JPH0215352B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrial robot having a multi-jointed arm.

Conventionally, various types of industrial robots have been proposed. By the way, when the free end of the robot comes into contact with other equipment due to an unexpected cause, if the support relationship between the various parts of the robot is strong, the operating elements supported by the free end of the robot, the various parts of the robot, and various equipment will be damaged. etc., may be damaged.
For this reason, there is a desire for a robot equipped with safety devices to prevent damage to various parts, but a practical industrial robot has not yet been realized.

An object of the present invention is to provide an articulated arm type industrial robot equipped with a safety device to prevent damage to each part.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

In FIGS. 1 to 4, reference numeral 1 denotes a base plate supported by a fixed member 2 so as to be able to rotate in the horizontal direction by a drive machine (not shown); 3 and 4 are first fulcrums for the base plate 1; A lower arm and a link lever are rotatably supported around ₁ , a rear arm 5 is rotatably supported by a link lever 4, 6 is a second fulcrum at the other end of the lower arm 3; around O ₂ This upper arm 6 is rotatably supported by the other end of the rear arm 5, and the upper arm 6, lower arm 3, link lever 4, and rear arm 5 form a parallel link mechanism. is formed. 7 is attached to the free end of the upper arm 6.
Fulcrum: Joint member supported rotatably around O ₃ ; 8 is a third fulcrum; fourth fulcrum approximately perpendicular to O ₃ ; supported by joint member 7 so as to be rotatable around O ₄ . For example, the operating element 8 includes a support member 81 and an operating tool 82. Of course, the operating tool 82 may be an assembly tool, a paint spray gun, a welding gun, or a cutting tool for performing appropriate work, or may also include an adjustment mechanism that allows the positions of these tools to be adjusted as appropriate. Can be done. The joint member 7 and the operating element 8 are configured such that their relative rotational states can be set as appropriate by a pressurizing mechanism 11, which will be described later. For example, the operating element 8 is rotatably supported by the joint member 7, and the operating element 8 and the joint member 7 are brought into contact with each other by a spring member 9. Further, the contact surfaces of the joint member 7 and the operating element 8 may be engaged with each other, for example, a groove 101 disposed on the joint member 7 side and a groove 101 disposed on the operating element 8 side may be engaged with each other. An engaging portion 10 consisting of a protrusion 102 is provided. A pressurizing mechanism 11 is constituted by the spring member 9 and the engagement member 10.
12 and 13 are first and second rotary drive machines supported by the base plate 1, and the lower arm 3 is rotated by the first rotary drive machine 12 via a reduction gear with the _first fulcrum; The upper arm 6 is rotated in the front-rear direction, and the upper arm 6 is rotated by the second rotary drive machine 13 via a speed reducer. 2 fulcrums: Swivels up and down with _O2 as the center of rotation. 14 and 17
are first and fourth rotation transmitting members separated from the lower arm 3 and upper arm 6, respectively, and this rotation transmitting member 1
4 and 17 are rotatably supported around a first fulcrum; O ₁ and a third fulcrum; O ₃ , respectively.
15 and 16 are separated from the lower arm 3 and upper arm 6 as a second fulcrum; second and third rotation transmitting members are integrally rotatable around O ₂ ; 18 and 19 are a first rotation transmission member; Between the transmission member 14 and the second rotation transmission member 15 and the third rotation transmission member 16
and the fourth rotation transmitting member 17, and 20 and 21 are first and second spring means, and the first spring means 20 is connected to each of the first and second fulcrums. The second spring means 21 is disposed, for example, on the left side from the first fulcrum toward the second fulcrum on a plane perpendicular to the axis, and the second spring means 21 is arranged on a plane perpendicular to the axes of the second and third fulcrums. It is disposed on the right side from the second fulcrum on the top toward the third fulcrum. That is, in FIG. 2, the first and second
The spring means 20 and 21 are arranged at positions on the same side of the first fulcrum and the third fulcrum, respectively, with the second fulcrum as a reference. Furthermore, as detailed in FIG. 4, these spring means 20 and 21 are provided with a so-called turnbuckle mechanism 201, so that the urging force applied to the coupling member can be adjusted. A winding transmission device 22 is constituted by the above 14 to 21. Note that the joint member 7 is the fourth
It is supported so as to rotate integrally with the rotation transmission member 17 of. Further, the first rotation transmission member 14 is appropriately supported on the base plate 1, and in the illustrated case, it is fixedly supported on the base plate 1. Furthermore, in the above, the first to fourth rotation transmission members 14 to 17 are, for example, chain sprockets each having the same number of teeth, and the first and second coupling members 18 and 19 are chains. In this case, in order to minimize the effect of chain elongation,
It is preferable to provide connecting rods 181 and 191 in sections other than the required length.

