JPH01132452A - Hydraulic booster device - Google Patents

Abstract

PURPOSE:To improve the operating feeling of a brake pedal by providing a stopper for determining the returning position of a piston, in a cylinder bore in which the piston is fitted while forming the contact area thereof with the piston small. CONSTITUTION:In the captioned device in which a master cylinder portion is provided on one side in a cylinder body 2 while providing a booster device portion 4 on the other side, the booster device 4 has a piston 19 fitted into the stepped bore of the cylinder body 2 and a movable valve body 97 is fitted in a stepped bore 94 formed in the piston 19. An input chamber (a) on the periphery of the movable valve body 97 is connected to an accumulator pressure chamber 28 via a through hole 101 and a connecting chamber (b) on the periphery of a sleeve 104 fitted in the opening portion of the stepped bore 94 is connected to a booster pressure chamber 29. In such a device, a stopper pin 77 is inserted into the cylinder body 2 utilizing a through hole 83a, enabling the stepped portion of the large diameter portion 22 of the piston 12 to be engaged with the pin 77 to restrict the returning position of the piston 19.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic booster used in a brake device of a vehicle or the like.

[Conventional technology and its problems]

For example, in Japanese Patent Application Laid-open No. 60-191865, there is disclosed a cylinder body having a cylinder formed in communication with an inlet connected to a hydraulic pressure source and an outlet connected to a hydraulic pressure release source, and a cylinder body that is slidably inserted into a cylinder hole. an inserted piston, an inlet chamber that is divided and formed in the cylinder hole and communicates with the inlet, an outlet chamber that communicates with the outlet, a pressure chamber defined in the cylinder hole, and a pressure chamber that is formed in the piston. a hole, a valve device provided in the hole to control communication/blocking of the pressure chamber to the inlet chamber and the outlet chamber, and an input member that operably fits the valve device into the cylinder hole. A hydraulic booster is disclosed. However, when the piston comes into surface contact with the stepped portion of the cylinder body at the return position and starts operating, the operating resistance increases due to the surface tension of the liquid. This causes problems such as a delay in the rise of hydraulic pressure and an increase in pedal effort.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a hydraulic booster that can perform smooth operation by reducing operating resistance that also affects the operational feeling when starting the brake.

[Means for solving problems]

The above object includes: a cylinder body having a cylinder formed in communication with an inlet communicating with a hydraulic pressure source and an outlet communicating with a hydraulic pressure release source; a piston slidably inserted into a cylinder hole; an inlet chamber that is divided into an inlet chamber and communicates with the inlet; an outlet chamber that communicates with the outlet; a pressure chamber defined in the cylinder hole; a hole formed in the piston; A hydraulic booster comprising: a valve device that controls communication/blocking of the pressure chamber to the inlet chamber and the outlet chamber; and an input member that engages the valve device in the cylinder hole so as to enable the valve device to operate. This is achieved by a hydraulic booster in which a stopper that determines the return position of the piston is provided in the cylinder hole with a small contact area with the piston.

[For production]

In the return position, the piston contacts the stopper with a small contact area. Therefore, the surface tension of the liquid that acts during this time is also small, and when the brake is applied, the operating resistance (compared to conventional brakes) is reduced and the piston begins to move smoothly. Therefore, the operating feeling of the brake pedal is good, and the rise in hydraulic pressure can be made quick.

(Margin below) Description of Specification [Example] Hereinafter, a hydraulic booster according to an example of the present invention will be described with reference to the drawings.

In the figure, the device of this embodiment is indicated as (1) as a whole, and the mask cylinder part (8) is on the left side of the cylinder body (2), and the booster part (4) is on the right side. ) 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 the lid body (6).
) is occluded by The lid body (6) is fixed to the cylinder body (2) by a stop ring α6) with a seal ring (γ) interposed therebetween, and the entire device is fixed to a toe board (not shown).

(Margins below) A shaft-shaped input member (9) with a cup seal (B) attached to the rear end is slidably fitted into the center through hole (8) of the book cover (6) of the specification. and is biased rearward by a spring α0.

(In this specification, the front means the left side in the figure,
Rear shall mean to the right. ) Furthermore, the tip of a rod portion aS> of a connecting member (support) connected to a brake pedal (not shown) is received in a recess (b) formed at the rear end of the input member (9); Removal stop ring (1
5a) prevents removal. A boot (141) is fixed between the rod portion 08) and the rear end of the main body (2) to prevent dust.

The stepped hole (6) of the cylinder body (2) occupies most of the large diameter hole aη into which the lid (6) fits/JS diameter hole (g)
The first piston (to) is slidably fitted across the large-diameter hole (b) and the small-diameter hole (μs), and the second piston is on the left side of the small-diameter hole (e). (Company) is slidably fitted. The first piston (to) has a first large diameter part (gl) and a second large diameter part (gl) at the rear end, middle part, and front end, respectively.
4) and a third large diameter portion 128), the seal ring -,
Cup Seal (Foundation) (Foundation)) is attached. In this way, an unpressurized chamber (b) is formed between the second large diameter section specification and the third large diameter section, and the second large diameter section - and the first large diameter section (211 An achimulator pressure chamber (28) is formed between the first large diameter section (28) and the first large diameter section (28).
A boosting pressure chamber (2)) is formed between the lid (6) and the booster pressure chamber (2).

Of these no-pressure chambers (b), akinimulator pressure chambers (2), and boosting pressure chambers (2), only the no-pressure chamber (b) belongs to the mask cylinder section (8), and this no-pressure chamber - The front half of the first piston (toward) of the reservoir that defines the area belongs to the mask cylinder part (8), and hereinafter this mask cylinder part (
8) will be explained in detail. Pol) +811 is screwed onto the front end of the first piston (to), and this pole) (8
1) A socop-shaped spring receiver (B8) is engaged with the head, and a ring-shaped spring receiver (-) is engaged with the shaft.
These spring receivers 9321 (a spring is stretched between 881 in a compressed state, the spring receiver (roll)) is placed at the rear end of the second piston, and the spring receiver's cape is placed at the front end of the first piston (to). It is pressed into contact.

In addition, the above-mentioned cup seal (■) is attached to the third large-diameter part of the head formed at the front end of the first piston (2) in contact with this, and on the other hand, the second piston (2) is attached to the rear end of the second piston (2). A cup seal (@) is attached to the large diameter portion (86). According to the engraving of this specification, a first hydraulic pressure generating chamber is formed between the first piston (to) and the second piston (to). Ru.

A cup is also cooled on the large diameter part of the front end of the second piston.
is installed, thereby forming a pressureless chamber (89) between the front end large diameter part ■ and the rear end large diameter part ■, and this piston (
A second hydraulic pressure generating chamber 141> is formed between the cylinder main body (2) and the bottom wall portion of the cylinder body (2). The spring receiver fitted to the front end of the second piston (A) is biased to the right by a return spring (supplement) stretched between the decoy and the bottom wall of the cylinder body (2). . The front end of the cylinder body (2) has a second
An output port is formed in communication with the hydraulic pressure generating chambers, and is connected to the wheel cylinder of the front wheel via a pipe (not shown). In addition, two more output ports (not shown) are formed in the cylinder body (2) so as to communicate with the first hydraulic pressure generating chamber, and these are connected to the rear wheel cylinder via a pipe (not shown). Ru.

The earth wall at the front end of the cylinder body (2) has a boss section (4).
is formed, and the fluid connection hole β is in communication with the second fluid pressure specification generating chamber through the return hole when the brake shown in the figure is not in operation, and is connected to the non-pressure through the supply hole. Room■)
I am in constant communication with. Further, the connection cylinder portion of the reservoir is press-fitted into the liquid connection hole fI'4 via a grommet seal.

The reservoir diagram has a known structure, and the upper opening of the cylindrical main body -) is covered with a cap □□□・), and the interior includes a liquid level detection chamber (58), the first and second reservoir chambers ( 3
)) H.

A boss part higher than the above-mentioned boss part (51) is formed in the earthen wall part of the middle part of the cylinder body (2), and the liquid connection hole 16+1) is connected to the first liquid pressure generation chamber through the return hole part. It is in constant communication with the no-pressure chamber (transfer) via the supply hole f6[1. In addition, the upper part of the liquid connection hole (63) is connected to the other connection cylinder part of the reservoir via a grommet seal (■).
) is press-fitted.

Next, details of the booster section (4) will be explained.

The first piston (2) is also one of the main components in the booster section (4), and is located on the side of the above-mentioned accumulator royal μs) formed on the rear and side circumferences. As shown in FIG. 2, the cylinder body (2) is formed with a boss part specification writing cap, into which a connecting member (not shown) is screwed. A check valve consisting of a ball valve and a valve spring (not shown) is disposed inside the boss (88), and the forward direction is from the outside to the inside, and the connection is made through the through hole (83a). The conduit side connected to the member can communicate with the Achimulator Pressure Chamber (Incorporated). The Akishima Murator (88) is connected to the pipe (branch), and the discharge port of the hydraulic pump (91) is connected via the pipe (■). In addition, the hydraulic pump (the cylinder is driven by a motor, and its absorption port is connected to the connection port (43a) of the above-mentioned reservoir through a pipe line (time). The reservoir is connected to the above-mentioned mask cylinder part (8) and the double Power device part (4
) acts as a common reservoir of hydraulic fluid.

A working hole pass is formed in the axial direction at the rear part of the first piston (1 o'clock), and a movable valve body is slidably inserted across the small diameter hole part (95) and the medium diameter hole part ((g)). The small diameter hole part (95) of the stepped hole is fitted into the pressureless chamber through the radial through hole (122) on its front end side through the seal ring (9g). The movable valve corporal punishment is also formed with a through hole (97) that is aligned and communicates with the small diameter hole (95) of the stepped hole H in the axial direction.

A ring ((T) is arranged in the spring receiver so that the seal ring (991) is brought into contact with the step between the small diameter hole (95) and the medium diameter hole (-) of the stepped hole. A valve spring (
100) is tensioned, and the movable valve body (pressing the tuft backwards).

A sleeve (104) is fitted with a seal ring (103) at the rear end opening of the stepped hole of the first piston 0, and is prevented from being removed by a stopper (105). . The rear end of the movable valve body (97+) is a sleeve (10
4) so that it can slide freely, and the rear end surface is connected to the recess (107) formed in the front end surface of the input member (9) by a predetermined distance when the device shown in the figure is not in operation. They are facing each other. In other words, the movable valve corporal punishment has an annular protrusion (
97a) comes into contact with the front end (104a) of the sleeve (104), thereby restricting its rearward position relative to the first piston (2).

An input chamber a is formed around the middle part of the movable valve body in the medium diameter hole part (96) of the stepped hole, and this input chamber a is inputted through the through hole (101) formed in the first piston surface. It is in constant communication with the printer's pressure chamber (pressure chamber). Further, a communication chamber is formed around the sleeve (104), which is constantly in communication with the boosting pressure chamber (2) 1 through a groove (104b) formed in a part of the sleeve (104). There is. The annular protrusion (97a) of the movable valve body and the front end (104a) of the sleeve (104) constitute a supply valve, which is closed in the illustrated state, but when opened, the sleeve (104)
) The input chamber a communicates with the communication chamber (i.e., the boosting pressure chamber (29)) through an oblique hole (109) formed in the input chamber (a).

In addition, a discharge valve is constituted by the rear end face of the movable valve body (@) and the recess (107) at the front end of the input member (9), and in the illustrated state, it is opened and the axial through hole (97C) of the movable valve corporal punishment is opened. And the small diameter hole part (95) of the stepped hole of the first piston (2), the radial through hole (122), and the no-pressure chamber (rotation) are connected to the rear side and the boosting pressure chamber (291 side). are in communication, but when this closes, the communication between them is cut off.The input member (
9) is biased rearward by the spring as described above, but its rear position is restricted by the stopper (105) fixed to the rear end opening of the first piston (2). Note that the above-mentioned reaction force spring is interposed between the input member (9) and the sleeve (104).

Also, before inserting the piping connector (2)) through the through hole (83a) of the above-mentioned boss part (-), the stopper bin (2) is inserted, and its tip is formed with the inner wall of the main body (2). It is attached to the hole (Kobe). Furthermore, a protrusion (77a) is formed at the rear end portion, and this protrusion (77a) engages with a stepped portion of a part of the inner wall of the main body (2) to perform its positioning. Straight pin (2)
) is the second large diameter part (b) of the first piston (to)
It is in contact with the stepped part. That is, the first piston (2)
The return position is regulated.

Furthermore, according to this embodiment, a passage σ0) is formed above the stepped hole (6) in the axial direction of the cylinder body (2), and this passage σ0) is formed in the liquid connection hole (621) of the boss portion (621) to which the reservoir is attached. 5) and the boosting pressure chamber (b)).

A valve seat forming member σ1) is fitted into the right end opening of the passage σ0), and the valve body is opposed to this member and is biased by a valve spring. Part ffl
It is located away from the end of the center through-hole of +, that is, the valve is open, and communicates the boost pressure chamber (b) with one side of the lizard.

The valve body (to) in the specification is supported by the support plate (with
) is used to prevent extraction. The support plate c75) has a spring c7fl) stretched between this and the annular recess of the lid (6).
Although it is urged to the left by K, it comes into contact with the stepped portion of the input member (9) into which it is fitted, as shown, and its return position is restricted as shown.

The embodiment of the present invention is configured as described above, and its operation, effects, etc. will be explained next.

When the brake is not activated, each part is in the state shown.

In this state, the driver is in the state shown in the figure.

When the driver depresses the brake pedal (not shown) in this state, the connecting member (depressor) moves forward and pushes the input member (9).The recess (107) at the tip of the input member (9) It is seated at the tip.The support plate (2) also has a spring (to).
The valve body is moved to the left by the spring force of the valve seat forming member (71
). That is, the valve body is closed, and the discharge valve is closed, so that the boosting pressure chamber (2) and the reservoir (2) are placed in a non-communicating state. When the input member (9) moves further forward, the movable valve body moves to the left relative to the first binuton (19) against the elastic force of the valve spring (Zoo).
The annular projection (97a) is separated from the front end (]04a) of the sleeve (104). That is, the supply valve opens, and the pressure liquid flows from the input chamber a into the pressure chamber 1 through the communication chamber. As a result, the first piston receives hydraulic pressure on the right end surface of its first large diameter portion (21) and generates a movement force to the left. Note that when the vehicle starts running or when the brakes start operating, It is assumed that the motor is driving (7) and the hydraulic pump (91) is operating.

Pressure liquid is stored in the achievator (88) at a predetermined pressure. Pressure fluid is supplied into the achievator pressure chamber (28). The pressure of the achievable pressure chamber is constantly applied to the input chamber a through the through hole (101).

As the first piston (19) moves forward, the input member (9) also moves forward, and the discharge remains closed. 1st piston α9
) and a cup seal attached to the third large diameter part of the second piston ridge.
) pass through the return hole (6'JJ (5f)l), the first and second hydraulic pressure generating chambers 1!011411 become sealed with respect to the reservoir side, and from then on, the piston (19)
As (20) moves forward, the hydraulic pressure in the first and second hydraulic pressure generating chambers (...) increases equally.

In this way, the desired brake can be applied to the vehicle.

When the desired brake is applied, the input member (9
) through the connecting member (121) and the hydraulic pressure Pa introduced into the pressure chamber (b) are input to the input member (9).
If the force exerted on the first piston (2) is balanced, and the hydraulic pressure Pa does not reach the right end surface of the first piston (2), the force and the hydraulic pressure generated by the first hydraulic pressure generating chamber 紿 reach the left end surface of the first piston α9). The first piston stops and the supply valve closes as well. In other words, the annular protrusion of the movable valve corporal punishment (
97a) 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 4. This provides a boosting effect.

When the driver returns the brake pedal to release the brake, the input member (9) moves back to the right under the pressure of the hydraulic pressure in the pressure chamber (291) and the spring force of the spring. The point (107) is separated from the distal end surface of the movable valve body [1. That is, the discharge valve opens. The pressure fluid in the pressure chamber (291) It flows into Mutsu Gakuin through the engraving hole (122).

On the other hand, due to the movement of the input member (9) to the right, the center of the support plate)
The valve body (material) supported by is separated from the valve seat forming member C11), and the boost pressure chamber rigid and the reservoir/(- side are
0), and the pressure liquid in the boost pressure chamber (201) is rapidly refluxed to m reservoirs.

As the pressure in the pressure chamber (b) 1 decreases, the first piston α9) and the second piston move to the right due to the hydraulic pressure in the first hydraulic pressure generating chamber and the spring force of the return spring WIl. Then, take the position shown and release the brake.

The embodiment of the present invention operates as described above, but
Furthermore, the following effects are achieved.

That is, in this embodiment, the valve body, which can also be called a second valve, is
and a valve seat forming member 1), through which the reservoir (open side and boost pressure chamber) side is communicated or disconnected depending on the movement of the input member (9). I have to. As a result, at the end of operation, the pressure fluid in the boost pressure chamber (29) can be returned to the rear side more quickly than before, and the difference between the pedal force required to start operation and the press force at the end of operation is reduced. , the driver's operating feeling can be made even better than in the past.Furthermore, according to this embodiment, the large diameter portion (2) of the piston (19) is used to restrict the return position of the piston (19).
) and bottle (2), it is not due to surface contact like in the past, but at the start of operation, the operating resistance increases due to the surface tension of the liquid, which delays the rise of the liquid pressure and increases the pedal force. to ensure smooth operation.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the reservoir side (
(Margin) (1B) One passage was formed to communicate and disconnect from the boost pressure chamber (c) side, and a valve was provided at one end of the passage, but these may be omitted.

For example, in the above embodiment, a stopper pin is provided to restrict the return position of the piston 4, and the contact with the piston is a line contact, but instead of this, a point contact may be used. FIGS. 3 and 4 show this modification, and in these figures, parts corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals. That is, according to this modification, a stopper pin ■ having a different shape is similarly inserted at the position of the above-mentioned stopper pin ση, and its tip is fitted into the hole υ of the main body (2).
As shown in Figure 4, there is a concave notch (
80 m) is formed, and a dot-like protrusion (so
b) is formed. This protrusion (sob) points to the large diameter part of the piston 4.

As shown in Fig. 3, such pins are provided at the top and bottom, and the lower pin @2 is similarly constructed, but it takes one part to insert it into the cylinder body (2). A through hole is formed in the hole, and after the tip is inserted into the hole and the tip is fitted into the hole (2) of the main body (2), a blind stopper (C) is fitted into the hole to perform a sealing action. According to such a variation,
The return position of the piston 4 is regulated by a pair of upper and lower dot-shaped protrusions (sob), but the contact area can be made smaller than in the embodiment to further reduce the operating resistance. Can be done. However, compared to the example,
Although it is inferior in terms of durability, as long as this durability is guaranteed,
Its operability is even better. In addition, when using the abutment by the dot-like protrusions, the material of the pin ＠z may be made of a material with high wear resistance. Alternatively, a plurality of point-like protrusions may be formed.

〔Effect of the invention〕

As described above, according to the hydraulic booster of the present invention,
Since the contact area with the stopper that determines the return position of the piston is small, the operating resistance when applying the brake is reduced, the operational feeling is good, and the rise in hydraulic pressure is made quick.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view of a hydraulic booster according to an embodiment of the present invention, FIG. 2 is a cross-sectional view along the line ■-■ in FIG. 1, and FIG.
The figure is a sectional view similar to FIG. 2 showing a modification, and FIG. 4 is a sectional view taken along the line IV--IV in FIG. 3. In the figure,

Claims (1)

[Claims] A cylinder body having a cylinder formed in communication with an inlet connected to a hydraulic pressure source and an outlet connected to a hydraulic pressure release source, a piston slidably inserted into the cylinder hole, and a cylinder divided into the cylinder hole. an inlet chamber formed by and communicating with the inlet, an outlet chamber communicating with the outlet, a pressure chamber defined within the cylinder hole, and a hole formed in the piston;
A hydraulic doubler, comprising: a valve device provided in the hole to control communication and cutoff of the pressure chamber to the inlet chamber and the outlet chamber; and an input member that engages the valve device in the cylinder hole in an operable manner. In the hydraulic power device, a stopper for determining the return position of the piston is provided in the cylinder hole with a small contact area with the piston.