A forming device and forming method applied to a toothed hub type tooth-shaped part
By using a composite forming device and method, combining stamping forming with extrusion and upsetting deformation using a core die, inner die, outer die and anti-top punch, the problems of low material utilization and poor precision of toothed parts such as gear hubs are solved, and efficient and low-cost tooth forming is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BAOSHAN IRON & STEEL CO LTD
- Filing Date
- 2022-06-29
- Publication Date
- 2026-05-19
AI Technical Summary
Existing machining processes for toothed hub parts suffer from problems such as low material utilization, easy damage to material fibers, poor product precision, complex motion mechanisms, expensive equipment, process filling properties greatly affected by friction factors, and difficulty in mass production.
A composite forming device and method are adopted, including a core mold, an inner die, an outer die, and a counter-top punch. By combining stamping forming with extrusion and upsetting deformation, the precise manufacturing of toothed parts such as hubs is achieved, improving the filling rate of internal and external tooth profiles and forming efficiency.
It improves the forming efficiency and quality of gear hub parts, reduces equipment and part costs, and is applicable to the forming of gear hub parts with various tooth shapes. It solves the problems of complex forming equipment, incomplete tooth filling and low forming efficiency in the existing technology.
Smart Images
Figure CN117340176B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of machining mechanical parts, and more particularly to a forming apparatus and method for machining toothed parts such as gear hubs. Background Technology
[0002] The so-called gear hub type part refers to a thin-walled cylindrical complex part with internal and external tooth profiles. This type of part is widely used in the transmission systems of automobiles such as dual-clutch transmissions or automatic transmissions, and is an important part for transmitting motion and load.
[0003] As the supporting structure for clutch friction plates and steel plates, the precision and strength of gear hub parts directly affect the performance and lifespan of automotive clutches. High-end automotive clutches place even more stringent requirements on the forming precision of these parts.
[0004] The older manufacturing method for gear hub parts under current technology is to use a gear shaper. A gear shaper is a machine that uses a gear shaper cutter as a cutting tool to process the tooth shape of gears, racks, etc. During gear shaping, the gear shaper cutter makes a reciprocating cutting motion and rolls relative to the workpiece to produce the required gear hub parts.
[0005] Based on the observations of on-site workers after prolonged use, gear shaper processing suffers from problems such as low material utilization, easy damage to material fibers, and poor product precision due to its structure and inherent precision issues. Therefore, gear shapers have gradually begun to be phased out of the manufacturing field of gear hub parts. In recent years, plastic forming processing methods have been applied internationally to process such parts in order to improve the quality of the parts and the material utilization rate.
[0006] Currently, the more mature plastic forming methods for clutch hub-type toothed parts include Grob forming, roller extrusion forming, and spin forming. Each of these three forming methods has its own advantages and disadvantages, as follows:
[0007] 1. Grob forming and roller roll forming are two forming methods with good forming accuracy, but their motion mechanisms are complex, maintenance is difficult, and the equipment is expensive.
[0008] 2. Compared to the previous two processes, the equipment cost of spinning is relatively lower, but it has the disadvantages of lower forming efficiency and insufficient forming accuracy.
[0009] In addition to the three plastic forming methods mentioned above, stamping is also used to manufacture gear hub parts. This is mainly because stamping has the advantages of simple mechanism, low equipment cost, and high forming efficiency. However, gear hub parts, especially clutch gear hub parts, have dense serrated teeth arranged in the circumference of the parts, and the tooth shape and tooth wall have very demanding shape, size and surface requirements. Stamping is prone to problems such as material cracking, surface roughening and insufficient forming filling quality. Therefore, traditional stamping process is still difficult to apply to the processing of gear hub parts.
[0010] Patent No. 201610223506.8 discloses a progressive pultrusion forming apparatus for a clutch hub, comprising: a punch portion located at the bottom and a corresponding die portion located at the top and connected to a press, wherein the die portion includes a die with a variable cross-section cavity. By placing the drawn cylindrical part in the punch portion and driving the die portion downward by the press, gear forming is achieved in a single operation. This application adopts a stamping processing method, and its die has a longitudinally undulating variable cross-section structure, which enables single-pass deep drawing-extrusion composite forming of the gear hub, effectively improving forming efficiency. However, significant longitudinal flow of material still occurs during the deep drawing process, and the process filling is greatly affected by factors such as friction.
