JPS6350154B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gripping device that is attached to the tip of an arm of a transport device, a handling robot, or the like and grips an object.

Generally, a gripping device is attached to the tip of an arm of each of the above-mentioned conveyance devices, and has a claw that can be opened and closed by hydraulic pressure or air pressure, and grips an object by opening and closing the claw.

1 to 3 show such a conventional gripping device. This gripping device has a main body 21
A piston 22 is inserted into a cylinder formed inside so as to be movable up and down, and a drive shaft 23 is formed at the bottom of the piston 22 so as to extend below the main body 21. It is biased upward by a spring 24 provided on its lower end surface. Further, at the lower part of the main body 21, a pair of gripping members 25, 25 having an L-shaped appearance are connected to each other with claws 25a, 25a by pivots 26, 26, respectively.
It is rotatably provided with the two facing each other.
These gripping members 25, 25 and the drive shaft 2
It is connected in a ring shape to a swing shaft 27 provided at the bottom of 3.

However, in order to grip an object such as a component to be gripped by the lever gripping device, compressed air is introduced into the cylinder from the connection port 21a of the main body 21 above the object. The compressed air introduced into the cylinder pushes the piston 22 downward against the biasing force of the spring 24, so that the drive shaft 23 below the piston 22 descends. And this drive shaft 23
As the gripping members 25, 25 are connected to the swing shaft 27 of the drive shaft 23, the gripping members 25, 25 are rotated so that the respective claw portions 25a, 25a are separated from each other. After the object is positioned between the separated upper claw portions 25a, 25a, the compressed air introduced into the cylinder is discharged to the outside. Then, the piston 22 moves upward due to the biasing force of the spring 24, so the drive shaft 23 below the piston 22 also rises. Therefore, the gripping member 2
5 and 25 are rotated so that their claw portions 25a and 25a approach each other. And these claw parts 2
An object placed between the claws 25a and 25a is held between the opposing surfaces of the claws 25a and 25a.

However, with such conventional gripping devices,
Since the object is gripped between the opposing surfaces of the pair of claws 25a, 25a, there are the following drawbacks.

(b) Since the object is only gripped from the side, the object may shift vertically during movement, etc., and is not suitable for devices that require accurate positioning.

(b) If the machining accuracy of the opposing surfaces of the claws 25a, 25a or the surface of the object is poor, the mutual contact area will not be sufficient when gripping, and gripping will be similar to point contact. This reduces the gripping force, making it unsuitable for gripping heavy objects.

(c) For the same reason as (b), especially when the center of gravity of the object is above the position to be gripped, there is a risk that the object will rotate due to the rotational moment and fall.

This invention was made in view of the above circumstances,
It is an object of the present invention to provide a gripping device that can always reliably grip an object and thus eliminates the risk of the gripped object falling.

The present invention will be explained in detail below based on the drawings.

4 to 7 show a first embodiment of the gripping device of the present invention, in which FIG. 4 is a front view, FIG. 5 is a side view, and FIG. 6 is a bottom view. In FIGS. 4 to 6, reference numeral 1 indicates the main body of this gripping device. The main body 1 has a substantially rectangular parallelepiped appearance, and a groove portion 1a is formed in the substantially lower half of the main body 1. This groove 1a
is a rectangular parallelepiped groove opening on both side surfaces and the lower end surface of the main body 1, and due to this groove 1a, supporting plate parts 1b, 1b are formed at the lower part of the main body 1, facing each other with the groove 1a in between. It is formed. Between the support plate parts 1b and 1b, there are gripping members 2 and 2.
is inserted.

These gripping members 2, 2 include the support plate portion 1b,
It is formed by forming a plate-like member having a thickness substantially equal to the gap between 1b into an L-shape. These gripping members 2, 2 are inserted between the support plate parts 1b, 1b from both sides of the main body 1, respectively, with their short sides facing upward and the tip surfaces of the short sides facing each other. There is. Further, pivot shafts 3, 3 are provided at corners where the long sides and short sides of these gripping members 2, 2 intersect. These pivots 3, 3 are connected to the gripping members 2, 2 and the support plate portion 1 sandwiching them, respectively.
b, 1b. By means of these pivots 3, 3, the gripping members 2, 2
are swingable between the support plate portions 1b, 1b centering on these pivots 3, 3, respectively.

Further, the long sides extending downward of these gripping members 2, 2 are used as claw parts 2a, 2a, and these claw parts 2a, 2
Locking protrusions 2b, 2b which protrude inwardly from the main body 1 and are opposed to each other are formed at the distal end portions of a. These locking protrusions 2b, 2b are connected to the object W.
It is shaped so that it engages with the locking groove Wa of the object W when it is gripped. Here, as the locking groove Wa of the object W, a groove formed on the object W for gripping purposes or a groove formed in advance on the object W for its function can be used.

Also, in the center of the upper end surface of this main body 1, there is a through hole 1c that communicates with the groove 1a of this main body 1.
is formed. This through hole 1c has a shape in which the inner diameter is slightly enlarged in its upper half,
A drive shaft 4 and a connecting member 5 are inserted into this through hole 1c.

The drive shaft 4 has a cylindrical shape and is inserted into the through hole 1c, with its substantially lower half protruding into the groove 1a and positioned between the gripping members 2. At the lower end of this drive shaft 4, protrusions 4a, 4a are formed which protrude circularly toward the ends of the short sides of the gripping members 2, 2, respectively.
A circular notch 2 formed at the tip of the short side of 2
c, 2c. A female threaded portion is formed on the upper end surface of the drive shaft 4, and a male threaded portion formed at the lower end of the connection member 5 is screwed into this female threaded portion.

This connecting member 5 is a cylindrical body having the same diameter as the drive shaft 4, and is screwed onto the upper end of the drive shaft 4, and also has a male threaded portion formed at its upper end.
The upper male threaded portion of the connecting member 5 is screwed onto an output shaft 6a of a single-acting cylinder 6 fixed to the upper end surface of the main body 1.

Further, a flange 7 is fixed to the lower end surface of the main body 1. This flange 7 is the support plate portion 1
A pressing member 8 is provided in a through hole 7a formed in the center of the groove 1a between the lower end surfaces of the grooves 1b and 1b.

As shown in FIG. 7, this pressing member 8 is a rod-shaped member 8a inserted into the through hole 7a of the flange 7.
, a spring seat 8b horizontally joined to the upper end surface of the rod-shaped member 8a, and a pressing plate 8c horizontally joined to the lower end surface of the rod-shaped member 8a. The upper surface of the spring seat 8b and the drive shaft 4
A spring 9 is installed between the lower end surface and the spring 9, which causes the drive shaft 4 to move upward and the pressing member 8.
are each biased downward.

In order to grip the object W with such a gripping device, compressed air is first introduced into the single-acting cylinder 6 through its connection port 6b. Then, the output shaft 6a of the single-acting cylinder 6 descends, and thus the output shaft 6a
and a drive shaft 4 integrally coupled via a connecting member 5.
also descends while compressing the spring 9. Therefore, the gripping members 2, 2 engaged with the protrusions 4a, 4a at the lower end of the drive shaft 4 are pushed downward at their respective short sides. As a result, the gripping members 2, 2 are rotated about the pivot shafts 3, 3 in a direction in which the claw portions 2a, 2a are separated from each other, and are brought into an open state.

Next, the gripping device is lowered from above the object W toward the upper surface of the object W, and the pressing plate 8c is brought into contact with the upper surface of the object W. When this gripping device is further pressed against the upper surface of the object W, the pressing plate 8c moves upward while further compressing the spring 9. When the compressed air in the single-acting cylinder 6 is discharged in this state, the drive shaft 4 is pushed upward by the urging force of the spring 9. Therefore, the claws 2a, 2a of the gripping members 2, 2 rotate in the direction of gripping the object W, and the locking protrusions 2b, 2b engage the locking grooves Wa, Wa of the object W, respectively. and grasp it.

In such a gripping device, the spring 9
When pressed against the upper surface, the pressing member 8 compresses the drive shaft 4 due to the biasing force of the spring 9.
can be kept pressed upward at all times.
Therefore, the gripping members 2, 2 are held in a state in which the locking protrusions 2b, 2b are strongly engaged with the locking grooves Wa, Wa of the object W, so that a reliable gripping state can always be obtained. Further, in such a gripping device, the object W is held between the locking protrusions 2b, 2b and the spring 9.
3 with the pressing plate 8c of the pressing member 8 urged by
It is held at a point. Therefore, since no external power is required during movement, the object W
The grip will not shift or fall due to being released from the grip. Therefore, despite its simple structure, it is capable of reliably gripping a heavy object, and is particularly suitable as a gripping device when positioning of the object W is required.

8 to 10 show a second embodiment of the gripping device of the present invention, which is applied to a gripping device having gripping members 10, 10 that open and close by moving in the horizontal direction.

In the gripping device of this example, a piston 12 is installed inside a main body 11, and connecting ports 13a and 13b are formed at the upper and lower portions of the piston 12, respectively. The drive shaft 1 is located at the bottom of this piston 12.
4 are formed in succession.

Further, a groove portion 11a is formed in the lower part of the main body 11. This groove portion 11a is a groove portion that opens on both side surfaces and the lower end surface of the main body 11, similar to the above-mentioned groove portion 1a, and the width of this groove portion 11a is further widened so that the approximately central portion of the side surface is further gouged to form a stepped portion 11b. has been done. This stepped portion 11b is formed with a predetermined width between both side surfaces of the main body 11, and the gripping member 10,
10 are provided.

These gripping members 10, 10 have an L-shape when viewed from the front, and have a T-shape when viewed from the side by thickening the upper portions of their short sides. The gripping members 10, 10 have T-shaped both side edges 10a,
10a is placed on the step 11b of the groove 11a and inserted from both sides of the groove 11a, thereby being able to slide freely in the horizontal direction on the step 11b of the groove 11a. Further, the long side portion of the gripping member 10 extending downward is a claw portion 10b, and a locking protrusion 10c is formed at the lower end of this claw portion 10b. A V-shaped projection 10d is formed on the opposing surfaces of the claw portion 10b above the locking projection 10c and extends in a V-shape from above in the vertical direction of the claw portion 10b. Further, the groove portion 11a above the gripping members 10, 10
are provided with hinge plates 15, 15, respectively.

The hinge plate 15 is a substantially disc-shaped member, and is rotatable within the groove 11a of the main body 11 by a pivot shaft 16. The hinge plate 15 is formed with small circular protrusions 15a, 15a that bulge toward the upper end surface of the gripping member 10 and the side surface of the drive shaft 14, respectively. Further, the projections 15a, 15a are provided on the upper end surface of the gripping member 10 and the side surface of the drive shaft 14, respectively.
Recesses 10e and 14a are formed to engage with each other, respectively. By engaging the protrusions 15a and 15a in the recesses 10e and 14a, respectively, the gripping members 10 and 10 are configured to move horizontally as the drive shaft 14 moves up and down.

Further, at the bottom of the main body 11, a spring 17, a pressing member 18, and a flange 19 are provided for biasing the drive shaft 14 upward, similar to the above-described embodiment shown in FIG.

To grip the object W with the gripping device of this example,
First, compressed air is introduced into the upper part of the piston 12 from the connection port 13a to press the piston 12 downward. Then, the drive shaft 14 at the bottom of this piston 12
It also lowers while compressing the spring 17. Therefore, the gripping members 10, 10 connected to the drive shaft 14 via the hinge plate 15 move horizontally in the direction in which the respective claws 10b, 10b are separated from each other, as shown by the chain lines in the figure, and the gripping members 10, 10 are in the open state. becomes.

In this state, the gripping device is lowered from above the object W to bring the upper surface of the object W into contact with the pressing member 18 . By further pressing this gripping device against the upper surface of the object W, the spring 17 is further compressed. When the compressed air above the piston 12 is discharged, the drive shaft 14 rises due to the biasing force of the spring 17, and thus the claws 10b, 10b
The V-shaped protrusions 10d and 10d engage with grooves formed on the side surfaces of the object W. When the gripping device is raised, the object W is pressed by the pressing member 18 and slides along the grooves in which the V-shaped protrusions 10d and 10d engage, and the locking protrusions 10c and 10c at the bottom of the claws 10b and 10b. It is locked by. In this gripping device, by introducing compressed air into the connection port 13b to further press the piston 12 upward, the gripping state of the object W can be held more firmly.

In the case of such a gripping device, the above-mentioned first
In addition to being able to obtain the same effects as those of the embodiment, the claw portions 10b, 10b have V-shaped protrusions 10d,
10d, it is possible to achieve more reliable gripping and is suitable as a gripping device for an object W that requires more accurate positioning as shown by the chain line in FIG.

Note that in each of the above-mentioned embodiments, the gripping devices are provided with the claws 2a, 2a, 10b, and 10b facing downward, and grip the object W from above, but the present invention is not limited to this. Instead, the claw portion may be provided horizontally or diagonally.

As explained above, the gripping device of the present invention includes a reciprocating piston and a pair of claws that open and close in conjunction with the reciprocating movement of the piston, and grips the object by opening and closing the claws. In the gripping device, a pressing member consisting of a pressing plate and a spring seat is provided between the pair of claws so as to be movable in a direction perpendicular to the gripping direction of the claws, and the piston and the spring seat of the pressing member a spring is provided between the nail and a locking protrusion for locking the object;
When the object is gripped, the object is gripped by the pair of claws and the pressing plate of the pressing member due to the biasing force of the spring. According to this gripping device, the object is held at three points: the locking protrusion and the pressing member biased by the spring, so no external power is required during the movement. The object W will not shift or fall due to being released from the grip. As a result, even though the structure is simple, even heavy objects can be gripped reliably.

[Brief explanation of the drawing]

Figures 1 to 3 show an example of a conventional gripping device, with Figure 1 being a front view, Figure 4 being a side view, and Figure 4 being a side view.
Fig. 3 is a bottom view, Figs. 4 to 7 show a first embodiment of the gripping device of the present invention, Fig. 4 is a front view, Fig. 5 is a side view, and Fig. 6 is a bottom view. , 7th
The figure is an enlarged view of the "A" part of Figure 4, and Figures 8 to 1.
Figure 0 shows the second embodiment of this invention.
The figure is a front view, FIG. 9 is a side view, and FIG. 10 is a bottom view. 1, 11, 21...Main body, 2a, 10b, 25
a... Claw portion, 2b, 10c... Locking protrusion, 6...
Single acting cylinder, 12, 22...Piston, 8,
18...Press member, 8b...Spring seat, 8c...Press plate, 9, 17...Spring, W...Object.

Claims (1)

[Claims] 1. A gripping device comprising a reciprocating piston and a pair of claws that open and close in conjunction with the reciprocating movement of the piston, and grips an object by opening and closing the claws. A pressing member consisting of a pressing plate and a spring seat is provided between the pair of claws so as to be movable in a direction perpendicular to the gripping direction of the claws, and between the piston and the spring seat of the pressing member, A gripping device comprising a spring that simultaneously urges the claw portion and the pressing member in the gripping direction of the object when the object is gripped.