JPH0612904Y2 - Mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to improvement of a molding die used for molding an elastic material such as rubber.

[Prior Art] Conventionally, as shown in FIG.
01), a medium mold (102) and a lower mold (103), and a cavity between these molds (101) (102) (103) that are combined vertically.
(104) is formed, and the upper mold (101) is inserted into this cavity (104).
It is known that a molten material such as rubber is injected from a material injection port (105) provided in the.

[Problems to be solved by the device]

However, in the molding die as described above, the molding rubber material melted from the cavity (104) flows out to the contact portions (106) and (107), that is, the split surface to form a thin burr, and after the molding is completed,
There is a problem that a finishing process for removing thin burrs from the product part is required. Further, since the molds (101), (102) and (103) are in a closed state at the time when the molding is completed and the mold clamping pressure is released, it takes time to release the product.

In view of such problems, the present invention provides a molding die that prevents burr outflow from the cavity and facilitates mold release.

[Means for Solving the Problems]

For the above-mentioned purpose, the mold of the present invention is such that the outer periphery of the middle die is inclined so that the outer periphery is higher, and a step is formed on the upper surface of the middle die so that the inner periphery is convex, and the upper surface of the outer periphery is formed. The outermost peripheral portion is higher than the upper end of the step portion, and the outermost peripheral portion of the lower surface and the upper surface of the lower mold are not in contact with each other.

[Action]

According to the present invention, at the time of mold clamping, the middle mold first comes into contact with the outermost peripheral part of the upper surface and the inner peripheral part of the lower surface with the lower surface of the upper mold and the upper surface of the lower mold. Next, the middle mold is elastically deformed under the mold clamping pressure, and the contact surface pressure between the inner surface of the lower surface and the upper surface of the lower mold is increased accordingly. The inner peripheral portion of the upper surface and the lower surface of the upper mold are in close contact with each other. At this time, the repulsive force due to the elastic deformation of the outer peripheral portion acts so as to press the inner peripheral portion of the upper surface against the lower surface of the upper mold. When the mold clamping pressure is released after the molding is completed, the middle mold and the upper mold are immediately separated by the elasticity of the outer peripheral portion.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, (1) is an upper mold, (3) is a middle mold, (7) is a lower mold, and a space for molding is provided between these molds (1), (3) and (7) which are combined vertically. A cavity (9) is formed, the upper mold (1)
An injection port (10) for the molding rubber material into the cavity (9) is provided in the center of the.

A stepped portion (5) having a slight height such that the inner peripheral side, that is, the inner peripheral portion (4a) of the upper surface is convex is formed in a portion of the upper surface of the middle mold (3) near the cavity (9). ing. The upper peripheral portion (4b), which is the outer peripheral side of the stepped portion (5), forms a minute angle with respect to the lower surface of the flat upper die (1), and becomes a tapered surface whose outer peripheral side gradually increases. The outermost part (4
b ') is the height of the upper end of the stepped portion (5), that is, the inner peripheral portion of the upper surface (4
It is higher than the height of a). Further, the lower surface outer peripheral portion (6b) of the middle die (3) is a tapered surface corresponding to the upper surface outer peripheral portion (4b).

In other words, the outer periphery (3 ') of the medium mold (3) is gently inclined like a bowl as a whole, and the upper mold (1)
(3) and the lower die (7) are contacted, the inner periphery (4a) of the upper surface of the middle die (3) and the inner periphery (2a) of the flat lower surface of the upper die (1) facing it. ), A small gap (G ₁ ) is formed between the outermost peripheral portion (6b ′) of the lower surface of the middle die (3) and the outer peripheral portion of the upper surface (F) of the lower die (7) that faces the outermost peripheral portion (6b ′). A gap (G ₂ ) larger than the gap (G ₁ ) is formed between each of them and 8b).

(11) is a piston that is combined with the upper mold (1) and moves up and down, and after clamping the upper mold (1), the middle mold (3) and the lower mold (7) together, the piston (11) The rubber material for molding injected between the piston (11) and the upper mold (1) is pressed into the cavity (9) from the injection port (10) by operating the (1) downward.

In the above structure, when the mold is clamped, the middle mold (3) first has the lower outer circumference (2b) and the lower mold (2b) of the upper mold (1) at the outermost peripheral part (4b ′) of the upper surface and the inner peripheral part (6a) of the lower surface, respectively. It comes into contact with the inner peripheral portion (8a) of the upper surface of 7). And then the outer peripheral portion (3 ') is a gap receives the clamping pressure (G ₁₎ and elastically deformed in a direction to reduce the (G ₂₎ Medium (3), the lower surface in the circumferential Medium (3) by its repulsive force Department
(6a) and the inner peripheral surface (8a) of the upper surface of the lower mold (7) are in complete contact, and as shown in FIG. 2, the inner peripheral surface (4a) of the upper surface of the middle mold (3) is
And the lower die inner surface (2a) of the upper die (1) are also in contact with each other (G ₁ = 0), and the repulsive force due to the elastic deformation is due to the inner die (4) of the upper surface of the middle die (3).
It also acts in the direction in which the a) is pressed against the inner peripheral surface (2a) of the lower surface of the upper die (1), thus preventing burr outflow from the cavity (9). When the mold clamping is completed, a gap (g) remains between the outermost peripheral surface (6b ') of the lower surface of the middle mold (3) and the outer peripheral surface (8b) of the upper surface of the lower mold (7). In contact.

After the completion of molding, when the mold clamping pressure is released, the outer peripheral portion (3 ') of the middle mold (3), which has been deformed by receiving the pressure, does not elastically return to the state shown in Fig. 1, and as a result, the upper mold (1) Is forced up. That is, when the mold clamping pressure is released and the upper mold (1) and the middle mold (3) are automatically opened, as shown in FIG. 3, when the shape of the product part (12) is relatively complicated. Also, it can be easily released.

[Effect of device]

As described above, according to the present invention, when the upper mold, the middle mold, and the lower mold are combined and clamped, the outer periphery of the middle mold is elastically deformed between the upper mold and the lower mold, and the repulsive force of the middle mold causes the inner periphery of the middle mold to be deformed. Since the part is in close contact with the upper mold and the lower mold,
There is no burr outflow from the cavity, so the yield can be improved, and the finishing process can be reduced to improve the productivity. Also, if the mold clamping pressure is released after molding,
The repulsive force of the outer peripheral portion of the middle mold immediately separates the middle mold and the upper mold, which facilitates the mold release and shortens the operation time of the mold release.

[Brief description of drawings]

FIG. 1 is a half-cut sectional view showing an embodiment of the molding die of the present invention, FIG. 2 is a half-cut sectional view showing the same mold clamping state, and FIG. FIG. 4 is a half-cut sectional view showing a conventional example in a mold clamped state. (1) Upper mold, (2a) (6a) Lower surface inner peripheral part (2b) (6b) Lower surface outer peripheral part, (3) Medium size, (3 ') Outer peripheral part (4a) (8a) Upper surface inner peripheral part, (4b ) (8b) Upper surface outer peripheral part (4b ') Upper surface outermost peripheral part, (5) Stepped part (6b') Lower surface outermost peripheral part, (7) Lower mold (9) Cavity, (10) Injection port, (11) Piston (12) Product Department

Claims (1)

[Scope of utility model registration request] 1. A cavity (9) is formed between an upper die (1), a middle die (3) and a lower die (7) which are combined in an upper and lower direction, and the upper die (1) is molded into the cavity (9). In a mold having a material injection port (10), the outer peripheral part (3 ') of the middle mold (3) is inclined so that the outer peripheral side is higher, and the inner peripheral side is convex on the upper surface of the middle mold (3). A step portion (5) is formed in the outer peripheral portion (3 '), the outermost peripheral portion (4b') of the upper surface is higher than the upper end of the step portion (5), and the outermost peripheral portion (6b ') of the lower surface. And lower mold (7)
Molding die whose top surface is non-contact.