JPH0544831A - Automatic transmission of vehicle with pto - Google Patents

Abstract

PURPOSE:To provide an automatic transmission of a vehicle with PTO(Power- Take-Off) having a torque converter which can prevent loss of its driving force at the time of using PTO in all automatic transmission vehicles. CONSTITUTION:An oil pressure control valve 9 is provided between a pressure valve 2 and a manual valve 5. When the stopping state is detected in the PTO use mode, the oil pressure control valve 9 is switched off to put the manual valve 5 in N-range state, and further, if a hand brake 16 is in the ON state at this time, a lock-up clutch 4 is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a vehicle with a PTO, and more particularly to a PTO having a torque converter.
The present invention relates to an automatic transmission of a vehicle with (Power-Take-Off).

Vehicles with PTO are special vehicles including cargo handling vehicles such as garbage trucks and concrete mixer trucks.
It is a vehicle that takes out the power of the engine for a purpose other than running and plays a role corresponding to the purpose of use of the vehicle.

Even in such a vehicle with a PTO, an automatic transmission has come to be equipped in order to improve the driving and running as in the case of an ordinary passenger car. Among them, a torque converter is used for running. Driving and PTO driving are becoming popular.

On the other hand, a vehicle equipped with such a torque converter has a large loss of transmission driving force. Therefore, when the vehicle speed and the gear stage are constant, the torque converter is bypassed and the engine output and the transmission are separated. A lock-up mechanism that directly connects

FIG. 5 schematically shows an automatic transmission of a vehicle with a PTO having such a lockup mechanism. In the figure, 1 is an oil pump and 2 is this oil pump 1.
Pressure valve for distributing hydraulic pressure from 3 is distributed from pressure valve 2 to lock up (L / U)
Solenoid valves 5 for turning on / off (opening / closing) the hydraulic pressure to the clutch 4 apply the hydraulic pressure distributed from the pressure valve 2 to the hydraulic circuit 6 by manually interlocking with the shift lever (select lever) of the vehicle. It is a manual valve for switching the hydraulic pressure to the transmission gear unit 7.

In the operation of such an automatic transmission, when the shift lever is moved from the N range to the D range or from the P range to the D range, the manual valve 5 works in conjunction with this to operate the hydraulic circuit. D of 6
The hydraulic pressure advances to the port, the planetary gear clutch (not shown) is connected by this hydraulic pressure, and automatic gear selection of the transmission gear unit 7 is performed, and a gear stage corresponding to the vehicle speed and the accelerator pedal depression amount at that time is obtained. It is designed to be used.

On the other hand, the control oil pressure of the transmission gear unit 7 is distributed from the pressure valve 2, and the oil pressure is distributed from the pressure valve 2 to the lockup clutch 4 via the solenoid valve 3. When the vehicle runs at a constant gear and at a constant speed, the solenoid valve 3 is turned on by a control signal from a control unit (not shown) and the lockup clutch 4 is activated by the hydraulic pressure from the pressure valve 2. Is operated to disable the torque converter (not shown) to eliminate the loss of the transmission driving force by the torque converter.

A system for eliminating the loss of the transmission driving force by the torque converter is disclosed in, for example, Japanese Patent Laid-Open No. 60-203535.
As disclosed in the publication, it has already been realized in a vehicle with a PTO, and when the PTO is used, the lockup clutch is operated to eliminate the loss of the transmission driving force by the torque converter.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In JP-A-203535, when operating the lock-up clutch when using the PTO, it is necessary to create the N range state in the transmission. Therefore, it is realized by setting the clutch called the drag clutch inside the transfer to the neutral state. , The driving force from the engine was transmitted only to the PTO system and was not applied to the output shaft of the transmission.

Therefore, there is a problem that it can be applied only to a four-wheel drive automatic transmission vehicle having such a transfer.

Therefore, an object of the present invention is to eliminate the loss of the driving force by the torque converter when the PTO is used in all automatic transmission vehicles.

[0012]

In order to solve the above problems, in the automatic transmission for a vehicle with a PTO according to the present invention,
To the manual valve, which is inserted between the means for selecting the TO use mode and the traveling mode, the vehicle stop state detecting means, the starting intention detecting means, the manual valve and the pressure valve for controlling the hydraulic pressure to the manual valve. And a hydraulic control valve for controlling the hydraulic pressure on and off, and controlling the hydraulic control valve to be turned off when the stopped state is detected in the PTO use mode to cut off the hydraulic pressure to the manual valve and to control the pressure valve. Control means for turning on the connected lock-up clutch until the starting intention is detected, and invalidating the torque converter during that time.

Further, in the present invention, an engine speed detecting means is further provided, and the control means turns off the lock-up clutch when the starting intention is detected, and when the engine speed is an idle speed. Only the hydraulic control valve can be turned back on.

Further, in the present invention, the control means may turn on the lockup clutch again when the starting intention is not detected even when the engine speed is higher than the idle speed.

[0015]

In the present invention, the hydraulic control valve is provided between the pressure valve and the manual valve 5, which are usually equipped in the automatic transmission, and when the selecting means informs that the control means is in the PTO use mode. If the vehicle stop state detecting means detects the vehicle stop state, the hydraulic control valve is controlled to be turned off to cut the hydraulic pressure from the pressure valve to the manual valve to bring the manual valve 5 into the N range state.

At the same time, the control means keeps the lock-up clutch in the on state until the starting intention detecting means detects the starting intention, that is, while the driver intends to continue to maintain the vehicle stop state, during which the action of the torque converter is invalidated. Therefore, the engine driving force can be directly connected and transmitted only to the PTO system.

As a result, the lockup operation at the time of using the PTO can be realized only by providing the hydraulic control valve in the ordinary automatic transmission vehicle.

Further, in the present invention, the control means turns off the lockup clutch when the starting intention detecting means detects the starting intention. After that, the engine speed from the separately provided engine speed detecting means is changed. If the idling speed is reached, the hydraulic control valve is turned back on to prevent the vehicle from jumping out immediately after the start intention is detected.

Further, in the present invention, the control means again turns on the lock-up clutch to turn on the torque converter when the starting intention is not detected even when the engine speed detected by the engine speed detecting means is higher than the idle speed. By invalidating, the PTO use mode can be returned.

[0020]

FIG. 1 shows an embodiment of an automatic transmission for a vehicle with a PTO according to the present invention, in which the same reference numerals as those in FIG. 5 designate the same or corresponding parts. In the present invention, a hydraulic control valve 9 is provided between the pressure valve 2 and the manual valve 5, and the hydraulic control valve 9 is controlled by a control signal from the CPU 10.

The CPU 10 also includes a vehicle speed sensor 11, a throttle (accelerator opening) sensor 12, an engine speed sensor 13, a mode switch 14, and a brake switch 1.
5 and the output signals of the handbrake switch 16, the control signal is sent to the hydraulic control valve 9 as described above, and the control signals are also given to the hydraulic circuit 6 and the solenoid valve 3. A combination of the brake switch 15 and the vehicle speed sensor 11 constitutes a vehicle stop state detecting means, a combination of the hand brake switch 16 and the brake switch 15 constitutes a starting intention detecting means, and a CPU constitutes a controlling means. ..

In this embodiment, the hydraulic cylinder 41 is provided between the solenoid valve 3 and the lockup clutch 4.
A hydraulic control unit 40 including a hydraulic piston 42 and a hydraulic piston 42 is provided. When the solenoid valve 3 is turned on and the control hydraulic pressure from the pressure valve 2 is applied to the hydraulic control unit 40, the hydraulic piston 42 is pressed. As a result, the operating oil pressure from the pressure valve 2 is applied to the lockup clutch 4 to be turned on, and the operating oil is returned to the oil drain.

Further, similar to the hydraulic control unit 40, the hydraulic circuit 6 to which the working hydraulic pressure from the pressure valve 2 is supplied.
In this embodiment, the speed change gear unit 7 connected to is connected to the shift gear unit 7 includes seven clutches CL to hydraulic pressure by hydraulic pressure from the hydraulic pressure output ports 21 to 24 of the manual valve 5 which is interlocked with the shift lever 8 by a wire or a link shaft. A desired gear is obtained by combining some of the predetermined clutches CL through the circuit 6. The relationship between the range of the shift lever 8 and the output port of the manual valve 5 in this case is shown in FIG.

FIG. 3 shows the transmission gear unit 7 and PT shown in FIG.
This shows a well-known connection relationship between the O output system and the torque converter system. Power from the engine is transmitted from the input shaft 10 to the PTO output shaft 20 and the gear shift gear unit 7 via the torque converter TC or the lockup clutch LC. The power is transmitted and the power is obtained from the output shaft 30 by appropriately selecting the gear clutch of the transmission gear unit 7. In the figure, the torque converter TC is composed of an impeller TC2 on the engine side, a stator TC3 connected to the oil pump OP, and a turbine section TC1 on the transmission side, and PG1 to PG3 indicate planetary gears. Although OC1 to OC4 represent one-way clutches that idle only in one direction, detailed operations thereof will be omitted here.

CPU 1 in such an automatic transmission
The control algorithm of 0 is shown in FIG. 4, and the operation of FIGS. 1 and 3 will be described below along the flow of FIG.

First, the CPU 10 determines whether the mode switch 10 is on or off (step S1). This is because the PTO use mode is shown when the mode switch 10 is turned on by the driver, and the traveling mode is shown when it is off. When the mode switch 14 is turned on, it is not shown in FIG. Will be connected to the PTO system from the PTO output shaft 20. Therefore, the power from the engine is transmitted from the PTO output shaft 20 to the PTO system and the transmission gear unit 7 at this time.

Thereafter, the CPU 10 causes the brake switch 1
5 is input (step S2), it is determined whether the state of the brake switch 15 is ON or OFF (step S3), and the output signal of the vehicle speed sensor 11 is input (step S4). Then, it is determined whether or not the vehicle speed is approximately 0 km / h, that is, whether or not the vehicle is stopped (step S5). In this way, it is detected in steps S3 and S5 whether the vehicle is stopped.

When the brake switch is on and the vehicle speed is approximately 0 km / h as described above, the CPU 10 turns on the hydraulic control valve 9 (step S6). As a result, when the stopped state is detected, the manual valve 5 is set to the N range state, and the predetermined hydraulic pressure is not applied to the transmission gear unit 7 in FIG. 3, so that the driving force from the engine is transmitted from the input shaft 10 to the output shaft 30. Is not given to the vehicle and the vehicle becomes incapable of traveling.

Then, after waiting for a certain period of time by the timer (step S7), the solenoid valve 3 is turned on to turn on the lockup clutch 4 (step S8). This timer is provided to give a time (about 0.5 seconds) until the operation inside the transmission 7 is completely stopped after turning on the hydraulic control valve 9.

In this way, the lockup clutch 4 is activated, the torque converter TC (FIG. 3) is disabled, and the engine output is transmitted from the input shaft 10 through the lockup clutch 4 to the PTO output shaft 20 only.

Thereafter, the CPU 10 inputs the output signal of the handbrake switch 16 (step S9) and detects whether the handbrake switch is on or off, that is, whether or not the driver has a will to start (step S10). ). At this time, when the handbrake switch 16 is on and the vehicle is in the non-start intention state, steps S9 and S10 are repeatedly executed, and the next operation is prevented from proceeding.

When the handbrake switch 16 is turned off and the driver's intention to start is detected, the output signal of the brake switch 15 is further input (step S11) to determine whether the brake switch 15 is on or off (step S11). Step S12).

As a result, when the brake switch 15 is off and the brake pedal is not depressed, the output signal of the throttle sensor 12 is input (step S13), and the throttle (not shown) is turned on from the output of the throttle sensor 12. Or OFF is determined (step S14).

As a result, when the accelerator pedal (not shown) is not depressed and the throttle is off, the routine returns to step S11 to wait for the starting state, but the accelerator pedal is depressed and the throttle is turned on. If yes, the process returns to step S9 to check again whether or not the driver has the intention to start.

Therefore, since the hydraulic control valve 9 is in the N range while the lockup clutch 4 is in operation, no matter how much the accelerator pedal is depressed, the brake pedal is not depressed (that is, contrary to the driver's intention). Therefore, the vehicle does not start and the PTO output shaft 20 can obtain a driving force corresponding to the depression amount of the accelerator pedal.

When the driver attempts to start the vehicle after the PTO work is completed, the brake pedal is once depressed as in a normal automatic transmission vehicle, so the brake switch 15 is turned on (step S12). At this point, the CPU 10 gives a control signal for turning off the solenoid valve 3 to disengage the lockup clutch 4 (step S15).

Thereafter, the CPU 10 inputs the output signal of the engine speed sensor 13 (step S16) and determines whether or not the engine speed is an idle speed (step S17). This is because there is a risk that the vehicle will jump out if the driver shifts to running in this state because the engine speed is high when he / she depresses the accelerator pedal a lot after the driver has indicated his intention to start (switch on in step S12) Because there is.

Therefore, only when it is known that the engine speed is the idle speed, the CPU 10 turns off the hydraulic control valve 9 and returns to the beginning.

On the other hand, when the engine speed is higher than the idle speed, the output signal of the handbrake switch 16 is input again (step S19) to determine whether the handbrake switch is on or off, that is, whether or not there is a starting intention. Is determined (step S20), the hand brake switch 1
When 6 is off and the intention to start is shown, step S
Returning to step 16, steps S16, S17, S19 and S20 are repeated until the engine speed drops to the idle speed, but when the handbrake switch 16 is on and the intention to start is released, the process returns to step S8. The lockup clutch 4 is turned on so that the PTO work can be resumed.

[0040]

As described above, according to the present invention, the hydraulic control valve is provided between the pressure valve and the manual valve, and when the vehicle stop state is detected in the PTO use mode, the hydraulic control valve is turned off. Is configured to be in a travel-disabled state and the lock-up clutch is operated during the starting intention state. Loss can be eliminated.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an automatic transmission for a vehicle with a PTO according to the present invention.

FIG. 2 is a diagram showing a relationship between an output port of a manual valve and a range of a shift lever.

[Fig. 3] Torque converter, lock-up clutch, and P
It is the figure which showed the well-known connection relationship between the TO output shaft and the gear part of a transmission.

FIG. 4 is a flowchart of a program executed by a CPU used in the automatic transmission for a vehicle with a PTO according to the present invention.

FIG. 5 is a block diagram schematically showing a conventional automatic transmission equipped with a lockup clutch.

[Explanation of symbols]

 1 Oil Pump 2 Pressure Valve 3 Solenoid Valve 4 Lockup Clutch 5 Manual Valve 6 Hydraulic Circuit 7 Speed Change Gear 9 Hydraulic Control Valve 10 CPU 11 Vehicle Speed Sensor 12 Throttle Sensor 13 Engine Speed Sensor 14 Mode Switch 15 Brake Switch 16 Handbrake Switch In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A means for selecting a PTO use mode and a travel mode, a vehicle stop state detecting means, a starting intention detecting means, a manual valve and a pressure valve for controlling a hydraulic pressure to the manual valve. And a hydraulic control valve for controlling the hydraulic pressure to the manual valve on / off, and when the stop condition is detected in the PTO use mode, the hydraulic control valve is controlled to be turned off to cut off the hydraulic pressure to the manual valve. And a control means for turning on a lock-up clutch connected to the pressure valve until the starting intention is detected and invalidating the torque converter during that time. 2. An engine speed detection means is further provided, and the control means controls the hydraulic pressure only when the engine speed is an idle speed after the lock-up clutch is turned off upon detection of the starting intention. The automatic transmission for a vehicle with a PTO according to claim 1, wherein the valve is turned back on. 3. The PTO according to claim 2, wherein the control means turns on the lockup clutch again when the starting intention is not detected even when the engine speed is higher than the idle speed. Automatic transmission for vehicles equipped with.