JPH0694165B2 - A mold for fusing the ends of the thermoplastic resin band to each other - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for fusing the ends of a thermoplastic resin band together.

[0002]

2. Description of the Related Art When joining end portions of a belt made of a thermoplastic resin to each other, the end portions of the belt are butted against each other, and the butted portion is clamped by a die K and the die K is heated. , So that they are fused together. The above-mentioned mold K is composed of an iron male mold and a female mold, and in consideration of their mutual insertion and removal, a so-called clearance fit is made in the male and female mating states. is there.

Therefore, in the above heating step for the belt, as shown in FIG. 9, the molten resin squeezes out from the gap between the male die 1 and the female die 2, and this squeezed-out portion becomes a so-called burr after solidification. Therefore, a step of removing the burr after the mold release is necessary. The work of removing this burr is very troublesome and takes a lot of time.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a mold for fusing the ends of the thermoplastic resin band to each other, which reduces the occurrence of burrs in the molded product. To do.

[0005]

The invention according to claim 1 of the present application relates to a mold for fusing the ends of the thermoplastic resin band to each other, and the mold is clamped in the assembled state and the thermoplastic resin is melted. It is composed of a female mold and a male mold that are heated to the extent that the female mold is formed with a groove having a width slightly larger than the width of the thermoplastic resin band, and the male mold has the female mold. Is formed with a width slightly smaller than the groove width of the groove, the depth of the groove is set to be larger than the thickness of the thermoplastic resin band, and the male mold has a linear expansion coefficient larger than that of the female mold. It is composed of a large material.

[0006]

The invention of this application has the following functions. In this invention, since the male mold is made of a material having a larger linear expansion coefficient than the female mold, when the male mold and the female mold are heated, the side wall forming the groove of the female mold and the side wall of the female mold are fitted. The gap between the side walls of the formed male projection surface is smaller than that at normal temperature, and the amount of the molten thermoplastic resin protruding from the gap is small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the invention of this application will be described below with reference to the drawings shown as embodiments. In this example, a Kevlar fiber-embedded thermoplastic resin conveyor belt (width: 3
0 mm) is formed into a loop shape, and the invention of this application is adopted. As shown in FIG.
The both ends of the belt 3 in which is embedded are formed into finger shapes, and the finger portions are abutted to each other as shown in FIG.

In order to join the ends of the belt 3 to each other as described above, a mold K composed of a male mold 1 and a female mold 2 as shown in FIG. 3 is used. The female die 2 is made of an iron material, and as shown in FIG. 5, a groove 20 is formed on the upper surface thereof and the width of the groove 20 is 30.0 mm (tolerance: upper limit +
0.02, lower limit −0).

The male die 1 is made of an aluminum material. As shown in the figure, a projecting surface 10 is formed on the lower surface thereof and the projecting surface 10 has a width of 30.0 mm (tolerance: upper limit +0, The lower limit is set to -0.02). The depth of the groove 20 of the female die 2 is set to about 2 to 3 times the thickness of the belt 3.

Here, as shown in FIG. 6, a press machine 9 in which a heating / cooling board 4 serving as a heat source and a cooling source is attached to the pressing portion 90.
And using the mold K described above,
The ends of the belt 3 can be joined to each other in this order. ． The end portions of the belt 3 are formed in a finger shape as shown in FIG. ． As shown in FIG. 4, with the finger-shaped portions abutted against each other, the abutted portions are fitted into the grooves 20 of the female die 2, and then the male die 1 is assembled to the female die 2.
Incidentally, in this combined state, the state is as shown in FIG. 7, and the male die 1 and the female die 2 are fitted to each other with a clearance fit. ． Next, as shown in FIG. 6, the central portion (portion to be joined) of the mold K is clamped through the heating / cooling board 4 which has been heated by the press machine 9 described above.

In this embodiment, the male die 1 is
Minium material (coefficient of linear expansion: 23.5 × 10 ^-6), The female mold 2
Is an iron material (coefficient of linear expansion: 12.1 × 10^-6)
Since it has been made, the belt 3 melts up to about 180 ° C.
In the state of being heated by, the projecting surface 10 of the male die 1 as shown in FIG.
The fitting state between the groove 20 of the female die 2 and the female die 2 is so-called
It is a tight fit. Therefore, this kind of traditional gold
Compared with type K, burrs are generated as described in the column of action.
Will be very few. ． Demonstrate the cooling function of the heating / cooling board 4 after a certain period of time
If you do so, the melted ends will be joined together.
It becomes a state.

After that, when the belt 3 is removed from the mold K, a loop-shaped belt is completed. In the above embodiment, the male member 1 is made of an aluminum material and the female member 2 is made of an iron material. However, if the male die 1 is made of a metal having a larger linear expansion coefficient than the female die 2, it is almost the same. The same effect can be obtained. For example, there is a combination of magnesium and an amber alloy.

Further, in the above embodiment, if the surface of at least the molding space of the male mold 1 and the female mold 2 is subjected to metaflon treatment, the mold releasability of the molded product from the mold K is improved. Moreover, since the metaflon treatment can be performed thinner than, for example, a chromium plating treatment, the influence on expansion is small. Furthermore, although the mold of the present invention is used for joining both ends of the conveyor belt in the above-mentioned embodiment, the present invention is not limited to this, and any thermoplastic strip can be joined in the same manner.

Further, regarding the mold of the above embodiment, the female mold 2
It is also possible to form a plurality of grooves 20 on the male mold 1 and to form a projecting surface 10 corresponding to the grooves 20 on the male mold 1.

[0015]

Since the invention of this application has the above-mentioned structure, it has the following effects. With this type, the amount of molten thermoplastic resin that protrudes from the gap between the side wall that forms the female groove and the side wall of the male projecting surface that is fitted into this groove is small, so burr is generated in the molded product. Will be few. That is, it was possible to provide a mold for fusing the ends of the thermoplastic resin band to each other, which reduces the occurrence of burrs in the molded product.

[Brief description of drawings]

FIG. 1 is a perspective view of a belt end portion joined by a mold according to an embodiment of the present invention.

FIG. 2 is a perspective view of a loop-shaped belt formed by the mold of the embodiment of the present invention.

FIG. 3 is a perspective view of a mold according to an embodiment of the present invention.

FIG. 4 is a diagram in which a belt to be joined is set in a mold according to an embodiment of the present invention.

FIG. 5 is an explanatory view of a mold according to an embodiment of the present invention.

FIG. 6 is a diagram showing a method for manufacturing a loop-shaped belt by a mold according to an embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a state in which a belt is set in the mold of the embodiment of the present invention.

FIG. 8 is a view showing a fitted state of a male mold and a female mold when the mold of the embodiment of the present invention is heated to a resin melting temperature.

FIG. 9 is a view showing a fitted state of a male mold and a female mold when a conventional mold is heated to a resin melting temperature.

[Explanation of symbols]

 1 Male 2 Female 10 Groove 20 Projection surface

Claims (3)

[Claims] 1. A female mold and a male mold, which are clamped in an assembled state and heated to such an extent that the thermoplastic resin is melted, wherein the female mold has a width slightly smaller than the width of the thermoplastic resin band. A groove having a large width is formed and the male mold is formed with a projecting surface having a width slightly smaller than the groove width of the female mold.
The depth of the groove is set to be larger than the thickness of the thermoplastic resin band, and the male mold is made of a material having a larger linear expansion coefficient than that of the female mold. A mold for fusing. 2. A plurality of grooves are formed in the female mold, and a projecting surface corresponding to the grooves is formed in the male mold, and the ends of the thermoplastic resin strip are fused to each other. Mold for. 3. The mold for fusing the ends of the thermoplastic resin strips together according to claim 1, wherein the male mold is made of an aluminum material and the female mold is made of an iron material. .