JPS62871Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hand for an industrial robot, and more particularly to an improvement in the structure of the grasping fingers of the hand in order to improve the grasping function of the hand.

In general, industrial robots have recently been widely used for gripping and transporting heavy objects and for gripping and transporting workpieces of machine tools. In particular, in the above-mentioned applications for grasping and transporting heavy objects, as the range of applications for robots expands, the objects to be grasped (hereinafter collectively referred to as "workpieces") are becoming increasingly heavier, as well as workpieces with increasingly diverse shapes. It is now also used for gripping and transporting objects, contributing to further labor savings. However, when grasping and transporting such a heavy workpiece, conventional robots use a robot hand 1 as shown in Fig. 1, for example.
0 is normally provided to perform workpiece gripping and conveying operations. That is, in FIG. 1, the robot hand 10 has gripping fingers 12, 12' that open and close in the direction indicated by arrow A, that is, in the lateral direction, and grips a workpiece 1.
The workpiece 14 is gripped by approaching the workpiece 14 from the lateral direction of 4, that is, from the direction shown by arrow B, and closing the gripping fingers 12, 12'. However, this type of gripping method grips only two opposing sides of the workpiece, and is suitable for gripping and transporting workpieces with a circular planar shape or relatively light workpieces; When gripping and transporting a workpiece of 200 mm or more, or a workpiece having a rectangular planar shape, the gripping state often becomes unstable. Particularly when gripping a rectangular workpiece as described above, the workpiece may be gripped with a deviation from the gripping fingers, resulting in a very unstable gripping state, which may even be dangerous. Furthermore, if the workpiece is placed at a low position relative to the robot, such as on the floor of a factory, etc., it is extremely difficult to grip the workpiece in such a position due to the structure of the robot using the conventional hand described above. It is inconvenient and sometimes impossible to grasp. In order to deal with this, it is necessary to configure the robot arm, wrist, etc. into a special shape.

Therefore, in view of the above-mentioned problems of the prior art, the purpose of the present invention is to provide a device that can securely and stably grip even workpieces that are particularly heavy and have various shapes such as rectangular shapes, and that can be miniaturized with a simple configuration. The purpose is to provide a structured industrial robot hand.

According to the present invention, a hand board member is provided which is coupled to the wrist of the robot, and the hand board member is arranged so as to protrude perpendicularly from the palm surface of the board member, and is movable to open and close with two fingers facing each other. Two sets of gripping fingers are arranged so that their movement axes are orthogonal to each other, and the opposing gripping fingers are connected to be movable to open and close synchronously with respect to the workpiece gripping center simultaneously or independently for each set. In the industrial robot hand, the link mechanism is arranged to operate in an operating plane parallel to the movement plane of the grasping fingers, and a fluid cylinder for operating the link mechanism is arranged. The link mechanism includes two links provided respectively corresponding to the respective sets of grasping fingers and rotatably arranged around a common axis in the center of the hand base member; The two ends are rotatably and slidably connected to each other via pins, and each is slidably fitted to a guide shaft fixed to the center of the substrate member in a cross-shaped planar shape. 2 for fixedly supporting each of the gripping fingers;
a set of gripping finger support brackets, and each set of gripping fingers is individually constructed from the brackets, and the fluid cylinder is arranged such that its operating axis is parallel to the movement axis of the gripping fingers of each group. one for each of the two sets of link mechanisms is provided in the substrate member, and each of the fluid cylinders and the link mechanism is fixed to either one of the pair of gripping finger support brackets facing each other and has an operating plane thereof. There is provided a hand for an industrial robot, characterized in that the gripping fingers are connected to each other through an actuation bracket arranged parallel to the plane of movement of each of the gripping fingers.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 2 to 5 of the accompanying drawings.

Fig. 2 is a perspective view of the appearance of a robot equipped with an embodiment of the hand of an industrial robot according to the present invention. In Fig. 2, 20 is a fixed housing part of the industrial robot, and a rotating table 22 is provided on the upper part of this fixed housing part 20 so as to be capable of rotating forward and backward. Two vertical guide shafts 24 and 24' (not shown) are provided on the rotating table 22 to support a robot casing 26 so as to be movable up and down. Furthermore, upper and lower feed screw shafts 28 provided in parallel with the vertical guide shafts 24 and 24' support the robot casing 26.
6, and the robot casing 26 is connected to the guide shaft 24 and the 2
The robot casing 26 supports the robot arms 30, 30' so that they can be extended and retracted in the axial direction. A robot hand 34 according to the present invention is attached to the tip of the robot arms 30, 30' via a wrist mechanism 32.
The hand 34 is attached so as to be actuated by the wrist mechanism 32 for both rotational positioning and oscillating positioning.

FIG. 3 is an external perspective view of the hand 34 which is an embodiment of the present invention shown in FIG. In FIG. 3, reference numeral 34 indicates the entire hand, and the lower surface of the substrate member 36, that is, the surface on the side that grips the workpiece, is herein referred to as the palm surface 36a of the hand substrate member 36, and the surface on the opposite side is referred to as the palm surface 36a of the hand substrate member 36. This will be referred to as the back surface 36b of the substrate member 36. The hand 34 is provided with a palm surface 36a of the base member 36 and grip fingers 38 extending perpendicularly to the palm surface 36a.
consists of two sets of four gripping fingers, namely 38a and 38b, and 38c and 38d. The first set of grasping fingers 38a and 38b are arranged symmetrically with respect to the center of the palm surface 36a and are located opposite each other, and open and close parallel to and synchronously toward the center of the palm surface 36a. It is configured to move and grip a workpiece. On the other hand, the second set of gripping fingers 38c and 38d have the same direction of opening and closing operation as the first set of gripping fingers 38a.
The gripping fingers 38 of the first set are arranged perpendicularly to the opening/closing operation direction of the gripping fingers 38b and 38b.
The structure is similar to that of a and 38b. The opening/closing operation driving mechanism for the first and second sets of gripping fingers includes related members such as a link mechanism, a fluid cylinder, an electromagnetic switching valve, etc., as shown in FIG. are arranged for each set of gripping fingers, and are configured to be able to open and close the two sets of gripping fingers simultaneously or for each set. Also,
The tips of each of the gripping fingers 38 are provided with hook claws 38'a, 38'b, 38'c, and 38'd bent inward, respectively. It is formed to lock a workpiece. Therefore, it is particularly effective for safely and reliably gripping and transporting heavy workpieces.
Furthermore, in FIG. 3, a pressing device 50 is provided at the center of the palm surface 36a, and the pressing device 50 consists of a fixing portion 50a and a pressing finger 50b. Fixed part 50
The inside of a is connected to the pressing finger 50b and the pressing finger 50
An actuator, for example, a fluid cylinder (not shown), is formed to actuate the pressing finger 50b, and the pressing finger 50b is configured to be actuated in a vertical direction of the palm surface 36a so as to be expandable and retractable by the fluid cylinder. The pressing fingers 50b are the gripping fingers 38a, 38b, 38c.
and 38d are activated in a timely manner when gripping the workpiece, and press the workpiece against the hook claws 38'a, 38d.
38'b, 38'c, and 38'd to prevent the workpiece from being gripped in a biased manner. On the other hand, hand board member 3
A mounting bracket 37 is provided on the back surface 36b side of the wristwatch 6, and the mounting bracket 37 is formed so as to be attachable to the wrist mechanism section 32, as shown in FIG.

FIG. 4 is an explanatory diagram showing an example of the configuration of the actuating device of the hand 34. In FIG. 4, the first set of gripping fingers 38a and 38b are slidably connected to guide shafts 40a and 40b fixed to a fixed bracket 46 via gripping finger support brackets 42a and 42b, respectively. , 42b are connected to the link 4 via pins 44a, 44b, respectively.
It is slidably and rotatably connected to both ends of 4.
The center portion of the link 44 is rotatably supported by a fixed bracket 46 through a pin 44e. An actuation bracket 42 fixed to the base end of one of the support brackets 42a and 42b.
A working part of an actuator, such as a piston rod 48b of a fluid cylinder 48, is connected to the end of the piston e. Therefore, the piston 48 of the fluid cylinder 48
The gripping fingers 38a and 38b are configured to open and close parallel to each other along the guide shafts 44a and 44b along the guide shafts 44a and 44b via the link mechanism as the two fingers a reciprocate. On the other hand, the second set of gripping fingers 38c and 38d are arranged such that their opening/closing directions are perpendicular to the opening/closing directions of the first pair of gripping fingers 38a and 38b, and their opening/closing operations are fingers 38a and 3
A link mechanism configured with the same structure as in the case of 8b, that is, guide shafts 40c, 40d, gripping finger support brackets 42c, 42d, and operation bracket 42.
f, pins 44c, 44d, 44e, and link 4
It is configured to be opened and closed along the guide shafts 40c and 40d by a fluid cylinder 48' via a link mechanism constructed on the opposite side of the fixed bracket 46 by 4'. Therefore, the planes in which the two sets of gripping fingers 38a, 38b and 38c, 38d move are parallel to the planes in which the operating brackets 42e, 42f and the links 44, 44' operate. Further, 52 indicates a robot control device, and 52a, 52b, 52c, 52
d and 52e indicate electrical signal lines. 54 indicates a compressed air source, 54a, 54b, 54c, 54d,
54e, 54f, 54g and 54h indicate air passages. Reference numerals 56, 58 and 58' indicate electromagnetic switching valves for controlling the direction of the air passages, and the switching valves perform switching operations in response to electrical signals from the robot controller. That is, in FIG. 4, the electromagnetic switching valve 56
selectively communicates the passage 54h with either the passage 54f or 54g by a switching operation. In this case, the compressed air (hereinafter simply referred to as air) that has flowed into the passage 54f passes through the check valve 55 and flows into the passage 54e with an air pressure equal to the air pressure in the air source 54, while the air that has flowed into the passage 54g is reduced to a predetermined air pressure by the pressure reducing valve 60, passes through the check valve 55', and flows into the passage 54e. By controlling the air pressure in two stages in this manner, the driving force of the cylinders 48, 48' is controlled in two stages, strong and weak, and finally the gripping force of the hand is controlled in two stages, strong and weak. This means that the gripping force of the hand is appropriately selected depending on the weight of the workpiece, and either high or low air pressure is selected as appropriate to avoid wasteful air use and use air efficiently. This was taken into consideration. Of course, in this embodiment, the pneumatic pressure control is performed in two stages, but it is easily possible to construct a pneumatic control device with even more stages by adding related members such as pressure reducing valves. The electromagnetic switching valves 58 and 58' are configured identically, and for example, the electromagnetic switching valve 58 connects the passage 54e to the passage 54a or 54b.
This switching operation causes the air to flow through the cylinder 48.
The pistons 48a are alternately introduced into the cylinder chambers 48c or 48d to cause the pistons 48a to reciprocate. Of course, the electromagnetic switching valve 58 performs switching valve operation in the neutral position through the passage 54.
It is also possible to block air from flowing into the passage 54a or 54b by blocking the passage 54a or 54b. Therefore, by controlling both the electromagnetic switching valves 58, 58' at the same time, or one in operation and the other in the neutral position, etc., by operating an electric signal from the robot control device, the first set of gripping fingers 38a, 38b is controlled. and a second set of grasping fingers 38
It is possible to open and close both of c and 38d synchronously or individually for each set. Although the pressing device 50 shown in FIG. 3 is not shown in FIG. 4, it can be easily assembled by arranging related components such as an electromagnetic switching valve and a fluid cylinder. It is possible.

FIG. 5 is a front view of the hand seen from the palm side, showing an embodiment showing the arrangement of each member shown in FIG. 4, and reference numbers are the same as those shown in FIG. 4. . Incidentally, reference number 62 is an electromagnetic switching valve, which is used for the pressing device (see 50 in FIG. 3).

Next, a preferred example of the operation of the industrial robot hand according to the present invention will be explained with reference to time charts shown in FIGS. 4 and 6.

Hold the workpiece with the gripping fingers 38a, 38b, 38c in Fig. 4.
and 38d, in order to grip the workpiece in a correct state such that the center of the workpiece coincides with the gripping center of the hand, the gripping force is first held by one set of gripping fingers 38a and 38b with a weak gripping force. , and the other pair of gripping fingers 38c, 38
d with a strong gripping force, and then the gripping force of the pair of gripping fingers 38a, 38b is increased to a strong gripping force. By operating the gripping fingers in such a sequence, the center of the workpiece can be aligned with the gripping center of the hand more reliably than when two sets of gripping fingers are activated simultaneously.

FIG. 6 shows the signal lines 52a, 5 from the robot control device 52 in FIG. 4 when opening and closing the grip fingers.
Electrical signals S52a, S52b, S52c, S5 sent to 2b, 52c, 52d and 52e, respectively
2d and S52e time charts are shown. That is, when gripping a workpiece, the robot controller 52 first sets the signal S52e on the signal line 52e in FIG. The signal S52b is set to high level. As a result, the gripping fingers 38a, 38b grip the workpiece with a weak gripping force. Next, the control device 52 sets the signal S52e on the signal line 52e to a low level, and then
Set the signal on c to high level. As a result, the gripping fingers 38c and 38d grip the workpiece with strong gripping force. At this time, the center of the workpiece is the gripping finger 38c,
Even if the gripping fingers 38c and 38d are shifted in the moving direction,
Since the gripping force of 38d is greater than the gripping force of gripping fingers 38a and 38b, the center of the workpiece can be aligned with the gripping center of the hand. When the centers are aligned, the control device 52 sets the signal S52b on the signal line 52b to a high level. As a result, the gripping force of the gripping fingers 38a, 38b is switched to a strong gripping force. After these operations, the workpiece is moved to the taught position, and then the control device 52 connects the signal line 5.
The signals on 2a and 52d are set to high level. As a result, the gripping fingers 38a, 38b, 38c and 38d perform simultaneous opening operations under strong air pressure, releasing the workpiece at that position.

As described above in detail, the industrial robot hand according to the present invention can handle workpieces that are heavy and have various shapes such as rectangular shapes by arbitrarily setting the ratio of the distance between each pair of gripping fingers. However, it has great effects in that it can be gripped reliably and stably, and it can be downsized with a simple structure relative to the size of the maximum workpiece that can be gripped.

[Brief explanation of the drawing]

Figure 1 shows a conventional robot hand, and Figure 2 shows a conventional robot hand.
The figure is an external perspective view of an industrial robot equipped with a robot hand according to an embodiment of the present invention, and FIG.
4 is an explanatory diagram showing a configuration example of the hand actuating device shown in FIG. 3, and FIG. 5 is an implementation showing the arrangement of each member shown in FIG. 4. As an example, FIG. 6, which is a front view of the hand as seen from the palm side, is a time chart of signals sent from the control signals when opening and closing the grasping fingers. 34...Hand, 36...Hand board member, 3
6a...palm surface of hand board member, 36b...back surface of hand board member, 37...mounting bracket, 3
8, 38a, 38b, 38c, 38d...Gripping finger, 38'a, 38'b, 38'c, 38'd...Hook claw, 40a, 40b, 40c, 40d...Guiding shaft, 42a, 42b, 42c, 42d...Gripping finger support bracket, 42e, 42f...Operation bracket, 44, 44'...Link, 44a, 44
b, 44c, 44d, 44e...pin, 46...
Fixed bracket, 48, 48'...Fluid cylinder, 50...Pushing device, 56, 58.58', 6
2... Solenoid switching valve, 60... Pressure reducing valve.

Claims (1)

[Claims for Utility Model Registration] 1. A hand board member is provided which is coupled to the wrist of the robot, and which is arranged to protrude perpendicularly to the palm surface of the board member, and which opens and closes with two fingers facing each other forming a pair. Two possible sets of gripping fingers are arranged so that their movement axes are orthogonal to each other, and the opposing gripping fingers can be moved to open and close synchronously with respect to the workpiece gripping center simultaneously or independently for each group. In an industrial robot hand, a link mechanism to be connected is arranged to operate in an operating plane parallel to a plane of movement of the grasping fingers, and a fluid cylinder for operating the link mechanism is arranged. , the link mechanism includes two links provided respectively corresponding to the respective sets of grasping fingers and rotatably disposed around a common axis at the center of the hand base member; The links are rotatably and slidably connected to each other via pins at both ends of the link, and are slidably fitted to guide shafts fixed to the central part of the base plate in a cross-like planar shape. two sets of gripping finger support brackets fixedly supporting each of the gripping fingers; 1 for each of the two sets of link mechanisms, arranged in parallel with the axis of movement.
each of the fluid cylinders and the link mechanism are fixed to either one of the pair of opposing gripping finger support brackets, and the operating plane thereof is parallel to the movement plane of each of the gripping fingers. An industrial robot hand, characterized in that the hands are connected together via actuation brackets arranged so as to 2. Utility Model Registration Scope of Claims 1. In the hand of an industrial robot as set forth in claim 1, the grasping fingers are formed with hook claws protruding inwardly at their tips, and the workpiece pressing device is connected to the hand base plate. An industrial robot hand placed in the center of the palm of the member. 3. The industrial robot hand according to claim 1 or 2, wherein a mounting bracket is formed on the back side of the hand base plate member.