JPH07116979A - Manipulator for heavy object - Google Patents

Abstract

PURPOSE:To attain high accurately and surely handling a heavy object by forming two parallel direct acting links, whose length can be adjusted, in a set, arranging three sets of these links in a triangular shape, and providing a driving part for independently adjusting respective lengths of three sets of the parallel links. CONSTITUTION:A fixed plate 1 of equilateral triangle and a movable plate 10 of similar figure, arranged parallelly with a space apart relating to the fixed plate 1, are connected to each other by three sets of parallel link mechanisms provided in a top position of each triangle. That is, in a side of the fixed plate 1, in one top position (also the other top position is the same), a link receiving supporting equipment body 3a is rotatably supported by a swivel supporting bearing 2a, and two pinion gears 4a are provided in the supporting equipment body 3a. On the other hand, in a side of the movable plate 10, a similar supporting bearing 11a and supporting equipment body 9a are provided, and two direct acting links 5a, 6a are parallelly provided between both the supporting equipment bodies 3a, 9a, to stop one end of these links by a pin to the supporting equipment body 9a and to mesh a rack part 12a in another end with the pinion gear 4a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manipulator for handling a heavy object, and more particularly to a lightweight and highly rigid manipulator for a heavy object.

[0002]

2. Description of the Related Art First, as manipulators of this type, JP-A-3-264280 and JP-A-4-3588 are known.
What is shown in Japanese Patent Publication No. 3 is disclosed. These are suitable for high-speed motion because the displacement control of the fixed plate and the movable plate is performed only by the rotary joint type, but a large torque is generated in the joint portion with respect to a large output, so this is endured. Is difficult.

Further, as a manipulator for performing high-accuracy position control with high output, a structure in which six parallel links are appropriately arranged is disclosed in JP-A-3-294193. The basic link structure of this manipulator is as shown in FIG. 6, but in the case of heavy object handling, it is not necessary to use such a complicated mechanism of 6 degrees of freedom, and at most 3 degrees of freedom or 4 degrees of freedom is required. It is enough.

Further, multi-joint type robots are generally known as general-purpose robots. However, since the shoulder, elbow and wrist joints are usually connected in series, a large load is applied to the joint corresponding to the shoulder. It takes a lot of weight (all the weights of the wrist and elbow are on the shoulder), and it is difficult to handle a large load. For this reason, a proposal has been made for compensating for gravity using a balancer, but there is a problem that the device becomes bulky and the system becomes complicated and expensive.

[0005]

In any case, the conventional manipulators and robots have a structural or cost problem when handling a heavy object, which is a highly practical and structurally simple manipulator that solves this problem. Was requested.

The present invention has been made in view of the above circumstances, and provides a compact, high-power manipulator that enables heavy-weight handling, is lightweight, has high rigidity, and is capable of highly accurate and reliable operation. With the goal.

[0007]

SUMMARY OF THE INVENTION The gist of the present invention is to provide two parallel linear motion links with adjustable lengths.
Sets of three sets are arranged in a triangular shape to pivotally support between the fixed part and the movable part, and a link part is provided as a drive part for independently adjusting the lengths of the three sets of parallel links. The manipulator for heavy articles is characterized in that the movable part is provided at a position such that it can be moved to any x, y, z position.

In the present invention, it is also possible to provide the movable plate with a rotation drive system for rotating the movable plate around the z-axis to give the movable plate a movement of four degrees of freedom. In addition, since a highly accurate mechanism is required for the driving unit of the parallel link, for example, a pinion gear is rotated by a motor and transmitted to a rack provided on the link side to expand or contract the link. The screw may be rotated with to transmit this as expansion and contraction of the link via the nut.

[0009]

[Operation] The two linear motion links of each of the three sets are parallel and extend / contract by the same amount to keep the movable plate in a posture parallel to the fixed plate and adjust the length of each of the three sets independently. Therefore, the movable plate can be moved to any x, y, z position within a certain range. Moreover, since a plurality of links support the plates and support the force as an axial force instead of a torque, and at the same time, the drive system can be arranged on the fixed portion side, it is lightweight, has high rigidity, and can exert a large output.

[0010]

Embodiments will be described below with reference to embodiments shown in the drawings. Figure 1
As shown in FIG. 3, the fixed plate 1 having an equilateral triangle shape and the movable plate 10 having a similar shape and arranged in parallel with the fixed plate 1 at intervals are three parallel links provided at the apexes of each triangle. They are connected to each other by a mechanism. Since each parallel link mechanism has the same structure,
For convenience, one of the mechanisms (a is added to the reference numeral) will be described.

First, a rocking support bearing 2a is fixed to the fixed plate 1 at its apex position, and a link receiving support case is provided on the support bearing 2a so as to extend outward along the bisector of the apex angle. 3a is pivotally supported, and two pinion gears 4a are provided in the support casing 3a. The two pinion gears 4a are attached to the casing 3a via a distribution gear box 7a.
It is synchronously driven by the individual drive motors 8a. FIG. 2 shows a sectional structure of the support bearing 2 and the support casing 3.

On the other hand, a movable plate side swing bearing 11a and a support casing 9a are provided in the same state on the movable plate 10 side at positions corresponding to the swing support bearing 2a and the support casing 3a. However, no drive unit is provided.

Two linear motion links 5a and 6a are provided in parallel between the support casing 3a of the fixed plate 1 and the support casing 9a of the movable plate 10 described above, and one end of the link on the movable plate side is supported. Pinned to the housing 9a,
Further, a rack portion 12a that meshes with the pinion gear 4a in the fixed plate side support casing 3a is provided in a certain range of the link body on the other end side. Since one parallel link mechanism is configured in this way, by driving the drive motor 8a and rotating the pinion gear 4a, the lengths of these links 5a and 6a, that is, the support case 3a and the support case 3a, are increased. The distance from 9a can be adjusted arbitrarily.

