JPS6067254A - Negative-pressure booster - Google Patents

Abstract

PURPOSE:To increase the rigidity in the vicinity of the locking hook of a booster piston by inserting a valve cylinder into an insertion hole of a booster piston and locking the locking plate for supporting said valve cylinder with the locking hook of the piston and forming a reinforcing rib between the insertion hole of the piston and the locking hook. CONSTITUTION:A valve cylinder 14 is inserted into an inertion hole 41 of a booster piston 5, and a flange for preventing the slip-off of the valve cylinder 14 is locked between a locking plate 50 and the piston 5. Said locking plate 50 is locked with a locking hook 43 formed by the cutting and pulling-up on the piston 5. A circular reinforcing rib 42 is formed between the insertion hole 41 of the piston 5 and the opened port part 64 of the locking hook 43. Therefore, the vicinity of the opened port part 64 of the piston 5 is reinforced by the reinforcing rib 42.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a negative pressure booster used, for example, in operating a brake mask cylinder of a vehicle.

Conventionally, in this type of device, a booster piston that can freely reciprocate back and forth inside the booster shell has a first working chamber at the front that is constantly connected to a negative pressure source, and a control valve that alternately connects the first working chamber or the atmosphere to the atmosphere. It is known that the booster piston is divided into a second working chamber at the rear part whose communication is switched and controlled, and the booster piston is provided with a valve cylinder for accommodating a control valve.

In the above device, if the valve cylinder is assembled to the booster piston, it is economical because the booster piston can be changed and the valve cylinder can be used in common when manufacturing products with various output characteristics. However, conventionally, the booster piston and the valve barrel are integrally molded from synthetic resin, so the above-mentioned effects cannot be obtained, and the synthetic resin is expensive.

On the other hand, when making it possible to assemble the valve cylinder to the booster piston, the assembly must be made easy.
This will hinder the manufacturing efficiency of the booster.

In view of the above, the present invention is designed to allow a valve cylinder to be attached to a booster piston to facilitate its assembly, and to allow the valve cylinder to be used in common when manufacturing boosters having various output characteristics. The object of the present invention is to provide the booster which improves economic efficiency and reduces the cost of the booster piston, and the booster piston is formed from a steel plate and is located at the center of the booster piston. A fitting hole for the valve cylinder, a plurality of locking pawls located around the fitting hole and cut and raised toward the first working chamber side, and a plurality of locking pawls located between the locking pawls and the fitting hole and protruding toward the first working chamber side. The valve cylinder is fitted into the fitting hole from the first working chamber side, the retaining flange of the valve cylinder overlaps the booster piston inside the reinforcing rib, and the locking plate guides the reinforcing rib. The roller is characterized by the fact that it is rotated to engage the locking pawl and the retaining flange is clamped between the locking plate and the booster piston.

Hereinafter, an embodiment in which the present invention is applied to a brake mask sill will be described with reference to the drawings.

In FIG. 1, booster shell 1 of negative pressure booster S
consists of a pair of front and rear bowl-shaped bodies 1F and 1R molded from lightweight thin-walled steel plate or synthetic resin, and the rear bowl-shaped body 1R of 7c
A plurality of claw pieces 2 protruding from the opening at equal intervals on the circumference,
Both arm-shaped bodies 1F and IR are mutually positioned by engaging with a plurality of notches 3 formed at equal intervals on the circumference in the opening of the front bowl-shaped body 1F, and then both arm-shaped bodies 1F and IR are positioned. 1F, 1R front and rear facing walls +++1. + J+-L+□ノ+11. The connection structure between the booster shell 1 and the tie rod 4 will be described later.

The interior of the booster shell 1 is divided into a first working chamber A at the front and a second working chamber A at the rear by a booster piston 5 housed therein so as to be able to reciprocate back and forth, and a piston diaphragm 6 attached to the rear surface 5b of the booster piston 5. It is divided into a working chamber B.

