JPH0460863B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a vacuum-operated brake booster, and more particularly to a booster piston and a working chamber of the vacuum-operated brake booster that are sealed to the booster housing by a rolling diaphragm. a piston rod connected to the brake pedal to operate a dual valve that selectively communicates the pressure to a vacuum or a higher differential pressure, the first valve being connected to the valve seat on the booster piston in the direction of the valve seat. a vacuum-operated brake booster comprising a poppet valve energized by the valve, and a second valve comprising the same poppet valve as described above and a valve piston connected to the piston rod. Regarding.

West German Application Publication No. 2942416 discloses that the inside of a booster housing is divided into a first working chamber and a second working chamber, and includes a booster piston serving a valve cylinder, and the first working chamber is divided into a first working chamber and a second working chamber. is internally connected to a vacuum source, and a valve cylinder projects from the backside of the booster piston and includes a first annular valve seat in front thereof, the valve piston being slidably within the valve cylinder. a vacuum operated brake booster disposed and holding a second annular valve seat, the second annular valve seat being surrounded by the first valve seat and coupled to the drive rod; is disclosed. Further herein, the valve cylinder receives a valve member biased against first and second valve seats, and the first and second actuating chambers are arranged between the first valve seat and the valve member. Communication is effected by retraction of the valve piston through a gap between the valve piston and the second working chamber is communicated with the atmosphere through a gap between the second valve seat and the valve member by forward movement of the valve piston. A stop member is provided between the booster housing and the drive rod in the vacuum operated brake booster, and the stop member is configured such that the gap between the first valve seat and the valve member is in the non-operating position of the drive rod. The distance of contraction of the drive rod is defined so that it is smaller than the above-mentioned gap when the drive rod is retracted.

Although this conventional vacuum-operated brake booster can reduce idle movement before the device responds, the individual components that make up the control have no idle movement from the viewpoint of preventing leakage of the device. It cannot be removed because it affects the
Similarly, in other similar vacuum-operated brake systems, a special arrangement moves the valve piston toward the control housing sealed valve seat by approximately a "response idle travel."

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a vacuum operating system which can generate an output instantaneously during operation without causing idle movement, and which can improve both response time and release time at the same time. An object of the present invention is to provide a brake booster. Finally, it is desirable to construct the individual components of the vacuum-operated brake booster in a particularly linear configuration to facilitate assembly of the vacuum-operated brake booster. Finally, this vacuum-operated brake booster can have a particularly small external shape, allowing the master cylinder connected thereto to be provided at least in particular in the housing of the vacuum-operated brake device.

The above-mentioned objects of the invention include: a booster housing; a booster piston housed in the booster housing and partitioning an interior space of the booster housing into a vacuum chamber communicating with a source of negative pressure and a working chamber communicating with a source of working fluid; A rolling diaphragm that allows the booster piston to move and ensures sealing between the vacuum chamber and the working chamber while the booster piston is moving; A diaphragm that is provided in the booster housing and urges the booster piston toward the working chamber. force means;
a first control housing part that is connected to the booster piston and moves together with the booster piston; and an inner peripheral surface that has a cylindrical shape and is movably guided in the direction of movement of the booster piston with the outer peripheral surface sealed with respect to the booster housing. and a second control housing part that is assembled with the first control housing part so as to be relatively movable within a predetermined range in the direction of movement of the booster piston in a state where the second control housing part is sealed against the outer peripheral surface of the first control housing part. a control housing, wherein the second control housing portion is restricted from outward movement of the booster housing by outward movement restriction means provided on the second control housing portion and the booster housing and cooperating with each other; provided in the first control housing portion so as to be relatively movable within a predetermined range in the direction of movement of the booster piston, and provided with a first valve seat on an end surface on the second control housing portion side;
a valve piston biased toward the second control housing part; provided on the end face of the first control housing part on the second control housing part side;
a second valve seat that surrounds the valve seat of the booster housing; and a second valve seat that opens between the first valve seat and the second valve seat at the end face of the first control housing part on the second control housing part side; a working fluid introduction passage that communicates with the working chamber of the space; and an opening on the end surface of the first control housing part on the second control housing part side, in the radial direction of the first control housing part, outside of the second valve seat; and a working fluid discharge passage communicating with the vacuum chamber in the internal space of the booster housing;
The second control housing part is supported on the inner circumferential surface of the second control housing part in a sealed manner outwardly from the end face of the first control housing part on the second control housing part side in the moving direction of the booster piston. The valve piston of the first control housing part is biased toward the end face of the second control housing part of the valve piston of the first control housing part.
a poppet valve member seated on the valve seat and a second valve seat surrounding the same; extending an interior space of the second control housing portion and an interior space of the poppet valve member;
This can be achieved by a vacuum-operated brake booster characterized in that it comprises: a piston rod whose inner end is connected to the valve piston and whose outer end transmits the reciprocating motion of the brake pedal.

In particular, a control housing that slides in a sealed manner with respect to the booster housing in the direction of movement of the booster piston includes a first control housing portion that is connected to the booster piston and moves together with the booster piston, and a first control housing portion that has a cylindrical shape and has an outer periphery. The first control housing part is movably guided in the direction of movement of the booster piston with its surface sealed against the booster housing, and the inner peripheral surface is guided in the direction of movement of the booster piston with its inner peripheral surface sealed against the outer peripheral surface of the first control housing part. a second control housing portion that is relatively movable and interlocked within a predetermined range;
Since the second control housing part is restricted from outward movement of the booster housing by the outward movement restriction means provided on the second control housing part and the booster housing and cooperating with each other, the second control housing part is prevented from moving outwardly from the booster housing. The control housing combined with this reduces the empty travel distance when the brakes are applied, and is compact yet has sufficient strength.

In the vacuum-operated brake booster according to the present invention configured as described above, the outer circumferential surface of the first control housing section is covered by the inner circumferential surface of the second control housing section. Engagement recesses extending circumferentially are formed at least in two substantially diametrically opposite positions in the area where the inner space of the booster housing is sealed, and the engagement recesses extend in the circumferential direction at least in two substantially diametrically opposite positions. In the region located in the working space, elongated through grooves extending in the circumferential direction and penetrating from the outer circumferential surface to the inner circumferential surface of the circumferential wall are formed at least at two substantially diametrically opposite positions, and the second two legs of a generally U-shaped spring clip are fitted into at least two elongated through grooves in the peripheral wall of the second control housing part; The two legs of a generally U-shaped spring clip projecting radially inwardly from the opening on the inner circumferential side of the second control housing part are connected to the second control housing part in the direction of movement of the booster piston. Preferably, the first control housing part functions as an internal restriction member for movement within a predetermined range relative to the first control housing part.

The inner restricting member configured in this manner has a simple and inexpensive configuration, and facilitates disassembly and assembly of the telescoping control housing.

In the vacuum-operated brake booster according to the present invention, which is configured as described above, the outward movement restricting means of the control housing section moves from the outer peripheral surface of the second control housing section to the outer peripheral surface of the second control housing section. a collar member that protrudes outward in the radial direction of the second control housing section and extends in the circumferential direction of the outer peripheral surface of the second control housing section; It is preferable that the booster piston further includes an annular seal member that extends out from the outer circumferential surface of the second control housing portion and abuts against an end surface on the outer side in the moving direction of the booster piston with respect to the collar member on the outer peripheral surface of the second control housing portion.

The outward movement restricting means having such a configuration is simple and inexpensive.

A seal allowing movement of the first and second control housing portions of the telescoping control housing with respect to each other includes an outer circumferential surface of the first control housing portion and an inner circumferential surface of the second control housing portion. A sealed state between the two can be created by an annular seal member interposed between the outer circumferential surface and the inner circumferential surface.

