JPH0539838U - Feeder - Google Patents

Abstract

(57) [Summary] [Purpose] To reliably prevent vibration when the ball screw moves. A feed device in which a ball screw 1 is fixed to a movable body 4 which is movable along a guide portion 3, and the ball screw 1 is fed in an axial direction by rotation of a nut 7 rotatably provided at a fixed position. A ball screw supporting portion having a plurality of rollers 11 which rotate in contact with the outer peripheral surface of the ball screw 1 from at least three directions at positions separated by a predetermined distance in both directions of movement of the ball screw 1 around the nut 7. 10 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a feed device using a ball screw, for example, a machining table feed device, and more particularly to a feed device using a ball screw to prevent the ball screw from bending and swinging during movement.

[0002]

[Prior art]

 In this type of feeder, especially when a long moving body is stroked in the longitudinal direction using a ball screw and a nut, the length of the moving body plus the stroke is the normal nut feed type. Since it requires a ball screw, the ball screw feed type is generally adopted, and the ball screw fixed to the moving body is fed in the axial direction by rotating the nut at a fixed position.

However, when the ball screw is long, a phenomenon occurs in which the ball screw vibrates during movement. Therefore, conventionally, a V-shaped steady rest member 12 as shown in FIGS. 6 and 7 is installed at an appropriate position within the moving range of the ball screw.

[0004]

[Problems to be solved by the device]

 In such a conventional method, since the steady rest 12 and the ball screw 1 are in sliding contact, the steady rest 12 is arranged so as to maintain the clearance C at the maximum static deflection of the ball screw 1. .. Therefore, the vibration of the ball screw 1 cannot be completely canceled, which adversely affects the life of the ball screw 1.

Therefore, in the present invention, the steady rest is not slippery as in the conventional case, but is rolling type so that the ball screw is always supported from the outer peripheral direction in a restrained state, so that the vibration during the movement of the ball screw is reliably prevented. The purpose is to do.

[0006]

[Means for Solving the Problems]

 That is, the present invention relates to a feed device in which a ball screw is fixed to a movable body that is movable along a guide portion and the ball screw is fed in the axial direction by rotation of a nut that is rotatably provided at a fixed position. Since a ball screw supporting portion having a plurality of rollers that rotate in contact with the outer peripheral surface of the ball screw from at least three directions is provided at positions separated by a predetermined distance in both directions of movement of the ball screw around the nut. is there.

[0007]

[Action]

 As a result, when the nut is rotated and the ball screw is moved, each roller of the ball screw supporting portion on the side where the ball screw is located rotates with the movement of the ball screw while restraining the ball screw from at least three directions around the ball screw.

Since the three-point or four-point restraint by the roller is possible, the vibration of the ball screw can be completely eliminated. In addition, since it is not slipping, there is no wear on the steady rest, and the steady rest is effective.

When the ball screw is moved in the opposite direction and the ball screw enters between the rollers of the ball screw supporting portion on the opposite side, the ball screw is similarly supported between the rollers by the steady rest.

[0010]

【Example】

 Hereinafter, a specific embodiment of the present invention will be described.

FIG. 1 is a side view showing an embodiment of the feeding device of the present invention, FIG. 2 is an enlarged view of a main part thereof, FIG. 3 is a view seen from the direction A of FIG. 2, and FIG. 4 is a direction B of FIG. FIG. 5 is an enlarged view of an essential part viewed from above, and FIG. 5 is a view showing a modified example of the ball screw support part.

In FIG. 1, a movable body 4 such as a machining table is guided and supported along a guide portion 3 such as a linear guide provided on a base 2 so as to be movable in the left-right direction in the drawing. Both ends of the ball screw 1 are fixed to the lower surface of the moving body 4 in the longitudinal direction via a pair of brackets 5 in a non-rotating state.

A nut 7 is rotatably provided at a fixed position in a substantially middle portion of the base 2 by being screwed into the ball screw 1 via a bracket 6. A rotation transmission mechanism 8 including a pulley and a belt is connected to the nut 7, and the rotation force from the feed motor 9 is transmitted.

Further, ball screw support portions 10 are provided at two positions separated from the position of the nut 7 in both moving directions of the ball screw 1, that is, on the left and right sides of the drawing by a predetermined distance L, respectively. The above-mentioned distance L is, for example, about half the length of the ball screw 1 here, but depending on the rigidity and length of the ball screw 1 so that the ball screw 1 is supported at a length interval that does not cause bending, at least. The support interval and the number of ball screw support parts 10 to be installed are set.

As shown in FIG. 2 and FIG. 3, the ball screw support portion 10 is located at a position where it does not interfere with the bracket 5 that supports the ball screw 1 when the ball screw 1 moves, from the outer peripheral surface 4 direction of the ball screw 1. Four rollers 11 are rotatably supported around roller shafts 11a so as to be pressed toward the center of the ball screw 1. As shown in FIG. 5, each roller 11 is attached so as to rotate along the moving direction of the ball screw 1, that is, the axial direction, supports the ball screw 1 with four-point restraint, and prevents the ball screw 1 from vibrating. You can kill it completely.

In this configuration, when the moving body 4 is moved to the left from the center of the base 2, the ball screw 1 is disengaged from the right side ball screw support portion 10, and the ball screw support portion 10 between the rollers 11 of the left side ball screw support portion 10 is removed. Entered and restrained in the swing direction. During this movement, the middle nut 7 and the left side ball screw support portion 10 support the intermediate portion of the ball screw 1, so that the long ball screw 1 is supported at a distance L that does not cause bending. Therefore, it is possible to reliably prevent the deflection and the shake.

When the moving body 4 is moved to the right, the ball screw 1 is released from the left ball screw supporting portion 10, enters between the rollers 11 of the right ball screw supporting portion 10, and is restrained in the swinging direction. .. During this movement, the nut 7 in the center and the ball screw support portion 10 on the right side support the intermediate portion of the ball screw 1.

It should be noted that the ball screw support portion 10 may be supported by three rollers 11 with three-point restraint as shown in FIG. You can also do it.

[0019]

[Effect of the device]

 According to the present invention, when the nut is rotated and the ball screw is moved, the rollers of the ball screw supporting portion on the side where the ball screw is located rotate together with the movement of the ball screw while restraining the ball screw from at least three directions around the ball screw. To be done.

Since the roller is restricted by 3 or 4 points, it is possible to completely eliminate the vibration of the ball screw, and it is possible to reliably prevent the ball screw from flexing or swinging during movement, thus improving the life of the ball screw. it can. Also, since it is not slipping, there is no wear on the steady rest, and the steady rest is effective.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a feeding device of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a view seen from the direction A in FIG.

FIG. 4 is an enlarged view of a main part viewed from the direction B in FIG.

FIG. 5 is a view showing a modified example of the ball screw support portion.

FIG. 6 is a side view showing a steady rest of a ball screw provided in a conventional feeding device.

FIG. 7 is a view seen from the direction D in FIG.

[Explanation of symbols]

 1 Ball screw 3 Guide part 4 Moving body 7 Nut 10 Ball screw support part 11 Roller

Claims (1)

[Scope of utility model registration request] 1. A feed device in which a ball screw is fixed to a movable body that is movable along a guide portion, and the ball screw is fed in the axial direction by rotation of a nut that is rotatably provided at a fixed position. A ball screw support portion having a plurality of rollers that rotate in contact with the outer peripheral surface of the ball screw from at least three directions is provided at positions separated by a predetermined distance in both directions of movement of the ball screw around the nut. Feeding device.