JPS6334354A - Gear-off time controlling method for automatic transmission - Google Patents

Abstract

PURPOSE:To secure safety driving, by judging that gear-off occurs in the case where a detection signal showing the existing gear position is varied when a gear changeover is not carried out, and putting an actuator back to a gear position before the gear-off. CONSTITUTION:A central processing unit 18 judges an end of gear selector motion on the basis of a signal out of a shift position detector 10 with the gear selector motion, while the existing gear position is stored in a working memory 21. Under this state, if the signal comes off, it is judged that gear-off occurs. And, on the basis of this detection, the gear position data stored in the memory 21 is called out, and a clutch controlling actuator 6 is controlled to put it back to the gear before gear-off, then a speed change selector actuator 7 is driven and controlled so as to put the gear in the desired gear position. And, it is put back to the gear position before the gear-off again, and the actuator 6 is controlled. Therefore, any hindrance attributable to the gear-off is avoided and safety driving is always securable.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) This invention relates to a control method when an automatic transmission in a vehicle is out of gear.

(Prior Art) Conventionally, in a vehicle equipped with an automatic transmission, the gear position of each gear of the automatic transmission is changed by changing between the current intermediate speed and pressing down on the accelerator pedal.

(Problems to be Solved by the Invention) However, when the synchro ring of the transmission wears out, gears are more likely to slip out, and this gear slippage makes it impossible for both cars to continue running.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a vehicle that can detect whether an automatic transmission is in a gear, handle the situation, and continue traveling.

Structure of the Invention (Means for Solving Problems) In order to achieve the above object, the present invention includes a gear position switch for detecting the gear position of each gear and determining whether the gear is in a normal gear position. In automatic transmissions,
The current gear position is stored in a storage means, and when a detection signal indicating the current gear position changes while no gear change is being performed, it is determined that a gear dropout has occurred, and the gear is stored in advance in the storage means. An automatic transmission system in which the gear position data before gear disengagement is retrieved, the clutch is disengaged to return to the gear position before gear disengagement based on that data, and then the gear of the automatic transmission is placed in the gear position before gear disengagement. The gist of Gear 1 Friends is how to control time.

(Function) With the above means, when the detection signal indicating the current gear position changes when the gear is not changed, it is determined that a gear dropout has occurred, and the gear handling (preference) stored in the storage means in advance is determined. After calling out the gear position data of , and disengaging the clutch to return to the gear position before the gear disengagement based on that data, the automatic transmission is controlled to shift the gear to the gear position before the gear disengagement.

(Example) Hereinafter, an example in which the present invention is embodied in a forklift will be described with reference to the drawings.

Figure 1 shows the mechanism of the drive system of a forklift 1-, in which the output of the engine 1 is transmitted to an automatic transmission 3 via a dry single plate clutch 2, and the automatic transmission 3 has a differential gear mechanism II'M4. The drive wheels 5 are moved forward and backward at a predetermined gear ratio. The connection state of the dry single-plate clutch 2, which turns on and off the output of the engine 1, is adjusted relative to the stroke (2) of the rod 6a, which extends in response to the drive of the clutch control actuator 6.

The automatic transmission 13 changes gears between 1st speed (low speed) and 2nd speed (high speed) by driving the speed change actuator 7, and changes the gear position of the automatic transmission 3 by driving the forward/reverse change actuator 8. can be switched between three positions: forward, neutral, and reverse.

The forward/reverse position detector 9 consists of a limit switch of FM number, and is connected to the rod 8a of the forward/reverse switching actuator 8.
It detects the position of , and detects three positions: forward, neutral, and reverse. The shift position detector 10, which serves as a gear position switch, is comprised of a speed limit switch, and detects the position of the rod 7a of the shift switching actuator 7 to detect two positions, 1st speed and 2nd speed. Therefore, in this embodiment, the shift position detector 10 is composed of a first limit switch 10a that detects the gear position in the first speed state, and a second limit switch 10b that detects the gear position in the second speed state. has been done.

The vehicle speed sensor 11 detects the rotation of the output shaft V-shift 12 of the automatic transmission 3 and outputs a signal proportional to the rotation speed.

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

In FIG. 2, the accelerator opening sensor 13 is composed of a voistometer, and detects the depression 1 of an accelerator pedal 14 provided at the driver's seat. The signal is then converted into a digital signal by an A/D converter 15.

The lever position detector 16 includes a plurality of limit switches 1. s
+ buzz, and detects the switching state (3 positions of forward, neutral, and reverse) of the forward/reverse lever 17 provided on the driver's seat.

A central processing unit (hereinafter referred to as CPU) 18 receives detection signals from each of the detectors and sensors through an input/output interface 19. The CPU 18 operates based on the f, 13 m block O-gram stored in a program memory 20 consisting of a read-only memory (<ROM). Fork,
The working memory 21 as a storage means is a readable and rewritable memory (RAM), and is adapted to store the calculation results of the CPIJ 18.

Based on the detection signal from the forward/reverse position detector 9, the CPU 18 determines the current gear position, such as neutral, of the automatic shift l113, and also determines the first and second limit switches 10a, 10b of the shift position detector 10. Based on the detection signal from the transmission gear, the current transmission gear position is determined.

Further, the CPU 18 calculates the current traveling speed of the forklift based on the detection signal from the vehicle speed sensor 11.

The cpuis determines the current depression position of the accelerator pedal 14 based on the detection signal from the accelerator opening sensor 13, and determines the operating position of the forward/reverse lever 17 at that time based on the detection signal from the lever position detector 16. It's about to come out.

Further, the CPU 18 outputs a control signal to the seven-actuator drive circuit 22 via the input/output interface 19 to drive and control each of the actuators 6 to 8. This drive control is stored in a control program stored in the program memory 20. And C.P.L.J.
18, as shown in FIG. 3, when the vehicle is running, the automatic transmission 3 is shifted to either 1st speed or 2nd speed according to the depression of the accelerator pedal 14 according to the vehicle speed via an actuator drive circuit 22. The switching actuator 7 is driven and controlled, and the clutch υ[1 actuator 6 is also driven at the time of this switching.

CPtJ18 detects the shift position detector 1 during this gear change.
Based on the detection signals from the first and second limit switches 10a and 10b of 0, it is determined that the gear has been shifted to the target gear. That is, for example, when a gear change is performed from 1st gear to 2nd gear, the first limit switch 10a is turned off and the second limit switch 10b is turned on, the target gear position of 2nd gear is shifted. It is determined that the switching operation has ended.

Further, the CPU 18 always stores the current gear position in the working memory 21, and when the switching operation to the target gear position is completed, the gear position data is changed once. There is.

When the CPU 18 is not performing switching, the detection signal changes without indicating the current gear position, that is, the first or second limit switch 1Q of the shift position detector 10
When the on-signal output is no longer output from a and 10b, it is determined that gear slippage has occurred. When the CPU 18 detects the occurrence of this gear slippage, it calls out the gear position data before the gear slippage stored in the work memory 21 in advance. Furthermore, based on this data, after disengaging the dry deck clutch 2 to return to the gear position before gear disengagement, both actuators 6.7 are driven so as to shift the gear of automatic transmission Ia3 to the gear position before gear 1 friend U. Control.

These series of gear handling detection and processing operations by the CPU 1B are performed by the control program in the program memory 20.

Next, the operation of the forklift constructed as described above will be explained based on FIG. 4.

The CPU 18 operates the 1yi reverse lever 17 to the forward side (
With the automatic transmission 3 set in the forward gear position, the gear change operation from 1st gear to 2nd gear or from 2nd gear to 1st gear is performed based on the speed change map shown in FIG. 3 based on the vehicle speed and pedal opening. let it happen.

CPIJ18 detects the shift position detector 1 due to this switching operation.
0 first or second limit switch 1Qa, 10
Based on the signal from b, that is, when switching to 2nd speed, an on signal is input from the second limit switch 10b, and when switching to 1st speed, an on signal is input from the first limit switch 10a. When inputting , it is determined that the gear switching operation has finished and the current gear position is determined. (1″a or 2nd speed) is stored in the working memory 21.

CPLI 18 indicates this 1st or 2nd speed state (shift 9 position detection P!10 first or second limit switch 10a
, 10b is turned on (w3), when that signal is turned off, it is determined that gear slippage has occurred due to wear of the synchro ring or the like.

The CPU 18 uses the working memory 21 based on the detection of gear dropout.
The clutch control actuator 6 is driven 1 by calling the stored gear position data and setting the gear position before the gear disengagement as the target gear position in order to return to the gear position before the gear disengagement.
After the dry deck clutch 2 is disengaged, the speed change actuator 7 is driven and controlled so that the gear of the automatic speed change 13 is set at the target gear position (the gear position before the gear is disengaged).

Then, when the CPtJ 18 inputs the target gear position signal, that is, inputs the ON signal 8 from the first or second limit switch 10a, 10b of the shift position detector 10,
It is determined that the operation of shifting the gear of the automatic transmission 3 to the first or second gear and returning it to the gear position before the gear dropout is completed, and the current gear position is stored in the working memory 21 again. Further, the CPIJ 18 drives and controls the clutch control actuator 6 to connect the dry deck clutch 2.

In this embodiment, when gear slippage occurs, the occurrence of gear slippage is detected and control is performed to return the gear position to the gear position before the gear slippage, and the gear of the automatic transmission is returned to the gear position before the gear slippage. can be put in. Therefore, the forklift can continue to be able to travel.

Note that this invention is not limited to the above-mentioned actual IA example,
In the above embodiment, limit switches 1Qa and 10b are installed in the speed change position detector 10 as a gear position switch, but other contactless switches such as proximity switches may also be used.

Further, in the above embodiment, the present invention is applied to a forklift that can be switched to 2nd speed on the forward side, but it may also be applied to a vehicle that can be changed to 2nd speed on the reverse side, or it can be applied to a single vehicle that has 3rd or higher gears. . Furthermore, in the above embodiment, the gear position is determined by the detector 1.
0, but it may be applied to the rear movement position detector 9.

Effects of the Invention As explained in detail above, even if a gear slips out, this invention can detect that the same gear is handled and return to the original gear position before the gear slips out. It has an excellent effect of avoiding obstacles and ensuring safe driving at all times.

[Brief explanation of the drawing]

Fig. 1 is a mechanical diagram showing the mechanism of the drive system of a forklift embodying this invention, Fig. 2 is an electrical block diagram of the forklift as well, and Fig. 3 is an automatic shift-like shift according to vehicle speed and accelerator pedal depression number. A diagram showing the state, FIG. 4 is a flowchart 1-diagram for explaining the operation.

Claims (1)

[Claims] 1. In an automatic transmission equipped with a gear position switch for detecting the gear position of each gear and determining whether it is in the correct gear position, the current gear position is stored in the storage means and the gear is not changed. When the detection signal indicating the current gear position changes, it is determined that gear disengagement has occurred, and the gear position data before gear disengagement stored in the storage means is called up, and based on that data, the gear disengagement is determined to have occurred. A method of controlling an automatic transmission when a gear is disengaged, in which the gear of the automatic transmission is set to the gear position before the gear disengagement after the clutch is disengaged to return to the gear position.