Method for drilling and tapping a hub bearing

Abstract

The application relates to the machining technical field of hub bearings and particularly discloses a machining method for drilling and tapping of a hub bearing, a plurality of drilling and tapping fixtures for the hub bearing are installed on a workbench, the drilling and tapping fixture for the hub bearing comprises a clamping block, a supporting column, a positioning piece, an annular seat, a cylinder claw, a chip removal cylinder and an annular positioning seat; the positioning piece slides on a mounting seat, and a spring is arranged between the mounting seat and the positioning piece; the supporting column is hollow and the top and the bottom of the supporting column are through holes, and the bottom through hole is communicated with a chip removal channel; the cylinder claw comprises a connecting ring and an elastic clamping claw; the chip removal cylinder forms the chip removal channel; the chip removal cylinder penetrates through the annular positioning seat; and the method further comprises the following steps: S1, processing each hole of an inner ring of the hub bearing; and S2, adopting a mode of inserting a hooking cutter into the hole from top to bottom to perform chamfering processing on the bottom end of the hole. The scheme is used to solve the problems that the machining precision of the flange of the hub bearing cannot be guaranteed in the drilling and tapping machining and the surface of a cylinder column section of the inner ring of the hub bearing is easily damaged.

Description

[0001] This application is a divisional application of the patent application filed on June 30, 2023, with application number 2023108029740 and invention title "A Drilling and Tapping Fixture and Processing Method for Wheel Hub Bearings". Technical Field

[0002] This invention relates to the field of wheel hub bearing machining technology, specifically to a machining method for drilling and tapping wheel hub bearings. Background Technology

[0003] The main function of wheel hub bearings is to bear weight, and they are an indispensable part of automobiles. Wheel hub bearings include an inner ring, a small inner ring, an outer ring, rolling elements, and a cage. The outer ring has two rows of raceways, and the inner ring and the small inner ring each have one row of raceways. Under the action of the cage, the rolling elements are located in the raceways and move within the raceways when the inner and outer rings of the wheel hub bearing rotate relative to each other.

[0004] When wheel hub bearings are in use, they need to be connected to the wheel rim, brake disc, and steering knuckle. Therefore, drilling or even tapping is required on the inner and / or outer flanges of the wheel hub bearings. To ensure the machining accuracy of drilling and tapping, the machining of the inner or outer flanges of the wheel hub bearings requires the use of a clamp. For example, the wheel hub bearing machining clamp with patent publication number CN210997688U is used to clamp the inner ring of the wheel hub bearing to facilitate hole machining or grinding of the wheel hub bearing. During clamping, multiple clamping blocks on the clamp approach each other to surround and press the cylindrical section of the inner ring of the wheel hub bearing to achieve clamping.

[0005] However, in the existing clamping method, the inner ring of the wheel hub bearing is only clamped by circumferential clamping blocks. However, the flange of the wheel hub bearing has a large number of holes to be machined, and there are more than one specification. When machining holes, after machining holes of the same specification, the tool is changed to machine the next specification of hole. Moreover, each hole is eccentrically set on the inner ring of the wheel hub bearing. During hole machining, the force on the inner ring of the wheel hub bearing is uneven. It is difficult to guarantee the machining accuracy requirements of the holes by relying solely on multiple clamping blocks to circumferentially clamp the cylindrical section of the wheel hub bearing.

[0006] To ensure machining accuracy during drilling and tapping, it is necessary to increase the clamping force of the clamping block on the inner ring cylindrical section of the wheel hub bearing. However, while increasing the clamping force, it also increases the probability of the cylindrical section surface being damaged.

[0007] Furthermore, under the existing clamping method, the waste generated from machining the inner ring hole of the wheel hub bearing tends to accumulate on the clamping block, increasing the difficulty of cleaning the waste. Summary of the Invention

[0008] The present invention aims to provide a wheel hub bearing drilling and tapping fixture to solve the problems of difficulty in ensuring machining accuracy and easy damage to the cylindrical section surface of the inner ring of wheel hub bearings during the current drilling and tapping process.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A wheel hub bearing drilling and tapping jig includes multiple clamping blocks that can approach the center of the wheel hub bearing. The clamping blocks are used to clamp the outer periphery of the flange of the wheel hub bearing. It also includes a support column for supporting the flange of the wheel hub bearing. The contact position between the support column and the flange avoids the position on the flange where a hole needs to be drilled. It also includes a positioning element for restricting the circumferential rotation of the wheel hub bearing.

