JP2876566B2 - Endless belt manufacturing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing an endless belt for power transmission and conveyance by a flat belt or a toothed belt.

[0002]

2. Description of the Related Art Endless belts which are wound between pulleys on a driving side and a driven side to transmit power and convey articles include flat belts and toothed belts. Until now, when manufacturing an endless belt, a method of connecting both ends of one belt-shaped belt base material and performing endless processing has been a general manufacturing method. Such a manufacturing method by connecting both ends is disclosed in Japanese Patent Application Laid-Open No. 49-93755. 4 and 5 are a plan view and a side sectional view, respectively, showing a conventional endless belt manufacturing method including the technology disclosed in the above publication. That is, one belt-shaped belt base material processed to a required length is prepared, and a connecting portion (hereinafter, indicated by a reference numeral J for convenience of description) in which both end portions 1 and 2 of the belt base material are joined. It is set in the mold. In this case, the connecting shape of one end 1 of the belt base material is changed to the convex portion 1a.
An example is shown in which the connecting shape of the other end 2 is a concave portion 2a adapted to the convex portion 1a of the other end. The mold has an upper mold 3 and a lower mold 4 of a main part, and a convex portion 1a at one end 1 of the belt base and a concave portion 2 at the other end 2 between the upper and lower molds 3 and 4.
a are positioned in a temporary connection state where they face each other.
Heaters 5 and 6 for heating are embedded in the upper mold 3 and the lower mold 4, respectively. For example, when a thermoplastic resin or a thermoplastic elastomer is used as the material of the belt base material, the joints of the belt base materials are heated and melt-softened by turning on electricity to the heaters 5 and 6, and then the entire mold is cooled. I do. After cooling, the mold is released, and through a process such as natural cooling, an endless belt in which the convex portion 1a and the concave portion 2a of the connecting portion J are connected at the seam 7 by curing is manufactured. FIG.
And FIG. 7 also show a side sectional view and a front view of a conventional example .
In this case, as an alternative to the heaters 5 and 6 shown in FIG. 5, the heat plates 8 and 9 are sandwiched from the outside of the upper mold 3 and the lower mold 4 so as to be in contact with each other so that heat can be transferred. Let it be arranged. The heating method is basically the same as the heating method using the heating heaters 5 and 6, and is essentially changed to a structure and a manufacturing method in which the joints J inside the mold including the upper and lower molds 3 and 4 are heated by the heat plates 8 and 9. There is no.

[0003]

[SUMMARY OF THE INVENTION Incidentally, in the manufacturing method of the endless belt from the prior art by such two forms, heater 5, 6 or 6 shown in FIGS. 5 to
In the heating by the heat plates 8 and 9 shown in FIG. 7 , it is sufficient to connect only the joint 7 of the convex portion 1a and the concave portion 2a. However, the entire die and the entire joint J are also heated. . Therefore, in the vicinity of both ends 1 and 2 of the belt base material, the thermal expansion and the cooling rate between the portions of the upper and lower dies 3 and 4 that are not affected by heat outside of the die and the joining portion J disposed in the die. It is unavoidable that the difference in specification causes a difference in specification dimensions. The dimensional difference of the belt base material thus generated is particularly remarkable at the boundary between both ends of the mold. If a dimensional difference occurs around the connecting portion J after the endless processing, there may be no problem with a flat belt, but in the case of a toothed belt, inconvenience occurs in meshing with the toothed pulley on the side to be wound, In some cases, abnormal noise or tooth skipping may cause wear of the teeth and tearing of the belt itself. An object of the present invention is to provide a method and an apparatus for manufacturing an endless belt capable of maintaining quality by minimizing or minimizing a dimensional difference generated at a joint portion under the influence of heat during heating and cooling. .

[0004]

According to a method of manufacturing an endless belt according to the present invention, both ends of a belt-shaped belt base material arranged in a mold with the end faces abutting each other are surrounded by a metal at the joint between the end faces. Surround the other parts with ceramics or a metal that is less magnetic than the metal that surrounds the seam, and then melt and soften only the minimum area around the seam including the seam with a heated metal member, then cool and harden Let's connect the seams. Further, the endless belt manufacturing apparatus according to the present invention surrounds both ends of the belt-shaped belt base material arranged in the mold with the end faces abutting each other, the joint between the end faces is surrounded by metal, and the other parts are made of ceramics or the like. Surrounding the seam with a metal that is less magnetic than the surrounding metal, connecting the seam by cooling and hardening after melting and softening only the minimum area around the seam including the seam by the heated metal member,
A high-frequency induction heating coil is placed close to the mold, and a metal that surrounds the seam between the end faces of both ends of the belt-shaped belt base material inside the mold, ceramics that surrounds the other part, or a material that is less magnetic than the metal that surrounds the seam Are provided, and a metal member that generates heat by energizing the high-frequency induction heating coil is arranged at a joint.

[0005]

[Function] The metal member is heated by high frequency induction heating,
Heating and melting and softening only the seam between the end faces of both ends of the belt-shaped belt base material and its minimum area, and then cooling and hardening to connect the seam, both ends of the belt base material are hardly affected by heat. And there is no dimensional difference between the belt base material outside the mold due to thermal expansion and the like.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method and an apparatus for producing an endless belt according to the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing one belt-shaped belt base material for manufacturing a toothed belt as an endless belt by abutting one end portion 10 and the other end portion 20. 2 and 3 are a plan cross-sectional view showing a form in which one end 10 and the other end 20 of the belt base material set in the mold 40 are connected by abutting each other, and a side cross-sectional view taken along line XX of FIG. Is shown.

