Gear grinding method and gear grinding device

Abstract

To achieve a gear grinding method contributing to shortening of a gear grinding time.SOLUTION: Provided is a gear grinding method for performing grinding feeding in a thickness direction of a gear (2) that is an object to be cut while rotating a grindstone (3) having a screw shape around an axis, and grinding the gear (2) by using the grindstone (3). In the method, while a grinding feeding speed in the thickness direction of the gear (2) in the grindstone (3) is made constant, a rotation speed of the grindstone (3) is changed, and a plurality of grinding marks (2c) having an irregular interval of the grinding marks (2c) adjacent in the thickness direction of the gear (2) are formed in the gear (2).SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a gear grinding method and a gear grinding apparatus, for example, in which a threaded grinding wheel is rotated about an axis while a grinding feed is performed in the thickness direction of a gear, which is a workpiece to be ground, to grind the gear with the grinding wheel. [Background technology]

[0002] For example, the gear grinding method described in Patent Document 1 attempts to reduce gear meshing noise by continuously changing the grinding feed speed of the grinding wheel in the thickness direction of the gear when grinding the gear teeth with a threaded grinding wheel, thereby making the grinding marks formed on the gear teeth irregular. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-335061 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present applicant has found the following problem: The gear grinding method of Patent Document 1 has a problem in that since the grinding feed speed of the grinding wheel in the thickness direction of the gear is continuously changed, for example, when the speed is decelerated at a predetermined timing, the gear grinding time increases.

[0005] The present disclosure has been made in consideration of such problems, and provides a gear grinding method and gear grinding apparatus that contribute to shortening the gear grinding time. [Means for solving the problem]

[0006] A gear grinding method according to one aspect of the present disclosure includes: rotating a threaded grinding wheel about an axis while performing grinding feed in a thickness direction of a gear that is a workpiece to be ground, and grinding the gear with the grinding wheel, While maintaining a constant grinding feed speed of the grinding wheel in the thickness direction of the gear, the rotation speed of the grinding wheel is changed to form a plurality of grinding marks on the gear in which the spacing between adjacent grinding marks in the thickness direction of the gear is irregular.

[0007] In the above-mentioned gear grinding method, the rotation speed of the grindstone is preferably changed based on a multidimensional function or a trigonometric function.

[0008] In the above-mentioned gear grinding method, it is preferable that the rotation speed of the grindstone is changed randomly.

[0009] In the above-mentioned gear grinding method, it is preferable to grind the tooth flanks of each tooth of the gears so that the meshing orders of the gears are distributed.

[0010] A gear grinding apparatus according to one aspect of the present disclosure is a gear grinding apparatus that rotates a threaded grinding wheel about an axis while performing a grinding feed in a thickness direction of a gear that is a workpiece to be ground, and grinds the gear with the grinding wheel, The control unit controls a drive unit that moves the grinding wheel and the gear relative to one another by varying the rotation speed of the grinding wheel while keeping the grinding feed speed in the thickness direction of the gear constant, so that a plurality of grinding marks are formed on the gear with irregular intervals between adjacent grinding marks in the thickness direction of the gear. Effect of the Invention

[0011] According to the present disclosure, it is possible to realize a gear grinding method and a gear grinding apparatus that contribute to shortening the gear grinding time. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view showing a gear grinding device according to an embodiment; [Diagram 2] FIG. 2 is a block diagram showing a control system of the gear grinding device according to the embodiment. [Diagram 3] FIG. 2 is a perspective view showing a schematic view of ground gear teeth. [Figure 4]FIG. 1(a) is a diagram showing the relationship between the grinding feed speed of a typical grinding wheel, the rotation speed of the grinding wheel, and the grinding marks formed on the tooth surfaces of gear teeth, and FIG. 1(b) is a diagram for explaining the meshing of gears in the relationship of (a). [Diagram 5] FIG. 1( a ) is a diagram showing the relationship between the grinding feed speed of the grinding wheel, the rotation speed of the grinding wheel, and the grinding marks formed on the tooth surfaces of the gear teeth in a gear grinding method of an embodiment, and FIG. 1( b ) is a diagram for explaining the meshing of gears in the relationship of (a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, specific embodiments to which the present disclosure is applied will be described in detail with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In addition, the following description and drawings are appropriately simplified for clarity of explanation.

[0014] First, the configuration of the gear grinding device of this embodiment will be briefly described. Fig. 1 is a perspective view showing the gear grinding device of this embodiment. Fig. 2 is a block diagram showing a control system of the gear grinding device of this embodiment. Fig. 3 is a perspective view showing a schematic view of ground gear teeth. In the following description, for clarity, three-dimensional (XYZ) coordinates may be used.

[0015] As shown in Figures 1 and 2, the gear grinding device 10 includes, for example, a first drive unit 11 that rotates a gear 2, which is the workpiece, around the Z axis, a second drive unit 12 that rotates a grinding wheel 3 having thread-like teeth 3a formed thereon, around the Y axis, a third drive unit 13 that moves the grinding wheel 3 in the X-axis, Y-axis and Z-axis directions, and a control unit 14 that controls the first drive unit 11, the second drive unit 12 and the third drive unit 13.

[0016] Such a gear grinding device 10 is configured, for example, to insert the teeth 2a of the gear 2 between the teeth 3a of the grinding wheel 3, rotate the grinding wheel 3 around the Y axis, and perform grinding feed in the thickness direction of the gear 2, that is, the negative side of the Z axis (however, it may also be the positive side of the Z axis), thereby grinding the gear 2 with the grinding wheel 3.

[0017] At this time, a plurality of grinding marks 2c are formed on the tooth surface 2b of the tooth 2a of the gear 2 in the Z-axis direction, which is the grinding feed direction of the grinding wheel 3, as shown in Fig. 3. The gear grinding device 10 may preferably include a dressing device 15 for shaping the teeth 3a of the grinding wheel 3, as shown in Fig. 1.

[0018] Here, FIG. 4(a) is a diagram showing the relationship between the grinding feed speed of a typical grinding wheel, the rotation speed of the grinding wheel, and the grinding marks formed on the tooth surfaces of gear teeth, and FIG. 4(b) is a diagram for explaining the meshing of gears in the relationship of FIG. 4(a).

[0019] For example, as shown in Fig. 4(a), when a tooth 2a of a gear 2 is ground with the grinding feed rate and rotation speed of the grinding wheel 3 constant, four grinding marks (i.e., tooth waviness) 2c are formed at equal intervals in the Z-axis direction on the tooth surface 2b of the tooth 2a of the gear 2. The interval between the grinding marks 2c is the pitch between adjacent grinding marks 2c in the Z-axis direction as shown in Fig. 3, and is the interval D between the deepest ground positions of adjacent grinding marks 2c.

[0020] When such gears 2 are used in meshing operation, as shown in FIG. 4(b), for example, when the meshing order is fourth order, the meshing transmission error (TE) concentrates and forms a peak, resulting in meshing noise.

[0021] In the gear grinding method of this embodiment, the gear 2 is ground by the grinding wheel 3, thereby reducing meshing noise during meshing operation using the gear 2 and shortening the grinding time of the gear 2. The flow of the gear grinding method of this embodiment will be described below.

[0022] FIG. 5(a) is a diagram showing the relationship between the grinding feed speed of the grinding wheel, the rotation speed of the grinding wheel, and the grinding marks formed on the tooth surfaces of gear teeth in the gear grinding method of this embodiment, and FIG. 5(b) is a diagram for explaining the meshing of gears in the relationship of FIG. 5(a).

[0023] In detail, the control unit 14 controls the first driving unit 11, the second driving unit 12, and the third driving unit 13 to change the rotation speed of the grinding wheel 3 while keeping the grinding feed speed toward the negative side of the Z axis substantially constant, as shown in Fig. 5(a), and form a plurality of grinding marks 2c, the intervals between adjacent grinding marks 2c being irregular in the Z axis direction, on the tooth surface 2b of the tooth 2a of the gear 2. At this time, for example, five irregular grinding marks 2c are formed on the tooth surface 2b of the tooth 2a of the gear 2, as shown in Fig. 5(a).

[0024] When such gears 2 are used for meshing operation, the meshing orders are dispersed as shown in Fig. 5(b), and the peak of the meshing transmission error can be reduced compared to the case of Fig. 4(b). Therefore, peaks of meshing noise are less likely to form, and meshing noise can be reduced compared to the case where gears 2 are ground according to the relationship shown in Fig. 4(a).

[0025] Here, the rotation speed of the grinding wheel 3 may be changed based on a multidimensional function or a trigonometric function, or may be changed randomly; in short, it is sufficient if the tooth surface 2b of each tooth 2a of the gear 2 can be ground so that the meshing orders of the gear 2 are distributed.

[0026] In this way, the gear grinding method and gear grinding apparatus 10 of this embodiment keeps the grinding feed speed of the grinding wheel 3 toward the negative side of the Z axis substantially constant while varying the rotation speed of the grinding wheel 3, thereby forming a plurality of grinding marks 2c on the tooth flank 2b of the tooth 2a of the gear 2, the intervals between adjacent grinding marks 2c in the Z axis direction being irregular. This makes it difficult for peaks in meshing noise to form, and makes it possible to reduce meshing noise compared to the case where the gear 2 is ground with the relationship shown in Fig. 4(a).

[0027] Furthermore, since the gear grinding method and gear grinding apparatus 10 of this embodiment keep the grinding feed speed of the grinding wheel 3 toward the Z-axis negative side approximately constant, the grinding time of the gear 2 can be shortened compared to, for example, a case in which the grinding feed speed of the grinding wheel 3 toward the Z-axis negative side is decelerated at a predetermined timing to form multiple grinding marks 2c on the tooth surface 2b of the tooth 2a of the gear 2, with adjacent grinding marks 2c spaced irregularly in the Z-axis direction.

[0028] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present disclosure. [Explanation of symbols]

[0029] 1 Gear grinding equipment 2 gear, 2a tooth, 2b tooth surface, 2c grinding mark 3 grinding wheels, 3a teeth 10 Gear grinding device, 11 First drive unit, 12 Second drive unit, 13 Third drive unit, 14 Control unit

Claims

1. A gear grinding method comprising: rotating a screw-shaped grinding wheel about an axis while performing grinding feed in a thickness direction of a gear as a workpiece to be ground, and grinding the gear with the grinding wheel, A gear grinding method comprising: varying the rotation speed of the grinding wheel while keeping the grinding feed speed in the thickness direction of the gear constant, thereby forming a plurality of grinding marks on the gear, the spacing between adjacent grinding marks being irregular in the thickness direction of the gear.

2. The gear grinding method according to claim 1 , wherein the rotation speed of the grinding wheel is changed based on a multidimensional function or a trigonometric function.

3. 2. The gear grinding method according to claim 1, wherein the rotation speed of the grinding wheel is changed randomly.

4. 4. The gear grinding method according to claim 1, further comprising grinding a tooth flank of each tooth of the gears so that meshing orders of the gears are distributed.

5. A gear grinding device that rotates a screw-shaped grinding wheel around an axis while performing grinding feed in a thickness direction of a gear that is a workpiece to be ground, and grinds the gear with the grinding wheel, A gear grinding device comprising: a control unit that controls a drive unit that moves the grinding wheel and the gear relative to each other so that a plurality of grinding marks are formed on the gear in the thickness direction of the gear, the grinding feed speed of the grinding wheel in the thickness direction of the gear being constant while changing the rotation speed of the grinding wheel, and the spacing between adjacent grinding marks in the thickness direction of the gear is irregular.

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