JPH0780448B2 - Power pressure assisted brake pressure generator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power pressure assist type brake pressure generating device having a hydraulic pump which is used in a vehicle or the like and which is changed by power, and particularly to a master cylinder part and a servo. It relates to an integrated unit.

[Conventional technology and its problems]

For example, in the power pressure assisting type brake pressure generating device disclosed in JP-A-61-1134549, the hydraulic fluid reservoir of the master cylinder portion is directly connected to the suction side of the hydraulic pump. Although the master cylinder part is a two-system type, if one system fails and liquid leaks, the hydraulic fluid that can be supplied to the hydraulic pump will run out, and the operation of the servo part cannot be expected.

[Problems to be Solved by the Invention] The present invention has been made in view of the above problems, and a power pressure assisting type brake pressure generation capable of sufficiently expecting the operation of the servo unit even when one system of the master cylinder leaks liquid The purpose is to provide a device.

[Means for solving problems]

The above-mentioned objects are: a hydraulic pump driven by power; a servo section that introduces a servo pressure corresponding to an input from an input member from the discharge side of the pump; and a brake that operates by the assisting force of the input and the servo pressure. A master cylinder section that generates hydraulic pressure and a hydraulic fluid reservoir that stores hydraulic fluid supplied to the master cylinder section are provided. The suction side of the pump is connected to the hydraulic fluid reservoir, and the servo pressure of the servo section is increased. In a dynamic pressure assisted brake pressure generating device in which release is performed to the hydraulic fluid reservoir, a second hydraulic fluid that guarantees a minimum amount of liquid for a servo unit between the hydraulic fluid reservoir and the suction side of the hydraulic pump. A power pressure assisted breaker having a reservoir for sucking the hydraulic fluid stored in the hydraulic fluid reservoir by the pump via the second hydraulic fluid reservoir. Pressure generating device. Achieved by

[Action]

Even if one system of the master cylinder unit fails, the minimum amount of liquid for the servo unit is guaranteed in the second hydraulic fluid reservoir, so that the original operation of the servo unit can be expected.

〔Example〕

Hereinafter, a power pressure assist type brake pressure generator according to an embodiment of the present invention will be described with reference to the drawings.

In the figure, the apparatus of the present embodiment is generally indicated by (1), and in the cylinder body 2, a master cylinder section (3) is provided on the left side and a booster section (4) is provided on the right side. It is provided. A stepped hole (5) is formed in the cylinder body (2), the front end is a closed end, and the rear end opening is closed by a lid (6). The lid pair (6) is fixed to the cylinder body (2) by a stop ring (16) with a seal link (7) interposed, and the entire device is fixed to a toe board (not shown).

A shaft-shaped input member (9) with a cup seal (11) mounted on the rear end is slidably fitted in the central through hole (8) of the lid (6), and is connected by a spring (10). It is biased backwards. (In this specification, the front means the left side in the figure, and the rear side means the right side.) Further, in the recess (15) formed at the rear end of the input member (9). Connecting member (12) connected to a brake pedal (not shown)
The tip of the rod part (13) of the is received, and the rubber material (15a)
It has been prevented from coming off. A boot (14) is fixed between the rod portion (13) and the rear end of the main body (2) to prevent dust.

The stepped hole (5) of the cylinder body (2) is composed of a large diameter hole portion (17) into which the lid body (6) is fitted and a small diameter hole portion (18) which occupies most of the large diameter hole portion (17). ) And the small diameter hole (18), the first piston (19) is slidably fitted, and the second piston (20) is slidably fitted to the left side of the small diameter hole (18). I am fit. The first piston (19) has a first large diameter portion (21) and a second large diameter portion (2) at the rear end portion, the intermediate portion and the front end portion, respectively.
2) and the third large diameter part (23), the seal ring (2
4), cup seals (25) (26) are attached. Thus, the pressureless chamber (27) is formed between the second large diameter portion (22) and the third large diameter portion (23), and the second large diameter portion (22) and the first large diameter portion (21 ), An accumulator pressure chamber (28) is formed. Further, a boosting pressure chamber (29) is formed between the first large diameter portion (21) and the lid body (6). These pressureless chambers (2
7), accumulator pressure chamber (28) and boost pressure chamber (2
Only the pressureless chamber (27) out of 9) is the master cylinder part (3)
The front half of the first piston (19) for defining the pressureless chamber (27) belongs to the master cylinder part (3). The details of the master cylinder part (3) will be described below. Will be described. A bolt (31) is screwed onto the front end of the first piston (19), a generally cup-shaped spring bearing (33) is engaged with the head of the bolt (31), and a ring is attached to the shaft. -Shaped spring bearings (32) are fitted, and the springs (34) are stretched in a compressed state between these spring bearings (32) (33), and the spring bearings (33) of the second piston (20) are The spring receiver (32) is pressed against the front end of the first piston (19) at the rear end. Further, the cup seal (12) is attached to the first large diameter portion (23) as a head portion formed at the front end portion of the first piston (19) in contact with the first large diameter portion (23), while the second piston (2)
The cup seal (38) is also mounted on the rear end large diameter portion (36) of the first hydraulic pressure generating chamber (40) between the first piston (19) and the second piston (20). Is formed.

A cup seal (37) is also attached to the large-diameter portion (35) of the front end of the second piston (20), whereby a pressureless chamber is provided between the large-diameter portion (35) of the front end and the large-diameter portion (36) of the rear end. (39) is formed, and the second hydraulic pressure generating chamber (41) is formed between the piston (20) and the bottom wall of the cylinder body (2). The second piston (20) has a return spring (4) stretched between a spring receiver (48) fitted to the front end of the second piston (20) and the bottom wall of the cylinder body (2).
It is biased to the right by 7). An output port (42) is formed at the front end of the cylinder body (2) so as to communicate with the second hydraulic pressure generating chamber (41), and this is connected to the wheel cylinder of the front wheel via a pipe line (not shown). Further, although not shown, another output port is formed in the cylinder body (2) so as to communicate with the first hydraulic pressure generating chamber (40), which is connected to the wheel cylinder of the rear wheel through a pipe line (not shown). Connected.

On the upper wall of the front end of the cylinder body (2), the boss (5
1) is formed, and the liquid connection hole (52) communicates with the second hydraulic pressure generating chamber (41) through the return hole (50) when the normal brake (not shown) is operated, and the replenishment hole (49). It is in constant communication with the pressureless chamber (39) via. In addition, the hydraulic fluid reservoir (5) is connected to the fluid connection hole (52) through the grommet seal (53).
The connecting cylinder (55) of 4) is press-fitted.

The hydraulic fluid reservoir (54) has a known structure, the upper opening of the cylindrical main body (43) is covered by the cap (44), and the inside is the fluid level detection chamber (58), the first and second portions. It is defined in the reservoir chambers (45) (46).

A boss portion (62) higher than the above-mentioned boss portion (51) is formed in the upper wall portion of the intermediate portion of the cylinder body (2), and the liquid connection hole (63) of the boss portion (63) is formed through the return hole (61). Hydraulic pressure generation chamber (40)
And is in constant communication with the pressureless chamber (27) through the supply hole (60). Further, the other contact cylinder portion (65) of the hydraulic fluid reservoir (54) is press-fitted into the upper portion of the liquid connection hole (63) via the grommet seal (64).

Next, details of the booster unit (4) will be described.

The first piston (19) is one of the main components in the booster unit (4), but it is located above the accumulator pressure chamber (28) formed in the rear side peripheral region of the cylinder. A boss portion (83) is formed on the main body (2), and a connecting member (84) is screwed to the boss portion (83). The ball valve (8
5) and a check valve consisting of a valve spring (86) are arranged, and the direction from the upper side to the lower side is the forward direction, and the conduit (84a) is connected to the connecting member (84) through the through hole (83a). The 87) side can communicate with the accumulator pressure chamber (28). Pipeline (8
The accumulator (88) is connected to 7) and the pipeline (89)
The discharge port of the hydraulic pump (91) is connected via.
Further, the hydraulic pump (91) is driven by a motor (not shown), and its suction port is connected to the second hydraulic fluid reservoir (90) according to the present invention through the pipe line (93). That is, the suction port of the hydraulic pump (91) is connected to the first hydraulic fluid reservoir (54) via the second hydraulic fluid reservoir (90). This hydraulic fluid reservoir (90) has a conduit (92)
Via the connection port (43a) of the first hydraulic fluid reservoir (54). The first hydraulic fluid reservoir (54) acts as a common hydraulic fluid reservoir for the hydraulic fluid with respect to the master cylinder section (3) and the booster section (4), but the second hydraulic fluid reservoir (54 90) works to ensure the minimum amount of liquid for the servo part, and if the brake system connected to one of the hydraulic liquid reservoir chambers (46) fails, the liquid leaks and the liquid is supplied to the servo part. Even if it becomes impossible to operate, the hydraulic pump (91) has already sucked and stored a sufficient amount of liquid in the second hydraulic fluid reservoir (90) for the servo section to operate normally. Work for.

A stepped hole (94) is formed in the rear portion of the first piston (19) in the axial direction, and the movable valve body (97) is slidable over the small diameter hole portion (95) and the medium diameter hole portion (96). Has been inserted. The front end of the small-diameter hole (9
5) is fitted. The small diameter hole portion (95) of the stepped hole (94) communicates with the pressureless chamber (27) through the radial passage hole (122). Further, the movable valve body (97) is formed with a through hole (97c) axially communicating with the small diameter hole portion (95) of the stepped hole (94). Small diameter hole (95) and medium diameter hole (9) of stepped hole (94)
A spring bearing ring (98) is arranged so that the seal ring (99) is brought into contact with a step portion between the ring protrusion (6) and an annular projection (() formed on the outer periphery of the movable valve body (97). A valve spring (100) is stretched between it and 97a) and urges the movable valve element (97) rearward.

A sleeve (104) is fitted and fitted with a seal ring (103) at the rear end opening of the stepped hole (94) of the first piston (19), and this is prevented from coming off by a stopper (105). ing. A rear end portion of the movable valve body (97) is fitted into an inner hole of the sleeve (104) so as to be slidable, and a rear end surface thereof is a recess (107) formed in a front end surface of the input member (9). ) And a normal illustrated device are not in operation, they face each other with a predetermined distance. That is, the movable valve body (97) has an annular protrusion (97
When a) contacts the front end portion (104a) of the sleeve (104), its rear position relative to the first piston (19) is restricted.

Within the medium diameter hole (96) of the stepped hole (94), the movable valve body (9
An input chamber a is formed around the middle part of 7), and this is always in communication with the accumulator pressure chamber (28) through the through hole (101) formed in the first piston (19). A communication chamber b is formed around the sleeve (104) and is always in communication with the boosting pressure chamber (29). Movable valve body (97)
Annular protrusion (97a) and the front end of the sleeve (104) (104
The supply valve is composed of a) and is closed in the illustrated state, but when it is opened, it opens through the slanted hole (109) formed in the sleeve (104) to the input chamber a and the communication chamber b, that is, the boosting pressure. It communicates with the room (29). Further, the rear end surface of the movable valve body (97) and the recess (107) at the front end of the input member (9) constitute a discharge valve, and in the state shown in the figure, the discharge valve is opened and the movable valve body (97)
Through the axial through hole (97c) and the small diameter hole portion (95) of the stepped hole (94) of the first piston (19), the radial through hole (122) and the pressureless chamber (27). The booster pressure chamber (29) communicates with each other, but when it is closed, the communication between them is cut off. The input member (9) is a spring (1
It is urged rearward by the 0), but the first piston (1
9) The rear position is regulated by the stopper (105) fixed to the rear end opening. A seal member g is interposed between the input member (9) and the sleeve (104).

The embodiment of the present invention is configured as described above. Next, the operation, effect and the like will be described.

When the brake is not activated, each part is in the state shown in the figure.
When the driver depresses a brake pedal (not shown) in this state, the connecting member (12) moves forward and pushes the input member (9). The recess (107) at the tip of the input member (9) is seated on the tip of the movable valve body (97). That is, the discharge valve is closed and the boosting pressure chamber (29) and the first hydraulic fluid reservoir (54) side are not in communication with each other. When the input member (9) further advances, the movable valve body (97) moves to the left relative to the first piston (19) against the elastic force of the valve spring (100), and its annular protrusion ( 97a) is the front end (104a) of the sleeve (104)
Move away from. That is, the supply valve is opened, and the pressure liquid from the input chamber a flows into the pressure chamber (29) through the communication chamber b. As a result, the first piston (19) receives the hydraulic pressure at the right end surface of the first large diameter portion (21), and a moving force to the left is generated. It is assumed that the motor is driven and the hydraulic pump (91) is operated when the vehicle starts running or when the brake starts operating. The hydraulic fluid is accumulated in the accumulator (88) at a predetermined pressure. The second hydraulic fluid reservoir (90)
A predetermined amount of liquid is stored in. The pressure liquid is supplied into the accumulator pressure chamber (28) via the ball valve (85). The accumulator pressure chamber (2
The pressure of 8) is constantly applied.

The input member (9) also advances with the advance of the first piston (19), and the discharge valve remains closed. The cup seal (26) attached to the third large diameter portion (23) of the first piston (19) and the cup seal (37) attached to the large diameter portion of the second piston (20) are respectively returned holes (61). ) (50), the
The first and second hydraulic pressure generation chambers (40) (41) are in a sealed state with respect to the reservoir side, and thereafter, as the pistons (19) (20) advance, the first and second hydraulic pressure generation chambers (40) (41) ) Liquid pressure rises equally. The desired brake is thus applied to the vehicle.

The input F applied to the input member (9) through the connecting member (12) when the desired brake is applied.
And the force exerted on the input member (9) by the hydraulic pressure Pa introduced into the pressure chamber (29) are balanced, and the force exerted by the hydraulic pressure Pa on the right end face of the first piston (19) and the first hydraulic pressure generation. The hydraulic pressure P _m generated in the chamber (40) balances with the force exerted on the left end face of the first piston (19), so that the first piston (19) stops and the supply valve also closes. That is, the annular projection (97a) of the movable valve body (97) is in contact with the front end (104a) of the sleeve (104), and the above-mentioned constant hydraulic pressure Pa is introduced into the pressure chamber (29). There is. This gives a boosting effect.

When the driver returns the brake pedal to release the brake, the input member (9) receives the hydraulic pressure of the pressure chamber (29) and the spring force of the spring (10) and returns to the right. As a result, the recess (107) at the tip is separated from the tip surface of the movable valve body (97). That is, the discharge valve opens. The pressure liquid in the pressure chamber (29) passes through the through hole (97c) and the radial through hole (122) of the movable valve body (97).
To flow into the pressureless chamber (27).

As the pressure in the pressure chamber (29) decreases, the first hydraulic pressure generating chamber (4
The first piston (19) and the second piston (20) are moved to the right by the hydraulic pressure of (0) and the spring force of the return spring (47), and the brake is released by taking the position shown in the figure.

Although the embodiment of the present invention performs the above-mentioned operation,
Further, the following effects are exhibited.

That is, in this embodiment, since the second hydraulic fluid reservoir (90) is provided between the hydraulic pump (91) and the first hydraulic fluid reservoir (54), one of the master cylinder section (3) Even if there is a failure in the system, for example, the system of the hydraulic fluid reservoir chamber (46) of the first hydraulic fluid reservoir (54), and there is a fluid leak, a boosting action is created in the second hydraulic fluid reservoir (90). Since the minimum amount of liquid required for storage is stored, the original boosting action can still be performed. If the other system fails, that is, if the system of the reservoir chamber (45) fails, the other hydraulic fluid reservoir chamber (46) stores a sufficient amount of liquid for boosting. There is no problem because it is done.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiments, the second hydraulic fluid reservoir (90)
Is connected to the higher hydraulic fluid reservoir chamber (46) of the first hydraulic fluid reservoir (54) which is inclined, but instead of this, the lower hydraulic fluid reservoir chamber (45) is used. May be connected to. Alternatively, the connection port (43a) may be formed on the other side so that both hydraulic fluid reservoir chambers (45) (46) are connected to the second hydraulic fluid reservoir (90). Alternatively, two second hydraulic fluid reservoirs may be provided in parallel, and the respective hydraulic fluid reservoir chambers (45) (46) may be connected to each. Further, the two parallel hydraulic fluid reservoirs may be connected to only one hydraulic fluid reservoir chamber. Alternatively, two or more second hydraulic fluid reservoirs may be provided in parallel.

In the above embodiment, the first, second and third large diameter parts (21) (22) (23) of the first piston (19) have the same diameter. ) May have a smaller diameter. This makes the machining easier, and the gap between the inner wall of the cylinder body (2) can serve as a liquid supply passage. It should be noted that even in the embodiment, the liquid can be supplied to the master cylinder portion side through a small gap, but the flow path resistance becomes high.

〔The invention's effect〕

According to the power pressure assist type brake pressure generator of the present invention,
Even if one system of the master cylinder section leaks, the servo section can be expected to operate sufficiently.

[Brief description of drawings]

The drawing is a side sectional view of a power pressure assisted brake pressure generator according to an embodiment of the present invention. In the figure, (90) …… Second hydraulic fluid reservoir

Claims (1)

[Claims] 1. A hydraulic pump driven by power, a servo section for introducing a servo pressure corresponding to an input from an input member from the discharge side of the pump, and an actuating force by the input and the servo pressure. A master cylinder section that generates a brake fluid pressure and a working fluid reservoir that stores the working fluid supplied to the master cylinder section are provided. The suction side of the pump is connected to the working fluid reservoir and the servo pressure of the servo section is provided. In the dynamic pressure assisted brake pressure generator in which the release of the hydraulic fluid is performed to the hydraulic fluid reservoir, a second hydraulic fluid that guarantees the minimum fluid amount for the servo section between the hydraulic fluid reservoir and the suction side of the hydraulic pump. A reservoir is provided for this second
The hydraulic pressure assisting type brake pressure generating device, wherein the hydraulic fluid stored in the hydraulic fluid reservoir is sucked by the pump via the hydraulic fluid reservoir.