In the above configuration, a case will be described in which the lower arm 3 is rotated clockwise by an angle α around the first fulcrum _O1 as the rotation center by the first rotary drive machine 12.
It is assumed that the first rotation transmission member 14 is fixedly supported by the base plate 1. Also, for ease of explanation, only the lower arm 3 is tilted, and the second arm for the upper arm 6 is tilted.
It is assumed that the rotary drive machine 13 is maintained in a non-driving state. In this case, since the link lever 4 is maintained in a stationary state, the lower arm 3, the rear arm 5, and the upper arm 6 perform parallel movements with the link lever 4 as one fixed side. That is, the lower arm 3 tilts clockwise by an angle α about the first fulcrum _O1 . In this case, the first rotation transmission member 14 is fixed to the base plate 1, and the second and third rotation transmission members 15 and 16 are rotatably supported around _{the second} fulcrum; In FIG. 2, the first connector 18 in the _Y2 direction is wound around the first rotation transmitting member 14, and the one in the _Y1 direction is unwound from the first rotation transmitting member 14. becomes. That is, the first coupling member 18 moves as if the first rotation transmission member 14 was rotated counterclockwise by an angle α. Therefore, the second and third rotation transmitting members 15 and 16 rotate counterclockwise around the second fulcrum O ₂ at an angle α
Rotate only. As the third rotation transmission member 16 rotates, the fourth rotation transmission member 17 and the joint member 7
It also rotates counterclockwise by an angle α with the third fulcrum O ₃ as the center of the circle. That is, the rotation angle of the adjustment member 7 in the clockwise direction with respect to the initial state; Δ ₁ is Δ ₁ =−α (1) By the way, as shown in FIG. 1, the lower arm 3 and the upper arm 6 are approximately perpendicular to each other. When the lower arm 3 is tilted clockwise by an angle α, the upper arm 6 is moved in parallel while maintaining the initial state, for example, the horizontal state. In other words, the angle between upper arm 6 and lower arm 3 is 90°+
becomes α. In this state, the upper arm 6
the second fulcrum; angle counterclockwise around O ₂ ;
This is equivalent to a state rotated by α. In this way, when _the upper arm 6 rotates counterclockwise around the second fulcrum;
Of these, the one in the _Z1 direction is the third rotation transmission member 14
, and the one in the Z ₂ direction is wound around the third rotation transmission member 16 .

That is, the second connector 19 moves as if the third rotation transmitting member 16 was rotated clockwise by an angle α. Therefore, the fourth rotation transmission member 17 and the joint member 7 serve as the third fulcrum;
Rotate clockwise by an angle α around O ₃ . That is, the rotation angle of the joint member 7 in the clockwise direction with respect to the initial state; Δ ₂ is Δ ₂ = α ... (2) In the end, the lower arm ₃ is the first fulcrum; If the angle in the clockwise direction at which the joint member 7 actually rotates when tilted is Δα, then
From equations (1) and (2), Δ〓=Δ ₁ +Δ ₂ =O...(3).

Next, a case will be described in which the upper arm 6 is rotated clockwise by an angle β around the second fulcrum O ₂ . In this case, the first rotary drive machine 12 is maintained in a non-driven state, and the lower arm 3 is maintained in its initial state. Now, when the link lever 4 is rotated clockwise by an angle β by the second rotary drive device 13,
The link lever 4, the rear arm 5, and the upper arm 6 operate in parallel with the lower arm 3 as one fixed side, and the upper arm 6 tilts clockwise by an angle β about the second fulcrum _O2 . In this case, the first rotation transmission member 14
is fixed to the base plate 1, so the second and third
The rotation transmitting members 15 and 16 do not rotate.

In this way, the second and third rotation transmission members 15
If the upper arm 6 rotates by an angle β in the clockwise direction when the upper arm 6 and 16 are in the fixed state, the second connector 19 The movement is the same as when the third rotation transmission member 16 rotates by an angle β in the counterclockwise direction about the second fulcrum O ₂ . Therefore, the fourth rotation transmitting member 17 and the joint member 7 rotate by an angle β in the counterclockwise direction with respect to the upper arm 6.

In other words, when the upper arm 6 rotates by an angle β in a clockwise direction about the second fulcrum O ₂ , the fourth rotation transmitting member 17 and the joint member 7 rotate by an angle β in a counterclockwise direction with respect to the upper arm 6. Since the joint member 7 rotates, the posture of the joint member 7 is maintained in the same state as before the upper arm 6 rotates.

In the above, it goes without saying that even if the lower arm 3 and the upper arm 6 are rotated at the same time, the result will be the same as a combination of their respective rotation states.

Next, a case will be described in which the free end of the robot comes into contact with other equipment due to an unexpected cause. In FIGS. 1 and 2, when a clockwise force at the _third fulcrum; It acts in a direction to rotate the connector 19 and the third rotation transmission member 16 clockwise. As a result, the second rotation transmission member 15,
First connector 18 and first rotation transmission member 14
It also acts in a direction that rotates each clockwise.

By the way, since the first rotation transmission member 14 is arranged in a fixed state with respect to the base plate 1, it is expanded by the first spring means 20 and the second rotation transmission member 1 is expanded.
5 rotates clockwise. In this case, the second spring means 21 is arranged so that the third rotation transmission member 16 can rotate clockwise together with the second rotation transmission member 15.
The part also grows. Further, when a counterclockwise force from the _third fulcrum; act in a direction that causes movement. In this case, the second spring means 21 expands and the fourth rotation transmission member 17 rotates counterclockwise.

In the above, when the clockwise or counterclockwise acting force on the _third fulcrum; No sudden forces are applied, so there is no risk of damaging the parts of the robot and the equipment that abuts the free end of the robot.

Of course, the spring means 20 and 21 are provided with a turnbuckle mechanism 201 that can freely adjust the spring force as shown in FIG. The force can be adjusted freely.

Furthermore, in the above, the directions in which the first and second spring means 20 and 21 are expanded when a force greater than the allowable setting force is applied are fixed, respectively.
Connectors 1 are placed at predetermined positions on the lower arm 3 and upper arm 6, respectively.
Detection means 23 for detecting the positions of 8 and 19;
24 is provided, and by stopping the operation of the robot based on the output signals of the detection means 23 and 24, and activating appropriate alarm means, an abnormal state can be detected.

Further, the provision of the pressurizing mechanism 11 is advantageous when an acting force around the fourth fulcrum; O ₄ acts on the operating element 8 . That is, when an acting force is applied around the _fourth fulcrum; While rotating, the element 8 moves in the _Y1 direction by an amount corresponding to the height h of the protrusion 102. Of course, this state can be detected by means 25
It can be learned by Therefore, the various parts of the robot and other equipment will not be damaged. By arranging the winding transmission device 22 and the pressure mechanism 11 in this way, the force acting on the operating element 8 can be applied around the third fulcrum and the fourth fulcrum in almost any direction except for a specific direction. It can be broken down as an acting force,
Moreover, when the acting force around the third and fourth fulcrums exceeds the set force, each part of the robot automatically displaces, so there is no risk of damage to the parts of the robot and various equipment.

Also, as shown in Figure 2, the first and second
With respect to the connector, first and second spring means 20 and 21 are located at positions on the same side, respectively, toward the first fulcrum and the third fulcrum with respect to the second fulcrum.
, it is easy to adjust the respective spring forces in order to separately support the clockwise and counterclockwise acting forces around the third fulcrum O ₃ .

Specifically, if the first connector and the first spring means and the second connector and the second spring means are configured in substantially the same state, the influence on the operating element 8 is reduced. It is more effective because it cancels out the effects.

That is, if the first connector 18 is extended by ΔL, one side of the first connector 18, which is being pulled by the first spring means 20, is wound around the fixed first rotation transmitting member 14. Because the rotatable second connector is wrapped around the other end of the first connector 18,
The rotation transmitting member 15 is rotated counterclockwise by an angle Δψ corresponding to ΔL. Accordingly, the third and fourth rotation transmitting members 16 and 17 also rotate counterclockwise by Δφ.

On the other hand, if the second connector 19 is extended by ΔL, one side of the second connector 19 that is being pulled by the second spring means 21 is wrapped around the third rotation transmitting member 16 that is in a fixed state. On the other hand, the other end of the second connector 19 has a rotatable fourth
Since it is wound around the rotation transmission member 17 of the fourth
The rotation transmitting member 17 is rotated clockwise by an angle Δφ corresponding to ΔL. When the first and second connectors 18 and 19 are extended by the same amount in this way, the rotational state of the fourth rotation transmission member 17 is offset and the initial state is maintained. The articulation member 7 and the operating element 8 are therefore connected to the first and second couplings 18,
Even if 19 are each expanded by the same amount, they are maintained in the initial state. Therefore, when considering an actual robot, the arrangement state of the first and second rotation transmission members 14 and 15 with respect to the lower arm 3, the arrangement state of the third and fourth rotation transmission members 16 and 17 with respect to the upper arm 6, and First connector 18 and second connector 1
If 9 are arranged in the same way, for example, the first fulcrum;
O ₁ and the second fulcrum; _the distance between O ₂ and the second fulcrum;
If the distance between O ₂ and the third fulcrum; O ₃ is L ₂ , then L ₁ = L ₂ , and the first connector and the first spring means,
If the second connector and the second spring means are configured in the same state, the displacements of the first and second connectors due to changes in atmospheric temperature, etc. will be approximately the same;
Therefore, regardless of these variations, the joint member 7 and the operating element 8 are maintained in their initial states, making it possible to realize a so-called high-grade industrial robot. Note that even if the above-mentioned distances L ₁ and L ₂ are, for example, L ₂ >L ₁ , a change corresponding to L ₂ −L ₁ of the second connector 19 on the upper arm 6 side will cause the attachment state of the operating element 8 to be finely adjusted. However, in order to offset the displacement corresponding to the length of L ₁ of the upper arm 6 and lower arm 3, some error in the mounting state of the operating element 8 is allowed, and it can be used as a so-called low-grade industrial robot. Can be done.

FIG. 5 is a diagram showing another embodiment of the present invention, which has substantially the same structure as the embodiment shown in FIGS. 1 to 4. The difference is that the lower arm 3 and upper arm 6 are respectively the first fulcrum; O ₁ and the second fulcrum; O ₂
The first and second drive mechanisms for rotating the base plate 1 are each constituted by a hydraulic cylinder, and the base plate 1 is rotated in a direction perpendicular to the plane of the paper, for example.
That is, it is mounted on a cart 26 that is movable in the X direction. In this device as well, even if one or both of the first and second drive mechanisms 27 and 28 is operated, the tilting movement of the upper arm 6 or the lower arm 3 is Since the posture of the joint member 7 is automatically corrected, the joint member 7 is maintained in its initial state. Furthermore, if the base plate 1 is mounted on the cart 26 in this way, by determining the position of the cart in the X direction,
It is possible to move the joint member to an appropriate range of width in the Y direction and long in the X direction.In this case, of course, the base plate 1 shown in FIGS. 1 to 4 can be mounted on a trolley, Alternatively, the entire apparatus shown in FIGS. 1 to 4 can be mounted on a truck.

In the above description, the first to fourth rotation transmitting members may be pulleys having the same diameter, and the first and second connectors may each be tension belts.

Furthermore, by providing the wrap-around transmission device 22 in which the first rotation transmission member 14 is fixedly supported on the base plate 1 as described above, the joints and operating elements can be adjusted regardless of the rotational state of the lower arm and the upper arm. It operates so that the posture is maintained in the initial state. In spite of this, if the first rotation transmission member 14 is rotatably connected to a drive machine (not shown) and supported on the base plate 1, the joints can be moved only when the first rotation transmission member 14 is rotated appropriately. The postures of the members and operating elements can be changed with respect to their initial states. Furthermore, if the pressure mechanism 11 is constituted by the spring member 9 and the engaging part 10,
When the operating element 8 is not in the desired state, that is, in an abnormal state, the original state can be immediately restored by operating the engaging portion 10 to engage after learning this state. Despite this, the pressurizing mechanism 11 for appropriately setting the rotational state of the joint member 7 and the operating element may be a so-called torque limiter mechanism.
In other words, by bringing a face plate into contact with which the pressure can be adjusted,
Or shear a pin of appropriate diameter when excessive force is applied. It can have a so-called shear pin structure.

As described above, according to the present invention, the wrapped transmission device has the first
and a turnbuckle type spring means whose spring force can be freely adjusted by inserting a spring into each joint part of the second connector, and the first and second spring means are connected to the first and second connectors. Since the tool is placed at the same position on either side of the first fulcrum and the third fulcrum, with the second fulcrum as a reference, the joint members and operations can be easily performed without variations depending on the operator. The allowable setting force for the element can be freely adjusted. Of course, the first and second spring means
Since the clockwise and counterclockwise acting forces around the fulcrum O ₃ are carried separately, the spring forces of the first and second spring means can be adjusted separately and easily. Furthermore, even if an excessive force is applied to the tip of the robot in a clockwise or counterclockwise direction about the third fulcrum O ₃ , the connector can be expanded by either the first or second spring means. As a result, no sudden force is applied to the robot part, and therefore there is no risk of damaging the parts of the robot or other equipment. Furthermore, when the first and second connectors expand and contract due to temperature changes around the robot during operation of the robot, the first and second spring means cause the first and second connectors to expand and contract. Since most of the displacement is canceled out, the influence on the operating element 8 is minute.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a cross-sectional front view showing the main part of FIG. 1, and FIG.
FIG. 4 is a detailed sectional view of the "A" section in FIG. 2, and FIG. 5 is a front view showing another embodiment of the present invention. 1...Bedboard, 3...Lower arm, 6...Upper arm, 7...
Joint member, 8... operating element, 11... pressure mechanism,
14 to 17...first to fourth rotation transmission members,
18...first connector, 19...second connector,
20...first spring means, 21...second spring means, 22...wrap transmission device.

Claims (1)

[Claims] 1 The lower arm is arranged so as to be freely rotatable around a first fulcrum relative to the base plate, and the upper arm is arranged at the other end of the lower arm so as to be freely rotatable around a second fulcrum that is parallel to the first fulcrum. and a joint member is disposed at the other end of the upper arm so as to be rotatable around a third fulcrum parallel to the first fulcrum, and the lower arm and the upper arm are rotatable around the first fulcrum and the second fulcrum, respectively. In addition, a first rotation transmitting member is provided which is appropriately supported on the base plate so as to be concentric with the first fulcrum and is rotatable with respect to the lower arm, and a second rotation transmission member which is separated from the upper arm and is connected to the second fulcrum. second and third rotation transmission members that are integrally rotatable around a third fulcrum, and a fourth rotation transmission member that is rotatable around a third fulcrum and integrally connected to the joint member; It consists of first and second connectors disposed between the first rotation transmission member and the second rotation transmission member and between the third rotation transmission member and the fourth rotation transmission member, respectively. In a multi-joint arm type industrial robot equipped with a wrapped transmission device, the wrapped transmission device includes:
At each joint portion of the first and second connectors,
It has a turnbuckle type spring means whose spring force can be freely adjusted by inserting a spring, and the first spring means is arranged to move from the first fulcrum to the second fulcrum on a plane perpendicular to the axes of the first and second fulcrums. The second spring means is disposed at either the left or right position toward the fulcrum, and the second spring means is arranged at a position on either the left or right side toward the fulcrum, and the second spring means extends from the second fulcrum toward the third fulcrum on a plane perpendicular to the axes of the second and third fulcrums. An articulated arm robot characterized in that the robot is disposed at a position opposite to the spring means.