JP2504984B2 - Inching control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is an inching in a cargo handling vehicle provided with an accelerator pedal and an inching pedal which are operated by a single prime mover such as a forklift to perform traveling and cargo handling operations. The present invention relates to a control device.

(Prior Art) Conventionally, for example, in a forklift, one prime mover (engine) is used to perform traveling and cargo handling operations. Further, the vehicle is provided with an inching pedal, and when the inching pedal is stepped on, the clutch is disengaged, and when the pedal is further stepped on, the brake is applied, and the cargo handling operation can be performed simultaneously with the traveling stop operation.

(Problems to be Solved by the Invention) However, since the inching pedal and the engine throttle are completely independent, the throttle opening (engine speed) does not change even if the inching pedal is operated. Therefore, when performing the inching operation, it is necessary to depress the inching pedal and also depress the accelerator pedal in order to increase the engine speed, which causes a problem that the pedal operation becomes complicated.

An object of the present invention is to solve the above problems and provide an inching control device capable of performing an inching operation by a simple operation without requiring a complex compound operation of an accelerator pedal and an inching pedal at the time of an inching operation. It is in.

Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention provides a cargo handling vehicle including an accelerator pedal and an inching pedal, which are operated by a single prime mover to perform traveling and cargo handling operations. An inching control device including inching detection means for detecting operation of the inching pedal, and rotation speed control means for controlling the rotation speed of the prime mover to the rotation speed required for cargo handling operation when the inching detection means operates the inching pedal. Is the gist.

(Operation) When the inching detection means detects that the inching pedal is operated by the above means, the rotation speed control means controls the rotation speed of the prime mover to the rotation speed necessary for the cargo handling operation.
As a result, the cargo handling operation can be performed without operating the accelerator pedal.

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

As shown in FIG. 1, the output of the engine 1 as the prime mover is transmitted to the automatic transmission 3 via the dry single-plate clutch 2, and the output of the automatic transmission 3 is driven for traveling via the differential gear mechanism 4. The wheels 5 are driven forward and backward with a predetermined gear ratio. Further, the engine 1 drives a cargo handling hydraulic pump (not shown) to supply hydraulic oil to a lift cylinder, a tilt cylinder and the like to carry out cargo handling operation.

Further, the engine 1 has a throttle actuator 6
The throttle opening (engine speed) is adjusted by driving. An engine speed sensor 7 is provided on the output shaft 1a of the engine 1. The sensor speed is detected by the sensor 7 and the detection signal is output to the input / output interface 8.

The connection state of the dry single plate clutch 2 for turning on and off the output of the engine 1 is adjusted relative to the stroke amount of the rod 9a extending based on the drive of the clutch control actuator 9. Stroke detection sensor
Reference numeral 10 detects the stroke amount of the rod 9a of the clutch control actuator 9, and the signal is converted into a digital signal by the A / D converter 11 and output to the input / output interface 8.

The accelerator opening sensor 12 is composed of a potentiometer,
The amount of depression of the accelerator pedal 13 provided in the driver's seat is detected. Then, the signal is converted into a digital signal by the A / D converter 14 and output to the input / output interface 8. Further, the inching sensor 15 as the inching detection means is composed of a potentiometer,
The amount of depression of the inching pedal 16 as provided in the driver's seat is detected. Then, the signal is converted into a digital signal by the A / D converter 17 and output to the input / output interface 8.

A microcomputer 18 as a rotation speed control means includes a central processing unit (hereinafter, referred to as CPU) 19, a program memory 20 including a read-only memory (ROM) storing a control program, a reading and temporarily storing a calculation result of the CPU 19. The work memory 21 is composed of a rewritable memory (RAM). The CPU 19 operates according to the control program stored in the program memory 20.

CPU 19 is an accelerator opening sensor 12 and an inching sensor 1
The operation amount signal from 5 is input, and based on the signal, the throttle actuator 6 is driven through the actuator drive circuit 22 to adjust the throttle opening degree of the engine 1 and perform control so as to obtain a predetermined engine speed. .

That is, the CPU 19 controls the throttle actuator 6 to set the throttle opening corresponding to the depression amount of the accelerator pedal 13.
The throttle actuator 6 is controlled so that the throttle opening (engine speed) is set to the minimum throttle opening required for the cargo handling operation when the inching pedal 16 is operated. At this time, the CPU 19 inputs the detection signal from the engine speed sensor 7 and controls it to a predetermined engine speed by feedback control. It should be noted that the throttle opening by the operation of the accelerator pedal 13 and the inching pedal 16 is stored in the program memory 20 in advance.

The CPU 19 also controls the clutch control actuator 9 through the actuator drive circuit 23 by the input of an operation amount signal corresponding to the operation amount of the inching pedal 16 from the inching sensor 15 to connect and disconnect the dry single plate clutch 2. Then, the brake actuating actuator 24 is driven to control the brake drum 25. It should be noted that the CPU 19 performs a predetermined operation while the detection value of the stroke amount detected by the stroke detection sensor 10 is fed back when the dry single plate clutch 2 is connected and disconnected.

Next, the operation of the inching control device for a forklift thus constructed will be described with reference to FIG.

The CPU 19 opens the throttle corresponding to the accelerator pedal 13 when the inching pedal 16 is being operated while the accelerator pedal 13 is being depressed, but the inching pedal 16 is operated when the accelerator pedal 13 is not depressed.
When the inching pedal 16 continues to be operated, the throttle opening (engine speed) that is idling is opened to a predetermined throttle opening, and the engine speed is maintained by maintaining this opening. Raise. Then, when the engine speed is increased, the cargo handling operation can be performed without operating the accelerator pedal 13.

Further, the CPU 19 disengages the dry single-plate clutch 2 by the input of the operation amount signal from the inching sensor 15 which is shown when the inching pedal 16 is depressed, and further the inching pedal 16 is operated.
When 16 is depressed, the brake actuating actuator 24 is controlled to cause the brake drum 25 to perform the control operation.

Further, when the CPU 19 determines from the signal from the inch sensor 15 that the inching pedal 16 is not depressed, the throttle opening (engine speed) for idling is restored.

Thus, in this embodiment, the inching pedal 16
When the inching pedal 16 is operated, the throttle is opened to achieve the engine rotation required for the cargo handling operation, and therefore, when performing the inching operation, the inching pedal 16 and the accelerator pedals 13 and 16 are not operated. The operation is easy and the driver's fatigue is reduced.

Incidentally, the present invention is not limited to the above embodiment, for example, in the above embodiment, the accelerator opening during the inching operation was uniquely determined, but the state of the cargo handling (presence or absence of the cargo handling and cargo handling It is also possible to provide a cargo handling state detection sensor for detecting the weight) and set the optimum throttle opening (engine speed) according to the state. By doing so, fuel consumption can be improved and noise can be reduced.

Further, the present invention may be applied to various cargo handling vehicles other than forklifts.

Effects of the Invention As described in detail above, the present invention provides an inching pedal in an industrial vehicle equipped with a general accelerator pedal and an inching pedal, which does not require a complicated combined operation of the accelerator pedal and the inching pedal during an inching operation. Since the number of revolutions of the prime mover can be controlled and the cargo handling operation can be performed only by the operation of, the pedal operation is simplified and the driver's fatigue can be reduced, and the skill of pedal operation is not required. Since it is not necessary to make a change in the external structure of the industrial vehicle equipped with the accelerator pedal and the inching pedal, it is advantageous in terms of cost, and the present invention can be applied to the conventional industrial vehicle, so that the versatility is high. Exerts an excellent effect.

[Brief description of drawings]

FIG. 1 is a drive system and control system diagram of the same vehicle embodying the present invention in a forklift, and FIG. 2 is a flow chart diagram for explaining the operation of an inching control device. 1 is an engine as a prime mover, 6 is a throttle actuator, 13 is an accelerator pedal, 15 is an inching sensor as inching detecting means, 16 is an inching pedal, 18
Is a microcomputer as rotation speed control means, and 22 is an actuator drive circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Seiichi Hatake, 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Fujitsu Limited (56) References JP-A-61-238535 (JP, A)

Claims (3)

(57) [Claims] 1. A cargo handling vehicle including an accelerator pedal and an inching pedal that are depressed to perform traveling and cargo handling operations by one prime mover, and an inching detection means for detecting an operation of the inching pedal, and an inching detection means. And an inching control device for controlling the number of revolutions of the prime mover to the number of revolutions required for cargo handling operation when the inching pedal is operated. 2. The engine is the prime mover, and the rotation speed control means controls the engine rotation speed by driving a throttle actuator through an actuator drive circuit to adjust the throttle opening. The inching control device according to item 1. 3. The inching control device according to claim 2, wherein the rotation speed control means controls the predetermined throttle opening based on the cargo handling state detecting means for detecting the cargo handling state.