JPH01257511A - Tooth surface grinding method for helical bevel gear - Google Patents

Abstract

PURPOSE:To prevent the occurrence of polishing burning by a method wherein control is made so that the inclination angle, the moving direction, and a moving amount of a grinding stone part situated to a rotary cutting tool are changed, and a tooth surface forming part is cut in a state that the grinding stone part is brought into point contact or line contact with the tooth surface forming part of a helical tooth bevel gear. CONSTITUTION:A rotary shaft member 14 is rotated togetherwith a rotary grinding tool 10 through running of a motor 38. The whole of a rotary part 22 is rotated based on a casingform support part 20 through running of a motor 28 in a state that a grinding stone part 12 is rotated around a main spindle extending through the central part of a body part 11 of the tool 10 surrounded with the grindings tone part 12, and an inclination angle based on the rotary shaft of the rotary part 22 is changed with the aid of the motor. Further, through the motion of an elevating cylinder 40, the length, protruded from a rotary shaft holding part 24, of the member 14 is changed to change a position where the grinding stone part 12 is separated away from a holding part 24. As a result, since the grinding stone part 12 grinds a tooth surface forming part 51 in a state that it is always brought into point contact or line contact with the tooth surface forming part 51 of a helical tooth bevel gear 50, deficiency in grinding cooling liquid is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of grinding a tooth flank portion of a helical bevel gear using a rotary grinding tool provided with a grindstone.

(Prior Art) To grind the tooth surface of a gear, a rotary grinding tool having a grindstone portion is usually used, and the grindstone portion is brought into contact with the tooth surface forming portion of the gear, which is the part to be ground. It will be done. The grinding wheel portion of such a rotary grinding tool has abrasive particles ( A layer obtained by solidifying abrasive grains with a binder is provided and formed, and the shape of the grinding surface corresponds to the tooth surface of the gear to be ground. During the grinding process, the rotary grinding tool is driven to rotate in such a way that the grinding surface of the grindstone provided on the rotary grinding tool is maintained in surface contact with the tooth flank forming portion of the gear. As a result, the tooth surface forming portion of the gear is ground by the grindstone portion.

According to such a grinding method, even when the part to be ground has a relatively complicated shape, such as a tooth flank forming part of a helical bevel gear, the grinding process can be performed relatively easily. become.

(Problem to be Solved by the Invention) However, as described above, a state is maintained in which the grinding surface of the grinding wheel provided in the rotary grinding tool is brought into surface contact with the tooth surface forming portion of the gear that is the part to be ground. If the grinding wheel is used to perform grinding on the south face forming part of the gear, the grinding surface of the grindstone comes into contact with the south face forming part of the gear with a relatively large contact area. ,
Therefore, the grinding wheel portion rapidly wears out, and the grinding coolant is not sufficiently supplied between the tooth surface forming portion and the grinding surface of the grinding wheel portion, which come into contact with each other during the grinding process, and the grinding process location This may result in grinding burn.

In view of the above, the present invention uses a rotary grinding tool in which a grindstone portion is formed, and drives the rotary grinding tool to rotate by bringing the grindstone portion into contact with the south surface forming portion of a helical tooth bevel gear. When grinding the tooth flank forming part of a gear, effectively prevents the situation where grinding burn occurs at the grinding part due to insufficient supply of grinding coolant between the tooth flank forming part and the grinding wheel part that are in contact with each other. It is an object of the present invention to provide a method for grinding the tooth surface of a helical tooth bevel gear, which avoids the above problems.

(Means for Solving the Problem) In order to achieve the above-mentioned object, a method for grinding a tooth surface of a helical bevel gear according to the present invention includes a grinding wheel portion formed in an annular shape having a substantially circular cross section. A rotary grinding tool equipped with a rotary grinding tool is arranged with its grinding wheel part in contact with the tooth flank forming part of a helical bevel gear, and the main shaft of the rotary grinding tool surrounded by the grinding wheel part is rotated as the rotation axis. At the same time, the inclination angle, moving direction, and amount of movement of the grinding wheel section are controlled to change, and the grinding wheel section is in point or line contact with the tooth surface forming part of the twisted bevel gear. The grinding process is performed on the tooth surface forming portion.

(Function) According to the tooth flank grinding method for a helical bevel gear according to the present invention as described above, a rotary grinding tool is provided on the tooth flank forming part of the helical bevel gear, which is the part to be ground. The grinding process is performed on the tooth surface forming portion of the helical bevel gear by the grinding wheel part while the grinding wheel part is in point contact or line contact. Therefore, during the grinding process, the grinding wheel comes into contact with the tooth flank forming part of the helical bevel gear with an extremely small contact area. Grinding burn caused by insufficient supply of coolant is prevented.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 5 shows an example of a helical bevel gear to be ground by applying the tooth flank grinding method for a helical bevel gear according to the present invention, and this helical bevel gear 50 is formed as a ring gear. , and has a tooth surface forming portion 51.

FIGS. 6 and 7 show that an example of the tooth flank grinding method for a helical bevel gear according to the present invention involves grinding the tooth flank forming portion 51 of the helical bevel gear 50 shown in FIG.
An example of a rotary grinding tool used in the implementation is shown. This rotary grinding tool 10 is formed by providing a grindstone portion 12 formed in an annular shape with a substantially circular cross section on the annular peripheral edge of a main body portion 11 formed in a cup shape.

The grinding wheel portion 12 is formed substantially in the shape of a ring in one plane, and a grinding layer made of particles of cubic boron nitride (CBN), for example, is provided on its surface. There is. The rotary grinding tool 10 is attached to the rotary shaft member 14 by fixing the bottom of the cup-shaped main body 11 to the end surface of the rotary shaft member I4, for example, with a plurality of mounting screws 13. As the rotary shaft member 14 rotates, the entire rotary grinding tool 10 is surrounded by the grindstone portion 12 and rotated about its main shaft passing through the center of the main body portion 11 as a rotation axis.

FIGS. 1, 2, and 3 show an example of a method for grinding a crest of a single zero-tooth bevel gear according to the present invention, which is equipped with a rotating shaft member 14 to which a rotating grinding tool 10 is attached as described above. The grinding tool drive mechanism used in the implementation is shown.

The grinding tool drive mechanism 15 shown in FIGS. 1 and 3 includes a case-like support portion 20. Inside the box-like support part 20 1:
The rotary shaft holding section 24 is disposed within the rotary section IL22 and holds the rotary shaft member 14 having the rotary grinding tool 10 attached to the tip thereof. There is.

The rotating part 22 has a pulley 22a in the center of its h-plane part.
A -L axis of the pulley 22a is rotatably supported by a through hole 21 provided in the case-shaped support 20 with a bearing 23 interposed therebetween. A belt 32 is hung between the boo IJ 22a and a pulley 30 attached to the rotating shaft of the motor 28 fixed to the outer surface of the case-shaped support 20, and the motor 28 is operated. As a result, the rotating part 22 is rotated within the case-shaped support part 20.

The rotating shaft holder 24 includes a case-like member 33 into which the rotating shaft holder 1 is inserted, and a case-like member 33 that is fitted inside the rotating section 22 and fixed to the inner surface of the rotating section 22. It engages with a pair of opposing arcuate guide members 35a and 35b provided on a pair of opposing inner wall surfaces of the square tube cane member 34, respectively. The arcuate guide member 35a, which is one of the arcuate guide members 35a and 35b, has a rack 36 extending in an arc shape on its inner surface.9 As shown in FIG. 1 rotating shaft holding part 2, 1
An angle adjustment portion 37 provided on the side and facing the outside of the case-like member 33 is engaged with the angle adjustment portion 37 .

The angle adjustment section 37 includes a bevel gear 37 that meshes with the rack 36.
a and a motor 37b having a rotating shaft to which a bevel gear 37a is attached. And motor 3
7b is rotated, the bevel gear 37a is rotationally driven and moves according to the rack 36, whereby the entire rotary shaft holder 24 is rotated by the arc-shaped guide members 35a and 351.
), for example, to take the position shown by the solid line or the position shown by the dashed-dotted line in FIG.

The rotating shaft member 14 inserted into the case-like member 33 of the rotating shaft holding part 24 is connected to the rotating shaft of a motor 38 disposed inside the case-like member 33, and when the motor 38 is rotated, , is driven to rotate with the rotary grinding tool 10 attached to the distal end projecting downward from the case-like member 33. As a result, the grindstone portion 12 provided in the rotary grinding tool 10 is
It is driven to rotate around the main axis that passes through the center of. Bushing members 39a and 39b are interposed between the outer peripheral surfaces of each of the rotating shaft member 14 and the motor 38 and the inner surface of the case-like member 33 facing them, and the rotating shaft member 14 and the motor 38 are , can integrally move in the axial direction within the case-like member 33.

Further, an elevating cylinder 40 is attached to the upper part of the case-like member 33 of the rotating shaft holding part 24, and the tip of a piston rod 41 that protrudes downward from the inside thereof is disposed within the case-like member 33. It is connected to the motor 38. Therefore, when the elevating cylinder 40 operates, the rotary shaft member 14 and the motor 38 are moved in the axial direction along the case-like member 33 as the piston rod 41 moves back and forth. Grinding wheel part 12
The position from the lower end of the case-like member 33 is adjusted.

Furthermore, an operation control section 42 is provided on the outside of the case-shaped support section 20.
The operation control unit 42 controls the drive of the motors 28, 37b and 38, and the operation of the lifting cylinder 40, for example, using numerical control. The rotational speed, inclination angle, moving direction, moving amount, etc. of the grindstone portion 12 provided in the grinding tool 10 are changed according to set values prepared in advance.

FIGS. 4A and 4B show an example of a grinding device equipped with the above-mentioned grinding tool drive mechanism 15. In the grinding apparatus shown in FIGS. 4A and 4B, a workpiece support 62 having a workpiece fixing part 61 is disposed on a base 60, and a grinding tool drive mechanism is connected to the workpiece support 62. 15
However, the rotary grinding tool 10 attached to the tip of the rotating shaft member 14 is opposed to the workpiece fixing part 61, and the connecting part 6
3. The workpiece fixing part 61 is movable on the base 60, for example, in a direction approaching or away from the grinding tool drive mechanism 15, as shown by the arrow in FIG. Drive mechanism 1
5 is adjustable in angle, for example, as shown by the dashed line in FIG. 4B.

The grinding process for the tooth flank forming portion 51 of the helical bevel gear 50 shown in FIG. 5 according to an example of the tooth flank grinding method for a helical bevel gear according to the present invention is shown in FIGS. 4A and B described above. The grinding is carried out using a grinding device having the configuration as shown, and in that case, first, as shown in FIG. 4A,
A helical bevel gear 50 is fixed to a workpiece fixing part 61 provided on a workpiece support base 62 of a grinding device with its tooth surface forming part 51 facing upward. As shown in FIG. 8, the rotating shaft member 14 of the grinding tool drive mechanism 15 disposed in the grinding device is rotated against the tooth flank forming portion 51 of the helical bevel gear 50 fixed to the workpiece fixing portion 61. The rotary grinding tool 10 attached to the tip part is
is brought into contact with the tooth surface forming portion 51 of the helical bevel gear 50.

In order to bring the grindstone portion 12 of the rotary grinding tool 10 into contact with the tooth flank forming portion 51 of the helical bevel gear 50 as described above, the operation control portion 42 controls the driving states of the motors 28, 37b and 38, and the lifting cylinder. 40 operating states are numerically controlled. Such numerical control involves rotating the rotary shaft member 14 along with the rotary grinding tool 10 by the rotation of the motor 38, so that the grindstone portion 12 provided on the rotary grinding tool 10 is rotated.
The rotary grinding tool 100 surrounded by the grinding wheel part 12 rotates at a predetermined speed around the main shaft passing through the center of the main body part 11, and the entire rotating part 22 is supported in a box shape by the rotation of the motor 28. 20, and the rotation of the motor 37b changes the inclination angle of the rotating shaft holder 24 with respect to the rotating part 22, and therefore with respect to the rotating shaft of the rotating part 22, and further, Lifting cylinder 40
As a result, the protruding length of the rotating shaft member 14 from the rotating shaft holding part 24 is changed, and the separation position of the grinding wheel part 12 provided on the rotary grinding tool 10 from the rotating shaft holding part 24 is changed. , a grindstone part 1 provided in a rotary grinding tool 10
2 always maintains point contact or line contact with the tooth flank forming part 51 of the helical bevel gear 50 and grinding the tooth flank forming part 51.

Such control can be carried out, for example, by controlling the grinding wheel 12 provided on the rotary grinding tool 10 to form a tooth groove section that extends into the helical bevel gear 50 and to maintain a state of contact with each cross-sectional portion of the opposing tooth surface forming section 51. , rotate and move it as shown in the 9th article. In FIG. 9, the straight line CO is a circular plane (hereinafter referred to as
In other words, the cross section of the grindstone section 12 is shown, and the cross section of the grindstone section 12 is shown as the intersection point with the grindstone plane (referred to as the grindstone plane), that is, the trace of the movement of the center position of the grindstone plane. 51 (hereinafter, one side will be referred to as the tooth flank forming part 51A and the other as the tooth flank forming part 51B).
A comes into contact with the other tooth surface forming portion 51B. Therefore, first, the grindstone portion 12 is placed in a state immediately before contacting the tooth surface forming portion 51A so that the grindstone plane is placed at a position represented by the straight line P+, and then the center position of the grindstone plane is moved along the straight line Co. The angle of inclination of the grinding wheel plane is changed. and,
With the grindstone plane at the position represented by straight line P2,
The grindstone portion 12 is brought into contact with the upper end portion a of the tooth surface forming portion 51A. Next, the plane of the grinding wheel is sequentially drawn into a straight line P3.
and P4, and the grinding wheel part 12
The contact position of the tooth surface forming portion 51A with respect to the tooth surface forming portion 51A is
From the upper end portion a of 1A to the tooth surface forming portion 51A and the tooth surface forming portion 5
Move it to the bottom of the tooth between 1B and 1B. After that, the grindstone part 12 is brought into contact with the tooth surface forming part 51B, and the grindstone plane is moved from the position represented by the straight line P4 to the positions represented by the straight lines P5 and P6 in sequence, so that the grindstone part 12 The contact position with respect to the tooth surface forming portion 51) 3 of No. 12 is shifted from the tooth bottom portion to the upper end portion C of the tooth surface forming portion 51B.

In this way, the facing tooth flank forming parts 51 (tooth flank forming parts 51A and 51B) are ground by the grinding wheel part 12, and at that time, the lifting cylinder 40 is operated to move the center position of the grinding wheel plane upward. The protruding length of the rotating shaft member 14 from the rotating shaft holding part 24 is gradually reduced, and the inclination angle of the grinding wheel plane is changed by rotating the motor 37b to adjust the rotation axis relative to the rotating shaft of the rotating part 22. This is done by changing the inclination angle of the holding part 24.

Further, the contact state of the grindstone portion 12 with each of the tooth flank forming portions 51 of the helical bevel gear 50 is, for example, as shown in FIG. , the state represented by the curve Rh, and then the state represented by the curve Re. By doing so, the entire portion of the tooth surface of each twisted/bevel tooth from the upper end to the tooth bottom and from the inner edge to the outer edge can be ground by the grindstone portion 12.

As described above, the grindstone portion 12 that comes into contact with each of the tooth flank forming portions 51 of the helical bevel gear 50 has a circular cross section.

The grinding wheel portion 12 makes point contact or line contact with each of the tooth flank forming portions 51, and therefore, the grinding process for the tooth flank forming portions 51 in the helical bevel gear 50 is performed by the grinding wheel portion 12 making point contact with each of the tooth flank forming portions 51. Alternatively, it can be performed under a state of line contact.

(Effects of the Invention) As is clear from the above description, according to the method for grinding the tooth surface of a helical bevel gear according to the present invention, a rotary grinding tool provided with a grindstone portion is used, and the rotary grinding tool is rotationally driven. and bring the grindstone part into contact with the tooth surface forming part of the helical bevel gear.
When the grindstone part grinds the tooth flank forming part of the helical bevel gear, the grinding wheel part provided in the rotary grinding tool grinds the tooth flank forming part of the helical bevel gear, which is the part to be ground. While the grinding wheel is maintained in a point or line contact state, the tooth surface forming portion of the helical bevel gear can be ground by the grinding wheel.

Therefore, during the grinding process, the grinding wheel comes into contact with the tooth flank forming part of the helical bevel gear with an extremely small contact area, which results in cooling during grinding between the south face forming part and the grinding wheel that are in mutual contact. This means that it is possible to effectively avoid the occurrence of grinding burn caused by insufficient supply of liquid.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an example of a grinding tool drive mechanism used to carry out an example of the tooth surface grinding method for a helical bevel gear according to the present invention, and FIGS. 2 and 3 are similar to FIG. The cross-sectional view of the grinding tool drive mechanism shown in FIGS. 4A and B is similar to that shown in FIGS.
...A side view and a front view showing a grinding device equipped with the grinding tool drive mechanism shown in FIG. 3 and used to carry out an example of the method for grinding the tooth surface of a helical bevel gear according to the present invention, and FIG. A perspective view showing an example of a helical bevel gear which is subjected to grinding by applying the tooth surface grinding method for a helical bevel gear according to the present invention, FIGS. 6 and 7 are helical bevel gears according to the present invention. An example of the tooth surface grinding method is shown in Fig. 5 for grinding a helical bevel gear. 9 and 10 are diagrams for explaining the grinding process of a helical bevel gear, which is performed according to an example of the method for grinding the tooth surface of a helical bevel gear according to the present invention. In the figure, 10 is a rotary grinding tool, 11 is a main body part, 12 is a grindstone part, 14 is a rotating shaft member, 15 is a grinding tool drive mechanism, 20
22 is a rotating part, 24 is a rotating shaft holding part,
2B, 37b and 38 are motors, 40 is a lifting cylinder,
50 is a helical bevel gear, 51 is a tooth surface forming part, 61 is a workpiece fixing part, and 62 is a workpiece support base. Patent applicant Mazda Motor Corporation Fig. 5 5゜ Fig. 8 Fig. 3 Fig. 6 Fig. 10 Rotary grinding machine 12t2
: [*p Figure 7. . Figure 9〆 Figure 10

Claims (1)

[Claims] A rotary grinding tool is provided with a grindstone portion formed in an annular shape with a substantially circular cross section, and the grindstone portion is placed in contact with the tooth flank forming portion of a helical bevel gear. , the rotary grinding tool is rotated around a main axis of the rotary grinding tool surrounded by the grinding wheel part, and is controlled to change the inclination angle, moving direction, and amount of movement of the grinding wheel part, and the grinding wheel part is provided with the twisted tooth bevel. A method for grinding a tooth surface of a helical bevel gear, the method comprising grinding the tooth surface forming portion of the helical bevel gear while making point contact or line contact with the tooth surface forming portion of the gear.