JP2022105927A - Cam follower structure for turret - Google Patents

Abstract

To provide a cam follower structure of a turret which achieves improvement of indexing accuracy.SOLUTION: A cam follower 41 of a cam follower structure for a turret includes: a roller shaft 42 which has center holes 42e, 42f, extending from a tip to a root, and is coupled to the turret 12 by the root being inserted into a root hole 12h formed at the turret; a roller 43 which is provided coaxially with a tip part outer periphery of the roller shaft and rotates along a cam groove; rolling elements 44 disposed in an annular gap between the roller shaft and the roller; and a core member 45 which is formed of a material harder than the roller shaft and press-fitted into the center holes until reaching the interior of the root hole.SELECTED DRAWING: Figure 3

Description

The present invention relates to a cam mechanism for operating a circular table device.

Conventionally, for example, the technique described in Japanese Patent Application Laid-Open No. 2009-197897 (Patent Document 1) is known as a roller gear cam provided with a plurality of cam followers erected on the outer peripheral portion of the turret and a cam groove that meshes with the cam followers. The cam follower has a cylindrical roller and a roller shaft that rotatably supports the roller. The rollers come into contact with the roller gear cams and rotate along the cam grooves. The roller shaft with the roller is fixed to the turret with a mounting bolt as described in Japanese Patent Application Laid-Open No. 2018-151011 (Patent Document 2).

Japanese Unexamined Patent Publication No. 2009-197897 Japanese Unexamined Patent Publication No. 2018-151011

However, the conventional turret cam follower causes the problems described below. That is, if it is simply fixed to the turret with mounting bolts, the rigidity of the roller shaft may be insufficient. Then, the indexing accuracy of the turret decreases.

In view of the above circumstances, it is an object of the present invention to provide a cam follower structure for a turret with improved indexing accuracy.

For this purpose, the cam follower structure for a turret according to the present invention includes a turret that is rotatably supported, a plurality of cam followers that are erected at equal intervals in the circumferential direction on the turret, and a cam having a cam groove that sequentially meshes with the cam followers. However, the cam follower has a central hole extending from the tip toward the root, and is provided coaxially with the roller shaft whose root is inserted into the root hole formed in the turret and coupled to the turret, and the outer periphery of the tip of the roller shaft. It consists of a roller that rotates along the cam groove, multiple rolling elements placed in the roller shaft and the annular gap between the rollers, and a material that is harder than the roller shaft, and is press-fitted into the center hole of the roller shaft until it reaches the inside of the root hole. It is equipped with a core member.

According to the present invention, the core member is press-fitted into the central hole of the roller shaft and reaches the inside of the root hole. As a result, the rigidity of the cam follower is made larger than before. According to this embodiment, the precision of the engagement between the cam follower and the cam is improved. The connecting structure between the base of the roller shaft and the turret is not particularly limited. For example, the base of the roller shaft is screwed to the turret.

The core member extends along the axis of the cam follower, and its axial length is not limited. As one aspect of the present invention, one end of the core member is arranged inside the root hole, and the other end of the core member is arranged inside the roller. According to this aspect, the rigidity is increased from the root portion to the tip portion of the cam follower. As another aspect, one end and the other end of the core member are arranged inside the root hole. Alternatively, as another aspect, one end of the core member is arranged inside the root hole, the central region of the core member is passed through the inside of the roller, and the other end of the core member protrudes from the inside of the roller.

As a preferable aspect of the present invention, the root hole penetrates the turret, and the roller shaft has a male screw formed on the outer periphery of the root portion of the roller shaft and a male screw formed on the tip side of the male screw and having a diameter larger than that of the root portion of the roller shaft. It has a large diameter portion, and the cam follower further includes a nut for fastening with a male screw at the root portion of the roller shaft protruding from the root hole. According to this aspect, the cam follower is securely attached and fixed to the turret. As another aspect, instead of fastening with male screws and nuts, fastening with female screws and bolts, or other screwed structures may be used.

The arrangement of the cam followers is not particularly limited, but as a more preferable aspect of the present invention, the cam followers are erected in a posture parallel to the rotation axis of the turret. According to this aspect, the present invention fits into the barrel cam mechanism. In another aspect, multiple cam followers are arranged radially around the turret.

As described above, according to the present invention, the rigidity of the cam follower of the cam mechanism is increased, and the indexing accuracy of the turret is improved.

It is an overall view which shows the indexing circular table which comprises the cam follower structure of this invention. It is a vertical sectional view which shows the indexing circle table of FIG. It is a vertical sectional view which shows the cam follower structure which becomes one Embodiment of this invention. It is a side view which shows the core member taken out from FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall view showing an indexing circular table device provided with a turret cam follower structure according to an embodiment of the present invention, and shows a state of the circular table viewed in the direction of the rotation axis together with the inside of the device. FIG. 2 is a vertical cross-sectional view showing the indexing circular table device of the same embodiment, and shows a cross section of the device cut along a plane including the rotation axis of the circular table. In FIGS. 1 and 2, parts unrelated to the present invention are simply displayed.

The circular table device 10 includes a circular table 11, a housing 21 that rotatably supports the circular table 11, and a motor unit 31 that rotationally drives the circular table 11. As shown in FIG. 2, in the circular table 11, the front surface 11b faces the outside of the housing 21, and the back surface 11c is housed in the housing 21. A turret 12 is attached and fixed to the back surface 11c with bolts.

The turret 12 has an outer diameter smaller than the outer diameter of the circular table 11 and is built in the housing 21. The turret 12 is arranged on the outer edge of the disk portion 12b, the disk portion 12b coupled to the back surface 11c, the inner cylinder portion 12c arranged at the center of the disk portion 12b and protruding inward in the axial direction from the disk portion 12b, and the disk. It has an outer cylinder portion 12d protruding inward in the axial direction from the portion 12b, and a flange portion 12f formed at the protruding end of the outer cylinder portion 12d. The disk portion 12b, the inner cylinder portion 12c, the outer cylinder portion 12d, and the flange portion 12f are all coaxially arranged. The inside in the axial direction referred to here means the side facing inward of the housing 21 along the axis O of the circular table 11. On the other hand, the outside in the axial direction means the side facing outward of the housing 21 along the axis O of the circular table 11.

In the annular space partitioned by the inner cylinder portion 12c and the outer cylinder portion 12d, the bearing 13 and the substantially cylindrical turret support portion 22 integrally formed with the housing 21 are arranged coaxially with the axis O. The bearing 13 has an inner race 13b on the inner diameter side, an outer race 13c on the outer diameter side, and a plurality of rolling elements 13d between these races, and bears both an axial load in the axis O direction and a radial load in the radial direction. Can be done. The inner race 13b is screwed to the turret support portion 22 with bolts 23. The outer race 13c is screwed to the turret 12 with a bolt 14 penetrating the disk portion 12b.

The turret support portion 22 is a stationary member extending along the axis O, and rotatably supports the turret 12 and the circular table 11 via the bearing 13.

As shown in FIG. 1, a plurality of cam followers 41 are erected on the outer peripheral edge of the turret 12 at equal intervals in the circumferential direction. FIG. 3 is a vertical sectional view showing one cam follower 41 taken out. Each cam follower 41 includes a roller shaft 42, a roller 43, a plurality of rolling elements 44, and a core member 45.

The root of the roller shaft 42 is inserted and fixed in the root hole 12h formed in the turret 12. The root hole 12h is a through hole that penetrates the flange portion 12f and extends in parallel with the axis O.
The roller shaft 42 projects in a direction away from the circular table 11 with the flange portion 12f as the base and the side far from the circular table 11 as the tip.

A tip flange portion 42b is formed at the tip of the roller shaft 42. A flange portion 42c is formed on the outer periphery of the central portion of the roller shaft 42. The flange portion 42c has a smaller diameter than the tip flange portion 42b. A cylindrical roller 43 is covered on the outer periphery of the tip region of the roller shaft 42. The roller 43 accommodates the flange portion 42. The rolling element 44 is, for example, a needle-shaped roller, and is arranged in the annular gap between the roller shaft 42 and the roller 43. As a result, the roller 43 is rotatably supported. Further, the rolling element 44 is arranged between the tip flange portion 42b and the flange portion 42c, and the position is restricted between these flanges. Further, the roller 43 is prevented from coming off by the tip flange portion 42b.

At the center of the roller shaft 42, a series of central holes (42e, 42f, 42g) extending from the tip toward the root are formed. The central hole penetrates the roller shaft 42 in the axial direction, the tip portion 42e has a polygonal cross section, the root portion 42g has a small diameter hole, and the remaining central region 42f has a round hole having a constant inner diameter. These cross-sectional areas increase in the order of the root portion 42g, the central region 42f, and the tip portion 42e.

A connecting hole 42h connected to the outer peripheral surface of the roller shaft 42 is formed at the back of the hole at the tip portion 42e. The communication hole 42h communicates the space between the tip flange portion 42b and the flange portion 42c with the tip portion 42e of the central hole.

A male screw 42d is formed on the outer periphery of the base of the roller shaft 42. The male screw 42d protrudes from the root hole 12h of the turret 12 toward the circular table 11 side (FIG. 2) and is screwed with the nut 46. By fastening the nut 46, the flange portion 12f of the turret 12 is sandwiched between the nut 46 and the flange portion 42c, and the roller shaft 42 is attached and fixed to the turret 12. The central region 42f of the central hole is located in the root hole 12h on the root side, protrudes from the root hole 12h on the tip side, and is located in the roller 43.

The core member 45 is a pin whose end is rounded in a spherical shape, and is made of a material harder than the roller shaft 42. As a material harder than the roller shaft 42, for example, there is cemented carbide. On the other hand, the parts of the cam follower 41 other than the core member 45, such as the roller shaft 42, are made of steel, for example. The core member 45 is press-fitted into the central region 42f from the tip portion 42e of the central hole, and abuts on the step 42i connecting the central region 42f of the central hole and the root portion 42g. One end of the core member 45 is located in the root hole 12h. The other end of the core member 45 is located in the roller 43. The core member 45 solidifies the central region of the roller shaft 42. Then, the rigidity of the cam follower 41 is increased.

As shown in FIG. 1, the cam groove 52 is formed on the outer periphery of the cam 51 and extends spirally. The roller 43 of the cam follower 41 enters the cam groove 52 of the cam 51, and the cam follower 41 meshes with the cam 51. The cam 51 is coaxially provided in the central region of the cam shaft 53, and the cam 51 and the cam shaft 53 rotate integrally.

The camshaft 53 is rotatably supported by bearings 54 and 55 at both ends. A gear 56 is coaxially coupled to the end of the camshaft 53. The gear 56 meshes with a gear 33 coaxially coupled to the motor rotation shaft 32 of the motor unit 31. When the cam 51 is driven by the motor unit 31, a plurality of cam followers 41 sequentially mesh with the cam groove 52, and each roller 43 rotates while in contact with the cam 51. As a result, the turret 12 is rotated by a predetermined angle, and the circular table 11 is indexed.

According to the present embodiment, the core member 45 is press-fitted into the central hole of the roller shaft 42 and reaches the inside of the root hole 12h. As a result, the rigidity of the cam follower 41 is increased as compared with the conventional case. According to this embodiment, the indexing accuracy of the turret 12 and the circular table 11 is improved as compared with the conventional cam mechanism.

Further, according to the present embodiment, since one end of the core member 45 is arranged inside the root hole 12h and the other end of the core member 45 is arranged inside the roller 43, the rigidity of the cam follower 41 is increased to the root portion. It is enlarged from to the tip.

Further, according to the present embodiment, the root hole 12h penetrates the flange portion 12f of the turret 12, and the roller shaft 42 is formed on the male screw 42d formed on the outer periphery of the root portion of the roller shaft 42 and on the tip side of the male screw 42d. Since the nut 46 is screwed into the male screw 42d of the roller shaft 42 which has a flange portion 42c having a diameter larger than that of the root portion of the roller shaft 42 and protrudes through the root hole 12h, the cam follower 41 is a turret. It is firmly fastened to 12.

Further, since the cam follower of the present embodiment is erected in a posture parallel to the rotation axis O of the turret 12, it is suitable for the barrel cam mechanism.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to those of the illustrated embodiments. Various modifications and modifications can be made to the illustrated embodiment within the same range as the present invention or within the same range.

The present invention is advantageously used in machine tools.

10-yen table device, 11-yen table, 12 turrets,
12h root hole, 13 bearing, 21 housing,
22 Turret support, 31 Motor, 41 Cam follower,
42 roller shaft, 42b tip flange, 42d male screw,
42e Central hole tip, 42f Central area of central hole,
42g Central hole root, 42h connecting hole, 42i step,
43 rollers, 44 rolling elements, 45 core members, 46 nuts,
51 cams, 52 cam grooves, 53 cam shafts, O-axis lines.

Claims (4)

A turret that is rotatably supported and
A plurality of cam followers erected on the turret at equal intervals in the circumferential direction,
A cam having a cam groove that sequentially meshes with the cam follower is provided.
The cam follower has a central hole extending from the tip toward the root, and the base is inserted into the root hole formed in the turret and coupled to the turret, and the roller shaft is coaxial with the outer periphery of the tip of the roller shaft. It is made of a roller provided and rotating along the cam groove, a plurality of rolling elements arranged in the roller shaft and the annular gap between the rollers, and a material harder than the roller shaft until it reaches the inside of the root hole. A turret cam follower structure including a core member press-fitted into the center hole. The cam follower structure for a turret according to claim 1, wherein one end of the core member is arranged inside the root hole and the other end of the core member is arranged inside the roller. The root hole penetrates the turret and
The roller shaft has a male screw formed on the outer periphery of the root and a large diameter portion formed on the tip side of the male screw and having a diameter larger than that of the root.
The cam follower structure for a turret according to claim 1 or 2, further comprising a nut for fastening the cam follower to the male screw at the root protruding from the root hole. The cam follower structure for a turret according to any one of claims 1 to 3, wherein the cam follower is erected in a posture parallel to the rotation axis of the turret.

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