JP2000002330A - Electronic shift device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely operate a shift device even by an unfamiliarized person, by surely maintaining the transmission in a low speed condition when starting the engine of a machine body stopped for a long time, and eliminating malfuction such as starting the machine body at a high speed. SOLUTION: This device is equipped with gear type main and auxiliary transmissions 9 and 10 to be constituted so as to obtain a shift stage by combining both the transmissions, and also at least one of these transmissions 9 and 10 switches a solenoid valve by the command of a controller to actuate hydraulic actuators 33 and 34, so as to change a shift position. Turning a key switch ON commands a shift to the solenoid valve for changing the shift position to a first speed by the actuators 33 and 34. When a time measured by a timer is within a fixed time after stopping an engine, the shift position at that time is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic shift device, and is used for a moving vehicle such as a tractor.

[0002]

2. Description of the Related Art The applicant of the present invention has filed an electronic shift device in the past, and this electronic shift device is capable of shifting to an arbitrary position in response to an electric signal. A synchromesh type main transmission and an auxiliary transmission, and a hydraulic clutch for forward / reverse switching are provided immediately before these transmissions, and when a push button for a main transmission operation or a lever for an auxiliary transmission operation is operated, The hydraulic switch for forward switching is disengaged, the shifter operated by hydraulic pressure is moved to a target shift position, and then the hydraulic clutch is connected again to transmit power. .

[0003]

By the way, in the conventional apparatus as described above, when the operator sets the number of shift speeds, the shift position is stored even after the key switch is turned off. If you change, or even the same operator gets on the tractor at a later date, you do not know how fast the gear was shifting until then,
If the shift position is on the high speed side, there is a risk that the aircraft will suddenly start as soon as the engine is engaged and the clutch is engaged.

On the other hand, when the work is temporarily interrupted and the work is performed again, it is more efficient to return the shift position to the original shift position instead of the first speed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an extremely safe and efficient electronic shift device. Therefore, the following technical measures were taken. That is, a gear-type main transmission and a gear-type auxiliary transmission are provided, and a configuration is such that a gear stage can be obtained by a combination of both transmissions.
At least one of the transmissions is configured such that an electromagnetic valve is switched by a command from a controller and a hydraulic actuator is actuated to switch a shift position. An electronic shift device is provided with control means for issuing a shift command to the solenoid valve so as to change a shift position at which a shift can be performed by a hydraulic actuator to a first speed.

Further, in the electronic shift device according to the first aspect, the electronic shift device includes means for storing a current shift position and a timer for measuring time, and a key switch is provided within a predetermined time after the engine is stopped. The electronic shift device is provided with control means for issuing a shift command to the solenoid valve so as to shift to the stored shift position when is turned ON.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. First, from the configuration,
Denotes a tractor, 2 denotes a front wheel, and 3 denotes a rear wheel. An engine 4 is mounted on the front of the tractor 1, and a clutch housing 6 containing a main clutch 5 and a transmission case 8 containing a transmission are connected to the rear of the engine 4. The transmission case 8 has a synchromesh type main transmission 9 capable of four-speed shifting and a synchromesh type auxiliary transmission 10 capable of four-speed shifting.
And a hydraulic switching type forward / reverse switching device 11 for changing the traveling direction of the aircraft is provided in series. The hydraulic clutch 13 of the forward / reverse switching device 11 includes a forward (F side) hydraulic clutch 13a and a reverse (R side) hydraulic clutch 13b. Then, the combination of the main transmission 9 and the sub transmission 10 is configured so that the sixteen gears as shown in the table of FIG.

The arm portion of a single transmission lever 12 for operating the main transmission 9 and the auxiliary transmission 10 is a guide for an H-shaped transmission guide 15 beside the cockpit 14 as shown in FIGS. It is inserted into the groove 15a. A push button type shift switch 1 for speed increase is provided on a handle portion of the operation lever 12.
6 and a speed change switch 17 for deceleration are provided. For example, when the speed change switch 16 for speed increase is pressed, the gear is sequentially shifted up from the first speed to the fourth speed side. The transmission is downshifted from the first speed to the first speed, and thus the shift switches 16 and 17 are appropriately operated to operate the main transmission 9.
Is operated in the range of 1st to 4th speed.