The seal allowing movement between the first and second control housing parts of the telescoping control housing also includes an annular outer peripheral end at the end face of the first control housing part facing the second control housing part. The outer circumferential surface of the poppet valve member extends along the inner circumferential surface of the second control housing section to the outside of the end surface of the first control housing section on the second control housing section side. A surrounding annular protrusion is formed so that an end of the poppet valve member remote from an end face of the first control housing part on the second control housing part side in the direction of movement of the booster piston is connected to the first control housing part. by being supported in a sealed state at the tip of an annular projection of the first control housing part, following the relative movement of the first control housing part, and slidingly contacting the inner circumferential surface of the second control housing part in a sealed state. can be created.

In this case, the second part of the first control housing part
The end of the poppet valve member that is farthest in the direction of movement of the booster piston from the end face of the control housing part of the poppet valve member is located within the radius of the first control housing part from the inner peripheral surface of the annular protrusion of the first control housing part. a first sealing surface projecting outwardly in the direction and sealingly supported on the distal end of the annular projection; Preferably, the second control housing part has a second sealing surface projecting radially outwardly from the first control housing part in a tongue-like manner and slidingly contacting the inner circumferential surface of the second control housing part in a sealed manner.

Such a configuration of the end portion of the poppet valve member is simple and inexpensive, and also allows the end portion to be sealed against the tip of the annular projection on the end face of the first control housing portion on the second control housing portion side. the second control housing part and the second control housing part in a sealed manner.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in the cross-sectional view, the vacuum-operated brake booster according to the first embodiment of the present invention includes a booster housing 7 and 22 which are divided into two parts, and the inside of the booster housing is divided into two compartments: an operating chamber and a vacuum chamber. a rolling diaphragm 18 divided into 20 and 23;
diaphragm plate 19, vacuum hole 24, spring 25, two first and second control housing parts 2, 4, poppet valve 1, valve piston 16.
, a rubber reaction disk 30, and a piston rod 1
4 and a push rod 29 which cooperates with a master cylinder, which is not shown in detail.

A spring 25 biases the diaphragm plate 19 by means of the first control housing 2 against the poppet valve 1 and the sealing surface 11 through the sealing seat 12 and also against the second control housing part 4.
The diaphragm plate 19 is biased against the booster housing part 7 via the flange 26, the purpose of which is to support the spring 25 on the first control housing part 2 via the flange 26.

On the side remote from the sealing surface 11, the poppet valve 1 has a stop element 8 which rests on the control housing part 4 in the released position. The control housing part 4 then preferably rests against the annular sealing member 5 and assumes a rear position that is fixedly defined accordingly. In this position, the sealing seat 9 on the valve piston 16 is biased against the sealing surface 11 of the poppet valve 1, as is the sealing seat 12 in the control housing part 2 of the two-part control housing 2,4. There is. As a result, the valve piston sealing seat 9 can be immediately separated by actuation of the piston rod 14, and the vacuum-operated brake booster responds without any idle movement.

Actuation of the piston rod 14 advances the first control housing part 2 until the stop member 3 seats the second control housing part 4. The sliding surface for the annular sealing element 5 is therefore designed to be correspondingly short. The two control housing parts 2, 4 are preferably sealed together by an O-ring 40.

Since the stop element 3 limits the opening distance of the valve piston 16, the valve piston 16 is not rigidly connected to the disk 6, which serves for adjusting the boost transmission. By integrating the two control housings 2, 4, a large guiding length is achieved, which prevents deformations of the control housing parts 2, 4, such as bending, twisting or denting.

The two control housing parts 2, 4 perform a relative movement, and this relative movement is caused by the response of the vacuum-actuated brake booster and by the vacuum-actuated brake booster changing its rear position. This is done by taking it again. Among all other features,
The two control housing parts 2, 4 are relatively stationary.

Since the spring 25 and the piston rod return spring 10 are supported on the poppet valve 1 via the sealing surface 11 in the released position, the sealing seats 9 and 12 have a relatively large surface abutment after approximately 0.2 mm of deformation of the rubber. Preferably, the design is such that it can be engaged as such to prevent damage to the material. The restriction of the relative movement of the two control housing parts at the stop surface 3 is effected by a generally U-shaped spring clip 17 which slides laterally.

In the released position, the second control housing part 4
abuts with its collar 28 at the annular sealing member 5 with a stop surface 27, which annular sealing member 5 is pushed into the booster housing part 7, while the poppet valve 1 is pressed against the stop member 8 on the sealing seat 12.
It is in contact with. The sealing seat 9 of the valve piston 16 is biased by a spring 10 against the sealing surface 11 of the poppet valve, while the sealing seat 12 of the control housing part 2 is pressed against the spring 25 via a flange 26.
is biased against the sealing surface 11 of the poppet valve 1 by. When the two control housing parts 2, 4 are in the position shown, the pressures are balanced in the two compartments 20, 23.

By operation, the piston rod 14 is moved in the direction of arrow A, so that the valve piston sealing seat 9
is spaced from the poppet sealing surface 11, allowing atmospheric air to flow into one compartment 20. The pressure difference between the two compartments 20, 23 creates a force that presses the first control housing part 2 in the direction of the master cylinder, which is not shown in detail. The reaction force for the boosting effect is transmitted onto the piston rod 14 via a reaction disk 30 made of rubber.

The sealing seat 12 of the control housing part 2 is similar to the sealing seat 1
The sealing surface of the poppet valve 1 follows the control housing part 2 by virtue of the spring 15 supporting it via the sealing seat 12 of the control housing 2 until 2 and 9 assume such a defined reference position. 11 in a sealed state during the first stage of movement.

Initially, the control housing 4 is held stationary by operation until it is ridden by the spring clip 17 via the stop surface 3. After this relative movement, the spring 15 returns the two control housing parts 2, 4 to this position.

During release, the force on the piston rod 14 is removed, so that the spring 10 can bias the valve piston 16 with the sealing seat 9 until the sealing seat 12 of the control housing is opened. This opening distance is limited by the stop surfaces 3 of the two control housing parts 2, 4. At this time, the atmosphere passes through passages 31 and 32.
is extracted from section 20 via. The sealing seat 12 of the control housing is closed when the vacuum-operated brake booster returns to its initial position and the control housing part 4 abuts by its collar 28 on the stop surface 27 and the sealing seat 12 of the control housing part Gabane 2
5 until it is forced backwards by 5. In such an arrangement, the two control housing parts 2, 4 slide relative to each other and the stop surface 3 is released so that the vacuum-operated brake booster is set in its release position.

In a second embodiment of the vacuum operated brake booster as shown in FIG.
7 and biases it against the booster housing part 7 through the second control housing part 54, since the spring is connected to the first control housing part 53 through the flange 26. This is because it is supported above.

On the side remote from the sealing surface 57, the poppet valve 52 is connected to the control housing part 5 in the released position.
Stop member 6 abuts through sleeve 50 in 4
It has 0. The control housing part 54 is then preferably abutted against the annular sealing member 5 and is thus placed in a fixed rear position. In this position, the sealing seat 9 on the valve piston 16 and the sealing seat 58 in the control housing part 53 of the two-part control housing 53, 54 are urged against the sealing surface 57 of the poppet valve 52. As a result of this, the sealing seat 9 of the valve piston can be immediately separated by actuation of the piston rod 56, and the vacuum-actuated brake booster responds without any idle movement.

Operation of the piston rod 56 advances the first control housing part 53 until the stop member 55 rests on the second control housing part 54. For this purpose, the sliding surface for the annular sealing element 5 is designed to be correspondingly short. Two control housing parts 5
3 and 54 are sealed to each other by the sealing lip 51 of the poppet valve 52.

Since the stop element 55 limits the opening distance of the valve piston 16, the valve piston 16 is not rigidly connected to the disk 16, which serves to adjust the boost transmission. Since the two control housing parts 53, 54 are integrated, a very large guiding length can be achieved, which prevents the control housing parts 53, 54 from being deformed, such as bending, twisting or denting. Ru.

The two control housing parts 53, 54 effect a relative movement due to the response of the vacuum-operated brake booster and the vacuum-operated brake booster being placed in its rear position. During all other functions the two control housing parts 53, 54 are relatively stationary.

Since spring 25 and piston rod return spring 10 are supported on poppet valve 52 via sealing surface 57 in the released position, sealing seats 9 and 58
are preferably designed to engage in an abutting manner over a relatively large surface to avoid damage to the material after approximately 0.2 mm of deformation of the rubber. Two control housing parts 53, 54 in the stop member 55
The restriction of the relative movement of is effected by a laterally sliding spring clip 17.

In the released position, the second control housing part 54 rests with its collar 59 on the annular sealing member 5 with the stop surface 27, which is pressed into the booster housing part 7, during which time A poppet valve 52 abuts a stop member 60 in the control housing part 54 via a sleeve 50. The sealing seat 9 of the valve piston 16 is urged by a spring 10 against a sealing surface 57 of the poppet valve, while the sealing seat 58 of the control housing part 53 is urged by a spring 25 via the flange 26. Sealing surface 5 of poppet valve 52
7 so as to come into contact with the other end. When the two control housing parts 53, 54 are positioned as shown, the two compartments 20,
The pressure is balanced in 23.

By operation, the piston rod 56 is moved in the direction of arrow A, so that the sealing seat 9 of the valve piston is spaced from the sealing surface 57 of the poppet valve and atmospheric air is admitted into one compartment 20. The pressure difference between the two compartments 20, 23 creates a force that presses the first control housing part 53 in the direction of the master cylinder, which is not shown in detail. The reaction force for the boosting effect is transmitted onto the piston rod 56 via the rubber reaction disk 30.

By virtue of the spring 61, which is supported via the sealing seat 58 of the control housing, the sealing seat 58 of the control housing closes against the control housing part 5 until the sealing seats 58 and 9 assume the open position for the period described above.
A seal is maintained during the first phase of movement by a sealing surface 57 of the poppet valve 52, which follows the poppet valve 52.

Initially, the control housing part 54 remains operatively stationary until it is ridden by the spring clip 17 via the stop member 55. After this relative movement, spring 41 assisted by spring 61 holds the two control housing parts 53, 54 in this position.

During release, the force on the piston rod 56 is removed, so that the spring 10 can bias the valve piston 16 with the sealing seat 9 rearwardly until the sealing seat 58 of the control housing is opened. Its opening distance is limited by stop members 55 of the two control housing parts 53, 54. At this time, the atmosphere is passed through passages 31 and 32 to one compartment 2.
It can be extracted from 0. The sealing seat of the control housing is closed when the vacuum-operated brake booster returns to its initial position, the control housing part 54 rests on the stop surface 27 by means of its collar 59, and the sealing seat 58 of the control housing is pressed against the spring. It remains open until it is biased rearward by 25. In such an arrangement, the two control housing parts 53, 54 slide relative to each other and the stop member 55 is released, thereby bringing the vacuum-operated brake booster into its released position.

At its end remote from the piston rod 56, the valve piston 16 has an end surface of a callotte shape, i.e. the shape of a Catholic clergyman's hood, by means of which it rests on the disk 6, so that the disk 6 is prevented from becoming stuck in its guidance in the control housing part 53.

During assembly, the piston rod 56 along with the sleeve 50, poppet valve 52, valve piston 16 and springs 41 and 61 are assembled into the control housing part 53.
between which the bead 43 abuts on a tab 44 extending radially inwardly from the sleeve 50, so that the sleeve 50, via the piston rod 56, engages the poppet valve 52.
and the springs 41 and 61 are forcefully slid in. In the final stage of assembly, the control housing part 54 is slid onto the control housing part 53, during which time the cam 45 located on the control housing part 54 abuts against the sleeve 50 and biases the springs 41 and 61 to one side. ing. Finally, the two control housing parts 53, 54 are fixed relative to each other by a spring clip 17.

The poppet valve 52 is held and guided in the first control housing part 53 on the one hand, while the poppet valve 52 is held and guided in the second control housing part 5 on the other hand.
An annular sealing edge 51 on the cylindrical inner peripheral surface 46 of 4
, so that no additional annular sealing member is required to seal the two control housing parts 53, 54 from each other.

The poppet valve 52 includes four regions E, B, C, D, which region E has on its end surface the sealing edge 9 of the valve piston 16 and the first control housing part 53.
forming a sealing surface 57 which cooperates with both sealing edges 58 of the . A region D forming the other end of the poppet valve 52, located diametrically opposite to region E, has a generally square cross-sectional surface;
A radially outwardly projecting annular collar or sealing lip 51 bears sealingly on the cylindrical inner surface 46 of the second control housing portion 54 when the poppet valve 52 is installed. This region D of the poppet valve 52 is secured by a cylindrical sealing surface 47 arranged radially outwardly thereof.
is in sealing abutment against the first control housing part 53. Spring 41 among other things
A special clamping flange 48 serving to support the valve rests on the inner surface of region D and seals this part of the poppet valve 52 against its seat in the first control housing part 53. It is strong. Regions B and C both form a bellows,
As a result, the overall length L of the poppet valve 52 can be varied by the effect of forces along the longitudinal centerline.

In order to keep the forces exerted by atmospheric pressure on the rear part of the control housing part 54 as small as possible, the seal of the poppet valve 52 relative to the control housing part 54 is moved further radially outward;
The sealing lip 51 performs the above-mentioned sealing. The poppet valve 52 itself is sealed in the first control housing part 53. Thanks to this arrangement, atmospheric forces are very small and are totally compensated by the spring 41.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a vacuum-operated brake booster according to a first embodiment of the present invention; FIG. 2 is a plan view of the spring washer shown in FIG. 1; FIG. 3 is a top view of the spring washer shown in FIG. FIG. 4 is an enlarged longitudinal sectional view of a part of a vacuum-operated brake booster according to a second embodiment of the present invention; 5 is a cross-sectional view of the poppet valve of the control housing structure of FIG. 4; FIG. DESCRIPTION OF SYMBOLS 1... Poppet valve, 2... First control housing part, 3... Stop surface, 4... Second control housing part, 5... Annular sealing member, 6... Disc, 7...
...Booster housing, 8...Stopping member, 9...
Sealing seat, 10...Piston rod return spring, 11
... Sealing surface, 12 ... Sealing seat, 14 ... Piston rod, 15 ... Spring, 16 ... Valve piston,
17...Spring clip, 18...Rolling diaphragm, 19...Diaphragm plate, 20...Division, 22...Booster housing, 23...Division, 24...Vacuum hole, 25...Spring, 26...Flange , 27...Stopping surface, 28...Color, 2
9... Push rod, 30... Reaction disc, 3
1, 32...passage, 40...O ring, 41...
Spring, 43... Bead, 44... Tab, 45... Cam, 46... Inner peripheral surface, 47... Sealing surface, 48...
... clamping flange, 50 ... sleeve, 51 ... sealing lip, 52 ... poppet valve, 53 ... first control housing part, 54 ... second control housing part, 55 ... stop member, 56 ... Piston rod, 57...Sealing surface, 58...Sealing seat, 59...
... Collar, 60 ... Stopping member, 61 ... Spring.

Claims (1)

[Claims] 1. A booster housing; A booster piston that is housed in the booster housing and partitions the internal space of the booster housing into a vacuum chamber that is communicated with a negative pressure source and a working chamber that is communicated with a working fluid source; a rolling diaphragm that allows the booster piston to move and ensures sealing between the vacuum chamber and the working chamber during movement of the booster piston; a biasing means provided in the booster housing that biases the booster piston toward the working chamber; a first control housing part that is connected to the booster piston and moves together with the booster piston; and a second control housing part that is assembled with the second control housing part so as to be relatively movable within a predetermined range in the direction of movement of the booster piston in a state where the peripheral surface is sealed against the outer peripheral surface of the first control housing part. a control housing having a second control housing portion, wherein outward movement of the booster housing is restricted by outward movement restriction means provided on the second control housing portion and the booster housing and cooperating with each other; and; provided in the first control housing part so as to be relatively movable within a predetermined range in the moving direction of the booster piston, and a first control housing part provided on the end surface on the second control housing part side.
a valve seat provided on the end face of the first control housing part on the second control housing part side, the valve piston being biased toward the second control housing part; a second valve seat that surrounds the seat; and a second valve seat that opens between the first valve seat and the second valve seat at the end face of the first control housing part on the second control housing part side and that defines the internal space of the booster housing. a working fluid introduction passage communicating with the working chamber; a working fluid introduction passage that opens outward from the second valve seat in the radial direction of the first control housing part at the end face of the first control housing part on the second control housing part side; a second control housing of the first control housing part in the direction of movement of the booster piston on the inner peripheral surface of the second control housing part; The first valve piston of the first control housing part is supported in a sealed manner outwardly from the end face of the first control housing part and biased toward the end face of the second control housing part of the first control housing part. a poppet valve member seated on a valve seat and a second valve seat surrounding the valve seat; extending from the interior space of the second control housing portion and the interior space of the poppet valve member, the inner end being connected to the valve piston and the outer end being connected to the valve piston; A vacuum-operated brake booster comprising: a piston rod to which reciprocating motion of a brake pedal is transmitted; 2 Engagement recesses extending in the circumferential direction at at least two substantially diametrically opposite positions in the outer peripheral surface of the first control housing part are provided in a region covered by the inner peripheral surface of the second control housing part. formed on a peripheral wall of the second control housing portion,
In the area located in the sealed working space of the internal space of the booster housing, elongated through grooves extending in the circumferential direction and penetrating from the outer circumferential surface to the inner circumferential surface of the circumferential wall are formed at least at two substantially diametrically opposite positions in the radial direction. two legs of a generally U-shaped spring clip are fitted into at least two elongated through grooves in the peripheral wall of the second control housing part; The two legs of a substantially U-shaped spring clip projecting radially inward of the second control housing portion from openings on the inner peripheral surface side of at least two elongated through grooves of the booster piston extend in the direction of movement of the booster piston. Functions as an inner restriction member for movement within a predetermined range of the first control housing part relative to the second control housing part in the first control housing part. A vacuum-operated brake booster as described in . 3. When the second control housing part is in a state in which the outward movement restricting means of the control housing protrudes outward in the radial direction of the second control housing part from the outer peripheral surface of the second control housing part. a collar member extending in the circumferential direction on the outer circumferential surface; and a collar member supported by the booster housing and projecting radially inwardly on the outer circumferential surface of the second control housing portion in the direction of movement of the booster piston. 3. The vacuum-operated brake booster according to claim 1, further comprising: an annular sealing member that abuts an outer end surface of the brake booster. 4. A sealed state between the outer peripheral surface of the first control housing part and the inner peripheral surface of the second control housing part is created by an annular seal member interposed between the outer peripheral surface and the inner peripheral surface. The vacuum-operated brake booster according to any one of claims 1 to 3, characterized in that: 5. A second control housing part of the first control housing part is provided in an annular outer peripheral end region of the end face of the first control housing part on the second control housing part side along an inner peripheral surface of the second control housing part. an annular protrusion extending outward from an end surface of the poppet valve member on the side of the control housing portion and surrounding the outer peripheral surface of the poppet valve member; An end of the poppet valve member remote in the direction of movement of the booster piston is supported in a sealed manner on a tip of an annular projection of the first control housing part to follow the relative movement of the first control housing part. The vacuum-operated brake booster according to any one of claims 1 to 3, wherein the vacuum-operated brake booster is in sliding contact with the inner circumferential surface of the second control housing portion in a sealed manner. 6. An end of the poppet valve member remote from an end surface of the first control housing part on the second control housing part side in the direction of movement of the booster piston is connected to an inner circumferential surface of the annular protrusion of the first control housing part. a first sealing surface projecting radially outwardly of said first control housing portion from the side and sealingly supported on the tip of said annular projection; and from said first sealing surface further said first control housing. The first control housing part has a tongue-shaped projection projecting outward in the radial direction of the first control housing part beyond the outer peripheral surface of the annular projection of the second control housing part.
6. A vacuum-operated brake booster according to claim 5, further comprising a second sealing surface in sealing sliding contact with an inner circumferential surface of the control housing portion of the brake booster.