JPH0694166B2 - 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 conveyor 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 joined. It is heated so that it is fused. As shown in FIG. 13, the above-mentioned mold K is composed of a thin plate-shaped male mold 1 and a female mold 2. As shown in the same figure, the female mold 2 has an upper surface having a flat bottom surface. Groove 20
And a flat projection surface 10 to be fitted into the groove 20 is formed on the lower surface of the male die 1, and in the combined state of the male die 1 and the female die 2, the projection surface 10 and the groove are formed. The fitting with 20 is a so-called clearance fit.

Then, as shown in FIG. 14, the abutting portions of the end portions of the belt 3 are set in the mold K so as to be sandwiched between the projecting surface 10 and the bottom surface of the groove 20, and the pressing portion 90 is set.
A pressing machine 9 equipped with a heating / cooling board 4'is clamped to press the male die 1 and the female die 2 of the die K in the above-mentioned state against each other and corresponds to the abutting portion of the end portions of the belt 3 with each other. The die K portion is heated, and then the portion of the die K is cooled so as to solidify the resin constituting the belt. The heating / cooling board 4 ′ described above can be brought into a heating state or a cooling state as required.

However, in the above case, since the heating / cooling board 4'which has been once heated must be cooled from this state, it takes a lot of time for cooling, and the ends of the belt 3 are fused to each other. There is a problem that it takes a lot of time. As one means for solving the above problem, for example,
The vicinity of the die K portion corresponding to the abutting portion of the end portions of the belt 3, that is, only both end portions of the die K is clamped by the pressing portion 90 of the press machine 9 not equipped with the heating / cooling board 4 ′, A heating platen is brought into contact with the center of the mold K to melt the resin forming the belt, and then the heating platen is removed and a cooling plate separate from the heating plate is brought into contact with the belt forming resin to solidify the resin. You can take the method of making it.

However, when this method is adopted, although the above-mentioned problem of time can be solved, only the both end portions of the mold K are clamped, so that the clamping force acting on the abutting portions of the end portions of the belt 3 is the both ends. It becomes smaller than that of the portion, and as a result, a new problem occurs that the welded portion of the belt 3 is foamed. The above phenomenon may occur even when the pressing force between the male die 1 and the female die 2 of the die K is less than a predetermined value.

Further, the above problem is not limited to the fusion of the end portions of the belt, but a similar problem occurs in the fusion of the end portions of the belt-shaped body made of a thermoplastic resin.

[0007]

Therefore, in the invention of this application, it is possible to shorten the time for fusing the end portions of the strips made of the thermoplastic resin to each other, and to foam the fused portion. It is an object of the present invention to provide a mold for fusing the ends of the thermoplastic resin band to each other, which can prevent the above.

[0008]

In the invention according to claim 1 of this application, a female die having a groove having a width slightly larger than the width of the thermoplastic resin band, and a groove width of the female die are provided. And a male mold formed with a projecting surface having a slightly smaller width, and the male mold and the female mold are pressed against each other to press the thermoplastic resin band by the bottom surface of the groove and the projecting surface. In the die for fusing the abutting portions of the end portions with each other, in the longitudinal direction of the projecting surface, the projecting surface is a curved surface that gently projects from both ends of the projecting surface toward the center.

According to the second aspect of the present invention, the female die is provided with a groove having a width slightly larger than the width of the thermoplastic resin band, and the projecting surface having a width slightly smaller than the groove width of the female die. And a male mold having a groove formed therein, the male mold and the female mold are pressed against each other to press the thermoplastic resin band by the bottom surface and the projecting surface of the groove, and the end portions of the thermoplastic resin band are abutted with each other. In the mold for fusing, the bottom surface of the groove is a curved surface that gently protrudes from both ends of the groove toward the center in the length direction of the groove.

According to the third aspect of the present invention, the flat mold comprises a groove mold having a groove having a width slightly larger than the width of the thermoplastic resin band and a flat mold composed of a flat plate. A die for pressing the groove mold and the flat mold against each other in order to press the thermoplastic resin band by the surface portion of the groove and the bottom surface of the groove in the groove mold to fuse the abutting portions of the ends of the thermoplastic resin band. Here, in the direction of the flat mold corresponding to the direction in which the groove of the groove is formed, the surface portions of the flat mold are curved surfaces that gently project from both ends of the flat mold toward the center.

Further, in the invention according to claim 4, it is constituted by a groove type in which a groove having a width slightly larger than the width of the thermoplastic resin band is formed and a flat type constituted by a flat plate. A mold for pressing the groove mold and the flat mold against each other in order to press the thermoplastic resin band by the flat part of the groove and the bottom surface of the groove in the groove mold to fuse the end portions of the thermoplastic resin band to each other. In the groove-shaped groove forming direction, the bottom surface of the groove is a curved surface gently protruding from both ends of the groove toward the center.

