JP3239275B2 - Transmission control device for tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for electronically controlling a shift operation of a tractor.

[0002]

2. Description of the Related Art A tractor provided with an electronic control type shift control device, which selects a shift shift in accordance with a change in engine output accompanying work, and automatically performs a clutch on / off operation and a gear change operation. Is being developed.

[0003]

However, in the conventional automatic transmission tractor described above, the shift position is controlled uniformly so as to shift down when the engine load exceeds a certain value and to shift up when the engine load becomes a certain value or less. As a result, upshifting and downshifting were frequently repeated during traveling, and there was a problem in riding comfort. Also,
Since the operating force for connecting the clutch was always constant irrespective of the degree of load, the connection of the clutch sometimes lacked smoothness. In addition, the tractor is equipped with various work machines
Used, for example, by pulling a plow
When performing work, depending on the type of work equipment,
Because of the load, the rotational power of the engine can be
When performing a gear change operation after a break,
When a sudden difference in rotation occurs on the shaft and the clutch is connected again
However, there is a problem that a large impact occurs.

[0004]

In order to solve the above problems, the present invention has the following arrangement. That is, the shift control device for an agricultural work machine according to the present invention provides a shift control for a tractor having a hydraulically controlled clutch (3) for transmitting rotational power from a shaft on the engine (1) side to a shaft on the transmission (4) side. In the control device, a first rotational speed detecting means (30) for detecting the rotational speed of the shaft on the engine side, a second rotational speed detecting means (31) for detecting the rotational speed of the shaft on the transmission side, Deviation calculating means for calculating a deviation between the detection values of the first and second rotational speed detecting means, change amount calculating means for calculating a change amount of the deviation, and fuzzy inference using the deviation and the change amount as a condition part membership function Determining means for determining a shift position of the transmission and a hydraulic pressure for operating the clutch.

[0005]

The rotation speed of the shaft on the engine side is detected by the first rotation speed detection means, and the rotation speed of the shaft on the transmission side is detected by the second rotation speed detection means. Then, the deviation between the detection values of the first and second rotational speed detecting means is calculated by the deviation calculating means, and the amount of change of the deviation is calculated by the change amount calculating means. Fuzzy inference is performed by the determining means using the thus obtained deviation and the amount of change of the deviation as a condition part membership function, and the shift position of the transmission and the hydraulic pressure for operating the clutch are determined.

If the shift position of the transmission and the hydraulic pressure for operating the clutch are determined based on fuzzy inference, the shift change and the connection speed of the clutch can be adjusted in consideration of the expected load fluctuation. The shifting operation can be performed with a feeling similar to the operation of the vehicle, and the riding comfort is improved.

[0007]

FIG. 1 is a transmission system diagram of a tractor according to one embodiment of the present invention. In the figure, 1 is an engine, 2 is a main clutch, 3 is a forward / reverse switching device, 4 is a main transmission, 5 is an auxiliary transmission, 6 is a front wheel, 7 is a rear wheel, and a symbol bearing S indicates rotation. Symbols bearing the shaft and G represent gears, respectively. After passing through the main clutch 2, the rotational output of the engine 1 is separated into a traveling output and a PTO output. The traveling output is appropriately switched between a forward speed and a reverse speed by a forward / reverse switching device 3, is shifted by a main transmission 4 and a subtransmission 5, and is transmitted to front wheels 6 , 6 and rear wheels 7, 7.

The forward / reverse switching device 3 is configured to be operated by hydraulic pressure, and connects the shaft S4 with the gear G3 to connect the gears G2 and G2.
When the shaft S3 is transmitted from the shaft S3 to the shaft S4 via G3, the shaft S4 and the gear G6 are connected to each other. If not connected to any of G3 and G6, transmission from shaft S3 to shaft S4 is cut off. That is, the forward / reverse switching device 3 has a role of switching between forward and reverse, and a role as a clutch when shifting the main transmission 4 and the subtransmission 5 described later.

