| 摘要 |
PROBLEM TO BE SOLVED: To provide a four-way selector valve such that a lockscrew for fixing a piston to coupling metal fittings is securely prevented from being loosened, the number of components is decreased, and trouble in manufacture is saved.SOLUTION: A piston valve is accommodated in a valve housing. The piston valve comprises first and second pistons 1 and 2, coupling metal fittings 3, and a valve body. The piston 1 comprises a packing 11, a guide plate 12, a toothed lock spring 13, and a reinforcing plate 14. The piston 2 comprises a packing 21, a guide plate 22, a toothed lock spring 23, and a reinforcing plate 24. The piston 1 is fixed to a vertical plate 31 of the coupling metal fittings 3 with lockscrews N1, N2. The piston 2 is fixed to a vertical plate 32 of the coupling metal fittings 3 with lockscrews N3, N4. Molten layers P1, P2 are formed by resistance welding at a contact place between the lockscrew N1 and the guide plate 12 and at a contact place between the lockscrew N2 and the guide plate 12. Molten layers P3, P4 are formed by resistance welding at a contact place between the lockscrew N3 and the guide plate 22 and at a contact place between the lockscrew N4 and the guide plate 22. |
