Mandrel for radial forging and elongation of hollow shaft parts and method of using the mandrel
By designing a mandrel for hollow shaft parts, it sets several circumferentially distributed inclined surfaces at the intersection of the outer circle and the conical surface, the problem of poor contact between the traditional mandrel and the inner cavity of the part is solved, and the wall thickness of the part is achieved The stability of strength reduces equipment vibration during forging.
Patent Information
- Application Number
- CN202211248597.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-10-12
- Publication Date
- 2025-02-11
- Estimated Expiration
- 2042-10-12
AI Technical Summary
During the radial forging of hollow shaft parts, traditional mandrels have poor contact with the cone surface of the inner cavity of the part, resulting in large vibrations in the equipment, slipping or locking of the mandrels, making the wall thickness difficult to control, and the wall thickness and strength of the cone surface in the transition area of the part are difficult to control. Meet the requirements.
A mandrel for radially forging and elongating hollow shaft parts is designed, with one end of which is set as a conical surface, and several circumferentially distributed inclined surfaces are provided at the intersection of the outer circle and the conical surface. The mandrel comes into contact with the conical surface of the inner cavity of the part through the tapered surface, and the inclined surface comes into contact with the outer surface of the part, forming a stable circumferential fixation, reducing equipment vibration, and ensuring the stability of wall thickness and strength.
By setting the inclined surface, the mandrel forms a stable circumferential fixation with the parts, reducing equipment vibration during forging, ensuring the stability of the wall thickness of the part processing section, and achieving satisfactory results in the thickness and strength of the cone surface in the transition area.
Smart Images
Figure CN115446245B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of radial forging of hollow shaft parts, and in particular to a core rod used for radial forging and elongation of hollow shaft parts and a use method thereof. Background Art
[0002] In the radial forging and elongation process of hollow shaft parts, forging is usually carried out with the help of a mandrel. The traditional mandrel is generally a round rod. When there is a transition cone in the middle of the inner cavity of the hollow shaft part, there are some problems in the forging of the part: the mandrel extends into the inner cavity of the part, and the mandrel and the inner cavity cone of the part cannot ensure good contact, the equipment vibrates greatly during the forging process, the mandrel is prone to slipping or locking, the wall thickness of the part processing section is difficult to control, or the mandrel is difficult to remove; the wall thickness of the transition area of the part cone is difficult to control, and the strength is difficult to meet the product requirements. Summary of the invention
[0003] In view of the problems existing in the above-mentioned prior art, the present invention aims to propose a core rod for radial forging and elongation of hollow shaft parts and a method of using the same, so as to solve the problem of large vibration of equipment during the part forging process and difficulty in controlling wall thickness.
[0004] In order to achieve the above objectives, the present invention proposes a mandrel for radial forging and elongation of hollow shaft parts, wherein one end of the mandrel is set as a cone, and a plurality of inclined surfaces are set at the position where the outer circle of the mandrel intersects with the cone, and each of the inclined surfaces is evenly distributed along the circumference of the mandrel.
[0005] In the above scheme: the inclined surfaces are closely connected along the circumference of the core rod. When the inclined surfaces are of the same size, the more inclined surfaces there are, the more stable the circumferential fixation of the core rod and the corresponding hollow shaft parts during subsequent processing.
[0006] In the above scheme: the inclined surface is elliptical, and the elliptical inclined surface is easy to process and can be obtained by oblique cutting.
[0007] The present invention also proposes a method for using a mandrel for radial forging and elongation of hollow shaft parts. The hollow shaft parts are divided into an unprocessed section with a large inner diameter and a processed section with a small inner diameter. The inner cavity between the processed section and the unprocessed section of the part is in a conical transition. The method for using the mandrel comprises the following steps:
[0008] S1, loading, making the processed section of the part contact with the top holding mold;
[0009] S2, one end of the mandrel cone extends from the unprocessed section of the part, and the mandrel cone contacts the inner cone of the part to form a pre-tightening fixation;
[0010] S3, the mandrel drives the part into the forging box and drives the part to rotate, so that the outer surface of the part corresponding to the mandrel inclined surface is in the forging position first;
[0011] S4. The outer surface of the part corresponding to the mandrel inclined surface contacts the forging die, and the part begins to deform inward under the force, so that the gap between the mandrel inclined surfaces and the inner surface of the part is filled, the mandrel and the part are fixed in the circumferential direction, and the mandrel drives the part to rotate synchronously;
[0012] S5. The mandrel drives the part forward to feed the material, and the forging and drawing of the unprocessed section of the part is completed through the forging box;
[0013] S6. After the processing is completed, open the forging box, retreat the mandrel as a whole to the unloading position, fix the outer circle of the part, and then pull the mandrel out of the part. The mandrel is used once.
[0014] In the above scheme: the end of the core rod away from the conical surface is clamped in a rotating jaw, the rotating jaw and the holding mold are on the same axis, and the rotating jaw can drive the core rod to rotate and move axially.
[0015] In the above scheme: the outer diameter of the mandrel matches the inner diameter of the unprocessed section of the part, and the conical surface of the mandrel matches the conical surface of the inner cavity of the part, which is more conducive to the mandrel driving the part to rotate synchronously, reducing equipment vibration and ensuring the forging effect.
[0016] The beneficial effects of the present invention are:
[0017] A number of inclined surfaces are arranged along the circumferential direction at the intersection of the outer circle of the mandrel and the conical surface. This position is the first to be stressed during forging. After being stressed, the part material flows and deforms to fill the gap between the inclined surface and the conical surface of the part's inner cavity. The mandrel and the part are stably fixed in the circumferential direction. The part can drive the mandrel to rotate synchronously, which can effectively reduce the vibration of the equipment during the forging process and ensure the stability of the wall thickness of the part processing section. Moreover, the conical surface of the mandrel fits the conical surface of the inner cavity of the part. During forging, the wall thickness of the conical surface in the transition area of the part can be ensured to be stable, so that its strength meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the structure of the mandrel.
[0019] Figure 2 It is a schematic diagram of the structure after the core rod and parts are assembled. DETAILED DESCRIPTION
[0020] like Figure 1 As shown in FIG. 2 , a core rod for radial forging and elongation of hollow shaft parts is provided. One end of the core rod 1 is provided with a conical surface 101. A plurality of inclined surfaces 102 are provided at the position where the outer circle of the core rod 1 intersects with the conical surface 101. The inclined surfaces 102 are evenly distributed along the circumference of the core rod 1.
[0021] Preferably, the inclined surfaces 102 are closely connected along the circumference of the core rod 1. When the inclined surfaces 102 are of the same size, the more inclined surfaces 102 there are, the more stable the circumferential fixation of the core rod 1 and the corresponding hollow shaft part during subsequent processing.
[0022] Preferably, the bevel 102 is elliptical, and the elliptical bevel 102 is easy to process and can be obtained by oblique cutting.
[0023] Hollow shaft parts are divided into an unprocessed section with a large inner diameter and a processed section with a small inner diameter. The inner cavity between the processed section and the unprocessed section of part 2 is a conical transition. The method for using the mandrel for radial forging and elongation of hollow shaft parts mainly consists of the following steps:
[0024] Load the material and bring the processed section of part 2 into contact with the top holding mold 3.
[0025] One end of the conical surface 101 of the core rod 1 extends from the unprocessed section of the component 2, and the conical surface 101 of the core rod 1 contacts the conical surface of the inner cavity of the component 2 to form a pre-tight fixation.
[0026] The mandrel 1 drives the part 2 to extend into the forging box and drives the part 2 to rotate (the mandrel 1 does not drive the part 2 to rotate synchronously at this time), and firstly makes the outer surface of the part 2 corresponding to the inclined surface 102 of the mandrel 1 be in the forging position.
[0027] The outer surface of part 2 corresponding to the inclined surface 102 of mandrel 1 contacts the forging die, and part 2 begins to deform inward under force, so that the gap between the inclined surfaces 102 of mandrel 1 and the inner surface of part 2 is filled, mandrel 1 and part 2 are fixed circumferentially, and mandrel 1 drives part 2 to rotate synchronously.
