JP5770016B2 - Tube forming machine for tube tire - Google Patents

Description

  The present invention relates to a tube molding machine for tube tires.

Conventionally, a tube of a tire is formed into a ring shape by cutting a hollow cylindrical tube fabric obtained by extruding rubber or a synthetic resin material into a required length, and crimping both ends thereof.
FIG. 7 is a perspective view showing an example of conventional tube molding described in Patent Document 1. In FIG.
In the figure, reference numeral 101 denotes a heater that can move up and down and adjust the temperature. Cutters 102 a and 102 b are attached to both sides of the heater 101 so that the position in the vertical direction can be adjusted. Reference numerals 103 and 104 denote upper and lower holders (hereinafter referred to as molds). Here, the upper mold 103 is movable up and down relative to the lower mold 104, and the tube fabric 106 is joined when the tube fabric 106 is cut and joined. Is held between the upper and lower molds 103 and 104 (hereinafter referred to as a clamp) and held.
Here, the upper and lower molds 103 and 104 are configured so as to be able to contact and separate, for example, by moving one relative to the other stationary.

Reference numeral 105 denotes a support table that cuts the tube fabric 106 on the support table 105. The cutters 102a and 102b cut the tube dough 106 and then heat the tube dough 106 by maintaining the state in contact with the cut surface of the cut tube dough 106. When the ends of the cut tube fabric 106 are heated until they can be crimped, the cutters 102a and 102b are pulled up and the support base 105 is moved downward.
Subsequently, one of the upper and lower molds 103 and 104 is brought close to the other upper and lower molds 103 and 104, and the ends of the tube fabric 106 to be held are pressure-bonded (hereinafter referred to as vise).
A ring-shaped tube is formed by the above-described series of operations, and in the case of a rubber tube, the product tube is then vulcanized to produce a product tube.

By the way, although not described in the patent literature, in order to securely clamp the tube fabric and to crimp with a strong crimping force in a similar mechanism, the opposing surfaces of the upper die 103 and the lower die 104 are provided. As a pressure bonding means, there is one in which a lining rubber block 110 (see FIG. 8) is arranged.
When this lining rubber block 110 is used, the tube fabric 106 can be reliably clamped and a strong pressure-bonding force can be obtained as compared with the case where the lining rubber block 110 is not used.

FIG. 8 is a cross-sectional view schematically showing a state in which both ends of the tube fabric 106 are pressed against each other in a conventional tube forming machine provided with the lining rubber block 110.
The ends of the tube fabric 106 are protruded from the surface of the lining rubber block 110 in order to press the ends of the tube fabric 106 together. FIG. 8A is a diagram showing this state, and shows a state in which the tube fabric 106 held by the upper and lower molds 103 and 104 is clamped by the lining rubber block 110. From this state, for example, when the upper and lower molds 103 and 104 are brought closer, as shown in FIG. 8B, the protruding tube fabric ends 106a first come into contact with each other. When the upper and lower molds 103 and 104 are brought closer to each other, the lining rubber blocks 110 come into contact with each other as shown in FIG. 8C. In the process, the protruding rubber portion 106a is sandwiched between the lining rubber blocks 110, deforms (bends) the lining rubber block 110, and strongly presses the protruding rubber portion (tube fabric end) 106a by the reaction force of the deformation. can do.

  As described above, in the conventional molding of the tire tube, the tube fabric end portion 106a protruded between the upper and lower mold dies 103 and 104 as described above is formed in the lining rubber block 110 in the process in which the lining rubber blocks 110 are in contact with each other. The lining rubber block 110 is deformed and the pressure force of the tube fabric end portion 106a is secured by the reaction force caused by the deformation. On the other hand, the protruding rubber 107 is formed because it is crushed by the contact surface. However, if this protruding rubber 107 is present, the tube product becomes poor in appearance. Therefore, it is necessary to separately perform a step of buffing the molded tube before vulcanization to remove the protruding rubber 107 portion and adjusting the properties of the molded tube. Therefore, there are problems in that the production efficiency is reduced, costs and labor are required as compared with the case where there is no protruding rubber.

Further, when the lining rubber block 110 is repeatedly used, the pressure of the tube fabric 106 is weakened due to a decrease in rigidity of the lining rubber block due to repeated fatigue or deformation of the lining rubber itself, and the performance of the tube product is lowered. Also occurs.
Therefore, since the lining rubber block has been a rectangular parallelepiped conventionally, the lining rubber block 110 is cured or the volume thereof is increased in order to increase the pressure-bonding force and durability for use. However, since the amount of deformation decreases when the lining rubber block 110 is cured, it is necessary to increase the pressure (visce pressure) for pressure bonding of the molding machine in order to obtain the necessary amount of deformation. However, this not only causes a shortage of the capacity of the molding machine, but also causes another problem of reducing the durability of the lining rubber block 110. Even when the volume of the lining rubber block 110 is increased, the rigidity of the lining rubber block is increased, so that the necessary crimping force cannot be obtained unless the crimping capability of the molding machine is increased.

JP-A-62-267124

  The present invention has been made in view of the above-mentioned problems in conventional tube molding, and its purpose is to secure the pressure-bonding force of the tube fabric end portion (FIG. 2A 6a) even if the lining rubber block is less deformed. And it is to suppress the occurrence of protruding rubber and eliminate the buffing process.

The present invention is a tube molding machine for a tube tire that forms a ring-shaped tire tube by crimping the ends of a hollow cylindrical tube fabric or by thermocompression bonding, and the end of the tube fabric can be freely released. A pair of upper and lower molds for holding the clamp, and an elastically deformable crimping means that is provided on the opposing surface of the upper and lower molds and presses and crimps the tube fabric. An inner surface for clamping in a state of protruding a predetermined amount toward the crimping means, and a tip surface that contacts the mating crimping means, and a boundary between the tip surface and the inner surface is formed in a tapered surface together are, an outer surface of said crimping means, tubing tie having Katakin configured into a tapered surface inclined in a tube fabric direction for holding the distal direction from the upper and lower dies gold surface Which is a tube molding machine.

  According to the present invention, since the tube fabric end 6a is pressure-bonded within the tapered surface, there is no need to deform the lining rubber more than necessary, and an angle is provided on the outer surface of the lining rubber (FIG. 1A 10a). Therefore, a sufficient pressing force can be obtained even with the same rubber hardness / volume as conventional. In addition, since the tube fabric end portion 6a fits within the tapered surface, the occurrence of the protruding rubber that has occurred in the conventional tube molding is suppressed, and the tube joining portion performed after vulcanization after molding is buffed. There is no need to finish.

FIG. 1A shows a cross-sectional shape of a lining rubber block according to the present embodiment, and FIG. 1B is a view showing a cross-sectional shape of a conventional lining rubber block shown for comparison. It is sectional drawing which shows typically the shaping | molding of the tube performed using the up-and-down type metal mold | die provided with the lining rubber block which concerns on this embodiment, FIG. 2A is the state before crimping | compression-bonding of tube fabric, FIG. The state of crimping is shown. It is a figure which shows roughly the molding process of the tire tube by the tube molding machine provided with the lining rubber block which concerns on this embodiment. It is a figure which shows roughly the molding process of the tire tube by the tube molding machine provided with the lining rubber block which concerns on this embodiment. The cross-sectional shape of a lining rubber block is shown. List the numerical values of θ, A, B, and C of the lining rubber blocks of the products (1) to (4) of the present invention and the numerical values of θ, A, B, and C of the conventional products as comparative products. It is the table shown. FIG. 6 is an evaluation table of tubes formed by attaching the lining rubber block shown in FIG. 5 to the same tube molding machine. It is a perspective view which shows an example of the conventional tube shaping | molding. It is sectional drawing which shows typically the state which press-contacts the both ends of the tube fabric in the conventional tube molding machine provided with the lining rubber block.

Next, an embodiment of the present invention will be described.
The tube molding machine according to the present embodiment is the same as the conventional one described above in that a lining rubber block disposed on the upper and lower molds is used as the crimping means, but has a feature in the shape of the lining rubber block. Yes.
Then, next, this point is demonstrated with reference to drawings.

