JP2011126235A - Belt end joining method, method for manufacturing endless belt, and non-end flat belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the earthquake resistance and durability of an endless flat belt where both ends are adhered by heat welding. <P>SOLUTION: Both ends of a band-shaped flat belt 10 formed of a thermoplastic resin is die-cut into a complementary finger shape, both the ends of the fingers are placed on a matching pressing table 15, a pressing metal plate 17 shaped along an adhesive line 16 of the finger is pressed to an adhesive part thereof, the pressing metal plate 17 is heated to give heat only to the adhesive part so as to be fused, and then the resultant is cooled down to fuse both the ends thereof, whereby a band-shaped belt is made to be an endless belt. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an end joining method by heat fusion of a transmission or conveyance belt.

  As a method for joining both ends of a transmission and conveying flat belt, a lap joint, a finger joint, a mechanical racing joint, and the like are known. Of these, the finger joint is excellent in durability when used with a small pulley and is advantageous in terms of flatness, and thus has been widely used in recent years for transmission and conveyance flat belts. In a belt using a finger joint, the belt body is generally formed of a thermoplastic resin, both ends of the belt punched into a complementary shape are engaged, and both ends of the belt are joined by heat fusion using a heat press machine ( Patent Document 1).

Japanese Patent Publication No. 6-73911

  However, even with conventional finger joints using heat fusion, the thickness of the joint part inserted into the heat press machine is slightly reduced due to the heat flow of the thermoplastic resin during pressing, and an inflection point is generated. The step along the belt width direction is slightly formed at both ends of the joint portion. This gives vibration to the rotor and spindle that contact the belt, and also causes striped wear marks (zebra marks) on the belt itself, causing damage to the equipment and the belt.

  An object of the present invention is to improve the vibration control and durability of an endless flat belt having both ends joined by heat fusion.

  The belt end joining method of the present invention is a belt end joining method in which both ends of a belt-like belt are joined by thermal fusion, and the joining surfaces provided at both ends of the belt are surfaces other than the surfaces along the belt width direction. In this case, the complementary joint surfaces are joined together, the regions along the joint surfaces are melted, and both ends are fused together.

  The endless belt manufacturing method of the present invention is a method of manufacturing an endless belt by joining both ends of a belt-like belt by heat fusion, and the joining surfaces provided at both ends of the belt are along the belt width direction. It is characterized in that it is formed into a complementary shape including a surface other than the surface, the complementary bonding surfaces are butted together, and only an area along the bonding surface is thermally melted and fused to form an endless belt.

  In the thermal melting, a press metal plate having a shape along the joint surface is pressed against the joints at both ends, and heat is applied to the belt through the press metal plate. Moreover, it is preferable that a joining surface is a joining surface of a finger joint, for example.

  The tensile strength layer of the belt-like belt is formed, for example, by covering the core wire with a melt-extruded polyamide elastomer resin. Further, a rubber material is introduced during the extrusion process of the polyamide elastomer resin, and rubber layers are formed on both sides of the tensile strength layer.

  The endless flat belt of the present invention is an endless belt in which both ends of a belt-like belt formed in a complementary shape are abutted and joined by thermal fusion, and the joining surface to be thermally fused is along the belt width direction. The surface of the joint portion of the belt including the surface other than the surface has a dent along the joining surface.

  In the endless flat belt, for example, a core wire is used as the core, and the tensile strength layer is formed by covering the core with, for example, polyamide elastomer. Also, for example, rubber layers are directly formed on both sides of the tensile layer.

  ADVANTAGE OF THE INVENTION According to this invention, the damping property and durability of an endless flat belt to which both ends are joined using heat fusion can be improved.

It is a cross-sectional view of the flat belt of 1st Embodiment. It is a partial enlarged plan view of a joint part. It is a perspective view which shows the mode of the hot press process in this embodiment. It is the elements on larger scale of the joint part of a modification. It is a cross-sectional view of the flat belt of 2nd Embodiment. It is a layout figure of a vibration testing machine. It is a graph which shows the result of a vibration test.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of an endless flat belt according to a first embodiment manufactured using the belt end joining method of the present invention.

