JP2002221267A - Linear motion link mechanism device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a movement mechanism for realizing a linear motion which is improved in accuracy and rigidity simultaneously by using a plurality of link mechanisms eliminating the oscillation of a rotating shaft. SOLUTION: A first link mechanism 1 is formed by assembling the first and second rigid connecting members 11 and 12 rotatably by a shaft 13, and a second link mechanism 2 is basically composed similarly to the first link mechanism 1. Both one ends of the first and second connecting members are pivotally and rotatably attached to each other, and the other end of the first connecting member is also pivotally attached to a stand. The other axes of the connecting members of first and second link mechanisms are connected to a connector 4 by a couple of axes 42 and 43 provided on the block 41 thereof. Thereby, the connector can linearly be moved along a crossing line of both plain faces on which the first and second link mechanisms can be moved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for supporting a workpiece to perform highly accurate linear motion, and to connect the free ends of two sets of link mechanism devices which are mounted on a gantry. The present invention relates to a linear motion link mechanism device that realizes a complete linear motion of a connecting portion on a straight line along an intersection of different moving surfaces of the device.

[0002]

2. Description of the Related Art In technical fields such as an optical apparatus, a machine tool, and an exposure apparatus for manufacturing a semiconductor, there are often cases where accurate and high-precision linear motion is required. In such a technical field, in many cases, a work table or a table is mounted with guide rails provided to enable linear movement of a processing object, but in order to maintain high accuracy over the entire range of linear movement. In such a case, extremely precise work and maintenance management for maintaining accuracy are required, and as a result, product prices and management costs become high.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a device for driving a table or the like on which a workpiece is placed along a straight line, by omitting a guide rail requiring precise machining, and manufacturing the device relatively inexpensively. It is an object of the present invention to provide a mechanism capable of performing highly accurate linear motion using only a link mechanism device that is easy to operate. In order to achieve this object, the free ends of two sets of link mechanism devices which are pivotally mounted on a gantry are connected, and the link performs linear motion on a straight line along the line of intersection of different moving surfaces of each link mechanism device. It is an object to realize a mechanical device.

[0004]

Each end of at least two sets of link mechanism devices using a plurality of rigid connection members is pivotally mounted on a mount, and the moving surfaces of the other ends of the link mechanism devices are mutually connected. These are arranged so as to have a predetermined angle, and the other ends thereof are connected by a connector, and the intersection of the plane on which the first link mechanism device can move and the plane on which the second link mechanism device can move is formed. A linear motion link mechanism device that enables the connector to linearly move along the link is employed as means for solving the problem.

More specifically, the present invention provides a first link mechanism device in which one ends of first and second connection members are rotatably mounted on a shaft, and the other end of the first connection member is mounted on a gantry. A second link in which one end of each of the first and second connection members is rotatably mounted on a shaft, and the other end of the first connection member is mounted on a gantry so as to be movable at an angle different from that of the first link mechanism device. A mechanical device, a connector rotatably coupled at the other end of each of the first and second link mechanism devices, and a circular plane on which the other end of the first link mechanism device is movable; A linear motion link mechanism device characterized in that the connector can move on a straight line intersecting with a circular plane having the other end movable.

As another means, there is a first link mechanism, comprising a rigid first connecting member and a rigid second connecting member, one end of each member being rotatable relative to each other by a first shaft. And a second shaft is provided at the other end of the first connection member, and a shaft hole is formed at the other end of the second connection member so as to penetrate the third shaft. Are provided in parallel with each other, and the second link mechanism includes a rigid first connection member and a rigid second connection member, and one end of each member is mutually connected by the first axis. The first connecting member is provided with a second shaft at the other end thereof, and the other end of the second connecting member is provided with a shaft hole passing through the third shaft. And a third shaft is provided in parallel with each other, and the second shaft of the first link mechanism is rotatably fitted to a bearing fixed to the gantry, and the second link The second axis configuration, necessarily rotatably fitted in a bearing fixed to the frame, the third of the first link mechanism
One shaft of the connector is rotatably fitted in a shaft hole passing through the shaft of the second link mechanism, and the other shaft of the connector is rotatable in a shaft hole passing through the third shaft of the second link mechanism. And a linear motion link mechanism device in which the connector is capable of linear motion along a line of intersection between a plane on which the first link mechanism can move and a plane on which the second link mechanism can move. ing.

