JPS6364838A - Automatic inching control device for industrial vehicle - Google Patents

Abstract

PURPOSE:To omit an inching pedal and simplify the operating system of an industrial vehicle by making a clutch control means output a control signal to a clutch driving means in order to control a clutch position when it is judged a cargo operating time by a judging means. CONSTITUTION:A CPU 24 as an engine speed control means, a judging means, and a clutch control means is operated according to a control program stored in a ROM 25 and receives detected signals from sensors via an input/output interface 12. At the time of cargo work, the CPU 24 indexes the operating quantity of a cargo operating lever 20 based on the detected signal of a cargo work lever position sensor 19, while also indexing the traveling speed of a fork lift truck based on the detected signal from a vehicle speed sensor 11. And, based on this indexed operating quantity of the lever 20, the CPU 24 drives a throttle actuator and controls a throttle opening, to control an engine 1.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention relates to industrial vehicles such as forklifts, and more specifically relates to an automatic inching control ML device that performs cargo handling operations without using an inching pedal. .

(Prior Art) A forklift truck equipped with an automatic transmission with a clutch has been proposed. Then, during normal driving, the accelerator operation m and the traveling speed are detected, and based on the detected amount of rain, automatic gear change is performed and the clutch is turned on and off. This type of forklift is equipped with an inching pedal, and by depressing and operating this inching pedal, the cargo handling system and the traveling system can be separated. It has become.

(Problems to be Solved by the Invention) The purpose of the present invention is to simplify the operation system of an industrial vehicle by omitting the inching pedal, and to provide an automatic inching system for an industrial vehicle that can perform cargo handling operations similar to conventional ones. m equipment.

Structure of the Invention (Means for Solving Problems) This invention includes a clutch that turns on and off the output of an engine and transmits the output to an automatic transmission, and a clutch that operates the clutch to control the connection state of the clutch. For an industrial vehicle equipped with a clutch drive means, an accelerator pedal for traveling operation, an accelerator operation amount detector for detecting the operation amount of the accelerator pedal, and a cargo handling operation lever for cargo handling operation, a cargo handling operation amount detector that detects the operation state; an engine rotation speed control means that controls the engine rotation speed based on the detection of the cargo handling operation amount detector; a determining means for determining, and a clutch control means for outputting a control signal to a clutch driving means to control a clutch position based on a detection signal from an accelerator operation amount detector when the determining means determines that a cargo handling operation is being performed. The gist of this document is that it has been established.

(Function) When the cargo handling operation lever is operated, the cargo handling operation amount detector detects the operating state. Then, the engine speed control means controls the engine speed based on the detection by the manipulated variable detector. Further, the determining means determines that a cargo handling operation is being performed based on the detection by the cargo handling operation amount detector. When the determination means determines that the cargo handling operation is being performed, the clutch control means outputs a control signal to the clutch drive means to control the clutch position based on the detection signal from the accelerator operation item detector.

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

Figure 1 shows the mechanism of the drive system of a forklift, in which the output of the engine 1 is transmitted through a dry single-plate clutch 2 to an automatic transmission R3.
The automatic transmission a3 drives the running drive wheels 5 forward and backward at a predetermined gear ratio via the differential tooth 11 mechanism 4. The dry single plate clutch 2 that turns on and off the output of the engine 1 has a rod 6a that extends based on the drive of a clutch control actuator 6 as a clutch drive means.
The connection state of the clutch 2 is adjusted relative to the stroke amount.

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.

On the other hand, the automatic transmission 3 can shift between 1 (fast, low speed) and 2 (fast, high speed) by driving the shift switching actuator 7, and can change between forward traveling and backward traveling by driving the forward/reverse switching actuator 8. can be switched to

Next, an electric circuit for driving and controlling each of the actuators 6 to 8 will be explained with reference to FIG.

The vehicle speed sensor 11 detects the rotational speed of the output shaft of the automatic transmission 3, as shown in FIG. 1, and outputs the detection signal to the input/output interface 12. Engine speed sensor 13
detects the rotational speed of the output shaft of the engine 1, as shown in FIG. 1, and outputs the detection signal to the interface 12.

The stroke detection sensor 14 is composed of a potentiometer and detects the stroke of the O-rad 6a of the clutch control actuator 6, and the detection signal is sent to the A/D converter 15.
is converted into a digital signal at the interface 1.
2 is output.

Accelerator opening sensor 16 as an accelerator operation amount detector
consists of a potentiometer that detects the depression of the accelerator pedal 17 installed in the driver's seat, and its detection signal is A.
The signal is converted into a digital signal by the /D converter 18 and output to the interface 12.

Cargo handling operation lever position sensor 1 as cargo handling operation amount detector
9 is a potentiometer that detects the amount of operation of the cargo handling control lever 20 installed in the driver's seat, and its detection signal is sent to the A/D.
The signal is converted into a digital signal by the converter 21 and output to the interface 12.

Further, the cargo handling operation lever position sensor 19 includes an idle switch, and when the cargo handling operation lever 20 is operated, the idle switch is turned off, and is in an on state when the cargo handling operation lever 20 is not operated. Then, the on or off signal is output to the interface 12. Further, when the cargo handling operation lever 20 is operated, a lift cylinder for raising and lowering the fork and a tilt cylinder for tilting the mast are controlled via a hydraulic system.

The forward/reverse movement detection sensor 22 detects the switching state (forward, neutral, reverse) of a forward/reverse movement switching lever 23 provided at the driver's seat, and outputs the detection signal to the interface 12.

A central processing unit (CPU) 24 serving as an engine speed control means, a determination means, and a clutch control means operates according to a control program stored in a read-only memory (hereinafter referred to as ROM) 25, and communicates via the input/output interface 12. Detection signals from each of the sensors are input.

During normal driving without cargo handling work, the CPU 24 determines the amount of depression of the accelerator pedal 17 based on the detection signal from the accelerator opening sensor 16, and determines the traveling speed of the forklift based on the detection signal from the vehicle speed sensor 11. Find out.

Then, the CPU 24 uses this determined accelerator pedal 17.
controls the opening degree of the engine throttle by driving a throttle actuator (not shown) based on the amount of depression of the engine;
The rotation speed of the engine 1 is controlled. Note that the throttle opening degree corresponding to the amount of depression of the accelerator pedal 17 is set in advance, and the data is stored in the ROM2.
It is stored in 5.

During cargo handling work, the CPU 24 operates the cargo handling operating lever 20 based on the detection signal from the cargo handling operating lever position sensor 19.
The operation amount of the forklift truck is determined based on the detection signal from the vehicle speed sensor 11. Then, the CPU 24 executes this indexed cargo handling operation lever 2.
Based on the operator number 0, a throttle actuator (not shown) is driven to control the opening degree of the engine throttle;
The rotation speed of the engine 1 is controlled.

Note that the throttle opening degree for the operator of the cargo handling operation lever 20 is set in advance, and the data is stored in the ROM.
It is stored in 25.

Further, when the cargo handling operation lever 20 is operated and the idle switch is turned off to input an off signal, the CPtJ 24 determines that cargo handling operation is being performed based on the off signal. When determining that the cargo handling operation is being performed, the CPU 24 determines the amount of depression of the accelerator pedal 17 based on the detection signal from the accelerator opening sensor 16. Then, the CPU 24 outputs a control signal to the actuator drive circuit 26 based on the determined depression amount of the accelerator pedal 17 to drive the clutch control actuator 6 and control the clutch 2. That is, when the accelerator pedal 17 is depressed, the CPU 24 drives and controls the clutch 2 in the connecting direction in accordance with the amount of depression.

The degree of engagement of the clutch with respect to the amount of depression of the accelerator pedal 17 is set in advance, and the data is stored in the ROM 25.

In addition, the CPU 24 determines the optimum speed change state for the current driving state based on the detection signals from the vehicle speed sensor 11 and the accelerator opening sensor 16 except during cargo handling operations. Then, the CPU 24 outputs a drive control signal to the actuator drive circuit 27 via the input/output interface 12 based on the determined shift state to drive the shift switching actuator 7 to change the shift state of the automatic transmission 3 to 1. Switch to speed or 2nd speed.

At this time of switching, the CPU 24 outputs a drive signal to the actuator drive circuit 26 to drive the clutch control actuator 8 to disconnect the dry single plate clutch 2. Note that the speed change state for this running state is set in advance, and the speed change data is stored in the ROM2.
It is stored in 5.

Further, the CPU 24 switches the forward/reverse switching lever 23 (forward, neutral, reverse) based on the detection signal from the forward/reverse detection sensor 22.
Based on the switching, a drive control signal is output to the actuator drive circuit 28 via the interface 12 to drive the forward/reverse switching actuator 8 to set the automatic transmission 3 to a forward, neutral, or reverse state. Switch.

At this time of switching, the CPU 24 outputs a drive signal to the actuator drive circuit 26 to drive the clutch control actuator 8 to disconnect the dry single-plate clutch 2, as described above.

Note that readable and rewritable memory (hereinafter referred to as RA)
29 (referred to as M) is designed to temporarily store various calculation results of the CPU 24.

Next, the operation of the forklift constructed as described above will be explained.

Now, when you operate the cargo handling operation lever 20 to perform cargo handling operation,
The idle switch is turned off from the on state. Then, the CPLJ 24 determines that cargo handling operation is in progress based on the off signal from the idle switch.

Then, the CPLJ 24 determines the operation amount of the cargo handling operation lever 20 based on the detection signal from the cargo handling operation lever position sensor 19, and determines the traveling speed of the forklift based on the detection signal from the vehicle speed sensor 11. Then, CPtJ24 uses this indexed cargo handling operation lever 20.
Based on the operation amount, a throttle actuator (not shown) is driven to control the opening degree of the engine throttle, thereby controlling the rotation speed of the engine 1. Further, by operating the cargo handling operation lever 20, a lift cylinder for raising the fork and a tilt cylinder for tilting the mast are controlled via the hydraulic system.

On the other hand, if the driver wants to run the forklift during the cargo handling operation, he or she depresses the accelerator pedal 17. Then, the CPU 24 determines the amount of depression of the accelerator pedal 17 based on the detection signal from the accelerator opening sensor 16. Then, the CPU 24 operates the actuator drive circuit 2 based on the determined amount of depression of the accelerator pedal 17.
6, the clutch control actuator 6 is driven to control the clutch 2 in the connecting direction.

Therefore, when the accelerator pedal 17 is depressed, the clutch 2 is connected, and the forklift truck travels at a free speed. Conversely, when the accelerator pedal 17 is released, the clutch 2 is disconnected, the engine 1 and automatic transmission 3 are disconnected, and torque transmission is interrupted.

Furthermore, by depressing the accelerator pedal 17, it is also possible to bring the clutch into a partially engaged state.

Note that the present invention is not limited to the above embodiments,
Any changes may be made without departing from the spirit of the invention.

Effects of the Invention As described above, according to the present invention, it is possible to simplify the operation system by omitting the inching pedal, and the cargo handling operation can be performed only with the cargo handling operation lever, and travel control can be performed only with the accelerator pedal. can. Therefore, unlike the conventional method, it is possible to perform cargo handling work without operating the inching pedal, and this has an excellent effect that driving work can be performed easily.

[Brief explanation of the drawing]

FIG. 1 is a mechanical diagram showing the mechanism of a drive system of a forklift embodying the present invention, and FIG. 2 is an electrical block circuit diagram of the same forklift.

Claims (1)

[Scope of Claims] A clutch that turns on and off the output of the engine and transmits the output to an automatic transmission, a clutch drive means that operates the clutch and controls the connection state of the clutch, and a clutch for driving operation. An industrial vehicle comprising an accelerator pedal, an accelerator operation amount detector that detects an operation amount of the accelerator pedal, and a cargo handling operation lever for cargo handling operation, comprising: a cargo handling operation amount detector that detects an operation state of the cargo handling operation lever; , an engine rotational speed control means for controlling the engine rotational speed based on the detection by the cargo handling operation amount detector; and a determining means for determining that a cargo handling operation is being performed based on the detection by the cargo handling operation amount detector; An automatic inching control device for an industrial vehicle, comprising a clutch control means that outputs a control signal to a clutch drive means to control the clutch position based on a detection signal from an accelerator operation amount detector when it is determined that an accelerator operation amount detector is operating.