JP3062311B2 - Booster for clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch booster for reducing a pedaling force required for depressing a clutch pedal of an automobile, and is used particularly for a medium-sized or large-sized automobile having a large engine output.

[0002]

2. Description of the Related Art A manual transmission type motor vehicle is provided with a clutch device interposed between an engine and a transmission for connecting and disconnecting a driving force by moving a clutch plate toward and away from a flywheel. Generally, the operating mechanism of this clutch device includes a hydraulic operating mechanism that introduces pressure oil from a master cylinder into a release cylinder. In this mechanism, a release piston disposed in the release cylinder is provided via a release fork. Release the clutch plate from the flywheel
There are a so-called indirect operation type and a so-called direct operation type in which the release piston separates the clutch plate from the flywheel without passing through the release fork.

[0003] In the meantime, in the case of a medium-sized or large-sized vehicle employing the above-mentioned indirect-acting clutch device, the output of the engine is large. The elasticity of the spring for pressing the clutch plate against the flywheel must be increased. When the spring resilience is increased in this way, when the clutch is disengaged, the clutch plate is separated from the flywheel against the resilience of the strong spring, so the force required to press the release fork increases and the pedal effort increases. Resulting in. In particular, with the recent increase in engine output, the pedal effort tends to increase.

In order to reduce the pedaling force of such a large vehicle, the release fork is pressed with a force greater than the pedaling force applied to the clutch pedal using the force of compressed air from an air compressor. air assist clutches booster which is adapted to assist the pedaling force is provided (see JP-a-60-129431).

On the other hand, in the indirect actuated, the clutch booster is simplicity of the device, for reasons such as ease of handling, now, have been widely adopted in the medium and large vehicles, direct operated In such a case, it is difficult to arrange the air cylinder coaxially with the release cylinder, so it is impossible to design a booster of this type. That is, it is difficult to secure a sufficient space for arranging the air cylinder coaxially and in series with the release cylinder, and it is also necessary to design a hollow air cylinder, and particularly to design and require a pull-type air cylinder. There was a problem that it involved difficulties.

[0006]

When the above-mentioned air assist type clutch booster is applied to a so-called direct-acting type, an air cylinder having a large bore is coaxially connected with a power transmission shaft in series. However, in practice, it is difficult to secure a space for the arrangement, it is difficult to establish a hollow air cylinder, and furthermore, it is difficult to make it compatible with a pull type clutch. This air assist type clutch booster could not be applied to a direct actuation type.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned technical problems, to provide a direct-acting clutch operating mechanism capable of obtaining a sufficient assisting force with a small and simple structure and reducing manufacturing costs. An object of the present invention is to provide a hydraulic clutch booster.

[0008]

According to a first aspect of the present invention, there is provided a clutch booster having a cylindrical release piston in which an input shaft of a transmission is loosely fitted, and the release piston being fitted therein. formed between the tubular casing that is, a first oil chamber that is sealed push the release piston to shut off the side of the power transmission by introducing pressurized oil from the master cylinder by the hydraulic fluid, the first from the oil chamber in the axial direction of the release piston provided apart a predetermined distance, the second, which is sealed by introducing pressurized oil from the hydraulic source pushes the release piston by the pressurized oil to the cut-off side of the power transmission
A second oil chamber, a valve means for adjusting the introduction of pressure oil from the hydraulic pressure source to the second oil chamber, and a valve means in response to an increase in pressure of the pressure oil on the first oil chamber side. Interlocking means for introducing pressurized oil into the oil chamber.

[0009]

According to the above arrangement, when the clutch pedal is depressed, pressure oil is sent from the master cylinder to the first oil chamber, and the oil pressure on the first oil chamber side increases. In response to the increase in the oil pressure, the interlocking means is actuated by the valve means from the hydraulic source to the second
Pressurized oil into the oil chamber. As a result, the oil pressure in the second oil chamber is applied to the release piston in addition to the oil pressure in the first oil chamber, and the release piston is moved to the power transmission cutoff side by the assisting force of the oil pressure, and the clutch is disengaged. Can be

[0010] A sufficient assisting force can be obtained by the pressure oil introduced from the hydraulic pressure source into the second oil chamber. Further, an air cylinder having a large bore diameter such as an air assist type is not required.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a schematic sectional view showing a non-operating state of a push type clutch booster as one embodiment of the present invention, and FIG. 2 is a schematic sectional view showing an operating state thereof.
Hereinafter, the left and right in the figure are referred to as left and right. 1 and 2
Referring to, the input shaft 91 of the transmission 90 is
Through-hole 93 of clutch housing 93 via bearing 92
a. This clutch booster A is applied to a push-type clutch device in which when a clutch pedal 96 is depressed, a release spring 94 presses a diaphragm spring 95 to disconnect the clutch.

The clutch booster A includes a cylindrical casing 1 attached to a clutch housing 93,
A cylindrical release piston 2 which is slidably fitted in the casing 1 in the axial direction and has a release bearing 94 attached to the annular groove 24 at the left end, and is formed between the release piston 2 and the casing 1. A first oil chamber 3 for introducing pressure oil for pushing the release piston 2 from the master cylinder 97 side through the first oil passage 5;
Formed between the release piston 2 and the casing 1,
A second oil chamber 4 for introducing pressure oil for pressing the release piston 2 from the oil pump 98 side as a hydraulic pressure source through the second oil passage 6, and a pressure oil introduced to the second oil chamber 4 side The piston valve 7 is operated as a valve means for adjusting the pressure of the oil, and the piston valve 7 is operated so that the pressure oil is introduced into the second oil chamber 4 in accordance with an increase in the oil pressure on the first oil chamber 3 side. And interlocking means 8.

As the oil pump 98, an existing oil pump mounted on a vehicle, such as an oil pump for a power steering device or an oil pump for an engine lubrication system, can be used. The casing 1 includes a first casing 1a attached to the clutch housing 93,
The second casing 1b attached to the first casing 1a and the third casing 1c internally fitted to the first casing 1a are integrally formed. First casing 1
An inner diameter-increased portion 1d is formed at the left end of a, and an inner diameter-reduced portion 1e is formed at an intermediate portion of the first casing 1a. The third casing 1c has an L-shaped cross section,
An annular space for forming the second oil chamber 4 is provided between the third casing 1c and the reduced inner diameter portion 1e of the first casing 1a.

The release piston 2 is formed from the left end portion to the center portion, and is formed from the center portion to the right end portion with the enlarged diameter portion 21 fitted inside the inner peripheral enlarged diameter portion 1d of the first casing 1a. An annular groove is provided integrally with the reduced diameter portion 22 fitted inside the inner peripheral reduced diameter portion 1e of the first casing 1a and on the outer periphery of the middle portion of the enlarged diameter portion 21. 24 and a flange portion 23 having an L-shaped cross section.

An inner peripheral enlarged diameter portion 1d of the first casing 1a;
The first oil chamber 3 is formed between the release piston 2 and the outer periphery of the reduced diameter portion 22. The hydraulic pressure in the first oil chamber 3 causes the release piston 2 to move through the diaphragm spring through an annular intermediate pressure receiving surface 2a formed between the enlarged diameter portion 21 and the reduced diameter portion 22 of the release piston 2. 95
Acts to press to the side. Reference numerals 25 and 26 are oil seals for sealing the first oil chamber 3.

The right end of the release piston 2 (the right end of the reduced diameter portion 22) is inserted into the annular space.
The second oil chamber 4 is formed by the annular end pressure receiving portion 2b formed of the right end surface of the release piston 2, the inner peripheral reduced diameter portion 1e of the first casing 1a, and the third casing 1c. The hydraulic pressure in the second oil chamber 4 acts so as to press the release piston 2 toward the diaphragm spring 95 via the pressure receiving surface 2 b of the release piston 2. 27 is an oil seal for sealing the second oil chamber 4, and 28 is an O-ring.

The first oil passage 5 is provided with a master cylinder 5
And a first oil chamber 3. The oil passage communicates with the first oil chamber 3 and includes a portion radially penetrating the first casing 1a and the second casing 1b. When the clutch pedal 96 is depressed, the master cylinder 97 passes through the first oil passage 5,
Pressure oil is sent into the first oil chamber 3. Second oil passage 6
Is an oil passage communicating the oil pump 98 with the second oil chamber 4, and includes a first casing 1a and a second casing 1b.
Is radially penetrated. In the second casing 1b, there is formed an axially extending cylinder portion 71 in which the piston valve 7 as the valve means is inserted. Reference numeral 75 denotes a screw stopper for closing the cylinder unit 71.

A return port 72 for returning the pressure oil in the cylinder portion 71 to an oil tank 99 via a return path 73 is opened in the peripheral surface of the cylinder portion 71. The piston valve 7 opens the recirculation port 72 by moving to the left, and closes the recirculation port 72 by moving to the right. As shown in FIG. 1, when the piston valve 7 opens the return port 72, the pressure oil from the oil pump 98 is circulated to the oil tank 99 via the return path 73. When the recirculation port 72 is closed by the piston valve 7 as shown in FIG. 2, pressurized oil from the oil pump 98 is introduced into the second oil chamber 4, and the release piston 2 is pressed by the oil pressure of this pressurized oil. . In addition, a pressure regulating valve 74 composed of a ball valve is disposed in the return path 73. This pressure regulating valve 74 is
A constant preload is always applied to the oil chamber 4 side to push the release piston 2 toward the diaphragm spring 95.

The pressure of the pressurized oil is several kg · f / cm ² to several tens.
The pressure receiving area of the end pressure receiving surface 2b is set in consideration of the magnitude of available pressure and a desired desired assist force, which can be used in a wide range of 0 kg · f / cm ² . The interlocking means 8 is provided in the second casing 1b along the axial direction and intersects with the first oil passage 5.
1, a piston valve 82 which is moved rightward by the hydraulic pressure of the first oil chamber 3 side,
2 and a rod 83 connecting the piston valve 7 so as to be able to move integrally. 84 is the cylinder part 8
1 is a screw stopper for closing the screw 1. The interlocking means 8 is the first
When the oil pressure on the oil chamber 3 side increases, the piston valve 7
Is moved rightward, and the recirculation port 72 is closed by the piston valve 7. The clutch pedal 96
In the non-operating state of the clutch booster A in which the piston is not depressed, the piston valve 7 and the piston valve 82 are moved to the left position by the hydraulic pressure in the cylinder portion 71 as shown in FIG. Even in this state, the piston valve 82 does not block the first oil passage 5 by, for example, using the end surface of the screw plug 84 as a stopper.

According to this embodiment, the clutch pedal 96
Is depressed, the pressure oil fed from the master cylinder 97 is introduced into the first oil chamber 3 while moving the piston valve 82 in the cylinder portion 81 rightward (see FIG. 2). On the other hand, the piston valve 7 in the cylinder portion 71 is moved rightward with the movement of the piston valve 82, and the recirculation port 72 is closed, so that the pressure oil on the oil pump 98 side is discharged to the second position. It is introduced into the oil chamber 4. As a result, the oil pressure in the first oil chamber 3
Acts on the pressure receiving surface 2a in the middle of the second oil chamber 4
The inner pressure acts on the end pressure receiving surface 2b of the release piston 2, and the release piston 2 is pressed toward the diaphragm spring 95 by these hydraulic pressures, and the clutch is disengaged. Here, in addition to the oil pressure in the first oil chamber 3, the oil pressure in the second oil chamber 4 is applied to the release piston 2,
It is possible to obtain a sufficient assist force with respect to the clutch depression force. Moreover, this can be realized in a direct-acting type without using a large air cylinder such as an air-assist type, whereby the size, structure and weight can be reduced, and the manufacturing cost can be reduced. It can be cheap.

FIG. 3 shows an embodiment in which the clutch booster of the present invention is applied to a pull-type clutch device. Referring to the figure, this embodiment is different from the embodiment of FIG. 1 in that the oil pressure in first oil chamber 3 and second oil chamber 4 moves release piston 2 to the right. In addition, an intermediate pressure receiving surface 2a and an end pressure receiving surface 2b are provided. That is, the third casing 1c is not provided, and between the inner peripheral reduced diameter portion 1e formed on the left end side of the first casing 1a and the reduced diameter portion 22 formed on the left end side of the release piston 2. A first oil chamber 3 is provided, and an inner peripheral enlarged diameter portion 1d formed on the right end side of the first casing 1a and an enlarged diameter portion 21 formed on the right end side of the release piston 2 are provided.
A second oil chamber 4 is provided between the first and second oil chambers. The release bearing 94 is externally fitted to the left end of the release piston 2 and is engaged with the inner peripheral edge of the diaphragm spring 95 so that the inner peripheral edge of the diaphragm spring 95 can be pulled. The other configuration is substantially the same as that of the embodiment of FIG.
The same reference numerals are given to the drawings, and the description is omitted.

According to this embodiment, the same effect as that of the embodiment of FIG. 1 can be obtained by applying the clutch booster of the present invention to a pull type clutch device. in this way,
The clutch booster of the present invention can be easily applied to both push-type and pull-type clutch devices by partial modification. Note that the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention, for example, by adopting another known valve mechanism as the valve means. It is.

[0023]

As described above, according to the clutch booster of the present invention, in response to an increase in the oil pressure on the first oil chamber side, the interlocking means controls the oil pressure from the oil pressure source by the valve means. The release piston can be pushed by the pressure oil introduced into the second oil chamber. Therefore, in addition to the oil pressure in the first oil chamber, the oil pressure in the second oil chamber is exerted on the release piston, so that a sufficient assist force against the clutch depressing force can be obtained. In addition, this can be realized in a direct-acting type without using a large air cylinder such as an air-assist type, so that downsizing, structure simplification and weight reduction can be achieved, and manufacturing cost can be reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a non-operating state of a clutch booster as one embodiment of the present invention.

FIG. 2 is a schematic sectional view showing an operation state thereof.

FIG. 3 is a schematic sectional view showing a clutch booster of another embodiment.

[Explanation of symbols]

 A clutch booster 1 casing 2 release piston 3 first oil chamber 4 second oil chamber 7 piston valve (valve means) 8 interlocking means 90 transmission 91 input shaft 97 master cylinder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16D 25/08

Claims (1)

(57) [Claims] An input shaft of a transmission is formed between a cylindrical release piston in which a release piston is loosely fitted and a cylindrical casing in which the release piston is inserted. A sealed first oil chamber that presses the release piston to the power transmission cutoff side with the pressure oil, and a predetermined oil axial distance of the release piston from the first oil chamber. A closed second oil chamber that presses the release piston toward the cutoff side of power transmission by the pressure oil, valve means for adjusting the introduction of pressure oil from the hydraulic source to the second oil chamber, A clutch booster comprising: (1) interlocking means for introducing pressure oil to a second oil chamber by a valve means in accordance with an increase in pressure of the pressure oil on the oil chamber side.