JPH08294818A - Gear grinding device, gear grinding method and gear grinding wheel - Google Patents

Abstract

PURPOSE: To provide a gear grinding method by which a gear can be efficiently ground without causing a slip between it and a tooth-shaped surface over a tooth number range sufficient in practical use in a grinding wheel having the same shape. CONSTITUTION: One or the other grinding surfaces 11b and 11c constituting an edge part 11a of a grinding wheel 11 and one or the other tooth-shaped surfaces 2a and 2b constituting a gear groove of an internal teeth gear 2 are selectively contacted with each other, and the grinding surface 11b and the tooth-shaped surface 2a are rollingly contacted with each other in a tooth height direction, and the tooth shaped surfaces are ground. In this case, the tooth- shaped surface 2a and the grinding surface 11b are respectively divided into plural points of a prescribed interval, and coordinates of the respective points are made to coincide in order with each other, and normal angles at the respective points are made to coincide with each other, and the grinding surface 11b of the grinding wheel 11 and the tooth-shaped surface 2a are rollingly contacted with each other in a tooth height direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear grinding device for finishing a gear by grinding after gear cutting and hardening.
The present invention relates to a gear grinding method and a gear grinding wheel used therefor.

[0002]

2. Description of the Related Art Among gears, which require particularly high precision, it is necessary to grind the tooth mold surface and perform precise finishing after gear cutting and hardening. Many grinding methods have been proposed and adopted for external gears. However, with respect to the internal gear, there is a certain limit to the grinding method that can be adopted due to the constraint due to its shape.

The methods currently used for grinding internal gears are roughly divided into a "general type grinding wheel" and a method of grinding without generating motion and a "plate type grinding wheel". It is a method of performing tooth mold grinding by a creation movement.

The former method, as shown in FIG. 19, is a disk-shaped grinding in which the edge portion 1a is formed in exactly the same shape as the tooth profile surface shape (2a, 2b) of the tooth groove of the work 2. Wheel 1
By using a (genuine die wheel) and rotating this general die wheel 1 at high speed, the tooth surface 2a, 2b is ground. This grinding method is characterized in that it is possible to grind both the left and right tooth profile surfaces 2a and 2b at the same time without performing a generating motion. Further, as an apparatus adopting this method, there is, for example, one manufactured by Granding Machine Co.

On the other hand, as the internal gear grinding device adopting the latter grinding method, for example, a device manufactured by MAG Co. can be cited. In this device, as shown in FIG. 20, a dish type wheel 3 (dish type wheel) is used, and the dish type wheel 3 is attached to a creation motion mechanism, and the toothed work 2 and First, the left tooth mold face 3a is ground by the left dish mold wheel 3 by performing a relative motion between the two, and then the right tooth mold face 2b is ground by the right dish mold wheel (not shown). To do. The grinding surface 3a of the dish-shaped wheel 3 for performing such grinding is characterized in that it is formed flat unlike the general-purpose wheel 2 formed in the same shape as the tooth surface. .

[0006]

The conventional internal gear grinding method described above has the following problems to be solved. That is, in the former method, since the full-body wheel 1 having the edge 1a formed in the same shape as the tooth groove (tooth surface 2a, 2b) is used, even if the number of teeth is one. If the number of tooth spaces is different and the tooth groove shape is different,
It is necessary to process and modify the shape of the edge portion 1a of the general-purpose wheel 1 using a dresser or the like, or to create a new general-purpose wheel that fits the gear.

In recent years, there has been a demand for high-mix low-volume production of gears, and if a grinding wheel had to be machined for each gear, the gear production efficiency would be poor and the production cost would be high.

In the latter grinding method, the tooth profile surfaces 2a and 2b are ground by the generating motion. When this generating motion is performed, the tooth profile surfaces 2a and 2b are toothed. There is always slippage between the tip and the root. For this reason, sufficient grinding cannot be performed at the root and the tip of the tooth, and the grinding efficiency may become extremely poor. Further, when slippage occurs, the abrasion of the grinding wheel becomes severe, so that there is a problem that the life of the grinding wheel must be shortened.

The present invention has been made in view of the above circumstances, and it is a grinding wheel of the same shape, which is capable of efficiently grinding the tooth profile surface over a range of practically sufficient number of teeth. An object of the present invention is to provide a gear grinding device and a gear grinding method that can be used, and further to provide a grinding wheel suitable for these devices and methods.

[0010]

The first means of the present invention is, in a gear grinding device for grinding one and the other tooth profile surfaces of a tooth groove of a gear, forming a disk shape, wherein A grinding wheel that has an edge portion thinner than the distance between the two and one and the other of the grinding surfaces that make up this edge portion have a curved surface, and that holds this grinding wheel and that By relatively driving the grinding wheel holding part for rotating the wheel, the gear holding part for holding the gear, and the grinding wheel holding part and the gear holding part, the grinding wheel And a driving means for grinding the tooth profile surface of the gear.

The second means is, in the gear grinding apparatus of the first means, controlling the driving means so as to form the tooth groove with one or the other grinding surface of the edge of the grinding wheel. The present invention is characterized by further comprising control means for selectively contacting the other tooth profile surface and rollingly contacting the grinding surface and the tooth profile surface in the tooth height direction.

[0012] A third means is a gear grinding method for grinding one and the other tooth form surfaces of a tooth groove of a gear, which is an edge portion of a disk-shaped grinding wheel that is rotationally driven. One or the other grinding surface forming the edge of the wheel is selectively brought into contact with one or the other tooth profile surface forming the tooth groove, and the grinding surface and the tooth profile surface are in the tooth height direction. The method for grinding a gear is characterized in that it includes a step of grinding the tooth profile surface by rolling contact with the gear.

A fourth means is, in the gear grinding method according to the third means, in the step, the tooth profile surface and the grinding surface of the grinding wheel are divided into a plurality of points corresponding to each other. And the normal angle at each point are made to coincide with each other, so that the grinding surface of the grinding wheel and the tooth profile surface are brought into rolling contact with each other in the tooth height direction. It is a thing.

A fifth means is characterized in that, in the gear grinding method of the third means, when performing the above-mentioned step, the step of feeding and driving the grinding wheel in the tooth trace direction at a predetermined speed is included. It is a thing.

A sixth means is a gear grinding wheel which grinds one and the other tooth surface of the tooth groove of the gear, so that the one or the other tooth surface is selectively driven by being rotated. Has an edge part that can be ground to, and this edge part has one grinding surface that can grind the one tooth surface and the other grinding surface that can grind the other tooth surface, and the one grinding surface. Has a curved surface capable of rolling contact with the one tooth profile surface in the tooth height direction, and the other grinding surface has a curved surface capable of rolling contact with the other tooth profile surface in the tooth height direction. Wheel grinding wheel.

A seventh means is the wheel grinding wheel of the sixth means, wherein the thickness of the edge portion is determined by the distance between one tooth profile surface and the other tooth profile surface forming the tooth groove. It is also characterized in that it is formed thin.

An eighth means is the gear grinding wheel of the seventh means, wherein the thickness of the edge portion is such that the one ground surface is in contact with the tip or the root of the one tooth surface. When the other grinding surface has a dimension that does not contact the root or tip of the other tooth profile surface, and the other grinding surface is on the tip or root of the other tooth profile surface, While touching,
It is characterized in that the one ground surface has a dimension such that it does not come into contact with the root or the tip of the one tooth surface.

A ninth means is the wheel grinding wheel of the sixth means, wherein the curved surfaces of the one and the other grinding surfaces constituting the above-mentioned edge portion are the same module as the above-mentioned gear and are more than those of the above-mentioned gear. A reference gear having a small number of teeth is used as a reference, and the tooth profile of the reference gear is formed to have substantially the same shape as one and the other tooth profile surfaces.

A tenth means is the gear grinding wheel of the sixth means, wherein the curved surfaces of the one and the other grinding surfaces constituting the edge portion are the same as those of the gear when grinding an external gear. Based on a reference gear having the same module and a larger number of teeth than the above gear, the tooth profile of the reference gear is formed in substantially the same shape as one and the other tooth surface. To do.

[0020]

According to the apparatus of the first means, one and the other grinding surface having an edge portion formed thinner than the distance between the tooth surface forming the tooth groove of the gear and forming the edge portion. Since a grinding wheel having a curved surface is used, it is possible to grind the tooth groove of the external gear or the internal gear into a desired shape. Further, by rollingly contacting the grinding surface of the tool with the tooth surface, the tooth surface can be ground uniformly without slipping (overall tooth surface) (second means).

According to the method of the third means, the grinding surface of the tool and the tooth profile surface are brought into rolling contact with each other, so that the grinding of the tooth profile surface can be performed uniformly over all the tooth profile surfaces without slipping. it can. Also,
For this purpose, it is preferable to adopt the method of the fourth means. Further, like the fifth means, by advancing the tool in the tooth trace direction at the same time, grinding of the tooth profile surface in the tooth trace direction can also be performed.

According to the sixth aspect of the grinding wheel, since the grinding surface of the tool can be brought into rolling contact with the tooth profile surface, grinding without slippage can be performed. Further, as in the seventh and eighth means, by forming the edge portion thin, it is possible to effectively prevent the interference between the tool and the tooth surface. Further, when grinding an internal gear, if the curved surface of the grinding surface is made to have the same shape as the tooth profile surface of the reference gear having the smallest number of teeth in practice, as in the ninth means, the same module as this reference gear is used. -It can handle all gears with a large number of teeth.

On the other hand, when grinding the external gear, the first
If the curved surface of the grinding surface is made to have the same shape as the tooth profile surface of the reference gear having the largest number of teeth in practice, all the gears having the same module and the small number of teeth can be used. Can respond.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 (a) and 1 (b) are a front view and a plan view showing a schematic configuration of a gear grinding device of the present invention.

Reference numeral 2 in the same figure shows an internal gear as a work which is ground by this device. The internal gear 2 has already been subjected to gear cutting by a gear cutting machine or the like,
As shown by citing FIG. 19, a left side tooth profile 2a and a right side tooth profile 2b are formed. Further, the internal gear 2 is hardened after the above gear cutting.

In this apparatus, a disc-shaped grinding wheel 11 is used in FIG. 1, and while rotating the grinding wheel 11, the grinding wheel 11 and the internal gear 2 are rotated in four axial directions (XYθ and Z).
Of the internal gear 2 by making relative movement in each direction).
The tooth profile surfaces 2a, 2b of No. 1 are ground into a desired shape. Hereinafter, the configuration of this device will be described in detail.

Reference numeral 12 in FIG. 1 denotes a pedestal of this gear grinding apparatus. On this pedestal 12, a table portion 13 for holding the internal gear 2 and positioning it in the XYθ directions, and the grinding. A grinding wheel driving unit 14 that holds the wheel 11 and drives it in the Z direction is provided. Then, the table portion 13 and the grinding wheel driving portion 14 are shown at 15 in FIG.
It is controlled by the CNC control unit indicated by.

The table section 13 includes an XY drive table 16 held on the gantry 12 and the XY drive table.
And a .theta. Drive table 17 held by the bull 16.
A chuck mechanism 18 for gripping and fixing the internal gear 2 is provided on the upper surface of the θ drive table 17.

That is, in the internal gear 2 held by the chuck mechanism 18, the table portion 13 is actuated so that the grinding wheel 11 held by the grinding wheel driving portion 14 is The tooth profile surfaces 2a, 2b can be moved in any direction within the XY plane, and at that position, the inclination of the tooth profile surfaces 2a, 2b can be tilted at any angle in the θ direction. ing.

On the other hand, the grinding wheel driving unit 14 is provided with a column 19 which is erected on the pedestal 12 and the column 19.
Z drive mechanism 20 provided on the front surface of the arm 21, an arm 21 attached to the Z drive mechanism 20 and extending to the table portion 13 side, and a tip end portion of the arm 21. The grinding wheel 11 held with its axis of rotation horizontal.
Consists of

That is, the grinding wheel driving unit 14 is
The grinding wheel 11 is driven to rotate about a horizontal axis at a high speed, and the grinding wheel 11 is driven in the Z direction while slidingly contacting with the tooth surface 2a (2b) of the positioned internal gear 2. Then, the tooth mold surface 2a (2b) of this internal gear 2
Can be ground.

Next, the structure of the grinding wheel 11 will be described. This grinding wheel 11 is shown in FIGS. 1 (a) and 1 (b).
As shown in FIG. 5, it has a disk shape and has an edge portion 11a formed by electrodepositing abrasive grains such as borazon. The edge portion 11a of the grinding wheel 11 has the following shape with respect to the internal gear 2 '(work) having the module and the number of teeth defined as the reference.

FIG. 2A shows the shape of the tooth profile surfaces 2'a, 2'b of the reference (internal tooth) gear 2'and the edge portion 11 of the grinding wheel 11.
It shows the relationship of the shape of a. The reference gear 2 '
Is selected as a gear that is considered to have the smallest number of teeth in practical use in any module.

The edge portion 11a of the grinding wheel 11 is composed of left and right grinding surfaces 11b and 11c. The respective grinding surfaces 11b and 11c are formed in the same shape as the left tooth profile 2'a and the right tooth profile 2'b of the reference gear 2 '. However, the thickness t of the edge portion 11a
Are formed to be smaller than the distance T between the tooth mold surfaces.

The grinding wheel 11 is not used to grind the reference gear 2 ', but the module is equal to the reference gear 2'as shown in FIG. 2 (b). The internal gear 2 having the number of teeth larger than that of the reference gear 2 '(the above-mentioned work
It is used for grinding.

As for the shapes of the tooth profile surfaces 2a and 2b of the internal gear 2 having a large number of teeth as shown in FIG. 2 (b), the change in the tangent angle thereof causes the tooth profile surface 2 of the reference gear 2 '. 'A, 2'b
The feature is that it is smaller than the change in the tangent angle of.

When the grinding wheel 11 and the conventional grinding wheels 1 and 3 shown in FIGS. 19 and 20 are compared with each other, in the general-purpose wheel 1 (FIG. 19), the edge 1a has a tooth groove. Is different in that it is formed in exactly the same shape (the same in thickness), and the dish type wheel 3 (FIG. 20) is different in that its ground surface 3a is flat.

Next, the control (grinding method) of this apparatus by the CNC controller 15 will be described. The CNC control unit 15 includes a table unit 13 and a grinding wheel driving unit 14 based on a pre-programmed grinding method.
Is operated to perform the above grinding by simultaneous control of four axes.

The above grinding method is completely different from the conventional grinding method using a full-scale wheel (FIG. 19) and the grinding method using generating motion (FIG. 20). Do as described. The grinding process will be described below with reference to the flow chart shown in FIG.

As shown in FIG. 3, this grinding step includes a grinding preparation processing step, a grinding processing step, a dimension measuring step, and a correction and re-grinding step. The grinding preparation process is
As shown in FIG. 4, the step of attaching the grinding wheel 11 and the step of inputting a program corresponding to the tooth groove shape (shape of the tooth mold surfaces 2a and 2b) of the work (internal gear 2) to be ground. And the work of attaching the work.

The internal gear 2 serving as the work is, as described above, a gear having the same module as the reference gear 2'and a larger number of teeth than the reference gear 2 '. The internal gear 2 has already been gear-cut and hardened in the previous step.

On the other hand, the grinding process which is the main part of the present invention is carried out for each tooth groove of the internal gear 2 as shown in FIG. That is, when the fraction of this internal gear is z,
Grinding of the tooth spaces is performed in the order of the first, the third, the nth, the zth. The process of grinding the n-th tooth groove will be described below with reference to the perspective view of the n-th tooth groove shown in FIG. 8 and the flowcharts of FIGS. 6 and 7.

In the grinding process of the nth tooth groove, as shown in FIG.
As shown in, first, the "grinding cycle number" and the "feed pitch" are determined. In one grinding cycle in this grinding method, as shown by the solid line arrow in FIG. 8, (a) grinding from the tip of the left tooth profile to the root, and (b) grinding from the tooth tip of the right tooth surface to the tip. Grinding, (c) grinding from the tip of the right tooth profile to the root, and (d) grinding from the root of the left tooth surface to the tip. Then, during this one cycle of grinding, the grinding wheel 11 is fed by the dimension p in the tooth trace direction (Z direction). This dimension p becomes the Z feed pitch.

In this embodiment, as shown in FIG. 8, the grinding of all the tooth traces is completed in three cycles, and the dimension p which is one third of the tooth trace dimension P is the Z feed pitch.
Next, the grinding process of the nth cycle shown in FIG. 6 (in each example, the first, second and third cycles) is performed as shown in FIG.
First, as shown in FIG. 2B, the left tooth profile 2a and the right tooth of the internal gear 2 are described with reference to the flowchart of FIG. The mold surface 2b is divided into an arbitrary number of first to z-th points from the tip of the tooth toward the root of the tooth at equal intervals. In this embodiment, it is divided into first to ninth points.

Next, the grinding surface 11 of the grinding wheel 11
b and 11c are divided into first to z'th points at equal intervals with the respective points on the tooth profile surfaces 2a and 2b. In this embodiment, the first '
~ It is divided into the 9'th point.

In the present invention, the table portion 13 and the grinding wheel driving portion 14 are operated so that the n-th point of the tooth profile 2a can be ground at the n-th point of the grinding surface,
The internal gear 2 and the grinding wheel 11 are driven relative to each other.

This relative drive will be described with reference to FIGS. 9 and 10. FIG. 10 shows points 1 and 2 on the tooth surface 2a.
FIG. 3 is an enlarged schematic view of the points 1 ′ and 2 ′ of the grinding wheel 11.

In this figure (a), point 1 of the tooth surface 2a
The coordinates at X are (X1, Y1), and the normal at this point is θ1. On the other hand, the coordinates of the point 1 ′ of the grinding wheel 11 is (X1 ′, Y1 ′), and the normal line at this point is θ1 ′.

The control section 15 operates the θ table 17 of the table section 13 to control the inclination of the internal gear 2 to thereby make the normal angle θ of the internal gear 2 at point 1.
1 is made to coincide with the normal angle θ1 ′ of the tooth profile surface 2a. Next, by operating the XY table 16 of the table portion, the internal gear 2 is driven in the XY directions, and the coordinates of the point 1 on the tooth profile 2a are adjusted to the point 1'of the grinding wheel 11. The coordinates (X1 ′, Y1 ′) of

Thus, as shown in FIG. 10 (b),
The point 1'of the grinding wheel 11 and the points 1 of the internal gear contact each other. Since the grinding wheel 11 is driven to rotate, the grinding of the tooth surface 2a of the internal gear 2 is started from this point 1. This state is shown in FIG.

Next, the control unit 15 advances the grinding of the tooth surface 2a to the point 2 which is separated from the point 1 by the minute distance ds. In this case, the same distance ds from the point 1'of the grinding wheel 11
The point 2'of the tooth profile 2a is cut at a point 2'that is separated from the point 2 '.

Now, in FIG. 10B, the coordinates of the point 2 are defined as (X2, Y2), and the normal angle at this point is θ.
Set to 2. In addition, the coordinates of the point 2 ′ are (X2 ′, Y2
′), And the normal angle at this point is θ2 ′.

To proceed with the grinding from point 1 to point 2 above,
Similar to the case of the point 1, the table unit 13 may be controlled so that the point 2 and the point 2 ′ coincide with each other. That is,
The control unit 15 operates the table unit 13 to position and drive the internal gear 2 in the XYθ directions, and determines the coordinates (X2, Y2) of the point 2 on the tooth profile 2a of the internal gear 2. By making the internal gear 2 rotate clockwise at the same time as matching the coordinates (X2 ′, Y2 ′) of the point 2 ′ of the grinding wheel 11, the normal angle θ2 at the point 2 is set to 2 ′.
It is made to coincide with the normal angle θ2 ′ in. As a result, the grinding position moves from point 2 to point 2 '.

By repeating such control, the cutting is advanced from the point 1 in the tooth height direction of the tooth profile surface 2a (tooth height direction) from the tip to the root. FIG. 9B shows a point 4
FIG. 9C shows a state in which cutting is being performed, and this grinding is performed from point 4 to point 9 as shown in FIG. 9C.
Proceed to.

In FIG. 9, what is indicated by double lines on the tooth profile surfaces 2a, 2b of the internal gear 2 is a "grinding allowance", and the grinding proceeds so as to scrape off this grinding allowance. According to such a method, the tooth profile surfaces 2a, 2b of the internal gear 2 and the grinding surfaces 11a, 11b of the grinding wheel 11 are brought into rolling contact with each other to surely perform grinding without slipping at each point. be able to.

Since the thickness t of the grinding wheel 11 is smaller than the distance T between the right and left tooth mold surfaces as described above (see FIG. 2), it is shown in FIG. 9 (a). As described above, when the root portion of the left tooth profile 2a (near point 1) is ground by the left grinding surface (point 1 '), the right grinding surface 11c of the grinding wheel 11 is the right tooth of the work. It is possible to prevent interference with the tooth base portion (near point 9) of the mold surface 2b.

Further, as shown in FIG. 9C, when the tooth tip portion (point 9) of the left tooth profile 2a is ground by the left grinding surface (point 9 '), the right side of the grinding wheel 11 is used. It is possible to prevent the grinding surface 11c from interfering with the tooth tip portion of the right tooth mold surface 2b of the work.

When the grinding of the left tooth profile 2a is completed in this way, the grinding wheel 11 is prepared by the same method.
On the right grinding surface 11c of the right tooth profile surface 2b of the internal gear 2
To be ground. At this time, conversely, from point z to point 1
Grinding is advanced from the tooth root to the tooth tip (step shown in FIG. 8B).

Then, as shown in the lower three stages of the flowchart in FIG. 7, the right tooth mold surface 2b is continuously ground from the tip to the root ((c) in FIG. 8) and left side. Grinding from the root to the tip of the tooth profile surface 2a ((d) shown in FIG. 8) completes one cycle of the grinding process.

In this embodiment, the grinding of one tooth groove is completed by repeating this cycle three times as described above, and the entire internal gear 2 is ground by repeating such grinding for each tooth groove. To finish.

When the grinding of all tooth spaces is completed, the dimensions of the tooth mold surfaces 2a and 2b are measured as shown in FIG. If the measurement result is within the allowable size range, the grinding ends. On the other hand, if it is out of the allowable dimension, correction and re-grinding are performed.

With this structure, the effects described below can be obtained. First, even if the number of teeth of the work to be ground (internal gear 2) is changed, the grinding wheel 11 having the same shape can continue the grinding.

That is, in the conventional method using the full-scale wheel, it is necessary to prepare a grinding wheel having an edge portion having exactly the same shape as the tooth groove of the internal gear, so that the number of teeth is changed. Then, it was necessary to newly prepare a grinding wheel having a corresponding shape.

On the other hand, according to the present invention, if the same module as the reference gear 2'is used, all internal gears 2 having a larger number of teeth than the reference gear 2'are ground with the same shape. It can be dealt with in 11. Therefore, if a gear which has the same module and is considered to have the smallest number of teeth in practical use is selected as the reference gear 2 ', there is an effect that it can be applied to almost all internal gears 2.

The grounding surfaces 11b and 11c have the same shape as the reference gear 2 '.
The rate of change of the inclination angles of the tooth profile surfaces 2a, 2b of the gear 2 having a larger number of teeth than that of the reference gear 2'is equal to
This is because it is always smaller than the rate of change of the inclination angle of b. That is, by this, the grinding surfaces 11b and 11c
To all internal gears 2 having more teeth than the reference gear 2 '.
This is because it can be brought into rolling contact with the tooth profile surfaces 2a, 2b in the tooth height direction.

Secondly, since grinding can be performed without causing slippage, grinding efficiency is improved. In other words, conventionally, there has been a grinding method that utilizes a creation motion as a grinding method that can theoretically accurately grind an internal gear, but with this grinding method, there is a slip between the grinding wheel and the tooth surface. Occurs, and the grinding efficiency is reduced particularly at the tip and the root of the tooth.

However, according to this method, the grinding wheel 11 and the tooth surface 2a, 2b are controlled by four-axis control.
It is possible to make rolling contact at all points along the tooth height direction without slipping. Therefore, the tooth surface 2a, 2b
There is an effect that a uniform grinding result can be obtained over the entire length in the tooth height direction (from the tooth tip to the tooth root), and the grinding efficiency can be improved.

The grinding wheel 11 and the tooth surface 2a, 2b.
Since it is possible to prevent the occurrence of slippage between the wheel and the wheel, it is possible to reduce the wear of the grinding wheel 11 and to extend the tool life.

Thirdly, in this embodiment, the tooth surface is not ground all over the tooth line at once, but the grinding point is reciprocated in a direction (tooth height direction) substantially orthogonal to the tooth line direction. By repeating this process for a plurality of cycles, one tooth groove is ground (FIG. 8). This has the effect of enabling high-speed and accurate grinding.

That is, in the case of conventional grinding using a full-scale wheel or grinding using a creation motion, the tooth groove is ground by reciprocating the grinding wheel in the tooth trace direction (Z direction). Was there.

However, if such a method is adopted in the present invention, it may take a very long time to finish the grinding depending on the number of division points. Further, if the number of points to be divided is set to be small, the finishing accuracy will be reduced accordingly.

Therefore, according to the present invention, the tooth surface 2a, 2b is formed.
By setting the feed dimension p in the tooth trace direction in one cycle within the range in which the finished dimension of is within the allowable dimension, and reciprocating the grinding point in a direction substantially orthogonal to the tooth trace direction while feeding in the Z direction. The grinding was completed in a few cycles.

This has the effect that the grinding of the tooth gap can be completed in a relatively short time while maintaining the desired dimensional accuracy. Fourthly, since the thickness of the edge portion 11a of the grinding wheel 11 is made thinner than the distance between the tooth mold surfaces 2a and 2b forming the tooth groove, during grinding, the edge portion 11a and the tooth surface are formed. Two
This has an effect of effectively preventing interference between a and 2b.

Fifth, there is an effect that it is possible to produce a wide variety of small quantities of high-strength, compact and highly accurate internal gears. That is, the internal gear is a special gear as compared with the external gear, and its use is also limited. The internal gear, which is intended to be obtained by the present invention, is used, for example, in a gearbox of a wind power generator, has a large number of products and a limited number of products, and is compact (quality, strength, size). Good quality (including accuracy) is required. Improving the quality of the gears used in this wind power generator not only improves the reliability of power generation work but also leads to a fixed price of noise, which is a very important requirement.

In order to obtain a compact gear having high strength and good dimensional accuracy, it is preferable that the work is subjected to gear cutting, then hardened, and then ground to a precise size. In addition, in order to support high-mix low-volume production,
It is necessary that one type of grinding wheel can handle many types of gears.

In the case of grinding such an internal gear, it is difficult to apply the method using the above-mentioned general-purpose wheel because it cannot cope with small-lot production of a wide variety of products. Further, in the case of the grinding method utilizing the above-mentioned generating motion, it is difficult to grind a compact gear because a considerable space is required to perform the generating motion. Further, when a gear having high strength and demanding dimensional accuracy is produced, the slip and wear become very problematic.

Therefore, the conventional method is not suitable for grinding a compact internal gear after quenching, and it is very difficult to produce such a gear. However, according to the device of the present invention, many kinds of internal gears 2 can be ground with one kind of grinding wheel 11, and since no generating motion is performed, there are few problems of slippage and wear. Therefore,
Grinding that eliminates the drawbacks of the conventional devices can be performed, and there is an effect that it is easy to produce a compact, high-strength gear with good dimensional accuracy in a large variety of products.

Next, a second embodiment of the present invention will be described. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the grinding treatment process described in the first embodiment is referred to as a "finish grinding treatment process", and as a pre-process thereof, as shown in FIG.
As shown in FIG. 2, the rough grinding process step is performed.

This rough grinding process will be described with reference to the flowcharts of FIGS. 13 and 14 and FIG. In this rough grinding processing step, the tooth surface 2a, 2b and the grinding surface 11b, 11c are divided into points smaller than those in the finishing step and grinding is performed. In this embodiment, as shown in FIG.
It is divided into points.

Then, while rotating the grinding wheel 11, the tooth profile surface 2a is processed in the same manner as described above.
The point 1 of 1 is brought into contact with the point 1 ′ of the grinding wheel 11. Then, as shown by (e) in FIG. 11A, the grinding wheel 11 is moved in the Z direction over the entire tooth line dimension to perform grinding.

Subsequently, as shown in (f) and (g), grinding is also performed on the points 2 and 3 over the entire tooth line dimension.
By this, if the grinding of the left tooth profile 2a is completed,
The right side tooth surface 2b is also ground by the same method. However, with respect to the right-side ground surface 2b, the point 3, the point 2, and the point 1 are performed in this order.

This completes the rough grinding step. The shapes of the grinding surfaces 2a, 2b after the completion of the rough grinding step are extremely expressed as shown in FIG. 11 (b). That is, since the number of the division points is small and the grinding is performed at once over the entire tooth line dimension, a grinding margin remains between the points.

As shown in FIG. 12, when this rough grinding is completed, dimension measurement is performed to determine whether the size of the remaining grinding allowance falls within the allowable dimension. At this time, if it is within the allowable dimension, the grinding of the internal gear 2 is completed, and if it is not within the allowable dimension, the above-described finish grinding processing step (first embodiment) is subsequently performed.

According to this structure, since the grinding of the tooth surface is performed by rough grinding and finish grinding, there is an effect that more accurate grinding can be performed. Further, depending on the size of the allowable dimension required for the internal gear 2, it is possible to finish the grinding only by the rough grinding, and in this case, it is possible to finish the grinding in a shorter time. is there.

Next, a third embodiment of the present invention will be described. In the third embodiment, as shown in FIG. 15, the external gear 25 is ground. This external gear 25
The grinding can be performed in the same manner as in the first or second embodiment.

The edge portion 26a of the grinding wheel 26 used in this embodiment has a shape as shown in FIG.
Contrary to the case of the grinding wheel 11 for the internal gear 2, it has the same shape as the tooth groove of the external gear which is considered to have the largest number of teeth in practical use with the same module.

That is, in the case of the external gear 25, contrary to the case of the internal gear 2, as the number of teeth increases, the inclination angles of the tooth profile surfaces 25a and 25b are increased as long as the number of teeth is the same. In order to cope with this, the tooth profile surface 26 of the grinding wheel 26 is adjusted in accordance with the external gear (reference gear) having the tooth profile surface with the smallest inclination angle change rate.
It is sufficient to form b and 26c.

The thickness of the edge portion 26a of the grinding wheel 26 is smaller (thinner) than the distance between the tooth surface of the reference gear, like the grinding wheel 11 for the internal gear 2. Has been done.

By using such a grinding wheel 26 to grind the external gear 25 having the same module as the above-mentioned reference gear and a small number of teeth, it is possible to obtain the same structure as the first and second embodiments. Grinding can be performed in a similar manner.

That is, in this embodiment, as shown in the figure, the tooth profile surfaces 25 on the left and right sides of the external gear 25 are formed.
a, 25b are divided into points 1 to 12 (z), and the left and right grinding surfaces 26b and 26c of the grinding wheel 26 are divided into corresponding points 1'to 12 '(z'). To do.

Then, by controlling the table portion 13 so that the coordinates and normal angles of the points n and n'are matched, as shown in FIGS. 16 (a) to 16 (c), the grinding is performed. The grinding surface 26b (26c) of the wheel 26 is used as the tooth surface 25a.
Can be rolled in the tooth height direction with respect to (25b),
The same grinding as in the first embodiment can be performed.

According to this structure, even in grinding the external gear 25, the same effects as those of the first and second embodiments can be obtained. Further, according to such a grinding device, it is possible to handle both the internal gear 2 and the external gear 25 with the same device and the same program. At this time, a pair of grinding wheels 11 for internal teeth and external teeth,
Only by preparing 26, it is possible to cope with the grinding of various kinds of gears having different numbers of teeth with the same module.

The present invention is not limited to the above-described embodiment, but can be variously modified without changing the gist of the invention. For example, the shapes of the grinding wheels 11 and 26 are not limited to the one embodiment described above, and if the grinding wheels 11 and 26 have curved surfaces capable of rolling contact with the tooth surface of the internal gear 2 or the external gear 25, It may be a simple arc surface. For example, a grinding wheel having an arcuate surface that is convex on the outside for the internal gear 2 and a arcuate surface that is concave on the inside for the external gear 25 may be prepared. With such a configuration, the grinding wheel can be formed more easily.

Further, in the above embodiment, the work is the internal gear 2 and the external gear 25. However, the work is not limited to this, and other types of gears such as bevel gears may be used. May be.

Further, in the above-mentioned embodiment, the gears 2 and 25 as the work are driven in the XYθ directions, and the grinding wheels 11 and 26 are driven in the Z direction, but the invention is not limited to this. Not something. The point is that it is sufficient if both can be moved relative to each other in the four axis directions.

The grinding wheels 11 and 26 described in the above-mentioned embodiment had the edge portions formed thinner than the tooth spaces of the reference gear. However, when the dimensional accuracy of the gear is not so demanding, it is possible to perform grinding using a grinding wheel whose thickness is substantially equal to that of the tooth space. The grinding wheel and grinding method used in this case will be described below.

First, FIG. 17 is a schematic configuration diagram showing a meshing state of external gears. The mesh line is indicated by (h) in the figure. In this figure,
The meshing dimension (dimension from point 1 to point 6) of the meshing line (h) is divided into 5 equal parts, and points 1 to 6 (meshing points) are taken as shown in the figure.

The gear 25 shown on the lower side of the figure is an external gear, and when the above points 1 to 6 are moved to the tooth mold surfaces 25a and 25b, the points 1 to 6 shown in FIG. 18A are obtained. As shown.
In this figure, 26 'is a grinding wheel. The edge portion 26'a of the grinding wheel 26 'has exactly the same shape as the tooth groove of the gear 25 including the "thickness".

Next, the grinding surface 26 of the grinding wheel 26 'described above.
Points 1 ′ to 6 ′ are set on ′ b and 26′c as shown in the figure. The points 1 ′ to 6 ′ are points on the tooth profile surfaces 30a and 30b of the external gear 30 shown on the upper side of FIG. 17 that mesh with the points 1 to 6 of the external gear 25 located on the lower side ( (Not shown), points having the same intervals as these points are taken on the grinding surfaces 26'b and 26'c of the grinding wheel 26 '.

As shown in the figure, the points 1 to 6 are at substantially equal intervals (t1), while the intervals between the points 1'to 6'are at the root of the gear. It is longer than t1 at the corresponding portion (t2) and shorter than t1 at the portion corresponding to the tooth tip (t3).

In this example, the point n of the tooth profile surfaces 25a and 25b is controlled by substantially the same control method as in the first embodiment.
(1 to 6) and the point n '(1' on the grinding surfaces 26'b and 26'c
~ 6 ') are in contact with each other and the normal angles of the points are equal to each other, the grinding wheel 26' or the gear 2
5 is driven relatively. At this time, the above grinding wheel 26
To rotate at high speed.

By performing such control, the grinding wheel 26 'can be made to have the tooth surface (25a or 25a) being ground.
The tooth profile surface can be ground from the tooth root to the tooth tip without cutting into the other tooth profile surface facing b).

The grinding of the internal gear is also performed in FIG.
As shown in (b), if points 1 to 6 and points 1'to 6'are taken, the same grinding wheel 11 'having an edge 11'a having exactly the same shape as the tooth groove is used. Grinding can be performed by the method.

[0104]

According to the structure as described above, the grinding wheel of the same shape can be used for both the internal gear and the external gear over a practically sufficient number of teeth, and It is possible to obtain the effect of efficiently grinding the die surface without causing slippage.

[Brief description of drawings]

FIG. 1 is a front view and a top view showing a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the relationship between the shapes of the gear and the grinding wheel.

[FIG. 3] Similarly, a flow chart.

FIG. 4 is likewise a flowchart.

FIG. 5 is also a flow chart.

FIG. 6 is also a flow chart.

FIG. 7 is likewise a flowchart.

FIG. 8 is a perspective view showing a tooth groove in an enlarged manner.

FIG. 9 is a transverse cross-sectional view showing a grinding process, similarly.

FIG. 10 is a lateral cross-sectional view showing the grinding process in an enlarged manner.

FIG. 11 is a perspective view and a cross sectional view showing a second embodiment.

FIG. 12 is also a flowchart.

FIG. 13 is also a flow chart.

FIG. 14 is likewise a flowchart.

FIG. 15 is an enlarged transverse sectional view showing the third embodiment.

FIG. 16 is likewise a process drawing.

FIG. 17 is a schematic configuration diagram showing another embodiment.

FIG. 18 is a schematic configuration diagram showing another embodiment of the present invention.

FIG. 19 is a cross-sectional view showing a conventional grinding method.

FIG. 20 is a transverse cross-sectional view showing a conventional grinding method.

[Explanation of symbols]

2 ... Internal gear (gear), 2a ... Left tooth profile, 2b ... Right tooth profile, 11 ... Grinding wheel (grinding wheel), 11a ...
Edge portion, 11b ... right side ground surface, 11c ... left side ground surface, 13
... table part (gear holding part, driving means), 14 ... grinding wheel driving part (grinding wheel holding part, driving means), 15 ...
CNC control device (control means), 25 external gear (gear),
26 ... Grinding wheel.

Claims (10)

[Claims] 1. A gear grinding device that grinds one and the other tooth mold surfaces that form a tooth groove of a gear, and has a disk shape, and has an edge portion that is formed thinner than the distance between the tooth mold surfaces. A grinding wheel having one and the other grinding surface forming a curved surface, and a grinding wheel holding portion for holding the grinding wheel and rotating the grinding wheel. , A drive for grinding the tooth profile surface of the gear by the grinding wheel by relatively driving the gear holding section that holds the gear and the grinding wheel holding section and the gear holding section And a means for grinding a gear. 2. The gear grinding apparatus according to claim 1, wherein said driving means is controlled to form one or the other tooth surface of said grinding wheel on one or the other grinding surface of said grinding wheel edge and said tooth groove. A gear grinding device comprising a control means for selectively contacting a surface and rollingly contacting the grinding surface and the tooth profile in the tooth height direction. 3. A gear grinding method for grinding one and the other tooth surface of a gear wheel groove which is a rotationally driven disk-shaped grinding wheel, said edge of said grinding wheel. The one or the other grinding surface that constitutes the part and the one or the other tooth profile surface that constitutes the tooth groove, and the rolling surface and the tooth profile surface are brought into rolling contact with each other in the tooth height direction. Accordingly, there is provided a gear grinding method comprising a step of grinding the tooth profile surface. 4. The gear grinding method according to claim 3, wherein in the step, the tooth surface and the grinding surface of the grinding wheel are each divided into a plurality of points at predetermined intervals, and the coordinates of each point are sequentially determined. A grinding method characterized by including the step of bringing the grinding wheel grinding surface and the tooth profile surface into rolling contact with each other in the tooth height direction by matching and matching the normal angle at each point. 5. The gear grinding method according to claim 3, wherein, when the step is performed, the method includes a step of feeding and driving the grinding wheel in a tooth trace direction at a predetermined speed. 6. A gear grinding wheel for grinding one and the other tooth profile surfaces constituting a tooth groove of a gear, wherein the one or the other tooth profile surfaces can be selectively ground by being rotationally driven. The edge portion has one grinding surface capable of grinding the one tooth surface and the other grinding surface capable of grinding the other tooth surface, and the one grinding surface is the one grinding surface. Of the tooth grinding surface, and the other grinding surface has a curved surface capable of rolling contact with the other tooth shape surface in the tooth height direction. Then. 7. The gear grinding wheel according to claim 6, wherein the thickness of the edge portion is formed thinner than the distance between one tooth profile surface and the other tooth profile surface of the tooth groove. Wheel grinding wheel characterized by being. 8. The gear grinding wheel according to claim 7, wherein the thickness of the edge portion is such that when one of the ground surfaces is in contact with a tip or a root of one of the tooth profile surfaces. When the other grinding surface has a dimension that does not contact the root or tip of the other tooth profile, and the other grinding surface contacts the tip or root of the other tooth profile. In addition, the gear grinding wheel is characterized in that the one grinding surface has a dimension such that it does not come into contact with the root or the tip of the one tooth profile surface. 9. The wheel for grinding a gear according to claim 6, wherein the curved surfaces of the one and the other grinding surfaces constituting the edge portion are the same as those of the gear when grinding an internal gear. A gear having a smaller number of teeth than the above-mentioned gear as a reference, and is formed in substantially the same shape as one and the other tooth profile surfaces that form the tooth groove of this reference gear. Stone. 10. The wheel for grinding a gear according to claim 6, wherein the curved surfaces of the one and the other grinding surfaces constituting the edge portion are the same modules as the gear when grinding an external gear. For gear grinding, characterized in that it is formed in substantially the same shape as one and the other tooth profile surfaces that form the tooth groove of this reference gear, with a reference gear having more teeth than the above gear as a reference. Stone.