An inner and outer tooth forming device and method for a clutch hub

Abstract

The present application provides a kind of inner and outer tooth forming device and method of clutch hub, including die, the inside of the die is provided with reverse block for fixing blank, the upper side of the reverse block is equipped with bulging forming assembly or stamping forming assembly, the bulging forming assembly includes punch slider and driving mechanism for driving the radial movement of the punch slider, the stamping forming assembly includes punch that can be installed on press, the circumferential side of the punch is equipped with second forming part same with the shape of the internal tooth of target part, the bottom end outside of the punch is equipped with guide belt connected with second forming part;The present application has the following beneficial effects: the present application adopts bulging and stamping compound forming method, promotes the flow of blank material in the fillet portion, reduces the fillet gap at the fillet, not only effectively improves the filling quality of clutch hub class parts at the fillet, but also effectively avoids the generation of folding defects at the tooth shape inside close to the tooth root portion in the forming process.

Description

Technical Field

[0001] This invention relates to the field of forming technology for internal and external tooth profiles, and in particular to a device and method for forming internal and external teeth of a clutch hub. Background Technology

[0002] As a crucial core component in automotive transmissions, the clutch hub plays a vital role in the transmission of automotive power. Because it must withstand impact loads during operation, its forming precision and quality directly affect the smoothness of system operation and the comfort of shifting. As a type of thin-walled rotating part, the clutch hub is difficult to form. Its typical geometric features are circumferentially uniformly distributed tooth grooves and tooth walls with uniformly varying thickness. Since the transmission of clutch power relies on the tooth profile with varying sidewall thickness, the forming method of the hub, especially the forming method of the sidewall tooth profile, has always been of great interest.

[0003] Currently, the more mature clutch gear hub forming methods on the market include Grob roll forming, Schuler roller forming, LEIFELD spinning forming, and stamping forming. Among them, roll forming and roller forming have good forming accuracy, but their molds have complex structures and expensive equipment. In comparison, spinning process has lower cost, but it also has problems with lower forming efficiency and poor tooth filling quality. Among the above processes, stamping forming has a simple structure, lower equipment cost, and higher forming efficiency, but it also has potential risks such as surface roughening and cracking. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a device and method for forming internal and external teeth of a clutch hub, which solves the problems of complex structure and poor tooth filling quality in the prior art.

[0005] To achieve the above and other related objectives, the present invention provides the following technical solution:

[0006] A clutch hub gear forming device includes a die, an anti-ejector block for fixing a blank is provided inside the die, an bulging forming assembly or a stamping forming assembly is provided above the anti-ejector block, the bulging forming assembly includes a punch slider and a drive mechanism for driving the punch slider to move radially, the punch slider has a first forming part with the same tooth shape as the inside of the target part on its periphery, the stamping forming assembly includes a punch that can be mounted on a press, the punch has a second forming part with the same tooth shape as the inside of the target part on its periphery, and a guide band connected to the second forming part is provided on the outer side of the bottom end of the punch, the size of the guide band is smaller than the internal size of the target part.

[0007] In one embodiment of the present invention, the inner side of the top end of the die is provided with a first guide section, and the outer side of the bottom end of the punch is provided with a second guide section connected to the guide strip. The first guide section and the second guide section are both rounded, and the interior of the die is a die cavity with the external tooth shape of the target part.

[0008] In one embodiment of the present invention, the anti-ejection block includes a support column in contact with the blank and an ejector rod mounted on the support column. The end of the ejector rod away from the support column is mounted on a hydraulic press. In this technical solution, the anti-ejection block can move up and down under the action of the hydraulic press, thereby driving the blank to move up and down in the die cavity.

[0009] In one embodiment of the present invention, the punch slider includes a first slider and a second slider integrally formed with the first slider. The first slider has a first inclined surface on its inner side and a guide block located on the side of the second slider on its bottom side. The first forming part is disposed on the outer side of the second slider.

[0010] In one embodiment of the present invention, the driving mechanism includes a guide post and a mandrel that can be mounted on a press. The bottom periphery of the mandrel is provided with a second inclined surface corresponding to the first inclined surface. The second inclined surface matches the first inclined surface and is slidably connected to the first inclined surface. A groove is provided at the center of the bottom of the mandrel that is slidably connected to the guide post. In this technical solution, the mandrel moves up and down under the action of the press, thereby causing the second inclined surface to press the first inclined surface, driving the punch slider to move radially on the guide plate, thus achieving the purpose of bulging the bottom tooth shape of the blank.

[0011] In one embodiment of the present invention, the driving mechanism further includes a guide plate, on which a limiting groove is formed corresponding to the guide block. The guide block matches the limiting groove and is slidably connected to the limiting groove. A mounting hole for mounting a guide post is also formed at the center of the guide plate. In this technical solution, the sliding of the guide block in the limiting groove makes the radial movement of the punch slider on the guide plate more stable.

[0012] In one embodiment of the present invention, the support column is provided with a plurality of first pins corresponding to the process holes on the blank, and the guide plate is provided with a plurality of second pins corresponding to the process holes on the blank on the side away from the limiting groove. In this technical solution, the first pins can initially fix the blank on the anti-top block, and the second pins can further fix the blank on the anti-top block.

[0013] A method for forming the inner and outer teeth of a clutch hub according to any of the preceding claims, comprising an expansion forming process and a stamping forming process.

[0014] In one embodiment of the present invention, the bulging forming process includes: positioning the blank by means of a first pin on the anti-top block and a second pin on the guide plate; the mandrel moving downward under the action of the press causing the punch slider to slide radially; and the bulging forming of the bottom tooth shape of the blank being completed under the action of the punch slider and the die.

[0015] In one embodiment of the present invention, the stamping forming process includes: positioning the blank by means of a first pin on the anti-ejector block, and the punch moving downward under the action of a hydraulic press so that the blank passes through the concave mold cavity to form the inner and outer tooth shape of the blank.

[0016] As described above, the clutch hub internal and external tooth forming device and method of the present invention have the following beneficial effects:

[0017] This invention employs a combined bulging and stamping forming method, enabling the blank to sequentially undergo a process of partial external bulging of the bottom tooth shape and stamping to form the material. Compared to the traditional multi-step process of blanking and bulging forming, this invention only bulges the tooth root portion of the blank, promoting material flow in the rounded corners, reducing the rounded corner gaps, and effectively improving the filling quality of the rounded corners of clutch hub-type parts. Furthermore, bulging only the tooth root portion of the blank avoids the phenomenon of excessive bulging force during simple external bulging forming. In the stamping process, a specific structural feature is added to the punch, namely, a guide strip is added to the bottom of the punch, and the size of the guide strip is smaller than the internal size of the target part. Therefore, it effectively avoids the generation of folding defects near the tooth root portion inside the tooth shape during forming. This invention achieves good tooth filling quality with a simple structure, making it easy to promote and use. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the target part in the clutch hub internal and external tooth forming device disclosed in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the blank in the internal and external gear forming device of the clutch hub disclosed in an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the complete forming process of the inner and outer tooth profiles in the inner and outer tooth forming device of the clutch hub disclosed in the embodiments of the present invention.

[0021] Figure 4 This is a schematic diagram of the apparatus corresponding to the expansion forming process in the clutch hub internal and external tooth forming method disclosed in this embodiment of the invention.

[0022] Figure 5 This is a schematic diagram of the apparatus corresponding to the stamping forming process in the clutch hub internal and external tooth forming method disclosed in the embodiments of the present invention.

[0023] Figure 6 This is a three-dimensional (top) and front cross-sectional (bottom) view of the die in the clutch hub inner and outer tooth forming device disclosed in the embodiments of the present invention.

[0024] Figure 7 This is a three-dimensional schematic diagram of the anti-top block in the internal and external tooth forming device of the clutch hub disclosed in an embodiment of the present invention.

[0025] Figure 8 This is a three-dimensional schematic diagram of the guide plate in the internal and external tooth forming device of the clutch hub disclosed in an embodiment of the present invention.

[0026] Figure 9 This is a three-dimensional schematic diagram of the punch slider in the clutch hub internal and external tooth forming device disclosed in the embodiments of the present invention.

[0027] Figure 10 This is a three-dimensional schematic diagram of the mandrel in the clutch hub internal and external tooth forming device disclosed in an embodiment of the present invention.

[0028] Figure 11 This is a three-dimensional (top) and front cross-sectional (bottom) view of the punch in the clutch hub internal and external tooth forming device disclosed in an embodiment of the present invention.

[0029] Figure 12 The clutch hub internal and external gear forming device disclosed in the embodiments of the present invention. Figure 11 Enlarged view of point A in the middle;

[0030] Figure 13 This is a schematic diagram of the final forming effect of the inner and outer tooth profiles of the clutch hub inner and outer tooth forming device disclosed in the embodiments of the present invention.

[0031] Component designation explanation

[0032] 1. Die cavity; 101. First lead-in section; 102. Die cavity; 2. Ejector block; 201. Support column; 202. Ejector pin; 203. First pin; 3. Blank; 4. Guide plate; 401. Limiting groove; 402. Mounting hole; 403. Second pin; 5. Punch slider; 501. First slider component; 502. Second slider component; 503. First inclined surface; 504. Guide block; 505. First forming part; 6. Mandrel; 601. Second inclined surface; 602. Slide groove; 7. Guide post; 8. Punch; 801. Second forming part; 802. Guide strip; 803. Second lead-in section. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. It should be noted that, unless otherwise specified, the following embodiments and features described herein can be combined with each other.

[0034] The target part in this invention is a clutch hub-type part, and its dimensions and shape are as follows: Figure 1 As shown, it is a thin-walled cylindrical part with internal and external teeth; the blank 3 used in this invention is a pre-made toothed part with wavy teeth after stamping, and its size and shape are as follows. Figure 2 As shown, the prefabricated toothed part has larger inner and outer radii compared to the target part.

[0035] The complete forming process of the clutch hub-type parts involved in this invention is as follows: Figure 3 As shown, the sheet metal is processed into a circular blank by wire cutting or other methods, and then a cylindrical part is obtained by thinning and deep drawing or spinning. The cylindrical part is then pre-stamped to obtain a pre-toothed part with pre-made teeth. The toothed pre-made blank is then subjected to the bulging and stamping composite forming process proposed in this invention to obtain the final internal and external toothed part, which is the target part.

[0036] Please see Figures 4 to 7 The first embodiment of the present invention relates to an internal and external gear forming device for a clutch hub, including a die 1. The top inner side of the die 1 is provided with a first introductory section 101 with a rounded corner, and the interior of the die 1 is a die cavity 102 with the external tooth shape of the target part. A counter-ejector block 2 for fixing a blank 3 is provided inside the die 1. The counter-ejector block 2 includes a support column 201 in contact with the blank 3 and an ejector rod 202 mounted on the support column 201. The end of the ejector rod 202 away from the support column 201 is mounted on a hydraulic press. An expansion forming component or a stamping forming component is provided above the counter-ejector block 2. The counter-ejector block 2 can move up and down under the action of the hydraulic press, thereby driving the blank 3 to move up and down in the die 1.

[0037] Please see Figure 4 , Figure 9 and Figure 10The bulging forming assembly includes a punch slider 5 and a drive mechanism for driving the punch slider 5 to move radially. The punch slider 5 has a first forming portion 505 on its periphery that has the same tooth shape as the inside of the target part. The punch slider 5 includes a first slider part 501 and a second slider part 502 integrally formed with the first slider part 501. The inner side of the first slider part 501 has a first inclined surface 503, and the bottom side of the first slider part 501 has a guide block 504 located on the side of the second slider part 502. The first forming portion 505 is disposed on the second slider part 502. On the outside of 02, the drive mechanism includes a guide post 7 and a mandrel 6 that can be mounted on the press. The guide post 7 ensures that the mandrel 6 can move up and down in the vertical direction. The bottom periphery of the mandrel 6 is provided with a second inclined surface 601 corresponding to the first inclined surface 503. The second inclined surface 601 matches the first inclined surface 503 and is slidably connected to the first inclined surface 503. The inclination angle of the first inclined surface 503 and the second inclined surface 601 is 45 degrees. A groove 602 that is slidably connected to the guide post 7 is provided at the center of the bottom of the mandrel 6.

[0038] Please see Figure 7 , Figure 8 and Figure 10 The driving mechanism also includes a guide plate 4, on which a limiting groove 401 is provided corresponding to the guide block 504. The guide block 504 matches the limiting groove 401 and is slidably connected to the limiting groove 401. A mounting hole 402 for mounting the guide post 7 is also provided at the center of the guide plate 4. The mandrel 6 moves up and down under the action of the press, thereby causing the second inclined surface 601 to press against the first inclined surface 503, and then driving the guide block 504 on the punch slider 5 to slide radially within the limiting groove 401 on the guide plate 4. The movement achieves the purpose of bulging the bottom tooth shape of the blank 3. The support column 201 is provided with a number of first pins 203 corresponding to the process holes on the blank 3. The guide plate 4 is provided with a number of second pins 403 corresponding to the process holes on the blank 3 on the side away from the limiting groove 401. There are three first pins 203 and three second pins 403. There are six process holes on the blank 3. The first pins 203 can initially fix the blank 3 on the anti-top block 2, and the second pins 403 can further fix the blank 3 on the anti-top block 2.

[0039] Please see Figure 5 , Figure 11 and Figure 12The stamping forming assembly includes a punch 8 that can be mounted on a press. The punch 8 has a second forming part 801 on its periphery that has the same shape as the internal tooth shape of the target part. The bottom outer side of the punch 8 has a guide band 802 connected to the second forming part 801. The size of the guide band 802 is smaller than the internal size of the target part. The bottom outer side of the punch 8 has a second introductory section 803 with rounded corners connected to the guide band 802. The punch 8 moves down under the action of the hydraulic press, so that the blank 3 passes through the die cavity 102 to complete the forming of the internal and external tooth shape of the blank 3. And because the size of the guide band 802 is smaller than the internal size of the target part, the folding defect near the tooth root inside the tooth shape is effectively avoided during the forming process.

[0040] Please see Figure 4 and Figure 5 The second embodiment of the present invention relates to a method for forming the inner and outer teeth of a clutch hub, including an expansion forming process and a stamping forming process. The blank 3 is positioned by the first pin 203 on the anti-ejector block 2 and the second pin 403 on the guide plate 4. The mandrel 6 moves down under the action of the press, causing the punch slider 5 to slide radially. Under the action of the punch slider 5 and the die 1, the bottom tooth shape of the blank 3 is expanded. The stamping forming process includes: the blank 3 is positioned by the first pin 203 on the anti-ejector block 2, and the punch 8 moves down under the action of the hydraulic press, causing the blank 3 to pass through the die cavity 102 to form the inner and outer tooth shape of the blank 3.

[0041] Specifically, during the forming process of the blank 3, in the bulging process, the counter-pushing force of the counter-pushing block 2 is needed to keep the position of the counter-pushing block unchanged. First, three first pins 203 are inserted into the three process holes at the bottom of the blank 3, thereby initially fixing the blank 3 onto the counter-pushing block 2. Then, under the action of the hydraulic press, the counter-pushing block 2 drives the blank 3 downwards until the upper surface of the blank 3 is flush with the upper surface of the die 1. Then, three second pins 403 on the guide plate 4 are inserted into the other three process holes at the bottom of the blank, thereby further fixing the blank 3. At this time, the press drives the mandrel. 6. The mandrel 6 moves downward, and at this time, the mandrel 6 slides downward on the guide post 7. At the same time, the second inclined surface 601 slides on the first inclined surface 503 and squeezes the first inclined surface 503, thereby driving the guide block 504 on the punch slider 5 to slide radially in the limiting groove 401. When the set displacement is reached, part of the tooth forming is completed. The downward movement speed of the press should be 1 to 10 mm / s. Then the press drives the mandrel 6 to move upward, and the punch slider 5 and the guide plate 4 are rotated as a whole and aligned with the unformed area at the bottom of the blank 3. The forming process is repeated to complete the external expansion forming of all the teeth at the bottom of the blank 3.

[0042] In the stamping process, three first pins 203 are first inserted into the three process holes at the bottom of the blank 3 to fix the blank 3 onto the ejector block 2. Then, the press drives the punch 8 to move down until it contacts the upper bottom surface inside the blank 3, and continues to move down until the blank 3 is completely inside the die 1, completing the forming of the remaining tooth shape except for the expansion forming area. The press's downward movement speed is set to 1-5 mm / s. After forming, the punch 8 returns, and the blank 3 and the ejector block 2 are ejected under the action of the ejector force, completing the final tooth shape part removal. The ejector block 2 has an ejector force, that is, the hydraulic press also drives the ejector block 2 to move up, but the value of the ejector force is much smaller than the pressure value of the press. The function of the ejector force is to fix the blank 3 more firmly onto the ejector block 2.

[0043] Furthermore, numerical simulations have verified that the aforementioned technical methods, under certain frictional conditions (friction coefficient of die 1 is 0.1, friction coefficient of punch 8 is 0.12), can significantly reduce the maximum fillet clearance at the inner and outer corners of the toothed part: the initial maximum inner and outer fillet clearances of the toothed preform were 0.221mm and 0.161mm, respectively. After the above forming process, the final maximum inner and outer fillet clearances of the toothed part were reduced to 0.076mm and 0.129mm, respectively, representing reductions of 65.6% and 19.9%, without any defects such as folding or breakage. Specific forming effects are as follows: Figure 13 As shown, Figure 13 In the diagram, (a) is the cross-section of the bulging part, and (b) is the cross-section of the stamping part.

[0044] This invention employs a combined bulging and stamping forming method, enabling the blank 3 to sequentially undergo a process of partial external bulging of the bottom tooth shape and stamping to form the material. Compared to the traditional multi-step process of blanking and bulging forming, this invention only bulges the tooth root portion of the blank 3 through the bulging forming process. This promotes the flow of material in the rounded corner portion of the blank 3, reduces the rounded corner gap, and effectively improves the filling quality of the rounded corners of clutch hub-type parts. Furthermore, bulging only the tooth root portion of the blank 3 avoids the phenomenon of excessive bulging force during simple external bulging forming. In the stamping process, a specific structural feature is added to the punch, namely, a guide strip 802 is added to the bottom of the punch. The size of the guide strip 802 is smaller than the internal size of the target part, thus effectively avoiding the generation of folding defects near the tooth root portion inside the tooth shape during the forming process. This invention achieves good tooth filling quality with a simple structure, making it easy to promote and use.

[0045] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. All equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. A device for forming internal and external teeth of a clutch hub, comprising a die (1), characterized in that: The interior of the die (1) is provided with a counter-ejector block (2) for fixing the blank (3). Above the counter-ejector block (2) is a bulging forming component or a stamping forming component. The bulging forming component includes a punch slider (5) and a driving mechanism for driving the punch slider (5) to move radially. The periphery of the punch slider (5) is provided with a first forming part (505) that has the same tooth shape as the inside of the target part. The stamping assembly includes a punch (8) that can be mounted on a press. The punch (8) has a second forming part (801) on its periphery that has the same tooth shape as the inside of the target part. The bottom outer side of the punch (8) has a guide strip (802) that is connected to the second forming part (801). The size of the guide strip (802) is smaller than the internal size of the target part. The top inner side of the die (1) has a first inlet section (101). The bottom outer side of the punch (8) has a second inlet section (803) that is connected to the guide strip (802). The first inlet section (101) and the second inlet section (803) are both rounded.

2. The internal and external gear forming device for a clutch hub according to claim 1, characterized in that: The interior of the die (1) is a die cavity (102) with the external tooth shape of the target part.

3. The internal and external gear forming device for a clutch hub according to claim 1, characterized in that: The anti-top block (2) includes a support column (201) in contact with the blank (3) and a top rod (202) mounted on the support column (201), with the end of the top rod (202) away from the support column (201) mounted on a hydraulic press.

4. The internal and external gear forming device for a clutch hub according to claim 3, characterized in that: The punch slider (5) includes a first slider (501) integrally formed with the first slider (501) and a second slider (502). The first slider (501) has a first inclined surface (503) on its inner side and a guide block (504) located on the side of the second slider (502) on its bottom side. The first forming part (505) is located on the outer side of the second slider (502).

5. The internal and external gear forming device for a clutch hub according to claim 4, characterized in that: The driving mechanism includes a guide post (7) and a mandrel (6) that can be mounted on a press. The bottom periphery of the mandrel (6) is provided with a second inclined surface (601) corresponding to the first inclined surface (503). The second inclined surface (601) matches the first inclined surface (503) and is slidably connected to the first inclined surface (503). A groove (602) that is slidably connected to the guide post (7) is provided at the center of the bottom of the mandrel (6).

6. The internal and external gear forming device for a clutch hub according to claim 5, characterized in that: The driving mechanism also includes a guide plate (4), on which a limiting groove (401) is provided corresponding to the guide block (504). The guide block (504) matches the limiting groove (401) and the guide block (504) is slidably connected to the limiting groove (401). The guide plate (4) also has a mounting hole (402) for installing the guide post (7) at its center.

7. The internal and external gear forming device for a clutch hub according to claim 6, characterized in that: The support column (201) is provided with a number of first pins (203) corresponding to the process holes on the blank (3), and the guide plate (4) away from the limiting groove (401) is provided with a number of second pins (403) corresponding to the process holes on the blank (3).

8. A method for forming the internal and external teeth of a clutch hub, characterized in that: The internal and external gear forming apparatus for a clutch hub according to any one of claims 5 to 7 includes an expansion forming process and a stamping forming process.

9. The method for forming internal and external teeth of a clutch hub according to claim 8, characterized in that: The bulging forming process includes: positioning the blank (3) by the first pin (203) on the anti-top block (2) and the second pin (403) on the guide plate (4); the mandrel (6) moves down under the action of the press, causing the punch slider (5) to slide radially; and the bottom tooth shape of the blank (3) is bulged under the action of the punch slider (5) and the die (1).

10. The method for forming internal and external teeth of a clutch hub according to claim 8, characterized in that: The stamping process includes: positioning the blank (3) by the first pin (203) on the anti-top block (2), and the punch (8) moving down under the action of the hydraulic press so that the blank (3) passes through the concave mold cavity (102) to complete the forming of the inner and outer tooth shape of the blank (3).

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