JP2013160056A - Work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work machine capable of performing automatic regeneration of a DPF after surely confirming the will of an operator.SOLUTION: A tractor 1 includes a diesel engine 3, an exhaust emission control device 50 having a DPF 13 for collecting particulate matter included in exhaust gas exhausted from the diesel engine 3, and a filter regenerating means 65 for performing automatic regeneration for automatically burning and removing the particulate matter when a deposit quantity of the particulate matter deposited on the DPF 13 of the exhaust emission control device 50 exceeds a predetermined value. Moreover, the filter regenerating means 65 includes an automatic regeneration permitting means 70 for permitting performance of the automatic regeneration by an indication from an external part of the filter regenerating means 65, and the automatic regeneration permitting means 65 does not permit the performance of the automatic regeneration when starting.

Description

  The present invention relates to a working machine such as a tractor, a wheel loader, and a backhoe provided with a diesel particulate filter (DPF).

In order to improve and solve environmental problems in recent years, exhaust gas regulations for diesel engines and the like have been strengthened. Various techniques for reducing particulate matter (particulate matter) PM contained in exhaust gas have also been developed in work machines such as agricultural machines and construction machines in order to cope with such exhaust gas regulations. .
In general, diesel engines are provided with an exhaust gas purification device that collects particulate matter contained in the exhaust gas. The exhaust gas purification device collects particulate matter by passing the exhaust gas through a diesel particulate filter (DPF) provided therein. Since the collected particulate matter accumulates in the DPF of the exhaust gas purification device, the particulate matter is appropriately removed to regenerate the DPF so that the DPF gradually clogs and the air resistance of the exhaust system does not increase. I have to do it.

As a technique related to such DPF regeneration, for example, there is a DPF system disclosed in Patent Document 1.
The DPF system disclosed in Patent Document 1 is a diesel particulate filter comprising a filter connected to an exhaust pipe of a diesel engine and collecting PM in exhaust gas, and an oxidation catalyst provided on the upstream side of the filter, A temperature sensor provided on each of the upstream side and the downstream side of the oxidation catalyst, and a temperature detected by the upstream temperature sensor of the oxidation catalyst when a PM accumulation amount of the filter exceeds a predetermined amount; In a DPF system that regenerates a diesel particulate filter by setting the temperature detected by the downstream temperature sensor of the oxidation catalyst to a second threshold value or more, the failure of the upstream temperature sensor of the oxidation catalyst The second threshold value is changed upward when the signal is detected.

JP2011-256845A

  The DPF system of Patent Document 1 was proposed based on a conventional DPF regeneration method, and can be used for manual regeneration performed with the vehicle stopped, or for automatic regeneration that can be performed while the vehicle is running. Applicable technology. Patent Document 1 describes that automatic regeneration and manual regeneration each have merits and demerits, and are therefore preferably selected and used appropriately according to the situation.

  Here, as described in Patent Document 1, the automatic regeneration of the DPF is performed even if the vehicle is traveling, as long as the particulate matter deposited on the DPF exceeds a predetermined value, even if there is no instruction from the operator. This is a regeneration method in which the vehicle automatically starts regeneration of the DPF. As is well known, in the regeneration of the DPF, the particulate matter in the DPF is burned by increasing the temperature of the DPF, and the accumulated particulate matter is reduced. According to such automatic regeneration of the DPF, regardless of the will of the operator, the temperature of the DPF, that is, the exhaust temperature may become very high without the operator knowing.

  Even in agricultural machines, there are many inconvenient situations when the exhaust temperature becomes high without the operator's knowledge. For example, since a farm machine may run in a yard, there is a risk of adverse effects on crops if the exhaust temperature is high. In addition, since the agricultural machine may enter not only the yard but also a livestock shed, if the exhaust temperature is high, the livestock breeding environment may be adversely affected.

  Therefore, in the present invention, after confirming the operator's intention, the DPF temperature and the exhaust temperature are surely confirmed so as to avoid a very high temperature without knowing the operator's intention. An object of the present invention is to provide a working machine capable of automatically regenerating a DPF.

In order to achieve the above object, the present invention has taken the following measures.
That is, according to the working machine according to claim 1, the exhaust gas purifying apparatus having a diesel engine, a filter for collecting particulate matter contained in the exhaust gas discharged from the diesel engine, and the exhaust gas And a filter regeneration unit that performs automatic regeneration for automatically burning and removing the particulate matter when the amount of particulate matter deposited on the filter of the purification device exceeds a predetermined value. The filter regeneration means has automatic regeneration permission means for permitting execution of the automatic regeneration in accordance with an instruction from the outside, and the automatic regeneration permission means disallows execution of the automatic regeneration at startup. It is characterized by that.

  According to a work machine according to claim 2, the working machine includes an automatic regeneration permission switch that outputs an instruction for permitting execution of the automatic regeneration, and the filter regeneration unit has an amount of particulate matter accumulated exceeding the predetermined value. A notification signal indicating that it is necessary to perform the automatic regeneration, and the automatic regeneration permitting means outputs the notification signal from the automatic regeneration permission switch when the filter regeneration means is outputting the notification signal. When receiving an instruction to permit execution of the automatic regeneration, the filter regeneration means is permitted to perform the automatic regeneration.

According to the work machine of claim 3, the automatic regeneration permission switch outputs an instruction for permitting the execution of the automatic regeneration, and outputs an instruction for disabling the permitted automatic regeneration. It is characterized by that.
According to the work machine of claim 4, the filter regeneration unit outputs the notification signal to the permission switch, and the automatic regeneration permission switch performs the automatic regeneration based on the output notification signal. It is characterized by notifying that it is necessary to do.

  According to the first aspect, since the automatic regeneration permission means does not permit the automatic regeneration at the time of activation, the regeneration control of the DPF is performed so that the automatic regeneration does not start before the operator notices. Can do. As a result, the work implement always obtains an instruction from the operator when starting automatic regeneration. Therefore, regardless of whether it is a farm field or a livestock shed, automatic regeneration starts and the exhaust temperature rises at a place not desired by the operator. Can be prevented.

