JPH0328029A - Start control device of loaded vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a start control device for a cargo handling vehicle such as a forklift.

<Prior Art> In automatic transmissions based on conventional clutch-type transmissions, clutches and forward/forward gear switching, as well as l-speed. The switching of the second speed gear is performed by driving the actuator in response to a signal from each control section.

The engine speed is controlled by driving a throttle lever of an injection bomb of the engine using a stepping motor or the like to control the amount of fuel injected.

When starting a cargo handling vehicle equipped with this automatic transmission, when the operator switches the forward/reverse select lever to the forward/reverse position or the reverse position and depresses the accelerator pedal, the control unit switches between forward or reverse and controls the clutch actuator. and the stepping motor to start the vehicle.

At this time, the driving of the clutch actuator and the driving of the stepping motor are the solid lines A and C in FIG. 3 (aXb).
The clutch stroke and engine speed are controlled to increase in this pattern.

<Problem to be Solved by the Invention> However, in a vehicle such as a forklift truck, which is front-wheel drive and has rear wheels turned, the turning angle is large, and the load on the rear wheels is large due to balance weights etc. when no cargo is loaded. The problem with this is that the engine may stall or the engine may not be able to start smoothly unless the steering wheel is turned to produce a large amount of drive torque when starting.

In view of the above, the present invention makes it possible to smoothly start a vehicle without stalling when a large drive torque is required at the time of starting, by changing the control of engine speed and the connection pattern of the clutch from those during normal starting. The purpose is to provide a start control device that can

A means to solve problems. 〉 As shown in Fig. 1.2, the problem solving means according to the present invention includes a start detecting means 31 for detecting when the vehicle l starts, a steering angle detecting means 32 for detecting the steering turning angle when the vehicle starts, and A load determining means 33 determines the running load at the time of starting based on the detection results of the detecting means 31 and the steering angle detecting stage 32, and the output of the engine 34 is normally set to zero based on the load starting determination result of the load determining means 33. engine control means 35 for making the engine larger than the time;
A clutch control means 36 is provided for making the connection speed of the clutch 11 lower than that at the time of normal no-load start based on the load start judgment result of the load judgment means 33.

In the above problem solving means, when starting the vehicle, when the operator switches the forward/reverse select lever 22 to the forward/backward position or the reverse position and depresses the accelerator pedal 38,
The control unit 20 issues signals for switching between forward and reverse travel, driving the clutch actuator 17, and driving the stepping motor 53, and starts the vehicle.

At this time, if the steering angle detection means 32 detects the steering turning angle and the vehicle is started at an angle greater than or equal to the angle set by the steering wheel 47, the engine control means 35 and the clutch control means 36 detect the clutch 1
The connection pattern of No. 1 and the rise of engine rotation are indicated by the dotted line B in FIG. Control is performed as shown in D to generate a large starting torque and start the vehicle smoothly.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings, taking a forklift as an example of a cargo handling vehicle. Fig. 3 is a functional block diagram showing an embodiment of the starting control device for a cargo handling vehicle according to the present invention, Fig. 2 is a control flowchart, and Fig. 3 (a) is a rising state of the engine throttle when the vehicle starts. In the figure, the solid line A is a normal start-up diagram with no load, and the broken line B is a start-up diagram with a load when the steering angle is large and a large drive torque is required.

Fig. 3(b) is a diagram showing the clutch stroke rising state when the vehicle starts, where the solid line C in the figure is the rising line during normal no-load starting, and the broken line shows the rising state when starting with a load when a large drive torque is required. FIG.

Fig. 4 is a block diagram showing the overall structure of the start control device, Fig. 5(a) is a perspective view showing the structure of the steering angle detection means, Fig. 5(b) is a plan view thereof, and Fig. 6 1 is a side view of a forklift to which the present invention is applied.

First, to explain the outline of forklift l, it is:
As shown in FIG. 6, a mast 3 is erected at the front of the vehicle body 2, and a fork 4 is supported by the mast 3 so as to be movable up and down. Usually, in the forklift l, the front wheels 5 are driving wheels, and the rear wheels 6 are turning wheels. Further, a balance weight 7 is installed at the rear of the vehicle body 2 in order to load a load onto the front fork 4.

The forklift truck having the above structure is equipped with an automatic transmission 12 that automatically controls a transmission 1 and a clutch 11, as shown in FIG. The automatic transmission l2 connects and connects a forward/reverse actuator 13 and its drive unit 14 that change the forward and backward gears of the transmission l, a shift actuator l5 and its drive unit l6 that changes the speed gear of the transmission 1, and a clutch 11. Clutch control actuator l7 and its drive unit l
8, and a controller 20 that controls these actuators 13.15l7 and drive units 14, 16, 18.

During normal driving, the controller 20 operates the forward/reverse actuator 13 to change the forward/reverse gear of the transmission 1 based on the forward/reverse position signals of the forward/reverse select lever 22 disposed in the driver's cab 2l of the forklift 1. Switch. Further, the shift actuator 15 and the clutch control actuator 17 are actuated by a signal from the vehicle speed sensor 23 shown in FIG. 4 to switch the speed gear of the transmission 1 to perform automatic gear shifting.

A forklift 1 equipped with this automatic transmission l2 is provided with a start control device according to the present invention. As shown in FIG. 1, this start control device includes a start detecting means 3l for detecting when the vehicle 1 starts, a steering angle detecting means 32 for detecting a steering angle when the vehicle starts, the start detecting means 3l and Load determination means 3 that determines the running load at the time of starting based on the detection result of the steering angle detection means 32
3, an engine control means 35 for making the output of the engine 34 larger than the normal no-load start based on the load start judgment result of the load judgment means 33; A clutch control means 36 is provided for making the connection speed of the clutch 11 lower than that at the time of normal no-load start.

The start detection means 3l includes the select lever 22,
It consists of an idle switch 39 for the accelerator pedal 38 and a part of the control unit 2o that detects these signals.

As shown in FIG. 4, when the accelerator pedal 38 is not depressed, the idle switch 39 is turned on because its contact is pressed by the accelerator pedal 38, and when the accelerator pedal 38 is depressed, Since the pressure on the contact is released, it is turned off.

The controller 20 is composed of a general one-chip microcomputer, and includes a data RAM 4 1, a program ROM 4 2, a CPU 4 3, and an input/output device 44.

As shown in FIG. 4.5, the steering angle detecting means 32 includes a pitman arm 48 which is fixed at one end to a rotating shaft 46 of a steering unit 45 and swings in accordance with the turning angle of the steering wheel 47, and a pitman arm 48 which is fixed at one end to a rotating shaft 46 of a steering unit 45 and swings in accordance with the turning angle of the steering wheel 47. Steering switches 50 are arranged on both the left and right sides of the arm 48 so as to be turned on by the block 49 of the arm 48 when the arm 48 swings.
．． 51. In addition, in FIG. 5 (aXb),
52 is a steering switch 50 on the vehicle frame 53;
This is a bracket for fixing the 5l.

Note that the steering angle detection means 32 may have another configuration, for example, a potentiometer.

The load determining means 33 is composed of a CPU 43, and receives a start signal from the start detecting means 3l (when the select lever 22 enters the forward or reverse position, the accelerator pedal 3
8) and a steering switch 50.5 as the steering angle detection means 32.
A function that determines a load start when the ON signal of 1 is input and a steering switch 51.57 when the start signal is input.
It has a function that determines that the vehicle is starting without a load when an off signal is received.

The engine control means 35 is comprised of a stepping motor 53 and its driver 54 for rotating the throttle lever of the injection bomb of the engine 34, and a controller 20.

The clutch control means 36 is composed of the clutch control actuator l7 and its drive section 18, and a part of the control section 20.

In the above configuration, switching of the forward and backward gears of the clutch IL} and the transmission lO, and! Switching between the speed gears 1 and 2 is performed by driving actuators 13, 15 and 17 in response to signals from the control section 20, respectively.

The rotational speed of the engine 34 is controlled by driving a throttle lever of an injection bomb of the engine 34 using a stepping motor 53 or the like to control the amount of fuel injected.

When starting this vehicle, when the operator switches the forward/reverse select lever 22 to the forward/backward position or the reverse position and depresses the accelerator pedal 38, the control section 20 switches between forward and reverse, drives the clutch tuator 17, and performs stepping. A signal to drive the motor 53 is issued to start the vehicle.

At this time, if the steering turning angle is detected and the vehicle is started at an angle greater than or equal to the angle set by the steering wheel 47, the connection pattern of the clutch l1 and the rise of the engine rotation are controlled as shown by dotted lines B and D in FIG. To generate a large starting torque and start the vehicle smoothly.

That is, as shown in the flowchart of FIG. 2, in Sl,
If the select lever 22 is placed in either forward F or reverse R, and the accelerator pedal 38 is depressed in S3,
It is judged to be a departure.

At this time, it is determined in S4 whether the turning angle of the steering wheel 47 is greater than a certain value. If the torque exceeds a certain level, the rear wheels 6 are turning, so there is a risk that the engine will stall unless the vehicle is started with a large drive torque. Therefore,
In S5, the load start pattern data in the ROM 42 is selected, and based on this data, the clutch 11 and the engine 34 are controlled in a rising state as indicated by dotted lines B and D in FIGS. 3(a) and 3(b).

Furthermore, when the steering angle has not reached a certain value, the vehicle is not subjected to a considerable load when starting, so it is possible to start with a small drive torque. Therefore, in S6, the no-load start pattern data is selected from the ROM to control the clutch 11 and the engine 34.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, in the above embodiment, a forklift was described, but the present invention is not limited to this and can be applied to other cargo handling vehicles, civil engineering vehicles, and the like.

Further, in the above embodiments, a manned vehicle has been described, but it goes without saying that the present invention can also be applied to an unmanned vehicle.

Effects of the Invention> As is clear from the above description, according to the present invention, when the steering angle is detected by the steering angle detection means and the vehicle is started when the steering angle is greater than or equal to the set steering angle, the engine control means and The clutch control means changes the clutch connection pattern and the start-up pattern of the engine rotation so that a large starting torque can be produced, so there is an excellent effect that the vehicle can be started smoothly without stalling.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the starting control device for a cargo handling vehicle according to the present invention, FIG. 2 is a control flowchart, and FIG. 3(a) shows the startup state of the engine throttle when starting the vehicle. 3(b) is a diagram showing the clutch stroke rising state when the vehicle starts, FIG. 4 is a block diagram showing the overall configuration of the control device at the time of starting, and FIG. 5(a) is a diagram showing the steering angle detection. FIG. 6 is a perspective view showing the configuration of the means, FIG. 6 is a plan view thereof, and FIG. 6 is a side view of a forklift to which the present invention is applied. l: vehicle, 1l: clutch, 3l: start detection means, 32
: Steering angle detection means, 33: Load determination means, 34
: Engine, 35; Engine control means, 36: Clutch control means.

Claims (1)

[Claims] A start detecting means for detecting when the vehicle starts; a steering angle detecting means for detecting a steering turning angle when the vehicle starts; and determining a running load at the time of starting based on the detection results of the start detecting means and the steering angle detecting means. a load determining means; an engine control means for increasing the output of the engine to be higher than normal no-load starting based on the loaded start determining result of the load determining means; A starting control device for a cargo handling vehicle, comprising a clutch control means for making the connection speed lower than when starting without a normal load.