  The flat belt 10 is, for example, a tangential belt used for power transmission to a spindle or rotor of a textile machine or the like, or a conveyance belt used for conveying paper sheets used in printing, bookbinding, paperwork, mail, or the like. As shown in FIG. 1, the flat belt 10 is composed of five upper and lower layers.

  A plurality of core wires 12 are embedded as core bodies (strength members) along the longitudinal direction of the belt in the tensile layer 11 disposed in the center of the belt cross section. Moreover, the core wires 12 are arranged at regular intervals in the belt width direction. The canvas 13 is adhered to both the upper and lower surfaces of the tensile layer 11, and rubber layers 14 as surface materials are formed on the outer sides thereof.

  A fiber cord is used for the core wire 12, and natural fibers such as cotton, chemical fibers such as polyamide fibers, aramid fibers, polyester fibers, and glass fibers, or combinations thereof are used. For the tensile strength layer 11 in which the core wire 12 is embedded, a thermoplastic resin such as polyamide elastomer or polyurethane elastomer is used. The tensile layer 11 is formed by coating the core wires 12 arranged at a constant interval in the belt width direction with a melt-extruded thermoplastic resin. The canvas 13 is made of woven or knitted fabric using polyamide fibers, and the rubber layer 14 is made of, for example, NBR rubber.

  FIG. 2 is a schematic plan view showing an enlarged joint at both ends of the flat belt 10 shown in FIG. 1, and FIG. 3 is a perspective view showing an example of a press used in the hot press processing of the present embodiment. FIG. The belt end joining method of the present embodiment will be described with reference to FIGS.

  First, the joining surfaces formed at both ends of the flat belt 10 are formed into a complementary shape including a surface other than the surface along the belt width direction. That is, the belt cross-section punched out as the joining surface is not composed of a single plane along the belt width direction, but from a cross-section including a plane or curved surface in a direction different from the belt cross-section, or a combination thereof. Composed. In this embodiment, both ends of the flat belt 10 are punched into a finger shape. Both ends of the belt punched into the finger shape are arranged on the press table 15 in a state where the fingers are butted (engaged) with each other as shown in FIG.

  In the hot press process of this embodiment, the press metal plate 17 along the joining line 16 of the fingers engaged with each other is used. That is, the press metal plate 17 is formed as a metal plate member having a predetermined width along the bonding line 16 and is pressed against the both ends of the belt placed on the press table 15 so as to cover the bonding line 16. . Thereafter, the press metal plate 17 is heated for a predetermined time by a heat source (not shown) and further cooled, and this hot press process is completed.

  That is, in this heat press process, the press metal plate 17 is pressed only to the heating region 17A along the joining line 16 shown by slant lines in FIG. 2 and heat is applied, so that the thermoplastic resin constituting the belt is also finger-joined. It melts only in this region along the part. In addition, in the example of FIG. 3, the press metal plate along the finger shape was pressed from one side to the finger joint portion placed on the press stand, but the joint portion was formed by a pair of upper and lower press metal plates along the finger shape. You may heat-press on both sides.

  As described above, according to the first embodiment, since the area that is thermally melted during the hot press process is the area along the joining line (joining surface), a step (slight dent) is generated in this area. The position of the step in the longitudinal direction of the belt moves along the belt width direction. As a result, the step generated by heat fusion is dispersed throughout the longitudinal direction of the joint, and the influence of the step in contact with the roller and the spindle is reduced, thereby suppressing vibration due to this.

  Further, in the flat belt of the present embodiment, by using a core wire as a core body, the degree of freedom in tension design is increased, and while having flexibility, only the region along the joining line is thermally melted, The runnability can be maintained by preventing the core wire from being disturbed during heat fusion. In the present invention, since the step (inflection point) generated by heat fusion only has to be dispersed in the belt longitudinal direction, for example, as shown in FIG. Can do.

  In the first embodiment, a flat belt using a core wire as the core has been described as an example. However, the present invention can be applied to any belt as long as heat fusion is used for joining the end portions. It can also be applied to belts that use stretched film or canvas for the core, belts that do not have canvas between the rubber layers, or belts that have a surface material (rubber layer) made of materials other than rubber. be able to.

  Next, an endless flat belt according to a second embodiment manufactured using the belt end joining method of the present invention will be described with reference to FIG.

  The endless flat belt 20 of the second embodiment is a conveyance belt used for conveyance of paper sheets used in printing, bookbinding, paperwork, mail, and the like. As shown in the cross-sectional view of FIG. 5, the flat belt 10 is composed of upper and lower three layers.

  A plurality of core wires 22 are embedded along the longitudinal direction of the belt as core bodies (strength members), and the core wires 22 are arranged at regular intervals in the belt width direction. . Further, rubber layers 23 as surface materials are respectively formed on the upper and lower surfaces of the tensile layer 21.

  For the core wire 22, natural fibers such as cotton, chemical synthetic fibers such as polyamide-based synthetic fibers, polyester fibers, and glass fibers, or combinations thereof are used. For the core wire 22, for example, a para-aramid cord 1100 dtex / 3 is used. That is, para-aramid cords 1100 dtex / 3 are twisted alternately with S and Z at equal intervals in the belt width direction at a density of 4.5 pieces / cm, and this is covered with a melt-extruded polyamide elastomer resin. A 1.5 mm tensile strength layer 21 is formed.

  In the flat belt 20 of the second embodiment, rubber such as NBR is directly bonded to both sides of the tensile strength layer 21 to form the rubber layer 23. Adhesion of the rubber layer 23 to the tensile strength layer 21 is performed by introducing NBR rubber during the formation of the tensile strength layer 21, that is, during extrusion processing of the polyamide elastomer resin.

  The long belt body formed in the above process is punched so as to have a complementary shape at both ends with a predetermined length, and is heat-sealed by using the joining method described in the first embodiment. It is said.

  As described above, also in the second embodiment, the same effect as that of the first embodiment can be obtained. In addition, the conventional conveyor belt uses a structure of a total of seven layers of canvas 3ply including a thermoplastic resin layer in order to obtain necessary tension and lateral rigidity and to perform bonding by heat fusion. In the belt, the core wire is used to increase the tensile strength, and the polyamide elastomer is used for the tensile strength layer to maintain the lateral rigidity, and the tensile strength layer has a function as a heat sealing material for bonding, so the structure is simplified. Thus, the manufacturing cost can be reduced.

  Moreover, it can maintain on a pitch line, without disturbing a core wire, employ | adopting a core wire as a main tensile body by performing heat sealing | fusion using the said heat press machine. Accordingly, the traveling property is maintained without using an adhesive or the like for joining the end portions, the increase in bending resistance is suppressed, the bending loss is reduced, and the creep loss is reduced by obtaining a high tensile strength. In particular, the second embodiment has a three-layer structure that does not use a canvas, and therefore has a great effect on cost reduction and bending loss reduction by simplifying the structure.

  Next, with reference to FIG. 6 and FIG. 7, a specific effect of reducing belt vibration by the belt end joining method of the present invention will be described. FIG. 6 is a layout of a testing machine used for the vibration test, and FIG. 7 is a graph showing the result of the vibration test.

  In the test, both ends of a flat belt composed mainly of a thermoplastic resin were punched into complementary finger shapes, and the fingers at both ends were heat-sealed by the method described in the first embodiment to form an endless belt. Example 1 was subjected to the vibration test of Comparative Example 1 in which an endless belt was formed by performing a conventional hot pressing process. The belts of Example 1 and Comparative Example 1 are both endless belts having a width of 25 mm and a length of 3100 mm, and the configuration other than the hot press process is the same.

  As shown in FIG. 6, the flat belt 30 of Example 1 and Comparative Example 1 is wound around a driving pulley 31 and a driven pulley 32 each having a diameter of 150 mm with a mounting tension of 850 N / 25 mm and a belt speed of 8.4 m / Ran in seconds. The tension side span of the belt includes three rollers 33 to 35 each having a diameter of 8 mm and three pressure rollers 36 to 38 that are paired with the rollers 33 to 35 so that they are in line contact with the belt surface and the back surface. Arranged at intervals, the rollers 33-35 were rotated at 20,000 rpm. The measurement was performed by measuring the position of the middle pressure roller 37 located substantially in the center of the three pressure rollers 36 to 38 with a laser displacement meter.

  FIG. 7 shows the displacement (mm) from the balance position of the pressure roller 37 in time series. In FIG. 7, the displacement when traveling on the flat belt of Example 1 is indicated by a curve E, and the displacement when traveling on the flat belt of Comparative Example 1 is indicated by a curve C.

  As shown in the graph of FIG. 7, in the belt of Comparative Example 1, a large displacement exceeding 0.4 mm appears at a period of about 0.369 seconds corresponding to the contact with the roller of the joint. In this belt, this displacement is greatly reduced to an order of about 0.1 mm (1/4 or less).

  As described above, according to the belt end portion joining method of the present invention, it is possible to greatly suppress the occurrence of vibration due to the step formed in the joint portion. The vibration control effect is particularly great for tangential belts that run at high speeds.

  In this embodiment, the heat source is applied to the press metal plate for melting, but for example, a high-frequency welder or an ultrasonic welder may be applied to the mold to heat-seal the belt. Moreover, although the finger shape illustrated by this embodiment is formed only with the straight line, the shape comprised by a curve or a straight line may be sufficient as the shape of a finger.

DESCRIPTION OF SYMBOLS 10 Flat belt 11 Tensile layer 12 Core wire 13 Canvas 14 Rubber layer 16 Joining wire 17 Press metal plate 17A Heating area 20 Flat belt 21 Tensile layer 22 Core wire 23 Rubber layer

Claims (12)

  A belt end joining method in which both ends of a belt-like belt are joined by heat-sealing, wherein joining surfaces provided at both ends of the belt are formed into a complementary shape including a surface other than a surface along the belt width direction. The belt end joining method characterized in that the complementary joining surfaces are abutted and only the region along the joining surface is thermally melted to fuse the both ends.   2. The belt according to claim 1, wherein in the heat melting, a press metal plate having a shape along the joint surface is pressed against the joint portion at both ends, and heat is applied to the belt through the press metal plate. End joining method.   The belt end joining method according to claim 1, wherein the joining surface is a joining surface of a finger joint.   A method of manufacturing an endless belt by joining both ends of a belt-like belt by heat fusion, wherein joining surfaces provided at both ends of the belt have a complementary shape including a surface other than a surface along the belt width direction. A method of manufacturing an endless belt, wherein the endless belt is formed by molding, butting the complementary joining surfaces, and heat-melting only a region along the joining surface.   The endless press according to claim 4, wherein, in the heat melting, a press metal plate having a shape along the joint surface is pressed against the joint portion at both ends, and heat is applied to the belt through the press metal plate. A method for manufacturing a belt.   The method for manufacturing an endless belt according to claim 4, wherein the joint surface is a joint surface of a finger joint.   The endless belt manufacturing method according to any one of claims 5 and 6, wherein the tensile strength layer of the belt-like belt is formed by covering a core wire with a melt-extruded polyamide elastomer resin. Method.   8. The method for producing an endless belt according to claim 7, wherein a rubber material is introduced during extrusion processing of the polyamide elastomer resin, and rubber layers are formed on both sides of the tensile strength layer.   An endless belt in which both ends of a belt-shaped belt formed into a complementary shape are butted and bonded by thermal fusion, and a bonded surface to be thermally fused includes a surface other than a surface along the belt width direction, An endless flat belt, wherein a surface of a joint portion of the belt has a dent along the joining surface.   The endless flat belt according to claim 9, wherein a core wire is used as the core body.   11. The endless flat belt according to claim 10, wherein the tensile strength layer is formed by coating the core with a polyamide elastomer. The endless flat belt according to claim 11, wherein a rubber layer is directly formed on both sides of the tensile strength layer.

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