JPS6189819A - Molding die - Google Patents

Abstract

PURPOSE:To prevent burr from generating and consequently eliminate the need to finish-work for deburring by a structure wherein liners are supported through supporting means, which are shiftable normal to the axis center line of an insert protruded part, respectively by a stationary mold and by a movable mold. CONSTITUTION:After a steering wheel core metal 8, which serves as an insert, is set to a movable mold 13 by inserting its boss 8d onto a set pin 30, a mold is closed. In this case, even if the set spoke part core metal 8a is dislocated with respect to a stationary mold 12 and the movable mold 13, liners 17 and 18 are supported through supporting means 20 respectively by the stationary mold 12 and by the movable mold 13 so as to absorb the dislocation through the deflections of elastic bodies 22 in order for the liners 17 and 18 to block the outer periphery of the spoke part core metal 8a at the end surface of a molded coating layer 9. Consequently, even when molding material M is poured in a cavity 14, burr can be prevented from generating at the outer periphery of the spoke part core metal 8a, which protrudes from the coating layer 9 after molding.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a molding method that can prevent the occurrence of cracks on the outer periphery of an insert protrusion when molding a molded product in which a part of the insert is protruded. Regarding molds for use.

(Prior Art) Conventionally, in a molded product of this type in which a part of the insert is protruded, a spoke part core bar 8 as shown in FIG.
a・Ring part core metal 8b-post play) 8C and post 8d
Examples include a steering wheel 7 in which a steering wheel core bar 8 connected to the steering wheel core bar 8 is used as an insert, 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. .

Then, a mold 1 for forming the steering wheel 7
As shown in FIG. 8, it consists of a fixed mold 2 and a movable mold 3 each having cavity mold surfaces 2a and 3a, which form a predetermined cavity 4 when the mold is closed, and a movable mold 3 that forms a predetermined cavity 4 at a predetermined portion when the mold is closed. The fixed mold 2 and the movable mold 3 are equipped with a lunner gate 5, a sprue 6, etc. that allow the molding material M to be injected into the mold.
In order to prevent the coating layer 9 from being formed in areas other than predetermined portions of the spoke core metal 8a, recesses 2b to 3b were respectively formed to close the outer periphery of the spoke core metal 8a.

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

(Problem to be Solved by the Invention) However, inserts such as the steering wheel core metal 8 are formed by joining together a plurality of members: a spoke part core metal 8a, a ring part core metal 8b, a post plate 8c, and a post 8d. Because of this, there is a risk of variation in the assembly dimensional accuracy, and in consideration of the dimensional variation, four parts of each of the fixed mold 2 and the movable mold 3 that close the outer periphery of the spoke part core bar 8a that becomes the insert protrusion are 2b and 3b, as shown in FIG. 9, were formed with the upper limit of the tolerance for positional deviation larger than the cross section of the spoke part core metal 8a in the direction orthogonal to the axis.

Therefore, when the mold is closed, a space is created in that area, and the occurrence of flash during molding is unavoidable, making it necessary to perform a finishing process to remove flash after the mold is released.

This problem is not limited to steering wheel core metal, but also applies to molded products in which the insert itself is set in a mold after bending, etc., and then a part of the insert is made to protrude. Similarly, it is very difficult to prevent the occurrence of paris, especially when the insert itself is bent (means for solving the problem). A mold for molding a molded product in which a part of the mold is protruded, and includes a fixed mold and a movable mold that form a predetermined cavity when the mold is closed. A plurality of inserts are arranged to close the outer periphery of the insert protrusion on the end face of the molded part of the molded product, and each of the inserts is attached to a fixed die or By supporting the device movably, the above-mentioned problems are solved.

(Operations and Effects of the Invention) In the molding die according to the present invention, a plurality of inserts are arranged in the fixed mold and the movable mold to close the outer periphery of the insert protrusion on the end surface of the molded product molding part when the mold is closed. The inserts are each supported by a fixed mold or a movable mold via supporting means that allow them to move in a direction perpendicular to the axis of the insert protrusion. Even if the protruding position (position relative to the fixed mold and movable mold) is shifted, each insert is supported by the supporting means so that it can move relative to the fixed mold or the movable mold in a direction perpendicular to the axis of the insert protrusion. Because of this, the multiple inserts absorb the misalignment and close the outer periphery of the insert.

During molding, it is possible to prevent burr from occurring on the outer periphery of the insert protrusion at the end face of the molded part of the molded product, and the number of finishing steps after mold release can be reduced.

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 the dimensional viscosity and processing accuracy of the insert. 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 the mold surfaces for each cavity form a predetermined cavity 14 when the mold is closed. It is equipped with a fixed mold 12 and a movable mold 13 in which molds 12a and 13a are formed, and a runner gate 1 is provided at a predetermined portion so that molding material M can be injected into the cavity 14 when the mold is closed.
5. A sprue 16 and the like are provided, and the movable mold 13 is provided with a set pin 30 into which a post 8d of a steering wheel core metal 8 serving as an insert can be inserted.

The fixed mold 12 and the movable mold 13 each have a recess 12b-- in a direction perpendicular to the axis of the spoke core 8a, located at the end surface of the coating layer 9 on the outer periphery of the spoke core 8a to be molded. 13b are formed, and each recess 11
Inserts 17 and 18 are provided at 2b and 13b.

These two inserts 17 and 18 are respectively provided with recesses BB17a and 18a that correspond to the outer shape in the direction perpendicular to the axis of the spoke core metal 8a protruding from the end surface of the coating layer 9 to be molded and when the mold is closed. Each of the fixed mold 12 and the movable mold 13 is supported via a support means 20 that is set at the time of mold closing and is movable in a direction orthogonal to the axis of the boke part core metal 8a (Fig. 3). reference).

The support means 20 has insertion holes 17b-18 for the inserts 17 and 18.
b respectively, and the head 21a is inserted through the insertion holes 17b and 18.
The pin 21 is screwed onto the fixed mold 12 and the movable mold 13 so that it cannot be removed from b, and the inserts 17 and 18 are connected to the fixed mold 12, respectively.
- An elastic body 22 such as urethane rubber, which is disposed between the movable mold 13 and allows the inserts 17 and 18 to move in a direction perpendicular to the axis of the spoke core metal 8a set when the mold is closed.
It is composed of. The inserts 17 and 18 are connected by pins 21, respectively, to the head 21a of the pin 21, the circumference of the insertion holes 17b-18b, the gap S1, and the gap S1 between the pin 21 and the circumference of the insertion holes 17b-18b. It is movably supported relative to the fixed type 12 movable type 13 by a distance of S2, and the gaps S1 and S2 are replaced by the spoke part core metal 8a.
This is the upper limit of the tolerance for positional deviation.

Therefore, in this mold 11, the steering wheel core metal 8 serving as an insert is inserted into the post 8d by the set pin 30.
(See Figures 2 and 4), and then close the mold to see if the temporarily set spoke part core bar 8a has shifted its position relative to the fixed mold 12 and movable mold 13. Also, the inserts 17 and 18 are supported by a fixed mold 12 and a movable mold 13, respectively, so as to be movable in a direction perpendicular to the axis of the spoke part core metal 8a by means of a supporting means 20, and when the elastic body 22 is bent, the misalignment occurs. Covering layer 9 that absorbs and forms
The outer periphery of the spoke part core metal 8a on the end face is inserted into inserts 17 and 18.
As a result, even if the molding material M is injected into the cavity 14, it is possible to prevent the formation of cracks on the outer J gate of the spoke part core metal 8a protruding from the coating layer 9 after molding. The number of finishing steps for the #-shaped steering wheel 7 can be reduced compared to the conventional one.

In addition, in the conventional mold l, taking into account the misalignment of the set spoke core metal 8a between the fixed mold 2 and the movable mold 3,
Although it was necessary to carry out the insert fitting process within the upper limit of the tolerance, of course, if the predetermined inserts 17 and 18 are arranged as in the embodiment, the insert fitting process can be made unnecessary.

In addition, in the am l embodiment, the supporting means 20 composed of an elastic body 22 made of rubber or the like and a pin 21 is shown between the inserts 17 and 18 and the fixed mold 12 and the movable mold 13, respectively. Like the inserts 47 and 48 of the second embodiment shown in FIG.
The support means 50 may be configured with pins 51 similar to those in the embodiment, and the inserts 47048 may each have a tapered surface 47c.
- 48C 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, nests 17, 18, 47, 48
However, it is of course possible to divide the outer periphery of the insert protrusion into multiple parts such as 3 or 4 and arrange it on a fixed or movable mold to create a tapered surface. It may be configured such that the mutual nesting can close the outer periphery of the insert protrusion using the above.

Furthermore, in the first and second embodiments, nests 17-18, 47,
The supporting means 20 and 50 for movably supporting the fixed die 12 and the movable die 13 in a direction orthogonal to the axis of the insert protrusion include a pin 21 and an elastic body 22, a pin 51 and a coil spring 52. Fixed type 1
If the insert can be supported movably in the direction orthogonal to the axis of the insert protrusion, one end will be fixed to the fixed mold 12 and the movable mold 13, and the other end will be fixed to the insert. The support means may be composed only of biasing means such as an elastic body or a coil spring.

[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. Figure 4 is a cross-sectional view showing the state of the insert when the mold is opened in the same embodiment, Figure 5 is a cross-sectional view showing the second embodiment, and Figure 6 is the mold in the same embodiment. 7 is a plan view showing the steering wheel to be molded, FIG. 8 is a sectional view of a conventional mold, and FIG. 9 is the I of FIG.
It is a sectional view taken along line X-IX. l・11... Mold, 2.12... Fixed mold, 3.13
...Movable rack, 8...(Insert) Steering wheel core metal, 8a... Spoke part core metal, 9... (Molded part) Covering layer, 17, 18, 47, 48... Nesting ,2
0.50...Supporting means. Patent applicant No. 1 Figure 22 18 13b 21 22 U! 87 Figure 9 Figure 53 5D Figure 8

Claims (1)

[Claims] A mold for molding a molded product in which a part of the insert is protruded, which comprises a fixed mold and a movable mold that form a predetermined cavity when the mold is closed, and further includes an end surface of the molded part of the molded product when the mold is closed. A plurality of inserts for closing the outer periphery of the insert protrusion are disposed on the fixed mold and the movable mold, respectively, and the inserts are movable in a direction orthogonal to the axis of the insert protrusion through support means. A molding die characterized in that each of the molds is supported by the fixed mold or the movable mold.