[0012]

The invention of this application has the following functions. (Operation of the invention according to claim 1 or 2) In the state where the thermoplastic resin strip is sandwiched by the bottom surface and the projecting surface of the groove by clamping only both end portions of the die K, the end of the thermoplastic resin strip is clamped. The clamping force acting on the abutting portions of the parts becomes large as compared with the mold described in the section of the prior art. (Operation of the invention according to claim 3 or 4) In a state in which only the both ends of the mold K are clamped and the thermoplastic resin band is clamped by the bottom surface of the groove in the groove mold and the flat surface portion in the flat mold,
The sandwiching force acting on the abutting portions of the ends of the thermoplastic resin band is larger than that of the mold described in the section of the related art.

[0013]

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. As shown in FIG. 4, 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 same 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 be about 2 to 3 times the thickness of the belt 3, and on the other hand, as shown in FIG.
In the length direction (direction corresponding to the length direction of the belt), the projecting surface 10 is a curved surface that gently projects from both ends of the projecting surface 10 toward the central part (in addition to this embodiment,
Only the central part and its vicinity may be curved).

Here, the heating plate 4, the cooling plate 5, and the scissors-shaped clamp 6 as shown in FIG. 5 (the intervals between the operating parts can be fixed at desired positions), and the above-mentioned mold. When K and K are used, the end portions of the belt 3 can be fused to each other in the order of to shown below. ． The end portions of the belt 3 are formed in a finger shape as shown in FIG. ． As shown in FIG. 6, with the finger-shaped portions abutting each other, the abutting 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. 5, the clamp 6 clamps the die K in the state as shown in FIG. 5 near both ends and maintains the clamped state. In the mold K of this embodiment, in the longitudinal direction of the projecting surface 10, the projecting surface 10 is a curved surface that gently protrudes from both ends of the projecting surface 10 toward the central part. As described above, the clamping force acting on the abutting portions of the ends of the belt 3 is larger than that of the mold K described in the section of the related art. ． Then, as shown in FIG. 8, the heating platen 4 heated up to about 180 ° C. from above and below is brought into contact with the central portion of the mold K (the portion corresponding to the abutting portion of the end portions of the belt 3).

In this embodiment, the male die 1 is made of an aluminum material (coefficient of linear expansion: 23.5 × 10 ⁻⁶ ) and the female die 2 is made of iron material (coefficient of linear expansion: 12.1 × 10 ⁻⁶ ). Since it is configured, as shown in FIG. 9, when the belt 3 is heated up to about 180 ° C. where it melts, the projecting surface 1 of the male die 1
The fitting state of 0 and the groove 20 of the female mold 2 is so-called tight fitting or tight fitting. Therefore, as compared with the conventional mold K of this type, the occurrence of burrs is extremely small as described in the section of the action. ． After a certain period of time, the heating platen 4 is removed from the mold K while maintaining the clamp 6 as it is, and the cooling platen 5 is brought into contact with the central part of the mold K from above and below as shown in FIG. Then, the immobilization of the thermoplastic resin band in the molten state starts rapidly. In the above solidification, the clamping force acting on the abutting portions of the end portions of the belt 3 is larger than that of the mold K described in the section of the prior art, so that the belt 3 Foaming of the fused portion will be prevented. ． After a certain period of time, the clamp 6 is unfastened and the belt 3 is removed from the mold K, whereby the loop-shaped belt 3 as shown in FIG. 2 is completed. When the belt 3 is detached from the mold K, the projecting surface 10 of the male mold 1 and the groove 20 of the female mold 2 are loosely fitted to each other. Separation from 2 is easy.

In the above embodiment, in order to prevent foaming at the fused portion of the belt 3, the projecting surface 10 is gradually loosened from both ends thereof toward the center in the length direction of the projecting surface 10. Although it is a curved surface that protrudes to, instead of this,
In the longitudinal direction of the groove 20, the bottom surface of the groove 20 may be a curved surface that gently protrudes from both ends of the groove 20 toward the central portion, and both the protruding surface 10 and the bottom surface of the groove 20 may be the curved surface. Good.

In the above embodiment, the mold K is composed of the male mold 1 and the female mold 2. However, the mold K is not limited to this. The mold is a flat mold and a groove mold (a mold formed by forming grooves in the flat mold). ) And a mold K, and the belt 3 is sandwiched between the bottom surface of the groove and the flat surface of the flat mold. In this case, in order to prevent foaming in the fused portion of the belt 3, in the direction of the flat mold corresponding to the groove forming direction, the surface portions of the flat mold are directed from both end portions thereof toward the central portion. It may be a curved surface that gently protrudes, or in the direction of the groove-shaped groove formation, the bottom surface of the groove may be a curved surface that gently protrudes from both ends of the groove toward the center, and both of them may be formed. It may be a curved surface.

