JPH01167426A - Autocruise controller for tractor - Google Patents

Abstract

PURPOSE:To permit the autocruise control by carrying out the control by a gear controller when the constant speed traveling control by a means for selecting the load curve corresponding to the load without changing the engine revolution speed can not be maintained. CONSTITUTION:A controller (b) for an agricultural tractor equipped with a rotor receives each signal of a variety of sensors (a), and when an autocruise switch 1-10 is turned-ON, a rotary solenoid 1-15, and a high speed solenoid 1-16 in an injection pump are controlled without changing the engine revolution speed by a means for selecting the load curve corresponding to the lead, and the constant speed traveling control through the selection of the load curve is executed, and when disposition is impossible, the depth of a rotor is controlled by a solenoid valve 1-17. When the constant speed traveling control can not be maintained even in this control, the gear stage is controlled at the sleeve position where the durability of the tractor is not deteriorated by a gear position selecting solenoid valve 1-18 and a clutch operating solenoid valve 1-19, and the constant speed traveling is permitted.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an auto-cruise control device that maintains a constant speed of a tractor equipped with a rotary tiller for tilling soil. [Conventional technology]

Some tractors used for agriculture are equipped with rotary wheels for tilling the soil. The speed of this type of tractor is related to what kind of load curve the installed engine is producing and what kind of load is being applied to the rotary. Conventionally, a tractor equipped with a rotary was operated so as to output power along a full load curve, and the load on the rotary was adjusted manually by changing its depth. The engine load curve and the engine control of the agricultural tractor will be explained below. (About engine load curve) Fig. 8 shows a load curve showing the relationship between engine speed and output torque. A curve QT in the figure is a full load curve, and a vehicle such as a passenger car is operated with its operating point set in a region below this full load curve. If the throttle is fixed at full throttle, the vehicle will be operated on the full load curve, and if the throttle is fixed at a lower throttle, a corresponding curve (for example, ql) that is lower than the full load curve will be identified, and the vehicle will be operated on that curve. Driving is carried out in Operation on the full load curve QT will be explained. Assume that point A is currently operating. That is, the engine rotational speed is n, and output torque P is produced. Assuming that the load increases and it becomes impossible to overcome it without producing output torque P2, the engine climbs on the full load curve QT in search of that torque, and eventually reaches a point. When climbing up to that point, reduce the engine speed to n.
,→n2. In other words, the vehicle speed decreases. When the load decreases, the operating point moves in the opposite direction and the vehicle speed increases. When the load becomes larger than the output torque P+ corresponding to point C, which is the highest point, the operating point will exceed point C, so
The engine speed gradually decreases and the engine stalls. From the viewpoint of engine durability, a curve having a flat portion of the maximum output torque P, such as the curve Q0, may be acceptable, but this curve is not convenient to use. This is because when the engine is operating in the flat area, even a slight change in load causes a large change in engine speed. Therefore, the full load curve Q7 that is actually used is one in which the output torque is lowered at a large portion of the engine rotational speed (for example, near point A), and a slope is created between it and point C. This is because if the slope is applied, even if the load changes and the operating point moves on the full load curve, the engine speed (vehicle speed) will not change significantly. When the throttle is tightened and fixed, a curve (eg, ql) below the full load curve QT is identified, and as the load increases or decreases, the operating point moves on this curve. (Regarding engine control of agricultural tractors) Fuel injection control of the engine installed in agricultural tractors, etc. has traditionally been mechanically controlled using a governor, etc., but it is different from that of vehicles such as passenger cars. Control is performed on the full load curve. Fig. 9 shows an overview of an agricultural tractor. In Fig. 9, 9 is an agricultural tractor, 9-1 is a rotary rotary that rotates to till the soil, 9-2 is a support culm for raising and lowering the rotary, 9- 3 is the tail wheel, and 9-4 is the rear wheel. When plowing a farm with such an agricultural tractor 9, the size of the soil changes in relation to the vehicle speed, and if the vehicle speed changes too much, it is unfavorable for the worker's working feeling. Therefore, the vehicle speed is approximately However, hard soil, heavy soil, soft soil, etc. are irregularly distributed on the farm, and when a portion of hard soil is encountered, the load applied to the rotary 9-1 increases. However, the vehicle speed decreases.Auto cruise control (constant engine speed control,
(Constant Speed Driving Control), which is carried out in vehicles equipped with an engine controlled by an electronic control unit. Auto-cruise control is performed by changing over a number of load curves. For example, the load curve ql in Figure 8
When operating at point 2 with the engine speed n2 above, the load increases and the output torque P! If it becomes necessary to issue a fuel injection amount and injection timing, the electronic control unit changes the commands for the fuel injection amount and injection timing, changing the operating point from knee point E to point mouth while keeping the engine speed constant. The load curve is changed one after another to produce a predetermined output torque. This allows the vehicle to run at a constant speed even when the load fluctuates. However, this technology cannot be used for agricultural tractors. This is because agricultural tractors operate on a full load curve, so even if the load increases, there is no curve above which to move. Therefore, in the past, rotary 9
Manually adjust the depth of rotary 9-1 by making the depth of rotary 9-1 shallower and increasing it in soft soil.
I was trying to keep the vehicle speed from decreasing. Note that a document regarding fuel injection control at full load is JP-A-60-47842, and a document regarding constant-speed running of an automobile is JP-A-57-153934. Japanese Patent Application Laid-Open No. 57-168038 and Japanese Patent Application Laid-Open No. 59-206649 are documents related to a technique for changing the engine rotational speed depending on when the tiller is raised and lowered.

[Problems to be solved by the invention]

However, if the depth of the rotary is changed manually, when the load increases rapidly, the timing of operating the rotary tends to be delayed, the vehicle speed decreases, and in extreme cases, the engine stalls. was there. The present invention was developed in view of the above-mentioned problems, and its purpose is to temporarily cause the engine to output excessive output to maintain a constant vehicle speed when an excessive load is applied. It is something to do.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention incorporates the idea of auto cruise control into agricultural tractors, in order to improve the finish of farm plowing and the driver's work feeling, and to improve the performance of agricultural tractors. The aim is to improve this. Agricultural tractors are usually used on the full load curve QT, so when the load increases, there is no negative curve to transfer to, which means auto cruise control is used to adjust the output to the load without changing the vehicle speed. I can't do that. Therefore, in the present invention, several special load curves exceeding the total load curve 0 are set so that it is possible to transfer to these. However, considering the durability of the engine, it was decided that operation on these load curves would be terminated within a limited time. When it becomes impossible to maintain a constant speed with control based on changing the load curve, the gear position is controlled. That is, in the tractor auto-cruise control device of the present invention, there is a means for setting a plurality of load curves that output an output exceeding the full load curve and each having a permissible operating time, and a means for setting the engine rotation from among the plurality of load curves. At least a fuel injection control device for an engine having a means for selecting an output that outputs an output according to a load without changing the number, and a gear control device for controlling a gear stage so that the sleeve position becomes a predetermined value, When constant speed driving control using the former method could no longer be maintained, the latter method was used.

[For production]

A load curve that produces an output that exceeds the full load curve makes it possible to produce output according to the load without changing the engine speed when the engine load increases. Since the allowable operating time is determined for the load curve,
There is no negative effect on engine durability. A means for selecting a load curve according to the load without changing the engine speed enables auto-cruise operation when the load increases □ from the full load curve. The gear control device controls the gear stage at a sleeve position (hereinafter referred to as S) that does not cause problems in terms of the durability of the tractor, and enables constant speed running.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. In the present invention, load curve data is stored in the memory of an electronic fuel injection control device in accordance with the purpose described below, and a predetermined calculation is first performed based on the data and signals from various sensors. select the load curve to be used for operation and control fuel injection. If that is not enough, the gears are controlled to adjust the driving force. However, since it is also effective to interpose rotary depth control before gear control, the embodiment will be described in which this is interposed. Hereinafter, the setting of the load curve, the configuration of the fuel injection control device, the selection of the load curve, the depth control of the lowering hole, and the gear control will be explained in this order. (Regarding Setting of Load Curves) FIG. 2 shows a group of special load curves Q set in the present invention. A group of such load curves Q is collectively called a Q map. Above the total load curve Q7, there is first the load curve Q (which does not pose a problem in terms of durability, but is difficult in terms of usability), and above that, Q. Q2. ...Set Q and A. Suppose that an agricultural tractor is being operated in automatic cruise mode, and the load increases when it encounters hard soil. In order to overcome this load, the output must be increased. Then, the auto cruise control is activated and the operating point is moved through points E, low, C, etc., and then settles at the output that overcomes the load. In other words, the engine handles the load by moving through the set load curve one after another without changing the engine speed (vehicle speed is proportional to this). The output of the engine is determined by the fuel injection amount and its injection timing (the angle before the upper hole point), so in order to produce an output that exceeds the full load curve, the fuel injection amount and injection timing should be determined accordingly. These are shown in FIGS. 3 and 4. FIG. 3 shows a load curve of fuel injection amount corresponding to the Q map shown in FIG. F7 is a load curve corresponding to the total load curve QT, Fo is Qo, F is Ql, and F is Q
. Each corresponds to ×. FIG. 4 shows an injection timing curve corresponding to the Q map of FIG. θ7 is a curve corresponding to the full load curve Q, and θ
. corresponds to Qo, θ corresponds to Q, and θMAX corresponds to QMA, respectively. FIG. 5 shows the allowable operating time for each pre-meal curve set beyond the full load curve QT. Curve 5-1゜5-2.5-3
Although three examples are shown, a curve different from these may be determined. In any case, operation with these load curves will cause problems in terms of durability, so the operation will be discontinued after a short period of time. The higher the output load curve, the shorter the allowable operating time. time T
, is the allowable operating time of the load curve Q, for example, 30
It can be about seconds. Time T, AX is load curve QK
This is the allowable operation time of Ax, and can be set to about 2 to 3 seconds, for example. As described above, by storing data related to the matters described in Figs. 2 to 5 in the memory shown in Fig. 1, which will be explained next, multiple Load curves can be set. (Configuration of Fuel Injection Control Device) FIG. 1 shows a block diagram of an auto-cruise control device for a tractor according to an embodiment of the present invention. In Figure 1, a represents sensors, b represents controllers, and C
are actuators. The sensors include engine speed sensor 1-3, vehicle speed sensor 1-5. Sleeve position sensor 1-7, injection timing sensor 1-9. Auto cruise signal sensor 1-1
0. Brake signal sensor 1-11, rotary position sensor 1-12, transmission gear position sensor 1-13
, and other sensors 1-14. Inside controller b, there is a CPU (central processing unit) 1-
1. Memory 1-25 Rotation change rate calculation section 1-4. Vehicle speed change rate calculation unit 1-6. There is a sleeve position change rate calculating section 1-8. The memory 1-2 stores data regarding the matters described in FIGS. 2 to 5, and a plurality of load curves exceeding the full load curve are set. Actuators c include rotary solenoids 1-15 within the injection pump. High speed solenoid 1 in the injection pump
-16. Solenoid valve for adjusting depth of rotor 1-17, solenoid valve for gear position switching 1-18, solenoid valve for clutch operation 1-
19.Other actuator indicators 1-20
．． There is a warning indicator or buzzer 1-21. Each of the actuators described in 1-15 to 1-19 functions as described in the right column. A predetermined calculation is performed based on the signal from the sensor 41 (a) and the data in the memory 1-2, and the sleeve position is moved by the rotary solenoid 1-15 in the injection pump to adjust the injection amount. High speed solenoid 1 inside
-16 to adjust the injection timing by changing the pump internal pressure. These allow auto-cruise switching by changing the load curve beyond the full load curve within the time constraints imposed by durability. If the above control is unable to respond due to overtime, etc., the depth of the rotary is controlled. The depth of the rotary is detected by the rotary position sensor 1-12, and the support culm 9-2 This is done by turning the hydraulic circuit on and off using the rotary depth adjustment solenoid valve 1-17.Furthermore, if the rotary depth control reaches its limit, gear control is performed. To change the gear stage, the gear position is detected by the transmission gear position sensor 1-13, and the clutch actuating solenoid valve 1-19 and the gear position switching solenoid valve 1-1
This is done by sending commands to each of the 8 actuators. FIG. 6 shows a circuit diagram of the electronic fuel injection control device. 6th
In the figure, 7 (, 6-1 is the controller, 6-2 is the engine speed sensor, 6-3 is the fuel temperature sensor, 6-4 is the sleeve position sensor, 6-5 is the sleeve actuator,
6-6 is fuel cant pulp, 6-7 is injection timing control pulp, 6-8 is fuel injection pipe, 6-9 is nozzle, 6-10 is water temperature sensor, 6-11 is brake switch, 6-12 is clutch Switch, 6-13 is auto cruise lamp, 6-14 is auto cruise switch, 6-
15 is the main switch, 6-16 is the main lamp, 6-
17 is a resume switch, 6-18 is a center switch, 6-19 is a tachometer, 6-20 is a self-diagnosis display lamp, 6-21 is a vehicle speed sensor, 6-22 is an air conditioner switch, 6-23 is an accelerator sensor, 6- 24 is an accelerator pedal, 6-25 is a dropping register, 6-26 is a key switch, and 6-27 is a battery. Fuel is delivered to the engine via fuel injection pipes 6-8 and nozzles 6-9. The fuel injection amount and injection timing are determined by controlling the sleeve actuator 6-5 and the injection timing control pulp 6-7. Control signals to them are given by the controller 6-1 based on information taken in from various sensors (engine speed sensor 6-2, sleeve position sensor 6-4, etc.). When performing auto cruise operation, set switch 6-
Turn on 18. Then, the vehicle speed (engine speed) etc. at that time are stored and controlled to be maintained thereafter. Auto cruise can be canceled by operating the brake switch 6-11 after the brake is applied.
or when a signal is input from the clutch switch 6-12 to the controller 6-1. In addition, the resume switch 6
If you press -17, the vehicle speed etc. that were previously set will be set again. This switch is a so-called instantaneous reproducible switch. (Regarding load curve selection) By performing predetermined calculations in the controller based on signals from various sensors, output according to the load can be selected from among multiple set load curves without changing the engine speed. The output is selected, and the calculation is performed in the flow described below. FIGS. 7(a) to 7(d) show flowcharts for explaining the present invention in detail. The item numbers ■ to [phase] in the following description correspond to steps ■ to [phase] in the flowchart, respectively. ■ Driving normally. Normal operation means that auto cruise operation (auto cruise switch ON) or the like is not performed. ■ To perform auto cruise operation, check whether the auto cruise switch is turned on. ■、■ Decide whether to reset the warning, and if so, reset it. ■Turn the auto cruise switch ONL (step■
) to enter auto cruise operation. ■ Perform initialization processing. Setting N=O means that the subscript number of the load curve Q is set to 0, that is, Qo is first selected as the load curve used for operation. Setting M=O means that the load curve to be used is still Q, L.
This is because they are not mobilized. M is supposed to contain the largest subscript number of the load curve Q mobilized for use after starting autocruise operation. The larger the subscript number, the greater the output of the load curve. The reason for setting TN=O is to make the allowable operation time correspond to the load curve Q0. The reason TN=O is not written in FIG. 5 is that if it were written, it would be at infinity in the vertical axis direction. As long as it is operated according to the load curve Q, there is no problem in terms of durability, so it can be operated indefinitely, that is, the allowable operating time is infinite. ■ Carry out auto-cruise control based on the selected load curve Q (initially QO). ■ Check whether N>, M. This is a check to see if the load curve currently in use produces an even greater output than the one that produces the maximum output among the load curves that have been mobilized so far since starting autocruise operation. Initially, N=M=O, so proceed to step ■. ■ When the load curve has an output smaller than the maximum load curve used so far, check whether it is Qo. [Phase] If step ■ is No, then N=0
In other words, since Qo is used, M, TN
is set to 0 corresponding to it. Since the initial flow is set to 0 at step ■, it looks like the same process is performed twice, but in the case of the flow coming from B to step ■, what kind of load curve is it using? I don't know. In that case, step ■
, [phase] brings meaning. (2) In step (2), it was found that the load curve currently in use produces a greater output than the load curve used up until now, so the allowable operating time TN is updated to a new one corresponding to this. As shown in FIG. 5, the allowable operating time corresponding to a large output becomes shorter. ■ Update the subscript number of the load curve Q to the number of the largest load curve currently in use. ■ Check whether the allowable operating time TN specified in step ■ is smaller than TO (infinity) corresponding to the load curve Q0. ■ Reset the warning. This is because this step comes when TN=To, that is, the load curve Q0
This is because when using . At this time, no warning is required. ■ Decide whether to cancel auto cruise operation. If released, normal operation (step ■) is returned via step [phase]. If not released, the process proceeds to the flow shown in FIG. 7(b). [Phase] Operation using the load curve Q that produces an excessive output (load curve that produces an output greater than QG) is the allowable operation time T set in step ■. Check to see if it has been done in excess of the specified amount. The allowable operation time determined in step (2) is the shortest time because it corresponds to the maximum load curve that has been mobilized since the start of auto-cruise operation (see FIG. 5). The reason we decided to look at the time over based on the shortest time was to ensure a failsafe. @ The reason why the warning flashes is currently the load curve Q.
This is to indicate that the vehicle is being operated with a load curve that exceeds 0. [Phase] Before canceling auto cruise operation and returning to normal operation, reset the warning. [Phase] Vehicle speed ■ is the set vehicle speed ■ for auto cruise operation. Check if it is larger. If the gear cannot be changed, the vehicle speed is proportional to the engine speed, so the engine speeds may be compared instead of the vehicle speed. From this step to step [phase], the flow is to shift to the optimum load curve while checking the engine condition. [Phase] Check whether the vehicle speed V is smaller than the lower limit vehicle speed VMIN. The lower limit vehicle speed V□ is set in consideration of the fact that if the vehicle speed decreases below this, the engine stalls. ■ When the vehicle speed is lower than the lower limit vehicle speed VMIN, set it to N-MAX. That is, Q, A, which produces the maximum output among the load curves,
use. This is because it is an emergency situation that could lead to engine stall if something is not done quickly. After this, return to step (2) and perform operation using QMAII. ◎ When the vehicle speed is higher than the lower limit vehicle speed VNIN, check whether the sleeve position S is smaller than the maximum sleeve position SN in the load curve currently being used. 0 If you say NO to step ◎, it means S ”” S N
This means that the sleeve is at its maximum position. Therefore, check whether N<MAX and check whether the load curve currently being used is the one with the maximum output. if,
If it is not the one with the maximum output, it means there is a higher one, so there is room to switch to a load curve one level higher. [Phase] Checks whether the load curve in use is Q. If N-0, that is, Q, there is no longer a load curve to transfer down. @ To change to N-N-1 means to switch to the load curve one step lower. @ To change to N-N+1 means to change to the load curve one step higher. O Check whether the current sleeve position change rate S' is greater than the sleeve position change rate S, 7 set in auto cruise operation. A sudden increase in the sleeve position change rate S' means that the engine is trying to cope with a sudden large load (for example, when encountering hard soil). In the following steps, the appropriate load curve will be used. [Phase] Check whether the current vehicle speed change rate V' is greater than the vehicle speed change rate v0' set in auto cruise operation. If it is small (which means that the deceleration rate is large), then the load curve currently being used is not appropriate. There is, so proceed to step 0 and onwards.
After all, it will shift to an appropriate load curve. Note that the size comparison here is as follows. For example, V' = -30Orpm/sec,
V6' --20Orl) m/5eeO, V'
It is determined that <V6'. In other words, the magnitude is compared including the positive and negative signs. 0 When the vehicle speed change rate is greater than the set value, it means that there is some margin in the output, so it is necessary to lower the load curve to be used. Therefore, check whether N>0 and check whether there is a lower load curve. [Phase] When you come to this step, there is a lower load curve, so select the load curve one step lower. [Phase] This step is at the bottom left corner of FIG. 7(a). Displays that the permissible operating time has been exceeded. This means that control by moving over a load curve that is set above the full load curve has reached its limit. (About rotary depth control) Now we will start controlling the rotary depth. By controlling the rotary depth, the magnitude of the load can be adjusted. Here, instead of changing the engine output according to the load, the load is changed according to the engine output. In other words,
The load is adjusted so that the vehicle can run at a constant speed with a load curve that poses no problems in terms of durability even after long periods of operation. Such a load curve may be one below the load curve Q in Figure 2, but here it is assumed that the load curve is maintained at Qo (when entering auto-cruise operation, the ). C-■ Check whether the vehicle speed ■ is smaller than the set vehicle speed v0 set when entering auto cruise operation. If it is smaller, in order to avoid engine stalling, the process proceeds to step C-@ and takes the maximum load reduction measure that can be used to perform emergency low-flying control. C-■ Check whether the sleeve position S is smaller than the maximum sleeve position ZS, , □ when the load curve Q, lAX. If it is smaller, it means that control by changing over the load curve is possible, so return to step (3). C-■ This step is reached when the sleeve position S is equal to the above S wax (because S is never greater than S + smx). At this time, the depth of the row recess is set to a depth R1 that is one step shallower than the initial depth Ro. C-■ Check whether the sleeve position S is larger than the sleeve position S0 (value set when entering auto cruise control) at the time of load curve Q0. If it is large, you need to lighten the load a little more,
If it is small, you can put a little more load on it. In addition to this step, there are other steps to check the sleeve position S, but the reason for performing this check is that the Q map that exceeds the full load curve has been set, so if left unchecked, the sleeve position will reach the limit in normal operation. This is because there will be cases where the value exceeds So. Block C starting from here - mouth and the next block C
- The port outputs a predetermined output (at a predetermined vehicle speed (engine speed)
This block is used to search for a rotary depth suitable for continuing to output the maximum output permissible in terms of durability corresponding to the sleeve position S0. C-■ Increase the rotary depth by one step. In other words, in this case, it returns to Ro. C-■ Set the rotary depth to R2, one step shallower. C-■ Check the sleeve position in the same way as C-■. C-■ Return the rotary to R1, one step deeper. C-■ Set the rotary to R1, one step shallower. C-■ Check the sleeve position. C-■ Return the low chest to R5in-1, one step deeper. C-■ Set the low chest to the shallowest R@in. At this time,
This is the lightest load that can be achieved by rotary depth control. The C-0 warning will light up to indicate that the limit of low depth control has been reached. Note that it does not matter if the control returns to the load curve transfer immediately after entering the rotary depth control, but if this is not the case, after entering the rotary depth control and a predetermined period of time has elapsed, The awning may be lit to indicate that you are plowing at a different depth than planned. (About gear control) Now we will start gear control. It maintains a constant speed by changing gears to cope with the required load. D-■ Check whether the vehicle speed V is smaller than the set vehicle speed V0 set when starting auto cruise operation. If it is smaller, the process proceeds to step D-■ in order to change to a gear one step lower. D-■ Check whether the sleeve position S is greater than 80 even if the vehicle speed V has not decreased. If it is large, it means that it is difficult to cope with the load with the gear currently in use, and the process proceeds to step D-■ in order to lower the gear by one step. If it is small, it means that there is some margin, so we return to rotary control. D-■ Adjust the rotary depth from the shallowest position R187 to 1
Lower it to a deep position Rmln-+. And step C
− Return to [phase] (if low-return control is not to be performed, return to step ■). D-■ Change the gear to G, which is one step lower than G0 when auto cruise control was entered. The block C-port and the next block C-port starting from this step check the vehicle speed ■ and the sleeve position S in the lowered gear, and if there is room, return the gear to the original position, or if not, take the next action ( This block further lowers the gear stage and turns on a warning when it reaches its limit. D-■, D-■ This is a check of the vehicle speed V and sleeve position S at gear stage G. D-■ When the vehicle speed has not decreased and there is room for the sleeve position, return the gear to Go, which is one step higher. D-■ or D-■ Gear stage G! D when lowered to
- Performs the same processing as block A. D-@ This is a display to indicate that the limit of gear control has been reached. In addition, in a vehicle such as a passenger car, a technique for maintaining a constant speed by lowering the gear when the load increases on a climbing road or the like is disclosed in, for example, Japanese Patent Application Laid-Open No. 57-121713. However, unlike the present invention, this is not performed while also monitoring the sleeve position, and this differs from the present invention in this point. As described above, first, constant speed traveling control is performed by controlling by selecting the load curve, and when this cannot be handled, the depth of the rotary is controlled. If you still can't deal with it, you can control the gear to deal with it. The rotary depth can be controlled if necessary (
You can omit it. Even with the above-described control, if the situation is still insufficient, that is, when step D-@ is reached, constant speed driving is abandoned and normal driving is resumed. [Effects of the Invention] As described above, according to the present invention, auto cruise control (constant speed traveling control, constant engine speed control) is possible even in agricultural tractors etc. equipped with a rotary. . Therefore, in the case of an agricultural tractor, the size of the soil pile created by plowing (related to the running speed of the agricultural tractor)
There were no major changes in the tillage, and the result was good.Also, since it ran at a constant speed, the driver's working feeling was improved.

[Brief explanation of the drawing]

Fig. 1: Auto-cruise control device for a tractor according to an embodiment of the present invention Fig. 2: Q map used in the present invention (diagram showing the relationship between engine speed and output torque) Fig. 3: ...Drawing showing the load curve of fuel injection amount corresponding to the Q map of Fig. 2...Fig. 4 showing the injection timing curve corresponding to the Q map of Fig. 2...Fig. 5...Full load curve Figure 6 shows the allowable operating time for each load curve set beyond vAQT...Circuit diagram of the electronic fuel injection control device Figure 7 (a
) to FIG. 7(d)... Flowchart for detailed explanation of the present invention FIG. 8... Engine load curve FIG. 9... Outline diagram of an agricultural tractor.
are sensors, b is a controller, C is an actuator, 6-1 is a controller, 6-2 is an engine speed sensor, 6-4 is a sleeve position sensor, 6-5 is a sleeve actuator, 6-7 is an injection timing control valve,
6-8 is a fuel injection pipe, 6-14 is an auto cruise switch, 9 is an agricultural tractor, 9-1 is a rotary, 9
-3 is the tail wheel. Patent applicant Isu-Jidosha Co., Ltd.

Claims (1)

[Claims] Means for setting a plurality of load curves that output an output exceeding a full load curve and each having a permissible operating time, and output according to the load from among the plurality of load curves without changing the engine speed. and a gear control device that controls the gear stage so that the sleeve position reaches a predetermined value, and when the former cannot maintain constant speed driving control, the latter An auto-cruise control device for a tractor, characterized in that it performs control by.