JPH0569018B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift start control method for industrial vehicles and the like.

(Prior art) Conventionally, when starting a shift in an industrial vehicle, etc., the driver first depresses the accelerator pedal and then
Next, after operating the forward/reverse switching lever in the forward or reverse direction, the clutch control device disengages the clutch, then switches the gear of the automatic transmission in the forward or reverse direction, and then connects the clutch. Shift start control was performed in this order.

(Problems to be Solved by the Invention) In the conventional shift start control method described above, the clutch is disengaged after the driver operates the forward/reverse switching lever in the forward or reverse direction and before the vehicle starts. The start time lag was long due to the operation, the gear change operation of the automatic transmission, and the operation of connecting the clutch, which caused problems in terms of driving feeling and work efficiency.

Therefore, it is a technical object of the present invention to solve the above problem by shortening the start time lag by disengaging the clutch when the accelerator pedal is depressed.

(Means for solving the problem) The technical means for solving the problem described above includes a clutch that transmits or cuts off engine output to an automatic transmission, and a clutch control device that controls the connection state of the clutch. , a gear position detection sensor that detects a neutral state of the automatic transmission; a forward/reverse switching control device that controls switching of gears of the automatic transmission to forward or reverse by switching the forward/reverse switching lever; and the forward/reverse switching lever. a forward/reverse switching lever position detection sensor that detects the switching direction and outputs a signal corresponding to the switching direction; an accelerator pedal depression amount detection sensor that outputs a signal corresponding to the accelerator pedal depression amount; and the gear position detection sensor. After inputting the respective output signals from the forward/reverse switching lever position detection sensor and the accelerator pedal depression amount sensor and subjecting them to predetermined arithmetic processing, the clutch control device and the forward/reverse switching control device are controlled. A shift start control method in a vehicle comprising a control circuit that outputs a signal is such that the control circuit recognizes that the automatic transmission is in a neutral state based on the detection signal of the gear position detection sensor, and When it is confirmed that the accelerator pedal is depressed based on the detection signal of the pedal depression amount detection sensor, a clutch disengagement signal is output to the clutch control device to disengage the clutch, and then the longitudinal switching lever position is detected. When it is confirmed that the forward or backward switching lever has been operated in forward or reverse based on the detection signal of the sensor, a drive signal corresponding to the switching direction of the lever is output to the forward/reverse switching control device to synchronize the gears of the automatic transmission. After switching to the switching direction and confirming that the detection signal of the gear position detection sensor becomes a non-neutral signal, the clutch is controlled in the order of outputting a clutch connection signal to the clutch control device to bring the clutch into a connected state. It is.

(Operation) According to the above shift start control method, the driver can
When the accelerator pedal is pressed while the automatic transmission is in neutral, the clutch is disengaged, and when the forward/reverse switching lever is then operated in the forward or reverse direction, the gears of the automatic transmission are switched in the same direction. Then the clutch is connected,
The engine output is transmitted to the automatic transmission, and the vehicle shifts and starts.

(Embodiment) Hereinafter, a preferred embodiment in which the present invention is embodied in a forklift will be described with reference to the drawings.

In FIG. 1, the output of an engine 1 is transmitted to an automatic transmission 3 via a dry single-plate clutch 2, and the automatic transmission 3 controls driving drive wheels 5 via a differential gear mechanism 4. It drives forward and backward depending on the gear ratio. The dry single plate type clutch 2 that turns on and off the output of the engine 1 has its connection state adjusted relative to the stroke amount of the rod 6a that extends based on the drive of a clutch control actuator 6 as a clutch control device. be done.

The engine 1 is also used as a drive source for a hydraulic pump that supplies hydraulic oil to a lift cylinder for raising and lowering the fork and a tilt cylinder for tilting the mast.

The accelerator pedal depression amount detection sensor 7 is composed of a potentiometer and detects the depression amount of the accelerator pedal 12 installed in the driver's seat, and its detection signal is A/
The signal is converted into a digital signal by the D converter 13 and output to the interface 14. A forward/reverse switching lever position detection sensor 16 is provided at the driver's seat, which outputs a signal corresponding to the switching direction when the forward/reverse switching lever 15 is operated in the forward or reverse direction, and the detection signal is output to the interface 14. Ru. Furthermore, a gear position detection sensor 21 is provided to detect that the automatic transmission 3 is in a neutral state, and a detection signal from the sensor 21 is output to the interface 14.

A central processing unit (hereinafter referred to as CPU) 17, which forms the core of shift start control, operates according to a shift start control program stored in a read-only memory ROM 18 as a storage device, and communicates with each of the sensors via the interface 14. Input the detection signal from the random access memory RAM19.
to be memorized.

The CPU 17 operates the clutch control actuator 6 based on detection signals from the accelerator pedal depression amount detection sensor 7, the forward/reverse switching lever position detection sensor 16, and the gear position detection sensor 21.
Clutch actuator drive circuit 2 that drives
2 and outputs a drive signal to a gear switching actuator drive circuit 24 that drives a forward/reverse gear switching actuator 23 that controls gear switching of the automatic transmission 3.

Next, the operation of this embodiment will be explained with reference to FIGS. 2 and 3.

FIG. 2 shows the operation by the driver when shifting and starting the forklift, and the sequence of operations of the clutch 2 and automatic transmission 3 by the CPU 17. Further, FIG. 3 is a shift start control flowchart corresponding to the operations and sequence of operations shown in FIG. 2.

When the driver depresses the accelerator pedal 12 when shifting and starting the forklift, the accelerator pedal depression amount detection sensor 7 outputs an accelerator pedal depression signal indicating that the accelerator pedal 12 has been depressed.
It is output to the CPU 17. When the CPU 17 inputs the accelerator pedal depression signal, the CPU 17 recognizes that the automatic transmission 3 is in a neutral state based on the signal output from the gear position detection sensor 21, and then activates the clutch actuator drive circuit 22. A disconnection signal is output to bring the clutch 2 into a disconnected state. Next, when the driver puts the forward/reverse switching lever 15 into the forward or reverse direction, the forward/reverse switching lever position detection sensor 16 outputs a switching signal corresponding to the forward or reverse direction.The CPU 17 inputs the switching signal. Then,
Recognizing that the forward/reverse switching lever 15 has been operated in the forward or reverse direction, the forward/reverse gear switching actuator 23 causes the gear switching actuator drive circuit 24 to change the gear of the automatic transmission 3 to the gear corresponding to the switching signal. Outputs a drive signal for switching direction. Thereby, the gear of the automatic transmission 3 is switched to the forward or reverse direction, and the signal from the gear position detection sensor 21 is transmitted to the automatic transmission 3.
changes to a non-neutral signal, which means that it is no longer in a neutral state. As a result, the CPU 17 outputs a clutch connection signal to the clutch actuator drive circuit 22 so that the clutch control actuator 6 brings the clutch 2 into the connected state. As a result, the output of the engine 1 is transmitted to the automatic transmission 3 via the clutch 2, and the forklift is shifted and started.

As described above, with this shift start control, the clutch 2 is disengaged when the accelerator pedal 12 is depressed, so the start time lag is in the range T as shown in Figure 2, and the time lag in the conventional shift start is becomes shorter.

(Effects of the Invention) As described above, according to the present invention, when the accelerator pedal is depressed while the automatic transmission is in a neutral state, the clutch is released, and the forward/reverse switching lever is operated in the forward or reverse direction. Since the operation process after the automatic transmission shifts gears and engages the clutch, the shift start time lag from when the forward/reverse selector lever is placed in the forward or reverse direction until the vehicle starts is longer than before. It is shorter than shift start control and has the effect of improving driving feeling and work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the drive system mechanism and its electrical control block of a forklift according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the shift start process,
FIG. 3 is a shift start control flowchart. 1... Engine, 2... Clutch, 3... Automatic transmission, 6... Clutch control actuator,
7... Accelerator pedal depression amount detection sensor, 12...
...Accelerator pedal, 13...A/D converter, 14
...interface, 15...forward/reverse switching lever, 16...forward/reverse switching lever position detection sensor,
17...CPU, 18...Read-only memory, 1
9... Random access memory, 21... Gear position detection sensor, 22... Clutch actuator drive circuit, 23... Forward/forward gear switching actuator, 24... Gear switching actuator drive circuit.

Claims (1)

[Scope of Claims] 1. A clutch that transmits or cuts off engine output to the automatic transmission, a clutch control device that controls the connection state of the clutch, and a gear position detection sensor that detects the neutral state of the automatic transmission. a forward/reverse switching control device that controls switching of gears of the automatic transmission to forward or reverse by switching the forward/reverse switching lever; and a forward/reverse switching control device that detects the switching direction of the forward/reverse switching lever and generates a signal corresponding to the switching direction. a forward/reverse switching lever position detection sensor that outputs an output, an accelerator pedal depression amount detection sensor that outputs a signal corresponding to the amount of accelerator pedal depression, the gear position detection sensor, the forward/reverse switching lever position detection sensor, and the accelerator pedal depression amount. A shift start in a vehicle equipped with a control circuit that inputs respective output signals from a detection sensor, performs predetermined arithmetic processing, and outputs control signals to the clutch control device and the forward/reverse switching control device. The control method includes: in a state where the control circuit recognizes that the automatic transmission is in a neutral state based on a detection signal of the gear position detection sensor, the accelerator pedal is adjusted based on the detection signal of the accelerator pedal depression amount detection sensor. When it is confirmed that the pedal is depressed, a clutch disengagement signal is output to the clutch control device to disengage the clutch, and then the forward/reverse switching lever is turned off based on the output signal of the forward/reverse switching lever position detection sensor. When it is confirmed that the lever has been operated forward or reverse, a drive signal corresponding to the switching direction of the lever is output to the forward/reverse switching control device to switch the gear of the automatic transmission in the same switching direction, and the gear position detection sensor is activated. After confirming that a detection signal has become a non-neutral signal, a clutch connection signal is output to the clutch control device to put the clutch in a connected state.