JPS63207584A - 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 Field of the Invention The present invention relates to an industrial robot, and more particularly to an industrial robot configured to reduce the weight of an arm and to save installation space.

Conventional technology For example, an industrial robot that has an arm swingably attached to the top of a support that stands up on a rotating table is equipped with a balance mechanism to prevent the arm from rotating downward due to its own weight. . An example of this type of balance mechanism is one in which a connecting member connected to a link parallel to the column is provided at the rear of the arm, and one end of a spring member is locked at one end to the connecting member, and the other end is locked to the arm. There is.

Another balance mechanism is one in which a link is provided at the rear of the arm parallel to the column, and a pair of spring members that are individually locked to the link and column rotate and bias the link and column in opposite directions. .

Problems to be Solved by the Invention However, in the former case, the above-mentioned conventional industrial robot has a problem in that the spring member is provided on the arm, which increases the weight of the arm, and furthermore, the support column has to be rotated to the front. If the movable arm also rotates downward by more than 90 degrees from the horizontal position, there is a problem in that the positional relationship between the column and the link may be reversed. In addition, in the case of the latter of the above-mentioned industrial [] hohora, in order to lock the other end of the spring member that biases the link and the support respectively to the surrounding fixed part,
There is a problem in that the spring member protrudes from the rotating table and requires a large installation space.

Therefore, an object of the present invention is to provide an industrial robot that solves the above problems.

Means and Function for Solving Problems The present invention provides the above-mentioned industrial robot, in which a rotating body rotationally driven by the output shaft of a motor is connected to an arm, and the arm is rotated as the rotating body rotates. The rotating body and the urging means are provided on the swivel base, which reduces the weight and size of the arm. It was designed to achieve this.

Embodiment FIGS. 1 and 2 show an embodiment of the industrial robot according to the present invention. In both figures, an industrial robot 1 is a playback type electric robot that performs painting work, sealing work, etc., for example. The industrial robot 1 generally has a structure in which a turning table 3 is provided on a base 2, a column 4 is supported on the turning table 3, and an arm 5 is provided on the upper end of the column 4 so as to be swingable in the direction of arrow A. . The support column 4 is rotatably supported between brackets 6.7 on the turning table 3 in the direction of arrow B, and a motor 8. for arm driving is mounted on the side of the bracket 6.7. A motor 9 for driving the column is provided.

Further, the support column 4 is held in a balanced manner by the tensile force of a coil spring 10.11 secured to the bracket 6.7. At the rear of the column 4, there is a drive machine 11 having a motor and a speed reduction mechanism for driving the wrist mechanism 12 at the tip of the arm 5.
3 is a provision.

As shown in Figure 3.4, a balance [4] is provided between the brackets 6 and 7 on the rotating table 3 to prevent the arm 5 from rotating in the direction of lowering the tip due to its own weight.
-14 is provided. Further, the balance mechanism 14 holds the arm 5 via a pair of links 15 and 16 whose upper ends are connected to pins 5a+ and 5a2 of the rotating portion 5a of the arm 5. A first sprocket 18 is provided on the output shaft 17 driven by the motor 8 for driving the arm, and bins 19a and 19b provided integrally with the first sprocket 18 have lower ends of the links 15 and 16. are connected. Further, both ends of the links 15 and 16 are connected at positions shifted by an angle of 90 degrees. Therefore, a pair of links 15. '16 is the drive of the motor 8)] is transmitted to the arm 5 to rotate the arm 5, and at the same time, the biasing force of the balance mechanism 14 is applied to the arm 5.

As shown in FIG. 5.6, a second sprocket 20 is provided below the first sprocket 18. The second sprocket 20 has the same diameter and the same number of teeth as the first sprocket 18, and a chain 21 is wound between the sprockets 18 and 20. Note that the rotation @22 of the sprocket 20 is supported by a bearing portion 23 on the turning table 3.

