JPS6346177Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an inner gripping device, and particularly to an inner gripping device suitable for gripping a workpiece having a small inner diameter or a soft workpiece from the inside thereof.

For example, a cylindrical base 1 as shown in FIG.
When a cylindrical workpiece 3 having a truncated conical head 2 connected to the base is attached to or removed from the chuck 4 of the lathe, it is desirable to perform this work automatically. if,
It is necessary to grip the workpiece 3 using some kind of gripping device, but since the head 2 of this workpiece 3 is formed in a tapered shape, this part cannot be gripped. It is necessary to grasp the inner diameter 5. At this time, the inner diameter 5 of the workpiece 3
If the dimensions of the workpiece 3 are sufficiently large, it is possible to use a conventional gripping device having inner diameter gripping claws, but if the dimension of the inner diameter 5 is small, a conventional gripping device can be used to hold the workpiece 3. It is impossible to grasp the inner diameter of the

In addition, when the workpiece 3 is a soft material such as an aluminum alloy, if the inner diameter 5 is gripped using a conventional gripping device, the inner diameter gripping claws may damage the surface of the inner diameter 5 that has been finished. Sisters,
There is a problem in that the accuracy of the product decreases.

This idea was created in view of the above, and its purpose is to reliably grip the workpiece from the inside even when the workpiece has a small inner diameter or is made of soft material. The object of the present invention is to provide an inner gripping device that can be used.

The inner gripping device of this invention, which meets the above objectives, has a guide shaft protruding from the base of a hand frame, etc. driven by the main body of the device, and a cylindrical elastic body arranged around the guide shaft. A fluid receiving portion is formed between the two, and a fluid passage is formed in the guide shaft for guiding the fluid to the fluid receiving portion through the inside thereof, while a spherical bushing or the like is formed on the outer circumference of the guide shaft. A workpiece abutting member is swingably attached to the workpiece abutting member through a supporting means, and the workpiece abutting member is provided with a workpiece pressing surface extending in a direction intersecting the guide axis. The end face of the workpiece can be brought into contact with the workpiece pressing surface when the workpiece is gripped.

As a result, the elastic body part of the inner gripping device is inserted inside the workpiece, and in this state, the elastic body is expanded radially outward by guiding fluid into the fluid receiving part through the fluid passage, The workpiece can be gripped by pressing and bringing the circumferential side of the elastic body into contact with the inner diameter of the workpiece.

Moreover, when moving the hand frame etc. to grip the workpiece, the workpiece pressing surface plays the role of a stopper, so the insertion depth of the guide shaft into the workpiece can always be constant. A reliable gripping operation can be achieved.

Next, specific embodiments of this invention will be described in detail with reference to the drawings.

In FIG. 2, A indicates the base to which the inner gripping device is attached, and in this case, the base A is the hand frame 10 that is driven and position controlled by the device main body (not shown). An example is shown, and the workpiece is this hand frame 1
0 from a predetermined location (for example, the chuck part of a lathe) to another predetermined location.

A guide shaft 11 is attached to the hand frame 10, and the guide shaft 11 has a disk-shaped base 12 and a substantially cylindrical guide portion 13 extending forward from the base 12. The guide shaft 11 has an appropriate number of bolts 14 at its base 12.
It is fixed to the hand frame 10 by.
Note that an O-ring 15 is interposed between the hand frame 10 and the base 12 for sealing fluid at a connecting portion between a fluid passage 36 and a fluid passage 37, which will be described later.

The guide portion 13 of the guide shaft 11 includes a base 1
From the 2nd side toward the free end, the male threaded portion 16
A tapered portion 17 that continues to the tip of the male screw portion 16 and gradually becomes smaller in diameter, and a shaft portion 18 that further extends from the tip of the tapered portion 17 are formed. A wide groove 19 is provided around the shaft portion 18, and a screw hole 20 is formed in the free end thereof.

A bottomed cylindrical elastic body 21 is fitted onto the outer peripheral portion of the guide shaft 11 between the tapered part 17 and the shaft part 18 from the free end side of the shaft part 18. , for example, is made of a material such as nitrile rubber or a thin ductile metal, and has a through hole formed in its bottom. The bottom of the elastic body 21 is fixed to the free end of the shaft 18 by a bolt 22 that is threaded into a screw hole 20 of the shaft 18 through the through hole. In addition, 23 is a washer,
This is for uniformly pressing substantially the entire bottom portion of the elastic body 21 against the free end portion of the shaft portion 18 .

The elastic body 21 further presses against the circumferential side of the tapered portion 17 of the guide shaft 11 near the opening thereof.
Fixed. The fixing structure will be explained below, and in the case of the figure, this structure uses a fixing sleeve 24 and a fixing nut 25.
The fixing sleeve 24 is a ring-shaped member with a wedge-shaped cross section having approximately the same inclination as the tapered portion 17 of the guide shaft 11, and the elastic body 2 is formed on the inclined inner circumferential surface thereof.
1 can be pressed against the tapered portion 17. Further, the fixing nut 25 is a substantially cylindrical member, and has the guide shaft 11 on the inner circumferential surface on one end side thereof.
A female threaded portion 26 that can be screwed into the male threaded portion 16 is formed, and a protrusion 27 that extends radially inward is provided around the other end. Therefore, by screwing the female screw portion 26 of the fixing nut 25 into the male screw portion 16 of the guide shaft 11, the fixing sleeve 24
is pressed in the axial direction by the projecting edge 27, and as a result, the elastic body 21 is pressed and held against the tapered portion 17 by the inclined inner circumferential surface of the fixing sleeve 24.

As mentioned above, the guide shaft 11 circumferential side and the elastic body 2
1 is sealed at two places, the base end side and the free end side of the guide shaft 11, so that a sealed fluid reception is created between the circumferential side of the guide shaft 11 and the elastic body 21. A section 28 is formed.

