JPS6117832Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention mainly relates to an industrial robot used for assembly work, etc., and it is also intended to be used for assembly work of machines etc. by means of a working part provided at the end of the arm system. This invention relates to the improvement of industrial robots.

In the following description, the horizontal movement of the working part relative to the robot body is expressed as θ (sheeter).
It's called moving. Further, the movement in which the actuating part linearly approaches (retreats) or separates (advances) from the robot body along a horizontal path is called x (x) movement. The linear movement of the working part along a horizontal path orthogonal to this x movement is called z movement.

Various industrial robots of the type described above have been proposed in the past, but all of them have various drawbacks as described below.

The first type is called the orthogonal type, in which the main block moves in z and the sub-block moves in x on a horizontal arm attached to it, and the working part moves in z in response. be. However, because of this orthogonal structure, it inevitably takes up too much space in the horizontal direction, which limits the places where it can be used. Moreover, since each part is supported by horizontal levers, it becomes cantilever-like and lacks stability.

The second type is called a cylindrical type. A sub-block is combined to be movable in z with respect to a main block that moves θ, and a working part is attached to the tip of an arm that moves in x relative to the main block. With this type, the tail of the arm will protrude significantly rearward in the backward state of x movement, increasing the horizontal space. Furthermore, if the robot enters the θ movement in this state, the tail will swing significantly, increasing the danger to workers working near the robot. In addition, in the forward state of x movement, the arm protrudes significantly forward, resulting in a cantilever-like shape that lacks stability in posture.

The third type is called the joint type. This is θ
An arm system is constructed by connecting the second arm to the end of the first arm that vibrates in the vertical direction relative to the moving main block so that it vibrates in the vertical direction, and supports the operating part. It is. Since each part performs a predetermined movement simply by turning, it is extremely difficult to design how to control the movement appropriately. In addition, since the control motor for the second arm is provided in the arm system, the weight of the arm system increases, which not only makes it difficult to operate at high speeds, but also makes it so-called top-heavy, making the posture of the entire robot unstable. I can't escape it.

The fourth type is called the SCARA type, which uses first and second arms that are connected to each other like the indirect type, but both are pivoted in the horizontal direction. Its drawbacks are the same as those of the indirect type.

Therefore, we have developed an industrial robot that eliminates the drawbacks of the above-mentioned types, has a simple structure and control, provides a large degree of freedom in the movement of the operating parts, does not take up horizontal space, and has high work safety. In order to provide this, the applicant has already proposed the following industrial robot.

That is, as shown in FIG.
0, a drive system 200, and an arm system 300, and the control system includes control motors 150, 160, and 130 for x and z movement, and more preferably for θ movement, which are all housed in a base case, and the drive system is It has two shafts 210 and 220 that are operatively connected to the control motors for x and z movement, respectively, and a nut that fits onto these shafts, and is housed all together in an upright case erected on the base case 110. . The arm system has a triangular structure consisting of two arms connected to the nut. Then, the x-movement control motor 150 is driven to transform the triangle and the working section moves x, and the z-movement control motor 160 is driven to move the above-mentioned triangle up and down in parallel to move the working section to z. The triangle is driven by the θ-movement control motor 130, and the above-mentioned triangle rotates so that the actuating portion moves θ.

By the way, this industrial robot has achieved the purpose of solving this problem, but from the standpoint of work efficiency and versatility, it is necessary to have a wider range of arm movement and a faster movement speed. has been done.

This device was proposed in response to such demands. By changing the support structure of the arm that has a working part at the tip, it is possible to widen the range of motion of the arm, and therefore the working range of the working part, and to increase the operating speed. The purpose of this invention is to provide an industrial robot that can quickly perform the following tasks.

That is, the gist of this invention is that x, z, more preferably θ
A control system with a motor for directional movement, a spline shaft and a screw shaft connected to the motors for x and z movement, a gear mechanism that transmits rotational power between these two shafts, and a gear mechanism that is slidably fitted to the spline shaft. In this robot, the lower end of the first arm is supported by the upper block. The upper end of the third arm is journalled and connected to the upper end of the second arm, the lower end of the third arm is journaled to the lower block, and its upper end is journaled at the longitudinal center of the second arm, and the upper end of the fourth arm is connected to the lower block. By bearing the upper block and bearing the lower end approximately at the center of the third arm, a diamond-shaped parallel chain structure is constructed. This invention will be explained in more detail below based on the attached drawings.

FIG. 2 shows the appearance of one embodiment of the industrial robot of this invention. Briefly, the robot consists of three parts: a control system, a drive system, and an arm system. A part of the control system is divided into a flat cylindrical base case 4 provided at the base of the robot, and the other part is divided into an upper part of an elongated cylindrical upright case 6 mounted on the base case. The arm system is comprised of a plurality of arms protruding forward from an elastic bellows plate 7 formed on the front surface of the upright case 6, and has a working part A at its front end.

FIG. 3 shows the details of the internal structure of the industrial robot having the above-mentioned general structure. Note that a part of the arm system 3 in the figure is omitted.

