JPH0437292B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to an inching control device for an industrial vehicle, and more particularly to clutch connection control during an inching operation.

(Prior Art) Conventionally, for example, in a forklift equipped with an automatic transmission with a dry single-plate clutch, the stroke amount of the clutch drive means relative to the depression amount of the inching pedal during inching operation, that is, the clutch connection state is shown in FIG. It is controlled as follows.

(Problem to be Solved by the Invention) However, when the driver releases the inching pedal to move after carrying out cargo handling work using the inching pedal, the clutch follows and engages, resulting in an accident. If you release the inching pedal too soon, the clutch will suddenly engage, causing an unpleasant shock or sudden start. Therefore, when releasing the inching pedal, you need to make delicate operations similar to the clutch pedal of a manual transmission car. It was necessary, and drivers were required to be skilled.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide an inching control device that does not cause a shock and does not cause a sudden start even if the inching pedal is suddenly released during an inching operation.

Structure of the Invention (Means for Solving Problems) The inching control device of the present invention includes a clutch that turns on and off the output of the engine and transmits the output to the transmission, and a clutch that operates the clutch to control the connection state of the clutch. The vehicle is provided with a clutch drive means for controlling the clutch, a clutch detection means for detecting the connected state of the clutch, an accelerator pedal for driving operation, and an accelerator operation amount detection means for detecting the operation amount of the accelerator pedal.

Furthermore, an inching pedal for inching operation, an inching operation amount detection means for detecting the operation amount of the inching pedal, an engine state detection means for detecting the state of the engine, and an inching pedal for inching operation is provided. a calculation means for calculating a clutch engagement speed based on detection signals from the engine condition detection means, the accelerator operation amount detection means, and the clutch detection means; and a first calculation means for controlling the clutch drive means based on the calculation results. A drive control means is provided.

Further, a determining means for determining whether the clutch has reached a position corresponding to the amount of operation of the inching pedal based on a detection signal from the clutch detecting means;
When the determining means determines that the clutch has reached a position corresponding to the amount of operation of the inching pedal,
The gist of the inching control device is that it is provided with a second drive control means for stopping the drive control of the clutch drive means.

(Function) When the inching pedal is operated in the direction of release, the calculating means calculates the clutch engagement speed based on the detection signals from the engine state detecting means, the accelerator operation amount detecting means, and the clutch detecting means. The first drive control means controls the clutch drive means based on the calculation result. The determining means determines whether the clutch has reached a position corresponding to the amount of operation of the inching pedal based on the detection signal from the clutch detecting means, and determines that the clutch has reached a position corresponding to the amount of operation of the inching pedal. When the determination means makes a determination, the second drive control means stops the drive control of the clutch drive means.

(Embodiment) Hereinafter, a preferred embodiment in which the present invention is embodied in a forklift will be described with reference to FIGS. 1 to 3.

FIG. 1 shows the mechanism and electric block circuit of the drive system of a forklift. 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 is connected to a differential gear mechanism 4. The running drive wheels 5 are driven forward and backward at a predetermined gear ratio via the drive wheel. The dry single-plate clutch 2 that turns on and off the output of the engine 1 has a 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 drive means. That is, the clutch transmission torque is controlled.

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.

Next, an electric circuit for driving and controlling the actuator 6 will be explained.

A stroke detection sensor 11 as a clutch detection means is composed of a potentiometer and detects the stroke of the rod 6a of the clutch control actuator 6, that is, the clutch connection state, and the detection signal is converted into a digital signal by an A/D converter 12. It is converted into a signal and output to the input/output interface 13.

The inching sensor 14, which serves as inching operation amount detection means, is composed of a potentiometer and detects the amount of depression of the inching pedal 15 provided at the driver's seat.The detected signal is converted into a digital signal by the A/D converter 16. It is output to the interface 13.

The accelerator sensor 17, which serves as an accelerator operation amount detection means, is also composed of a potentiometer and detects the amount of depression of an accelerator pedal 18 provided at the driver's seat, and the detection signal is converted into a digital signal by an A/D converter 19. and output to the interface 13. An engine rotation speed sensor 10 serving as an engine state detection means detects the rotation speed of the output shaft of the engine 1 and outputs the detection signal to the interface 13.

A central processing unit (hereinafter referred to as CPU) 20 serving as first and second drive control means, calculation means, and judgment means inputs detection signals from the respective sensors via the input/output interface 13, and stores them in a storage means. The controller operates according to a control program stored in a storage device 21. The CPU 20 determines the stroke amount C of the rod 6a of the clutch control actuator 6, that is, the connected state of the dry single plate clutch 2, based on the detection signal from the stroke detection sensor 11.
Further, the CPU 20 determines the depression amount I of the inching pedal 15 based on the detection signal from the inching sensor 14, and determines the depression amount A of the accelerator pedal 18 based on the detection signal from the accelerator sensor 17.

It should be noted that each of these calculations is made based on the data of the stroke, inching, connection to each detection signal of the accelerator sensors 11, 14, and 17, and the amount of depression, which are stored in advance in the storage device 21. In addition, the CPU 20 further transmits the connection and depression amounts C and A determined in response to the stroke and detection signals of the accelerator sensors 11 and 17.
are variable data for calculating the clutch connection speed stored in advance in the storage device 21 (Fig. 2 a, b).
), the variables f(C) and f(A) are processed in correspondence with the variables f(C) and f(A).

Further, the CPU 20 determines the respective engine rotational speeds for the calculated inching pedal depression amount I or accelerator pedal depression amount A based on the data stored in the storage device 21, and uses the interface 13 to adjust the engine rotational speed to the calculated rotational speed.
The rotation speed of the engine 1 is controlled via the .

Furthermore, the CPU 20 is the engine speed sensor 1
Based on the detection signal from 0, the amount of change ΔE in the engine rotation speed per 50 msec is calculated. Further, the CPU 20 processes the variable f(ΔENG) by making the amount of change ΔE of the calculation result correspond to the variable data shown in FIG.

The storage device 21 also stores information about the amount of depression of the inching pedal 15 and the rod 6a of the actuator 6.
stroke amount (i.e. clutch connected state)
Data is stored.

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

Now, when the inching pedal 15 is operated from the depressed state to the direction in which it is released, the CPU 2
0 reads the detection signal from the accelerator sensor 17 at that time and determines the amount A of depression of the accelerator pedal 18 at that time. The result is stored in a predetermined storage area of the storage device 21 (step 1, hereinafter the step will be denoted by S). Next, the CPU 20 determines the stroke amount C of the rod 6a of the clutch control actuator 6 based on the detection signal from the stroke detection sensor 11, and stores the result in a predetermined storage area of the storage device 21 (S2).

Subsequently, the CPU 20 calculates the amount of change ΔE in the engine speed per 50 msec based on the detection signal from the engine speed detection sensor 10, and stores the result in a predetermined storage area of the storage device 21 (S3). And CPU20 is inching sensor 1
Inching pedal 1 based on the detection signal from 4.
5 and stores the result in a predetermined storage area of the storage device 21 (S4). next
The CPU 20 stores the connection and depression amounts C, A, and the change amount ΔE stored in the storage device 21 in the storage device 21.
The variables f(C), f(A), and f(ΔENG) are calculated and determined in correspondence with the variable data shown in FIG. 2 stored in advance (S5).

Then, the CPU 20 calculates the variable f(C),
Based on f(A) and f(ΔENG), the optimum clutch connection speed F(speed) is determined according to the following formula (S6).

F (speed) = K×f(C)×f(A)×f(ΔENG) Note that K is a constant.

Based on the obtained result, the CPU 20 controls and drives the clutch control actuator (S7).
Therefore, the rod 6a is driven slowly at the clutch connection speed F (speed) as a result of the calculation, and the clutch 2 is gradually connected.

Meanwhile, during this operation, the CPU 20 moves the rod 6 based on the detection signal from the stroke detection sensor 11.
It is sequentially determined whether the clutch 2 is connected to the position where a corresponds to the amount of depression of the inching pedal 15 (S8). If the clutch 2 is not connected to the position corresponding to the amount of depression of the inching pedal 15, the control program returns to S1.

When the clutch 2 is connected to the position corresponding to the amount of depression of the inching pedal 15, the CPU 2
0 ends the control of the actuator 6 and stops the connection of the clutch 2 (S9).

In this embodiment, the accelerator pedal 18
The clutch is connected at the optimum clutch connection speed that matches the vehicle condition at that time, using parameters such as the amount of depression of the clutch, the stroke amount of the clutch control actuator 6, and the amount of change in the engine 1, thereby preventing shock when the clutch is connected. can do.

In the above embodiments, a dry single-plate clutch was explained, but wet-type clutches, multi-plate clutches, etc.
It may also be applied to other clutches.

Effects of the Invention As detailed above, in this invention, when the inching pedal is operated in the direction in which the inching pedal is released, the clutch driving means does not immediately correspond to the stroke amount relative to the depression amount of the inching pedal.
Since the clutch connection speed is calculated to be the optimum connection speed and the clutch is loosely connected based on the result, there is no risk of large torque fluctuations occurring at the time of start and causing the forklift to suddenly start. Moreover, unlike the conventional method, there is no need for sophisticated inching pedal operation to prevent this sudden start, which has the excellent effect of improving work efficiency.

[Brief explanation of drawings]

Fig. 1 shows the mechanism and electric block circuit diagram of a forklift embodying this invention, Fig. 2 shows various data for calculating the clutch connection speed, where a is the accelerator pedal depression amount and the variable f(A). b is the correspondence diagram between the clutch stroke amount and the variable f(C), c is the correspondence diagram between the engine change amount and the variable f
(ΔENG), FIG. 3 is a flowchart showing the action of the forklift, and FIG. 4 is a diagram showing the relationship between the connection state of the rod and clutch with respect to the amount of depression of the inching pedal. DESCRIPTION OF SYMBOLS 1... Engine, 2... Dry single plate clutch, 3... Automatic transmission, 6... Clutch control actuator as clutch driving means, 6a... Rod, 10...
Engine speed sensor as engine state detection means, 11... Stroke detection sensor as clutch detection means, 14... Inching sensor as inching operation amount detection means, 15... Inching pedal, 17... Accelerator sensor as accelerator operation amount detection means. , 18...Accelerator pedal, 20...Calculating means, determining means, central processing unit (CPU) as first and second drive control means, 21...Storage device, 22...Actuator drive circuit.

Claims (1)

[Scope of Claims] 1. A clutch that turns on and off the output of the engine and transmits the output to the transmission, a clutch driving means that operates the clutch and controls the connection state of the clutch, and a connection state of the clutch. an accelerator pedal for traveling operation; an accelerator operation amount detection means for detecting the amount of operation of the accelerator pedal; an inching pedal for inching operation; and an inching pedal for detecting the amount of operation of the inching pedal. an operation amount detection means, an engine state detection means for detecting the state of the engine, and a detection signal from the engine state detection means, the accelerator operation amount detection means, and the clutch detection means when the inching pedal is operated in a direction in which the inching pedal is released. a first drive control means for controlling the clutch drive means based on the result of the calculation, and a first drive control means for controlling the clutch drive means based on the detection signal from the clutch detection means; determining means for determining whether the clutch has reached a position corresponding to the amount of operation of the inching pedal; and when the determining means determines that the clutch has reached a position corresponding to the amount of operation of the inching pedal, stopping drive control of the clutch drive means. Second to do
An inching control device for an industrial vehicle, comprising a drive control means.