Further, a workpiece abutting member 30 is swingably attached to the outer circumference of the fixing nut 25 via a spherical bushing 29. , a workpiece pressing surface 3 extending radially inward from the tip of this cylindrical portion 31.
2, and the outer circumferential portion of the spherical bushing 29 is fitted into the inner circumferential portion of the cylindrical portion 31. The workpiece pressing surface 32 serves as a stopper when gripping the workpiece 3, and a through hole 33 is formed in the center of the workpiece pressing surface 32, through which the guide shaft 11 and the guide shaft 11 and An elastic body 21 is led out. In addition, both 34 and 35 are spherical bushes 2.
This is a ring to prevent 9 from slipping out.

The guide shaft 11 is provided with a fluid passage 36 that opens toward the base 12 and communicates with the fluid receiving portion 28 through the inside of the guide shaft 11 . Further, a fluid passage 37 is formed in the hand frame 10 for supplying fluid from a fluid supply source (not shown) to the fluid passage 36, and the fluid is passed from the fluid supply source through the fluid passages 36 and 37 to a fluid receiving section. Fluid can be supplied to 28.

Using the above-mentioned inner gripping device, the workpiece 3 as shown in FIG. 1 is gripped and the chuck 4 of the lathe is
When removing the device from the hand frame 10, first drive the device main body (not shown) as shown in FIG.
is moved and the guide shaft 11 is inserted into the workpiece 3. At this time, the hand frame 10 is moved until the workpiece pressing surface 32 comes into contact with the end surface of the workpiece 3. In this state, fluid is supplied from a fluid supply source (not shown) to the fluid receiving portion 28 via the fluid passage 37 and the fluid passage 36. As a result, the elastic body 21 expands radially outward due to this fluid pressure, as shown in FIG. 4, and presses and contacts the inner diameter 5 of the workpiece 3. will be held from within. Next, the chuck is loosened, the hand frame 10 is moved to a predetermined position, and the fluid in the fluid receiving part 28 is released to the outside air through the fluid passage 36 and the fluid passage 37, thereby returning the elastic body 21 to its original state. Then, the guide shaft 11 is extracted from the workpiece 3 to complete the conveyance.

Although one embodiment of this invention has been described above, it goes without saying that the inner gripping device of this invention is not limited to the above embodiment, and can be implemented with various modifications. For example, when forming the fluid receiving portion 28, the groove 19 of the guide shaft 11 may be omitted and the fluid may be directly guided between the guide shaft 11 and the elastic body 21. In addition, the structure for sealing between the circumferential side of the guide shaft 11 and the elastic body 21 at two locations, the proximal end side and the free end side of the guide shaft 11, may be a structure other than the above, such as an adhesive. In some cases, a structure in which adhesive is used is adopted. Further, a bottomed cylindrical elastic body 2 is provided on the circumferential side of the guide shaft 11.
In some cases, the fluid receiving part 28 is formed by fitting the guide shaft 1 into the guide shaft 11 and sealing between the two only on the base end side of the guide shaft 11. Further, even if the through hole of the workpiece has a shape other than the circular cross section described above, for example, a square cross section, it is of course possible to grip the workpiece in the same manner as described above. If the inner diameter of the workpiece to be gripped changes, the guide shaft 11 may be removed from the hand frame 10 and replaced with another guide shaft 11 that has been completely set.

The inner gripping device of this invention is constructed as described above, and therefore, even if the inner diameter of the workpiece is small, the workpiece can be reliably gripped from the inside. becomes possible. In addition, since the contact between the elastic body and the inside of the workpiece is a surface contact, the contact surface pressure can be reduced, so even if the workpiece is a soft material such as aluminum, There is no risk of damaging the inside. Moreover, even though it can be held stably, the structure is simple, so the overall weight can be reduced, and the only consumable part is the elastic body, so it is economical.

Further, the workpiece abutting member 3 is connected to the outer circumference of the fixing nut 25 via a support means such as a spherical bush 29.
0 is swingably mounted, and this workpiece abutting member 3
Since the workpiece pressing surface 32 is provided on the 0, the workpiece pressing surface 32 plays the role of a stopper when moving the hand frame 10 etc. to grip the workpiece 3. The insertion depth of the guide shaft 11 into the object 3 can always be kept constant, so that a reliable gripping operation can be achieved. Moreover, since the workpiece abutting member 30 is made swingable,
Even when the workpiece 3 is arranged in a slightly inclined state with respect to the guide shaft 11, the above-mentioned reliable gripping state can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a workpiece to be gripped by the inner gripping device of this invention, FIG. 2 is a longitudinal sectional view showing an embodiment of the inner gripping device of this invention, and FIG. and FIG. 4 are explanatory diagrams each showing a state in which a workpiece is gripped by the inner gripping device. A...Base, 10...Hand frame, 11...
... Guide shaft, 21 ... Elastic body, 28 ... Fluid receiving section, 30 ... Workpiece contact member, 32 ... Workpiece pressing surface, 36 ... Fluid passage, 3 ... Workpiece.

Claims (1)

[Scope of utility model registration request] Hand frame 1 driven by the device body
A guide shaft 11 is provided protruding from the base A of the 0 etc., and a cylindrical elastic body 21 is provided around the guide shaft 11.
A fluid receiving section 28 is formed between the guide shaft 11 and the fluid receiving section 28, and a fluid passage 36 is formed in the guide shaft 11 for guiding fluid to the fluid receiving section 28 through the inside thereof. A workpiece abutting member 30 is swingably attached to the outer periphery of the guide shaft 11 via support means such as a spherical bushing 29. A workpiece pressing surface 32 extending in a direction of An inner gripping device consisting of: