JPH0246986Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to the molding of a molded product, such as a rubber roll, which is made by vulcanizing and adhering a rubber material to the outer periphery of a core metal having a required length. It concerns the improvement of molds.

[Conventional technology]

Conventionally, shaft portions S′,
When molding a rubber roll R molded product made by vulcanizing and adhering a rubber material G of an appropriate thickness to the outer periphery of a cylindrical core S with S' protruding from it, a mold as shown in Fig. 4 is used. ing. That is, in the same figure, numeral 1 is the upper mold, 2 is the lower mold, and 3 and 4 are the opposing core bars S.
A holding fitting for the holding fittings 3 and 4,
Holding recesses 5 and 6 are formed in the center of the facing surfaces of the core bar S, in which the exposed portions of the core metal S in the product shape shown in FIG. 3, including the shaft portions S' and S', are inserted and fitted. When both ends of the core metal S are inserted into the holding recesses 5 and 6 and the mold is clamped, a cavity 7 having a substantially cylindrical space centered around the core metal S is formed. code 8
is a material injection port that communicates the cavity 7 with a material reservoir 10 formed on the upper surface of the upper mold 1 through a notch 9 formed on the periphery of the core metal holding fitting 3 on the left side of the figure; A piston die 11 is disposed which engages in a freely insertable and removable manner, and the unvulcanized rubber material G' filled in the material reservoir 10 is poured into the cavity 7 by pushing down the piston die 11.

[Problem that the invention attempts to solve]

However, according to the mold according to this conventional example, at the stage of pouring the rubber material G' into the cavity 7, the pouring progresses gradually as the piston die 11 is pushed down, so that the rubber material G' is pressed against the core metal S. The load starts to be applied unevenly, especially on the core metal S.
When the core metal S has a small diameter or a long length, there is a problem in that the core metal S is deformed such as warping.

The present invention was made in view of the above points, and aims to provide a molding die that does not cause deformation such as warping of the core metal even under the above settings and can mold products with excellent molding accuracy. .

[Means for solving the problem] In order to achieve this purpose, the mold of the present invention has the following features:
The structure in which the rubber material injection port for the cavity is opened at one end in the installation direction of the core metal remains unchanged, and the rubber material injected into the cavity is inserted outside the core metal and injected into the cavity so as to divide the cavity into two chambers. We decided to install a slide fitting inside the cavity that slides inside the cavity using the pressure of the material.

[Effect]

In the mold having the above configuration, the slide fitting is installed in the stroke range closest to the rubber material injection port in the molding preparation stage, and the unvulcanized rubber material is pressure-injected from the injection port. As the pressure increases, the portion of the cavity filled with rubber material gradually expands while sliding the slide fitting.

〔Example〕

Next, one embodiment of the present invention will be explained with reference to the drawings.The mold shown in FIGS. 1 and 2 is used to mold the rubber roll R molded product shown in FIG. 3 in the same way as the conventional example described above. In the cavity 7, an annular slide fitting 12 that is inserted onto the core metal S and slides in the left-right direction in the figure is installed so as to divide the cavity 7 into two left and right chambers.

In this mold, in the preparation stage, the unvulcanized rubber material G' is poured by pressure after the slide metal fitting 12 is positioned at its left stroke limit. Due to the pressure, it gradually slides to the right (FIG. 1) and comes into contact with the core metal holding fitting 4' on the right side of the figure (FIG. 2). Therefore, in the cavity 7, the space on the left side of the slide fitting 12 is always filled with rubber material G', which applies uniform pressure to the core metal S in the circumferential direction and also causes the core metal S itself to Since it is held by the slide metal fitting 12, deformation such as warping of the core metal S can be prevented. In addition, since the slide fitting 12 is stored in a state in which it is in contact with the core metal holding fitting 4' at the right stroke limit, the space occupied by the slide fitting 12 is saved in advance.
Form cavity 7 to be larger.

[Effect of idea]

As explained above, the mold of the present invention prevents deformation such as warping of the core metal installed in the cavity during the pouring stage of unvulcanized rubber material, and can mold products in large quantities with excellent molding accuracy. It has the characteristics of being able to

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of a mold according to an embodiment of the present invention during pouring of unvulcanized rubber material, Figure 3 is a cross-sectional view of a rubber roll molded product, and Figure 4 is a conventional example. FIG. 3 is a cross-sectional view of the mold when pouring an unvulcanized rubber material. 1... Upper mold, 2... Lower mold, 3, 4, 4'... Core metal holding fitting, 7... Cavity, 8... Material injection port, 10... Material reservoir, 11... Piston type,
12...Slide metal fitting, R...Rubber roll, S...
Core metal, G′...Unvulcanized rubber material.

Claims (1)

[Scope of utility model registration request] In a mold for molding a molded product such as a rubber roll by clamping a split mold to form a cavity therein, and vulcanizing and adhering a rubber material to the outer periphery of a core metal installed approximately horizontally within the cavity, A rubber material injection port for the cavity is opened at one end side in the installation direction of the core metal, and the rubber material is inserted into the cavity so as to divide the cavity into two chambers,
A mold characterized by being equipped with a slide fitting that slides within the cavity due to the pressure of the injected rubber material.