A convex portion 11 for a seam is provided at the tip of one end 10 of the belt base material, and a concave portion 21 is formed at the tip of the other end 20 so as to fit with the convex portion 11 of the other party. .
The convex portion 11 and the concave portion 21 are butted with a seam 30,
The joint J including the joint 30 is set in the mold 40. The mold 40 is made of a highly magnetic metal such as iron and ceramics.
Or a combination with a metal having a weak magnetic property such as aluminum.
It consists of 3 mag. Insulating materials 47 and 48 are in contact with the upper mold 41 and the lower mold 42 from outside thereof so as to sandwich the upper mold 41 and the lower mold 42.
Further, on the outside of them, high-frequency induction heating coils 44, 44
Is installed. One of the high-frequency induction heating coils may be used. Since the horizontal dies 43, 43 shown in FIG. 2 make much contact with the belt substrate other than the seam 30, it is preferable to use ceramics or a metal having weak magnetism rather than metal.

When the high-frequency induction heating coils 44 are energized, the metal upper mold 41 and lower mold 42 generate heat,
The heat acts on the periphery of the convex portion 11 and the concave portion 21 including the seam 30 of the belt base material, but receives the heat in a minimum necessary range, that is, minimizes the narrow band area around the seam 30 and the periphery thereof. Apply heat only to the area. Therefore, the metal member 46 that efficiently generates heat by energizing the high-frequency induction heating coils 44, 44 is formed along the joint 30 as a pair of upper and lower parts 46a, 46b in the embodiment.
Are sandwiched from above and below. Therefore, the joint J
Only the metal members 46a and 46b that efficiently generate heat in direct contact with the metal material that efficiently generates heat in the entire area are located along the seam 30. Ceramics or substitutes
The metal member (46) is brought into contact with a metal member (45) having weaker magnetism than the metal member (46) .

Since the apparatus is configured as described above with the mold 40 as a main part, the high-frequency induction heating coil 44,
By turning on the power to 44, the metal member 46 is efficiently heated by the formation of an electromagnetic field. As a result, only the seam 30 formed by the convex portions 11 and the concave portions 21 of both end portions 11 and 21 of the belt-shaped belt base material and a minimum region thereof are heated and melt-softened. Thereafter, the power supply to the high-frequency induction heating coils 44, 44 is turned off, and the entire mold 40 or the upper mold 41 and the lower mold 4 are turned off.
2 is cooled and the connected part is cooled and hardened.

As described above, since only the narrow region including the joint 30 is heated at the joint J, the ceramic at the joint J of the other portion disposed inside the mold 40 is heated.
Scan or weak metal member 45 of magnetic than metallic member (46)
Thus, it is shielded from the heat effect by the heat generating metal member 46. For this reason, at the boundaries 12 and 22 between the ends 10 and 20 at both ends of the mold 40, there is no dimensional difference due to thermal expansion or the like between the outside and the inside of the mold, and even if it occurs, the difference is small.

[0011]

The method and apparatus for manufacturing an endless belt according to the present invention are designed to heat the seam formed by the end faces of both ends of the belt-shaped belt base material and only the minimum area thereof, and to connect the seam by melt softening. Because it is, there is almost no heat effect at the joint at the both ends of the belt arranged inside the mold,
Therefore, there is no dimensional difference between the belt base material outside the mold due to thermal expansion and the like. This manufacturing method can also be applied to the case of a cored endless belt, in which case the steel cord forming the core is also heated by high frequency induction.

[Brief description of the drawings]

FIG. 1 is a plan view showing a single long belt-shaped belt base material manufactured using a toothed belt as an example of an endless belt manufacturing apparatus according to the present invention.

FIG. 2 is a plan cross-sectional view showing a form in which both ends of a belt base material set in a mold are abutted and connected by the apparatus of the embodiment.

FIG. 3 is a side sectional view of the apparatus according to the embodiment taken along line XX of FIG. 2;

FIG. 4 is a plan cross-sectional view showing a form in which both ends of a belt base material set in a mold in a conventional endless belt manufacturing apparatus are abutted and connected.

FIG. 5 is a side sectional view of a conventional endless belt manufacturing apparatus.

FIG. 6 is a side view of another conventional endless belt manufacturing apparatus.

FIG. 7 is a front view of another conventional endless belt manufacturing apparatus.

[Description of Signs ] 10, 20 Both ends of belt-shaped belt base material 11 Convex portion of joint portion 21 Concavity of joint portion 30 Joint 40 Type 44 High-frequency induction heating coil 45 Ceramics (or a metal that is less magnetic than 46) 46 Efficient heat generation Metal parts

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 65/32 B29L 29:00 B29D 29/00

Claims (2)

(57) [Claims] An end portion of a belt-shaped belt base material arranged in a mold with its end surfaces abutting each other is surrounded by a metal at a seam formed by the end surfaces thereof, and the other portion is made of ceramic or metal surrounding the seam. Surrounded by weak magnetic metal, high frequency
A method for producing an endless belt, comprising melting and softening only a minimum area around a seam including a seam by a metal member heated by an induction heating coil, and then cooling and hardening the seam to connect the seam. 2. A belt-shaped belt base material, which is arranged in a mold with its end faces abutting each other, surrounds both ends of the belt-shaped belt base material with metal, and the other part is made of ceramic or metal surrounding the seam. An endless belt manufacturing device that is surrounded by a weakly magnetic metal and melts and softens only the minimum area around the seam including the seam with a heated metal member, then cools and hardens and connects the seam. In the mold, a metal that surrounds the seam between the end faces of the belt-shaped belt base material at both ends, a ceramic that surrounds the other part, or a member that is less magnetic than the metal that surrounds the seam is provided. An endless belt manufacturing apparatus, wherein a metal member that generates heat by energizing a coil is disposed at a joint.