JPH07205159A - Mold - Google Patents

Abstract

PURPOSE:To stabilize quality of a product by facilitating removal of splash. CONSTITUTION:A core 1 is disposed at a center, an outer mold 8 is disposed outside, a lower mold 6 is disposed at lower parts of the core 1 and the mold 8, an upper mold 10 is disposed at upper parts of the core 1 and the mold 8 to form a cavity 12 among the four molds in the case of clamping, and splash grooves 13, 14, 15, 16 are respectively formed between the core 1 and the mold 6, between the core 1 and the mold 10, between the mold 8 and the mold 6, and between the mold 8 and the mold 10. The groove 13 formed between the mold 6 and the core 1 has a combination of an annular groove 7a having at least two partition walls opened at the core 1 side, and a plurality of grooves 2a opened at the core 1 side. Thus, a splash formed at the part of the grooves 7a, 2a is formed of a partly cut annular part and a plurality of semispherical parts formed integrally with the one surface of the annular part in an axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die effective for molding an annular rubber molded product, and more particularly to a molding die which can easily remove burrs.

[0002]

2. Description of the Related Art Generally, a molding die for molding an annular rubber molded product is constructed as shown in FIG.

That is, this molding die is located in a substantially columnar core die 21, an annular outer die 28 which surrounds the core die 21, and a lower portion of the core die 21 and the outer die 28. Lower mold 26 and upper mold 3 located above core mold 21 and outer mold 28
0 and the cavity 32 is formed in a portion surrounded by these four molds at the time of mold clamping, and between the upper mold 30, the lower mold 26 and the outer peripheral portion of the core mold 21, Burr grooves 23, 24, 2 communicating with the cavity 32 between the upper die 30 / lower die 26 and the inner peripheral portion of the outer die 28.
5 and 26 are formed, and a rubber molded product that matches the cavity 32 and a burr 3 that matches each burr groove 23, 24, 25, 26
8 and 8 are integrally formed.

In this case, the upper die 30, the lower die 26 and the core die 2
The burr grooves 23 and 24 formed between the outer peripheral portion of the core mold 1 and the outer peripheral portion of the core mold 21 are located on the outer peripheral side of the core die 21, and are formed in the burr groove 23 between the lower die 26 and the core die 21. 38 is a core type 21
Since it is formed in a state of surrounding (see FIG. 7), it must be cut by an appropriate means to remove it, and its work is troublesome. Moreover, the quality of the product may be affected by forgetting to remove the burr 38.

On the other hand, in order to solve the above problems, a forming die as shown in FIG. 8 has been proposed, and this forming die is formed between the lower die 26 and the core die 21. The burr groove 23 is configured by an annular groove 26a having a partition wall 26b in a part of the lower die 26 or the core die 21 (lower die 26 in this example) (FIG. 9). Since the burr 40 formed in this burr groove has an annular shape with a part cut away, it does not require any complicated work such as cutting to remove it, and is easily removed by blowing air or the like. It will be possible (see FIG. 10).

However, as shown in FIG. 11, since one surface in the axial direction of the burr 40 is a completely flat surface, that portion adheres to the core mold 21 side depending on the rubber material,
Product quality will be affected.

In order to prevent such sticking to the core mold 21, both the core mold 21 and the lower mold 26 are partially provided with partition walls 26.
The burr groove may be formed by forming the annular groove 26a having b and combining them, but it is difficult to match the positions of the partition walls 26b of the annular grooves 26a with the usual core mold 21 shape. Becomes Therefore, as shown in FIG. 12 and FIG. 13, a part of the center die 21 must be processed into a square shape or a semicircular shape, which not only takes time and labor but also is difficult to maintain the processing accuracy. Becomes Further, when the core die 21 having such a shape is used, a problem such as galling may occur, which may affect the quality of the product.

The present invention solves the above-mentioned problems of the conventional ones, and an object of the present invention is to provide a mold capable of easily removing burrs and ensuring the quality of products. To do.

[0009]

In order to solve the above problems, the present invention has a core mold at least in the center,
An annular cavity is formed around the core die during mold clamping, and an annular burr groove is formed between the outer periphery of the core die and another die so as to communicate with the cavity. In a molding die comprising a plurality of dies, the burr groove is
Corresponding to an annular groove having partition walls at least at two locations drilled in either the outer peripheral portion of the core mold or another mold, and the annular groove of the outer periphery of the core mold or any other mold It is constituted by a plurality of recessed grooves formed in a portion to be formed, and at the time of mold clamping, the recessed grooves are not located on at least one partition wall of the annular groove.

[0010]

According to the present invention, by adopting the above-mentioned means, the burr groove is an annular groove having partition walls at least at two positions which are formed in either the core mold or the other mold. It will be formed by a combination with a plurality of recessed grooves formed in the other, in this case, so that a part of the plurality of recessed grooves is not located in at least one partition wall of the annular groove,
Since the position of the partition wall of the annular groove and the interval between the plurality of concave grooves are set, the burr formed in the burr groove has an annular shape in which at least a part is cut, and the bottom surfaces of both grooves are rounded. By providing it, the both surfaces in the axial direction are not formed to be flat.

[0011]

Embodiments of the present invention shown in the drawings will be described below. 1 and 2 show an embodiment of a molding die according to the present invention. The molding die comprises a core mold 1 having a substantially columnar shape, and a core mold 1 surrounding the core mold 1. An annular outer mold 8 located at a predetermined distance outwardly in the radial direction of 1
And a lower mold 6 located below the core mold 1 and the outer mold 8, and an upper mold 10 located above the middle mold 1 and the outer mold 8.

On the upper surface of the lower die 6, there is integrally formed an annular convex portion 7 which projects upward in the drawing, and the lower surfaces of the core die 1 and the outer die 8 come into contact with the convex portion 7. In addition, a hole 6a penetrating in the vertical direction in the drawing is formed in the center of the convex portion 7 so that the lower end of the core mold 1 is fitted in the hole 6a. It has become.

Further, on the upper surface side of the convex portion 7, an annular groove 7a having a radial cross section having a partition wall 7b partially on the inner peripheral side is formed.
A groove 7c having a semicircular cross-section is formed on the outside thereof in a ring shape so as to be concentric with the annular groove 7a on the inner peripheral side. In this case, the partition wall 7b of the annular groove 7a on the inner peripheral side may be provided at at least two places, and the thickness and position thereof are the same as the intervals and sizes of the plurality of concave grooves 2a of the core mold 1 described later. It should be set accordingly. In this embodiment, the holes 6a are provided at opposite positions (two positions) with the center of the hole 6a as the center.

The core die 1 has a large diameter portion 2,
The medium diameter portion 3 and the small diameter portion 4 are formed in three stages, and an overhanging portion 5 that annularly projects outward in the radial direction is integrally formed at an appropriate position on the outer peripheral surface of the large diameter portion 2. With the small diameter portion 4 and the medium diameter portion 3 fitted in the hole 6a of the lower die 6, the lower surface side of the large diameter portion 2 contacts the upper surface side of the convex portion 7 of the lower die 6.

The lower die 6 on the lower surface side of the large diameter portion 2
As shown in FIG. 4, a plurality of concave grooves 2a having a spherical inner surface are formed at predetermined intervals in a portion of the convex portion 7 corresponding to the annular groove 7a on the inner peripheral side. In this case, when the molds are clamped, even if the lower mold 6 and the core mold 1 rotate relative to each other, a part of the plurality of concave grooves 2a is located inside the lower mold 6. It is set so as not to be located at the position of at least one partition wall 7b of the annular groove 7a on the circumferential side. Further, a groove 2b having a semicircular cross section is formed in an annular shape on the outer peripheral edge portion on the upper surface side of the large diameter portion 2 over the entire circumference thereof.

