JPH083718Y2 - Engine overrun prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an engine overrun prevention device for a vehicle.

[Conventional technology]

In recent years, a power shift device has been attached to the transmission, or a tower has been provided when the shift range of each forward stage including reverse is specified by the select and shift operations, and this shift tower has the same select position as the second speed, In addition, the operability of the shift has been dramatically improved, such as the proposal of a vehicle transmission having a position for designating an automatic shift stage on the side opposite to the shift position for the second speed. 61-87249, etc.).

[Problems to be solved by the device]

However, as a result of the improved operability of the shift, it is easier to shift the gear, and for example, when downshifting during overtaking or downhill, the engine is accidentally downshifted from the 6th speed to the 3rd speed to overrun the engine. There is a risk that

Therefore, in order to prevent such an overrun, for example, in order to prevent such an overrun, for example, a power shift cylinder that operates a gear shift fork in a transmission and an actuating rod that is axially moved by a shift operation of a change lever are used to shift the liquid pressure to the above power shift. In a power shift device of a transmission having a control valve for switching between supply and discharge, an electromagnetic valve is provided in a fluid pressure supply path to the power shift cylinder, a select position sensor and a vehicle speed sensor provided in the transmission. And a controller that closes the electromagnetic valve at the shift position, which is the engine overrun range at the select position, to prevent damage to the engine due to overrun. A proposal has been made (See Japanese Patent Laid-Open No. 1-216148).

As a means for preventing engine overrun, the present invention focuses on a clutch booster mounted on the clutch mechanism of the vehicle instead of the above-mentioned conventional example, and positively uses this to disengage the clutch to operate the gear. It is an object of the present invention to provide an engine overrun prevention device which prevents an overrun due to a mistake in gear selection.

[Means for solving the problem]

In order to achieve such an object, an engine overrun prevention device according to a first aspect of the present invention is a vehicle clutch mechanism including a clutch booster that reduces the pedal effort of a clutch pedal by using compressed air from an air reservoir as a boost source. A double check valve is installed in the air pipe connecting the control valve part of the clutch booster and the power cylinder part, and the air outlet of the double check valve and the power cylinder part of the clutch booster are connected by the air pipe. , The other air inlet of the double check valve and the air reservoir are connected through an air pipe equipped with an electromagnetic valve, and the electromagnetic valve is provided with an overrun occurrence signal from an engine overrun detection means provided in the drive system of the vehicle. Provided on the input overrun state detection switch and the clutch mechanism Connect the overrun detection switch for inputting a clutch engagement signal from clutch engaging and disengaging detecting means in series, each to each overrun detection switch,
When the overrun generation signal and the clutch connection signal are input, the electromagnetic valve is operated to open the air pipe flow path.

The overrun prevention device according to claim 2 is an energization state holding switch that is turned on by inputting a valve energization signal to an electromagnetic valve in parallel with the overrun state detection switch that inputs the overrun generation signal from the engine overrun detection means. With the provision of a neutral detection signal from the neutral detection means provided in the transmission, a neutral state detection switch that is turned off when the transmission is in neutral, is provided in series with the energization state holding switch. Claim 3
In the overrun prevention device according to the present invention, the engine overrun detecting means is an engine speed detecting means provided in the engine or a crankshaft speed detecting means provided in the transmission.

[Action]

According to the first aspect of the invention, when the overrun occurrence signal and the clutch connection signal are input to the respective overrun state detection switches, the electromagnetic valve is actuated to open the air pipe flow path and the compressed air from the air reservoir is released to the clutch. It will flow into the booster and the clutch will be positively disengaged.

Also, in the invention according to claim 2, when the overrun generation signal and the clutch connection signal are input to the respective overrun state detection switches, the electromagnetic valve operates to open the air pipe flow path to compress the air from the air reservoir. Air flows into the clutch booster and the clutch is positively disengaged, but the valve energization signal is input to the electromagnetic valve to turn on the energization state holding switch, and the neutral detection signal from the neutral detection means is input. When the neutral state detection switch is turned off, even if the overrun generation signal is cut off, unless the driver disengages the clutch or sets it to neutral, the electromagnetic valve operates and compressed air from the air reservoir flows into the clutch booster, The disengaged state of the clutch will be maintained.

Further, according to the invention of claim 3, the engine speed detecting means provided in the engine or the crankshaft speed detecting means provided in the transmission outputs an overrun occurrence signal to each of the overrun state detecting switches. Become.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a first embodiment of an engine overrun prevention device according to the present invention. In the drawing, reference numeral 1 is a clutch booster for reducing the pedal effort of the clutch pedal 3 by using compressed air from an air reservoir as a boost source. The clutch booster 1 includes a hydraulic cylinder portion 7 associated with the outer lever 5 of the clutch body, a control valve portion 9 connected to an air reservoir, and a power connected to the control valve portion 9 via an air pipe 11. Cylinder part 13
It has and. When the hydraulic pressure corresponding to the depression force of the clutch pedal 3 is applied to the control valve 9a of the control valve unit 9 via the hydraulic cylinder chamber 15,
The control valve 9a opens according to the oil pressure, guides the compressed air from the air reservoir to the power cylinder portion 13, and the boosted force pushes the hydraulic piston 19 connected to the tip thereof via the power piston 17, and The force is transmitted to the clutch body.

Further, reference numeral 21 is a double check valve mounted on the air pipe 11, and has one air inlet 21a and one air outlet 2
Air pipe 11 is connected to 1b, and the other air inlet
21c is connected to an air reservoir via an air pipe 25 to which a three-way electromagnetic valve 23 is attached. In the double check valve 21, the valve body 21d moves in the direction of the arrow, and both the air pipes 11 and 2 of the air pipe 11 from the control valve portion 9 and the air pipe 25 from the three-way electromagnetic valve 23 are provided.
Of the five, the one having the higher pressure and the air outlet 21b are ventilated, and the one having the lower pressure is closed.

On the other hand, a normally open relay switch 27 that operates by inputting an overrun generation signal from a tachometer to the three-way electromagnetic valve 23 and a clutch pedal switch 29.
Input the clutch connection signal from the clutch pedal 3
An electric circuit 33 is formed in which a normally open relay switch 31 that operates when is depressed is formed. That is, these days, the engine speed is the upper limit (eg 2500
rpm) or higher, the needle comes into contact with the contact provided on the tachometer to detect engine speed, and engine speed detection means is provided.The overrun buzzer is activated by the overrun generation signal from the engine speed detection means. Many truck vehicles are equipped with an overrun alarm that sounds. Although not shown, such a device is also mounted in this embodiment. Therefore, the driver hears the overrun buzzer and disengages the clutch.
It is adapted to be input to the operation electromagnetic coil 35 of 27. In response to this signal, the operation electromagnetic coil 35 turns on the relay switch 27, and unless the driver depresses the clutch pedal 3 to release the clutch, the clutch connection signal from the clutch pedal switch 29 is received. , The relay switch 31 is
When turned on, the three-way electromagnetic valve 23 is energized. When the three-way electromagnetic valve 23 is energized in this manner, the three-way electromagnetic valve 23 opens the flow path of the air pipe 25 to supply the compressed air from the air reservoir to the clutch booster 1 side, and When energized, the three-way electromagnetic valve 23 closes the flow path of the air pipe 25 and opens the compressed air between the double check valve 21 and the atmosphere.

In addition, in the figure, reference numeral 39 is a transmission, 41 is a clutch fluid reservoir, 43 is a clutch master cylinder, and
Reference numeral 45 is a stopper of the outer lever 5, and the stopper 45
Protects the outer lever 5 from moving beyond the allowable range and damaging the clutch body when compressed air is supplied from the air pipe 25 on the three-way electromagnetic valve 23 side.

Since the present embodiment is configured in this way, when the driver steps on the clutch pedal 3 to operate the gear, the hydraulic pressure corresponding to the stepping force is applied to the control valve section 9 via the hydraulic cylinder chamber 15 as described above. Control valve 9a on the control valve 9a opens according to the hydraulic pressure, and compressed air from the air reservoir is supplied to the air pipe 11,
It is guided to the power cylinder unit 13 via the double check valve 21. Then, the force boosted by the clutch booster 1 is transmitted via the power piston 17 to the hydraulic piston.
When you press 19, the force is transmitted to the clutch body and the clutch is disengaged.

Then, the driver operates the gear to engage the clutch to complete the gear shifting operation, but when the engine is not overrun due to the gear operation, the overrun occurrence signal is an electromagnetic coil 35 for operating the relay switch 27.
Therefore, the relay switch 27 is turned off, the electric circuit 33 is not energized, and the air pipe 25 is closed by the three-way electromagnetic valve 23.

On the other hand, when overrun occurs as a result of engaging the clutch, the needle comes into contact with the contact provided on the tachometer, the overrun buzzer sounds, and the relay switch 27 is turned on by the overrun generation signal. The driver listens to the overrun buzzer and disengages the clutch. If the driver does not disengage the clutch by depressing the clutch pedal 3, the relay switch 31 is turned on in response to the clutch connection signal from the clutch pedal switch 29. 3-way solenoid valve
23 is energized to open the flow path of the air pipe 25, and as a result, compressed air from the air reservoir is pressure-fed to the power cylinder portion 13 via the air pipe 25 and the double check valve 21, and the power piston 17 and hydraulic The force is transmitted to the clutch body by the piston 19 and the clutch is forcibly disengaged, and engine overrun is prevented thereafter.

After that, when the driver steps on the clutch pedal 3, the clutch connection signal is cut off, so the relay switch 31 is turned off.
As a result, the three-way electromagnetic valve 23 is de-energized to close the air pipe 25 and open the compressed air between the double check valve 21 and the atmosphere.

As described above, in this embodiment, when the driver does not release the clutch by depressing the clutch pedal 3 even if an engine overrun condition occurs, an overrun generation signal from the conventional overrun alarm device or a clutch pedal switch 29 from The three-way electromagnetic valve 23 is operated based on the clutch connection signal so that compressed air is sent from the air pipe 25 to the clutch booster 1 to positively disengage the clutch. The overrun of the engine can be easily prevented by utilizing the overrun detecting means mounted on the vehicle.

FIG. 2 shows a second embodiment of the present invention. In addition to the structure of the first embodiment, this embodiment is equipped with a neutral detecting means (not shown) in the transmission, and the relay switch 27 and In parallel, a normally open relay switch 47 for inputting a valve energization signal to the three-way electromagnetic valve 23 at the time of energizing the three-way electromagnetic valve 23 to maintain the energized state is connected, and the neutral detecting means 47 is also provided. OFF by inputting the neutral detection signal from
Relay switch 49 for neutral state detection
The relay switch 47 is connected in series. In addition, reference numerals 51 and 53 in FIG. 2 are electromagnetic coils for operating the relay switches 47 and 49, respectively. Since the other configurations are similar to those of the first embodiment, the same components are designated by the same reference numerals and their structural description is omitted.

The second embodiment of the present invention is constructed as described above, and its operation will be described below.

Similar to the first embodiment, when the gear operation does not cause the engine to overrun, the relay switch 27 is turned off.
Therefore, the three-way electromagnetic valve 23 is not energized, and the air pipe 25 is closed by the three-way electromagnetic valve 23.

However, if an overrun occurs as a result of engaging the clutch, the relay switch 27
Turns on. At this time, the driver operates the clutch pedal 3
If you do not release the clutch by pressing, the relay switch 31 will receive a clutch connection signal from the clutch pedal switch 29.
Turns on. Then, as shown in the logic diagram of FIG. 3, the three-way electromagnetic valve 23 is satisfied by satisfying these conditions.
As a result, the three-way electromagnetic valve 23 opens the flow path of the air pipe 25, the compressed air from the air reservoir is guided to the clutch booster 1 through the air pipe 25 and the double check valve 21, and the clutch is opened. It will be forcibly cut.

When the clutch is forcibly disengaged in this way, the engine speed naturally decreases. In the first embodiment, when the overrun occurrence signal is cut off due to the decrease in the engine speed, the relay switch 27 is turned off so that the three-way electromagnetic valve 23 is de-energized and the clutch is engaged. However,
As a result of the forced disengagement of the clutch, if the engine speed drops but the speed is still high, an overrun occurs again because the clutch is engaged and an overrun signal is sent to the relay switch 27. When the connection signal is input to the relay switch 31, the compulsory disengagement of the clutch and the overrun of the engine are repeated.

Thus, the present embodiment uses the relay switches 47 and 49 as described above.
Is connected to the three-way electromagnetic valve 23, the valve energization signal is input to the relay switch 47 and the relay switch 47 is turned on even if the engine speed drops and the overrun generation signal is cut off. Then, even if the overrun occurs again and the overrun buzzer sounds, the clutch is not disengaged and the gear is not set to the neutral state, so that the three-way electromagnetic valve 23 is energized as shown in the logic diagram of FIG. The condition is maintained and the forced disengagement of the clutch is maintained.

Then, when the driver shifts the gear to neutral or depresses the clutch pedal 3, the forced disengagement of the clutch is released only there. The table shown in FIG. 4 shows changes in the operating state of the three-way electromagnetic valve 23 depending on the respective input signal states.

Therefore, according to this embodiment, like the first embodiment,
The desired object can be achieved, of course, as compared with the first embodiment, there is an advantage that engine overrun and repeated forced disconnection of the clutch can be eliminated.

In each of the above embodiments, the engine speed detection means provided in the tachometer is used to input the overrun generation signal to the relay switch 27. However, instead of such a structure, the rotation speed of the counter shaft of the transmission is changed. It is also possible to provide the transmission with a counter shaft rotation speed detection means for detecting and to input an overrun occurrence signal to the relay switch 27 from the counter shaft rotation speed detection means.

Thus, according to such a structure, there is an advantage that the state of the engine overrun can be known in advance before the engine is overrun once by engaging the clutch.

In addition, a free piston as disclosed in Japanese Utility Model Laid-Open No. 63-89830 may be provided in the hydraulic cylinder chamber 15 of the clutch booster 1 to prevent oil suction of the oil line of the clutch booster 1. .

[Effect of device]

As described above, according to the invention according to each claim, the overrun of the engine can be easily prevented by diverting the overrun detecting means conventionally mounted on the vehicle.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, there is an advantage that the overrun of the engine and the repeated forced disconnection of the clutch can be eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an overrun prevention device according to a first embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of an overrun prevention device according to a second embodiment of the present invention. FIG. 3 is an operation logic diagram of the three-way electromagnetic valve, and FIG. 4 is a change table of the operation state of the three-way electromagnetic valve according to each input signal. 1 ... Clutch booster 3 ... Clutch pedal 7 ... Hydraulic cylinder part 9 ... Control valve part 9a ... Control valve 11,25 ... Air piping 13 ... Power cylinder part 15 ... Hydraulic cylinder chamber 17 ... Power piston 19 ... Hydraulic piston 21 … Double check valve 23… 3-way solenoid valve 27, 31, 47, 49… Relay switch 29… Clutch pedal switch 33… Electrical circuit 45… Stopper.

Claims (3)

[Scope of utility model registration request] 1. In a clutch mechanism of a vehicle equipped with a clutch booster for reducing the depression force of a clutch pedal by using compressed air from an air reservoir as a boost source, a control valve section of the clutch booster and a power cylinder section are connected. Install a double check valve in the air pipe, connect the air outlet of the double check valve and the power cylinder of the clutch booster with the air pipe, and connect the other air inlet of the double check valve and the air reservoir. An overrun condition detection switch, which is connected through an air pipe equipped with an electromagnetic valve, inputs an overrun occurrence signal from an engine overrun detection means provided in a vehicle drive system to the electromagnetic valve, and a clutch provided in the clutch mechanism. Input the clutch connection signal from the connection / disconnection detection means. Characterized in that the solenoid valve is connected in series, and when the overrun generation signal and the clutch connection signal are input to each overrun state detection switch, the solenoid valve is actuated to open the air pipe flow path. Engine overrun prevention device. 2. A valve energization signal for an electromagnetic valve is input in parallel with the overrun state detection switch for inputting an overrun occurrence signal from an engine overrun detection means.
An energization state holding switch that turns on is provided, and a neutral state detection switch that turns off when the transmission is in neutral by inputting a neutral detection signal from the neutral detection means provided in the transmission is provided in series with the energization state holding switch. The engine overrun prevention device according to claim 1, wherein 3. The engine overrun detecting means according to claim 1, wherein the engine overrun detecting means is an engine speed detecting means provided in the engine or a crankshaft speed detecting means provided in a transmission. Overrun prevention device.