Punching rod for inner hole sizing burnishing forming
By designing a punch for sizing and extruding the inner hole, the problem of parts with small inner hole diameter tolerances being unable to be directly formed was solved, achieving stable control of the inner hole diameter and a smooth surface, thus improving production efficiency and reducing costs.
Patent Information
- Application Number
- CN202520572718.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-29
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-03-29
AI Technical Summary
During the cold heading process, parts with an inner diameter tolerance of less than 0.03 mm cannot be directly formed, resulting in high production costs, poor surface finish, and reduced production efficiency.
Design a punch for sizing and calendering inner hole, including a through-feed calendering punch, wherein the diameter of the calendering part is larger than that of the through-feed end, and there is a smooth transition design between the calendering part and the through-feed end to ensure that the inner hole diameter is controlled within 0.02mm, and a secondary calendering is formed through a sloped transition structure and a circular arc transition area to ensure that the inner surface of the hole is smooth.
It achieves inner hole diameter tolerance control within 0.02mm, eliminates steps, improves production efficiency, reduces production costs, and ensures a smooth inner hole surface.
Smart Images
Figure CN223932506U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cold heading technology, specifically to a punch for internal diameter sizing and calendering. Background Technology
[0002] In the cold heading process of parts with through holes, it is generally necessary to first use one or more punches to draw the hole, and finally use one punch (such as...) Figure 3 As shown, the remaining undrawn and excess waste material is discharged. The diameter of this discharge punch is generally 0.03-0.05mm smaller than that of the drawing punch. This results in a 0.03-0.05mm step in the inner hole after forming, and the step in the inner hole will not be smooth. For products that require an inner hole diameter tolerance of less than 0.03mm, cold heading cannot be used directly. After forming, additional precision machining is required, resulting in high production costs, poor inner hole surface finish, and reduced production efficiency. Utility Model Content
[0003] The purpose of this utility model is to provide a punch for sizing and extruding parts with inner diameter tolerance less than 0.03mm, which solves the problem that parts cannot be directly formed by a through punch and require precision machining, resulting in high cost, low surface finish, and reduced production efficiency.
[0004] Technical Solution: This utility model provides a punch for internal hole sizing and calendering, comprising: a through-hole calendering punch, the through-hole calendering punch including a body and a through-hole head, the through-hole head being disposed at the front end of the body, the through-hole head including a transition section, a calendering section, and a through-hole end, the transition section connecting to the body, the calendering section being disposed at the front end of the transition section, and the through-hole end being disposed at the front end of the calendering section; the diameter of the calendering section is 0.03-0.1mm larger than the diameter of the through-hole end, and the calendering section has a smooth transition design between the through-hole end and the transition section. Setting the diameter of the calendering section to be larger than the through-hole end ensures that the inner diameter of the internal hole after through-hole calendering can be controlled within a tolerance of 0.02mm.
[0005] Furthermore, in the aforementioned punch formed by extrusion with a fixed inner diameter, the diameter of the punch body is larger than the diameter of the transition section, and the transition section has a sloping transition structure.
[0006] Furthermore, in the aforementioned punch formed by extrusion with a fixed inner diameter, the diameter of the feed end is greater than or equal to the diameter of the transition section.
[0007] Furthermore, in the aforementioned punch for sizing and calendering an inner hole, the calendering section includes a calendering area, an arc transition area, and a material exit transition area. An arc transition area is provided between the calendering area and the material exit end, and a material exit transition area is provided between the calendering area and the transition section. The arc transition area and the material exit transition area are designed for smooth transitions. The smooth transition design at both ends of the calendering section allows for secondary calendering during the reciprocating motion of the punch, ensuring a smooth inner surface and more stable dimensions.
[0008] Furthermore, in the aforementioned punch formed by sizing and calendering the inner hole, the diameter of the calendering zone is 0.03-0.1 mm larger than the diameter of the feed end.
[0009] Furthermore, in the aforementioned punch formed by extrusion with a fixed inner diameter, the radius of the arc transition zone is 6.5 mm, and the radius of the arc of the material exiting the transition zone is 5 mm.
[0010] Furthermore, in the aforementioned punch formed by extrusion with a fixed inner diameter, the outer periphery of the feed end has a rounded chamfer with a radius of 0.3 mm.
[0011] As can be seen from the above technical solution, this utility model has the following beneficial effects: The punch for inner hole sizing and calendering described in this utility model has a simple structure and is easy to use. The diameter of the calendering zone is 0.03-0.1mm larger than the diameter of the feed end, which can eliminate the steps left in the hole during the drawing process and ensure that the inner hole diameter of the part can be controlled within the tolerance range of 0.02mm after feed calendering. The two ends of the calendering section have a smooth transition design, and a secondary calendering is formed during the reciprocating motion of the punch, which ensures that the inner surface of the hole is smooth, the inner hole size is more stable, the production efficiency is improved, the secondary processing steps after cold heading are reduced, and the production cost is reduced. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of a punch structure for extrusion forming of inner hole sizing according to the present invention;
[0013] Figure 2 This is a schematic diagram of the feed head structure of this utility model;
[0014] Figure 3 This is a schematic diagram of the general punch structure of this utility model.
[0015] In the figure: 1. Extrusion punch 1, 11. Extrusion head 12, 121. Transition section 122. Extrusion section 123. Extrusion end 1221. Extrusion zone 1221. Arc transition zone 1222. Extrusion exit transition zone 1223. Detailed Implementation
[0016] Example 1
[0017] like Figure 1-2The illustrated punch for sizing and calendering an inner hole includes: a through-hole calendering punch 1, comprising a body 11 and a through-hole head 12. The through-hole head 12 is located at the front end of the body 11 and includes a transition section 121, a calendering section 122, and a through-hole end 123. The transition section 121 connects to the body 11, the calendering section 122 is located at the front end of the transition section 121, and the through-hole end 123 is located at the front end of the calendering section 122. The diameter of the calendering section 122 is larger than the diameter of the through-hole end 123, and the calendering section 122 has a smooth transition design between the through-hole end 123 and the transition section 121. The calendering section 122, with a diameter larger than that of the through-hole end 123, removes the step left during hole drawing, ensuring that the inner diameter of the inner hole after through-hole calendering can be controlled within the allowable tolerance range.
[0018] In this embodiment, the diameter of the rod body 11 is larger than the diameter of the transition portion 121, and the rod body 11 and the transition portion 121 are connected by a sloped transition structure.
[0019] like Figure 2 The punch shown is an internally sized extruded punch, wherein the diameter of the feed end 123 is greater than or equal to the diameter of the transition portion 121.
[0020] In this embodiment, the diameter of the extrusion zone 1221 is 0.03-0.1 mm larger than the diameter of the feed end 123, which can eliminate the step left in the hole during the drawing process and ensure that the inner diameter of the part can be controlled within the tolerance range of 0.02 mm after the feed end is extruded.
[0021] Example 2
[0022] Based on Example 1, in this example, as... Figure 2 The diagram shows a punch for sizing and calendering an inner hole. The calendering section 122 includes a calendering area 1221, an arc transition area 1222, and a material exit transition area 1223. The arc transition area 1222 is provided between the calendering area 1221 and the material exit transition area 123, and the material exit transition area 1223 is provided between the calendering area 1221 and the transition section 121. The arc transition area 1222 and the material exit transition area 1223 are designed for smooth transition. The arc transition area 1222 and the material exit transition area 1223 at both ends of the calendering area 1221 form a secondary calendering during the reciprocating motion of the punch, ensuring a smooth inner surface of the hole and more stable dimensions.
[0023] In this embodiment, the radius of the arc of the arc transition zone 1222 is 6.5 mm, and the radius of the arc of the material exit transition zone 1223 is 5 mm.
[0024] In this embodiment, the outer periphery of the feed end 123 has a rounded chamfer with a radius of 0.3mm. This facilitates the insertion of the punch into the inner hole of the part.
[0025] It should be noted that the above description is merely a technical solution of the utility model and not a limitation. Although the present utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of the utility model without departing from the scope of the present utility model, and all such modifications and substitutions should be covered within the scope of the claims of the present utility model.
Claims
1. A punch formed by extrusion with a fixed inner diameter, characterized in that: include: A feed calendering punch (1) is provided, comprising a body (11) and a feed head (12). The feed head (12) is located at the front end of the body (11). The feed head (12) includes a transition section (121), a calendering section (122), and a feed end (123). The transition section (121) is connected to the body (11). The calendering section (122) is located at the front end of the transition section (121), and the feed end (123) is located at the front end of the calendering section (122). The diameter of the calendering section (122) is larger than the diameter of the feed end (123). The calendering section (122) has a smooth transition design between the feed end (123) and the transition section (121).
2. A punch formed by extrusion with a fixed inner diameter according to claim 1, characterized in that: The diameter of the rod body (11) is larger than the diameter of the transition part (121), and the rod body (11) and the transition part (121) are connected by a sloping transition structure.
3. A punch formed by extrusion with a fixed inner diameter according to claim 1, characterized in that: The diameter of the feed end (123) is greater than or equal to the diameter of the transition section (121).
4. A punch formed by extrusion with a fixed inner diameter according to claim 1, characterized in that: The calendering section (122) includes a calendering area (1221), an arc transition area (1222), and a material exit transition area (1223). An arc transition area (1222) is provided between the calendering area (1221) and the material exit end (123), and a material exit transition area (1223) is provided between the calendering area (1221) and the transition section (121). The arc transition area (1222) and the material exit transition area (1223) are designed as smooth transitions.
5. A punch formed by extrusion with a fixed inner diameter according to claim 4, characterized in that: The diameter of the calendering zone (1221) is 0.03-0.1 mm larger than the diameter of the feed end (123).
6. A punch formed by extrusion with a fixed inner diameter according to claim 4, characterized in that: The radius of the arc in the arc transition zone (1222) is 6.5 mm, and the radius of the arc in the material exit transition zone (1223) is 5 mm.
7. A punch bar formed by extrusion with a fixed inner diameter according to claim 1, characterized in that: The feed end (123) has a rounded chamfer with a radius of 0.3 mm on its outer periphery.