JP7619285B2 - Cutting method - Google Patents

Description

The present invention relates to a cutting method.

Patent Document 1 discloses an apparatus and method for cutting hypoid gears using a grinding wheel.
In addition to the method described in Patent Document 1, there is also a method of cutting hypoid gears using a gear cutting milling cutter equipped with a blade made of cemented carbide.
Incidentally, the blade of a gear milling cutter may be cut by grinding wheel cutting in order to reshape the cutting edge.

JP 2013-212577 A

Gear cutting milling blades are generally made from ultra-hard materials, so cutting the blades with a grinding wheel can easily cause chipping of the blades and cause significant wear on the cutting wheel.

The present invention was made to solve these problems, and aims to provide a cutting method that can reduce chipping of the gear cutting milling blade and reduce wear on the cutting wheel.

The cutting method according to the present invention comprises the steps of:
A cutting method for cutting a gear milling blade with a rotating disk-shaped cutting wheel, comprising the steps of:
The blade has a bottom surface having a rake surface and opposing side surfaces having clearance surfaces;
The cutting wheel is moved from one side of the blade to the other side to cut the blade.
This is a cutting processing method.

With this configuration, the cutting wheel cuts the gear milling blade from the side with the lower hardness, reducing the cutting load. As a result, chipping of the blade is suppressed and the amount of wear on the cutting wheel is reduced.

The present invention provides a cutting method that can reduce chipping of the gear cutting blade and reduce wear on the cutting wheel.

FIG. 2 is a perspective view showing the shape of a blade. FIG. 2 is a perspective view showing the shape of a hypoid gear. FIG. 2 is a perspective view showing a gear cutting milling cutter for cutting hypoid gears. 1 is a perspective view showing the positions of a scooping face 111 and a bottom face A. FIG. 1 is a perspective view showing the positions of the clearance surface 112 and the side surface B. FIG. 1 is a perspective view showing a process for reshaping the cutting edge of a blade. FIG. 1A to 1C are schematic diagrams for explaining a cutting method according to a general technique. 1 is a schematic diagram showing a configuration of a cutting apparatus according to a first embodiment; 1A to 1C are schematic diagrams for explaining a cutting method according to a first embodiment.

(First embodiment)
<Gear cutting milling blade>
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, the gear milling cutter blade according to this embodiment will be described in detail.
However, hereinafter, the blade of the gear cutting milling cutter will be simply referred to as the blade.

Figure 1 is a perspective view showing the shape of a blade according to the first embodiment. The blade 1 according to this embodiment is a rod-shaped blade having a cutting edge 11, and is made of a cemented carbide alloy whose main component is, for example, tungsten carbide.

However, it should be understood that the right-handed xyz Cartesian coordinate system shown in FIG. 1 and other drawings is merely for the sake of convenience in explaining the positional relationships of the components. In this embodiment, the z-axis is taken in the direction in which the blade 1 extends, the x-axis is taken parallel to the bottom surface A, which will be described later, and the y-axis is taken parallel to the side surface B, which will be described later.

The blade 1 is used, for example, in cutting a hypoid gear W as shown in FIG.
Fig. 3 is a perspective view showing a gear cutting milling cutter for cutting hypoid gears. As shown in Fig. 3, the blade 1 is attached to a gear cutting machine 2 of the gear cutting milling cutter F. More specifically, the blade 1 is attached to the gear cutting machine 2 by inserting the part other than the cutting edge 11 into a hole-shaped mounting portion 21 provided in the gear cutting machine 2.
The blade 1 attached to the gear cutting machine 2 rotates in the circumferential direction of the gear cutting machine 2 as the gear cutting machine 2 rotates about a rotation axis X. The rotating blade 1 cuts the hypoid gear W to perform gear cutting.
For simplicity, only one blade 1 is attached to the gear cutting machine 2 in FIG. 3, but in practice, it is preferable that a plurality of blades 1 be attached.

Returning to the explanation of FIG.
The cutting edge 11 is a part that cuts the hypoid gear W, and includes a cutting face 111 and a clearance face 112 .

4A is a perspective view showing the position of the rake face 111. The rake face 111 is a surface that comes into direct contact with the surface of the hypoid gear W when cutting the hypoid gear W, and gouges out the surface of the hypoid gear W.
4B is a perspective view showing the position of the bottom surface A. In this specification, among the surfaces of the blade 1, the surface A on which the rake surface 111 is formed is defined as the bottom surface A of the blade 1.

5A is a perspective view showing the position of the flank 112. The flank 112 is a surface that shares a common side with the rake face 111. It is preferable that the flank 112 does not come into direct contact with the surface of the hypoid gear W when cutting the hypoid gear W.
5B is a perspective view showing the position of side surface B. In this specification, among the surfaces of the blade 1, surface B on which the relief surface 112 is formed is defined as the side surface B of the blade 1.
For simplicity, only one clearance surface 112 and one side surface B are shown in Figures 5(a) and 5(b), but there are two clearance surfaces 112 and two side surfaces B for one blade, and the two side surfaces B face each other.

As described above, the rake face 111 is in direct contact with the surface of the hypoid gear W, and the flank face 112 is not in direct contact with the surface of the hypoid gear W. Therefore, the blade 1 is manufactured so that the hardness of the bottom surface A, which includes the rake face 111, in the out-of-plane direction is higher than the hardness of the side surface B, which includes the flank face 112, in the out-of-plane direction. In other words, the hardness of the blade 1 in the y-axis direction is higher than the hardness in the x-axis direction.

In addition, when comparing the short-side length of bottom surface A to the short-side length of side surface B, the short-side length of side surface B is longer. In other words, when comparing the length of blade 1 in the x-axis direction to the length of blade 1 in the y-axis direction, the length in the y-axis direction is longer.

<How the issue arose>
Next, the circumstances under which the problem of the present invention arises will be described.
There are cases where the blade 1 needs to have the cutting edge 11 reshaped due to, for example, a change in the design of the hypoid gear W. Fig. 6 is a perspective view showing a process for reshaping the cutting edge 11 of the blade 1.
The reshaping of the blade portion 11 includes a step of removing the blade portion 11 from the blade 1 by cutting, and a step of grinding the blade 1 from which the blade portion 11 has been removed to form a new blade portion 11.

Figure 6(a) is a perspective view showing the shape of the blade 1 before the blade portion 11 is reshaped. First, the blade 1 is cut at a cutting plane C parallel to the xy plane, and the blade portion 11a before reshaping is removed.

Figure 6(b) is a perspective view showing the shape of the blade 1 after the cutting edge 11a has been removed. The blade 1 after the cutting edge 11a has been removed is then molded into a new cutting edge 11c, for example, by grinding. Figure 6(c) is a perspective view showing the shape of the blade 1 after the remolding of the cutting edge 11 has been completed.

Here, a method for cutting off the blade portion 11 before reshaping from the blade 1 in a general technique, that is, a cutting processing method according to a general technique, will be described.
7 is a schematic diagram for explaining a cutting method according to a general technique. In the cutting method according to the general technique, the blade 1 is cut by a rotating disk-shaped cutting grindstone 931 to perform cutting processing. That is, in the cutting method according to the general technique, the blade 1 is cut by grindstone cutting.

In a cutting method according to a common technique, first, the blade 1 is placed on the work table 932 and fixed by the vices 933a and 933b. More specifically, in order to stabilize the blade 1, the blade 1 is placed and fixed so that the side B is supported by the work table 932.

Next, while rotating, the cutting grindstone 931 is moved horizontally toward the bottom surface A of the blade 1 to cut the blade 1, and cut the blades 1a and 1b along the cutting plane C shown in FIG. 6. In other words, the cutting grindstone 931 cuts and cuts the blade 1 while moving in the out-of-plane direction of the bottom surface A.

As described above, the hardness of the bottom surface A in the out-of-plane direction is higher than the hardness of the side surface B in the out-of-plane direction. That is, in a cutting method according to a general technique, the blade 1 is cut from the direction having higher hardness.
In cutting with a grindstone, the harder the workpiece is, the more the cutting wheel wears and the more likely the workpiece will chip.
In other words, the cutting method according to the general technology has a problem in that the cutting wheel wears a lot and the blade 1 is easily chipped.

<Overview of the embodiment>
In order to solve the above-mentioned problems, the cutting method according to this embodiment cuts the blade 1 from the direction of lower hardness. That is, in the cutting method according to this embodiment, the cutting wheel is moved from one side B of the blade 1 to the other side B to cut the blade 1.

<Cutting equipment>
Hereinafter, a cutting method according to the present embodiment will be described with reference to the drawings. The cutting method according to the present embodiment is performed by a cutting apparatus 3 shown in FIG.
First, the configuration of the cutting device 3 will be described in detail.