FIG. 1A shows a cross-sectional shape of a lining rubber block according to the present embodiment, and FIG. 1B is a view showing a cross-sectional shape of a conventional lining rubber block shown for comparison.
As shown in FIG. 1B, since the conventional lining rubber block 110 has a rectangular parallelepiped shape, its cross-sectional shape is a rectangle. In contrast, as shown in FIG. 1A, the cross-sectional shape of the lining rubber block 10 of the present embodiment is the outer surface 10a of the lining rubber block 10 (here, “inner” is closer to the tube fabric held by the clamp, and farther away). The direction is called “outside”, and is a surface having an angle in the tube fabric direction (referred to as inward) with respect to the horizontal, that is, from the surface of the upper die 3 to the tip direction (surface opposite to the upper die 3 or free end) The inner surface 10b of the lining rubber block 10 is similarly a surface having an angle inward from the horizontal surface (here, the inner surface of the mold). That is, it is configured with a tapered surface directed inward.
Therefore, the attachment surface 10e of the lining rubber block 10 to the upper mold 3 is formed larger than the front end surface 10d that is a contact surface of the front end portion with the mating lining rubber block 10.
In addition, the angle with respect to the horizontal of the outer surface 10a and the inner surface 10b of the lining rubber block 10 is larger on the outer surface 10a as shown in the figure.

In addition, a tapered surface 10c is formed at a boundary portion of the lining rubber block 10 so as to chamfer the front end surface (the surface opposite to the mold side or the free end side) and the inner surface 10b.
The tapered surface 10c is for preventing the tube fabric 6 from being sandwiched by the lining rubber block 10 when the end portions 6a (see FIG. 2) of the tube fabric 6 are pressure-bonded to each other.
The lining rubber block 10 for the upper die 3 has been described above, but the same applies to the lining rubber block 10 for the lower die 4.

FIG. 2 is a cross-sectional view schematically showing tube forming using the upper and lower molds 3 and 4 provided with the lining rubber block 10 according to the present embodiment. FIG. 2A is a state before the tube fabric 6 is pressed. FIG. 2B shows a state of pressure bonding during molding pressure bonding.
That is, in the state of FIG. 2A, the tube fabric 6 clamped and held by the upper and lower molds 3 and 4 is clamped by the tapered surface of the inner surface 10b of the lining rubber block 10, and its end 6a is for crimping. The lining rubber block 10 slightly protrudes from the tip of the lining rubber block 10 (here, the protruding amount is referred to as an overhang amount).

In the state of FIG. 2B, the lining rubber blocks 10 are brought into contact with each other by bringing the upper and lower molds 3 and 4 close to each other (one may be moved relative to the other, or both may be moved relative to each other). In this state, the amount of overhang of the tube fabric 6 described above is accommodated in the tapered surface 10c of the lining rubber block 10, so that it is not sandwiched by the lining rubber block 10 as in the prior art.
On the other hand, the protruding tube fabric end 6a is crushed by a vice in the same way as in conventional tube molding, deforming the lining rubber block 10, and the crimping force indicated by the arrow F in the figure acts on the tube fabric 6 from its reaction. Then, crimping is performed.
In the tube forming machine of the present embodiment, the tube dough end portion 6a is pressure-bonded within the tapered surface on the premise of the lining rubber block 10 having the same volume as compared with the case where the conventional tube dough end portion 6a is sandwiched. Therefore, it is not necessary to deform the lining rubber more than necessary, and since the outer surface of the lining rubber (FIG. 1A 10a) is provided with an angle, sufficient pressure can be obtained even with the same rubber hardness / volume as before. .

According to this embodiment, since the shape of the lining rubber block 10 is configured as described above, the following operational effects can be obtained. That is,
(I) Since the outer surface 10a of the lining rubber block 10 is configured as a tapered surface toward the distal end, the bending thereof can be suppressed, and a necessary crimping force can be obtained without increasing the rigidity or volume of the lining rubber itself. . Further, since the deformation amount of the lining rubber block 10 is reduced, the durability is improved as compared with the conventional one.
(Ii) Since the inner surface 10b of the lining rubber block 10 is configured as a tapered surface toward the distal end, the clamping force is improved, and the influence of warping due to repeated deformation of the lining rubber block 10 can be reduced. For example, the tube fabric 6 can be sufficiently clamped even if the lining rubber block 10 is subjected to repeated fatigue to reduce the rigidity of the lining rubber block or deformation of the lining rubber itself.
(Iii) Since the tapered surface 10c is provided at the boundary between the inner surface 10b and the tip surface 10d of the lining rubber block 10, the tube fabric 6 is not sandwiched and no protruding rubber is generated.
Therefore, a buffing finish or the like is not required after molding as in the prior art, and accordingly, cost and labor are saved, and molding efficiency is improved.

FIGS. 3A to 3G are views schematically showing a tube molding machine including the molds 3 and 4 with the lining rubber block 10 according to the present embodiment described above and a tire tube molding process using the tube molding machine.
FIG. 3A shows the moving side lower die 4 and fixed side lower die 4 each having a lining rubber block 10 as a crimping means, and the vise table 8 moving from the direction of the arrow toward the lower die 4. The incoming tube fabric 6 is shown. Here, pressure-bonding means comprising lining rubber blocks 10 are provided on the opposing surfaces of the moving-side and fixed-side molds 3, 4, respectively.
FIG. 3B shows a state in which the tube fabric 6 is disposed at the normal positions on the moving side and fixed side molds 3 and 4, respectively.
FIG. 3C shows the state before the upper die 3 is lowered to the tube fabric 6 arranged at the normal position on the moving side and fixed side lower die 4 and clamped by the crimping means constituted by the lining rubber block 10. Shows the state.
FIG. 3D shows a state in which the left and right tube fabrics 6 are clamped by the lining rubber block 10.

FIG. 3E shows a state before the clamped tube fabric 6 is cut by the electric heating knife 2. For example, the tube fabric 6 is cut with an electric heating knife heated by a heater to form a joint surface composed of the cut surfaces.
After cutting with the electric heating knife 2, the electric heating knife is returned to its original position. The bonding surface formed at this time may or may not be heated.

When the electric knife 2 is returned to its original position, the moving upper and lower molds 3 and 4 are immediately moved toward the fixed upper and lower molds 3 and 4 (FIG. 3F), and the contact surfaces of the tube fabric 6 are pressure-bonded. The state of the crimping is as shown in FIG. 2B, and as described above, no protruding rubber is produced as in the prior art. After the crimping, the upper die 3 is raised, and then the moving side upper and lower dies 3, 4 are moved away from the fixed side upper and lower dies (FIG. 3G).
As described above, the molding of the tire tube according to the present embodiment is completed.

EXAMPLE Next, the Example of the lining rubber block 10 is demonstrated with the result of having compared the conventional product as a comparative product.
FIG. 4 shows a cross-sectional shape of the lining rubber block 10.
Here, the angle formed by the horizontal surface of the outer surface 10a of the lining rubber block is θ, the vertical length between the inner surface (or the bottom surface) of the mold metal and the inner end of the tip surface 10d of the lining rubber block 10 is A, the mold metal The vertical length between the inner surface and the tip of the tapered surface 10c of the lining rubber block 10 is B, and the taper surface 10c at the boundary between the inner end of the tip surface 10d of the lining rubber block 10 and the tip of the inner surface 10b is shown. Let C be the surface length in the horizontal direction.

FIG. 5 is a list of values of θ, A, B, and C of the products (1) to (4) of the present invention and values of θ, A, B, and C of a conventional product as a comparison product. It is the table shown.
That is, θ, A, B, and C were all 0 for the conventional product, but the implemented product (1) was 30 °, 0.5 mm, 0.5 mm, 0.5 mm, and the implemented product (2) was 5 °. , 0.3 mm, 0.3 mm, 0.3 mm, the product (3) is 15 °, 0.5 mm, 0.5 mm, 0.3 mm, and the product (4) is 45 °, 0.5 mm,. 5 m and 0.5 m.
In addition, all the materials of the tube were a butyl rubber compounding material, and the joint surface total gauge of the tube fabric end 6a was 5 mm.

