JPH07243502A - Motion mechanism - Google Patents

Abstract

PURPOSE:To secure accurate synchronous motion even though the drive force acting on parallel displacement members is in unbalance and also construct the mechanism in a lightweight structure. CONSTITUTION:The first shaft 20 and the second shaft 24 are installed rotatably on parallel displacement members 18a, 18b. The first pinions 26a, 26b are secured to the first shaft 20 and meshed with racks 14a, 14b. The second pinions 28a. 28b are fixed to the second shaft 24 and meshed with the racks 14a, 14b. The first pinions 26a, 26b are meshed with the racks 14a, 14b in the condition that the first shaft 20 is previously given a torsion in the first circumferential direction relative to the axis, and the second pinions 28a, 28b are meshed with the racks 14a, 14b in the condition that the second shaft 24 is previously given a torsion in the second circumferential direction opposing to the first circumferential direction about the axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion mechanism, and more particularly to a motion mechanism for moving a pair of parallel moving bodies arranged in parallel in the same direction at the same speed.

[0002]

2. Description of the Related Art A conventional motion mechanism for moving a pair of parallel moving bodies arranged in parallel in the same direction at the same speed is shown in FIG.
This movement mechanism 200 includes a pair of linear motion guides 202a, 2
02b is arranged parallel to the Y-axis direction. The pair of parallel moving bodies 204a and 204b are connected to the linear motion guides 202a and 2b.
It is movable in the Y-axis direction along 02b. A connecting member 20 is provided between the pair of parallel moving bodies 204a and 204b.
6 is erected and connects both. A ball screw 208 arranged in the Y-axis direction is screwed into one of the parallel moving bodies 204a. The ball screw 208 is rotationally driven by a motor 210. Conventional motion mechanism 2 having the above configuration
At 00, the motor 210 is driven to drive the ball screw 20.
When 8 is rotated, the parallel moving body 204a moves the linear motion guide 2
02a moves in the Y-axis direction. Parallel moving body 2
Since 04a and 204b are connected by the connecting member 206 having rigidity, the parallel moving body 204b is
With 04a, it moves in the same direction at the same speed. Exercise mechanism 2
In 00, for example, by attaching a positioning tool, a work or the like to the connecting member 206, it is possible to determine the position of the tool, the work or the like in the Y-axis direction.

[0003]

However, the above-described conventional motion mechanism 200 has the following problems. One of the parallel moving bodies 204a is directly driven by the ball screw 208, and the other of the parallel moving bodies 204b is driven via the connecting member 206. Therefore, the driving force of the same magnitude does not act on both of the parallel moving bodies 204a and 204b at the same time.
As a result, although the parallel moving body 204a is slightly moved, the parallel moving body 204a starts moving before the parallel moving body 204b. Due to this time difference, the connecting member 206 originally supposed to be provided in parallel with the X axis tilts with respect to the X axis, and the connecting member 206
An error will occur in the positioning of the tool, work, etc. attached to the. That is, the parallel moving bodies 204a and 204b
If the driving forces acting on the two are not balanced, the accurate synchronous movement of the two becomes impossible, and for example, there is a problem that the positioning cannot be performed accurately. The same problem also occurs when an external force acts on the movable part. Therefore, in the movement mechanism 200 shown in FIG.
When the driving force acting on b is unbalanced or an external force acts on a movable part, a method has been proposed in which the coupling member 206 is made more robust to correct the movement difference between the parallel moving bodies 204a and 204b. However, the weight of the movable part becomes large, high-speed operation becomes difficult, and the load of the motor 210 also becomes large, so that there is a problem that the motor 210 having a large output is required. Therefore, it is an object of the present invention to provide a motion mechanism which is capable of accurate synchronous motion and has a lightweight structure.

To achieve the above object, the present invention has the following configuration. That is, the basic configuration is such that a pair of racks that are spaced apart and arranged in parallel in the first direction, a pair of parallel moving bodies that are movable in the first direction in parallel with the rack, and the first And a first shaft rotatably provided on the pair of parallel moving bodies, the first shaft being disposed in the second direction at a right angle to the direction of, and the pair of the first shaft being disposed in the second direction. Second rotatably provided on the parallel moving body
Shaft, a pair of first pinion gears fixed to the first shaft and capable of meshing and rolling with the pair of racks, respectively, and a pair of first pinion gears fixed to the second shaft. A pair of second pinion gears capable of meshing with and rolling on the rack, respectively, the first pinion gear having a first circumferential torsion applied to the first shaft in advance to the first shaft. The second pinion gear is meshed with the rack in a closed state,
It is characterized in that the second shaft is meshed with the rack in a state in which a torsion in a second circumferential direction opposite to the first circumferential direction is applied to the axis in advance.

As a second basic structure, a pair of first racks which are spaced apart from each other and arranged in parallel to the first direction are spaced apart from each other and a second direction which is perpendicular to the first direction. A pair of second racks arranged parallel to each other, and the first rack
Pair of first parallel moving bodies movable in the first direction in parallel with the rack, and the second parallel body in parallel with the second rack.
A pair of second parallel moving bodies, a first shaft arranged in the second direction and rotatably provided to the pair of first parallel moving bodies; Second
And a second shaft rotatably provided to the pair of first parallel moving bodies, and a pair of the second parallel moving bodies arranged in the first direction. A third shaft rotatably provided to the second parallel moving body, and a fourth shaft rotatably provided to the pair of second parallel moving bodies and arranged in the first direction. A pair of first pinion gears fixed to the shaft and capable of meshing and rolling with the pair of first racks, respectively, and fixed to the second shaft and to the pair of first racks. A pair of second pinion gears capable of meshing and rolling, and a pair of third pinion gears fixed to the third shaft and capable of meshing and rolling respectively to the pair of second racks. Fixed to the fourth shaft Rutotomoni, respectively and a fourth pinion gear pair can be engaged and rolling to a pair of said second rack, said first pinion gear, said first
Is engaged with the first rack in a state where a first circumferential direction torsion is applied to the shaft in advance, and the second pinion gear is applied to the second shaft in advance with respect to the axis. The second pinion gear is meshed with the first rack in a state in which a second circumferential torsion opposite to the first circumferential direction is applied, and the third pinion gear is attached to the third shaft in advance with respect to the axis. The third pinion gear is meshed with the second rack in a state in which a third circumferential torsion is applied, and the fourth pinion gear is attached to the fourth shaft in a direction opposite to the third circumferential direction with respect to the axis in advance. The fourth rack is engaged with the second rack in a state in which the fourth circumferential torsion is applied.

