JP2000039055A - Gear member and forming method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear member, where the generation of noise and vibration is reduced, and a forming method therefor. SOLUTION: The tooth surface shape of a gear 2 being a workpiece is formed in a different gear surface shape at a given cycle and the formation position of an individual tooth is not arranged in the objective position of the surface of the gear but arranged at random at a given cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear member and a method of manufacturing the same, and more particularly, to a gear member manufactured by plunge cut shaving and the like and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, when a gear member (hereinafter referred to as a "gear") is formed by machining, a tool for shaving a target gear is prepared in advance, and a workpiece having a predetermined shape is cut by the tool. Will be

FIG. 7 and FIG. 8 are diagrams for explaining a general method of producing a gear as a conventional example. FIG.
FIG. 8 shows an example in which a gear 12 as a workpiece is cut by an external gear type tool 11, and FIG. 8 shows an example in which a gear 14 as a workpiece is cut by a so-called internal gear type tool 13. ing.

In a conventional general machining method using such a tool, all the teeth of the tool are prepared in advance in a similar tooth surface shape, and the tool having the tooth surface prepared and a workpiece having a predetermined shape are combined. By rotating while contacting
The surface of the work is cut or ground. As a result, teeth having a shape in which the tooth surface of the tool is inverted are formed on the surface of the work. In this case, since all the teeth of the tool have the same tooth surface shape, all the teeth of the gear created by the tool have a uniform shape.

[0005]

However, in the above-mentioned conventional processing method, since all the teeth of the completed gear have a uniform shape, when the gear is actually engaged with another gear and rotated, the gear is rotated. In addition, unpleasant noise is generated by vibration due to rotation, and resonance occurs due to regular vibration of the meshed gears, which may make normal rotation operation difficult.

Accordingly, an object of the present invention is to provide a gear member which generates less noise and vibration, and a method for producing the same.

[0007]

To achieve the above object, a gear member according to the present invention has the following features.

That is, the total number of teeth Ng of the gear member
Is the number of teeth equally divided into k (where k is a natural number) is defined as one period, and the tooth flank shape of a plurality of teeth included in the one period is different from each other, and is included in another period. The pattern of the tooth surface shape of the plurality of teeth is the same as the pattern of the tooth surface shape in the one cycle.

Further, preferably, each tooth included in the one cycle is displaced by a different distance from a reference position obtained by equally dividing the periphery of the gear member by the number of teeth Ng around the rotation axis of the gear member. It is good to be formed in the position which did.

In order to achieve the above object, a method of manufacturing a gear member according to the present invention has the following features.

That is, a method of producing a gear member using a predetermined tool, wherein the number of teeth N
g is set to be divisible by an arbitrary natural number Nf,
The number of teeth Nc of a tool for forming the gear member is represented by Ng / Nf.
= K (k is a natural number), and Nc = (nk + 1) Nf (where n = 0, 1, 2,...) Is set so as to satisfy the following relationship. As one cycle, the tooth surface shape of the plurality of teeth included in the one cycle is different from each other, and the pattern of the tooth surface shape of the plurality of teeth included in another cycle,
It is characterized in that the gear member is formed by the tool with the same pattern as the tooth surface shape in the one cycle.

Further, preferably, each tooth included in the one cycle of the tool is different from a reference position obtained by equally dividing the periphery of the member by the number of teeth Ng around the rotation axis of the gear member. It is preferable that the gear member is formed at a position displaced by a distance and the tool is used to form the gear member.

[0013]

An embodiment of the present invention will be described below in detail with reference to the drawings. In the present embodiment, a method of manufacturing a gear member according to the present invention will be described by way of example, as applied to plunge cut shaving using an external gear type tool as shown in FIG.

First, an outline of the present embodiment will be described.
In order to reduce noise and vibration generated when using the completed gear, as a specific means, [1] the tooth surfaces of a plurality of teeth on the gear surface are formed into different tooth surfaces at a predetermined cycle. [2] The individual tooth formation positions are not arranged at target positions on the surface of the gear, but are randomly arranged at a predetermined cycle. This disturbs the periodicity of the meshing state when the completed gears are used, reduces the generation of noise, and prevents the meshed gears from resonating.

[1] First, a description will be given of a specific method of forming the tooth surface shapes of a plurality of teeth on the gear surface so as to be different at a predetermined cycle.

In this embodiment, first, the number of teeth Ng of a gear as a workpiece is set so as to be divisible by an arbitrary natural number Nf. Next, the number of teeth Nc of the tool is calculated as N
Assuming that g / Nf = k (k is a natural number), Nc = nNg + Nf = (nk + 1) Nf (where n = 0, 1, 2,...) (1) .

FIG. 1 shows an example in which the number of gear teeth Ng and the number of tool teeth Nc are set so as to satisfy the above equation (1).
This will be described with reference to FIG.

FIG. 1 is a diagram showing a positional relationship between a tool and a gear in an external gear type tool as one embodiment of the present invention, and shows a case where n = 2 and k = 3.

In the tool 1 shown in FIG. 1, among all the number of teeth Nc of the tool, 7 teeth having the same tooth surface shape are included.
(For example, at each position from, the tooth surface shape is the same). Further, in the Nf continuous teeth of the tool 1, the individual tooth surface shapes are different, and in the present embodiment, a plurality of tooth patterns (hereinafter, pattern A) having Nf different tooth surface shapes are used. Present 7 times.

On the other hand, the gear 2 is machined by the tool 1 provided with teeth having the same tooth surface shape as Nf, and in FIG. 1, since there is a relationship of Ng = 3Nf, a and b , C, a tooth having the same tooth surface shape is formed.

Here, the shape of the teeth of the tool 1 will be described.

FIG. 3 is a perspective view showing one of the tooth flank shapes of the external gear type tool as one embodiment of the present invention.
One of the Nc teeth is shown.

As shown in the figure, the teeth 11 are provided with a plurality of serrations for cutting the abutted working surface. Each of these serrations is arranged at a predetermined pitch, but Nf teeth (teeth 1) included in pattern A are included.
In 1), the shape of each serration is different, and the inverted shape of these teeth is the gear 2 which is the workpiece.
Formed on the surface.

Next, the fact that the teeth of the tool 1 for machining a certain position a on the gear 2 are a plurality of teeth having the same tooth surface shape on the tool 1 will be described with reference to FIG. .

FIG. 4 is a diagram for explaining the positional relationship between the tool and the gear according to the embodiment of the present invention.

Referring to the case where the position a of the gear 2 and the position of the tool 1 shown in FIG. 1 are in contact with each other, when the gear 2 makes one rotation from this state, the position a of the gear 2 , And when it makes another rotation, the position a of the gear 2 comes into contact with the position of the tool 1 (= nk + 1). Then, after the rotation is further repeated, when the gear 2 rotates seven times, the position a at the time of zero rotation again is obtained.
Is returned to the state where the gear and the position are in contact with each other, and it can be seen that there is periodicity between the gear 2 and the tool 1.

Therefore, when the tool 1 and the gear 2 satisfying the above conditions are brought into contact with each other and rotated, the same portion (position a) of the gear 2 is included in the tool 1 and a plurality of teeth having the same shape are included. By the faces (,...), The tooth faces can be formed in an inverted shape.

FIG. 5 is a view showing the shape of teeth formed on a tool according to an embodiment of the present invention.

In the teeth 21 shown in FIG. 2, CRN indicates a so-called crowning amount, TW indicates a tip tip correction amount, and RW indicates a root correction amount. In this embodiment, if the gear 2 is machined by the tool 1 shown in FIG. 1, every Nf teeth,
A tooth having the same tooth flank shape as the CRN, TW, and RW values can be formed.

FIG. 2 shows the case of an internal gear type tool (n =
2, k = 3), indicating that the tool 3 is located outside the gear 4 but is the same as the case of the external gear type tool described above.

[2] Next, a specific method of randomly arranging the positions of the teeth of the gear 2 at a predetermined cycle will be described with reference to FIG.

FIG. 6 is a view for explaining the arrangement of the positions of the gear teeth in an embodiment of the present invention.

In this embodiment, the formation position of each tooth is
The target positions on the surface of the gear 2, that is, the centers of the formation positions of the individual teeth, are arranged at every (360 / number of teeth Ng) ° in which all the positions of the teeth are centered on the rotation axis of the gear 2. (This position is indicated by a broken line in the figure as a normal tooth position P), and is created differently at a predetermined cycle.

More specifically, as shown in the drawing, the displacement amount D is set to a different value for each of the Nf teeth forming positions included in the pattern A, and the same displacement amount is set for every (Nf + 1) sheets. The individual teeth may be formed so that the D tooth 21 is repeated. That is, in order to realize such an arrangement, the position of the tooth surface of the tool 2 is set to a different value for the displacement amount D for each of the positions of forming the Nf teeth included in the pattern A, and ( (Nf + 1) Each tooth may be formed such that the teeth 21 having the same displacement amount D are repeated every sheet.

As described above, in the present embodiment, the tooth surface shape of the gear 2, which is the workpiece, is formed in a different tooth surface shape at a predetermined cycle, and the formation position of each tooth is determined by the gear position. Are not arranged at target positions on the surface, but are randomly arranged at a predetermined cycle. Accordingly, the periodicity of the meshing state when the completed gear is used can be disturbed, noise can be reduced, and the meshed gears can be prevented from generating a resonance state. Therefore, noise and vibration generated when the completed gear is used can be reduced.

In this embodiment described above, for convenience of explanation, the method of forming the tooth surface shapes of a plurality of teeth on the gear surface into different tooth surface shapes at a predetermined cycle has been described in [1]. Later, the method of randomly arranging the formation positions of the individual teeth at a predetermined cycle was described in [2]. However, in the design process before manufacturing the tool 2, the order of [2] → [1] was changed. Needless to say, the design may be performed by using the above.

[0037]

As described above, according to the present invention,
It is possible to provide a gear member that generates less noise and vibration and a method for manufacturing the same.

That is, according to the first and third aspects of the present invention, the periodicity of the meshing state when the completed gear is used is disturbed, thereby reducing the generation of noise.
Vibration caused by causing the engaged gears to resonate is reduced.

According to the first and fourth aspects of the present invention, the periodicity of the meshing state when a completed gear is used is made by randomizing the formation positions of the plurality of teeth included in the one cycle. Is further disturbed, thereby further reducing the possibility of noise and resonance caused by the meshed gears.

[0040]

[Brief description of the drawings]

FIG. 1 is a diagram showing a positional relationship between a tool and a gear in an external gear type tool as one embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship between a tool and a gear in an internal gear type tool as one embodiment of the present invention.

FIG. 3 is a perspective view showing one tooth surface shape of a tooth of an external gear type tool as one embodiment of the present invention.

FIG. 4 is a diagram illustrating a positional relationship between a tool and a gear according to an embodiment of the present invention.

FIG. 5 is a view showing the shape of teeth formed on a tool according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating an arrangement of gear tooth positions according to an embodiment of the present invention.

FIG. 7 is a view for explaining a general method of producing a gear as a conventional example (in the case of an external gear type tool).

FIG. 8 is a view for explaining a general method of producing a gear as a conventional example (in the case of an internal gear type tool).

[Explanation of symbols]

 1, 3, 11, 13: tool, 2, 4, 12, 14: gear, 5: serration, 11: tooth of tool 1, 21: tooth of gear 2,

Claims (6)

[Claims] 1. The number of teeth Ng of a gear member is represented by k
(However, k is a natural number) The number of equally divided teeth is defined as one cycle, and the tooth surfaces of the plurality of teeth included in the one cycle are different from each other, and the plurality of teeth included in another cycle are included. The gear member according to any one of claims 1 to 4, wherein the tooth surface pattern is the same as the tooth surface pattern in the one cycle. Further, each tooth included in the one cycle is displaced by a different distance from a reference position where the circumference of the gear member is equally divided by the number of teeth Ng around the rotation axis of the gear member. The gear member according to claim 1, wherein the gear member is formed at a position. 3. A method for creating a gear member using a predetermined tool, wherein the number of teeth Ng of all gear members to be created is set so as to be divisible by an arbitrary natural number Nf. The number of teeth Nc of the tool to be created is represented by Ng / Nf
= K (k is a natural number), and Nc = (nk + 1) Nf (where n = 0, 1, 2,...) Is set so as to satisfy the following relationship. One period, the tooth surface shape of the plurality of teeth included in the one period is different from each other, and the pattern of the tooth surface shape of the plurality of teeth included in the other period is the tooth in the one period. A method of making a gear member, wherein the gear member is made by using the tool, the gear member having the same pattern as the surface shape. 4. Further, each tooth included in the one cycle of the tool is at a different distance from a reference position where the circumference of the gear member is equally divided by the number Ng of teeth around the rotation axis of the gear member. The method according to claim 3, wherein the gear member is formed at a position displaced only by the tool and the tool is used to form the gear member. 5. The method according to claim 3, wherein a plurality of serrations are provided on each tooth of the tool. 6. The method according to claim 3, wherein when the gear member is formed by the tool, the gear member is formed by plunge cut shaving.