Method for producing belt, and two-layer bonding machine

1. A method of producing a belt including a compression layer comprised of a surface layer and a core layer, the surface layer forming a surface portion of the belt, the core layer forming an inner portion, of the belt, having one or a plurality of ridges, the method comprising:

preparing a surface sheet which is to constitute the surface layer, a core sheet which is to constitute the core layer, a core-shaping flat roll having a flat surface, and a surface-shaping grooved roll having a plurality of trapezoidal grooves each of which corresponds to the ridge and which are arranged in an axial direction of the surface-shaping grooved roll;

forming the plurality of ridges on a surface of the core sheet by passing the core sheet between the core-shaping flat roll and a core-shaping grooved roll having a plurality of trapezoidal grooves each of which corresponds to the ridge and which are arranged in an axial direction of the core-shaping grooved roll; and

while the core-shaping flat roll and the surface-shaping grooved roll are heated such that core-shaping flat roll has a higher temperature than the surface-shaping grooved roll, bonding the surface sheet to the core sheet having the plurality of ridges formed thereon, thereby forming a compression layer-forming portion, the bonding being carried out by passing the surface sheet and the core sheet between the core-shaping flat roll and the surface-shaping grooved roll, wherein the surface sheet is processed to have a shape corresponding to the plurality of ridges when being passed between the rolls.

2. The method of claim 1 , wherein

the forming the plurality of ridges is carried out by passing the core sheet between the core-shaping grooved roll and the core-shaping flat roll in an upstream portion, and thereafter

the bonding is carried out by bonding the surface sheet on the surface of the core sheet that has moved on the core-shaping flat roll.

3. The method of claim 1 , further comprising:

deforming the surface sheet into a shape corresponding to the ridges by passing the surface sheet between the surface-shaping grooved roll and a surface-shaping ridged roll having a plurality of trapezoidal ridges which correspond to the grooves of the surface-shaping grooved roll and are arranged adjacent to each other in an axial direction of the surface-shaping ridged roll.

4. The method of claim 1 , further comprising:

deforming the surface sheet into a shape corresponding to the ridges by causing the surface sheet to wrap around a portion of the surface-shaping grooved roll as the surface-shaping grooved roll is rotationally driven, wherein

the bonding of the surface sheet to the core sheet is carried out while the surface sheet deformed into the shape corresponding to the ridges is placed over the surface of the core sheet.

5. The method of claim 1 , wherein

the surface sheet is comprised of a covering fabric.

6. The method claim 1 , wherein

the surface sheet is comprised of a surface rubber sheet.

7. A method of producing a belt including a compression layer comprised of a surface layer and a core layer, the surface layer forming a surface portion of the belt, the core layer forming an inner portion, of the belt, having one or a plurality of ridges, the method comprising:

preparing a surface sheet which is to constitute the surface layer, a core sheet which is to constitute the core layer, a core-shaping flat roll having a flat surface, and a surface-shaping grooved roll having a plurality of trapezoidal grooves each of which corresponds to the ridge and which are arranged in an axial direction of the surface-shaping grooved roll;

forming the plurality of ridges on a surface of the core sheet;

while the core-shaping flat roll and the surface-shaping grooved roll are heated such that core-shaping flat roll has a higher temperature than the surface-shaping grooved roll, bonding the surface sheet to the core sheet having the plurality of ridges formed thereon, thereby forming a compression layer-forming portion, the bonding being carried out by passing the surface sheet and the core sheet between the core-shaping flat roll and the surface-shaping grooved roll, wherein the surface sheet is processed to have a shape corresponding to the plurality of ridges when being passed between the rolls;

forming a shaped structure by wrapping the core sheet having the surface sheet bonded thereon around a layered structure in which the layered structure includes a cord and rubber or a thermoplastic elastomer that are stacked together, the shaped structure having a cylindrical shape and including a plurality of ridges extending in a circumferential direction and arranged adjacent to each other in an axial direction of the shaped structure;

crosslinking the shaped structure; and

cutting the crosslinked shaped structure into pieces each including at least one of the ridges.

8. A two-layer bonding machine configured to bond a surface sheet and a core sheet together, the surface sheet constituting a surface layer of a belt, the core sheet constituting a core layer forming an inner portion, of the belt, having one or a plurality of ridges, the machine comprising:

a core-shaping flat roll having a flat surface and configured to press the core sheet; and

a surface-shaping grooved roll having a plurality of trapezoidal grooves each of which corresponds to the ridge and which are arranged in an axial direction of the surface-shaping grooved roll, the surface-shaping grooved roll being configured to press the surface sheet, wherein

the core-shaping flat roll and the surface-shaping grooved roll are capable of being heated to different temperatures,

the core-shaping flat roll is heated to a higher temperature than the surface-shaping grooved roll; and

a core-shaping grooved roll having a plurality of trapezoidal grooves each of which corresponds to the ridge and which are arranged in an axial direction of the core-shaping grooved roll, wherein

the core-shaping grooved roll is disposed at a position at which the core-shaping grooved roll presses the core sheet in conjunction with the core-shaping flat roll.