JPS6327156B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrial robot that appropriately controls the position of a driven member.

In general, industrial robots can appropriately control the position of driven members by, for example, rotating a rotary drive machine, but this state is only possible after the robot has been assembled and various adjustments have been completed. , there are problems during assembly, adjustment and repair. For example, in an articulated arm robot, if the electrical wiring is done in advance so that the rotary drive machine, such as an electric motor, can be driven when the robot is assembled, the electric motor may be accidentally driven when the mechanical rotation transmission mechanism is assembled. If this happens, there is an extremely high risk of causing personal injury, and for this reason, electrical wiring is usually not done until the assembly of each mechanical part of the robot is completed. Therefore, in order to operate each part of the robot during assembly, the operator must, for example, push or pull the articulated arm, which is extremely tiring and troublesome. Also, if you want to adjust the robot in the middle of electrical wiring, you will naturally not be able to drive unconnected motors, and there is also the possibility of a wiring mistake, so if you try to drive a specific motor prematurely, If the robot operates in an unexpected direction or other motors are driven, the tip of the robot may come into contact with other equipment or workers located near the robot, causing damage to other equipment or other parts of the robot. There was a high risk of causing personal injury. Furthermore, when repairing a robot or inspecting each part, there is a possibility that the driven member may be driven in an unexpected direction due to operator error or abnormality in the control device, which is a so-called runaway. It was extremely dangerous and the workability was poor. Therefore, it has been desired to be able to safely and easily drive the driven member of a robot in any desired state and to hold the driven member in any desired position.

SUMMARY OF THE INVENTION An object of the present invention is to provide an industrial robot that eliminates the above-mentioned conventional drawbacks and has particularly good workability.

The present invention will be explained in detail below with reference to the illustrated embodiments. 1 to 3, reference numeral 1 denotes a first rotary drive machine, such as an electric motor, supported by a first box 2, 4 an input shaft of a first reduction gear 6, 3 and 5
is for transmitting the rotation of the electric motor 1 to the input shaft 4,
For example, the bevel gear 7 is a bearing that supports one end of the first input shaft 4, and is attached to the first box body 2. 8
is a first braking means, for example, an electromagnetic brake, which is provided in the first box body 2 and brakes the first input shaft 4 into an appropriate rotational state. 9 is an output shaft of the first reducer 6; 10 is a first driven member, such as a lower arm, which is integrally supported by the first output shaft 9 at its lower end; 11 is a second box body 12; The supported second rotary drive machine 14 is a second reducer, and this second reducer 14 and the second rotary drive machine 1
1 is disposed between the first rotary drive machine 1 and the first speed reducer 6, and similarly connected by a transmission mechanism having a brake means. Reference numeral 13 denotes an input shaft of the second reduction gear 14. A free end 131 of the second input shaft 13 penetrates the second box body 12 and protrudes to the outside.The free end 131 has a cross section, for example. A rectangular notch is formed so that a handle for rotating the input shaft 13 can be attached and detached. Note that the free end 41 of the first input shaft 4 is also formed in the same manner. Reference numeral 15 denotes an output shaft of the second reduction gear 14. Bearings 16, 16 are disposed at the free end of the second output shaft 15, and the lower arm 10 and the second 2 output shaft 15
are coaxial and rotatable with respect to each other. Reference numeral 17 denotes a link lever in which one of its opposing surfaces is fixed to the second output shaft, and the other opposing surface is rotatably supported by the first output shaft 9 via a bearing 18. The rotational axes of the first and second output shafts 9 and 15 and the lower arm 10 are concentric. 19 is an underframe that supports the first and second box bodies 2 and 12; 20 is a link rod whose one end is rotatably supported by the free end of the link lever 17; and 21 is the link rod 20 and the lower arm 10. A second driven member, for example an upper arm, rotatably supported at each free end of the upper arm 21,
Lower arm 10 link rod 20 and link lever 1
7 constitutes a parallel link mechanism. 22
is a joint member supported by the free end of the upper arm 21,
This joint member 22 is fixedly or rotatably arranged with respect to the upper arm 21. For example, the joint member 22 includes an operating element 23 and a mechanism for appropriately pivoting the operating element 23 horizontally and vertically.

Next, the operation of the present invention will be explained.

As shown in the figure, each axis of the parallel link is a first fulcrum: O ₁ , a second fulcrum: O ₂ , a third fulcrum: O ₃ and a fourth fulcrum: O ₄ . It is also assumed that the robot is in the initial state shown in FIG. 1, and that the second output shaft 15 is not rotated. 1 to 4, when the first rotary drive machine 1 is driven in this state, the lower arm 10 moves to the first fulcrum: O ₁
Rotate, for example, clockwise around the center. If the control input to the first rotary drive machine 1 is cut off when the above tilting angle becomes α ₁ , that is, in the state shown in FIG. The lower arm 10 attempts to rotate clockwise around the first fulcrum: _O1 due to the weight of the arm 10, upper arm 21, etc. This force that causes the lower arm 10 to rotate acts on the first input shaft as an eccentric rotational force via the first reduction gear 6. By the way, the first electromagnetic brake 8 is arranged so as to brake the first input shaft 4 when the control power is turned off.
The eccentric rotational force acting on the input shaft 4 of the robot is canceled out by the braking force of the electromagnetic brake 8, and the robot
It remains stationary in the state shown in the figure. on the other hand,
Since the reduction ratio of the first reducer 6 is 1/100 to 1/250, when the rotational moment due to the above-mentioned eccentric load acting on the first output shaft 9 is about 10 kg-m. , the eccentric rotational force acting on the first input shaft 4 has a value of about several kg-cm at the maximum. Therefore, even if the braking force of the electromagnetic brake 8 is small, the tilting of the lower arm 10 can be restrained against the eccentric rotational force.
If you use one with a value of several kg-cm, the lower arm will be 10
Even if the control power is turned off during the tilting, the eccentric load is offset by the braking force of the electromagnetic brake 8, so the lower arm 10 remains stationary at any position regardless of the tilting state of the lower arm 10. Note that when the operating handle is attached to the free end 41 of the first input shaft and manually rotated with the control power turned off, the first input shaft 4 may be manually rotated by several tens of meters, depending on the effective radius of the handle. It is extremely easy to impart a rotational force of Kg-cm. That is, for example, if the effective radius of the handle is 5 to 10 cm and the operator rotates the handle with a force of 5 kg, the first input shaft 4
A rotational force of 25 to 50 kg-cm acts on the.

By the way, the lower arm 10 rotates counterclockwise from the state shown in FIG. 1 around the first fulcrum: O ₁ , and the rotational moment around the first fulcrum: O ₁ becomes zero, for example. Assuming that such a situation occurs, the first input shaft 4 is connected to the electromagnetic brake 8 by the number 10.
This means that the brake is applied with a braking force of Kg-cm.
In this case, as described above, when an operating handle is attached to the free end 41 of the first input shaft 4 and the handle is turned manually, a rotational force of several tens of kg-cm is imparted to the input shaft 4. It's extremely easy. Therefore, it is easy to operate the handle to rotate the input shaft 4 against the braking force of the electromagnetic brake 8, and therefore, regardless of the tilting state of the lower arm 10, it is possible to operate the handle even when the control power is turned off. Tilting the lower arm 10 to any desired state, that is, turning the lower arm 10 in the vertical direction, can be accomplished extremely easily by operating the manual handle.

Next, a case will be described in which the lower arm 10 is fixed and the upper arm 21 is pivoted in the vertical direction. In order to simplify the explanation, it is assumed that the initial state of the robot is the state shown in FIG. Figures 1 to 3
In the figure and FIG. 5, the second rotary drive machine 11
When driven, the link lever 17 fixed to the second output shaft 15 moves around the first fulcrum: _O1 ,
For example, rotate clockwise. When this tilting angle reaches α ₂ , that is, in the state shown in FIG. 5, it is assumed that the control input to the second rotary drive machine 11 is cut off, that is, the second rotary drive machine 11 is placed in a non-energized state. lower arm 1
0 is fixed, and if the link lever 17 rotates clockwise around the first fulcrum O ₁ by an angle α ₂ as described above, the upper arm 21 will move towards the lower arm 10.
It performs a parallel movement with 2 as a fixed side, and tilts clockwise by an angle of α ₂ about the second fulcrum: O ₂ , that is, pivots downward. In this case, the second fulcrum: upper arm 21 located in the _Y1 direction with _O2 as the boundary
and the weight of the joint member 22 etc. is W ₁ , and the second
fulcrum: Upper arm 21 located in the _Y2 direction from _O2 ,
If the weight of the link rod 20, link lever 17, etc. is _W2 , then the upper arm 21 is the second fulcrum:
It is assumed that the link lever 17, which is rotated clockwise about O ₂ and forms a parallel link mechanism, is rotated clockwise about the first fulcrum: O ₁ . In this case, the force that rotates the link lever 17 acts on the second input shaft 13 via the second reduction gear 14 as an eccentric rotational force. In this case, similarly to the first rotary drive system, the eccentric load is offset by the braking force of the electromagnetic brake (not shown) housed in the second box body 12, and therefore, despite this eccentric load, the link lever 17 remains stationary. For this reason, the upper arm 21 is maintained in the state shown in FIG. Note that the braking force of the electromagnetic brake used in the second rotational drive system may be smaller than that of the first rotational drive system, but it can be made approximately equal to the braking force of the first electromagnetic brake 8.
Therefore, similarly to when operating the handle of the lower arm 10, regardless of the tilting state of the upper arm 21, it is impossible to tilt the upper arm 21 to an arbitrary state, that is, to rotate it in the vertical direction with the control power turned off. This can be accomplished very easily by attaching an operating handle to the free end 131 of the input shaft 13 of No. 2 and manually rotating the handle.

6 to 8 are views showing a second embodiment of the present invention, in which 53 is a first box-shaped body rotatably supported on the underframe 51 via a bracket 52. The first box-shaped body 53 has an opening 531 that opens in the axial direction, for example, in the _X1 direction, at least on one side thereof. 54 is the first
A first rotary drive machine, e.g., an electric motor, 55 is provided at an end of the box-like body 53, and a first rotary drive machine 55 is rotatably supported by the first box-like body 53 via bearings 56, 56.
The screw shaft is connected to the drive shaft of the first rotary drive machine 54 via a coupling 57. Reference numeral 58 designates a first braking means, such as an electromagnetic brake, which is disposed at the other end of the first box-shaped body 53 and is used to brake the first screw shaft 55 into an appropriate rotational state. A free end 551 of the first screw shaft 55 projects outwardly through the first braking means 58;
1 is provided with a cutout having a rectangular cross section, for example, and is formed so that a handle for rotating the first screw shaft 55 can be attached and detached. 59 is a first nut having a female screw portion that engages with the first screw shaft 55;
The nut 59 has an opening 53 in the first box-like body 53.
A shaft portion 60 is provided that penetrates through the shaft portion 1 and projects outward. 61 is the underframe 51 as shown in FIG.
The link lever 62, which is rotatably supported around the first fulcrum: _O1 , is an L-shaped lower arm, and the L-shaped base is rotatably supported with respect to the underframe 51. The rotation axis is concentric with the first fulcrum: _O1 . 63 is a link rod, and one end of the link rod 63 and the free end of the link lever 61 are connected as shown in FIG.
They are rotatably connected to each other by a shaft portion 60 disposed on the first nut 59. 21 to 23
As shown in FIG. 6, the upper arm, joint members and operating elements are similar to those shown in the first embodiment,
The upper arm 21, the lower arm 62, the link rod 63, and the link lever 61 constitute a parallel link mechanism. At a predetermined position in the _X1 direction of the first drive device 64 constituted by the above-mentioned 53 to 60, there is a 5-5
A second drive device 64' consisting of 3' to 60' is arranged opposite to each other. This second drive device 6
The shaft portion 60' of the lower arm 62 is rotatably connected to the L-shaped end portion of the lower arm 62.

Comparing the second embodiment with the first embodiment, the screw shafts 55, 5 in the second embodiment are
5' corresponds to the input shaft of the first embodiment, the connection between the screw shaft and the nut serves as a speed reducer, and the shaft portion protruding from the nuts 59 and 59' serves as the output shaft or driven shaft. It consists of

In the above, when the first rotary drive machine 54 is driven, the first nut 59 that engages with the first screw shaft 55 moves, thereby causing the link lever 61 to rotate around the first fulcrum: _O1. . Also, due to the above, the upper arm 2 of the parallel link mechanism
1 pivots vertically around the second fulcrum: _O2 . When the second rotary drive unit 54' is further driven, the second nut 59' that engages with the second screw shaft 55' moves, thereby moving the lower arm 62 via the L-shaped arm to the first fulcrum: O ₁
Rotate vertically around the center.

By the way, as explained in the first embodiment, by tilting the upper arm 21 and the lower arm 62, the link lever 61 and the L-shaped lower arm 62 are moved to the first fulcrum: O ₁
An eccentric rotational force acts to rotate the nut 59, 59' about the center, and this eccentric rotational force tends to displace the first or second nut 59, 59' in an appropriate direction. In this case, the screw shafts 55, 55'
and nuts 59, 59' have good rotation transmission efficiency,
For example, in a ball-screw system, if the control input to the first and second rotary drive machines 54, 54' is cut off while the eccentric rotational force is generated, the eccentric rotational force will be generated. Screw shaft 55, via nuts 59, 59'
55' rotates, and the upper arm 21 and lower arm 62 are about to further rotate about the first fulcrum: _O1 . By the way, the first and second electromagnetic brakes 5
8 and 58' have sufficient braking force to stand still the screw shafts 55 and 55' against the eccentric rotational force when the control power is turned off, and therefore prevent the generation of the eccentric rotational force. Despite this, upper arm 21
And the lower arm 62 stands still at any position. Book 2
The control force of the electromagnetic brakes 58, 58' in this embodiment is approximately the same as that in the first embodiment, and therefore, regardless of the tilting state of the upper arm 21 and lower arm 62, the control power can be turned off. By attaching operating handles to the free ends 551, 551' of the screw shaft in the hanging state and rotating the handles manually, the upper arm 21 and lower arm 62 can be tilted to any desired state, that is, rotated in the vertical direction. Can be done.

In addition, in industrial robots, stoppers are installed to appropriately restrict the movement range of each part in case each part of the moving member goes out of control, and when the moving member is restrained by this stopper, a danger signal is sent by a detector. This causes the control input to the rotary drive machine for driving the moving member to be maintained in a state where it is cut off. Generally, the rotation of a rotary drive machine is detected by a rotation detector, such as a rotary encoder, and if a command signal to this rotary drive machine is not generated, for example, the rotary drive machine maintains its current position with the minimum pulse of the rotation detector. It is finely driven to maintain a so-called self-lock state. However, even if the control input to the rotary drive machine is turned on, if the movable member contacts the stopper as described above and the moving direction of the movable member is restricted to only one direction, the rotary drive machine It is difficult to maintain a self-locked state, and for this reason, the electric circuit is often constructed so that the control input to the rotary drive machine is cut off.

That is, when the movable member is in contact with the stopper, the control input to the rotary drive machine for driving the movable member is generally maintained in a cut-off state, so that the movable member cannot be moved into the use area. This work was troublesome because a rotary drive machine could not be used. However, in the industrial robot of the present invention, each part of the industrial robot can be operated manually by rotating the operating handle while the control input to the rotary drive machine is cut off, making work easier. Can be done.

As explained above, if an electric motor is used as the rotary drive machine, the position of the driven body can be easily controlled, but a rotary machine operated by fluid pressure can also be used as the rotary drive machine. Furthermore, although the mounting shape of the operating handle has been described as being rectangular in cross section, if it is formed in this way, it is easy to machine the handle and the handle attachment/detachment portion. Despite this, the operating handle attachment shape can be made non-circular in cross section. Furthermore, if a mounting part is formed on the shaft for attaching and detaching the operating handle, the operating handle will not rotate together with the shaft when the robot is operated, which will prevent workers from touching the handle and causing personal injury. There is no risk of it being triggered. Further, in this case, if a cover is provided for attaching and detaching the operating handle, the rotating part will not be exposed to the outside and it will be safe. In this case, it goes without saying that the cover must be removed to operate the handle. Note that the state in which the control input to the rotary drive machine is cut off means that an appropriate clutch means is disposed between the rotary shaft of the rotary drive machine and the input shaft of the reducer, and when the handle is operated, the clutch means is switched. Of course, this also includes a case where the rotating shaft of the rotary drive machine and the input shaft of the reducer are in a state where rotation is not transmitted. In this case, even if the rotary drive machine can be driven when the handle is operated, the manual handle operation work can be performed without any problem, but when the handle is operated, another worker may mistakenly switch the clutch means and rotate the When the driving machine is driven, the operating handle may also be rotated, which is somewhat dangerous from a work safety standpoint. Moreover, notwithstanding the above, the operating handle can also be integrally fastened to the input shaft of the speed reducer.

Further, in the first embodiment, the output shaft of the speed reducer is directly connected to the lower arm and the link lever, respectively, but it is of course possible to arrange an appropriate rotation transmission mechanism between them. Furthermore, if an electromagnetic brake is used as the braking means, the robot will operate smoothly because no braking force is generated by the electromagnetic brake when there is no manual handle operation, that is, when the robot is operating.
Despite this, it is also possible to provide a manual switching brake or a mechanical brake mechanism that constantly generates braking force. Note that if the brake means is placed on the input shaft of the reducer, a small braking force is required, making the device more compact. It is also possible to configure the input shaft so that it does not act on the input shaft.

In the above explanation, the robot is an articulated arm type robot, but the present invention is also applicable to an industrial robot in which an eccentric rotational force from various parts of the robot is applied to the input shaft when no input is transmitted to the input shaft, including the rotating shaft of a rotary drive machine. Therefore, it goes without saying that the present invention also includes industrial robots using cylindrical coordinates, rectangular coordinates, polar coordinates, and the like. Further, as the operating elements, a welding torch, an assembly tool, a gripping tool, a spray gun of a painting device, etc. are used as appropriate.

As described above, according to the present invention, each part of the industrial robot can be operated manually by rotating the operating handle when the input shaft of the reducer is not transmitting the driving force to the input shaft. Furthermore, no matter how tilted each part of the robot is when no input is transmitted to the input shaft, including the rotating shaft of the rotary drive machine, each part of the robot is kept still in that tilted state by the brake means, making assembly and adjustment of the robot easier. It is also advantageous during repairs, has extremely good workability and can be carried out safely, and is industrially useful.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a right side view of FIG. 5 and 5 are explanatory diagrams of the operation of FIG. 1, FIG. 6 is a front view showing another embodiment of the present invention, FIG. 7 is a left side view of FIG. 6, and FIG. 8 is a diagram of FIG. - is a line cross-sectional view with some parts not in cross-section. 1, 11, 54, 54'...Rotary drive machine, 6, 1
4...Reducer, 4, 13, 55, 55'...Input shaft,
9, 15... Output shaft, 8, 58, 58'... Brake means.

Claims (1)

[Scope of Claims] 1. A drive shaft of a rotary drive machine and an input shaft of a reducer are connected, a driven member is connected to an output shaft of the reducer, and an operating handle is integrated at one end of the input shaft. or an industrial robot comprising a brake means which is removably attached and which substantially offsets the eccentric rotational force acting on the input shaft at least when the driving force is not transmitted to the input shaft, and which is disposed on the input shaft or output shaft of the speed reducer. . 2. The industrial robot according to claim 1, wherein the driven member is an arm rotation axis of an articulated arm type robot. 3. The industrial robot according to claim 1 or 2, wherein the braking means is an electromagnetic brake. 4. The industrial device according to any one of claims 1 to 3, wherein a clutch means for switching the driving force of the rotary drive machine to a transmission state or a non-transmission state is disposed on the input shaft side. Robot.