The first working chamber A is always in communication with the intake manifold (not shown) of the internal combustion engine, which is a negative pressure source, through the negative pressure introduction pipe 1.
The second working chamber B is connected to the first working chamber A via a control valve 8, which will be described later.
Alternatively, the air inlet 11 opened in the end wall 10 of the rear extension tube 9 of the booster shell 1 is alternately connected and controlled.

The booster piston 5 is always urged in the backward direction, that is, toward the first working chamber side, by a return spring 12 contracted in the first working chamber A, and its backward limit is reached by a projection 13 formed protrudingly formed on the back surface of the piston diaphragm 3. It is regulated by coming into contact with the inner surface of the rear wall of the shell 1.

The booster piston 5 is provided with a valve cylinder 14 that protrudes rearward from its center, and the valve cylinder 14 is slidably supported by a flat bearing 15 provided on the extension cylinder 9, and its rear end is connected to the atmosphere introduced into the cylinder 9. It is opened toward the mouth 11.

The control valve 8 is configured in the valve cylinder 14 as follows. That is, an annular first valve seat 16□ is formed on the inner wall of the front part of the valve cylinder 14, and a valve piston 18 connected to the input rod 17 and forming the front end thereof is slid on the front part of the valve cylinder 14. An annular second valve seat 16 □ surrounded by the first valve seat 16 is formed at the rear end of the valve piston 18 .

A base end portion 20 of a cylindrical valve body 19 with both ends open is held on the inner wall of the valve cylinder 14 via a valve body holding cylinder 21 that is fitted into the valve cylinder 14 . The valve body 19 is made of an elastic material such as rubber, and a thin diaphragm 22 extends radially inward from its base end 20, and a thick valve portion 23 is connected to the inner peripheral end of the valve body 19. The valve portion 23 is provided with the first and second valve seats 16. ．． Opposed to 162. Therefore, valve part 2
3 can move back and forth by deforming the diaphragm 22, and can also come into contact with the front end surface of the valve body holding cylinder 21.

An annular reinforcing plate 24 is embedded in the valve portion 23, and the valve portion 23 is connected to both valve seats 16. A valve spring 25 is connected to bias toward +t62.

The outer part of the first valve seat 16□ is connected to the first working chamber A through a pair of through holes 26 of the booster piston 5, and to the first and second
The middle part of the valve seats 16□ and 162 is connected to the second working chamber B through another pair of through holes 27, and the inner part of the second valve seat 16□ is connected to the atmosphere inlet 11 through the inside of the valve body 19. Both are in constant communication.

The booster piston 5 is provided with a large-diameter cylinder hole 28 that opens at the center of its front surface, and a small-diameter cylinder hole 29 that opens at the inner end surface of the cylinder hole 28. An elastic piston 3o made of rubber or the like and an output piston 31 of the same diameter are sequentially slid together from the back, and the elastic piston 3o is inserted into the small diameter cylinder hole 29.
A reaction piston 32 having a diameter smaller than 0 is slid together. Furthermore, a small shaft 33 protruding from the front end surface of the valve piston 18 enters the small diameter cylinder hole 29 and opposes the rear end surface of the reaction piston 32 . An output rod 34 is installed in front of the output piston 31.
is provided in a protruding manner, and its output rod 34 is disposed within the first working chamber A.

The input rod 17 is always urged in the backward direction by the return spring 37, and its retreat limit is reached when the movable stopper plate 35 screwed onto the input rod 17 comes into contact with the inside of the end wall 10 of the rear extension tube 9. regulated by.

When the movable stopper plate 35 is rotated, the screwing position between the movable stopper plate 35 and the input rod 17 changes, so that the retraction limit of the input rod 17 can be adjusted back and forth. After the adjustment, the movable stopper plate 35 is fixed by tightening a locking nut 36 which is also screwed onto the input rod 17. A vent hole 38 is formed in the movable stopper plate 35 so that the movable stopper plate 35 does not block the air inlet 11.

