JP2021119315A - Ball screw shaft support structure and actuator - Google Patents

Abstract

To provide a ball screw shaft support structure and an actuator that can operate at high speed by preventing distortion of a ball screw shaft with a simple and compact configuration and suppressing vibration and noise.SOLUTION: A ball screw shaft support structure comprises: a ball screw shaft; a ball screw nut that is movably screwed onto the ball screw shaft; and a support member that is detachably installed on the ball screw shaft, is pressure-welded against the ball screw shaft with elastic means, and is separated from the ball screw shaft against the urging force of the elastic means due to the approach of the ball screw nut. The ball screw shaft support structure is provided with a buffer mechanism for buffering the approaching motion of the support member with respect to the ball screw shaft.SELECTED DRAWING: Figure 2

Description

The present invention relates to the ball screw shaft support structure and the actuator, and in particular, the ball screw shaft can be prevented from bending due to its simple and compact configuration, and vibration and noise can be suppressed to cope with high speed. Regarding what was devised.

Patent Document 1 and Patent Document 2 disclose, for example, a ball screw shaft support structure and an actuator configuration.
The anti-vibration stabilizer for a long lead screw described in Patent Document 1 supports the long lead screw (ball screw shaft) of the actuator by a support roller to prevent its bending and suppress vibration.
The support roller is rotatably attached to the support component, and the support component is always urged by a spring toward the slider side of the actuator. Lower pressure rollers are rotatably attached to both sides of the support component in the width direction. Further, inclined surfaces are provided on both sides of the slider in the traveling direction.
When the slider approaches the support component, the inclined surface of the slider causes the support component and thus the support roller to be retracted downward against the elastic force of the spring via the lower pressure roller.

Further, in the drive member moving mechanism of a machine tool or the like described in Patent Document 2, a shaft runout prevention device is provided next to the ball screw shaft. This shaft runout prevention device is composed of an actuating arm rotatably installed and a bearing portion provided at the tip of the actuating arm. The operating arm is always urged toward the ball screw shaft side by a coil spring, and the ball screw shaft is supported by the bearing portion. A roller is installed in the bearing portion, and a guide plate is installed in the drive block driven by the ball screw shaft. When the drive block approaches the shaft runout prevention device, the roller is brought into contact with the guide plate, and the bearing portion is moved in a direction away from the ball screw shaft against the elastic force of the coil spring.

Jikkenhei 7-3936 Gazette Jitsufuku No. 3-40038

However, the above-mentioned conventional configuration has the following problems.
That is, in the anti-vibration stabilizer for the long lead screw described in Patent Document 1, not only the support roller is rotatably attached to the support component to support the long lead screw, but also the inclined surface of the slider. The lower pressure roller that is in sliding contact with the wheel is also attached, and there is a problem that the structure of the support component and its surroundings is complicated.
Further, in the drive member moving mechanism of the machine tool or the like described in Patent Document 2, the shaft runout prevention device is installed at a position next to the ball screw shaft so as to avoid buffering with the moving drive block. Therefore, there is a problem that the configuration in the vicinity of the drive member moving mechanism becomes large in the lateral direction.

The present invention has been made based on such a point, and an object of the present invention is that the ball screw shaft can be prevented from bending due to a simple and compact configuration, and vibration and noise can be suppressed to cope with high speed. The purpose is to provide a ball screw shaft support structure and actuator that can be used.

In order to solve the above problems, the ball screw shaft support structure according to claim 1 of the present invention can be detached from the ball screw shaft, the ball screw nut movably screwed to the ball screw shaft, and the ball screw shaft. It is provided with a support member which is installed in the above and is pressed against the ball screw shaft by the elastic means and is separated from the ball screw shaft against the urging force of the elastic means by the approach of the ball screw nut. It is characterized in that a shock absorbing mechanism for buffering the approaching motion of the support member with respect to the ball screw shaft is provided.
Further, the ball screw shaft support structure according to claim 2 is the ball screw shaft support structure according to claim 1, wherein the buffer mechanism includes a leaf spring and an abutting member that comes into contact with the leaf spring. It is a thing.
The ball screw shaft support structure according to claim 3 is the ball screw shaft support structure according to claim 1, wherein the shock absorber is a damper.
Further, the ball screw shaft support structure according to claim 4 is the ball screw shaft support structure according to any one of claims 1 to 3, wherein the surface of the support member on the anti-ball screw shaft side is cushioned for the support member. It is characterized in that the material is installed.
The ball screw shaft support structure according to claim 5 is the ball screw shaft support structure according to any one of claims 1 to 4, wherein the support member includes a support member main body and a receiving member that receives the ball screw shaft. It is characterized in that it is composed of a cushioning material for a receiving member inserted between the support member main body and the receiving member.
Further, the ball screw shaft support structure according to claim 6 is characterized in that, in the ball screw shaft support structure according to claim 5, the receiving member is detachably installed.
The ball screw shaft support structure according to claim 7 is the ball screw shaft support structure according to claim 5 or 6, wherein the cushioning material for the receiving member is felt.
Further, the ball screw shaft support structure according to claim 8 is the ball screw shaft support structure according to any one of claims 5 to 7, wherein the support member main body has the ball screw shaft along the axial direction. It is characterized in that the support member side inclined surfaces are provided on both sides of the receiving member.
Further, the ball screw shaft support structure according to claim 9 is characterized in that, in the ball screw shaft support structure according to claim 8, a cushioning material for the support member side inclined surface is installed on the support member side inclined surface. It is something to do.
Further, in the ball screw shaft support structure according to claim 10, in the ball screw shaft support structure according to claim 8 or 9, the ball screw nut side roller is installed on the ball screw nut side, and the ball screw nut side is installed. The side roller rolls along the inclined surface on the side of the support member, so that the support member comes into contact with the ball screw shaft.
Further, in the ball screw shaft support structure according to claim 11, in the ball screw shaft support structure according to claim 8, ball screw nut side inclined surfaces are provided on both sides of the ball screw nut side along the axial direction of the ball screw shaft. The ball screw nut side inclined surface is provided so as to slide along the support member side inclined surface, so that the support member comes into contact with the ball screw shaft.
Further, in the ball screw shaft support structure according to claim 12, in the ball screw shaft support structure according to claim 11, a cushioning material for an inclined surface is installed on at least one of the inclined surface on the support member side or the inclined surface on the ball screw nut side. It is characterized by being done.
Further, the ball screw shaft support structure according to claim 13 is the ball screw shaft support structure according to any one of claims 5 to 7, wherein the support member main body is provided with a support member side roller. It is a feature.
Further, in the ball screw shaft support structure according to claim 14, in the ball screw shaft support structure according to claim 13, a ball screw nut side inclined surface is provided on the ball screw nut side, and the ball screw nut side inclined surface is provided. The support member is brought into contact with the ball screw shaft by rolling the roller on the support member side along the surface.
Further, the ball screw shaft support structure according to claim 15 is characterized in that, in the ball screw shaft support structure according to claim 14, a cushioning material for an inclined surface is installed on the inclined surface on the ball screw nut side. be.
Further, the actuator according to claim 16 is characterized in that one support member of the ball screw shaft support structure according to any one of claims 1 to 15 is installed.
The actuator according to claim 17 is characterized in that a plurality of support members having a ball screw shaft support structure according to any one of claims 1 to 15 are installed.

