JPH04124363U - slide table unit - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the positioning accuracy of a slide table unit and to reduce its weight and size. [Structure] The slide table unit includes a ball screw 1 having a screw shaft 1a and a ball nut 1b screwed onto the screw shaft 1a, a table 2 fixed to the top surface of the ball nut 1b, and a slide table unit mounted on both sides of the ball nut 2b. roller 3,
It is composed of a linear guide rail 5 that guides and supports the rollers 3, and a base 6 for fixing the linear guide rail 5. Four rollers 3 (cam followers) are arranged, two on each side of the ball nut 1b, and the rollers on each side are distributed and attached to the ball nut 1b in the front-rear direction. Therefore, all the unbalanced loads of the ball nut 1b in the rolling direction and the yawing direction are supported by the rollers 3.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention can be used as a positioning table for automatic assembly lines for electrical components. Regarding the slide table unit used.

0002

[Conventional technology]

The slide table can be driven by a hydraulic cylinder or driven by a ball screw. However, with recent advances in precision, it has become possible to use ball screw drives. things have come to dominate. When driven by a ball screw, the table The screw is fixed to the ball nut of the screw, and the ball nut can be moved in the axial direction by rotating the screw shaft. It is designed to slide as you move. Then the table slides A pair of linear Insert the guide bar on both the left and right sides of the ball nut, and insert the ball into this linear guide bar. I'm trying to guide the nut.

0003

[Problem that the idea aims to solve]

Both ends of the above linear guide bar are fixedly supported on a base, etc., but the middle part is in the air. It is in a floating state, and when an unbalanced load from the table is applied, the middle part changes. This may cause table rolling or yawing (axial yaw), etc. live. Therefore, with conventional slide tables, sufficient positioning accuracy is required. It was difficult to secure.

0004 Also, adjust the width of the ball nut by the amount necessary to insert the linear guide bar. Since the law has to be made larger, the overall unit tends to become larger.

[0005] Therefore, the purpose of this invention is to improve the positioning accuracy of the slide table unit. The objective is to reduce the weight and size of the vehicle.

[0006]

[Means to solve the problem]

The slide table unit of the present invention includes a screw shaft and an axial direction that is screwed onto the screw shaft. A ball screw consists of a ball nut that moves in the opposite direction, and a ball screw that is fixed to the ball nut. A table that moves in the axial direction and rollers rotatably mounted on both sides of the ball nut. and a linear guide rail fixed to the base and guiding and supporting the roller. It is characterized by the fact that

[0007]

[Effect]

Rollers are rotatably mounted on both sides of the ball nut, and the nut is rotated in the axial direction. When moving, this roller slides onto the guide surface of the linear guide rail fixed to the base. to ensure smooth movement of the ball nut. Table on ball nut The table is fixed, and the load from the table is transferred via ball nuts and rollers. Supported by linear guide rails.

[0008]

【Example】

Hereinafter, embodiments of the present invention will be described based on the drawings.

[0009] As shown in Fig. 1, the slide table unit of the present invention has a screw shaft 1a and a screw shaft 1a. A ball screw 1 including a ball nut 1b screwed onto the same shaft 1a, and a ball nut 1b A table 2 is fixed to the top surface of the ball nut 1b, and rollers 3 are attached to both sides of the ball nut 1b. , a linear guide rail 5 that guides and supports the roller 3, and a linear guide rail 5. It consists of a base 6 for fixing.

0010 As shown in FIG. 2, a spiral groove 1c is formed on the outer circumferential surface of the screw shaft 1a. A spiral circulation between the groove 1c and the spiral groove 1d formed on the inner peripheral surface of the ball nut 1b. A plurality of balls (not shown) are arranged in the ring path so as to be able to roll and circulate freely. The screw shaft 1a is It is connected to a servo motor (not shown) and is rotationally controlled by the servo motor. . When the screw shaft 1a rotates, the ball nut 1b slides in the axial direction. Ma In addition, a bolt hole 1f is formed on the upper surface of the ball nut 1b, and this bolt hole 1f is The table 2 can be fixed using bolts (not shown). four rows Two rollers 3 are arranged on each side of the ball nut 1b, and each The ones on the side are attached to the ball nut 1b in a distributed manner in the front and back direction. therefore, All unbalanced loads in the rolling direction and yawing direction that act on the ball nut 1b are and is supported by rollers 3. In this example, the roller 3 is a cam follower. (an outer ring rotatably supported around a shaft by a needle, etc.) The shaft of the cam follower is screwed onto the ball nut 1b.

[0011] The linear guide rail 5 is fixed to the base 6 and guides and supports the roller 3 from below. The lower rail 5a is fixed to the upper surface of the lower rail 5a and the roller 3 is fixed to the upper surface of the lower rail 5a. It is composed of an upper rail 5b that restricts movement.

0012 As shown in FIG. 3, the end surfaces of the upper and lower rails 5b and 5a correspond to the shape of the rollers 3. A corresponding upper stage part 5d and lower stage part 5c are formed. The roller 3 is connected to the upper and lower sections 5. It fits into the U-shaped recess formed by d and 5c, and is guided by the upper surface of the lower part 5c. Supported. In addition, in order to ensure rolling of the roller 3, the lower surface of the upper part 5d and the roller 3, and between the side surfaces of the upper and lower portions 5d and 5c and the end surface of the roller 3. are provided with slight gaps δ1 and δ2, respectively.

[0013] From the viewpoint of preventing rolling and yawing of the ball nut 1b, the above It is desirable to make the gaps δ1 and δ2 as small as possible. This gap δ1 and As a means for managing δ2 and δ2, for example, the following means can be used. figure 4, a grinding allowance S1 is provided on the lower surface of the lower rail 5a, and a grinding allowance S1 is provided on the lower surface of the lower rail 5a. Measure the dimension L from the bottom end to the top surface of the base 6, and then adjust the lower rail according to this dimension L. Grind the lower surface of the wheel 5a. At the same time, the grinding allowance S is also applied to the lower surface of the upper rail 5b. 2 is provided, and the lower surface of the upper rail 5b is currently ground to match the gap δ1. child By doing as follows, a predetermined gap δ1 can be obtained. Also, top and bottom By slidingly adjusting the section rails 5b and 5a relative to the roller 3, a predetermined gap can be created. The interval δ2 can be obtained. In this embodiment, the linear guide rail 5 is The main reason for dividing the rail into the rail 5b and the lower rail 5a is that the gap δ1 is This is because it can be easily managed.

[0014] When the screw shaft 1a is rotationally driven by the servo motor, the ball nut 1b is rotated in the axial direction. The table 2 slides in the direction along with this. Roller 3 is , along with the ball nut 1b while rolling on the upper surface of the lower step 5c of the lower rail 5a. Moving.

[0015]

[Effect of the idea]

According to the present invention, since the rollers are attached to both sides of the ball nut, Compared to the conventional linear guide bar, the width of the ball nut itself has been increased. There is no need to listen to the noise, and the entire unit can be made lighter and smaller.

[0016] In addition, the rollers are guided and supported by linear guide rails fixed to the base. This ensures that the linear guide rail will not be displaced even if it receives an uneven load from the table. , high positioning accuracy can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a slide table unit according to the present invention.

FIG. 2 is a perspective view showing a ball screw portion in FIG. 1;

FIG. 3 is an enlarged sectional view of the peripheral portion of the roller in FIG. 1;

FIG. 4 is a sectional view showing a method of forming a gap between a linear guide rail and a roller.

[Explanation of symbols]

1 Ball screw 1a Screw shaft 1b ball nut 2 table 3 Roller (cam follower) 5 Linear guide rail 5a Lower rail 5b Upper rail 6 base

Claims (1)

[Scope of utility model registration request] 1. A ball screw comprising a screw shaft and a ball nut that is screwed onto the screw shaft and moves in the axial direction; a table that is fixed to the ball nut and moves in the axial direction;
A slide table unit comprising a roller rotatably mounted on both sides of the ball nut, and a linear guide rail fixed to a base and guiding and supporting the roller.