Filters 39 and 40 are attached to the outer end opening of the valve cylinder 14 to purify the air introduced from the atmospheric air inlet 11 and to be deformable so as not to interfere with the operation of the input rod 11.

Next, the assembly structure of the valve cylinder 14 to the booster piston 5 will be explained. As shown in Figs. A cylinder fitting hole 41 is formed. In addition, the pusher biston 5 includes a pair of arc-shaped reinforcing lips 42 that are arranged so as to surround the insertion hole 41 and protrude from the front surface 5α, and a pair of arc-shaped reinforcing lips 42 that are arranged so as to surround the insertion hole 41 and protrude from the front surface 5α. A pair of locking claws 4 cut to the side
3 are provided. When both image retaining claws 43 are biased to one side of both reinforcing lips 42, they are both disposed point-symmetrically with respect to the center of the insertion hole 41.

The valve cylinder 14 is molded from thermosetting synthetic resin such as phenol resin, and has a cylindrical main body 44 and a retaining flange 45 protruding from the outer peripheral surface of one end of the main body 44. The outer circumferential surface of the connecting portion with the retaining flange 45 is formed into a tapered surface 46 with the flange 45 side being the larger diameter side. The retaining flange 45 has the large-diameter cylinder hole 28 on its end face, and has a truncated conical short cylindrical part 47 concentric with the main body 44, and a flat top surface 48 disposed to sandwich the short cylindrical part 47. The first through hole 26 has a pair of protrusions 49 having a top surface 48 thereof.

Further, the other through hole 27 is opened on the small diameter side of the tapered surface 46.

The locking plate 50 includes a flat plate part 52 having a frustoconical cap part 51 into which the short cylindrical part 47 can be loosely fitted, and a flat plate part 52 that is bent diagonally from both ends of the flat plate part 52 in a direction opposite to the protruding direction of the cap part 51. It consists of a pair of legs 53 and a pair of locking parts 54 extending further outward from both ends of the legs 53. The connecting portion between the flat plate portion 52 and the leg portion 53 is formed in a clear arc shape on the outer peripheral edge of the retaining flange 45, and the connecting portion between the leg portion 53 and the locking portion 5
4 is formed in an arc shape along the outer peripheral edge of the reinforcing lip 42.

Reinforcing edges 55 are formed by bending on both side edges of the locking plate 50 except for one end of both image locking portions 54 which are point symmetrical with respect to the center of the camp portion 51 .

A through hole 56 having a smaller diameter than the output piston 31 and a larger diameter than the output rod 34 is formed in the top wall of the camp part 51, and a pair of through holes 56 communicating with the through hole 26 are formed on the base end side of the camp part 51 of the flat plate part 52. A communication hole 57 is formed.

When assembling the valve cylinder 14 to the booster piston 5, the main body 44 of the valve cylinder 14 is inserted into the insertion hole 41 of the booster piston 5 from the front face 5α side, and the retaining flange 45 is positioned inside both reinforcing lips 42. and polymerizes into the booster piston 5. Then, as shown in FIG. 4, the camping part 51 of the locking plate 50 is loosely fitted into the short cylinder part 47, and the connecting part between the flat plate part 52 and the leg part 53 is pulled out at the position where it is removed from the locking claw 43. The outer periphery of the stop flange 45 and the connecting portion between the leg portion 53 and the locking portion 54 are aligned with the outer periphery of the reinforcing lip 42, and from this state, the locking plate 50 is connected to the leg portion 53 and the locking portion 54. When the connecting portion is brought into contact with the reinforcing lip 42 and rotated in the direction of the arrow α in FIG. As a result, the retaining flange 45 is caught between the locking plate 50 and the booster piston 5, and the valve cylinder 14
is assembled to the booster piston 5. In this case, a reinforcing edge 5 located at one end of the locking part 54 is attached to the edge of the locking claw 43.
5 abut against each other, the rotation angle of the locking plate 50 is regulated, and the locking plate 5
The communication hole 57 of 0 and the communication hole 26 match. Further, the movable end of the return spring 12 engages with the camp portion 51 of the locking plate 50,
The resilient force of the return spring 12 prevents the locking plate 50 from rotating.

