JPH03243199A - Positioning device - Google Patents

Abstract

PURPOSE:To effect positioning with a high accuracy by a method wherein two sets of linear motors, arranged in parallel, are provided with a position detecting unit respectively while one side of a third member, orthogonal to each other, is permitted to move into only a rotating direction and the other side of the same is restrained in the direction of two sets of linear motors. CONSTITUTION:The guide fixing member 1a of a linear motor is provided with a position detector 3 at the outside thereof to detect the position of a movable piece 1b on the guide fixing member 1a and make the present position of the movable piece 16 clear. A Y-2 axis motor 2 is provided in parallel to the direction of y-axis of a Y-1 axis motor 1. The position of a movable piece 2b, running on a guide fixing member 2a, is detected in the Y-2 axis motor 2. The movable piece 1b and another movable piece 2b are provided with a guide stator member 4, mounted in the direction of x-axis orthogonal to the direction of y-axis while the guide stator member 4 is constituted so as to be a stator and a X-axis movable piece 5, which becomes an armature running of the member 4, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a positioning device such as an XY plotter or an XY table used in fields such as metering, control equipment, office equipment, and industrial equipment.

(Prior Art) Conventionally, as a general device for positioning or freely moving a controlled object to any position on a secondary plane of this type, a flat table (hereinafter referred to as a flat table) is used, as shown in FIG. A guide and fixing member 21 for the X-axis near motor is provided on one side of the
A shaft rotor 22 is provided, and the X-axis rotor 22 is provided with a guide stator member 23 for a Y-axis near motor extending perpendicularly to the guide fixing member 21. 23 is provided with a slidable Y-axis rotator 24, and the X-axis rotator 22 and the Y-axis rotator 24 are connected to
The flat head 2 is moved by the shaft near motor and
0, the Y-axis rotator 24 is moved to a predetermined position, and printing is performed using, for example, a pen block 25 attached to the Y-axis rotator 24. In the figure, 26 is a recording paper, and 27 is a frame that supports the guide and fixing member 21 and the flat bed 20.

In the conventional positioning device described above, since the guide stator member 23 that guides the Y-axis rotator 24 is a cantilever beam, the rigidity is low, and the high acceleration/deceleration drive prevents twisting due to the offset of the thrust application point. This tends to occur easily, and has disadvantages such as backlash and errors due to deflection, and there is a risk that the features of the linear motor cannot be fully utilized.

Therefore, as shown in FIG. 7, the guide and fixing member 21
A second guide and fixing member 21A is provided at a position parallel to and sandwiching the flat bed 20, and this second guide and fixing member 21A
A second X-axis rotator 22A is slidably provided on the guide fixing member 21, and this second
The stator member 23A guides the shaft rotor 22A in a bridge shape.
A Y-axis rotator 24 is slidably provided on the guide stator member 23A, and the X-axis rotator 22 and the second X-axis rotator 22A are driven synchronously by a potentiometer. At the same time, move the Y-axis rotator 24 to a predetermined position,
A positioning device has been proposed that marks the recording paper 26 with a pen block 25 attached to the shaft rotator 24 (
(Japanese Unexamined Patent Publication No. 58-186364). In addition, 27 in the figure is a frame that supports the guide and fixing member 21, the second guide and fixing member 2LA, and the flannel hand 20.

In the positioning device proposed in this way, the X-axis direction is held by two guiding and fixing members, so the rigidity is high, and torsion is prevented due to the high acceleration/deceleration drive caused by the deflection of the guiding stator member 23 and the uneven thrust. However, depending on the parallelism and curvature of the guide and fixing members 21 and 21A, pressure or tension may be generated between the X-axis rotator 22 and the second X-axis rotator 22A, and the cannot be moved smoothly, and therefore high precision is required in processing and assembling parts. Further, there were drawbacks such as not taking into account the effects of temperature changes on elongation of the member. For this reason, the 8th
As shown in the figure, an elongated member 28 having an open end is provided at one end of the guide stator member 23A to which the Y-axis rotator 24 is attached, and a cylindrical protrusion 29 is provided at the top of the X-axis rotator 22. ,
By engaging the protrusion 29 with the elongated portion 28 of the guide stator member 23A and attaching the guide stator member 23A and the X-axis rotator 22 so as to be slidable in the Y-axis direction, the guide fixing members 21 and 21A are fixed. A proposal has been made to eliminate the pressure or tension on the X-axis rotator 22 caused by the parallelism or curvature of the
5707).

With this, it has been possible to solve the problems of the parallelism of the two guiding and fixing members, the degree of curvature, and changes in the members due to temperature changes and the like.

(Problem to be Solved by the Invention) However, the above-mentioned various positioning devices are designed to compensate for mechanical deficiencies, and do not take into consideration the imbalance in the thrust of each linear motor. Vibrations due to thrust imbalance are treated as non-existent. However, in reality, the quasi-unbalance of the linear motor generates vibrations, which often causes a biasing force to be applied to the fixed support portion, which often has an adverse effect on running.

The present invention has been made in view of the above circumstances, and its purpose is to provide a positioning device that can take advantage of the features of a linear motor.

(Means for Solving the Problems) To achieve the above object, the positioning device of the present invention includes: (1) a first linear motor disposed along the first ring direction; a second linear motor disposed parallel to the first axial direction at a predetermined interval; and along a second axial direction perpendicular to the first axial direction,
and one end of the first and second linear motors is supported by a movable member so as to be movable only in the rotational direction, and the other end is restrained from moving only in the first axial direction. A third member serving as a support or a linear motor, and having a control device for controlling each linear motor, and each of the first and second linear motors is provided with a position detector for detecting the position thereof, The first N4 commandment is to drive the first and second linear motors synchronously based on the signals of these position detectors. (2) Also, the first and second linear motors and the third member or linear motor A detector, such as an angle detector, for detecting the relative position between the first and second linear motor movers is provided between the two, and the first and second linear motors are synchronized based on the signal from this detector. (3) Furthermore, as a third configuration, in the first or second configuration, unbalance due to load on the first or second linear motor, friction, etc. is detected. It is characterized by the fact that the thrust is adjusted by

(Function) In the flea positioning device as described above, in the first configuration, a position W and a detector are provided for each of the two linear motors arranged in parallel, and a detector is provided for each of the two linear motors arranged in parallel. The joint part with the third member or linear motor has a structure in which one can only move in the rotational direction, and the other is restricted only in the direction of the two linear motors, so that the joint part with the third member or linear motor can be moved only in the direction of the two linear motors. It can absorb the parallelism and curvature of the motor, and can be controlled to eliminate positional differences using signals from the position detector, so it has the feature of being able to perform positioning without error.

In the second configuration, the joint section is the same as that of the first m-precept, but an angle detector is used instead of a position detector. This angle detector detects the relative displacement of the movers of two linear motors arranged in parallel, and the two linear motors are controlled to eliminate this relative displacement, so positioning can be performed without error.

In the third configuration, when the third member or the linear motor perpendicular to the first and second configurations approaches one of the movers of the two linear motors and the load increases, the load is unbalanced. Since the thrust can be adjusted with respect to the balance, highly accurate synchronous drive is possible, and positioning can be performed without error.

(Example 1) The present invention will be explained in detail below.

1 to 3 show a first embodiment of the present invention, and show the main parts of a positioning device. In the figure, the workpiece is a Y single-axis motor, and this Y single-axis motor 1 has a guide fixed member 1a that is fixed on a frame (not shown) and forms a stator, and an armature that runs on this guide fixed member la. This is a linear motor composed of a movable element 1b.

A position detector 3 using, for example, magnetic pulses is provided outside the guide and fixing member 1a of the linear motor.

This position detector 3 detects the position of the movable element 1b on the guiding and fixing member 1a, and is designed to be able to clearly detect where on the guiding and fixing member 1a the current position of the movable element 1b is located. There is.

Two Y axis motors 2 are arranged parallel to the Y axis direction of the Y single axis motor 1 at a predetermined interval. The Y two-axis motor 2 installed in parallel also has a configuration of the Y one-axis motor 1.
Similarly, the position detector 3 is provided outside the guide and fixing member 2a, so as to be able to detect the position of the movable element 2b running on the guide and fixing member 2a. The movable element 1a and the movable element 2a are provided with a guide stator member 4 installed in the X-axis direction perpendicular to the y-axis direction, and this guide stator member 4 is configured as a stator. The X-axis rotator 5 becomes the armature that runs on this
is the provision.

The guide stator member 4 is attached to the movable element 1b by the second
As shown in the figure, the tll command is given. That is, a shaft 6 serving as a fulcrum is fixed to a predetermined position of the movable element 1b,
A rotatable roller 7 is provided on this shaft 6, and this roller 7 is fitted into a through hole 8 provided in the guide stator member 4 without any gap. It is configured to be rotatably supported around the center. 20 When supporting rotation, the lower surface of the guide stator member 4 is installed in a state slightly raised from the upper surface of the movable element 1b (Figure 2).
), the rotation of the guide stator member 4 is taken into account so that there is no hindrance.

Further, the joint portion on the other end side of the guide stator member 4 to the movable element 2b is constructed as shown in FIG. In FIG. 3, reference numeral 6 denotes a shaft serving as a fulcrum provided at a predetermined position of the movable element 2b.A rotatable roller 7 is provided on this shaft 6, and this roller 7 is provided on the guide stator member 4. The guide stator member 4 is fitted into the elongated through hole 9 without a gap, and the guide stator member 4 rotates around the fulcrum of the movable element la, and accordingly, the roller 7 of the movable element 2b moves inside the elongated through hole 9. Axial direction and axis 6
It is configured to rotate around the center.

The guiding stator member 4 of the positioning device can travel smoothly while maintaining the state perpendicular to the y-axis direction due to the action of the position detector 3 that detects the position of the above-mentioned engine) and movers 1b and 2b. becomes. This movement can be carried out regardless of the parallelism of the guide and fixing members 1a and 2a in the y-axis direction, the degree of curvature, or expansion and contraction due to temperature changes.

(Example 2) The positioning device having the second configuration is as shown in FIG.
On the guide stator member 4 supported in a rotational state about the shaft 6 in FIG. 2 forming the joint portion on the movable element lb provided on the guide fixed member la, A detector IO is provided. The angle detector 10 has a structure including a built-in magnetic disk, for example, and detects the rotational direction and angle of the movable element 1b and the guide stator member 4, and this detection signal is transmitted to one wheel of a separately provided Y. The information is sent to the control device for the motor, and by controlling and synchronizing either the YO 1-axis motor or the Y 2-axis motor, the guide stator member 4 of the positioning device maintains a state perpendicular to the y-axis direction and moves smoothly. It becomes possible to travel to. This movement can be carried out regardless of the parallelism of the guide and fixing members 1a and 2a in the y-axis direction, the degree of curvature, or expansion and contraction due to temperature changes.

(Embodiment 3) As shown in FIG. 5, the third configuration is basically the same as the first and second configurations, and has the same structure as the Y single-axis motor 1, with a predetermined interval. The movable element of the Y l-axis motor 1 consists of a Y-axis two-axis motor 2 installed in parallel with each other, a guide stator member 4 installed orthogonally to these two motors, and an X-axis movable element 5. 1b and the mover 2b of the Y two-axis motor 2.
The joint portions with the through holes 8 in FIG.
and is supported by the long through hole 9 in FIG.

Then, as the X-axis movable element 5 on the guide stator member 4 moves in the X-axis direction, the weight of the movable element 5 is added to the movable element 1b or 2b in the moving direction and becomes a load. This load causes an unbalanced state, so 1 of Y
The thrust is increased and adjusted by increasing the current value of the axis motor 1 or the Y two-axis motor 2. By this adjustment, the unbalance due to the load is eliminated regardless of the position of the movable element 5, and highly accurate synchronous driving becomes possible.

The position of the movable element 5 can be easily detected by using, for example, a position detector shown in FIG. 1 along the guide stator member 4.

(Effects of the Invention) As explained in detail above, the positioning device of the present invention includes: (1) a first linear motor disposed along the first axial direction; and a predetermined interval between the first linear motor and the first linear motor. a second linear motor disposed parallel to the first axial direction with a gap between them; A third member or a linear motor whose one end is supported to be movable only in the rotational direction and whose other end is supported to be restricted from moving only in the first axial direction; The first linear motor and the second linear motor are each provided with a position detector for detecting their position, and the first and second linear motors are each provided with a position detector for detecting their position. The first linear motor and the second linear motor are driven synchronously. a second 'J linear motor arranged parallel to the first axial direction; and a second linear motor arranged along a second axial direction orthogonal to the first axial direction, each i
A third member or a linear motor is provided on the movable element that moves at one end, one end of which is supported so as to be movable only in the rotational direction, and the other end of which is supported such that movement is restricted only in the first axial direction. and a control device for controlling each linear motor, and an angle detector or the like between the first and second linear motors and a third member or linear motor. A detector is provided to detect the relative position between the movers, and the first and second
3) In the positioning device according to the first and second items, an unbalance due to load, friction, etc. on the il or the second linear motor is detected, and the linear motor is driven synchronously. Since the thrust of the first or second linear motor is adjusted, the positioning device can take advantage of the characteristics of the linear motor, and has the advantage of completely eliminating errors in positioning.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the main parts of the positioning device in the first embodiment of the present invention, FIG. 2(a) is a perspective view of the joint part in FIG. FIG. 4 is a perspective view of the main parts of the positioning device in the second embodiment; FIG. 5 is a perspective view of the main parts of the positioning device in the third embodiment; 6 to 8 are perspective views of conventional examples. 4...Third member or third linear motor 5...Mover 6.7.8.9.Joint section part 10...
・・Angle detector

Claims (3)

[Claims] (1) A first linear motor disposed along the first axial direction, and a second linear motor disposed parallel to the first axial direction with a predetermined interval from the first linear motor. a linear motor, along a second axial direction perpendicular to the first axial direction;
and the first and second linear motors each constitute a movable element, one end of which is supported so as to be movable only in the rotational direction, and the other end of which is restricted from movement only in the first axial direction. A third member serving as a support or a linear motor, and having a control device for controlling each linear motor, and each of the first and second linear motors is provided with a position detector for detecting the position thereof, A positioning device characterized in that first and second linear motors are driven synchronously based on signals from these position detectors. (2) A first linear motor disposed along the first axial direction, and a second linear motor disposed parallel to the first axial direction at a predetermined interval from the first linear motor. a linear motor, along a second axial direction perpendicular to the first wheel direction;
and the first and second linear motors each constitute a movable element, one end of which is supported so as to be movable only in the rotational direction, and the other end of which is restricted from movement only in the first axial direction. a third member or linear motor serving as a support, a control device for controlling each linear motor, and an angle detection device between the first and second linear motors and the third member or linear motor. A detector for detecting the relative position between the first and second linear motor movers, such as a
A positioning device characterized by synchronously driving linear motors. (3) In the positioning device of the first or second item, detect the load on the first or second linear motor, unbalance due to friction, etc., and adjust the thrust of the first or second linear motor. A positioning device characterized by: