JPS63312563A - Precision positioning device - Google Patents

Abstract

PURPOSE:To make it possible to perform precision positioning with high speed by providing a connecting member for connecting both ends thereof with a removal body and a slide table through respective universal joints and clamping the movable body and slide table via a spherical body. CONSTITUTION:A spring arm 12 is made flexible by the adjustment of a connecting rod in length so that a movable body 2 and a slide table 1, which are clamped by a spherical body 3 and arms 11, 21, are attracted to each other. This forms a pre-load condition for bringing the spherical body 3 into contact with the arms 11, 21 in the load as desired in the sliding direction. When the movable body 2 is made in a linear motion by a linear driving device 5, the movable body 2 pushes the table 1 and the spherical body 3 while pulling them through the connecting rod 4 so as to move the table 1. In this case, even if motion occurs to the movable body 2 in the radial direction and the motion around the shaft crosses orthogonally with the linear motion direction, they are absorbed by the rolling of the spherical body 3 and the universal joint 40 for preventing the motion around the shaft from transmitting to the table 1.

Description

[Detailed description of the invention] 【Technical field】

The present invention relates to a precision positioning device used for an XY table or the like.

[Background technology]

In order to move a slidably supported slide table to a predetermined position in an XY table, etc., the slide table is generally moved directly by a linear drive device such as a feed screw mechanism or a near motor. Shaking and rattling in directions other than directions, especially in the radial direction, are transmitted to the slide table, making it unsuitable when precise positioning is required. To this end, as shown in FIG. 18.19
A device located in between is proposed in Japanese Patent Laid-Open No. 59-71712. Both nozzle play here) 18
．． Reference numeral 19 includes a nozzle 17 that jets high-pressure air toward the plate 29, and forms a gas bearing between the nozzle 17 and the plate 29. However, this method has the following problems. First, even though it is a gas bearing, force is transmitted over the entire bearing surface, so the slide table 1 is affected by the imbalance of the parallelism between the slide table 1 and the movable body 2, as well as the displacement and fluctuation of the movable body 2 due to the linear drive device. This appears as pitching or yawing, which causes positioning errors. #
Since S2 has low rigidity per unit area, it requires a large gas bearing to transmit a large force, making it impractical when high-speed positioning is required. The third problem is that with gas bearings, there are many design factors such as the diameter and arrangement of the nozzle 17, clearance, air pressure, etc., and it is necessary to determine the optimal design values each time according to the usage conditions, which increases the degree of freedom. Limited versatility. However, JP-A-61-293745 and JP-A-6
As shown in Japanese Patent No. 1-293746, there is a system in which a roller or a sphere is interposed between the slide table and the movable body, and a permanent magnet or a coil spring is used to draw them together. Problem 1 is almost solved. However, even in these cases, the second problem and the third problem are not solved.
Problems remain in terms of large force transmission, design freedom, and versatility. The spring force of the coil spring and the attractive force of the permanent magnet will not change unless the design changes or parts are replaced.
This is because it cannot be changed.

[Purpose of the invention]

The present invention was created in view of these points, and its purpose is to be able to transmit a large force in the sliding direction, while at the same time being able to transmit movements in other directions to the slide table. The purpose of this invention is to provide a precision positioning system that enables high-speed precision positioning.

[Disclosure of the invention]

