spline, and the second gear 1c spline is a helical tooth spline.

[0057] like Figure 4 and Figure 5As shown, the integrated tooth rolling plate 2 includes a first split plate 2a and a second split plate 2b which are fixedly connected and both are in the shape of long strips. The top surface of the first split plate 2a is used to form the first gear 1b spline, and the top surface of the second split plate 2b is used to form the second gear 1c spline. One side surface of the second split plate 2b in the length direction is a vertical positioning surface 2b1, and the vertical positioning surface 2b1 has a vertically protruding horizontal positioning platform 2b2, and the top surface of the horizontal positioning platform 2b2 is a horizontal positioning surface, and the bottom surface of the horizontal positioning platform 2b2 is flush with the bottom surface of the second split plate 2b. The bottom surface of the first split plate 2a is against the horizontal positioning surface of the horizontal positioning platform 2b2, and one side surface of the first split plate 2a in the length direction is against the vertical positioning surface 2b1. The first split plate 2a and the second split plate 2b are formed by slow-wire cutting. Four positioning pins 2c arranged in sequence along the length direction are fixed on the horizontal positioning platform 2b2. The positioning pins 2c are inserted into the first sub-plate 2a. The first sub-plate 2a and the second sub-plate 2b are positioned by the positioning pins 2c. The number of positioning pins 2c can be two or three. A step hole is provided on the bottom surface of the horizontal positioning platform 2b2. The step hole is penetrated by mounting bolts for fixing the first sub-plate 2a and the second sub-plate 2b. There are several step holes arranged along the length direction of the second sub-plate 2b. Each step hole is provided with a mounting bolt, which is not shown in the figure. Two integral gear rolling plates 2 correspondingly arranged up and down are installed on the gear rolling machine. The integral gear rolling plates 2 are installed on the gear rolling machine with the horizontal positioning platform 2b2 as the horizontal reference. The two tops of the gear rolling machine are inserted and pressed into the center hole 1a of the semi-finished shaft so that the semi-finished shaft is horizontally clamped in the gear rolling machine.

[0058] D. Inspection: Use the detection auxiliary device 3 to vertically fix the drive motor shaft 1, take the outer circle of the rotor assembly gear 1f as the positioning reference, take the outer circle of the first bearing gear 1d and the outer circle of the second bearing gear 1h as the measurement reference at the gear measurement center, and measure the coaxiality of the first gear 1b spline pitch circle and the second gear 1c spline pitch circle.

[0059] like Figure 6As shown, the detection auxiliary device 3 includes a flat bottom plate 3a and a vertical plate 3b vertically fixed on the bottom plate 3a. A ball 3c is embedded on the bottom plate 3a on one side of the vertical plate 3b, and a spring 3d is connected to the bottom end of the ball 3c. Under the action of the spring 3d, the top end of the ball 3c protrudes from the upper surface of the bottom plate 3a. A finger cylinder 3f is fixed on the vertical plate 3b, and the fingers 3f1 of the finger cylinder 3f are arranged opposite to each other in the horizontal direction, and the space between the fingers 3f1 of the finger cylinder 3f is located directly above the ball 3c. The finger cylinder 3f, also known as the pneumatic finger 3f1, is an existing product that can be purchased directly on the market. This embodiment adopts a two-finger finger cylinder 3f, and the two fingers 3f1 of the finger cylinder 3f are arranged horizontally to facilitate the vertical placement of the drive motor shaft 1 between the two fingers 3f1 of the finger cylinder 3f. The bottom plate 3a is provided with a mounting hole 3a1 in the shape of a small step at the top and a large step at the bottom. The ball 3c is located at the upper part of the mounting hole 3a1, and the spring 3d is located at the lower part of the mounting hole 3a1. A flat plate-shaped pad 3e is fixedly connected to the bottom surface of the bottom plate 3a, and the bottom end of the spring 3d is against the pad 3e. A convex ring with a reduced aperture is provided on the hole wall surface of the upper opening of the mounting hole 3a1, and the aperture of the convex ring is smaller than the diameter of the ball 3c, so as to prevent the ball 3c from falling out of the mounting hole 3a1. The bottom surface of the vertical plate 3b is against the upper surface of the bottom plate 3a, and the bottom plate 3a is also provided with a countersunk hole 3a2 in the shape of a small step at the top and a large step at the bottom. A fixing bolt 3k for fixing the bottom plate 3a and the vertical plate 3b is passed through the countersunk hole 3a2. The rod of the fixing bolt 3k passes through the countersunk hole 3a2 and is threadedly connected to the vertical plate 3b. The pad 3e closes the fixing hole 3e1. There are several countersunk holes 3a2, such as two or three, and each countersunk hole 3a2 is provided with a fixing bolt 3k. The backing plate 3e is provided with a fixing hole 3e1 in the shape of a step with a small top and a large bottom, and a connecting bolt 3m is passed through the fixing hole 3e1 to fix the backing plate 3e and the bottom plate 3a. There are several fixing holes 3e1, such as three or four, and each fixing hole 3e1 is provided with a connecting bolt 3m. Adjustment bolts 3g are vertically passed through and threadedly connected above and below the finger cylinder 3f on the vertical plate 3b, and a dial gauge 3h is fixed between the finger cylinder 3f and the two adjustment bolts 3g on the vertical plate 3b. The fixing rod 3h1 of the dial gauge 3h is vertically passed through the vertical plate 3b, and all the adjustment bolts 3g, all the fixing rods 3h1 of the dial gauge 3h and the finger cylinder 3f are arranged in a straight line in a direction perpendicular to the bottom plate 3a. The adjusting bolt 3g is symmetrically arranged with respect to the finger cylinder 3f, and the fixing rod 3h1 of the dial gauge 3h is symmetrically arranged with respect to the finger cylinder 3f. The dial gauge 3h located at the top is close to the adjusting bolt 3g located at the top, and the dial gauge 3h located at the bottom is close to the adjusting bolt 3g located at the bottom. The adjusting bolt 3g is a plastic part or a plastic head is fixed at the bottom end of the adjusting bolt 3g to prevent the adjusting bolt 3g from scratching the workpiece.

[0060] like Figure 7As shown, the detection auxiliary device 3 is equipped with a straight rod-shaped calibration rod 4, the outer diameter of the calibration rod 4 is equal to the maximum tolerance diameter of the outer circle of the rotor assembly file 1f, the bottom surface of the calibration rod 4 is perpendicular to the outer peripheral surface of the calibration rod 4, and a positioning hole 4a is provided at the center of the bottom end surface of the calibration rod 4.

[0061] The inspection includes the following steps:

[0062] D.1. Zero adjustment: Place the detection auxiliary device 3 at the center of the gear measurement center workbench; Figure 6 As shown, the calibration rod 4 is vertically placed between the fingers 3f1 of the finger cylinder 3f, and the ball 3c is embedded in the positioning hole 4a, the bottom surface of the calibration rod 4 is against the upper surface of the base plate 3a, and then the finger cylinder 3f is activated to clamp the calibration rod 4; then the two adjusting bolts 3g are rotated to make the bottom ends of the adjusting bolts 3g abut against the outer circumference of the calibration rod 4, and then the position of the dial indicator 3h is adjusted to make the probe 3h2 of the dial indicator 3h abut against the outer circumference of the calibration rod 4, and the pointer of the dial indicator 3h is rotated to the zero scale line, that is, the dial indicator 3h is zeroed; then the finger cylinder 3f is activated to loosen the calibration rod 4 and take out the calibration rod 4.

[0063] D.2. Install the drive motor shaft 1: Figure 8 As shown, the first gear 1b of the drive motor shaft 1 is placed vertically upward between the fingers 3f1 of the finger cylinder 3f, and the ball 3c is embedded in the center hole 1a at the bottom end of the drive motor shaft 1, the bottom end of the drive motor shaft 1 is against the upper surface of the base plate 3a, the outer peripheral surface of the rotor assembly gear 1f is against the bottom end of the adjusting bolt 3g, and the probes 3h2 of the two dial indicators 3h are against the outer peripheral surface of the rotor assembly gear 1f, and then the adjusting bolt 3g is slightly turned to adjust the center position of the drive motor shaft 1 so that the readings of the two dial indicators 3h are the same; then the finger cylinder 3f is actuated to clamp the drive motor shaft 1.

[0064] D.3. Measurement: The gear measurement center first measures the outer circle of the first bearing block 1d and the outer circle of the second bearing block 1h to determine the center of the first bearing block 1d and the center of the second bearing block 1h. Then the center of the first bearing block 1d and the center of the second bearing block 1h are used as the measurement center, i.e., the measurement reference. The pitch circle of the first block 1b spline and the pitch circle of the second block 1c spline are measured to calculate the coaxiality of the first block 1b spline pitch circle and the second block 1c spline pitch circle. When measuring the second bearing block 1h, it is necessary to pay attention to the avoidance of the vertical plate 3b to prevent the probe 3h2 of the gear measurement center from colliding with the vertical plate 3b. After the coaxiality is measured, other configuration tolerances can also be measured. After the measurement is completed, the finger cylinder 3f moves to loosen the drive motor shaft 1, remove the drive motor shaft 1, and then put in another drive motor shaft 1 to repeat steps D.2 and D.3.

[0065] When the drive motor shaft 1 is fixed vertically, the influence of gravity on the coaxiality detection can be reduced. The drive motor shaft is adjusted to a vertical state by a dial indicator and an adjusting bolt to make the coaxiality measurement accurate. Taking the outer circle of the rotor assembly gear 1f as the positioning reference can avoid the problem that the outer circle of the first bearing gear 1d and the outer circle of the second bearing gear 1h are used for installation and positioning but cannot be detected. Moreover, the outer circle of the first bearing gear 1d, the outer circle of the rotor assembly gear 1f and the outer circle of the second bearing gear 1h are processed by one-time clamping and fine grinding. The outer circle of the first bearing gear 1d, the outer circle of the rotor assembly gear 1f and the outer circle of the second bearing gear 1h have high coaxiality. Using the outer circle of the rotor assembly gear 1f as the positioning reference does not affect the coaxiality detection accuracy, and ensures the accuracy of the detection reference of the outer circle of the first bearing gear 1d and the outer circle of the second bearing gear 1h, thereby improving the accuracy of the coaxiality detection of the first gear 1b spline and the second gear 1c spline. Improving the accuracy of detection is also conducive to improving processing accuracy. During the product processing, due to the wear of the tool, the adjustment of processing parameters is a dynamic process. Accurate detection can ensure the accuracy of the adjustment of processing parameters, thereby improving processing accuracy and also helping to improve coaxiality.

[0066] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for manufacturing a shaft of a vehicle drive motor, characterized in that: The following steps are involved: A. Rough machining: drilling center holes (1a) at both ends of the blank, turning the blank and then rough grinding the outer diameter to form a semi-finished shaft with several cylindrical sections. The semi-finished shaft at least includes a first gear (1b), a second gear (1c), a first bearing gear (1d), a rotor assembly gear (1f) and a second bearing gear (1h); B. Heat treatment: the first stage (1b) and the second stage (1c) of the semi-finished shaft are subjected to continuous high-frequency quenching so that the quenching layer (1m) of the first stage (1b) and the quenching layer (1m) of the second stage (1c) are connected, and then the semi-finished shaft is tempered; C. Finishing: C.

1. Grinding the center hole; C.

2. Fine grinding of the outer circle: With the center hole (1a) as the clamping reference, clamp once and fine grind the outer circle of the first gear (1b), the outer circle of the second gear (1c), the outer circle of the first bearing gear (1d), the outer circle of the rotor assembly gear (1f) and the outer circle of the second bearing gear (1h); C.

3. Fine spline rolling: With the center hole (1a) as the clamping reference, the splines are clamped once, and the integrated tooth rolling plate (2) is used to roll the teeth at the outer circle of the first gear (1b) and the outer circle of the second gear (1c) at the same time to form the first gear (1b) spline and the second gear (1c) spline respectively.

2. The method for manufacturing a shaft of a vehicle drive motor according to claim 1, characterized in that: In step C.2, after fine grinding the outer circle, the outer circle of the second stage (1c) is fine ground into a drum shape with the center hole (1a) as the clamping reference.

3. The method for manufacturing a shaft of a vehicle drive motor according to claim 2, characterized in that: In step C.2, the protrusion of the outer circle of the second stage (1c) is 0.015mm-0.025mm.

4. The method for manufacturing a shaft of a vehicle driving motor according to claim 1, characterized in that: In step C.3, the integrated gear rolling plate (2) comprises a first split plate (2a) and a second split plate (2b) which are fixedly connected and both are in the form of long strips, the top surface of the first split plate (2a) is used to form a first gear (1b) spline, the top surface of the second split plate (2b) is used to form a second gear (1c) spline, a side surface of the second split plate (2b) in the length direction is a vertical positioning surface (2b1), the vertical positioning surface (2b1) has a vertically protruding horizontal positioning platform (2b2), the bottom surface of the first split plate (2a) is against the horizontal positioning platform (2b2) ​​and a side surface of the first split plate (2a) in the length direction is against the vertical positioning surface (2b1); the integrated gear rolling plate (2) is installed on the gear rolling machine with the horizontal positioning platform (2b2) ​​as a horizontal reference, and the semi-finished shaft is horizontally clamped in the gear rolling machine.

5. The method for manufacturing a shaft of a vehicle driving motor according to claim 4, characterized in that: In step C.3, a plurality of positioning pins (2c) arranged in sequence along the length direction are fixed on the horizontal positioning platform (2b2), and the positioning pins (2c) are all inserted into the first sub-plate (2a).

6. The method for manufacturing a shaft of a vehicle driving motor according to any one of claims 1 to 5, characterized in that: In step B, after tempering, the surface hardness of the first-stage (1b) quenched layer (1m) and the second-stage (1c) quenched layer (1m) is 40HRC-45HRC.

7. The method for manufacturing a shaft of a vehicle driving motor according to any one of claims 1 to 5, characterized in that: In step B, the rotor assembly section (1f) is also subjected to high-frequency hardening and tempering.

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