JPS63269739A - Clutch control device - Google Patents

Abstract

PURPOSE:To secure always stabilized driving regardless of load conditions by comparing an actual engine rpm with an optimum engine rpm corresponding to an accelerator travel and, when the former is smaller than the latter, changing a half-clutch target position toward a disengagement side. CONSTITUTION:A microprocessor 18 is actuated by a CPU 19 based on a program memory 20. Detected signals from various sensors 7, 10-13,16 for detecting various operating conditions of an engine 1, clutch 2 and automatic transmission 3 are inputted via an input-output interface 9 to the CPU. On the other hand, various control signals are outputted via the input-output interface 9 to respective drive circuits 22-24 to control the engine 1, clutch 2 and automatic transmission 3. In this case, if the engine rpm detected by the sensor 12 is smaller than an optimum engine rpm corresponding to the travel (depressed amount) of an accelerator pedal 14 detected with a sensor 13, a half-clutch target position is changed toward a disengagement side.

Description

[Detailed description of the invention] purpose of invention (Industrial application field) The present invention relates to a clutch control device.

(Prior art) Conventionally, in a vehicle equipped with an automatic transmission equipped with a dry single-plate clutch, such as a forklift, the vehicle is started with the clutch in a half-clutch state, and a clutch control method for this purpose is described, for example, in Japanese Patent Laid-Open No. 5
Various proposals have been made as described in Japanese Patent No. 9-1821. As an example, the half-clutch state fi (half-clutch target position) is uniquely determined by the amount of depression of the accelerator pedal, and the clutch is actuated to this half-clutch target position to transmit the engine output to the transmission. When the rotation speed matches the rotation speed of the input shaft of the transmission, the clutch is fully engaged (completely connected).
.

(Problem to be solved by the invention) However, when a vehicle is towing another vehicle or trying to push something, the load on the vehicle is large and the engine may stop when the clutch is engaged. There was a problem with putting it away.

SUMMARY OF THE INVENTION An object of the present invention is to provide a clutch control device that solves the above-mentioned problems and allows stable running at all times regardless of load conditions.

Structure of the Invention (Means for Solving Problems) In order to achieve the above object, the present invention includes a pedal depression amount detection means for detecting the depression claw of the pedal, and an engine rotation speed for detecting the rotation speed of the output shaft of the engine. a detection means, a transmission input side rotational speed detection means for detecting the rotational speed of the input shaft of the transmission, and a clutch engagement position control means for controlling a clutch engagement position, and the pedal depression by the pedal depression amount detection means is provided. Based on the same, the clutch is actuated to a predetermined half-clutch target position by the clutch engagement position control means to transmit the engine output to the transmission, and the engine rotation speed and the transmission input side are detected by the engine rotation speed detection means. In a clutch control device that completely engages the clutch when the input side rotational speed of the transmission becomes equal based on the rotational speed detection means, the optimum engine rotational speed for the amount of pedal depression when the clutch is operated to the half-clutch target position is provided. a storage means for storing the number; a comparison means for comparing the actual engine rotation speed determined by the engine rotation speed detection means with the optimum engine rotation speed for the current pedal depression amount stored in the storage means; The clutch control device is comprised of a half-clutch target position changing means for changing the half-clutch target position to a new position when the engine speed is lower than the optimum engine speed.

(Function) With the above configuration, the comparison means compares the actual engine rotation speed detected by the engine rotation speed detection means and the pedal depression m at that time.
The half-clutch target position changing means changes the half-clutch target position to a new position when the actual engine speed is smaller than the optimum engine speed.

(Example) Hereinafter, an example in which the present invention is embodied in a forklift equipped with an automatic transmission with a dry single-plate clutch will be described with reference to the drawings.

FIG. 1 shows the mechanism and electrical configuration of a forklift drive system. The output of an engine 1 is transmitted to an automatic transmission 3 via a dry single-plate clutch 2, and is transmitted to the driving drive wheels via a differential gear mechanism 4. 5 is moved forward and backward at a predetermined gear ratio.

The dry single-plate clutch 2 that turns on and off the output of the engine 1 has a rod 6 that extends based on the drive of a clutch control actuator 6 as clutch connection position control means.
The connection state (connection position) of the clutch is controlled relative to the stroke amount of the clutch a.

The stroke detection sensor 7 consists of a potentiometer,
The stroke of the O-rad 6a of the clutch control actuator 6 is detected, and the detection signal is converted into a digital signal by the A/D converter 8 and output to the input/output interface 9. An input shaft rotation speed sensor 10 serving as transmission input side rotation speed detection means detects the rotation speed of the input shaft 3a of the automatic transmission 1f13 and outputs the detection signal to the input/output interface 9. Vehicle speed sensor 11
is automatic transmission! 13 and outputs the detection signal to the input/output interface 9. An engine rotation speed sensor 12 serving as engine rotation speed detection means detects the rotation speed of the output shaft 1 a of the engine 1 and outputs the detection signal to the input/output interface 9 .

The accelerator opening sensor 13, which serves as a means for detecting the amount of pedal depression, is composed of a potentiometer, and detects the amount of depression of the accelerator pedal 14 installed in the driver's seat, and converts the detection signal into a digital signal by the A/D converter B15. Output to input/output interface 9. In this embodiment, the forward/reverse lever position detection sensor 16 is composed of a plurality of limit switches, and detects the switching state (forward, neutral, reverse) of the forward/reverse lever 17 provided at the driver's seat, and transmits the detection signal to the input/output interface. Output to 9.

The microcomputer 18 as a clutch engagement position control means, comparison means, and half-clutch target position changing means includes a central processing unit (hereinafter referred to as CPU) 19 and a program memory 20 as a storage means consisting of a read-only memory (ROM). , and a working memory 21 consisting of a readable and rewritable memory (RAM) in which the pruning processing results of the CPU 19 are temporarily stored. The CPU 19 operates based on the control program stored in the program memory 20.

The CPU 19 receives detection signals from each of the sensors via the input/output interface 9. And CPU 1
Reference numeral 9 indicates the rod 6a of the clutch control actuator 6 based on the detection signal from the stroke detection sensor 7.
In other words, the connected state of the dry single plate clutch 2 is determined, and the vehicle speed of the forklift at that time is determined based on the detection signal from the vehicle speed sensor 11. Further, the cpul 9 determines the current engine speed based on the detection signal from the engine speed sensor 12, and determines the current automatic transmission 3 based on the detection signal from the input shaft speed sensor 10.
The rotation speed of the input shaft 3a is determined.

Furthermore, the CPU 19 determines the amount of depression of the accelerator pedal 14 at that time based on the detection signal from the accelerator opening sensor 13, and determines the lever operation position at that time based on the detection signal from the forward/reverse lever position detection sensor 16. It has become.

Note that the 8 values for each of the detection signals are determined by the program menu 2.
It is determined based on control program data stored in advance in 0.

When the engine 1 is running and the forklift is stopped, the CPU 19 enters the start mode by depressing the accelerator pedal 14 when the forward/reverse lever 17 is in the forward or reverse position, and the CPU 19 enters the start mode by depressing the accelerator pedal 14, which is stored in the program memory 20 in advance. Controls the start of the forklift based on the start data.

This start control is performed by controlling the clutch engagement position of the dry single-plate clutch 2 based on the finger pressed on the accelerator pedal 14. That is, the half-clutch target position for the depression of the accelerator pedal 14 shown in FIG. 2 is stored in advance in the program memory 20, and the CPtJ
19 determines a half-clutch target position for the amount of depression of the accelerator pedal 14 at that time, and controls the clutch control actuator 6 so that the clutch is positioned at the half-clutch target position.

The specific control at the time of starting is performed by controlling the stroke amount of the rod 6a of the clutch control actuator 6 via the actuator drive circuit 22. The connection state of the clutch between the strokes of the rod 6a W! 1 (half-clutch target position) has a certain relationship in advance, so the data of the maximum torque generation engine rotation speed with respect to the throttle opening (depression of the accelerator pedal 14) shown in FIG. 3 is stored in advance in the program memory 2o. There is. This data is the engine rotational speed (for example, Ne1 to Ne4) that generates the maximum torque for each throttle opening shown in FIG.

The CPU 19 also controls the rotation speed of the engine 1 by controlling the throttle valve via the throttle actuator drive circuit 23 relative to the depression of the accelerator pedal 14, and also controls the depression amount of the accelerator pedal 14 and the vehicle speed during driving. Based on this, as shown in FIG. 5, the automatic speed change II3 is controlled to be either 1st or 2nd speed via the gear switching actuator drive circuit 24 to control its gear ratio.

Next, the operation of the clutch control device configured as described above will be explained based on FIG. 6.

Now, when the forklift is stopped and the forward/reverse lever 17 is in the neutral state, when the forward/reverse lever 17 is operated from the neutral position to the forward position in order to move forward, the CPU 19 moves the automatic transmission 3 to the forward and first gear. Control in position.

Then, when you step on the accelerator pedal 14, CPtJ19
enters the start mode and reads out the start data stored in the program memory 20 in advance.

Based on the data shown in FIG. 2, the CPU 19 reads the half-clutch target position relative to the pedal depression of the accelerator pedal 14 at that time. Furthermore, the CPU 19 drives the clutch control actuator 6 so that the clutch position becomes the half-clutch target position.

Then, the CPU 19 reads the engine rotation speed Ne and also reads the input shaft rotation speed Ni. C.P.
U19 compares the engine rotation speed Ne and the input shaft rotation speed Ni, and sets the clutch control actuator so that if both rotation speeds Ne and Ni are equal, the clutch position is in the fully engaged position (fully connected state). Drive 6.

On the other hand, the CPU 19 controls the engine speed Ne as described above.
If the input shaft rotational speed Ni is not equal to the input shaft rotational speed Ni, the engine rotational acceleration dNe is calculated. In other words, the difference in engine speed (N e2 - N
By determining el>, the engine rotational acceleration dNe
(= (Ne2-Ne1)/Δt) is calculated.

When the CPL 119 determines that the engine rotational acceleration dNe thus obtained is a negative value and the engine rotation is decreasing, it reads the maximum torque generating engine rotational speed hNe from the correction map shown in FIG. The maximum torque generating engine rotation speed hNe is compared with the actual engine rotation speed Ne. As a result, the CPU 19 determines that the actual engine speed Ne is the maximum torque generation engine speed h.
If it is smaller than Nt, the half-clutch target position determined from FIG. 2 is slightly corrected to the forward side. After that, the CPU
19 drives the clutch control actuator 6 so that the clutch is in the half-clutch position corrected to the disengaged side.

At this time, as a result of the clutch position shifting to the disengaged side, the engine 1 does not stop even if a load is applied when the vehicle starts.

In this way, the CPLJ 19 performs clutch control at the maximum torque-generating engine speed, and when the engine speed Ne and the input shaft speed Ni become equal, the clutch is fully engaged as described above, and normal running begins.

Further, the CPU 19 performs a similar latch operation when changing gears while the vehicle is running. At this time, the engine speed is adjusted to the speed that generates the maximum torque at the throttle opening, so even at vehicle speeds that require half-clutch driving, the engine speed is clutch-controlled and stabilized to the speed that generates the maximum torque. It can be run.

In this way, in this embodiment, when performing operations such as towing or pushing, with conventional clutch control devices, there was a risk of engine stop when attempting to operate the clutch to the half-clutch target position, but the engine speed is the third
If the engine speed is smaller than the optimum engine speed determined by the correction map shown in the figure, the load on the engine 1 is reduced by shifting the half-clutch target position to the disengaged side, allowing stable towing and pushing without engine stoppage. operations can be performed. Furthermore, even during normal running, clutch control is performed in accordance with the maximum torque, ensuring stable running.

Note that the present invention is not limited to the above-mentioned embodiments, and, for example, the optimum engine speed may be an engine speed close to the maximum torque-generating engine speed, in addition to the maximum torque-generating engine speed.

Further, the clutch control may be performed using an inching pedal other than the accelerator pedal 14.

Furthermore, it goes without saying that the present invention may be applied to other vehicles.

Effects of the Invention As detailed above, according to the present invention, when a load is applied, the half-clutch target position is shifted to the disengaged side, so stable running can always be performed even under a load. Demonstrates excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the mechanism and electrical configuration of the drive system of a forklift embodying the present invention, Fig. 2 is a diagram showing the amount of depression of the accelerator pedal and the clutch position, and Fig. 3 is a diagram showing the throttle opening. Figure 4 is a diagram showing the relationship between engine rotation speed and torque, Figure 5 is a diagram showing the speed change state with respect to vehicle speed and amount of accelerator pedal depression, and Figure 6 is a diagram showing the relationship between engine rotation speed and torque. It is a flowchart figure for demonstrating the effect|action of the forklift 1-. In the figure, 1 is an engine, 2 is a dry single plate clutch, 3 is an automatic transmission, 3a is an input shaft, 6 is a clutch control actuator constituting a clutch connection position control means, and 10 is a transmission input side rotation speed detection means 12 is an engine rotation speed sensor as an engine rotation speed detection means, 13 is an accelerator opening sensor as a pedal depression amount detection means, 14 is an accelerator pedal, and 18 is a clutch connection position control means. a microcomputer as a comparison means and a half-clutch target position changing means, 19 a central processing unit (CPU), 2
0 is a program memory as a storage means. Patent applicant Toyoda Automatic Loom Works Co., Ltd. Representative
Person Patent Attorney On 1) Hirosen 15 Figure 8 WJ 4th WJ

Claims (2)

[Claims] 1. Pedal depression amount detection means for detecting the amount of pedal depression; engine rotation speed detection means for detecting the rotation speed of the output shaft of the engine; and transmission input side rotation speed detection means for detecting the rotation speed of the input shaft of the transmission. and a clutch engagement position control means for controlling an engagement position of the clutch, the clutch engagement position control means operating the clutch to a predetermined half-clutch target position based on the pedal depression amount detected by the pedal depression amount detection means. to transmit the output of the engine to the transmission, and completely engage the clutch when the engine rotation speed detected by the engine rotation speed detection means and the input rotation speed of the transmission determined by the transmission input side rotation speed detection means become equal. In the clutch control device according to the present invention, a storage means stores an optimum engine speed corresponding to the amount of pedal depression when the clutch is operated to the half-clutch target position, and an actual engine speed detected by the engine speed detecting means. Comparison means for comparing the optimal engine speed with respect to the pedal depression amount stored in the storage means at that time; and the comparison means causes the half-clutch target position to be set to the disengaged side when the actual engine speed is smaller than the optimal engine speed. A clutch control device comprising means for changing a half-clutch target position. 2. 2. The clutch control device according to claim 1, wherein the optimum engine speed for the amount of pedal depression stored in the storage means is the maximum torque generating engine speed.