| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized and compact brake wheel cylinder having a simple structure small in the number of part items. SOLUTION: A cylinder body 11 having an end wall 12 at its one end defines therein with a hydraulic chamber 15 incorporating a slidable piston 14 and communicated with a hydraulic pressure introduction port. The piston 14 is formed therein with an insertion hole 19 opened at one end of the piston 14 which is opposed to the hydraulic chamber 15, and an adjusting bolt 21 is meshed with a female thread part 20 formed in the inner periphery of the opening of the insertion hole 19. A spring 25 for urging the adjusting bolt 21 is incorporated in the insertion hole 19, and a thread gap is formed between thread engaging parts of the male thread part 22 of the adjusting bolt 21 and the female thread part 20, and accordingly, the piston 14 is moved to an extent given by the thread gap so that a brake shoe is pressed by the piston 14. When the brake shoe is worn so that the outward displacement of the piston 14 becomes larger, resulting in that the distal end part of the adjusting bolt 21 is separated from the end wall 12, the adjusting bolt 21 is rotated so as to be axially moved in order to absorb a degree of abrasion of the brake shoe, thereby it is possible to uniformly maintain the gap between the brake shoe and a brake drum.
|