Therefore, the precision positioning device according to the present invention connects a slide table supported slidably, a movable body slidably driven by a linear drive device, and these movable bodies and the slide table whose sliding directions are the same. and a transmission member that transmits the movement of the movable body to the slide table, and the transmission member is rotatably arranged between opposing surfaces of the movable body and the slide table in the sliding direction, and transmits the movement of the movable body and the slide table. It consists of a contacting sphere, and a connecting member whose both ends are respectively connected to the movable body and the slide table via free joints, and which draws the movable body and the slide table to each other across the sphere,
The free joint at at least one end of the connecting member is characterized in that it is connected to a spring arm provided on the movable body or the slide table. According to the present invention, the sphere located between the movable body and the slide table prevents the transmission of unnecessary force, and although the connecting rod is used to transmit large force,
The presence of the spring arm ensures reliable movement of the sphere, and the presence of the free joint prevents the effects of movement other than in the sliding direction from being transmitted through the connecting rod. The present invention will be described below in detail based on the illustrated embodiment. A slide table 1 supported by a slide guide 10 in a freely sliding manner includes an arm 11 and a spring arm 1.
2 are fixed at each end. A ball 3, which is a hardened steel ball, is rotatably held on the side surface of the arm 11 via a ball guide 15. The movable body 2, which is slidably supported by the sub-slide guide 201, is arranged within the sub-slide guide 20 or linearly driven by a near motor if(#it drive device 5), and its sliding direction is The arm 21 is parallel to the sliding direction of the table 1. One end of an arm 21 that protrudes toward the slide table 1 side is fixed to the movable body 2. The spherical body 3 is in contact with the hardened and polished side surfaces of both arms 11 and 21, as shown in Figure Pt54. It is connected to the spring arm 12 by a connecting rod 4. The connecting rod 4 here has a right-hand threaded part and a left-hand threaded part called a turnbuckle or a-rad end, and its length can be adjusted freely. and both ends are connected to the arm 21 and the spring 7-m 12, respectively, via free joints 40 and 40, which have degrees of freedom in three-dimensional directions and are composed of a sphere and a bearing surrounding the sphere. Fig. 3 shows an example in which a feed screw W1 structure composed of a feed screw 50 rotationally driven by a motor 52, a feed nut 51, a guide shaft 53, etc. is used as the linear drive device W15. In this precision positioning device, the connecting rod 4
By bending the spring arm 12 by adjusting the length of the slide table 1, the movable body 2, which holds the sphere 3 between the arms 11 and 21, and the slide table 1 are drawn together, and the sliding direction of the slide table 1 is adjusted. arm 1
1. A preloaded state is created in which the sphere 3 is in contact with the point 21 with a required pressure. Now, when the movable body 2 is driven by the linear drive device 5 and performs a linear motion, the movable body 2 pushes the slide table 1 through the sphere 3 and pulls it through the connecting rod 4.
Move the slide table 1. At this time, even if the movable body 2 has a movement in the radial direction or a movement around the sleeve that intersects with the direction of linear motion, this is absorbed by the rolling of the sphere 3 and the free joint 40, so the slide table 1
The slide table 1 will not cause pitching or yawing. In reality, the rolling resistance of the sphere 3 and the rotational resistance of the free joint 40 are factors that transmit unnecessary movement to the slide table 1, but these are sufficiently small compared to the force that should be transmitted in the sliding direction and are not suitable for practical use. There is no problem if you ignore the above. Since the spring arm 12 acting as a leaf spring element can generate a sufficiently large force by appropriately selecting its plate thickness, the presence of the spring arm 12 does not limit the magnitude of the force to be transmitted. I almost never give it away (,
It can also handle high-speed, high-acceleration positioning where large inertial forces act. In the illustrated example, a spring arm 12 is provided on the slide table 1 side.
Although the spring arms are provided on the movable body 2 side, it is of course possible to connect the spring arms provided on both sides with the connecting rod 4. [Effects of the Invention] As described above, in the present invention, components other than the necessary components of the movement of the movable body can be absorbed by the rolling of the sphere or the rotation of the free joint. Only the movement of The slide table can be precisely positioned without any end of shaking in the direction, and since the slide table is driven by the movable body by the ball or connecting rod and the spring arm, it does not require a large force. Therefore, it is possible to handle high-speed positioning.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is an exploded perspective view of the same, FIG. 3 is a perspective view showing the other side of the linear drive device, and FIG. 4 is a cross-sectional view of the same. Figure 5 is a perspective view of a conventional example, in which 1 is a slide table, 2 is a movable body, 3 is a sphere, 4 is a connecting rod, 5 is a linear drive 2 device, 12 is a spring 7-m, and 40 is a free joint. show. Agent Patent Attorney Ishi 1) Ai 71 Slide table 2 Movable body 3 Sphere 4 Connecting rod 5 Linear drive device 12 Spring arm 40 Free joint 1 Figure 2

Claims (2)

[Claims] (1) A slide table supported so as to be slidable,
It consists of a movable body that is slidably driven by a linear drive device, and a transmission member that connects these movable bodies and a slide table whose sliding direction is the same and transmits the movement of the movable body to the slide table, and the above-mentioned The transmission member includes a sphere rotatably disposed between opposing surfaces of the movable body and the slide table in the sliding direction and in contact with the movable body and the slide table, and a spherical body having both ends connected to the movable body and the slide table via free joints, respectively. It consists of a connecting member that is connected to draw the movable body and the slide table to each other across the sphere, and a free joint at at least one end of the connecting member is connected to a spring arm provided on the movable body or the slide table. A precision positioning device characterized by: (2) The precision positioning device according to claim 1, wherein the connecting member is a turnbuckle or rod end whose length is adjustable.