On the other hand, in the above embodiments, the molds of the present invention were used to fuse the ends of the conveyor belt to each other. However, the present invention is not limited to this, and any thermoplastic belt-shaped member may be fused. Similar effects can be obtained when wearing. Further, in the above embodiment, the clamp 6 clamps only both ends of the mold K in the assembled state, but the clamp 6 is not limited to this, and may be clamped by the pressing portion of the press machine. As shown in FIG. 11, a clamp 6 of a type in which the male die 1 is pressed against the female die 2 by tightening a bolt 70 may be adopted, and other known clamps may be employed.

[0021]

Since the invention of this application has the above-mentioned structure, it has the following effects. (Effect of the invention described in claim 1 or 2) Even if only the both ends of the mold K are clamped, the clamping pressure acting on the abutting portions of the ends of the thermoplastic resin band is described in the section of the prior art. Since the size is larger than that of the mold, foaming of the fused portion in the thermoplastic resin band can be prevented. That is, it was possible to provide a mold capable of shortening the time required for fusing ends of a band-shaped body made of a thermoplastic resin to each other and preventing foaming of the fused part. (Effect of the invention described in claim 3 or 4) Even if only the both ends of the mold K are clamped, the clamping pressure acting on the abutting portions of the ends of the thermoplastic resin band is described in the section of the prior art. Since the size is larger than that of the mold, foaming of the fused portion in the thermoplastic resin band can be prevented. That is, it was possible to provide a mold capable of shortening the time required for fusing ends of a band-shaped body made of a thermoplastic resin to each other and preventing foaming of the fused part.

[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 an explanatory view of a mold according to an embodiment of the present invention.

FIG. 5 is a view showing a clamp for holding the mold of the embodiment of the present invention and a method for manufacturing a loop belt.

FIG. 6 is a diagram in which a belt to be joined is set in 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 state in which a heating platen is brought into contact with the upper and lower sides of the mold according to the embodiment of the present invention.

FIG. 9 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. 10 is a view showing a state in which cooling plates are brought into contact with the upper and lower sides of the mold of the embodiment of the present invention.

FIG. 11 is an explanatory view of another type of clamp.

FIG. 12 is a side sectional view showing a projecting surface of a male mold forming the mold of the embodiment of the present invention.

FIG. 13 is a perspective view of a conventional mold.

FIG. 14 is an explanatory view of a conventional method for fusing belt end portions made of a thermoplastic resin to each other.

[Explanation of symbols]

 K Mold 1 Male 2 Female 10 Groove 20 Projection surface

Claims (4)

[Claims] 1. A female die having a groove having a width slightly larger than the width of the thermoplastic resin band, and a male die having a projecting surface having a width slightly smaller than the groove width of the female die. A die for pressing the male and female dies against each other to press the thermoplastic resin strip by the bottom surface and the projecting surface of the groove to fuse the end portions of the thermoplastic resin strip to each other. At
A mold for fusing the ends of a thermoplastic resin band to each other in the lengthwise direction of the projecting surface, wherein the projecting surface is a curved surface that gently projects from both ends of the projecting surface toward the center. 2. A female die in which a groove having a width slightly larger than the width of the thermoplastic resin band is formed, and a male die in which a projecting surface having a width slightly smaller than the groove width of the female die is formed. A die for pressing the male and female dies against each other to press the thermoplastic resin strip by the bottom surface and the projecting surface of the groove to fuse the end portions of the thermoplastic resin strip to each other. At
A mold for fusing the ends of the thermoplastic resin band to each other in the longitudinal direction of the groove, wherein the bottom surface of the groove is a curved surface gently protruding from both ends of the groove toward the center. 3. A groove die in which a groove having a width slightly larger than the width of the thermoplastic resin band is formed, and a flat die made of a flat plate. The surface portion of the flat die and the groove in the groove die are formed. In the die for pressing the groove mold and the flat mold against each other to press the thermoplastic resin band against each other by the bottom surface and fusing the abutting portions of the ends of the thermoplastic resin band, In the direction of the flat mold corresponding to the forming direction, the end portions of the thermoplastic resin band are fused to each other, characterized in that the flat surface portions are curved surfaces projecting gently from both end sides toward the center. Mold for. 4. A groove die in which a groove having a width slightly larger than the width of the thermoplastic resin band is formed, and a flat die made of a flat plate, and the flat surface portion of the flat die and the groove in the groove die. In the mold for pressing the groove mold and the flat mold against each other to press the thermoplastic resin band against each other by the bottom surface of the thermoplastic resin band to fuse the abutting portions of the ends of the thermoplastic resin band, the groove of the groove type is used. In the forming direction of the groove, the bottom surface of the groove is a curved surface that gently protrudes from both ends of the groove toward the center, and a mold for fusing the ends of the thermoplastic resin band to each other.