JPH1143039A - Brake boosting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive brake boosting device in addition to securing screw loosening torque. SOLUTION: In a brake boosting device for a vehicle, which boosts up the footing force of a brake pedal so as to output it to an output rod, and outputs force to a master cylinder by way of an adjusting screw 12 mounted to the output rod 11, either one of the adjusting screw 12 or the output rod 11 is threaded, and the other one is left as is uncut so as to be formed up, and screw loosening torque due to tapping is thereby secured when the adjust screw 12 is fastened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake booster for a vehicle.

[0002]

2. Description of the Related Art In a conventional brake booster for a vehicle, the size of a gap between the brake booster and the master cylinder deteriorates brake feeling, and the port of the master cylinder is closed or dragged by pushing up. Because of the risk of occurrence, attach an adjusting screw to the output rod of the brake booster and adjust the protrusion of the adjusting screw from the output rod to optimize the gap between the brake booster and the master cylinder. Had taken the form.

For example, as shown in FIG. 3, in a brake booster 20, an adjusting screw 22 is attached to the tip of an output rod 21. As shown in FIG. 4, this portion is formed with a female thread in the recess 21a at the tip of the output rod. In addition, a screw is not formed on the tip end 22a of the adjusting screw 22, but a male screw is formed on the central portion 22b, and a trapezoidal screw is formed on the base portion 22c. Adjusting screw 2
When the head 22d of the second part 22 is rotated, the central part 22b
The adjusting screw 22 meshes with the output rod 2
Go inside one. If you continue turning, the base part 22
Since c advances while crushing the female screw of the recess 21a, the adjusting screw 22 and the output rod 21 are firmly connected,
Screw loosening torque can be secured.

[0004]

However, in this technique, the output rod 21 needs to be internally threaded, and further, the adjusting screw 22 needs to be internally threaded and trapezoidal threaded, which is expensive. Was. Therefore, an object of the present invention is to provide an inexpensive brake booster while securing a screw loosening torque.

[0005]

According to a first aspect of the present invention, there is provided a motor vehicle comprising: a booster for boosting a depressing force of a brake pedal and outputting the boosted force to an output rod; In a brake booster for a vehicle that outputs to a master cylinder via an adjusting screw attached to the output rod, one of the adjusting screw or the output rod is threaded, and the other is formed without threading, and the adjusting screw is formed. At the time of fastening of the screw to secure the screw loosening torque due to tapping.

[0006] According to this, it is only necessary to thread the one of the adjusting screw and the output rod, and the machining cost can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle brake booster according to the present invention will be described with reference to the drawings.

In FIG. 1, a brake booster 10 outputs a force from an output rod 11 in accordance with the depression of a brake pedal (not shown). An adjusting screw 12 is attached to the tip of the output rod 11,
Energize a master cylinder (not shown). This part is shown in FIG.
As shown in the figure, the tip of the output rod 11 has a cylindrical portion 11a.
have. The inside of the cylindrical portion is not threaded. The adjusting screw 12 has a male screw 12a.
Has been processed. Adjusting screw 12 head 12
When b is rotated, the male screw 12a enters the cylindrical portion 11a while tapping. By this tapping, the adjusting screw 12 and the output rod 11 are firmly connected, and a screw loosening torque can be secured.

Here, the screw may be formed on the inside of the cylindrical portion and the adjust screw 12 may not be screwed.

[0010]

According to the above means, only one of the adjusting screw and the output rod needs to be threaded, and the machining cost can be reduced. Further, since the screw tightening torque by tapping can be secured, the position between the master cylinder and the master cylinder can be easily adjusted, the brake feeling can be adjusted, and the closing of the port of the master cylinder and the dragging due to the pushing up can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of a brake booster according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a sectional view of a conventional brake booster.

FIG. 4 is an enlarged view of a main part of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Brake booster 11 Output rod 11a Cylindrical part 12 Adjusting screw 12a Male screw 12b Head

Claims (1)

[Claims] 1. A brake booster for a vehicle, which boosts the depression force of a brake pedal and outputs the boosted force to an output rod, and outputs the output to a master cylinder via an adjustment screw attached to the output rod. A brake booster for a vehicle, characterized in that one of the output rods is formed by threading and the other is formed without threading, and a screw loosening torque due to tapping is secured when the adjusting screw is fastened.