JPS60191863A - Assembled body consisting of master cylinder and hydraulic booster - Google Patents

Abstract

PURPOSE:To aim at the promotion of reduction in a cylinder hole of a master cylinder, by forming the cylinder hole of the master cylinder into a stepped one, while constituting a front end part of a booster piston of a hydraulic booster so as to make it holdable in a part of the said cylinder hole. CONSTITUTION:An assembled body bearing the above caption consists of a master cylinder M and a hydraulic booster B to be connected to the rear end of a cylinder body 1. And, a master piston 5 inside the cylinder body 1 and a booster piston 19, which is housed inside a booster cylinder 16 of the hydraulic booster B and actuated for boosting according to the input, are coupled together via a reaction mechanism 12 which feed-facks actuating reaction force of the master cylinder M to the input side. In this case, a cylinder hole 3 of the master cylinder M is made up of each of large diametral holes 3a and 3b, while the master piston 5 is made up of both small and large diametral piston parts 5a and 5b. And, in time of the booster piston 19 going forward, this master piston is made so as to be insertable into the large diametral hole 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an assembly of a mask cylinder and a hydraulic booster;
In particular, a booster cylinder is connected to the rear of the mask cylinder, and a mask piston that slides into the cylinder hole of the mask cylinder to generate hydraulic pressure, and a booster that slides into the cylinder hole of the booster cylinder and performs boost operation in response to input. The present invention relates to an assembly in which a piston is connected to the mask piston via an output rod that contacts the back surface of the mask piston, and a reaction mechanism that feeds the operational reaction force of the mask cylinder to the input side.

Conventionally, in such an assembly, the mask cylinder and booster cylinder were provided with dedicated cylinder holes that individually guided the mask piston and booster piston of different diameters throughout the entire sliding stroke, so that the assembly The total length is very long (for this reason, when installed in a narrow engine room of a car, for example, to operate the hydraulic brake of a car, it may interfere with the engine or its accessories, making installation difficult. Ta.

Therefore, the present invention aims to shorten the cylinder hole of the booster cylinder so that a part of the cylinder hole of the mask cylinder can accommodate the front end of the advancing booster piston, thereby providing the assembly with a short overall length. purpose.

In order to achieve this object, the present invention provides a mask piston that includes a small diameter piston part that is slidably fitted in the small diameter hole and a large diameter piston part that is slidably fitted in the large diameter hole; The piston is characterized in that the piston is brought close to the large diameter piston portion so that when it moves forward, it enters the large diameter hole.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1, M is a tandem type mask cylinder for a two-system hydraulic brake of an automobile, and an oil tank 2 is formed on the upper side of the cylinder body 1. The lower half of the interior is divided into a front oil sump 21 and a rear oil sump 22 by a partition wall 2a.

The cylinder hole 3 of the cylinder body 1 has a small diameter hole 3a passing directly below the oil tank 2, and a large diameter hole 3h connected to the rear end of the small diameter hole 3a.
It can be formed into a stepped shape. A front oil reservoir 21 is provided in the small diameter hole 3a.
The entire front mask piston 4 defines a front hydraulic chamber (not shown) that can be refilled with oil between the front end wall of the cylinder hole 3, and the rear hydraulic chamber 6 that can be refilled with oil from the rear oil sump 22. The front end of the rear mask piston 5 defined between the mask piston 4, that is, the small diameter piston part 5a, is slid together, and the rear end of the rear mask piston 5, that is, the large diameter piston part 5b, is fitted into the large diameter hole 3b. It is rubbed together. Therefore, the rear mask piston 5 is composed of a small-diameter piston portion 5a and a large-diameter piston portion 515 having a larger diameter than the small-diameter piston portion 5a.

A supply oil chamber 7 is defined in the large diameter hole 3b by both piston portions 5a and 5b, and this oil chamber 7 is communicated with the rear oil sump 22 via an oil passage 8.

An elastic piston cup 9 is provided on the front surface of the small diameter piston portion 5a.
A relief port 10 is bored in the cylinder body 1 and opens just before the piston cup 9 at the retraction limit of the rear mask piston 5 to communicate between the rear hydraulic chamber 6 and the oil passage 8. A through hole 11 that communicates the replenishment oil chamber 7 with the back of the Hineton camp 9 is bored in the portion 5a.

The front hydraulic chamber (not shown) and the rear hydraulic chamber 6 accommodate return springs 12 that bias the front and rear mask pistons 4 and 5 in the backward direction, respectively.

When the rear mask 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.
and a brake hydraulic circuit (not shown) in communication with the brake hydraulic pressure circuit (not shown).

When the rear mask 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. As a result, the oil in the rear oil sump 2□ flows into the oil path 8,
It flows into the rear hydraulic chamber 6 through the supply oil chamber 7 and the through hole 11,
Hydraulic oil is replenished, and if excessive replenishment occurs, the excess is returned to the rear oil sump 22 from the relief boat 10.

The front mask 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 is retracted, the oil in the front oil reservoir 2I can be completely replenished into the front hydraulic chamber, but the mechanism for generating oil pressure and the mechanism for replenishing oil are substantially the same as those on the rear hydraulic chamber 6 side. Therefore, detailed explanation thereof will be omitted.

As clearly shown in FIG. 2, a booster cylinder 16 of a hydraulic booster B is connected to the rear end of the cylinder body 1 of the mask cylinder M with a guide ring 15 in between, and the cylinder body 1 and the booster cylinder 16 are connected by bolts 17. tied together.

Now, open the small diameter hole 3a of the cylinder hole 3 of the mask cylinder M.
The diameter of the hole is Dl, the diameter of the large diameter hole 3h is D2, and the guide ring 15
The inner diameter of the booster cylinder 16 is D3, and the cylinder hole 18 of the booster cylinder 16 is
If the diameter of is , then these dimensions are set in the following relationship.

D+ <D3<D4 <D2 Guide ring 15 and cylinder hole 18 of booster cylinder 16
The small-diameter piston portion 19a and large-diameter piston portion 19b of the booster piston 19 are slid together, respectively, and the rod portion 19. is provided protruding from the rear end surface of the large-diameter piston portion 19b. ?
penetrates the rear end wall of the booster cylinder 16 in an oil-tight manner and projects 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.

Thus, in the cylinder hole 18, the guide ring 15 and the large diameter piston portion 19b define an input hydraulic pressure chamber 20 therebetween,
Further, the large diameter piston portion 19b and the rear end wall of the booster cylinder 1G define an output hydraulic pressure chamber 21 therebetween. The output hydraulic chamber 21 is naturally formed to have a larger pressure receiving area than the input hydraulic chamber 20. Further, the large-diameter piston portion 5b of the rear mask piston 5 of the mask cylinder lV and the small-diameter piston portion 19a of the booster piston 19 define an outlet chamber 22 therebetween.

The input hydraulic chamber 20 is connected to the oil tank 2 by a supply oil passage 23, and a hydraulic pump 24 is installed in the oil passage 23 to forcefully feed the oil stored in the oil tank 2 to the input hydraulic chamber 20. A pressure accumulator 25 is connected to the downstream side.

An inlet valve 26 and an outlet valve 27 are arranged in parallel on the booster piston 19 .

The large mouth valve 26 includes a cylindrical valve chamber 29 formed in the axial direction of the booster piston 19 in the middle of an oil passage 28 that communicates between the output hydraulic chambers 20 and 21, and a rear end wall of this valve chamber 29. A spherical valve body 30 that opens and closes the oil passage 28 in cooperation with a valve seat formed in the valve seat, a valve spring 31 that biases the valve body 30 in the closing direction within the valve chamber 29, and a force of the valve spring 31. Valve body 30 against
The operating rod 32 can be opened, making it more normally closed. The operating rod 32 is fitted into the booster piston 19 so as to be slidable in its axial direction, and its rear end protrudes into the output hydraulic chamber 21 .

The outlet valve 27 is composed of a valve cylinder 33 fitted to the booster piston 19 on the axis of the piston 19, and a valve piston 35 slidably engaged with the inner hole of the valve cylinder 33, that is, the valve hole 34. The rear end of the piston 35 is connected to a brake pedal 37 via a bridge 36. The valve cylinder 33 has an outlet port 38 connected to the output oil 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. The oil passage 4o 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 guide ring 15. ), is communicated with 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 .

In the output hydraulic chamber 21, a pin 45 is fitted into the valve piston 35 so as to be perpendicular to its axis. Both ends of this bottle 450 are connected to the valve cylinder 33 and the rond part 19 of the booster piston 19.
The protruding ends 45Q, 45 (1 is formed in a truncated cone shape) protrude from the outer circumferential surface of the rond part 19C through the long holes 46, 47 in the axial direction drilled in C, respectively. Projecting end portion 45a.

45a, as shown in FIG. 3, there is a connecting hole 49.4 of the two-part interlocking ring 48 that is slidably engaged with the outer peripheral surface of the rond part 19C.
9 is fitted, and a coil spring 50 is installed around the outer periphery of the interlocking ring 48 in order to maintain the connection state between the bin 45 and the interlocking ring 48.
The wrapping is omitted. The interlocking ring 48 is disposed opposite the rear end of the inlet valve 26 so as to push the operating rod 32 of the inlet valve 26 forward in response to the advance of the valve piston 35.

In order to define the retracting limit of the valve piston 35, a circlip 51 capable of supporting the rear end is locked to the inner circumferential surface of the rond part 19C, and a return spring 52 that biases the valve piston 35 in the retracting direction is attached. It is compressed between the rond part 19c and the valve piston 35. This return spring 52 also has the function of maintaining the fixed position of the valve cylinder 33 to the booster piston 19.

Here, when the booster piston 19 and the valve piston 35 are at their respective backward limits, the forward stroke of the valve piston 35 required to close the outlet valve 27 is Ll, and the inlet valve 2 is
If the forward stroke of the valve piston 35 required to open the valve 6 is L2, then Ll<L2 is set.

The booster piston 19 has a large diameter hole 53 opening on the front surface thereof, and a small diameter hole 54 extending from the large diameter hole 53 to the valve hole 34. An elastic piston 55 and a pressure receiving piston 56 having the same diameter as the elastic piston 55 are slidably fitted together, and a reaction piston 57 whose both ends are able to abut the opposing surfaces of the valve piston 35 and the elastic piston 550 is slid into the small diameter hole 54.

An output rod 58 is integrally protruded from the front surface of the pressure-receiving piston 56, and this output rod 5B penetrates deeply into the four parts 59 on the rear surface of the rear mask piston 5 and comes into contact with the piston 5. 5 and the booster piston 19 are arranged as close as possible.

The depth of the recess 59 is selected to be equal to or larger than the radius of the large diameter piston portion 5h of the rear mask piston 50. In this way, when the rear mask piston 5 is pushed by the output rod 58, an alignment action can be given to the piston 5.

In the above, the pressure receiving piston 56, the elastic piston 55, and the reaction piston 57 constitute a reaction mechanism R that transmits the operational reaction force of the mask cylinder M 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 is held at the retracting limit by the force of the return spring 52 together with the interlocking ring 48 as shown, and the annular groove 39 occupies a position communicating with the outlet port 38, so that the outlet valve 27 is in an open state. On the other hand, in the large mouth valve 26, the operating rod 32 is connected to the interlocking ring 4.
Since the valve element 30 is seated on the valve seat of the valve chamber 29 by the force of the valve spring 31, the valve is in a closed state. Therefore, the connection between the person and the output hydraulic chambers 20 and 21 is shut off by the large mouth valve 26, and the output hydraulic chamber 21
are the outlet port 38, the annular groove 39, the oil passage 40, and the outlet chamber 2.
2. Since it communicates with the oil tank 2 through the radial groove 42, the annular oil passage 43, and the return oil passage 44 and is under atmospheric pressure, the front and rear mask pistons 4.5 and the booster piston 19
are held at the retracting limit by the force of the return spring 12 of each mask piston.

Further, in this case, the input hydraulic pressure chamber 20 is introduced with hydraulic pressure from the hydraulic pump 24 or the pressure accumulator 25, and this hydraulic pressure acts on the front surface of the large diameter piston portion 19b of the booster piston 19. 19 is held at the backward limit.

Further, since the spherical valve body 30 has a high obstructing property, leakage of pressure oil from the input hydraulic chamber 20 to the output hydraulic chamber 21 can be reliably prevented.

Now, when the brake pedal 37 is depressed to brake the car, the valve piston 35 and the interlocking ring 48 are pushed forward from the brake pedal 37 via the push rod 36, and from the relationship L+<12, the annular groove 39 is first pushed forward. Outlet port 3
8, that is, the outlet valve 27 is closed. The interlocking ring 48 then comes into contact with the rear end of the operating rod 32 and pushes it forward, thereby separating the valve body 30 from the valve seat, that is, opening the inlet valve 26. As a result, the output hydraulic chamber 21 is disconnected from the oil tank 2, and the hydraulic pump 24 or the pressure accumulator 25 is cut off.
The hydraulic pressure that has been introduced into the input hydraulic chamber 2o through the oil passage 28 and the valve chamber 29 is completely introduced into the output hydraulic chamber 21, and the booster piston 19 receives the hydraulic pressure on its rear end face and moves forward. Rear mask piston 5 via output rod 58
move forward. That is, the mask cylinder M is actuated with increased force.

Then, the booster piston 19 advances its front end into the large diameter hole 3b of the mask cylinder M so as to track the rear mask piston 5. In this way, the large diameter hole 3z is
In addition to guiding the large diameter piston portion 5h of the rear mask piston 50, it also serves to receive the front end portion of the booster piston 19 moving forward.

While the booster piston 19 is pushing the rear mask piston 5, the pressure receiving piston 56 receives the operational reaction force of the mask cylinder M from the rear mask piston 5 and operates to compress the elastic piston 55, and the compression force is A portion of the brake force is fed to the valve piston 35 via the reaction piston 57 and further to the brake pedal 37 via the push 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 5
If the cross-sectional area of the piston 6 is 81 and the cross-sectional area of the reaction piston 57 is 52, it becomes 70.

In the illustrated example, the oil tank 2 of the mask cylinder M is used as the oil tank of the hydraulic booster B, but an oil tank exclusively for the hydraulic booster B may be provided.

As described above, according to the present invention, both the mask cylinder and the mask piston are composed of a small-diameter piston portion that slides into the small-diameter hole and a large-diameter piston portion that slides into the large-diameter hole, and when the booster piston moves forward, Since the booster piston is placed close to the large-diameter piston so as to enter the large-diameter hole, the front end of the booster piston is received in the cylinder hole of the mask cylinder during boosting operation, and the front end of the booster piston is accommodated in the cylinder hole of the mask cylinder. The length of the cylinder hole of the star cylinder is shorter than that of the conventional one, and as a result, an assembly with a shortened overall length can be obtained, and can be easily installed in a narrow engine room of an automobile.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view showing one embodiment of the assembly of the present invention, FIG. 2 is an enlarged view of its main parts, and FIG. 3 is tn-■ of FIG. 1.
FIG. 4 is an enlarged cross-sectional view taken along the i-line, and FIG. 4 is a cross-sectional view taken along the -1V line of FIG. M...Mask cylinder, B...Hydraulic booster, R.
...Reaction mechanism, 1... Cylinder body, 3... Cylinder hole, 3a, 3
h...Small, large diameter hole, 5...Mask piston, 5α,
5b...Small and large diameter piston portion, 16...Booster cylinder, 15...Guide ring, 18...Cylinder hole, 1
9...Booster piston, 19a, 19b...Small,
Large diameter piston part, 20.21...Person, output hydraulic chamber, 2
4...Hydraulic pump, 25...Pressure accumulator, 26, 27
...person, Yamaguchi dialect, 35...valve histone, 37...
Brake pedal, 48... Interlocking ring, 58... Output rod Patent applicant: Nissin Kogyo Co., Ltd. Agent: Ken Ochiai, patent attorney □ ・ (・−

Claims (1)

[Claims] A booster cylinder is connected to the rear of the mask cylinder, and hydraulic pressure is generated in the cylinder hole of the mask cylinder. An assembly of a mask cylinder and a hydraulic booster, in which an actuated booster piston is connected via an output rod that contacts the back surface of the mask piston, and a reaction mechanism that feeds back the actuation reaction force of the mask cylinder to the input side. The cylinder hole of the mask cylinder is composed of a small diameter hole at the front and a rear hole having a diameter larger than the front end of the booster cylinder, and the mask piston is slid into the small diameter hole.
It is composed of a non-piston part and a front diameter IK Kashisuke type piston part, and the booster piston is placed close to the large diameter piston part so that when it moves forward, it enters the large diameter hole. An assembly of a mask cylinder and a hydraulic booster, characterized by: