JP3107886B2 - Pneumatic booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic booster which assists the operation of a master cylinder or the depression of a clutch in a vehicle or the like in response to a brake operation or the like.

[0002]

2. Description of the Related Art As a conventional pneumatic booster, one having the configuration shown in FIG. 3 is employed. The pneumatic booster 100 includes a front shell 101 and a rear shell 1.
02 and the housing 1
03 is slidably fitted into a fitting hole 104 provided in a rear shell 102 of the rear shell 102 at a substantially bottomed cylindrical valve body portion 105, and an air introduction passage for introducing air into an inner peripheral portion of the valve body portion 105. A power piston 107 provided with a valve body 106 and a bottom 1 of a valve body 105
08, a valve plunger 110 inserted into a valve plunger chamber 109, and the valve plunger 1
10, an operating rod 111 that is connected to the input of the pedal, and is operated by the power piston 107. The inner peripheral side is supported by the power piston 107, and the outer peripheral part is supported by the housing 103. 114, which is divided into a negative pressure chamber 112 on the side and a working pressure chamber 113 on the rear shell 102 side, a seat surface 115 provided on the valve plunger 110, a seat surface 116 provided on the valve body 105, and these seat surfaces 115 , 116 poppet valve 11
7, the communication between the working pressure chamber 113 and the atmosphere, and the communication between the working pressure chamber 113 and the atmosphere.
And a shutoff valve mechanism 118.

[0003] Dust and the like in the atmosphere are introduced into the air introduction passage 106 of the valve body 105 by the valve body 10.
An air passage member 119 is provided, which is made up of at least one of a filter member for preventing intrusion into the inside 5 and a silencer member for suppressing generation of sound when air is introduced.

[0004]

However, in the pneumatic booster 100, the amount of the air stored in the air-passing member 119 which has already passed through the air-passing member 119 is limited. In the initial stage of the boosting operation at the time of depressing the pedal, the amount of the stored air that does not receive the intake resistance due to the air passage member 119 is insufficient, so that the rise of the pneumatic booster is delayed, and the opening area of the air introduction passage 106 is reduced. The flow rate of the air which is limited and is introduced through the atmosphere passage member 119 provided in the atmosphere introduction passage 106 (that is, the flow rate of the atmosphere introduced into the negative pressure working pressure chamber 113 through the valve mechanism 118) ) Is small, the operation of the power piston 107, that is, the response of the pneumatic booster 100 itself is deteriorated. In order to solve this problem, an attempt has been made to improve the material and the like of the air passage member 119 that becomes the intake resistance, but there is a limit to the improvement of the responsiveness by this improvement.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pneumatic booster which has an excellent response with a rapid rise of the output in the initial stage of the boost operation and a large flow rate of the air when the air is introduced. It is to be.

[0006]

To achieve the above object, according to the solution to ## pneumatic booster according to claim 1 of the present invention is slidably supported in the housing, extraordinary one side in the housing
And the valve body part whose other side protrudes out of the housing.
A power piston having a protruded outside the housing
Formed at the end of the cylindrical part of the valve body
A first air introduction passage for introducing air into the interior of the I unit, the <br/> power piston and the housings in together, communicating with a vacuum source
A diaphragm which partitions into the working pressure chamber which is selectively communicated with the negative pressure chamber and the negative pressure chamber or the first air introduction passage which is,
The valve is provided inside the valve body , and is connected to the working pressure chamber.
Communication between the negative pressure chamber and the first air introduction passage.
A valve mechanism that, for causing operation of the valve mechanism, the first air
Leads out of the valve body through the introduction passage opening
And operating rods, said power piston
Connected to the negative pressure chamber and an output shaft for taking out the thrust of the power piston that moves by the differential pressure between the working pressure chamber, and the first air introduction passage includes at least a filter member and a silencer member. be one in which the first air passage member made of either are provided, said bars
Is provided at the end of the cylindrical portion of the lube body, and is provided inside the end of the cylindrical portion.
The first air passage member and the operating rod
The first air introduction passage provided and the first air introduction passage provided
A cylindrical member partitioned into a passage independent of
It is held by the cylindrical member, and the middle part projects from the housing to the outside.
Extends to surround the outer surface of the valve body
A tubular boot member whose other end is held by the housing,
The boot member is formed with an inner peripheral surface of the boot member and a valve.
Atmosphere in the space formed between
A second air inlet to be introduced, and a
At least one of the filter member and the silencer member.
A second air passage member comprising at least one of
A passage independent of the air introduction passage and the boot member;
A space formed between the peripheral surface and the outer peripheral surface of the valve body
And the second air introduction passage is formed by
The first air introduction passage and the second air introduction passage
It is characterized by the fact that the atmosphere is introduced. Ma
The pneumatic booster according to claim 2 of the present invention is
Ring is slidably supported lifting, the extraordinary one side in the housing
And the valve body part whose other side protrudes out of the housing.
And a power piston having a
Formed at the end of the cylindrical part of the valve body
A first air introduction passage for introducing air into the interior of the
Communicates inside the housing with the power piston to a negative pressure source
Selected negative pressure chamber and the negative pressure chamber or first air introduction passage
A diaphragm that is partitioned into a working pressure chamber that is
The valve is provided inside the valve body, and is connected to the working pressure chamber.
Communication between the negative pressure chamber and the first air introduction passage.
Valve mechanism, and the first atmosphere for operating the valve mechanism.
Leads out of the valve body through the introduction passage opening
Operating rod and power piston
And the differential pressure between the negative pressure chamber and the working pressure chamber
An output shaft for extracting the thrust of the moving power piston;
A filter member and a first air introduction passage.
And at least one of the silencer members
(A) an air passage member is provided, and
The valve mechanism and the first air passage member in a lube body portion
Without the space between the first air passing member
A passage space communicating with the outside, wherein the passage space is
Second air introduction passage that expands and contracts due to sliding of the valve body
Is provided between the space portion and the second air introduction passage.
Filter member and silencer member while forming road space
A second air passage member comprising at least one of
It is characterized by being provided.

[0007]

The pneumatic booster according to claim 1 of the present invention.
For example, at the end of the tubular portion of the valve body,
The first air passage member and the operating rod
The first air introduction passage provided and the first air introduction passage
There is a cylindrical member that is divided into independent passages.
In addition, one end side is held by the cylindrical member, and the intermediate portion is housed.
Remove the outer peripheral surface of the valve body protruding from the
A cylindrical shape that extends so as to surround and has the other end held by the housing
Boot member, and is independent of the first air introduction passage.
Standing passage, inner peripheral surface of boot member and outer periphery of valve body
The second air introduction passage is defined by the space formed between
While the valve mechanism has a first air introduction passage and
Since the air is introduced through the second air introduction passage and
The cylindrical part of the valve body part for the passage formed by the cylindrical member
The space inside the end can be increased, and this and the inner peripheral surface of the boot member
And the space formed between the valve body and the outer peripheral surface.
Introduces into working pressure chamber by forming second air introduction passage
The internal space to secure the atmosphere can be enlarged. Also book
According to the pneumatic booster according to claim 2, wherein the invention, during pedaling, etc., in the early time of introducing the atmosphere, Ru already passed already der the first air passage member, the valve mechanism in the valve body The air stored in the space between the first air passage member and the first air passage member (ie, the intake resistance by the first air passage member)
Air that has not passed through the second atmosphere passage member, and the valve mechanism in the valve body and the first atmosphere
Pass the first air passage member in the space between the passage member and the passage member.
Air that is stored in the passage space of the second air introduction passage communicating without the (or first air passage member and a second air
The atmosphere that does not receive any intake resistance of the passage member) is introduced into the working pressure chamber. Therefore, the atmosphere that does not receive the intake resistance is sufficiently stored, and this atmosphere is introduced into the working pressure chamber at the beginning of the boosting operation. There is no delay in the rise of the output. In addition, the atmosphere is introduced from the outside. At this time, the atmosphere is introduced from the first atmosphere introduction passage provided on the inner peripheral side of the valve body, and the valve mechanism in the valve body is Atmosphere is also introduced from the second atmosphere introduction passage that connects the space between the first atmosphere passage member to the outside, and the introduction flow rate of the atmosphere is increased.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pneumatic booster according to a first embodiment of the present invention will be described below with reference to FIG. Note that the left and right in the following description use the left and right in the drawings for convenience.

FIG. 1 is a sectional view showing a main part of a pneumatic booster of this embodiment. This pneumatic booster is a tandem pneumatic booster, which includes a not-shown center plate, a front diaphragm, a front power piston, and the like. It is not different from a type booster. In the drawing, reference numeral 4 denotes a rear shell which fits on the right side of a front shell (not shown) to form a housing together with the front shell, reference numeral 6 denotes a power piston which is slidably supported by the rear shell 4 of the housing, and reference numeral 7 denotes a power piston. An output shaft having a right end provided on the power piston 6 and a left end protruding from an insertion hole (not shown) provided in the front shell and outputting leftward toward a master cylinder (not shown) by moving the power piston 6 in the left direction. Reference numeral 13 denotes a rear diaphragm in which the inner peripheral portion 14 is supported by the power piston 6 and the outer peripheral portion (not shown) is supported by the housing.

The rear diaphragm 13 communicates with the inside of the housing from a negative pressure communication pipe (not shown) to a negative pressure source (not shown). It is divided into a rear working pressure chamber 19 on the side of the rear shell 4 from which the air is introduced or the introduced air is discharged in response to the operation of the operating rod 18 which moves in the left-right direction by operating a brake pedal (not shown).

The power piston 6 includes a tubular portion 20 formed to protrude from the rear shell 4 and extending in the left-right direction, and a tubular portion provided on the left side of the tubular portion 20 and housed in a housing. Large-diameter part 21 with a predetermined diameter larger than 20
And a substantially bottomed cylindrical valve body portion 23 having therein a valve mechanism 22 for controlling the introduction and discharge of the atmosphere of the rear working pressure chamber 19, and an outer periphery of a large diameter portion 21 of the valve body portion 23. And a piston portion 24 extending outward from the portion and receiving a pressure difference between the rear negative pressure chamber 17 and the rear working pressure chamber 19.

The rear shell 4 is provided with a cylindrical large-diameter projection 4a projecting to the right and a small-diameter projection 4b on the right side of the large-diameter projection 4a and smaller in diameter than the large-diameter projection 4a. The cylindrical portion 20 of the valve body 23 is slidably fitted and supported in a fitting hole 25a of a substantially cylindrical rear seal and support member 25 supported on the inner peripheral side of the small diameter projecting portion 4b. The rear working pressure chamber 19 is surrounded by the rear shell 4, the rear diaphragm 13, the valve body 23, the rear seal and support member 25, and the like. Here, a reinforcing member 26 for improving the strength is provided in the rear seal / support member 25, and the reinforcing member 26 includes a cylindrical main body 26 a provided in the rear seal / support member 25 and a reinforcing member 26. An inner flange portion 26b extending radially inward from the left side of the main body 26a; and a rear seal and support member 2 extending radially outward from the right end of the main body 26a.
5, a contact flange 26 c is provided to contact the right end of the small-diameter protrusion 4 b of the rear shell 4.

An inner peripheral portion of the cylindrical portion 20 of the valve body portion 23 has a large-diameter inner peripheral portion 30 having a predetermined diameter provided from a right end thereof to a predetermined position and a left-hand side of the large-diameter inner peripheral portion 30. A small-diameter inner peripheral portion 31 having a smaller diameter than the large-diameter inner peripheral portion 30 by a predetermined amount;
A bottom portion 32 on the left side of the small-diameter inner peripheral portion 31, and a stepped portion extending along a direction perpendicular to the axis of the valve body portion 23 at a boundary between the large-diameter inner peripheral portion 30 and the small-diameter inner peripheral portion 31. The part 33 is formed over the circumferential direction.

In the vicinity of the bottom 32 at the left end of the small diameter inner peripheral portion 31 of the valve body 23, an opening is formed near the bottom 32 and penetrates through the valve body 23 to form the rear negative pressure chamber 17.
Is provided with a first communication hole 34 that communicates with
A small-diameter inner peripheral portion 31 is provided on a bottom portion 32 inside the first communication hole 34.
A valve plunger chamber 35 having a smaller diameter than the predetermined amount is provided. And, thereby, this valve plunger chamber 3
The first seat surface 36 is formed on the bottom portion 32 near the boundary between 5 and the small-diameter inner peripheral portion 31 along a direction orthogonal to the axial direction of the valve body portion 23.

A valve plunger 38 is slidably inserted into the valve plunger chamber 35 of the valve body 23. On the other hand, the valve body 23 has
A second communication hole 39 is provided in a direction perpendicular to the axis of the valve body portion 23 from the valve plunger chamber 35. The second communication hole 39 allows the valve plunger chamber 35 and the rear working pressure chamber 19 to communicate with each other. ing. Further, on the left side of the valve plunger 38 of the valve body portion 23, a right end 41 of the output shaft 7 is provided with a reaction disk 40 as a pressure deformable member held therebetween.

