JP2008185009A - Rotation controller of work vehicle engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a change in running speed by changing gears or the like to be smoothly performed when an engine rotation number is set at a high-speed rotation and the running speed to be safely increased without a rapid speed increase when the engine rotation number is switched from a low-speed rotation to a high-speed rotation during running in a work vehicle including a means for setting the engine rotation number in a plurality of stages by the running device of a tractor, a transporting work vehicle or the like. <P>SOLUTION: A device for controlling the rotation of the work vehicle engine comprises engine rotation number set means A for setting the engine rotation number in a plurality of stages from a low speed to a high speed, and a transmission shift means B for shifting an engine output rotation in a plurality of stages from a low speed to a high speed, wherein a rotation increment rate control is provided which makes a rotation increment rate when the engine rotation number set means A is switched from a low speed to a high speed during a transmission shift in a high-speed stages smaller than a rotation increment rate when the engine rotation number set means A is similarly switched during a transmission shift in a low-speed step. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine rotation control device for a work vehicle, such as a tractor or a transport work vehicle, provided with means for setting the engine speed in a plurality of stages and a transmission for shifting the output rotation of the engine in multiple stages.

As a transmission that changes the traveling speed of the work vehicle, the engine rotation speed is set in multiple stages and the engine output rotation can be changed in multiple stages by gear shift etc. Set to a low speed to reduce the fuel consumption by changing the gear speed to the desired driving speed, and set the engine speed to a higher speed during heavy work or climbing and driving to the desired driving speed by gear shifting etc. There is something that you can do. For example, in Japanese Patent Application Laid-Open No. 2005-344756, when the engine speed can be set to high / low speed with an accelerator lever and the speed is increased with an accelerator pedal when the speed is set to low speed, the engine speed increases. At the same time, a transmission is described in which the gear speed is changed to a speed increasing stage to increase the traveling speed.
JP 2005-344756 A

  In the conventional engine rotation control device for a work vehicle, if the acceleration operation is performed with the accelerator pedal while the engine speed is set to a high speed with the accelerator lever, the traveling speed suddenly increases as the engine speed shifts to a higher speed. Since it is dangerous to run, if the accelerator pedal is used to increase the speed only when the engine speed is set to a low speed using the accelerator lever, the gear shift is changed to the speed increasing stage as the engine speed increases. However, there is a case where the engine speed is set to a high speed and the gear shift is further set to a high speed for high speed driving.

  Even if the engine speed is set to low speed or high speed, the gear shift can be switched to high speed. When the engine speed is set to low speed, the feeling of acceleration / deceleration due to gear shift and when the engine speed is set to high speed There is a difference from the feeling of acceleration / deceleration due to gear shifting, and there is a danger of sudden increase / decrease in speed setting.

  In the present invention, even when the engine speed is set to a high speed, the travel speed is smoothly changed by gear shifting or the like, and even if the engine speed is switched from a low speed to a high speed during travel, the speed does not increase rapidly. It is an object to be able to increase the traveling speed safely.

The problems of the present invention are solved by the following means.
The invention according to claim 1 is provided with engine speed setting means A for setting the engine speed in a plurality of stages from low speed to high speed and transmission transmission means B for shifting the engine output speed in a plurality of stages from low speed to high speed. In the engine rotation control device for a car, the rotation increase rate when the engine speed setting means A is switched from the low speed to the high speed during the high speed transmission shift by the transmission transmission means B is the same as that during the low speed transmission shift by the transmission transmission means B. The present invention is characterized in that a rotation increase rate control is provided that is smaller than the rotation increase rate when switching to.

With this control, the traveling speed does not suddenly accelerate even when the engine speed setting means A is switched from low speed to high speed at the time of high-speed transmission.
Further, the invention according to claim 2 is provided with a clutch sensor 1 for detecting the engagement / disengagement of the travel clutch, and the control of claim 1 is performed only when the clutch sensor 1 detects the engagement of the travel clutch. .

  By this control, when the traveling clutch is engaged, that is, sudden acceleration during traveling is prevented, the engine speed setting means A speeds up changing the rotation of only the engine without traveling.

  According to the first aspect of the present invention, when the engine speed setting means A is switched from the low speed to the high speed while the transmission gear shifting stage is set to be constant, the traveling speed is increased by the increase of the engine speed. When the transmission gear shift is set to the high speed stage, the engine speed slowly rises to prevent sudden acceleration travel, and when the transmission gear shift stage is set to the low speed, the engine speed setting means A increases the speed setting. Thus, the engine speed rises quickly, but since the running speed is low, the speed is increased quickly to the extent that there is no shift shock, and safe driving becomes possible.

  According to the second aspect of the present invention, the speed increase of the engine is slow only when traveling with the traveling clutch engaged, and the normal speed is increased during inspection and adjustment of the engine alone. Adjustment is easy.

Embodiments of the present invention will be described below with reference to the drawings.
In the present specification, the left and right directions in the forward direction of the work vehicle are referred to as left and right, respectively, the forward direction is referred to as front, and the reverse direction is referred to as rear.

  FIGS. 1 and 2 are drawings showing an entire tractor as an example of a work vehicle. Front and rear wheels 10 and 10 and rear wheels 11 and 11 are provided at the front and rear of the fuselage, and the rotational power of an engine 12 mounted at the rear of the fuselage. Is appropriately decelerated by a gear transmission and a hydraulic transmission in the transmission case 13 and transmitted to the front wheels 10 and 10 and the rear wheels 11 and 11.

  A steering handle 15 is supported on the handle post 14 at the center of the machine body, and a cockpit 16 is provided behind the steering handle 15. A forward / reverse lever 17 is provided on the lower left side of the steering handle 14 to switch the advancing direction of the airframe to the front / rear direction. When the forward / reverse lever 17 is moved to the front side, the aircraft moves forward, and when it is moved backward, the aircraft moves backward.

  An accelerator lever 18 is provided on the opposite side of the forward / reverse lever 17 with the handle post 14 in between, and an accelerator pedal 20 and left and right brake pedals 21 and 22 are disposed at the right corner of the step floor 19. A clutch pedal 23 is disposed at the left corner of the step floor 19.

  Further, the HST lever 24 that can select the gear position from the first speed to the eighth speed is located in the left front portion of the cockpit 16, and the auxiliary transmission lever 25 that can select any of the low speed, medium speed, high speed, and neutral positions is thereafter Further, a PTO speed change lever 26 that can select a neutral position from the first speed to the third speed is provided on the rear side.

  Further, on the right side of the cockpit 16, there are a position lever 27 for setting the height of a working machine (not shown), an automatic tilling lever 28 for automatically setting the tilling depth of the field, and these levers 27, 28. Is followed by a right-up switch 29 and a right-down switch 30 of the work implement, followed by an automatic horizontal switch 31 (when turned on, the absolute horizontal position of the tractor (not horizontal with respect to the field scene but horizontal with respect to the horizontal plane of the earth)) And the backup switch 32 (when the forward / reverse lever 23 is in the reverse position and the work implement raising link 33 raises the work implement). In addition, the link 33 for connecting the work machines is provided behind the machine body.

  As the engine 12 used in this tractor, an accumulator type fuel injection diesel engine is used. The outline of the rotation control method of the accumulator type fuel injection diesel engine will be described.

  The accumulator fuel-injection diesel engine performs fuel supply to the injectors that inject fuel into each cylinder in the diesel engine through a common rail (accumulation chamber) at the required pressure. The fuel injection control state will be described.

  The fuel in the fuel tank 40 is sucked into the high pressure pump 43 driven by the engine 12 through the fuel filter 42 through the suction passage 41, and the high pressure fuel pressurized by the high pressure pump 43 is guided to the common rail 45 through the discharge passage 44. Stored.

  The high-pressure fuel in the common rail 45 is supplied to injectors (fuel injection valves) 47 corresponding to the number of cylinders through the high-pressure fuel supply passages 46, and for each cylinder based on a command from an engine control unit (hereinafter referred to as “ECU”) 48. The injector 47 is opened to supply high-pressure fuel into each combustion chamber of the engine 12.

Excess fuel (return fuel) in each injector 47 is guided to the common return path 50 by each return path 49 and returned to the fuel tank 40.
Further, a pressure control valve 51 is provided in the high-pressure pump 43 in order to control the fuel pressure in the common rail 45 (common rail pressure). The pressure control valve 51 adjusts the flow area of the return path 50 of the surplus fuel from the high pressure pump 43 to the fuel tank 40 by a duty signal from the ECU 48, thereby adjusting the fuel discharge amount to the common rail 45 side. Thus, the common rail pressure can be controlled. Specifically, the target common rail pressure is set according to the engine operating conditions, and the common rail pressure is fed back via the pressure control valve 51 so that the common rail pressure detected by the common rail pressure sensor 52 matches the target common rail pressure. Control.

  In this way, the engine speed can be controlled by changing the fuel injection amount by changing the common rail pressure. For example, if the rotational speed fluctuation is monitored and there is a rotational fluctuation of 100 rpm or more in 0.1 second, the common rail pressure It is possible to make the fluctuation of the rotational speed moderate by reducing the.

The pressure-accumulated fuel-injection diesel engine 12 is controlled in output by rail pressure, main injection timing, and number of pilot injections derived from the data map.
In the data map, patterns for controlling the output of the engine 12 are set in three types of accelerator torque maps AM, that is, a travel mode (droop control) M1, a normal work mode (isochronous control) M2, and a heavy work mode M3 shown in FIG. Yes. This accelerator torque map AM is composed of the relationship between the rotational speed and the output torque. The travel mode M1 is a mode in which the output torque decreases when a load is applied. Is a mode that keeps the output torque constant and is used during normal work, and the heavy work mode M3 is a mode that raises the speed and increases the limit when the output torque reaches the limit, especially when the work load increases. To increase the working limit.

  FIG. 5 is a control block diagram showing the flow of the tractor control signal and the engine control signal. The shift operation position of the HST lever 24 is input from the main shift sensor 59 to the ECU 48, and the sub-shift lever 25 is operated at low, medium and high speeds. The position is input from the shift sensor 60 to the ECU 48. In addition, a setting value such as 3000, 2500, 2000 rpm, or the forward / reverse switch of the forward / reverse lever 17 from the rotational speed setting switch 61 (which corresponds to the engine rotational speed setting means A of the present invention) for setting the maximum engine rotational speed. A forward / neutral / reverse position signal from 62, a clutch on / off signal from the clutch sensor 63 of the clutch pedal 23, and a work / travel setting signal from the work / travel switch 64 are input to the ECU 48.

  In addition to the above, the ECU 48 appropriately captures control data from the accelerator torque map, and inputs data such as the rotational speed and the outside air temperature from each engine sensor 69 to control the common rail pressure to the common rail pressure control valve 51. Output as a signal. Further, the multi-eye 65, which is a travel speed indicator, displays the maximum travel speed and the actual travel speed at the time of the shift setting.

  The work / travel change-over switch 64 sets the use mode of the accelerator torque map AM and controls it using the normal work mode M2 when working, and controls using the travel mode M1 when traveling. Become. The work / travel switching switch 64 may be provided alone, but the accelerator lever 18 may be provided with a road travel / work switching position to output a signal at this switching position. It may be linked. When the acceleration lever 18 is increased in speed, the control is shifted from the normal work mode M2 to the heavy work mode M3. In this control, when the accelerator lever 18 is set to travel, the engine speed control by the accelerator pedal 20 has priority, and when the accelerator lever 18 is operated, the work control for maintaining the engine speed at a set value. Takes precedence.

  In addition, unlike the above, it may be switched to work control by an ON signal of the PTO switch 34 that detects that the PTO shift lever 26 has moved to the shift position. The PTO switch 34 may be provided alone.

  Furthermore, the shift to the work control can be performed more accurately if the work machine is lowered by using an ON signal from the work machine lowering sensor 70 for detecting the lowering operation of the position lever 27 and the lowering of the link 33. It can be detected.

  If both the PTO switch 34 and the work implement lowering sensor 70 shift to work control with an ON signal and the work control is canceled when either signal is turned OFF, the engine rotation is reduced and the work is interrupted. The fuel consumption of the engine 12 can be reduced. In this case, if the work control state is set by setting the rotation speed again with the rotation speed setting switch 61 while releasing the work control, it is easy to respond to the start of work. At this time, the engine speed is gradually returned to the set speed by the clutch engagement signal to shift to work control, so that the work machine can be started up smoothly.

  If the shift operation of the HST lever 24 or the sub-shift lever 25 is detected and the operation control is performed so that the decrease in engine rotation due to the load fluctuation that occurs during the shift is reduced, the shift shock can be reduced. This work control state is limited to a very short time from the start to the end of the gear shift, so that the response of the engine rotation change after the gear shift operation is good.

The work control can be stopped suddenly by depressing the left and right brake pedals 21 and 22, so that once the work control is released, the release becomes a sustained state.
In addition to the above conditions, when the work control is released by the clutch disengagement signal from the clutch sensor 63 of the clutch pedal 23 and shifts to the work control by the clutch on signal, the engine rotation at the time of traveling stop is reduced and the fuel consumption is reduced. The rate can be reduced.

  FIG. 6 is a flowchart of the control for changing the rotation increase rate of the engine 12 at the shift positions of the HST lever 24 and the auxiliary transmission lever 25 which are the transmission transmission means B of the present invention. If the engine speed is changed from, for example, 2000 rpm to 2500 rpm in step S1, the HST lever 24 or the auxiliary transmission lever 25 is moved to the high speed position in step S2 (in this embodiment, the HST lever 24 is at the fifth speed or higher and the auxiliary transmission lever 25 is If it is YES, it is further determined in step S3 that the clutch pedal 23 is turned on. If this determination is also YES, the engine speed is slowly increased in step S4. As described above, the change time from 2000 rpm to 2500 rpm is lengthened so that the running speed is slowly increased. The means for slowly increasing and decreasing the engine rotation is performed, for example, by slowing the common rail pressure increasing speed and gradually increasing the fuel supply amount. If the determination in either step S2 or step S3 is NO, the engine sudden increase in step S5 is performed.

  FIG. 7 is a flowchart of control for limiting the engine speed setting value depending on the position of the forward / reverse switching lever 17 and prevents the engine speed from becoming high during reverse travel and high speed reverse travel. In step S10, the engine speed T is set by the rotation setting switch 61. If the forward / reverse switch 62 is reverse (back) in step S11, the engine speed T is 80% (0.8T) in step S12. To do. If the forward / reverse switch 62 is not reverse (forward or neutral) in step S11, the rotation of the engine 12 is increased at the engine speed T in step S13. Specifically, when the set rotational speed is 2000 rpm, the rotational speed at the time of back is 1600 rpm.

In the above example, the engine speed at the time of reverse travel is calculated as 80% at the time of forward travel or neutral, but a reduced rotational speed for reverse travel may be determined as appropriate.
FIG. 8 is a flowchart of the engine speed setting control. Hereinafter, the engine speed setting value is referred to as an accelerator memory.

  In step S20, the data of each sensor and operation switch is read. If the accelerator memory is not determined in step S21, the process proceeds to the determination in step S22 that there is an accelerator memory operation. If YES, the accelerator memory in step S23 is determined. If it is set and NO, the engine speed is controlled by the set speed at the accelerator lever 18 and the accelerator pedal 20 at step S24.

  If it is determined in step S21 that the accelerator memory is present, the process proceeds to step S25 to determine whether the accelerator memory is being operated. If YES, the accelerator memory in step S26 is set. If NO, the clutch in step S27 is set. It is determined from the sensor 63 that there is a clutch disengagement signal. If YES, the engine speed in step S28 is held at the accelerator lever set speed, and if NO, the engine speed is controlled by the accelerator memory speed in step S29. To do.

  In step S30, a signal from the PTO switch 68 is used to determine whether the PTO clutch has been turned on or off. If YES, the engine speed in step S31 is held at the accelerator lever set speed, and if NO, step S32 is executed. The process proceeds to a determination of whether both the left and right brakes 21 and 22 are ON. If YES, the accelerator memory in step S33 is reset. If NO, it is determined whether or not the PTO clutch has been turned on in step S34. If NO, the process jumps to before step S38, which will be described later, and if YES, the process proceeds to PTO clutch boost completion determination in step S35. If NO, the engine speed in step S36 is held at the accelerator lever set speed, and if YES, the engine speed is controlled by the accelerator memory speed in step S37.

  In step S38, the accelerator memory increase / decrease operation is determined. If NO, the control is terminated as it is, and if YES, the set rotational speed of the accelerator memory is changed in step S39, and the control is terminated.

  FIG. 9 is a flowchart of the traveling speed display control to the display device (also called multi-eye) 65 that displays the traveling speed. In step S40, data of each sensor and operation switch is read, and whether the HST lever 24 in step S41 is neutral. If YES in step S42, the vehicle speed display blinks in step S42 with the maximum vehicle speed calculated from the current engine speed and sub-shift position. If NO, the clutch pedal 23 is determined to be turned off in step S43, and if YES, the vehicle speed is displayed in step S45, and the maximum vehicle speed calculated from the current engine speed, sub-shift position, and HST lever position is flashed.

  If NO in step S43, the determination of whether the forward / reverse lever 17 is neutral is further made in step S44. If YES, the process in step S45 is performed. If NO, a vehicle speed display is displayed at the vehicle speed (actual traveling speed) of the current vehicle speed sensor in step S46.

It is a whole side view of a work vehicle (tractor). 1 is an overall plan view of a work vehicle. It is a fuel supply control schematic diagram of an engine. It is a control mode figure of an engine. It is a control block diagram of an engine. It is an engine control flowchart. It is an engine control flowchart. It is an engine control flowchart. It is a display control flowchart figure of a display apparatus.

Explanation of symbols

1 Clutch sensor 24 HST lever 25 Sub transmission lever 61 Speed setting switch A Engine speed setting means B Transmission speed change means

Claims (2)

  Engine rotation control of a work vehicle provided with engine speed setting means (A) for setting the engine speed in a plurality of stages from low speed to high speed and transmission transmission means (B) for shifting the engine output speed in multiple stages from low speed to high speed In the apparatus, when the engine speed setting means (A) is switched from the low speed to the high speed during the high speed transmission shift by the transmission transmission means (B), the rotation increase rate is determined during the low speed transmission transmission by the transmission transmission means (B). Similarly, an engine rotation control device for a work vehicle, provided with a rotation increase rate control that is smaller than a rotation increase rate at the time of switching.   The operation according to claim 1, wherein a clutch sensor (1) for detecting the engagement / disengagement of the travel clutch is provided, and the rotation increase rate control is executed only when the clutch sensor (1) detects the engagement of the travel clutch. Car engine rotation control device.

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