JP2012154302A - Engine control of tractor - Google Patents

Abstract

In the present invention, an engine output mode corresponding to a work mode is automatically selected without switching the engine output mode so that the engine is not stopped during the work.
An engine speed fluctuation control mode in which the output of the engine fluctuates due to fluctuations in the engine speed, an engine speed maintenance control mode in which the engine speed remains constant even when the load increases, and an engine speed In addition to maintenance control, it has a heavy load mode in which the output is increased by increasing the number of revolutions when approaching the load limit.In addition, in the tractor engine control that allows selection of the standard output curve and fuel efficiency output curve, Separately, a connection sensor that detects that the left and right brake pedals to be braked are integrally connected is provided, and the engine speed fluctuation control mode and the low fuel consumption output curve are selected and controlled by detecting the connection signal of the connection sensor. The engine control of the tractor characterized by
[Selection] Figure 6

Description

  The present invention relates to engine control in a tractor of an agricultural machine.

  An engine output torque curve in standard mode that secures a predetermined power and an engine output torque curve in fuel consumption reduction mode that reduces fuel consumption compared to standard mode are provided, and the mode switching means selects either standard mode or fuel consumption reduction mode There is an engine output control technology that can be used.

JP 2007-231848 A

  Since the engine load fluctuates, such as traveling on a road with a light driving load and tilling work driving with a heavy driving load, it is often necessary to switch the engine output mode according to the driving mode. If the switch is neglected, the heavy load operation is performed in the fuel consumption reduction mode, and the engine may be stopped due to a sudden increase in traveling load.

  Therefore, in the present invention, an engine output mode corresponding to a work form is automatically selected without switching the engine output mode so that the engine is not stopped during the work. And

The problems of the present invention are solved by the following technical means.
According to the first aspect of the present invention, the engine speed fluctuation control mode A in which the output of the engine E is fluctuated by the fluctuation of the engine speed, and the engine speed maintenance that maintains the engine speed constant even when the load increases. In addition to the control mode B and engine speed maintenance control, the tractor is equipped with a heavy load mode C that increases the engine speed and increases the output when approaching the load limit, and further allows the standard output curve N and the low fuel consumption output curve S to be selected. In the engine control, a connection sensor 103 for detecting that the left and right brake pedals 102R and 102L for separately braking the left and right traveling devices 17 and 18 are integrally connected is provided, and the engine is detected by detecting the connection signal of the connection sensor 103. The engine control of the tractor is characterized in that the engine speed control mode A and the low fuel consumption output curve S are selected and controlled.

  With this configuration, when the vehicle simply travels on the road or in the field, the left and right brake pedals 102R and 102L are connected together to control the driving as an integrated brake pedal. By detecting at 103, the engine speed fluctuation control mode A and the low fuel consumption output curve S are obtained, and the light load state of the engine E is less consumed and the travel speed is suppressed quickly by pressing the left and right brake pedals. You can drive to.

  In the engine control of the tractor in which the standard output curve N and the low fuel consumption output curve S can be selected, the invention according to claim 2 includes the standard output mode transition opening O2 in the accelerator opening O of the accelerator changing means 146, The fuel efficiency output mode transition opening O1 smaller than the standard output mode transition opening O2 is provided, and when the accelerator opening O reaches the standard output mode transition opening O2 in the fuel efficiency output curve S, the standard output curve N is selected and the low The engine control of the tractor is characterized in that the low fuel consumption output curve S is selected and controlled when the fuel consumption output mode transition opening O1 or less continues for a predetermined time T.

  In this configuration, when the accelerator changing means 146 is opened largely to increase the output of the engine E, the output immediately becomes the standard output curve N and the output is increased, and the accelerator changing means 146 is reduced to the accelerator and the output is suppressed. The fuel consumption is reduced by the fuel efficiency output curve S when the state where the fuel consumption output mode transition opening degree O1 is equal to or less than the predetermined time T continues.

  According to a third aspect of the present invention, the DPF 172b for processing the exhaust of the engine E is provided, and the regeneration process of the DPF 172b is performed only with the standard output curve N. The engine control of the described tractor was adopted.

With this configuration, the regeneration process for increasing the temperature of the DPF 172b is performed in a state where the engine E is at a high output and the temperature is high, so that the regeneration process is performed quickly.
The invention described in claim 4 provides the engine control of the tractor according to claim 3, wherein the regeneration process of the DPF 172b is performed in the engine speed maintenance control mode B.

  With this configuration, the regeneration process of the DPF 172b that places a load on the engine E is performed in the engine speed maintenance control mode B, so that a decrease in the engine speed due to an increase in the load can be prevented.

  With the configuration of claims 1 to 4, the output switching by the standard output curve N and the low fuel consumption output curve S of the engine E is automatically and accurately performed, and the operator at the time of maneuvering can be concentrated on the maneuvering operation. , Work safety can be ensured.

Schematic illustration of common rail engine Comparison with engine speed control mode Engine output characteristics Overall side view of tractor Power transmission diagram in the mission case Control block diagram Enlarged view of the meter panel Enlarged view of the data display An enlarged perspective view of a part around the right side of the steering handle Illustration of engine intake and exhaust systems Diesel particulate filter perspective view Expanded side view of the diesel particulate filter mount Engine perspective view Figure of engine intake system and exhaust system as another embodiment Cross section of diesel particulate filter

Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.
FIG. 1 is an overall configuration diagram of a pressure accumulation type fuel injection device. The accumulator type fuel injection device is applied to, for example, a multi-cylinder diesel engine, but may be a gasoline engine. The accumulator fuel injection device pressurizes the common rail 1 that accumulates fuel at an injection pressure that appropriately controls the fuel, the rail pressure sensor 2 that is attached to the common rail 1, and the fuel pumped up from the fuel tank 3 to the common rail 1. A high-pressure fuel pump 4 for pumping, a high-pressure injector 6 for injecting high-pressure fuel accumulated in the common rail 1 into the cylinder 5 of the engine E, an engine control device for controlling the fuel high-pressure pump 4, the high-pressure injector 6 and other operations. (ECU) 12 and the like.

Thus, the common rail 1 makes the fuel injected into each cylinder 5 of the engine E a pressure necessary for the required output.
The fuel in the fuel tank 3 is sucked into the fuel high-pressure pump 4 driven by the engine E through the fuel filter 7 through the suction passage, and the high-pressure fuel pressurized by the fuel high-pressure pump 4 passes through the discharge passage 8 to the common rail 1. To be stored.

  The high-pressure fuel in the common rail 1 is supplied to the high-pressure injectors 6 corresponding to the number of cylinders through the respective high-pressure fuel supply passages 9, and the high-pressure injectors 6 are operated based on commands from the ECU 12. The surplus fuel (return fuel) in each high pressure injector 6 is guided to the common return passage 10a by each return passage 10 and returned to the fuel tank 3 by this common return passage 10a.

  In addition, a pressure control valve 11 is provided in the fuel high-pressure pump 4 in order to control the fuel pressure (common rail pressure) in the common rail 1, and this pressure control valve 11 is sent from the fuel high-pressure pump 4 to the fuel tank by a signal from the ECU 12. The flow area of the common return passage 10a for surplus fuel to 3 is adjusted, whereby the common rail pressure can be controlled by adjusting the fuel supply amount to the common rail 1 side.

  Specifically, the target common rail pressure is set according to the operating condition of the engine E, and the common rail pressure is fed back via the pressure control valve 11 so that the common rail pressure detected by the rail pressure sensor 2 matches the target common rail pressure. It is configured to control.

  In the control without the pressure control valve 11, the common rail pressure is controlled to be lowered by adjusting the opening of the high-pressure injector 6 according to the degree of return of the accelerator while the accelerator is being returned and performing slight injection. .

Furthermore, the common rail pressure can be adjusted by the accelerator opening and the rate of change of the engine rotation so as to increase or decrease the speed at an appropriate speed.
As shown in FIG. 2, the ECU 12 of the diesel engine E having the common rail 1 in the agricultural machine such as a tractor has an engine speed fluctuation control mode A, an engine speed maintenance control mode B, and a heavy load in relation to the speed and output torque. The mode C has three types of control modes.

  In the engine speed fluctuation control mode A, the output fluctuates due to the fluctuation of the engine speed. Basically, it is used when moving and running, but it is also used during work to prevent sudden engine stalls. For example, in the case of mobile travel, if the travel speed is reduced or stopped by applying a brake, the engine speed decreases as the travel load increases, so the travel speed can be safely reduced or stopped. Is. Further, during the work, when the work load is applied, the engine speed decreases according to the load.

  The engine speed maintaining control mode B is control for maintaining the engine speed constant even when the load increases. Basically, it is used when working. For example, the tractor is when the field is hard during the plowing operation and resistance is applied to the plowing blade, and the combine is when the rotation speed is maintained even when the load is increased during the harvesting operation.

  In the heavy load mode C, in addition to the control for maintaining the engine speed constant even when the load fluctuates, as in the engine speed maintenance control mode B, the heavy load mode C increases the engine speed to increase the output when the load is close to the load limit. This is a control with added control. In particular, it is used when working near the load limit. For example, when plowing work with a tractor, the engine output increases beyond the normal limit even when encountering hard cultivated land, so work can be performed efficiently without interruption. .

FIG. 3 is a graph showing the relationship between the rotational speed and the output representing the output characteristics of the engine E.
The low fuel consumption output curve S and the standard output curve N show the relationship between the engine speed (rpm) and the output (kw).

  The low fuel consumption output curve S is a control in which the fuel supply amount is lower than the fuel consumption rate of the standard output curve N. This low fuel consumption output curve S has an output that is 1 higher than the standard output curve N in the entire rotation range. Decrease by about 10%.

  The symbol ST indicates the relationship between the engine speed (rpm) and the torque (N · m) at the time of the low fuel consumption output curve S, and the symbol NT indicates the engine speed (rpm) at the standard output curve N. And the torque (N · m).

  In order to use the engine E by switching between the low fuel consumption output curve S and the standard output curve N, the mode selection means (hereinafter referred to as the engine power selection switch) 134 is operated and set. The engine power selection switch is shown in FIGS.

  When the tractor travels, it automatically switches to the engine speed fluctuation control mode A. Then, the standard output curve N is selected by the engine power selection switch 134, and the ON state of the PTO drive means (hereinafter referred to as PTO drive switch) 151 for driving the work machine mounted on the tractor is enabled together. The engine speed maintaining control mode B is automatically switched. The PTO driving means may be configured to detect an operation of a lever or the like with a switch or the like.

  By selecting the low fuel consumption output curve S with the engine power selection switch 134 and enabling the on state of the PTO drive switch 151 for driving the work implement, it is automatically switched to the engine speed fluctuation control mode A. Configure.

  While the engine power selection switch 134 selects the standard output curve N and the PTO drive switch 151 is turned on, the engine speed control is automatically performed in the engine speed maintenance control mode B. When it is determined that the engine load is sufficient, the mode selection means 134 selects the low fuel consumption output curve S, and this selection automatically switches to the engine speed fluctuation control mode A.

  While the engine power selection switch 134 selects the low fuel consumption output curve S and the PTO drive switch 151 is turned on, the engine speed control is automatically performed in the engine speed fluctuation control mode A. When it is determined that there is no margin in the engine load, the engine power selection switch 134 selects the standard output curve N, and this selection automatically switches to the engine speed maintenance control mode B.

  Since the allowable maximum load of the low fuel consumption output curve S is lower than the allowable maximum load of the standard output curve N, there is a high possibility that the allowable maximum load will be reached. For this reason, if the allowable maximum load is reached when working in the engine speed maintenance control mode B in the selected state of the low fuel consumption output curve S, there is a problem that the engine stalls at once.

  Therefore, when working in the low fuel consumption output curve S and the engine speed fluctuation control mode A, the engine speed decreases according to the action of the load. The problem of having to restart can be prevented. Further, since the engine speed decreases according to the load, the operator can easily grasp the state of the load.

  Further, when the standard output curve N is selected by the engine power selection switch 134 and the ON state of the PTO drive switch 151 for driving the work machine is both enabled, the engine speed maintaining control mode B is automatically switched. Since the engine can be operated at a constant rotational speed up to the maximum allowable load of the engine itself, the engine efficiency can be maximized to improve the work efficiency.

  When the PTO drive switch 151 is turned on, the PTO clutch sol (solenoid) 54b shown in FIG. 6 described later is energized, and the PTO clutch 54a shown in FIG. 5 is turned on.

  Further, as shown in FIG. 6, an engine speed storage means (hereinafter referred to as an engine speed storage switch) 152 for storing a specific engine speed, and an engine speed for reproducing the stored specific engine speed. Reproduction means (hereinafter referred to as an engine speed reproduction switch) 153 is provided. By providing the engine speed reproduction switch 153, the engine speed can be automatically set to a specific value, so that an operation of an accelerator lever or the like is not required, and operability is improved.

  The engine power selection switch 134 is used to select the low fuel consumption output curve S, and when the engine speed reproduction switch 152 is turned on together, the engine speed change control mode A is automatically switched. To do.

  The engine speed storage switch 152 stores a specific engine speed desired by the operator in the travel control device 120. Then, the engine speed reproduction switch 153 is operated to reproduce the stored engine speed. Thus, when reproducing the specific engine speed memorize | stored with the engine speed reproduction switch 153, it is a case where work is performed. When the stored engine speed is reproduced and the low fuel consumption output curve S is selected by the engine power selection switch 134, the engine speed change control mode A is automatically switched.

  As described above, when the work is performed, the stored engine speed is reproduced, and when the low fuel consumption output curve S is selected by the engine power selection switch 134, the engine speed change control mode A is automatically switched. Since the engine speed decreases according to the action of the load, the engine speed stalls at a stretch and the engine must be restarted can be prevented. . Further, since the engine speed decreases according to the load, the operator can easily grasp the state of the load.

  Further, as automatic control, when the load factor of the PTO output shaft 54c (FIG. 5) that drives the work machine is detected and the work is performed or running at a standard output curve N for a certain period of time with a load factor of approximately 70% or less. Then, it is configured to automatically switch to the low fuel consumption output curve S. This makes it possible to perform efficient and fuel-efficient work and travel.

  Conversely, when the vehicle is operating or running at a load factor of approximately 70% or more in the low fuel consumption output curve S for a certain period of time, the standard output curve N is automatically switched. The load factor of the PTO output shaft 54c is calculated from the current rotational speed with respect to the specified rotational speed.

  In addition, when a travel shift lever (not shown) is set to a travel position on the road (a position at which high speed travels at a high shift position) or travels for a certain time (about 10 minutes) on a standard output curve N, fuel efficiency is automatically reduced. You may make it switch to the output curve S.

  In the engine speed fluctuation control mode A, the engine speed maintenance control mode B, and the heavy load mode C, a shift operation of a traveling speed change lever of a farm vehicle (tractor, combine, rice transplanter, etc.) or a work clutch (whether it is a tractor) It may be configured to automatically switch to the engine speed maintenance control mode B by an on / off operation or the like of a PTO clutch for rotary drive or the like, and for a combine, a drive clutch for a reaping part or a threshing part. In the tractor, even if the PTO clutch is disengaged, if the lift arm connecting the work machine is lower than the uppermost position and the lift arm is raised and lowered, it is plow work or plastic work, The engine speed maintaining control mode B and heavy load mode C are automatically set.

  Further, the engine speed fluctuation control mode A, the engine speed maintenance control mode B, and the heavy load mode C may be manually switched by operating the engine speed control mode changeover switch 148 (FIG. 6). Good. In the case of manual operation, the driver selects it.

  In addition, when the sub-shift lever is set to the road running position, the engine speed fluctuation control mode A is automatically set. However, in the case of road driving, the load is small, so the fuel efficiency output curve S is automatically set. May be. In this case, when the sub-shift lever is shifted to a position other than the on-road travel position, if the standard output curve N has been selected in advance, it is returned to the standard output curve N. Thereby, efficient driving | running | working is attained.

  Further, when the engine power selection switch 134 is in the on state, the engine speed fluctuation control mode A may be always set. The engine speed change control mode A may also be used when the engine power selection switch 134 is off and the shift is automatically performed by operating the accelerator pedal.

  Further, when the engine power selection switch 134 is turned off, the manual switch 150 (FIG. 6) is turned off, and when the PTO clutch is turned on, the engine speed maintaining control mode B may be automatically set. Instead of the condition that the PTO clutch is engaged, the working machine may be in the lowered state or the engine speed reproduction switch 153 may be in the engaged state. When the PTO clutch is disengaged, the working machine is in the raised state, or the engine speed reproduction switch 153 is in the disengaged state, the engine speed fluctuation control mode A is automatically set.

If the manual switch 150 is in the on state, the engine speed maintaining control mode B is always set. Thereby, efficient work and traveling are possible.
FIG. 10 is a schematic diagram of intake and exhaust into the cylinder 5 of the engine, which is an embodiment of a four-cycle diesel engine. The air supercharged by the intake turbine 160 of the supercharger TB passes through the intake turbine 160 and the intercooler 162 from the air cleaner 161 and is sent from the intake manifold 163 into the cylinder 5. 164 is an intake valve, and 165 is a piston. Reference numeral 166 denotes a cam that opens and closes the intake valve 164 and the exhaust valve 168 via a rocker arm 167.

  The exhaust gas combusted in the cylinder 5 passes through the exhaust manifold 42 from the exhaust valve 168 and is then discharged by driving the supercharger TB with the exhaust turbine 169 of the supercharger TB.

  This diesel engine has an EGR (exhaust gas recirculation device) circuit 170 for mixing a part of the exhaust gas into the intake side. The EGR circuit 170 is configured to reduce the amount of oxygen (O 2) by mixing a part of the exhaust gas into the intake side, thereby reducing the generation of nitrogen oxides NOx. However, if the EGR rate increases too much, the amount of oxygen decreases and incomplete combustion occurs. Therefore, it is necessary to adjust the EGR rate according to the combustion state. This adjustment is performed by the EGR valve 171. The EGR circuit 170 connects between an exhaust pipe 173 downstream of a post-processing device 172, which will be described later, and an intake pipe 174 upstream of the intake turbine 160 of the supercharger TB. In addition, an EGR cooler 175 is provided in the middle of the EGR circuit 170. The amount of exhaust gas reduced into the cylinder 5 changes depending on how the EGR valve 171 is opened and closed.

  The exhaust gas that has passed through the exhaust turbine 169 passes through the aftertreatment device 172 and is discharged from the muffler 176 into the atmosphere. The post-processing device 172 includes an oxidation catalyst (DOC) 172a and a diesel particulate filter (DPF) 172b.

  The oxidation catalyst (DOC) 172a burns the incombustible chamber, and the DPF 172b collects the granulated material (PM). The EGR valve 171 and the throttle valve 177 are configured to be controlled by the ECU 12. The post-processing device 172 may be composed of only the DPF 172b. When an oxidation catalyst (DOC) is provided, the non-combustible material burns, so that the exhaust gas becomes cleaner.

  When the state of the exhaust gas is low (low load) continues for a long time, the DPF 172b has a concern that PM will accumulate and the capacity may be reduced. Therefore, a throttle valve 177 is provided on the lower side of the post-processing device 172. When the throttle valve 177 is throttled, the pressure in the DPF 172b is kept high, and the temperature also rises. As a result, the DPF 172b can be regenerated under the influence of a high temperature. That is, when the exhaust gas having a high temperature passes through the DPF 172b, the DPF 172b is regenerated by burning off the PM present in the DPF 172b.

  In the DPF regeneration operation for regenerating the DPF 172b, both the EGR valve 171 and the throttle valve 177 are throttled. Then, the gas temperature in the DPF 172b is raised together with the retard (retard) of the fuel injection timing so that the DPF 172b starts to be regenerated. This eliminates the need for fuel after-injection (in order to increase the exhaust gas temperature) and reduces the number of after-injections, so that the amount of fuel consumption can be suppressed and the environment is good.

In the tractor, the DPF regeneration operation may be performed at the drive timing of the PTO shaft, and the DPF regeneration operation may be performed under a predetermined condition when the PTO shaft is not driven for a long time.
As a condition for performing such a DPF regeneration operation, a pressure sensor 178 is provided on the upper side of the post-processing device 172, and an estimated deposition value (pressure and temperature detected by the pressure sensor 178) is detected by the pressure sensor 178. When the predicted deposition value estimated by the temperature detected by the sensor 179 becomes equal to or greater than a predetermined value, PM accumulates in the DPF 172b and becomes a resistance, so the DPF regeneration operation is performed. Accurate deposition predicted values can be calculated by mapping the pressure against the engine speed in advance.

  In addition, if the state in which the DPF regeneration operation is started continues for a long time, an overheating state occurs and the DPF 172b is damaged. Therefore, a temperature sensor 179 is provided on the lower side of the post-processing device 172, and when the value of the temperature sensor 179 exceeds a predetermined value, the DPF regeneration operation is stopped and the normal operation is resumed.

  In normal operation, the EGR valve 171 and the throttle valve 177 are simultaneously controlled to appropriately control the EGR amount. In particular, by having the throttle valve 177, the gas temperature in the DPF 172b can be kept high.

  Whether or not the opening degree of the EGR valve 171 is appropriate is determined by monitoring the EGR valve standing estimated by the air flow sensor and the negative pressure sensor provided in the air cleaner 161, but if it exceeds the normal range, it is determined by the engine control device 12 that there is an abnormality. And alert the operator with warnings and displays.

  With the configuration as described above, an intake throttle is not required. In other words, since the intake side pressure is high in an engine with a supercharger, an exhaust throttle valve or an intake throttle is required to secure the amount of EGR gas, and control in conjunction with the EGR valve is required, but such a system is unnecessary. It becomes.

  Further, since the exhaust gas downstream of the DPF 172b is taken out, it is possible to prevent the performance deterioration caused by the dirt of the supercharger TB. And since EGR gas is cooled by the EGR cooler 175, an effect becomes large with respect to NOx reduction.

  As described above, in the DPF forced regeneration mode in which the DPF regeneration operation is performed, the exhaust throttle valve 177 is throttled, and the EGR valve 171 is fully closed by ON-OFF control. Therefore, since the exhaust gas is not reduced, NO increases, and this NO is converted to NO2 by the oxidation catalyst (DOC) 172a, and regeneration of the DPF 172b is promoted.

  Further, when the engine rotation shifts to low idle during the forced regeneration of the DPF 172b, the EGR valve 171 is fully opened. Since the temperature sensor 179 is provided on the downstream side of the DPF 172b, it may be added to the condition that the detected value by the temperature sensor 179 has risen to a predetermined value or more.

  In such a DPF forced regeneration mode, even if the rotation control of the engine E is in the engine speed fluctuation control mode A, the load is increased by switching the rotation control to the engine speed maintenance control mode B. Prevents rotation drop due to. Further, the DPF forced regeneration mode does not enter the low fuel consumption output curve S but enters the exhaust gas temperature high in the high load region of the standard output curve N.

  In addition, when the DPF forced regeneration mode is executed in the travel stop state, the rear wheel 18 is jacked up and floated, and the engine driving force is transmitted to the rear wheel 18 via the transmission case 16 to apply the driving load, thereby reducing the exhaust. Increase temperature.

  Further, if it is determined that the DPF 172b is clogged with the accumulation amount estimated by the pressure detected by the pressure sensor 178 and the temperature detected by the temperature sensor 179, the shift stage is limited to start at the lowest speed. Therefore, the generation of granulated substances (PM) such as soot is reduced.

  In order to improve startability at low temperatures, an intake throttle valve that adjusts the amount of air to the intake manifold 163 is provided, and if the intake amount is reduced at start-up, temperature drop in the cylinder due to cold air is prevented and ignitability is improved. I can do it. Also, in order to prevent the exhaust gas temperature from decreasing due to a load decrease during turning, the intake air amount is throttled by the intake throttle valve.

FIG. 4 shows a tractor 15 as a work vehicle in which the present invention is implemented.
The tractor 15 has an engine E mounted in a bonnet at the front part of the machine body, transmits the rotational power of the engine E to the transmission in the transmission case 16, and the rotational power decelerated by the transmission is transmitted to the front wheels 17 and the rear wheels 18. To tell. The area around the cockpit 22 on the aircraft is covered with a cabin 19. A steering handle 20 is erected from a dashboard 13 provided with a meter panel 117 on the front side of the cockpit 22 inside the cabin 19, and a forward / reverse lever, a parking brake lever, a PTO shift lever, and the like are disposed around the steering handle 20.

  This engine E is a diesel engine of the above-described common rail type, and is equipped with a DOC 172a and a DPF 172b nearby, and the DPF 172b, which has high heat in the DPF forced regeneration mode, is provided with a heat shield on the engine E side so that heat is not transmitted. I have to.

Further, the bonnet containing the engine E, the DOC 172a, and the DPF 172b is lifted up and held open with the front side as a fulcrum, thereby facilitating maintenance work.
FIG. 11 shows an attached state of the DPF 172b. The DPF 172b is mounted on the support frames 181a and 181b of the gantry 180 and fixed with the steel belt 182 and the tension bolt 185. The gantry 180 is made easy by cutting out a standard square material into an arc shape and mounting the DPF 172b. As shown in FIG. 12, the buffer rubber 184 is laid under the support frames 181a and 181b and attached to the inner side of the U-shaped square member 183, so that heat is hardly transmitted to the buffer rubber 184.

  The DPF 172b may be supported by a curved bracket having a high coefficient of thermal expansion such as a bimetal suspended from the body frame, and the DPF 172b may be pressed by a bonnet cover.

  FIG. 13 shows a state in which the supercharger TB and the DPF 172b are attached to the engine E so that the exhaust gas discharged from the supercharger TB flows directly into the DPF 172b without bending, thereby improving the flow of the exhaust gas. ing. With this configuration, the DOC 172a is incorporated into the exhaust pipe 187.

  FIG. 14 shows another embodiment of the intake / exhaust circuit of the engine E. Bypass intake passage for intake without passing through the intercooler 162 to the intake circuit for intake into the cylinder 5 from the supercharger TB via the intercooler 162 via the intake slot valve 156 157 is provided so that the cylinder 5 is sucked through the bypass intake passage 157 in the DPF forced regeneration mode. This speeds up the exhaust temperature rise of the DPF 172b.

  A DPF differential pressure sensor 154 detects the air pressure at the inlet of the DPF 172b and an air flow sensor 155 detects the intake air pressure from the air cleaner 161. A first switching valve 158 is provided at the inlet of the bypass intake passage 157, and the outlet A second switching valve 159 is provided.

The intake slot valve 156 is opened according to the clogging of the DPF 172b detected by the DPF differential pressure sensor 154, and the intake air amount is adjusted to ensure the optimum air-fuel ratio.
Further, in order to increase the exhaust temperature during automatic regeneration of the DPF 172b, the intake slot valve 156 is throttled to adjust the intake air amount.

  The failure of the air flow sensor 155 is performed based on the intake efficiency map and the calibration flow rate of the air flow sensor 155. If it is determined that there is a failure, the failure flag is set and the map is switched to manually control the rotation / intake efficiency map.

  FIG. 15 shows a filter 186 provided at the outlet of the DPF 172b. By making the mesh of the central filter 186a finer than the mesh of the peripheral filter 186b, the exhaust gas flow is guided to the periphery to the periphery when the DPF is regenerated. The filter 189 is allowed to incinerate the granular material at a high temperature.

  In the fuel injection amount control of the engine E, if the rotation is 300 rpm or less (cracking rotation) and is reduced by 40% from the other injection amounts, an increase in knock-on due to the ignition delay of the first explosion can be prevented.

  In addition, at the time of start-up, pilot injection is performed twice up to 1000 rpm, once the engine speed exceeds 1000 rpm, one pilot injection is performed once, and once the rotation exceeds 1000 rpm, the pilot injection is performed once and the after-injection is performed once. Smoke generation can be suppressed.

  Further, as engine control, the shift shock can be reduced by temporarily reducing the engine rotation at the time of shifting by changing the gear position of the forward / reverse lever operation position sensor 129 or the sub-shift lever operation position sensor 130.

It is also conceivable to detect the drive torque of the drive shaft and control the fuel injection amount so that sudden torque fluctuation does not occur.
A hitch 21 and a three-point link (not shown) are provided between the left and right rear wheels 18 and 18 so that a working machine such as a rotary is mounted.

  FIG. 7 is an enlarged view of the meter panel 117. FIG. 8 is an enlarged view of the liquid crystal data display unit 14 in the meter panel 117 and shows an example of display. FIG. 9 is an enlarged perspective view around the right side of the steering handle 20 erected on the dashboard 13.

  The meter panel 117 on the front side of the steering handle 20 is provided with an engine tachometer 24 at the center, a liquid crystal data display unit 14 on the right side, and an energy saving monitor lamp 23 on the left side.

  The data display unit 14 includes a shift speed display 14a for displaying the current shift speed, a fuel consumption rate display 14b, and the like, and the fuel consumption rate display 14b is switched to the traveling speed display 14c at regular intervals. The fuel consumption rate is the ratio of the fuel injection amount that is actually injected to the fuel injection amount for producing the maximum output at the engine speed at that time. The data display unit 14 is also configured to display a fuel gauge 14d and a cooling water temperature gauge 14e of the engine E.

The energy saving monitor lamp 23 is lit when the low fuel consumption output curve S is selected by the engine power selection switch 134, and lights in green.
Further, as shown in FIG. 9, an engine power selection switch 134 is provided on the dashboard 13 on the right side of the steering handle 20. When the engine power selection switch 134 is pressed, the engine is controlled by the low fuel consumption output curve S.

FIG. 5 is a diagram showing a transmission mechanism of the transmission in the transmission case 16. A power transmission configuration from the engine E to the front wheels 17 and the rear wheels 18 will be described.
A first gear 26 is fixed to the input shaft 25 directly connected to the output shaft of the engine E, and a forward / reverse switching clutch 27 is mounted.

  One second gear 28 of the forward / reverse switching clutch 27 meshes with a third gear 30 fixed to the first transmission shaft 29 and decelerates, and the other fourth gear 31 of the forward / reverse switching clutch 27 moves the counter gear 32. Through the fifth gear 33 fixed to the first transmission shaft 29, and the power is transmitted in the reverse direction. That is, when the forward / reverse switching clutch 27 is placed (connected) on the second gear 28 side, the rotation of the input shaft 25 is transmitted in the reverse direction to the first transmission shaft 29, and when it is placed on the fourth gear 31 side, The neutral state in which the rotation of 25 is transmitted to the first transmission shaft 29 in the forward direction and is separated from both the second gear 28 and the fourth gear 31 is the main clutch disengaged state in which the power transmission is cut off. The main clutch disengaged state can be maintained by controlling the hydraulic valve. That is, the forward / reverse switching clutch 27 that operates during automatic control, when operating the forward / reverse lever, and when operating the clutch pedal functions as a main clutch.

On the first transmission shaft 29 on the lower transmission side of the forward / reverse switching clutch 27, a first transmission clutch 34 for switching to the first / third speed and a second transmission clutch 35 for switching to the second / fourth speed are mounted. ing.
The first clutch gear 36 and the second clutch gear 37 of the first transmission clutch 34 for switching between the first speed and the third speed mesh with the third clutch gear 39 and the fourth clutch gear 40 fixed to the second countershaft 38, The rotation of the first transmission shaft 29 is transmitted to the second counter shaft 38 for the first speed or the third speed.

  Further, the fifth clutch gear 41 and the sixth clutch gear 42 of the second speed / second speed switching second transmission clutch 35 are engaged with the seventh clutch gear 43 and the eighth clutch gear 44 fixed to the second counter shaft 38. Thus, the rotation of the first transmission shaft 29 is transmitted to the second counter shaft 38 for the second speed or the fourth speed.

  The third counter shaft 45 is connected to the lower transmission side of the second counter shaft 38 by a coupling 46, and the rotation is transmitted as it is. A small gear 47 and a large gear 48 are fixed to the third counter shaft 45. The small gear 47 and the large gear 48 mesh with the large clutch gear 51 and the small clutch gear 52 of the high / low speed switching clutch 50 mounted on the second transmission shaft 49, respectively, and the third counter shaft 45 rotates at high speed or low speed. The power is transmitted to the second transmission shaft 49 at a low speed.

  A sixth gear 53 is fixed to the lower transmission side end portion of the second transmission shaft 49, and the sixth gear 53 is a large gear 56 of a large and small gear 55 portion rotatably supported on the third drive shaft 54. And is decelerating.

  The small gear 57 of the large and small gears 55 meshes with the seventh gear 60 of the double auxiliary transmission clutch 59 that is pivotally supported by the bevel gear shaft 58 and is transmitted at a reduced speed. Further, an eighth gear 61 provided integrally with the seventh gear 60 is engaged with a second large gear 63 fixed to the fifth counter shaft 62 for transmission at a reduced speed.

  A second small gear 64 is further fixed to the fifth counter shaft 62, and the second small gear 64 meshes with the third large gear 65 of the bevel gear shaft 58 to further reduce the transmission. Accordingly, the rotation of the second transmission shaft 49 is as follows: sixth gear 53 → large gear 56 → small gear 57 → seventh gear 60 → eighth gear 61 → second large gear 63 → second small gear 64 → third large gear. It is transmitted while being decelerated sequentially with 65.

  The first shifter 66 and the second shifter 67 of the double auxiliary transmission clutch 59 operated by the auxiliary transmission lever are slidably engaged with the bevel gear shaft 58 in the axial direction, and the first shifter 66 is engaged with the seventh gear. When slid to 60 side and engaged, the rotation of the seventh gear 60 is transmitted to the bevel gear shaft 58, and when the second shifter 67 is slid and engaged to the eighth gear 61 side, the rotation of the eighth gear 61 is rotated to the bevel gear shaft. As a result, the bevel gear shaft 58 is rotated at a low speed.

  The rotation of the bevel gear shaft 58 is transmitted to the differential gear 70 through the first bevel gear 68 and the second bevel gear 69, and is transmitted from the differential gear 70 to the rear wheel 18 through the axle 71 and the planetary gear 72.

  In summary, the rotation of the input shaft 25 is first switched to forward rotation or reverse rotation by the forward / reverse switching clutch 27, and the first transmission clutch 34 for the first speed / three speed switching and the second speed / fourth speed switching first clutch 34. The speed is changed in four stages from first to fourth speed by the two-speed clutch 35, the speed is changed to two speeds of high speed and low speed by the high / low speed switching clutch 50, and further, high, medium and low speed 3 are selected by two sub-shift clutches 59 The gear is shifted in stages and transmitted to the bevel gear shaft 58. That is, the rotation of the input shaft 25 is shifted to 4 × 2 × 3 = 24 speeds and transmitted to the axle 71.

  For driving force transmission to the front wheel 17, the ninth gear 74 is fixed to the bevel gear shaft 58, the ninth gear 74 is meshed with the relay gear 75, and further meshed with the tenth gear 77 fixed to the third drive shaft 76. Then, the third drive shaft 76 is driven. The third drive shaft 76 is connected by a second coupling 78 to a transmission shaft 80 on which a front wheel speed increasing clutch 79 is mounted. The eleventh gear 81 and the twelfth gear 82 of the front wheel speed increasing clutch 79 are engaged with the thirteenth gear 84 and the fourteenth gear 85 fixed to the seventh countershaft 83, so that the front wheel drive is changed from the normal front wheel drive to the front wheel. The speed is switched to speedup. When the front wheel acceleration clutch 79 is neutral, the front wheel 17 is not driven and only the rear wheel is driven.

  The seventh counter shaft 83 is connected to the front wheel drive shaft 87 by a third coupling 86, and is further connected to the front wheel drive bevel shaft 91 by a fourth coupling 88, an extension shaft 89 and a fifth coupling 90.

  The power of the front wheel drive bevel shaft 91 is as follows: front first bevel gear 92, front second bevel gear 93, front differential gear 94, front differential gear shaft 95, front third bevel gear 96, front fourth bevel gear 97, vertical shaft 98, front fifth bevel gear. 99, the front wheel 17 is driven through the front sixth bevel gear 100 and the front planetary gear 101.

  A PTO output shaft 54 c is connected to the lower transmission side of the third drive shaft 54. The PTO output shaft 54c is configured to be driven via a PTO transmission 54d, a PTO counter shaft 54e, and a third drive shaft 54.

  Although not shown, when the oil pump is mounted on the cylinder block of the engine E, the circular insertion flange of the oil pump is sealed and inserted into the circular mounting hole of the cylinder block with an O-ring.

Next, the flow of the control signal will be described with reference to the control block diagram of FIG.
First, the engine ECU (engine control device) 12 receives the exhaust temperature from the engine exhaust temperature sensor 106, the engine speed from the engine rotation sensor 107, and the engine lubricating oil pressure from the engine oil pressure sensor 108, The coolant temperature is input from the engine water temperature sensor 109, the pressure of the common rail 1 is input from the rail pressure sensor 2, the drive signal is output to the fuel high-pressure pump 4, and the fuel supply adjustment control signal is output to the high-pressure injector 6.

  Next, the work implement elevating control device 110 includes an operation signal for the position control sensor 111 provided on the work implement elevating lever, an elevating signal for the lift arm sensor 112, a raising position regulating signal for the raising position regulating dial 113, and a lowering speed. The descent speed setting signal of the adjustment dial 114 is input, and the work implement elevating signal is output to the main ascending solenoid 115 and the main descent solenoid 116 to operate the work implement elevating cylinder.

  The engine ECU 12, the work implement lifting control device 110, and a travel control device 120, which will be described later, communicate with each other alternately (CAN1 and CAN2 communication), so that the engine E has a standard output curve N or a low fuel consumption output curve. The state of S, the raising / lowering state of the work implement, the traveling speed of the traveling device, and the like are displayed on the meter panel 117, and the operation positions of the levers and pedals are displayed on the operation panel 118.

  The travel control device 120 receives a clutch engagement signal, that is, a gear position of a multi-stage gear transmission, from a shift 1 clutch pressure sensor 121, a shift 2 clutch pressure sensor 122, a shift 3 clutch pressure sensor 123, and a shift 4 clutch pressure sensor 124. That is, it is a signal of the first speed / third speed switching first transmission clutch 34 and the second speed / fourth speed switching second transmission clutch 35. The shift position of the sub clutch is input from the Hi (high speed) clutch pressure sensor 125 and the Lo (low speed) clutch pressure sensor 126. That is, the signal of the high / low speed switching clutch 50.

  From the forward clutch pressure sensor 127 and the reverse clutch pressure sensor 128, forward / neutral / reverse of the main clutch is input. That is, it is a signal of the forward / reverse switching clutch 27. A shift operation position signal is input from a forward / reverse lever operation position sensor 129 that detects the position of a forward / reverse lever that moves the tractor forward and backward, and an auxiliary transmission lever operation position sensor 130 that detects an operation position of the auxiliary transmission lever.

  The travel speed is input from the vehicle speed sensor 131, the temperature of the mission oil is input from the mission oil temperature sensor 132, the depression signal of the clutch pedal is input from the clutch pedal operation position sensor 133, and the standard output curve is output from the engine power selection switch 134. N and a low fuel consumption output curve S selection signal are input, and an engine control mode switching signal is input from an engine speed control mode switching switch 148. An on / off signal is input from the manual switch 150.

  Furthermore, the accelerator opening degree O by the depression of the accelerator pedal which is the accelerator change means 146 is input from the accelerator sensor 146a. The accelerator opening degree O controls the output of the engine E. About 80% of the full opening is set as the standard output mode transition opening degree O2, and when the standard output mode transition opening degree O2 is exceeded, the vehicle travels on the low fuel consumption output curve S. Is also changed to the standard output curve N to increase the output. Further, about 60% of the full opening is set as the low fuel consumption output mode transition opening degree O1, and when the low fuel consumption output mode transition opening degree O1 continues for a predetermined time T (5 seconds) or longer, the vehicle travels on the low fuel consumption output curve S and runs out of fuel. Reduce consumption. The accelerator changing unit 146 may be an accelerator lever that is manually operated.

  A signal is also input from an accelerator shift setting switch 144 that performs automatic shift (on the road) while the accelerator pedal is depressed, and an operation signal of a main shift acceleration / deceleration operation switch 145 that manually increases or decreases the shift is input. An accelerator operation signal is input by detecting the position of the lever, and an accelerator adjustment signal of an accelerator fine adjustment lever sensor 147 for finely adjusting the accelerator is input.

  The depression of the left brake pedal 102L is input from the left brake sensor 105, and the depression of the right brake pedal 102R is input from the right brake sensor 104, and the left and right brakes are operated. The left brake pedal 102L and the right brake pedal 102R are selectively used during work travel. When traveling on the road, the left brake pedal 102L and the right brake pedal 102R are connected together and connected by the left and right brake connection sensor 103. Is detected. When a connection signal is input from the left and right brake connection sensor 103, engine output control using the low fuel consumption output curve S is performed in the engine rotation speed fluctuation control mode A, and fluctuations in the engine rotation according to fluctuations in the driving load are performed. This is done, and the travel speed is quickly reduced by stepping on the left brake sensor 105 and the right brake sensor 104.

  As for the output from the traveling control device 120, a forward / reverse switching clutch switching signal is output to the forward / reverse switching sol (solenoid) 135, and the hydraulic relief for driving the forward / reverse switching sol (solenoid) to the linear booster sol (solenoid) 136 is output. A pressure adjustment signal is output to reduce the clutch connection shock, and an on / off signal is output to the clutch sol (solenoid) 137.

  Further, a first-speed or third-speed input signal is output to a shift 1-3 switching sol (solenoid) 138 of the hydraulic cylinder that drives the first-speed / three-speed switching first shift clutch 34, and the shift 1-3 boost sol ( Solenoid) 139 outputs a relief pressure adjustment signal for the hydraulic pressure that drives the first speed / third speed switching first shift clutch 34 to reduce the shock of clutch engagement. A second or fourth speed on signal is output to the shift 2-4 switching sol (solenoid) 140 of the hydraulic cylinder that drives the second shift clutch 35 for second / fourth speed switching, and the shift 2-4 boosting sol (solenoid) is output. 141 outputs a relief pressure adjustment signal for hydraulic pressure that drives the second speed / fourth speed switching second shift clutch 35 to reduce the shock of clutch engagement. A high-speed clutch input signal and a low-speed clutch input signal are supplied to the Hi (high-speed) clutch switching sol (solenoid) 142 and the Lo (low-speed) clutch switching sol (solenoid) 143 that operate the hydraulic cylinder that drives the high / low speed switching clutch 50. It is the structure which outputs.

  It can also be applied to other industrial vehicles.

A Engine speed fluctuation control mode B Engine speed maintenance control mode C Heavy load mode E Engine N Standard output curve O1 Low fuel consumption output mode transition opening S2 Standard output mode transition opening S Low fuel consumption engine output curve T Predetermined time 102R Right Brake pedal 102L Left brake pedal 103 Connection sensor 146 Accelerator changing means 172b DPF
O Accelerator opening O1 Low fuel consumption output mode transition opening O2 Standard output mode transition opening

Claims (4)

  An engine speed fluctuation control mode (A) in which the output of the engine (E) is fluctuated by fluctuations in the engine speed, and an engine speed maintenance control mode (B) in which the engine speed is kept constant even when the load increases. In addition to the engine speed maintenance control, it is equipped with a heavy load mode (C) that increases the engine speed and increases the output when it is close to the load limit, and the standard output curve (N) and low fuel consumption output curve (S) can be selected. In the engine control of the tractor, the connection sensor (103) for detecting that the left and right brake pedals (102R) and (102L) for braking the left and right traveling devices (17) and (18) are integrally connected is provided. The detection of the connection signal of the connection sensor (103) selects and controls the engine speed fluctuation control mode (A) and the low fuel consumption output curve (S). Tractor engine control that.   In the engine control of the tractor in which the standard output curve (N) and the low fuel consumption output curve (S) can be selected, the accelerator opening (O) of the accelerator changing means (146) is added to the standard output mode transition opening (O2), A fuel efficiency output mode transition opening (O1) smaller than the standard output mode transition opening (O2) is provided, and the accelerator opening (O) becomes the standard output mode transition opening (O2) in the fuel efficiency output curve (S). When it reaches, the standard output curve (N) is selected, and when the fuel consumption output mode transition opening (O1) or less continues for a predetermined time (T), the low fuel consumption output curve (S) is selected and controlled. Tractor engine control.   The DPF (172b) for treating the exhaust of the engine (E) is provided, and the regeneration process of the DPF (172b) is performed only with the standard output curve (N). Engine control of the tractor as described in   The tractor engine control according to claim 3, wherein the regeneration process of the DPF (172b) is performed in an engine speed maintaining control mode (B).

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