A face-milling spline ball raceway clamp for a ball cage universal joint

Abstract

The application discloses a kind of end face spline ball cage universal joint milling ball channel clamps, belong to processing fixture technical field, comprising: clamp base, clamp main body, clamp upper cover plate, clamp inner core, clamping spring, deep groove ball bearing, reset spring and guide column;The upper end surface of clamp base is provided with through hole and recess, and the guide column is penetrated on the outer wall of clamp base;With the guide groove on the outer wall of clamp main body is matched;Clamp main body outer wall is equipped with clamping spring groove;The lower end surface of clamp main body is equipped with end surface tooth;The inner wall of the lower end surface of clamp main body is equipped with boss, and is matched with the outer ring of deep groove ball bearing;The outer wall of clamp inner core is equipped with second boss, and is matched with the inner ring of deep groove ball bearing;One end of reset spring is installed in the cavity in the upper part of clamp inner core, and one end is installed in the recess of clamp upper cover plate;The device can reduce the scrap rate in production process, and the machining reference and assembly reference are consistent, which reduces the difficulty of assembly in the whole vehicle assembly process.

Description

Technical Field

[0001] This invention belongs to the field of machining fixture technology, specifically a milling fixture for end-face spline ball cage universal joints. Background Technology

[0002] Currently, passenger vehicles use constant velocity joint driveshafts with circular splines, which drive the wheels through a spline connection with the wheel hub unit. After final assembly, an abnormal noise is detected at start-up. Analysis of the wheel hub unit's assembly structure confirmed that a gap in the spline fit between the fixed end of the constant velocity joint driveshaft and the wheel hub unit is the root cause of the noise. Solutions include increasing the spline pitch of the driveshaft, pressing in anti-friction shims, or applying anti-loosening adhesive to the gap between the fixed end of the driveshaft and the wheel hub unit to reduce the noise during vehicle start-up. New energy vehicles, due to the use of electric drive systems instead of traditional internal combustion engines, have higher NVH requirements, and the above solutions cannot completely solve the wheel hub noise problem. The best solution for wheel hub noise in new energy vehicles is to redesign the assembly structure between the ball joint and the wheel hub unit, using an end-face spline structure instead of the traditional circular spline, such as... Figure 1 .

[0003] The machining process of the end-face spline ball cage universal joint consists of finishing and roughing. The roughing process mainly involves turning, using the tooth surface of the end face spline as a reference for turning the shape. The machining process is done manually, with the operator visually identifying the tooth surface of the end face spline before loading the material to ensure the meshing of the end face tooth surface and the fixture tooth surface.

[0004] The entire finishing process is as follows: internal cavity quenching - tempering - soft turning of the outer diameter - hard turning of the inner spherical surface and hard milling of the ball tracks - shank drilling and tapping - flaw detection - cleaning - application of anti-rust oil - final inspection. The end-face spline ball cage universal joint has eight ball tracks evenly distributed at 45° intervals in its inner cavity. The hard turning of the inner spherical surface and hard milling of the ball tracks requires starting milling from specific ball tracks, so a fixed positioning plate is needed for loading and unloading. The machine tool spindle clamps the parts through a series of actions such as lifting and clamping. Currently, the hard turning of the inner spherical surface and hard milling of the ball tracks uses the small end face of the shank of the end-face spline ball cage universal joint as the positioning reference and the outer diameter of the universal joint as the clamping reference for machining. See... Figure 2 .

[0005] The current clamping method for milling the ball joint's inner cavity results in severe deviations in coaxiality and perpendicularity between the inner cavity and the end face spline. This leads to a high scrap rate during production, difficulties in assembling the fixed end during vehicle assembly, and poor dynamic balance during vehicle operation after assembly. The root cause of these problems is that the spindle in the hard milling process for the ball joint's inner spherical surface can only move up and down when gripping the part, unable to rotate. Furthermore, the mechanical spindle lacks a vision recognition system, failing to identify the tooth surface of the end face spline and thus preventing machining from using it as a positioning reference. Summary of the Invention

[0006] To address the above problems, this invention provides a milling fixture for a ball cage type universal joint with end-face spline, comprising: a fixture base, a fixture body, a fixture upper cover plate, a fixture inner core, a retaining ring, a deep groove ball bearing, a return spring, and guide posts; the upper end face of the fixture base has three first through holes evenly spaced at 120° intervals, and three first grooves evenly spaced at 120° intervals, with threaded holes on the bottom surface of the first grooves for fixing the fixture upper cover plate; the outer wall of the fixture base has three second through holes evenly spaced at 120° intervals for installing guide posts; the outer wall of the fixture body has three sets of guide grooves evenly spaced at 120° intervals, with guide posts matching guide grooves; a retaining ring groove is provided near the upper end face of the fixture body for installing retaining rings; the lower end face of the fixture body has three end face teeth evenly spaced at 120° intervals; the interior of the fixture body is hollow, with a first boss near the lower end face for mating with the outer ring of the deep groove ball bearing; the outer surface of the fixture inner core... A second boss is provided on the wall for mating with the inner ring of the deep groove ball bearing; the inner cavity of the fixture core is hollow, with a partition in the middle dividing the cavity into two, and a return spring is installed in one of the cavities; three third bosses are evenly distributed at 120° intervals on the lower end face of the fixture upper cover plate, and the third bosses have countersunk holes for connecting with the fixture base. A second groove is provided in the center of the fixture upper cover plate for fixing the return spring; one end of the return spring is installed in the cavity in the upper part of the fixture core, and the other end is installed in the second groove of the fixture upper cover plate; in the hard milling process of the ball track in the hard turning process, the end face spline tooth surface is used as the positioning reference for machining the inner cavity of the universal joint, ensuring that the coaxiality and perpendicularity of the inner cavity of the universal joint relative to the end face spline are qualified, reducing the scrap rate in the production process, and keeping the machining reference and assembly reference consistent reduces the assembly difficulty in the whole vehicle assembly process. The problem of poor dynamic balance during vehicle operation after it rolls off the production line is also improved.

[0007] The technical solution of this invention is as follows: a milling fixture for a ball cage type universal joint with end spline, comprising: a fixture base, a fixture body, a fixture upper cover plate, a fixture inner core, a retaining ring, a deep groove ball bearing, a return spring, and guide posts; the upper end face of the fixture base has three first through holes evenly spaced at 120° intervals, and three first grooves evenly spaced at 120° intervals, with threaded holes on the bottom surface of the first grooves for fixing the fixture upper cover plate; the outer wall of the fixture base has three second through holes evenly spaced at 120° intervals for installing guide posts; the outer wall of the fixture body has three sets of guide grooves evenly spaced at 120° intervals, with guide posts matching guide grooves; a retaining ring groove is provided at a distance from the upper end face of the fixture body for installing retaining rings; the fixture body... The lower end face of the fixture has three teeth evenly spaced at 120° intervals. The interior of the fixture body is a cavity, with a first boss near the lower end face for mating with the outer ring of the deep groove ball bearing. The outer wall of the fixture core has a second boss for mating with the inner ring of the deep groove ball bearing. The inner cavity of the fixture core is a cavity, with a partition dividing the cavity in two. One cavity contains a return spring. The lower end face of the fixture cover plate has three third bosses evenly spaced at 120° intervals. The third bosses have countersunk holes for connecting with the fixture base. The center of the fixture cover plate has a second groove for fixing the return spring. One end of the return spring is installed in the cavity at the top of the fixture core, and the other end is installed in the second groove of the fixture cover plate.

[0008] Furthermore, the angle between the normal of the first groove and the normal of the first through hole is 60°.

[0009] Furthermore, each set of guide slots has two different directions of rotation.

[0010] Furthermore, the distance between the circlip groove and the upper surface of the fixture body is 1-3mm.

[0011] Furthermore, the first protrusion is annular.

[0012] Furthermore, the second protrusion is annular.

[0013] Furthermore, the second groove is circular.

[0014] The beneficial effects of this invention are as follows:

[0015] The milling track fixture of the present invention is a purely mechanical structure with simple structure and high stability. The rotation of the fixture body is achieved by two guide rails with different rotation directions, which can rotate in both clockwise and counterclockwise directions. It does not require the use of visual inspection, rotary cylinders or other additional devices, thus avoiding maintenance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a splined ball cage universal joint in the prior art.

[0017] Figure 2This is a schematic diagram of the end face of the handle of a splined ball cage universal joint in the prior art.

[0018] Figure 3 This is a schematic diagram of the device of the present invention.

[0019] Figure 4 This is a schematic diagram of the fixture base of the present invention.

[0020] Figure 5 This is a schematic diagram of the main body of the fixture of the present invention.

[0021] Figure 6 for Figure 5 Schematic diagram of section AA.

