JPS6344103B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a booster shell of a negative pressure booster on the front surface of the front wall of the vehicle compartment, and a cylinder body of a master cylinder operated by the booster on the front of the booster shell. The present invention relates to a master cylinder mounting device for a vehicle in which each is installed.

Generally, the master cylinder is configured to be attached to the front wall of the vehicle interior via a booster shell, and in such a configuration, if the booster shell is insufficiently rigid, it may cause damage while the vehicle is running. As the master cylinder vibrates vertically and horizontally, the booster shell flexes and violently vibrates vertically and horizontally, causing bubbles that can cause a vapor lock phenomenon in the hydraulic oil stored in the master cylinder reservoir. There is also a risk of hydraulic oil leaking from the reservoir cap's vent hole. In order to avoid such inconveniences, the booster shell has conventionally been made of a light alloy casting such as aluminum alloy or a relatively thick steel plate to maintain the rigidity of the booster shell. The problem is that it becomes quite heavy.

The present invention has been proposed in view of the above, and even if the booster shell is formed to be lightweight and thin, vibrations in the vertical and horizontal directions of the master cylinder can be effectively suppressed. An object of the present invention is to provide a master cylinder mounting device for a vehicle, which is prevented from being deformed by the elastic force of a return spring, negative pressure in a booster shell, etc.

In order to achieve this purpose, the present invention
A booster shell of a negative pressure booster is disposed in front of the front wall of the vehicle compartment, and a cylinder body of a master cylinder operated by the booster is disposed in front of the booster shell. The booster piston is housed so as to be able to reciprocate back and forth, and a negative pressure chamber is defined in front of the booster piston, and the negative pressure chamber houses a return spring that springs the booster piston in the backward direction. In the booster shell, a pair of tie rods extending parallel to the center line are passed through both the front and rear walls of the booster shell, sandwiching the center line of the booster shell and at intervals vertically and horizontally, and each tie rod includes: A spring receiving plate is fixed to the inner surface of the front wall of the booster shell and supports the fixed end of the return spring, and a mounting flange of the cylinder body is superimposed on the outer surface of the front wall of the booster shell. and the front wall of the booster shell is integrally sandwiched between the spring receiving plate and a nut screwed onto the front end of the tie rod, and the rear end of the tie rod is fixed to the front wall of the vehicle compartment. The tie rod, the mounting flange, the spring receiving plate, and the front wall of the vehicle compartment form a rectangular rigid frame that extends in the front-rear and diagonal up-down directions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a brake master cylinder mounting device will be described below with reference to the drawings.

The booster shell 1 of the negative pressure booster S consists of a pair of front and rear bowl-shaped bodies 1F and 1R molded from a lightweight thin-walled steel plate or synthetic resin;
A plurality of claw pieces 1a protruding from the opening of R at equal intervals on the circumference are engaged with a plurality of notches 1b formed at an opening of the front bowl-shaped body 1F at equal intervals on the circumference. The two bowl-shaped bodies 1F, 1R are positioned relative to each other, and the two bowl-shaped bodies 1F, 1R are connected via two tie rods 30 between their front and rear opposing walls. The connection structure between the booster shell 1 and the tie rod 30 will be described later.

A booster piston 2 is housed inside the booster shell 1 so as to be able to reciprocate back and forth, and an annular groove 61 is formed in the rear surface of the booster piston 2.

Annular beads 3a and 3b are formed on the outer and inner peripheries of the piston diaphragm 3, respectively, and the annular beads 3a on the outer periphery have two positioning holes protruding from the end surface thereof at equal intervals on the circumference. Protrusion 3
c into each positioning hole 1c formed on the outer periphery of the rear bowl-shaped body 1R, and both bowl-shaped bodies 1F, 1R are assembled.
It is clamped by. The annular bead 3b on the inner circumference is fitted into the annular groove 61 of the booster piston 3, and the piston diaphragm 3 and the booster piston 2 allow the inside of the booster shell 1 to
It is divided into a working chamber A and a second working chamber B at the rear.

The pressure receiving portion 3d of the piston diaphragm 3 is in close contact with the rear surface of the booster piston 2 and protrudes toward the first working chamber A between the outer circumferential surface of the booster piston 2 and the inner circumferential surface of the front bowl-shaped body 1F. U
The U-shaped bent portion allows the booster piston 2 to move forward and backward by rolling.

A notch 65 is provided in the rear wall 61a of the annular groove 61 of the booster piston 2, and a portion of the inner circumferential annular bead 3b of the piston diaphragm 3 facing the notch 65 is formed into a thin wall portion 63, which is connected to the booster piston. 2, so that they can be separated freely. Further, a channel-shaped positioning projecting wall 64 is integrally raised from the peripheral edge of the thin portion 63, and this projecting wall 64 is engaged with the notch 65. This engagement restricts relative rotation between the booster piston 2 and the diaphragm 3.

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 a negative pressure introduction pipe 4, and the second working chamber B is connected to a control valve 5, which will be described later.
The air inlet port 6 is alternately connected to the first working chamber A or to the air inlet 6 which opens in the end wall 1e of the rear extension tube 1d of the booster shell 1 through the opening. Thus, the first working chamber A constitutes the negative pressure chamber of the present invention.

The booster piston 2 is always urged in the backward direction, that is, toward the second working chamber B, by a return spring 7 contracted in the first working chamber A, and its backward limit is reached by a protrusion 3e formed protrudingly 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 booster shell 1.

The booster piston 2 is integrally formed with a valve cylinder 8 projecting in the axial direction from the rear surface of its central portion, and is slidably supported on a flat bearing 9 provided in the extension cylinder 1d, and its rear end is connected to the atmosphere. It opens toward the introduction port 6.

The control valve 5 is configured in the valve cylinder 8 as follows. That is, an annular first valve seat 1 is provided on the front inner wall of the valve cylinder 8.
0 ₁ , and at the front of the valve cylinder 8 is a valve piston 12 connected to the input rod 11 and forming its front end.
are slid together to form an annular second valve seat 10 ₂ surrounded by the first valve seat 10 ₁ at the rear end of the valve piston 12 .

A base end 13a of a cylindrical valve element 13 with both ends open is clamped to the inner wall of the valve cylinder 8 via a valve element holding cylinder 14 fitted into the valve cylinder 8. This valve body 13 is made of an elastic material such as rubber, and its base end 1
A thin-walled diaphragm 13b extends radially inward from 3a, and a thick-walled valve portion 13c is connected to the inner peripheral end of the thin-walled diaphragm _13b . Facing ₂ . Thus, the valve portion 13c can move back and forth by deforming the diaphragm 13b, and can also come into contact with the front end surface of the valve body holding cylinder 14.

An annular reinforcing plate 15 is embedded in the valve portion 13c, and a valve spring 16 acts on the annular reinforcing plate 15 to bias the valve portion 13c toward both valve seats 10 ₁ and 10 ₂ .

The outer part of the first valve seat ₁₀₁ is the booster piston 2
into the first working chamber A through a through hole 17, and an intermediate portion between the first and second valve seats 10 ₁ and 10 ₂ through another through hole 1
8 to the second working chamber B, and the second valve seat 10 ₂
The inner parts of the valve body 13 are in constant communication with the atmospheric air inlet 6 through the inside of the valve body 13.

The booster piston 2 is provided with a large diameter hole 19 that opens at the center of its front surface, and a small diameter hole 20 that opens at the inner end surface of the large diameter hole 19.
An elastic piston 21 made of rubber or the like and an output piston 22 of the same diameter are sequentially inserted into the small diameter hole 20, and a reaction piston 23 with a smaller diameter than the elastic piston 21 is slid into the small diameter hole 20.
0, the small shaft 12a protruding from the front end surface of the valve piston 21 is inserted to face the rear end surface of the reaction piston 23. The output piston 22 integrally has an output rod 22a that projects forward.

The input rod 11 is always urged in the backward direction by the return spring 24, and its retraction limit is determined by the movable stopper plate 25 screwed onto the input rod 11 when the rear extension tube 1d
It is regulated by contacting the inner side of the end wall 1e. If the movable stopper plate 25 is rotated, the screwing position between it and the input rod 11 changes, so that the retraction limit of the input rod 11 can be adjusted back and forth. After the adjustment, the movable stopper plate 25 is fixed by tightening a lock nut 26 which is also screwed onto the input rod 11. A ventilation hole 27 is bored in the movable stopper plate 25 so as not to block the air inlet 6.

Filters 28 and 29 are attached to the outer end opening of the valve cylinder 8 to purify the air introduced from the atmosphere inlet 6 and to be deformable so as not to interfere with the operation of the input rod 11.

Next, the connection structure between the tie rod 30 and the booster shell 1 will be explained.

A mounting bolt 33 that penetrates the front wall of the booster shell 1 and projects forward thereof is integrally formed on the tie rod 30, and a spring receiving plate 34 that overlaps the inner surface of the front wall of the booster shell 1 is fixed. The mounting bolt 33 is passed through the mounting flange 36 of the brake master cylinder M superimposed on the outer surface of the front wall of the booster shell 1, and the nut 35 is screwed onto the tip of the bolt 33 and tightened.
The front wall of the booster shell 1 and the mounting flange 36 are integrally sandwiched between the tie rod 3 and the tie rod 3.
0, the front wall of the booster shell 1, the spring receiving plate 34, and the mounting plate 36 are integrally connected. that time,
An annular seal member 38 for sealing the tie rod through hole in the front wall of the booster shell 1 is fitted into an annular groove 37 formed on the front surface of the spring receiving plate 34 so as to surround the bolt 33. The spring support plate 34 supports the fixed end of the return spring 7, and allows the tie rod 30 to bear the elastic force of the return spring 7, thereby removing the load on the booster shell 1.

Furthermore, the tie rod 30 is integrally formed with a mounting bolt 39 that penetrates through the rear wall of the booster shell 1 and projects rearward thereof, and a stepped flange 41 that abuts the inner surface of the rear wall of the booster shell 1. The stepped flange 41 is fitted into the support tube 43 that is welded and fixed to the inner surface of the rear wall, and its retaining ring 42 is locked to the support tube 43, thereby integrating the tie rod 30 and the rear wall of the booster shell 1. Connect to. At that time, the small diameter part of the stepped flange 41 and the support tube 4
An annular seal member 45 for sealing the tie rod through hole in the rear wall of the booster shell 1 is fitted into the annular groove 44 between the booster shells 1 and 3.

The mounting bolt 39 is inserted into the front wall W of the vehicle compartment, and a nut 40 is screwed onto the tip of the bolt 39 and tightened to attach the tie rod 30 to the front wall W of the vehicle compartment.
sticks to.

Thus, the booster shell 1 is attached to the front wall W of the passenger compartment via the tie rod 30, and the brake master cylinder M is connected to the booster shell 1 via the tie rod 30.

A pair of tie rods 30 are arranged so as to sandwich the center line of the booster shell 1, that is, the axis of the input rod 11, and extend parallel to the center line at predetermined intervals vertically and horizontally. A rigid frame in the form of a rectangle extending in the front-rear and diagonal up-down directions has the tie rods 30, 30 as one opposing side and the front wall W of the vehicle interior and the mounting flange 36 of the brake master cylinder M as the other opposing side. configured. Further, a pair of bolts 66 exclusively for attachment to the front wall W of the vehicle interior are welded to the rear wall of the booster shell 1, facing the tie rods 30, 30, and spaced apart from each other by a predetermined distance in the vertical and horizontal directions. It will be fixed. In the illustrated example, the distance a between the shafts of both tie rods 30, 30 in the vertical direction is set to be longer than the distance b between the shafts in the left and right direction.

Booster piston 2 penetrated by tie rod 30
In order to seal the through hole 31 so as not to interfere with the operation of the piston 2, a sealing means is provided between the booster piston 2 and the tie rod 30. The sealing means is constituted by a bellows-shaped retractable boot 46 made of an elastic material such as rubber, and the boot 46 surrounds the tie rod 30 in the first working chamber A, and the front end 46a is formed on the outer peripheral surface of the tie rod 30. The rear end 46b is fitted into the annular groove 47 and the through hole 31, respectively.

In the vehicle interior, a brake pedal 52, which is pivoted 51 on a fixed bracket 50, is connected to the rear end of the input rod 11 of the booster S via a connecting fitting 53. 54 is a return spring that biases the brake pedal 52 rearward.

Cylinder body 55 of brake master cylinder M
The rear end penetrates the front wall of the booster shell 1 and enters the first working chamber A, and the cylinder body 5
The output rod 22a of the booster S is opposed to the rear end of the operating piston 56 in the booster S.

Next, to explain the operation of this embodiment, the illustrated state shows the non-operating state of the booster.
The valve piston 12, the input rod 11, and the brake pedal 52, which are connected to each other, are returned to a predetermined retracted position where the movable stopper plate 25 abuts the fixed end wall 1e, and are held by the spring force of the spring 24, and the valve piston 12 is held by the spring force of the spring 24. The front face of the valve part 13c is pressed through the second valve seat ₁₀₂ , and the front face of the valve part 13c is pushed back until it lightly contacts the front face of the valve body holding cylinder 14.
A slight gap g is formed between the valve seat ₁₀₁ and the valve portion 13c. Such a state can be easily obtained by adjusting the movable stopper plate 25 described above.

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 17, the gap g, and the through hole 18, and also through the front opening of the valve portion 13c. is closed by the second valve seat ₁₀₂ , 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 B are balanced. Therefore, the booster piston 2 also returns to the spring 7.
occupies the illustrated retracted position with a resilient force of .

Now, if the brake pedal 52 is depressed to brake the vehicle and the input rod 11 and the valve piston 12 are moved forward, the valve portion 13c, which is urged forward by the valve spring 16, will move forward following the valve piston 12. Since the gap g between the first valve seat 10 ₁ and the valve part 13c is extremely narrow as described above, the valve part 13c immediately seats on the first valve seat 10 ₁ to establish communication between the working chambers A and B. At the same time, the second valve seat ₁₀₂ is closed to the valve part 13.
The second working chamber B is communicated with the atmosphere inlet 6 through the through hole 18 and the inside of the valve body 13, apart from the second working chamber B. Therefore, the atmosphere is quickly introduced into the second working chamber B, and the pressure in this chamber B becomes higher than that in the first working chamber A, and the pressure difference between the two chambers A and B causes the booster piston 2 to resist the return spring 7. Since the output rod 22a is moved forward via the elastic piston 21,
The actuating piston 56 of the brake master cylinder M is driven forward, and the vehicle is braked. In this case, the line segment connecting the axes of both tie rods 30, 30 corresponds to vibrations of the brake master cylinder M in the vertical and horizontal directions with a predetermined inclination angle.
In other words, both tie rods 30, 30 work together to resist vibrations in the vertical and horizontal directions, and as a result, vibrations in the vertical and horizontal directions of the brake master cylinder M are suppressed, so that the hydraulic fluid in the reservoir is reduced. There is no air bubbles that can cause a vapor lock phenomenon, and there is no leakage of hydraulic oil from the reservoir cap ventilation holes, and the braking action is performed reliably. Furthermore, while a running vehicle generally vibrates more strongly in the vertical direction than in the horizontal direction, each vibration in the vertical and horizontal directions can be rationally dealt with due to the relation between the axes a>b of the tie rods 30, 30. be able to. Further, due to the pressure difference generated between the two working chambers A and B, the thin wall portion 63 of the annular bead 3b tightly contacts the booster piston 2, so that the working chambers A and B are reliably isolated.

When the actuating piston 56 is driven, a forward thrust load is applied to the cylinder body 55, and this load is transmitted to the vehicle body, that is, the front wall W of the vehicle interior, through the tie rod 30 and is supported. Therefore, the above-mentioned load does not act on the booster shell 1.

On the other hand, due to its advancement, the small shaft 12a of the valve piston 12 passes through the reaction piston 23 to the elastic piston 2.
1, a part of the reaction force is fed back to the brake pedal 52 side via the valve piston 12 due to the bulging deformation of the elastic piston 21 toward the reaction piston 23 side due to the actuation reaction force of the output rod 22a. This allows the driver to sense the output of the output rod 22a, that is, the braking force.

Next, when the depressing force of the brake pedal 52 is released, the input rod 11 is moved backward due to the reaction force applied to the valve piston 12 and the elastic force of the return spring 24, which causes the second valve seat 10 ₂ to move toward the valve portion 13c. and seat the valve portion 13c in the valve body holding cylinder 14.
The valve part 13c is brought into contact with the front surface of the input rod 1.
Compressive deformation occurs in the axial direction due to the retreating force of 1.
As a result, a gap larger than the initial gap g is formed between the first valve seat 10 ₁ and the valve part 13c, so that the air pressures in both working chambers A and B are quickly balanced with each other through this large gap. When the pressure difference between them disappears, the booster piston 2 moves back due to the elastic force of the return spring 7, and the protrusion 3 of the piston diaphragm 3
e comes into contact with the inner surface of the rear wall of the booster shell 1 and stops. Then, when the input rod 11 comes into contact with the end wall 1e, the valve part 13c is released from the retreating force of the input rod 11 and returns to its original shape, so that the gap with the first valve seat ₁₀₁ is reduced to the small gap g again. It can be narrowed down.

If the brake pedal 52 is depressed and the booster piston 2 is moved forward with no negative pressure stored in the first working chamber A, the air in the first working chamber A will flow sufficiently toward the intake manifold due to pipe resistance, etc. Since the residual air in the first working chamber A is compressed, if the pressure in the first working chamber A becomes higher than that in the second working chamber B, part of the residual air in the first working chamber A is compressed. portion enters between the rear surface of the booster piston 2 and the front surface of the piston diaphragm pressure receiving portion 3d and presses the thin wall portion 63 rearward, so that the booster piston 2
A gap is formed between the thin wall portion 63 and the thin wall portion 63, and the working chambers A and B communicate with each other through the gap. Therefore, the air pressures in both the working chambers A and B are quickly balanced through the above-mentioned gap, so that problems such as excessive rearward pressing force acting on the piston diaphragm 3 and causing it to bulge rearward are prevented. Prevented. When the above-mentioned pressure difference disappears, the thin wall portion 63 comes into close contact with the booster piston 2 again.

As described above, according to the present invention, the booster shell of the negative pressure booster is mounted on the front surface of the front wall of the vehicle compartment, and the cylinder body of the master cylinder operated by the booster is mounted on the front of the booster shell. A booster piston is housed inside the booster shell so as to be able to move back and forth, and a negative pressure chamber is defined in front of the booster piston, and the booster piston is housed in the negative pressure chamber. A pair of tie rods that house a return spring that springs in the backward direction, and extend parallel to the center line of the booster shell on both the front and rear walls of the booster shell, sandwiching the center line of the booster shell and spaced apart from each other vertically and horizontally. A spring support plate is fixed to each of the tie rods, which overlaps the inner surface of the front wall of the booster shell and supports the fixed end of the return spring, and the cylinder body is fixed to the outer surface of the front wall of the booster shell. The mounting flanges and the front wall of the booster shell are integrally sandwiched between the spring receiving plate and a nut screwed onto the front end of the tie rod, and the rear end of the tie rod is The tie rod, the mounting flange, the spring receiving plate, and the front wall of the vehicle compartment form a rectangular rigid frame extending in the front and rear and diagonally vertical directions, so that vibrations caused by running the vehicle can be avoided. Even if the master cylinder tries to vibrate violently in the vertical and horizontal directions, each vibration is effectively absorbed by the cooperation of a pair of tie rods that are firmly supported on the front wall of the passenger compartment and are spaced apart in the vertical and horizontal directions. As a result, it is possible to prevent inconveniences associated with the above-mentioned vibration of the master cylinder, such as the generation of bubbles from the oil stored in the reservoir and the leakage of the stored oil from the vent hole of the reservoir cap. On top of that,
There is no need to make the booster shell itself particularly highly rigid in order to prevent vibrations of the master cylinder, and this can contribute to making the booster shell lighter and smaller.

In particular, the spring receiving plate, which is fixed to each tie rod, overlaps the inner surface of the front wall of the booster shell, and supports the fixed end of the return spring of the booster piston, supports the front wall of the booster shell which is strongly pressed rearward as the nut is tightened. It functions as a ``shell front wall support member'' that allows the tie rod to receive pressure easily with a wide pressure receiving area, and as a ``spring receiving member'' that allows the tie rod to directly receive the strong elastic force of the return spring without going through the booster shell. It is possible to simultaneously achieve these functions and contribute to the simplification of the structure, and it is also possible to freely select the optimal rigid material to fulfill these functions, regardless of the material of the booster shell. This can also contribute to increasing the rigidity of the front wall of the booster shell itself, and as a result, even if the booster shell itself is made of synthetic resin or a thin metal plate, the front wall of the shell will not absorb the tightening force of the nut. There is no risk of deformation or damage due to the elastic force of the return spring, the large negative pressure in the negative pressure chamber, etc., and the booster shell can be further reduced in weight and size.

[Brief explanation of the drawing]

The drawings show one embodiment of the device of the present invention, in which Fig. 1 is a side view, Fig. 2 is a rear view, Fig. 3 is a cross-sectional view taken along the line shown in Fig. 2, and Fig. 4 is a sectional view taken along the line shown in Fig. 3. figure,
FIG. 5 is a partial perspective view of the piston diaphragm. A...First working chamber as a negative pressure chamber, M...Brake master cylinder as a master cylinder, S
...Negative pressure booster, W...Front wall of passenger compartment, 1...
Booster shell, 2... Booster piston, 7...
...Return spring, 30...Tie rod, 34...Spring receiving plate, 35...Nut, 36...Mounting flange,
55... Cylinder body.

Claims (1)

[Claims] 1. A booster shell of a negative pressure booster is mounted on the front of the front wall of the vehicle compartment, and on the front of the booster shell,
A cylinder body of a master cylinder operated by the booster is provided, and a booster piston is accommodated in the booster shell so as to be able to move back and forth, and a negative pressure chamber is defined in front of the booster piston. The negative pressure chamber accommodates a return spring that urges the booster piston in the backward direction, and the booster shell is provided with springs on both the front and rear walls of the booster shell, on both sides of the center line of the booster shell, and in the upper and lower and left and right directions. A pair of tie rods extending parallel to the center line at intervals are passed through the tie rod, and a spring receiving plate is fixed to each of the tie rods, overlapping the inner surface of the front wall of the booster shell and supporting the fixed end of the return spring. Further, a mounting flange of the cylinder body is superimposed on the outer surface of the front wall of the booster shell, and the mounting flange and the front wall of the booster shell are interposed between the spring receiving plate and a nut screwed onto the front end of the tie rod. At the same time, the rear end of the tie rod is fixed to the front wall of the vehicle compartment, and a rectangular shape extending in the front and rear and diagonally vertical directions is formed by the tie rod, the mounting flange, the spring receiving plate, and the front wall of the vehicle compartment. A master cylinder mounting device for a vehicle comprising a rigid frame. 2. In the device described in claim 1, the distance between the axes of both tie rods in the vertical direction is
A master cylinder mounting device in a vehicle that is set to be longer than the distance between the shafts in the left and right direction.