Another means is to provide a shaft hole through the third shaft of the first link mechanism, and to provide a shaft hole through the third shaft of the second link mechanism. The connector has two shafts, and the two shafts are fixed such that their centers maintain a predetermined angle from the connector and project rigidly from each other, and the first link mechanism One shaft of the connector is rotatably fitted in a shaft hole through which the third shaft passes, and the other shaft of the connector is fitted in a shaft hole through which the third shaft of the second link mechanism passes. There is a linear motion link mechanism device which is rotatably fitted.

Further, in the above link mechanism, a plurality of the first link mechanism, the second link mechanism, or both the first link mechanism and the second link mechanism are provided, and the strength can be increased. In addition, a plurality of linear motion link mechanisms are installed on the pedestal as a unit, and the moving directions of the connectors of each linear motion link mechanism are matched, so that a single moving table can be linearly moved by a plurality of connectors. The linear motion link mechanism device supported by the above can be used as the means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing a main part of a first embodiment of the present invention. In order to explain a shaft of each link mechanism, a shaft hole or a bearing through which the shaft passes, FIG. Portions hidden behind the members and not visible are also shown by broken lines. Figure 1
In the drawings, 1 is a first link mechanism, 2 is a second link mechanism as a whole, 3 is a symbol of a part of a gantry supporting each link mechanism, and 4 is a connector block. I have. Here, the connector 4 is simply illustrated in a cubic shape for the purpose of explanation, but a more complicated shape may be adopted for mounting the shaft or mounting on a table or the like.

In the first link mechanism 1 shown in FIG. 1, a rigid first connection member 11 and a rigid second connection member 12 are assembled so as to be rotatable about a shaft 13. The shaft 13 is supported by bearings 131 and 132 provided on the first connection member 11. The shaft 13 may be rotated in a shaft hole provided on the second connection member 12, or may be supported by the bearings 131 and 132. The shaft 13 may be rotated at a portion. In the latter case, the bearing 13
Ball bearings can be used for parts 1 and 132.

A shaft hole is provided at an end of the first connection member 11 opposite to the shaft 13, and a shaft 14 is inserted therein. Axis 14
Is supported by bearings 141 and 142. in this case,
The shaft 14 may be fixed to a gantry and rotated in a shaft hole provided in the first connection member 11, or the shaft 14 may be fixed to the first connection member 11.
, And both ends of the shaft may be rotatably supported by bearings 141 and 142. In the latter case, ball bearings can be used for the bearings 141 and 142. The shaft 14 of the first connection member 11 is held horizontally or at a predetermined angle with respect to the gantry.

The structure of the second link mechanism 2 is basically the same as that of the first link mechanism 1. That is, the rigid first connection member 21 and the rigid second connection member 22 are assembled rotatably by the shaft 23. The shaft 23 passes through a shaft hole provided in the second connection member 22 and supports both ends of the shaft 23 by bearings 231 and 232 (not shown) provided in the first connection member 21. The shaft 23 may be rotated in a shaft hole provided in the second connection member 22 or may be rotated in the bearings 231 and 232. In the latter case, a ball bearing can be used as the bearing.

A shaft hole is provided at an end of the first connecting member 21 on the side opposite to the shaft 23, and a shaft 24 is inserted into the connecting member 2.
1 is rotatably supported. Since the second link mechanism is rotatably supported only by the shaft 24, it is necessary that the second link mechanism maintain sufficient strength with respect to the gantry and can rotate smoothly with high precision. In the illustrated embodiment, the shaft 24 is firmly attached to the gantry by the shaft attaching member 241.
The structure which fits with the shaft hole provided in the first connection member 21 is shown.

