Vehicle disc brake

1. A vehicle disc brake comprising:

a disc rotor;

a pair of friction pads disposed on both side portions of the disc rotor; and

a pads returning spring suspended over radially outer sides of the friction pads and over an outer circumferential side of the disc rotor and configured to pull the friction pads away from the disc rotor when brakes are released and hydraulic pressure is removed, the pads returning spring having

a base portion extending in an axial direction of the disc rotor,

first spring portions extending from both end portions of the base portion along an outer circumference of the disc rotor while moving away from each other, and

engagement portions provided individually at distal ends of the first spring portions so as to engage with the friction pads, and

wherein a middle portion of the base portion in the axial direction of the disc rotor is depressed toward the distal ends of the first spring portions, thereby forming a second spring portion.

2. The vehicle disc brake of claim 1 ,

wherein the pads returning spring is configured such that, when the brakes are applied, the second spring portion starts to be elastically deformed after the first spring portions are elastically deformed.

3. The vehicle disc brake of claim 1 ,

wherein the pads returning spring is configured such that, when the brakes are not applied and the friction pads are in initial positions, only the first spring portions are elastically deformed as long as the friction pads are totally new or wear less than a previously-set wear amount, and both of the first spring portions and the second spring portion are elastically deformed if the friction pads wear more than the previously-set wear amount.

4. The vehicle disc brake of claim 1 ,

wherein the engagement portions of the pads returning spring are brought into engagement with portions of the friction pads at a side from which the disc rotor enters into the vehicle disk brake when a vehicle travels ahead.

5. The vehicle disc brake of claim 1 , further comprising:

a caliper body which has a ceiling opening portion formed to visually expose the base portion therethrough.

6. The vehicle disc brake of claim 1 ,

wherein the middle portion is depressed in the direction of the disc axis into a V-shape and the pads returning spring is formed substantially into an M-shape as a whole.

7. The vehicle disc brake of claim 6 , further comprising engagement portions which project individually from distal ends of the first spring portions towards a center of the disc rotor.

8. The vehicle disc brake of claim 7 ,

wherein the each of the engagement portions are bent substantially at right angles to each of the first spring portions.

9. The vehicle disc brake of claim 8 ,

wherein the engagement portions are inserted into corresponding engagement holes in the friction pads on opposing sides of the disk rotor.

10. The vehicle disc brake of claim 9 ,

wherein the base portion is disposed in a position which corresponds to a ceiling opening portion which lies between the friction pads.

11. The vehicle disc brake of claim 10 ,

wherein as the friction pads move towards the disc rotor, the first spring portions are elastically deformed, and the engagement portions of the first spring portions approach each other, whereafter the second spring portion is elastically deformed nearly into a linear state from the V-shape.

12. A vehicle disc brake comprising:

a pair of friction pads; and

a pads returning spring suspended over radially outer sides of the friction pads and configured to pull the friction pads away from each other when brakes are released and hydraulic pressure is removed, the pads returning spring having

a base portion,

first spring portions extending from both end portions of the base portion while moving away from each other, and

engagement portions provided individually at distal ends of the first spring portions, and

wherein a middle portion of the base portion is bent inwardly in an axial direction towards the first spring portions, thereby forming a second spring portion.

13. The vehicle disc brake of claim 12 ,

wherein the first spring portions are a pair of first spring portions which extend from both end portions of the base portion along an outer circumference of a disc rotor while moving away farther from each other as they so extend.

14. The vehicle disc brake of claim 13 , further comprising engagement portions which project individually from distal ends of the first spring portions towards a center of the disc rotor.

15. The vehicle disc brake of claim 13 ,

wherein the middle portion is depressed a middle portion in the direction of a disc axis into a V-shape and the pads returning spring is formed substantially into an M-shape as a whole.

16. The vehicle disc brake of claim 14 ,

wherein each of the engagement portions are bent substantially at right angles to the first spring portions.

17. The vehicle disc brake of claim 14 ,

wherein the engagement portions are inserted into corresponding engagement holes in friction pads on opposing sides of the disk rotor.

18. The vehicle disc brake of claim 17 ,

wherein the base portion is disposed in a position which corresponds to a ceiling opening portion which lies between the friction pads.

19. The vehicle disc brake of claim 17 ,

wherein as the friction pads move towards the disc rotor, the first spring portions are elastically deformed, and the engagement portions of the first spring portions approach each other, whereafter the second spring portion is elastically deformed nearly into a linear state from the V-shape.