Steering input and output shaft centering device and method

Abstract

The present invention discloses a device and method for centering a steering input and output shaft, comprising a base, an input shaft clamping mechanism for fixing the input shaft is installed on the upper surface of one side of the base, a slide rail is installed on the upper surface of the other side of the base in the direction of the input shaft, a slide seat is slidably connected to the slide rail, an operating unit for driving the output shaft to rotate left and right and converting the rotation angle into a linear displacement is installed on the slide seat, the operating unit is connected to the output shaft through a clamping member, and also includes a calculation display for calculating the rotation midpoint of the input shaft and the output shaft according to the linear displacement, and the operating unit is electrically connected to the calculation display. The present invention effectively converts the relative rotation angle value between the input and output shafts into a linear displacement value, and calculates the linear displacement value in a formulaic manner, which can quickly and accurately locate the rotation midpoint between the input shaft and the output shaft, ensure the accuracy and stability of the relative midpoint of the input shaft and the output shaft, and greatly improve the driving safety performance of the vehicle.

Description

Technical Field

[0001] The invention relates to the technical field of automobile parameter measurement, in particular to a steering input and output shaft centering device and method. Background Art

[0002] The Electric Power Steering system (EPS) is a power steering system that directly relies on the motor to provide auxiliary torque. The electric steering input and output shafts are part of the electric power steering system. The relative rotation between the input shaft and the output shaft causes the sensor to generate a potential change and send out a power assist signal. During the assembly process, the intermediate angle of the relative rotation between the input shaft and the output shaft needs to be centered before drilling. In the prior art, the input shaft end is measured by a dial indicator, the input shaft is rotated left and right manually, and the change value of the dial indicator pointer is read to manually find the intermediate angle of the relative rotation between the input shaft and the output shaft, and then a marking method is used to ensure that the intermediate angle does not misalign during the drilling and clamping process. This method is completely guaranteed by manual operation during the processing process, the operation is cumbersome, the risk of reading and calculation errors is high, and the forces applied by different personnel to rotate the input shaft are inconsistent, and the left and right rotation is uneven, the centering angle quality is not high, and the error generated after drilling is too large, which greatly affects the driving safety performance of the vehicle. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a steering input and output shaft centering device and method, which can solve the shortcomings of the prior art.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a steering input and output shaft centering device, comprising a base, an upper surface of one side of the base is provided with an input shaft clamping mechanism for fixing the input shaft, and an upper surface of the other side of the base is provided with a slide rail facing the input shaft direction, a slide seat is slidably connected to the slide rail, an operating unit for driving the output shaft to rotate left and right and converting the rotation angle into a linear displacement is provided on the slide seat, the operating unit is connected to the output shaft through a clamping member, and also includes a calculation display that calculates the rotation midpoint of the input shaft and the output shaft according to the linear displacement, and the operating unit is electrically connected to the calculation display.

[0005] As a further improvement of the above technical solution:

[0006] The operating unit includes an angle turntable, a turntable mounting seat, a crank, a rotating shaft, a linear sensor, a sensor mounting seat, a wire rope, a tension piece and a balancing piece. The turntable mounting seat is fixedly mounted on the slide seat, the sensor mounting seat is fixedly mounted on the inner upper end of the turntable mounting seat, the rotating shaft is rotatably connected to the turntable mounting seat, one end of the rotating shaft is fixedly connected to the angle turntable and the crank, the other end of the rotating shaft is fixedly connected to the clamping piece, the wire rope is wound around the angle turntable, the linear sensor and the tension piece are fixedly mounted on the sensor mounting seat, one end of the tension piece applies external tension to the wire rope to move the wire rope horizontally, the other end of the tension piece abuts against the protruding end of the linear sensor, the balancing piece is installed on the side of the turntable mounting seat away from the tension piece, one end of the balancing piece abuts against the lower end of the crank, and the linear sensor is electrically connected to the computer display.

[0007] The tension member includes a first connecting rod, a first spring and a first limiting nut. The first connecting rod is slidably connected to the sensor mounting seat. A limiting block is provided at one end of the first connecting rod close to the linear sensor. The first spring is sleeved on the first connecting rod. One end of the first spring abuts against the limiting block, and the other end abuts against the side wall of the sensor mounting seat. The limiting block abuts against the linear sensor. The end of the first connecting rod away from the limiting block is threadedly connected with the first limiting nut. A steel wire rope is connected to the first connecting rod between the first limiting nut and the sensor mounting seat.

[0008] The balancing member includes a second connecting rod, a second spring, a second limiting nut and a mounting block. The mounting block is fixedly mounted on the lower end of the turntable mounting seat close to the angle turntable. The second connecting rod is slidably connected to the mounting block. A limiting block is installed on the side of the second connecting rod close to the crank. The second spring is sleeved on the second connecting rod. One end of the second spring abuts against the limiting block, and the other end abuts against the mounting block. The limiting block abuts against the crank. The second limiting nut is threadedly connected to one end of the second connecting rod away from the second spring.

[0009] The input shaft clamping mechanism includes a clamping seat, a V-shaped mounting groove is provided on the upper surface of the clamping seat, a pressure plate is installed on the V-shaped mounting groove, one end of the pressure plate is hinged to the clamping seat, and the other end of the clamping seat is rotatably connected to a clamping screw rod, a clamping nut is threadedly connected to the clamping screw rod, and an open groove matching the clamping screw rod is provided on the pressure plate.

[0010] An output shaft clamping mechanism for fixing the output shaft is also installed on the upper surface of the slide seat. The input shaft clamping mechanism has the same structure as the output shaft clamping mechanism and is highly adapted.

[0011] An adjustment mechanism is installed between the slide and the base, and the adjustment mechanism includes a fixed seat fixed on the base and a connecting block fixed on the upper side wall of the slide. An adjustment screw is installed on the fixed seat, and the adjustment screw is threadedly connected to the fixed seat, and the adjustment screw is rotatably connected to the connecting block.

[0012] The present invention also discloses a method for centering the relative rotation angle between the steering input and output shafts, which is performed by using the centering device mentioned above and is characterized in that it comprises the following steps:

[0013] S1: Place the input shaft on the input shaft clamping mechanism for fixing;

[0014] S2: Insert one end of the output shaft into the input shaft, slide the slide seat, adjust the distance between the input shaft clamping mechanism and the clamping member, and connect the other end of the output shaft to the clamping member;

[0015] S3: Turn the crank in the clockwise direction, and the crank drives the angle dial to rotate clockwise. The extension amount of the extended end of the linear sensor changes continuously. The linear sensor sends a signal to the computing display. Observe the change of the position value displayed on the computing display. When the angle dial rotates clockwise to the limit position, the extension amount of the linear sensor is the smallest, and the minimum position value is displayed on the computing display. Then turn the crank in the opposite direction, so that when the angle dial rotates counterclockwise to the limit position, the extension amount of the linear sensor is the largest, and the maximum position value is displayed on the computing display. At the same time, the computing display locates the current position value in real time and calculates the intermediate position value.

[0016] S4: Finally, move the crank handle to the middle position value and fix the output shaft with the output shaft clamping mechanism.

[0017] The calculation formula of the intermediate position value in step S3 is: the sum of the maximum position value and the minimum position value corresponding to the two extreme positions of the angle dial divided by two.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention is provided with an angle turntable, a steel wire rope and a linear sensor, which effectively converts the relative rotation angle value between the input and output shafts into a linear displacement value. The calculation display performs a formula calculation on the linear displacement value, which can quickly and accurately locate the rotation midpoint between the input shaft and the output shaft, ensure the accuracy and stability of the relative midpoint between the input shaft and the output shaft, improve product quality, and greatly improve the driving safety performance of the vehicle.

[0020] 2. The present invention has the advantages of simple manufacturing, stable performance, safety and reliability. The centering of the device is minimally affected by human factors and is very practical. It can be used for assembly operations on an assembly line. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a front view of the present invention;

[0022] Figure 2 A top view of the present invention;

[0023] In the figure: 1. base; 2. operating unit; 21. angle turntable; 22. turntable mounting seat; 23. crank; 24. rotating shaft; 25. linear sensor; 26. sensor mounting seat; 27. wire rope; 28. tension member; 281. first connecting rod; 282. first spring; 283. first limiting nut; 29. ​​balancing member; 291. second connecting rod; 292. second spring; 293. second limiting nut; 294. mounting block; 3. input shaft; 4. input shaft clamping mechanism; 41. clamping seat; 42. pressure plate; 43. clamping screw; 44. clamping nut; 5. slide rail; 6. slide seat; 7. output shaft; 8. clamping member; 9. computing display; 10. output shaft clamping mechanism; 11. adjusting mechanism; 111. fixing seat; 112. connecting block; 113. adjusting screw. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The clockwise direction described in this embodiment is from right to left as a reference direction.

[0026] like Figure 1 to Figure 2As shown, the steering input and output shaft centering device of this embodiment is installed on a reaming drilling machine and is used for centering before reaming drilling. It includes a base 1, and an input shaft clamping mechanism 4 for fixing the input shaft 3 is installed on the upper surface of one side of the base 1, and a slide rail 5 is installed on the upper surface of the other side of the base 1 towards the input shaft 3. A slide seat 6 is slidably connected to the slide rail 5, and an operating unit 2 is installed on the slide seat 6 to drive the output shaft 7 to rotate left and right and convert the rotation angle into a linear displacement. The operating unit 2 and the output shaft 7 are connected to each other through a clamping member 8, and the output shaft 7 and the clamping member 8 are connected by a spline. This method has strong transmission performance. The output shaft 7 is inserted into the clamping member 8, and then fastened to the clamping member 8 through the fastening member 8. The bolts are fixed so that the output shaft 7 is driven to rotate synchronously when the clamping member 8 rotates (the specific structure of the clamping member 8 is the prior art and is not the key structure to be protected by the present invention, so the specific structure will not be described here). The centering device also includes a calculation display 9 for calculating the rotation midpoint of the input shaft 3 and the output shaft 7 according to the linear displacement. The calculation display 9 is installed on the reamer drilling machine. The operating unit 2 is electrically connected to the calculation display 9. The input end of the input and output shaft assembly is fixed by the input shaft clamping mechanism 4. After the operating unit 2 converts the left and right rotation angles of the output shaft 7 into linear displacement, the calculation display 9 calculates the relative midpoint position value of the input shaft 3 and the output shaft 7 according to the change in the linear displacement.

[0027] In this embodiment, the operating unit 2 includes an angle turntable 21, a turntable mounting seat 22, a crank 23, a rotating shaft 24, a linear sensor 25, a sensor mounting seat 26, a wire rope 27, a tension member 28 and a balancing member 29. The turntable mounting seat 22 is fixedly mounted on the slide 6, the sensor mounting seat 26 is fixedly mounted on the inner upper end of the turntable mounting seat 22, the rotating shaft 24 is rotatably connected to the turntable mounting seat 22, one end of the rotating shaft 24 is fixedly connected to the angle turntable 21 and the crank 23, and the rotating shaft 24 is fixedly connected to the angle turntable 21 and the crank 23. The other end of the shaft 24 is fixedly connected to the clamping member 8, the wire rope 27 is wound on the angle turntable 21, the linear sensor 25 and the tension member 28 are fixedly mounted on the sensor mounting seat 26, one end of the tension member 28 applies an external tension to the wire rope 27 to make the wire rope 27 move horizontally, and the tension member 28 drives the upper end of the wire rope 27 to move horizontally, and the rotation angle of the angle turntable 21 can be completely converted into linear displacement, and the other end of the tension member 28 is in contact with the protruding end of the linear sensor 25 The tension piece 28 causes the extension amount of the linear sensor 25 to change. The extension amount of the linear sensor 25 changes as the angle dial 21 rotates. The balance piece 29 is installed on the side of the turntable mounting seat 22 away from the tension piece 28. One end of the balance piece 29 abuts against the lower end of the crank 23. When the tension piece 28 applies an external tension to the wire rope 27 at the upper end, it drives the angle dial 21 and the crank 23 to rotate clockwise. At this time, the balance piece 29 applies an opposite force to the lower end of the crank 23 to balance the angle dial 21 and the crank 23. In the absence of external force, the external tension applied by the tension piece 28 to the wire rope 27 is equal to the force applied by the balance piece 29 to the lower end of the crank 23, and the angle dial 21 does not rotate. When the crank 23 is turned by hand, the angle dial 21 rotates, the extension amount of the linear sensor 25 changes, and the linear sensor 25 sends a signal to the calculation display 9, and the calculation display 9 calculates and displays the current position value and the intermediate position value.

[0028] In this embodiment, the tension member 28 includes a first connecting rod 281, a first spring 282 and a first limiting nut 283. The first connecting rod 281 is slidably connected to the sensor mounting seat 26. A limiting block is provided at one end of the first connecting rod 281 close to the linear sensor 25. The first spring 282 is sleeved on the first connecting rod 281. One end of the first spring 282 abuts against the limiting block, and the other end abuts against the side wall of the sensor mounting seat 26. The limiting block abuts against the linear sensor 25. The end of the first connecting rod 281 away from the limiting block is threadedly connected with the first limiting nut 283. A wire rope 27 is connected to the first connecting rod 281 between the first limiting nut 283 and the sensor mounting seat 26. Under normal circumstances, under the action of the first spring 282, the external pulling force applied by one end of the first connecting rod 281 to the wire rope 27 is equal to the force applied by the balance member 29 to the lower end of the crank 23, and the directions are opposite. The angle dial 21 will not rotate. When the crank 23 is turned clockwise, the angle dial 21 rotates clockwise, the first spring 282 is restored, and the first connecting rod 281 moves to retract the extended end of the linear sensor 25. The value change on the calculation display 9 is observed. When the crank 23 rotates clockwise to the limit position, the calculation display 9 displays the minimum position value of the linear sensor 25. The crank 23 is turned in the opposite direction by hand, and the crank 23 drives the angle dial 21 to rotate in the opposite direction. , the wire rope 27 pulls the first connecting rod 281 to compress the first spring 282, and the extending end of the linear sensor 25 extends out, and then the numerical changes on the calculation display 9 are observed. When the crank 23 rotates counterclockwise to the extreme position, the calculation display 9 displays the maximum position value of the linear sensor 25. The calculation display 9 obtains the relative midpoint position value of the input shaft 3 and the output shaft 7 through the formula of maximum position value + minimum position value and then divides it by two. Turn the angle dial 21 and observe the numerical changes on the calculation display 9 to make the current position value on the calculation display 9 the same as the middle position value. At this time, the input shaft 3 and the output shaft 7 can be quickly aligned in the rotation direction.

[0029] In this embodiment, the balancing member 29 includes a second connecting rod 291, a second spring 292, a second limiting nut 293 and a mounting block 294. The mounting block 294 is fixed to the lower end of the turntable mounting seat 22 close to the angle turntable 21. The second connecting rod 291 is slidably connected to the mounting block 294. A limiting block is installed on the side of the second connecting rod 291 close to the crank 23. The second spring 292 is sleeved on the second connecting rod 291. One end of the second spring 292 abuts against the limiting block, and the other end abuts against the mounting block 294. The limiting block abuts against the crank 23. The second limiting nut 293 is threadedly connected to one end of the second connecting rod 291 away from the second spring 292.

[0030] In this embodiment, the input shaft clamping mechanism 4 includes a clamping seat 41, a V-shaped mounting groove is provided on the upper surface of the clamping seat 41, a pressing plate 42 is installed on the V-shaped mounting groove, one end of the pressing plate 42 is hinged to the clamping seat 41, and the other end of the clamping seat 41 is rotatably connected to a clamping screw 43, a clamping nut 44 is threadedly connected to the clamping screw 43, and an open groove matching the clamping screw 43 is provided on the pressing plate 42. The input shaft 3 is placed on the V-shaped mounting groove, the pressing plate 42 is rotated to press the input shaft 3, the clamping screw 43 is rotated upward to make the clamping screw 43 snap into the open groove, and then the clamping nut 44 is rotated to make the lower surface of the clamping nut 44 close to the pressing plate 42, and the input shaft 3 can be fixed.

[0031] In this embodiment, an output shaft clamping mechanism 10 for fixing the output shaft 7 is also installed on the upper surface of the slide 6. The input shaft clamping mechanism 4 has the same structure as the output shaft clamping mechanism 10 and is highly adapted. The output shaft clamping mechanism 10 fixes the output shaft 7, and the positions of the input shaft 3 and the output shaft 7 do not change, ensuring that the input shaft 3 and the output shaft 7 are coaxial and the intermediate angles of the input shaft 3 and the output shaft 7 are aligned.

[0032] In this embodiment, an adjustment mechanism 11 is installed between the slide 6 and the base 1, and the adjustment mechanism 11 includes a fixed seat 111 fixedly mounted on the base 1 and a connecting block 112 fixedly mounted on the upper side wall of the slide 6. An adjustment screw 113 is installed on the fixed seat 111, and the adjustment screw 113 is screwed and connected to the fixed seat 111, and the adjustment screw 113 is rotatably connected to the connecting block 112. Rotating the adjustment screw 113 can drive the connecting block 112 and the slide 6 to move left and right.

[0033] A method for centering the relative rotation angle between a steering input and output shaft of this embodiment includes the following steps:

[0034] S1: placing the input shaft 3 on the input shaft clamping mechanism 4 for fixing;

[0035] S2: insert one end of the output shaft 7 into the input shaft 3, slide the slide 6, adjust the distance between the input shaft clamping mechanism 4 and the clamping member 8, and drive connect the other end of the output shaft 7 to the clamping member 8;

[0036] S3: Turn the crank 23 in the clockwise direction, the crank 23 drives the angle dial 21 to rotate clockwise, the extension amount of the extension end of the linear sensor 25 changes continuously, the linear sensor 25 sends a signal to the computing display 9, and the change of the position value displayed on the computing display 9 is observed. When the angle dial 21 rotates clockwise to the limit position, the extension amount of the linear sensor 25 is the smallest, and the minimum position value is displayed on the computing display 9. Then turn the crank 23 in the opposite direction, so that when the angle dial 21 rotates counterclockwise to the limit position, the extension amount of the linear sensor 25 is the largest, and the maximum position value is displayed on the computing display 9. At the same time, the computing display 9 locates the current position value in real time and calculates the intermediate position value;

[0037] S4: Finally, the crank handle 23 is moved to the middle position value, and the output shaft 7 is fixed by the output shaft clamping mechanism 10 .

[0038] The calculation formula of the intermediate position value in step S3 is: the sum of the maximum position value and the minimum position value corresponding to the two extreme positions of the angle dial 21 divided by two.

[0039] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A steering input and output shaft centering device, characterized in that: The invention comprises a base (1), wherein an input shaft clamping mechanism (4) for fixing an input shaft (3) is arranged on the upper surface of one side of the base (1), and a slide rail (5) is arranged on the upper surface of the other side of the base (1) in the direction of the input shaft (3), and a slide seat (6) is slidably connected to the slide rail (5), and an operating unit (2) for driving an output shaft (7) to rotate left and right and convert the rotation angle into a linear displacement is arranged on the slide seat (6), and the operating unit (2) and the output shaft (7) are connected to each other by a clamping member (8), and further comprises a calculation display (9) for calculating the rotation midpoint of the input shaft (3) and the output shaft (7) according to the linear displacement, and the operating unit (2) and the calculation display (9) are electrically connected; The operating unit (2) comprises an angle turntable (21), a turntable mounting seat (22), a crank (23), a rotating shaft (24), a linear sensor (25), a sensor mounting seat (26), a wire rope (27), a tension member (28) and a balancing member (29); the turntable mounting seat (22) is fixedly mounted on the slide seat (6); the sensor mounting seat (26) is fixedly mounted on the inner upper end of the turntable mounting seat (22); the rotating shaft (24) is rotatably connected to the turntable mounting seat (22); one end of the rotating shaft (24) is fixedly connected to the angle turntable (21) and the crank (23); and the other end of the rotating shaft (24) is fixedly connected to the clamping member (29). The component (8) comprises a steel wire rope (27) wound on the angle turntable (21), a linear sensor (25) and a tension member (28) fixedly mounted on a sensor mounting seat (26), one end of the tension member (28) applying an external tension to the steel wire rope (27) to make the steel wire rope (27) move horizontally, the other end of the tension member (28) abuts against the protruding end of the linear sensor (25), the balance member (29) is mounted on a side of the turntable mounting seat (22) away from the tension member (28), one end of the balance member (29) abuts against the lower end of the crank (23), and the linear sensor (25) is electrically connected to a computing display (9); The tension member (28) comprises a first connecting rod (281), a first spring (282) and a first limiting nut (283), wherein the first connecting rod (281) is slidably connected to the sensor mounting seat (26), a limiting block is provided at one end of the first connecting rod (281) close to the linear sensor (25), the first spring (282) is sleeved on the first connecting rod (281), one end of the first spring (282) abuts against the limiting block, and the other end abuts against the side wall of the sensor mounting seat (26), the limiting block abuts against the linear sensor (25), the end of the first connecting rod (281) away from the limiting block is threadedly connected to the first limiting nut (283), and a steel wire rope (27) is connected to the first connecting rod (281) between the first limiting nut (283) and the sensor mounting seat (26).

2. The steering input and output shaft centering device according to claim 1, characterized in that: The balancing member (29) comprises a second connecting rod (291), a second spring (292), a second limiting nut (293) and a mounting block (294); the mounting block (294) is fixedly mounted on the lower end of the turntable mounting seat (22) close to the angle turntable (21); the second connecting rod (291) is slidably connected to the mounting block (294); a limiting block is installed on the side of the second connecting rod (291) close to the crank (23); the second spring (292) is sleeved on the second connecting rod (291); one end of the second spring (292) is in contact with the limiting block, and the other end is in contact with the mounting block (294); the limiting block is in contact with the crank (23); and the second limiting nut (293) is threadedly connected to one end of the second connecting rod (291) away from the second spring (292).

3. The steering input and output shaft centering device according to claim 2, characterized in that: The input shaft clamping mechanism (4) comprises a clamping seat (41), the upper surface of the clamping seat (41) is provided with a V-shaped mounting groove, a pressure plate (42) is mounted on the V-shaped mounting groove, one end of the pressure plate (42) is hinged to the clamping seat (41), the other end of the clamping seat (41) is rotatably connected to a clamping screw (43) up and down, a clamping nut (44) is threadedly connected to the clamping screw (43), and an open groove matching the clamping screw (43) is provided on the pressure plate (42).

4. The steering input and output shaft centering device according to claim 3, characterized in that: An output shaft clamping mechanism (10) for fixing the output shaft (7) is also mounted on the upper surface of the slide seat (6); the input shaft clamping mechanism (4) and the output shaft clamping mechanism (10) have the same structure and are highly compatible.

5. The steering input and output shaft centering device according to claim 4, characterized in that: An adjusting mechanism (11) is arranged between the slide seat (6) and the base (1), the adjusting mechanism (11) comprising a fixing seat (111) fixedly mounted on the base (1) and a connecting block (112) fixedly mounted on the upper side wall of the slide seat (6), an adjusting screw (113) being arranged on the fixing seat (111), the adjusting screw (113) being threadedly connected to the fixing seat (111), and the adjusting screw (113) being rotatably connected to the connecting block (112).

6. A method for centering a steering input and output shaft, using the centering device described in any one of claims 1 to 5, characterized in that: The following steps are involved: S1: placing the input shaft (3) on the input shaft clamping mechanism (4) to fix it; S2: insert one end of the output shaft (7) into the input shaft (3), slide the slide seat (6), adjust the distance between the input shaft clamping mechanism (4) and the clamping member (8), and drive connect the other end of the output shaft (7) to the clamping member (8); S3: The crank (23) is turned in the clockwise direction, and the crank (23) drives the angle dial (21) to rotate in the clockwise direction. The extension amount of the extension end of the linear sensor (25) changes continuously, and the linear sensor (25) sends a signal to the computing display (9). The change of the position value displayed on the computing display (9) is observed. When the angle dial (21) rotates clockwise to the limit position, the extension amount of the linear sensor (25) is the minimum, and the minimum position value is displayed on the computing display (9). The crank (23) is then turned in the reverse direction, so that when the angle dial (21) rotates counterclockwise to the limit position, the extension amount of the linear sensor (25) is the maximum, and the maximum position value is displayed on the computing display (9). At the same time, the computing display (9) locates the current position value in real time and calculates the intermediate position value. S4: Finally, the crank handle (23) is moved to the middle position value, and the output shaft (7) is fixed by the output shaft clamping mechanism (10).

7. The centering method according to claim 6, characterized in that: The calculation formula of the intermediate position value in step S3 is: the sum of the maximum position value and the minimum position value corresponding to the two extreme positions of the angle dial (21) divided by two.

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