When the main transmission 4 is transmitted from the shaft S4 to the shaft S5 via the gears G7 and G8, the first speed, the gears G9 and G10
Transmission from the shaft S4 to the shaft S5 via the second gear, the gear G1
1. When transmitted from shaft S4 to shaft S5 via G12, 3
Speed, from the shaft S4 to the shaft S via the gears G13 and G14.
When it is transmitted to 5, it becomes 4th. In addition, 1st speed, 2nd speed, 3rd speed,
The transmission ratio increases in the order of the fourth speed. These shift operations are performed by the shifters 10 and 11.

When the shaft S5 and the shaft S6 are directly connected to each other, the sub-transmission 5 transmits high-speed transmission, and G15, G16, S
6, G17 and G18, the transmission from the shaft S5 to the shaft S6 results in a medium speed transmission, G15, G19 and S among the gears and shafts.
8, G20, G21, and S9, when the shaft S5 is transmitted to the shaft S6, a low-speed transmission is performed.
9, S8, G20, G21, S9, G22, G23, S
Transmission from the shaft S5 to the shaft S6 via 7, G17, G18 results in an ultra-low speed transmission. These shift operations are performed by shifter 1
Perform steps 2 and 13.

FIG. 2 shows a main part of a hydraulic circuit diagram of the tractor. The oil delivered from the pump 15 is divided in two directions by the flow dividing valve 16, and the oil in one direction is supplied to the pressure increasing control valve 17.
, And the oil in the other direction is supplied to the switching valves 20, 21, 22, and 23 that switch the main transmission 4 and the subtransmission 5. . Reference numerals 24 and 25 in the figure denote hydraulic cylinders that operate the shifters 10 and 11 of the main transmission 4. Note that the switching valves 22 and 23 of the sub transmission 5 are also connected to the switching valve 2 of the main transmission.
The configuration is the same as that of the shifters 12 and 1.
3 are connected to hydraulic cylinders (not shown) 26 and 27.

FIG. 3 schematically shows the speed change control system of the tractor. That is, the rotation speeds of the shafts S2, S4, and S6 are detected by the rotation sensors 30, 31, and 32, respectively. The shaft S2 is a shaft on the engine side with respect to the forward / reverse switching device (hydraulic clutch) 3, and the rotation sensor 30 for detecting the rotation speed of this shaft is used as first rotation speed detection means. Also, the axis S
4 is a shaft on the transmission side with respect to the forward / reverse switching device 3;
The rotation sensor 31 that detects the rotation speed of the shaft is used as second rotation speed detection means. Furthermore, the shifter 1 of the main and auxiliary transmissions
The movement amount of 0, 11, 12, 13 is also the stroke sensor 3.
3, 34, 35 and 36 are detected. The detection results of these sensors and setting commands given from the operation unit 37 are processed by the controller 38, and hydraulic valves 18 and 2 for controlling the forward / reverse switching device 3, the main transmission 4 and the auxiliary transmission 5 are provided.
Output commands are issued to 0, 21, 22, 23. This is shown in a block diagram in FIG.

As for the shift control, a first pressure for adjusting the hydraulic pressure for operating the forward / reverse switching device 3 which is a hydraulic clutch is described.
And the second control for determining the shift position of the main transmission 4 and the auxiliary transmission 5 is performed. Hereinafter, both controls will be described. Note that when the operator performs a shift operation, the first control
Only when the controller performs a gear change operation.
The first control and the second control are performed.

First, for the first control, a detection value R _{1 of} the first rotation speed detecting means (rotation sensor) 30 is compared with a detection result R ₂ of the second rotation speed detecting means (rotation sensor) 31.
A deviation D (= R ₁ −R ₂ ) between the _two is calculated. Further, the variation ΔD of the deviation D is calculated. And these deviations D
Fuzzy inference is performed using the change amount ΔD as an input variable (membership function of the condition part) and the opening correction amount Cv of the hydraulic valve 18 as an output variable.

When performing fuzzy inference, fuzzy control rules shown in Table 1 are employed. A vertical line is a deviation D, a horizontal line is a change amount ΔD, and the valve opening correction amount C is shown in the table.
v . Here, NB means negative and large, NM is negative and medium, NS is negative and small, Z0 is zero, PS is positive and small, PM is positive and medium, and PB is positive and large.
About the valve opening correction amount Cv , based on Z0,
The closer to PB, the faster the clutch is engaged, and the closer to NB, the slower the clutch.

[0016]

[Table 1]

The meaning of Table 1 will be explained in words.
Is as follows.

Regarding one row and one column, "If the rotational speed of the shaft on the engine side is smaller than the rotational speed of the shaft on the transmission side (NB), and the difference fluctuates in the negative direction. (N
If B), increase the valve opening (PB). "That's what it means. At this time, if the time chart of the deviation D is shown in FIG.
The rotation speeds R ₁ and R ₂ are changed as shown in FIG. Although this does not occur very much in practice, there are cases such as when the vehicle is accelerating due to inertia on a downhill or the like. When you put the clutch in such a case, since the load will not suddenly larger worry, to as to connect the clutch at once. When the clutch is engaged, the two rotation speeds R ₁ and R ₂ match,
Thereafter, the engine speed R ₁ (=
R ₂ ) decreases.

Regarding 1 row and 7 columns, "If the rotational speed of the shaft on the engine side is smaller than the rotational speed of the shaft on the transmission side (NB), and the difference fluctuates in the positive direction. (P
If B), do not change the valve opening (Z0). "That's what it means. This corresponds to the portion B in FIG.
₁ and R ₂ are as shown in FIG. The engine state is, for example, when the vehicle is idling and the tractor body is running by inertia. When the clutch is engaged in such a case, the clutch may be engaged at a standard speed.

Regarding the 7th row and 1st column, "If the rotation speed of the shaft on the engine side is larger than the rotation speed of the shaft on the transmission side (PB), and the difference fluctuates in the negative direction. (N
If B), do not change the valve opening (Z0). "I leave it <br/> it. This corresponds to the portion D in FIG.
_1, R ₂ is as shown in FIG. 9. Tractor machine stopped
From the clutch on the engine side.
The rotational power is smoothly transmitted from the transmission to the shaft on the transmission side.
Connect the clutch to

Regarding 7 rows and 7 columns, "If the rotational speed of the shaft on the engine side is higher than the rotational speed of the shaft on the transmission side (PB ), and the difference fluctuates in the positive direction. (P
If B), increase the valve opening (PB). "That's what it means. Corresponds to the C portion in FIG. 5, both the rotation speed R _1, R ₂ is as shown in FIG. 8. Step on the accelerator while driving
And so on. In this case, quickly engage the clutch
Good.

The deviation D of the rotational speed, the variation ΔD thereof, and the valve opening correction amount Cv are shown in FIGS.
Are classified according to their size as shown in FIG.

Assuming that the deviation D is d and the variation ΔD is Δd , the valve opening correction amount Cv in this case is determined (see FIG. 13). Membership values of the deviation D at this time is a ₂ given from a ₁ and PS given from Z0, membership value of the variation ΔD is P
B ₁ given by S and b ₂ given by PM. A membership area U of the valve opening correction amount Cv is obtained according to the fuzzy rule, and the position of the center of gravity of this area in the horizontal axis direction is set as the correction amount Cv .

Next, in the second control, the deviation D of the rotation speeds R ₁ and R ₂ and the variation ΔD thereof are calculated in the same manner as in the first control, and the deviation D and the variation ΔD are input. Fuzzy inference is performed using the variable (condition part membership function) and the shift change amount Cc as output variables.

When performing fuzzy inference, fuzzy control rules shown in Table 2 are employed. The vertical line is the deviation D, and the horizontal line is the change amount ΔD.
Cc . Regarding the shift change amount Cc , a positive value means speed increase and a negative value means deceleration.

[0026]

[Table 2]

As in the case of the control 1, the meaning of Table 2 is described in words as follows.

[0028] The first row and first column is varied "If the actual direction of rotation of the engine side is smaller than the rotational speed of the transmission side (NB), and the difference is in the negative direction (N
If B), shift up (PB). "That's what it means. This corresponds to the portion A in FIG. 5 and the load is rapidly reduced, and the speed is rapidly increased.

[0029] For 1 rows and seven columns is varied "If the actual direction of rotation of the engine side is smaller than the rotational speed of the transmission side (NB), and the difference is in the positive direction (P
If B), do not shift (Z0). "That's what it means. This corresponds to the portion B in FIG. 5, which is when the load is light but the load starts to be applied rapidly at the present time, and the load change is estimated to prevent the unnecessary shift change.

[0030] For 7 rows and one column are varied "If the actual direction of rotation of the engine side is larger than the rotational speed of the transmission side (PB), and the difference is in the negative direction (N
If B), do not shift (Z0). "That's what it means. This corresponds to the portion D in FIG. 5 where the current load is large but the load is rapidly reduced. In this case as well, the shift change is not performed by estimating the subsequent load fluctuation.

[0031] For 7 rows 7 columns is varied "If the actual direction of rotation of the engine side is larger than the rotational speed of the transmission side (PB), and the difference is in the positive direction (P
If B), shift down (NB). "That's what it means. This corresponds to the portion C in FIG. 5 where the load at the present time is large and the load is further increased, and the load is reduced by quickly decelerating quickly.

The second control membership function D, Ｄ D
Is represented as shown in FIGS. 14 to 16. Also,
FIG. 17 shows an example of how to determine the shift change amount Cc .

[0033]

As described above, the tractor shift control apparatus according to the present invention utilizes fuzzy inference to perform shift shifting.
Connect the clutch with the optimal connection pressure while determining the
Because, it is carried out running condition of the tractor aircraft, the field of the state, the shift operation close to the operation feeling of the people in accordance with the working conditions, etc.
This has made it possible to eliminate unnecessary shift changes and to smoothly perform the operation of engaging the clutch, thereby improving ride comfort.

[Brief description of the drawings]

FIG. 1 is a transmission system diagram of a tractor as one example of the present invention.

FIG. 2 is a diagram showing a main part of a hydraulic circuit of the tractor shown in FIG.

FIG. 3 is a diagram schematically showing a transmission control device.

FIG. 4 is a block diagram of a transmission control device.

FIG. 5 is a time chart of a deviation between the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side.

FIG. 6 is a time chart of the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side.

FIG. 7 is a time chart of the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side.

FIG. 8 is a time chart of the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side.

FIG. 9 is a time chart of the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side.

FIG. 10 is a diagram showing a membership function of a deviation between the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side in control 1.

FIG. 11 is a diagram showing a membership function of a change amount of a deviation between the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side in control 1.

FIG. 12 is a view showing a membership function of a valve opening correction amount in control 1.

FIG. 13 is a diagram illustrating an example of a method of obtaining a valve opening correction amount in control 1.

FIG. 14 is a diagram showing a membership function of a deviation between the rotation speed of the shaft on the engine side and the rotation speed of the shaft on the transmission side in the control 2;

FIG. 15 is a diagram showing a membership function of a change amount of a deviation between a rotational speed of an engine-side shaft and a rotational speed of a transmission-side shaft in a control 2;

FIG. 16 is a diagram showing a membership function of a shift change amount in control 2;

FIG. 17 is a diagram illustrating an example of a method of obtaining a shift change amount in control 2;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 engine 3 forward / reverse switching device (clutch) 4 main transmission device 5 auxiliary transmission device 30 rotation sensor (first rotation speed detecting means) 31 rotation sensor (second rotation speed detecting means) 38 controller (deviation calculating means, change amount calculation) means,
Determination means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 61/00-61/24 F16D 48/00-48/12 B62D 49/00

Claims (1)

(57) [Claims] 1. A transmission from a shaft on the engine (1) side
(4) In a tractor shift control device provided with a hydraulically controlled clutch (3) for transmitting rotational power to a shaft on the side, a first rotation speed detecting means (30) for detecting the rotation speed of the shaft on the engine side. A second rotation speed detecting means (31) for detecting the rotation speed of the shaft on the transmission side;
A deviation calculating means for calculating a deviation of the detected value of the rotational speed detecting means, a change amount calculating means for calculating a change amount of the deviation, and performing the fuzzy inference using the deviation and the change amount as a condition part membership function, Deciding means for deciding a shift position of the device and a hydraulic pressure for operating the clutch.