JPH032452Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention and Field of Application] The present invention relates to a tandem booster for vehicles used as a brake booster for vehicles such as automobiles.

[Prior art]

For example, the tandem type booster for vehicles is
As described in Japanese Patent No. 21833 and shown in FIG. 2, a pair of front shells 12 and rear shells 13
A front constant pressure chamber 17, a front variable pressure chamber 18, and a rear constant pressure chamber are formed by a fixed wall 14, a front movable wall 15, and a rear movable wall 16 disposed before and after the fixed wall 14. 1
The front constant pressure chamber 17 and the rear constant pressure chamber 19 are connected to the intake manifold of the engine, which is a negative pressure source, and are connected to the pedal 22 by an input rod 21. A control valve mechanism 23 that selectively communicates the rear variable pressure chamber 20 with the front constant pressure chamber 17 and the rear constant pressure chamber 19 and the atmosphere, and a front movable wall 15.
The forward force of the rear movable wall 16 is transferred to the front shell 1.
Piston 25 of master cylinder 24 coupled to 2
and a reaction mechanism 26 that transmits part of the reaction force from the piston 25 to the control valve mechanism 23. The control valve mechanism 23 includes a plunger 27 connected to the front end of the input rod 21, an air seat 27a formed at the rear end of the plunger 27, a vacuum seat 28a formed at the hub 28 of the rear movable wall 16, and a vacuum seat 28a formed at the hub 28 of the rear movable wall 16. It consists of a poppet valve 29 whose front end faces the seats 27a and 28a.
The reaction mechanism 26 consists of an output rod 30 and a reaction disk 31 made of rubber.

By the way, in the conventional device shown in FIG. 2, the hub 32 of the front movable wall 15 is threadedly engaged with the hub 28 of the rear movable wall 16 at its rear end, so that both hubs 2
8 and 32 are integrated, and both movable walls 1
The back and forth movement of 5 and 16 is caused by the rear shell 13 and the fixed wall 1.
It is guided by 4. Further, the rear end of the output rod 30 is slidable in the inner hole of the hub 32, but is fitted in such a manner that it does not tilt.

[Problems with conventional technology and their technical analysis]

The master cylinder 24 and the front shell 12 are generally connected by bolts, and accurate concentricity between the master cylinder 24 and the output rod 30 cannot be expected. This master cylinder 2
4 and the output rod 30 exerts a prying force on the output rod 30 that tends to tilt the output rod 30 when the booster is activated. This prying force is transmitted from the output rod 30 to both hubs 28, 32, and is applied to the rear shell 13 and fixed wall 14 that guide them. Through the transmission of prying force from the hubs 28, 32 to the rear shell 13 and fixed wall 14, the guided surfaces of the hubs 28, 32, the rear shell 13,
The guide surface of the fixed wall 14 may be damaged, the sliding resistance may become abnormally large, or the hubs 28, 32 and rear shell 1 may be damaged.
3. There is a problem in that the sealing members 33 and 34 that seal the sliding parts with the fixed wall 14 are damaged.

[Technical issues]

Therefore, in the present invention, when a prying force is applied to the output rod to tilt it, this prying force guides the back and forth movement of both movable walls.
Avoid joining the guide part of the fixed wall.
This is a technical issue.

[Technical means]

The technical means taken to solve the above technical problem is to guide the back and forth movement of the rear movable wall by a rear shell and a fixed wall, and to incorporate a control valve mechanism into this rear movable wall, so that the front movable wall can be moved to the rear. The front movable wall is capable of tilting but is brought into contact with and supported so as not to move in the radial direction of the booster, and a recoil mechanism is built into the front movable wall.

[Effect of technical means]

The above technical means works as follows. That is, the prying force applied to the output rod of the reaction mechanism is transmitted from the output rod to the front movable wall, but the rear movable wall is guided by the rear shell and the fixed wall, and the front movable wall is tiltably supported by the rear movable wall. Because of this, the tilting of the front movable wall eliminates the transmission of prying force to the rear movable wall. Therefore, scratches on the guided surface of the movable wall and the guide surfaces of the rear shell and fixed wall are eliminated, and the sliding resistance of the movable wall becomes abnormally large, and the sliding parts between the movable wall, the rear shell, and the fixed wall are prevented. This solves the problem of damage to the sealing member.

[Special effects produced by the present invention]

The present invention produces the following unique effects. In other words, in the conventional model, the front movable wall and the rear movable wall are integrally connected, so when assembling the booster, the front movable wall, rear movable wall, and fixed wall are assembled into a subassembly. , this subassembly and both shells will be assembled. However, creating such a subassembly increases the number of steps required to assemble the booster and increases manufacturing costs. In contrast, in the present invention, the front movable wall and the rear movable wall are not integrally connected, but are made in contact with each other so that they can be separated, so when assembling the booster, parts close to one shell The above sub-assembly process can be omitted and manufacturing costs can be lowered than in the past.

〔Example〕

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

In FIG. 1, 10 is the entire tandem booster, 11 is the housing, 12 is the front shell,
13 is the rear shell. These shells 12,1
3 is made of steel plate, and the front shell 12
The plate thickness of the rear shell 13 is smaller than that of the rear shell 13.
The fixed wall 14 consists of a front member 14a made of a steel plate welded to the inner surface of the front end wall of the front shell 12, and a rear member 14b made of a steel plate fitted into and coupled to the rear end opening of the front member 14a. . The front member 14a also functions as a reinforcing member that disperses the load applied from the master cylinder mounting bolt 35 to the front end wall portion of the front shell 12.
The inside of the fixed wall 14 is divided into a front constant pressure chamber 17 and a front variable pressure chamber 18 by a front movable wall 15 comprising a pressure plate 36 made of a steel plate and a diaphragm 37 made of rubber. The space between the housing 11 and the fixed wall 14 is defined by a rear movable wall 16 made of a hub 28 made of resin, a pressure plate 38 made of steel plate, and a diaphragm 39 made of rubber.
It is divided into a rear constant pressure chamber 19 and a rear variable pressure chamber 20.

The hub 28 of the rear movable wall 16 has a large diameter portion 28b that passes through the rear member 14b of the fixed wall 14 in an airtight and slidable manner, and a small diameter portion 28c that passes through the rear shell 13 in an airtight and slidable manner. 33 and 34 are seal members, and 40 and 41 are guide bearing members made of resin. The longitudinal momentum of the plunger 27 of the control valve mechanism incorporated in the center hole 28d of the hub 28 with respect to the hub 28 is determined by the plunger 27 inserted into the radial hole 28e of the hub 28 and the forked portion of the inner end of the plunger 27 being inserted into the circumferential groove 27b of the plunger 27. is limited by a key member 42 that engages. The key member 42 is prevented from coming off from the radial hole 28e by the inner periphery of the diaphragm 39, and the rear movable wall 16 is prevented from retreating from the radial hole 28e.
The front wall surface of e is in contact with the front surface of the key member 42, and the rear surface of the key member 42 is baked on the rubber 43.
It is restricted by coming into contact with the inner surface 13a of the rear shell 13 via the inner surface 13a of the rear shell 13. When the rear movable wall 16 is in its retreated position, the air seat 27a of the plunger 27 and the vacuum seat 28a of the hub 28 occupy the same position in the booster axial direction, and the poppet valve 29 contacts both seats 27a and 28a. Alternatively, the vacuum seat 28a is located slightly rearward of the air seat 27a so that the poppet valve 29 contacts the air seat 27a and forms a slight gap between the poppet valve 29 and the vacuum seat 28a. . 44 is a spring that biases the poppet valve 29 forward, and 45 is a spring that biases the input rod 2 when the pedal 22 is released.
1 and the plunger 27 until their retraction with respect to the hub 28 is restricted by the key member 43. When the pedal 22 is depressed, the poppet valve 29 comes into contact with the vacuum seat 28a, cutting off communication between the hole 28f of the hub 28 and the chamber 46 on the rear outer circumference of the plunger 27, and the air seat 27a is separated from the poppet valve 29. The chamber 46 is the inner chamber 4 of the poppet valve 29.
Connects with 7. The hole 28f of the hub 28 communicates with the rear constant pressure chamber 19 through the hole 28g, and the chamber 46 communicates with the rear variable pressure chamber 20 through the hole 28h of the hub 28.
The chamber 47 communicates with the atmosphere through air filters 48, 49 and a hole 50a in the boot 50. In order to enable the poppet valve 29 to be lifted a large amount from the vacuum seat 28a by the retreat of the input rod 21 and the plunger 27 when the depressed pedal 22 is released, the plate thickness of the key member 42 is set so that the key member 42 has a radial hole. It is smaller than the booster axial dimension of 28e, and the key member 42
can be retracted relative to the hub 28 until its rear surface abuts the rear end surface of the radial hole 28e.

The rear constant pressure chamber 19 is located at the front member 1 of the fixed wall 14.
Front constant pressure chamber 1 is opened by hole 14C provided in 4.
7, and the rear transformation chamber 20 communicates with the front transformation chamber 18 through the hole 42a of the key member 42, the hole 28i of the hub 28, and the groove 28j on the inner periphery of the large diameter part of the hub 28. A port 51 is provided for communicating both constant pressure chambers 17, 19 with the intake manifold of the engine.

Pressure plate 36 of front movable wall 15
A protrusion 36a that fits inside the large diameter portion 28b of the hub 28 is formed at the center of the hub 28. A case member 52 is welded to the rear end wall of this protruding portion 36a, and a rubber reaction disk 31 and a rear end portion 31a of the output rod 31 are fitted into a large diameter hole 52a of this case member 52. A reaction mechanism 26 is configured. Small diameter hole 52b of case member 52
A plate 53 independently limits the amount of protrusion of the reaction disk 31 into the small diameter hole 52b when the pedal 22 is released, independent of the amount of retraction of the plunger 27 (the amount of retraction of the plate 53 is greater than the amount of retraction of the plunger 27). ) is installed.

The rear end wall of the protrusion 36a is brought into contact with a plurality of (for example, three) projections 28k of the hub 28, and this contact causes the forward force of the rear movable wall 16 to be applied to the front movable wall 1.
5. In order to allow the front movable wall 15 to tilt with respect to the rear movable wall 16 but not to move in the radial direction of the booster, the inner circumference of the large diameter portion 28b of the hub 28 is tapered, and the protrusion 36
A has a straight cylindrical front end and is tapered at the other end, so that the outer periphery of the protruding portion 36a and the inner periphery of the large diameter portion 28b of the hub 28 make point contact at a point A.

The operation of the booster 10 configured as described above will be easily understood by those skilled in the art from the above explanation, so a description thereof will be omitted.

It should be noted that the present invention is not limited to the above-mentioned embodiment, but can be modified as appropriate within the scope of the claims for utility model registration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional device. 11...Casing, 12...Front shell, 13...Rear shell, 15...Front movable wall, 16...Rear movable wall, 17...Front constant pressure chamber, 18...Front variable pressure chamber, 19...Rear constant pressure chamber , 20...Rear transformation chamber, 23...Control valve mechanism,
26... Recoil mechanism.

Claims (1)

[Scope of utility model registration request] The interior of the housing, which is formed by joining a pair of front shell and rear shell, is formed by a fixed wall, a front movable wall and a rear movable wall arranged before and after the fixed wall to form a front constant pressure chamber, a front variable pressure chamber, a rear constant pressure chamber, The rear variable pressure chamber is divided into four chambers, and the front constant pressure chamber and rear constant pressure chamber are connected to a negative pressure source.
A control valve mechanism that is linked to the pedal and selectively communicates the front variable pressure chamber and rear variable pressure chamber with the front constant pressure chamber and rear constant pressure chamber and the atmosphere, and the forward force of the front movable wall and the rear movable wall are coupled to the front shell. A tandem booster for a vehicle is provided with a reaction mechanism that transmits a reaction force to a piston of a master cylinder and also transmits a part of reaction force from the piston to a control valve mechanism, wherein the back and forth movement of the rear movable wall is controlled by the rear shell and the fixation mechanism. The control valve mechanism is guided by a wall, and the control valve mechanism is built into the rear movable wall.
A tandem type booster for a vehicle, wherein the front movable wall is tiltable by the rear movable wall but abuts and supported so as not to move in the radial direction of the booster, and the reaction force mechanism is built into the front movable wall.