JPH01279124A - Clutch control device for industrial vehicle - Google Patents

Abstract

PURPOSE:To smoothen an acceleration rate in front and rear directions at the start by controlling a clutch to be under a condition of specified connection, while driving a clutch driving means according to stored connection data from the time of the actuation of an operation means to the judgement of clutch- meeting. CONSTITUTION:In a CPU 21, an acceleration sensor 13 detects the actuation of an acceleration pedal 14 and then a timer means 20a for measuring the passing time from the actuation. Clutch connection data are read out from a previously stored ROM 22 corresponding to the passing time. According to the connection data, an actuator 6 for clutch connection is driven through a clutch actuator driving circuit 17, and a clutch 2 is driven for connection. A connection control for the clutch 2 is performed according to the speed of an engine 1 detected by engine speed sensors 9, 10 and the speed of an input shaft 3a of an automatic transmission 3 until the clutch-meeting is judged. Acceleration in front/rear directions at the start is smoothened irrespective of presence/ absence or size of mounted load.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an industrial vehicle equipped with an automatic transmission such as a forklift, and more particularly to a clutch control device that controls clutch engagement.

[Prior Art] Conventionally, in a clutch control device for a vehicle equipped with an automatic transmission that is directly connected to the engine without using a torque converter, the clutch stroke at the time of starting is determined according to the characteristic line X between the engine speed and the clutch stroke shown in FIG. By controlling the clutch on the basis of That's what I do.

[Problems to be Solved by the Invention] However, the optimal conditions for the clutch stroke at which the clutch meets are different when there is a live load on the vehicle and when there is no live load. In other words, the clutch stroke at which the clutch meets is based on the vehicle's live load. When is maximum, the characteristic line Y is shown in FIG. 4, and when there is no live load, the characteristic line Z is shown in FIG. 4. However, since the conventional clutch control device does not have a means to recognize the fluctuation of the product f2 load, the clutch stroke is controlled based on the characteristic line X which is between the characteristic cottons Y and Z. It is not possible to smooth the acceleration at the time of starting with all live loads.

That is, for example, if the clutch stroke is controlled based on the characteristic line X when the live load is maximum, the transmitted torque will be Because T1 is small, the engine speed does not meet, and the engine speed increases to the speed N (high speed range) where the clutch stroke is 82, as shown in Fig. 4, and the transmitted torque T becomes "l". 2 Xα(α
is the rate of increase in output torque as the engine speed increases)
As a result, the clutch engages, resulting in a large increase in acceleration in the high rotation range.

Also, if the clutch stroke is controlled based on the characteristic line X when there is no live load, the clutch stroke should be So at engine speed No. Nevertheless, it became Sl,
As is clear from Fig. 5, the transmitted torque is T+ (>T
o), and the increase in acceleration at the initial stage of starting becomes large.

Furthermore, if the clutch stroke is controlled based on the characteristic line Z shown in FIG. Also, if the clutch stroke is controlled based on the characteristic line Y, when there is no live load, the acceleration in the low rotation range will increase more than when the clutch stroke is controlled based on the characteristic line X. It gets bigger.

This invention was made to solve the above-mentioned problems, and its purpose is to solve the above-mentioned problems. ! The object of the present invention is to provide a clutch control device for an industrial vehicle that can smooth acceleration in the longitudinal direction when the vehicle starts, regardless of the magnitude.

[Means for Solving the Problems] In order to achieve the above object, the present 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! a clutch drive means for controlling the connection state of the clutch; an engine rotation speed detection means for detecting the rotation speed of the engine; and an input shaft rotation speed for detecting the rotation speed of an input shaft connecting the clutch and the automatic transmission. a detection means, an operation means for starting the vehicle to travel, an operation detection means for detecting the operation of the operation means, and a timekeeping means for starting a timing operation based on the operation detection of the operation means by the operation detection means. , storage means for storing in advance the connection state of the clutch with respect to the elapsed time from the activation of the operating means as connection data, and the engine rotation speed detected by the engine rotation speed detection means and detected by the input shaft rotation speed detection means. an engagement determining means for determining whether or not the clutch is engaged based on the input shaft rotational speed; The gist of the present invention is a clutch control device for an industrial vehicle, comprising: control means for driving the clutch drive means based on connection data read from the means; and control means for controlling the clutch to a predetermined connected state.

[Operation] Therefore, when the operation detecting means detects the operation of the operating means, the time measuring means measures the time elapsed since the operation of the operating means vJ. Connection data corresponding to the elapsed time measured by the control means is read out by the means 10, and the clutch drive means is driven based on the connection data, so that the clutch is actuated in the engagement direction. Then, the clutch drive means is driven based on the connection data read from the storage means by the drive means until the clutch meet determination means determines whether the clutch is engaged based on the engine rotational speed and the input shaft rotational speed. is controlled to a predetermined connection state.

[Embodiment] An embodiment in which the present invention is embodied in a forklift will be described below 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 the engine 1 is transmitted to an automatic transmission 3 via a type 122 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.

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 dry single-plate clutch 2 that turns on and off the output of the engine 1 is operated relative to the stroke amount of a rod 6a that expands and contracts based on the drive of a clutch control actuator 6 as a clutch drive means, and its connection state is adjusted. . On the other hand, the automatic transmission 3 can be shifted between first speed (low speed) and second speed (high speed) by driving a shift switching actuator (not shown).

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

The vehicle speed sensor 7 detects the rotational speed of the output shaft of the automatic transmission 3, that is, the vehicle speed when the vehicle is stopped and while the vehicle is running, and outputs the detection signal to the input/output interface 8. A rotation speed sensor 9 serving as input shaft rotation speed detection means detects the rotation speed of the input shaft 3a of the automatic transmission 3, and outputs the detection signal to the interface 8.

Further, an engine rotation speed sensor 10 serving as an engine rotation speed detection means detects the rotation speed of the output shaft of the engine 1 and outputs the detection signal to the interface 8.

The stroke detection sensor 11 is composed of a potentiometer and detects the stroke amount 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 the A/D converter 12 and sent to the interface. 8 is output.

An accelerator pedal 14 as an operating means for starting the vehicle to travel is provided at the driver's seat, and an accelerator sensor 13 as an operation detecting means is composed of a potentiometer, detects the start of depression and the amount of depression of the accelerator pedal 14, and outputs a detection signal thereof. is converted into a digital signal by the A/D converter 15 and output to the interface 8.

A central processing unit (hereinafter referred to as CPU) 21 as a meat determination means and control means is equipped with a read-only memory (hereinafter referred to as ROM) 22 and a readable and rewritable memory (hereinafter referred to as RAM) 23 as storage means. There is. A control program is stored in the ROM 22, and as shown in FIG.
Furthermore, connection and depression amount data for each detection signal of the accelerator sensor 13 are stored. CPU21 is ROM
It operates according to a control program stored in 22, and inputs detection signals from each of the sensors via the input/output interface 8. Further, the CPU 21 is equipped with a timer 21a as a time measurement means.

Then, the CPU 21 controls the clutch control actuator 6 based on the detection signal from the stroke detection sensor 11.
The stroke amount of the rod 6a, that is, the connected state of the clutch 2 is determined. Also, CPU21
is designed to determine the amount of depression of the accelerator pedal 14 based on the detection signal from the accelerator sensor 13.

It should be noted that each of these calculations is determined based on the connection and depression amount data for each detection signal of the stroke detection sensor 11 and the accelerator sensor 13, which are stored in the ROM 22 in advance.

The CPU 21 determines the engine rotation speed corresponding to the calculated accelerator pedal depression amount based on the data stored in the ROM 22, and calculates the engine rotation speed via the input/output interface 8 and the throttle actuator drive circuit 16 to achieve the determined rotation speed. is designed to be controlled.

Further, the CPU 21 determines whether the accelerator pedal 14 has started to engage 'd3' based on the detection signal from the accelerator sensor 13, and when it determines that the pedal 14 is not being operated, it completely disengages the clutch 2. The clutch control actuator 6 is driven and controlled via the interface 8 and the clutch actuator drive circuit 17 so as to maintain the clutch control actuator 6 in the same state.

Furthermore, the CPU 21 calculates the rotational speed of the input shaft 3a based on the detection signal from the rotational speed sensor 9, and calculates the rotational speed of the engine 1 based on the detection signal from the engine rotational speed sensor lO. When the difference between the rotational speed and the rotational speed of the imbedded shaft 1-3a falls within a certain range, it is determined that the clutch 2 has engaged.

The CPLI 21 calculates the vehicle speed of the forklift based on the detection signal from the vehicle speed sensor 7, and determines whether the vehicle speed is "0", that is, the forklift is in a stopped state and the accelerator pedal 14 is in a completely disengaged state when the clutch 2 is completely disengaged. When the pedal starts to be depressed, a timer 21a starts to measure time.

Further, the CPU 21 reads out the clutch stroke S of the dry single plate clutch 2 for the elapsed time t measured by the timer 21a from a map (see FIG. 3) stored in the ROM 22, and based on the read connection data,
The clutch control actuator 6 is driven and controlled via the interface 8 and the clutch actuator drive circuit 17, and the clutch 2 is controlled to a predetermined connected state. f
It is designed to do f1l.

The results of each calculation by the CPU 21 are stored in the RAM 2.
3 is temporarily stored.

Next, in the forklift configured as above, C
The process executed by the PU 21 when the forklift l-starts will be explained based on the flowchart shown in FIG.

First, when the vehicle speed is "0", that is, the forklift is in a stopped state and the clutch 2 is completely disengaged, the CPU 21 determines whether or not the accelerator pedal 14 has started to be depressed (step 1). When it is determined that the accelerator pedal 14 has started to be depressed, the timer 21a starts measuring time (step 2).

Next, the CPU 21 reads out the clutch stroke S of the dry single plate clutch 2 for the elapsed time t measured by the timer 21a from a map (see FIG. 3) stored in the ROM 22, and based on the read connection data, the interface 8 and clutch actuator drive circuit 17
The clutch control actuator 6 is connected to the drive side via the ? ffl (step 3).

Subsequently, the CPU 21 selects the input shaft 3a at that time.
It is determined whether the clutch 2 has engaged by comparing the rotational speed of the engine 1 with the rotational speed of the engine 1, that is, whether the difference between the rotational speed of the engine 1 and the rotational speed of the input shaft 3a is within a certain range. In step 4), if it is determined that the meat has not been met, the process moves to step 2, and the processes of steps 2 to 4 are repeatedly executed based on the new elapsed time t measured by the timer 21a.

Then, in step 4, clutch 2 met,
That is, the rotational speed of the engine 1 and the input shaft 3a
When it is determined that the difference between the rotational speed and the rotational speed of the vehicle is within a certain range, this start processing is terminated.

As a result, when the forklift starts, regardless of the engine speed (as shown in FIG. 3, if there is no loaded load, the clutch stroke S3 at the elapsed time t1
If the live load is the maximum, the clutch 2 will meet at the clutch stroke S4 at the elapsed time t2, and if the live load is present and not the maximum, the clutch stroke will be in the middle of the latch strokes 83 to S4. Clutch 2 will meet at
It is possible to smooth the acceleration in the longitudinal direction when the forklift is started, regardless of the presence or absence of a live load or the magnitude thereof.

In the above embodiment, the map of the clutch stroke S relative to the elapsed time (from the start of depression of the accelerator pedal 14) is stored in advance in the ROM 22, but the calculation formula for the elapsed time is written in the ROM 22 as connection data. , the clutch stroke may be calculated.

Further, although the forklift is used in the above embodiment, the invention may also be applied to a vehicle such as a passenger car or a truck. - [Effect of the Invention 1] As detailed above, the present invention has an excellent effect of smoothing the longitudinal acceleration when the vehicle starts, regardless of the presence or absence of a live load or the magnitude thereof.

[Brief explanation of the drawing]

Fig. 1 is a mechanical and electrical block circuit diagram of a forklift embodying the present invention, Fig. 2 is a flowchart showing the processing by the CPU when the forklift starts, and Fig. 3 shows the progress from the start of pressing the accelerator pedal in this embodiment. Is the map of clutch stroke versus time, Figure 4, a conventional clutch system? ) Map of clutch stroke versus engine speed in the II device. FIG. 5 is a characteristic diagram showing the relationship between clutch stroke and clutch transmission torque. In the figure, l is the engine, 2 is a dry single plate clutch, 3 is an automatic transmission, 3a is an input shaft, 6 is a clutch control actuator as a clutch driving means, and 9 is a rotation speed sensor as an input shaft rotation speed detection means. ,
10 is an engine rotation speed sensor as an engine rotation speed detection means, 13 is an accelerator sensor as an operation detection means,
Reference numeral 14 designates an accelerator pedal as an operating means, 21 a CPU as a single stage meet discrimination and control means, 21a a timer as a time measuring means, and 22 a ROM as a storage means. Patent Applicant Toyota Industries Corporation Toyota Central Research Institute Representative Patent Attorney On 1) Hironobu The elapsed time from the start of accelerator pedal depression is shown in Fig. 4 Fig. 5 Kura 1 ν Ti Stroke S

Claims (1)

[Scope of Claims] 1. 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 that controls the rotational speed of the engine. An input shaft rotation speed detection means for detecting the rotation speed of an input shaft that connects the clutch and the automatic transmission; an operation means for starting the vehicle to run; and the operation means. an operation detecting means for detecting the operation of the operating means; a timing means for starting a timing operation based on the operation detection of the operating means by the operation detecting means; storage means for storing connection data; and determining whether the clutch has engaged based on the engine rotation speed detected by the engine rotation speed detection means and the input shaft rotation speed detected by the input shaft rotation speed detection means. a meeting determination means for determining whether the clutch is engaged, and driving the clutch driving means based on the connection data read from the storage means from the time the operating means is actuated until the clutch is determined to have been engaged by the meeting determination means; A clutch control device for an industrial vehicle, comprising a control means for controlling a predetermined connection state.