Tokico, Ltd.

Takuya Obata

Toshio Takayama

Kunihiro Matsunaga

There is provided a pneumatic booster having an ejector, which achieves space-saving and enables easy piping. An ejectoris provided within a constant-pressure chamberformed in an outer shell. A connecting pipecommunicated with an outlet of a diffuser and a connecting pipe communicated with an inlet of a nozzle extend outward of the shell, and a suction port is open to the inside of the constant-pressure chamberthrough a check valve. The connecting pipeis communicated with the constant-pressure chamberthrough a check valve, and is connected to a suction pipe of an engine (a source of a negative pressure). The connecting pipe on the inlet side of the nozzle is connected to an air cleaner (the atmosphere). A negative pressure is directly supplied from the connecting pipeto the constant-pressure chamberthrough the check valve. The ejectoris operated to supply a high degree of vacuum to the constant-pressure chamberthrough the suction port. The ejectoris provided within the constant-pressure chamberso as to achieve space-saving. The check valveis provided in the ejectorand the connecting pipeis extended outward of the shell, so as to enable easy piping.

Pneumatic booster

The present invention provides a brake booster that, although simple in construction, capable of adjusting the braking force derived by operation of a solenoid mechanism without worsening the braking response. In the brake booster according to the present invention, when a movable member ( ) is shifted toward the rear side by electromagnetic force of a solenoid ( ), the shifting movement is transmitted to a valve seat member ( ) through pins ( ) to open an atmospheric valve ( ) through which air is introduced into a variable pressure chamber ( ), whereby a pressure difference is created between the variable pressure chamber and a constant pressure chamber and generates booster output (thrust output force). In the present invention, pressure in the constant pressure chamber is introduced into a chamber ( ) formed at one end of the movable member ( ) through a passage ( ), and atmosphere is introduced into a chamber ( ) formed at the other end of the movable member ( ) through a passage ( ), thereby exerting on the movable member ( ) a reaction force caused by the pressure difference between the variable pressure chamber and the constant pressure chamber. Thus, the booster output becomes proportional to the electric current supplied to the solenoid ( ). Further in the present invention, the size of the passage ( ) is determined properly so as to limit air introduced therethrough into the chamber ( ) and keep the reaction force small until the booster output reaches an adequately level, thereby preventing the breaking response from deteriorating.

Brake booster

The present invention provides a control booster which is capable of appropriately detecting a pedal-operated brake operation during an automatic brake operation. For moving a stop key from a position on a side of a rear-side abutment surface (where a reaction force of a switch acting on a switch operating rod and a spring force of a switch spring are balanced) toward an intermediate position, when the stop key is located on a side of the rear-side abutment surface, only a return force of the spring acts on a contact operating element of the switch. On the other hand, when the stop key moves toward the intermediate position, an abutment portion is separated from the contact operating element (that is, the switch operating rod moves in a direction for separation relative to the switch), so that no load is applied to the contact operating element. Breakage of the switch can be avoided when the brake pedal is operated during the automatic brake operation and operation of the brake pedal can be detected from the turning-off of the switch.

Control booster

The present invention provides a booster in which magnitude of output can be adjusted also by an operation of a solenoid mechanism. An armature (,) is shifted to the right (in FIG.,) in opposition to a returning spring by applying electricity to a solenoid (,), with the result that a space (,) on one end of the armature is communicated with a constant pressure chamber (,) through a passage (T,). When an electromagnetic force acting on the armature (,) exceeds a predetermined value, a distal end of a valve member (,) is shifted to the right (in FIG.,) via a cylindrical member (,) to open an atmospheric valve (,), thereby introducing the atmosphere into a variable pressure chamber (,). The pressure in the variable pressure chamber is applied to the other end of the armature and the difference in the pressure tends to move the armature toward its home position.

Growing community of inventors

Yamanashi-ken, Japan

Takuya Obata