[0006]

[Operation] The operation will be described. In the basic configuration of the motion mechanism according to the present invention, the first pinion gear is meshed with the rack in a state in which the first shaft is preliminarily subjected to the first circumferential torsion with respect to the axis. The second pinion gear is meshed with the rack in a state in which a second circumferential torsion that is opposite to the first circumferential direction with respect to the axis is applied to the second shaft in advance. Therefore, the tooth surface of the first pinion gear is pressed against the tooth surface of the rack by the second return force in the circumferential direction, and the second pinion gear is pressed by the tooth force of the rack by the first return force in the circumferential direction. It is pressed against the surface. By this pressing,
Inclination of the first shaft and the second shaft with respect to the second direction is prevented. Also in the second basic configuration, the first pinion gear is meshed with the first rack in a state in which the first shaft is preliminarily applied with the first circumferential torsion with respect to the axis. The second pinion gear is the second
The shaft is engaged with the first rack in a state in which a torsion in a second circumferential direction opposite to the first circumferential direction with respect to the axis is applied in advance to the shaft. The third pinion gear is the third
The shaft is meshed with the second rack in a state in which a third circumferential torsion is applied to the shaft in advance.
The fourth pinion gear is meshed with the second rack in a state in which a fourth circumferential torsion in a direction opposite to the third circumferential direction with respect to the axis is previously applied to the fourth shaft.
Therefore, the tooth surface of the first pinion gear is pressed against the tooth surface of the first rack by the return force in the second circumferential direction, and the tooth surface of the second pinion gear is pressed by the return force in the first circumferential direction. Since it is pressed against the tooth surface of the first rack, the inclination of the first shaft and the second shaft with respect to the second direction is prevented. On the other hand, the third pinion gear causes the tooth surface to move to the second side due to the return force in the fourth circumferential direction.
Is pressed against the tooth surface of the rack. The tooth surface of the fourth pinion gear is pressed against the tooth surface of the second rack by the return force in the third circumferential direction. Therefore, the inclination of the third shaft and the fourth shaft with respect to the first direction is prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. (First Embodiment) The motion mechanism of the first embodiment will be described with reference to FIGS. Reference numerals 12a and 12b denote bases, which are arranged apart from each other in the X-axis direction and arranged in parallel to the Y-axis direction which is an example of the first direction. Racks 14a and 14b are fixed on the bases 12a and 12b, respectively. The racks 14a and 14b are arranged parallel to the Y-axis direction. 16a and 16b are linear motion guides,
They are fixed on the bases 12a and 12b, respectively. The linear motion guides 16a and 16b are provided inside the racks 14a and 14b, and are arranged parallel to the Y-axis direction. 18
Reference numerals a and 18b denote parallel moving bodies, which are linear motion guides 16a and 1b.
It is slidably attached to 6b and cannot be pulled out upward. Therefore, the parallel moving bodies 18a and 18b are moved by the linear motion guide 1
Y parallel to racks 14a and 14b along 6a and 16b
It is movable in the axial direction.

Reference numeral 20 denotes a first shaft, which is arranged in the X-axis direction which is an example of the second direction. The first shaft 20 is a metal shaft. The first shaft 20 is rotatably inserted in the parallel moving bodies 18a and 18b.
Both ends of the first shaft 20 have parallel moving members 18a, 18
It projects to the outside of b. A retaining ring 22 is fitted on the outer peripheral surface of the first shaft 20 protruding to the outside of the parallel moving bodies 18a and 18b, and restricts the movement of the first shaft 20 in the axial direction. A second shaft 24 is arranged in the X-axis direction. The second shaft 24 is also a metal shaft. The second shaft 24 is rotatably inserted in the parallel moving bodies 18a and 18b. Both ends of the second shaft 24 project to the outside of the parallel moving bodies 18a and 18b. A stop ring 22 is fitted on the outer peripheral surface of the second shaft 24 protruding to the outside of the parallel moving bodies 18a and 18b, and restricts the movement of the second shaft 24 in the axial direction. The first shaft 20 and the second shaft 20
Since the shaft 24 is inserted into the parallel moving bodies 18a and 18b, the parallel moving bodies 18a and 18b can be integrally moved in the Y-axis direction.

Reference numerals 26a and 26b are first pinion gears, which are fixed to the respective ends of the first shaft 20. The first pinion gears 26a and 26b are the rack 1
4a and 14b are rotatably engaged with each other. Therefore, when the parallel moving bodies 18a and 18b move in the Y-axis direction, the first pinion gears 26a and 26b rotate integrally with the first shaft 20 and roll on the racks 14a and 14b. 28a and 28b are second pinion gears,
Each is fixed to each end of the second shaft 24. The second pinion gears 28a and 28b are also attached to the rack 14
The a and 14b are rotatably meshed with each other. Therefore, when the parallel moving bodies 18a and 18b move in the Y-axis direction, the second pinion gears 28a and 28b also rotate integrally with the second shaft 24 and roll on the racks 14a and 14b.