Figure 8 is a schematic diagram showing the configuration of the cutting device according to the first embodiment. The cutting device 3 is a cutting device that cuts the workpiece with a grindstone, and includes a cutting wheel 31, a worktable 32, and a vice 33.

The cutting grindstone 31 is a disk-shaped grindstone that rotates in a circumferential direction around a rotation axis 311. In Fig. 8, the cutting grindstone 31 is illustrated as rotating counterclockwise, but it may also rotate clockwise.
The cutting wheel 31 may be rotated by, for example, a motor (not shown) as a power source. The rotational movement of the cutting wheel 31 may be controlled by a control computer (not shown).
The cutting wheel 31 is configured to be movable horizontally along the rotation plane. The movement of the cutting wheel 31 may be controlled by a control computer (not shown).
The cutting wheel 31, while rotating, moves toward the blade 1 fixed by a work table 32 and a vise 33, and cuts and cuts the blade 1. More specifically, the cutting wheel 31 moves from one side B of the blade 1 to the other side B, and cuts the blade 1.
The cutting wheel 31 may cut one blade 1 or a plurality of blades 1 in one cutting process.

The work table 32 is a table for supporting the blade 1. The work table 32 supports the bottom surface A of the blade 1.
The vice 33 is a fixture for fixing the blade 1. Two vices 33 are present on the workbench 32, and in Fig. 8, they are indicated as vices 33a and 33b. The vices 33 apply a force to the blade 1 so as to clamp it from the horizontal direction and fix it. More specifically, the vice 33 applies a force in the out-of-plane direction to the side surface B of the blade 1 to clamp it and fix it.

Here, the work table 32 and the vice 33 may fix one blade 1 or multiple blades 1. However, from the viewpoint of the stability of the blade 1, it is preferable that the work table 32 and the vice 33 fix multiple blades 1, and it is even more preferable to fix a number of blades 1 such that the total length of the short side of the bottom surface A of the blade 1 exceeds the length of the short side of the side surface B.

<Cutting method>
Next, the cutting method according to this embodiment will be described in detail.
FIG. 9 is a schematic diagram for explaining the cutting method according to the first embodiment.

In the cutting method according to this embodiment, first, the work table 32 and the vice 33 fix the blade 1. The number of blades 1 to be fixed may be one or more, but it is preferable to fix more than one in terms of the stability of the blade 1. In Fig. 9, four blades 1 are fixed as an example.
The blade 1 has a bottom surface A supported on a work table 32 and a side surface B fixed by a vice 33 from the out-of-plane direction.

Next, the rotating cutting grindstone 31 moves from one side surface B of the blade 1 to the other side surface B along the rotation plane. The rotating cutting grindstone 31 starts cutting the blade 1 from the out-of-plane direction of the side surface B from the timing when it comes into contact with the blade 1, and continues moving until all of the fixed blades 1 are cut.
In order to prevent thermal cracking of the blade 1, cutting of the blade 1 may be performed while spraying cooling water on the blade 1.

In this way, the cutting method according to this embodiment cuts the blade 1 while moving from one side B of the blade 1 to the other side B, so that the blade 1 can be cut from the out-of-plane direction of the side B. In other words, the cutting method according to this embodiment can cut the blade 1 from the direction of lower hardness, and as a result, the occurrence of chipping of the blade 1 can be suppressed, and the amount of wear of the cutting wheel 31 can be suppressed.

The present invention has been described above in accordance with the above embodiment, but the present invention is not limited to the configuration of the above embodiment, and of course includes various modifications, alterations, and combinations that a person skilled in the art could make within the scope of the invention of the claims of this application.

1, 1a to 1d Blade 2 Gear cutting machine 3, 903 Cutting processing device 11, 11a, 11c Blade portion 21 Mounting portion 31, 931 Cutting wheel 32, 932 Work table 33, 33a, 33b, 933, 933a, 933b Vice 111 Rake surface 112 Relief surface 311 Rotation shaft W Hypoid gear F Gear cutting milling cutter

Claims (1)

A cutting method for cutting a gear milling blade with a rotating disk-shaped cutting wheel, comprising the steps of:
The blade has a bottom surface having a rake surface and opposing side surfaces having clearance surfaces;
The cutting wheel is moved from a side where one of the flanks is located to a side where the other of the flanks is located in a direction perpendicular to the extending direction of the blade , thereby cutting the blade.
Cutting processing method.

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