Such a parallel link mechanism has the same structure as the other two.
It is also provided at the one vertex position. The other two link mechanisms are shown with reference numerals b and c. By independently controlling the lengths of the respective link portions of these three sets of parallel link mechanisms, the movable plate 10 is moved and adjusted with respect to any position in the xyz directions over a predetermined range (within the movable range of the link). It becomes possible to do. Moreover, since the two parallel links of each set move by the same amount by one drive source, the fixed plate 1 and the movable plate 10 are held in parallel, and the posture of the movable plate is always kept constant.

When the manipulator of the present invention is applied to an actual device, the movable plate 10 is provided with a jig or tool for holding or gripping a target heavy object, and the fixed plate is hung and moved by another appropriate means. It is attached to the means and used in the field.

FIG. 3 is a schematic view showing another embodiment of the present invention, which is an example of a parallel link mechanism using a slide bearing portion and a screw / nut expansion / contraction driving portion. One end (lower end) of two link arms 5 and 6 is pinned to the side of the supporting housing 3 which is axially supported by the fixed portion, and slide arms 15 and 16 are combined with the link arms so as to be slidable in the axial direction.
One end (upper end) of the slide arm is pinned to the side of the support housing 9 pivotally supported by the movable plate 10, and the lower end of the slide arm is attached to the nut 1.
9, a screw 18 that meshes with the nut 19 is attached to a motor 8 that is axially supported by the support housing 3 on the fixed side.

Even with the parallel link mechanism shown in FIG. 3, if the drive motor 8 is driven to rotate the screw 18 and move the nut 19, the positional relationship between the link arm and the slide arm is relatively large. Change. By changing the positional relationship of each of the three link mechanisms, the xyz of the movable plate 10 can be changed similarly to the mechanism of FIG.
It is possible to adjust the position in the direction.

FIG. 4 shows an example in which the parallel link mechanism of FIG. 3 is further provided with a link tilt synchronizing mechanism. That is, the slide arms 15 and 16 and the nut 19
The fixed gears 20 and 21 are provided around the point where they are connected to each other.
2 is interposed. Since the fixed gears 20 and 21 reliably rotate in the same direction by the same amount by this tilt synchronizing mechanism,
A highly accurate link tilting motion can be obtained. In addition,
This parallel link tilt synchronizing mechanism is not essential, and the arrangement is not limited to the nut portion, and it is also possible to arrange the parallel link mounting portion on another fixed plate or movable plate portion.

In the example of FIG. 1, the parallel link is installed at the apex position of the triangle. However, the present invention is not limited to this, and the parallel link is installed at the side of the triangle as shown in FIG. May be. In this case, the mounting direction of the parallel link is different from that in FIG. 1, but in principle, the position adjustment in the xy directions is the same.

Further, in the illustrated example, the manipulator capable of obtaining the movement of three degrees of freedom in the xyz directions is shown.
In the present invention, a manipulator having four degrees of freedom capable of rotating around the z axis may be used. In this case, a z-axis turning drive system may be provided on the movable plate, a drive motor may be installed on the fixed plate, and they may be connected by a universal shaft.

[0021]

As described above, according to the manipulator of the present invention, the following effects can be expected. Since it is sufficient to have three drive systems for three degrees of freedom and four drive systems for four degrees of freedom, it is possible to configure a lightweight, highly rigid and high output manipulator. Since the movement of the movable part is always in parallel with the fixed part, the conversion matrix for posture control can be a simple multi-degree-of-freedom mechanism, and 3 or 4 degrees-of-freedom handling of heavy objects can be performed with high precision in a small space. be able to. Within the movable range of the link, it can be easily moved to any position in the xyz direction, which is very practical.

[Brief description of drawings]

FIG. 1 is a bird's-eye view showing an embodiment of the present invention which adopts a rack and pinion type expansion / contraction mechanism.

FIG. 2 is a cross-sectional view of a movable plate swing support portion in FIG.

FIG. 3 is a schematic view showing an example of a parallel link portion of the present invention using a slide bearing.

FIG. 4 is an explanatory view showing an example in which a tilt synchronizing mechanism using gears is adopted in the parallel link portion of FIG.

FIG. 5 is a schematic diagram of an embodiment of the present invention in which a parallel link mechanism is arranged on the sides of a triangle.

FIG. 6 is a schematic view showing a conventional 6-DOF manipulator.

[Explanation of symbols]

 1 Fixed Plate 2, 11 Support Bearing 3, 9 Support Housing 4 Drive Unit 5, 6 Direct Link 7 Distributed Gear 8 Drive Motor 10 Movable Plate 15, 16 Slide Arm 18, 19 Screw Nut 20, 21 Fixed Gear 22 Connection gear

Claims (3)

[Claims] 1. A set of two parallel / linear motion links each having an adjustable length, three sets of which are arranged in a triangular shape to pivotally support a fixed part and a movable part, and A manipulator for heavy goods, characterized in that a driving unit for independently adjusting the length of each of the three sets of parallel links is provided in the link unit, and the movable unit can be moved to any x, y, z position. . 2. The manipulator according to claim 1, wherein the movable plate is provided with a turning drive system for rotating the movable plate around the z-axis. 3. The manipulator according to claim 1, wherein the drive unit for adjusting the length of the parallel link is a motor provided on the fixed unit side and a rack and pinion or a screw nut.