[0028] The core rod 1 drives the part 2 to be fed forward, and the forging and drawing of the unprocessed section of the part 2 is completed through the forging box.
[0029] After the processing is completed, the forging box is opened, the core rod 1 is retreated as a whole to the unloading position, the outer circle of the part 2 is fixed, and then the core rod 1 is pulled out from the part 2, and the core rod 1 is used once.
[0030] Preferably, the end of the core rod 1 away from the conical surface 101 is clamped in a rotating jaw, and the rotating jaw and the supporting mold 3 are on the same axis. The rotating jaw can drive the core rod 1 to rotate and move axially.
[0031] Preferably, the outer diameter of the mandrel 1 matches the inner diameter of the unprocessed section of the part 2, and the conical surface 101 of the mandrel 1 matches the conical surface of the inner cavity of the part 2, which is more conducive to the mandrel 1 driving the part 2 to rotate synchronously, reducing equipment vibration and ensuring the forging effect.
Claims
1. A method for using a mandrel for radial forging and elongation of hollow shaft parts, characterized in that: One end of the mandrel (1) is provided with a conical surface (101), and a plurality of inclined surfaces (102) are provided at the position where the outer circle of the mandrel (1) and the conical surface (101) intersect, and each of the inclined surfaces (102) is evenly distributed along the circumference of the mandrel (1); the hollow shaft part is divided into an unprocessed section with a large inner diameter and a processed section with a small inner diameter, and the inner cavity between the processed section and the unprocessed section of the part (2) is in a conical transition; The method of use includes the following steps: S1, loading, bringing the processed section of the part (2) into contact with the holding mold (3); S2, one end of the conical surface (101) of the mandrel (1) extends into the unprocessed section of the component (2), and the conical surface (101) of the mandrel (1) contacts the conical surface of the inner cavity of the component (2) to form a pre-tightening fixation; S3, the mandrel (1) drives the part (2) to extend into the forging box and drives the part (2) to rotate, so that the outer surface of the part (2) corresponding to the inclined surface (102) of the mandrel (1) is first placed in the forging position; S4, the outer surface of the part (2) corresponding to the inclined surface (102) of the mandrel (1) contacts the forging die, and the part (2) begins to deform inwards under force, so that the gaps between the inclined surfaces (102) of the mandrel (1) and the inner surface of the part (2) are filled, the mandrel (1) and the part (2) are fixed in the circumferential direction, and the mandrel (1) drives the part (2) to rotate synchronously; S5, the mandrel (1) drives the part (2) to move forward and feed the material, and the unprocessed section of the part (2) is forged and stretched through the forging box; S6. After the processing is completed, the forging box is opened, the mandrel (1) is retreated as a whole to the unloading position, the outer circle of the part (2) is fixed, and then the mandrel (1) is pulled out from the part (2), and the mandrel (1) is used once.
2. The method for using the mandrel for radial forging and elongation of hollow shaft parts according to claim 1, characterized in that: The inclined surfaces (102) are closely connected along the circumference of the core rod (1).
3. The method for using the mandrel for radial forging and elongation of hollow shaft parts according to claim 2, characterized in that: The inclined surface (102) is elliptical.
4. The method for using the mandrel for radial forging and elongation of hollow shaft parts according to claim 1, characterized in that: One end of the core rod (1) away from the conical surface (101) is clamped in a rotating clamp. The rotating clamp and the holding mold (3) are on the same axis. The rotating clamp can drive the core rod (1) to rotate and move axially.
5. The method for using the mandrel for radial forging and elongation of hollow shaft parts according to claim 1, characterized in that: The outer diameter of the core rod (1) matches the inner diameter of the unprocessed section of the part (2), and the conical surface (101) of the core rod (1) matches the conical surface of the inner cavity of the part (2).
Citation Information
Patent Citations
Car longitudinal thrust seamless steel pipe's for pole cold drawing mould
CN208728336U