[0022] Figure 7 This is a schematic diagram of the inner core of the fixture of the present invention.

[0023] Figure 8 for Figure 7 Schematic diagram of section AA.

[0024] Figure 9 This is a schematic diagram of the upper cover plate of the fixture of the present invention.

[0025] Figure 10 for Figure 9 Schematic diagram of section AA.

[0026] In the picture:

[0027] 1. Fixture base; 2. Fixture body; 3. Fixture upper cover plate; 4. Fixture inner core; 5. Snap ring; 6. Deep groove ball bearing; 7. Return spring; 8. Guide post; 101 first through hole; 102 first groove; 103 second through hole; 201 guide groove; 202 end face tooth; 203 first boss; 301 third boss; 302 countersunk hole; 303 second groove; 401 outer wall; 402 second boss. Detailed Implementation

[0028] It should be noted that in the description of this invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; a connection can be a mechanical connection or an electrical connection; a link can be a direct connection or an indirect connection through an intermediate medium, and can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] A milling fixture for a ball cage type universal joint with end spline, comprising: fixture base 1, fixture body 2, fixture upper cover plate 3, fixture inner core 4, retaining ring 5, deep groove ball bearing 6, return spring 7, and guide post 8.

[0031] The upper end face of the fixture base 1 has three first through holes 101 evenly distributed at 120° intervals for connecting to the machine tool spindle;

[0032] Three first grooves 102 are evenly distributed at 120° intervals on the upper end face of the fixture base 1. Each first groove 102 has a threaded hole on its bottom surface for fixing the upper cover plate 3 of the fixture. The angle between the normal of the first groove 102 and the normal of the first through hole 101 is 60°.

[0033] Three second through holes 103 are evenly distributed at 120° intervals on the outer wall of the fixture base 1 for installing guide posts 8;

[0034] Three sets of guide grooves 201 are evenly distributed at 120° intervals on the outer wall of the fixture body 2.

[0035] Each set of guide grooves has two different directions of rotation, used to drive the rotation of the fixture body 2;

[0036] There is a retaining ring groove 2mm away from the upper end face of the fixture body 2 for installing retaining ring 5; three end face teeth 202 are evenly distributed at 120° intervals on the lower end face of the fixture body 2 for meshing with the end face teeth of the target part. The meshing of the three end face teeth 202 achieves higher three-point positioning accuracy; the interior of the fixture body 2 is a cavity, and there is a first boss 203 near the lower end face for mating with the outer ring of the deep groove ball bearing 6.

[0037] The first boss 203 is a circular boss.

[0038] The inner core of the clamp is provided with a second boss 402 on the outer wall 401 of the inner core of the clamp, which is used to mate with the inner ring of the deep groove ball bearing 6; the inner cavity of the inner core of the clamp is a hollow cavity with a partition in the middle; the lower part of the inner core of the clamp is used to accommodate the handle of the end face spline universal joint, and the upper part of the inner core of the clamp is used to fix the return spring 7.

[0039] The second boss 402 is a circular boss.

[0040] The upper cover plate 3 of the fixture has three third bosses 301 evenly distributed at 120° intervals on its lower end face. The third bosses 301 have countersunk holes 302 for connecting with the fixture base 1. The upper cover plate 3 of the fixture has a second groove 303 in the center for fixing the reset spring 7.

[0041] The second groove 303 is circular.

[0042] In the initial state of the fixture, the guide post 8 is located at the highest point of the guide groove 201. At this time, the return spring 7 is in a state of incomplete compression, providing preload for the milling ball track fixture.

[0043] Return spring 7: One end is installed in the cavity at the top of the inner core 4 of the clamp, and the other end is installed in the second groove 303 of the upper cover plate 3 of the clamp;

[0044] A guide groove 201 is provided on the outer circumference of the fixture body 2, and three first through holes 101 are provided on the outer circumference of the fixture base 1. After the fixture body 2 is installed into the inner cavity of the fixture base 1, guide pins 8 are inserted into the three second through holes 103 on the outer circumference of the fixture base 1. The guide pins 8 are engaged in the guide grooves 201 distributed on the outer circumference of the fixture body 2. After the device of the present invention is connected to the machine tool spindle through the three first through holes 101 of the fixture base 1, the machine tool spindle grips the workpiece, and the end face teeth 202 on the end face of the fixture body 2 contact the end face of the workpiece being processed. When the downward pressure applied by the machine tool spindle is greater than the elastic force of the return spring 7 inside the fixture, the guide pins 8 slide along the guide groove 201 from the initial position of the guide groove 201, thereby driving the fixture body 2 to rotate, so that the end face teeth 202 on the end face of the fixture body 2 and the end face teeth of the workpiece being processed complete the meshing. After machining, the machine tool spindle releases the workpiece and rises simultaneously. Driven by the internal return spring 7, the fixture body 2 rotates in the opposite direction along the guide groove 201 to return to its initial position. The milling track fixture of this invention has a purely mechanical structure, is simple in design, and has high stability. The rotation of the fixture body 2 is achieved through two guide grooves 201 with different rotation directions, allowing for clockwise and counterclockwise rotation. This eliminates the need for visual inspection, rotary cylinders, or other auxiliary devices, thus avoiding maintenance.

[0045] No visual inspection device is needed to identify the tooth surface of the end face spline;

[0046] A purely mechanical rotary positioning fixture that requires no electrical control is driven to rotate by the downward pressure of the machine tool spindle, thus completing the engagement between the fixture and the end face spline.

[0047] It can rotate in both clockwise and counterclockwise directions;

[0048] As an emerging product, the end-face spline ball cage universal joint is currently only used in high-end new energy vehicles. Its processing and manufacturing technology is not as advanced as that of traditional drive shafts, so there is no alternative solution in the entire drive shaft manufacturing industry that can achieve the purpose of this invention.

[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be included within the scope of protection of the present invention. Furthermore, all content not described in detail in this specification is prior art known to those skilled in the art.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

Claims

1. A milling fixture for ball track of a ball cage type universal joint with end spline, characterized in that, include: The fixture comprises a base, a body, a top cover, an inner core, a retaining ring, a deep groove ball bearing, a return spring, and guide posts. The upper surface of the base has three first through holes spaced 120° apart, and three first grooves spaced 120° apart. The bottom surface of each first groove has threaded holes for fixing the top cover. The outer wall of the base has three second through holes spaced 120° apart for mounting guide posts. The outer wall of the body has three sets of guide grooves spaced 120° apart for guiding… The column matches the guide groove; a retaining ring groove is provided on the upper end face of the fixture body for installing the retaining ring; three end face teeth are evenly distributed at 120° intervals on the lower end face of the fixture body; the interior of the fixture body is a cavity, with a first boss near the lower end face for mating with the outer ring of the deep groove ball bearing; a second boss is provided on the outer wall of the fixture core for mating with the inner ring of the deep groove ball bearing; the inner cavity of the fixture core is a cavity, with a partition dividing the cavity into two, and a return spring is provided in one of the cavities; the fixture... Three third protrusions are evenly distributed at 120° intervals on the lower end face of the cover plate. The third protrusions have countersunk holes for connection with the fixture base. The upper cover plate of the fixture has a second groove in the center for fixing the return spring. One end of the return spring is installed in the cavity in the upper part of the fixture core, and the other end is installed in the second groove of the upper cover plate of the fixture. Each set of guide grooves has two different directions of rotation. In the initial state of the fixture, the guide post is located at the highest point of the guide groove. The three first through holes of the fixture base are connected to the machine tool spindle. When the downward pressure applied by the machine tool spindle is greater than the elastic force of the return spring in the fixture, the guide post slides along the guide groove from the initial position of the guide groove, thereby driving the fixture body to rotate, so that the end face teeth of the fixture body and the end face teeth of the workpiece are engaged. After the machining is completed, the machine tool spindle releases the workpiece and rises at the same time. The fixture body is driven by the internal return spring to rotate back to the initial position along the guide groove in the opposite direction. The rotation of the fixture body is achieved through two guide grooves with different directions of rotation, which can rotate in both clockwise and counterclockwise directions.

2. The end-face spline ball cage universal joint milling ball track fixture as described in claim 1, characterized in that, The angle between the normal of the first groove and the normal of the first through hole is 60°.

3. The end-face spline ball cage universal joint milling ball track fixture as described in claim 1, characterized in that, The distance between the circlip groove and the upper surface of the fixture body is 1-3mm.

4. A milling fixture for end-face spline ball cage type universal joints as described in any one of claims 1 to 3, characterized in that, The second groove is circular.

5. A milling fixture for end-face spline ball cage type universal joints as described in claim 4, characterized in that, The first protrusion is circular.

6. The end-face spline ball cage universal joint milling ball track fixture as described in claim 4, characterized in that, The second protrusion is circular.

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