JPH0344937B2 - - Google Patents

Description

Detailed Description of the Invention A. Purpose of the Invention (1) Industrial Field of Application The present invention relates to a hydraulic booster used for boosting a brake master cylinder of an automobile, in particular, a booster cylinder and a booster cylinder. a booster piston that is slid into the cylinder hole of the booster cylinder and divides its interior into a front input hydraulic chamber connected to a hydraulic pressure source and a rear output hydraulic chamber that has a larger pressure receiving area; An input rod that is connected to move forward and backward; and an inlet valve that is interposed in the oil passage connecting the input and output hydraulic chambers, and that is linked to the input rod so that it closes when the input rod retreats and opens when the input rod moves forward. ; an outlet valve interposed in the oil passage connecting the output hydraulic chamber and the oil tank, and linked to the input rod so as to open when the input rod moves backward and close when the input rod moves forward;

(2) Prior Art Conventionally, in this type of booster, both the inlet valve and the outlet valve are arranged coaxially with the input rod (see, for example, Japanese Patent Laid-Open No. 78855/1983).

(3) Problems to be Solved by the Invention As mentioned above, if both the inlet valve and the outlet valve are arranged coaxially with the input rod, the axial length of the booster increases, making it difficult to make the device more compact. The problem is that it is difficult.

The present invention was made in view of such circumstances,
It is an object of the present invention to provide the above-mentioned hydraulic booster which can shorten the entire axial length.

B. Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention arranges the outlet valve coaxially with the input rod and the inlet valve on one side of the input rod. At the same time, the operating end of the inlet valve is arranged on the outer periphery of the rod part of the booster piston that passes through the output hydraulic chamber, and both ends of the pin attached perpendicularly to the input rod are connected to the axial direction provided on the rod part. Fitting both ends of the pin into a multi-segment interlocking ring that protrudes to the outer periphery of the rod portion through a long hole and that can slide on the outer periphery of the rod portion and push the operating end of the inlet valve;
It is characterized in that a coil spring is wound around the outer periphery of the interlocking ring.

(2) Effect The outlet valve arranged coaxially with the input rod and the inlet valve arranged on one side of the inlet rod are arranged in the radial direction of the input rod, and the booster This contributes to reducing the axial length of the

Moreover, the input rod and the inlet valve include a pin attached perpendicularly to the input rod and passing through a long hole in the booster piston rod, and an interlocking ring that slides on the outer periphery of the rod and fits with both ends of the pin. Since the interlocking ring is guided by the outer peripheral surface of the rod part, it moves smoothly in the axial direction together with the input rod.
The inlet valve can be opened and closed accurately.

Further, since the interlocking ring is divided into a plurality of pieces, it is easy to fit it to both ends of the pin, and the fitted state is maintained by a coil spring, so that assembly is easy.

(3) Embodiment Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. First, in FIG.
This figure shows a tandem type master cylinder for a systematic hydraulic brake, in which an oil tank 2 is formed on the upper side of the cylinder body 1, and the lower half of the oil tank 2 is separated by a partition wall 2a into a front oil sump 2 ₁ and a rear oil sump 2 _{2 .} It is divided into

The cylinder hole 3 of the cylinder body 1 is formed in a stepped manner by a small diameter hole 3a passing directly below the oil tank 2 and a large diameter hole 3a continuous to the rear of the small diameter hole 3a. The small diameter hole 3a contains the entire front master piston 4 that defines a front hydraulic chamber (not shown) that is supplied with oil from the front oil sump ₂₁ between the front end wall of the cylinder hole 3, and a rear oil sump. 2 A rear master piston 5 defining a rear hydraulic chamber 6, which is supplied with oil from ₂ , between the front master piston 4 and the rear hydraulic chamber 6.
The front end of the small diameter piston 5a is slidably connected to the small diameter piston 5a.
The rear end of the rear master piston 5 is located in the large diameter hole 3b.
That is, the large diameter piston portion 5b is slid together. Therefore, the rear master piston 5 has a small diameter piston portion 5a.
and a large-diameter piston portion 5b having a larger diameter than this.

Both piston portions 5a and 5b provide a large diameter hole 3b.
A replenishment oil chamber 7 is defined in the area, and this oil chamber 7 is connected to an oil passage 8.
It is linked with the rear oil sump ₂₂ via.

An elastic piston cup 9 is attached to the front surface of the small-diameter piston portion 5a, and a relief port 10 opens immediately before the piston cup 9 when the rear master piston 5 is at its retracting limit to connect the rear hydraulic chamber 6 and the oil passage 8. is bored in the cylinder body 1, and a through hole 11 is bored in the small diameter piston portion 5a to communicate the supply oil chamber 7 with the back of the piston cup 9.

The front hydraulic chamber (not shown) and the rear hydraulic chamber 6
A return spring 12 for biasing the front and rear master pistons 4 and 5 in the backward direction is housed in the piston.

When the rear master piston 5 is pushed forward and the piston cup 9 crosses the opening of the relief port 10, hydraulic pressure is generated in the rear hydraulic chamber 6.
The hydraulic pressure is supplied to a brake hydraulic circuit (not shown) communicating with the rear hydraulic chamber 6.

When the rear master piston 5 retreats from the forward position and the rear hydraulic chamber 6 is depressurized, the outer periphery of the piston cup 9 bends forward due to the pressure difference between the front and rear, creating a gap between it and the inner surface of the cylinder hole 3. result,
The oil in the rear oil reservoir ₂₂ flows into the rear hydraulic chamber 69 through the oil passage 8, the replenishment oil chamber 7, and the through hole 11, and the hydraulic oil is replenished. At that time, if excessive replenishment occurs,
The excess oil is transferred from the relief port 10 to the rear oil sump 2.
Returned to ₂ .

The front master piston 4 moves forward as the pressure in the rear hydraulic chamber 6 increases, generates hydraulic pressure in the front hydraulic chamber, and supplies this to the corresponding brake hydraulic circuit. Furthermore, when the piston 4 retreats, the oil in the front oil reservoir ₂₁ is replenished into the front hydraulic chamber.
Since it is substantially the same as the side, detailed explanation thereof will be omitted.

As clearly shown in FIG. 2, the front end of the booster cylinder 16 of the hydraulic booster B is fitted to the rear end of the cylinder body 1 of the master cylinder M with the annular body 15 in between, and the cylinder body 1 and the booster cylinder 16 are They are fastened together by bolts 17.

Here, the diameter of the small diameter hole 3a of the cylinder hole 3 of the master cylinder M is D ₁ , the diameter of the large diameter hole 3b is D ₂ ,
The inner diameter of the annular body 15 is D ₃ and the booster cylinder 16 is
Assuming that the diameter of the cylinder hole 18 is _D4 , these dimensions are set in the following relationship.

D ₁ <D ₃ <D ₄ <D ₂ The booster piston 19 consists of a small diameter piston part 19a at the front, a large diameter piston part 19b at the rear, and a rod part 19c protruding from the rear end surface of the large diameter piston part 19b. , the small diameter piston part 19a and the large diameter piston part 19b are oil-tightly slid into the annular body 15 and the cylinder hole 18 of the booster cylinder 16, respectively, and the rod part 19c penetrates the rear end wall of the booster cylinder 16 in an oil-tight manner. protruding to the outside. In order to define the retraction limit of the booster piston 19, a stepped portion 18a capable of supporting the rear end surface of the large diameter piston portion 19b is formed at the rear end of the cylinder hole 18.

The annular body 15 supports the rear end of the rear master piston 5 on its front end surface and defines its retraction limit. Further, in the cylinder hole 18, the annular body 15 and the large diameter piston portion 19b define an input hydraulic chamber 20 therebetween, and the large diameter piston portion 19b and the rear end wall of the booster cylinder 16 define an output hydraulic chamber 21 therebetween. to be accomplished. The output hydraulic chamber 21 is naturally formed to have a larger pressure receiving area than the input hydraulic chamber 20. Also, the large diameter piston portion 5b of the rear master piston 5 of the master cylinder M and the booster piston 1
The small diameter piston portion 19a of No. 9 has an outlet chamber 22 therebetween.
Define.

The input hydraulic chamber 20 is connected to the oil tank 2 by a supply oil passage 23, and a hydraulic pump 24 as a hydraulic pressure source for pumping the oil stored in the oil tank 2 to the input hydraulic chamber 20 is interposed in the oil passage 23. , and a pressure accumulator 25 is connected downstream of the pump 24.

The booster piston 19 is provided with first and second ball-type inlet valves 26 ₁ and 26 ₂ and one spool-type outlet valve 27 in parallel.

The first inlet valve 26 ₁ has input and output hydraulic chambers 20 and 2.
1. A cylindrical valve chamber 2 formed along the axial direction of the booster piston 19 in the middle of the oil passage 28 ₁ .
9 ₁ and a ball valve body 30 ₁ that opens and closes the oil passage 28 ₁ in cooperation with the valve seat formed on the rear end wall of the valve chamber 29 ₁
, a valve spring 31 ₁ that biases the valve body 30 ₁ in the closing direction within the valve chamber 29 ₁ , and an operating rod 32 _{1 that can open the ball valve body 30 1 against} the force of the valve spring 31 ₁ . It is configured to be more normally closed. The operating rod 32 ₁ is fitted into the booster piston 19 so as to be slidable in its axial direction,
The rear end portion protrudes into the output hydraulic chamber 21 .

The second inlet valve 26 ₂ is arranged symmetrically with the first inlet valve 26 ₁ with respect to the axis of the booster piston 19, and its configuration is similar to that of the first inlet valve 26 2 except for the difference in length of the operating rods 32 ₁ and 32 ₂ . It is the same as the inlet valve 26 ₁ ,
In the figure, the portion corresponding to the first inlet valve 26 ₁ is given the same large numeral with a small numeral " ₂ " at the end.

Therefore, in order to make the opening timing of the first inlet valve 26 ₁ earlier than that of the second inlet valve 26 ₂ , the first inlet valve 26 1 is opened earlier than that of the second inlet valve 26 2 .
The operating rod 32 ₁ of 6 ₁ is connected to the operating rod 3 of the second inlet valve 26 _2.
2. When the valve is closed, the facing gap _L1 between the rear end of the operating rod ₃₂₁ and the front surface of the interlocking ring 48, which will be described later, is
It is set smaller than the opposing gap L ₂ between the rear end of the operating rod 32 ₂ and the front surface of the interlocking ring 48 . That is, L ₁ <L ₂ .

The outlet valve 27 includes a valve cylinder 33 fitted to the booster piston 19 on the axis of the piston 19, and a valve piston 35 serving as an input rod that is slid into the inner hole of the valve cylinder 33, that is, the valve hole 34. A push rod 36 operated by a brake pedal 37 is connected to the rear end of the valve piston 35. The outlet valve 27 is thus arranged coaxially with the input rod.

The valve cylinder 33 has an outlet port 38 connected to the output hydraulic pressure chamber 21, and the valve piston 35 has an annular groove 39 that blocks and communicates with the outlet port 38 according to its advance/retreat, and an oil port connected to the annular groove 39. 40. This oil passage 40 is communicated with the outlet chamber 22 via an oil passage 41 formed in the booster piston 19, and the outlet chamber 22 is connected to a radial groove 42 (see FIG. 4) provided on the front end surface of the annular body 15. ), the oil tank 2 via an annular oil passage 43 formed at the rear end of the cylinder body 1 and a return oil passage 44 connected to the oil passage 43.
will be communicated to.

In the output hydraulic chamber 21, a pin 45 is fitted into the valve piston 35 so as to be orthogonal to its axis.
Both ends of this pin 45 pass through long holes 46 and 47 in the axial direction formed in the valve cylinder 33 and the rod part 19c of the booster piston 19, respectively, and protrude from the outer peripheral surface of the rod part 19c. 45
a, 45a are formed into a truncated conical shape. As shown in FIG. 3, connecting holes 49, 49 of a two-part interlocking ring 48, which is slidably engaged with the outer circumferential surface of the rod portion 19c, are fitted into the two protruding ends 45a, 45a, and this pin 45 A coil spring 50 is wound around the outer periphery of the interlocking ring 48 in order to maintain the connection between the interlocking ring 48 and the interlocking ring 48 . Therefore, the interlocking ring 48 is connected to the valve piston 35.
The actuating rods 32 ₁ , 32 ₂ of the inlet valves 26 ₁ , 26 ₂ are disposed opposite to the rear ends thereof in response to the forward movement of the inlet valves 26 1 , 26 2 .

In order to define the retracting limit of the valve piston 35, a circlip 51 capable of supporting the rear end surface is engaged with the inner circumferential surface of the rod portion 19c, and a return spring 52 that biases the valve piston 35 in the retracting direction is attached to the rod portion. 19c and the valve piston 35. This return spring 52 is connected to the booster piston 1 of the valve cylinder 33.
It also has the function of holding the fixed position to 9.

Here, when the booster piston 19 and the valve piston 35 are at their respective backward limits, the forward stroke L ₃ of the valve piston 35 required to close the outlet valve 27 is equal to the forward stroke L 3 of the valve piston 35 required to open the first inlet valve 26 ₁ . It is set smaller than the forward stroke _L1 of 35. That is, L ₃ <L ₁ .

The booster piston 19 has a large diameter hole 53 that opens on the front surface thereof, and a small diameter hole 54 that opens on the rear end wall of the large diameter hole 53. An elastic piston 55 and a pressure receiving piston 56 of the same diameter are slid together, and a valve piston 35 and an elastic piston 5 are fitted in the small diameter hole 54.
a recoil piston 57 that can abut both ends on the opposing surface of the piston 5;
are rubbed together.

An output rod 58 is integrally protruded from the front surface of the pressure receiving piston 56, and this output rod 58 deeply enters a recess 59 on the rear surface of the rear master piston 5 and comes into contact with the piston 5. Piston 5 and booster piston 19 are arranged as close as possible.

The depth of the recess 59 is determined by the depth of the rear master piston 5.
The radius is selected to be equal to or larger than the radius of the large diameter piston portion 5b. In this way, when the rear master piston 5 is pushed by the output rod 58, an alignment effect can be applied to the piston 5.

In the above, the pressure receiving piston 56, the elastic piston 55 and the reaction piston 57 are connected to the master cylinder M
A reaction mechanism R is configured to transmit the actuation reaction force to the valve piston 35.

Next, the operation of this embodiment will be explained.

When the brake pedal 37 is not actuated, the valve piston 35 together with the interlocking ring 48 is held at the retracting limit by the force of the return spring 52 as shown, and the annular groove 39 occupies a position in communication with the outlet port 38. The outlet valve 27 is in an open state. on the other hand,
In the first and second inlet valves 26 ₁ and 26 ₂ , the operating rod 3
2 ₁ , 32 ₂ are released from the interlocking ring 48 , and the ball valve bodies 30 ₁ , 30 ₂ are seated on the valve seats of the valve chambers 29 ₁ , 29 ₂ by the force of the valve springs 31 ₁ , 31 ₂ . Therefore, both valves are closed. Therefore, between the input and output hydraulic chambers 20 and 21, both inlet valves 26 ₁ ,
26 ₂ , and the output hydraulic chamber 21
is connected to the oil tank 2 via the outlet port 38, annular groove 39, oil passage 40, outlet chamber 22, radial groove 42, annular oil passage 43, and return oil passage 44, and is at atmospheric pressure. , rear master piston 4, 5
The booster pistons 19 and 19 are each held at the retracting limit by the force of the return spring 12 of each master piston.

Furthermore, in this case, hydraulic pressure from the hydraulic pump 24 or the pressure accumulator 25 is introduced into the input hydraulic chamber 20, and this hydraulic pressure acts on the front surface of the large diameter piston portion 19b of the booster piston 19. Booster piston 19 is held at the backward limit. Further, since the ball valve bodies 30 ₁ and 30 ₂ have high obstructing properties, leakage of pressure oil from the input hydraulic chamber 20 to the output hydraulic chamber 21 can be reliably prevented.

Now, to brake the car, brake pedal 37 is pressed.
When the brake pedal 37 is depressed, the valve piston 35 and the interlocking ring 48 are
is pushed forward, and from the relationships L ₃ < L ₁ and L ₁ < L ₂ , the annular groove 39 is first shut off from the outlet port 38, that is, the outlet valve 27 is closed, and then the interlocking ring 4
8 comes into contact with the rear end of the operating rod 32 ₁ of the first inlet valve 26 ₁ and pushes it forward, thereby separating the ball valve body 30 ₁ from its valve seat, after which the interlocking ring 48 The second inlet valve 26 ₂ comes into contact with the rear end of the operating rod 32 ₂ and pushes it forward, thereby separating the ball valve body 30 ₂ from its valve seat. In this way, the first and second inlet valves 26 ₁ and 26 ₂ are sequentially opened.

By the way, the outlet valve 27 is closed and the first inlet valve 2
At the initial stage when 6 ₁ opens, the output hydraulic chamber 21
The communication with the oil tank 2 is cut off, and the hydraulic pressure introduced into the input hydraulic chamber 20 from the hydraulic pump 24 or the pressure accumulator 25 is supplied to the output hydraulic chamber 21 through the oil passage 28 ₁ and the valve chamber 29 ₁ . The hydraulic chambers 20 and 21 have approximately the same pressure. Therefore, the second inlet valve 26 ₂ before opening
In this case, the ball valve body 30 ₂ receives approximately the same hydraulic pressure on both the front and rear sides, and the closing force of the ball valve body 30 ₂ due to the hydraulic pressure in the input hydraulic chamber 20 is equal to that of the output hydraulic chamber 21 .
This is canceled out or greatly reduced by the valve opening force generated by the hydraulic _{pressure of} Above, the ball valve body 30 ₂ can be easily opened simply by resisting the force of the valve spring 31 ₂ .

Then, when both inlet valves 26 _{1 and} 26 ₂ open,
Since the pressure oil in the input oil pressure chamber 20 is smoothly supplied to the output oil pressure chamber 21 through both oil passages 28 ₁ and 28 ₂ , the booster piston 19 can be rapidly moved forward using the oil pressure.

The advancing booster piston 19 is driven by a reaction mechanism R.
and advances the rear master piston 5 via the output rod 58. In this way, the master cylinder M is actuated with boost.

The booster piston 19 is the rear master piston 5
While pushing , the pressure receiving piston 56 receives the actuation reaction force of the master cylinder M from the rear master piston 5 and operates to compress the elastic piston 55 , and a part of the compression force acts on the reaction piston 57 . Feedback is fed back to the valve piston 35 via the input rod 36 and to the brake pedal 37 via the input rod 36, so that the driver can sense the magnitude of the braking force. The boost ratio at this time is the pressure receiving piston 56
S ₁ is the cross-sectional area of the reaction piston 57, and S ₂ is the cross-sectional area of the reaction piston 57, then S ₁ /S ₂ is obtained.

In such a booster B, the outlet valve 27 is arranged coaxially with the valve piston 35 which is the input rod, and the first and second inlet valves 26 ₁ and 26 ₂ are arranged on one side of the valve piston 35, respectively. Therefore, the outlet valve 27 and the inlet valves 26 ₁ and 26 ₂ are arranged in the radial direction of the valve piston 35, and the axial length of the booster B can be shortened.

Moreover, the valve piston 35 and the inlet valves 26 ₁ , 26 ₂
This refers to a pin 45 that is fitted orthogonally to the valve piston 35 and passes through the long hole 47 of the rod portion 19c of the booster piston 19, and an interlocking mechanism that slides on the outer periphery of the rod portion 19c and fits with both ends of the pin 45. Ring 48
Therefore, the interlocking ring 48 operates smoothly in the axial direction together with the valve piston 35 while being guided by the outer peripheral surface of the rod portion 19c, and the inlet valve 2
6 ₁ and 26 ₂ can be opened and closed accurately.

Further, since the interlocking ring 48 is divided into two parts, it is easy to fit the pin 45 to both ends thereof, and the fitted state is maintained by wrapping a coil spring 50 around the outer periphery of the interlocking ring 48. Therefore, assembly is extremely easy.

In the illustrated example, the first and second inlet valves 26 ₁ , 2
6 ₂ ball valve bodies 30 ₁ and 30 ₂ are formed to have the same diameter, but in order to minimize the opening resistance of the first inlet valve 26 ₁ which opens early, the ball valve bodies 30 ₁ are formed to have the same diameter.
It is also effective to form the ball valve body 302 with a small diameter and to make the ball valve body ₃₀₂ a large diameter in order to minimize the flow resistance.It is also effective to further increase the number of inlet valves and open them one after another. It is also effective to have a valve.

C. Effects of the Invention As described above, according to the present invention, the outlet valve is disposed coaxially with the input rod, and the inlet valve is disposed on one side of the input rod. They can be arranged in the radial direction, making it possible to shorten the entire device in the axial direction and thereby make it more compact.

In addition, the operating end of the inlet valve is arranged on the outer periphery of the rod part of the booster piston that passes through the output hydraulic pressure chamber, and both ends of the pin attached perpendicularly to the input rod are connected to the elongated hole in the axial direction provided in the rod part. Both ends of the pin are fitted into a multi-segment interlocking ring that protrudes to the outer periphery of the rod portion through the rod portion and can slide on the outer periphery of the rod portion to push the operating end of the inlet valve, and a coil spring is attached to the outer periphery of the interlocking ring. Since the interlocking ring is wrapped around the interlocking ring, the operation of the interlocking ring is smooth and the inlet valves can be operated accurately regardless of the number of inlet valves, and the interlocking ring can be easily assembled.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention;
2 is an enlarged view of the main part thereof, FIG. 3 is an enlarged cross-sectional view taken along the line -- in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line -- in FIG. B... Booster, 2... Oil tank, 16... Booster cylinder, 19... Booster piston, 19c
... Rod part, 20 ... Input hydraulic chamber, 21 ... Output hydraulic chamber, 22 ... Outlet chamber, 23 ... Supply oil path,
24... Hydraulic pump as hydraulic source, 25... Pressure accumulator, 26 ₁ , 26 ₂ ... Inlet valve, 27... Outlet valve, 32 ₁ , 32 ₂ ... Operating rod, 35... Valve as input rod. Piston, 45... Pin, 47... Long hole, 48... Interlocking ring, 50... Coil spring, 58
...output rod.

Claims (1)

[Claims] 1 a booster cylinder; a booster piston that is slid into the cylinder hole of the booster cylinder and divides its interior into a front input hydraulic chamber connected to a hydraulic pressure source and a rear output hydraulic chamber having a larger pressure receiving area; An input rod is connected to the booster piston so that it can move forward and backward; it is interposed in the oil passage connecting the input and output hydraulic chambers, and is linked to the input rod so that it closes when the input rod retreats and opens when it moves forward. an inlet valve that is interposed in the oil passage connecting the output hydraulic chamber and the oil tank, and an outlet valve that is linked to the input rod so that it opens when the input rod moves backward and closes when the input rod moves forward;
In a hydraulic booster, the outlet valve is disposed coaxially with the input rod, the inlet valve is disposed on one side of the input rod, and the booster piston is arranged so that the working end of the inlet valve passes through the output hydraulic chamber. The pin is placed on the outer periphery of the rod part, and both ends of the pin attached perpendicular to the input rod are made to protrude to the outer periphery of the rod part through a long hole in the axial direction provided in the rod part, and are slid onto the outer periphery of the rod part. A hydraulic booster, characterized in that both ends of the pin are fitted into a multi-segment interlocking ring capable of pushing an operating end of an inlet valve, and a coil spring is wound around the outer periphery of the interlocking ring.