JPS58177281A - Industrial robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrial robot, and more particularly to an improvement in an industrial robot that grasps and transports an object using a holder provided at the tip of an arm system.

In the following description, the horizontal movement of the holder relative to the robot body will be referred to as θ (theta) movement. The movement of the holder linearly approaching (retreating) or moving away from (advance) the robot body along the horizontal sewing path is called X movement.

In addition, the linear movement of the holder along a horizontal path perpendicular to this X movement is called y movement.Moreover, the movement of the holder linearly up and down along a vertical path with respect to the robot body is called 2 (Y) movement. Z) called movement.

Industrial robots are required to have various performances, but the main ones are that they do not take up much space in the horizontal direction, that there is little danger to workers, and that their posture is stable during operation. It is easy to design how to precisely control the operation, and it is lightweight, sturdy, and can operate at high speed.

Various types of industrial robots have been developed and put into practical use, but none of them have had all of the above-mentioned performances.

In view of these circumstances, the present inventors have already proposed an industrial robot that has both the above-mentioned performances.

The proposed robot is composed of a control system, a drive system, and an arm string, and the control system is for X and 2 movements, more preferably θ
It has a movement control motor and is housed all together in a base case, and the drive system has two shafts that are operatively connected to the X and 2 movement motors, respectively, and a nut that fits into these. The arm system has an isosceles triangular structure consisting of two arms connected to the above-mentioned nuts. Driven by the control motor for X movement, the isosceles triangle above transforms and the holder moves in the , the isosceles triangle is rotated by the θ movement control motor, and the holder is moved by θ.

This industrial robot is very well-balanced and has all of the above-mentioned performances, but it has some operational inconveniences because horizontal movement other than X movement is done by θ movement of the holder. there were.

First of all, in the case of a robot, it is desirable that the movement of the arm system be as similar to that of a human being as possible, but the above-mentioned θ movement is not often seen in humans, and is too robot-like and unnatural. Accompany.

Further, the θ movement means that the holder moves along an arcuate trajectory centered on the center of the main body. Therefore, when an object is moved from position 8 or C to position 8 or C using a holder and some processing is to be performed there, the processing equipment installed at position B or C will move along the above-mentioned arcuate trajectory. It must be placed so that it faces.

This is because the front and rear surfaces of the object are 8 or C of the above circular arc trajectory.
This is because it is parallel to the tangential direction at the position. Since industrial robots are often used in processing lines where objects are conveyed in a substantially straight line, the arrangement of processing equipment as described above in the processing station is inconvenient in terms of compatibility with the processing line.

From the above point of view, it is desirable that the horizontal movement other than the X movement be along a straight path as much as possible, and that the holder and, by extension, the front and rear surfaces of the object always maintain a constant angular relationship with the front surface of the robot body. The purpose of this invention is to meet these demands.

That is, the robot of the present invention is composed of a control system, a drive system, and an arm system. It is constructed by modifying the control motor for pseudo Y movement disposed in the connecting part. The term "pseudo y movement" here means that, as will be explained in detail later, in the case of this invention, it is possible to give the holder a linear movement in the horizontal direction that is different from the X movement, but the direction is basically This is because although it is technically in the y direction, it cannot be said that it is a pure IF4 direction.

The drive system has two upright shafts each operatively connected to the X and 2 movement control motors, one upright shaft parallel to these, and a nut that engages these, and is integrally connected to the two upright shafts. It is housed in an upright case that stands on top of the base case.

The arm system consists of left and right arm groups with the same structure, and each arm group has an isosceles triangular structure consisting of two arms connected to a connecting plate, and both arm groups support both ends of the holder at their tips. I support it.

Driven by the X-movement control motor, the above isosceles triangle transforms and the holder moves in the The arm system having the above-mentioned isosceles triangular structure is moved by a control motor for pseudo-y movement, and transforms from side to side to move in pseudo-y.

The present invention will be explained in more detail below with reference to the accompanying drawings.

FIG. 1 shows the appearance of one embodiment of the industrial robot of the present invention. Briefly, the robot is composed of three parts: a control system 1, a drive system 2, and an arm system 5. Most of the control system 1 is housed in a hand box base case 4 provided at the base of the robot, and the drive system 2 is housed in a long box-shaped upright case 6 mounted on the base case 4. The arm system 5 is comprised of a group of left and right arms that protrude forward from an elastic bellows plate 7 formed on the front surface of the upright case B, and has a holder at its front end that grips an object. It has an H.

FIG. 2 shows details of the internal structure of the industrial robot having the above-mentioned schematic configuration. In the figure, a part of the arm system 5 is omitted.

As described above, the drive system 2 is housed all together in the upright case 6, and has a spline shaft 21, a threaded shaft 22, and a guide shaft 29 that are parallel to each other and extend in the vertical direction. These shafts are each rotatably supported at the top by bearings (not shown).

A nut 2 is fitted onto the spline shaft 21, and the nut 25 can move vertically along the spline shaft 21, but cannot rotate relative to the spline shaft 21. A gear 24 is integrally formed at the top of this nut 25.

However, it is sufficient that the two are in a fixed relationship, even if they are not necessarily one and the same.

A pair of upper and lower nuts 25 and 26 are screwed into the screw shaft 22. A gear 27 is attached in fixed relation to the top of the upper nut 25, and this gear 27 is loosely fitted to the threaded shaft 22 and meshed with the gear 24 on the spline shaft 21. .

The nuts) 25, 25 on both shafts 21, 22 are connected by a connecting plate 28, and both nuts) 25, 24 can freely rotate with respect to this connecting plate 28, but the vertical direction of one nut is The movement is transmitted to the other nut by this connecting plate 2B, and both are configured to move simultaneously, in the same direction, and to the same extent. Note that an arm mounting seat 28a is formed at the front end of the connecting plate 28. An arm mounting seat 26a is similarly formed at the front end of the lower nut 26.

As described above, most of the control system 1 is housed in the base case 4, and includes an X-movement control motor 15.
Output shafts (not shown) of the control motor 16 and the second movement control motor 16 are connected to a spline shaft 21 and a screw shaft 22, respectively. Furthermore, a pseudo Y movement control motor 17 is installed on the arm mounting seat 28a of the connecting plate 28, and its output shaft (not shown) is connected to one arm group of the arm string 5, as will be described later. Operationally linked.

Before entering into a description of the arm thread 5, the operation of the combination of the control system 1 and drive system 20 having the above-described configuration will be described.

When the control motor 15 rotates, the gear 24 rotates together with the spline shaft 21, and the gear 27 that meshes with the gear 24 rotates as well as the nut 25. Then, due to the threaded relationship between the nut 25 and the screw shaft 22, the nut 25 moves vertically on the screw shaft 22. Due to the presence of the connecting plate 28, the nut 25 also moves on the spline shaft 21 at the same time, in the same direction, and to the same extent. On the other hand, since the screw shaft 22 does not rotate, the lower nut 26 remains stationary. Therefore, as will be described later, the holder H moves in the X direction.

When the control motor 16 rotates, the upper and lower nuts 25 and 26 simultaneously move vertically in the same direction and to the same extent due to the screw engagement therewith. Therefore, the holder H moves two times as will be described later.

In this case as well, since the connecting plate 2B is present, the nuts 25 move on the spline shaft 21 at the same time, in the same direction, and to the same extent.

Next, the arm system 5 will be explained with reference to FIG. 5(A). Note that each part is shown in simplified form in FIGS. 5(A) to 5(0). The arm spool is composed of a pair of left and right arm groups, but since they all have the same structure, the arm group on the left in the figure will be explained in detail below, and the same parts of the arm group on the right will be marked with a dash. and display it.

The arm group includes a first arm 51, a second arm holder 2, and a sub-arm 55. This inner arm 55 is provided to maintain the verticality of the holder H, and the connecting piece 54 and the holder 8 are connected via a hinge. The first arm 51 is rotatably supported by the connecting piece 54 at its upper end, extends obliquely downward, and has a holder H at its lower end.
is supported by a bearing (S). The connecting piece 54 is rotatably supported (T) on the upper arm mounting seat 28a, and is operatively connected to the output shaft (not shown) of the pseudo Y movement control motor 17 via a suitable speed reduction device. The second arm roller 2 is rotatably supported (Q+) on the connecting piece 55 at the lower end, and is rotatably supported (R) at the longitudinal center portion of the first arm 51 at the upper end.
has been done. This connecting piece 55 is connected to the lower arm mounting seat 26.
It is supported (T) on the shaft a.

Therefore, from the viewpoint of mechanics, the arm group is composed of isosceles triangles RPQ and RQH, both of which have the bearing point R as their apex. It is well known to those skilled in the art that when a downward load is applied to XH, the isosceles triangular structure as described above is the strongest.

By the way, in the illustrated example, the control motor 17 for pseudo-y movement is
It was installed at the upper connection part of the left arm group, but the arm thread 5
Since there are four connection parts between the drive system 2 and the drive system 2 on the left, right, front and rear, it is sufficient to provide one or more of them depending on the load condition.

When driven by the control motor 17 for pseudo-y movement, the arm system 5 maintains an isosceles triangular structure uniquely determined by the vertical positions of the upper and lower nuts 23° and 26 at that time. Swings from side to side.

Next, the second movement will be explained with reference to FIG. 5(B), taking as an example the case where the holder H is lowered. When the control motor 16 rotates in either direction in the state shown in FIG. 5(A),
The screw shaft 22 rotates, and accordingly the screw shaft 22 rotates up and down) 25.26
simultaneously descend in the same direction and to the same extent. Upper and lower oak)25.
Since there is no change in the vertical relative position of 26, arm system 5 is the fifth
It descends while maintaining the isosceles triangular structure shown in Figure (A). That is, since it is a kind of parallel movement, the holder H lowers from its original position to a new position h' directly below while maintaining its position in the X direction. Of course, the nut 25 also follows the downward movement of the nut 25.

Similarly, when the control motor 16 rotates in the opposite direction, the holder H maintains its X-direction position and rises from its original position to a new directly above position.

Next, the X movement will be explained using FIG. 5(C), taking as an example the case where the holder H moves forward. When the control motor 15 rotates in either direction in the state shown in FIG. 5(A),
Because of the combination of gears 24 and 27, the nut 2 on the screw shaft 22
5 rotates and descends. However, since the screw shaft 22 itself is not rotating, the lower nut 26 remains stationary. Therefore, since the upper nut 25 approaches the lower nut 26, the isosceles triangular structure shown in FIG. 52 swings downward around the bearing point Q, and has an isosceles triangular structure that is flatter than the previous one. That is, holder H
moves forward from its original position to a new appearance position W while maintaining its two-way position. Of course, the nut 25 also follows the downward movement of the nut 25.

Similarly, if the control motor 15 rotates in the opposite direction,
Holder H maintains its two-direction position and retreats from its original position to a new inner position.
0) will explain pseudo-y movement. First, Figure 4 (A
), the arm string 5 and holder H have bearing points T, T', and S when viewed from above.

It forms a right angled quadrilateral consisting of S'.

When the control motor 17 rotates in either direction, the arm system 5 swings to the left about the bearing points T and T', and the fourth
As shown in Figure CB+, the above right-angled quadrilateral transforms into a parallelogram. As a result, holder H moves to the left by X, but
At this time, a slight amount of X movement is also involved.

For this reason, this movement of holder H is called pseudo-y movement.

When the control motor 17 rotates in the opposite direction, the arm string 5 swings to the right about the bearing points T and T', and the right angled quadrilateral transforms into a parallelogram as shown in FIG. 4(C). As a result, the holder H moves to the right in pseudo-y.

In the state shown in FIG. 4(A), the holder H forms one side of the quadrilateral and is parallel to the front surface of the main body (upright case 6). Furthermore, the parallelism of the opposing sides of the quadrilateral is maintained even during subsequent metamorphosis. Therefore, the holder H is always parallel to the front surface of the main body.

In the above, for convenience of explanation, the X movement, 2-movement, and Commercially available reversible motors are appropriately used as these control motors, and these are excited by electrical signals generated according to an appropriately set program.

As is clear from the above, in this invention, the arm system is composed of a pair of arms having an isosceles triangular structure each consisting of two arms, so it is structurally very simple and , very robust against loads.

In addition, the isosceles triangular structure is adopted, and the movement in the X direction and 2.
The direction movement and the y-direction movement can be performed individually or in combination.

Furthermore, since the holder follows a straight trajectory during X movement,
Since the facing direction of the holder and therefore the object remains unchanged,
Not only does the movement itself become natural, close to that of the human body, but when the robot is placed at a processing line station, the arrangement of related equipment becomes rational.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the appearance of an embodiment of the industrial robot of the present invention, Fig. 2 is a partially omitted perspective view showing its internal structure, and Fig. 5' (A1-(0) shows its operation). Side explanatory view shown in Fig. 4 (
A) to (C) are plan explanatory views showing the operation. 1... Control system 2... Drive system 5... Arm system H... Holder 15... Control motor for X movement 16... Control motor for 2 movement 17... Control for pseudo Y movement Motor 21...Spline shaft 22...Screw shaft 25, 25, 26...Nut 28...Connecting plate 51, 52...Arm Patent applicant Nippon Gakki Manufacturing Co., Ltd. Patent application agent Patent attorney Suga Hara - Part Pit / 12] Dragon 2 Picture Maku 3 Figure (A) 1 3 Figures (8? / Enter 3 Figures (C) Ground 4 Figures and 4) Figure 4 Figures (C) Hole 4 Figures (ε)

Claims (2)

[Claims] (1) A spline shaft (21) and a threaded shaft (22) that are parallel to each other and extend in the vertical direction are actuated by the X-movement control motor (15) and the two-movement control motor (16) at their lower ends, respectively. A first nut (25) with a gear is slidably fitted into the spline shaft, and a second nut (25) with a gear which engages with the gear and a fifth nut (25) with a gear are connected to the screw shaft. The nuts (26) are screwed together, and an arm system is constituted by a pair of left and right arms that are parallel to each other and have the same structure.In one arm group, the first arm (51) is the base arm. The end is supported by a connecting plate (28) so as to be able to swing horizontally and vertically, and the holder (H) is supported by a shaft at the tip.
A second arm (52) is pivotally supported at the base end by a fifth nut so as to be able to swing horizontally and vertically, and is pivotally supported at the distal end at the center in the longitudinal direction of the first arm. The base end of either arm is operatively connected to an X-movement control motor (17) to swing left and right. An industrial robot characterized in that the other arm group is configured to follow the movement of the one arm group. (2) The industrial robot according to claim 1, wherein a sub-arm is arranged in parallel with the positive arm to maintain the verticality of the holder.