JPH0625321Y2 - Ended toothed belt manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an apparatus for manufacturing a belt with end teeth made of a thermoplastic elastomer or a thermoplastic resin.

(Prior Art) Toothed belts are widely used in general industrial machinery, precision machinery, etc. because they can transmit power synchronously. Conventionally, such a toothed belt is produced by injecting a liquid elastomer between an inner mold whose outer peripheral surface is uneven at a predetermined pitch in the circumferential direction and an outer mold fitted to the inner mold. It is manufactured by forming a wide endless belt with teeth by curing and cutting the wide endless belt with a predetermined width.

However, in such a manufacturing method, since the belt length (circumferential length) is limited, in order to manufacture belts having different lengths, a mold corresponding to the manufactured belt length is required. ， Also, it is impossible to manufacture a long toothed belt.

In place of such a manufacturing method, a manufacturing method of a long toothed belt is disclosed in JP-A-54-15701, JP-A-63-162225, and JP-A-63-126707. In the manufacturing method disclosed in each of the publications, an endless toothed belt is formed and then endless in another step or at the installation site of the toothed belt. As shown in FIG. 5, the toothed belt manufacturing apparatus used in the manufacturing method has a rotatable cylindrical mold 70. The mold
70 is a pair of flange portions 71 projecting outward at appropriate intervals on each side in the outer peripheral portion in the axial direction (width direction).
And 71 are provided all around. The mold
Recesses 71b are formed at a predetermined pitch in the circumferential direction on the peripheral surface between the respective flanges 71 of the 70, and the protrusions 71a between the recesses 71b are formed.
By the, the peripheral surface is uneven in the direction. A predetermined cavity is formed by the outer peripheral surface and each flange portion 71. Protrusions (pip) 71c extending in the width direction are provided at the circumferential center of the outer peripheral surface of each protrusion 71a.

A die 80 for injecting a thermoplastic resin or elastomer into the cavity is disposed above the mold 70, and the cavity is filled with the thermoplastic resin or elastomer from the die 80.

On the downstream side of the die 80 in the mold 70 rotation direction, the mold
A band member 90 is disposed on the outer peripheral surface of each flange portion 71 of the member 70 so as to contact the outer peripheral surface of the flange portion 71 for a predetermined circumferential length to close the cavity. The band body 90 can be wound around a plurality of pulleys, for example, so as to move along with the mold 70 over a substantially half circumference.

In such an endless toothed belt manufacturing apparatus, a mold is used.
A thermoplastic resin is applied from the die 80 while the mold 70 is rotated so that a plurality of core wires as anti-longitudinal bodies are wound around the pips 71c of the 70 at predetermined intervals in the width direction. Is filled in the cavity. By rotating the mold 70, the thermoplastic resin or the elastomer becomes a band body.
It is closed at 90 and the thermoplastic resin or elastomer is filled in the cavity. Then, while the band body 90 moves integrally with the mold 70 with the cavity closed, until the thermoplastic resin or elastomer is cured,
A thermoplastic resin or elastomer is retained in the cavity. Then, the thermoplastic resin or the elastomer is cured in the cavity, so that a toothed belt having a predetermined shape in which the core wire is embedded is obtained.

(Problems to be Solved by the Invention) In such a conventional apparatus for manufacturing a belt with end teeth, when the viscosity of the thermoplastic resin or elastomer extruded into the cavity is high, the thermoplastic resin is applied to every corner of the cavity. The resin or elastomer does not spread, and air may remain in the corners of the cavity. In particular, air is likely to remain at the corners of the recess 71b of the cavity corresponding to the tip of the timing tooth, and the toothed belt obtained in this way has the teeth formed as specified due to the air. Is not done or the tip of the timing tooth is missing,
Tooth strength may be significantly reduced, or the meshing condition may not be appropriate. The tip of the tooth is susceptible to force and the tip of the tooth is very easily damaged.

The present invention solves the above-mentioned conventional problems, and an object thereof is to improve the thermoplastic resin or elastomer injected into the cavity of a mold even in every corner of the cavity even if the viscosity is high. An object of the present invention is to provide an endless toothed belt manufacturing apparatus which can be filled with a resin or an elastomer and can very easily manufacture a toothed belt having high strength at the tooth tips and the like.

(Means for Solving the Problems) The manufacturing apparatus for an endless toothed belt according to the present invention has flange portions projecting outward on each side portion in the axial direction on the outer peripheral surface, and between the flange portions. A mold having a cylindrical shape whose peripheral surface is uneven at a predetermined pitch in the circumferential direction, and in which a cavity is formed in the outer peripheral portion by each flange portion and the peripheral surface between the flange portions, and each mold of the mold. A band member that abuts on the flange portion and closes the cavity so that the cavity is not hermetically sealed, and the endless teeth are formed by curing the molten resin or the elastomer in the cavity closed by the band member. A device for manufacturing a belt with a cover, wherein each flange portion of the mold is provided with a vent hole for communicating the cavity with the outside, whereby the above object is achieved.

(Embodiment) An embodiment of the present invention will be described below.

As shown in FIGS. 1 and 2, the manufacturing apparatus for an endless toothed belt of the present invention has a rotatable cylindrical mold 10. The mold 10 is provided with a pair of flange portions 11 and 11 projecting outward at appropriate intervals from each other on each side portion in the axial direction (width direction) on the outer peripheral portion over the entire circumference. On the peripheral surface between the flange portions 11 of the mold 10, concave portions 12b having a predetermined pitch are formed in the circumferential direction, and the convex portions 12a between the concave portions 12b form an uneven shape. A predetermined cavity is formed by being surrounded by the peripheral surface and each flange portion 11. Each convex portion 12a
A ridge (pip) 12c extending in the width direction is provided at the center of the outer peripheral surface in the circumferential direction.

A vent hole 15 is provided on the outer peripheral portion of each flange 11 to connect the cavity of the mold 10 to the outside of the mold 10. The vent hole 15 is formed, for example, as shown in FIG. 3, in the flange portion 1 facing the recess 12b in the cavity.
1, provided so as to extend in the radial direction. Vent 1
The width dimension of 5 is set to about several mm so that the thermoplastic elastomer filled in the cavity does not pass but only air can pass.

A die 20 for injecting the thermoplastic elastomer 30 into the cavity of the mold 10 is provided above the mold 10. From the die 20, a thermoplastic elastomer 30 is extruded onto the aligned cores in the cavity.

The mold 10 rotation direction downstream rule of the die 20 is:
The band body 53 is provided to close the cavity. The band body 53 has a widthwise dimension capable of contacting the outer peripheral surface of the flange portion 11 of the mold 10. The band body
Reference numeral 53 denotes a wrapping belt wound around rollers 52a and 52b arranged above and below the mold 10 and a roller 51 arranged on the side of the mold 10, and a flange portion of the mold 10. 11 Abut on the outer peripheral surface for about half the circumference to close the cavity so that it does not become a sealed state,
It moves integrally with the mold 10.

In the toothed belt manufacturing apparatus having such a configuration, a plurality of core wires 40 as tensile members are wound between the flange portions 11 of the mold 10 at appropriate intervals in the width direction. In this state, the mold 10 is rotated and the thermoplastic elastomer 30 is extruded from the die 20 onto the aligned core wires in the cavity. The core wire 40 rotates with the mold 10 while being supported by the pip 12c of the mold 10. Core 40
The thermoplastic elastomer 30 extruded on top of the band body 53
Reaches a region in contact with the flange portion 11, and the thermoplastic elastomer 30 in the cavity is compressed by the band body 53.

At this time, the air remaining in the cavity is compressed by the thermoplastic elastomer 30 and flows out from the ventilation hole 15 to the outside. Since the width of the vent hole 15 is set so that only the air passes and the thermoplastic elastomer does not pass,
The thermoplastic elastomer in the cavity has no risk of flowing out, only the air in the cavity is reliably discharged, and the thermoplastic elastomer is surely spread to every corner of the cavity. As a result, the thermoplastic elastomer 30
Has a predetermined toothed belt shape corresponding to the shape of the cavity.

The band body 53 that closes the cavity so as not to be sealed moves together with the mold 10 while the cavity is closed, and the thermoplastic elastomer 30 in the cavity is held by the band body 53 until it is cured. Then, the thermoplastic elastomer 30 is cured while the band body 53 moves together with the mold 10 over a substantially half circumference.
A toothed belt with a predetermined shape in which the core wire 40 is embedded,
Manufactured sequentially.

As described above, the thermoplastic elastomer injected into the cavity is pressed by the band body 53 without the precise control of the injection amount, and the air in the cavity is reliably discharged from the ventilation hole 15, It has a predetermined shape in which the thermoplastic elastomer is filled all the way into the cavity.

When the toothed belt having a predetermined length is manufactured in this manner, the toothed belt is once cut. Then, the toothed belt is made endless in another step or at the site where the toothed belt is to be arranged.

The vent holes 15 do not have to extend in the radial direction of the mold 10. For example, as shown in FIG. 4, the vent holes 15 are opposed to the bottom of the recess 12b of the cavity and are provided intermittently in the circumferential direction of the mold 10. Good.

(Effect of the Invention) Since the belt manufacturing apparatus with the toothed end according to the present invention is provided with the vent holes for discharging only the air in the cavity in each flange portion as described above, heat is generated in every corner of the cavity. It is very easy to obtain a belt with end teeth, which has excellent tooth strength and has a predetermined tooth tip shape that easily spreads with a plastic resin or elastomer.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an example of an apparatus for producing a belt with end teeth according to the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIGS. 3 and 4 are the present invention respectively. FIG. 5 is a cross-sectional view of another embodiment of the belt manufacturing apparatus with end teeth, and FIG. 5 is a schematic front view of the manufacturing apparatus of the conventional belt with end teeth. 10 …… Mold, 11 …… Flange part, 12a …… Convex part, 12b
...... Concave, 12c ...... Pip, 15 ...... Vent, 20 ...... Die, 30 ...... Thermoplastic elastomer, 40 ...... Core wire, 53 ......
Band body

Claims (1)

[Scope of utility model registration request] 1. A cylindrical shape having flange portions projecting outward on respective side portions in the axial direction on the outer peripheral surface, and the peripheral surface between the respective flange portions being uneven in a circumferential direction at a predetermined pitch. And a mold in which a cavity is formed in the outer peripheral portion by each flange portion and the peripheral surface between the flange portions, and the mold is abutted against each flange portion of the mold to close the cavity so as not to be hermetically closed. An apparatus for manufacturing a belt with end teeth by curing a molten resin or an elastomer in a cavity closed by the band body, comprising: An endless toothed belt manufacturing device that has ventilation holes that connect the cavity to the outside.