In the second connecting member 12 of the first link mechanism 1, a shaft hole 15 is provided on the side opposite to the shaft 13.
Similarly, in the second connection member 22 of the second link mechanism 2, a shaft hole 25 is provided on a side opposite to the shaft 23.
The shaft 14, the shaft 13 and the shaft hole 15 of the first link mechanism 1 are provided in parallel with each other. Therefore, the shaft hole 15 is
4 can be moved in a plane perpendicular to the axis. On the other hand, the shaft 24, the shaft 23, and the shaft hole 25 of the second link mechanism 2 are provided in parallel with each other. Therefore, the shaft hole 25 can move around the shaft 24 in a plane perpendicular to the shaft.

In the description relating to FIG. 1, various types of shafts, bearings, bearings by ball bearings, and the like are schematically illustrated, but typical examples of specific structures are collectively referred to with reference to FIGS. explain. FIG. 2 shows a state in which the shaft 24 in FIG.
Is an embodiment of a structure for rotatably supporting, which is partially shown in cross section. The shaft 24 is provided with a shaft mounting member 241 having a diameter larger than the diameter of the shaft. The shaft 24 slides with a shaft hole provided in the first connection member 21 and a bolt integrally provided on the opposite side of the shaft mounting member 241. A part 242 is provided. Shaft 24
A snap ring housing groove 249 is provided near the end of the groove.

A bolt 242 is inserted into a hole provided in the gantry 3 and a washer (including a spring washer if necessary) 24
3 and fixed by a nut 244. Shaft 2 on gantry 3
When 4 is fixed, the shaft hole provided in the first connection member 21 is inserted into the shaft 24, and the snap ring 248 is fitted and fixed in the snap ring receiving groove 249. The vertical load applied to the first connecting member 21 is supported on the upper surface of the shaft mounting member 241, and the shaft 24 supports the stress component in the direction perpendicular to the shaft. The snap ring 249 is for preventing the first connection member 21 from moving upward or coming out of the shaft 24.
Due to its own weight and the weight of the members above it, it is stably supported on the shaft mounting member 241 in a normal operation state, and unnecessary movement in the axial direction is prevented. Also, the shaft 24 and its shaft hole have only a gap that does not hinder smooth rotation.
Unnecessary movement other than rotation of the link mechanism device can be prevented.
Apply a lubricating substance such as lubricating oil to the rotating part as needed.

FIGS. 3 and 4 are views illustrating the structure of the bearing at the connection between the second connection member 12 and the first connection member 11 in the first link mechanism 1. FIG. In FIG.
The shaft 13 is inserted into the shaft hole of the second connecting member, and the fixing bolt 1 is inserted.
The shaft is fixed by 35. The end of the shaft 13 is rotatably supported by ball bearings 133 and 134 attached to the first connection member 11. One ball bearing 13
4 is supported by a bearing support member 136 for easy assembly, and attached to the first connection member 11 by bolts 137. The ball bearing uses a flange, and prevents outward movement by the flange. At the final stage of assembly, the bearing support member 136 is connected to the first connecting member 11 by the bolt 1.
It is assembled at 37, but the compression force between the shaft and the ball bearing is adjusted to prevent both axial movement and smooth rotation.

In FIG. 4, the ball bearing 13
3, 134 are received from outside the first connection member 11 in the receiving holes 139.
And fix the flange to the connection member side,
The shaft and mounting bolt 47 is inserted into the inside of the ball bearing, and is screwed and connected to a nut provided on the second connection member 12. The gap can be adjusted by inserting a spacer 48 between the ball bearing and the connection member 12.
In addition, a slit 49 is provided in a part of the first connecting member 11 to provide a spring effect, and a preload is applied to the ball bearing to eliminate unnecessary movement in the operation of the link mechanism. Alternatively, by providing a surface bearing as a receiving hole of the ball bearing, a normal type ball bearing without a flange can be used.

FIG. 5 shows an embodiment of a block constituting the connector 4 and a shaft attached thereto. Connector 4
Block 41, two shafts 42 and 43 are attached at a predetermined angle. The two shafts 42 and 43 are inserted into the shaft holes 15 and 25 as described above. In order to facilitate the assembly, after attaching the first and second link mechanisms to the gantry, one of the shafts 42 or 43 is inserted into the shaft hole 15 or 25 provided in the node of the link mechanism to be axially mounted. . Next, the shaft is inserted into the shaft hole of the other link mechanism for attaching the other shaft, and the shaft 42 or 4 is inserted into the screw hole provided in the block 41.
3 can be fixed by a means such as screwing in and fixing the screw 46 provided in 3. Also, at the other end of the shafts 42 and 43,
A method of providing a groove 44 and attaching a snap ring 45 to prevent falling off can be used.

According to the present invention, as shown in FIG. 6, the first link mechanism 1 can freely move about the shaft 14 on the gantry, the shaft hole 15 that can move freely in the plane 61, and the second link mechanism 2 A freely movable shaft hole 25 around the shaft 24 on the gantry can move in the plane 62.
By connecting the shaft hole 5 and the shaft hole 25 with a shaft provided in the connector 4, it is based on the principle that it moves only within a straight line 63 where the planes 61 and 62 intersect. Therefore, when the two planes are parallel, it is clear that a linear motion cannot be obtained, and the predetermined angle A is selected. Although the first embodiment has been described by selecting the angle to be 90 degrees, an arbitrary angle, for example, 60 degrees may be selected. The straight line 63 shown in FIG. 6 corresponds to the straight line 7 passing through the connector 4 in FIG. 1 and having arrows 8 and 9 in the moving direction, and indicates a range in which the connector can move linearly. Although the moving plane is indicated by a circle, the link shafts 15 and 25 cannot cover the vicinity of the center of the moving plane depending on the structure of the link mechanism, and the movable range is not a circle but a ring. However, it is possible to move within a straight line determined by the intersection of the two annular planes.

Unnecessary movements and swings in the axial direction other than the required rotational movement impair the accuracy of the linear movement of the link mechanism. Therefore, the accuracy of the shaft and the bearing is increased, and the connection member is increased in rigidity against torsion and bending. There is a need. As an example, assuming a linear moving device in a stepper for exposing a silicon wafer, a large wafer has a diameter of 38 mm.
In such an application, the linear moving device system of the present invention can cope with sufficient accuracy. However, in a linear moving device that handles a large processing object, the size and weight of the processing table on which the object to be linearly mounted is increased, so that it is difficult to support with one set of link mechanism devices. In this case, a plurality of linear motion link mechanism devices are installed on a gantry, the linear motion of each connector is adjusted so as to be in the same direction, and the processing table is mounted on the connector. By using three linear motion link mechanisms as an example, stable support is possible.

The rigid first connecting member and the rigid second connecting member constituting the first and second link mechanisms do not need to be dense inside, and may have any shape such as an H shape, a hollow body, and a pipe shape. Shapes can be employed. The material is selected from metal materials such as steel, aluminum alloy, magnesium alloy and titanium, engineering plastics, non-metallic materials such as carbon fiber reinforced plastics and ceramics, and composite materials such as carbon fiber reinforced metals. Or it can be used in combination. Utilizing the characteristics of these materials, it is also possible to combine components such as a bearing and a main body and to form a connecting member by combining them.

The above description is the most basic embodiment in which the first and second link mechanisms are attached to the gantry, but various changes can be made in practical use. In another embodiment, a plurality of sets of the first link mechanism can be used instead of one set. Similarly, the strength of the second link mechanism can be improved by using a plurality of sets. Further, a plurality of sets of both the first link mechanism and the second link mechanism may be used. As an example, two sets of the first link mechanisms 1 of FIG. 1 are arranged in parallel, and two shafts 42 of the connector 4 are provided, and each of them is attached to each other. With respect to the second link mechanism 2, the connecting member is divided into two upper and lower stages, and the load can be distributed by using the shaft of the connector 4 as a common shaft and two sets of the shafts 42.

In the first embodiment, the planes on which the first link mechanism and the second link mechanism can move are arranged so as to be orthogonal to each other, and the linear movement is realized along the orthogonal straight line. Even if the plane created by the mechanism and the second link mechanism is arranged at an angle other than a right angle, the plane can be moved along a straight line intersecting the planes of the two movement ranges. If an angle other than a right angle is selected in this way, it becomes possible to arrange the link mechanism outside the path along which the connector moves,
In a device utilizing linear motion, there is an advantage that the link mechanism can be prevented from hindering the movement.

Since the connector 4 performs a linear motion, the connector itself can be used as a work table using the linear motion. If the work table requires special specifications or equipment, a work table can be separately provided and fixed to the connector. When the area required as the work table is large or when the weight to support is large, it may be difficult to support with only one linear motion link mechanism. In order to solve this, a plurality of link mechanism devices that independently perform linear motion are installed on the gantry, the moving direction of each connector is matched, and a single processing table or table is connected to a plurality of connectors. It can be placed and combined to distribute the load and perform linear motion.

In order to apply and control the linear motion to the link mechanism device, a linear drive device, such as a cylinder, a motor, etc., installed outside the link mechanism is connected to the connector or the link mechanism, and The required movement can be realized under control. In addition, it is possible to connect a driving means such as a motor to the shaft of the link mechanism device, apply a required rotational motion to the shaft or the connecting member, and drive the link mechanism device to perform a linear motion. In order to accurately position a processing table such as a table, a minute measuring device such as an infrared interferometer and a precision driving device are required. However, a rapid drive device such as a stepping motor for driving a link mechanism device is useful for accurately positioning a minute distance after rapidly moving a predetermined distance in a step operation.

An object of the present invention is to realize a linear motion by a link mechanism, but it is possible to obtain a two-dimensional or three-dimensional motion by combining the functions of the linear motion. One way to realize this is to place a second-layer link mechanism that performs a linear motion in a different direction on a table that performs a linear motion by a first-layer link mechanism. The movement of the two-layer link mechanism can be individually controlled to obtain a required two-dimensional composite movement. Similarly, by installing the link mechanism of the third layer, a three-dimensional movement by only the link mechanism can be realized.

[0028]

According to the present invention, a linear motion with high accuracy can be achieved by using at least two link mechanisms, which are relatively inexpensive and easy to manufacture, without using guide rails requiring precision machining, and connecting them with connectors. A simple mechanism device can be realized. By using a plurality of link mechanisms, it is possible to cope with a large load.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a first embodiment of the present invention.

FIG. 2 is a view showing an embodiment of a structure for rotatably supporting a connecting member.

FIG. 3 is a perspective view showing an embodiment of a structure for rotatably supporting a connecting member.

FIG. 4 is a perspective view showing an embodiment of a structure for rotatably supporting a connecting member.

FIG. 5 is a diagram showing a structure of a connector.

FIG. 6 is a view showing a straight line intersecting the plane of movement of the link mechanism and the plane.

