JPH06100254B2 - Two-dimensional movement mechanism - Google Patents

Description

The present invention relates to a two-dimensional movement mechanism such as an XY stage.

(Prior Art) Conventionally, a movable body is provided so as to be movable within a predetermined rectangular plane.
The dimensional movement mechanism was developed by the inventor of the present application and
There is a technique disclosed in Japanese Patent Publication No. 88556. Although this technique is a three-dimensional movement mechanism, two sets of X-axis guides arranged in parallel and two sets of Y-axis guides arranged in parallel and orthogonal to each other in substantially the same plane. A movable body that is movable within a rectangular plane formed by being surrounded by the X-axis guide and the Y-axis guide, and two X-axis drive units that are arranged so as to be movable along the X-axis guide. , Two Y-axis drive units movably arranged along the Y-axis guide, and an X-axis that is inserted into the moving body in parallel with the Y-axis guide and has both ends connected to the X-axis drive unit. The moving body has a rod and a Y-axis rod that is inserted into the moving body in parallel with the X-axis guide and has both ends connected to the Y-axis drive unit. The moving body is configured to perform two-dimensional movement.

The two X-axis drive sections are driven in the same direction by the two motors, and the two Y-axis drive sections are also driven in the same direction by the two motors.

(Problems to be Solved by the Invention) However, the above-described motion mechanism has the following problems.

In the two-dimensional motion mechanism having such a configuration, the repeated positioning accuracy of the moving body is important. That is, when moving the moving body within the rectangular plane, it is necessary to prevent the position of the moving body from being displaced each time when a certain specific position is designated and repeatedly moved. If the two motors that drive the two X-axis drive units and the two motors that drive the two Y-axis drive units are not synchronized with each other, the repetitive positioning accuracy decreases. Therefore, there is a problem that it is difficult to adjust the synchronization between the motors, and the accuracy of the synchronization cannot be improved unless a high-precision motor is combined, resulting in high cost.

Therefore, the present invention has high repeatability positioning accuracy of the moving body,
An object is to provide an inexpensive two-dimensional motion mechanism.

(Means for Solving the Problems) In order to solve the above problems, the present invention has the following configuration.

That is, two X-axis ball screws arranged in parallel, two Y-axis ball screws arranged in parallel and having their axes orthogonal to the axis of the X-axis ball screw, and the X-axis of each of them. Two X-axis driving bodies screwed to the ball screw and movable on the X-axis ball screw as the X-axis ball screw rotates, and screwed to each of the Y-axis ball screws, and the Y-axis moves as the Y-axis ball screw rotates. Two Y-axis driving bodies that are movable on the ball screw, both ends of which are respectively connected to the X-axis driving body, and an X-axis rod that is provided in parallel to the Y-axis ball screw, and both ends of which are the Y-axis. A Y connected to the driving body and provided in parallel with the X-axis ball screw.
A two-dimensional movement mechanism having an axial rod, a movable body that is inserted through the X-axis rod and the Y-axis rod, and is movably provided on the X-axis rod and the Y-axis rod. X-axis driving means for directly rotating the X-axis, two first bevel gears rotatably provided integrally with the respective X-axis ball screws, and the two first bevel gears at both ends. The first transmission shaft is provided with a bevel gear that meshes with each other, and the rotational force of the X-axis driving means is transmitted to the other X-axis ball screw, while the other X-axis ball screw is in the same direction as the X-axis ball screw. A first transmission mechanism for rotating the Y-axis ball screw, one Y-axis driving unit for directly rotating one of the Y-axis ball screws, and two second rotation units integrally provided with the respective Y-axis ball screws. Bevel gears,
And a second transmission shaft provided at both ends with a bevel gear that meshes with the two second bevel gears, respectively, for transmitting the rotational force of the Y-axis drive means to the other Y-axis ball screw and the other And a second transmission mechanism for rotating the Y-axis ball screw in the same direction as the one Y-axis ball screw.

(Operation) The operation will be described.

Since one X-axis ball screw is directly rotated by one X-axis driving means and the other X-axis ball screw is rotated by the first transmission mechanism, one X-axis ball screw can be rotated with respect to the other X-axis ball screw. The deviation of synchronization is determined by the backlash of the first transmission mechanism. Similarly Y
The deviation of synchronization between the axial ball screws is determined by the backlash of the second transmission mechanism. Therefore, the synchronization deviation between the X-axis ball screws and the Y-axis ball screws can be made constant, so that both ball screws can be moved via the X-axis driver, the Y-axis driver, the X-axis rod, and the Y-axis rod. It is possible to secure the repeated positioning accuracy of the moving body.

(Examples) Hereinafter, preferred examples of the present invention will be described in detail with reference to the accompanying drawings.

First, the configuration will be described with reference to FIG.

In the figure, 10 is a frame, which is a rectangular frame with the center removed.

Reference numerals 12 and 14 denote X-axis ball screws, which are arranged in parallel with each other in the same plane. The X-axis ball screw 12 is directly driven and rotated by a motor 16 which is an X-axis driving means. To the X-axis ball screw 14, two first bevel gears, which are rotatably provided integrally with the X-axis ball screws 12 and 14, and curved bevel gears 18 and 20, and the curved bevel gears 18 and 20, The motor 16 is driven via a first transmission mechanism including a first transmission shaft 22 provided at both ends with curved bevel gears 22a and 22b meshing with each other.
Is transmitted. This allows the X-axis ball screw 14
Can be rotated in the same direction as the X-axis ball screw 12 at the same speed. Incidentally, 24 is a coupler, which connects the gear shaft 26 and the motor shaft 28. Further, reference numerals 30, 32 and 34 are position adjusting couplers, which will be described in detail later. The tip of the X-axis ball screws 12, 14 (the left end in the drawing) is a suitable support frame 36 ...
・ Supported by.

Reference numerals 38 and 40 denote Y-axis ball screws, which are arranged parallel to each other and in the same plane, and whose axes are substantially orthogonal to the axes of the X-axis ball screws 12 and 14 in the same plane. Y-axis ball screw
38 is directly driven by a motor 42 which is a Y-axis driving means to rotate. To the Y-axis ball screw 40, there are two second bevel gears, which are rotatably provided integrally with the Y-axis ball screws 38 and 40, and bevel gears 44 and 46, and the bevel gears 44 and 46. The rotational force of the motor 42 is transmitted through a second transmission mechanism including a second transmission shaft 48 provided at both ends with curved bevel gears 48a and 48b that mesh with each other. As a result, the Y-axis ball screw 40 can be rotated in the same direction at the same speed as the Y-axis ball screw 38. Reference numeral 50 denotes a coupler, which connects the gear shaft 52 and the motor shaft 54. Also 56,
Reference numerals 58 and 60 are position adjusting couplers, which will be described later in detail. Further, the tips of the Y-axis ball screws 38, 40 (lower ends in the drawing) are also pivotally supported by appropriate support frames 62 ....

64 and 66 are X-axis driving bodies, and each X-axis ball screw 1
Since the X-axis ball screws 12 and 14 are screwed to 2 and 14 and are prevented from rotating by an X-axis rod described later, the X-axis ball screws 12 and 14 can simultaneously move in the X-axis direction by rotating in the same direction.

68 and 70 are Y-axis driving bodies, and each is a Y-axis ball screw 3
Since the Y-axis ball screws 38 and 40 are screwed into the shafts 8 and 40 and are prevented from rotating by a Y-axis rod described later, the Y-axis ball screws 38 and 40 can move in the Y-axis direction at the same time by rotating in the same direction.

Reference numeral 72 is an X-axis rod, which is arranged parallel to the Y-axis and is inserted into a slider 74 which is a moving body.
It is fixed to 64 and 66. This causes the slider 74 to move to X
X-axis drive bodies 64 and 66 whose rotation is blocked by the shaft rod 72
It moves in the X-axis direction along with the movement in the X-axis direction.

Reference numeral 76 is a Y-axis rod, which is arranged parallel to the X-axis and is inserted into a slider 74 which is a moving body.
It is fixed to 68 and 70. Therefore, the Y-axis rod 76 is orthogonal to the X-axis rod 72 inside the slider 74. The slider 74 is Y
The Y-axis drive bodies 68 and 70 whose rotation is blocked by the shaft rod 76.
It also moves in the Y-axis direction along with the movement in the Y-axis direction. This X
The combination of movement in the axial direction and the Y-axis direction allows the slider 74 to move to any position within the rectangular plane 78.
The X-axis rod 72 and the Y-axis rod 76 are preferably metal rods having appropriate rigidity and elasticity.

80 ... is a gear box provided at each corner of the frame 10, and the curved bevel gears 18, 20, 22a, 22b, 44,
It covers 46, 48a, 48b, etc.

Next, the position adjusting couplers 30, 32, 34, 56, 58, 60 will be described.

The X-axis rod 72 and the Y-axis rod 76 cannot be accurately positioned unless they are orthogonal to each other in the slider 74. Therefore, the position adjustment coupler is used for adjustment. FIG. 2 shows the phase adjustment coupler 34. In the figure, (a) is a partially cutaway plan view showing a state in which the position adjusting coupler 34 connects the shaft 82 of the X-axis ball screw 14 and the gear shaft 84 of the helical gear 20 and (b) is a side view thereof. It is a figure. Both end flanges 86, 88 of the position adjustment coupler 34
Two slits 90 ... Are engraved in each of the holes, and the tips of the shaft 82 and the gear shaft 84 are inserted into the central through hole 92. Then, the flanges 86, 88 have slits 90 ...
When tightened via, the inner walls of the flange portions 86 and 88 are reduced in diameter and come into close contact with the outer periphery of the shaft 82 and the gear shaft 84, so that both shafts 82 and 84 are connected. The other position adjusting couplers 30, 32, 56, 58 and 60 also connect the two shafts in a similar manner. X axis rod here
A position adjusting method for obtaining the orthogonality between 72 and the Y-axis rod 76 will be described.

First, the X-axis ball screw driven directly by the motor 16
With the position of the X-axis driver 64 screwed to 12 as the reference side,
The motor 42 is driven to move the slider 74 from the X-axis driver 64 to X.
The shaft driver 66 is moved in the direction (Y-axis direction). At that time, the amount of displacement of the slider 74 in the X-axis direction is measured. Correction of this amount of change (error amount) is position adjustment. To do this, use the bolts on one side of the flanges 86, 88 of the alignment coupler 34.
90 ... is loosened, the shaft 82 or the gear shaft 84 is unfixed, the above-mentioned error is adjusted, and the bolts 90 ... are tightened again to complete the position adjustment. At that time, the X-axis rod 72 may not be exactly parallel to the Y-axis ball screws 38 and 40. However, since such a difference in position is absorbed by the elasticity of the X-axis rod 72, the operating load on the X-axis ball screw 14 of the X-axis driving body 66 does not increase. The position adjustment of the X-axis drive body 66 can be performed by the position adjustment coupler 30 or 32.

Similarly, the position adjustment of the Y-axis drive bodies 68 and 70 can also be performed by adjusting the position of the Y-axis drive body 70 by the position adjustment coupler 56, 58 or 60, so that the X-axis rod 72 and the Y-axis rod 76 can be adjusted.
The orthogonality of can be adjusted.

Here, the slider in the two-dimensional movement mechanism according to the present invention
The repeatable positioning accuracy of 74 will be described.

In this embodiment, when the backlash of the curved bevel gears 18 and 22a and 20 and 22b is ± 3 minutes, the lead of the X-axis ball screw 14 is 5 m.
If m, the maximum amount of displacement of the slider 74 on the X axis is as follows.

That is, the maximum error of the slider 74 in the X-axis direction is 0.0027 mm. This maximum error is determined in advance because the X-axis ball screws 12, 14 are driven by the single motor 16 and the X-axis ball screw 14 is driven via the first transmission mechanism.
It is suppressed within the error range due to backlash of 8, 20, 22a, 22b. Similarly, the maximum error of the slider 74 in the Y-axis direction is predetermined. Therefore, the error can be suppressed and the amount of the error is unstable by using, for example, the curved bevel gears 18 and 20 having a small backlash without performing the difficult work of synchronizing the two motors. 2
Unlike the synchronous adjustment method of the individual motors, the maximum stroke of the slider 74 can guarantee the error range. By ensuring this error range, high repeatability positioning accuracy of the slider 74 can be obtained.

The two-dimensional motion mechanism configured in this way is used for positioning XY for processing equipment and robot work (including mounting multiple heads).
It is suitable for use in a stage or in-plane motion mechanism controlled by a program.

Also, although the slider as the moving body is a block-shaped one, if a frame-shaped slider with the center removed is used, the work on the slider can be processed from both the up and down directions, which is in the range of application. It becomes a wide two-dimensional movement mechanism.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, but X
In order to secure the linearity of movement of the shaft driver and the Y-axis driver and to support the load, the X-axis driver and the Y-axis driver may be provided with guides parallel to the X-axis or the Y-axis, respectively. Of course, many modifications can be made without departing from the spirit.

(Effects of the Invention) When the two-dimensional motion mechanism according to the present invention is used, two X-axis ball screws and two Y-axis ball screws are respectively used as one X-axis driving means and one Y-axis driving means. To rotate,
Since it is possible to reliably suppress the deviation of synchronization between the X-axis ball screws and between the Y-axis ball screws within the error range due to the backlash of the first and second transmission mechanisms, it is possible to secure the repetitive positioning accuracy of the moving body. Further, since the number of driving means is two and half compared with the conventional one, there is no need to perform the synchronous adjustment work between the motors, and the cost of the mechanism can be reduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view showing an embodiment of a two-dimensional movement mechanism according to the present invention, and FIG. 2 is a partially cutaway plan view showing a usage state of the position adjusting coupler shown in FIG. (B) It is a partially broken side view. 12, 14, 14 ... X-axis ball screw, 16 ... motor, 18, 20, 22
a, 22b …… Curved bevel gear, 22 …… First transmission shaft, 30,32,34
…… Phase adjustment coupler, 38,40 …… Y-axis ball screw, 42…
… Motors, 44,46,48a, 48b …… Curved bevel gears, 48 …… Second
Transmission shaft, 56,58,60 …… Position adjustment coupler, 64,66 …… X
Axial drive, 68, 70 ... Y-axis drive, 72 ... X-axis rod, 7
4 …… Slider, 76 …… Y-axis rod, 78 …… Rectangular plane, 8
0 …… Gearbox.

Claims (1)

[Claims] 1. Two X-axis ball screws arranged parallel to each other, two Y-axis ball screws arranged parallel to each other and having an axis perpendicular to the axis of the X-axis ball screw, 2 X-axis driving bodies screwed to the X-axis ball screw and movable on the X-axis ball screw as the X-axis ball screw rotates, and screwed to the Y-axis ball screws respectively to rotate the Y-axis ball screw. Along with this, two Y-axis drive bodies that can move on the Y-axis ball screw, both ends of which are respectively connected to the X-axis drive body, and an X-axis rod that is provided in parallel to the Y-axis ball screw, The Y-axis rod connected to the Y-axis driving body and provided in parallel to the X-axis ball screw, the X-axis rod and the Y-axis rod are inserted, and move on the X-axis rod and the Y-axis rod. Free movement In a two-dimensional movement mechanism having, one X-axis drive means for directly rotating one of the X-axis ball screws, and two first caps rotatably provided integrally with each X-axis ball screw. A gear and a first transmission shaft provided at both ends with a bevel gear that meshes with the two first bevel gears, respectively, and transmits the rotational force of the X-axis drive means to the other X-axis ball screw. A first transmission mechanism for rotating the other X-axis ball screw in the same direction as the X-axis ball screw, one Y-axis drive means for directly rotating one of the Y-axis ball screws, and each Y-axis ball screw And two second bevel gears rotatably provided integrally with each other, and a second transmission shaft provided at both ends with bevel gears respectively meshing with the two second bevel gears. The rotational force of the shaft drive means is applied to the other Y Together transmitted to the ball screw, two-dimensional movement mechanism, characterized by comprising a second transmission mechanism for rotating the other of Y-axis ball screw to one of the Y-axis ball screw in the same direction.