JPH0621657B2 - Gear position confirmation device when the vehicle is parked - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a gear position confirmation device when a vehicle is parked.

(Prior Art) Conventionally, when parking a vehicle such as an automobile or a forklift, for safety reasons, the gear of the transmission is put in a gear position other than neutral to prevent the vehicle from naturally moving due to the load of the engine ( Hereafter, this is called gear parking).

(Problems to be Solved by the Invention) However, a transmission changeover in which a transmission changeover actuator is drive-controlled based on a detection signal from a lever position detection sensor that detects a gear selection position of a shift lever to change over the transmission. In a vehicle equipped with a so-called automatic transmission having a control circuit, the shift lever and the transmission are not mechanically connected to each other, and it takes time to move the transmission switching actuator. There was a time lag between the completion of the gear change.

Therefore, in the case where the gear parking is performed, if the shift lever is switched to a mode other than neutral and the ignition key is immediately turned off to turn off the ignition switch, the engine immediately stops and the transmission switching actuator driven by the engine operates. It becomes inoperable on the way.

As a result, the transmission is not in the gear position corresponding to the shift lever, and the driver may park without knowing it.

An object of the present invention is to solve the above-mentioned problems and determine whether the driver is in a gear parking state based on the detection results of the actual gear meshing position of the transmission and the lever selection position of the shift lever when the engine is stopped. Another object of the present invention is to provide a gear position confirmation device when a vehicle is parked, which can be surely parked in a gear by notifying such a situation.

Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention provides a shift lever, a lever position detecting means for detecting a gear selection position relating to forward and backward movement of the shift lever, and a forward and backward movement of a transmission. Transmission switching means for switching and driving the gear position related to the engine based on the driving force of the engine, gear position detecting means for detecting a gear position related to forward and backward movement of the transmission, and the above-mentioned based on a detection signal from the lever position detecting means. In a vehicle equipped with a transmission switching control means for driving the transmission switching means to switch the transmission, when the ignition key operation position is switched from the engine drive operation position to the engine stop operation position, Does the gear selection position of the shift lever and the actual gear meshing position of the transmission match at a gear position other than neutral? A gear position confirming device at the time of parking of a vehicle, which is provided with an informing control means for deciding whether or not it is based on each detection signal from the lever position detecting means and the gear position detecting means, and informing the decision result by an informing device. Is the gist.

(Operation) When the operation position of the ignition key is switched from the engine drive operation position to the engine stop operation position, the notification control means is such that the gear meshing position of the transmission and the gear selection position of the shift lever at that time are gear positions other than neutral. It is determined whether there is a match in. Then, the result of the determination is notified from the notification device, and the driver is informed whether or not the vehicle is in the gear parking state at the time of the engine stop operation.

(Embodiment) An embodiment of the forklift according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the mechanism of the drive system of a forklift, and the output of the engine 1 is transmitted via a dry single plate clutch 2 to an automatic transmission 3
The automatic transmission 3 is adapted to move the drive wheels 5 for traveling forward and backward through the operating gear mechanism 4 at a predetermined gear ratio. The dry single plate clutch 2 for turning on and off the output of the engine 1 is a clutch control actuator 6
The engagement state of the clutch 2 is adjusted relative to the stroke amount of the rod 6a extending based on the drive of the clutch.

The automatic transmission 3 is driven by a gear shift switching actuator 7 to shift gears by switching between first speed (low speed) and second speed (high speed), and also drives a forward / rearward travel switching actuator 8 as a transmission switching means. The gear position of the automatic transmission 3 can be switched between forward, neutral and reverse positions.

Each of the actuators 6, 7, and 8 is composed of a hydraulic cylinder in the present embodiment, and an ignition switch 9 described later is used.
Is turned on to operate with hydraulic oil supplied by driving the hydraulic pump 10 powered by the engine 1 in operation. The forward / reverse position detector 11 as a gear position detecting means is composed of a plurality of limit switches, and detects the position of the rod 8a of the forward / reverse switching actuator 8 to detect three positions of forward, neutral and reverse. The shift position detector 12 is composed of a plurality of limit switches as gear position switches, and detects the position of the rod 7a of the shift switching actuator 7 to detect two positions, the first speed and the second speed.

