A method for improving the coaxiality of the kingpin hole of an arm steering knuckle

Abstract

The present invention relates to the field of mechanical processing technology. The present invention provides a method for improving the coaxiality of a kingpin hole of an arm-steering knuckle, comprising: obtaining a horizontal processing method for the arm-steering knuckle and a horizontal processing fixture used therein; analyzing the horizontal processing method for the arm-steering knuckle and the horizontal processing fixture used therein, and determining that the cause of the coaxiality deviation of the kingpin hole of the arm-steering knuckle is that the arm-steering knuckle is deformed by the force applied to it during clamping; formulating and implementing a process adjustment plan based on the cause of the coaxiality deviation of the kingpin hole of the arm-steering knuckle, and reducing the force applied to the arm-steering knuckle by changing the force applied to the arm-steering knuckle and the position thereof during clamping, so that the coaxiality tolerance of the kingpin hole of the arm-steering knuckle in each detection link is within an acceptable range. The present invention can reduce the force applied to the arm-steering knuckle during the processing, thereby reducing the risk of the coaxiality deviation of the kingpin hole of the arm-steering knuckle during the processing, and can improve the first-time qualified rate of the product, thereby enhancing the product's quality assurance capability and production and supply capability.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, and in particular to a method for improving the coaxiality of a kingpin hole of an arm steering knuckle. Background Art

[0002] The steering knuckle, also known as the "ram's horn", is one of the important parts in the vehicle's steering system. It enables the vehicle to drive stably and sensitively transmit the driving direction. It effectively transmits the steering wheel rotation angle value to the vehicle and controls the vehicle's route in a timely manner, thereby ensuring the vehicle's safe and accurate operation.

[0003] The steering knuckle's kingpin seat has two coaxially aligned tapered holes (also known as kingpin holes). The ability to maintain the coaxiality of the kingpin holes determines the knuckle's production and supply capabilities. The current international high-end market demand for steering knuckles (especially those with arms) requires a 100% strict coaxiality tolerance of less than 0.05mm.

[0004] Currently, arm-steering knuckles are processed horizontally. During machining, the knuckle is clamped and secured using a horizontal machining fixture. After securing, two brakes are symmetrically installed on the large disc surface of the knuckle to suppress vibration. During production testing, the coaxiality tolerance of the knuckle's kingpin hole is tightened to within 0.04mm in accordance with internal control requirements. However, during re-testing of the finished product, a certain percentage of products had kingpin hole coaxiality exceeding 0.05mm. The re-test results were between 0.05-0.12mm, indicating that the coaxiality of the kingpin holes exceeded tolerance and did not meet storage and factory requirements.

[0005] In order to meet the demand of the international high-end market for steering knuckles with arms, improve the quality assurance capability of the coaxiality of the steering knuckle kingpin hole, and further improve the production and supply capacity of the steering knuckle, the problem of excessive coaxiality of the kingpin hole must be solved.

[0006] In view of this, overcoming the defects of the above-mentioned prior art is an urgent problem to be solved in this technical field. Summary of the Invention

[0007] The invention provides a solution to the technical problem of excessive coaxiality of a kingpin hole in a current horizontal machining method for an arm-mounted steering knuckle.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for improving the coaxiality of a kingpin hole of an arm steering knuckle, comprising:

[0010] S10, obtaining a horizontal processing method for the steering knuckle with an arm and a horizontal processing fixture used;

[0011] S20, analyzing the horizontal machining method and the horizontal machining fixture used for the arm-steering knuckle, and determining that the cause of the coaxiality deviation of the kingpin hole of the arm-steering knuckle is that the arm-steering knuckle is deformed due to the force applied during clamping;

[0012] S30. Based on the reasons for the excessive coaxiality of the kingpin hole of the steering knuckle with arm, a process adjustment plan is formulated and implemented. The force on the steering knuckle with arm is reduced by changing the force mode and position of the steering knuckle with arm during clamping, so that the coaxiality tolerance of the kingpin hole of the steering knuckle with arm in each inspection link is within an acceptable range.

[0013] Preferably, in S30, the formulating and implementing the process adjustment plan to reduce the force on the arm steering knuckle by changing the force mode and position of the arm steering knuckle during clamping includes:

[0014] S31, adjusting part of the processing content in the horizontal processing mode of the steering knuckle with arm to the vertical processing mode;

[0015] S32, after the processing method is adjusted, the matching new horizontal processing fixture and vertical processing fixture are redesigned;

[0016] S33, uses new horizontal processing fixtures and vertical processing fixtures to fix the steering knuckle with arm.

[0017] Preferably, in S31, the adjusted horizontal processing method includes: rough / fine milling of the inner side surface, rough / fine boring of the kingpin hole; the vertical processing method includes: milling of the large surface, drilling of the disc hole, drilling of the limit bolt hole, and drilling and reaming of the ABS hole.

[0018] Preferably, in S32, the vertical machining fixture includes: a support column, an oil circuit plate with a through hole in the middle, a first positioning mechanism and a first hydraulic locking device, and the support column, the first positioning mechanism and the first hydraulic locking device are respectively arranged on the oil circuit plate, and the support column, the first positioning mechanism and the first hydraulic locking device are respectively fixedly connected to the oil circuit plate.

[0019] Preferably, the first positioning mechanism includes: a first pad, a second pad, a third pad, a fourth pad and an adjustable support, the first pad and the second pad are arranged in a ring around the through hole, and the third pad and the fourth pad are located on both sides of the through hole; in S33, the use of a vertical processing fixture to fix the arm steering knuckle specifically includes: the first pad and the second pad act on the inner shaft diameter end face of the arm steering knuckle, the third pad and the fourth pad act on the large disk surface of the arm steering knuckle, and the adjustable support acts on one side wall of the large disk surface of the arm steering knuckle.

[0020] Preferably, the first hydraulic locking device includes: a first pressure plate, a second pressure plate, a single-acting cylinder seat and a sequence valve, the first pressure plate and the second pressure plate are located on both sides of the through hole and correspond one-to-one to the third pad and the fourth pad, and the sequence valve is used to sequentially drive the first pressure plate, the second pressure plate and the single-acting cylinder seat; in S33, the use of a vertical machining fixture to fix the arm steering knuckle specifically includes: the first pressure plate and the second pressure plate act on the side wall of the inner shaft diameter end face of the arm steering knuckle, and the single-acting cylinder seat acts on the other side wall of the large disk surface of the arm steering knuckle.

[0021] Preferably, in S32, the new horizontal machining fixture includes: a base, a bracket, a second positioning mechanism and a second hydraulic locking device, the bracket is arranged on the base, and the second positioning mechanism and the second hydraulic locking device are respectively arranged on the bracket.

[0022] Preferably, the second positioning mechanism includes: a first positioning column, a second positioning column, a third positioning column and a fourth positioning column; in S33, the use of a new horizontal machining fixture to fix the arm steering knuckle specifically includes: the first positioning column is provided on the base to act on the large disk positioning hole of the arm steering knuckle, the second positioning column acts on the arm of the arm steering knuckle through the first connecting block provided on the base, the third positioning column and the fourth positioning column act on the arm of the arm steering knuckle through the second connecting block provided on the base.

[0023] Preferably, the second hydraulic locking device includes: a top plate, a bottom plate, a shell, a chuck, a sleeve and a claw sleeve which are coaxial and have through holes in the center; the shell is arranged between the top plate and the bottom plate, the chuck and the sleeve are arranged inside the shell, and the claw sleeve is arranged inside the chuck and is threadedly connected to the sleeve; in S33, the use of a new horizontal machining fixture to fix the arm steering knuckle specifically includes: the top plate acts on the inner shaft diameter end face of the arm steering knuckle, and the claw sleeve acts on the shaft neck of the arm steering knuckle.

[0024] Preferably, the new horizontal processing fixture further includes: a pressure gauge and a sealing ring; wherein, the pressure gauge is arranged on the top of the bracket, and the sealing ring is arranged inside the second hydraulic locking device.

[0025] In view of the deficiencies in the prior art, the present invention can achieve the following beneficial effects:

[0026] The present invention adjusts the current processing method of the arm steering knuckle, adjusts part of the current horizontal processing technology to vertical processing, and designs and uses new horizontal processing fixtures and vertical processing fixtures to replace the old horizontal processing fixtures. By changing the fixing method and position of the arm steering knuckle, the force on the arm steering knuckle during processing is reduced, thereby reducing the risk of coaxiality deviation of the kingpin hole of the arm steering knuckle during processing, which can improve the first-time qualified rate of the product, and further enhance the product quality assurance capability and production supply capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0028] Figure 1 This is a flow chart of a method for improving the coaxiality of a kingpin hole in an arm steering knuckle provided by the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of a horizontal machining fixture with an arm steering knuckle in the prior art;

[0030] Figure 3 This is a top view of a clamping method of a horizontal machining fixture with an arm steering knuckle in the prior art;

[0031] Figure 4 This is a side view of a clamping method of a horizontal machining fixture with an arm steering knuckle in the prior art;

[0032] Figure 5 This is a comparison chart of the coaxiality changes of the main pin hole of the front arm steering knuckle;

[0033] Figure 6 This is a diagram showing the runout measurement during the horizontal machining of a steering knuckle with an arm;

[0034] Figure 7 This is a flow chart of another method for improving the coaxiality of the kingpin hole of an arm steering knuckle provided by the present invention;

[0035] Figure 8 It is a diagram showing that part of the processing content in the horizontal processing method of the arm steering knuckle is adjusted to the vertical processing method;

[0036] Figure 9 This is a schematic structural diagram of a vertical machining fixture for a steering knuckle with an arm provided by the present invention;

[0037] Figure 10 This is a top view of a clamping method of a vertical machining fixture with an arm steering knuckle provided by the present invention;

[0038] Figure 11 This is a side view of a clamping method of a vertical machining fixture with an arm steering knuckle provided by the present invention;

[0039] Figure 12 This is a schematic structural diagram of a new horizontal machining fixture for a steering knuckle with an arm provided by the present invention;

[0040] Figure 13 This is a schematic diagram of the second hydraulic locking device of a new horizontal machining fixture for a steering knuckle with an arm provided by the present invention;

[0041] Figure 14 This is an exploded view of the second hydraulic locking device of a new horizontal machining fixture for a steering knuckle with an arm provided by the present invention;

[0042] Figure 15 This is a schematic diagram of a clamping method for a new horizontal machining fixture for a steering knuckle with an arm provided by the present invention;

[0043] Figure 16 This is a comparison chart of the changes in the coaxiality of the kingpin hole of the rear-arm steering knuckle after improvement.

[0044] In the accompanying drawings, like reference numerals are used to denote like components or structures, wherein:

[0045] 1-Support column; 2-Oil circuit board; 3-First pad; 4-Second pad; 5-Third pad; 6-Fourth pad; 7-Adjustable support; 8-First pressure plate; 9-Second pressure plate; 10-Single-acting cylinder seat; 11-Sequence valve; 12-Base; 13-Bracket; 14-First positioning column; 15-Second positioning column; 16-Third positioning column; 17-Fourth positioning column; 18-First connecting block; 19-Second connecting block; 20-Top plate; 21-Base plate; 22-Shell; 23-Chuck; 24-Sleeve; 25-Pull claw sleeve; 26-Pressure gauge; 27-Sealing ring. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0047] In the description of the present invention, the terms "inside", "outside", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

[0048] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] Example 1:

[0050] In order to solve the technical problem of excessive coaxiality of the kingpin hole in the current horizontal machining method of the arm-steering knuckle, this embodiment 1 provides a method for improving the coaxiality of the kingpin hole of the arm-steering knuckle, such as Figure 1 FIG. 1 is a flow chart of a method for improving the coaxiality of a kingpin hole of an arm steering knuckle provided by the present invention, comprising:

[0051] S10, obtaining a horizontal processing method for the arm steering knuckle and a horizontal processing fixture used.

[0052] like Figure 2-Figure 4 As shown, a horizontal processing fixture for arm-steering knuckle and its clamping method in the prior art are shown. The horizontal processing fixture includes: a base plate, an adjustable support, a block, a positioning sleeve, a push rod, a pad, a pressure plate and other components; during the processing of the arm-steering knuckle, the block, the positioning sleeve, the push rod, the pad and the pressure plate act on different parts of the arm-steering knuckle respectively. Specifically, there are three push rods, three pads and three pressure plates respectively. When the arm-steering knuckle is clamped and fixed, the force is mainly distributed on the periphery of the arm-steering knuckle.

[0053] S20, analyzing the horizontal machining method of the arm-steering knuckle and the horizontal machining fixture used, and determining that the cause of the coaxiality deviation of the kingpin hole of the arm-steering knuckle is that the arm-steering knuckle is deformed due to the force applied during clamping.

[0054] like Figure 5 As shown, it is a comparison chart of the coaxiality changes of the kingpin hole of the front arm steering knuckle. When tested in the production link, the coaxiality tolerance of the kingpin hole of the arm steering knuckle did not exceed 0.04mm, which met the internal control requirements. When re-tested in the finished product link, the overall coaxiality tolerance of the kingpin hole of the arm steering knuckle changed significantly, tending to be larger. The re-test results did not meet the customer's requirement of within 0.05mm, and did not meet the requirements for warehousing and delivery.

[0055] Researchers found that the coaxiality of the kingpin hole of the current arm steering knuckle is out of tolerance, mainly because the product is deformed by force when clamped during horizontal processing. After a certain period of time, the deformation is released, which ultimately leads to the coaxiality of the kingpin hole of the product not meeting the requirements in the finished product inspection process.

[0056] After further analysis, it was found that the main reason for the deformation of the product under stress during clamping was related to the improper current horizontal processing method. Specifically, after the arm steering knuckle was clamped and fixed by the horizontal processing fixture, two brakes were symmetrically installed on the large disc surface of the arm steering knuckle. Since the brake was installed on the large disc surface of the arm steering knuckle, it was far away from the center of the arm steering knuckle. During the processing, the large disc surface of the arm steering knuckle had poor stability and large runout when subjected to stress relative to the inner shaft diameter end face of the arm steering knuckle.

[0057] like Figure 6 The figure shows the runout measurement during the horizontal processing of the steering knuckle with arm. In the figure, the inner ring represents the inner shaft diameter end face contour of the steering knuckle with arm, and the outer ring represents the large disk surface contour of the steering knuckle with arm. The measured results show that the maximum runout at the inner shaft diameter end face contour of the steering knuckle with arm is 0.05mm, while the maximum runout at the large disk surface contour of the steering knuckle with arm is 0.15mm.

[0058] S30. Based on the reasons for the excessive coaxiality of the kingpin hole of the steering knuckle with arm, a process adjustment plan is formulated and implemented. The force on the steering knuckle with arm is reduced by changing the force mode and position of the steering knuckle with arm during clamping, so that the coaxiality tolerance of the kingpin hole of the steering knuckle with arm in each inspection link is within an acceptable range.

[0059] In S30, the various inspection links include: a production inspection link and a finished product inspection link; in actual application, in strict accordance with customer requirements, the coaxiality tolerance of the kingpin hole of the arm steering knuckle is 0-0.05mm.

[0060] In specific implementation, in S30, the process adjustment plan is formulated and implemented to reduce the force on the arm steering knuckle by changing the force mode and position of the arm steering knuckle during clamping, such as Figure 7 As shown, including:

[0061] S31, adjusting part of the processing content in the horizontal processing method of the steering knuckle with arm to a vertical processing method.

[0062] In S31, the adjusted horizontal processing methods include: rough / fine milling of the inner side surface, rough / fine boring of the kingpin hole; the vertical processing methods include: milling of the large surface, drilling of the disc hole, drilling and tapping of the limit bolt hole, and drilling and reaming of the ABS hole.

[0063] like Figure 8 As shown in the figure, part of the processing content in the horizontal processing method of the arm steering knuckle is adjusted to the vertical processing method, that is, the specific steps of milling the large surface, drilling the disc hole, drilling the limit bolt hole, and drilling and reaming the ABS hole in the original horizontal processing method are adjusted to the vertical processing method, and only the rough / fine milling of the inner side surface and the rough / fine boring of the kingpin hole are retained as the horizontal processing method.

[0064] S32, after the processing method is adjusted, the matching new horizontal processing fixture and vertical processing fixture are redesigned.

[0065] Due to the adjustment of the above-mentioned processing method, in order to meet production requirements and realize mass production, it is also necessary to design new matching horizontal processing fixtures and vertical processing fixtures.

[0066] like Figures 9-11As shown, the vertical machining fixture includes: a support column 1, an oil circuit plate 2 with a through hole in the middle, a first positioning mechanism and a first hydraulic locking device. The support column 1, the first positioning mechanism and the first hydraulic locking device are respectively arranged on the oil circuit plate 2. The support column 1, the first positioning mechanism and the first hydraulic locking device are respectively fixedly connected to the oil circuit plate 2. The through hole on the oil circuit plate 2 is used to pass through the journal of the steering knuckle with an arm; wherein, the system design pressure is 4Mpa-7Mpa. When the system pressure is 4Mpa, there should be no oil leakage during continuous oil supply for 8H. During the implementation process, as a preferred implementation method, the first positioning mechanism includes: a first pad 3, a second pad 4, a third pad 5, a fourth pad 6 and an adjustable support 7. The first pad 3 and the second pad 4 are arranged in a ring around the through hole. There is a notch between the first pad 3 and the second pad 4, and the notch is used to form an avoidance area. The third pad 5 and the fourth pad 6 are located on both sides of the through hole. During the processing, the above four pads can be in smooth contact with the inner shaft diameter end face of the arm steering knuckle; further, the first hydraulic locking device includes: a first pressure plate 8, a second pressure plate 9, a single-acting cylinder seat 10 and a sequence valve 11. The first pressure plate 8 and the second pressure plate 9 are located on both sides of the through hole and correspond one-to-one to the third pad 5 and the fourth pad 6. The sequence valve 11 is used to orderly drive the first pressure plate 8, the second pressure plate 9 and the single-acting cylinder seat 10. In actual application, the number of sequence valves 11 is 2. During the processing, the above two pressure plates can be in smooth contact with the large disk surface of the arm steering knuckle.

[0067] like Figure 12-14 As shown, the new horizontal machining fixture includes: a base 12, a bracket 13, a second positioning mechanism and a second hydraulic locking device. The bracket 13 is arranged on the base 12, and the base 12 is used to provide support for the bracket 13. The second positioning mechanism and the second hydraulic locking device are respectively arranged on the bracket 13, and the bracket 13 is used to provide support for the second positioning mechanism and the second hydraulic locking device. During the implementation process, as a preferred implementation method, the second positioning mechanism includes: a first positioning column 14, a second positioning column 15, a third positioning column 16 and a fourth positioning column 17; further, the second hydraulic locking device includes: a top plate 20, a bottom plate 21, a shell sleeve 22, a chuck 23, a sleeve 24 and a claw sleeve 25 which are coaxial and have through holes in the center; the shell sleeve 22 is arranged between the top plate 20 and the bottom plate 21, the chuck 23 and the sleeve 24 are arranged inside the shell sleeve 22, and the claw sleeve 25 is arranged inside the chuck 23 and is threadedly connected to the sleeve 24, wherein the claw sleeve 25 is provided with an elastic claw at one end and an external thread at the other end, and the sleeve 24 is provided with an internal thread.

[0068] In order to facilitate real-time observation and monitoring of the pressure conditions, in one of the implementations, the new horizontal processing fixture also includes: a pressure gauge 26 arranged on the top of the bracket 13; in order to improve the sealing inside the second hydraulic locking device, in another of the implementations, the new horizontal processing fixture also includes: a sealing ring 27 arranged inside the second hydraulic locking device.

[0069] S33, uses new horizontal processing fixtures and vertical processing fixtures to fix the steering knuckle with arm.

[0070] In S33, the use of a vertical machining fixture to fix the arm steering knuckle specifically includes: the first pad 3 and the second pad 4 act on the inner shaft diameter end face of the arm steering knuckle, the third pad 5 and the fourth pad 6 act on the large disk surface of the arm steering knuckle, and the adjustable support 7 acts on one side wall of the large disk surface of the arm steering knuckle; at the same time, the first pressure plate 8 and the second pressure plate 9 act on the side wall of the inner shaft diameter end face of the arm steering knuckle, and the single-acting cylinder seat 10 acts on the other side wall of the large disk surface of the arm steering knuckle.

[0071] In S33, the new horizontal machining fixture is used to fix the arm steering knuckle, specifically including: the first positioning column 14 is provided on the base 12 to act on the large disk positioning hole of the arm steering knuckle, the second positioning column 15 acts on the arm of the arm steering knuckle through the first connecting block 18 provided on the base 12, the third positioning column 16 and the fourth positioning column 17 act on the arm of the arm steering knuckle through the second connecting block 19 provided on the base 12 respectively; at the same time, the top plate 20 acts on the inner shaft diameter end face of the arm steering knuckle, and the pull claw sleeve 25 acts on the shaft neck of the arm steering knuckle.

[0072] like Figure 15 The figure shows a new horizontal machining fixture clamping method of the arm-steering knuckle provided by the present invention. The implementation method is as follows: during the machining process, under hydraulic drive, the sleeve 24 starts to rotate, generating a pulling force on the claw sleeve 25. Under the limitation of the chuck 23, the elastic claw at one end of the claw sleeve 25 starts to shrink. During the shrinkage process, the elastic claw clamps the shaft neck of the arm-steering knuckle and generates a pulling force on the shaft neck of the arm-steering knuckle until the top plate 20 fully contacts the inner shaft diameter end face of the arm-steering knuckle. During this process, the large disc surface of the arm-steering knuckle is suspended in the air, and the top plate 20 acts on the inner shaft diameter end face of the arm-steering knuckle. Compared with the traditional method of installing the brake on the large disc surface of the arm-steering knuckle (such as Figure 6 As shown in the figure), it can not only effectively avoid the axial force on the large disc surface of the steering knuckle with arm, but also reduce the vibration during the processing, which can greatly reduce the force on the steering knuckle with arm during the processing, thereby reducing the stress inside the steering knuckle with arm during the processing.

[0073] like Figure 16The figure shows the comparison of the coaxiality changes of the kingpin hole of the steering knuckle with arm after improvement. During the inspection in the production link, the coaxiality tolerance of the kingpin hole of the steering knuckle with arm did not exceed 0.04mm, which met the internal control requirements. During the re-inspection in the finished product link, the overall coaxiality tolerance of the kingpin hole of the steering knuckle with arm did not change much and tended to be stable. The re-inspection results met the customer's requirement of within 0.05mm and met the requirements for warehousing and delivery.

[0074] To sum up, this embodiment 1 provides a method for improving the coaxiality of the kingpin hole of the arm steering knuckle. By adjusting the current processing method of the arm steering knuckle, part of the current horizontal processing process is adjusted to vertical processing, and a new horizontal processing fixture and a vertical processing fixture are designed and used to replace the old horizontal processing fixture. By changing the fixing method and position of the arm steering knuckle, the force on the arm steering knuckle during the processing is reduced, thereby reducing the risk of coaxiality deviation of the kingpin hole of the arm steering knuckle during the processing, which can improve the first-time pass rate of the product, thereby enhancing the product's quality assurance capability and production supply capability.

[0075] It should be noted that this embodiment 1 provides a method for improving the coaxiality of the main pin hole of a steering knuckle with an arm. In actual application, it can be applied to improving the coaxiality of the main pin hole of a double-arm steering knuckle with an arm (such as Figure 10 -like Figure 11 As shown), it can also be used to improve the coaxiality of the kingpin hole of the single-arm steering knuckle (as shown Figure 15 shown).

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for improving the coaxiality of the kingpin hole of an arm steering knuckle, characterized in that: include: S10, obtaining a horizontal processing method for the arm steering knuckle and a horizontal processing fixture used; S20, analyzing the horizontal machining method and the horizontal machining fixture used for the arm-steering knuckle, and determining that the cause of the coaxiality deviation of the kingpin hole of the arm-steering knuckle is that the arm-steering knuckle is deformed due to the force applied during clamping; S30: Based on the cause of the out-of-tolerance coaxiality of the kingpin hole of the arm-steering knuckle, formulate and implement a process adjustment plan. By changing the force application method and location of the arm-steering knuckle during clamping, reduce the force on the arm-steering knuckle, so that the coaxiality tolerance of the kingpin hole of the arm-steering knuckle in each inspection link is within the acceptable range, including: S31, adjusting part of the processing content in the horizontal processing mode of the steering knuckle with arm to the vertical processing mode; S32, after the processing method is adjusted, the matching new horizontal processing fixture and vertical processing fixture are redesigned; S33, using new horizontal and vertical machining fixtures to fix the steering knuckle with arm; In S32, the new horizontal machining fixture includes: a base, a bracket, a second positioning mechanism and a second hydraulic locking device, the bracket is provided on the base, and the second positioning mechanism and the second hydraulic locking device are respectively provided on the bracket; The second positioning mechanism includes: a first positioning post, a second positioning post, a third positioning post, and a fourth positioning post; in S33, the use of the new horizontal machining fixture to fix the arm steering knuckle specifically includes: the first positioning post is provided on the base and acts on the large disk positioning hole of the arm steering knuckle, the second positioning post is provided on the base through a first connecting block, the third positioning post and the fourth positioning post are provided on the base through a second connecting block respectively acting on the arm of the arm steering knuckle; The second hydraulic locking device includes: a top plate, a bottom plate, a shell, a chuck, a sleeve and a claw sleeve which are coaxial and have through holes in the center; the shell is arranged between the top plate and the bottom plate, the chuck and the sleeve are arranged inside the shell, and the claw sleeve is arranged inside the chuck and is threadedly connected to the sleeve; in S33, the use of a new horizontal machining fixture to fix the arm steering knuckle specifically includes: the top plate acts on the inner shaft diameter end face of the arm steering knuckle, and the claw sleeve acts on the shaft neck of the arm steering knuckle.

2. The method for improving the coaxiality of the kingpin hole of the arm steering knuckle according to claim 1, characterized in that: In S31, the adjusted horizontal processing methods include: rough / fine milling of the inner side surface, rough / fine boring of the kingpin hole; the vertical processing methods include: milling of the large surface, drilling of the disc hole, drilling and tapping of the limit bolt hole, and drilling and reaming of the ABS hole.

3. The method for improving the coaxiality of the kingpin hole of the arm steering knuckle according to claim 2, characterized in that: In S32, the vertical machining fixture includes: a support column, an oil circuit plate with a through hole in the middle, a first positioning mechanism and a first hydraulic locking device. The support column, the first positioning mechanism and the first hydraulic locking device are respectively arranged on the oil circuit plate, and the support column, the first positioning mechanism and the first hydraulic locking device are respectively fixedly connected to the oil circuit plate.

4. The method for improving the coaxiality of the kingpin hole of the arm steering knuckle according to claim 3, characterized in that: The first positioning mechanism includes: a first pad, a second pad, a third pad, a fourth pad and an adjustable support, the first pad and the second pad are arranged in a ring around the through hole, and the third pad and the fourth pad are located on both sides of the through hole; in S33, the use of a vertical processing fixture to fix the arm steering knuckle specifically includes: the first pad and the second pad act on the inner shaft diameter end face of the arm steering knuckle, the third pad and the fourth pad act on the large disk surface of the arm steering knuckle, and the adjustable support acts on one side wall of the large disk surface of the arm steering knuckle.

5. The method for improving the coaxiality of the kingpin hole of the arm steering knuckle according to claim 4, characterized in that: The first hydraulic locking device includes: a first pressure plate, a second pressure plate, a single-acting cylinder seat and a sequence valve. The first pressure plate and the second pressure plate are located on both sides of the through hole and correspond one-to-one to the third pad and the fourth pad. The sequence valve is used to sequentially drive the first pressure plate, the second pressure plate and the single-acting cylinder seat; in S33, the use of a vertical machining fixture to fix the arm steering knuckle specifically includes: the first pressure plate and the second pressure plate act on the side wall of the inner shaft diameter end face of the arm steering knuckle, and the single-acting cylinder seat acts on the other side wall of the large disk surface of the arm steering knuckle.

6. The method for improving the coaxiality of the kingpin hole of the arm steering knuckle according to claim 5, characterized in that: The new horizontal processing fixture also includes: a pressure gauge and a sealing ring; wherein the pressure gauge is arranged on the top of the bracket, and the sealing ring is arranged inside the second hydraulic locking device.

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