Numerals 24a and 24b are bins provided integrally with the sprocket 20, and are provided at positions eccentric from the rotating shaft 22. 25.26 is a spring with pins 24a and 2 at one end.
A hooking portion 25a at the other end is connected to the connecting members 27a and 27b that fit into the connecting member 4b.

26a is a bracket 28a on the turning table 3.

28b, and its tensile force urges the rotating shaft 22 to rotate clockwise (as shown in FIG. 6).

Therefore, the biasing force of the coil springs 25 and 26 is the pin 24a,
24b, suf0ket20. It acts on links 15 and 16 through chain 21 and sprocket 18. Therefore, the arm 5 is held in its current rotational position by the tensile force of the coil springs 25,26. Note that the balance mechanism 14 includes the first sprocket 18, the chain 21,
Second sprocket 20. Rotating shaft 22, pin 24a.

24b and coil springs 25 and 26.

Therefore, the arm 5 is not provided with a spring member for holding the arm 5, so that the arm 5 can be made lighter and smaller. In addition, since the coil springs 25 and 26 are installed compactly within the turning table 3, there is no problem of the spring members protruding to the surroundings and increasing the installation space of the industrial robot, which is the case with conventional methods, and space saving is possible. It is planned.

Further, since the coil springs 25 and 26 are suspended horizontally on the turning table 3, they do not get in the way, and the balance mechanism 14 is installed compactly within a limited space on the turning table 3.

Next, the operation of the balance mechanism 14 as well as the operation of the industrial I-bots 1 to 1 having the above structure will be explained.

In FIG. 4, when the arm 5 is in a horizontally extending position, the pins 24a and 24b are located above the rotating shaft 22. The coil springs 25 and 26 bias the second sprocket 20 in the opening direction by their tensile force, and bias the first sprockets 1 to 18 in the same direction via the chain 21. Therefore, while the arm 5 attempts to rotate counterclockwise due to its own weight, the rotating portion 5a of the arm 5 is urged to rotate clockwise by the links 15 and 16 connected to the first sprocket 18. . In this way, the balance mechanism 14
Since the tensile force of the coil springs 25 and 26 is acting on the rotating part 5a, the biasing force of the coil springs 25 and 26 and the arm 5
balance with its own weight.

That is, the arm 5 is prevented from rotating counterclockwise by the biasing force of the balance mechanism 14, and is stably held in a horizontal state.

Next, when the motor 8 is activated and the output shaft 17 is driven, the driving force is transmitted to the rotating portion 5a of the arm 5 via the links 15, 16. Therefore, when the first sprocket 18 rotates counterclockwise, the arm 5 rotates counterclockwise as shown by the dashed line in FIG. 4, thereby moving the wrist mechanism 12 downward. In this case, the rotation of the first sprocket 18 is transmitted to the sprocket 20 via the chain 21, and the sprocket 20 rotates in the counterclockwise direction. Therefore, the coil springs 25 and 26 are further tensed, and the force acting on the arm 5 becomes larger. Therefore, even if the arm 5 rotates downward from the horizontal direction, the arm 5 is stably held at the downwardly rotated position.

Further, when the first sprocket 18 rotates in the cutting direction, contrary to the above, the arm 5 further rotates clockwise from the horizontal position in FIG. 4, and the wrist mechanism 12 at the tip moves upward. In this case, the sprocket 20 rotates clockwise as the sprocket 18 of the box 1 rotates. Therefore, coil spring 2
5.26 tensile forces are relieved. Therefore, the arm 5 rotates clockwise and the force that tries to rotate the arm 5 downward is reduced, but the spring force of the coil springs 25 and 26 is also relieved, so that the biasing force of the coil springs 25 and 26 is reduced. The balance of arm 5 is maintained without becoming excessive. As a result, even when the arm 5 is rotated upward, it is stably held at that rotational position by the biasing force of the balance mechanism 14.

Further, as shown in FIG. 7, the support 4 may be tilted counterclockwise and the arm 5 may be rotated counterclockwise. In this case, since not only the arm 5 but also the support column 4 has rotated, the arm 5 has rotated counterclockwise by 90 degrees or more from the horizontal position shown in FIG. 4.

Therefore, a force is applied to the arm 5 due to its own weight to cause it to rotate clockwise. However, coil spring 25.
26 is connected to the pin 24a.

24b is the arm 5 from above the rotating shaft 22 shown in FIG.
It rotates counterclockwise by approximately the same angle as the rotation angle of , and is located below the rotating shaft 22. Therefore, the second sprocket 20
is rotated counterclockwise by the tensile force of coil springs 25, 26, and arm 5 is also rotated by chain 21. Sprocket 18. It is pivoted counterclockwise via links 15,16. Therefore, when the arm 5 rotates 90 degrees or more counterclockwise from the horizontal position, the tensile force of the coil spring acts to urge the arm 5 to rotate counterclockwise.
Arm 5 is held stably.

Note that when the pins 24a, 24b rotate approximately 90 degrees counterclockwise from the upper position of the rotating shaft 22, the pins 24a, 24b
is the hooking portion 25a between the rotating shaft 22 and the coil spring 25°26,
It is located at the dead center on the line connecting 26a. However, since the arm 5 also rotates 90 degrees from the horizontal position and extends in the vertical direction, no rotational force due to its own weight acts on the arm 5. Therefore, when the bins 24a and 24b are displaced to the dead center position of the sprocket 20, the arm 5 is set to be in a vertical state, so there is no problem.

In the above embodiment, in the balance mechanism 14, the tensile force of the coil springs 25, 26 is transferred to the second sprocket 20.
Chain 21. Although the power is transmitted via the first sprocket, the transmission is not limited thereto, and may be transmitted by meshing a plurality of gears, for example.

Further, in the above embodiment, the pair of links 15, 16 are used to rotationally displace the arm 5 and apply the biasing force of the coil spring 25, 26 to the arm 5, but the present invention is not limited to this. Alternatively, the arm 5 may be driven by

Effects of the Invention As described above, the industrial robot according to the present invention has a biasing means for holding the arm on the swivel base. It is possible to reduce the weight and size of the device, and since the spring member that holds the arm does not protrude to the surroundings as in conventional devices, the installation space can be saved.

Furthermore, by setting the arm so that it rotates vertically when the connection position of the spring member reaches the dead center, the arm can be rotated even if the arm rotates more than 90 degrees downward from the horizontal position. It has features such as being able to be stably held in a moving position.

[Brief explanation of the drawing]

1 and 2 are a side view and a rear view of an embodiment of the industrial one-pot device according to the present invention, FIG. 3 is a rear view showing a mechanism for driving an arm, and FIG. 5 and 6 are plan views and side views showing the configuration of the balance mechanism, respectively, and FIG. 7 is a side view for explaining in detail, and FIG. 7 is for explaining the operation when the arm is rotated downward by 90 degrees or more. FIG. 1...Industrial robot, 3...Swivel table, 4...
...Strut, 5...Arm, 6,7...Bracket,
8, 9...Motor, 14...Balance mechanism, 15.
16...Link, 17...Output shaft, 18...First
sprocket, 20...second sprocket, 21
... Chain, 22 ... Rotating shaft, 25.26 ...
coil spring. Patent applicant: Tokiko Co., Ltd. Figure 3 Figure 4 Figure 6 Special opening, mG3-207584 (6) Rod Figure 7 (゛\, 16 4 \■ 518゛\ii

Claims (1)

[Claims] An industrial robot comprising a support that swings upright on a swivel base, an arm that is rotatably mounted on the top of the support, and a motor that is installed on the swivel base and drives the arm, a rotating body rotationally driven by the output shaft of the motor;
a connecting member that connects the rotary body and the arm and rotates the arm as the rotary body rotates; and an urging means that biases the rotary body so that the arm does not displace due to its own weight; An industrial robot characterized in that the rotating body and the urging means are provided on the rotating base.