JPH0925948A - Clutch intermittent device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To prevent generation of negative pressure in a hydraulic passage due to automatic clutch disengagement operation. A clutch connection / disconnection device 1 according to the present invention includes an air pressure supply unit 2 for supplying an air pressure, and a booster device 7 for assisting a disengagement operation of a clutch 8 by supplying the air pressure.
A first pneumatic pressure supply path a connecting the booster 7 and the pneumatic pressure supply means 2 and a first valve 7 provided in the first pneumatic pressure supply path a.
a, a master cylinder 10 for supplying a hydraulic pressure for opening the first valve 7a, and a pneumatic pressure for pushing the piston 48 to the back side of the piston 48 of the master cylinder 10 from the pneumatic pressure supply means 2 The air pressure supply path b, the second valves 78 and 79 provided in the second air pressure supply path b, and the control device 72 that controls the opening and closing of the second valves 78 and 79. Is.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a clutch connecting / disconnecting device, and more particularly to a clutch connecting / disconnecting device capable of automating a vehicle clutch.

[0002]

2. Description of the Related Art Recently, there has been an increasing demand for automatic shifting of large vehicles such as buses and trucks. Since these vehicles generally have a large vehicle weight and a large payload, and use of a fluid torque converter such as that employed in a passenger car as a clutch type causes a large loss and is disadvantageous in terms of fuel efficiency, so in such a large vehicle, In particular, the friction clutch is turned on and off by automatic operation, the output of which is sent to a transmission, and this transmission is also automatically operated, thereby achieving automatic transmission. As a clutch intermittent device for automatically operating the clutch, a device provided with a booster (clutch booster) for intermittently operating the friction clutch by supplying and discharging air pressure is generally used.

On the other hand, the operation of the clutch is delicate when the vehicle is started, and the device becomes complicated and expensive if the operation is automatically controlled. Therefore, only in this case, the manual operation using the clutch pedal (manual operation) is required. ) There are some aimed at simplifying the device and reducing the cost by making it possible to operate. In this case, the hydraulic pressure is supplied and discharged from the master cylinder by operating the clutch pedal, and the supply and discharge of the hydraulic pressure is performed to supply and discharge the pneumatic pressure to and from the booster. (Related technology; Japanese Utility Model Publication No. 4-8023)

[0004]

By the way, during automatic gear shifting except when starting, pneumatic force is supplied to and discharged from the booster without operating the clutch pedal. In particular, the booster is adapted to push the internal power piston to operate the clutch in the disengagement direction when pneumatic pressure is supplied.

However, in the conventional structure, the passage for sending the hydraulic pressure from the master cylinder communicates with the hydraulic cylinder of the booster whose volume changes according to the movement of the power piston, and the hydraulic pressure is generated by pushing the power piston. When the cylinder volume increases, a negative pressure is generated in the hydraulic passage, air bubbles are mixed, and there is a problem that an accurate manual operation of the clutch cannot be performed.

In order to prevent the occurrence of such negative pressure, it is necessary to equip the hydraulic pressure output portion of the booster with a cancel mechanism for manual operation and automatic operation, as in Japanese Utility Model Publication No. 4-8023. However, the mechanism is complicated and reliability is also problematic. Therefore, in order to prevent the generation of negative pressure without changing the booster, the master cylinder can be driven not only by the clutch pedal but also by the control system (pneumatic pressure supply circuit) and without interfering with each other. It is desirable to do.

[0007]

DISCLOSURE OF THE INVENTION The present invention is directed to pneumatic pressure supply means for supplying pneumatic pressure, a booster for assisting the clutch disengagement operation by the supply of the pneumatic pressure, a booster and the above-mentioned pneumatic actuator. A first pneumatic pressure supply path connecting the pressure supply means, a first valve provided in the first pneumatic pressure supply path, a master cylinder for supplying hydraulic pressure for opening the first valve, and a master cylinder A second air pressure supply passage for supplying air pressure for pushing the piston to the back side of the piston from the air pressure supply means; a second valve provided in the second air pressure supply passage; And a control device for performing opening / closing control of the valve. According to this configuration, since the clutch is automatically disengaged by the control device by pushing the piston of the master cylinder with air pressure,
This can pressurize the hydraulic passage and prevent negative pressure in the hydraulic passage.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the air pressure supply means, a compressor normally equipped in a large vehicle, a compressor of a turbocharger, or the like is used. As the first and second air pressure supply passages, pipes suitable for air pressure supply, that is, air circulation are used. As the first valve, a hydraulic cylinder type valve that opens and closes with hydraulic pressure from the master cylinder is used. An electromagnetic switching valve is used as the second valve, which supplies air pressure to the master cylinder when it is open (ON), stops air pressure supply when it is closed (OFF), and discharges air pressure from the master cylinder. To do so. This achieves automatic clutch engagement and disengagement. On the other hand, if a clutch pedal is connected to the piston of the master cylinder, manual interruption using the clutch pedal is also possible. It is preferable that the clutch pedal and the piston can be disengaged from each other so that the clutch pedal does not move during automatic clutch on / off operation. In particular, in the present invention, when the clutch is automatically disengaged, air pressure is supplied from the second air pressure supply passage to push the piston in the master cylinder, so that hydraulic pressure is generated by the pushing operation. A negative pressure can be prevented by pressurizing the inside of the hydraulic passage.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram showing a clutch connecting / disconnecting device according to the present invention. The clutch connecting / disconnecting device 1 has pneumatic pressure supply means 2 for supplying pneumatic pressure. The pneumatic supply means 2
A compressor 3 driven by an engine (not shown) to generate a relatively high air pressure (air pressure), an air dryer 4 for drying air from the compressor 3, and air sent from the air dryer 4 at high pressure. Air tank 5 for storing, and check valve 6 provided on the inlet side of air tank 5
Mainly consists of and. The air pressure from the air pressure supply means 2 is sent to a booster (clutch booster) 7, and the booster 7 operates the friction clutch 8 to the separating side (right side) A by supplying the air pressure. ing. Booster 7
By operating the clutch pedal 9, the master cylinder 10
The hydraulic pressure is also supplied from.

FIG. 2 is a vertical sectional view showing details of the booster 7. The booster 7 is configured in the same manner as the conventional one. As shown, the booster 7 has a cylinder shell 12 connected to its body 11,
A piston plate (power piston) 13 is provided inside 2 by a return spring 14 urged to the pneumatic pressure introducing side (left side in the drawing). An air pressure nipple 15 is attached to one end of the cylinder shell 12, and this air pressure nipple 15 forms an air pressure inlet to substantially introduce air pressure from the air tank 5. When air pressure is introduced, the piston plate 13 is pushed toward the clutch 8 side (right side in the figure), and when this happens, the piston plate 13 is pushed by the piston rod 16, the hydraulic piston 17, and the push rod 1.
8 to push the clutch lever 8a (FIG. 1) to disengage the clutch 8.

On the other hand, inside the body 11, a hydraulic passage 20 is formed which communicates with a hydraulic nipple 19 which is a hydraulic pressure inlet. The hydraulic passage 20 includes a hole 21 formed at one end (lower end) of the body flange portion 11a, a hydraulic cylinder (hydraulic cylinder) 22 that accommodates the hydraulic piston 17 (formed on the body cylinder portion 11b), and a hydraulic cylinder. It is mainly formed by the control hole 23 on the other end (upper end) side communicating with the lick cylinder 22 via the small hole 23a. When the hydraulic pressure of the hydraulic piping 54 (FIG. 1) is introduced from the hydraulic nipple 19, the hydraulic pressure passes through the above passage and passes through the control hole 23.
And pushes the control piston 24 rightward along the control cylinder 25. In this way, the body flange portion 11a
A control valve portion 7a for controlling air pressure supply to the booster 7 is formed on the upper end side of the.

The control valve portion 7a is defined by a control body portion 26 protruding rightward. The control body portion 26 is formed with a control chamber 27 and a pneumatic port 28 that coaxially communicate with the control cylinder 25. A control valve 29 is slidably housed in the control chamber 27, and a poppet valve 30 is slidably housed in the pneumatic port 28. A nipple 31 is attached to the air pressure port 28, and a pneumatic pipe 67 (FIG. 1) is connected to the nipple 31 to constantly supply air pressure.

Normally, the poppet valve 30 is biased to the left by pneumatic pressure and a poppet spring 32, and closes a communication port 33 which connects the control chamber 27 and the pneumatic port 28. Therefore, the air pressure from the nipple 31 is cut off at the position of the poppet valve 30. However, when the hydraulic pressure is supplied from the master cylinder 10 through the hydraulic pipe 54, the control piston 24 and the control valve 29 push the poppet valve 30 to the right to open the communication port 33. In this case, the air pressure that has entered the control chamber 27 through the communication port 33 is
The air enters into the cylinder shell 12 through the pneumatic pipe 34 (FIG. 1) communicating with the piston plate 13, pushes the piston plate 13 to the right, and operates the clutch 8 to the disengagement side.

Here, the booster 7 operates the clutch 8 for a predetermined stroke according to the magnitude of the supplied hydraulic pressure. That is, for example, when the hydraulic pressure is increased by a relatively small value, the piston plate 13 is pushed to the right by the above-described pneumatic action, and in conjunction with this, the hydraulic piston 17 is pushed to the right by a predetermined stroke. Then, the volume of the hydraulic passage 20 increases and the control hole 23
The hydraulic pressure inside is reduced. In this case, the control piston 24 presses the control valve 29 against the poppet valve 30, and the poppet valve 30 closes the communication port 33, so that a balance state occurs, whereby the control chamber 27,
Predetermined air pressure is maintained in the air pressure pipe 34 and the inside of the rear side of the piston plate 13 to hold the piston plate 13 at a predetermined stroke position and the clutch 8 at a predetermined position.

When the hydraulic pressure is completely released, the control hole 2
3, the control piston 24 is returned to the leftmost home position as shown. When this happens, the control valve 29 separates from the poppet valve 30, and the open port 3 provided inside the control valve 29
6 comes into communication with the control chamber 27 and the like. Then, the held air pressure is released to the atmosphere from the opening port 36 through the bleeder 37, whereby the air pressure pushing the piston plate 13 is released, and the clutch 8 is operated to the connecting side (left side) B.

In the booster 7, 38 is a seal member for partitioning the cylinder chamber 12a defined by the cylinder shell 12 and the hydraulic cylinder 22 into an oil-tight seal.
9 and 40 are atmospheric pressure ports communicating with the bleeder 37, 4
Reference numeral 1 is a bleeder capable of bleeding hydraulic oil when loosened.

FIG. 3 is a longitudinal sectional view showing details of the master cylinder 10. As shown in FIG. As shown, the master cylinder 10
Has a cylinder body 45 extending in the longitudinal direction. The cylinder body 45 has a cylinder bore 46 having a large diameter portion 46a and a small diameter portion 46b therein, and in particular, two pistons 47 and 48 are independently slidably inserted into the cylinder bore 46. A tip end portion of a push rod 49 that is inserted / removed in accordance with the depression or return operation of the clutch pedal 9 is inserted into one end (left end) opening portion of the cylinder bore 46, and the first piston 4 is inserted into the opening end portion.
A snap ring 56 for restricting the movement of 7 is provided. The push rod 49 and the first piston 47 can be separated from each other. A return spring 52 that biases the first and second pistons 47 and 48 toward one end is provided on the other end (right side) in the cylinder bore 46. The other end of the cylinder bore 46 communicates with a hydraulic pressure supply port 53 formed in the cylinder body 45.
The hydraulic pipe 54 shown in FIG.

In the illustrated state, the first and second pistons 47 and 48 are biased by the return spring 52 and are positioned at their original positions on one end side. At this time, the cylinder body 45 is located between the pistons 47 and 48, and an air pressure introduction port 55 is provided. Particularly in the master cylinder 10, when the clutch pedal 9 is stepped on, both pistons 47, 48 are pushed to supply hydraulic pressure, which enables manual operation, while the pneumatic pressure introduction port 55 allows the pistons 47, 48 to move. Gap 55a between
Due to the supply of air pressure to the second piston 48, only the second piston 48 is pushed from the rear surface side to supply the hydraulic pressure, thereby enabling automatic operation. At this time, since the first piston 47 does not move, the clutch pedal 9 does not move. Reference numeral 57 denotes an oil supply port connected to an oil supply pipe 59 from a hydraulic oil reservoir tank 58 (FIG. 1), and 60 and 61.
Shows a small diameter port and a large diameter port for supplying oil to the right side of the second piston 48 and the position of the second piston 48, respectively.

As shown in FIG. 1, the air pressure introducing port 55 of the master cylinder 10 and the air tank 5 are connected by an air pressure pipe 62, and the air pressure pipe 62 is provided with a branch 63. A pneumatic pipe 67 is connected to the branch 63, and the pneumatic pipe 6 is connected.
The other end of 7 is connected to the nipple 31 of the booster 7.

Here, the pneumatic pipes 62, 67, and 34 that branch from the air tank 5 to the branch 63 and connect to the pneumatic nipple 15 of the booster 7 form a first pneumatic supply path a. The control valve portion 7a provided in the first air pressure supply passage a
Form a first valve that opens and closes the air pressure supply passage a by the hydraulic pressure from the master cylinder 10.

Here, the air tank 5 and the master cylinder 1
The pneumatic pipe 62 connecting to 0 is the second pipe of the master cylinder 10.
A second air pressure supply passage b for supplying air pressure is formed on the rear surface side of the piston 48, and in particular, the pipe 62 thereof is provided with two electromagnetic switching valves 78, 79 forming a second valve. .
These switching valves 78, 79 are switched and controlled by a computer type control device (controller) 72, and are opened when ON to allow the supply of pneumatic pressure to the downstream side, and when OFF, shut off the pneumatic pressure supply. The air pressure on the downstream side is released to the atmosphere. And especially the switching valve 7 on the upstream side
8 is designed to open the air pressure on the downstream side to the atmosphere through a throttle.

Therefore, if the combination of ON and OFF of the switching valves 78 and 79 is ON / ON, air pressure is supplied to the master cylinder 10, and if ON / OFF, air pressure is discharged in a relatively short time, OFF / ON. If so, the air pressure is discharged in a relatively long time. When OFF / OFF, it is substantially the same as when ON / OFF. In particular, since it is possible to select two stages of clutch connection speeds, it is possible to reduce the clutch connection shock by selecting the optimum combination. The disconnection of the clutch 8 is performed at a relatively high constant speed.

The transmission 71 is configured to perform automatic shifting, that is, when the shift position is selected by the manual shift lever, the shift signal from the electric switch is transmitted to the control device 7.
2, the actuator (not shown) is operated to perform a substantial gear shift operation. Therefore, the driver only switches the switch.

In addition, the control device 72 includes an accelerator pedal 7
5, a stroke sensor 82 and an idle switch 83, an emergency switch 84 provided near the shift lever of the transmission 71, a vehicle speed sensor 85 provided near the output shaft of the transmission 71, and a pressure provided at the air tank 5. A switch 86, a pedal switch 87 provided on the clutch pedal 9, a clutch stroke sensor 88 provided on the clutch 8 and the like are connected.

The operation of the above embodiment will be described below. At the time of gear shifting, the control device 72 turns on or opens both switching valves 78 and 79 by the input of the gear shifting signal by the driver's shift operation, and the master cylinder 1 is turned on through the second pneumatic supply path b.
Supply air pressure to zero. When the clutch 8 is disengaged and the gear shift operation of the transmission 71 is completed by an actuator (not shown), the switching valves 78 and 79 are turned off in a predetermined combination, and the air pressure on the rear side of the second piston 48 of the master cylinder 10 is set to a predetermined speed. Then, the clutch 8 is disengaged and the clutch 8 is connected to complete the shift.

Referring now to FIG. 2, when the clutch 8 is automatically disengaged, air pressure is conventionally introduced into the air pressure nipple 15 from another air pressure supply passage to operate the master cylinder 10 without operating the piston. The plate 13 was pushed. However, in this case, the hydraulic piston 17 moves to the right in conjunction with the piston plate 13,
The volume of the hydraulic cylinder 22 filled with the hydraulic oil increases, which causes the hydraulic passage 20 and the hydraulic pipe 54 to move.
Negative pressure may be generated in the inside (collectively referred to as the hydraulic passage), and bubbles may be mixed in the hydraulic oil. In this case, the hydraulic pressure cannot be supplied accurately, and in the worst case, the manual operation of the clutch 8 cannot be performed, which causes a problem that the vehicle cannot be started.

Therefore, in this embodiment, when the clutch 8 is automatically disengaged, the second piston 48 of the master cylinder 10 is pneumatically pushed so that the hydraulic passage is pneumatically pressurized. As a result, it is possible to prevent the pressure in the hydraulic passage from becoming negative, and to prevent trouble.

During the automatic connection operation of the clutch 8, the air pressure on the rear side of the second piston 48 is appropriately released to the atmosphere from the switching valves 78 and 79. In this case, the second piston 48 can be returned to the original position.

On the other hand, the manual operation of the clutch 8, particularly the disengagement thereof, is achieved by depressing the clutch pedal 9 to send the hydraulic pressure from the master cylinder 10 to open the control valve portion 7a to supply pneumatic pressure to the booster 7. To be done. On the contrary, the connection is made by returning the clutch pedal 9 and releasing the hydraulic pressure.

In addition, in this embodiment, the manual operation is prioritized over the automatic operation, that is, the signal is sent from the pedal switch 87 at the moment when the clutch pedal 9 is depressed, and the switching valve 78 is operated. , 79 are both
Both pistons 47 and 4 of the master cylinder 10 are turned off.
Allow 8 moves. Although the switching valves 78 and 79 are not controlled during the manual operation, the negative pressure does not occur because the hydraulic pressure is supplied by depressing the clutch pedal 9 in the hydraulic passage. In this way, by prioritizing the manual operation, even if the automatic operation becomes impossible due to an electric system trouble or the like, the clutch can be engaged and disengaged by the manual operation.

In this embodiment, the pneumatic pressure is applied to the large diameter portion 48a of the second piston 48 so that the hydraulic pressure can be reliably supplied even with the relatively small pneumatic pressure.

The pneumatic pressurization of the hydraulic passage as described above can be carried out by changing the internal structure around the hydraulic cylinder 22 of the booster 7, but if this is done, a complicated structure can be obtained in a narrow space. I have no choice but to adopt
There are problems such as seals, which are disadvantageous in terms of reliability and maintainability. Since this embodiment corresponds to the structure of the master cylinder 10 and the structure of the pneumatic circuit without changing the booster 7 similar to the conventional one, the structure is simple without any of the above-mentioned drawbacks and sufficient reliability is obtained. , Maintainability, etc. can be secured. Then, by the mechanical drive and pneumatic pressure supply control by the clutch pedal 9, it is possible to generate a desired hydraulic pressure without interfering with each other.

Although air pressure is sent to the master cylinder 10 in this embodiment, a separate hydraulic pump may be provided to change the circuit and send hydraulic pressure.

Although the preferred embodiment of the present invention has been described above, the above embodiment is merely one form of the present invention, and the present invention can naturally take other forms.

[0036]

The present invention exhibits the following excellent effects.

(1) When the clutch is automatically operated, it is possible to prevent a negative pressure state in the hydraulic passage and to prevent bubbles from being mixed in the hydraulic oil, so that a trouble such as a manual operation of the clutch cannot occur. Can be prevented.

(2) Since the effect of (1) can be obtained with a simple structure without largely changing the conventional device, sufficient reliability can be secured.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a clutch connecting / disconnecting device according to the present invention.

FIG. 2 is a vertical sectional view showing a booster.

FIG. 3 is a longitudinal sectional view showing a master cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Clutch connecting / disconnecting device 2 Air pressure supply means 7 Booster device 7a Control valve part (first valve) 8 Clutch 10 Master cylinder 48 Second piston (piston) 72 Control device 78 Switching valve (second valve) 79 Switching valve (Second valve) a First air pressure supply path b Second air pressure supply path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Yamamoto 8 Tsutana, Fujisawa, Kanagawa Prefecture Isuzu Central Research Institute (72) Inventor Takao Takano 3-25-1, Tonomachi, Kawasaki-ku, Kanagawa Prefecture Isuzu (72) Inventor Takahiro Tani 3-25-1 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Isuzu Motors Ltd., Kawasaki Factory

Claims (1)

[Claims] 1. Air pressure supply means for supplying air pressure,
A booster that assists the clutch disengagement operation by supplying the pneumatic pressure, and a first connecting the booster and the pneumatic supply means.
And a first air pressure supply path provided in the first air pressure supply path.
No. 2, a master cylinder for supplying hydraulic pressure for opening the first valve, and a second pneumatic cylinder for supplying pneumatic pressure for pushing the piston to the back side of the piston of the master cylinder from the pneumatic pressure supply means. A clutch engagement / disengagement device comprising: a pressure supply passage, a second valve provided in the second air pressure supply passage, and a control device that executes opening / closing control of the second valve.