JPH0450234B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to the opening and closing of works that can be opened and closed relative to the main body, such as the bonnet or trunk cover of a car being transported on an assembly line. This invention relates to an industrial robot suitable for use in industrial robots.

[Conventional technology]

Generally, when assembling a car that is transported on an assembly line by a conveyance means such as a chain conveyor, in order to paint or weld the hood of the car or the inside of the car body, the bonnet must be removed. You need to lift it open. However, in the case of conventional industrial robots, it is known that a gripping device for gripping a workpiece and a support device consisting of a hook-shaped support member for locking to a bonnet, etc. are attached to the tip of the arm. For gripping devices and support devices, if a car body is accidentally lifted instead of a workpiece that can be opened and closed, such as a bonnet, the malfunction should be automatically detected and the operation of the robot should be stopped. The disadvantage is that it cannot be done.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and is capable of lifting and opening a workpiece that is openable and closable with respect to the main body, and also automatically detects whether or not a predetermined workpiece is being lifted without fail. An object of the present invention is to provide an industrial robot that can detect objects.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a robot body that has a rotatable arm and lifts a workpiece by driving the arm, and a mounting plate provided on the arm tip side of the robot body. and,
a support member rotatably provided on the mounting plate, the distal end of which protrudes from the mounting plate and serves as a workpiece support for lifting the work; and a supporting member stretched between the support member and the mounting plate; a spring that allows the support member to pivot to a first position when the workpiece is lifted by the workpiece support portion of the support member;
a workpiece detection switch that detects rotational displacement of the support member to a first position against the spring;
detecting that the support member receives a load greater than the workpiece and that the support member is rotated against a spring to a second position greater than the first position, and controls the operation of the robot body; A configuration consisting of a stop switch is adopted.

[Effect]

With the above configuration, when the arm of the robot body is driven to lift a workpiece with the workpiece support part of the support member, the workpiece detection switch normally detects the rotational displacement of the support member to the first position against the spring. It can be detected when the device is in operation, and it can be confirmed that the predetermined workpiece is being lifted without fail.

Furthermore, when the support member lifts a load greater than the workpiece, such as the body of a car, a stop switch is set to prevent the support member from rotating to a second position that is larger than the first position. It can be detected and the operation of the robot body can be automatically stopped.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

A first embodiment of the present invention is shown in FIGS. 1 to 3. In the figure, 1 is a workpiece conveyance means such as a chain conveyor installed on the floor 2 of the workshop;
Reference numeral 3 denotes an automobile body which is placed on the workpiece conveying means 1 and conveyed in the direction of arrow A in the figure.The automobile body 3 is provided with a bonnet 4 serving as a workpiece so as to be openable and closable. Reference numeral 5 denotes a base made of a frame, which is located above the workpiece conveyance means 1 and in front of the bonnet 4 in the direction of movement, and is fixed to a high place 6 in the work place, and the base 5 extends downward from the high place 6. It is installed protrudingly.

Reference numeral 7 denotes a robot body that is suspended from the base 5 in order to open and close the bonnet 4. a first arm 9 which is rotatably supported by the mounting part 8 and whose other end protrudes from the mounting part 8 so as to face the moving direction A of the bonnet 4;
is rotatably supported at the tip of the first arm 9 at a position near the upper end, and has a mounting bracket 10 at the lower end.
A is provided between one end of the first arm 9 and the mounting portion 8 in order to rotate the second arm 10 from which A is protruded and the first arm 9 in the direction of arrow B in the figure. In order to urge the first actuator 11 and the first arm 9 to rotate upward, the first actuator 11 is stretched between one end side of the first arm 9 and the inner part of the mounting part 8. Biasing spring 1 made of a tension spring
2, and a second arm provided between the upper end of the second arm 10 and the tip of the first arm 9 in order to rotate the second arm 10 in the direction of arrow C in the figure.
actuator 13. The first arm 9 and the second arm 10 are connected by parallel links 14A and 15A, so that regardless of the rotational position of each arm 9, 10, the lifting device 16 (described later) is horizontal. It is now possible to go up and down.

Reference numeral 16 denotes a lifting device for opening and closing the bonnet 4, and the lifting device 16 is connected to a pair of mounting brackets 18A, 18 erected on the upper surface of a rectangular mounting plate 17.
A to the second arm 10 via the support pin 19
By connecting to the mounting bracket 10A of
It is rotatably supported with respect to the second arm 10. In addition, the pair of mounting brackets 18A,
Parallel link 15 is connected to 18A via connecting pin 20.
The lower ends of A are connected, and the mounting plate 17 is always maintained in a horizontal state regardless of the rotational position of the second arm 10.

A pair of mounting brackets 21A and 21A are located at both ends of the mounting plate 17 in the width direction and protrude downward. A support shaft 22 is rotatably supported between the mounting brackets 21A and 21A. Support shaft 2
A pair of support blocks 23A, 23A are fitted into each of the mounting brackets 2 at positions closer to the respective mounting brackets 21A. Reference numerals 24 and 24 denote support members made of round bars that are inserted in each of the support blocks 23A and the support shaft 22 and are provided in parallel with the mounting plate 17 in order to lift the bonnet 4 from below. One side 24A protrudes from the mounting plate 17 facing the moving direction A of the bonnet 4, and the tip from the middle thereof is bent upward to become a workpiece support part 25, and the tip of the support part 25 is equipped with rubber or the like. A cap-shaped buffer member 26 made of an elastic material is attached to the cap. Each support member 24 is rotatable about the support shaft 22 in the direction of arrow D.

Reference numeral 27 denotes a rectangular flat plate-shaped connecting member located at the rear end of the other side 24B of each of the supporting members 24 and installed between the supporting members 24, and the upper end is formed into a tapered surface 28A at the center of the upper surface of the connecting member 27. contact pin 28
has been erected. The contact pin 28 is attached to the mounting plate 17.
The contact pin 28 is slidably inserted into a cylindrical guide member 29 provided in the cylindrical guide member 29 with its upper end protruding, and the contact pin 28 moves vertically relative to the mounting plate 17 as each support member 24 rotates. It is starting to shift to Reference numeral 30 denotes a compression spring that is fitted onto the contact pin 28 and tensioned between the mounting plate 17 and the connecting member 27, and the spring force of the spring 30 causes the support member 24 to lift the bonnet 4. By appropriately selecting the spring force, the amount of rotational displacement of the support member 24 can be regulated.

Reference numeral 31 designates a workpiece detection switch that is installed on the rear end of the upper surface of the mounting plate 17 via an L-shaped mounting bracket 32 so as to face the contact pin 28. A contact 31A that contacts the contact pin 28 to close the switch 31 is provided in a protruding manner. and,
The switch 31 is connected to a notification device (not shown) so that it can issue a notification when the support member 24 has correctly lifted the bonnet 4.

Further, a workpiece detection switch 31 is mounted on the top surface of the mounting plate 17 via an L-shaped mounting bracket 34.
A stop switch is located on the opposite side of the switch 31 and above the switch 31 and is erected to face the contact pin 28, and the support member 24 applies a load larger than a predetermined load to the stop switch 33. received,
A contact 33A is protrudingly provided, which contacts the contact pin 28 and opens the stop switch 33 when the contact pin 28 contacts the contact 31A of the workpiece detection switch 31 and then projects further upward. The stop switch 33 is connected to a control device (not shown) for the robot body 7, and the control device is configured to prevent the support member 24 from accidentally lifting the vehicle body 3 when the stop switch 33 is activated. The system is configured to determine this and stop the operation of the robot body 7.

The present embodiment is constructed as described above, and its operation will be described next.

The robot main body 7, which operates based on teaching, rotates each arm 9, 10 by the driving force of each actuator 11, 13, and lifts the lifting device 16 into the first position.
Position it as shown by the solid line in the figure. When the bonnet 4 as a workpiece is moved in the direction of arrow A by the chain conveyor 1 together with the automobile body 3, and the tip of the bonnet 4 is positioned above the support member 24 of the lifting device 16, each actuator 1
1 and 13 rotate the respective arms 9 and 10 and begin to lift the lifting device 16 upward while keeping it in a horizontal state.

