Method of forging tooth profile

Abstract

To provide a forge-forming method of a tooth form in which the blank fluidity is sufficiently generated and a material is filled into the vicinity of a projection part.SOLUTION: A forge-forming method of a tooth form by using a mold structure which includes at least an upper punch, a tooth form die, a lower punch, and a sleeve punch and in which an upper end of the lower punch is protruded. In the forge-forming method, the lower punch is lowered (S15) after raising the lower punch to mold a material end surface (S14) when performing extrusion molding of the tooth form, and the upper punch is lowered so that a material tip is brought into contact with the sleeve punch (S16).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for forging a tooth profile. [Background technology]

[0002] Patent document 1 describes a method for forming a tooth-shaped product by forging, in which pressure is applied with a tapered portion formed at the upper end of a lower punch, causing part of the material to flow into the area where the tooth shape is formed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-154794 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 has a problem in that the vicinity of the protrusions becomes a sealed space during molding, resulting in insufficient flow of the material. [Means for solving the problem]

[0005] In one embodiment, the method for forging a tooth profile uses a mold structure that includes at least an upper punch, a tooth die, a lower punch, and a sleeve punch, with the upper end of the lower punch protruding. When extruding the tooth profile, the lower punch is raised to form the end surface of the material, and then the lower punch is lowered, and the upper punch is lowered to bring the tip of the material into contact with the sleeve punch. [Effects of the Invention]

[0006] According to the method of forging the tooth profile disclosed herein, sufficient material flow occurs, and molding can be achieved in which the material is filled even near the protrusions. [Brief explanation of the drawings]

[0007] [Figure 1] 3 is a flowchart showing an example of a method for forging a tooth profile according to the present embodiment. [Figure 2] 3A to 3C are cross-sectional views illustrating steps of a method for forging a tooth profile according to the present embodiment. [Figure 3] 10 is a schematic diagram illustrating the details of the tip of the workpiece. [Figure 4] 10 is a schematic diagram illustrating the details of the tip of the workpiece. DETAILED DESCRIPTION OF THE INVENTION

[0008] This embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an example of an apparatus having a die structure consisting of an upper punch, a tooth-profile die, a lower punch, and a sleeve punch, in which each die can be freely operated, will be described. FIG. 1 is a flowchart showing an example of a method for forging a tooth profile according to this embodiment. FIG. 2 is a cross-sectional view of each step of the method for forging a tooth profile according to this embodiment. FIG. 2 shows the state of the die structure corresponding to each step of the flowchart in FIG. 1.

[0009] First, in step S11, the blank 110 is set in the tooth-profile die 101. Then, the process proceeds to step S12.

[0010] Next, in step S12, the upper punch 102 is lowered to force the material 110 into the tooth-shaped die 101. This operation starts extrusion molding of the tooth-shaped die 101. Then, the process proceeds to step S13.

[0011] Next, in step S13, the upper punch 102 is lowered to a predetermined position, and then the lowering of the upper punch 102 is stopped. Then, the process proceeds to step S14.

[0012] Next, in step S14, the lower punch 103 rises while the upper punch 102 maintains its position. This action forms the end surface of the material. Furthermore, by causing the material to flow outward, the material fills the underfill area at the tip of the tooth profile in the tooth profile portion 104. Figure 3 is a schematic diagram illustrating the details of the tip of the material. As shown by the arrow in Figure 3, the underfill area 120 at the tip of the material is formed by the lower punch 103, and the material fills the underfill area at the tip of the tooth profile. Then, the process proceeds to step S15.

[0013] Next, in step S15, the lower punch 103 is raised to a predetermined position to perform forming, and then the lower punch 103 is lowered and withdrawn, and the process then proceeds to step S16.

[0014] Next, in step S16, the upper punch 102 is lowered to extrude the tooth profile, and the tip of the material 110 is brought into contact with the sleeve punch 105. FIG. 4 is a schematic diagram illustrating the details of the material tip. As shown by the arrow in FIG. 4, when the material 110 comes into contact with the sleeve punch 105, the space (hole) created in step S14 is used to create a divided flow, with the material flowing inside and outside. As a result, the material is filled at low pressure at the tooth profile tip without creating an enclosed space. Then, the molding is completed.

[0015] Thus, according to the method of forging the tooth profile of this embodiment, the lower punch is raised to form the end surface of the material, and then the lower punch is lowered, and the upper punch is lowered, and the tip of the material is brought into contact with the sleeve punch, thereby causing sufficient flow of the material and filling the tip of the tooth profile with material.

[0016] Furthermore, according to the method of forging the tooth profile of this embodiment, the space can be created in one process, so there is no need for inner diameter drilling before forming, and the process can be shortened.

[0017] Furthermore, according to the method of forging the tooth profile of this embodiment, it is possible to reduce the occurrence of underfill at the tip of the tooth profile where material is not filled, thereby extending the life of the tooth profile.

[0018] Furthermore, according to the method of forging the tooth profile of this embodiment, there is no need to use back pressure to fill the material at the tip of the tooth profile, and no special equipment is required.

[0019] Furthermore, according to the method of forging the tooth profile of this embodiment, unlike the divided flow method in which an enclosed space is not created to fill the material of the tooth profile and reduce the forming load, there is no need for a process such as drilling the inner diameter of the material before the tooth profile is formed, and therefore no additional processes are required, resulting in cost reduction.

[0020] The present invention is not limited to the above-described embodiment, and modifications can be made as appropriate without departing from the spirit and scope of the present invention. The above-described embodiment is a forging method suitable for tooth profiles, specifically helical tooth profiles used in transaxles, but it can be applied to any component that requires shaping at the tip of the material. Furthermore, while the above-described embodiment describes an upper punch, tooth profile die, lower punch, and sleeve punch, the upper punch and lower punch are not limited to vertical movement, and any punches that push against each other in a non-vertical direction can be used. [Explanation of symbols]

[0021] 101 Tooth die 102 Upper Punch 103 Lower Punch 104 Tooth shape area 105 Sleeve Punch 110 Materials 120 parts

Claims

[Claim 1] A method for forging a tooth profile using a die structure including at least an upper punch, a tooth-profile die, a lower punch, and a sleeve punch, the upper end of the lower punch protruding, When extruding the tooth profile, the lower punch is raised to form the end surface of the material, and then the lower punch is lowered. This method involves lowering the upper punch and bringing the tip of the material into contact with the sleeve punch.

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