JP2600326Y2 - Fastening device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastening device for detachably fastening a member to be fastened such as a hand for performing a predetermined operation on a workpiece.

[0002]

2. Description of the Related Art In an assembly factory of various mass-produced parts and products, various operations may be performed on a workpiece such as a part in one work stage, or the workpiece may be gripped and transported. . In such a case, a robot is used to perform work in order to improve work efficiency.

In order to be able to perform a plurality of types of work by one robot, a large number of hands (members to be fastened) are held on a hand support, and a fastening device is provided for the robot. It has been proposed that a specific hand is selected from the large number of hands and detachably mounted to perform a predetermined operation on a workpiece such as a part.

FIGS. 5 and 6 show a main part of a conventional fastening device provided in such a robot.

The fastening mechanism of the fastening device 34 is such that a plurality of steel balls 43 provided on a hollow support shaft 41 inserted into the fastening holes 32b of the hand 32 so as to be freely displaceable in the radial direction are slid by, for example, fluid pressure. FIG. 5 shows the most desirable outward displacement state due to the outward displacement by the shaft 45. In this FIG.
3 is completely displaced outward by the fastening surface 45a of the fastening shaft 45. According to this, the steel ball 43 is always displaced outward even by vibrations during operation, and the stable fastening is achieved. This is because a state is obtained.

[0006]

However, in order to displace the steel ball 43 in the state shown in FIG. 5 and prevent the steel ball 43 from moving inward at the fastening surface 45a, a high precision is required for machining the fastening shaft 45. That is, when the diameter of the fastening shaft 45 is small, rattling of the fastening portion occurs. On the other hand, when the fastening shaft 45 is large, that is, when it is larger than the design value due to a processing error, as shown in FIG.
Is in an unstable state in which the fastening is performed in a state of contacting the corner between the tapered release surface 45b and the fastening surface 45a instead of the fastening surface 45a, and the fastening is performed due to a load variation or a decrease in fluid pressure. The shaft 45 is easily moved in the retreating direction. Then, the steel ball 43 is displaced inward to release the fastening state, and the hand 32 may be inadvertently detached.

It is an object of the present invention to provide a technique relating to a fastening device capable of obtaining a stable fastening state with a member to be fastened without requiring high working accuracy for a fastening shaft.

[0008] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0009]

Means for Solving the Problems Of the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, a fastening device according to the present invention comprises a housing body having a through hole formed in an axial direction and having a hollow support shaft inserted into the fastening hole of a member to be fastened, and a radially extending hollow support shaft. A plurality of steel balls, which are provided so as to be displaceable and are engaged with the fastening holes of the member to be fastened by being displaced outward, and being disengaged by being displaced inward. The steel ball is slidably provided in the through hole of the hollow support shaft in the axial direction, and the steel ball is displaced outwardly to be in the engaged state and the fastening surface is displaced inwardly to be in the disengaged state. A fastening shaft having a tapered release surface formed thereon, and a separation between the fastening surface and the release surface of the fastening shaft having a smaller diameter than the fastening surface and substantially along the axial direction of the fastening shaft. Forming a surface, and connecting the steel ball to the fastening surface with a smaller diameter Is contacted with either the anti-separation surface, characterized in that the workpieces have to be fastened to the housing body.

[0011]

According to the fastening device having the above-described configuration, even if the outer diameter of the fastening surface becomes larger than the design value due to a processing error, and the steel ball does not contact the fastening surface, the inner diameter of the steel ball is reduced. Displacement in the direction is prevented by the separation preventing surface. Therefore, it is possible to obtain a stable fastening state between the fastened member and the fastened member without requiring a high processing accuracy for the outer diameter of the fastened surface of the fastened shaft and without the possibility that the fastened member is accidentally detached.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is an explanatory view showing an industrial robot using a fastening device according to an embodiment of the present invention, FIG. 2 is a sectional view showing the fastening device, and FIG. It is principal part sectional drawing of a fastening device.

As shown in FIG. 1, the fastening device of this embodiment is provided, for example, for fastening a hand (member to be fastened) 2 in an industrial robot 1. The manifold 2 incorporating the fastening device 4 (FIG. 2) is attached, and the hand 2 is fastened.
The work is performed on the work 7 on the work table 6.

A hand support 8 is provided adjacent to the robot 1, and a number of hands 2 each of which is operated by a fluid pressure are mounted on the hand support 8. Then, a predetermined operation can be performed on the work 7 by the hand 2 by selectively operating the robot 1 by selectively and detachably attaching any of the hands 2 to the fastening device 4.

Each hand 2 has a hand holder 2a mounted on the fastening device 4, and a hand drive unit 9b attached to the hand holder 2a to drive the hand unit 9a.

The work on the work 7 by the hand 2 includes various works such as a work of gripping and transporting the work 7, a work of vacuum-sucking and transporting the work 7, and a drilling work for the work 7. What performs some work on the work 7 including all the jigs, tools, fingers, actuators, and the like for performing the work is referred to as a hand 2 here.

A fastening device 4 for fastening such a hand 2 to the manifold solenoid valve unit 5 is as shown in FIG.

That is, the solenoid valve 5 for driving the fastening device 4
a output port 5a ₁ and was communicated two supply and discharge ports 1
0a and 10b are opened, and the supply / discharge port 10
A housing main body 10 in which a pressurizing chamber 10c communicating with a and 10b is formed is connected to the manifold solenoid valve unit 5. A through hole 11a communicating with the pressurizing chamber 10c is formed in the axial direction, and a fastening hole 2b of the hand 2 is formed.
Is fixed to the housing main body 10 by a screw member 12.

A plurality of receiving holes 11b are formed at the tip of the hollow support shaft 11 so as to penetrate from the inner wall surface to the outer wall surface. In each of the receiving holes 11b, a steel ball is displaceable in the radial direction of the hollow support shaft 11. 13 are accommodated. The steel ball 13 is hollow support shaft 11 is engaged in contact with the tapered surface 2b ₁ formed in the fastening hole 2b by displacing outward in a state of being inserted into the fastening hole 2b of the hand 2, The engagement state is released by being displaced inward. The hollow support shaft 11 and the housing body 10
The wall of the pressurized chamber 10c formed by the sealing member 14 is sealed by a sealing material 14.

In the through hole 11a of the hollow support shaft 11, a fastening shaft 15 for displacing the steel ball 13 outward to fasten the hand 2 while displacing the steel ball 13 inward to release the fastening is provided with the hollow support shaft 15. It is provided slidably in the axial direction of the shaft 11.

[0022] That is, as shown in FIG. 3, the fastening shaft 15 is advanced axially displaces the steel balls 13 outwards, fixing this in the tapered portion 2b ₁ and the engagement of the fastening hole 2b a fastening surface 15a for, retracted by displacing inwardly the steel balls 13, a tapered release surface 15b for releasing the engagement between the tapered portion 2b ₁ are formed. Further, between the fastening surface 15a and the release surface 15b, a separation prevention surface 15c having a smaller diameter than the fastening surface 15a and substantially along the axial direction of the fastening shaft 15 is formed. This separation prevention surface 15c
Means that when the hand 2 is fastened, the steel ball 13
This prevents the hand 2 from being disengaged from being displaced inward along the release surface 15b, thereby preventing the hand 2 from accidentally detaching. The fastening surface 15
A tapered surface 15d is formed between the a and the separation preventing surface 15c, so that the steel ball 13 is smoothly guided to the fastening surface 15a when the steel ball 13 advances in the axial direction.

As shown in FIG. 2, a sealing member 16 is attached to the outer peripheral surface of the base 15e of the fastening shaft 15 located in the pressurizing chamber 10c of the housing body 10, and the base member 15e is in contact with the wall of the pressurizing chamber 10c. The space is sealed. The sealing material 16 allows the pressurizing chamber 10c to be divided into two supply / discharge ports 10a,
The pressurizing chamber 10c is divided into two pressurizing chambers 10c communicating with each other, and when a fluid flows in from the supply / discharge port 10a, the pressurizing chamber 10c above the drawing is pressurized and the fastening shaft slides in the forward direction, and When it flows in from the discharge port 10b, the pressurizing chamber 10c below the drawing is pressurized and slid in the retreating direction. In the pressurizing chamber 10c, a spring 17 for urging the fastening shaft 15 in the forward direction is provided along the axial direction of the fastening shaft 15. Further, a sealing material 18 such as a V-ring is provided between the fastening shaft 15 and the hollow support shaft 11.
To prevent leakage of fluid flowing from the supply / discharge port 10b.

The following describes the hand fastening operation of the fastening device 4 of the present embodiment with reference to FIG. 2 and FIG.

As shown in FIG. 2, when the hollow support shaft 11 is inserted into the fastening hole 2b of the hand 2, the solenoid valve 5a
From the pressurizing chamber 10c above the drawing via the supply / discharge port 10a.
, The pressurizing chamber 10c is pressurized, and the fastening shaft 15 is advanced in the axial direction. Then, the steel ball 13 is pushed up to the fastening surface 15a of the fastening shaft 15 is displaced radially outwardly of the hollow support shaft 11 becomes engaged contact with the tapered portion 2b ₁ formed fastening holes 2b, which Thereby, the hand 2 is fastened to the fastening device 4.

At this time, if the diameter of the fastening shaft 15 is larger than the design value due to a machining error, as shown in FIG. When the hand 2 is operated or the fluid pressure in the pressurizing chamber 10c is reduced in this state, the steel ball 1
The fastening shaft 15 is pushed back in the retreating direction by the inward pressing force of 3. Even in such a state, FIG.
As shown in (b), the steel ball 13 is in a state of being held on the separation prevention surface 15c. Therefore, the aforementioned tapered portion 2
The engagement state with b ₁ is still maintained, and the steel ball 1
Is prevented from displacing inward along the release surface 15b. Therefore, in the fastening device 4 of the present embodiment, the fastened hand 2 does not accidentally come off, and a stable fastening state can be obtained.

When the diameter of the fastening shaft 15 is the most desirable size, the steel ball 13 is moved by the tapered surface 15d formed between the fastening surface 15a and the separation preventing surface 15c when the fastening shaft 15 moves forward. At the fastening surface 15a.

When fluid flows from the solenoid valve 5a into the pressurizing chamber 10c below the drawing via the supply / discharge port 10b, the fastening shaft 1
5 moves backward against the urging force of the spring 17. Then, the steel ball 13 is guided by the release surface 15b of the fastening shaft 15 and is displaced inward in the radial direction of the hollow support shaft 11 to release the engaged state, and the hand 2 is detached from the fastening device 4.

(Embodiment 2) FIG. 4 is a sectional view of a main part of a fastening device according to another embodiment of the present invention.

As shown, the fastening device 24 of the present embodiment is
Is a fastening shaft 25 that reciprocates in the axial direction and displaces the steel ball 13 in the radial direction of the hollow support shaft 11, in which a fastening surface 25a, a release surface 25b, and a separation preventing surface 25c are formed.
A step is formed between the fastening surface 25a and the separation preventing surface 25c, and the tapered surface 15d as in the first embodiment is not formed.

In the case where the fastening device 24 itself is small and the fastening shaft 25 is small, the steel ball 13 can be moved forward in the axial direction without forming the tapered surface 15d unlike the fastening shaft 24 of this embodiment. It is smoothly guided to the fastening surface 25a.

Although the invention made by the present inventors has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say.

Further, in the above description, the invention made by the present inventor has been mainly described with respect to the hand fastening device as the background, but the present invention is not limited thereto, and is applicable to various other fastening devices. It is possible to

[0034]

[Effects of the Invention] Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described.
It is as follows.

(1) Even if the outer diameter of the fastening surface of the machined fastening shaft is larger than a design value due to a machining error, the steel ball is not a fastening surface but a portion between the fastening surface and the separation preventing surface. As a result, the inward movement is prevented. Therefore, even if the fastening shaft is pushed back in the retreating direction due to a change in load or a decrease in fluid pressure, the steel ball is held on the separation prevention surface having a smaller diameter than the fastening surface, and the steel ball is released during fastening. Inward movement along the plane is prevented.

(2) Therefore, according to the fastening device of the present invention, the possibility that the member to be fastened is inadvertently disengaged without requiring high working accuracy for the fastening shaft is prevented. A stable fastening state can be obtained in between.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an industrial robot using a fastening device according to a first embodiment of the present invention;

FIG. 2 is a sectional view showing the fastening device.

3A is a sectional view of a main part showing a state in which a steel ball of the fastening device is displaced outward, and FIG. 3B is a sectional view of the steel ball when the fastening shaft is pushed back in the fastening device in the fastening device. It is principal part sectional drawing which shows a position.

FIG. 4 is a sectional view of a main part of a fastening device according to a second embodiment of the present invention;

FIG. 5 is a sectional view of a main part showing a conventional fastening device.

FIG. 6 is a sectional view of a main part showing a conventional fastening device.

[Explanation of symbols]

Reference Signs List 1 robot 2 hand (member to be fastened) 2a hand holder 2b fastening hole 2b ₁ taper portion 3 arm 4 fastening device 5 manifold solenoid valve unit 5a solenoid valve 5a ₁ output port 6 work table 7 work 8 hand support stand 9a hand section 9b hand Drive unit 10 Housing body 10a Supply / discharge port 10b Supply / discharge port 10c Pressurizing chamber 11 Hollow support shaft 11a Through hole 11b Housing hole 12 Screw member 13 Steel ball 14 Seal material 15 Fastening shaft 15a Fastening surface 15b Release surface 15c Release prevention surface 15d Tapered surface 15e Base 16 Sealing material 17 Spring 18 Sealing material 24 Fastening device 25 Fastening shaft 25a Fastening surface 25b Release surface 25c Separation prevention surface 32 Hand 32b Fastening hole 34 Fastening device 41 Hollow support shaft 43 Steel ball 45 Fastening shaft 45a Fastening surface 45b Release surface

Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16B 21/00

Claims (3)

(57) [Scope of request for utility model registration] 1. A housing body having a through hole formed in an axial direction and having a hollow support shaft inserted into a fastening hole of a member to be fastened, and a housing body provided movably in a radial direction of the hollow support shaft. A plurality of steel balls that are disengaged in the direction to be engaged with the fastening hole of the member to be fastened, while being displaced inwardly and released from the engaged state, A fastening surface which is provided slidably in the axial direction in the through hole, and which displaces the steel ball outward and engages, and a tapered release surface which displaces inward to disengage the steel ball. Formed between the fastening surface and the release surface of the fastening shaft, and having a diameter smaller than the fastening surface and substantially preventing the detachment along the axial direction of the fastening shaft.
And forming the steel ball with the fastening surface and a separation prevention surface having a smaller diameter than the fastening surface.
And the member to be fastened is brought into contact with the housing.
A fastening device characterized in that the fastening device is fastened to a main body . 2. The fastening device according to claim 1, wherein a tapered surface is formed between the fastening surface and the separation preventing surface. 3. The fastening device according to claim 1, wherein the member to be fastened is a hand for performing a predetermined operation on a work.