Reference numeral 30 is a ball screw which is an example of driving means for the parallel moving bodies 18a and 18b. Ball screw 30
Are arranged on the base 12a in the Y-axis direction. The ball screw 30 includes a support member 32a fixed on the base 12a,
It is rotatable about the axis via 32b. The ball screw 30 is screwed into the parallel moving body 18a. Therefore, when the ball screw 30 rotates about the axis, the parallel moving bodies 18a and 18b move in the Y-axis direction. Reference numeral 34 is a servo motor that is an example of a driving unit that rotationally drives the ball screw 30, and is fixed to the base 12a. The output shaft 36 of the motor 34 is connected to the ball screw 3 via the coupler 38.
It is linked to 0. By adjusting the rotation speed and rotation direction of the motor 34, the speed and movement direction of the parallel moving bodies 18a and 18b can be adjusted.

In the motion mechanism 10 having the above structure,
When the motor 34 is driven to rotate the ball screw 30,
The parallel moving body 18a is guided by the linear motion guide 16a and moves in the Y-axis direction. Since the parallel moving bodies 18a and 18b are connected by the first shaft 20 and the second shaft 24, the parallel moving body 18b, together with the parallel moving body 18a,
It moves synchronously in the same direction at the same speed. Therefore, for example, by attaching a tool, a work, or the like to the first shaft 20 and the second shaft 24 while allowing the rotation of the first shaft 20 and the second shaft 24, the tool, the work, or the like can be attached in the Y-axis direction. It is possible to determine the position of.

Subsequently, with reference to FIG. 2 and FIG.
The pinion gears 26a and 26b and the second pinion gears 28a and 28b will be described in detail. As clearly shown in FIG. 3, the first pinion gear 26a is fitted onto the end of the first shaft 20 and is fixed to the first shaft 20 by tightening the fixing screw 40. Although not shown, the first pinion gear 26b is similarly fixed to the other end of the first shaft 20.
The second pinion gears 28a and 28b are similarly fixed to the respective ends of the second shaft 24. The first pinion gears 26a and 26b are preliminarily applied to the first shaft 20 by a torsion (torsion force) in the direction of arrow A, which is an example of the first circumferential direction with respect to the axis, and thus the racks 14a and 14b.
It is meshed with b. On the other hand, the second pinion gear 28
The a and 28b are preliminarily applied to the second shaft 24 in the direction of arrow B, which is an example of the second circumferential direction with respect to the axis, and are meshed with the racks 14a and 14b.

A first shaft 20 in which the first pinion gears 26a and 26b are inserted into the parallel moving bodies 18a and 18b.
One method for fixing to will be described. First, the fixing screw 40 is tightened while the first pinion gear 26b is meshed with the rack 14b, and is fixed to the first shaft 20.
In this state, the fixing screw 40 of the first pinion gear 26a meshing with the rack 14a is loosened, and the first shaft 2
0 allows free rotation with respect to the first pinion gear 26a. In this state, for example, a torque wrench is used to apply torsion in the direction of arrow A to the first shaft 20.
By tightening the fixing screw 40 of the first pinion gear 26a while maintaining the state in which this torsion is applied,
Both first pinion gears 26 a, 26 b are fixed to the first shaft 20.

Similarly, the second pinion gears 28a, 28a
A method for fixing b to the second shaft 24 inserted into the parallel moving bodies 18a and 18b will be described. First, the fixing screw 40 is tightened while the second pinion gear 28b is meshed with the rack 14b, and is fixed to the second shaft 24. In this state, the second gear meshing with the rack 14a
The fixing screw 40 of the pinion gear 28a is loosened so that the second shaft 24 can freely rotate with respect to the second pinion gear 28a. In this state, for example, a torque wrench is used to apply torsion in the direction of arrow B to the second shaft 24. The second while holding the state where this torsion is added
By tightening the fixing screw 40 of the pinion gear 28 a, both the second pinion gears 28 a and 28 b are fixed to the second shaft 24. It should be noted that the magnitude of the torsion applied to the first shaft 20 and the second shaft 24 depends on the size of the first shaft 20 and the second shaft 24.
If the thicknesses are the same, they are set to the same level, and a value may be selected according to the thickness.

When the first pinion gears 26a and 26b are meshed with the racks 14a and 14b while the first shaft 20 is subjected to the torsion in the direction of arrow A, the first pinion gears 26a are always engaged. A return torsion in the direction of arrow C acts. Similarly, a return torsion in the direction opposite to the direction of arrow C always acts on the first pinion gear 26b. On the other hand, the second pinion gears 28a and 28b
However, when the second shaft 24 is engaged with the racks 14a and 14b in a state where the torsion in the arrow B direction is applied, the return torsion in the arrow D direction always acts on the second pinion gear 28a. Similarly, a return torsion in the direction opposite to the arrow D direction always acts on the second pinion gear 28b.

Therefore, the first pinion gear 26a and the second pinion gear 26a
The tooth surfaces of the pinion gear 28a are pressed against the tooth surfaces of the rack 14a by the return torsions in the opposite directions. Similarly, the first pinion gear 26b and the second pinion gear 2
The tooth flanks of 8b are pressed against the tooth flanks of the rack 14b by return torsions in opposite directions. The first pinion gears 26a and 26b and the second pinion gears 28a and 28b
The tooth surfaces of the racks 14a, 14b are constantly pressed against the tooth surfaces of the racks 14a, 14b, so that the first pinion gears 26a, 26b and the second pinion gears 28a, 28b and the racks 14a, 1b.
Backlash with 4b is eliminated. Especially the first
In the embodiment, when two parallel shafts 20 and 24 in which opposite directions of torsion are stored in advance are used, since the opposite directions of torsion are always applied to the shafts 20 and 24, the torsion always causes the shaft 20 and 24 to operate. The twisted state of 24 is maintained in the initial state. As a result, for example, the parallelism of the shafts 20 and 24 with respect to the X axis is always kept constant, the tilt is prevented, and the parallel moving bodies 18a and 18 are prevented.
It is possible to position the tools, workpieces, etc. provided on movable parts such as b, the first shaft 20, and the second shaft 24 in the Y-axis direction with extremely high accuracy. Further, by directly driving the parallel moving body 18a and following the parallel moving body 18b, the first shaft 20 and the second shaft 24 are moved.
Since the bending moment applied to the first shaft 20 and the second shaft 24 can be converted into the twisting moment of the first shaft 20 and the second shaft 24, the followability of the parallel moving body 18b that follows can be improved. As a result, it is possible to position the tools, works, etc. provided on the movable portion in the Y-axis direction with extremely high accuracy. In addition, in the first embodiment, two parallel shafts 2 in which torsions in opposite directions are accumulated in advance are provided.
Although 0 and 24 were used, the number of shafts is not limited to two,
Plural pairs of parallel shafts may be used in which torsions in opposite directions are stored in advance.

(Second Embodiment) The motion mechanism of the second embodiment will be described with reference to FIG. Reference numeral 102 denotes a base, which is formed in a rectangular frame shape with a hollowed central portion. 104a,
The first racks 104b are fixed on the base 102, respectively. First rack 104a, 104b
Are arranged parallel to the Y-axis direction, which is an example of the first direction. The second racks 106a and 106b are fixed on the base 102, respectively. Second rack 1
06a and 106b are arranged parallel to the X-axis direction, which is an example of the second direction. Reference numerals 108a and 108b denote first linear motion guides, which are fixed on the base 102, respectively. The first linear motion guides 108a and 108b are provided inside the first racks 104a and 104b, and are arranged parallel to the Y-axis direction. 110a and 110b are second linear motion guides, which are fixed on the base 102, respectively. The second linear motion guides 110a and 110b are provided inside the second racks 106a and 106b, and are arranged parallel to the X-axis direction.

Reference numerals 112a and 112b denote first parallel moving bodies, which are slidably fitted in the first linear guides 108a and 108b and are fixedly fitted upward. Therefore, the first parallel moving bodies 112a and 112b move along the first linear guides 108a and 108b to the first racks 104a and 1b.
It is movable in the Y-axis direction in parallel with 04b. 11
Reference numerals 4a and 114b denote second parallel moving bodies, which are slidably fitted to the second linear motion guides 110a and 110b and are upwardly and undetachably fitted. Therefore, the second parallel moving body 11
4a and 114b are second linear motion guides 110a and 110b.
Along with the second racks 106a and 106b are movable in the X-axis direction.

Reference numerals 116a and 116b denote first pipes, which are arranged parallel to the X-axis direction. First pipe 11
Both ends of 6a and 116b have a first parallel moving body 112a,
It is fixed to 112b. Reference numeral 118 is a first shaft, which is arranged in the X-axis direction. First shaft 118
Is a metal shaft. The first shaft 118 has a first
Pipe 116a and first parallel moving body 112a, 1
12b is rotatably inserted. First shaft 1
Both ends of 18 project to the outside of the first parallel moving bodies 112a and 112b. First parallel moving bodies 112a, 11
A retaining ring is fitted on the outer peripheral surface of the first shaft 118 projecting to the outside of 2b, and restricts the movement of the first shaft 118 in the axial direction.

Reference numeral 120 denotes a second shaft, which is arranged in the X-axis direction. The second shaft 120 is also a metal shaft. The second shaft 120 includes the first pipe 116.
b and the first parallel moving bodies 112a and 112b are rotatably inserted. Both ends of the second shaft 120 project to the outside of the first parallel moving bodies 112a and 112b. A retaining ring is fitted on the outer peripheral surface of the second shaft 120 projecting to the outside of the first parallel moving bodies 112a and 112b, and restricts the movement of the second shaft 120 in the axial direction. It should be noted that the first shaft 118 and the second shaft 120 have the first parallel moving bodies 112a and 11a.
Since it is inserted into 2b, the first parallel moving body 112a
And 112b are movable together in the Y-axis direction.
In addition, the lubricant 1 is placed in the first pipes 116a and 116b.
The first shaft 118, the second shaft 120 and the first pipe 116 are filled with 17 (for example, grease).
It prevents abrasion and noise from being generated between a and 116b.

Reference numerals 122a and 122b denote first pinion gears, which are fixed to the respective ends of the first shaft 118. First pinion gears 122a, 122b
Are rotatably meshed with the first racks 104a and 104b. Therefore, the first parallel moving body 112
When a and 112b move in the Y-axis direction, the first pinion gears 122a and 122b rotate integrally with the first shaft 118 and roll on the first racks 104a and 104b. The second pinion gears 124a and 124b are fixed to the end portions of the second shaft 120, respectively. The second pinion gears 124a and 124b also have the first
Racks 104a and 104b are rotatably engaged with each other. Therefore, the first parallel moving bodies 112a, 11
When 2b moves in the Y-axis direction, the second pinion gear 12
4a and 124b also rotate integrally with the second shaft 120 and roll on the first racks 104a and 104b. 1
The second pipes 26a and 126b are arranged in parallel with each other in the Y-axis direction. Both ends of the second pipes 126a and 126b are fixed to the second parallel moving bodies 114a and 114b.

Reference numeral 128 denotes a third shaft, which is arranged in the Y-axis direction. The third shaft 128 is a metal shaft. The third shaft 128 has a second pipe 126.
a and the second parallel moving bodies 114a and 114b are rotatably inserted. Both ends of the third shaft 128 project to the outside of the second parallel moving bodies 114a and 114b. A retaining ring is fitted on the outer peripheral surface of the third shaft 128 protruding to the outside of the second parallel moving bodies 114a and 114b, and restricts the movement of the third shaft 128 in the axial direction.

Reference numeral 130 denotes a fourth shaft, which is arranged in the Y-axis direction. The fourth shaft 130 is also a metal shaft. The fourth shaft 130 has a second pipe 126.
b and the second parallel moving bodies 114a and 114b are rotatably inserted. Both ends of the fourth shaft 130 project to the outside of the second parallel moving bodies 114a and 114b. A retaining ring is fitted on the outer peripheral surface of the fourth shaft 130 protruding to the outside of the second parallel moving bodies 114a and 114b, and restricts the movement of the fourth shaft 130 in the axial direction. In addition, the third shaft 128 and the fourth shaft 130 cause the second parallel moving bodies 114 a and 11 a to move.
4b, the second parallel moving body 114a
And 114b are integrally movable in the X-axis direction.
In addition, the lubricant 1 is also provided in the second pipes 126a and 126b.
17 (for example, grease) is filled, and the third shaft 128, the fourth shaft 130, and the second pipe 126 are filled.
It prevents wear and noise between the a and 126b.

Reference numerals 132a and 132b denote third pinion gears, which are fixed to the respective ends of the third shaft 128. Third pinion gears 132a, 132b
Are rotatably meshed with the second racks 106a and 106b, respectively. Therefore, the second parallel moving body 114
When a and 114b move in the X-axis direction, the third pinion gears 132a and 132b rotate integrally with the third shaft 128 and roll on the second racks 106a and 106b. Reference numerals 134a and 134b denote fourth pinion gears, which are fixed to the respective ends of the fourth shaft 130. The fourth pinion gears 134a and 134b are also rotatably engaged with the second racks 106a and 106b, respectively. Therefore, the second parallel moving bodies 114a, 1
When 14b moves in the X-axis direction, the fourth pinion gear 1
34a and 134b also rotate integrally with the fourth shaft 130 and roll on the second racks 106a and 106b.

Reference numeral 136 denotes the first parallel moving bodies 112a and 1a.
A first ball screw, which is an example of a first driving unit that drives 12b, is arranged on the base 102 in the Y-axis direction. The first ball screw 136 is pivotally supported by a corner block 138 provided on the base 102 and is rotatable about the axis thereof. The first ball screw 136 has a first
Of the parallel moving body 112a. Therefore, the first
When the ball screw 136 of 1 rotates about the axis, the first parallel moving bodies 112a and 112b move in the Y-axis direction.
Reference numeral 140 denotes a first ball screw 136 for rotating the first ball screw 136.
The first servomotor is an example of the driving means of the above, and is fixed to the base 102. The output shaft of the first motor 140 is connected to the first ball screw 136 via a coupler. By adjusting the rotation speed and the rotation direction of the first motor 140, the first parallel moving bodies 112a, 11a
The speed and moving direction of 2b can be adjusted.

Reference numeral 142 is a second parallel moving member 114a, 1
The second ball screw is an example of a second driving unit that drives 14 b, and is arranged on the base 102 in the X-axis direction. The second ball screw 142 is pivotally supported by a corner block 138 provided on the base 102 and is rotatable about the axis thereof. The second ball screw 142 has a second
Of the parallel moving body 114a. Therefore, the second
When the ball screw 142 of 1 rotates about the axis, the second parallel moving bodies 114a and 114b move in the X-axis direction.
144 denotes a second ball screw 142 that drives the second ball screw 142 to rotate.
The second servo motor is an example of a driving unit of the above, and is fixed to the base 102. The output shaft of the second motor 144 is connected to the second ball screw 142 via a coupler. By adjusting the rotation speed and the rotation direction of the second motor 144, the second parallel moving bodies 114a and 114a
The speed and moving direction of 4b can be adjusted.

Reference numeral 146 is a moving body, which is the first pipe 11.
6a, 116b and the second pipes 126a, 126b
It can be moved over. Therefore, the moving body 146 moves in the Y-axis direction as the first parallel moving bodies 112a and 112b move in the Y-axis direction. On the other hand, when the second parallel moving bodies 114a and 114b move in the X-axis direction, the moving body 1
46 moves in the X-axis direction along with the movement. Mobile 1
By mounting an object to be mounted such as a tool, a robot head, and a work on the object 46, the object to be mounted can be positioned in the XY directions. In the second embodiment, the moving body 146 is connected to the first pipes 116a and 116b and the second pipe 1.
26a and 126b are movable, but they may be directly movable on the first shaft 118, the second shaft 120, the third shaft 128, and the fourth shaft 130.

In the motion mechanism 100 having the above structure, the first motor 140 is driven to drive the first ball screw 1
When 36 is rotated, the first parallel moving body 112a moves to the first
Guided by the linear motion guide 108a, the movable body 146 moves in the Y-axis direction together with the moving body 146. Since the first parallel moving bodies 112a and 112b are connected by the first pipes 116a and 116b, the first parallel moving body 112b and the first parallel moving body 112a move synchronously in the same direction at the same speed. To do. Similarly, when the second motor 144 is driven to rotate the second ball screw 142, the second parallel moving body 114 is moved.
a is guided by the second linear motion guide 110a, and the moving body 14
Along with 6, move in the X-axis direction. Second parallel moving body 11
Since 4a and 114b are connected by the second pipes 126a and 126b, the second parallel moving body 114b is the second pipe.
Together with the parallel moving body 114a of FIG. Therefore, by mounting the mounted object on the moving body 146 as described above, the position of the mounted object in the XY direction can be determined.

In the second embodiment, the first pinion gears 122a and 122b, the second pinion gears 124a and 1b.
24b, third pinion gears 132a, 132b, fourth
The mounting structure of the pinion gears 134a and 134b of
This is similar to the first embodiment. That is, the first pinion gears 122a and 122b move to the first racks 104a and 104b in a state in which a first circumferential torsion (torsion force) is applied to the first shaft 118 in advance. It is meshed. On the other hand, the second pinion gears 124a, 1
24b is meshed with the first racks 104a, 104b in a state in which a torsion in a second circumferential direction opposite to the first circumferential direction is applied to the second shaft 120 in advance with respect to the axis. Third pinion gears 132a, 132b
Is the second rack 10 with a third circumferential torsion applied to the third shaft 128 in advance in the axial direction.
It is meshed with 6a and 106b. On the other hand, the fourth pinion gears 134 a and 134 b are provided with the second rack 106 in a state in which a torsion in the fourth circumferential direction opposite to the third circumferential direction with respect to the axis is previously applied to the fourth shaft 130.
It is meshed with a and 106b.

The method of fixing each pinion gear to each shaft may be the same as that of the first embodiment, for example. The first
If the thickness of the first shaft 118 and the second shaft 120 is the same, the magnitudes of the torsions applied to the shaft 118 and the second shaft 120 of the first shaft 118 and the second shaft 120 are approximately the same. Just select it. Also, the third
If the third shaft 128 and the fourth shaft 130 have the same thickness, the magnitudes of the torsions applied to the shaft 128 and the fourth shaft 130 of the third shaft 128 and the fourth shaft 130 are similar, and a value is selected according to the thickness. do it.

First pinion gears 122a, 122b
However, when the first rack 118 is meshed with the first racks 104a and 104b with the first circumferential torsion applied, the first pinion gear 122a is always kept in the second circumferential direction. Return torsion works. Similarly, the first return torque in the circumferential direction always acts on the first pinion gear 122b. On the other hand, the second pinion gears 124 a and 124 b are not moved to the second shaft 120.
By being meshed with the first racks 104a and 104b in a state in which the circumferential torsion is applied, the first circumferential return torsion always acts on the second pinion gear 124a. Similarly, the second pinion gear 124b
A second return torsion in the circumferential direction always acts on.

Third pinion gears 132a, 132b
However, when the third rack 128a, 106b is meshed with the third shaft 128 in a state in which the third circumferential torsion is applied, the third pinion gear 132a is always kept in the fourth circumferential direction. Return torsion works. Similarly, a third return torsion in the circumferential direction always acts on the third pinion gear 132b. On the other hand, the fourth pinion gears 134 a and 134 b are moved to the fourth shaft 130 to the fourth position.
By being meshed with the second racks 106a and 106b in the state in which the circumferential torsion is applied, the third return torsion in the circumferential direction always acts on the fourth pinion gear 134a. Similarly, the fourth pinion gear 134b
A fourth return torsion in the circumferential direction always acts on.

Therefore, the tooth flanks of the first pinion gear 122a and the second pinion gear 124a are pressed against the tooth flanks of the first rack 104a by return torsions in opposite directions. Similarly, the tooth flanks of the first pinion gear 122b and the second pinion gear 124b are pressed against the tooth flanks of the first rack 104b by return torsions in opposite directions. This first pinion gear 122a, 122b and the second
The tooth surfaces of the pinion gears 124a and 124b are constantly pressed against the tooth surfaces of the first racks 104a and 104b, so that the first pinion gears 122a and 122b and the second pinion gears
Of the pinion gears 124a, 124b and the first rack 10
Backlash between 4a and 104b is eliminated.
As a result, the first pipes 116a, 1
16b, the first shaft 118 and the second shaft 1
A tilt of 20 is prevented.

On the other hand, the third pinion gear 132a and the fourth pinion gear 132a
The tooth surface of the pinion gear 134a is pressed against the tooth surface of the second rack 106a by the return torsions in the opposite directions. Similarly, the tooth flanks of the third pinion gear 132b and the fourth pinion gear 134b are pressed against the tooth flanks of the second rack 106b by return torsions in opposite directions. This third pinion gear 132a, 132b and the fourth
Since the tooth surfaces of the pinion gears 134a and 134b are constantly pressed against the tooth surfaces of the second racks 106a and 106b, the third pinion gears 132a and 132b and the fourth pinion gears 132a and 132b.
The pinion gears 134a, 134b and the second rack 10
The backlash between 6a and 106b is eliminated.
As a result, the second pipes 126a, 1 with respect to the Y-axis direction
26b, the third shaft 128 and the fourth shaft 1
Tilt of 30 is prevented. By removing the backlash, the position of the moving body 146 and the mounted object mounted on the moving body 146 in the XY direction can be positioned with extremely high accuracy. In the second embodiment as well, two parallel shafts in which opposite torsions in the X-axis direction and the Y-axis direction are previously stored are arranged, but the number of shafts in each direction is limited to two. Instead, it is possible to use a plurality of pairs of parallel shafts in which torsions in opposite directions are stored in advance.

(Third Embodiment) The motion mechanism of the third embodiment will be described with reference to FIGS. The third embodiment is a modification of the first embodiment, and the same members as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In the first embodiment, the parallel moving bodies 18a and 18b are used as the driving means.
A ball screw 30 and a motor 34 that rotationally drives the ball screw 30 are used to drive the. In the third embodiment, the servo motor 30 mounted on the parallel moving body 18a as the driving means.
0 and a transmission member for transmitting the rotation of the motor 300 to rotate the first shaft 20 and the second shaft 24 in the same direction. The transmission member of the third embodiment is the first member fixed to the output shaft 302 of the motor 300.
Timing pulleys 304a and 304b, second timing pulleys 306a and 306b fixed to the first shaft 20 and the second shaft 24, first timing pulley 304a and second timing pulley 306a.
And a timing belt 308a stretched between the first timing pulley 304b and the second timing pulley 306b.
And 8b.

When the motor 300 is driven, the first timing pulleys 304a, 304b, the second timing pulleys 306a, 306b, the timing belts 308a, 3
08b through the first shaft 20 and the second shaft 2
4 rotates in the same direction. When the first shaft 20 and the second shaft 24 rotate, the first pinion gears 26a and 26b meshing with the racks 14a and 14b and the second pinion gears 28a and 28b roll on the racks 14a and 14b. By this rolling, the first shaft 20 and the second shaft 20
Parallel moving bodies 18a, 1 connected by a shaft 24 of
8b synchronously moves in the same direction at the same speed. The effects of backlash removal and high positioning accuracy in the third embodiment are similar to those in the first embodiment. In the third embodiment, both shafts 20 and 24 are rotated simultaneously by the motor 300, but it is also possible to rotate only one shaft by the motor 300 and allow the other shaft to rotate freely. Further, as the transmission member, the first shaft 20 or the second shaft 24 is directly connected to the motor 300.
A coupler that can be connected to the output shaft 302 may be used.

(Fourth Embodiment) The motion mechanism of the fourth embodiment will be described with reference to FIG. The fourth embodiment is a modification of the second embodiment, and the same members as those in the second embodiment are designated by the same reference numerals and the description thereof will be omitted. In the second embodiment,
The first ball screw 1 is used as the first and second driving means.
36, the second ball screw 142, the first motor 140 and the second motor 144 were used. In the fourth embodiment,
Similar to the third embodiment, the first servomotor 400 mounted on the first parallel moving body 112a as the first driving means.
And a first transmission member for transmitting the rotation of the first motor 400 to rotate the first shaft 118 and the second shaft 120 in the same direction. The first transmission member is a first timing pulley 404a, 404b fixed to the output shaft 402 of the first motor 400.
And a first shaft 118 and a second shaft 120.
Timing pulleys 406a, 406 fixed to
b, and first timing belts 408a and 408b that are wound around the first timing pulleys 404a and 404b and the second timing pulleys 406a and 406b.

On the other hand, the second driving means is a second servo motor 410 mounted on the second parallel moving body 114a,
It is composed of a second transmission member for transmitting the rotation of the second motor 410 and rotating the third shaft 128 and the fourth shaft 130 in the same direction. The second transmission member includes third timing pulleys 414a and 414b fixed to the output shaft 412 of the second motor 410,
Fourth timing pulleys 416a, 416b fixed to third shaft 128 and fourth shaft 130
And the third timing pulleys 414a and 414b and the fourth timing pulleys 414a and 414b.
The second timing belts 418a and 418b are stretched between the timing pulleys 416a and 416b.

When the first motor 400 is driven, the first shaft 118 and the second shaft 120 rotate in the same direction. Similarly, when the second motor 410 is driven, the third motor 410
Shaft 128 and fourth shaft 130 rotate in the same direction. This shaft 118, 120, 128, 130
Rotation of the first parallel moving bodies 112a and 112b causes the first parallel moving bodies 112a and 112b to move synchronously in the Y-axis direction at the same speed.
4a and 114b move synchronously in the X-axis direction at the same speed. As a result, the moving body 146 can be moved in the XY directions. The effects of the backlash removal and the high positioning accuracy of the moving body 146 in the fourth embodiment are similar to those in the second embodiment. In the fourth embodiment, the first motor 400 simultaneously rotates the shafts 118 and 120, and the second motor 410 simultaneously rotates the shafts 128 and 130. However, the motors 400 and 410 rotate one shaft. The other may be freely rotatable.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, each rack is arranged inside each parallel moving body, and each rack is arranged. Needless to say, many modifications can be made without departing from the spirit of the invention, for example, a pinion gear may be provided in the middle of each shaft.

[0041]

In the basic structure of the motion mechanism according to the present invention,
The first pinion gear is meshed with the rack in a state where a first circumferential torsion is applied to the first shaft in advance in the first shaft. The second pinion gear is meshed with the rack in a state in which a second circumferential torsion that is opposite to the first circumferential direction with respect to the axis is applied to the second shaft in advance. Therefore, the tooth surface of the first pinion gear is pressed against the tooth surface of the rack by the second return force in the circumferential direction, and the second pinion gear is pressed by the tooth force of the rack by the first return force in the circumferential direction. It is pressed against the surface. This pressing prevents the inclination of the first shaft and the second shaft with respect to the second direction. Therefore, in spite of the simple and lightweight structure, even if the driving force acting on the parallel moving body is unbalanced or an external force acts on the movable portion, accurate synchronous movement is possible.

Also in the second basic configuration, the first pinion gear is meshed with the first rack in a state in which a first circumferential torsion is applied to the first shaft in advance in the first shaft. . The second pinion gear is meshed with the first rack in a state in which a second circumferential torsion that is opposite to the first circumferential direction with respect to the axis is applied to the second shaft in advance. The third pinion gear is meshed with the second rack in a state in which a third circumferential torsion is applied to the third shaft in advance on the third shaft. The fourth pinion gear is meshed with the second rack in a state in which a fourth circumferential torsion in a direction opposite to the third circumferential direction with respect to the axis is previously applied to the fourth shaft. Therefore, the first pinion gear has the tooth surface of the first pinion due to the second return force in the circumferential direction.
Is pressed against the tooth flank of the rack, and the second pinion gear is the first
Since the tooth surface is pressed against the tooth surface of the first rack by the return force in the circumferential direction, the inclination of the first shaft and the second shaft with respect to the second direction is prevented. On the other hand, the tooth surface of the third pinion gear is pressed against the tooth surface of the second rack by the return force in the fourth circumferential direction. The tooth surface of the fourth pinion gear is pressed against the tooth surface of the second rack by the return force in the third circumferential direction. Therefore, the inclination of the third shaft and the fourth shaft with respect to the first direction is prevented. As a result, despite the simple and lightweight structure, it is possible to achieve a remarkable effect such as accurate synchronous movement.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of a motion mechanism according to the present invention.

FIG. 2 is a partial side view showing the vicinity of a first pinion gear and a second pinion gear in the first embodiment.

FIG. 3 is a partial cross-sectional view showing the vicinity of a first pinion gear in the first embodiment.

FIG. 4 is a plan view showing a motion mechanism of a second embodiment.

FIG. 5 is a plan view showing a motion mechanism of a third embodiment.

FIG. 6 is a side view showing a motion mechanism of a third embodiment.

FIG. 7 is a plan view showing a motion mechanism of a fourth embodiment.

FIG. 8 is a plan view showing a conventional motion mechanism.

[Explanation of symbols]

 10 Motion Mechanisms 14a, 14b Racks 18a, 18b Parallel Moving Objects 20 First Shafts 24 Second Shafts 26a, 26b First Pinion Gears 28a, 28b Second Pinion Gears 100 Motion Mechanisms 104a, 104b First Racks 106a , 106b Second rack 112a, 112b First parallel moving body 114a, 114b Second parallel moving body 118 First shaft 120 Second shaft 122a, 122b First pinion gear 124a, 124b Second pinion gear 128 3rd shaft 130 4th shaft 132a, 132b 3rd pinion gear 134a, 134b 4th pinion gear 146 Moving body

Claims (8)

[Claims] 1. A pair of racks which are spaced apart from each other and are arranged in parallel in a first direction, a pair of parallel moving bodies movable in the first direction in parallel with the rack, and the first A first shaft that is arranged in a second direction perpendicular to the direction and is rotatably provided to the pair of parallel moving bodies; and a pair of parallel shafts that are arranged in the second direction. A second shaft rotatably provided on the moving body; a pair of first pinion gears fixed to the first shaft and capable of meshing with and rolling on the pair of racks; A pair of second pinion gears which are fixed to the shaft of the rack and which can be meshed with and rolled by the pair of racks respectively; and drive means for moving the pair of parallel moving bodies in the first direction. , The first pinion gear is The first shaft is meshed with the rack in a state in which a first circumferential direction torsion is applied to the axis in advance, and the second pinion gear is attached to the second shaft in advance with respect to the axis. A motion mechanism characterized by being meshed with said rack in a state in which a second circumferential torsion opposite to the first circumferential direction is applied. 2. The driving means comprises a ball screw arranged in the first direction and screwed into the parallel moving body, and a motor for rotating the ball screw about an axis. The movement mechanism according to claim 1. 3. The driving means transmits a rotation of the motor provided in the parallel moving body and rotation of the motor to rotate at least one of the first shaft and the second shaft. The movement mechanism according to claim 1, wherein the movement mechanism comprises a member. 4. A pair of first racks which are spaced apart and arranged in parallel to a first direction, and a pair of first racks which are spaced apart and arranged in parallel to a second direction perpendicular to the first direction. A pair of second racks, a pair of first parallel moving bodies that are movable in the first direction in parallel with the first rack, and a pair of second racks in the second direction in parallel with the second rack. A pair of movable second parallel moving bodies; a first shaft arranged in the second direction and rotatably provided to the pair of first parallel moving bodies; A second shaft rotatably provided to the pair of first parallel moving bodies and arranged in the first direction, and to the pair of second parallel moving bodies while being arranged in the first direction. A third shaft rotatably provided, and a pair of second shafts arranged in the first direction. A fourth shaft rotatably provided on the line mobile, is fixed to said first shaft, a pair can be respectively engaged and rolling to a pair of the first rack first
Pinion gear and a pair of second pinions fixed to the second shaft and capable of meshing with and rolling on the pair of first racks, respectively.
Pinion gear and a pair of third pinions that are fixed to the third shaft and that can mesh with and roll on the pair of second racks, respectively.
Pinion gear and a pair of fourth racks fixed to the fourth shaft and capable of meshing with and rolling on the pair of second racks, respectively.
A pinion gear, first driving means for moving the pair of first parallel moving bodies in the first direction, and second driving means for moving the pair of second parallel moving bodies in the second direction The first pinion gear is meshed with the first rack in a state in which a first circumferential torsion is applied to the first shaft in advance in the first shaft, The second pinion gear is meshed with the first rack in a state in which a torsion in a second circumferential direction opposite to the first circumferential direction with respect to the axis is previously applied to the second shaft, The third pinion gear is meshed with the second rack in a state in which a third circumferential torsion is applied to the third shaft in advance with respect to the axis, and the fourth pinion gear is To the fourth shaft in advance with respect to the axis Circumferential direction opposite the direction of the fourth circumferential movement mechanism, characterized in that torsion is engaged to said at an applied state the second rack. 5. A movable in the second direction along the first shaft and the second shaft, and a movable in the first direction along the third shaft and the fourth shaft. The movement mechanism according to claim 4, further comprising a moving body. 6. The first driving means is arranged in the first direction, and has a first ball screw screwed into the first parallel displacement body, and the first ball screw is centered on an axis line. To drive to rotate first
The second drive means is arranged in the second direction, and has a second ball screw that is screwed into the second parallel moving body, and the second ball screw has an axis line. Second rotation driven to the center
The motor according to claim 4 or 5,
The described movement mechanism. 7. The first drive means transmits a rotation of the first motor to the first motor provided in the first parallel moving body, and transmits the rotation of the first motor to the first shaft and the first shaft. A second transmission means for rotating at least one of the two shafts, wherein the second drive means is a second motor provided in the second parallel moving body, and the second motor. 6. The movement mechanism according to claim 4, further comprising a second transmission member for transmitting at least one of the third shaft and the fourth shaft by transmitting the rotation of the second shaft. 8. A pair of first pipes arranged in the second direction, each end of which is fixed to the pair of first parallel moving bodies, and a pair of first pipes arranged in the first direction. A pair of second pipes whose end portions are respectively fixed to the pair of second parallel moving bodies are provided, and the first shaft and the second shaft are respectively rotatable to the pair of first pipes. 8. The motion mechanism according to claim 4, 5, 6 or 7, wherein the third shaft and the fourth shaft are rotatably inserted through the pair of second pipes, respectively.