JP3353879B2 - Seal jig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing jig used for a leak test of a hollow part of a work having a hollow part required to have a sealing property, and particularly to a sealing jig fitted to the sealing jig. The present invention relates to a sealing jig that prevents an O-ring from rubbing against a work.

[0002]

2. Description of the Related Art A round bar-shaped shaft member 20 as shown in FIGS. 3A and 3B is used as a sealing jig used for a leak test of a hollow work. A groove 21 is formed on the outer periphery of the distal end of the shaft member 20, and an elastic O-ring 22 is fitted into the groove 21. The outer diameter of the O-ring 22 is
The outer diameter of the O-ring 22 in a normal state is set slightly larger than the inner diameter of the circular work hole 2 formed in the work 1 to be leak-tested, as shown in FIG. I have.

When the shaft member 20 is inserted into the work hole 2 as shown in FIG . 2 (B), the outer periphery of the O-ring 22 is pressed against the inner circumferential surface of the work hole 2 and the O-ring 22 is slightly compressed.
In this state, the O-ring 22 slides on the inner peripheral surface of the work hole 2 in the axial direction. When the shaft member 20 is inserted to the fixed position of the work hole 2, the O-ring 22 elastically contacts the inner peripheral surface of the work hole 2 to seal the work hole 2, and a desired leak test is performed. When the leak test is completed, the O-ring 22 is slid along the inner peripheral surface of the work hole 2 and the shaft member 20 is extracted from the work hole 2.

[0004]

The sealing jig as described above has a simple structure. However, when the shaft member 20 is inserted into and removed from the work hole 2, the O-ring 22 is connected to the inner peripheral surface of the work hole 2 and the shaft member 20. Of the O-ring 2
2, the sealing property of the work hole 2 was deteriorated at an early stage.
Therefore, when the sealing property of the O-ring 22 deteriorates, the O-ring 22 is replaced with a new one. However, the frequency of replacement is uneconomical, and the trouble of parts management and replacement due to the O-ring replacement is reduced. There was a troublesome problem.

[0005]

According to the present invention, a work hole formed in a work to be subjected to a leak test is inserted, and an elastic O-ring is brought into elastic contact with an inner peripheral surface of the work hole to seal the work hole. The sealing jig achieves the above object by adopting a structure in which an O-ring is supported by the following jig main body, convex step portion, cylindrical pressing body, drive shaft, and spring material .

The jig main body is a cylindrical shaft on which an O-ring having an outer diameter smaller than the diameter of the work hole is fitted on the outer periphery of the distal end portion. The convex step portion is provided on the outer periphery of the front end of the jig body with an outer diameter smaller than the diameter of the work hole, and has a step surface at the rear end with which an O-ring fitted to the jig body comes into contact. Shape. The cylindrical pressing body is a cylindrical body that is axially slidably fitted on the outer periphery of the jig body and has a distal end surface facing the O-ring, and has an outer diameter smaller than the diameter of the work hole. The drive
The shaft is integrally connected to the cylindrical pressing body with a connecting pin, and a jig
It is inserted into the main body so as to be movable in the axial direction. The spring material is
It is compressed and mounted between the driving shaft and the jig body.

In the sealing jig of the present invention, after inserting the jig main body with the O-ring mounted thereon into the work hole with the protruding step first, the cylindrical pressing body is moved toward the protruding step side with respect to the jig main body. The O-ring is moved forward to press the O-ring against the step surface of the convex step, and the pressing force compresses the elastic O-ring so as to enlarge its outer diameter. And seal it. When the jig body inserted into the work hole is to be pulled out of the work hole, the jig body is pressed back from the O-ring, and the outer diameter of the O-ring is reduced to its original size. . When the sealing jig is inserted into and removed from the work hole in this manner, the O-ring does not strongly rub against the inner peripheral surface of the work hole during insertion and removal, and wear of the O-ring is reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIGS. 1A and 1B , a cylindrical pressing body 7 is retracted by a spring material 10. FIG. The jig body 5 is a cylinder, into which the drive shaft 11 is inserted so as to be movable in the axial direction, and the drive shaft 11 and the cylindrical pressing body 7 are inserted.
Are integrally connected by a connecting pin 12. The spring material 10 compressed in the axial direction is mounted between the drive shaft 11 and the jig body 5. The spring member 10 constantly urges the drive shaft 11 rearward so that the drive shaft 11 and the drive shaft 11 are in a normal position where the cylindrical pressing body 7 is lightly in contact with the O-ring 4 as shown in FIG. The pressing body 7 is held.

The jig body 5 has an outer diameter smaller than the inner diameter of the work hole 2, and a frusto-conical cap-shaped convex step 6 is coaxially formed at the tip thereof. The outer diameter of the convex step 6 is set to be larger than the outer diameter of the jig main body 5 and smaller than the inner diameter of the work hole 2, and a step surface orthogonal to the outer periphery of the jig main body 5 is formed at the rear end of the convex step 6. Is done.

The outer diameters of the convex step 6 and the cylindrical pressing body 7 are as follows.
Desirably, it is set to be approximately the same as the outer diameter of the O-ring 4 or slightly smaller than the outer diameter of the O-ring 4.

An O-ring 4 is fitted between the outer periphery of the distal end of the jig body 5 and the step surface of the convex step 6. The O-ring 4 is a rubber ring or the like having a circular cross-section, and its outer diameter in a normal state is set to be slightly smaller than the inner diameter of the work hole 2. Normal state of the O-ring 4 is shown in FIG. 1 (A). This O-ring 4
Is pressed into the jig main body 5 so as to sandwich it with the step surface of the convex step portion 6. The distal end surface of the cylindrical pressing body 7 faces in parallel with the step surface, and the O-ring 4 is pressed from both sides by the distal end surface and the step surface.

[0012] FIG 1 (A) sealing jig 3 in a state of being inserted into the workpiece hole 2, the forward drive shaft 11 is automatically or manually with respect to the jig main body 5 as shown in FIG. 1 (B) Move. As a result, the spring member 10 is compressed, the drive shaft 11 moves forward, the cylindrical pressing body 7 moves forward via the connecting pin 12, compresses the O-ring 4, and expands the outer diameter of the O-ring 4 to increase the work hole. 2 is brought into elastic contact. When the external force for moving the drive shaft 11 forward is released, the drive shaft 11, the connecting pin 12, and the cylindrical pressing body 7 automatically return to their original normal positions by the elastic force of the spring member 10.

A leak test of the work 1 is performed in the state shown in FIG. 1 (B). When the leak test is completed, the cylindrical pressing body 7 is retracted to the original rear position. As a result, the O-ring 4 returns to the normal state shown in FIG. 1A due to the elastic return force, and the sealing jig 3 is pulled out of the work hole 2 in this state. Also at this time, the O-ring 4 is pulled out of the work hole 2 without being rubbed against the inner peripheral surface of the work hole 2.

As described above, when the seal jig 3 is inserted into and removed from the work hole 2, the O-ring 4 does not rub against the inner peripheral surface of the work hole 2, and even if rubbed, the O-ring 4 slides lightly. Wear of the O-ring 4 is reduced, and the frequency of replacement of the O-ring 4 is greatly reduced. Also, when the sealing jig 3 is inserted into and removed from the work hole 2, the O-ring 4 does not strongly rub against the inner peripheral surface of the work hole 2, so that the frictional resistance at the time of inserting and removing the sealing jig 3 is reduced. Jig insertion / removal workability is improved.

In the embodiment shown in FIGS. 2A and 2B, the distal end surface n of the cylindrical pressing body 7 is formed as a conical tapered pressing surface n 'that expands the inner diameter R of the O-ring 4. Things. The tapered pressing surface n 'is a conical surface extending rearward from the distal end of the cylindrical pressing body 7, and in an ordinary state, as shown in FIG. Contact so that it bites into the inside diameter side of the. When the O-ring 4 is pressed by moving the cylindrical pressing body 7 forward with respect to the jig main body 5 in this state, as shown in FIG.
Presses the O-ring 4 so as to widen the inner diameter R ′ of the O-ring 4 to increase the outer diameter of the O-ring 4. Therefore, O-ring 4
The O-ring 4 more reliably and firmly makes elastic contact with the inner peripheral surface of the work hole 2 to seal the work hole 2.

Incidentally, similarly to the tapered pressing surface n 'of the cylindrical pressing body 7, the step surface m of the convex step portion 6 may be a conical tapered surface which expands the O-ring 4 from the inner diameter side. Alternatively, only the stepped surface m may be a conical tapered surface that expands the O-ring 4 from the inner diameter side.

[0017]

According to the seal jig of the first aspect, the outer diameter of the O-ring when the seal jig is inserted into and removed from the work hole is smaller than the inner diameter of the work hole. The ring is not rubbed by the work hole. Therefore, the wear of the O-ring is greatly reduced, the life of the O-ring can be extended, and the frequency of replacement of the O-ring can be greatly reduced. Further, since the O-ring does not rub against the work hole when the seal jig is inserted into and removed from the work hole, the frictional resistance when inserting and removing the seal jig is reduced, and the workability of inserting and removing the seal jig is improved. .

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a sealing jig showing an embodiment of the present invention, where (A) is a cross-sectional view when inserted into a work hole, and (B) is a cross-sectional view when the work hole is sealed.

FIGS. 2A and 2B are partial cross-sectional views of a sealing jig showing a second embodiment of the present invention. FIG.
FIG. 4 is a sectional view when a work hole is sealed.

3A and 3B are partial cross-sectional views of a conventional sealing jig. FIG. 3A is a cross-sectional view before insertion into a work hole, and FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Work 2 Work hole 3 Seal jig 4 O-ring 5 Jig main body 6 Convex step part 7 Cylindrical pressing body 10 Spring material 11 Drive shaft

Claims (1)

(57) [Claims] 1. A sealing jig which is inserted into a work hole formed in a work to be subjected to a leak test and seals the work hole by elastically contacting an elastic O-ring with an inner peripheral surface of the work hole. An axial jig main body for fitting an O-ring having an outer diameter smaller than the hole diameter of the hole to the outer periphery of the tip end; A protruding step having at the rear end a step surface with which the O-ring fitted to the jig body comes into contact; and a tip surface facing the O-ring, which is slidably fitted in the outer periphery of the jig body in the axial direction. A cylindrical pressing body having an outer diameter smaller than the outer diameter of the O-ring, and an integrally connected cylindrical pressing body,
A drive shaft inserted so as to be movable in the direction, and compressed axially between the drive shaft and the jig body.
After comprising a spring member, inserting the O-ring jig body fitted with the hole in the workpiece before the convex stepped portion, the spring in the drive shaft with respect to the jig main body
By compressing the material and moving the cylindrical pressing body forward to the convex step side, the O-ring is pressed against the step surface of the convex step by the distal end surface of the cylindrical pressing body, and the elastic O-ring is pressed by this pressing force. A sealing jig, which is compressed so as to increase its outer diameter, and makes the expanded O-ring elastically contact the inner peripheral surface of a work hole.