According to the second aspect, the operator is informed that automatic reproduction is possible, and the automatic reproduction is performed or continued after an instruction from the operator. As a result, automatic reproduction at a place not desired by the operator can be avoided, and automatic reproduction can be performed at an appropriate time at a place desired by the operator.
According to the third aspect, the automatic reproduction once started can be arbitrarily interrupted at a timing desired by the operator. Further, if the automatic reproduction has not started yet, the automatic reproduction can be prevented from starting later.

  According to the fourth aspect, since the switch that outputs an instruction for permitting the automatic reproduction is notified that the automatic reproduction is possible, for the operator, the member that receives the notification and the automatic reproduction permission Are the same switches. For example, since the switch blinks, it is notified that automatic reproduction is possible, so that the operator can simply instruct permission of automatic reproduction by operating the blinking switch.

It is a figure which shows the structure of the exhaust-gas purification apparatus provided in the exhaust system of the diesel engine of the tractor by embodiment of this invention. It is a figure which shows schematic structure of the display apparatus of the tractor by embodiment of this invention. It is a figure showing the transition of a display of a display apparatus, an automatic regeneration permission switch, and a parking regeneration start switch accompanying the change of the accumulation amount of particulate matter in the embodiment of the present invention. It is a figure showing the transition of a display of a display apparatus, an automatic regeneration permission switch, and a parking regeneration start switch accompanying the change of the accumulation amount of particulate matter in the embodiment of the present invention. It is a figure showing the transition of a display of a display apparatus, an automatic regeneration permission switch, and a parking regeneration start switch accompanying the change of the accumulation amount of particulate matter in the embodiment of the present invention. It is a side view of the tractor by the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The working machine of the present invention includes a diesel particulate filter (DPF). Examples of the work machine include a farm work machine such as a tractor and a construction work machine such as a backhoe and a compact truck loader (CTL). In this embodiment, a tractor will be described as an example of a farm work machine.

  As shown in FIG. 6, in the tractor 1, an engine (for example, a diesel engine) 3, a transmission 4 and the like are mounted on a traveling vehicle body 2 having wheels on the front and rear sides. A three-point link mechanism 5 is provided at the rear portion of the traveling vehicle body 2 so as to be movable up and down. Various working devices 6 (in the illustrated example, a tilling device) 6 are detachably attached to the three-point link mechanism 5. Power from the diesel engine 3 is transmitted to the work device 6 through the PTO shaft. In addition, an independently mounted cabin 7 is provided behind the diesel engine 3, and a driver seat 8 is provided in the cabin 7. For example, in front of the driver seat 8 along the traveling direction of the tractor 1. Is provided with a display device 20 for displaying the state of the tractor 1. With such a configuration, the tractor 1 can perform traveling and work by the work device 6.

Here, with reference to FIG. 2, a display device 20 that displays the operating state of the tractor 1, such as a meter and a monitor provided around the driver's seat 8, will be described.
As shown in FIG. 2, the display device 20 includes a liquid crystal panel 201 and an LED display unit 202. The liquid crystal panel 201 disposed at the upper center of the display device 20 toward the paper surface can freely display characters and figures by liquid crystal display, and can freely change the characters and figures to be displayed.

Further, in FIG. 2, an LED display unit 202 is provided below the liquid crystal panel 201. The LED display unit 202 displays detection information detected by each sensor connected to the control unit 60 (engine ECU 61 and main ECU 62), which will be described later, by turning on, turning off, and blinking pictograms and figures by LED elements. .
Specifically, the LED display unit 202 includes an automatic regeneration notification LED display unit 202a that informs the state of automatic regeneration of the DPF, a parking regeneration request LED display unit 202b that requests parking regeneration of the DPF, and a rotation that requests an increase in engine speed. A number increase request LED display unit 202c and a dealer call notification LED display unit 202d for informing that maintenance work is required at a dealer (dealer) are provided.

  In addition to the four LED display units described above, the LED display unit 202 is a warning LED display unit indicating that a certain warning has been issued, a hydraulic LED display unit indicating an engine oil pressure warning, and a battery charge state warning. A battery LED display unit indicating a speed warning, a speed LED display unit indicating a speed warning, an exhaust LED display unit indicating an exhaust temperature warning, and the like. Such an LED display unit 202 can be freely changed in display form not only by turning on, turning off, and blinking, but also by changing lighting time, turn-off time, blinking interval, and brightness at the time of lighting.

  Pictographs and figures indicated by the LED display units 202 in FIG. 2 can also be displayed on the liquid crystal panel 201. If the pictograms and figures of the LED display unit 202 are displayed on the liquid crystal panel 201, non-displayed, inverted display, etc., information equivalent to the LED display unit 202 can be displayed. Therefore, pictograms and figures shown as the LED display unit 202 in the present embodiment may be displayed on the liquid crystal panel 201.

  In the display device 20 illustrated in FIG. 2, pointer-type meters are provided on the left and right sides of the liquid crystal panel 201 and the LED display unit 202 toward the paper surface. A pointer-type engine tachometer that displays the number of revolutions of the diesel engine 3 is provided on the left side of the page, and on the right side, a pointer-type fuel fuel gauge that displays the remaining amount of fuel, and a diesel engine. 3 is a pointer-type water thermometer that displays the temperature of the cooling water.

As shown in FIG. 2, the display device 20 including various display means is housed in a meter hood 30. The meter hood 30 surrounds the periphery of the display device 20, thereby protecting the display device 20 and also serving as a bag for preventing external light from entering the display device 20 and making display content difficult to see.
In the meter hood 30, on the right side of the paper surface, on the right side, an automatic regeneration permission switch 301 for permitting and not permitting the automatic regeneration of the DPF, and a parking regeneration start switch for instructing the start of the parking regeneration of the DPF 302 is provided. The automatic regeneration permission switch 301 and the parking regeneration start switch 302 are button type switches that are switched by being pressed, for example. The functions of the automatic regeneration permission switch 301 and the parking regeneration start switch 302, and the automatic regeneration and parking regeneration of the DPF will be described later.

Then, the structure of the exhaust system of the diesel engine 3 and the diesel engine 3 is demonstrated, referring FIG. In many cases, the diesel engine 3 is a multi-cylinder engine having a plurality of cylinders (cylinders). FIG. 1 shows and describes the configuration of one of the cylinders 40.
As shown in FIG. 1, an intake port 41, which is an opening for introducing air into the cylinder 40, is formed in the upper part of the cylinder 40 of the diesel engine 3, and gas after combustion (combustion gas) is stored in the cylinder. An exhaust port 42, which is an opening for discharging from 40, is formed. Further, an intake valve 43 for opening and closing the intake port 41 and an exhaust valve 44 for opening and closing the exhaust port 42 are provided at the upper portion of the cylinder 40.

  The intake port 41 is connected to a tubular intake manifold 45 serving as a flow path for air introduced into the cylinder 40. The exhaust port 42 is connected to a tubular exhaust manifold 46 that serves as a flow path for combustion gas discharged from the cylinder 40. A silencer 47 for reducing exhaust noise is provided at the end of the exhaust manifold 46, and the combustion gas passes through the silencer 47 and is discharged into the environment.

  In the exhaust manifold 46, an exhaust gas purification device 50 is provided between the exhaust port 42 and the silencer 47. The exhaust gas purification device 50 collects and purifies particulate matter (PM) contained in the passing combustion gas. That is, the combustion gas discharged from the cylinder 40 through the exhaust port 42 passes through the exhaust manifold 46 as exhaust gas, is purified by the exhaust gas purification device 50, and reaches the silencer 47.

  The exhaust gas purification device 50 has a diesel particulate filter (DPF) 13 inside. The DPF 13 is a filter for collecting the particulate matter PM contained in the exhaust gas. For example, the DPF 13 is made of ceramic or metal and has a cross section having a honeycomb structure. In other words, a number of hexagonal column-shaped polygonal through holes are adjacent to each other along the longitudinal direction from one end to the other end of the DPF 13, and each through hole has a predetermined interval along the longitudinal direction of the DPF 13. A porous partition is provided. The DPF 13 having such a honeycomb structure is configured such that the positions of the partition walls formed in the through holes in the longitudinal direction of the DPF 13 are different from the positions of the partition walls formed in the adjacent through holes.

  The exhaust gas that has entered from one end of the DPF 13 flows toward the other end of the DPF 13 while passing through a porous partition formed in the through hole. Particulate matter contained in the exhaust gas is collected and deposited in the DPF 13 by adhering to the porous partition walls or adhering to the inner walls of the through holes. That is, since the DPF 13 has a structure that causes clogging when the amount of the particulate matter deposited increases, the DPF 13 is not appropriately cleaned so that the amount of particulate matter deposition (PM deposition amount) does not increase too much. must not.

In the present embodiment, this cleaning of the DPF 13 is referred to as “DPF regeneration”, and the operation for that purpose is referred to as “DPF regeneration operation”. In the regeneration operation of the DPF 13, by raising the temperature of the DPF 13 to a predetermined temperature or more, the accumulated particulate matter is combusted and gasified, and discharged into the environment together with the exhaust gas.
In addition to the DPF 13, the exhaust gas purification device 50 includes an oxidation catalyst for oxidizing the fuel in the particulate matter and the nitrogen oxide in the combustion gas, although not shown.

  An inlet side pressure sensor 66 that detects the exhaust pressure near the inlet of the exhaust gas cleaner 50 is provided on the inlet side of the exhaust gas cleaner 50, and an outlet pressure sensor that detects the exhaust pressure near the outlet on the outlet side. 67 is provided. The entry-side pressure sensor 66 and the exit-side pressure sensor 67 are general pressure sensors composed of, for example, piezoelectric elements. The inlet side pressure sensor 66 and the outlet side pressure sensor 67 are connected to a differential pressure sensor 69 described below.

  The differential pressure sensor 69 is a difference between the exhaust pressure detected by the inlet pressure sensor 66 and the exhaust pressure detected by the outlet pressure sensor 67, that is, the difference between the exhaust pressure on the inlet side and the outlet side of the exhaust gas purification device 50, that is, Detect differential pressure. In general, when there is no particulate matter accumulated in the DPF 13 and there is no clogging, the pressure loss due to the DPF 13 is very small. Therefore, the difference between the exhaust pressure detected by the inlet pressure sensor 66 and the outlet pressure sensor 67 is small. The differential pressure detected by the differential pressure sensor 69 is also a small value. However, when particulate matter accumulates on the DPF 13 and the degree of clogging increases, the pressure loss due to the DPF 13 increases, so the differential pressure detected by the differential pressure sensor 69 also increases. Since the magnitude of the differential pressure corresponds to the degree of clogging of the DPF 13, the magnitude of the differential pressure can be converted into the degree of clogging of the DPF 13, that is, the amount of PM accumulated in the DPF 13.

  As shown in FIG. 1, the exhaust manifold 46 that connects the diesel engine 3 and the exhaust gas purification device 50 detects the temperature (exhaust temperature) of the combustion gas that is exhausted from the diesel engine 3 and travels toward the exhaust gas purification device 50. An exhaust temperature sensor 68 is provided. The exhaust temperature sensor 68 is composed of, for example, a thermistor. The differential pressure detected by the differential pressure sensor 69 and the exhaust temperature detected by the exhaust temperature sensor 68 are sent to the control unit 60.

The control unit 60 includes a plurality of control devices (ECUs) that control the tractor 1. For example, the control unit 60 includes an engine ECU 61 that controls the diesel engine 3 and a main ECU 62 that controls the operation of the entire tractor 1. doing. The engine ECU 61 and the main ECU 62 are constituted by, for example, a CPU.
The engine ECU 61 obtains information from sensors installed at various locations of the diesel engine 3 and the power transmission system, and calculates the optimum fuel injection amount, injection timing, ignition timing, idle speed, etc. according to the state of the diesel engine 3. The control command is issued to the diesel engine 3 or the like. For example, if a hand accelerator or a foot accelerator provided around the driver's seat 8 is operated (by performing the accelerator operation), the engine ECU 61 detects the operation amount (opening) of the accelerator and changes the fuel injection amount. . In this way, the engine speed of the diesel engine 3 can be increased and decreased.

  The sensors that provide information to the engine ECU 61 include an accelerator opening sensor that detects the accelerator opening, a differential pressure sensor 69 that detects the differential pressure of the exhaust gas purification device 50, an exhaust temperature sensor 68 that detects the exhaust temperature, and intake air. There are an air flow meter for detecting the amount, a crank position sensor for detecting the engine speed, a water temperature sensor for detecting the coolant temperature, a throttle position sensor for detecting the opening of the valve, and the like. In addition to these, there are a cam position sensor for detecting the crank position, an oxygen concentration sensor for detecting the oxygen concentration in the intake air, and the like.

The main ECU 62 controls various devices (traveling device, working device, etc.) provided in the tractor 1 in cooperation with the engine ECU 61. For example, the main ECU 62 performs flow control for supplying hydraulic oil to a hydraulic device that operates a three-point link mechanism.
This flow rate control is performed based on the operation amount of the operation member (operation lever) provided around the driver's seat 8 by the main ECU 62. Specifically, when the operation lever is swung to one side (front side) from the neutral position and a front operation amount is input, the main ECU 62 applies a predetermined current (operation signal) to the solenoid of the electromagnetic proportional valve of the three-point link mechanism. Output. As a result, the electromagnetic proportional valve opens according to the current value, and the pilot pressure of the control valve of the three-point link mechanism is controlled, so that the three-point link mechanism operates in one direction (upward or downward). When the operation lever is swung from the neutral position to the opposite side and the operation amount on the rear side is input, the main ECU 62 operates the three-point link mechanism on the opposite side from when it is swung to the front side. Thus, by operating the operation lever, the tractor 1 can be operated under the control of the main ECU 62.

The main ECU 62 also controls the operation of the entire tractor 1 including the display device 20. Here, the display device 20, the engine ECU 61, and the main ECU 62 are connected to each other via a vehicle communication network such as a controller area network (CAN communication), and can transmit and receive data to and from each other. The vehicle communication network is not particularly limited as long as data can be transmitted and received among the display device 20, the engine ECU 61, and the main ECU 62. For example, it may be FlexRay or another network.

The main ECU 62 in this embodiment has a filter regeneration means 65 for regenerating the DPF 13 of the exhaust gas purification device 50. The filter regeneration unit 65 is realized by a computer program executed by the main ECU 62.
The filter regeneration means 65 shown in FIG. 2 performs automatic regeneration based on the amount of particulate matter deposited on the DPF 13 (PM deposition amount). The filter regeneration unit 65 includes a deposition amount acquisition unit 63 and an automatic regeneration permission unit 70.

The accumulation amount obtaining means 63 receives from the engine ECU 61 the differential pressure of the exhaust gas purifying device 50 (value detected by the differential pressure sensor 69), the exhaust temperature detected by the exhaust temperature sensor 68, the coolant temperature, and the oxygen in the intake air. Information such as concentration and fuel injection amount is obtained, and the amount of particulate matter deposited on the DPF 13 is calculated and acquired.
The automatic regeneration permission unit 70 permits the automatic regeneration by the filter regeneration unit 65 based on an instruction from the outside. Specifically, the automatic regeneration permission unit 70 detects the PM accumulation amount by the accumulation amount acquisition unit 63 and then filters the PM regeneration amount when the automatic regeneration permission switch 301 is pressed when the PM accumulation amount is a predetermined value or more. The automatic reproduction by the reproduction means 65 is switched from non-permission to permission.

  Specifically, the automatic reproduction permission means 70 has an automatic reproduction flag indicating whether automatic reproduction is permitted or not. If the automatic regeneration flag of the automatic regeneration permitting means 70 indicates that automatic regeneration is not permitted, the filter regeneration hand 65 performs automatic regeneration even if the PM accumulation amount of the DPF 13 exceeds a predetermined value (first accumulation amount). Hold without starting. When the PM accumulation amount exceeds the first accumulation amount and the automatic regeneration is suspended, the operator of the tractor 1 presses the automatic regeneration permission switch 301 and the automatic regeneration flag changes from disapproval to permit, filter regeneration. The hand 65 immediately starts automatic reproduction.

  Conversely, if the automatic regeneration flag permits automatic regeneration from the beginning, the filter regeneration hand 65 starts automatic regeneration as soon as the PM accumulation amount of the DPF 13 exceeds the first accumulation amount. The automatic regeneration flag described above always prohibits automatic regeneration when the diesel engine 3 is started, when the control unit 60 is activated, or when the main ECU 62 is activated. However, as described above, the automatic regeneration permission switch When 301 is pressed, switching from non-permission to permission is performed. Further, after the automatic regeneration permission switch 301 is switched to the flag indicating permission, the operator can return to the flag indicating disapproval by pressing the automatic regeneration permission switch 301 again.

When automatic regeneration of the filter regeneration means 65 is permitted (a state where the automatic regeneration flag of the automatic regeneration permission means 70 permits automatic regeneration), the filter regeneration means 65 automatically detects the exhaust temperature in the exhaust gas purifying device 50. Is automatically regenerated to a temperature at which the particulate matter deposited on the DPF 13 burns (for example, 500 ° C. to 600 ° C.).
Specifically, the filter regeneration means 65 increases the load on the diesel engine 3 by, for example, instructing the engine ECU 61 to throttle the intake throttle of the diesel engine 3 as the first regeneration step when the PM accumulation amount exceeds a predetermined value. Control is performed to increase the exhaust temperature (the temperature of the DPF 13) to about 250 ° C. When the first reproduction step is completed, it is confirmed whether or not automatic reproduction is permitted by the input of the automatic reproduction permission switch 301 and the process proceeds to the second reproduction step. That is, the filter regeneration means 65 raises the exhaust gas temperature by about 250 ° C., waits for automatic regeneration permission by the automatic regeneration permission means 70, and proceeds to the second step if the automatic regeneration permission means 70 permits.

In the second regeneration step that is performed when the DPF 13 is equal to or higher than a predetermined temperature (for example, about 250 ° C.), the filter regeneration means 65 performs post-injection of fuel or in-pipe injection to reduce the exhaust temperature (the temperature of the DPF 13). Further, the temperature of the DPF 13 is increased to about 500 ° C. to 600 ° C. The particulate matter deposited on the DPF 13 is combusted (oxidized) by heat of 500 ° C. to 600 ° C. and decreases from the DPF 13. Here, post injection and in-pipe injection are techniques that have been widely used in common rail diesel engines and conventional diesel engines. The diesel engine 3 according to this embodiment is
This is a common rail diesel engine that performs post injection.

That is, in the first regeneration step, when the exhaust temperature (the temperature of the DPF 13) is about 250 ° C. at which the fuel injected into the combustion gas by the post-injection surely burns and the automatic regeneration permission means 70 has permission, The filter regeneration means 65 performs the second regeneration step and performs automatic regeneration.
In the first regeneration step, the filter regeneration means 65 performs control for causing the engine ECU 61 to throttle the intake throttle of the diesel engine 3 for the purpose of raising the exhaust temperature (the temperature of the DPF 13) to about 250 ° C. . The second regeneration step is a control in which the filter regeneration means 65 causes the engine ECU 61 to perform post-injection, and the exhaust temperature (temperature of the DPF 13) increased in the first regeneration step is further increased to increase the temperature of the DPF 13. Is intended to be raised to about 500 ° C. to 600 ° C.

  In this way, the filter regeneration unit 65 causes the tractor to be triggered by exceeding the first accumulation amount if the PM accumulation amount of the DPF 13 acquired by the accumulation amount acquisition unit 63 exceeds a predetermined value (first accumulation amount). The first reproduction step is automatically started regardless of the will of the first operator. After the exhaust temperature reaches about 250 ° C., the second regeneration step is automatically performed if automatic regeneration is permitted. Thus, if the PM accumulation amount of the DPF 13 exceeds a predetermined value (first accumulation amount), the exhaust temperature is automatically raised to 250 ° C. regardless of the will of the operator of the tractor 1 in the first regeneration step. In the second regeneration step in which the exhaust temperature becomes high, the intention of the operator of the tractor 1 is always confirmed by the automatic regeneration permission switch 301.

In other words, in the present invention, the exhaust temperature does not become very high without the operator's awareness, and the exhaust temperature is prevented from becoming very high without the operator's being aware by the automatic regeneration permission means 70 or the like. be able to.
The first accumulation amount is, for example, a value indicating about 40% of the capacity of the DPF 13, and it is not necessary to urgently regenerate the DPF 13, but it is preferable that the first accumulation amount is not exceeded in order to keep the DPF 13 in good condition. .

  In addition, the exhaust temperature may not reach about 250 ° C. only with the throttle of the intake throttle in the first regeneration step. However, if the tractor 1 performs the work with the throttle of the intake throttle maintained in the first regeneration step, The engine speed increases with the contents, and the exhaust temperature rises to about 250 ° C. due to the throttle of the intake throttle and the increase of the engine speed.

  The filter regeneration unit 65 includes a parking regeneration start unit 71 in addition to the automatic regeneration permission unit 70. The parking regeneration start means 71 performs parking regeneration in which regeneration of the DPF 13 is performed when the tractor 1 is parked based on an instruction from the parking regeneration start switch 302. This parking regeneration is performed in a state where the tractor 1 is parked while satisfying a predetermined parking condition (parking regeneration condition) when the PM accumulation amount of the DPF 13 exceeds the second accumulation amount larger than the first accumulation amount. Playback control.

Here, the predetermined parking regeneration condition is a condition indicating that the tractor 1 is surely parked, such as traveling neutrality, idling state of the diesel engine 3, parking brake lock, and PTO switch off.
As described above, the filter regeneration means 65 is configured to perform the first regeneration step when the amount of particulate matter deposited exceeds the first amount of deposition. Here, the filter regeneration means 65 has a function (notification means) for outputting a notification signal indicating that it is necessary to perform automatic regeneration when the accumulation amount of the particulate matter exceeds the first accumulation amount. ing. Specifically, the informing means informs the automatic regeneration informing LED display 202a of permission to execute the second regeneration step if the automatic flag of the automatic regeneration permission means 70 indicates that automatic regeneration is not permitted. (A notification signal indicating that it is necessary to perform automatic regeneration) is output, and the automatic regeneration notification LED display unit 202a blinks. The notification means also outputs a notification signal indicating that it is necessary to perform automatic reproduction to the automatic reproduction permission means 70. If the automatic regeneration permitting unit 70 is in a state where the notification signal is input (during the period when the filter regeneration unit 65 outputs the notification signal) and receives an instruction from the automatic regeneration permission switch 301 to permit execution of automatic regeneration, The filter regeneration means 65 is allowed to perform automatic regeneration.

  When the automatic regeneration notification LED display unit 202a is informed and the operator depresses the automatic regeneration permission switch 301 and outputs a signal for permitting automatic regeneration of the DPF 13, the automatic regeneration permission means 70 performs automatic regeneration. The automatic regeneration flag that is not permitted is switched to an automatic regeneration flag that indicates that automatic regeneration is permitted. When the filter regeneration means 65 refers to the automatic regeneration flag of the automatic regeneration permission means 70 and detects that automatic regeneration is permitted, the filter regeneration means 65 executes the suspended second regeneration step.

  In the present embodiment, the automatic regeneration permitting means 70 has a flag that always prohibits automatic regeneration when the filter regeneration means 65 is activated. That is, when the control unit 60 is activated and the diesel engine 3 is started, the automatic regeneration is not permitted by the automatic regeneration permission means 70. In this way, by automatically disabling automatic regeneration when the diesel engine 3 is started, automatic regeneration will not start unless the operator permits it. As a result, it is possible to avoid that the automatic regeneration starts without the operator's knowledge and the exhaust temperature becomes very high.

  The informing means is not limited to the automatic regeneration described above, but also indicates that it is necessary to perform the parking regeneration when the particulate matter accumulation amount exceeds the second accumulation amount even in the parking regeneration performed by the filter regeneration means 65. Output a signal. Specifically, the notification means outputs a signal (notification) indicating that it is necessary to perform parking regeneration on the parking regeneration request LED display unit 202b when the accumulation amount of the particulate matter exceeds the second accumulation amount. To do. The notifying means for notifying that it is necessary to perform automatic regeneration or parking regeneration outputs a signal to the rotation speed increase request LED display 202c even when the exhaust temperature does not rise sufficiently and is lower than 250 ° C. And request to increase the engine speed.

  When the parking regeneration request LED display unit 202b is informed, the operator satisfies the parking conditions of the tractor 1 such as driving neutrality, idling state of the diesel engine 3, parking brake lock, and PTO switch off. Then, when the operator depresses the parking regeneration start switch 302 and outputs a signal permitting the parking regeneration of the DPF 13, the parking regeneration starting means 71 notifies the filter regeneration means 65 that the parking regeneration is started. To do.

  The filter regeneration means 65 that has received the notification starts from the first regeneration step if the acquired exhaust temperature is lower than a predetermined temperature (for example, 250 ° C.), and starts from the second regeneration step if the acquired exhaust temperature is equal to or higher than the predetermined temperature. The DPF 13 is regenerated. Thus, the parking regeneration of the DPF 13 is instructed to start by the operator only when the PM accumulation amount of the DPF 13 exceeds the second accumulation amount.

  As described above, the regeneration of the DPF 13 according to the present embodiment is characterized in that automatic regeneration is not started unless permitted by the automatic regeneration permission means 70. As already described, the regeneration of the DPF 13 according to this embodiment is performed by the diesel engine 3 of the tractor 1, the control unit 60, the display device 20, the automatic regeneration permission switch 301 and the parking regeneration start switch 302 provided around the display device 20. Further, it is realized by an instruction from the operator via the automatic regeneration permission switch 301 and the parking regeneration start switch 302.

  Accordingly, automatic regeneration and parking regeneration in the present embodiment will be described in detail with reference to FIGS. 3 to 5 show the process of regenerating the DPF 13 according to the present embodiment. The automatic regeneration notification LED display section 202a, the parking regeneration request LED display section 202b, the rotation speed increase request LED display section 202c, and the dealer call notification LED display section 202d. It is a figure explaining in the state of the automatic reproduction | regeneration permission switch 301 and the parking reproduction start switch 302. FIG.

FIG. 3 shows a case where the PM accumulation amount gradually increases immediately after the start of the diesel engine 3. Immediately after starting the diesel engine 3, it is assumed that the PM accumulation amount of the DPF 13 is less than the first accumulation amount (level 0) that does not require regeneration of the DPF 13. Here, the first accumulation amount means about 40% of the capacity of the DPF 13 as described above.
Case C1 shown in FIG. 3 shows an initial state immediately after the engine is started. Immediately after the engine is started, the automatic regeneration permission means 70 does not permit automatic regeneration as an initial state, and the automatic regeneration permission switch 301 is turned off. Further, the PM accumulation amount is less than the first accumulation amount, and the parking regeneration start switch 302 is also turned off. In addition, the automatic regeneration notification LED display unit 202a, the parking regeneration request LED display unit 202b, the rotation speed increase request LED display unit 202c, and the dealer call notification LED display unit 202d are also turned off because the PM accumulation amount is less than the first accumulation amount. doing.

3 to 5, each switch and LED display unit represents a light-off state in gray scale and a blinking state by surrounding it with a broken line. In addition, the lighting state is surrounded by a solid line and written in black.
After starting the diesel engine 3, for example, when the tractor 1 enters a hay or a livestock shed and the operator does not want automatic regeneration to start regardless of his / her will, the operator presses the automatic regeneration permission switch 301. Otherwise, the automatic regeneration is not permitted (prohibited) in the automatic regeneration permitting means 70, and neither the switch nor the LED display unit is lit or blinked as shown in case C2.

  However, when it is determined that the automatic regeneration can be started regardless of the will of the operator, such as when working on a safe cultivated land, if the operator presses the automatic regeneration permission switch 301, the case C3 is shown. As described above, the automatic regeneration permission switch 301 changes from turning off to lighting, and can output a permission signal for permitting automatic regeneration to the automatic regeneration permission means 70 in advance even if the PM accumulation amount is less than the first accumulation amount. Based on the output permission signal, the automatic regeneration permission means 70 switches the automatic regeneration flag that prohibits automatic regeneration to a flag indicating permission. The filter regeneration means 65 can perform automatic regeneration when the PM accumulation amount increases to be equal to or more than the first accumulation amount and the DPF needs to be regenerated.

  Now, when the operation of the tractor 1 starts and the PM accumulation amount of the DPF 13 exceeds the first accumulation amount, when the regeneration control becomes level 1, the automatic regeneration permission switch 301 is not depressed as shown in case C4. However, the automatic regeneration notification LED display 202a blinks. The blinking of the automatic regeneration notification LED display unit 202a indicates that the second regeneration step of automatic regeneration is not executed or that automatic regeneration is not permitted. When the PM accumulation amount reaches level 1, the filter regeneration means 65 starts a first regeneration step for reducing the intake throttle of the diesel engine 3 in order to increase the exhaust temperature to about 250 ° C.

At this time, when the operator recognizes that the automatic regeneration notification LED display unit 202a is blinking and presses the automatic regeneration permission switch 301, or the operator has already performed automatic regeneration permission switch 301 at level 0. When is pressed, the display shown in any of cases C5 to C7 is made.
First, Case C5 shows a case where the PM accumulation amount exceeds the first accumulation amount and the exhaust temperature has not risen sufficiently (up to about 250 ° C.) even though the automatic regeneration permission switch 301 is pressed. ing. In case C5, the pressed automatic regeneration permission switch 301 is turned on, the automatic regeneration notification LED display 202a indicating that the second regeneration step is not executed blinks, and in addition, the engine rotation is performed to increase the exhaust temperature. The rotation speed increase request LED display section 202c that prompts the number to increase is blinking.

The filter regeneration means 65 starts the first regeneration step when the PM accumulation amount reaches level 1, but the exhaust temperature does not necessarily rise in a short time just by reducing the intake throttle. A case like the case C5 in which the increase of the engine speed is requested by the notification means that has been performed may occur.
Here, if the automatic regeneration permission switch 301 is pressed again to prohibit automatic regeneration, the display of the case C5 returns to the case C4.

  Next, the case C6 shows a case where the operator receives the request in the case C5 and operates the hand accelerator or the foot accelerator of the tractor 1 to increase the engine speed to a predetermined speed or more. In case C6, the exhaust temperature has not yet increased sufficiently (up to about 250 ° C.), but since the engine speed is equal to or higher than the predetermined speed, the exhaust temperature increases with time, so the engine speed increases. The request LED display unit 202c is turned off.

However, if the engine speed becomes less than the predetermined speed before the exhaust temperature rises sufficiently (to about 250 ° C.), the exhaust temperature does not rise until the second regeneration step can be performed. The display returns to case C5.
Next, Case C7 shows a case where the filter regeneration means 65 filter regeneration control means starts the second regeneration step after the exhaust temperature has risen sufficiently. In case C7, post-injection is performed by performing the second regeneration step. Therefore, post-injection is performed by changing the automatic regeneration notification LED display unit 202a blinking in case C6 to lighting. Inform the operator.

  In this way, at level 1, the blinking of the automatic regeneration notification LED display unit 202a provides very important information for the operator, and shows two states depending on whether the automatic regeneration permission switch 301 is turned on or off. . The first is a case where the automatic regeneration permission switch 301 is turned off, and automatic regeneration is not permitted, but indicates that the PM accumulation amount has increased to a level where automatic regeneration is necessary. The second is the case where the automatic regeneration permission switch 301 is lit, and automatic regeneration is permitted, but the second regeneration step has not yet been executed and the exhaust temperature has not become high. Show.

  Further, at level 1, even after the automatic regeneration permission switch 301 is turned on and automatic regeneration is permitted, the operator depresses the automatic regeneration permission switch 301 to turn off the automatic regeneration permission switch 301 and perform automatic regeneration. Can be disallowed again. That is, the automatic regeneration permission switch 301 outputs an instruction for permitting the execution of automatic regeneration and an instruction for disallowing the permitted automatic regeneration. Even if the second regeneration step has already been performed and the DPF 13 and the exhaust gas are very hot, the second regeneration step is stopped by disabling automatic regeneration again, and the temperatures of the DPF 13 and the exhaust gas are reduced. Can be reduced. After the temperatures of the DPF 13 and the exhaust gas are sufficiently lowered, the operator can enter the tractor 1 into a hay or a livestock shed.

  However, if automatic regeneration is not permitted at level 1, or if particulate matter is not sufficiently burned by automatic regeneration, the PM deposition amount further increases. In this case, when the accumulation amount acquisition unit 63 of the filter regeneration unit 65 detects that the PM accumulation amount of the DPF 13 exceeds the second accumulation amount (for example, 60% of the capacity of the DPF 13), the regeneration of the DPF by the filter regeneration unit 65 is performed. Control passes to level 2.

As shown in FIG. 4, at level 2, the filter regeneration means 65 lights up the parking regeneration request LED display unit 202b that informs that the amount of PM accumulation that needs to be reconstructed.
In the parking regeneration, the engine speed is forcibly increased in order to raise the exhaust temperature. Therefore, the tractor 1 must be surely parked in order to perform the parking regeneration. The conditions for confirming that the tractor 1 is parked are, as described above, parking conditions such as neutral driving, idling state of the diesel engine 3, parking brake lock, PTO switch off, etc. (hereinafter referred to as parking regeneration conditions). It is.

At level 2, when the parking regeneration condition is set, the parking regeneration start switch 302 can be pressed to instruct the filter regeneration means 65 to start parking regeneration.
In the case C8, the parking regeneration request LED display unit 202b for notifying that the PM accumulation amount exceeds the second accumulation amount and is the PM accumulation amount that requires parking regeneration is lit. This is a case where the parking reproduction start switch 302 is turned off because it is not arranged. That is, the parking regeneration is necessary, but the parking regeneration cannot be started because the parking regeneration start switch 302 is turned off.

Next, when the parking regeneration conditions are adjusted, as shown in case C9, in addition to the parking regeneration request LED display unit 202b being lit, the parking regeneration start switch 302 blinks and the parking regeneration conditions are in place and the parking regeneration is complete. Is now possible.
Here, when the operator presses the parking regeneration start switch 302, the parking regeneration start switch 302 changes from blinking to lighting as shown in case C10. When the parking regeneration start switch 302 is pressed, the filter regeneration means 65 is instructed to start parking regeneration, and the filter regeneration means 65 that receives the instruction starts parking regeneration. When parking regeneration starts, the parking regeneration request LED display unit 202b is turned off.

As shown in FIG. 4, at level 2, there is a slight allowance in the amount of accumulated PM as compared to the collection capacity of the DPF 13, so it is not always necessary to regenerate the DPF 13 by parking regeneration. Level 2 is a level at which both automatic regeneration and parking regeneration are possible, and the operator can appropriately determine which one to implement.
Subsequently, the PM accumulation amount of the DPF 13 further increases, and the accumulation amount acquisition unit 63 of the filter regeneration unit 65 detects that the PM accumulation amount of the DPF 13 exceeds the third accumulation amount (for example, 80% of the capacity of the DPF 13). Then, DPF regeneration control by the filter regeneration means 65 shifts to level 3.

  At level 3, as shown in cases C12 and C13, the filter regeneration means 65 strongly requests the operator to perform parking regeneration by blinking the parking regeneration request LED display unit 202b. Further, the filter regeneration means 65 causes the dealer call notification LED display unit 202d to blink, so that the PM accumulation amount increases so that the DPF 13 cannot be regenerated unless the parking regeneration is performed at this level 3. Notify the operator that work is required.

At level 3, the filter regeneration means 65 turns off the automatic regeneration permission switch 301 and disallows automatic regeneration. Thereafter, even if the automatic regeneration permission switch 301 is pressed to instruct the filter regeneration means to permit automatic regeneration, the filter regeneration means does not accept the permission instruction.
At this time, the filter regeneration means 65 performs the display shown in case C12 if the operator does not adjust the parking regeneration condition, and blinks the parking regeneration start switch 302 as illustrated in case C13 if the parking regeneration condition is adjusted.

  When the operator receives the display of case C13 and presses the parking regeneration start switch 302, the parking regeneration start switch 302 changes from blinking to lighting as shown in case C14. When the parking regeneration start switch 302 is pressed, the filter regeneration means 65 is instructed to start parking regeneration, and the filter regeneration means 65 that receives the instruction starts parking regeneration. When parking regeneration starts, the parking regeneration request LED display unit 202b is turned off. When the post-injection by the execution of the second regeneration step is started in the case C14, the filter regeneration unit 65 lights the automatic regeneration notification LED display unit 202a to notify the operator that the post-injection is being performed.

At level 3, since the operator did not perform parking regeneration, the PM accumulation amount of the DPF 13 further increased, and the accumulation amount acquisition means 63 of the filter regeneration means 65 caused the PM accumulation amount of the DPF 13 to become the fourth accumulation amount (for example, When it is detected that the capacity exceeds 95% of the capacity of the DPF 13, the DPF regeneration control by the filter regeneration means 65 shifts to level 4.
At level 4, the DPF 13 cannot be regenerated by the filter regenerating means 65. Therefore, the filter regeneration means 65 requests the operator to perform maintenance work by changing the dealer call notification LED display unit 202d from blinking to lighting. Therefore, at level 4, the filter regeneration means 65 performs the display shown in case C15.

  At level 4, no maintenance work is performed, the PM accumulation amount of the DPF 13 increases to the upper limit of the collection capacity, the accumulation amount acquisition means 63 of the filter regeneration means 65, and the PM accumulation amount of the DPF 13 becomes the fifth accumulation amount (for example, DPF13). 99), the DPF regeneration control by the filter regeneration means 65 shifts to level 5. At level 5, the filter regeneration means 65 performs the display shown in case C16 similar to case C15. At level 5, the DPF 13 needs to be replaced, but the filter regeneration means 65 displays a message requesting the replacement of the DPF 13 on the liquid crystal panel 201 of the display device 20 as character information or the like.

  In the tractor 1 according to the present embodiment, the regeneration control of level 1 to level 5 as described above is performed by the filter regeneration means 65. The tractor 1 according to the present embodiment is particularly characterized in the level 1-2 playback control among such playback controls. The filter regeneration means 65 always prohibits automatic regeneration when the diesel engine 3 is started, and permits automatic regeneration in accordance with an operator's instruction at levels 1-2.

In this way, if automatic regeneration is not permitted when the diesel engine 3 is started, automatic regeneration will not start unless the operator permits it. As a result, it is possible to prevent the exhaust gas temperature from becoming very high due to the automatic regeneration being started without the operator's knowledge.
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  In the above embodiment, the filter regeneration means 65 outputs the notification signal for notifying the necessity of automatic regeneration to the automatic regeneration notification LED display unit 202a, but outputs the notification signal to the automatic regeneration permission switch 301. May be. If the automatic regeneration permission switch 301 has a light source such as an LED, it is necessary to perform automatic regeneration based on the notification signal output from the filter regeneration means 65, similarly to the automatic regeneration notification LED display unit 202a. It can be notified that there is.

In addition, the automatic regeneration in the above-described embodiment has been described by taking “intake throttle throttle” as an example, but automatic regeneration is not limited to “intake throttle throttle”, and automatic regeneration of DPF regeneration by fuel post-injection You may add to. Post-injection is an operation that promotes the temperature rise of the DPF 13 by injecting fuel into the gas after combustion.
Furthermore, the regeneration control described in the present embodiment can be applied not only to the tractor 1 but also to construction machines and agricultural machines that perform operations such as a compact truck loader (CTL) and a tractor.

DESCRIPTION OF SYMBOLS 1 Tractor 2 Traveling vehicle body 3 Diesel engine 4 Transmission 5 Three-point link mechanism 6 Working device 7 Cabin 8 Driver's seat 13 DPF
DESCRIPTION OF SYMBOLS 20 Display apparatus 40 Cylinder 41 Intake port 42 Exhaust port 43 Intake valve 44 Exhaust valve 45 Intake manifold 46 Exhaust manifold 47 Silencer 50 Exhaust gas purification apparatus 60 Control part 61 Engine ECU
62 Main ECU
63 Accumulation amount acquisition means 65 Filter regeneration means 66 Inlet pressure sensor 67 Outlet pressure sensor 68 Exhaust temperature sensor 69 Differential pressure sensor 70 Automatic regeneration permission means 71 Parking regeneration start means 201 Liquid crystal panel 202 LED display unit 202a Automatic regeneration notification LED display Section 202b Parking regeneration request LED display section 202c Speed increase request LED display section 202d Dealer call notification LED display section 301 Automatic regeneration permission switch 302 Parking regeneration start switch

Claims (4)

Diesel engine, exhaust gas purification device having a filter for collecting particulate matter contained in exhaust gas exhausted from the diesel engine, and the amount of particulate matter deposited on the filter of the exhaust gas purification device A filter regeneration means for performing automatic regeneration for automatically burning and removing the particulate matter when the amount exceeds a predetermined value,
The filter regeneration means has an automatic regeneration permission means for permitting execution of the automatic regeneration according to an instruction from the outside, and the automatic regeneration permission means prohibits the execution of the automatic regeneration at the time of activation. A working machine that features. An automatic regeneration permission switch for outputting an instruction for permitting the execution of the automatic regeneration;
The filter regeneration means outputs a notification signal indicating that the automatic regeneration needs to be performed when the amount of particulate matter deposited exceeds the predetermined value,
When the automatic regeneration permission means receives an instruction to permit the automatic regeneration from the automatic regeneration permission switch while the filter regeneration means is outputting the notification signal, the automatic regeneration permission means The work machine according to claim 1, wherein execution of automatic regeneration is permitted.   3. The automatic regeneration permission switch outputs an instruction for permitting the execution of automatic regeneration and outputs an instruction for disabling the permitted automatic regeneration. The working machine described.   The filter regeneration means outputs the notification signal to the permission switch, and the automatic regeneration permission switch notifies that it is necessary to perform the automatic regeneration based on the output notification signal. The working machine according to claim 3.