The output rod 34 is loosely inserted into the through hole 56 of the cap portion 51, but since the diameter of the through hole 56 is smaller than that of the output piston 31, the camp portion top wall 51α around the through hole 56 is inserted into the cylinder hole 28. Output piston 3 facing the opening of
As a result, when the booster piston 5 is assembled, problems such as the output piston 31 and the output rod 34 falling from the valve cylinder 14 will not occur.

1st. As shown in FIG. 3, the piston diaphragm 6 is formed with annular inner and outer peripheral beads 58 and 59, and the outer peripheral bead 59 has a positioning protrusion 60 protruding from its end surface in a rear bowl shape. It is fitted into each positioning hole 61 formed on the outer periphery of the body 1R and sandwiched between the arm-like bodies 1p and 1R.

The inner peripheral bead 58 is fitted into the edge of the insertion hole 410 of the booster piston 5, but in the free state, the inner peripheral bead 58 has a front surface 5α of the booster piston 5 as shown by the chain line in FIG.
A series of bulges 58a that protrude inward from the sides and the insertion hole 41
is formed. When the retaining flange 45 of the valve cylinder 14 is clamped between the locking plate 50 and the booster piston 5 as described above, the retaining flange 45 moves the center of the fitting hole 41 as shown by the arrow. In the linear direction, the valve barrel 14 is strongly pressed radially outward of the fitting hole 41 as shown by arrow C by the taper 46 of the valve barrel 14, and is compressed into the annular recess 62 around the fitting hole 41, whereby the valve barrel 14 and The space between the booster pistons 5 is reliably sealed.

The pressure receiving part 63 of the piston diaphragm 6 is in close contact with the rear surface of the booster histone 5, and protrudes toward the first working chamber A between the outer peripheral surface of the booster piston 5 and the inner peripheral surface of the front bowl-shaped body 1F. It is bent into a U-shape, and the booster piston 5 is allowed to move forward and backward by shifting this U-shaped bent part.

1st. As shown in FIG. 5, an opening 64 is formed in the portion of the booster piston 5 where the locking pawl 43 is cut and raised, and a connection between the booster piston 5 and the piston diaphragm 6 is established through the opening 64. Since they are communicated with chamber A, no air pockets will be generated between them. Further, the portion of the piston diaphragm 6 facing the opening 64 is formed into a thick wall portion 65, whereby the atmosphere is introduced into the second working chamber B, and the air pressure in the second working chamber B is changed to the first working chamber A. Even if the height of the piston diaphragm 6 is higher than that of the piston diaphragm 6, the thick portion 65 will not bulge into the opening 64.
Damage caused by the opening 64 can be prevented.

Next, the connection structure between the tie rod 4 and the booster shell 1 will be explained.

As shown in FIG. 1, the tie rod 4 has a mounting bolt 66 that penetrates the front wall of the booster shell 1 and projects forward.
are integrally formed, and a spring receiving plate 61 that comes into contact with the inner surface of the front wall of the booster shell 1 is fixed. Then, the mounting bolt 66 is passed through the mounting flange 68 of the brake mask cylinder M stacked on the front surface of the booster shell 1, and a Nand 69 is screwed onto the tip of the bolt 66 and tightened.
The spring receiving plate 67, the front wall of the booster shell 1, and the enclosure of the flange 68 are integrally connected. At that time, bolt 66
An annular seal member 71 for sealing the tie rod through hole in the front wall of the booster shell 1 is fitted into an annular groove 70 formed on the front surface of the spring receiving plate 67 so as to surround the spring receiving plate 67 . The spring receiving plate 67 supports the fixed end of the return spring 12,
By making the tie rod 4 bear the elastic force of the return spring 12, the load on the booster shell 1 can be removed.

Furthermore, the tie rod 4 is integrally formed with a mounting bolt 72 that penetrates the rear wall of the booster shell 1 and projects rearward thereof, and a stepped flange 73 that abuts the inner surface of the rear wall of the booster shell 1. The step flange 73 is fitted into a support tube 74 that is welded and fixed to the inner surface of the rear wall of the booster shell 1, and its retaining ring 75 is locked to the support tube 74, so that the quirod 4 and the rear wall of the booster shell 1 are connected to each other. connected together. At that time, the annular groove 7 between the small diameter part of the stepped flange 73 and the support tube 74
6, an annular seal member 77 for sealing the tie rod through hole in the rear wall of the booster shell 1 is fitted.

The mounting bolt 72 is passed through the front wall W of the vehicle compartment, and a nut 78 is screwed onto the tip of the bolt 72 and tightened, thereby fixing the tie rod 4 to the front wall W of the single compartment.

(Then, the booster shell 1 is attached to the front wall W of the passenger compartment via the tie rod 4, and the brake mask sill M
are connected to the booster shell 1 via tie rods 4.

Next, a seal structure between the tie rod 4, booster piston 5, and piston diaphragm 6 will be explained.

The booster piston 5 has a first. As shown in FIG. 3, a pair of tie rod through holes 79 are formed between both reinforcing ribs 42, and a plurality of notches 80 (in the illustrated example, three) are formed at equal intervals on the circumference of the tie rod through holes 79. It is located in the corner. Further, the piston diaphragm 6 also has a through hole 8 corresponding to the through hole 79.
1 is formed.

A thick portion 82 is formed at the edge of each through hole 81 .

Third. As shown in FIG. 6, three locking pawls 84 corresponding to the notches 80 are provided at one end of the outer surface of the two seal combat barrels 83, and four tool locking claws are provided at the other end. A retaining flange 86 having a mating recess 85 is provided in a protruding manner. The top surface 84aVC of each locking pawl 84 has a fitting guide inclined surface 84b that slopes downward from the intermediate portion toward the end surface of the seal mounting tube 83, and the rising surface 84cK extends from the intermediate portion toward one end. A rotation guiding inclined surface 84d having a downward slope is formed.

The direction of inclination of the rotation guiding inclined surface 84d in each locking pawl 84 is the same.

The seal mounting cylinders 83 are assembled to the booster piston 5 before the valve cylinder 14 is assembled to the booster piston 5. are fitted into the respective notches 80 and inserted into the through holes 81° 79 of the piston diamond 77m 6 and the booster piston 5. In this case, the fitting guide inclined slope 846 of the top surface 84α of each locking pawl 84
This allows the seal mounting cylinder 83 to fit smoothly into the through hole 79 of the booster piston 5. And the 6th.
As shown in FIG.
into each tool engagement recess 85, and press the tool 87 by applying the receiver 90 to the front surface 5α of the booster piston 5 to compress the thick part 82 of the booster piston 5). Rotate in the direction of arrow d in Fig. 7.

As a result, each locking pawl 84 is misaligned with each notch 80, and the through hole 7 of the booster piston 5 and piston diaphragm 6 is located between the rising surface 84c of each locking pawl 84 and the retaining flange 86.
The edges 9 and 810 are clamped, and the space between the booster piston 5 and the seal mounting cylinder 83 is sealed. In this case, each locking pawl 84 smoothly enters the edge of the through hole 790 of the booster piston 5 due to the rotation guiding inclined surface 84d of the rising surface 84c of each locking pawl 84, and the aforementioned clamping is performed reliably.

Second. As shown in FIG. 3, the retaining flange 4 of the valve cylinder 14
5 includes adjacent locking claws 84 on both seal mounting tubes 83.
Notch 9 with a concave arc-shaped inner circumferential surface to match the outer circumferential surface between l-
2 is formed, and when the valve cylinder 14 is fitted into the insertion hole 41 of the booster piston 5 as described above and each notch 92 and each seal mounting cylinder 83 are fitted in a concave and convex manner, each notch 92 in the retaining flange 45 is formed. The locking claws 8 whose outer peripheral surfaces are adjacent to each other near both ends of the
4, and the valve cylinder 14 and the seal mounting cylinder 83 are mutually prevented from rotating. As another rotation preventing means, as shown in FIG. 8, a groove 93 which can be engaged with one locking pawl 84 may be formed in the notch 92 of the retaining flange 45 in the valve cylinder 14. good.

As shown in FIG. 1, the seal mounting tube 83 and tie rod 4
A sealing means is provided between them to allow the booster piston 5 to operate. The sealing means is composed of a bellows-shaped telescopic boot 94 made of an elastic material such as rubber, and the boot 94 surrounds the tie rod 4 in the I1 working chamber A, and the front end 94a is inserted into the annular groove 95 of the tie rod 4. Further, the rear ends 94h are fitted into the openings of the seal barrel 83, respectively.

In the vehicle interior, at the rear end of the input rod 17 of the booster S, there is a brake pedal 98 that is pivotally supported 97 on a fixed bracket 96.
are connected via a connecting fitting 99. 100 is a return spring that biases the brake pedal 98 rearward.

The rear end of the cylinder body 101 of the brake mask cylinder A/ penetrates the front wall of the booster shell 1 and protrudes into the first working chamber A, and a booster is installed at the rear end of the working piston 102 in the cylinder body 101. 5 output rods 34 are facing each other.

Next, to explain the operation of this embodiment, the state shown in FIG. The valve piston 18 is returned to the predetermined retracted position where it abuts the valve body 10 and is held by the spring force of the buff 37, and the valve piston 18 presses the front surface of the valve portion 23 via the second valve seat 16□ to push it against the valve body. The front surface of the holding cylinder 21 is moved back until it comes into contact with the front surface of the holding cylinder 21, thereby forming a slight gap g between the first valve seat 16° and the valve portion 23. can be easily obtained by adjustment.

As described above, during engine operation, the first working chamber A, which always stores negative pressure, communicates with the second working chamber B through the through hole 26, the gap y, and the through hole 27, and also through the front opening of the valve part 23. is closed by the second valve seat 162, the negative pressure in the first working chamber A is transmitted to the second working chamber B, and the air pressures in both working chambers A and H are balanced.

Therefore, the booster piston 5 also occupies the illustrated retracted position by the elastic force of the return spring 12.

Now, step on the brake pedal 98 to brake the vehicle,
When the input rod 17 and the valve piston 18 are moved forward, the valve portion 23, which is urged forward by the valve spring 25, is moved forward by the valve piston 1.
8, but since the gap [of the flute 1 light enemy 1 ile-) valve part 3> is extremely narrow as mentioned above, the valve part 23
Immediately remove the first valve seat 16. The second valve seat 16□ separates from the valve portion 23 and introduces the atmosphere through the through hole 27 and the inside of the valve body 19. It communicates with the port 11. Therefore, the atmosphere is quickly introduced into the second working room BK, and the classroom B is transferred to the first working room A.
The booster piston 5 moves forward against the return spring 12 due to the pressure difference created between the two chambers A and B, and moves the output rod 34 forward via the elastic piston 30.
The actuating piston 102 of the Plagimaster Schilling M is driven forward, and the vehicle is braked.

When the operating piston 102 is driven, the cylinder body 10
A forward thrust load is applied to the vehicle body 1, and this load is transmitted to and supported by the vehicle body, that is, the single-chamber front wall W, via the tie rod 4. Therefore, the above load does not act on the booster shell 1.

On the other hand, when the small shaft 33 of the valve hist/18 comes into contact with the elastic piston 30 via the reaction piston 32 due to its advancement,
Due to the bulging deformation of the elastic piston 30 toward the reaction piston 32 side due to the actuation reaction force of the output rod 34, a part of the reaction force is fed banked to the brake pedal 98 side via the valve piston 18, so that the operator can output The output of the rod 34, that is, the braking force can be sensed.

Next, when the depression force on the brake pedal 98 is released, the reaction force applied to the valve piston 18 and the return spring 37 are
The input rod 17 retreats due to the elastic force of , thereby seating the second valve seat 162 on the valve portion 23 and bringing the valve portion 23 into contact with the front surface of the valve body holding cylinder 21. Compressive deformation occurs in the axial direction due to the backward force of the rod 17.

As a result, a gap larger than the initial gap is formed between the first valve seat 161 and the valve part 23, so that the air pressures in both working chambers A and H can quickly become equal to each other through this small gap. , when the pressure difference between them disappears, the booster piston 5 moves backward by the elastic force of the return spring 12, and the protrusion 13 of the piston diaphragm 6 comes into contact with the inner surface of the rear wall of the booster shell 1 and stops. Then, when the input rod 17 comes into contact with the end wall 10, the valve part 23 is released from the retreating force of the input rod 17 and returns to its original shape, so that the gap with the first valve seat 161 is narrowed to the small gap I again. Can be fitted.

As described above, according to the present invention, since the booster piston is formed from a steel plate, its cost can be reduced, and the locking plate, the arcuate reinforcing lip, and the locking pawl cut and raised on the booster piston cooperate with each other. This makes it possible to assemble the valve cylinder to the booster piston extremely easily and accurately, and the valve cylinder can be commonly used in boosters having different pole specific force characteristics, improving economic efficiency. can. Furthermore, even if a plurality of locking claws are cut and raised on the booster piston, the rigidity of the booster piston is not impaired because the vicinity of the opening formed by the cut and raised portion is reinforced by the reinforcing ribs.

[Brief explanation of drawings]

1 to 7 show one embodiment of the present invention.
The figure is a longitudinal sectional front view of the whole, and corresponds to the case taken along the line I-I in Figure 2. Figure 2 is a side view showing the attachment relationship of the valve cylinder, locking plate, and seal mounting cylinder to the booster piston, and
The diagram shows the booster piston, piston diaphragm, valve cylinder,
An exploded perspective view of the locking plate and the seal tube, FIG. 4 is a side view showing how the valve cylinder is assembled to the booster piston, and FIG. 5 is a partially enlarged longitudinal sectional front view showing the seal structure of the booster piston and the valve cylinder. , Fig. 6 is a perspective view showing the relationship between the seal mounting cylinder and the tool, Fig. 7 is the booster screw + -, yy -h
w -t -t -/ ++, +J'n I=+ '#
n)ffo h+Irtoshishin;; -r mfFF
Figure 8 is a partial side view of a modified example showing the relationship between the valve cylinder and the seal mounting cylinder. A, B... 1st. 2nd working chamber, 1... booster shell, 5... booster piston,
8... Control valve, 14... Valve cylinder, 41... Fitting hole,
42... Reinforcement rib, 43... Locking claw, 45... Retaining flange, 50... Locking plate patent applicant Nissin Kogyo Co., Ltd.

Claims (1)

[Claims] Inside the booster shell, a first working chamber at the front part is always in communication with a negative pressure source by a booster piston that can freely reciprocate back and forth, and a rear part is controlled by being alternately communicated with the first working chamber or the atmosphere through a control valve. In the negative pressure booster, the booster piston is divided into a second working chamber, and the booster piston is provided with a valve cylinder that accommodates the control valve. a plurality of locking claws located around the fitting hole and cut and raised toward the first working chamber; and further a plurality of locking claws located between the locking claws and the fitting hole, An arcuate reinforcing lip protruding toward the first working chamber is provided, and the valve barrel is fitted into the fitting hole from the first working chamber side, and the retaining flange of the valve barrel is inserted into the reinforcing lip inside the reinforcing lip. The retaining flange is clamped between the retaining plate and the booster piston by overlapping the booster piston and rotating the retaining plate using the reinforcing lip as a guide to engage the retaining pawl. Features a negative pressure booster.