The shift lever 12 can also switch the sub-transmission 10, but in this embodiment, when switching the sub-transmission 10, the clutch pedal 7 is depressed to disengage the main clutch 5 before shifting. It is composed. That is, after the main clutch 5 is disengaged, if the speed change lever 12 is moved back and forth or right and left along the speed change guide groove 15a, a high speed (L speed), a low speed (L speed), a medium speed (M speed), and an ultra low speed ( LL speed). The shift may be performed by disengaging the hydraulic clutch 13 of the forward / reverse switching device 11 instead of the main clutch 5. The movement of the speed change lever 12 is used for timing adjustment (step-up control) for connecting the clutch of the hydraulic clutch 13 and for monitor display.
Position detection sensors 20 and 21 for detecting the movement are embedded in the lateral sides of the transmission case 8.

FIG. 3 shows the detailed structure. 2
The shifter pins 23 and 24 are pivotally supported at two upper and lower stages in the transmission case 8 along the front-rear direction.
Shifters 25 and 26 for switching the transmission gears are fitted and mounted, respectively. 27 and 28 are shifter pins 23 and 2
The upper surfaces of these protrusions 27 and 28 are cut out in a U-shape to form recesses 27a and 28a, and the spherical portion 12a at the lower end of the transmission lever 12 is formed by this recess. 27a and 28a are alternatively inserted. Then, the spherical portion 12 of the transmission lever 12 is recessed 27
a (or 28a), the shifter 25 (or 26) of the auxiliary transmission 10 is moved in the front-rear direction to perform a shift.

At this time, when the shifters 25, 26 move in the front-rear direction, the cam 2 integrated with the shifters 25, 26 is moved.
Reference numerals 5a and 26a depress the pins 20a and 21a of the position detection sensors 20 and 21 embedded in the wall of the transmission case 8 to detect a shift position. Specifically, the detection position is determined by the amount of movement of the pins 20a and 21a, the position detection sensor 20 detects each position of H speed-neutral (N) -L speed, and the position detection sensor 21 Each position of speed-neutral (N) -LL speed is detected. FIG. 4 is a cross-sectional view of a main part of the speed change operation unit as viewed from the front.

As described above, in this embodiment, only the main speed change operation is performed by the no-clutch operation, and the speed change switches 16 and 17 of the speed change lever 12 are pressed to switch the main speed change device 9. Sometimes, first, the hydraulic clutch 13 of the forward / reverse switching device 11 is turned off.
State, and then the shifter 3 of the main transmission 9
When the piston rods 33 and 34 as actuators for operating the shifters 31 and 32 are forcibly moved in the longitudinal direction of the shaft by hydraulic pressure, and when it is electrically detected that the shifters 31 and 32 have reached the predetermined shift positions, they are moved back and forth again. The hydraulic clutch 13 of the forward switching device 11 is connected. These switching operations are all electrically controlled by a controller 35 described later.

FIG. 9 is a block diagram for explaining the relationship between the controller 35 constituting the control system, input means including sensors and switches, and output means such as a solenoid. The controller 35 includes the shifter 3 of the main transmission 9.
Solenoids 37, 38, 39, and 40 for switching the solenoid valves 18 and 19 for operating the first and second switches 32, solenoids 41 and 42 of the solenoid valve 22 for switching the hydraulic clutch 13 of the forward and backward switching device 11, and forward and backward switching devices 11 is connected to a proportional solenoid 47 for controlling a proportional pressure reducing valve 45 for boost control. The proportional solenoid 47 controls the timing for connecting the hydraulic clutch 13 by changing the duty ratio of the pulse. Specifically, when the hydraulic clutch 13 is connected, as shown in FIG. 7, in the initial stage of the connection, in order to quickly move the piston to the target position, only one short time (50 to 100 msec as the initial time) is set.
A pulse current of 00% duty is applied, and then
The pressure is reduced and the duty ratio of the pulse is gradually increased in order to smoothly connect the clutch.

In FIG. 9, reference numeral 48 denotes a monitor lamp, and 49 denotes a position sensor for detecting the position of a shifter for operating the main transmission 9. The controller 35
A rotation sensor 52 for detecting the number of rotations of the engine 4;
Switch to a wheel rotation sensor 53 for detecting the number of rotations of the rear wheel 3, an FR switch 54 provided on the forward / reverse switching lever 30, a buzzer 55 as an alarm, and an inspection mode for checking the operating state of each sensor. A check switch 56 to be pressed at the time, a main key switch 57 for supplying power to each unit, and the like are connected.

In the controller 35, a program for issuing a gear shift command in conjunction with the operation of the key switch 57 is written in its storage means (not shown) together with a program for automatic shifting of the main transmission 9. ing. Hereinafter, this program will be described. In the flowchart shown in FIG. 10, first, the state of each sensor and switch is read in step S1, and the key switch 57 is turned off.
Immediately after N (step S2), a command to excite the first speed solenoid 37 of the main transmission 9 is issued from the controller 35, and the first speed is selected (step S3). Therefore, no matter how fast the auxiliary transmission 10 is set, the main transmission 9 is switched to the low speed side, so that the aircraft does not start at high speed.

Thereafter, the operator operates the main transmission 9 to increase the speed of the switch 16 or the deceleration switch 1
7, the main transmission 9 is switched within the range from the first speed to the fourth speed, and the auxiliary transmission 10 also operates the transmission lever 12 along the guide groove 15a of the H-type transmission guide 15. Thus, four-speed shifting can be performed in the range from H speed to LL speed. The control contents of the main shift operation and the sub-shift operation are defined in a subroutine of "shift change processing" in step S4. In addition to this control, a program is set such that when the auxiliary transmission 10 is operated, the main transmission 9 is also automatically switched. That is, when the auxiliary transmission 10 is switched from the high speed side to the low speed side,
The main transmission 9 immediately moves from the previous position to the fourth position.
The main transmission 9 is configured to shift down to the first speed when the auxiliary transmission 10 is shifted from the low speed side to the high speed side. These are controlled in accordance with the speed change table shown in FIG. 8, and are intended to prevent the vehicle speed from suddenly increasing or decreasing when the shift lever 12 is operated to switch the subtransmission device 10.

The "clutch pressure increasing process" shown in step S5 of the flowchart is a subroutine for gradually increasing the clutch pressure of the hydraulic clutch 13 to smoothly and quickly connect the clutch. As is apparent from the above embodiment, when the key switch 57 is turned on, a command to immediately set the main transmission 9 to the first speed is issued from the controller 35, so that the aircraft may move forward or backward at high speed. As a result, a safe electronic shift device was obtained. In this embodiment, when the key switch 57 is turned on, the main transmission 9
Is switched to the first speed, but the auxiliary transmission 1
0 may be switched to a low LL speed,
Alternatively, both the main transmission 9 and the sub transmission 10 may be switched to the low speed side.

In this embodiment, the main transmission 9
And the auxiliary transmission 10 are operated by a single transmission lever 12, so that the number of operation levers is reduced as compared with the conventional transmission, and the number of parts is reduced, so that the configuration can be made inexpensively. . Next, FIGS. 11 and 12 will be described. In the above example, when the key switch 57 is turned on, the main transmission 9 is immediately set to the first speed.
When the work is temporarily interrupted and the work is performed again, it is often more efficient that the main transmission 9 is in the original shift position instead of the first speed. Therefore, this improved device is provided with a main transmission 9 when a long time has elapsed since the engine 4 was stopped.
Is switched to the first speed, and when the temporarily interrupted work is resumed, control is performed so as to maintain the original shift position. Components having the same configuration as in the block diagram of FIG. 9 are denoted by the same reference numerals, and different components are denoted by new reference numerals.

In FIG. 11, reference numeral 61 denotes a starter motor, 62 denotes a starter relay, 63 denotes a generator, and 64 denotes a battery. In FIG. 12, first, the state of switches and sensors is read (step # 1), and when the operator turns off the key switch 57 of the tractor 1 (step # 2), a timer incorporated in the controller 35 is immediately activated (step # 2). At step # 3), the current shift position is stored at the same time (step # 4). When it is confirmed that a sufficient time has elapsed after storing the tractor 1 in a warehouse or the like, the output command to the main transmission 9 is set to the first speed, and this is stored in the storage means (step # 6).

At this time, when the engine 4 is stopped,
The automatic output for gear shifting control is turned off so that an extra output command is issued from the controller 35 and the battery 64 is not discharged (step # 7). On the other hand, when the engine 4 stopped during the operation is restarted, the key switch 57 is turned on. In this case, since the first speed is not written in the storage means as the output command to the main transmission 9, it is determined that the original shift command before the stop of the engine 4 is valid, and the shift position set by the operator is returned to the shift position. It is controlled (steps # 10, # 11, # 12).

FIGS. 13 to 16 illustrate the proportional pressure reducing valve 45 for controlling the pressure of the hydraulic clutch 13 to increase. When pressure control is performed by changing the drive current of the proportional solenoid 47 by duty control, a drive frequency of about 100 Hz is normally used. At this time, the pressure is 100
The frequency fluctuates minutely at the frequency of Hz, and the fluctuation (2 to 3 kg
f / cm 2), and control is performed so that the averaged pressure becomes the set pressure. In this case, the pressure in the hydraulic clutch 13 is detected by the pressure sensor 70 connected to the hydraulic circuit. However, if the cycle of pressure fluctuation and the cycle of detection are the same, the same point (for example, point P in FIG. 14) is always used. Therefore, there is a problem that the pressure cannot be detected accurately because the pressure of the pressure is detected.

Therefore, in this improved example, the conventional 10
What was detected at msec intervals is half of that of 5 msec
c interval. In order to make the average pressure accurate, it is preferable to further shorten the detection cycle and increase the average number.

[0023]

As described above, the present invention comprises a gear-type main transmission and a gear-type auxiliary transmission so that a gear can be obtained by combining the two transmissions, and at least one of the transmissions is provided. First, in an electronic shift device configured to switch an electromagnetic valve according to a command from a controller and to operate a hydraulic actuator to switch a shift position, the electronic shift device can be shifted by the hydraulic actuator when a key switch is turned ON. Since the control means for issuing a shift command to the solenoid valve to change the shift position to the first speed is provided, when the engine of the aircraft which has been stopped for a long period of time is started, the transmission is always set to the low speed state. As a result, there is no problem that the aircraft starts at a high speed, and even an unfamiliar person can safely operate the aircraft.

Further, in the electronic shift device according to the first aspect, the electronic shift device includes means for storing a current shift position, and a timer for measuring time, and a key switch is provided within a predetermined time after the engine is stopped. Is turned on, there is provided a control means for issuing a shift command to the solenoid valve in order to shift to the stored shift position, so that when the work is temporarily interrupted, the shift is returned to the original shift position. Therefore, work efficiency is not impaired.

[Brief description of the drawings]

FIG. 1 is an overall side view of a tractor.

FIG. 2 is a plan view of the tractor.

FIG. 3 is a diagram illustrating a relationship between a position detection sensor and a shifter of the auxiliary transmission.

FIG. 4 is a diagram illustrating a relationship between a shifter and a shift lever of the auxiliary transmission.

FIG. 5 is a power transmission diagram.

FIG. 6 is a hydraulic circuit diagram of a forward / reverse switching device and a main transmission.

FIG. 7 is a diagram illustrating a pattern of boost control.

FIG. 8 is a table illustrating the number of gear positions.

FIG. 9 is a control block diagram.

FIG. 10 is a control flowchart.

FIG. 11 is a block diagram of an improvement device.

FIG. 12 is a control flowchart of the improvement device.

FIG. 13 is a hydraulic circuit diagram of the improvement device.

FIG. 14 is a graph illustrating a state of a change in operating pressure of a hydraulic clutch.

FIG. 15 is a control flowchart.

[Explanation of symbols]

 Reference Signs List 1 tractor 9 main transmission 10 auxiliary transmission 18 solenoid valve for main transmission 19 solenoid valve for main transmission 35 controller 57 key switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Ikegawa 1st Hachikura, Tobe-cho, Iyo-gun, Ehime Prefecture Iseki Agricultural Machinery Co., Ltd. Inside

Claims (2)

[Claims] 1. A gear-type main transmission and a gear-type auxiliary transmission, wherein a gear stage is obtained by a combination of the two transmissions, and at least one of the transmissions is provided.
First, in an electronic shift device configured to switch an electromagnetic valve according to a command from a controller and to operate a hydraulic actuator to switch a shift position, the electronic shift device can be shifted by the hydraulic actuator when a key switch is turned ON. An electronic shift device, further comprising control means for issuing a shift command to the electromagnetic valve to change a shift position to a first speed. 2. The electronic shift device according to claim 1, wherein the electronic shift device stores a shift position.
A timer for measuring a time; and a control means for issuing a shift command to the solenoid valve to shift to the stored shift position when the key switch is turned on within a predetermined time after the engine is stopped. An electronic shift device characterized by the above-mentioned.