JPH0173459U - - Google Patents

Description

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a vertical sectional side view of a tandem negative pressure booster in a rest state, and FIGS. 2 and 3 are sectional views taken along lines - and - in FIG. 1. , Fig. 4 is a plan view of the piston boss, Fig. 5 is a cross-sectional view taken along the line - - in Fig. 4, and Fig. 6 is a partial vertical sectional side view showing the state immediately before the negative pressure booster finishes its operation and returns to its rest state. It is. B...Negative pressure booster, a...Front long hole, b...Tapered hole, c...Rear long hole, 1...Booster shell, 1a,
1b... Shell half body, 1c... Partition plate, 2... Front shell chamber, 2a... Front negative pressure chamber, 2b... Front working chamber, 3
... Rear shell chamber, 3a... Rear negative pressure chamber, 3b... Rear working chamber, 4... Front booster piston, 5... Front diaphragm, 5a... Inner peripheral bead, 6... Rear booster piston, 7... Rear diaphragm, 7a... Inner peripheral bead, 10...Piston boss, 13...Connecting cylinder, 1
3a... End wall plate, 14... Holding plate, 15... Through bolt, 16... Nut, 25... Valve cylinder, 30... First port, 31... Second port, 31A... Axial direction port, 3
1R...Radial port, 32...Control valve, 33...Air inlet, 35...Input rod, 53...Output rod.

Claims (1)

[Scope of utility model registration request] A partition plate that partitions the inside of the booster shell into a front shell chamber and a rear shell chamber is fixed to the booster shell, and the front shell chamber is divided into a front negative pressure chamber on the front side and a front working chamber on the rear side. and a rear booster piston that partitions the rear shell chamber into a front rear negative pressure chamber and a rear rear working chamber, and a piston boss that is slidably supported by the partition plate and that is connected to the output rod. A valve cylinder that protrudes from the rear end and is slidably supported on the rear wall of the booster shell is integrally connected to this piston boss, and the inside of this valve cylinder is communicated with both negative pressure chambers. A first port and a second port communicating the inside of the valve cylinder with a negative working chamber are provided,
This second port is composed of an axial port that communicates between the front and rear working chambers, and a radial port that communicates between the rear working chamber and the valve cylinder, and an input rod that can move back and forth inside the valve cylinder. A control valve is provided to communicate the second port with the first port and the atmosphere in accordance with the forward and backward movement of the input rod, and a recess for receiving a return spring that urges the piston boss in the backward direction is provided in the boss. In the tandem negative pressure booster installed at the front, the second
The axial port of the port is connected to a rear elongated hole extending from the rear end of the piston boss to near the recess with its major diameter directed in the circumferential direction of the piston boss, and a rear elongated hole that is flatter and has a larger major diameter than the rear elongated hole and extends from the front end of the piston boss. The front long hole extends close to the rear long hole, and the front long hole,
A tandem negative pressure booster characterized by having a tapered hole that continuously connects the rear long holes.