FIG. 6 is an evaluation table of tubes formed by attaching the lining rubber block 10 shown in FIG. 5 to the same tube molding machine.
That is, it is an evaluation table in which the evaluation of the conventional products and the implementation products (1) to (4) is performed in five stages, and the evaluation values are summarized in a list.

Adhesive strength of conventional products (for example, tensile breaking strength at the product tube bonding position), amount of protruding rubber (the width of the protruding rubber or visual observation), durability of the lining rubber block (for example, changes in the number of times used until die change) ) Is 3, 5, 5, 5 for the implementation product (1), 4, 4, 4 for the implementation product (2), 4, 3, 4, for the implementation product (3) ( 4) was 4, 5, and 5.
From the above, when the angle θ is large, the durability of the lining rubber block 10 is increased, and when A, B and C are large (however, between 0 and 0.5 mm), the amount of protrusion tends to be small. I understand.
Therefore, it was found that the operation and effect as aimed by the present invention can be obtained.

  In the above description, the pressure-bonding means has been described as a lining rubber block. However, in carrying out the present invention, the material is not necessarily limited to rubber, and may be another material having elasticity. In addition, the crimping means has been described as having a block shape including an outer surface formed as a tapered surface, an inner surface, and a tapered surface of the boundary portion, but these requirements do not necessarily have to be provided at the same time, at least of which One may be provided.

  DESCRIPTION OF SYMBOLS 1 ... Tube molding machine, 2 ... Electric heating knife, 3 ... Upper die, 4 ... Lower die, 6 ... Tube cloth, 8 ... Vise table, 10 ... Lining Rubber block, 101... Heater, 102a, 102b... Cutter, 105.

Claims (4)

A tube molding machine for a tube tire that forms a ring-shaped tire tube by crimping the ends of a hollow cylindrical tube fabric or by thermocompression bonding,
A pair of upper and lower molds for releasably clamping the end of the tube fabric;
An elastically deformable crimping means provided on the opposing surfaces of the upper and lower molds to vise and crimp the tube fabric;
The crimping means has an inner surface for clamping the tube fabric end in a state of projecting a predetermined amount toward the mating crimping means, and a tip surface that comes into contact with the mating crimping means, The boundary part of the inner surface is formed as a tapered surface, and the outer surface of the pressure-bonding means is configured as a tapered surface inclined in the tube cloth direction held from the upper and lower mold surface toward the distal end. A tube molding machine for tube tires. In the tube molding machine of the tube tire having the mold according to claim 1,
The inclination angle of each of the outer surface and the inner surface of the crimping means with respect to the horizontal direction is larger at the outer surface than the inner surface, and when the tube fabric ends are crimped to each other, the tube fabric ends at the tapered surface of the boundary portion. A tube molding machine for a tube tire having a mold that prevents the pinching of the tube. In the tube molding machine of the tube tire having the mold according to claim 1 or 2,
The angle between the outer surface of the crimping means and the horizontal plane is θ, the vertical length between the inner surface of the mold die and the inner end of the tip end surface of the crimping means is A, and between the inner surface of the die mold and the tip of the tapered surface of the crimping means Where B is the vertical length, and C is the horizontal surface length of the tapered surface at the boundary between the inner end portion and the inner end portion of the crimping means,
A tube molding machine for tube tires having a die of 5 ≦ θ ≦ 45 °, 0.3 mm ≦ A ≦ 0.5 mm, 0.3 mm ≦ B ≦ 0.5 mm, 0.3 mm ≦ C ≦ 0.5 mm. . In the tube molding machine of the tube tire having the mold according to any one of claims 1 to 3,
Said crimping means Ri lining rubber blocks der,
The lining rubber block, between the pair of upper and lower molds gold, its outer surface and inner surface, both the upper and lower mold gold surface of the tube tire that is disposed inclined to the tube dough direction for holding toward the distal end Tube molding machine.

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