BRAKE BOOSTER

8 + 9 inch tandem brake booster has been installed. In addition, variable amplification device which increases the brake booster gain has been adopted <Vehicles for Hong Kong spec.>.

VARIABLE AMPLIFICATION MECHANISM

The variable amplification mechanism is of a structure that has a valve plunger with a smaller diameter than for conventional plungers and has a valve body with a groove. This mechanism changes the reaction force that works on the valve plunger at assisting operation, to vary brake booster input/output characteristics in two steps.

AT INITIAL ASSISTING

At initial assisting, the reaction disk rubber does not contact the concave section of the groove in the valve body when receiving the reaction force from the master cylinder. At this time, the area receiving the reaction force that works on the valve plunger is A, the area with the outer diameter of the groove. Because this area receiving the reaction force is equal to the conventional valve plunger area, the brake booster input/output characteristics at initial assisting operation are the same as the conventional characteristics.

AT AN INCREMENT OF ASSIST RATIO

As the input from the brake pedal increases, the reaction force from the master cylinder also increases, and the groove in the valve body is filled with the reaction disk rubber because of a change in the rubber contour.
From this point, the area B with the diameter of the valve plunger becomes the reaction force reception area, changing the brake booster input/output characteristics.


BRAKE BOOSTER
8 + 9 inch tandem brake booster has been installed. In addition, variable amplification device which increases the brake booster gain has been adopted <Vehicles for Hong Kong spec.>.
VARIABLE AMPLIFICATION MECHANISM The variable amplification mechanism is of a structure that has a valve plunger with a smaller diameter than for conventional plungers and has a valve body with a groove. This mechanism changes the reaction force that works on the valve plunger at assisting operation, to vary brake booster input/output characteristics in two steps.
AT INITIAL ASSISTING At initial assisting, the reaction disk rubber does not contact the concave section of the groove in the valve body when receiving the reaction force from the master cylinder. At this time, the area receiving the reaction force that works on the valve plunger is A, the area with the outer diameter of the groove. Because this area receiving the reaction force is equal to the conventional valve plunger area, the brake booster input/output characteristics at initial assisting operation are the same as the conventional characteristics.
AT AN INCREMENT OF ASSIST RATIO As the input from the brake pedal increases, the reaction force from the master cylinder also increases, and the groove in the valve body is filled with the reaction disk rubber because of a change in the rubber contour. From this point, the area B with the diameter of the valve plunger becomes the reaction force reception area, changing the brake booster input/output characteristics.