Secondary extrusion forming device for intermediate shaft blank

Abstract

The utility model relates to an intermediate shaft blank secondary extrusion forming device which comprises an upper die plate and a lower die plate which correspond to each other up and down, a lower die core with a lower tooth blank positioning core hole is fixedly arranged on the top surface of the lower die plate, sliding die holders capable of transversely sliding are arranged on the two sides of the lower die plate, and core grooves are formed in the opposite sides of the two die holders. An outer limiting base is fixed to the bottom face of the upper die plate, a sliding hole is formed in the outer limiting base in the vertical direction in a penetrating mode, an inner limiting sleeve capable of vertically sliding is arranged in the sliding hole, a limiting hole is formed in the inner limiting sleeve, and the lower portion of the upper die plate is provided with a lower tooth blank positioning core hole. The upper die core is fixed to the portion, on the inner side of the limiting hole, of the upper die plate and provided with the extrusion core hole, the circular truncated cone part of the sliding die base is wedged into the lower end of the inner limiting sleeve to achieve positioning during die assembly, then the upper die core is pressed downwards to complete blank extrusion forming, accurate alignment is achieved through wedge-shaped matching of the sliding die base and the limiting sleeve, and the extrusion forming precision and efficiency are improved.

Description

Technical Field

[0001] This utility model relates to the field of gear shaft processing, specifically to a device for secondary extrusion molding of intermediate shaft blanks. Background Technology

[0002] Intermediate shafts, as core components of mechanical transmission systems, are widely used in various power equipment to perform torque transmission and rotational support functions. In traditional intermediate shaft manufacturing processes, especially for intermediate shafts with double gear structures, a method of machining from a single forged blank by turning is typically employed. Specifically, the manufacturing company first prepares a solid cylindrical blank with a diameter equivalent to the maximum outer diameter of the gear blank. Then, a CNC lathe sequentially cuts the connecting areas between the gear blanks, ultimately forming a shaft structure that meets the design requirements.

[0003] However, this traditional processing method has significant technical drawbacks: when the axial distance between the two tooth blanks is too long, a large amount of material in the middle area needs to be removed by cutting. This not only results in a serious waste of metal material, but also leads to a longer processing cycle, increased tool wear, and a significant increase in overall production costs due to the large number of cutting operations. To address these technical bottlenecks, those skilled in the art began to explore the application of plastic forming technology. Finite element simulation analysis revealed that a step-by-step extrusion process can effectively reduce the cutting allowance while ensuring the continuity of material flow lines. However, in practical applications, after the first tooth blank is extruded, the shaft blank needs to be re-clamped, which changes the positioning datum of the shaft blank. Therefore, it is necessary to control the phase relationship and axial distance between the two tooth blanks. Thus, designing a forming die that can meet the requirements of secondary clamping and positioning of the shaft blank, as well as the phase relationship and axial distance requirements between the two tooth blanks, requires further consideration. Utility Model Content

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to provide a secondary extrusion molding device for intermediate shaft blanks that can meet the requirements of secondary clamping and positioning of shaft blanks and the phase relationship and axial spacing between the two tooth blanks.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A secondary extrusion forming device for intermediate shaft blanks includes an upper template and a lower template arranged opposite each other. A lower mold core is fixedly connected to the top surface of the lower template. A lower tooth blank positioning core hole is provided on the top of the lower mold core along the vertical direction. Sliding mold seats are respectively provided on the top surface of the lower template and on both sides of the lower mold core. A core groove is provided on the opposite side of the two sliding mold seats along the vertical direction. The core groove is a through groove. When the two sliding mold seats are closed in the opposite direction, the upper part of the two sliding mold seats can form a frustum-shaped structure, and the two core grooves can close to form an upper tooth blank forming core hole that is co-centered and connected with the lower tooth blank positioning core hole.

[0007] An outer limiting seat is fixedly connected to the bottom surface of the upper template and above the lower mold core. A sliding hole is provided on the outer limiting seat in the vertical direction. An inner limiting sleeve slides in the sliding hole in the vertical direction. The outer limiting seat is provided with a limiting part that can limit the upper end of the inner limiting sleeve from sliding out of the lower end of the sliding hole. The inner limiting sleeve has a limiting hole that passes in the vertical direction. An upper mold core is fixedly connected to the bottom surface of the upper template and inside the limiting hole. The bottom of the upper mold core is provided with an extrusion core hole that is co-centered with the positioning core hole of the lower tooth blank. When the upper template moves downward, the frustum-shaped upper structure formed by the two sliding mold seats after mold closing can extend into the lower end of the limiting hole and wedge with the limiting hole. After the frustum-shaped upper structure formed by the two sliding mold seats after mold closing is wedge with the limiting hole, the upper template can move downward so that the upper mold core can extrude and shape the blank to be processed.

[0008] In this invention, after the first extrusion, a first tooth blank is formed on the shaft blank. Therefore, the shaft blank is inverted, with the end containing the first tooth blank facing down, and placed in the positioning core hole of the lower tooth blank. The positioning core hole of the lower tooth blank is used to provide a reference positioning for the entire shaft blank. This allows the position of the forming core hole of the upper tooth blank formed by the sliding mold base to be determined based on the position of the first tooth blank. The two sliding mold bases are placed above the lower mold core to form a mold closing structure, ensuring the positions of the positioning core hole of the lower tooth blank and the forming core hole of the upper tooth blank. Then, the upper mold plate is controlled to move downward. Under its own weight, the inner limiting sleeve slides downward and is limited by the upper limiting part of the outer limiting seat. During the downward movement, the inner limiting sleeve first fits onto the frustum-shaped upper structure formed by the mold closing of the two lower sliding mold bases and engages with the frustum-shaped upper structure at an oblique wedge. Therefore, the inner limiting sleeve will not move vertically, and the two sliding mold bases are restricted by the inner limiting sleeve, thus preventing horizontal movement and completing the limitation of the two sliding mold bases. As the upper die plate continues to descend, the upper end of the shaft blank extends into the extrusion core hole. The upper die core then extrudes the shaft blank downwards, forming a second toothed blank within the upper toothed blank forming core hole. Afterward, the shaft blank can be removed. In this way, by positioning and fixing the first toothed blank, the extrusion forming of the second toothed blank is completed, effectively controlling the phase relationship and axial spacing between the two toothed blanks, and facilitating subsequent machining.

[0009] As an optimization, multiple telescopic springs are provided within the limiting hole and located between the inner limiting sleeve and the upper template. These springs are evenly spaced around the center line of the limiting hole. The upper end face of the inner limiting sleeve and the bottom face of the upper template are respectively recessed with vertically oriented spring mounting holes corresponding to the positions of the springs. Both ends of the telescopic springs extend into the corresponding spring mounting holes and abut against the bottom of the holes. After the inner limiting sleeve engages with the wedge of the frustum-shaped upper structure, it can compress the telescopic springs during the downward movement of the upper template. The spring force of the telescopic springs then acts in the opposite direction on the inner limiting sleeve, generating a downward force. This ensures that the inner limiting sleeve maintains its limiting control over the two sliding mold bases, improving the quality of the blank forming.

[0010] As an optimization, the limiting part includes multiple sliding grooves evenly spaced on the inner wall of the sliding hole, extending vertically downwards from the upper end of the sliding hole. A slider protrudes from the upper end of the inner limiting sleeve corresponding to each sliding groove, extending into the corresponding groove and slidingly engaging with it along the groove's extension direction. This not only limits the inner limiting sleeve from sliding out of the outer limiting seat but also guides the inner limiting sleeve.

[0011] As an optimization, the upper surface of the lower template is recessed with a core mounting hole, and the lower end of the lower core is fitted into the core mounting hole with a clearance fit. A pressing ring is formed on the circumferential surface of the lower core, circumferentially surrounding it. A pressure plate is also fixedly connected to the lower template, acting on the pressing ring to press the lower core against the bottom of the core mounting hole. The sliding mold base is located on the surface of the pressure plate. The core mounting hole reduces the height of the top of the lower core relative to the lower template, thereby reducing the overall height of the sliding mold base and facilitating the setting of the mold between the upper and lower templates.

[0012] As an optimization, a mold base driving device is also installed on the lower template and on the back side of the two sliding mold bases, respectively, for driving the two sliding mold bases to perform mold opening and closing operations. The sliding mold bases can slide on the lower template along the opposite or back-to-back directions of the two sliding mold bases under the drive of the mold base driving device. Mold closing is performed by the mold base driving device, improving the degree of automation.

[0013] As an optimization, multiple oil grooves are formed on the contact surface between the bottom of the sliding mold base and the lower mold plate. The oil grooves are through grooves and extend parallel to the sliding direction of the sliding mold base. The multiple oil grooves are spaced apart perpendicular to the sliding direction of the sliding mold base. By injecting oil into the oil grooves, the friction of the sliding mold base during sliding can be reduced, making the movement smoother.

[0014] As an optimization, guide strips, fixedly connected to the lower mold plate, are respectively provided on both sides of the two sliding mold bases along their moving direction. Each sliding mold base includes a sliding plate placed on the top surface of the lower mold plate and located between the two guide strips, and a forming module fixed to the top surface of the sliding plate. The core groove is located on the forming module. The sliding plate and the guide strip on its respective side form wedge-shaped guide surfaces that slide against each other and extend parallel to the moving direction of the two sliding mold bases. This guiding mechanism improves the mold closing accuracy of the two sliding mold bases, thus improving the quality of the billet extrusion molding.

[0015] As an optimization, the bottom of the positioning core hole of the lower tooth blank is provided with an upper ejector pin hole aligned with its center line. The diameter of the upper ejector pin hole is smaller than the diameter of the bottom of the positioning core hole of the lower tooth blank. A lower ejector pin hole, aligned with the center line of the upper ejector pin hole, is provided on the lower template at a position corresponding to the upper ejector pin hole. After the blank is extruded, the ejector pin can be used to eject the blank from the mold through the upper and lower ejector pin holes, facilitating material removal.

[0016] As an optimization, a vertically extending guide tube is fixedly connected to the lower template, and a guide post, aligned with the center line of the guide tube, is fixedly connected to the upper template. The lower end of the guide post extends into the inner hole of the guide tube and can slide vertically with the guide tube. This provides guidance for the movement of the upper template.

[0017] Compared with the prior art, this utility model effectively controls the phase relationship and axial spacing between the two tooth blanks by positioning and fixing the first tooth blank, combined with limiting the two sliding mold seats after mold closing, thereby improving the quality of the blank extrusion molding. Attached Figure Description

[0018] Figure 1 A cross-sectional schematic diagram for utilizing this utility model. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely represents selected embodiments of the utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0020] like Figure 1 As shown, the intermediate shaft blank secondary extrusion molding device in this embodiment includes an upper template 1 and a lower template 2 arranged opposite to each other. A lower mold core 3 is fixedly connected to the top surface of the lower template 2. A lower tooth blank positioning core hole is provided on the top of the lower mold core 3 in the vertical direction. Sliding mold seats are respectively provided on the top surface of the lower template 2 and on both sides of the lower mold core 3. A core groove is provided on the opposite side of the two sliding mold seats in the vertical direction. The core groove is a through groove. When the two sliding mold seats are closed in the opposite direction, the upper part of the two sliding mold seats can form a frustum-shaped structure, and the two core grooves can close to form an upper tooth blank forming core hole that is co-centered with and connected to the lower tooth blank positioning core hole.

[0021] An outer limiting seat 4 is fixedly connected to the bottom surface of the upper template 1 and above the lower mold core 3. A sliding hole is provided on the outer limiting seat 4 in the vertical direction. An inner limiting sleeve 5 is slidably fitted in the sliding hole in the vertical direction. A limiting part is provided on the outer limiting seat 4 to limit the upper end of the inner limiting sleeve 5 from sliding out of the lower end of the sliding hole. The inner limiting sleeve 5 has a limiting hole in the vertical direction. An upper mold core 6 is fixedly connected to the bottom surface of the upper template 1 and inside the limiting hole. An extrusion core hole is provided at the bottom of the upper mold core 6 and is aligned with the positioning core hole of the lower tooth blank. When the upper template 1 moves downward, the frustum-shaped upper structure formed by the two sliding mold seats after mold closing can extend into the lower end of the limiting hole and wedge-fit with the limiting hole. After the frustum-shaped upper structure formed by the two sliding mold seats after mold closing fits with the wedge-fit of the limiting hole, the upper template 1 can move downward so that the upper mold core 6 can extrude and shape the blank to be processed.

[0022] In this specific embodiment, a plurality of telescopic springs 7 are provided in the limiting hole and at the position between the inner limiting sleeve 5 and the upper template 1. The plurality of telescopic springs 7 are evenly spaced around the center line of the limiting hole. The upper end surface of the inner limiting sleeve 5 and the bottom surface of the upper template 1 are respectively provided with spring mounting holes in the vertical direction corresponding to the positions of the telescopic springs 7. The two ends of the telescopic springs 7 extend into the spring mounting holes on the corresponding sides and abut against the bottom of the spring mounting holes.

[0023] In this specific embodiment, the limiting part includes multiple sliding grooves evenly spaced on the inner wall of the sliding hole and around the center line of the sliding hole. The sliding grooves extend downward from the upper end of the sliding hole in a vertical direction. The upper end of the inner limiting sleeve 5 is provided with a slider 8 corresponding to the position of each sliding groove. The slider 8 extends into the corresponding sliding groove and can slide and cooperate with the sliding groove along the extension direction of the sliding groove.

[0024] In this specific embodiment, the upper surface of the lower template 2 is recessed with a mold core mounting hole, the lower end of the lower mold core 3 is fitted into the mold core mounting hole with a clearance, and a pressing protrusion ring is formed on the circumferential surface of the lower mold core 3, which is circumferentially arranged around the lower mold core 3. A pressure plate 9 is also fixedly connected to the lower template 2, which acts on the pressing protrusion ring to press the lower mold core 3 against the bottom of the mold core mounting hole. The sliding mold base is located on the surface of the pressure plate 9.

[0025] In this specific embodiment, a mold base driving device for driving the two sliding mold bases to perform mold splitting and mold closing operations is also installed on the lower template 2 and on the back side of the two sliding mold bases respectively. The sliding mold bases can slide on the lower template 2 along the opposite or opposite directions of the two sliding mold bases under the drive of the mold base driving device.

[0026] In this specific embodiment, multiple oil grooves 10 are formed on the contact surface where the bottom of the sliding mold base contacts the lower template 2. The oil grooves 10 are through grooves and extend along the sliding direction parallel to the sliding mold base. The multiple oil grooves are spaced apart along the sliding direction perpendicular to the sliding mold base.

[0027] In this specific embodiment, guide strips 11 fixedly connected to the lower template 2 are respectively provided on both sides of the two sliding mold bases along their moving direction. The sliding mold base includes a slide plate 12 placed on the top surface of the lower template 2 and located between the two guide strips 11, and a molding module 13 fixed on the top surface of the slide plate 12. The core groove is located on the molding module. The slide plate 12 and the guide strip 11 on its respective side form a wedge-shaped guide surface that slides and engages with each other and extends parallel to the moving direction of the two sliding mold bases.

[0028] In this specific embodiment, the bottom of the positioning core hole of the lower tooth blank is provided with a top rod upper hole with the same center line as it. The diameter of the top rod upper hole is smaller than the diameter of the bottom of the positioning core hole of the lower tooth blank. The lower template 2 is provided with a top rod lower hole with the same center line as the top rod upper hole at the position corresponding to the position of the top rod upper hole.

[0029] In this specific embodiment, a vertically extending guide tube 14 is fixedly connected to the lower template 2, and a guide post 15 arranged with the same center line as the guide tube 14 is fixedly connected to the upper template 1. The lower end of the guide post 15 extends into the inner hole of the guide tube 14 and can slide and cooperate with the guide tube 14 in the vertical direction.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of this utility model that do not depart from the spirit and scope of this technical solution should be covered within the scope of the claims of this utility model.

Claims

1. A secondary extrusion forming device for intermediate shaft blanks, comprising an upper template and a lower template arranged opposite each other, characterized in that: A lower mold core is fixedly connected to the top surface of the lower mold template. A lower tooth blank positioning core hole is provided on the top of the lower mold core in the vertical direction. Sliding mold seats are respectively provided on the top surface of the lower mold template and on both sides of the lower mold core. A core groove is provided on the opposite side of the two sliding mold seats in the vertical direction. The core groove is a through groove. When the two sliding mold seats are closed in the opposite direction, the upper part of the two sliding mold seats can form a frustum-shaped structure, and the two core grooves can close to form an upper tooth blank forming core hole that is on the same center line as the lower tooth blank positioning core hole and is connected to it. An outer limiting seat is fixedly connected to the bottom surface of the upper template and above the lower mold core. A sliding hole is provided on the outer limiting seat in the vertical direction. An inner limiting sleeve slides in the sliding hole in the vertical direction. The outer limiting seat is provided with a limiting part that can limit the upper end of the inner limiting sleeve from sliding out of the lower end of the sliding hole. The inner limiting sleeve has a limiting hole that passes in the vertical direction. An upper mold core is fixedly connected to the bottom surface of the upper template and inside the limiting hole. The bottom of the upper mold core is provided with an extrusion core hole that is co-centered with the positioning core hole of the lower tooth blank. When the upper template moves downward, the frustum-shaped upper structure formed by the two sliding mold seats after mold closing can extend into the lower end of the limiting hole and wedge with the limiting hole. After the frustum-shaped upper structure formed by the two sliding mold seats after mold closing is wedge with the limiting hole, the upper template can move downward so that the upper mold core can extrude and shape the blank to be processed.

2. The intermediate shaft blank secondary extrusion molding apparatus according to claim 1, characterized in that: Multiple telescopic springs are provided inside the limiting hole and at a position between the inner limiting sleeve and the upper template. The multiple telescopic springs are evenly spaced around the center line of the limiting hole. The upper end face of the inner limiting sleeve and the bottom face of the upper template are respectively recessed with spring mounting holes in the vertical direction corresponding to the positions of the telescopic springs. The two ends of the telescopic springs extend into the spring mounting holes on the corresponding sides and abut against the bottom of the spring mounting holes.

3. The intermediate shaft blank secondary extrusion molding apparatus according to claim 1, characterized in that: The limiting part includes multiple sliding grooves evenly spaced on the inner wall of the sliding hole and around the center line of the sliding hole. The sliding grooves extend vertically from the upper end of the sliding hole downwards. The upper end of the inner limiting sleeve has a slider protruding at the position corresponding to each sliding groove. The slider extends into the corresponding sliding groove and can slide and cooperate with the sliding groove along the extension direction of the sliding groove.

4. The intermediate shaft blank secondary extrusion molding apparatus according to claim 1, characterized in that: The upper surface of the lower template is recessed with a core mounting hole, and the lower end of the lower core is fitted into the core mounting hole with a clearance. A pressing protrusion is formed on the circumferential surface of the lower core, which is circumferentially arranged around the lower core. A pressure plate is also fixedly connected to the lower template, which acts on the pressing protrusion to press the lower core against the bottom of the core mounting hole. The sliding mold base is located on the surface of the pressure plate.

5. The intermediate shaft blank secondary extrusion molding apparatus according to claim 1, characterized in that: On the lower template and on the back side of the two sliding mold bases, mold base driving devices are respectively installed for driving the two sliding mold bases to perform mold opening and closing operations. The sliding mold bases can slide on the lower template along the opposite or opposite directions of the two sliding mold bases under the drive of the mold base driving devices.

6. The intermediate shaft blank secondary extrusion molding apparatus according to claim 5, characterized in that: Multiple oil grooves are formed on the contact surface of the bottom of the sliding mold base that contacts the lower mold plate. The oil grooves are through grooves and extend along the sliding direction parallel to the sliding mold base. The multiple oil grooves are spaced apart along the sliding direction perpendicular to the sliding mold base.

7. The intermediate shaft blank secondary extrusion molding apparatus according to claim 5, characterized in that: Guide strips are respectively provided on both sides of the two sliding mold bases along their moving direction and are fixedly connected to the lower mold plate. The sliding mold base includes a sliding plate placed on the top surface of the lower mold plate and located between the two guide strips and a molding module fixed on the top surface of the sliding plate. The core groove is located on the molding module. The sliding plate and the guide strip on its side respectively form a wedge-shaped guide surface that slides and extends parallel to the moving direction of the two sliding mold bases.

8. The intermediate shaft blank secondary extrusion molding apparatus according to claim 1, characterized in that: The bottom of the positioning core hole of the lower tooth blank is provided with a top rod upper hole with the same center line as it. The diameter of the top rod upper hole is smaller than the diameter of the bottom of the positioning core hole of the lower tooth blank. The lower template is provided with a top rod lower hole with the same center line as the top rod upper hole at the position corresponding to the top rod upper hole.

9. The intermediate shaft blank secondary extrusion molding apparatus according to claim 1, characterized in that: A vertically extending guide tube is fixedly connected to the lower template, and a guide post is fixedly connected to the upper template, which is arranged along the same center line as the guide tube. The lower end of the guide post extends into the inner hole of the guide tube and can slide and cooperate with the guide tube in the vertical direction.

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