As described above, according to the ball screw shaft support structure according to claim 1 of the present invention, the ball screw shaft, the ball screw nut movably screwed to the ball screw shaft, and the ball screw shaft are separated from each other. It is provided with a support member which is installed so as to be contactable, is pressed against the ball screw shaft by an elastic means, and is separated from the ball screw shaft against the urging force of the elastic means by the approach of the ball screw nut. Since a shock absorbing mechanism is provided to buffer the approaching motion of the support member with respect to the ball screw shaft, the ball screw shaft can be prevented from bending due to a simple and compact configuration, vibration and noise can be suppressed, and the ball screw shaft can be operated at high speed. Can be done. In particular, the buffer mechanism can suppress abrupt movement of the support member and prevent noise.
Further, according to the ball screw shaft support structure according to claim 2, in the ball screw shaft support structure according to claim 1, the cushioning mechanism is composed of a leaf spring and an abutting member that comes into contact with the leaf spring. With this configuration, it is possible to suppress the sudden movement of the support member and prevent noise.
Further, according to the ball screw shaft support structure according to claim 3, in the ball screw shaft support structure according to claim 1, since the cushioning mechanism is a damper, a simple configuration suppresses abrupt movement of the support member. Noise can be prevented.
Further, according to the ball screw shaft support structure according to claim 4, in the ball screw shaft support structure according to any one of claims 1 to 3, the support member is on the surface of the support member on the anti-ball screw shaft side. Since the cushioning material is installed, the cushioning material can absorb the impact when the support member is moved downward.
Further, according to the ball screw shaft support structure according to claim 5, in the ball screw shaft support structure according to any one of claims 1 to 4, the support member receives the support member main body and the ball screw shaft. Since it is composed of the receiving member and the cushioning material for the receiving member inserted between the support member main body and the receiving member, the impact when the receiving member collides with the ball screw shaft can be easily configured. It can be relaxed.
Further, according to the ball screw shaft support structure according to claim 6, in the ball screw shaft support structure according to claim 5, the receiving member is detachably installed, so that it can be easily replaced.
Further, according to the ball screw shaft support structure according to claim 7, in the ball screw shaft support structure according to claim 5 or 6, the cushioning material for the receiving member is felt, so that the receiving member has a simple structure. Can suppress the impact when the ball collides with the ball screw shaft and absorb the impact sound.
Further, according to the ball screw shaft support structure according to claim 8, in the ball screw shaft support structure according to any one of claims 5 to 7, the support member main body is attached to the support member body along the axial direction of the ball screw shaft. Since the support member side inclined surfaces are provided on both sides of the receiving member, the support member side inclined surfaces can be used to facilitate the disengagement operation of the support member.
Further, according to the ball screw shaft support structure according to claim 9, in the ball screw shaft support structure according to claim 8, a cushioning material for the support member side inclined surface is installed on the support member side inclined surface. With a simple configuration, the impact of collision with the inclined surface on the support member side can be suppressed and noise can be prevented.
Further, according to the ball screw shaft support structure according to claim 10, in the ball screw shaft support structure according to claim 8 or 9, a ball screw nut side roller is installed on the ball screw nut side, and the ball Since the screw nut side roller rolls along the support member side inclined surface, the support member comes into contact with the ball screw shaft, so that the operation of the support member can be made smooth.
Further, according to the ball screw shaft support structure according to claim 11, in the ball screw shaft support structure according to claim 8, the ball screw nut side tilts on both sides of the ball screw nut side along the axial direction. A surface is provided, and the support member is separated from the ball screw shaft by sliding the inclined surface on the ball screw nut side along the inclined surface on the support member side, so that a simpler configuration can be made. can.
Further, according to the ball screw shaft support structure according to claim 12, in the ball screw shaft support structure according to claim 11, a cushioning material for an inclined surface is provided on at least one of the inclined surface on the support member side or the inclined surface on the ball screw nut side. Is installed, so that the impact of the collision between the inclined surface on the support member side and the inclined surface on the ball screw nut side can be suppressed and noise can be prevented by a simple configuration.
Further, according to the ball screw shaft support structure according to claim 13, in the ball screw shaft support structure according to any one of claims 5 to 7, the support member main body is provided with a support member side roller. Therefore, the operation of the support member can be made smooth.
Further, according to the ball screw shaft support structure according to claim 14, in the ball screw shaft support structure according to claim 13, a ball screw nut side inclined surface is provided on the ball screw nut side, and the ball screw nut is provided. Since the support member is separated from the ball screw shaft by rolling the support member side roller along the side inclined surface, the operation of the support member can be made smooth by a simple configuration.
Further, according to the ball screw shaft support structure according to claim 15, in the ball screw shaft support structure according to claim 14, a cushioning material for an inclined surface is installed on the inclined surface on the ball screw nut side, so that a simple configuration is provided. As a result, the impact of collision between the ball screw nut side inclined surface and the support member side roller can be suppressed, and noise can be prevented.
Further, according to the actuator according to claim 16, since one support member having the ball screw shaft support structure according to any one of claims 1 to 15 is installed, the ball screw shaft has a simple and compact configuration. It is possible to prevent the bending of the ball, suppress vibration and noise, and operate at high speed.
Further, according to the actuator according to claim 17, since a plurality of support members having the ball screw shaft support structure according to any one of claims 1 to 15 are installed, the ball screw shaft may be long. However, the simple and compact configuration prevents the ball screw shaft from bending, suppresses vibration and noise, and enables high-speed operation.

It is a figure which shows the 1st Embodiment of this invention, and is the perspective view of the actuator. It is a figure which shows the 1st Embodiment of this invention, is a partial vertical sectional view of an actuator, and is an enlarged view of the vicinity of a support member. It is a figure which shows the 1st Embodiment of this invention, is a cross-sectional view of III-III of FIG. It is a figure which shows the 1st Embodiment of this invention, is a partial perspective view which enlarged the vicinity of the support member of an actuator. It is a figure which shows the 1st Embodiment of this invention, and is the perspective view of the ball screw shaft support structure. It is a figure which shows the 1st Embodiment of this invention, is a partial vertical sectional view of an actuator, and is the enlarged view of the vicinity of a support member when a slider approaches a support member. It is a figure which shows the 1st Embodiment of this invention, is a partial perspective view of the state which a part of the actuator is removed, and is the enlarged view of the vicinity of the support member when a slider approaches a support member. It is a figure which shows the 1st Embodiment of this invention, is a partial vertical cross-sectional view of an actuator, a roller on a ball screw nut side rides on an inclined surface on a support member side, and the support member separates from a ball screw shaft. It is an enlarged view of the vicinity of the support member at the time of starting. It is a figure which shows the 1st Embodiment of this invention, is a partial vertical sectional view of an actuator, the said support member is separated from a ball screw shaft, and the lower surface side sliding member provided on the lower surface side of a receiving member and a slider. It is an enlarged view of the vicinity of the support member in a state where the ball is in sliding contact. It is a figure which shows the 1st Embodiment of this invention, is a partial vertical sectional view of the actuator, and is the enlarged view of the vicinity of the support member in the state immediately after the slider has passed through the support member. It is a figure which shows the 2nd Embodiment of this invention, FIG. 11 (a) is a partial perspective view of the state which a part of the actuator is removed, and FIG. 11 (b) is the XIb- of FIG. 11 (a). It is a cross-sectional view of XIb. It is a figure which shows the 3rd Embodiment of this invention, FIG. It is a cross-sectional view of XIIb. FIG. 13A is a perspective view of a ball screw shaft support structure, FIG. 13B is a view in which a part of the ball screw shaft support structure is removed, and FIG. 13 is a diagram showing a fourth embodiment of the present invention. (C) is a cross-sectional view of XIIIc-XIIIc of FIG. 13 (a). FIG. 14A is a perspective view of a ball screw shaft support structure, and FIG. 14B is a cross-sectional view taken along the line XIVb-XIVb of FIG. 14A. FIG. 15A is a perspective view of a ball screw shaft support structure, and FIG. 15B is a cross-sectional view taken along the line XVb-XVb of FIG. 15A. It is a figure which shows the 7th Embodiment of this invention, and is the perspective view of the actuator.

Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 10. FIG. 1 is a perspective view showing the overall configuration of the actuator 1 according to the first embodiment, FIG. 2 is a vertical sectional view of a main part, and FIG. 3 is a sectional view taken along line III-III of FIG. As shown in FIGS. 1 to 3, there is a base 3 having a substantially U-shaped cross section. Guide rails 5 and 5 are installed on the left and right inner side surfaces of the base 3. Guide grooves 7 and 7 are formed in the guide rails 5 and 5, respectively.

Further, a ball screw shaft 9 is built in the base 3. Further, as shown in FIG. 1, the bearing portion 8a is on the front end side (lower left side in FIG. 1) of the base 3, and the bearing portion 8b is on the rear end side (upper right side in FIG. 2) of the base 3. be. The ball screw shaft 9 is pivotally supported by these bearing portions 8a and 8b. A spiral groove 9a is formed in the ball screw shaft 9.

As shown in FIGS. 1 and 2, a slider 11 is installed on the base 3 so as to be movable in the left-right direction. End caps 13 and 13 are installed on one side of the width direction of the slider 11 (upper left side in FIG. 1) and at both ends in the front-rear direction (direction from lower left to upper right in FIG. 1). Further, end caps 15 and 15 are installed at both ends of the slider 11 on the other side in the width direction (lower right side in FIG. 1) and in the front-rear direction (direction from lower left to upper right in FIG. 1). The end cap on the rear end side is not shown.) A return path (not shown) is formed in the end caps 13 and 15. No-load circulation paths (not shown) are formed on both sides of the slider 11 in the width direction (direction from the upper left to the lower right in FIG. 1). Further, guide grooves (not shown) are formed on both side surfaces of the slider 11 in the width direction (direction from the upper left to the lower right in FIG. 1).

One non-load circulation path (not shown) in the slider 11, the return path of the one end cap 13, the return path of the other end cap 13, and the guide groove 7 and the slider of the one guide rail 5. A steel ball (not shown) is rolled and circulated in the space between the guide grooves (11) (not shown). Further, the other non-load circulation path (not shown) in the slider 11, the return path of the one end cap 15, the return path of the other end cap 15, and the guide groove 7 of the other guide rail 5 Steel balls (not shown) are also rolled and circulated in the space between the other guide grooves (not shown) of the slider 11. With such a configuration, the slider 11 can be moved with respect to the base 3.

Further, as shown in FIG. 2, the slider 11 has a ball screw nut accommodating member 27, and the ball screw nut 31 is fixed in the ball screw nut accommodating member 27. The ball screw nut 31 includes a ball screw nut main body 33, an end cap 35 on the front end side (left side in FIG. 2), and an end cap 37 on the rear end side (right side in FIG. 2). The ball screw shaft 9 penetrates the ball screw nut 31. A spiral groove 39 is formed on the inner peripheral surface of the ball screw nut body 33. Further, a no-load circulation path (not shown) is formed in the ball screw nut main body 33, and a return path (not shown) is formed in the end caps 35 and 37.

In the non-load circulation path (not shown) of the ball screw nut body 33, the return path (not shown) of the end caps 35 and 37, and the spiral groove 39 of the ball screw nut body 33 and the spiral groove 9a of the ball screw shaft 9. A steel ball 41 is rolled and circulated in the space between them. Further, as shown in FIG. 1, a motor 43 is installed on the rear end side (upper right side in FIG. 1) of the base 3. The ball screw shaft 9 is rotated and driven by the motor 43. When the ball screw shaft 9 is rotated and driven, the slider 11 is moved in the front-rear direction (left-right direction in FIG. 2).

Further, as shown in FIG. 2, a resin front roller 21 is used as a ball screw nut side roller on both sides in the width direction (both sides in the middle paper surface direction in FIG. 2) on the lower front end side (left side in FIG. 2) of the slider 11. , 21 are rotatably installed (the front roller 21 on the front side in FIG. 2 is not shown). Further, resin rear rollers 23, 23 can be rotated as ball screw nut side rollers on both sides in the width direction (both sides in the middle paper surface direction in FIG. 2) on the lower rear end side (right side in FIG. 2) of the slider 11. It is installed (the rear roller 23 on the front side in FIG. 2 is not shown). Further, plate-shaped lower surface side sliding members 25, 25 are installed on both end sides in the width direction (both sides in the middle paper surface direction in FIG. 2) on the lower side of the slider 11 (lower surface side slide on the front side in FIG. 2). The moving member 25 is not shown.)

Further, for example, as shown in FIGS. 2 and 4, the support member accommodating recess 51 is formed in the base 3. A ball screw shaft support structure 47 is installed in the support member accommodating recess 51. The ball screw shaft support structure 47 first includes a support member support member 50. The support member support member 50 has a support member base 53. Support member base mounting plates 54, 54 are fixed to both front and rear ends of the support member base 53. Through holes 52 and 52 are formed at both ends of the support member base mounting plate 54. The support member base mounting plates 54, 54 are fixed to the support member base 53 by fixing screws 58. The support member support member 50 includes support member guide columns 55 and 55. The support member guide columns 55, 55 are erected at both ends of the support member base 53 in the front-rear direction (left-right direction in FIG. 2). The guide columns 55, 55 are fixed to the support member base 53 by fixing screws 56, 56.
As shown in FIG. 2, a support member base accommodating hole 49 is formed at the bottom of the support member accommodating recess 51, and the support member base 53 is installed in the support member base accommodating hole 49. ing.
By passing the fixing screw 59 through the through hole 52 of the support member base mounting plate 54 and screwing it into the base 3, the support member base 53, and eventually the support member support member 50, becomes the base 3. It is fixed to.
Further, the support member support member 50 has a coil spring 65 as an elastic means. The coil spring 65 is stretched between the support member 61, which will be described later, and the support member base 53.
A U-shaped leaf spring 57, which is a part of a cushioning mechanism described later, is installed at the center of the support member base 53 in the front-rear direction (left-right direction in FIG. 2).

The ball screw shaft support structure 47 has a support member 61. The support member 61 is installed in the support member accommodating recess 51 and above the support member base 53. As shown in FIG. 5, the support member 61 has a support member main body 62, and guide through holes 63, 63 are provided on both ends of the support member main body 62 in the front-rear direction (direction from the lower left to the upper right in FIG. 5). Is formed. The slide bearings 64 and 64 are press-fitted into the guide through holes 63 and 63, and the support member guide columns 55 and 55 are arranged so as to penetrate the slide bearings 64 and 64. It is designed to be in contact with 64. The support member 61 is movable in the vertical direction along the support member guide columns 55, 55. Further, as shown in FIG. 2, a coil spring 65 as the elastic means is stretched between the support member 61 and the support member base 53. The support member 61 is constantly pressed and urged toward the ball screw shaft 9 side (upper side in FIG. 2) by the coil spring 65.
As described above, the support member support member 50 includes the support member base 53, the support member base mounting plates 54 and 54 fixed to the support member base 53, and the support member guide columns 55 and 55. It is composed of a coil spring 65 that elastically supports the support member main body 62.

Front side inclined surfaces 71 and 71 as support member side inclined surfaces are formed on both sides in the width direction (direction from upper left in FIG. 5 to lower right) on the upper surface side of the support member main body 62. On both sides of the support member main body 62 in the width direction behind the upper surface side (upper right in FIG. 5) (direction from the upper left in FIG. 5 to the lower right), the rear inclined surface 73 as the supporting member side inclined surface 73. , 73 are formed. The support member 61 includes, for example, low-resilience rubber front cushioning materials 75 and 75 and rear cushioning materials 77 and 77 as cushioning materials for the inclined surface on the support member side. The front cushioning materials 75 and 75 are installed on the front inclined surfaces 71 and 71, and the rear cushioning materials 77 and 77 are installed on the rear inclined surfaces 73 and 73.

As shown in FIG. 2, the slider 11 moves toward the support member 61, and the front rollers 21, 21 roll on the rear cushioning materials 77, 77 of the rear inclined surfaces 73, 73. Then, the support member 61 is pressed and urged toward the lower side in FIG. 6 against the elastic force of the coil spring 65. Further, the slider 11 moves from the side opposite to the direction shown in FIG. 2 to the support member 61 side, and the rear rollers 23, 23 roll to the front cushioning materials 75, 75 of the front inclined surfaces 71, 71. Even when moving, the support member 61 is pressed and urged toward the lower side in FIG. 6 against the elastic force of the coil spring 65.

Further, the support member 61 has a support portion 81. A support portion recess 79 is formed in the center of the upper surface side of the support member main body 62, and the support portion 81 is installed in the support portion recess 79. The support portion 81 includes, for example, a receiving member 83 made of POM (polyoxymethylene) and, for example, a cushioning material 87 made of felt for the receiving member. The receiving member 83 is arranged on the upper surface side to receive the ball screw shaft 9. The receiving member 83 is detachably installed in the support portion recess 79 via the cushioning material 87 for the receiving member.
Through holes 88 and 88 with counterbore are formed in the receiving member 83, and the receiving member 83 is formed in the recess 79 for the support portion by passing the bolts 89 and 89 through the through holes 88 and 88. It is fixed to the support member main body 62 by being screwed into the female screw portions 67, 67. The cushioning material 87 for the receiving member is fastened and fixed together with the receiving member 83 by the bolts 89 and 89. Further, the set screws 84 and 84 are screwed from the lower surface side of the support member main body 62 of the female screw portions 67 and 67 formed in the recess 79 for the support portion, and the screwing positions of the set screws 84 and 84 are set. By adjusting, the cushioning material 87 for the receiving member is prevented from being crushed more than necessary, and the height of the receiving member 83 is adjusted.
A recess 85 for receiving the ball screw shaft 9 is formed on the upper surface side of the receiving member 83. Both sides (in FIG. 5) of the recess 85 of the receiving member 83 in the width direction are flat sliding portions 86, 86. As shown in FIG. 2, when the support member 61 is pressed and urged upward in FIG. 2 by the elastic force of the coil spring 65, the ball screw shaft 9 is formed by the recess 85 of the receiving member 83 of the support portion 81. The vicinity of the center is supported, and the bending of the ball screw shaft 9 is prevented.
Further, a front inclined surface 82a substantially continuous with the front inclined surfaces 71 and 71 of the support member main body 62 is formed in front of the receiving member 83, and the support member main body is formed behind the receiving member 83. A rear inclined surface 82b that is substantially continuous with the rear inclined surfaces 73 and 73 of 62 is formed.

The felt cushioning material 87 is for alleviating the impact of the receiving member 83 when it collides with the ball screw shaft 9, and is also provided on the lower surface side of the support member main body 62, for example. , Low-resilience rubber cushioning materials 91 and 91 for support members are installed. These support member cushioning materials 91 and 91 alleviate the impact when the support member 61 collides with the support member base 53.
As described above, the support member 61 includes the support member main body 62, the support portion 81 installed on the support member main body 62, the front inclined surfaces 71 and 71 of the support member main body 62, and the rear inclined surface. It is composed of the front side cushioning materials 75 and 75 and the rear side cushioning materials 77 and 77 installed in 73 and 73.

Further, as shown in FIG. 2, a U-shaped leaf spring 57, which is a part of a cushioning mechanism described later, is installed at the center of the support member base 53 in the front-rear direction (left-right direction in FIG. 2) for fixing. It is fixed to the support member base 53 by screws 96 and 96. Further, as shown in FIGS. 3 and 5, contact members 93 and 93, which are a part of a cushioning mechanism described later, are fixed to both sides of the support member 61 in the width direction (left-right direction in FIG. 3). .. The support member 61 is inserted between both ends of the leaf spring 57 via the contact members 93 and 93. The buffer mechanism 95 is composed of the leaf spring 57 and the contact members 93, 93. The buffer mechanism 95 buffers the upward movement of the support member 61, that is, the movement of approaching the ball screw shaft 9.

Next, the operation according to this first embodiment will be described. When the ball screw shaft 9 is rotated and driven by the motor 43, the slider 11 is advanced and retracted in the front-rear direction. In a state where the slider 11 is separated from the support member 61, as shown in FIG. 2, the support member 61 is pressed and urged upward in FIG. 2 by the elastic force of the coil spring 65, and the support portion 81 The recess 85 of the receiving member 83 supports the vicinity of the center of the ball screw shaft 9, and prevents the ball screw shaft 9 from bending.

As shown in FIGS. 6 and 7, when the slider 11 approaches the support member 61 from the right side in FIG. 6, the front rollers 21 and 21 come into contact with the rear cushioning materials 77 and 77 of the rear inclined surfaces 73 and 73. It comes into contact and begins to roll. As a result, the support member 61 is pressed and urged toward the anti-ball screw shaft 9 side (lower side in FIG. 6) against the elastic force of the coil spring 65, and the ball screw shaft by the recess 85 of the receiving member 83. The support of 9 is released. The impact when the front rollers 21 and 21 collide with the rear cushioning materials 77 and 77 is alleviated by the rear cushioning materials 77 and 77. FIG. 8 shows a state in which the slider 11 is further closer to the support member 61 side, and the support member 61 is further pressed and urged toward the anti-ball screw shaft 9 side (lower side in FIG. 8).
When the slider 11 further moves to the left side in FIG. 8, the front rollers 21 and 21 come into contact with the rear inclined surfaces 82b and 82b of the receiving member 83 and roll, and then the sliding portion 86 of the receiving member 83. , 86 and roll, and further abut and roll on the front inclined surfaces 82a and 82a of the receiving member 83.

As shown in FIG. 9, when the slider 11 moves directly above the support member 61, the front rollers 21 and 21 are separated from the receiving member 83, but the sliding portion 86 of the receiving member 83 of the support member 61. , 86 are slidably contacted with the lower surface side sliding members 25, 25 of the slider 11. At this time, the support member 61 is pressed and urged to the lowermost side. The impact when the support member 61 collides with the support member base 53 is mitigated by the support member cushioning materials 91 and 91.

Next, as the slider 11 passes above the support member 61, the rear rollers 23 and 23 of the slider 11 move to the rear inclined surfaces 82b and 82b of the receiving member 83 and the sliding portions 86 and 86. After being rolled in contact with the front inclined surfaces 82a and 82a, the support member 61 is applied to the elastic force of the coil spring 65 via the front cushioning materials 75 and 75 of the front inclined surfaces 71 and 71. The anti-ball screw shaft 9 side (lower side in FIG. 10) is pressed and urged against it, but the pressing and urging is gradually released by the movement of the slider 11. Then, as shown in FIG. 10, when the slider 11 is moved to the left side in FIG. 10, the support member 61 is again pressed and urged upward in FIG. 10 by the elastic force of the coil spring 65, and the support portion 81 The recess 85 of the receiving member 83 supports the vicinity of the center of the ball screw shaft 9, and the ball screw shaft 9 is prevented from bending. The impact when the receiving member 83 is brought into contact with the ball screw shaft 9 again is cushioned by the cushioning material 87 for the receiving member.
Further, the sudden rise when the support member 61 returns to the upper side is alleviated by the contact between the leaf spring 57 of the buffer mechanism 95 and the contact member 93, which acts as a resistance, thereby preventing the generation of noise. is doing.

The same applies to the case where the slider 11 approaches and passes through the support member 61 from the side opposite to the direction shown in FIG. In this case, the rear rollers 23, 23 of the slider 11 come into contact with the front side cushioning materials 75, 75 of the front side inclined surfaces 71, 71 of the support member 61 and roll, so that the support member 61 rolls with the coil spring 65. It will be pushed down against the urging force of.
Further, the ball screw shaft support structure 47 has a structure that can be attached to and detached from the support member accommodating recess 51 as one unit.

Next, the effect of this first embodiment will be described.
First, the simple and compact configuration can prevent the ball screw shaft 9 from bending, and can suppress vibration and noise to increase the speed. That is, the support member 61 provided with the receiving member 83 that supports the ball screw shaft 9 is always urged toward the ball screw shaft 9 side by the coil spring 65, and these are the front rollers 21, 21 and the rear rollers 23 of the slider 11. 23. This is because the support member 61 is configured to be appropriately pushed down by the cooperation of the front inclined surfaces 71 and 71 and the rear inclined surfaces 73 and 73.
Further, since the cushioning material 87 for the receiving member is interposed between the receiving member 83 and the support member main body 62, the impact when the receiving member 83 collides with the ball screw shaft 9 is simply configured. Can be alleviated by.
Further, since the receiving member 83 is detachably installed, it can be easily replaced.
Further, since the cushioning material 87 for the receiving member is made of felt, the structure is simple and its cushioning effect and sound absorbing effect are high.
Further, since the support member cushioning materials 91 and 91 are also installed on the lower surface side of the support member 61, the impact when the support member 61 collides with the support member base 53 can be mitigated. ..
Further, since the support member 61 is moved up and down by the cooperation of the front roller 21, the rear roller 23, the front side inclined surfaces 71 and 71, and the rear side inclined surfaces 73 and 73, the support member 61 can be raised and lowered. It can be smooth.
Further, since the front cushioning materials 75, 75 and the rear cushioning materials 77, 77 are installed on the front inclined surfaces 71, 71 and the rear inclined surfaces 73, 73, the front rollers 21 and the rear rollers 23 It is possible to cushion the impact when a collision occurs.
Since the cushioning materials 91 and 91 for the support member, the front cushioning materials 75 and 75, and the rear cushioning materials 77 and 77 are made of, for example, low-resilience rubber, a high cushioning effect can be obtained with a simple configuration. Can be done.
Further, since the shock absorbing mechanism 95 is provided, it is possible to suppress a sudden rise of the support member 61, alleviate the impact on the ball screw shaft 9, and prevent noise. Further, since the shock absorbing mechanism 95 is composed of the leaf spring 57 and the contact members 93 and 93, the configuration is also simple.
Further, since one of the support members 61 is installed in the actuator 1, its configuration is simple.

Next, a second embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 11, the actuator 101 according to the second embodiment is provided with the ball screw shaft support structure 47 as in the case of the first embodiment described above, but under the slider 11. The front inclined surface members 103 and 103 are provided on the side instead of the front rollers 21 and 21, and the rear inclined surface members 105 and 105 are provided instead of the rear rollers 23 and 23.

As shown in FIG. 11B, for example, the front inclined surface member 103 is a member provided with a ball screw nut side inclined surface 107 parallel to the rear inclined surface 73 of the support member main body 62. Further, the rear inclined surface member 105 is a member provided with a ball screw nut side inclined surface 109 parallel to the front inclined surface 71 of the support member main body 62.

