Forge-forming method of tooth form

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 on the upper end of a lower punch, causing a portion of the material to flow into the area where the tooth shape is formed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-154794 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technique disclosed in Patent Document 1 has a problem in that the vicinity of the protrusions becomes an enclosed 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 die structure including at least an upper punch, a tooth profile 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 face 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. Effect 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 in the vicinity of the protrusions. [Brief description of the drawings]

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

[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-shaped die, a lower punch, and a sleeve punch, and capable of freely operating each die, 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 material 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 push 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. In addition, by applying an outward material flow, the material is filled into the underfilled portion of the tooth tip of the tooth portion 104. FIG. 3 is a schematic diagram for explaining the details of the material tip. As shown by the arrow in FIG. 3, the underfilled portion 120 of the material tip is formed by the lower punch 103, and the material is filled into the underfilled portion of the tooth tip. 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 retreated, and the process 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 for explaining 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 generate a divided flow in which the material flows on the inside and outside. As a result, the material at the tooth profile tip is filled at low pressure 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 to bring the tip of the material 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 internal drilling prior to forming, and the process can be shortened.

[0017] In addition, according to the method of forging the tooth profile of this embodiment, the occurrence of underfill at the tip of the tooth profile where material is not filled can be reduced, and the life of the tooth profile can be extended.

[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 tip of the tooth profile with material, 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 in order to fill the material for 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. Since there is no increase in the number of processes, costs can be reduced.

[0020] The present invention is not limited to the above-mentioned embodiment, and can be modified as appropriate without departing from the spirit of the present invention. The above-mentioned embodiment is a forging method suitable for a tooth type, specifically a helical tooth type used in a transaxle, but any member that requires shaping at the tip of the material can be applied. In addition, the above-mentioned embodiment is described as an upper punch, a tooth type die, a lower punch, and a sleeve punch, but the upper punch and the lower punch are not limited to vertical movements, and any punch that pushes against each other in a non-vertical direction can be applied. [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 being 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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