The vehicle speed sensor 13 detects the rotation of the output shaft 14 of the automatic transmission 3 and outputs a signal proportional to the rotation speed. The engine rotation speed sensor 15 detects the rotation of the engine 1 and outputs a signal proportional to the rotation speed.

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

In FIG. 2, an accelerator opening sensor 16 is composed of a potentiometer and detects the depression amount of an accelerator pedal 17 provided in the driver's seat. Then, the signal is the A / D converter 1
It is adapted to be converted into a digital signal at 8.

The lever position detector 19 as lever position detecting means is composed of a plurality of limit switches, and the forward / backward lever 20 as a shift lever provided in the driver's seat is switched (forward, forward,
3 positions (neutral and reverse) are detected.

A central processing unit (hereinafter referred to as CPU) 21 as a transmission switching control means and a notification control means inputs the detection signals from the respective detectors and sensors through an input / output interface 22. The CPU 21 is a read-only memory (R
It operates based on the control program stored in the program memory 23 composed of OM).

The CPU 21 determines the traveling speed of the forklift at that time based on the detection signal from the vehicle speed sensor 13 and the rotational speed of the engine 1 at that time based on the detection signal from the engine speed sensor 15. There is.

The CPU 21 outputs a control signal to the actuator drive circuit 24 through the input / output interface 22 to drive and control the actuators 6 to 8. In this embodiment, the actuators 6 to 8 and the hydraulic pressure are controlled. Electromagnetic control valve B for clutch control, shift switching, and forward / reverse switching provided in a hydraulic circuit composed of the pump 10 and the like.
The corresponding actuators 6 to 8 are driven by controlling 1, B2, and B3. This drive control is stored in the control program stored in the program memory 23. When the vehicle is running, as shown in FIG. 3, depending on the amount of depression of the accelerator pedal 17 with respect to the vehicle speed, the actuator drive circuit 24 and the gear shift switch are used to change the speed change state of the automatic transmission 3 to either the first speed or the second speed. The shift control actuator 7 is driven and controlled via the electromagnetic control valve B2, and the clutch control actuator 6 is controlled to be driven via the clutch control solenoid control valve B1 during this switching.

Further, the CPU 21 determines that the gear has been switched to the target gear based on the detection signal from the shift position detector 12 when the gear is switched.

The CPU 21 determines the amount of depression of the accelerator pedal 17 at that time based on the detection signal from the accelerator opening sensor 16 and the operation position of the forward / backward movement lever 20 at that time based on the detection signal from the lever position detector 19. It has become.

The CPU 21 determines a gear position such as neutral of the automatic transmission 3 at that time on the basis of a detection signal from the forward / rearward movement position detector 11, and based on the detection signal from the shift position detector 12, the automatic transmission 3 at that time. It is designed to determine the shift gear position.

Further, the ignition key operation detector 25 detects the operation position of the ignition key, that is, the engine drive operation position (ignition switch 9 is on) and the engine stop operation position (ignition switch 9 is off), and the detection signal is detected by the CPU 21. Output to. The neutral lamp 26 and the gear parking indicator lamp 27 as an alarm are provided on the instrument panel of the driver's seat, and the CPU
Lighting control is performed at 21.

The work memory 28 is a readable and rewritable memory (RAM), and is configured to temporarily store the calculation result of the CPU 21.

Next, the operation when the forklift configured as described above is parked in a gear will be described.

When the stopped forklift is idling, the forward / reverse lever 20 is in the neutral position, and the meshing state of the automatic transmission 3 is in the neutral,
When the forward / backward lever 20 is switched to the forward or reverse position for gear parking, the lever position detector 19 outputs the detection signal to the CPU 21.

In response to the detection signal, the CPU 21 drives and controls the forward-reverse switching electromagnetic control valve B3 to operate the forward-reverse switching actuator 8 in order to set the gear meshing state of the transmission 3 to the forward or reverse position. Since the engine 1 is driven during this operation, the hydraulic pump 10 is also in a drivable state, and hydraulic oil is continuously supplied to the forward / reverse switching actuator 8 via the forward / reverse switching electromagnetic control valve B3. .

When the driver operates the ignition key to turn off the ignition switch 9 after the gear meshing state of the transmission 3 is completely in the forward or reverse position, the ignition key operation detector 25 detects the ignition of this driver. A detection signal based on a key operation, that is, the ignition switch 9 being turned off is output to the CPU 21. CPU21
Responds to this detection signal and determines the meshing state of the transmission 3 at that time based on the detection signal of the forward / backward movement position detector 11. At this time, since the transmission 3 is in the gear meshing state of the forward or reverse position as described above, the gear parking display lamp 27 is turned on and the timer built in the CPU 21 is operated for a certain period of time. Control lighting. Then, the driver can confirm that the vehicle is in the gear parking state by seeing the lighting of the lamp 27 for a certain period of time.

On the contrary, when the driver operates the ignition key to turn off the ignition switch 9 at the same time when the forward / reverse lever 20 is switched to the forward or reverse position, the engine 1 immediately stops, and accordingly the hydraulic pump 10 also. Will stop. Along with this stop, hydraulic oil is not supplied to the forward / reverse switching actuator 8 via the forward / reverse switching electromagnetic control valve B3, and the forward / reverse switching actuator 8 becomes inoperative, so that the transmission 3 Will not be in the gear meshing state of the forward or reverse position, that is, the state of not being in the gear parking will be maintained.

On the other hand, the ignition key operation detector 25 outputs a detection signal to the CPU 21 based on the operation of the ignition key by the driver, that is, the ignition switch 9 being turned off. In response to this detection signal, the CPU 21 determines the meshing state of the automatic transmission at that time based on the detection signal of the forward / backward movement position detector 11. At this time, as described above, since the transmission 3 is not in the gear meshing state of the forward or reverse position,
U21 does not turn on the gear parking indicator lamp 27.

Therefore, even though the driver has operated the lever for gear parking, the driver can confirm that the gear parking indicator lamp 27 does not light up and that the driver is not in gear parking yet. You can re-run and park the forklift safely.

The present invention is not limited to the above embodiment,
For example, instead of the gear parking display lamp 27, a buzzer may be used, and the buzzer may be sounded for a certain period only in the gear parking state.

Further, in the above-mentioned embodiment, the gear parking display lamp 27 is lit for a fixed time only in the gear parking state. However, this is reversed, and the gear parking display lamp 27 is lit as a warning lamp when not in the gear parking state. May be.

As described above in detail, according to the present invention, whether or not the actual gear meshing position of the transmission and the lever selection position of the shift lever coincide with each other at a gear position other than neutral when the engine is stopped. Is judged, and based on the judgment result,
Since the driver is informed of whether or not the vehicle is in the gear parking state when the engine is stopped, it is possible to perform reliable gear parking, which is an industrially excellent invention as a gear position confirmation device when the vehicle is parked. Is.

[Brief description of drawings]

FIG. 1 is a mechanism diagram showing a mechanism of a forklift drive system embodying the present invention, FIG. 2 is an electric block diagram of the forklift, and FIG. 3 is a gear shift of an automatic transmission with respect to a vehicle speed and an accelerator pedal depression amount. It is a figure which shows a state. In the figure, 1 is an engine, 2 is a clutch, 3 is an automatic transmission as a transmission, 8 is a forward / reverse switching actuator as transmission switching means, 9 is an ignition switch, and 11 is a forward / reverse position as gear position detecting means. A detector, 19 is a lever position detector as lever position detecting means, 20 is a forward / backward lever as a shift lever, and 21 is a central processing unit (CP) as transmission switching control means and notification control means.
U) and 25 are ignition key operation detectors, and 27 is a gear parking display lamp as an alarm.

Claims (2)

[Claims] 1. A shift lever, a lever position detecting means for detecting a gear selection position for forward and backward movement of the shift lever, and a transmission switching means for switching and driving a gear position for forward and backward movement of the transmission based on the driving force of the engine. Gear position detecting means for detecting a gear position relating to forward and backward movement of the transmission, and transmission switching for driving and controlling the transmission switching means on the basis of a detection signal from the lever position detecting means. In a vehicle equipped with a control means, when the ignition key operation position is switched from the engine drive operation position to the engine stop operation position, the gear selection position of the shift lever and the actual gear mesh position of the transmission at that time are in neutral. From the lever position detecting means and the gear position detecting means. It determined based on the detection signal, a gear position confirmation device when the vehicle is parked comprising providing a notification control means for notifying at annunciator the determination result. 2. The gear position confirmation device for parking a vehicle according to claim 1, wherein the alarm is a gear parking display lamp or a buzzer.