JP3131707B2 - Method for manufacturing resin molded article having insert fitting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for tightening bolts.
Purpose such as coupling with other members or using as sliding parts
In a state where the axial end faces of the insert fitting is exposed from the resin molded article surface, the method for producing a resin molded article insert fittings are integrated.

[0002]

2. Description of the Related Art In a resin molded product obtained by disposing an insert fitting in a mold cavity and simultaneously molding the resin material with the mold and integrating the insert fitting.
As shown in FIG. 3, when it is desired to expose the axial end face of the insert fitting 2 to the surface of the resin molded product 1 for the purpose of coupling with another member by tightening a bolt or using as a sliding portion. There is.

[0003] Conventionally, as shown in FIG. 4, such a resin molded product 1 has surfaces (hereinafter, referred to as exposed surfaces) 2a and 2b of an insert metal fitting 2 to be exposed, and a cavity formed by dies 3 and 4. It is obtained by bringing the inner surfaces 3a and 4a into close contact with each other and filling the periphery thereof with a resin material. In this case, conventionally, the insert fitting 2 is attached to the exposed surface 2a.
Cutting is performed so that the dimension between a and 2b becomes a dimension obtained by adding a predetermined crush amount to the dimension L between the inner faces 3a and 4a of the molds 3 and 4, and the exposed faces 2a and 2b and the mold inner faces 3a and It is general to prevent resin burrs from appearing at the contact portion 4a.

[0004]

However, if the crushing amount at the time of mold clamping is excessive, the mold cannot be clamped and the mold is damaged, or the insert fitting 2 is broken by excessive stress and the bolt is tightened. With other members
And may not function as a sliding part. Conversely, if it is too small, burrs will leak to the exposed surfaces 2a and 2b, so that the dimensional tolerance of the insert fitting 2 in the crushing direction must be suppressed to a strict value of ± 0.02 with respect to the dimension L. Therefore, the cutting work of the insert fitting 2 is performed with high accuracy, and considerable labor and cost are required.

[0005] In particular, if the processing of the insert fitting 2 is entirely performed by cutting, there is not much problem. However, as in the case of sintering, high-precision processing can be performed only by that step.
If it can be obtained by a difficult processing method, cutting as additional processing is necessary, so the original advantages of the sintering process , such as lower cost and shorter time than cutting, will not be used. . Therefore, according to the prior art, when the resin molded product 1 in which the axial end face of the insert fitting 2 is exposed is obtained, the cost is high due to the high precision cutting of the insert fitting 2 at present.

The present invention has been made in view of the above circumstances, and the technical problem thereof is that a resin molding
The destruction of the generation and insert fittings of Bali leakage at the time of
It can be reliably prevented, and other
For the purpose of connecting with members and using as sliding parts,
The axial end surface of the insert bracket made of
To obtain an integrated resin molded product exposed from
It is to obtain a tree fat moldings having insert fittings.

[0007]

Means for Solving the Problems The technical problems described above are:
This can be effectively solved by the present invention. In other words, the manufacturing method of the present invention can be applied to other parts by tightening bolts.
For the purpose of bonding with materials and using as sliding parts,
The end face in the axial direction of the insert metal fitting made of resin
In order to obtain an integrated resin molded product in a state exposed from the
Has endless continuous projections on the outer peripheral portion of the axial end face
And the axial end face on the inner peripheral side of the projection is an exposed face.
After sintering , a sizing is performed to compress the tip of the projection by a required amount, and the insert is placed in the mold with the projection being in close contact with the inner surface of the mold. The inserter in the mold
The outer peripheral space of the metal fitting is filled with a resin material .

[0008]

[Function] Continuous endless metal insert made of sintered body
The projections that have passed through the sizing process
Because it is finished with precision, in the resin molding process,
It is arranged so as to be able to come into close contact with the inner surface of the mold. And mold clamping
At the same time, the protrusions on the inner surface of the mold should be
It is uniformly pressed all around the circumference, and the press fitting is
The resin material filled in the outer peripheral space of is sealed.

[0009]

Next, the manufacturing method of the present invention will be described with reference to an embodiment shown in FIGS. In the molding process shown in FIG. 1, reference numeral 10 denotes a cylindrical insert, 20 denotes a resin material in the process of being integrally molded on the outer periphery of the insert 10, and 30 denotes a molding die for filling the resin 20. Show some. As shown in FIG. 2, the insert fitting 10 is integrated with the axial end face thereof as an exposed face 11 and exposed to the inner diameter of the end face of the resin molded product 21.

The insert fitting 10 is manufactured through a sintering step through a sintering step. An outer diameter portion of the exposed surface 11 on the resin material 20 side has a continuous annular shape. Are formed. The protrusions 12 are used to form the inner surface 3 of the mold 30 during the molding process of the resin molded product 21.
1 is pressed with an appropriate amount of squeezing. Typically, the sectional shape is an R shape such as a semicircle as shown in FIG. It is appropriately determined in consideration of dimensions and the like.

The arc-shaped tip of the protrusion 12 can easily give a required amount of crushing deformation in a sizing step performed after the insert fitting 10 is formed by sintering . For this reason, the dimension of the insert fitting 10 in the squeezing direction (axial direction in the present embodiment) in the mold 30 is easily determined by the sizing, despite the tight tolerance of ± 0.02. It can be within the tolerances, so that the protrusions 12 can be given a proper crushing allowance.

In the molding process of the resin molded product 21 shown in FIG. 1, the insert fitting 10 inserted into the cavity of the mold 30 is pressed by the mold so that the annular projection 12 is properly pressed against the inner surface 31 of the mold 30. Close all around the generation. Therefore, when filling the resin material 20 in the outer peripheral space of the insert fitting 10 in the cavity, since the resin material 20 is sealed by the contact portion of the projection 12 and the mold inner surface 31, axially exposed surface of the insert fitting 10 No burrs leak to the side 11, and the projection 12 is integrated with the resin molded product 21 with the inner diameter side exposed from the resin surface 20 a.

In the above embodiment, the insert 1
The projection 12 is formed in an annular shape because 0 is cylindrical and the exposed surface 11 is provided on the end surface, but the shape is appropriately changed according to the shape of the exposed surface 11.

[0014]

According to the manufacturing method of the present invention, the sintered body
The endless continuous projection of the insert
Finished to a predetermined accuracy through the
In the resin molding process,
It is arranged in a state to obtain. When closing the mold, respond to the clamping force.
In the meantime, the protrusion has an appropriate pressing margin on the inner surface of the mold.
It is uniformly pressed all around the circumference, and the press fitting is
The resin material filled in the outer peripheral space of is sealed. Also,
Excessive stress is required at the pressure contact part to prevent resin leakage
Therefore, the axial end face of the insert
Cracks and deformation due to the excessive stress do not occur. But
Therefore, the function as a sliding part or the connection with other members is impaired.
There is no fear.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a molding step showing an embodiment of the present invention together with an insert fitting, a resin molded product integrally formed therewith, and a molding die.

FIG. 2 is a partial front view of a resin molded product into which an insert fitting is integrated by the manufacturing method of the present invention.

FIG. 3 is a partial front view showing an example of a resin molded product in which insert fittings are integrated by a conventional manufacturing method.

FIG. 4 is an explanatory diagram of a molding step showing an example of a conventional manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Insert metal fittings 11 Exposed surface 12 Projection 20 Resin material 20a Resin surface 21 Resin molded product 30 Mold 31 Inner surface

Claims (1)

(57) [Claims] (1) as a fastening surface or a sliding surface with another member;
The axial end face of the insert fitting 10 to be formed has a resin surface 20a.
A method for manufacturing a resin molded product 21 in which an insert fitting 10 is integrated in a state of being exposed from an end surface , wherein an endless continuous projection 12 is formed on an outer peripheral portion of the axial end surface.
And the axial end face on the inner peripheral side of the projection 12
The insert metal fitting 10 serving as the exposed surface 11 and forming by sintering, and sizing step of the required amount of compression processing the tip of the projection 12, the insert fitting 10 the projection 12 has intimate contact with the inner surface 31 of the mold 30 While placed in the mold 30 in the state ,
Outer circumference of the insert fitting 10 in the mold 30
Method for producing a resin molded article having an insert fitting characterized by comprising a resin material 20 from the filling molding space.