JPS6155452A - Automatic speed change controller for industrial vehicle - Google Patents

Abstract

PURPOSE:To improve the acceleration performance and the fuel consumption by preparing independent speed change data suitable respectively for no-load travel and on-load travel and switching the clutch on the basis of the speed chage data read out selectivey with corresponding to the travel condition. CONSTITUTION:Advance/back of forklift is controlled with corresponding to coupling condition of advance/back cluch 6 while to couple 3-speed clutch 10c through excitation of 3-speed switching solenoid valve 8, 1-speed clutch 10a through non-excitation of 2-speed switching solenoid valve 9 and 2-speed clutch 10b through excitation of said valve 9 thus to achieve predetermined speed change stage. Upon decision of no-load travel or on-load travel in CPU16 on the basis of the output from a load detector or a pressure switch 11, speed change data for no-load or on load stored in ROM17 is read out to function said valves 8, 9 on the basis of said data thus to control coupling of clutches 10a-10c for desired speed change.

Description

DETAILED DESCRIPTION OF THE INVENTION Purpose of the Invention (Field of Industrial Application) This invention relates to an automatic transmission control device for industrial vehicles such as forklifts 1 to 1 with automatic transmission. The present invention relates to an automatic transmission control device that controls an automatic transmission in response to unloaded travel when no load is loaded, and loaded travel when a load is loaded.

(Prior Art) For example, in a forklift truck equipped with an automatic transmission, a clutch for changing gears is controlled to be switched based on the traveling speed of the forklift truck 1- and the accelerator distance. In general, when the shifting clutch changes from 1st gear (low speed) to 2nd gear (medium speed), or from 2nd gear (medium speed) to 3 faster and higher speeds (shift 1 to up), the shift map is The shift boundary line L1, shown by the solid line in FIG. 6, determines the shift region. Switching is controlled according to L2.

On the other hand, when the shift clutch changes from 3rd gear to 2nd gear or from 2nd gear to 1st gear (downshift), the shift map shows the shift boundary line where the shift clutch determines the shift range shown by the two-dot chain line in Figure 6. L4. Switching is controlled according to L3.

(Problem to be Solved by the Invention) However, the above-mentioned forklift uses the same speed change map when traveling both in a loaded state and in an unloaded state. Therefore, the shift point is determined regardless of whether the vehicle is loaded or not, which tends to result in poor operational feeling and poor fuel efficiency.

Structure of the Invention (Means for Solving Problems) In order to solve the above-mentioned problems, an automatic transmission control device for an industrial vehicle according to the present invention includes a plurality of transmission clutches and a switching connection of each of the transmission clutches. A clutch switching drive means for shifting, a load detector that detects whether a load is loaded, and a load detector that detects the presence or absence of a load.
A first storage device that stores shift data for traveling when no load is set to set the shifting state to a shifting state suitable for traveling when no load is applied, and when traveling when a load is loaded.
A second storage device storing shift data for driving under load and a detection signal from the load detector are inputted to set the speed change state to a speed change state suitable for driving under load. a determining means for determining whether the vehicle is traveling under no-load conditions or under a load condition based on the signal; and when the determining means determines that the vehicle is traveling under no-load conditions, the determination means determines whether the vehicle is traveling under no-load conditions based on the signal; a first control means for reading out shift data for the vehicle and actuating the shift clutch switching drive means to connect the corresponding shift clutch based on the same data; and when the determining means determines that the vehicle is running under load; and a second control means for reading the speed change data for the load condition stored in the second storage device and operating the speed change clutch switching drive means based on the data to connect the corresponding speed change clutch. The gist of this article is as follows.

(Function) With the above configuration, the shift data for setting the shift state to a shift state suitable for running under no load, and the shift data for setting the shift state to a shift state suitable for running under load, are provided. Stores shift data for running under load in a storage device,
When the determining means determines that the vehicle is running under no-load conditions based on the detection signal from the load detector, the first control means reads out the speed change data for traveling under no-load conditions stored in the storage device and uses the same data. Based on this, the gear shifting clutch switching drive means is operated to connect the corresponding gear shifting clutch.

On the other hand, when the determining means determines that the vehicle is traveling under load, the second control means reads out the shift data for traveling under load stored in the storage device and controls the shift clutch switching drive means based on the same data. Activate it and connect the corresponding gear shifting clutch.