The outer die 8 has an annular shape, and a convex portion 9 that projects radially inward in an annular shape is integrally formed on the inner peripheral surface, and the lower surface side of the convex portion 9 is a convex portion of the lower die 6. It comes into contact with the upper surface side of 7. In this case, a groove 9a having a semicircular cross section is formed in an annular shape over the entire circumference in a portion corresponding to the groove 7c on the outer peripheral side of the convex portion 7 of the lower mold 6 on the lower surface side of the convex portion 9. Further, a groove 9b having a semicircular cross section is formed in an annular shape on the inner peripheral edge portion on the upper surface side of the convex portion 9 over the entire circumference.

The upper die 10 has a disc shape and
A convex portion 11 projecting downward in the drawing is integrally formed in the central portion, and the lower surface side of the convex portion 11 abuts on the upper surface of the core mold 1 and the upper surface of the convex portion 9 of the outer mold 8. ing. In this case, in the portion corresponding to the groove 2b on the upper surface side of the large diameter portion 2 of the core mold 1 on the lower surface side of the convex portion 11, a groove 10a having a semicircular cross section is formed in an annular shape over the entire circumference. Further, in a portion corresponding to the groove 9b on the upper surface side of the convex portion 9 of the outer die 8 which is provided outside the groove 10a, a groove 10b having a semicircular cross section over the entire circumference is formed in an annular shape. Has been drilled.

Then, the molding die composed of the four dies 1, 6, 8 and 10 constructed as described above is clamped to form the core die 1, the outer die 8, the lower die 6 and the upper die 10. An annular cavity 12 is formed in the enclosed portion, and a plurality of concave grooves 2a on the lower surface side of the large diameter portion 2 of the core die 1 and an annular groove 7a on the inner peripheral side of the convex portion 7 of the lower die 6 are formed. Between the groove 2b on the upper surface side of the large diameter portion 2 of the core mold 1 and the groove 10a on the inner peripheral side of the convex portion 11 of the upper mold 10, and the groove on the outer peripheral side of the upper surface of the convex portion 7 of the lower mold 6. 7c and the groove 9a on the lower surface side of the convex portion 9 of the outer mold 8, and between the groove 10b on the outer peripheral side of the convex portion 11 of the upper mold 10 and the groove 9b on the upper surface side of the convex portion 9 of the outer mold 8. Burr grooves 13, 14, 15, 16 communicating with the cavity 12 are formed, respectively, and a rubber molded product and the respective burr grooves 13, 14, 1 matching the cavity 12 are formed. Burrs that match the 16 is adapted to be integrally formed.

In this case, the annular groove 7a on the inner peripheral side of the convex portion 7 of the lower die 6 and the plurality of concave grooves 2a on the lower surface side of the large diameter portion 2 of the core die 1 are formed.
As shown in FIG. 5, the burr 18 formed between
An annular portion 19 having a cutout portion, one surface in the axial direction being a rounded surface, and the other surface being a flat surface, and a plurality of hemispherical portions 20 integrally formed on the flat surface of the annular portion 19. And at least one notch is open.

Therefore, the shape of the burr 18 can be an annular shape with a part cut away, and both axial surfaces can be spherical or rounded surfaces, which allows cutting by some method. Easy and unnecessary burr 18
Can be removed. In addition, since both surfaces in the axial direction are rounded surfaces or spherical surfaces, there is no sticking to the core mold 1 unlike the conventional flat surface, and the quality of the product is not affected. .

In the above embodiment, a plurality of concave grooves 2a are provided on the core die 1 side and an annular groove 7a is provided on the lower die 6 side, and the burr groove 13 is formed by a combination thereof. An annular groove may be provided on the side, a plurality of concave grooves may be provided on the lower die 6 side, and a burr groove may be configured by a combination thereof. Further, the bottom surfaces of the plurality of concave grooves 2a and the annular groove 7a are spherical surfaces or rounded surfaces, but the invention is not limited to this, and projections may be formed on both surfaces in the axial direction of the burr to be molded. Further, in the above description, the molding die is composed of four dies, but the present invention is not limited to this, and
One, three, or four or more molds may be formed, and the core mold is located at least in the center, and the burr groove and the cavity are formed outside the core mold. Anything is fine.