[0011] Patent 201911245073.6 discloses a clutch hub tooth profile axial multi-point roll forming device. This application proposes a tooth hub axial multi-point extrusion forming method. It adopts servo control of the rolling device, which can realize the progressive forming of tooth profile features. However, its device structure is complex and the coordination of the forming motion mechanism is required to be high, making it difficult to apply to the mass production of clutch hub tooth profile parts.
[0012] In summary, there is an urgent need for a new type of forming device and forming method for toothed hub-type toothed parts. Summary of the Invention
[0013] To address the problems of low material utilization, easy damage to material fibers, poor product precision, complex motion mechanisms, difficult maintenance, high equipment cost, and the significant impact of friction on process filling in existing gear hub tooth-shaped parts manufacturing processes, as well as the difficulty in applying these technologies to mass production, this invention provides a forming device and method for gear hub tooth-shaped parts. This method enables precise manufacturing of gear hub tooth-shaped parts, improves the filling rate of internal and external teeth, and enhances forming efficiency. It also solves the technical problems of complex forming equipment, incomplete tooth filling, and low forming efficiency in existing clutch gear hub tooth-shaped parts forming processes.
[0014] The present invention provides a forming apparatus and forming method for toothed parts of the gear hub type, the specific structure and steps of which are described below:
[0015] A forming apparatus for toothed parts such as gear hubs, comprising a blank, characterized in that:
[0016] The blank is specifically a cylindrical blank with a process hole at the top and an open bottom. The blank is placed in a forming device assembly, which clamps and fixes the blank. By applying force and pressure to the forming device assembly, the blank is pressed downward into a preset toothed hub-like toothed part.
[0017] According to the present invention, a forming device for toothed parts of the gear hub type is characterized in that the forming device assembly includes a core mold, an upper punch, an inner die, an outer die, and a top punch, wherein the core mold is a stepped cylinder with an external thread on its upper section, and the diameter of the upper section of the core mold is equal to the diameter of the process hole. The upper section of the core mold passes through the process hole and connects to the central threaded hole of the cylindrical upper punch to fix and clamp the blank.
[0018] The diameter of the lower section of the core mold is the same as the inner diameter of the blank. An inner die is provided below the core mold. An inner die through hole is opened in the center of the inner die. The inner die through hole fits with the lower section of the core mold, so that it can slide up and down in the inner die through hole.
[0019] The upper end of the outer cavity of the inner die is provided with a tapered surface with an inclination, and the inner surface of the outer die body of the inner die below the tapered surface is provided with a toothed surface of the preset target toothed hub part.
[0020] An inner die is located inside an outer die. The outer die is cylindrical in shape, and the upper part of the outer die is a cylindrical cavity with a diameter equal to the outer diameter of the blank. A slope is provided below the cylindrical cavity, which corresponds to the conical surface of the inner die. The connection is made with rounded corners. The lower part of the outer die is the outer surface tooth shape of the preset target toothed hub. The outer surface tooth shape mates with the inner surface tooth shape of the inner die to form the preset target toothed hub.
[0021] The anti-ejection punch is located in the space between the inner surface tooth profile and the outer surface tooth profile. The lower end of the anti-ejection punch is flush with the bottom surface of the inner and outer dies. The anti-ejection punch has a structure with a preset target tooth profile, that is, the anti-ejection punch can slide up and down in the space between the inner surface tooth profile and the outer surface tooth profile.
[0022] The anti-ejection punch acts like a plug. As the blank is deformed by stamping, it comes into contact with the anti-ejection punch. The anti-ejection punch bears the load pressure and provides reverse pressure to the blank. As the pressure increases until it exceeds the set threshold, the hydraulic device drives the anti-ejection punch downward. The blank enters the stable deformation stage, the upper punch reaches the preset stroke, and the blank completes the preset overall deformation, that is, the forming of the inner and outer tooth profiles of the gear hub is completed, turning it into a finished product.
[0023] According to the present invention, a forming apparatus for toothed parts of the gear hub type is characterized in that the core mold, inner die, and outer die together form a forming cavity, and the shape of the forming cavity changes as the upper punch applies force and presses down to slide the core mold into the inner die; the thickness and slope of the bridge portion of the toothed part of the gear hub type are adjusted by changing the assembly height of the inner die and the outer die or the slope of the conical surface and the inclined surface; and the forming of parts adapted to different preset target toothed parts of the gear hub type is achieved by adjusting the inner surface tooth shape of the inner die and the outer surface tooth shape of the outer die.
[0024] A forming method for toothed parts of the gear hub type, based on the aforementioned forming apparatus for toothed parts of the gear hub type, comprises the following specific steps:
[0025] 1) Place the blank through the process hole at its top onto the upper section of the core mold, and confirm that the inner diameter of the blank is equal to the outer diameter of the lower section of the core mold.
[0026] 2) Screw the upper section of the core mold into the center threaded hole of the upper punch to fix and clamp the blank, thus completing the blank placement process;
[0027] 3) Select the inner and outer dies according to the preset target tooth shape of the toothed hub. Confirm that the lower section of the core mold can slide up and down in the die through hole opened at the center of the inner die. Confirm that the diameter of the cylindrical cavity in the upper section of the outer die is equal to the outer diameter of the blank. The conical surface and inner surface tooth shape of the inner die match the inclined surface and outer surface tooth shape of the outer die to form the bridge cavity and inner and outer surface tooth shape cavities of the preset target toothed hub.
[0028] 4) The press is started and pressure is applied to the upper punch, causing it to move downward. The core die moves downward together. The cavity changes as the core die moves downward along the die hole. The blank is also deformed by the downward pressure and flows into the bridge cavity and the inner and outer surface tooth cavities. In this step, the inner and outer dies are kept relatively fixed to ensure that the bridge cavity and the inner and outer surface tooth cavities do not change. The blank fills these cavities to form the preset target toothed hub tooth shape.
[0029] 5) During step 4), as the blank is pressed down and comes into contact with the anti-ejection punch, the anti-ejection punch also provides reverse pressure to the blank when it is under load. As the pressure increases, when the reverse pressure provided by the anti-ejection punch reaches the set threshold, the anti-ejection punch begins to move downward under the action of the hydraulic device, and the blank enters the stable deformation stage until the upper punch reaches the preset stroke.
[0030] 6) In step 5), when the upper punch reaches the preset stroke, the forming of the inner and outer tooth profiles of the toothed hub is completed. Then, the upper punch and the outer die return upward together to remove the formed toothed hub-like toothed part, and the material can be unloaded.
[0031] According to a forming method for toothed parts of the present invention, the blank undergoes flaring, diversion extrusion and upsetting deformation in steps 4) and 5) during the pressure application process, wherein the diversion extrusion and upsetting deformation stages directly affect the forming of the toothed part of the toothed part.
[0032] The following beneficial effects are achieved by using the forming apparatus and forming method of the present invention for toothed parts of the gear hub type:
[0033] 1. The present invention provides a forming device and forming method for toothed parts of the gear hub type. By combining extrusion and upsetting in stamping forming, the tooth filling rate and forming efficiency of the gear hub parts are improved. The forming process has a short production flow and the formed parts have good performance. It has the advantages of lightweight and low cost, and solves the technical problems of complex forming equipment, incomplete tooth filling and low forming efficiency of existing clutch gear hub toothed parts.
[0034] 2. A forming apparatus and forming method for toothed parts of the present invention, by adding a counter-ejector punch, effectively improves the filling performance of the internal and external tooth profiles of the toothed parts of the toothed parts and ensures forming efficiency;
[0035] 3. The forming apparatus and forming method of the present invention for toothed parts of the toothed hub type can be effectively applied to the forming of toothed hub parts with various tooth shapes by replacing different inner or outer dies. Attached Figure Description
[0036] Figure 1 This is a schematic diagram of the specific structure of a forming device assembly for a forming device and forming method for toothed parts of the present invention.
[0037] Figure 2 This is a schematic diagram of the inner die structure of a forming device and forming method for toothed parts of the present invention.
[0038] Figure 3 This is a schematic diagram of the outer die structure of a forming device and forming method for toothed parts of the present invention.
[0039] Figure 4 This is a schematic diagram of the processing procedure of a forming apparatus and forming method for toothed parts of the present invention (from left to right);
[0040] Figure 5 This is a schematic diagram of the longitudinal section of a blank used in a forming apparatus and forming method for toothed parts of the present invention.
[0041] Figure 6This is a longitudinal cross-sectional schematic diagram of a finished toothed part of a toothed part produced by a forming apparatus and forming method for toothed parts of a toothed part according to the present invention.
[0042] In the figure: 1-Blank, 1a-Process hole, A-Forming device assembly, A1-Including core mold, A2-Upper punch, A3-Inner die, A4-Outer die, A5-Reverse punch, A2a-Center threaded hole, A3a-Inner die through hole, A3b-Conical surface, A3c-Inner surface tooth profile, A4a-Cylindrical cavity, A4b-Inclined surface, A4c-Outer surface tooth profile. Detailed Implementation
[0043] The technical means, creative features, objectives, and effects of the forming apparatus and forming method for toothed parts of the present invention, applied to the toothed hub type, will be further described below with reference to the accompanying drawings and embodiments.
[0044] Example
[0045] like Figures 1-6 As shown, a forming device for toothed parts of the hub type includes a blank 1, which is specifically a cylindrical blank with a process hole 1a at the top and an open bottom. The blank is placed in a forming device assembly A, and the forming device assembly clamps and fixes the blank. By applying force and pressure to the forming device assembly, the blank is pressed downward into a preset toothed part of the hub type.
[0046] The forming device assembly A includes a core mold A1, an upper punch A2, an inner die A3, an outer die A4, and a top punch A5. The core mold is a stepped cylinder with an external thread on its upper section. The diameter of the upper section of the core mold is equal to the diameter of the process hole 1a. The upper section of the core mold passes through the process hole and connects to the central threaded hole A2a of the cylindrical upper punch to fix and clamp the blank 1.
[0047] The diameter of the lower section of the core mold is the same as the inner diameter of the blank. An inner die is provided below the core mold. An inner die through hole A3a is opened in the center of the inner die. The inner die through hole fits with the lower section of the core mold, so that it can slide up and down in the inner die through hole.
[0048] A tapered surface A3b with an inclination is provided at the upper end of the outer surface of the inner die, and an inner surface tooth A3c of a preset target toothed hub is provided on the outer die body of the inner die below the tapered surface.
[0049] An inner die is located inside an outer die. The outer die is cylindrical in shape, and the upper part of the inner die is a cylindrical cavity A4a. The diameter of the cylindrical cavity is equal to the outer diameter of the blank. A slope A4b is provided below the cylindrical cavity. The slope corresponds to the conical surface of the inner die, and the connection is smoothed with rounded corners. The lower part of the inner die is the outer surface tooth A4c of the preset target toothed hub part. The outer surface tooth A4c mates with the inner surface tooth A3c of the inner die to form the preset target toothed hub part tooth shape.
[0050] The anti-ejection punch is located in the space between the inner surface tooth profile A3c and the outer surface tooth profile A4c. The lower end of the anti-ejection punch is flush with the bottom surface of the inner and outer dies. The anti-ejection punch has a structure with a preset target tooth profile, that is, the anti-ejection punch can slide up and down in the space between the inner surface tooth profile and the outer surface tooth profile.
[0051] The core mold A1, inner die A3, and outer die A4 together form a forming cavity, and the shape of the forming cavity changes as the upper punch A2 applies force to press down and slides the core mold into the inner die. By changing the assembly height of the inner die and the outer die or the slope of the conical surface A3b and the inclined surface A4b, the thickness and slope of the bridge part of the toothed hub part can be adjusted. By adjusting the inner surface tooth shape A3c of the inner die and the outer surface tooth shape A4c of the outer die, the part forming can be adapted to different preset target toothed hub parts.
[0052] A forming method for toothed parts of the gear hub type, based on the aforementioned forming apparatus for toothed parts of the gear hub type, comprises the following specific steps:
[0053] 1) Place the blank 1 through the process hole 1a at its top onto the upper section of the core mold A1, and confirm that the inner diameter of the blank is equal to the outer diameter of the lower section of the core mold.
[0054] 2) Screw the upper section of the core mold into the center threaded hole A2a of the upper punch A2 to fix and clamp the blank, thus completing the blank placement process;
[0055] 3) Select the inner die A3 and the outer die A4 according to the preset target tooth shape of the tooth hub. Confirm that the lower section of the core mold can slide up and down in the die through hole A3a opened at the center of the inner die. Confirm that the diameter of the cylindrical cavity A4a in the upper section of the outer die is equal to the outer diameter of the blank. The conical surface A3b and the inner surface tooth shape A3c of the inner die cooperate with the inclined surface A4b and the outer surface tooth shape A4c of the outer die to form the bridge cavity and the inner and outer surface tooth shape cavities of the preset target tooth hub.
[0056] 4) The press is started and pressure is applied to the upper punch, causing it to move downward. The core die moves downward together. The cavity changes as the core die moves downward along the die hole. The blank is also deformed by the downward pressure and flows into the bridge cavity and the inner and outer surface tooth cavities. In this step, the inner and outer dies are kept relatively fixed to ensure that the bridge cavity and the inner and outer surface tooth cavities do not change. The blank fills these cavities to form the preset target toothed hub tooth shape.
[0057] 5) During step 4), as the blank is pressed down and comes into contact with the anti-ejection punch A5, the anti-ejection punch also provides reverse pressure to the blank when it is under load pressure. As the pressure increases, when the reverse pressure provided by the anti-ejection punch reaches the set threshold, the anti-ejection punch begins to move downward under the action of the hydraulic device, and the blank enters the stable deformation stage until the upper punch reaches the preset stroke.
[0058] 6) In step 5), when the upper punch reaches the preset stroke, the forming of the inner and outer tooth profiles of the toothed hub is completed. Then, the upper punch and the outer die return upward together to remove the formed toothed hub-like toothed part, and the material can be unloaded.
[0059] During the pressure application process in steps 4) and 5), the billet 1 undergoes flaring, diversion extrusion and upsetting deformation in succession. Among them, the diversion extrusion and upsetting deformation stages directly affect the forming of the tooth profile of the tooth hub.
[0060] The present invention provides a forming apparatus and forming method for toothed parts of the gear hub type, which effectively improves the filling performance of the internal and external tooth profiles of the gear hub type, improves forming efficiency and part quality, and reduces equipment and part costs. The forming apparatus and forming method of the present invention can be effectively applied to the forming of automotive clutch gear hub parts and gear hub parts with various tooth profiles, and has good potential for lightweighting and cost reduction.
[0061] However, those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any changes or modifications to the above embodiments within the spirit and essence of this application will fall within the scope of the claims of this application.
Claims
1. A forming apparatus for toothed parts of the gear hub type, comprising a blank (1), characterized in that: The blank (1) is specifically a cylindrical blank with a process hole (1a) at the top and an open bottom. The blank is placed in a forming device assembly (A), and the forming device assembly clamps and fixes the blank. By applying force and pressure to the forming device assembly, the blank is punched downward into a preset toothed hub-like toothed part. The forming device assembly (A) includes a core mold (A1), an upper punch (A2), an inner die (A3), an outer die (A4), and a top punch (A5). The core mold is a stepped cylinder with an external thread on its upper section. The diameter of the upper section of the core mold is equal to the diameter of the process hole (1a). The upper section of the core mold passes through the process hole and connects to the central threaded hole (A2a) of the cylindrical upper punch to fix and clamp the blank (1). The diameter of the lower section of the core mold is the same as the inner diameter of the blank. An inner die is provided below the core mold. An inner die through hole (A3a) is opened in the center of the inner die. The inner die through hole fits with the lower section of the core mold, so that it can slide up and down in the inner die through hole. A tapered surface with an inclination (A3b) is provided at the upper end of the outer surface of the inner die, and an inner surface tooth profile (A3c) of a preset target toothed hub is provided on the outer die body of the inner die below the tapered surface. An inner die is located inside an outer die. The outer die is cylindrical in shape, and the upper part of the inner die is a cylindrical cavity (A4a). The diameter of the cylindrical cavity is equal to the outer diameter of the blank. A slope (A4b) is provided below the cylindrical cavity. The slope corresponds to the conical surface of the inner die, and the connection is smoothed with rounded corners. The lower part of the inner die is the outer surface tooth shape (A4c) of the preset target toothed hub part. The outer surface tooth shape cooperates with the inner surface tooth shape (A3c) of the inner die to form the preset target toothed hub part tooth shape. The anti-ejection punch is located in the space between the inner surface tooth profile (A3c) and the outer surface tooth profile (A4c). The lower end of the anti-ejection punch is flush with the bottom surface of the inner and outer dies. The anti-ejection punch has a structure with a preset target tooth profile, that is, the anti-ejection punch can slide up and down in the space between the inner surface tooth profile and the outer surface tooth profile.
2. The forming apparatus for toothed parts of the gear hub type as described in claim 1, characterized in that, The core mold (A1), inner die (A3), and outer die (A4) together form a forming cavity, and the shape of the forming cavity changes as the upper punch (A2) applies force and presses down to slide the core mold into the inner die. By changing the assembly height of the inner die and the outer die, or the slope of the conical surface (A3b) and the inclined surface (A4b), the thickness and slope of the bridge part of the toothed hub-type toothed part can be adjusted. By adjusting the inner surface tooth shape (A3c) of the inner die and the outer surface tooth shape (A4c) of the outer die, the part forming can be adapted to different preset target toothed hub tooth shapes.
3. A forming method for toothed parts of the gear hub type, based on the forming apparatus for toothed parts of the gear hub type according to any one of claims 1 to 2, the specific steps of which are as follows: 1) Place the blank (1) through the process hole (1a) at the top of the blank onto the upper section of the core mold (A1), and confirm that the inner diameter of the blank is equal to the outer diameter of the lower section of the core mold. 2) Screw the upper section of the core mold into the center threaded hole (A2a) of the upper punch (A2) to fix and clamp the blank, thus completing the blank placement process; 3) Select the inner die (A3) and outer die (A4) according to the preset target tooth shape of the tooth hub. Confirm that the lower section of the core mold can slide up and down in the die through hole (A3a) opened at the center of the inner die. Confirm that the diameter of the cylindrical cavity (A4a) of the upper section inside the outer die is equal to the outer diameter of the blank. The conical surface (A3b) and inner surface tooth shape (A3c) of the inner die are matched with the inclined surface (A4b) and outer surface tooth shape (A4c) of the outer die to form the bridge cavity and inner and outer surface tooth shape cavities of the preset target tooth hub. 4) The press is started and pressure is applied to the upper punch, causing it to move downward. The core die moves downward together. The cavity changes as the core die moves downward along the die hole. The blank is also deformed as it is pressed down and flows into the bridge cavity and the inner and outer surface tooth cavities. In this step, the inner and outer dies are kept relatively fixed to ensure that the bridge cavity and the inner and outer surface tooth cavities do not change. The blank fills these cavities to form the preset target toothed hub tooth shape. 5) During step 4), as the blank is pressed down and comes into contact with the anti-ejection punch (A5), the anti-ejection punch also provides reverse pressure to the blank when it is under load pressure. As the pressure increases, when the reverse pressure provided by the anti-ejection punch reaches the set threshold, the anti-ejection punch begins to move downward under the action of the hydraulic device, and the blank enters the stable deformation stage until the upper punch reaches the preset stroke. 6) In step 5), when the upper punch reaches the preset stroke, the forming of the inner and outer tooth profiles of the gear hub is completed. Then, the upper punch and the outer die return upward together to remove the formed gear hub-like tooth profile parts, and the material can be unloaded.
4. The forming method for toothed parts of the gear hub type as described in claim 3, characterized in that, During the pressure application process in steps 4) and 5), the billet (1) undergoes flaring, diversion extrusion and upsetting deformation in succession. Among them, the diversion extrusion and upsetting deformation stages directly affect the forming of the tooth profile of the tooth hub.