US 6,386,087 B2Granted

Control booster

AssigneeTokico Ltd.

InventorsToshio Takayama, Kunihiro Matsunaga, Takuya Obata

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Abstract

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.

Claims17

Dependent claims

A control booster comprising:

a power piston dividing an inside of a housing into a constant pressure chamber and a variable pressure chamber;
a valve mechanism which controls supply of a working fluid to the variable pressure chamber in accordance with movement of a plunger connected to an input rod associated with a brake pedal, the valve mechanism being provided in a valve body supported by the power piston;
an electromagnetic bias means having a movable element which operates the valve mechanism independently of operation of the input rod, the control booster being adapted to generate a thrust in the power piston due to a differential pressure generated between the variable pressure chamber and the constant pressure chamber based on operation of the valve mechanism;
a switch for detecting relative movement of the input rod relative to the valve body;
a switch operating rod for operating the switch;
and
a switch spring for biasing the switch operating rod in a direction for pushing-in a contact operating element of the switch,
wherein when the input rod is operated in a direction for increasing an output of the booster in a state where a reaction force of the switch acting on the switch operating rod and a spring force of the switch spring are balanced, the switch operating rod moves in a direction for separation relative to the switch.

5 more elements

A control booster comprising:

a power piston dividing an inside of a housing into a constant pressure chamber and a variable pressure chamber;
a valve mechanism which controls supply of a working fluid to the variable pressure chamber in accordance with movement of a plunger connected to an input rod associated with a brake pedal, the valve mechanism being provided in a valve body supported by the power piston;
an electromagnetic bias means having a movable element which operates the valve mechanism independently of operation of the input rod, the control booster being adapted to generate a thrust in the power piston due to a differential pressure generated between the variable pressure chamber and the constant pressure chamber based on operation of the valve mechanism;
a switch for detecting relative movement of the input rod relative to the valve body;
a switch operating rod for operating the switch;
a switch spring for biasing the switch operating rod in a direction for pushing-in a contact operating element of the switch;
and
an operating member for pressing the switch operating rod against an action of the switch spring and moving the switch operating rod in a direction for separation relative to the switch.

5 more elements

Dependencies are inferred from the claim text.