Transmission belt

1. A power transmission belt including a belt body made of an elastomer, and a cord made of carbon fibers and provided to be embedded in the belt body and to form a helical pattern having a pitch in a belt width direction,

a belt tension T 0.2 per 1 mm belt width at 0.2% of a belt extension rate being 70 N/mm or more, a belt tension T 0.5 per 1 mm belt width at 0.5% of the belt extension rate being 220 N/mm or more, a ratio of the belt tension T 0.2 to the belt tension T 0.5 being 0.33 or more.

2. The power transmission belt of claim 1 , wherein

the belt body is made of a polyurethane resin.

3. The power transmission belt of claim 1 , wherein

the carbon fibers forming the cord are PAN-based carbon fibers.

4. The power transmission belt of claim 1 , wherein

the carbon fibers have a filament diameter of 4 μm or more to 9 μm or less.

5. The power transmission belt of claim 1 , wherein

a total number of filaments of the carbon fibers forming the cord is 6000 or more to 48000 or less.

6. The power transmission belt of claim 1 , wherein

the cord is a single twist yarn obtained by twisting a filament bundle of the carbon fibers in one direction.

7. The power transmission belt of claim 6 , wherein

the number of twists of the cord of the single twist yarn per 10 cm length is 4/10 cm or more to 12/10 cm or less.

8. The power transmission belt of claim 1 , wherein

the number of cords per 10 mm belt width is 6/10 mm or more to 10/10 mm or less.

9. The power transmission belt of claim 1 , wherein

a belt tension T 0.2 per 1 mm belt width at 0.2% of the belt extension rate is 140 N/mm or less.

10. The power transmission belt of claim 1 , wherein

a belt tension T 0.5 per 1 mm belt width at 0.5% of the belt extension rate is 440 N/mm or less.

11. The power transmission belt of claim 1 , wherein

the belt tension T 0.2 /the belt tension T 0.5 is 0.55 or less.

12. The power transmission belt of claim 1 , wherein

the belt body is a toothed belt body.