As a result, when driving with no load, a gear shift state suitable for running with no load can be immediately obtained, and when running with a load, a gear shift state suitable for running with a load can be immediately obtained. In particular, the ability to re-accelerate by downshifting in the case of overload has been improved, and the conventional problem of not being able to obtain torque and poor acceleration even when the accelerator is pressed down/V has been resolved, and the fuel consumption and operation feel have also been improved. The problem of bad rings is also solved. Furthermore, when there is no load, upshifts can be performed quickly, which improves fuel efficiency.

(Embodiment) Next, a preferred embodiment in which the present invention is embodied in a forklift will be described below with reference to the drawings.

FIG. 1 shows a hydraulic and electrical circuit diagram of a forklift. A clutch oil pump 1 is driven by an engine (not shown), and pressure fluid from the pump 1 is supplied to a regulator valve 2. This pressure fluid is then regulated to a constant pressure by a regulator valve 2 and supplied to a forward/reverse clutch switching valve 4 via a pressure control valve 3.

The forward/reverse clutch switching valve 4 is turned on or off based on the operation of a clutch switching lever 5 provided at the driver's seat of the forklift vehicle, and supplies pressurized fluid to the forward/reverse clutch 6 to connect the forklift to drive the forklift forward or backward.

The pressure control valve 3 is adapted to adjust the pressure of the pressure fluid supplied to the forward/reverse clutch 6 and control the connection state of the clutch 6, and is configured to open and close an electromagnetic solenoid valve provided in the pressure control valve 3. By doing so, the pressure of the pressure fluid supplied to the forward/reverse clutch 6 is adjusted. This electromagnetic solenoid valve is driven and controlled by an electromagnetic solenoid 7 of the same valve.

Therefore, by controlling the excitation of the electromagnetic solenoid 7,
The connection state of the forward/reverse clutch 6 is controlled.

When the solenoid 8a of the third-speed switching electromagnetic valve 8, which serves as a clutch switching drive means, is de-energized, the pressure fluid from the regulator valve 2 is supplied to the next-stage two-speed switching electromagnetic valve 9, which also serves as a clutch switching drive means. On the other hand, when energized, pressure fluid is sent to a three-speed clutch (hereinafter referred to as a 3rd speed clutch) 10C, which connects the forklift to 3rd speed (high speed).

The two-speed switching Jθ electromagnetic valve 9 is a valve for switching the speed of the forklift 1 to 1 speed (high speed, low speed) and 2) medium speed (medium speed), and when the solenoid 9a is de-energized, The pressurized fluid is applied to the single-speed clutch (hereinafter referred to as 1st speed clutch) 10a), and the connection for the 1st speed of the forklift is conversely, when energized, the pressure fluid is applied to the 2-speed clutch (1st speed clutch, 2nd speed clutch). 10b (referred to as a speed clutch) to establish a connection for second gear of the forklift.

Next, an electric circuit for driving and controlling the solenoids 7.8a, 9a to adjust the pressure of the pressure fluid supplied to the clutches 6.10a, 10b, 10C will be described.

The pressure switch 11 as a load detector is a lift cylinder (not shown) that raises and lowers a fork (not shown).
The fork is installed in a hydraulic circuit, and detects whether a load is loaded or not on the fork based on the pressure of the pressure oil in the hydraulic circuit.

The accelerator opening sensor 13 consists of a potentiometer,
The amount of depression of the accelerator pedal 14 is detected. In this embodiment, the accelerator pedal 14 is not mechanically connected to the engine throttle that operates the engine throttle valve, and the accelerator pedal 14 is only mechanically connected to the opening sensor 13.

The vehicle speed sensor 15 detects the rotation speed of the drive shaft of the forklift and outputs a detection signal thereof.

A central processing unit (hereinafter referred to as CPU) 16 as first and second control means and determination means is written in a read-only memory (hereinafter referred to as ROM) 17 as a first and second storage device. the pressure switch 11 via the interface 18.
, the respective detection signals from the σ sensor 13 and the vehicle speed sensor 15 are input between the accelerator and the accelerator.

Then, the CPU 16 quickly determines the amount of depression of the accelerator pedal 14 based on the detection signal from the accelerator sensor 13, and calculates the accelerator opening at that time. Calculate speed] r. Then, the CPU 16 controls the opening degrees of the engine throttles 1 to 3 based on the determined accelerator distance KC'3, and controls the engine rotational speed. Note that the throttle distance 1 for the depression of the accelerator pedal 4 is set in advance, and the data is stored in the ROM 17.

Further, the CPU 16 outputs a predetermined drive signal to a solenoid drive circuit 19 via an interface 18, and controls the excitation of the electromagnetic solenoid 7 of the electromagnetic solenoid valve via the drive circuit 19.

The ROM 1.7 contains the control program as well as the file format (
Shift data for traveling with a load loaded on the fork (not shown) and irritating no-load traveling, and shift data for running with a load loaded on the fork (not shown) are stored.

The shift data for driving is determined based on the amount of depression of the accelerator pedal 14, that is, the amount of opening of the accelerator, and the traveling speed of the forklift.
This is shift data for switching the G to the optimum shift state, and based on the data, the first to third gear gears 10a to 1 are changed.
0c is switched and controlled. In this embodiment, the data of each shift range for the accelerator opening amount and the traveling speed are set according to the relationship shown in FIG. 3 for no-load driving, and as shown in FIG. 4 for loaded driving. Each shift area, that is, each shift boundary line L1 to 1-4 and 15 to L8
is set upward to the right in the figure, and the shift boundary lines 1-1 to 1-4 and 1-5 to L8 are different depending on whether the shift is up or down to shift 1. Shift boundary lines L1 to L4 for traveling without load, and shifting boundary line L5 for traveling with load.
- L8 as a whole, the latter is set to have a gentler inclination than the curver.

Therefore, the data for traveling with a load is such that the first and second speed regions occupy a wider speed range than the shift data for traveling without a load.

Further, the CPU 16 determines whether the slope A (not shown) is traveling under no load, when no load is loaded, or under load, when a load is loaded, based on the detection signal of the pressure switch 11. Discern.

When the CPU 16 determines that the vehicle is traveling under no-load conditions, the CPU 16 selects the shift data for traveling during no-load conditions, and performs a predetermined speed change for traveling under no-load conditions based on the accelerator opening amount and traveling speed. Read the data from the ROM 17 and send the drive signal to 1. Solenoids 8a of the 3rd speed and 2nd speed switching solenoid valves 8 and 9 output to one tunoid drive circuit;
9a is driven and controlled.

On the other hand, when it is determined that the vehicle is traveling under load, the CPU 16 selects the shift data for traveling under load, and based on the travel speed and the amount of accelerator opening, the CPU 16 selects the shift data for traveling under load from the ROM 17. The solenoid 8a is output as a read drive signal to the solenoid drive circuit 19.
, 9a.

A readable and rewritable memory (hereinafter referred to as RAM) is designed to temporarily store various calculation results of the CPU 16.

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

Now, when the forklift is moving forward with no load and no load is loaded, the CPU 16 is operating the pressure switch 1.
Based on the detection signal from 1, it is determined that the vehicle is running without load,
The process moves on to read-out processing of shift data for traveling under no-load conditions. The CPU 16 calculates the current accelerator opening amount based on the detection signal from the accelerator opening sensor 13, calculates the current traveling speed based on the detection signal from the vehicle speed sensor 15, and calculates a predetermined amount based on the output values of both lines. Shift data for normal driving is read from ROIVj17.

Next, the CPU 16 controls the solenoid 8a of the 3rd speed and 2nd speed switching electromagnetic valves 8 and 9 via one solenoid drive circuit based on the read speed change data.

Drive control of 9a, 1st to 3rd speed gears 10a to 10C
are connected to a predetermined state and set to a shift state based on the read shift data.

Therefore, when driving under no load, the forklift should be
Shift data for running under no-load conditions is read from the OM 17, and the shift state is controlled based on the read shift data.

Nowadays, shift data for driving under no load occupies a wider area on the high speed side than shift data for driving under load, so it is possible to shift up earlier when accelerating, improving fuel efficiency. be able to.

Next, a load is loaded on the fork (not shown).
When the forklift is traveling forward in a loaded state, the CPU 16 determines that the forklift is traveling under load based on the detection signal from the pressure switch 11, and proceeds to read out the speed change data for traveling under load. c p U 1.6 calculates the accelerator opening amount at that time based on the detection signal from the sensor 13 and the vehicle speed sensor 15.
The current running speed is calculated based on the detection signal from the
Shift data for a predetermined normal running is read out from the ROM 17 based on the two ejection values.

Next, the CPU 16 drives and controls the solenoids 8a and 9a of the 3rd and 2nd speed switching electromagnetic valves 8 and 9 through one solenoid drive circuit based on the read speed change data, and controls the 1st to 3rd speed clutches 108 to 3. The 10G is connected to a predetermined state, and a shift state is established based on the read shift data.

At this time, since the 1st and 2nd gear regions occupy a wide speed range in the first gear shift data for running under load, the shift state is immediately changed to 1st or 2nd gear, which is suitable for running under load. I will be moving. As a result, when running with a load, acceleration is performed in a lower speed range than when running without a load, so the acceleration is larger.
You can get Herc and have excellent acceleration.

In this way, different speed change data suitable for driving with no load and driving with a load are selected and read out, and each clutch 98 to 9 is based on the speed change data.
C is switched and controlled. Therefore, when driving with no load, a gear shift state suitable for running with no load is immediately obtained, and when driving with a load, a gear shift state suitable for running with load is immediately obtained. It is possible to improve the operability of the A-crit and to improve the acceleration performance under load.

Effects of the Invention As detailed above, the present invention provides separate gear shift data suitable for traveling with no load and traveling with a load, which are different for traveling with no load and traveling with a load. The prepared speed change data for driving and driving under load can be read out with the selection 1 button, and each clutch is controlled to switch based on the speed change data. A gear shift state suitable for traveling under load can be immediately obtained, and a shift state suitable for traveling under load can be immediately obtained, and the operating feeling of the forklift can be improved, and furthermore, It has the excellent effect of improving acceleration performance under no load and under load, as well as improving fuel efficiency.

[Brief explanation of drawings]

Fig. 1 is a hydraulic and electrical block circuit diagram of a forklift embodying this invention, Fig. 2 is a diagram showing the contents of a readable and rewritable memory (ROM), and Fig. 3 is an accelerator during no-load driving. Figure 4 shows the shift range based on the accelerator opening amount and travel speed when driving under load. Figure 5 shows the processing operation of the central processing unit (CPU). FIG. 6 is a flowchart for explaining the shift range based on the accelerator opening amount and the traveling speed. In the figure, 1 is the clutch oil pump, 2 is the regulator valve, and 3 is the Pressure control valve, 4 is a forward/reverse clutch switching valve, 5 is a clutch switching lever, 6 is a forward/reverse clutch, 8 is a 3rd speed switching solenoid valve, 9 is a 2nd speed switching solenoid valve, 10a
is a 1st speed clutch, 10b is a 2nd speed clutch, 10c is a 3rd speed clutch, 11 is a pressure switch, 13 is an accelerator opening sensor, 15 is a vehicle speed sensor, and 16 is a central processing unit (CPU).
), 17 is a read-only memory (ROM), and 19 is a solenoid drive circuit. Patent applicant: Toyota Industries Corporation Fuji
General Co., Ltd. Agent Patent Attorney 1) Hirosen □ = 18 - Traveling speed Traveling speed - One traveling speed

Claims (1)

[Scope of Claims] A plurality of speed change clutches, a speed change clutch switching drive means for switching and connecting each of the speed change clutches, a load detector for detecting whether or not a load is loaded, and a load detector that detects whether or not a load is loaded. a first storage device storing shift data for no-load running, which sets the gear shift state to a gear shifting state suitable for no-load running; a second storage device that stores shift data for driving under load, which sets the speed change state to a speed change state suitable for driving under load; and inputting a detection signal from the load detector. and a determining means for determining whether the vehicle is running under no load or under load based on the detection signal; a first control means for reading speed change data for no-load conditions and actuating the speed change clutch switching drive means based on the data to connect a corresponding speed change clutch; When the determination is made, a second control for reading the speed change data for the load condition stored in the second storage device and operating the speed change clutch switching drive means based on the same data to connect the corresponding speed change clutch. An automatic transmission control device for an industrial vehicle, characterized by comprising: means.