[0022]

As described above, according to the present invention, the burr groove formed on the outer side of the core mold is divided into at least two locations which are formed in either the outer peripheral portion of the core mold or another mold. It is composed of an annular groove having a wall and a plurality of concave grooves formed at predetermined intervals in a portion corresponding to the outer peripheral portion of the core die or the other annular groove of the other die, and mold clamping At this time, the position of the partition wall of the annular groove and the interval between the plurality of concave grooves are set so that a part of the plurality of concave grooves is not located in at least one partition wall of the annular groove. The burr formed inside has an annular shape with at least a portion cut away, and the bottom surfaces of the annular groove and the plurality of concave grooves are formed into rounded surfaces or spherical surfaces, so that both axial surfaces are rounded surfaces or spherical surfaces. Can be Therefore, when removing the burr, no complicated work such as cutting by any method is required, the removal of the burr becomes extremely easy, and since there are no flat portions on both sides in the axial direction of the burr, the burr is eliminated. It has an excellent effect such that the product does not stick to the core mold and becomes hard to be peeled off, and a product of stable quality can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing an entire molding die according to the present invention.

FIG. 2 is an enlarged view of a portion A shown in FIG.

FIG. 3 is a partial view of what is shown in FIG. 2 viewed from a B direction.

FIG. 4 is a partial view of what is shown in FIG. 2 viewed from a direction C.

5 is a schematic view showing burrs formed by the forming die shown in FIG. 1. FIG.

FIG. 6 is a schematic view showing an entire example of a conventional molding die.

FIG. 7 is a schematic view showing the relationship between the core mold and the burr shown in FIG.

FIG. 8 is a partial view showing another example of a conventional molding die.

FIG. 9 is a partial view of what is shown in FIG. 8 as seen from the F direction.

10 is a schematic view showing a burr formed by the one shown in FIG.

11 is an explanatory diagram showing the relationship between the burr and the core type shown in FIG.

FIG. 12 shows another example of a conventional core type,
(A) is the schematic which shows the whole, (b) is a bottom view of what is shown in (a).

FIG. 13 shows another example of the conventional core type,
(A) is the schematic which shows the whole, (b) is a bottom view of what is shown in (a).

[Explanation of symbols]

1, 21 ... Core type 2 ... Large diameter part 2a ... Recessed groove 2b, 7c, 9a, 9b, 10a, 10b ... Groove 3 ... Medium diameter part 4 ... Small diameter part 5 ... Overhang part 6, 26 ... Lower mold 6a ... Hole 7, 9, 11 ... Convex portion 7a, 26a ... Annular groove 7b, 26b ... Partition wall 8, 28 ... Outer mold 10, 30 ... Upper mold 12, 32 ... Cavities 13, 14, 15, 16, 23, 24, 25, 26 ...
Burr groove 18, 38, 40 ... Burr 19 ... Annular portion 20 ... Hemispherical portion

Claims (1)

[Claims] 1. A core mold (1) is provided at least in a central portion, and an annular cavity (12) is formed around the core mold (1) during mold clamping, and the core mold (1) is also formed. A plurality of molds (1) (6) (8) (which are designed to form an annular burr groove (13) communicating with the cavity (12) between the outer peripheral portion of the mold and another mold (6). In the molding die consisting of 10), the burr groove (13) is provided with a partition wall (7b) at least at two locations formed in either the outer peripheral portion of the core die (1) or the other die (6). The annular groove (7a) and the plurality of recessed grooves (2a) formed in the outer peripheral portion of the core mold (1) or in the other mold (6) corresponding to the other annular groove (7a). And the concave groove (2a) is not located in at least one partition wall (7b) of the annular groove (7a) during mold clamping. Molding die characterized in that.