JPH0314571Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a press-fit bolt that is fixed to a member to be fixed by press-fitting.

BACKGROUND ART A press-fit bolt is known that sequentially includes a head, a press-fit portion, and a male screw portion, and is fixed by press-fitting the press-fit portion from the male screw portion side into a fitting hole provided in a member to be fixed.

Problems to be solved by this invention However, after such a press-fit bolt is press-fitted, it is difficult to avoid the formation of a microscopic gap between the press-fit part and the fitting hole of the fixed member. Therefore, when the member to be fixed requires airtightness, it is difficult to fix the press-fit bolt airtightly by press-fitting. This is particularly noticeable when a plurality of protrusions (serrations) are formed in the press-fit portion of the press-fit bolt in a direction substantially parallel to the axis. For this reason, bolts are fixed by welding, but there is a problem in that bolts made of materials with poor weldability to the member to be fixed, such as high-tensile materials, cannot be used.

On the other hand, as shown in FIG. 8 of Japanese Utility Model Application Publication No. 48-75049, for example, an annular groove is formed on the outer circumferential surface of the press-fit portion of the press-fit bolt at an axially intermediate portion of the press-fit portion. In addition, by fixing the press-fit bolt in the fitting hole of the fixed member with a sealant applied to the outer peripheral surface of the press-fitting part, a part of the sealant is accommodated in the annular groove. is possible. However, in this case, when the sealing material is moved toward the annular groove by the periphery of the fitting hole when the press-fitting bolt is press-fitted, when passing through the annular groove, the sealing material slightly enters into the annular groove. The sealing material cannot be forcibly pushed into the annular groove when the press-fit bolt is press-fitted. It is difficult to fill the annular groove with a sealing material to the extent that airtightness between the annular groove and the annular groove can be ensured.

Means for Solving the Problems The present invention was developed against the background of the above circumstances, and its gist is to provide a head, a press-fit part with a smaller diameter than the head, and a press-fit part with a diameter smaller than the press-fit part. In the press-fit bolt, which is provided with male threaded portions in sequence and is fixed by press-fitting the press-fitted portion from the male threaded portion side into a fitting hole provided in a member to be fixed until the bearing surface of the head abuts the member to be fixed, When the press-fitting bolt, which has a sealing material applied to the outer circumferential surface of the press-fitting part and a portion adjacent to the head thereof, is press-fitted into the fitting hole of the fixed member, As the sealing material is press-fitted, the sealing material is moved toward the head side by the peripheral edge of the fitting hole.
A housing groove is formed around the entire circumference, into which the housing groove is forcibly pushed by being pressed between the head and the member to be fixed.

Effects of operation and invention With this method, the press-fitting bolt, whose outer peripheral surface of the press-fitting part is coated with a sealant, can be inserted into the fitting hole of the fixed member from the external thread side of the press-fitting bolt, so that the seat surface of the head is connected to the fixed member. When press-fitted until they make contact, the sealing material on the outer circumferential surface of the press-fitting part is moved toward the head by the periphery of the fitting hole, and the moved sealing material comes into contact with the head of the press-fitting bolt. Since the sealing material is forcibly pushed into the housing groove by being pressed with the fixed member, the housing groove can be sufficiently filled with the sealing material. As a result, even if the gap exists between the press-fitting part and the fitting hole, the sealing material filled in the accommodation groove maintains the airtightness between the fixed member and the press-fitting bolt due to the material of the press-fitting bolt. can be easily secured regardless of the

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

Figure 1 shows a press-fit bolt 10 to which the present invention is applied.
FIG. 3 is a diagram showing a state in which the fixing member 12 is press-fitted into the fixed member 12. FIG. The press-fit bolt 10 has a head 14, a plurality of protrusions in a direction parallel to the axis, and a head 14.
It is constructed by sequentially comprising a press-fitting part 16 with a smaller diameter and a male thread part 18 with a smaller diameter than the press-fitting part 16, and the part of the press-fitting part 16 adjacent to the head 14 has a predetermined width and depth over the entire circumference. An annular housing groove 20 is formed by cutting out the groove and housing a sealing material 28, which will be described later. A fitting hole 22 is formed in the fixed member 12, and the press-fitting portion 16 of the press-fitting bolt 10 is inserted into the fitting hole 22 so that the seat surface 24 of the head 14 substantially contacts one surface 26 of the fixed member 12. In addition, the housing groove 20 is press-fitted with a sealing material 28 filled therein. As a result, the male threaded portion 18 is made to protrude from the other surface 30 of the fixed member 12, and airtightness between the fitting hole 22 and the press-fit bolt 10 is ensured by the sealing material 28.
A press-fit bolt 10 is fixed to a member 12 to be fixed.

The sealing material 28 is, for example, a coating type sealing material that has rubber as its main component and has high pressure resistance, and has a viscosity of, for example, 1000 to 1000.
9000cp/25℃ is moderate. This sealing material 28 is filled into the housing groove 20 in the following manner.

A press-fitting bolt 10 with a sealing material 28 applied to the outer circumferential surface of the press-fitting part 16 at a predetermined thickness is attached to the male threaded part 1 of the press-fitting bolt 10.
When the sealing material 28 is press-fitted into the fitting hole 22 of the fixed member 12 from the 8 side, as shown in FIG. It is pushed out toward the accommodation groove 20 for storage. Immediately before the press-fitting of the press-fitting part 16 into the fitting hole 22 is completed, as shown in FIG. and the one surface 26. When the press-fitting bolt 10 is further pushed in from this state, the sealing material 28 is exposed to the inside of the housing groove 20 and the head 1.
4. The sealing material 28 is pushed out in opposite directions toward the outer circumferential side, and as a result, a part of the sealing material 28 is pushed out toward the outer circumferential side.
0 with a predetermined pressing force, and the remaining portion of the sealing material 28 is filled into the head 14.
It is inserted in the form of a thin film between the seat surface 24 of the member 12 and one surface 26 of the fixed member 12, and further protrudes from the outer peripheral side of the head 14, resulting in the state shown in FIG. The amount of sealing material 28 to be applied is determined depending on the volume of the housing groove 20 for housing the sealant, and the above-mentioned airtightness can be ensured in the housing groove 20 when the press-fitting bolt 10 is press-fitted. predetermined to be filled to a certain extent.

As described above, according to the present embodiment, the press-fit bolt 1 has the sealing material 28 applied to the outer peripheral surface of the press-fit portion 16.
0 into the fitting hole 22 of the fixed member 12 from the male threaded portion 18 side, the sealing material 28
is forcibly pushed into the accommodation groove 20 for accommodating it with a predetermined pressing force, so that the accommodation groove 20 can be sufficiently filled with the sealing material 28. Even if there is a gap between the fitting hole 22 and the press-fit bolt 10, the sealing material 28 filled in the accommodation groove 20 maintains airtightness between the fitting hole 22 of the fixed member 12 and the press-fit bolt 10, regardless of the material of the bolt. can be easily secured regardless of the

Further, according to this embodiment, the seat surface 24 of the head 14
A sealing material 2 is placed between the surface 26 of the fixed member 12 and
Since a part of 8 will be inserted in a thin film form,
This also ensures the airtightness.

In addition, in the above-mentioned embodiment, the sealing material 28
is applied only to the outer peripheral surface of the press-fit part 16,
In addition, it may also be applied to the inside of the accommodation groove 20 and the seat surface 24 of the head 14.

In addition, in the above-mentioned embodiment, the press-fit bolt 1
Although a plurality of protrusions are formed in the press-fit portion 16 of No. 0, it goes without saying that the effects of the present invention can be obtained even when no protrusions are formed.

In addition, various changes may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a state in which a press-fit bolt to which the present invention is applied is fixed to a member to be fixed. FIGS. 2 and 3 are diagrams for explaining that the housing groove is filled with a sealing material when the press-fitting bolt is press-fitted into the fixed member. 10: Press-fit bolt, 12: Fixed member, 14:
Head, 16: Press-fitting part, 18: Male screw part, 20: Accommodating groove, 22: Fitting hole, 24: Seat surface, 28: Sealing material.

Claims (1)

[Scope of Claim for Utility Model Registration] A head, a press-fitted part with a smaller diameter than the head, and a male threaded part with a smaller diameter than the press-fitted part in this order, and the press-fitted part is fitted into a member to be fixed from the side of the male threaded part. In a press-fit bolt that is fixed by press-fitting the head into a hole until the seat surface of the head comes into contact with the fixed member, the press-fit part is provided on the outer peripheral surface of the press-fit part and in a portion adjacent to the head. When the press-fitting bolt, the outer peripheral surface of which is coated with a sealing material, is press-fitted into the fitting hole of the fixed member, the press-fitting bolt is moved toward the head side by the peripheral edge of the fitting hole as the press-fitting occurs. A press-fit bolt, characterized in that a housing groove is formed around the entire circumference of the sealing material into which the sealing material is forcibly pushed in by being pressed between the head and the member to be fixed.