JPH0319048B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention provides a molding method that can prevent burrs from forming on the outer periphery of an insert protrusion when molding a molded product in which a part of the insert protrudes. Regarding molds for use.

(Prior Art) Conventionally, in a molded product of this type in which a part of the insert is protruded, as shown in FIG. The steering wheel 7 includes, as an insert, a steering wheel core bar 8 to which the steering wheel core bar 8d is connected, and a coating layer 9 made of a synthetic resin material is formed on a part of the outer periphery of the spoke part core bar 8a and the outer periphery of the ring part core bar 8b. It will be done.

As shown in FIG. 8, the mold 1 for molding the steering wheel 7 includes a fixed mold 2 and a movable mold 3 each having cavity mold surfaces 2a and 3a that form a predetermined cavity 4 when the mold is closed. It also has a cavity 4 in a designated area when the mold is closed.
It is equipped with a runner gate 5, a sprue 6, etc. so that the molding material M can be injected into the inside, and also has a fixed mold 2.
and the movable mold 3 have a spoke part core bar 8 when the mold is closed.
At the part a, the coating layer 9 is attached to the spoke core bar 8.
Recesses 2b and 3b were respectively formed to close the outer periphery of the spoke part core bar 8a so that the recesses 2b and 3b would not be formed in areas other than the predetermined portions of the spoke part core bar 8a.

During molding, the steering wheel core bar 8 was set in the movable mold 3 by inserting the boss 8d into the set pin 10 provided on the movable mold 3, and after the mold was closed, the molding material M was injected and molded.

(Problem to be Solved by the Invention) However, the inserts of the steering wheel core metal 8, etc.
b. Since the boss plate 8c and the boss 8d are formed by joining a plurality of members, there is a risk that the dimensional accuracy of the assembly may vary.Taking this dimensional variation into account, the spokes that will become the insert protrusions are As shown in FIG. 9, the recesses 2b and 3b of the fixed mold 2 and the movable mold 3, which close the outer periphery of the spoke core bar 8a, have a tolerance for positional deviation larger than the cross section in the direction perpendicular to the axis of the spoke core bar 8a. It was formed at the upper limit.

Therefore, when the mold is closed, a space is created in that area,
The generation of burrs during molding was unavoidable, and a finishing process to remove burrs was required after release from the mold.

This problem is not limited to steering wheel core metals, but also applies to molded products in which the insert itself is set in a mold after bending, etc., and then molded with a part of the insert protruding, due to the processing accuracy. The same is true because variations in the insert are taken into account, and it is extremely difficult to prevent burrs from occurring, especially when the insert itself is curved.

(Means for Solving the Problems) The present invention is a mold for molding a molded product in which a part of the insert is protruded, and includes a fixed mold and a movable mold that form a predetermined cavity when the mold is closed. A plurality of nests are arranged in each of the fixed mold and the movable mold at positions that extend around the entire outer periphery of the insert protrusion and touch the end surface of the molded part of the molded product when the mold is closed. , for closing the entire circumference of the insert protrusion by bringing the plurality of inserts into contact with the outer periphery of the insert protrusion, respectively;
A closing recess into which the insert protrusion fits and a mold surface that forms the end face of the molded part of the molded product are provided to restrict movement of the insert protrusion in a direction parallel to the axis of the molded product, and to prevent the insert from moving in a direction parallel to the axis of the insert. The insert is movable along a plane orthogonal to the axis of the protrusion and is housed in a fixed or movable housing recess, and is further interposed between the housing recess and the insert so that the insert protrudes. Via a support means that has flexibility to follow the movement of the insert along a plane perpendicular to the axis of the insert and urges the insert in a direction toward the insert protrusion, By supporting the fixed type or movable type, the above-mentioned problems can be solved.

(Operations and Effects of the Invention) In the molding die according to the present invention, when the mold is closed, the set insert is positioned relative to the fixed mold and the movable mold at a portion protruding from the end surface of the molded product molding part (insert protrusion Even if the fixed and movable types are disposed at different positions in the direction perpendicular to the axis of the insert, the biasing force of the supporting means that biases the insert in the direction of approaching the insert protrusion allows it to be stored in the specified position. Each nest stored in the recess for
While moving along the plane perpendicular to the axis of the insert protrusion, the insert protrusion absorbs the deviation, fits into each closing recess, and as one unit covers the entire outer circumference of the insert protrusion. This will result in blockage. In addition, since the support means that biases the insert has flexibility, even if the insert moves along a plane perpendicular to the axis of the insert protrusion, the biasing force thereof will not be significantly reduced. The insert can be supported and biased while being bent without being bent, and the insert can be reliably brought closer to the insert protrusion.

In addition, when the respective inserts are integrated to close the entire outer periphery of the insert protrusion, the inserts are housed in the predetermined storage recess and rotate in a direction parallel to the axis of the insert protrusion. Since it moves without shifting, the mold surface of the insert can be appropriately placed at the end surface portion of the molding part of the molded product.

Therefore, it is possible to prevent burrs from being generated on the outer periphery of the insert protrusion at the end face of the molded part of the molded product during molding, and it is possible to reduce the number of finishing steps after mold release.

In addition, with conventional molds, it was necessary to process the part where the insert protrusion is located at the upper limit of the tolerance (insert matching process), taking into account variations in insert assembly dimensional accuracy and processing accuracy. In the invention, since the insert closes the outer periphery of the insert protrusion as described above, the conventional insert matching process can be made unnecessary.

(Example) As shown in FIG. 1, the mold 11 of the first example is used to mold a steering wheel 7 similar to the conventional one, and each cavity mold surface forms a predetermined cavity 14 when the mold is closed. 12a, 13a
A fixed mold 12 and a movable mold 13 are formed.
In addition, a runner gate 15, a subbleum 16, etc. are provided at a predetermined portion so that the molding material M can be injected into the cavity 14 when the mold is closed, and the movable mold 13 is capable of inserting a boss 8d of the steering wheel core bar 8, which serves as an insert. A set pin 30 is provided.

The fixed mold 12 and the movable mold 13 each have a spoke core metal 8a at a portion located on the end surface of the coating layer 9 on the outer periphery of the spoke core metal 8a to be molded.
Storage recesses 12b, 13 in a direction perpendicular to the axis of
b are formed, each with a storage recess 12
Inserts 17 and 18 are arranged in b and 13b. The shapes of these storage recesses 12b and 13b are such that the length dimension along the axis of the spoke core metal 8a matches the length dimension in the same direction of each insert 17 and 18, and Each insert 17, 18 has a shape in which the length dimension in the direction perpendicular to the axis of 8a is larger than the dimension in the same direction of each insert 17, 18.
18, which can restrict the movement of the spoke part core metal 8a in the direction parallel to the axis, and which can restrict the movement of the spoke part core metal 8a in the direction parallel to the axis.
It is formed so that it can move along a plane perpendicular to the axis of the

The two inserts 17 and 18 correspond to the outer shape of the spoke part core bar 8a protruding from the end surface of the molded coating layer 9 in a direction perpendicular to the axis, and are designed to close the entire circumference of the spoke part when the mold is closed. It is provided with closing recesses 17a and 18a into which the core bar 8a is fitted.

Moreover, these inserts 17 and 18 are provided with mold surfaces 17c and 18c that mold the end surfaces of the coating layer 9 when the mold is closed.

Furthermore, these inserts 17 and 18 are placed in the storage recess 1 with respect to the fixed mold 12 and the movable mold 13, respectively.
2b, 13b and the inserts 17, 18, and has flexibility that can follow the movement of the inserts 17, 18 along a plane orthogonal to the axis of the spoke part core metal 8a when the mold is closed. The inserts 17 and 18 are supported via a support means 20 that urges the inserts 17 and 18 toward the spoke core metal 8a (see FIG. 3).

The support means 20 of the first embodiment is composed of a pin 21 and an elastic body 22.

The pin 21 is inserted into the insertion holes 17b of the inserts 17 and 18,
18b respectively, and the head 21a cannot be removed from the insertion holes 17b, 18b so that the fixed type 12.
It is screwed onto the movable mold 13.

The elastic body 22 is made of flexible urethane or the like, and is disposed between the inserts 17 and 18 and the fixed mold 12 and the movable mold 13, respectively, and connects the inserts 17 and 18 to the spokes set when the molds are closed. Part core metal 8
Assuming that it is movable along a plane perpendicular to the axis of a,
The inserts 17 and 18 are urged to approach the spoke core metal 8a.

The inserts 17 and 18 each have a pin 21
Accordingly, the head 21a of the pin 21 and the insertion hole 17
b, 18b and the gap S2 between the pin 21 and the circumferential surface of the insertion holes 17b and 18b. Spoke part core metal 8
This is the upper limit of the tolerance for positional deviation in a.

Therefore, in this mold 11, the steering wheel core bar 8 serving as an insert is set in the movable mold 13 by inserting the boss 8d into the set pin 30 (see FIGS. 2 and 4), and then closing the mold. ,
Even if the set spoke part core metal 8a is shifted in position with respect to the fixed mold 12 and the movable mold 13 in the direction perpendicular to its axis, it will not move in the direction approaching the spoke part core metal 8a. Due to the biasing force of the biasing support means 20, the storage recesses 12b, 13b
While the inserts 17 and 18 housed therein move along a plane perpendicular to the axis of the spoke part core bar 8a,
The displacement is absorbed and each closing recess 17a, 18a
The spoke part core metal 8a is fitted into the spoke part core metal 8a, and the entire outer periphery of the spoke part core metal 8a is closed off.

Note that the support means 20 that urges the inserts 17 and 18
Since it is provided with the flexible elastic body 22, even if the inserts 17 and 18 move along a plane perpendicular to the axis of the spoke part core bar 8a, the biasing force thereof is significantly reduced. Insert 1 without bending
7, 18 are supported and biased, the inserts 17, 18
can be reliably brought close to the spoke core metal 8a.

In addition, when the respective inserts 17 and 18 are integrated to close the entire outer periphery of the spoke core bar 8a, the inserts 17 and 18 are connected to the storage recess 12b,
13b and move without shifting in a direction parallel to the axis of the spoke part core metal 8a, the mold surfaces 17c and 18 of the inserts 17 and 18 are appropriately arranged at the molding site of the end surface of the covering layer 9. can be done.

Therefore, since the inserts 17 and 18 neatly close the outer periphery of the spoke core bar 8a on the end face of the coating layer 9, even if the molding material M is injected into the cavity 14 after the mold is closed, it will not flow from the coating layer 9. It is possible to prevent the occurrence of burrs on the outer periphery of the protruding spoke part core metal 8a, and the steering wheel 7 is released from the mold after molding.
The number of finishing steps can be reduced compared to conventional methods.

In addition, in the conventional mold 1, it was necessary to take into account the misalignment of the set spoke part core metal 8a between the fixed mold 2 and the movable mold 3, and perform the insert matching process at the upper limit of the tolerance. By arranging predetermined inserts 17 and 18 as in the embodiment, the insert matching process can be made unnecessary.

In addition, in the first embodiment, the nests 17 and 1 are respectively
8 and the fixed mold 12 and the movable mold 13, a supporting means 20 composed of an elastic body 22 made of rubber or the like and a pin 21 is shown, The elastic body may be formed of a coil spring 52 like the elements 47 and 48, and the support means 50 may be formed of a pin 51 similar to that of the first embodiment. Also,
Tapered surfaces 47c and 48 are provided on the inserts 47 and 48, respectively.
c may be formed, and when the fixed mold 12 and the movable mold 13 are closed, the tapered surfaces 47c and 48c may be brought into sliding contact to close the outer periphery of the set insert 80.

In addition, in the first and second embodiments, inserts 17, 18, 4
7 and 48 are shown as being formed by a pair of inserts, but of course, inserts in which the outer periphery of the insert protruding part is divided into many parts such as 3 or 4 parts can be arranged in a fixed mold or a movable mold, for example. Alternatively, the tapered surfaces may be used so that the mutual inserts can close the outer periphery of the insert protrusion.

Furthermore, in the first and second embodiments, the inserts 17, 1
8, 47, 48 with respect to the fixed mold 12 and the movable mold 13.
, an elastic body 22, a pin 51, and a coil spring 52 are shown. However, for the fixed mold 12 and the movable mold 13, the inserts are moved by following the movement of the inserts along a plane perpendicular to the axis of the insert protrusion, and the inserts are moved relative to the insert protrusion. If it can be supported so as to bias it in the approaching direction, only biasing means such as a flexible elastic body or a coil spring with one end fixed to the fixed mold 12 and the movable mold 13 and the other end fixed to the nest can be used. The supporting means may also be configured with:

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a mold showing a first embodiment of the present invention, FIG. 2 is a sectional view showing a state in which a steering wheel core metal is set in the mold of the same embodiment, and FIG.
The figure is a cross-sectional view of FIG. 1, FIG. 4 is a cross-sectional view showing the state of the insert when the mold is opened in the same embodiment, FIG. 5 is a cross-sectional view showing the second embodiment, and FIG. 6 is a cross-sectional view of the same embodiment. A sectional view showing the state when the mold is opened in the example,
FIG. 7 is a plan view showing a steering wheel to be molded, FIG. 8 is a cross-sectional view of a conventional mold, and FIG. 9 is a cross-sectional view taken from FIG. 1,11...mold, 2,12...fixed mold, 3,
13...Movable type, 8...(insert) steering wheel core metal, 8a...spoke part core metal, 9
... (molding part) coating layer, 12b, 13b ... storage recess, 17, 18, 47, 48 ... insert, 17
a, 18a...Closing recess, 17c, 18c...
Mold surface, 20, 50...supporting means.

Claims (1)

[Claims] 1. A mold for molding a molded product with a part of the insert protruding, comprising a fixed mold and a movable mold that form a predetermined cavity when the mold is closed, the fixed mold and the movable mold include, when the mold is closed,
A plurality of inserts are respectively disposed at positions extending over the entire outer periphery of the insert protrusion and in contact with an end surface of the molded part of the molded product, and each of the plurality of inserts is arranged around the outer periphery of the insert protrusion. a closing recess into which the insert protrusion is fitted, for abutting the outer periphery and closing the entire outer periphery of the insert protrusion, and a mold surface for forming an end face of the molded part of the molded product; and formed in the fixed type or movable type so that movement in a direction parallel to the axis of the insert protrusion is regulated and movable along a plane orthogonal to the axis of the insert protrusion. The insert is housed in the storage recess, and is further interposed between the storage recess and the insert, and is capable of following the movement of the insert along a plane perpendicular to the axis of the insert protrusion. A molding characterized in that the insert is supported by the fixed mold or the movable mold via a support means that has flexibility and urges the insert in a direction toward the insert protrusion. Mold for use.