In the case of the second embodiment, the ball screw nut side inclined surface 107 of the front side inclined surface member 103 abuts on the rear side inclined surface 73 of the support member main body 62, or the rear side inclined surface member When the ball screw nut side inclined surface 109 of 105 comes into contact with the front side inclined surface 71 of the support member main body 62, the support member 61 is pushed down.
Further, as shown in FIG. 5, the front side cushioning material 75 and the rear side cushioning material 77 are installed on the front side inclined surface 71 and the rear side inclined surface 73 of the support member main body 62. A cushioning material (not shown) may be installed on the surface 107 and the inclined surface 109.
Further, it is also conceivable that the cushioning material is not installed on the front inclined surface 71 and the rear inclined surface 73 of the support member main body 62, and cushioning materials (not shown) are installed on the inclined surface 107 and the inclined surface 109. ..
The same reference numerals are given to the configurations common to those of the first embodiment, and the description thereof will be omitted.

Next, a third embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 12, in the actuator 201, the front inclined surface members 103 and 103 and the rear inclined surface members 105 and 105 are installed under the slider 11 as in the case of the second embodiment described above. However, the ball screw shaft support structure 203 is installed in the support member accommodating recess 51 of the base 3.

The ball screw shaft support structure 203 includes a support member 204 and a support member support member 50. The support member 204 includes a support member main body 205. Guide through holes 207 and 207 are formed at both ends of the support member main body 205 in the front-rear direction (direction from the lower left to the upper right in FIG. 12A). The slide bearings 209 and 209 are press-fitted into the guide through holes 207 and 207, and the support member guide columns 55 and 55 are arranged so as to penetrate the slide bearings 209 and 209. It is designed to be in contact with.

Support member side rollers 211 and 211 are rotatably installed at both ends of the support member main body 205 in the width direction (direction from the upper left to the lower right in FIG. 12A). In the case of the third embodiment, the support member side rollers 211 and 211 hit the inclined surface 107 of the front side inclined surface member 103 installed on the slider 11 and the inclined surface 109 of the rear side inclined surface member 105. By being brought into contact with and rolled, the support member 204 is pressed downward and urged.
Further, it is also conceivable to install a cushioning material (not shown) on the inclined surface 107 or the inclined surface 109.
The same reference numerals are given to the configurations common to those of the first embodiment, and the description thereof will be omitted.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
In this fourth embodiment, the ball screw shaft support structure 301 as shown in FIG. 13 is used. The ball screw shaft support structure 301 has substantially the same configuration as the ball screw shaft support structure 47 in the first embodiment and the second embodiment described above, but the buffer mechanism 303 is used instead of the buffer mechanism 95. It is provided.

The shock absorbing mechanism 303 is provided on both sides of a contact member 305 having a substantially U-shaped cross-sectional shape fixed to a support member base 53 and a support member main body 62 in the width direction (middle left and right direction in FIG. 13C). It is composed of the installed leaf springs 307 and 307.
For example, as shown in FIG. 13 (a), the support member 61 is arranged inside the contact member 305, and the tip side of the leaf springs 307 and 307 is shown in FIGS. 13 (b) and 13 (c). As described above, the contact member 305 is in contact with and urged on the inner side surface.

According to the buffer mechanism 303, the upward movement of the support member 61, that is, the operation of approaching the ball screw shaft 9, is buffered, as in the case of the buffer mechanism 95 in the case of the first embodiment.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
In this fifth embodiment, the ball screw shaft support structure 401 as shown in FIG. 14 is used. The ball screw shaft support structure 401 has substantially the same configuration as the ball screw shaft support structure 47 in the first embodiment and the second embodiment described above, but in the width direction of the support member main body 62 (FIG. 14). (B) Middle left and right directions) Buffer mechanisms 403 and 403 are provided on both sides.

The shock absorber 403 has a damper mounting member 405. As shown in FIG. 14A, stepped through holes 407 and 407 are provided in the center of the damper mounting member 405. The damper mounting member 405 is fixed to the support member main body 62 by penetrating the fixing screws 409 and 409 through the stepped through holes 407 and 407 and screwing them into the support member main body 62.
Further, as shown in FIG. 14A, dampers 411 and 411 are installed at both ends of the damper mounting member 405 in the front-rear direction. The damper 411 has a cylinder 413 and a rod 415. Oil (not shown) is sealed in the cylinder 413, and a piston (not shown) is fixed to the end of the rod 415 on the inner side of the cylinder 413. The lower end of the rod 415 in FIG. 14 is fixed to the base of an actuator (not shown). Therefore, when the support member 61 is moved in the vertical direction in FIG. 14, the cylinder 413 is moved relative to the rod 415. At this time, the movement of the cylinder 413 and, by extension, the support member 61 is buffered by the resistance of oil (not shown) in the cylinder 413.

Next, a sixth embodiment of the present invention will be described with reference to FIG.
In this sixth embodiment, the ball screw shaft support structure 501 as shown in FIG. 15 is used. The ball screw shaft support structure 501 has substantially the same configuration as the ball screw shaft support structure 47 in the first embodiment and the second embodiment described above, but the support member base 53 has a cushioning mechanism 503. is set up.
The buffer mechanism 503 has a rectangular plate 505 fixed to the support member base 53. Dampers 507, 507, 507, and 507 (the leftmost damper 507 in FIG. 15A is not shown) are installed at each corner of the plate 505. The damper 507 has the same configuration as the damper 411 of the fifth embodiment described above, and includes a cylinder 509 and a rod 511. The cylinder 509 is fixed to the plate 505, and the upper end of the rod 511 in FIG. 15 is fixed to the bottom surface of the support member main body 62.
The damper 507 buffers the vertical movement of the support member 61 in FIG. 15.

Next, a seventh embodiment of the present invention will be described with reference to FIG.
In the case of the first embodiment, a configuration in which one ball screw shaft support structure 47 is provided at one central position in the axial direction has been described as an example, but the actuator according to the seventh embodiment has been described. In the case of 701, the ball screw shaft support structures 47 and 47 are installed at two locations in the axial direction, respectively.
The other configurations are the same as those of the first embodiment, and the same parts in the drawings are designated by the same reference numerals and the description thereof will be omitted.

The seventh embodiment also has the same actions and effects as those of the first embodiment, but the seventh embodiment has a higher effect than that of the first embodiment. Even if the ball screw shaft 9 is long, it is possible to prevent the ball screw shaft 9 from bending, suppress vibration and noise, and operate the ball screw shaft 9 at high speed.

The present invention is not limited to the first to seventh embodiments.
First, in the case of the first to seventh embodiments, the case where one or two support members are provided has been described, but the present invention is not limited to this, and three or more support members may be provided.
Further, as the material of the receiving member, in addition to POM, various cases such as an oil-impregnated sintered material having good slidability can be considered.
Further, as the material of the cushioning material, in addition to felt and low-resilience rubber, various cases such as other cloth, rubber, resin, gel-like material, and porous material such as sponge can be considered.
Further, the material of the roller may be various cases such as rubber, oil-impregnated sintered material, etc. in addition to resin.
Further, the support member base can be integrated with the actuator base, and the support member guide support can be directly fixed to the base.
In addition, the illustrated configuration is just an example.

The present invention relates to a ball screw shaft support structure and an actuator, and in particular, a device devised to prevent the ball screw shaft from bending by a simple and compact configuration to suppress vibration and noise and to operate at high speed, for example. Suitable for industrial robots.

1 Actuator 9 Ball screw shaft 11 Slider 21 Front roller 23 Rear roller 31 Ball screw nut 57 Leaf spring (part of buffer mechanism)
61 Support member 65 Coil spring (elastic means)
71 Front inclined surface 73 Rear inclined surface 81 Support part 83 Receiving member 87 Cushioning material for receiving member 95 Cushioning mechanism 101 Actuator 201 Actuator 303 Cushioning mechanism 403 Cushioning mechanism 503 Cushioning mechanism 701 Actuator

Claims (17)

Ball screw shaft and
A ball screw nut that is movably screwed onto the above ball screw shaft,
A support that is detachably installed on the ball screw shaft and is pressed against the ball screw shaft by elastic means and is separated from the ball screw shaft by the approach of the ball screw nut against the urging force of the elastic means. Members and
Equipped with
A ball screw shaft support structure characterized in that a buffer mechanism for buffering the approaching motion of the support member with respect to the ball screw shaft is provided. In the ball screw shaft support structure according to claim 1,
The ball screw shaft support structure is characterized in that the cushioning mechanism comprises a leaf spring and an abutting member that comes into contact with the leaf spring. In the ball screw shaft support structure according to claim 1,
The ball screw shaft support structure is characterized in that the shock absorber is a damper. In the ball screw shaft support structure according to any one of claims 1 to 3.
A ball screw shaft support structure characterized in that a cushioning material for the support member is installed on the surface of the support member on the anti-ball screw shaft side. In the ball screw shaft support structure according to any one of claims 1 to 4.
The ball is characterized in that the support member is composed of a support member main body, a receiving member that receives the ball screw shaft, and a cushioning material for the receiving member that is interposed between the support member main body and the receiving member. Screw shaft support structure. In the ball screw shaft support structure according to claim 5,
The ball screw shaft support structure is characterized in that the receiving member is detachably installed. In the ball screw shaft support structure according to claim 5 or 6.
The ball screw shaft support structure is characterized in that the cushioning material for the receiving member is felt. In the ball screw shaft support structure according to any one of claims 5 to 7.
The ball screw shaft support structure is characterized in that the support member main body is provided with inclined surfaces on the support member side on both sides of the receiving member along the axial direction of the ball screw shaft. In the ball screw shaft support structure according to claim 8,
A ball screw shaft support structure characterized in that a cushioning material for the inclined surface on the support member side is installed on the inclined surface on the support member side. In the ball screw shaft support structure according to claim 8 or 9.
A ball screw nut side roller is installed on the ball screw nut side, and the support member is separated from the ball screw shaft by rolling along the inclined surface on the support member side. The ball screw shaft support structure is characterized by. In the ball screw shaft support structure according to claim 8,
The ball screw nut side inclined surface is provided on both sides of the ball screw nut side along the axial direction of the ball screw shaft, and the ball screw nut side inclined surface slides along the support member side inclined surface. A ball screw shaft support structure characterized in that the support member is brought into contact with the ball screw shaft as a result. In the ball screw shaft support structure according to claim 11,
A ball screw shaft support structure characterized in that a cushioning material for an inclined surface is installed on at least one of the inclined surface on the support member side or the inclined surface on the ball screw nut side. In the ball screw shaft support structure according to any one of claims 5 to 7.
A ball screw shaft support structure characterized in that the support member main body is provided with a roller on the support member side. In the ball screw shaft support structure according to claim 13,
An inclined surface on the ball screw nut side is provided on the ball screw nut side.
A ball screw shaft support structure characterized in that the support member is separated from the ball screw shaft by rolling the support member side roller along the ball screw nut side inclined surface. In the ball screw shaft support structure according to claim 14,
A ball screw shaft support structure characterized in that a cushioning material for an inclined surface is installed on the inclined surface on the ball screw nut side. An actuator characterized in that one support member of the ball screw shaft support structure according to any one of claims 1 to 15 is installed. An actuator characterized in that a plurality of support members having a ball screw shaft support structure according to any one of claims 1 to 15 are installed.

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