[Explanation of symbols]

1 first link mechanism, 2 second link mechanism, 3 gantry,
4 connector, 7,63 moving straight line, 11 rigid first connecting member, 12 rigid second connecting member, 13 axis, 131,
132 bearing, 14 shaft, 141, 142 bearing, 21
Rigid first connecting member, 22 rigid second connecting member, 2
3 shafts, 231 bearings, 41 connector blocks, 42,
43 axis, 44 groove, 45 snap ring, 46 screw, 49 slit, 133,134 ball bearing, 61, 62 moving plane.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Koichi Aoyama 2-3-2 Shimomeguro, Meguro-ku, Tokyo Inside Tamura Electric Works, Ltd. (72) Inventor Satoru Shimada 2-3-2 Shimomeguro, Meguro-ku, Tokyo No. Co., Ltd. within Tamura Electric Works (72) Inventor Junko Seki 2-12-12 Shin-Yokohama, Yokohama 2-12-12 Shin-Yokohama, Kohoku-ku, Yokohama No.12 Shin-Yokohama IK Building 203 Yukigaya Co., Ltd. F-term in Control Laboratory 3C048 BC01 DD00 EE00 EE07 3J062 AA21 AA28 AA36 AB27 AC09 BA14 BA16 CB02 CB17 CB18 CB28 CB32 3J105 AA05 AA13 AA15 AA41 AB16 AC01 BA04 BA07 BA32 BB07

Claims (5)

[Claims] A first connecting member rotatably mounted on one end of each of the first and second connecting members, and a first connecting member having the other end mounted on a gantry;
A link mechanism device and one end of each of the first and second connection members are rotatably mounted on a shaft, and the other end of the first connection member is mounted on a gantry so as to be movable at a different angle from the first link mechanism device. A second link mechanism device, and a connector rotatably coupled to the other end of each of the first and second link mechanism devices, and a circular plane on which the other end of the first link mechanism device is movable; A linear motion link mechanism device characterized in that the connector can move on a straight line that intersects a circular plane on which the other end of the link mechanism device can move. 2. A first link mechanism comprising a rigid first connecting member and a rigid second connecting member, wherein one end of each member is rotatably connected to each other by a first shaft. And the first
The other end of the connecting member is provided with a second shaft, and the other end of the second connecting member is provided with a shaft hole through which the third shaft passes, and the first to third axes are parallel to each other. A second link mechanism, comprising a rigid first connecting member and a rigid second connecting member, wherein one end of each member is mutually rotatable by a first shaft. The first connecting member is provided with a second shaft at another end thereof, and the other end of the second connecting member is provided with a shaft hole passing through the third shaft, and the first through third shafts are provided. The shafts are provided in parallel with each other, and the second shaft of the first link mechanism is rotatably fitted to a bearing fixed to the gantry, and the second shaft of the second link mechanism is mounted on the gantry. A second link mechanism is rotatably fitted to a bearing fixed to the first link mechanism, and one shaft of the connector is rotatably fitted to a shaft hole passing through the third shaft of the first link mechanism. The other shaft of the connector is rotatably fitted in a shaft hole through which the third shaft passes, and the intersection of the plane in which the first link mechanism can move and the plane in which the second link mechanism can move A linear motion link mechanism device in which the connector is capable of linear motion along a line. 3. A shaft hole passing through a third shaft of the first link mechanism is provided; a shaft hole passing through a third shaft of the second link mechanism is provided; And the two shafts are fixed such that their centers protrude rigidly from each other while maintaining a predetermined angle from the connector, and a third shaft of the first link mechanism. One shaft of the connector is rotatably fitted in a shaft hole through which the connector is inserted, and the other shaft of the connector is rotatably fitted in a shaft hole through the third shaft of the second link mechanism. The linear motion link mechanism device according to claim 2, wherein the linear motion link mechanism device is combined. 4. The link mechanism according to claim 1, wherein a plurality of the first link mechanism or the second link mechanism, or both the first link mechanism and the second link mechanism are provided. The linear motion link mechanism device according to claim 3. 5. A plurality of linear motion link mechanisms are installed on a gantry, the moving directions of the connectors of the respective linear motion link mechanisms are matched, and a single moving table is supported by the plurality of connectors so as to be capable of linear motion. The linear motion link mechanism device according to claim 1, wherein: