| 摘要 |
PURPOSE: To improve the operating characteristic of a pneumatic brake booster by coupling the first portion of a valve body part with a booster housing part to form a magnetic return of an electromagnet assembly, and coupling the first portion of the valve body part with the second portion of the valve body part. CONSTITUTION: A valve body part 14 is constituted of a first portion 16 arranged with an electromagnet assembly 12 inside and a second portion 18 coupled with the first portion 16. A control valve assembly 10 is stored in the second portion 18. The first portion 16 is made of soft iron and forms a magnetic path of the electromagnet assembly 12. A solenoid assembly 20, a magnetic flux conducting molding (mold part) 22, an armature 24 and a counter armature part 26 are inserted. A recess 22a is formed on the mold part 22, and part of air ducts 28, 29 is formed to make connections between a vacuum chamber and a working chamber or between the working chamber and the ambient atmosphere. The first portion 16 serves as a cover of the control valve assembly 10 and the electromagnet assembly 12 to guarantee mechanical strength and to improve easiness of assembling. |