[0010] The principle and advantages of this scheme are: 1. When adopting this solution, by replacing the clamping block that holds the cylindrical section of the wheel hub bearing with the clamping block that holds the outer circumference of the flange, the contact area during clamping is significantly increased because the outer circumference of the flange is the largest outer diameter point on the wheel hub bearing. This avoids damaging the cylindrical section of the wheel hub bearing and significantly increases the contact area during clamping, ensuring greater clamping force when machining the flange. In addition, this solution provides bottom support for the flange supported by the support column and circumferential limitation for the positioned component, ensuring the accuracy of the hole machining on the wheel hub bearing flange even if the drilling and tapping holes on the flange are eccentrically machined, under the conditions of greater clamping force, bottom support, and circumferential limitation.

[0011] 2. In this solution, the clamping block is clamped on the outer circumference of the flange. Compared to clamping on the cylindrical section, the outer surface of the cylindrical section of the inner ring of the wheel hub bearing is the raceway surface and the mating surface with the small inner ring. Therefore, if this surface is damaged, it will have a significant impact on the performance of the wheel hub bearing. In this solution, clamping on the outer circumference of the flange, where the surface quality requirements are low, ensures that the outer circumference of the cylindrical section, which has high surface precision requirements, is not affected by the machining, thus avoiding the possibility of the cylindrical section being damaged. At the same time, because the contact area is larger when clamped on the outer circumference of the flange, the clamping force is greater and more stable, and the probability of the clamping block damaging the outer circumference of the flange is also reduced.

[0012] 3. This solution avoids the contact position between the support column and the flange at the opening position, ensuring that the machining of the holes on the flange is not affected by the support column, and ensuring that the machining of the holes is efficient while maintaining high precision.

[0013] Preferably, as an improvement, the support column is hollow inside and has through holes at the top and bottom. The holes that need to be opened on the flange are located in the hollow space of the support column, and the through hole at the bottom of the support column is connected to a chip removal channel.

[0014] Beneficial effects: This solution allows the waste chips generated during processing to fall directly from the top through-hole of the support column into the hollow space of the support column, and then enter the chip removal channel from the bottom through-hole of the hollow space, and finally be discharged from the chip removal channel, thus avoiding the accumulation of waste chips on the fixture.

[0015] Preferably, as an improvement, it also includes an annular seat and a cylindrical claw located within the annular seat. The cylindrical claw includes a connecting ring and a plurality of elastic claws evenly distributed on the connecting ring around the circumference. Each elastic claw is equipped with a clamping block. The elastic claws engage with the annular seat via an inclined surface. When the connecting ring moves vertically, the elastic claws can move along the inclined surface.

[0016] Beneficial effects: This solution, through the setting of the annular seat with an inclined surface, enables the vertical movement of the entire cylinder claw, that is, it allows the elastic claw to move on the inclined surface, thereby forcing the clamping block away from or close to the flange of the wheel hub bearing, thus realizing the loosening or clamping of the flange of the wheel hub bearing.

[0017] Preferably, as an improvement, it also includes a chip discharge cylinder located below the support column, the chip discharge cylinder forming a chip discharge channel, the chip discharge cylinder being able to move vertically, and the chip discharge cylinder being fixedly connected to the connecting ring.

[0018] Beneficial effects: The vertically movable chip discharge cylinder of this solution can not only drive the connecting ring to move vertically, thus controlling whether the clamping block is clamped or not, but also form a chip discharge channel to facilitate the discharge of waste chips. In addition, during the vertical movement, it can also help the waste chips hanging on the inner wall of the chip discharge cylinder to fall down.

[0019] Preferably, as an improvement, it also includes an annular positioning seat, with the chip discharge cylinder passing through the annular positioning seat. The annular positioning seat is provided with an annular groove surrounding the chip discharge cylinder, and a closed cavity is formed between the annular groove and the chip discharge cylinder. A piston is fixed on the outer periphery of the chip discharge cylinder, and the piston is vertically slidably connected to the annular groove and divides the cavity into two independent chambers, each of which is connected to a flow channel.

[0020] Beneficial effects: This solution controls the pressure in the upper and lower chambers through their respective flow channels, thereby enabling vertical lifting control of the chip conveyor with piston. This ensures that the clamping block is held in place by lifting, while also meeting the chip removal requirements of the chip conveyor. It does not increase the overall space of the fixture, making the fixture compact and with a small footprint. This allows for the installation of more drilling and tapping fixtures on the worktable of a CNC machine tool of the same size, increasing the number of workpieces processed in a single operation, thereby improving processing efficiency and the consistency of workpiece processing quality.

[0021] Preferably, as an improvement, a pull plate is fixedly connected to the chip discharge cylinder, the pull plate and the connecting ring are located on the upper and lower sides of the annular positioning seat, and a connecting rod is fixedly connected between the pull plate and the connecting ring, the connecting rod being vertically slidably connected to the annular positioning seat.

[0022] Beneficial effects: This solution simplifies the connection structure, while the annular positioning seat guides the vertical movement of the connecting rod, resulting in higher stability of the vertical movement of the cylinder claw and extending its service life.

[0023] Preferably, as an improvement, the annular positioning seat includes an upper cylindrical section and a lower cylindrical section. The outer diameter of the lower cylindrical section is larger than that of the upper cylindrical section. The lower cylindrical section is partially embedded in the annular seat. The annular gap between the annular seat and the upper cylindrical section is used to accommodate the connecting ring. The annular seat is provided with an upward-facing weight-reducing groove. The weight-reducing groove and the clamping block are staggered in the circumference of the annular seat.

[0024] Beneficial effects: The upper and lower cylindrical sections of the annular positioning seat not only shield the lower cylindrical section of the annular positioning seat through the annular seat itself, preventing waste chips from falling directly between the annular seat and the lower cylindrical section of the annular positioning seat, but also play a role in dust prevention and protection for the annular positioning seat. The weight-reducing groove on the annular seat not only reduces the weight of the annular seat, but also allows waste chips that do not fall from the machining holes in time to fall from the empty areas on both sides of the clamping block to the weight-reducing groove, preventing the accumulation of waste chips on the clamping block. In addition, the lifting and lowering action of the connecting ring also helps to push out the waste chips accumulated on the connecting ring and the weight-reducing groove.

[0025] Preferably, as an improvement, the bottom through hole of the support column is a tapered hole, with the smaller end of the tapered hole close to the chip removal channel.

[0026] Beneficial effects: This solution allows waste chips to fall from the hollow space of the support column into the chip discharge cylinder in a timely manner through the conical hole, facilitating the timely discharge of waste chips. At the same time, it also ensures that after the support columns of different specifications are installed on the annular positioning seat, the waste chips can fall into the chip discharge cylinder through the conical hole in a timely manner.

[0027] This invention also provides a machining method for drilling and tapping wheel hub bearings, which requires using the aforementioned wheel hub bearing drilling and tapping fixture to clamp the workpiece. The positioning element can be pressed against a non-machined position on the upper surface of the flange. The method also includes the following machining steps: S1, machining hole positions; S2. Use a hook cutter to chamfer the bottom of the hole by inserting it from top to bottom.

[0028] Preferably, as an improvement, the wheel hub bearing drilling and tapping chuck has multiple chucks, and the multiple wheel hub bearing drilling and tapping chucks are mounted on the same worktable.

[0029] The beneficial effects of this invention are as follows: 1. During processing, the present invention uses a clamping block to hold the flange of the wheel hub bearing, a support column to support the flange from the bottom, and a positioning element to press and restrict the circumferential rotation of the flange from above. Furthermore, the contact positions of the support column and positioning element with the flange avoid the holes that need to be processed. Therefore, with all directions of the wheel hub bearing restricted, the hook cutter can extend below the bottom of the hole. This allows for chamfering of the bottom of the hole without needing to flip the wheel hub bearing flange, improving processing efficiency. It also avoids the need for repositioning and re-aligning the workpiece after processing, ensuring the quality of the chamfering.

[0030] 2. Due to the compact design of the wheel hub bearing drilling and tapping fixture, this invention allows multiple fixtures to be installed on a CNC machine tool workbench, facilitating the processing of multiple wheel hub bearings on the fixture. Actual verification shows that the original workbench could only accommodate 2 fixtures. After the design improvement of the wheel hub bearing drilling and tapping fixture in this invention, the number of fixtures that can be placed on the original workbench has reached 6, far exceeding expectations, which greatly improves processing efficiency and significantly increases enterprise production capacity. Attached Figure Description

[0031] Figure 1 This is a three-dimensional structural schematic diagram of the wheel hub bearing drilling and tapping fixture according to an embodiment of the present invention.

[0032] Figure 2 for Figure 1 Top view.

[0033] Figure 3 for Figure 2 AA rotated section view in the image.

[0034] Figure 4 for Figure 2 BB rotated section view.

[0035] Figure 5 This is a partial exploded view of the wheel hub bearing drilling and tapping fixture according to an embodiment of the present invention.

[0036] Figure 6 This is a top sectional view of the positioning component in the wheel hub bearing drilling and tapping fixture according to an embodiment of the present invention.

[0037] Figure 7 This is a three-dimensional structural diagram of an embodiment of the present invention after six wheel hub bearing drilling and tapping fixtures are installed on the same workbench.

[0038] Figure 8 for Figure 7 Top view.

[0039] Figure 9 for Figure 7 Front sectional view.

[0040] Figure 10 This is a schematic diagram of the processing method of this invention when chamfering the bottom end of the hole in the inner ring of a wheel hub bearing. Detailed Implementation

[0041] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: worktable 100, main fixture 101, main channel one 1011, main channel two 1012, worktable body 102, rib plate 103, chip removal guide plate 104, wheel hub bearing inner ring 10, annular seat 1, weight reduction groove 11, cylinder claw 2, elastic gripper 21, clamping block 211, connecting ring 22, limiting component 221, connecting rod 23, support column 3, annular positioning seat 4, end cap 41, mounting hole 42, flow channel one 43, flow channel two 44, upper chamber 401, lower chamber 402, pull plate 5, chip removal cylinder 6, piston 61, annular sleeve plate 7, positioning component 8, mounting seat 81, spring 82, baffle 83, hook cutter 9, extension rod 91, and wheel hub bearing drilling and tapping fixture 200.

[0042] The basic implementation examples are as follows: Figures 1 to 10 As shown, a machining method for drilling and tapping wheel hub bearings requires drilling, tapping, and chamfering the flange of the inner ring 10 of the wheel hub bearing using a CNC machine tool. A wheel hub bearing drilling and tapping fixture 200 is needed. Specifically, multiple wheel hub bearing drilling and tapping fixtures 200 are installed on the worktable 100 of the CNC machine tool. Each wheel hub bearing drilling and tapping fixture 200 is used to fix and clamp one inner ring 10 of the wheel hub bearing. The specific structure of the wheel hub bearing drilling and tapping fixture 200 is as follows: Combination Figures 1 to 6 As shown, the wheel hub bearing drilling and tapping fixture 200 includes an annular seat 1, a claw 2, a support column 3, an annular positioning seat 4, and a positioning element 8. Both the annular seat 1 and the annular positioning seat 4 are fixed to the worktable 100 with screws. The annular positioning seat 4 cooperates with the claw 2 to clamp the outer circumference of the flange of the inner ring 10 of the wheel hub bearing. The support column 3 supports the inner ring 10 of the wheel hub bearing from the bottom of the flange. The annular positioning seat 4 is used to fix the support column 3 in place, and the positioning element 8 is used to circumferentially limit and press the flange of the inner ring 10 of the wheel hub bearing from above.

[0043] The cylindrical claw 2 is located inside the annular seat 1. The cylindrical claw 2 includes an integrally formed connecting ring 22 and a plurality of elastic claws 21 evenly distributed on the connecting ring 22. Each elastic claw 21 includes a thin-walled section integrally formed with the connecting ring 22 and a chuck located at the free end of the thin-walled section. A clamping block 211 is installed on the chuck of each elastic claw 21 by screws. The elastic claw 21 and the annular seat 1 are engaged by an inclined surface. When the connecting ring 22 moves vertically, the elastic claw 21 can move along the inclined surface.

[0044] The annular positioning seat 4 includes an integrally formed upper cylindrical section and a lower cylindrical section. The outer diameter of the lower cylindrical section is larger than that of the upper cylindrical section. The lower cylindrical section is partially embedded in the annular seat 1. The annular gap between the annular seat 1 and the upper cylindrical section is used to accommodate the connecting ring 22. The annular seat 1 is provided with an upward-facing weight-reducing groove 11. The weight-reducing groove 11 and the clamping block 211 are staggered around the annular seat 1.

[0045] A downward-facing connecting rod 23 is fixed on the bottom of the connecting ring 22 of the claw 2. The connecting rod 23 is vertically slidably connected to the annular positioning seat 4. In this embodiment, a pull plate 5 is fixedly connected to the bottom end of the connecting rod 23 through the annular positioning seat 4. The vertical movement of the pull plate 5 drives the connecting rod 23 to move vertically and stably along the annular positioning seat 4, thereby driving the connecting ring 22 to move vertically. During the vertical movement, the elastic gripper 21 moves along the inclined surface of the annular seat 1 to realize that the clamping blocks 211 on the multiple elastic grippers 21 move closer to each other or further away from each other.

[0046] The support column 3 is fixed to the upper cylindrical section of the annular locating seat 4 by screws. Multiple rows of mounting holes 42 are machined on the upper cylindrical section of the annular locating seat 4. Each row of mounting holes 42 is radially arranged along the inner ring 10 of the wheel hub bearing. Mounting holes 42 located on different circumferences can correspond to different support columns 3. The contact position between the support column 3 and the flange avoids the location on the flange where holes are required. Specifically, the support column 3 is hollow inside, with through holes at both the top and bottom. The locations on the flange where holes are required are located within the hollow space of the support column 3. The bottom through hole of the support column 3 is a tapered hole, with the diameter decreasing as it moves further away from the inner ring 10 of the wheel hub bearing. The bottom through hole of the support column 3 connects to a chip removal channel.

[0047] A chip discharge cylinder 6 is vertically slidably connected to the middle of the annular positioning seat 4. The bottom of the chip discharge cylinder 6 passes through the annular positioning seat 4, and the top of the chip discharge cylinder 6 is connected to the bottom through hole of the support column 3. An annular sleeve plate 7 is provided between the chip discharge cylinder 6 and the support column 3. The annular sleeve plate 7 is fixed to the annular positioning seat 4 by screws. The chip inlet end of the annular sleeve plate 7 is machined with a guide slope. The annular sleeve plate 7 covers the chip discharge cylinder 6 and forms a shield for the chip cylinder. At the same time, it facilitates the rapid fall of waste chips into the chip discharge cylinder 6. The chip discharge channel at the bottom of the support column 3 is formed by the annular sleeve plate 7 and the chip discharge cylinder 6.

[0048] The pull plate 5 is fixed on the outer periphery of a section at the bottom of the chip discharge cylinder 6 so that the pull plate 5 rises and falls synchronously with the chip discharge cylinder 6.

[0049] The annular positioning seat 4 is machined with an annular groove surrounding the chip discharge cylinder 6, forming a closed cavity between the annular groove and the chip discharge cylinder 6. A piston 61 is fixed on the outer periphery of the middle part of the chip discharge cylinder 6. The piston 61 is vertically slidably connected to the annular groove and divides the cavity into two independent chambers. The annular positioning seat 4 is provided with a flow channel 1 43 and a flow channel 2 44. The flow channel 1 43 is connected to the upper chamber 401, and the flow channel 2 44 is connected to the lower chamber 402.

[0050] The workbench 100 has a main channel 1011 and a main channel 2 1012. Each main channel 1011 and main channel 2 1012 is connected to multiple branch channels. Each branch channel on the main channel 1011 is connected to the flow channel 43 of the positioning plate on one of the wheel hub bearing drilling and tapping jigs 200. Each branch channel on the main channel 2 1012 is connected to the flow channel 44 of the positioning plate on one of the wheel hub bearing drilling and tapping jigs 200.

[0051] The main channels 1011 and 1012 on the worktable 100 are used to deliver hydraulic oil to each wheel hub bearing drilling and tapping jig 200 and to return the oil in the wheel hub bearing drilling and tapping jig 200. This facilitates the synchronous movement of the chip discharge cylinder 6 with piston 61 on all jigs by controlling the oil supply or return of the main channels 1011 and 1012, reducing control costs and making the structure of all jigs on the entire worktable 100 more compact.

[0052] In this embodiment, to ensure the airtightness of the cavity, sealing rings are installed above and below the annular groove. To ensure the formation of the annular groove and the ease of installation of the chip discharge cylinder 6 with piston 61, a detachable end cap 41 is installed at the bottom of the annular positioning seat 4. The end cap 41 is fitted over the chip discharge cylinder 6, and there are sealing rings between the end cap 41 and the annular positioning seat 4, and between the end cap 41 and the chip discharge cylinder 6.

[0053] In this embodiment, to avoid the chip discharge cylinder 6 moving downwards for too long, resulting in excessive clamping force of the clamping block 211 on the inner ring 10 of the wheel hub bearing, a limiting member 221 is installed on the connecting ring 22. The bottom of the limiting member 221 protrudes from the bottom surface of the connecting ring 22 and can abut against the upper surface of the annular positioning seat 4. In this embodiment, the limiting member 221 is a limiting screw.

[0054] The positioning element 8 is horizontally slidably connected to the fixed mounting base 81, which is fixed on the worktable 100. A spring 82 is installed between the mounting base 81 and the positioning element 8. The extension and retraction direction of the spring 82 is parallel to the radial direction of the inner ring 10 of the wheel hub bearing. The spring 82 is used to push the positioning element 8 toward the inner ring 10 of the wheel hub bearing. Specifically, the positioning element 8 has a blind hole along the radial direction of the inner ring 10 of the wheel hub bearing. A spring 82 extending out of the blind hole is installed in the blind hole. A baffle 83 is fixed on the mounting base 81. The baffle 83 is directly opposite the blind hole. The spring 82 is located between the baffle 83 and the bottom of the blind hole. The positioning element 8 is horizontally slidably connected to the mounting base 81, and the sliding direction of the positioning element 8 is parallel to the radial direction of the inner ring 10 of the wheel hub bearing.

[0055] Combination Figures 7 to 9 To ensure timely removal of waste chips during the processing, the worktable 100 has been optimized and improved in this processing method. The worktable 100 includes a fixture main board 101, a worktable body 102, and multiple ribs 103 disposed between the fixture main board 101 and the worktable body 102. The annular seat 1 and annular positioning seat 4 of all wheel hub bearing drilling and tapping fixtures 200 are fixed on the fixture main board 101, so that the fixture main board 101 and all wheel hub bearing drilling and tapping fixtures 200 on it form an integral whole, which facilitates installation and disassembly on the worktable body 102. Rib 103 creates a hollow space between the main clamp 101 and the worktable 100. A chip removal hole is opened on the main clamp 101 facing the chip removal cylinder 6, and an inclined chip removal guide plate 104 is installed below the chip removal hole. The inclined end of the chip removal guide plate 104 extends outward from the worktable body 102, so that the waste chips are discharged to the outside of the worktable 100 along the chip removal guide plate 104 after falling from the chip removal cylinder 6.

[0056] The machining method for drilling and tapping wheel hub bearings includes the following steps: The first step is to inject hydraulic oil into the second main channel 1012, so that the first main channel 1011 is used for oil return. The hydraulic oil on the second main channel 1012 enters the flow channel 44 of the annular positioning seat 4 on each fixture through its various branch channels, and finally enters the lower chamber 402 of the fixture, so that the lower chamber 402 is filled with oil, which causes the chip discharge cylinder 6 to move upward. The chip discharge cylinder 6 drives the elastic gripper 21 to move upward through the pull plate 5 and the connecting rod 23. The clamping block 211 fixed on the elastic gripper 21 moves outward under the elastic action, providing space for the placement of the inner ring 10 of the wheel hub bearing.

[0057] The second step is to place the inner ring 10 of the wheel hub bearing onto the support column 3 of each fixture. Before placement, control the positioning element 8 so that the positioning element 8 is far away from the center of the fixture to avoid the positioning element 8 interfering with the inner ring 10 of the wheel hub bearing.

[0058] The third step is to place the inner ring 10 of the wheel hub bearing to be processed onto the support column 3. After placement, release the control of the positioning element 8, so that the positioning element 8 moves radially under the action of the spring 82 and presses against the protruding position on the flange upper surface of the inner ring 10 of the wheel hub bearing, forming a downward pressing and circumferential limiting on the inner ring 10 of the wheel hub bearing.

[0059] Fourth step, inject hydraulic oil into the main channel 1011, so that the main channel 2 1012 is used for oil return. The hydraulic oil on the main channel 1011 enters the flow channel 43 of the annular positioning seat 4 on each fixture through its various branch channels, and finally enters the upper chamber 401 of the fixture, so that the upper chamber 401 is filled with oil and causes the chip discharge cylinder 6 to move downward. During the downward movement of the chip discharge cylinder 6, the pull plate 5, the connecting rod 23, and the connecting ring 22 move downward synchronously. The elastic gripper 21 moves along the inclined surface of the annular seat 1, so that the clamping block 211 approaches the inner ring 10 of the wheel hub bearing to achieve clamping of the outer periphery of the flange of the inner ring 10 of the wheel hub bearing.

[0060] The fifth step is to process each hole of the clamped inner ring 10 of the wheel hub bearing. When processing the holes, the same specification tool is used to process all holes of the same size on all inner rings 10 of the wheel hub bearing on the worktable 100 before changing the tool to process holes of other specifications.

[0061] Step 6: After machining the holes, tap the holes that need tapping and chamfer the holes that need chamfering. During the chamfering process, the bottom of the hole is chamfered using a hook cutter 9, specifically as follows... Figure 10 As shown, the hook knife 9 is fixed on the extension rod 91, and the extension rod 91 is fixed on the tool rotation output shaft of the CNC machine tool. The extension rod 91 with the hook knife 9 is inserted into the hole from top to bottom. The hook knife 9 at the bottom end of the extension rod 91 contacts the bottom end of the hole. The tool rotation output shaft drives the extension rod 91 to rotate, thereby driving the hook knife 9 to achieve the chamfering of the bottom end of the hole.

[0062] In this embodiment, by replacing the clamping block 211 that holds the cylindrical section of the inner ring 10 of the wheel hub bearing with the outer circumference of the flange, damage to the cylindrical section of the inner ring 10 of the wheel hub bearing is avoided, and the contact area during clamping is greatly increased, ensuring that the inner ring 10 of the wheel hub bearing has a greater clamping force when machining the flange. In addition, in this embodiment, the flange of the inner ring 10 of the wheel hub bearing is supported by the support column 3 at the bottom and circumferentially limited by the positioning member 8 from the top, so that even if the holes on the flange are eccentrically machined, the accuracy of the hole machining on the flange of the wheel hub bearing can be guaranteed under the conditions of greater clamping force, bottom support and top circumferential limitation.

[0063] In addition, most of the waste generated during the processing of this embodiment will fall from the machining holes of the flange into the hollow space of the support column 3, and then through the bottom conical hole of the support column 3, the guide slope of the annular sleeve plate 7, the chip discharge cylinder 6, and the chip discharge hole. Finally, the waste will be discharged from the chip discharge guide plate 104 to the outside of the worktable 100. Some of the waste will fall into the space formed by the weight reduction groove 11. Only a few wastes will remain on the upper surface of the clamping block 211 and the upper surface of the flange of the inner ring 10 of the wheel hub bearing. This realizes the timely discharge of machining waste and reduces the probability of waste accumulating on the clamping block 211 or the flange of the inner ring 10 of the wheel hub bearing.

[0064] In addition, the design of the positioning plate and chip conveyor 6 in this embodiment not only ensures stable workpiece support, stable clamping, and timely chip removal, but also makes the structure of each wheel bearing drilling and tapping fixture 200 very compact. This allows for the installation of more fixtures on the existing CNC machine tool's worktable 100, reducing tool changes and improving machining efficiency. In this embodiment, the original worktable 100 could only accommodate two wheel bearing drilling and tapping fixtures 200; after the improvement, six wheel bearing drilling and tapping fixtures 200 can be installed. Furthermore, the improved processing method eliminates the need for workpiece flipping and reprocessing to chamfer the bottom of the hole, greatly improving the company's production efficiency and capacity.

[0065] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A machining method for drilling and tapping wheel hub bearings, comprising installing multiple wheel hub bearing drilling and tapping fixtures on a machine tool worktable, each wheel hub bearing drilling and tapping fixture being used to fix and clamp an inner ring of a wheel hub bearing, the wheel hub bearing drilling and tapping fixture including multiple clamping blocks that can approach the center of the wheel hub bearing, the clamping blocks being used to clamp on the outer periphery of the flange of the wheel hub bearing, characterized in that: The wheel hub bearing drilling and tapping fixture also includes a support column for supporting the wheel hub bearing, an annular seat, a claw located in the annular seat, a chip discharge cylinder located below the support column, and an annular positioning seat. The contact position between the support column and the flange avoids the location on the flange where holes need to be opened; it also includes a positioning component to limit the circumferential rotation of the hub bearing; The positioning component is horizontally slidably connected to a fixed mounting base, which is fixed on the worktable. A spring is installed between the mounting base and the positioning component. The extension and retraction direction of the spring is parallel to the radial direction of the wheel hub bearing, and the sliding direction of the positioning component is parallel to the radial direction of the wheel hub bearing. The spring is used to push the positioning component toward the wheel hub bearing. The support column is hollow inside and has through holes at the top and bottom. The holes that need to be opened on the flange are located in the hollow space of the support column. The through hole at the bottom of the support column is connected to a chip removal channel. The cylinder jaw includes a connecting ring and multiple elastic jaws evenly distributed on the connecting ring. Each elastic jaw is equipped with a clamping block. The elastic jaws and the ring seat are engaged by an inclined surface. When the connecting ring moves vertically, the elastic jaws can move along the inclined surface. The chip discharge cylinder forms a chip discharge channel, and the chip discharge cylinder can move vertically. The chip discharge cylinder is fixedly connected to the connecting ring. The chip discharge cylinder passes through the annular positioning seat, and the annular positioning seat is provided with an annular groove surrounding the chip discharge cylinder. A closed cavity is formed between the annular groove and the chip discharge cylinder. A piston is fixed on the outer periphery of the chip discharge cylinder. The piston slides vertically on the annular groove and divides the cavity into two independent chambers. Each chamber is connected to a flow channel. A pull plate is fixedly connected to the chip conveyor. The pull plate and the connecting ring are located on the upper and lower sides of the annular positioning seat. A connecting rod is fixedly connected between the pull plate and the connecting ring. The connecting rod is vertically slidably connected to the annular positioning seat. The worktable has two main channels, Main Channel 1 and Main Channel 2, each connected to multiple branch channels. Each branch channel on Main Channel 1 connects to a flow channel 1 of the annular locating seat on one of the wheel bearing drilling and tapping chucks, and each branch channel on Main Channel 2 connects to a flow channel 2 of the annular locating seat on one of the wheel bearing drilling and tapping chucks. The main channels on the worktable are used to deliver hydraulic oil to each wheel bearing drilling and tapping chuck and to return the oil within the chucks. The worktable also includes the following machining steps: S1. Machining holes: Machining each hole on the inner ring of the clamped wheel hub bearing; S2. Use a hook cutter to chamfer the bottom of the hole by inserting it from top to bottom. Before step S1, the steps A and B are also included: Step A: Place the inner ring of the wheel hub bearing to be processed onto the support column. After placement, release the control of the positioning component, so that the positioning component moves radially under the action of the spring and presses against the protruding position on the flange upper surface of the inner ring of the wheel hub bearing, forming a downward pressing and circumferential limit on the inner ring of the wheel hub bearing. Before step A, the following operations are also included: Hydraulic oil is injected into the second main channel, so that the first main channel is used for oil return. The hydraulic oil in the second main channel enters the flow channel 2 of the annular positioning seat on each fixture through its various branch channels, and finally enters the lower cavity of the fixture, so that the lower cavity is filled with oil and causes the chip discharge cylinder to move upward. The chip discharge cylinder drives the elastic jaws to move upward through the pull plate and connecting rod. The clamping block fixed on the elastic jaws moves outward under the elastic action, providing space for the inner ring of the wheel hub bearing. Place the inner ring of the wheel hub bearing onto the support columns of each fixture. Before placing, control the positioning component to keep it away from the center of the fixture to avoid interference with the inner ring of the wheel hub bearing. Step B: Inject hydraulic oil into the main channel one, so that the main channel two is used for oil return. The hydraulic oil on the main channel one enters the flow channel one of the annular positioning seat on each fixture through its various branch channels, and finally enters the upper chamber of the fixture, so that the upper chamber is filled with oil and causes the chip discharge cylinder to move downward. During the downward movement of the chip discharge cylinder, the pull plate, connecting rod and connecting ring move downward synchronously. The elastic gripper moves along the inclined surface of the annular seat, so that the clamping block is close to the inner ring of the wheel hub bearing to achieve clamping of the outer circumference of the flange of the inner ring of the wheel hub bearing.

2. The machining method for drilling and tapping wheel hub bearings according to claim 1, characterized in that: When machining holes in step S1, the same specification tool is used to machine all holes of the same size on all wheel hub bearing inner rings on the worktable before changing the tool to machine holes of other specifications.

3. The machining method for drilling and tapping wheel hub bearings according to claim 2, characterized in that: Step S2 is as follows: Fix the hook knife on the extension rod, and fix the extension rod on the tool rotation output shaft of the CNC machine tool. Insert the extension rod with the hook knife into the hole from top to bottom. The hook knife at the bottom of the extension rod contacts the bottom of the hole. The tool rotation output shaft drives the extension rod to rotate, thereby driving the hook knife to achieve chamfering at the bottom of the hole.

4. The machining method for drilling and tapping wheel hub bearings according to any one of claims 1-3, characterized in that: A limiting component is installed on the connecting ring. The bottom of the limiting component protrudes from the bottom surface of the connecting ring and abuts against the upper surface of the annular positioning seat.

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