JP3031879B2 - Vehicle speed change control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shift control device for a vehicle having a plurality of change mechanisms.

[0002]

2. Description of the Related Art Conventionally, a transmission for a vehicle includes a reverse change mechanism, a main change mechanism, a sub-change mechanism, a creep change mechanism, and the like. The structure is changed over by a shift lever. However, it is difficult to shift the plurality of transmissions to the target vehicle speed by switching accurately. At this time, if the change mechanism is manually switched, the vehicle speed is greatly changed.

[0003]

SUMMARY OF THE INVENTION According to the present invention, there is provided a vehicle transmission having the following configuration. That is, in a vehicle that transmits the rotational power of the engine 8 to the driving wheels 6 (7) via a plurality of change mechanisms 2, 3, a change mechanism 3 that manually switches the form of the change mechanism, and a manual change mechanism each change position of the 3, further configured with a change mechanism 2 to switch the change position via a command from the control unit C, and when switching the change position of the former change mechanism 3 at a high speed side, the latter change mechanism 2 Change position
Position, and switch this change position 2 to the lowest speed position.
Gear shift control device for controlling the vehicle speed to be maintained or maintained .

On the other hand, when the former change mechanism 3 is switched to the lower speed side, the chain of the latter change mechanism 2 is changed.
Judge position and switch this change position to the highest speed position.
And shift control apparatus for a vehicle for controlling the so that to place or maintain.

[0005]

According to the shift control device for a vehicle constructed as described above, when one change mechanism 3 is manually operated, the control device C determines the other change position.
Since the position is switched or maintained to the highest speed position or the lowest speed position where the vehicle speed fluctuation is the smallest according to this position, the fluctuation of the vehicle speed before and after the manual shift of the vehicle is suppressed as much as possible, and the operability of the vehicle can be improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, the tractor has a front wheel 6 and a rear wheel 7, which are steered by a steering handle 5, in a four-wheel drive mode in which the rotational power of an engine 8 is transmitted to drive and drive. On the left side of the cockpit 9, a manual lever 4 for switching the sub-change mechanism 3 is provided, and a switching operation is performed along a lever guide 10 from a neutral position N to a high speed H, a medium speed M, a low speed L, a low speed LL, and the like. It has become. On the right side of the cockpit 9, a designation lever 12 for switching the main change mechanism 2 and a monitor 11 for displaying a designated stage of the designation lever 12 are provided. The operation of the designated lever 12 is input to a control device C, which will be described later. When the lever 12 is operated forward (+) from the lock position O along the lever guide 13, the speed is increased by one step, and when the lever 12 is operated rearward, the speed is reduced by one step. Configuration.

An instrument panel 14 in front of the steering handle 5 has a rotation indicator 1 for the engine 8 mounted thereon.
5, a PTO shaft rotation display 16, a vehicle speed display 17, a display 18 of the main change mechanism 2, a display 19 of the sub-change mechanism 3, and the like.

On the steering floor below the steering handle 5, there are provided a clutch petal 20 for connecting and disconnecting the main clutch 25, steering brake petals 21 and 22 for independently braking the left and right rear wheels 7, 7, and an accelerator petal. 23 etc. are provided. A lift arm 24 is provided at the rear end of the vehicle body, and a working device connected to the lift arm 24 is moved up and down.

The vehicle body of the tractor is integrally formed from the front engine 8 to a rear rear axle housing and the like via a clutch housing and a transmission case.
A main clutch 25, a transmission and the like are provided inside these. The rotational power of the engine 8 is turned on and off by the main clutch 25, and the rotational power output from the clutch 25 is sequentially transmitted to the traveling shaft 26 through the sub-change mechanism including the reverse change mechanism 1, the main change mechanism 2, and the creep change mechanism 27. 3 and the transmission. The traveling shaft 26 has a path for transmitting rotational power to the left and right rear wheels 7 via a differential gear 28, a switching gear 29 of a two-wheel drive and four-wheel drive for switching the front wheels 6 between a driving state and a non-driving state, and the front wheels 6. And a path for transmitting the left and right front wheels 6 via a front wheel high-speed switching device 30 that switches the rotation of the front wheels faster than the rotation of the rear wheels 7, a front wheel differential gear 31, and the like.

Power is transmitted from the main clutch 25 to a PTO shaft 32 at the rear of the vehicle body, and a PTO transmission 33 using a synchromesh gear is provided in the middle of the transmission. Of the transmissions 1, 2, 3
The reverse change mechanism 1, which switches the traveling direction of the vehicle body back and forth, is a friction disk clutch type, which is pressed by hydraulic pressure to switch from a neutral position N to a forward position F and a reverse position R. Is switched by a command from a control device C having a CPU. In addition, the form of the reverse change mechanism 1 may be a form using a synchromesh gear instead of the friction disc clutch.

The main change mechanism 2 operates from the first speed to the fourth speed.
The gear shift is performed up to the first gear, and the shifter is operated by a hydraulic cylinder to select any one of the first to fourth gears and transmit the power to the sub-change mechanism 3. . The hydraulic cylinder has a configuration in which a solenoid valve 37 for main change is operated by a command from the control device C.

The sub-change mechanism 3 shifts at a very low speed LL, a low speed L, a medium speed M, and a high speed H, and is formed by a synchromesh gear. The operation of the manual lever 4 is controlled by the control device C or the like. The switching is performed by direct transmission via a connecting member or the like without a command. The relationship between the speed of the main change mechanism 2 and the speed of the sub-change mechanism 3 configured as described above is such that the speed increases in order from the low speed LL1 to the high speed H4 as shown on the monitor 11 in FIG. .

The shift and operation positions of the main change mechanism 2 and the sub-change mechanism 3 are configured such that the movement of each shifter is detected by the main and sub-shifter sensors 35 and 36. Also, the reverse change mechanism 1 is provided with a reverse change lever for manually switching the same as the sub-change mechanism 3, and the main change mechanism 2 is configured to be able to be manually switched by a main change lever different from the designated lever 12. I have.

The control device C is configured to detect and input an operation of a designation lever 12, a main change lever 37, a change mode switch 38 to be described later, and the like.
And a main change solenoid valve 37, and various indicators (PTO speed indicator 16, vehicle speed indicator 17, main change indicator 1) of the instrument panel 14.
8. It outputs the electric command to the sub-change display 19).

In the tractor constructed as described above, for example, as shown in FIG. 4, the current change position is FH3 (reverse change mechanism 1 is forward F, subchange mechanism 3 is high speed H, main change mechanism 2 is third F). When the main change mechanism 3 is shifted to the fourth speed, that is, FH4, by the designated lever 12 at the time of (speed), the lever operation is first input to the control device C, and the control device C performs the reverse change operation. And the reverse change mechanism 1 is set to the neutral position N. Thereafter, the solenoid valve 37 for main change is switched by the command of the control device C, the hydraulic cylinder is operated, and the change position of the main change mechanism 2 is switched from the third speed to the fourth speed. Finally, the reverse change mechanism 1 is connected to the forward position F.

Next, a case in which the sub-change mechanism 3 is shifted from a low speed L to a high speed H by the manual lever 4 will be described. For example, when shifting from the change position of FL4 to the change position of FH4, if the sub-change mechanism 3 is operated from the low speed L to the neutral range by the manual lever 4 as shown in FIG. Detected,
This is input to the control device C and the main change mechanism 2
Not only the speed change region but only the reverse change mechanism 1 is temporarily switched to the neutral position. Then, after the manual lever 4 is switched to the high speed H, the main change mechanism 2 returns to the fourth speed, and the reverse change mechanism 1 is connected to the forward F, and
This is the H4 change position.

As described above, when shifting the speed of the main change mechanism 2 or the sub-change mechanism 3 having the synchromesh type gear structure, the synchronizing mechanism can be easily tuned, and a clutch mechanism is separately provided for transmitting the power. The transmissions 1, 2, 3 can be simply configured without providing them.

Next, an example in which a part of the instrument panel 14 is formed in another form will be described with reference to FIGS. Here, when the change mode switch 38 connected to the control device C is switched to the "manual mode", the main change mechanism 2 and the sub-change mechanism 3 are switched by dedicated levers 37 and 4, respectively. In this case, the display section of the instrument panel 14 indicates which of the main change mechanism 2 and the sub-change mechanism 3 should be operated when shifting up or down only one gear from the current change position. 39 is displayed.

At this time, as shown in FIG. 10, the change position is determined on the table from 1 to 16 shift speeds. The shift position of the main change mechanism 2 and the sub-change mechanism 3 at the time of up-shifting and down-shifting. Which operation should be performed is displayed on the display unit 39. For example, as shown in FIG. 2 of the previous example, when the driver wants to shift up by one step while traveling in FL4, the designated lever 12 is operated only once to increase the speed, and the display unit 39 displays as shown in FIG. Display of contents according to the table of FIG. 10 "Up: L → M, Down: 4 →
3 "is performed, the driver switches the manual lever 4 according to this display to change the monitor 11 display of the sub-change mechanism 3 from L to M, and the main change mechanism 2 shifts from the fourth gear to the first gear. And displayed as “FM1”.

Next, the operation of the shift control when the change mode switch 38 of the present invention is switched to the "automatic mode" will be described with reference to flowcharts of the entire shift control shown in FIGS. 7, 8, and 9. . In the main routine shown in FIG. 7, when the power system of the tractor is ON, a subroutine 1 for actuator (hydraulic cylinder) operation processing and a subroutine 2 for monitor display are constantly repeated.

In subroutine 1, it is first determined whether or not a request for shifting the main change mechanism 2 by the designated lever 12 has been detected. If this is YES, the main change mechanism 2 is switched. If NO here, each sensor value of the sub-change shifter or the like is read. Then, it is determined whether or not the sub-change mechanism 3 has moved to the neutral position, that is, whether or not a shift operation has been performed. If YES here, the main change mechanism 2 is held in neutral, and the detection values of the main shifter sensor 35, the sub shifter sensor 36, etc. are read again to determine whether the sub change mechanism 3 has been operated to the shift position.
Here, the switching state of the change mode switch 38 is determined, and if it is the "manual mode", the main change mechanism 2 is connected to the same change position as before the shift. Also,
In the case of the "automatic mode", it is determined whether the operation of the sub-change mechanism 3 has been decelerated or the speed has been increased. If the operation has been decelerated, the main change position before the shift has been determined and this is the first speed. At this time, the speed is changed to the highest speed within the change position, that is, the fourth speed, and the connection is established.

If the operation of the sub-change mechanism 3 is increased, the main change position before the shift is determined, and when this is the fourth speed, the main change position is set to the lowest speed within this change position, that is, the first speed. Change and connect.

As described above, only when the sub-change mechanism 3 is manually operated, particularly when only one stage is operated, that is, when the driver wants to finely adjust the vehicle speed, the control device C controls the change in which the vehicle speed does not change. It switches to the position. This makes it possible to minimize fluctuations in vehicle speed before and after the speed change operation of the tractor, thereby improving the operability of the tractor.

In the subroutine 2, after the actuator processing is completed, an operation for obtaining a vehicle speed closest to the current change position is displayed. First, the change position is determined from the sensor, and in response to this, FIG. Is displayed on the monitor based on the change position table shown in FIG.

[Brief description of the drawings]

FIG. 1 is a diagram showing a transmission mechanism of a tractor.

FIG. 2 is a plan view of the tractor.

FIG. 3 is a block diagram showing a connection state of a control device.

FIG. 4 is a flowchart illustrating an example of a shift control.

FIG. 5 is a flowchart illustrating an example of a shift control.

FIG. 6 is a plan view showing another form of the instrument panel.

FIG. 7 is a flowchart of shift control.

FIG. 8 is a flowchart showing a subroutine of FIG. 7;

FIG. 9 is a flowchart showing a subroutine of FIG. 7;

FIG. 10 is a chart of a change position table.

[Explanation of symbols]

 1 reverse change mechanism 2 main change mechanism 3 sub change mechanism 4 manual lever C control device

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-256957 (JP, A) JP-A-60-237257 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] 1. In a vehicle for transmitting rotational power of an engine 8 to a driving wheel 6 (7) via a plurality of change mechanisms 2, 3, a change mechanism 3 for manually changing the form of the change mechanism, Change mechanism 3
Each change position, further via a command from the control device C Ji of
When the change position of the former change mechanism 3 is switched to the high-speed side, the change position of the latter change mechanism 2 is determined.
Switch this change position to the lowest speed position
Is a vehicle shift control device that controls to maintain . 2. A vehicle for transmitting rotational power of an engine 8 to drive wheels 6 (7) through a plurality of change mechanisms.
A change mechanism 3 for switching by manual operation in the form of the change mechanism, at each change position of the manual change mechanism, change position further through the instruction of the control unit C
When the change position of the former change mechanism 3 is switched to the low-speed side, the change position of the latter change mechanism 2 is determined.
Switch or maintain the change position of
Shift control device for a vehicle that controls so that.