Here, the valve plunger 38 includes:
A groove 43 is provided at a predetermined position on the outer peripheral portion, and a spherical portion 44 of the operating rod 18 is provided on the right side thereof.
Is provided with an operating rod connection hole 45 to which is connected. Outside the operating rod connection hole 45, a sheet portion 47 extending a predetermined length to the right is provided.
Is provided, and the right end of the seat portion 47 constitutes the second seat surface 48.

The operating rod 18
Is a first shaft portion 49 having a predetermined diameter on the right side, and the first shaft portion 49 provided at a predetermined position on the left side of the first shaft portion 49 with a predetermined width.
A flange portion 50 having a larger diameter by a predetermined amount; a second shaft portion 51 having a predetermined length provided on the left side of the flange portion 50 and having substantially the same diameter as the first shaft portion 49; A third shaft portion 52 provided at a predetermined length further to the left side and having a diameter smaller than the second shaft portion 51 by a predetermined amount and having a tapered shape; and the spherical portion 44 provided on the left side of the third shaft portion 52. Consists of And the collar 5
One end of a first spring 53 described later is provided at a boundary between the first shaft 53 and the second shaft 51, and one end of a second spring 54 described later is provided at a boundary between the second shaft 51 and the third shaft 52. Each comes into contact.

The second communication hole 3 of the valve body 23
A plate 56 is inserted into a plate insertion hole 55 provided on the left side of the plate 9 with a gap having a predetermined width, and the upper end of the plate 56 is formed in the groove 4 of the valve plunger 38.
3 is inserted with a gap of a predetermined width. Further, the lower end portion thereof can be brought into contact with a stopper 57 mounted in the rear shell 4 so that movement of the lower end portion beyond a predetermined position in the right direction is restricted. The plate 56 regulates a limit position of the right movement of the power piston 6 and regulates a positional relationship between the power piston 6 and the valve plunger 38.

A retainer 58, a poppet valve 59, a first spring 53 and a second spring 54 are provided between the valve body 23 and the operating rod 18. Next, these will be described. In addition, the above-described valve mechanism 22 includes a poppet valve 59.
And the first sheet surface 36 and the second sheet surface 48 described above.
It is composed of

The retainer 58 has a diameter substantially the same as that of the large-diameter inner peripheral portion 30 of the valve body portion 23 provided at one end thereof, and extends along the axial direction of the valve body portion 23 (the left-right direction in the drawing). A first cylindrical portion 60 having a length, and a first perforated disk portion 6 extending radially inward from a left end of the first cylindrical portion 60
A second cylindrical portion 62 extending a predetermined length to the left in the axial direction from the inside of the first perforated disk portion 61 and having a predetermined diameter smaller than the large diameter inner peripheral portion 30; 62 is an integrally molded product having a second perforated disk portion 63 extending radially inward from the left end of 62.

The poppet valve 59 is provided at a portion surrounded by the first perforated disk portion 61, the second cylindrical portion 62, the large-diameter inner peripheral portion 30 and the step portion 33 of the valve body portion 23 of the retainer 58. An outer peripheral bead portion 64 is fitted, and the outer peripheral bead portion 64 blocks communication between the outer peripheral side of the retainer 58 and the inner peripheral side of the valve body portion 23.

The boundary between the second cylindrical portion 62 and the second perforated disk portion 63 of the retainer 58 and the boundary between the flange 50 and the second shaft 51 of the operating rod 18 are located between A first spring 53 having a predetermined urging force is provided. The operating rod 18 is urged rightward by the first spring 53, and the second seat surface 48 of the valve plunger 38 to which the operating rod 18 is connected is moved to the third position of the poppet valve 59 by the urging force or the like. It is designed to sit on the seat surface 65.

The poppet valve 59 has, on the left side, the outer peripheral bead portion 64 and the third seat surface 65 which can be separated and seated on the first seat surface 36 of the valve body portion 23 and the second seat surface 48 of the valve plunger 38, respectively. The valve section 66 includes a valve section 66 provided, and an elastic rolling section 67 for connecting the valve section 66 and the outer peripheral bead section 64.
A reinforcing disk 68 is fixed to the right side of the disk 6.

The second spring 5 having a predetermined urging force is provided between the disk 68 and the boundary between the second shaft portion 51 and the third shaft portion 52 of the operating rod 18.
4 are provided. The second spring 54
Urges the third seat surface 65 of the poppet valve 59 to be seated on the first seat surface 36 of the valve body 23 and the second seat surface 48 of the valve plunger 38.

Here, when the third seat surface 65 of the poppet valve 59 is separated from and seated on the first seat surface 36 of the valve body 23, the communication between the rear working pressure chamber 19 and the rear negative pressure chamber 17 is established and interrupted. When the third seat surface 65 is separated from and seated on the second seat surface 48 of the valve plunger 38, the communication between the rear working pressure chamber 19 and the atmosphere is interrupted. The third sheet surface 65 and the first sheet surface 3
6 is called a vacuum valve, and the third seat surface 65
And a valve constituted by the second seat surface 48 is called an atmospheric valve.

In the vicinity of the opening of the valve body 23, a cylindrical portion 70 is inserted into the large-diameter inner peripheral portion 30 of the valve body 23 at a predetermined interval. A claw portion 71 projecting outward in the direction by a predetermined amount and abutting against the large-diameter inner peripheral portion 30 of the valve body portion 23; and a hook projecting radially inward from a right end of the cylindrical portion 70 opposite to the claw portion 71. One-piece locking retainer 73 having a stop 72
Is provided. Here, the locking retainer 73 is locked to the valve body portion 23 by the claw portion 71 such that the cylindrical portion 70 is disposed at a position substantially coaxial with the valve body portion 23.

The cylindrical portion 70 of the retaining retainer 73
A space between the first air introduction passage 74 and the operating rod 18 constitutes a first air introduction passage 74.
4, a first air passage member 75 is provided at a position where the first air passage member 75 abuts against the flange 50 of the operating rod 18.
3 is provided in a fixed state. The first atmosphere communication member 75 is composed of at least one of a filter member that prevents dust and the like in the atmosphere from entering the valve body portion 23 and a silencer member that suppresses generation of sound when the atmosphere is introduced. The filter member is formed of a sponge or the like formed to have a coarseness enough to remove dust and the like in the atmosphere, and the silencer member is compression-molded to have a finer coarseness than the filter member. It is made of felt or the like.

The locking portion 72 of the locking retainer 73 locks one end of a boot 76 for preventing dust and the like from adhering between the valve body 23 and the rear seal and support member 25. The boot 76 is an integrally molded product made of an elastic material, and has an inner engaging portion 7 that engages with the locking portion 72.
7, an extendable bellows portion 78 extending radially outward from the right end of the inner engaging portion 77 and then extending leftward;
And an outer engagement portion 79 provided at the left end of the bellows portion 78. Note that the right end of the bellows portion 78 is in contact with the right end of the valve body portion 23, and the bellows portion 7
Reference numeral 8 denotes an outer space (a part of the passage space) 80 formed between the valve body 23 and the outer periphery of the valve body 23.

The outer engaging portion 79 of the boot 76 is locked by the holder 81. The holder 81 has a cylindrical portion 8 having a predetermined diameter larger than the outer peripheral portion of the large diameter projecting portion 4 a of the rear shell 4.
2, a locking claw 83 projecting radially inward from one end of the cylindrical portion 82 to lock the cylindrical portion 82 with the large-diameter projecting portion 4a, and radially outward from the other end of the cylindrical portion 82. An outer flange portion 84 that protrudes and engages the outer engaging portion 79 of the boot 76, and an inner flange portion 85 that abuts the holder 81 on the right end of the small-diameter protruding portion 4b of the rear shell 4. The part 82 is provided with a plurality of air inlets 86 at predetermined positions in the circumferential direction. The first air passage member 75 described above is provided between the inside of the cylindrical portion 82 and the small-diameter projecting portion 4b of the rear shell 4.
Similarly to the above, at least one of a filter member for preventing dust and the like in the air introduced from the air inlet 86 from entering the valve body portion 23 and a silencer member for suppressing generation of sound at the time of air introduction. Is provided.

Then, at the right end of the valve body 23,
A notch (part of the passage space) 88 is provided at a predetermined position where the power piston 6 does not open to the rear working pressure chamber 19 when the power piston 6 moves leftward.
The outer space 80 between the valve body 6 and the valve body 23, the small-diameter protrusion 4 b of the rear shell 4 and the air inlet 86 are provided separately from the first air inlet passage 74 and the valve mechanism 22 in the valve body 23. A second air introduction passage 89 is provided for communicating an inner space (space) 90 between the first air passage member 75 and the outside to the outside.

According to the pneumatic booster of the first embodiment having the structure described above, the poppet valve 59 is actuated by the urging force of the second spring 54 or the like in a normal state (such as a state where the brake pedal is not depressed). The third seat surface 65 is brought into contact with the first seat surface 36 and the second seat surface 48 to close the vacuum valve and the atmospheric valve, and the first communication hole between the rear working pressure chamber 19 and the rear negative pressure chamber 17 is formed. 34, valve plunger chamber 35
Further, the communication through the second communication hole 39 is cut off, and the communication between the rear working pressure chamber 19 and the atmosphere through the valve plunger chamber 35 and the second communication hole 39 is cut off.

Then, the brake pedal is depressed, and the valve plunger 38 is moved through the operating rod 18.
Moves to the left with respect to the valve body portion 23, the second seat surface 48 and the third seat surface 65 of the poppet valve 59 are separated from each other, the atmospheric valve is opened, and the valve plunger chamber is opened in the rear working pressure chamber 19. Atmosphere is introduced through the second working hole 35 and the second communication hole 39, and the rear working pressure chamber 19 and the rear negative pressure chamber 1 are introduced.
7, the power piston 6 moves leftward to cause the output shaft 7 to protrude, and the boost operation is performed. Here, in the initial stage of introducing the atmosphere, the valve mechanism in the valve body 23 has already passed through the first atmosphere passage member 75 (that is, does not receive the intake resistance by the first atmosphere passage member 75). In addition to the air stored in the inner space 90 between the first air passage member 75 and the second air passage member 75,
The air stored in the passage space such as the outer space 80 of the second air introduction passage 89 that has passed through the passage 7 is introduced into the rear working pressure chamber 19. Therefore, the air which does not receive the intake resistance is sufficiently stored, and this air is introduced into the rear working pressure chamber 19 at the beginning of the boosting operation. There is no delay in the rise of the output of the force device.
Atmospheric air is also introduced from the outside. At this time, the air from the opened atmospheric valve to the rear working pressure chamber 19 is introduced from the first atmospheric introduction passage 74 and the second atmospheric It will also be introduced from the passage 89. Therefore, the flow rate of the introduced atmosphere is increased, and the power piston 6 moves immediately, resulting in excellent responsiveness throughout the boost operation. Moreover, the first air introduction passage 74
And the second air introduction passage 89 is provided with the first air passage member 7.
Since the fifth air passage member 87 and the second air passage member 87 are provided, functions such as prevention of intrusion of dust and the like in the atmosphere and suppression of generation of sound when the air is introduced into the atmosphere are naturally fulfilled.

In the first embodiment, the boot 76
An air inlet 86 is provided in the vicinity of a connection portion with the rear shell 4 of the outer space 8 between the boot 76 and the valve body 23.
0, the second air introduction passage 89 is formed, and the second air passage member 87 is provided near the air introduction port 86. However, the present invention is not limited to this. It can also be provided separately so that it can communicate directly with the outside. However, the rear shell 4 of the boot 76
An air inlet 86 is provided in the vicinity of the connecting portion with the air inlet 86, and a second air inlet passage 89 is formed including the outer space 80 between the boot 76 and the valve body portion 23, and the second air inlet 89 is located near the air inlet 86. With the provision of the air passage member 87, the volume of the internal atmosphere that is not affected by the first air passage member 75 and the second air passage member 87 increases without increasing the size of the pneumatic booster itself. Preferred. Moreover, since the atmosphere in the outer space 80 is pushed out toward the inner space 90 due to the contraction of the boots 76 due to the movement of the power piston 6, the responsiveness is further improved.

Next, a pneumatic booster according to a second embodiment of the present invention will be described below with reference to FIG. In addition,
The pneumatic booster according to the second embodiment is different from the pneumatic booster according to the first embodiment mainly in the part in which the holder is abolished. The following description focuses on the differences.

In the second embodiment, the contact flange portion 26c of the reinforcing member 26 is further extended radially outward by a predetermined amount, and an engagement cylindrical portion 26d is provided at the outer end thereof. At the right end of the cylindrical portion 26d, an outer flange portion 26e extending radially outward by a predetermined amount is provided.
The outer engaging portion 79 of the boot 76 is engaged with e. At a predetermined position of the contact flange portion 26c, a plurality of air inlets 26f are provided in the circumferential direction for communicating the outside space portion 80 with the outside from the radial outside of the small diameter projecting portion 4b of the rear shell 4.

Here, a second air passage member 87 similar to that of the first embodiment is provided on the outer peripheral portion of the small diameter projecting portion 4b of the rear shell 4 so as to cover the air inlet 26f. In addition,
In the second embodiment, the cutout 88 at the right end of the valve body 23, the outer space 80 between the boot 76 and the valve body 23, the air inlet 26f, and the outer periphery of the small-diameter projection 4b of the rear shell 4 are provided. The portion constitutes a second air introduction passage 89 that communicates an inner space portion 90 between the valve mechanism 22 in the valve body portion 23 and the first air passage member 75 to the outside.

According to the pneumatic booster of the second embodiment having such a structure, the effect of the first embodiment is obtained, that is, the air introduction port 26f is provided near the connection between the boot 76 and the rear shell 4. With boot 76 and valve body 2
3 and the second air introduction passage 89 including the outer space 80.
And the second air passage member 87 is provided in the vicinity of the air inlet 26f, so that the volume of the inside air that is not affected by the first air passage member 75 and the second air passage member 87 increases, and the air valve At the beginning of the operation when the valve is opened, a large amount of the internal air is introduced into the rear working pressure chamber 19,
The effect such as excellent responsiveness in the initial stage of operation and the like, and the atmosphere from the opened atmosphere valve to the rear working pressure chamber 19 is introduced from the first atmosphere introduction passage 74 and the second atmosphere introduction passage 89. Since the introduction flow rate of the atmosphere is increased, the function of preventing the intrusion of dust and the like in the atmosphere and suppressing the generation of sound when introducing the atmosphere is performed, and further, the responsiveness is excellent throughout the boost operation. In addition to the effect described above, since the outer engaging portion 79 of the boot 76 is engaged by using the reinforcing member 26 of the rear seal and support member 25, it is used in the first embodiment. The holder 81 becomes unnecessary, the diameter of the holder 81 does not increase, and the number of parts is reduced, so that the number of assembling steps is reduced.

In the first and second embodiments, a pneumatic booster for assisting the brake operation has been described as an example. However, it is of course possible to apply a pneumatic booster for assisting the depression of the clutch. It is. In the above description, only the rear working pressure chamber 19 and the like on the rear side have been described. However, the same can be said for the front working pressure chamber and the like (not shown) communicating with the rear working pressure chamber 19. .

[0039]

As described in detail above , claim 1 of the present invention
According to the described pneumatic booster, the cylindrical shape of the valve body
In the end portion, inside the end portion of the cylindrical portion, the first air passage member and
First air introduction passage with operating rod
And a tube partitioned into a passage independent of the first air introduction passage.
A cylindrical member is provided, and one end of the cylindrical member is retained.
With the middle part protruding outside from the housing.
Extends around the outer peripheral surface of the
A tubular boot member held by the jing is provided,
A passage independent of the first air introduction passage and the inner periphery of the boot member
A space formed between the surface and the outer peripheral surface of the valve body
To form the second air introduction passage, while the valve mechanism
Is larger due to the first and second air introduction passages.
To introduce the air, the passage formed by the cylindrical member
The space inside the end of the cylindrical part of the valve body
This, the inner peripheral surface of the boot member and the outer peripheral surface of the valve body
Forms a second air introduction passage with the space formed between
To secure the atmosphere to be introduced into the working pressure chamber.
Space can be enlarged. Therefore, the power piston
Moves to the seat and has excellent responsiveness throughout the boost operation
Will be. Further , according to the pneumatic booster according to claim 2 of the present invention, at the initial stage of introducing the atmosphere, such as when the pedal is depressed , the air has already passed through the first air passage member.
That, air (i.e. the first air passage which is stored in the space between the valve mechanism and the first air passage member within the valve body portion
Air that does not receive the intake resistance caused by the excess member) and the valve body
First space in the space between the valve mechanism in the inside and the first air passage member.
The air stored in the passage space of the second air introduction passage that communicates without passing through the air passage member (that is, the first air passage)
The intake resistance of both
Air) is introduced into the working pressure chamber.
Therefore, the atmosphere that does not receive the intake resistance is sufficiently stored, and this atmosphere is introduced into the working pressure chamber at the beginning of the boosting operation. There is no delay in the rise of the output. In addition, the atmosphere is introduced from the outside, but the atmosphere is introduced from the first atmosphere introduction passage provided on the inner peripheral side of the valve body, and the valve mechanism in the valve body and the first atmosphere are introduced. Atmosphere is also introduced from the second atmosphere introduction passage that connects the space between the passage member and the outside to the outside, and the introduction flow rate of the atmosphere is increased. Therefore,
The power piston moves instantly, resulting in excellent responsiveness throughout the boost operation. In addition, the second atmosphere
The passage space volume of the passage expands and contracts due to sliding of the valve body
The air in the passage space of the second air introduction passage
To the space between the first air passage member and
Therefore, the responsiveness is further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a pneumatic booster according to a first embodiment of the present invention, showing a non-operating state.

FIG. 2 is a sectional view showing a main part of a pneumatic booster according to a second embodiment of the present invention, showing a non-operating state.

FIG. 3 is a sectional view showing a conventional pneumatic booster,
It shows a non-operation state.

[Explanation of symbols]

 Reference Signs List 6 power piston 7 output shaft 13 diaphragm 17 rear negative pressure chamber (negative pressure chamber) 18 operating rod 19 rear working pressure chamber (working pressure chamber) 23 valve body part 74 first air introduction passage 75 first air passage member 80 outer space Part (passage space) 87 Second air passage member 88 Notch (passage space) 89 Second air introduction passage 90 Inner space part (space part)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Microfilm (JP, U) (JP, U) which photographed the contents of the specification and drawings attached to the application form of Japanese Utility Model Application No. 1-339393 (Japanese Utility Model Application No. 2-68260). 58) Field surveyed (Int. Cl. ⁷ , DB name) B60T 13/57

Claims (2)

(57) [Claims] 1. A supported freely sliding in the housing, one side
Faces inside the housing and the other side projects out of the housing
Power piston having a valve body portion formed and a cylindrical end of the valve body portion protruding outside the housing
The air is introduced into the interior of the valve body
A first air introduction passage, said power piston and the housings in together, and the working pressure chamber which is selectively communicated with the negative pressure chamber and the negative pressure chamber or the first air introduction passage which is communicated with the negative pressure source A diaphragm provided inside the valve body portion and connected to the working pressure chamber.
Communication between the negative pressure chamber and the first air introduction passage.
A valve mechanism for opening the first air introduction passage for operating the valve mechanism.
An operating rod led out of the valve body through an opening; and an operating rod connected to the power piston and moved by a differential pressure between the negative pressure chamber and the working pressure chamber . Thrust
And an output shaft to take out, wherein the first air introduction passage, the pneumatic booster of the first air passage member made from at least one is provided in the filter member and the silencer member, the valve body Provided at the end of the cylindrical portion of the portion,
Inside the end, the first air passage member and the operating rod
The first air introduction passage provided with a head and the first air introduction passage.
A tubular member that is partitioned into a passage independent of the entrance passage, one end of which is held by the tubular member, and an intermediate portion that is defined as a housing.
Enclose the outer peripheral surface of the valve body that protrudes to the outside.
The cylindrical boot that extends
And a boot member, formed on the boot member, and an inner peripheral surface of the boot member and a valve.
Atmosphere in the space formed between
A second air inlet to be introduced, and a filter member and a sieve provided at the second air inlet.
The second atmosphere composed of at least one of the lens members
A passage member, a passage independent of the first air introduction passage, and the boot portion
It is formed between the inner peripheral surface Barububo Di outer peripheral surface of the wood
While forming the second air introduction passage with the space,
The valve storage mechanism includes the first air introduction passage and the second air introduction passage.
A pneumatic booster configured to introduce the atmosphere through an entrance passage . 2. One side slidably supported by a housing.
Faces inside the housing and the other side projects out of the housing
Power piston having a valve body portion formed and a cylindrical end of the valve body portion protruding outside the housing
The air is introduced into the interior of the valve body
The inside of the housing together with the first air introduction passage and the power piston is connected to a negative pressure source.
To the connected negative pressure chamber and the negative pressure chamber or the first air introduction passage.
Diaphragm partitioned into working pressure chamber selectively communicated
And a connection of the working pressure chamber provided inside the valve body.
Communication between the negative pressure chamber and the first air introduction passage.
And a valve mechanism for operating the valve mechanism.
An operation led out through the mouth to the outside of the valve body
A connecting rod , connected to the power piston, the negative pressure chamber and the operation
Thrust of the power piston that moves due to differential pressure with the pressure chamber
And a filter member and a sieve in the first air introduction passage.
First air passage made of at least one of
In a pneumatic booster provided with an excess member , the valve mechanism in the valve body portion and the first air passage
The space between the member and the first air passage member
Has a passage space that communicates with the outside
The second air guide expands and contracts due to the sliding of the valve body.
An inlet passage is provided, and a passage space is provided between the second air introduction passage and the space.
Fewer filter members and silencer members while forming
And a second air passage member consisting of either
A pneumatic booster characterized by: