JPH07121662B2 - Driving control method in industrial vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a travel control method in an industrial vehicle for controlling switchback travel of an industrial vehicle equipped with a clutch type automatic transmission.

[Conventional technology]

In the above industrial vehicle, when the forward / reverse switching lever is switched to switch back in the opposite direction while the vehicle is traveling in a fixed direction, the forward / reverse switching lever is switched and the clutch is disengaged to brake. Braking control is performed, or the throttle opening is rapidly set to zero so as to reduce the traveling speed of the vehicle to a vehicle speed at which the forward and reverse gears can be switched.

[Problems to be Solved by the Invention]

Among the above-mentioned conventional travel control methods, in the former case, there is a problem that the engine becomes idle due to clutch disengagement, and an abnormal sound due to an increase in engine rotation occurs, and in the latter case, a sudden engine There is a problem that the brake is applied and a deceleration shock is applied. In either case, the switchback traveling is uncomfortable against the operator.

The present invention has been made in view of the above, and when switching the forward / reverse switching lever in the current traveling direction and the reaction direction for switchback traveling, there is no deceleration shock and abnormal noise is generated. It is an object of the present invention to provide a traveling control method for an industrial vehicle, which enables smooth switchback traveling without the operator feeling uncomfortable.

[Means for Solving the Problems]

In order to achieve the above object, a traveling control method for an industrial vehicle according to the present invention comprises an engine speed detection means, an engine throttle opening detection means, a forward / reverse switching lever position detection means, and each of these detection means. Detection signal from
In an industrial vehicle equipped with a CPU that outputs a predetermined signal to a throttle actuator and a clutch control actuator by performing arithmetic processing on the basis of signals from ROM and RAM, a forward / reverse switching lever for switchback traveling When the is switched to the direction opposite to the current running direction, the clutch is gradually disengaged from the contact state to the disengagement state via the half-clutch, and the engine speed during this period is kept constant at the switching speed. , The throttle opening is changed and the throttle opening is set to zero when the clutch is disengaged.

[Action]

When the forward / reverse switching lever is switched, the clutch gradually disengages while maintaining the engine speed at this time,
The throttle opening becomes zero with the clutch completely disengaged.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a control block of an industrial vehicle to which the method of the present invention is applied. In the figure, 1 is an engine speed detection sensor for detecting an engine speed, and 2 is a throttle opening for detecting an engine throttle opening. Degree detection sensor, 3 is a vehicle speed detection sensor that detects the vehicle speed, 4 is an accelerator pedal stroke detection sensor that detects the amount of depression of the accelerator pedal, 5 is a clutch stroke detection sensor that detects the clutch stroke amount, and 6 is a forward / reverse gear shift A forward / reverse gear position detection sensor for detecting the position, 7 is a first / second gear position detection sensor for detecting the shift positions of the first gear and the second gear, and 8 is a forward / reverse movement for detecting the position of the forward / reverse switching lever. It is a switch lever position detection sensor. These detection signals are input to the CPU (central processing unit) 10 directly or through the A / D converter 9, and the CPU 10 performs predetermined arithmetic processing. 11 is a ROM for storing data in advance and loading it into the CPU 10 at any time,
Reference numeral 12 is a RAM for storing data via the CPU 10 and fetching this data into the CPU 10 at any time.

One is a D / A converter that D / A converts the signal from the CPU 10, 14 is a throttle actuator such as a stepping motor that opens and closes the throttle, 15 is a clutch control actuator that controls the clutch, and 16 is a forward / reverse gear. An actuator for shifting forward and backward gears, 17 is a first speed gear and 2
It is an actuator for switching between 1st and 2nd speed gears that switches between high speed gears. Reference numeral 18 denotes an actuator drive circuit that controls the actuators 15 to 17 based on the signal from the D / A converter 13.

A travel control method according to the present invention using the above configuration will be described with reference to the flowchart of FIG.

The engine speed N ₀ while the vehicle is traveling is detected by the engine speed detection sensor 1 (step (1)) and the signal is input to the CPU 10. When the forward / reverse switching lever is switched in this state (step (2)), the engine speed N _{0 at} this time is stored in the RAM 12 via the CPU 10.
At the same time, a signal for moving the clutch by one step (ΔC) to the disengaged side is output to the actuator drive circuit 18 via the D / A converter 13 (step (3)) to control the clutch. Drive the actuator 15 for.

Next, the engine speed N at this time is detected (step 4)
And the above step 1 stored in the RAM 12 by the CPU 10
Remove the engine rotational speed N ₀ in the rotational speed N, N ₀
Are compared (step (5)). As a result, when N ≧ N ₀ , the CPU 10 outputs a signal to the throttle actuator 14 to close the throttle opening by one step (Δζ). Then, steps (4), (5), until N becomes N <N ₀ ,
Go around the loop of (6).

Next, when N <N _0, and the clutch engagement amount at that time has not reached the disengagement, the clutch is stepped once again (ΔC).
Only to the disconnect side (step (3)). Then, it goes around the loop of steps (4), (5), and (6) again, and N <
When N ₀ is reached, the process proceeds to step (7). When the clutch engagement amount has not reached the disengagement, the process returns to step (3) and the clutch is further moved to the disengagement side by one step.

When the clutch engagement amount is disengaged by repeating the above process, the CPU 10 sends a signal to the throttle actuator 14 to rapidly set the throttle opening to zero.

When the throttle opening becomes zero, brake control is performed (step (9)), and then it is determined whether the vehicle speed ν at this time is a vehicle speed ν _2-1 that shifts down from the second speed to the first speed (step (10)). .

When the CPU10 determines that the vehicle speed is downshift, the 1st and 2nd gear position detection sensor (7) detects whether the current gear position is 1st or 2nd (clutch (11)) and is in 2nd gear. Sometimes gear change from 2nd speed to 1st speed (step (1
2)).

In this first speed running state, the vehicle speed ν is compared with a vehicle speed ν _G at which the forward / reverse switching gear can shift in the opposite direction to the current traveling direction (step (13)), and the vehicle speed ν can shift. If it is smaller than ν _G, forward / reverse switching is performed.
At this time, it is first judged whether or not the forward / reverse gear has been changed (step (14)), and then the forward / reverse gear is changed (step 15).

When the forward / reverse gear is switched and the vehicle ν before the vehicle starts traveling in the opposite direction to the traveling direction becomes zero (step (16)), the throttle is opened (step 17) and the clutch is engaged (step (18)) thereafter. ), The throttle opening degree is set according to the amount of depression of the accelerator pedal, and the speed is controlled by the amount of depression of the accelerator pedal.

The engine speed, the clutch engagement amount, and the throttle opening in the operations from step (2) to step (8) are as shown in FIG. 3, FIG. 4, and FIG. 5, respectively, and the engine speed is From the time point A when the forward / reverse switching lever is switched to the throttle opening zero (step (8)), the engine speed N ₀ at the time of switching the forward / reverse switching lever is kept constant, and the throttle opening is suddenly set to zero. descend.

The clutch engagement amount is gradually disengaged at a constant rate α from the time of switching to the lever until the clutch disengagement in step (7).

The throttle opening ζ is gradually closed from the time the lever is switched to the time when the throttle opening is zero in step (8) so that the engine speed during this time is kept constant.

〔The invention's effect〕

According to the present invention, when the forward / reverse switching lever is switched in a direction opposite to the current traveling direction for switchback traveling, there is no sudden torque disconnection due to clutch sudden disconnection, and abrupt throttle valve sudden closure. There is no deceleration shock due to lack of engine brake, no engine blow-up due to sudden clutch disengagement, and no abrupt engine brake due to sudden throttle closure, so no abnormal noise is generated and the operator does not feel uncomfortable. Allows smooth switchback travel.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of the method of the present invention, FIG. 2 is a block diagram showing a shift control system, FIG. 3, FIG.
FIG. 5 is a diagram showing the relationship between the time before and after the switching of the forward / reverse switching lever and the engine speed, the clutch engagement amount, and the throttle opening. 1 is an engine speed detection sensor, 2 is a throttle opening detection sensor, 3 is a forward / reverse switching lever position detection sensor, and 10 is
CPU, 11 is ROM, 12 is RAM, 14 is a throttle actuator, and 15 is a clutch control actuator.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Shiro Iwata 2-3-4 Akasaka, Minato-ku, Tokyo Komatsu Forklift Co., Ltd. (72) Tsuneo Ogawa 2-3-4 Akasaka, Minato-ku, Tokyo Komatsu Forklift Co., Ltd. (56) References JP-A-62-152929 (JP, A) JP-A-62-39334 (JP, A)

Claims (1)

[Claims] 1. An engine speed detecting means, an engine throttle opening detecting means, a forward / reverse switching lever position detecting means, detection signals from these detecting means, and a ROM and a RAM.
In an industrial vehicle equipped with a CPU that outputs a predetermined signal to a throttle actuator and a clutch control actuator by performing a calculation process based on a signal from the When switching to the opposite direction to the running direction, gradually open the clutch from the contact state to the disengaged state via the half-clutch, while opening the throttle to keep the engine speed constant at the switching speed during this period. A travel control device for an industrial vehicle, characterized in that the throttle opening is changed to zero when the clutch is disengaged.