Support part 25 protruding above the support member 24
When the tip comes into contact with the lower surface of the tip of the bonnet 4 and lifts the bonnet 4 upward, the load of the bonnet 4 is applied to the support portion 25, and the support member 24 resists the spring force of the spring 30 and moves the support shaft 22. It rotates clockwise in Fig. 2 around . And the support member 2
4 is rotated to the first position, the contact pin 2
8 protrudes above the mounting plate 17 and pushes the contact 31A of the workpiece detection switch 31, and the workpiece detection switch 31 is opened.
The normal operation of the bonnet 4 can be immediately detected, and it can be confirmed that the support member 24 is correctly lifting the bonnet 4 by normal means, so that the subsequent lifting work can be continued with peace of mind.

Furthermore, if the supporting member 24 lifts up the automobile main body 3 which is heavier than the bonnet 4 due to a malfunction of the robot main body 7, the supporting member 24
The second position is rotated against the spring force of the second position, which is larger than the first position. As a result, the contact pin 28 protrudes further upward beyond the position of the workpiece detection switch 31, pushes the contact 33A of the stop switch 33, closes the stop switch 33, and immediately corrects the malfunction of the robot body 7. Since the robot body 7 can be detected immediately, the control device can stop the robot body 7 and immediately stop the operation of moving the lifting device 16 upward.

Therefore, according to this embodiment, by providing the workpiece detection switch 31 and the stop switch 33, it is possible to distinguish between normal operation and malfunction of the robot body 7 and perform two-step detection operation. In addition, in the event of a malfunction, the robot main body 7 can be stopped immediately to prevent damage to the lifting device 16, etc., and safety during lifting work can be ensured.

In the embodiment, the bonnet 4 which is provided in the car body 3 so as to be openable and closable is used as an object to be operated by the lifting device 16, but the bonnet 4 is not limited to this. This can be applied to various types of workpieces provided, and in this case, the spring force of the spring 30 may be selected in accordance with the load of the workpiece applied to the support member 24.

Further, in this embodiment, the lifting device 16 includes parallel links 14A and 15A incorporated in each arm 9 and 10.
In the above description, it is assumed that the lifting device 16 can be raised and lowered in a horizontal state, but if the lifting device 16 only needs to be moved up and down in a small amount, the lifting device 16 may be fixed to the tip of the arm 10. It's good.

Furthermore, the robot main body 7 is not limited to the type that is installed so as to be suspended from a high place 6 in the work place as shown in the figure, but also includes a base and a vertical arm installed on the base via a turntable. The robot body may be a ground-mounted robot body consisting of the vertical arm and a horizontal arm rotatably provided, and the robot body may have various configurations.

Next, a second embodiment of the present invention is shown in FIG.
Note that the same reference numerals are given to the same components as those of the first embodiment described above, and the explanation thereof will be omitted.

In the figure, 41 is a lifting device, 42 is a rectangular mounting plate that constitutes the lifting device 41, and the mounting plate 42
A pair of dogleg-shaped mounting brackets 43A, 43A (however, one is not shown) is provided upright at the rear end of the upper surface, and a second
The mounting bracket 10A of the arm 10 and the parallel link 15A are connected via a support pin 19 and a connecting pin 20, respectively.

44, 44 (however, one is not shown) is a support member whose tip side is bent upward to become a support portion 45, and whose rear end portion is provided with a mounting bracket 46 projecting upward, and each of the support members 44 is located on the lower surface side of the mounting plate 42, and is rotatably supported via a mounting bracket 46 by a support shaft 47 installed between the pair of mounting brackets 43A, 43A.
Reference numeral 48 denotes a rectangular flat plate-shaped connecting member located between the supporting members 44 and installed between the supporting members 44, and 49 denotes an interlocking pin located at the center of the connecting members 48 and protruding upward. , the interlocking pin 49 is slidably inserted into a guide member 50 provided on the mounting plate 42 and protrudes to the upper surface side of the mounting plate 42, and as each support member 44 rotates, the interlocking pin 49 is slidably inserted into a guide member 50 provided on the mounting plate 42. , which can be displaced downward.

Reference numeral 51 denotes a spring seat located on the upper surface side of the mounting plate 42 and fixed to the interlocking pin 49. Between the spring seat 51 and the guide member 50 is a spring 52 made of a compression spring.
By appropriately setting the spring force of the spring 52, the amount of displacement of the support member 44, which rotates around the support shaft 47 in response to the load of the workpiece, can be regulated. ing. Reference numeral 53 denotes a disc-shaped sliding plate located above the spring seat 51 and fixed to the interlocking pin 49, and on the outer peripheral surface of the sliding plate 53 are contactors 54 of each switch 54, 56, which will be described later.
A tapered sliding surface 53A is formed to be in sliding contact with A and 56A.

54 is attached to the mounting plate 42 via the mounting bracket 55.
A workpiece detection switch is provided upright on the upper surface of the workpiece detection switch 54, and when the sliding contact plate 54 is displaced downward together with the interlocking pin 49, the sliding contact plate 53
the contact 5 which is pushed by the switch 54 to close the switch 54;
4A is provided protrudingly. On the other hand, 56 is a stop switch located below the workpiece detection switch 54 and erected on the upper surface of the mounting plate 42 by means of a mounting bracket 57. under heavy load,
The sliding contact plate 53 is the contact 5 of the workpiece detection switch 54
A contact 56A is provided in a protruding manner, which is pushed by the sliding contact plate 53 to open the switch 56 when the contact 56A is further displaced downward after contacting the contact 4A.

Reference numeral 58 denotes an airtight casing provided on the upper surface of the mounting plate 42 to integrally cover the spring 52, the switches 54, 56, etc. and isolate them from the outside air.

The present embodiment is constructed as described above, and there is no substantial difference in operation from the first embodiment. According to this embodiment, the spring 52,
Since the workpiece detection switch 54, stop switch 56, etc. are covered with an airtight housing, when the industrial robot is used in a painting atmosphere, spray paint does not adhere to the spring 52, each switch 54, 56, etc. This can be reliably prevented.

[Effects of the Invention] As detailed above, according to the present invention, when the arm of the robot body is driven to lift a workpiece with the workpiece support portion of the support member, the support member resists the spring and lifts the workpiece. a workpiece detection switch that detects rotational displacement to a position; and a workpiece detection switch that detects rotational displacement of the support member to a second position larger than the first position when the support member receives a load larger than the workpiece. When lifting a workpiece, the workpiece detection switch can detect this as normal operation, and not only can it be confirmed that the specified workpiece is being lifted without error, but also when the load is higher than the workpiece. When a large object is lifted, the stop switch can detect this as a malfunction, and the operation of the robot body can be immediately stopped.

Therefore, the workpiece detection switch and the stop switch can distinguish between normal operation and malfunction of the industrial robot, and two-step detection operation is possible.
This has various effects such as preventing damage to the lifting device and improving safety during lifting operations.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, FIG. 1 is an overall configuration diagram showing an industrial robot, FIG. 2 is a left side view of a lifting device, and FIG. 3 is a lifting device. FIG. 4 is a left side view of a lifting device according to a second embodiment of the present invention. 7... Robot body, 10... Arm, 16,
41... Lifting device, 17, 42... Mounting plate, 2
4, 44...Support member, 25, 45...Work support part, 30, 52...Spring, 31, 54...Work detection switch, 33, 56...Stop switch.

Claims (1)

[Claims] 1. A robot body having a rotatable arm and lifting a workpiece by driving the arm;
a mounting plate provided on the distal end side of the arm of the robot body; and a support member rotatably provided on the mounting plate, the distal end protruding from the mounting plate and serving as a workpiece support for lifting the workpiece. , a spring that is stretched between the support member and the mounting plate and allows the support member to pivot to the first position when the workpiece is lifted by the workpiece support portion of the support member; a workpiece detection switch for detecting that the support member is rotationally displaced to a first position against the spring; An industrial robot comprising: a stop switch that detects rotational displacement to a second position larger than the first position and stops the operation of the robot body.