Machining method of clutch gear hub part

Abstract

The invention discloses a method for machining clutch gear hub parts. The method mainly solves the technical problems that an existing method is not suitable for clutch gear hub parts with internal splines of bent structures and the like. The method comprises the following steps: preparing a blank; the end face of the blank is trimmed in a turning mode; an internal spline structure is machined in a cold extrusion mode; the two end faces and the outer circle of the blank piece are trimmed in a turning mode; a radial oil hole is punched in the circumferential direction of the blank piece through a punching tool; the blank piece is internally bent by 90 degrees through an oil press to be machined into a preset bent structure; rough machining is conducted on the bent structure in a turning mode, then a snap spring groove is machined in the corresponding position of the inner spline, and a gear hub semi-finished product is obtained; carrying out tufftriding heat treatment on the gear hub semi-finished product; and an inner hole of the gear hub semi-finished product subjected to heat treatment is turned through an after-heating inner hole turning tool, and a clutch gear hub finished product is obtained. The method is high in machining precision and machining efficiency.

Description

Technical Field

[0001] The invention relates to a method for processing a part, in particular to a method for processing a clutch gear hub part. Background Art

[0002] For clutch hub parts with internal splines, the processing method of the internal splines, process design and control of deformation of thin-walled parts are key. For this structure, the traditional processing method usually uses integral forging blanks, and then turns and electrosparks to process the internal spline structure.

[0003] The Chinese patent with publication number CN109822003A discloses a manufacturing method and structure of a thin-walled gear hub. The method first uses a grinding tool to round the edge of the sheet, then forms a ring body, and then processes the corresponding annular groove, bevel and external spline to achieve the processing of the thin-walled gear hub. This method has improved processing efficiency compared to traditional methods, and the method can also be used to process internal spline structures. However, for clutch gear hub parts with internal splines with bending structures, since such parts also have the processing steps of bending structures and radial oil holes, the above method cannot be applied.

[0004] In addition, the existing method of processing the bending structure is generally carried out by removing materials, which has low material utilization, long time consumption and high cost. At the same time, the clutch gear hub parts with internal splines of the bending structure have a large number of oil holes, which are usually processed by drilling in a machining center. This method has a long processing cycle, low efficiency, and large residual burrs, requiring the assistance of an auxiliary deburring process.

[0005] Therefore, there is an urgent need for a full-process process for clutch hub parts with internal splines of a bending structure to solve the above-mentioned problems. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problems that the existing processing methods are not applicable to clutch hub parts with internal splines of bending structures, or there are low processing efficiency, long time consumption and high cost for bending structures and radial oil holes, and to provide a processing method for clutch hub parts.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for processing a clutch hub part is characterized in that it comprises the following steps:

[0009] Step 1, prepare a corresponding blank according to the structure and size of the clutch hub part; the blank is a thin-walled annular structure, one end of which has a 90° inner bend, and the bend connection is a cambered transition;

[0010] Step 2: trimming the other end surface of the blank by turning; the other end surface is the end away from the bend;

[0011] Step 3: According to preset requirements, an internal spline structure is processed on the inner wall of the blank by cold extrusion;

[0012] Step 4: trimming the two end faces and outer circle of the blank by turning;

[0013] Step 5: Use a punching tool to punch radial oil holes in the circumference of the blank;

[0014] Step 6: Processing the blank with a 90° inward bend into a preset bending structure by using a hydraulic press and a pre-designed concave and convex die; the preset bending structure is bent inward, and one end of the bend is parallel to the side wall of the blank;

[0015] Step 7, rough-machining the bent structure processed in step 6 by turning, leaving a design margin, and then machining a retaining ring groove at a corresponding position on the internal spline to obtain a semi-finished gear hub;

[0016] Step 8, performing soft nitriding heat treatment on the gear hub semi-finished product;

[0017] Step 9, turning the inner hole of the heat-treated gear hub semi-finished product through the post-heat turning inner hole tooling, and removing the excess to obtain the finished clutch gear hub part; the inner hole refers to the inner circular hole formed at the end of the bending structure in the gear hub semi-finished product.

[0018] Furthermore, in step 1, the blank is obtained by processing the raw materials in sequence through hot-rolled steel plates, blanking, and pre-punching.

[0019] Furthermore, in step 3, the preset requirements of the internal spline structure include the shape, size, number of the key teeth and the distance between the roots of two adjacent key teeth.

[0020] Further, in step 5, the punching tool comprises a tool body, a punch installed on the side wall of the tool body, a punching die matched with the punch, a center positioning stopper and a clamping block installed above the tool body;

[0021] The side of the tool body on which the punch is installed is an outwardly convex arc surface, which is used to match the inner circular surface of the workpiece to be processed;

[0022] The head of the punch faces outward and extends radially out of the tooling body; the punching die is arranged close to the head of the punch, and a gap is left between the two; the side of the punching die close to the punch is a concave arc surface, which is used to match the outer cylindrical surface of the workpiece to be processed, and a groove matching the punch head is provided on the concave arc surface of the punching die;

[0023] The center positioning stop is in the shape of a disk and is mounted on the upper part of the tooling body through a bearing, and is used to position the end of the workpiece to be processed with an inner bend;

[0024] The pressing block is located above the central positioning stop and is used to press the end of the workpiece with the inner bend against the upper end surface of the central positioning stop.

[0025] Furthermore, it also includes a distance sensor installed on the side wall of the tooling body, and the distance sensor is used to connect to the driving device that controls the movement of the central positioning stop to detect the punching position of the workpiece to be processed.

[0026] Furthermore, in step 7, rough machining of the bending structure refers to turning the inwardly bent end portion of the bending structure and the outer side surface of the bent portion.

[0027] Further, in step 9, the post-heat turning inner hole tooling includes a chuck, a positioning assembly, a supporting assembly and a permanent magnetic chuck arranged on the chuck;

[0028] The positioning assembly comprises three positioning supports evenly installed above the chuck along the circumferential direction, and the three positioning supports have the same structure; each positioning support comprises a vertical support and a transverse support connected to each other, and the vertical support and the transverse support form an L-shaped structure; the free end of the vertical support faces upward and the inner side surface is a concave arc surface, and the arc surfaces of the three vertical supports form a positioning ring for positioning the outer cylindrical surface of the workpiece to be processed; the free end of the transverse support faces inward and is installed on the upper end surface of the chuck;

[0029] The support assembly comprises three support blocks mounted on the chuck and evenly distributed between the three lateral supports, and the thickness of the three support blocks is consistent with that of the three lateral supports;

[0030] The permanent magnetic suction cup is a circular ring structure, which is located inside the positioning ring, and the outer diameter is adapted to the inner diameter of the positioning ring; the lower end surface of the permanent magnetic suction cup is installed above the horizontal support and the support block, and the upper end surface is lower than the upper end surface of the vertical support; the upper end surface of the permanent magnetic suction cup is used to adsorb the bent end of the workpiece to be processed.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention adopts cold extrusion to process the internal spline, and then processes the bending mechanism through the cold stamping deformation method of the hydraulic press, and then processes the retaining ring groove, performs heat treatment, and uses the hot post-turning inner hole tooling to process the inner hole. The present invention adopts the plastic deformation method of cold extrusion and cold stamping to replace the traditional cutting method to remove materials, thereby improving material utilization and processing efficiency; at the same time, the sequential arrangement of each processing procedure also further ensures the processing accuracy.

[0033] 2. The present invention arranges the processing of the retaining spring groove after the processing of the bending structure, thereby ensuring the position accuracy of the retaining spring groove and further improving the conformity between the finished product and its connecting parts.

[0034] 3. The punching tooling of the present invention has high processing efficiency, precise positioning, and does not require an auxiliary deburring process.

[0035] 4. The post-heat turning inner hole tooling of the present invention performs post-heat turning of the inner hole by means of magnetic suction of the end face, which effectively avoids the influence of the outer circle ellipse on the roundness of the turned inner hole, thereby ensuring that the shape tolerance of the inner hole of the clutch hub part meets the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The figure is a flowchart of an embodiment of the present invention.

[0037] Figure 2 Schematic diagram of the structure of the punching tool used in step 5 of the embodiment of the present invention.

[0038] Figure 3 This is an exploded view of the structure of the hot post turning inner hole tooling used in step 9 of the embodiment of the present invention.

[0039] Figure 4 It is a structural schematic diagram of the workpiece to be processed being installed on the post-heat turning inner hole tooling in step 9 of an embodiment of the present invention.

[0040] Figure 5 It is a schematic diagram of the three-dimensional structure of the clutch hub part prepared according to an embodiment of the present invention.

[0041] Figure 6 This is a cross-sectional structural diagram of a clutch hub component prepared according to an embodiment of the present invention.

[0042] The reference numerals are as follows:

[0043] 1- tooling body, 2- punch, 3- punching die, 4- center positioning stop, 5- clamping block, 6- distance sensor, 7- chuck, 8- permanent magnetic suction cup, 9- positioning support, 10- support block. DETAILED DESCRIPTION

[0044] To make the purpose, advantages and features of the present invention clearer, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood by those skilled in the art that the embodiments of the present invention are only used to explain the technical principles of the present invention, rather than to limit the scope of protection of the present invention.

[0045] This embodiment analyzes the structure of the clutch hub part, which has both a bending structure and an internal spline structure. It is a typical thin-walled part with a wall thickness of only 3.125 mm at its thinnest point and a large overall elliptical deformation. In the process design, it is necessary to consider the processing methods of the internal spline and the end face bending structure, the control of the deformation of the thin-walled part, and the production cost.

[0046] Reference Figure 1 This embodiment provides a method for processing a clutch hub part, which can effectively solve the internal spline and bending structure and effectively control the deformation during the processing. The method includes the following steps:

[0047] Step 1: Prepare the corresponding blank according to the structure and size of the clutch hub parts

[0048] The blank described in this embodiment is a thin-walled annular structure with a 90° inner bend at one end, and the bend connection is an arc transition. The blank is obtained by processing the raw materials in sequence through hot-rolled steel plates, blanking, and pre-punching.

[0049] Step 2: Turning and finishing

[0050] The other end face of the blank is trimmed by turning, where the other end face refers to the end of the blank away from the bend. The preset requirements of the internal spline structure generally include the shape, size, number of key teeth and the spacing between the roots of two adjacent key teeth.

[0051] Step 3: Cold extrusion to form internal splines

[0052] According to the preset requirements, an internal spline structure is processed on the inner wall of the blank by cold extrusion (the inner wall of the bent part is not processed with a spline structure). In this embodiment, the internal spline of the clutch hub part is formed by cold extrusion by positioning the core mold with internal teeth, pressing the pressure block, and axially feeding the three external rotating wheels in an offset manner. It can also be obtained by conventional internal spline cold extrusion.

[0053] Step 4: Turning and trimming (material head)

[0054] The two end faces and outer circle of the blank are trimmed by turning. During the cold extrusion process, the radial and axial dimensions of the blank will change. Therefore, it is necessary to trim the two end faces and outer circle of the blank by turning so that its dimensions meet the standard requirements or the requirements of the corresponding processing parameters. The corresponding allowance is determined according to the specific requirements of the workpiece to be processed.

[0055] Step 5: Use the punching tool to punch radial oil holes in the circumference of the blank.

[0056] Reference Figure 2This embodiment utilizes a punch driven by a cam mechanism and a corresponding punching die to punch radial oil holes. Specifically, the punching tool includes a tool body 1, a punch 2 installed on the side wall of the tool body 1, a punching die 3 adapted to the punch 2, a center positioning stop 4 installed above the tool body 1, and a clamping block 5.

[0057] The tool body 1 is installed on the processing table of the machine tool. The side of the tool body 1 where the punch 2 is installed is an outwardly convex arc surface, which is used to adapt to the inner circular surface of the workpiece to be processed.

[0058] The head of the punch 2 faces outward and extends radially out of the tooling body 1, and the tail of the punch 2 is connected to the output end of the cam mechanism. The punching die 3 is arranged close to the head of the punch 2, and a gap is left between the two, and the gap is used to accommodate the side wall of the workpiece to be processed. The side of the punching die 3 close to the punch 2 is a concave arc surface, which is used to match the outer cylindrical surface of the workpiece to be processed, and the concave arc surface of the punching die 3 is provided with a groove that matches the head of the punch 2.

[0059] The center positioning stop 4 is disc-shaped and is installed above the tooling body 1 through a bearing. It is used to position the end of the workpiece with an inner bend. The center positioning stop 4 can rotate on the tooling body 1, thereby driving the workpiece to be processed to rotate synchronously.

[0060] The clamping block 5 is located above the center positioning stop 4 and is used to clamp the inner-bent end of the workpiece to be processed against the upper end surface of the center positioning stop 4, which is beneficial to ensure the accuracy of punching on the one hand and ensures that the workpiece to be processed is not deformed on the other hand.

[0061] When the punching tool is used, the punch 2 is extended outward by stamping so that its head penetrates the side wall of the workpiece to be processed and then extends into the groove of the punching die 3 to realize the processing of radial oil holes. After that, the processing of oil holes in different positions is realized by rotating or adjusting the position of the workpiece to be processed in the vertical direction. In addition, according to the size requirements of the oil holes, the punch 2 and the corresponding punching die 3 of the corresponding size can be pre-installed and stamped respectively, and the processing of oil holes of different sizes can be completed by a set of through-hole tooling. The single-piece beat of the punching tool can be controlled within 1.5 minutes, which is highly efficient. At the same time, the gap between the punch 2 and the punching die 3 can be adjusted to control burrs, and no auxiliary deburring process is required.

[0062] In addition, the present embodiment also includes a distance sensor 6 installed on the side wall of the tool body 1. The port of the distance sensor 6 is connected to the port of the machine tool through a quick-change socket, and the machine tool is a driving device for the rise / fall / rotation of the central positioning stop 4. The distance sensor 6 determines the punching position of the workpiece by sensing the distance between the tool body 1 and the major and minor diameters of the spline inside the workpiece. The distance sensor 6 is used to find teeth to perform positioning before punching holes, and the end face is pressed and automatically indexed at the same time, thereby improving processing efficiency and processing accuracy.

[0063] Step 6: End bending

[0064] The blank is processed into a preset bending structure with a 90° inward bend by a hydraulic press and a pre-designed concave and convex mold. The preset bending structure is bent inward, and one end of the bend is parallel to the side wall of the blank.

[0065] Step 7: Turning (head + inner groove)

[0066] The bending structure processed in step 6 is rough-machined by turning, and a design margin is left. Then, a retaining ring groove (inner groove) is machined at the corresponding position on the inner spline to obtain a semi-finished gear hub. Rough machining of the bending structure refers to turning the inwardly bent end of the bending structure and the outer side surface of the bent portion. In this embodiment, the processing of the retaining ring groove is placed after the processing of the bending structure, considering the positional relationship between the size of the retaining ring groove and the positional relationship between the rear end face of the bending, so as to ensure the accuracy of the position of the retaining ring groove.

[0067] Step 8: Perform soft nitriding heat treatment on the semi-finished gear hub to increase the hardness of the inner spline surface.

[0068] Step 9: Turn the inner hole of the heat-treated gear hub semi-finished product through the post-heat turning inner hole tooling, and remove the excess to obtain the finished clutch gear hub part. The inner hole here refers to the inner circular hole formed at the end of the bending structure in the gear hub semi-finished product.

[0069] In order to avoid elliptical deformation of the clutch hub parts after heat treatment, this embodiment designs a post-heat turning inner hole tooling, which performs post-heat turning of the inner hole by magnetically attracting the end face, thereby ensuring that the shape tolerance of the inner hole of the clutch hub parts is qualified.

[0070] Reference Figure 3 , Figure 4 The hot post-turning inner hole tooling of this embodiment includes a chuck 7, a positioning component, a supporting component and a permanent magnetic chuck 8 arranged on the chuck 7.

[0071] The positioning assembly includes three positioning supports 9 evenly installed above the chuck 7 along the circumferential direction, and the three positioning supports 9 have the same structure. Each positioning support 9 includes a vertical support and a lateral support connected to each other, and the vertical support and the lateral support form an L-shaped structure; the free end of the vertical support faces upward and the inner side surface is a concave arc surface, and the arc surfaces of the three vertical supports form a positioning ring for positioning the outer cylindrical surface of the workpiece to be processed; the free end of the lateral support faces inward and is installed on the upper end surface of the chuck 7.

[0072] The support assembly includes three support blocks 10 installed on the chuck 7 and evenly distributed between the three lateral supports. The three support blocks 10 have the same thickness as the three lateral supports. The outer end face and inner end face of each support block are arc-shaped, so that they are evenly and spaced apart from the three lateral supports on the chuck.

[0073] The permanent magnetic suction cup 8 is a circular ring structure, which is located inside the positioning ring, and the outer diameter is adapted to the inner diameter of the positioning ring; the lower end face of the permanent magnetic suction cup 8 is installed above the transverse support and the support block 10, and the upper end face is lower than the upper end face of the vertical support; the upper end face of the permanent magnetic suction cup 8 is used to adsorb the bent end of the workpiece to be processed, and the workpiece to be processed is adsorbed by magnetic attraction, and the stability of the positioning of the workpiece to be processed can be improved by adjusting the suction force.

[0074] In this embodiment, when processing the inner hole and inner end face of the workpiece to be processed after heat treatment, pre-centering is performed through the positioning component, that is, the outer circle of the workpiece to be processed is clamped with a low clamping force of 0.8Mpa, and at the same time, the end face of the workpiece to be processed with a bent end is lightly magnetically sucked in through the permanent magnetic suction cup 8, thereby completing the pre-fixing process.

[0075] After that, the lateral supports of the three positioning supports 9 are loosened from the chuck 7 to separate them from the outer circle of the workpiece to be processed, and then the suction force of the permanent magnetic chuck 8 is increased, and then the inner hole with one bent end and the bent inner end are processed by turning, and the excess is removed to obtain the clutch hub part. This tooling can effectively avoid the influence of the outer circle ellipse on the roundness of the turned inner hole and ensure the conformity of the product.

[0076] Figure 5 , Figure 6 This is a schematic diagram of the finished product of the clutch hub part obtained by the processing method of this embodiment. After completing the above processing, the clutch hub part is subjected to a comprehensive inspection of the finished product according to the process requirements. If it is qualified, the processing is completed. If it is unqualified, corresponding processing is carried out according to relevant requirements.

[0077] This embodiment first uses a steel plate pre-punched blank, then uses cold extrusion to form the internal spline of the clutch hub part, and then uses stamping deformation to process the end face bending mechanism. Plastic deformation methods such as cold extrusion and cold stamping replace cutting to remove materials, thereby improving material utilization and processing efficiency. At the same time, this processing method completely solves the production of such clutch hub parts and effectively ensures quality stability.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for processing a clutch hub part, characterized in that: The following steps are involved: Step 1, prepare a corresponding blank according to the structure and size of the clutch hub part; the blank is a thin-walled annular structure, one end of which has a 90° inner bend, and the bend connection is a cambered transition; Step 2: trimming the other end surface of the blank by turning; the other end surface is the end away from the bend; Step 3: According to preset requirements, an internal spline structure is processed on the inner wall of the blank by cold extrusion; Step 4: trimming the two end faces and outer circle of the blank by turning; Step 5: Use a punching tool to punch radial oil holes in the circumference of the blank; Step 6: Processing the blank with a 90° inward bend into a preset bending structure by using a hydraulic press and a pre-designed concave and convex die; the preset bending structure is bent inward, and one end of the bend is parallel to the side wall of the blank; Step 7, rough-machining the bent structure processed in step 6 by turning, leaving a design margin, and then machining a retaining ring groove at a corresponding position on the internal spline to obtain a semi-finished gear hub; Step 8, performing soft nitriding heat treatment on the gear hub semi-finished product; Step 9, turning the inner hole of the heat-treated gear hub semi-finished product through the post-heat turning inner hole tooling, and removing the excess to obtain the finished clutch gear hub part; the inner hole refers to the inner circular hole formed at the end of the bending structure in the gear hub semi-finished product.

2. The method for processing a clutch hub component according to claim 1, characterized in that: In step 1, the blank is obtained by processing the raw materials in sequence through hot-rolled steel plates, blanking, and pre-punching.

3. The method for processing a clutch hub component according to claim 2, characterized in that: In step 3, the preset requirements of the internal spline structure include the shape, size, number of key teeth and the distance between the roots of two adjacent key teeth.

4. The clutch hub component processing method according to claim 1, characterized in that: In step 5, the punching tool comprises a tool body (1), a punch (2) mounted on the side wall of the tool body (1), a punching die (3) matched with the punch (2), a center positioning stop (4) and a pressing block (5) mounted above the tool body (1); The side of the tool body (1) on which the punch (2) is mounted is an outwardly convex arc surface, which is used to match the inner circular surface of the workpiece to be processed; The head of the punch (2) faces outward and extends radially out of the tooling body (1); the punching die (3) is arranged close to the head of the punch (2), and a gap is left between the two; the side of the punching die (3) close to the punch (2) is a concave arc surface, which is used to match the outer cylindrical surface of the workpiece to be processed, and a groove matching the head of the punch (2) is provided on the concave arc surface of the punching die (3); The center positioning stop (4) is in the shape of a disk and is mounted on the upper side of the tooling body (1) via a bearing, and is used to position the end of the workpiece to be processed with an inner bend; The pressing block (5) is located above the central positioning stop (4) and is used to press the end of the workpiece with the inner bend against the upper end surface of the central positioning stop (4).

5. The clutch hub component processing method according to claim 4, characterized in that: It also includes a distance sensor (6) installed on the side wall of the tool body (1), and the distance sensor (6) is used to connect to a driving device that controls the movement of the central positioning stop (4) to detect the punching position of the workpiece to be processed.

6. The method for machining a clutch hub component according to claim 5, characterized in that: In step 7, rough machining of the bending structure refers to turning the inwardly bent end portion of the bending structure and the outer side surface of the bent portion.

7. The method for machining a clutch hub component according to claim 6, characterized in that: In step 9, the post-heat turning inner hole tooling includes a chuck (7), a positioning assembly, a supporting assembly and a permanent magnetic chuck (8) arranged on the chuck (7); The positioning assembly comprises three positioning support members (9) uniformly installed above the chuck (7) along the circumferential direction, and the three positioning support members (9) have the same structure; each positioning support member (9) comprises a vertical support and a transverse support connected to each other, and the vertical support and the transverse support form an L-shaped structure; the free end of the vertical support faces upward and the inner side surface is a concave arc surface, and the arc surfaces of the three vertical supports form a positioning ring for positioning the outer cylindrical surface of the workpiece to be processed; the free end of the transverse support faces inward and is installed on the upper end surface of the chuck (7); The support assembly comprises three support blocks (10) mounted on the chuck (7) and evenly distributed between the three lateral supports, and the thickness of the three support blocks (10) is consistent with that of the three lateral supports; The permanent magnetic suction cup (8) is a circular ring structure, which is located inside the positioning ring, and the outer diameter is matched with the inner diameter of the positioning ring; the lower end surface of the permanent magnetic suction cup (8) is installed above the transverse support and the support block (10), and the upper end surface is lower than the upper end surface of the vertical support; the upper end surface of the permanent magnetic suction cup (8) is used to absorb the bent end of the workpiece to be processed.

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