Machining method of annular besides-star wheel

Abstract

The machining method comprises the following procedures that OP10, a workpiece is fixed to a first tool clamp, the workpiece is in a circular ring shape and is provided with an outer circular face, an inner circular face, a first side end face and a second side end face, the first side end face and the second side end face are located between the outer circular face and the inner circular face and are oppositely arranged, and the outer circular face serves as a clamping face; the first side end face serves as a positioning face, the workpiece is clamped, the second side end face is subjected to rough turning and finish turning, and the inner circle face is subjected to rough turning and finish turning; and OP20, the workpiece is fixed to a second tool clamp, the machined inner circle face serves as an expanding face, the machined second side end face serves as a positioning face, the workpiece is expanded, rough turning and finish turning are conducted on the first side end face, rough turning and finish turning are conducted on the outer circle face, and rough turning and finish turning are conducted on the spigot face. The problems that an annular workpiece is prone to deformation and manual clamping is not in place are solved, and the technical requirements for the parallelism of the two end faces of a product, the coaxiality of the inner circle and the outer circle, the perpendicularity of the end faces and an inner hole / outer circle and the like are met.

Description

Technical Field

[0001] The invention belongs to the field of turning processing technology of mechanical processing, and in particular relates to a processing method of an annular outer star wheel. Background Art

[0002] The constant velocity joint is a key component in the car. It is a universal joint that connects the input and output shafts connected to the universal joint through a constant instantaneous angular velocity ratio to complete the transmission of motion. The constant velocity joint is a universal joint that connects two shafts with non-coincident axes so that they can achieve motion transmission at the same angular velocity. It is a universal joint with equal rotation speed (angular velocity) of the driving shaft and the driven shaft. Constant velocity joints can be divided into center fixed type and telescopic type according to their working characteristics, which are respectively used at the hub end and the gearbox end of the half shaft. Among them, the VL-DISC type belongs to the telescopic constant velocity joint. Because of its simple structure, long life, good stability and low cost, it is widely used at the gearbox end to achieve uniform transmission of the torque transmitted by the engine through the transmission to the drive wheel, and meet the axial expansion and steering requirements caused by wheel bounce. Its appearance has promoted the progress and development of front-wheel drive vehicles and all-wheel drive vehicles. At present, it has been widely used in Volkswagen PQ, MQB platform, Audi B6, B8, A5 series.

[0003] At present, the conventional turning processing methods of VL-DISC outer star wheels are generally as follows: S1, using CNC lathes to turn the end face and outer circle; S2, using CNC lathes to turn the end face and inner hole. The disadvantages of this processing method are: (1) The first S1 process uses a conventional three-jaw chuck to support the inner circle. The principle is to pull the pull rod through the spindle cylinder to connect the chuck core shaft to move axially, and complete the axial transformation into a radial unidirectional movement of the claw through the internal inclined slide rail. Due to the lack of axial force, this structure usually has certain requirements on the thickness of the workpiece. If the thickness is insufficient, the inner hole will have a certain amount of deformation during clamping, and an elliptical situation will appear after processing; in addition, the axial positioning needs to be guaranteed by manual clamping gesture experience, but it is difficult to do so under long-term work. To avoid the situation where the clamping is not in place, which will lead to uneven cutting allowance and affect the tool life, and even lead to insufficient allowance in the subsequent process and incomplete turning, resulting in appearance quality problems; (2) The S2 process also uses a conventional three-jaw chuck, and the clamping principle is the same as S1. After processing, different degrees of elliptical conditions will also be produced; (3) It is difficult to ensure consistency, and many defective parts or returned parts are often produced, which is time-consuming and labor-intensive; and each time after processing, there will be more or less iron filings left on the clamping jaws, affecting the next clamping and causing quality problems such as parallelism and surface clamping. Summary of the invention

[0004] In view of some deficiencies in existing turning processes, the present invention provides a method for processing an annular outer star wheel to solve the problems that the annular workpiece is easy to deform and manual clamping is easy to be out of place.

[0005] The processing method of the annular outer star wheel provided by the present invention includes the following steps: OP10: fixing the workpiece on a first fixture, the workpiece is in a circular ring shape, has an outer cylindrical surface and an inner cylindrical surface, and a first side end surface and a second side end surface located between the outer cylindrical surface and the inner cylindrical surface and opposite to each other, using the outer cylindrical surface as a clamping surface, using the first side end surface as a positioning surface, clamping the workpiece, performing rough turning and fine turning on the second side end surface, and performing rough turning and fine turning on the inner cylindrical surface; and OP20: fixing the workpiece on a second fixture, using the processed inner cylindrical surface as a holding surface, using the processed second side end surface as a positioning surface, holding the workpiece, performing rough turning and fine turning on the first side end surface, performing rough turning and fine turning on the outer cylindrical surface, and performing rough turning and fine turning on the stop surface.

[0006] Furthermore, the first tooling fixture has a fixture body, an inclined hole is provided inside the fixture body, an inclined column is provided in the inclined hole, a pull rod is provided in the middle of the fixture body, the pull rod is connected to the inclined column, and when the pull rod drives the inclined column to move, the first tooling fixture applies radial force and axial force to the workpiece at the same time.

[0007] Furthermore, a base jaw is provided on the right side of the inclined column, a secondary jaw is provided on the lower right side of the base jaw, and a first positioning block is provided in the middle of the right side of the back-pull clamp; after any side of the workpiece is placed in the back-pull clamp, the left side of the workpiece fits with the first positioning block, the machine tool cylinder pulls backward, and the inclined column is driven to move backward through the clamp pull rod, and under the action of the inclined hole, the base jaw drives the secondary jaw to move radially and axially at the same time; the radial movement causes the inner hole to shrink until it hugs the outer cylindrical surface of the workpiece, thereby achieving the clamping of the workpiece; the axial movement causes the secondary jaw to generate a pulling force to the left, so that the workpiece can be pressed against the first positioning block, thereby achieving the positioning of the workpiece.

[0008] Furthermore, a chip removal space is provided on the first positioning block.

[0009] Furthermore, the second tooling fixture has a main body, a boss is provided at the front end of the main body, the boss has an outer cone, and an equiangular inner cone rubber expansion sleeve matching the boss is provided on the outer side of the outer cone; when clamped, the rubber expansion sleeve contacts more than 80% of the surface area of ​​the inner hole of the workpiece and is evenly stressed, ensuring that the roundness does not deform before and after processing; the boss is conical in shape without any dead angle area.

[0010] Furthermore, the body has a tail end hole, in which there is an inner tie rod joint, a coupling ring is provided at the front end of the inner tie rod joint, the coupling ring connects the inner tie rod joint and the rubber expansion sleeve, and the inner tie rod joint and the rubber expansion sleeve are linked through the coupling ring.

[0011] Furthermore, a second positioning block is connected to the front end of the body of the second fixture, and the second positioning block is used to press the workpiece tightly when the rubber expansion sleeve moves to the left; the inner hole of the workpiece is sleeved on the outside of the rubber expansion sleeve, and the machine tool cylinder is pulled backward to move the inner pull rod joint to the left, and at the same time, the rubber expansion sleeve is synchronously moved to the left through the coupling ring and the rubber expansion sleeve. Under the action of the taper of the outer conical surface of the boss, the outer circle of the rubber expansion sleeve expands to tighten the inner hole of the workpiece, and at the same time, due to the leftward movement of the rubber expansion sleeve, the workpiece is pressed against the second positioning block.

[0012] Furthermore, the CNC lathes applicable to the processing method include standard single-spindle / single-turret CNC lathes, parallel dual-spindle / dual-turret CNC lathes, opposed dual-spindle CNC lathes, and inverted CNC lathes.

[0013] This application solves the problem that annular workpieces are easily deformed and manually clamped in place, and ensures technical requirements such as parallelism of the two end faces of the product, coaxiality of the inner and outer circles, and perpendicularity between the end face and the inner hole / outer circle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a flow chart of a method for processing an annular outer star wheel provided by a preferred embodiment of the present invention;

[0015] Figure 2 It is an overlay diagram of the workpiece and the finished turned product of the annular outer planetary wheel of a preferred embodiment of the present invention, wherein the grid line section area is the material removed by turning in the processing method of the present application.

[0016] Figure 3 This is a schematic diagram of positioning and fixing a workpiece by a first fixture in a preferred embodiment of the present invention;

[0017] Figure 4 This is a schematic diagram of positioning and fixing a workpiece by a second fixture in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words used, such as "up", "down", "left" and "right", can be the direction of the actual use or working state of the device, can also be the direction of the drawing with reference to the accompanying drawings, and can also refer to two relative directions; while "inside" and "outside" refer to the outline of the device.

[0019] See also Figure 1 and Figure 3 The preferred embodiment of the present application provides a method for processing an annular outer star wheel, comprising the following steps: OP10: Fixing a workpiece 101 on a first fixture 100, wherein the workpiece is roughly annular, having an outer cylindrical surface 102 and an inner cylindrical surface 105, and a first side end surface 103 and a second side end surface 104 located between the outer cylindrical surface 102 and the inner cylindrical surface 105 and arranged opposite to each other, with the outer cylindrical surface 102 serving as a clamping surface and the first side end surface 103 serving as a positioning surface, to clamp the workpiece 101, rough and fine turn the second side end face 104, and rough and fine turn the inner cylindrical surface 105, to provide a precision reference for the subsequent process; OP20: fix the workpiece 101 on the second fixture 200, use the inner cylindrical surface 105 after the previous process as the clamping surface, and use the processed second side end face 104 as the positioning surface to hold the workpiece, rough and fine turn the first side end face 103, rough and fine turn the outer cylindrical surface 102, and rough and fine turn the stop surface 106. This application solves the problem that the annular workpiece is easy to deform and the manual clamping is easy to be out of place, and ensures the technical requirements such as the parallelism of the two end faces of the product, the coaxiality of the inner and outer circles, and the verticality of the end face and the inner hole / outer circle.

[0020] The workpiece material of this application is UC1 (CF53), which is a high-quality medium-carbon steel and a special steel for transmission shafts. It has the characteristics of high strength, high wear resistance and high heat resistance. It can be mainly used in workpieces with large forces, wear resistance and torsion resistance. The workpiece is a hot forging with a ring-shaped shape. Due to the certain draft angle between the outer circle and the inner hole, the overall surface is high in the middle and slightly lower on both sides, and there is a certain depth of defect on the surface. The remaining tolerances are in accordance with the ordinary grade of GB12362-90. Figure 2 The annular outer star wheel is a hot forging workpiece, and the inner cylindrical surface 105, the outer cylindrical surface 102, the first side end surface 103, the second side end surface 104 and the stop surface 106 all need to be turned to achieve the required size and accuracy of the drawing.

[0021] See also Figure 3 In the OP10 process, the first fixture 100 is a back-pull fixture, which has clamping forces in both the X and Z directions, and can simultaneously apply radial and axial forces to the outer circle and end face of the workpiece. Since the back-pull chuck has two force directions, radial force and axial force, the radial force that would otherwise affect the outer circle deformation is reduced by 50% when clamping the workpiece, greatly reducing the deformation of the workpiece and ensuring that the shape and position errors such as the inner hole roundness and verticality are controlled within a very small range (≤0.01mm).

[0022] The back-pull clamp can generate a certain back-pull force after clamping the outer cylindrical surface 102. When clamping, one end face of the workpiece will be forced to be close to the positioning surface to prevent the workpiece from moving due to force during processing and maintain a high degree of stability after processing.

[0023] Continue to see Figure 3 The first fixture 100 has a fixture body 11, wherein an inclined hole 17 is provided inside the fixture body 11, wherein an inclined column 12 is provided in the inclined hole 17, wherein a pull rod 16 is provided in the middle of the fixture body 11, wherein the pull rod 16 is connected to the inclined column 12, and when the pull rod 16 drives the inclined column 12 to move, the first fixture applies radial force and axial force to the workpiece 101 at the same time, and when the workpiece 101 is clamped, the radial force that would otherwise affect the outer diameter deformation is reduced by 50%, thereby minimizing the deformation effect on the workpiece, and ensuring that the shape and position errors such as the roundness and verticality of the inner hole are controlled within a very small range (≤0.01mm). The number of inclined holes 17 and inclined columns 12 is preferably 3, evenly distributed along the circumference.

[0024] A base jaw 14 is provided on the right side of the inclined column, and an auxiliary jaw 15 is provided at the lower right side of the base jaw 14. A first positioning block 13 is provided in the middle of the right side of the back-pull clamp. After any side of the workpiece 101 is placed in the back-pull clamp, the left side of the workpiece 101 fits with the first positioning block 13, and the machine tool cylinder pulls backward, driving the inclined column 12 to move backward through the clamp pull rod 16. Under the action of the inclined hole 17, the base jaw 14 drives the auxiliary jaw 15 to move radially and axially at the same time. The radial movement causes the inner hole to shrink until it hugs the outer cylindrical surface of the workpiece 101, thereby clamping the workpiece 101. The axial movement causes the auxiliary jaw 15 to generate a pulling force to the left, so that the workpiece 101 can be pressed against the first positioning block 13, thereby positioning the workpiece 101. The cutting of the material of the second side end face 104 and the inner cylindrical surface 105 in the grid line area of ​​the workpiece 101 can be automatically completed through the turning program, such as Figure 2 After the processing is completed, the machine tool oil cylinder is pushed forward, which can push the inclined column 12 and drive the base claw 14 and the auxiliary claw 15 to move to the right and spread radially at the same time, so that the workpiece 101 can be removed and the processing of this process is completed.

[0025] The first positioning block 13 is specially provided with a chip removal space 18 to ensure that the iron chips generated during processing can be discharged smoothly, so as to avoid the situation of improper clamping due to residual iron chips during the next processing.

[0026] See also Figure 4 In the OP20 process, the fixture used in the process of turning the second side end face 104, the outer cylindrical surface 102 and the stop surface 106 is the second fixture 200, and the second fixture 200 is an internal expansion and rear pull type fixture, which positions the second side end face 104, and at the same time internally supports and holds the inner cylindrical surface 105, and is equipped with an airtightness detection function, such as Figure 4 As shown, the second positioning block 24 is provided with an airtight detection hole 29 for airtight detection, which can ensure that each clamping is in place (error value ≤ 0.03), so as to ensure that the shape and position tolerances such as the coaxiality, verticality and parallelism of the inner and outer circles are within a very small range (≤ 0.03).

[0027] Continue to see Figure 4 The second fixture 200 has a main body 21, and a boss 26 is provided at the front end of the main body 21. The boss 26 has an outer cone 27, and an equiangular inner cone rubber sleeve 25 matching with the outer cone 27 is provided on the outer side of the outer cone 27. Preferably, the main body 21 is cylindrical as a whole, the outer cone 27 is conical, and the rubber sleeve 25 is a cone evenly distributed in six equal parts. When clamped, the rubber sleeve 25 can contact more than 80% of the surface area of ​​the inner hole of the workpiece 101, and the force is very uniform, which can ensure that the roundness does not deform before and after processing (≤0.005mm). The inner side of the adopted internal support fixture has a conical shape without any dead angles, and the chip removal ability is very outstanding. Almost no iron chips will remain after processing, which is very suitable for the field of automated production.

[0028] The body 21 has a rear end hole 28, in which there is an inner tie rod joint 22, and a coupling ring 23 is provided at the front end of the inner tie rod joint 22, which connects the inner tie rod joint 22 and the rubber expansion sleeve 25, and the inner tie rod joint 22 and the rubber expansion sleeve 25 are linked by the coupling ring 23. A second positioning block 24 is connected to the front end of the body 21 of the second fixture 200, and the second positioning block 24 is used to close the workpiece 101 when the rubber expansion sleeve 25 moves to the left. The inner hole of the workpiece 101 is sleeved on the outside of the rubber expansion sleeve 25, and the machine tool cylinder is pulled back to move the inner tie rod joint 22 to the left. At the same time, the coupling ring 23 is linked with the rubber expansion sleeve 25 to make the rubber expansion sleeve move to the left synchronously. Under the taper of the outer cone surface 27 of the convex column 26 of the body 21, the outer circle of the rubber expansion sleeve 25 expands and tightens the inner hole of the workpiece 101. At the same time, due to the leftward movement of the rubber expansion sleeve 25, the workpiece 101 can be pressed against the second positioning block 24 to achieve the clamping and positioning of the workpiece 101. The material with grid lines in the workpiece 101 can be automatically removed through the turning program, such as Figure 2The outer cylindrical surface 102, the first side end surface 103 and the stop surface 106 of the grid line area are shown. After the processing is completed, the machine tool cylinder is pushed forward, the inner pull rod joint 22 moves to the right, pushing the coupling ring 23 to loosen the rubber expansion sleeve 25, and the workpiece 101 can be removed at this time to complete all processes.

[0029] This application mainly conducts research from the aspect of process methods, aiming to find a processing method suitable for such blanks under the premise of ensuring product quality and customer requirements, with the goal of improving product technical performance, reducing scrap rate, and achieving large-scale stable production capacity. This application solves the problem of easy deformation of annular workpieces and easy misalignment of manual clamping, and ensures the technical requirements such as parallelism of the two end faces of the product, coaxiality of the inner and outer circles, and perpendicularity of the end face to the inner hole / outer circle. This application solves the problem of previous process instability through process innovation, significantly improves product performance and quality, and at the same time reduces production scrap rate, effectively controls processing costs, enhances corporate competitiveness, and is fully prepared for large-scale production in the future. The equipment applicable to this process method can all be standard CNC lathes, and the equipment layout can be more reasonable and compact, providing a good foundation for subsequent automated production solutions. The processing method provided in this application is applicable to various forms of CNC lathes on the market, including standard single-spindle / single-turret CNC lathes, parallel dual-spindle / dual-turret CNC lathes, opposed dual-spindle CNC lathes, inverted CNC lathes, etc., without special configuration requirements, with a very wide range of applications, strong versatility, easy for employees to get started, no need for retraining, and low investment costs. In the OP10 and OP20 processes, the fixtures and processing methods used produce fewer dead angles, good chip removal capabilities, and iron filings are not easily left on the fixtures and workpieces after processing, which is very suitable for automated production.

[0030] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and evolutions of the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for processing an annular outer star wheel, characterized in that: Including the following processes: OP10: Fixing a workpiece on a first fixture, the workpiece being in a circular ring shape and having an outer cylindrical surface and an inner cylindrical surface, and a first side end surface and a second side end surface located between the outer cylindrical surface and the inner cylindrical surface and opposite to each other, using the outer cylindrical surface as a clamping surface and the first side end surface as a positioning surface, clamping the workpiece, performing rough turning and finish turning on the second side end surface, and performing rough turning and finish turning on the inner cylindrical surface; and OP20: Fix the workpiece on the second fixture, use the processed inner cylindrical surface as the holding surface, use the processed second side end surface as the positioning surface, hold the workpiece, perform rough turning and finish turning on the first side end surface, perform rough turning and finish turning on the outer cylindrical surface, and perform rough turning and finish turning on the stop surface.

2. The method for processing the annular outer planetary wheel according to claim 1, characterized in that: The first fixture has a fixture body, an inclined hole is provided inside the fixture body, an inclined column is provided in the inclined hole, a pull rod is provided in the middle of the fixture body, the pull rod is connected to the inclined column, and when the pull rod drives the inclined column to move, the first fixture applies radial force and axial force to the workpiece at the same time.

3. The method for processing the annular outer planetary wheel according to claim 2, characterized in that: A base jaw is provided on the right side of the inclined column, a secondary jaw is provided on the lower right side of the base jaw, and a first positioning block is provided in the middle of the right side of the back-pull clamp; after any side of the workpiece is placed in the back-pull clamp, the left side of the workpiece fits with the first positioning block, the machine tool cylinder pulls backward, and the inclined column is driven to move backward through the clamp pull rod, and under the action of the inclined hole, the base jaw drives the secondary jaw to move radially and axially at the same time; the radial movement causes the inner hole to shrink until it hugs the outer cylindrical surface of the workpiece, thereby achieving the clamping of the workpiece; the axial movement causes the secondary jaw to generate a pulling force to the left, so that the workpiece can be pressed against the first positioning block, thereby achieving the positioning of the workpiece.

4. The method for processing the annular outer planetary wheel according to claim 3, characterized in that: The first positioning block is provided with a chip removal space.

5. The method for processing an annular outer planetary wheel according to claim 1, characterized in that: The second tooling fixture comprises a main body, a boss is provided at the front end of the main body, the boss has an outer cone surface, and an equiangular inner cone rubber expansion sleeve matching the boss is provided on the outer side of the outer cone surface; when clamped, the rubber expansion sleeve contacts more than 80% of the surface area of ​​the inner hole of the workpiece and is subjected to uniform force, thereby ensuring that the roundness does not deform before and after processing; the boss has a conical shape without any dead angle area.

6. The method for processing the annular outer star wheel according to claim 5, characterized in that: The body has a tail end hole, an inner tie rod joint is in the tail end hole, a coupling ring is provided at the front end of the inner tie rod joint, the coupling ring connects the inner tie rod joint and the rubber expansion sleeve, and the inner tie rod joint and the rubber expansion sleeve are linked through the coupling ring.

7. The method for processing the annular outer planetary wheel according to claim 6, characterized in that: A second positioning block is connected to the front end of the body of the second fixture, and the second positioning block is used to press the workpiece tightly when the rubber expansion sleeve moves to the left; the inner hole of the workpiece is sleeved on the outside of the rubber expansion sleeve, and the machine tool cylinder is pulled backward to move the inner pull rod joint to the left, and at the same time, the rubber expansion sleeve is linked to the rubber expansion sleeve through the coupling ring to make the rubber expansion sleeve move to the left synchronously. Under the taper of the outer conical surface of the convex column, the outer circle of the rubber expansion sleeve expands to tighten the inner hole of the workpiece, and at the same time, due to the leftward movement of the rubber expansion sleeve, the workpiece is pressed against the second positioning block.

8. The method for processing an annular outer planetary wheel according to any one of claims 1 to 7, characterized in that: The CNC lathes applicable to this processing method include standard single-spindle / single-turret CNC lathes, parallel double-spindle / double-turret CNC lathes, opposed double-spindle CNC lathes, and inverted CNC lathes.

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