PNEUMATIC BRAKE BOOSTER HAVING A SEALING ELEMENT

• US 20190322260A1
• Filed: 11/17/2017
• Published: 10/24/2019
• Est. Priority Date: 12/08/2016
• Status: Active Grant

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Inventors: Faller, Jurgen, Jakobi, Ralf
• Granted Patent: US 11,148,650 B2
• Time in Patent Office: Days
• CPC Class Codes: B60T 11/16 Master control, e.g. master cylinders master cylinders associated with vacuum boosters B60T13/565
• CPC Class Codes: B60T 11/18 Connection thereof to initiating means
• CPC Class Codes: B60T 13/143 Master cylinder mechanically coupled with booster
• CPC Class Codes: B60T 13/144 Pilot valve provided inside booster piston
• CPC Class Codes: B60T 13/145 Master cylinder integrated or hydraulically coupled with booster
• CPC Class Codes: B60T 13/162 Master cylinder mechanically coupled with booster
• CPC Class Codes: B60T 13/165 Master cylinder integrated or hydraulically coupled with booster
• CPC Class Codes: B60T 13/44 with two-chamber booster units
• CPC Class Codes: B60T 13/45 with multiple booster units, e.g. tandem booster units
• CPC Class Codes: B60T 13/52 indirect, i.e. vacuum booster units
• CPC Class Codes: B60T 13/56 with two-chamber booster units
• CPC Class Codes: B60T 13/567 characterised by constructional features of the casing or by its strengthening or mounting arrangements
• CPC Class Codes: B60T 13/569 characterised by piston details, e.g. construction, mounting of diaphragm
• CPC Class Codes: B60T 17/223 Devices for pressurising brake systems acting on pedal
• CPC Class Codes: B60Y 2400/81 Braking systems

Abstract

A pneumatic brake booster having a booster housing. The booster housing has at least two thin-walled shell elements and an elastomer sealing element. The sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead. The sealing bead is sealingly clamped in a clamping space between the shell elements. The clamping space is formed by walls which are generated in the shell elements by deformation, its radial inner wall formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element. It is proposed that a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

Claims

1. A pneumatic brake booster having a booster housing, wherein the booster housing has at least two thin-walled shell elements and an elastomer sealing element, wherein the sealing element has a sealing bead, which is of encircling form radially at the outside, and at least one rolling diaphragm portion which adjoins the sealing bead, and the sealing bead is sealingly clamped in a clamping space between the shell elements, wherein the clamping space is formed by walls which are generated in the shell elements by deformation, wherein

a rolling-diaphragm-side end wall of the clamping space is formed by an encircling radial shoulder of the first shell element,

a radial outer wall is formed by a tubular projection which extends from the shoulder substantially in an axial direction,

a radial inner wall is formed by a tubular, axially forwardly extending projection, which is folded at its front edge, of the second shell element,

wherein a bead-side rear wall of the clamping space is formed by an encircling, radially outwardly projecting collar which is formed on the second shell element.

2. The brake booster as claimed in claim 1, wherein, between the rear wall and the outer wall of the clamping space, there is provided at least one positive locking portion which acts in the circumferential direction and axially in the direction of the sealing bead.

3. The brake booster as claimed in claim 2,

wherein the positive locking in the positive locking portion is formed by at least one lug on one of the shell elements which engages into a corresponding recess in the other shell element.

4. The brake booster as claimed in claim 3, wherein the lug is formed on the collar and the recess is formed on the projection.

5. The brake booster as claimed in claim 2, wherein multiple positive locking portions are arranged so as to be distributed on the circumference of the shell elements.

6. The brake booster as claimed in claim 5, wherein the positive locking portions are arranged so as to be distributed in irregular fashion on the circumference of the shell elements.

7. The brake booster as claimed in claim 1, wherein the shell elements are fixed to one another by bending tabs, wherein the bending tabs are formed on the projection so as to extend axially forwardly and are bent around a radial outer edge of the collar.

8. The brake booster as claimed in claim 1, wherein, between the projection and a wall region, which axially adjoins the shoulder, of the shell element, there is arranged an annular gap through which a region of the rolling diaphragm portion runs, wherein the wall region is of conical form in the region of the annular gap.

9. The brake booster as claimed in claim 8, wherein an axial extent of the annular gap is at least as large as its radial gap dimension at the opening into the clamping space.

10. The brake booster as claimed in claim 8, wherein an axial extent of the annular gap is twice as large as its radial gap dimension at the opening into the clamping space.