As described above, the drive system 2 is housed all together in the upright case 6, and has a spline shaft 21 and a threaded shaft 22 that are parallel to each other and extend in the vertical direction. It is rotatably supported by bearings 21a and 22a respectively attached to the substrate 11 at the portions thereof.

A spline bearing 23 is fitted into the spline shaft 21, and although the spline bearing 23 can move vertically along the spline shaft 21, it cannot rotate relative to the spline shaft 21. A gear 24 is integrally formed at the bottom of this spline bearing 23, as shown in FIG. However, they do not necessarily have to be one as long as they are in a fixed relationship.

A pair of first nuts 25 and a second nut 25 are attached to the screw shaft 22.
A nut 26 is screwed together. A gear 27 is fixedly attached to the lower part of the upper nut 25.
This gear 27 is loosely fitted onto the threaded shaft 22, and meshes with the gear 24 on the spline shaft 21. The spline bearing 23 of the spline shaft 21 and the first nut 25 of the threaded shaft 22 are rotatably connected to a common upper block 28, and the vertical movement of one nut is controlled by the upper block 2 of the other nut. The structure is such that both of them move simultaneously, in the same direction, and to the same extent. Note that an arm support piece 28a is formed at the front end of the upper block 28. A second nut 26 is provided below the screw shaft 22, and the nut 26 is rotatable and further includes a lower block 29 on which an arm support piece 26a is formed.

Next, in the control system, the θ-direction control system 1a includes a substrate 11 that supports the base ends of a spline shaft 21 and a screw shaft 22 via bearings 21a and 22a, and a gear 12 is arranged on the circumference of the substrate 11. This is in meshing engagement with a gear 14 that is tightly fitted to the output shaft of the θ movement control motor 13. In the X-direction and Z-direction control system 1b, pulleys 17a and 17b are firmly fitted to the upper ends of a spline bearing 21 and a screw shaft 22, respectively, and the pulley 17a attached to the spline shaft 21 is controlled in the x direction via a belt 19a. It is rotationally connected to a pulley 15a that is firmly fitted to an output shaft (not shown) of a movement control motor 15. A pulley 17b attached to the screw shaft 22 is similarly connected via a belt 19b to a pulley 16a tightly fitted to an output shaft (not shown) of a control motor 16 for moving in the z direction.

In the above description, the pulley and belt 19 are
a and 19b to the output shafts of the control motors for movement in the x and z directions, respectively, but this invention is not limited to this, and may be connected to the output shafts of the control motors for movement in the x and z directions, respectively. Of course, the control motor 150 for moving in the x direction and the control motor 160 for moving in the z direction may be connected to the lower ends of the spline shaft 210 and the screw shaft 220, that is, to the substrate 110 side, respectively.

Before entering into a description of the arm system, the operation of the combination of the control systems 1a, 1b and the drive system 2 having the above configuration will be described.

When the θ movement control motor 13 rotates, the gear 1
By the combination of 2 and 14, the entire robot is connected to the board 11.
The working part A at the tip of the arm system 3 moves by θ.

When the control motor 15 rotates, the gear 24 rotates together with the spline shaft 21 via the pulley 15a, the belt 19a, and the pulley 17a, and the gear 27 that meshes with the gear 24 rotates, which in turn rotates the first nut 25. Then, due to the threaded relationship between the first nut 25 and the screw shaft 22, the first nut 25 moves vertically on the screw shaft 22. Accordingly, the spline bearing 23 commonly attached to the upper block 28 also moves on the spline shaft 21 at the same time, in the same direction, and to the same extent. Since the one-way screw shaft 22 does not rotate, the lower second nut 26 remains stationary, and the working part A moves x as will be described later.

When the control motor 16 rotates, the pulleys 16a,
Screw shaft 2 via belt 19b and pulley 17b
2 is rotated. Then, due to the screw engagement with the screw shaft 22, the first nut 25 and the second nut 26 simultaneously move in the same direction and by the same extent in the vertical direction. Therefore, the working part A moves in the z direction, as will be described later.

Next, the operation mode of the arm system 3 will be explained with reference to FIG. In FIGS. 4A to 4G, each part will be explained in a simplified manner as viewed from the side of the robot body. However, in this case, the threaded shaft 22 is hidden behind the spline shaft 21, making it difficult to understand the meshing and engagement relationship between the gears 24 and 27.
22 is shown shifted back and forth in the robot's front-rear direction, that is, in the arm extension direction.

The arm system 3 includes a first arm 31 and a second arm 3.
2, a third arm 33, a fourth arm 34, and sub arms 35, 36. The first arm 31 is journalled at one end by the upper support piece 28a and extends diagonally upward, and further has a second arm 32 connected and supported at its tip that extends diagonally downward. The third arm 33 has approximately twice the length of the first arm 31, and has a lower support piece 2 at its lower end.
6a, and the second
The first point in the longitudinal direction of the arm 32 from the bearing S point
It is bearing R at a position having the same dimension and length as the arm 31. The fourth arm 34 has the same length as the first arm 31, and one end is connected to the upper support piece 28a.
Similarly to the first arm 31, the other end is supported by a shaft P at the center of the third arm 33. Therefore, the arm system 3 has a rhombic shape with the bearings P, S, R, and T at its vertices.

Next, the z movement will be explained with reference to FIG. 4B, taking as an example the case where the working part A is lowered.

When the control motor 16 rotates in a predetermined direction in the state shown in FIG. 4A, the screw shaft 22 rotates, and accordingly, the first nut 25 and the second nut 26 simultaneously descend in the same direction and to the same extent. Both nuts 25,
Since there is no change in the vertical relative position of 26, the arm system 3 has a diamond shape with the bearings P, S, R, and T as the vertices.
It descends in the same state as shown in Figure A. That is,
Since it is a kind of parallel movement, working part A maintains its position in the x direction and moves from its original position a to a position directly below.
Descend to a′. Of course, the spline bearing 23 also follows the descent of the nut 25.

Similarly, when the control motor 16 rotates in the opposite direction, the working part A rises from the original position a to the position directly above while maintaining its position in the x direction.

Next, the x movement will be explained with reference to FIG. 4C, taking as an example the case where the working part moves forward. When the control motor 15 rotates in a predetermined direction in the state shown in FIG. 4A, the spline shaft 21 also rotates and the gears 24, 27
Due to this combination, the nut 25 on the screw shaft 22 rotates and descends. However, since the screw shaft 22 itself does not rotate, the lower nut 26 remains stationary. Therefore, since the upper nut 25 approaches the lower nut 26, the rhombus connecting the bearing points P, S, R, and T collapses, and the first arm 31 moves downward with the bearing point P as its center. The arm 34 swings upwards around the bearing point P, the second arm 32 swings upwards around the bearing point S, and the third arm 33 swings downwards around the bearing point Q. has a diamond-shaped structure that is flatter on the sides than the front. That is, the working part A moves forward from the original position a to the outer position a'' while maintaining its z-direction position.Of course, the spline bearing 23 also follows the lowering of the nut 25.

Similarly, when the control motor 15 rotates in the opposite direction, the working part A retracts from position a to a new inner position while maintaining its z-direction position.

In the above, x movement and z movement have been explained separately for convenience of explanation, but in implementation, both control motors 1
By overlapping the rotations of 5 and 16, it is possible to perform two-dimensional movement in xz, and by also overlapping the rotation of control motor 13, it is possible to perform three-dimensional movement in x, z, and θ. is also possible.

As is clear from the above, in this invention, the first arm 31 and the second arm 32 are separated and bent downward at the bearing point S. The installation height is low. This is the same z axis on both axes as in the format shown in Figure 1.
This means that even when the amount of movement in a direction is required, the length dimensions of both shafts 21 and 22 can be shorter than that of the type shown in FIG. Therefore, the height of the robot can be reduced, and the robot can be installed more stably.

Further, since the dimensions of the bearing point R of the second arm and the working part A are twice as large as the bearing point SR, the working part A is given twice the momentum of the first nut 25. Therefore, in this device, the moving speed of the working part A in the x direction is twice that of the type shown in FIG. 1, and the movement in the x direction can be performed quickly.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted perspective view showing the internal structure of a conventional industrial robot, Fig. 2 is a perspective view showing the external appearance of an embodiment of the industrial robot of this invention, and Fig. 3 shows its internal structure. A partially omitted perspective view, FIGS. 4A, B, and C are side explanatory views showing its operation, and FIG. 5 is a sectional view of the main part of this invention. 1a, 1b...control system, 2...drive system, 3...
Arm system, A... Working part, 13... Motor for θ direction control, 15... Motor for x direction control, 16
... Z-direction control motor, 21 ... Spline shaft, 22 ... Screw shaft, 23 ... Spline bearing,
25, 26...Natsuto, 28...Upper block, 2
9...Lower block, 31, 32, 33, 34, 3
5, 36...arm.

Claims (1)

[Claims for Utility Model Registration] A spline shaft 21 and a threaded shaft 22, which extend in parallel and perpendicular to each other, are operatively connected to an X-movement control motor 15 and a Z-movement control motor 16 at their lower or upper ends, respectively. A spline bearing having a gear is slidably fitted to the spline shaft, and a first nut 25 and a second nut each having a gear to engage with the gear of the spline bearing are fitted to the threaded shaft. 26 are screwed together, the spline bearing and the first nut are rotatably attached to a common upper block 28, and the second nut is fixed to the lower block,
And the lower end of the first arm 31 is pivotally supported on the upper block, and its upper end is pivotally connected to the upper end of the second arm, and the lower end of the third arm 33 is pivotally supported on the lower block, and its upper end is connected to the longitudinal center of the second arm. Further, the upper end of the fourth arm 32 is supported on the block and the lower end is supported on the substantially center of the third arm, so that the arm engagement is formed into a diamond-shaped parallel chain structure. An industrial robot characterized by: