JP5795951B2 - Working machine - Google Patents

Description

  The present invention relates to a work machine such as a backhoe, a wheel loader, and a tractor 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. In work machines such as construction machines and agricultural machines, various techniques for reducing particulate matter (particulate matter) contained in exhaust gas have been developed in order to cope with strict 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 gradually accumulates in the DPF of the exhaust gas purification device, the particulate matter is appropriately removed to prevent the DPF from becoming clogged and increasing the air resistance of the exhaust system. I have to play it.

As a technique related to regeneration of such DPF, there is an exhaust gas purification filter regeneration device disclosed in Patent Document 1.
An exhaust gas purification filter regeneration device disclosed in Patent Document 1 regenerates an exhaust gas purification filter provided in an exhaust passage of an engine that drives a hydraulic pump for supplying hydraulic oil to a working hydraulic device via a hydraulic circuit. In the apparatus, a load oil passage connected to the hydraulic circuit, a filter regeneration load disposed in the load oil passage and for applying a load to the hydraulic pump, and the load oil during regeneration of the exhaust gas purification filter An oil passage opening / closing means for flowing hydraulic oil from the hydraulic pump to the passage and the filter regeneration load; and disposed in the load oil passage and operated by the pressure of the hydraulic oil from the hydraulic pump when the exhaust gas purification filter is regenerated. Hydraulic operation means for operating the fuel injection amount adjustment lever of the engine, and the oil passage for load by the oil passage opening and closing means when the exhaust gas purification filter is regenerated. And the flow of hydraulic oil from the hydraulic pump to the filter regeneration load increases the load on the engine by increasing the load on the hydraulic pump, and the fuel injection amount adjusting lever is operated by the hydraulic operating means. It is what.

JP 2005-337062 A

Patent Document 1 intends to regenerate the DPF by increasing the engine load while preventing fluctuations in the engine speed and, as a result, increasing the temperature of the exhaust gas, when it is determined that the DPF needs to be regenerated. Technology.
However, a slight increase in engine load as in Patent Document 1 causes a problem that the temperature of the exhaust gas cannot be increased to a temperature necessary for regenerating the DPF. As a result, not only cannot the DPF be regenerated, but there is also a problem that the fuel consumption is increased.

  Therefore, the present invention is an operation that can require the worker to increase the rotational speed of the diesel engine at an appropriate time in order to increase the temperature of the exhaust gas to a temperature necessary for regeneration of the DPF. The purpose is to provide a machine.

In order to achieve the above object, the present invention has taken the following measures.
That is, the working machine of the invention according to claim 1 includes a diesel engine capable of increasing the rotational speed by an accelerator operation, and a filter that collects particulate matter contained in exhaust gas discharged from the diesel engine. And a filter regeneration means for burning and removing particulate matter deposited on the filter of the exhaust gas purification apparatus, wherein the filter regeneration means is a temperature of the exhaust gas. automatically have rows AutoPlay by burning the particulate matter deposited in the filter is removed by raising the during automatic playback, the diesel engine the accelerator to the rotational speed to increase by the accelerator operation by the It is characterized by requesting the operator who performs the operation .

Working machine of the invention according to claim 2, wherein the filter regeneration means, in a state in which the automatic regeneration is being performed, and when the temperature indicator of the diesel engine is equal to or less than the first temperature, the rotational speed of the diesel engine The operator who performs the accelerator operation is requested to be raised by the accelerator operation .
According to a third aspect of the present invention, the filter regeneration means is in a state where the request is made and the temperature index related to the diesel engine is equal to or higher than the second temperature higher than the first temperature for a predetermined time or longer. Further, the request is stopped.

Working machine of the invention according to claim 4, wherein the filter regeneration means, in a state in which the automatic regeneration is being performed, and when the deposition amount of the particulate matter becomes first deposit amount or more, the diesel A feature is that the operator who performs the accelerator operation is requested to increase the engine speed by the accelerator operation .
In the working machine of the invention according to claim 5, in the state where the request is made, the filter regeneration unit has a deposition amount of the particulate matter that is less than a second deposition amount smaller than the first deposition amount. Sometimes, the request is stopped.

  The working machine of the invention according to claim 6 is characterized in that the temperature index is at least one of an intake air temperature, an exhaust gas temperature, and a cooling water temperature of the diesel engine.

According to the first aspect, it is possible to request the worker to increase the rotational speed of the diesel engine during the automatic regeneration period that is performed regardless of the operation of the worker. When the operator increases the engine speed in accordance with this requirement, the exhaust temperature of the diesel engine increases, so that combustion of particulate matter in the filter can be promoted to assist automatic regeneration.
According to the second aspect, when the temperature index related to the diesel engine is low, that is, when the effect of the automatic regeneration cannot be sufficiently expected, it is possible to request the worker to increase the rotational speed of the diesel engine. When the operator increases the engine speed in accordance with this request, the temperature index of the diesel engine increases, so that combustion of particulate matter in the filter can be promoted to assist automatic regeneration.

  According to claim 3, when the temperature index of the diesel engine that is the basis for calculating the PM accumulation amount is maintained at a predetermined temperature or higher for a certain period of time, and it is considered that automatic regeneration (combustion of particulate matter) is proceeding, The request to increase the rotational speed of the diesel engine can be stopped. That is, the operation of increasing the rotational speed of the diesel engine can be terminated at an appropriate time when automatic regeneration is progressing.

  According to the fourth aspect, when the amount of accumulated PM is large during the automatic regeneration period, the operator is requested to increase the rotational speed of the diesel engine. That is, when the effect of automatic regeneration is not sufficiently exhibited, it can be requested to increase the rotational speed of the diesel engine at an appropriate timing. When the operator increases the engine speed in accordance with this requirement, the exhaust temperature of the diesel engine increases, so that combustion of particulate matter in the filter can be promoted to assist automatic regeneration.

According to the fifth aspect, when the PM accumulation amount becomes smaller than the time when the request for increasing the rotational speed of the diesel engine is started, the request for increasing the rotational speed of the diesel engine is stopped. That is, when the automatic regeneration proceeds and the amount of accumulated PM is reliably reduced, the request for increasing the rotational speed can be appropriately stopped.
According to the sixth aspect, it is possible to make a request for an increase in the rotational speed by using a temperature index related to the calculation of the PM deposition amount, and at an appropriate timing according to the increase / decrease in the PM deposition amount easily and accurately. An increase in the rotational speed of the diesel engine can be requested and stopped.

It is a figure which shows the structure of the exhaust-gas purification apparatus provided in the exhaust system of the diesel engine provided in the backhoe by embodiment of this invention, a control part, and a display apparatus. It is a graph showing an example of the time change of the exhaust gas temperature with respect to operation time in 1st Embodiment of this invention. It is a figure which shows the display mode of the display apparatus in 1st Embodiment of this invention. It is a graph showing an example of the change of the deposition amount (PM deposition amount) of the particulate matter with respect to operation time in 2nd Embodiment of this invention. It is a side view of the backhoe by embodiment of this invention.

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

FIG. 5 is a side view showing a schematic configuration of the backhoe 1. As shown in FIG. 5, the backhoe 1 includes a lower traveling device 2 and an upper rotating body 3.
The traveling device 2 is a crawler traveling device including a pair of left and right traveling bodies 4 each having a rubber cover. The traveling device 2 is provided with a hydraulic motor that causes the crawler to travel using hydraulic pressure obtained from a hydraulic pump that operates with the output of the diesel engine 9, and a dozer 5 is provided at the front.

  The swivel body 3 includes a swivel base 7 supported on the traveling device 2 via a swivel bearing 6 so as to be turnable left and right about a swivel axis in the vertical direction, and a work device 8 (excavation) provided at the front of the swivel base 7 Device). On the swivel base 7, a diesel engine 9, a radiator, a driver's seat 10, a fuel tank, a hydraulic oil tank, a control valve for controlling hydraulic oil from the hydraulic oil tank, and the like are provided. Around the driver's seat 10, a display device 11 that displays various information about the backhoe 1 is provided. The driver's seat 10 is surrounded by a cabin 12 provided on the turntable 7.

  The work device 8 includes a swing bracket 14 supported by a support bracket 13 provided at the front portion of the swivel base 7 so as to be swingable left and right, and a boom having a base side supported by the swing bracket 14 so as to be swingable up and down. 15. An arm 16 is supported on the front end side of the boom 15 so as to be swingable back and forth, and a bucket 17 is provided on the front end side of the arm 16 so that a squeeze / dump operation can be performed.

  The swing bracket 14 swings due to the expansion and contraction of a swing cylinder provided in the swivel base 12. The boom 15 swings by expansion and contraction of a boom cylinder 18 provided between the boom 15 and the swing bracket 14. The arm 16 swings due to expansion and contraction of an arm cylinder 19 provided between the arm 16 and the boom 15. The bucket 17 performs a squeeze / dump operation by expansion and contraction of a bucket cylinder 20 provided between the bucket 17 and the arm 16.

Each of the swing cylinder, the boom cylinder 18, the arm cylinder 19, and the bucket cylinder 20 is configured to expand and contract with hydraulic oil whose flow rate is controlled by a control valve.
Here, the display device 11 provided around the driver's seat 10 will be described with reference to FIG.

  As shown in FIG. 1, the display device 11 includes a liquid crystal panel 112 and an LED display unit 113. The liquid crystal panel 112 can freely display characters and figures by liquid crystal display, and can freely change the characters and figures to be displayed. For example, in FIG. 1, on the left side of the liquid crystal panel 112, a fuel gauge showing the remaining amount of fuel in a bar graph gauge is displayed, and the length of the gauge, that is, the length of the bar graph corresponds to the remaining amount of fuel. doing. In addition, a water temperature gauge indicating the coolant temperature with a gauge is displayed on the right side of the liquid crystal panel, and a cursor indicating the current water temperature moves up and down according to the water temperature.

Further, in FIG. 1, in the central portion of the liquid crystal panel 112, an icon A indicating that automatic regeneration of the DPF is performed and character information for calling attention regarding the regeneration of the DPF, for example, “DPF is being regenerated” or “exhaust” “Temperature rise” is displayed. The type of information displayed on the liquid crystal panel 112 and the selection of display forms such as graphics and characters are arbitrary.
The LED display unit 113 displays detection information detected by each sensor connected to a control unit 46 (engine ECU 32 and main ECU 33), which will be described later, by turning on, turning off, and blinking LED elements. Specifically, as the LED display unit 113, a warning LED display unit 113a indicating that some warning has been issued, a hydraulic LED display unit 113b indicating a warning about engine oil pressure, and a battery LED display showing a warning about the state of charge of the battery 113c, a speed LED display 113d indicating a speed warning, an exhaust LED display indicating a warning about the exhaust temperature, and the like. The LED display unit 113 can freely change the display form by changing not only lighting, extinguishing, and blinking but also lighting time, extinguishing time, blinking interval, and lighting brightness.

As described above, FIG. 1 shows the display device 11 including the liquid crystal panel 112, but the display device 11 is limited to the one that displays using the liquid crystal panel 112 as long as the display can be performed. Not.
FIG. 1 is a diagram showing the structure of the diesel engine 9 and the exhaust system of the diesel engine 9. First, the exhaust system of the diesel engine 9 will be described. Although the diesel engine 9 is often a multi-cylinder engine having a plurality of cylinders (cylinders), FIG. 1 shows and describes the configuration of one of the cylinders 34.

  As shown in FIG. 1, the diesel engine 9 supplies power to various devices such as a hydraulic motor and a hydraulic pump mounted on the backhoe 1, for example. An intake port 35, which is an opening for introducing air into the cylinder 34, is formed in the upper part of the cylinder 34 of the diesel engine 9, and an opening for discharging the gas after combustion (combustion gas) from the cylinder 34. An exhaust port 36 is formed. Further, an intake valve 37 for opening and closing the intake port 35 and an exhaust valve 38 for opening and closing the exhaust port 36 are provided at the upper portion of the cylinder 34.

  The intake port 35 is connected to a tubular intake manifold 39 that serves as a flow path for air introduced into the cylinder 34. The exhaust port 36 is connected to a tubular exhaust manifold 30 serving as a flow path for combustion gas discharged from the cylinder 34. A silencer 40 for reducing exhaust noise is provided at the end of the exhaust manifold 30, and the combustion gas passes through the silencer 40 and is discharged into the environment.

  In the exhaust manifold 30, an exhaust gas purification device 31 is provided between the exhaust port 36 and the silencer 40. The exhaust gas purifying device 31 purifies the combustion gas and collects particulate matter (PM) contained in the passing combustion gas. That is, the combustion gas containing particulate matter discharged from the cylinder 34 through the exhaust port 36 passes through the exhaust manifold 30 as exhaust gas, is purified by the exhaust gas purification device 31, and reaches the silencer 40.

  This exhaust gas purification device 31 has a diesel particulate filter (DPF) 41 inside. The DPF 41 is a filter for collecting the particulate matter PM contained in the combustion gas. For example, the DPF 41 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 41, and each through hole has a predetermined interval along the longitudinal direction of the DPF 41. A porous partition is provided. The DPF 41 having such a honeycomb structure is configured such that the position of the partition wall formed in the through hole in the longitudinal direction of the DPF 41 is different from the position of the partition wall formed in the adjacent through hole.

  The exhaust gas that has entered from one end of the DPF 41 flows toward the other end of the DPF 41 while passing through a porous partition formed in the through hole. Particulate matter contained in the exhaust gas is collected and deposited on the DPF 41 by adhering to the porous partition walls or adhering to the inner walls of the through holes. In other words, the DPF 41 has a structure that causes clogging when the amount of accumulated particulate matter increases. Therefore, the DPF 41 is not appropriately cleaned so that the amount of particulate matter deposited (PM deposition amount) does not increase too much. must not.

In the present embodiment, this cleaning of the DPF 41 is referred to as “DPF regeneration”, and the operation for that purpose is referred to as “DPF regeneration operation”. In the regeneration of the DPF 41, the particulate matter deposited by burning the DPF 41 to a predetermined temperature or higher is combusted and gasified, and discharged into the environment together with the exhaust gas.
In addition to the DPF 41, the exhaust gas purification device 31 has 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 42 that detects the exhaust pressure near the inlet of the exhaust gas cleaner 31 is provided on the inlet side of the exhaust gas cleaner 31, and an outlet pressure sensor that detects the exhaust pressure near the outlet on the outlet side. 43 is provided. The entry-side pressure sensor 42 and the exit-side pressure sensor 43 are general pressure sensors composed of, for example, piezoelectric elements. The inlet side pressure sensor 42 and the outlet side pressure sensor 43 are connected to a differential pressure sensor 44 described below.

  The differential pressure sensor 44 determines the difference between the exhaust pressure detected by the inlet pressure sensor 42 and the exhaust pressure detected by the outlet pressure sensor 43, that is, the difference between the exhaust pressure on the inlet side and the outlet side of the exhaust gas purification device 31. Detect differential pressure. In general, when there is no particulate matter accumulation in the DPF 41 and no clogging, the pressure loss due to the DPF 41 is very small, so the difference between the exhaust pressure detected by the inlet pressure sensor 42 and the outlet pressure sensor 43 is small. The differential pressure detected by the differential pressure sensor 44 is also a small value. However, when particulate matter accumulates on the DPF 41 and the degree of clogging increases, the pressure loss due to the DPF 41 increases, so the differential pressure detected by the differential pressure sensor 44 also increases. Since the magnitude of the differential pressure corresponds to the degree of clogging of the DPF 41, the magnitude of the differential pressure can be converted into the degree of clogging of the DPF 41, that is, the amount of accumulated PM in the DPF 41.

  As shown in FIG. 1, the exhaust manifold 30 that connects the diesel engine 9 and the exhaust gas purification device 31 detects the temperature (exhaust temperature) of the combustion gas that is exhausted from the diesel engine 9 and travels toward the exhaust gas purification device 31. An exhaust temperature sensor 45 is provided. The exhaust temperature sensor 45 is composed of, for example, a thermistor. The differential pressure detected by the differential pressure sensor 44 as described above and the exhaust temperature detected by the exhaust temperature sensor 45 are sent to the control unit 46.

The control unit 46 controls the backhoe 1 and includes one or a plurality of control devices (ECUs). For example, the engine ECU 32 that controls the diesel engine 9 and the operation of the entire backhoe 1 are controlled. And a main ECU 33 to be controlled. The engine ECU 32 and the main ECU 33 are constituted by a CPU, for example.
The engine ECU 32 obtains information from sensors installed at various locations of the diesel engine 9 and the power transmission system, and calculates the optimal fuel injection amount, injection timing, ignition timing, idle speed, etc. according to the state of the diesel engine 9. The control command is issued to the diesel engine 9 or the like. For example, if an accelerator (accelerator lever) provided around the driver's seat 10 is operated (by operating the accelerator), the engine ECU detects the accelerator operation amount (opening) and increases or decreases the fuel injection amount. . By performing the accelerator operation in this way, the rotational speed of the diesel engine 9 can be increased or decreased.

  The sensors that provide information to the engine ECU 32 include an accelerator opening sensor that detects the accelerator opening, a differential pressure sensor 44 that detects the differential pressure of the exhaust gas purification device 31, an exhaust temperature sensor 45 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 33 controls various devices (traveling device, working device, etc.) provided in the backhoe 1 in cooperation with the engine ECU 32. For example, the main ECU 33 performs flow control for supplying predetermined hydraulic oil to each cylinder such as the swing cylinder, the boom cylinder 18, the arm cylinder 19, and the bucket cylinder 20.
This flow rate control is performed based on the amount of operation of an operating member (operating lever) provided around the driver's seat 10, and more specifically, the operating lever is swung from the neutral position to one side (left side). When the operation amount is input, a predetermined value of current (operation signal) is output to the solenoid of the electromagnetic proportional valve corresponding to the operated actuator (swing cylinder, boom cylinder 18, arm cylinder 19 and bucket cylinder 20). Then, the electromagnetic proportional valve opens according to the current value, the pilot pressure of the control valve corresponding to the operated actuator is controlled, and the actuator operates in one direction. When the operation lever is swung from the neutral position to the opposite side to input the operation amount on the right side, the actuator is operated on the opposite side from the swinging to the left side. Thus, the backhoe 1 can be operated by operating the operation lever.

  The main ECU 33 is a meter and a monitor provided around the driver's seat 10 and controls the operation of the entire backhoe 1 including the display device 11 that displays the operation state of the backhoe 1. The main ECU 33 in the present embodiment has filter regeneration means 47 for regenerating the DPF 41 of the exhaust gas purification device 31. The filter regeneration unit 47 is realized by a computer program executed by the main ECU 33.

  Here, the display device 11, the engine ECU 32, and the main ECU 33 are connected to each other via a vehicle communication network N such as a Controller Area Network (CAN communication), and can exchange data with each other. The vehicle communication network is not particularly limited as long as data can be transmitted and received among the display device 11, the engine ECU 32, and the main ECU 33. For example, it may be FlexRay or another network.

As shown in FIG. 1, the filter regeneration unit 47 includes a deposition amount acquisition unit 50 that acquires a deposition amount (PM deposition amount) of particulate matter deposited on the DPF 41, and a PM deposition amount acquired by the deposition amount acquisition unit 50. Filter regeneration control means 60 for regenerating the DPF 41 based on the above.
The accumulation amount acquisition means 50 receives from the engine ECU 32 the differential pressure of the exhaust gas purification device 31 (value detected by the differential pressure sensor 44), the exhaust temperature detected by the exhaust temperature sensor 45, the coolant temperature, and the oxygen in the intake air. Information such as concentration and temperature, fuel injection amount, and the like is obtained, and the amount of particulate matter deposited on the DPF 41 (PM deposition amount) is calculated and acquired.

  The filter regeneration control means 60 performs a regeneration operation for regenerating the DPF 41 in a plurality of modes (modes), and includes, for example, two modes such as a first regeneration control mode and a second regeneration control mode. Perform the playback operation. That is, the filter regeneration control unit 60 performs the first regeneration control mode and the second regeneration control mode based on the PM accumulation amount acquired by the accumulation amount acquisition unit 50, and regenerates the DPF 41.

Here, the first regeneration control mode is a mode in which the automatic regeneration of the DPF 41 is performed. As the automatic regeneration operation, for example, the intake throttle of the diesel engine 9 is throttled, and the exhaust temperature is reduced by the throttle of the intake throttle. To rise.
The second regeneration control mode is a mode for issuing a notification (warning) requesting the worker to increase the rotational speed of the diesel engine 9. Increasing the rotational speed of the engine 9 is to increase the rotational speed of the engine to at least the idling rotational speed, and preferably to increase the engine rotational speed to, for example, 1.5 times or more of the idling rotational speed. .

  Specifically, as shown in FIG. 3B, in the second regeneration control mode 52, an icon B that requests the operator to increase the engine speed (for example, increase it to 1800 or more) is displayed. While being displayed on the display device 11, an intermittent notification sound (warning sound) is also generated on the display device 11. At this time, when the operator operates the accelerator according to the displayed icon B and the generated warning sound and increases the engine speed to a predetermined speed of, for example, 1800 or higher, the exhaust temperature further increases, and the DPF 41 Combustion of the particulate matter deposited on the substrate is promoted, and the amount of PM deposition decreases.

  The filter regeneration control means 60 has a threshold value TH corresponding to the PM accumulation amount as a reference for determining the execution of the first regeneration control mode. This threshold value TH is for starting automatic regeneration as described above. For example, the threshold value TH is about 50% to about 60% with respect to the upper limit amount (collection limit value) of particulate matter that can be collected by the DPF 41. Is set to a value. For example, if the normal operation of the backhoe 1 (such as operation of the operation lever) is continued without performing the regeneration operation of the DPF 41 in a state where the PM accumulation amount exceeds 60% of the collection limit value, the PM accumulation amount Will further increase. In such a case, even if the automatic regeneration of the DPF 41 is started later, it may take time to raise the exhaust gas temperature and the like, and it may be difficult to advance the reduction of the PM accumulation amount in the DPF 41 by the automatic regeneration. is there. Therefore, the filter regeneration control means 60 starts automatic regeneration in the first regeneration control mode when the PM accumulation amount becomes equal to or greater than the threshold value TH.

Specifically, the filter regeneration control unit 60 compares the PM accumulation amount calculated by the accumulation amount acquisition unit 50 with the threshold value TH and determines whether or not to implement the first regeneration control mode. Specifically, if the calculated current PM accumulation amount is smaller than the threshold value TH, the first regeneration control mode is not performed. If the current PM accumulation amount is equal to or greater than the threshold value TH, the first regeneration control mode is performed. To implement.
FIG. 2 is a graph showing an example of the temperature change of the exhaust gas with respect to the operation time of the backhoe 1, that is, the time change of the exhaust gas temperature (exhaust temperature). The regeneration operation of the DPF 41 performed by the filter regeneration unit 47 will be described in detail with reference to FIG.

The accumulation amount acquisition means 50 continuously calculates and acquires the PM accumulation amount of the DPF 41 when the diesel engine 9 of the backhoe 1 is started. First, when the accumulation amount acquisition unit 50 calculates the PM accumulation amount, the filter regeneration control unit 60 compares the calculated PM accumulation amount with the threshold value TH.
As a result of the comparison, when the calculated PM accumulation amount is less than the threshold value TH, the filter regeneration control means 60 determines that regeneration of the DPF 41 is unnecessary, and the first regeneration control mode and the second regeneration control mode. (DPF 41 regeneration is not started).

Conversely, when the calculated PM accumulation amount is equal to or greater than the threshold value TH, that is, at time T1 in the graph of FIG. 2, the filter regeneration control means 60 determines that regeneration of the DPF 41 is necessary, and first The regeneration control mode is executed (reproduction of the DPF 41 is started).
The filter regeneration control means 60 outputs a command for starting automatic regeneration to the engine ECU 32 and the like by performing the first regeneration control mode, and regenerates the DPF 41. As an automatic regeneration operation, for example, as described above, the intake throttle of the diesel engine 9 is throttled, and the exhaust temperature rises due to the throttle of the intake throttle. The filter regeneration control means 60 thus starts automatic regeneration of the DPF 41, and burns and removes the particulate matter deposited on the DPF 41.

As shown in FIG. 3A, the filter regeneration control means 60 further displays an icon A indicating that automatic regeneration is being performed on the display device 11 to generate a continuous warning sound.
As described above, the automatic regeneration is a regeneration operation that does not require a special operation for the operator who operates the backhoe 1, and if the backhoe 1 is independently, that is, viewed from the operator, the automatic operation is automatic. This is an operation to increase the temperature of the DPF 41 and to burn the deposited particulate matter.

  Next, the filter regeneration control means 60 performs the second regeneration control mode when the temperature index related to the diesel engine 9 is lower than the first temperature after the start of the automatic regeneration. Here, the temperature index is a temperature at which combustion conditions such as whether or not particulate matter is combusted in the regeneration of the DPF 41, such as the intake air temperature, the exhaust gas temperature, and the cooling water temperature of the diesel engine 9. is there.

  For example, when the temperature index is the exhaust temperature of the diesel engine 9, if the exhaust temperature is high, the particulate matter deposited on the DPF 41 is likely to burn and the regeneration of the DPF 41 by automatic regeneration is likely to proceed. Conversely, when the exhaust temperature is low, the accumulated particulate matter is unlikely to burn, and it is considered that regeneration of the DPF 41 by automatic regeneration does not proceed easily.

  In the present invention, the degree of combustion of particulate matter deposited on the DPF 41 (ease of regeneration of the DPF 41) is evaluated by a temperature index such as the exhaust temperature of the diesel engine 9. That is, when the exhaust temperature is in a temperature range where the regeneration of the DPF 41 is difficult to proceed (below the first temperature), the second regeneration control mode is performed in order to assist and promote the automatic regeneration of the DPF 41. Thus, since the temperature index is used to evaluate the ease of regeneration of the DPF 41, the numerical value of the first temperature varies depending on the temperature index employed. As described above, when the temperature index is the exhaust temperature of the diesel engine 9, the first temperature is, for example, 250 ° C., and when the temperature index is the cooling water temperature, the first temperature is, for example, 70. ° C.

  The first temperature is a value that serves as a reference for determining whether or not the regeneration of the DPF 41 by automatic regeneration proceeds efficiently, and is set in consideration of a temperature increase due to a second regeneration control mode described later. Is preferred. For example, the first temperature is set to 50% or less of the target value of the exhaust temperature of the diesel engine 9 in the regeneration of the DPF 41. In the present embodiment, the target value of the exhaust temperature in regeneration of the DPF 41 is set to 580 ° C. or higher, and the first temperature is set to 250 ° C., which is about 43% of the target value.

Next, the second regeneration control mode for assisting and promoting the automatic regeneration of the DPF 41 will be described by taking the exhaust temperature of the diesel engine 9 as a temperature index as an example.
In the second regeneration control mode, a warning requesting to increase the rotational speed of the diesel engine 9 is issued within a period during which automatic regeneration is performed in the first regeneration control mode.
Specifically, as shown in FIG. 3B, the filter regeneration control means 60 causes the display device 11 to alternately display an icon B requesting to increase the engine speed and the icon A. , And generate intermittent warning sounds. When the operator operates the accelerator according to the display and the warning sound and increases the engine speed to a predetermined speed or higher (a higher speed than the idling speed, for example, 1800 or higher). Further, the exhaust temperature further rises, the combustion of the particulate matter deposited on the DPF 41 is promoted, and the PM deposition amount decreases.

  Here, the exhaust temperature rises smoothly and becomes a second temperature (for example, 580 ° C.) or higher that is higher than the first temperature (250 ° C.) that is a criterion for determining whether or not to implement the second regeneration control mode. And when the second temperature or higher is continued for a predetermined time, in other words, for a duration P (for example, 10 minutes), that is, when the exhaust temperature continues to be higher than the second temperature from time T2 to time T3 in the graph of FIG. The filter regeneration control means 60 determines that the particulate matter deposited on the DPF 41 has burned and decreased, stops the second regeneration control mode, that is, the request to increase the rotational speed of the diesel engine 9, and displays the display device 11. The display of the icon B is terminated.

  Here, as described above, the second temperature is a target value of the exhaust temperature in regeneration of the DPF 41, and is a temperature at which the particulate matter deposited on the DPF 41 is considered to burn almost certainly. That is, when the exhaust gas temperature is maintained at the second temperature or higher, it is considered that the particulate matter deposited on the DPF 41 is surely combusted and decreased, and therefore the exhaust gas temperature continues to be at the second temperature or higher. If so, the second regeneration control mode for assisting and promoting the automatic regeneration of the DPF 41 is terminated. Note that if the time (duration) P when the exhaust temperature is equal to or higher than the second temperature is long, it is considered that a large amount of particulate matter has burned, and if the duration of the second temperature is short, the burned particulate matter Since the amount of the substance is considered to be small, the amount of the burned particulate matter changes depending on the duration of the second temperature. For this reason, in the present invention, the burned amount of the particulate matter is calculated based on the duration of the second temperature or higher.

When the exhaust temperature exceeds 500 ° C. and reaches about 580 ° C., the amount of particulate matter combusted per minute becomes almost stable and becomes a constant value. Therefore, it can be said that the predetermined duration P of the second temperature is a time during which the particulate matter deposited on the DPF 41 is stably burned at a constant rate per hour.
Thus, for example, in this embodiment, the filter regeneration control means 60 allows the particulate matter deposited on the DPF 41 to be about 80% if the second temperature (580 ° C.) is maintained for a predetermined duration P (10 minutes). Judged to have decreased.

  Here, even if the filter regeneration control means 60 ends the second regeneration control mode, it does not immediately terminate the first regeneration control mode. In the first regeneration control mode, it is determined whether to execute or end the process based on the PM accumulation amount. Therefore, immediately after the end of the second regeneration control mode, the filter regeneration control means 60 ends the display of the icon B on the display device 11, and returns to the display of only the icon A as shown in FIG.

Thereafter, the filter regeneration control means 60 again performs the second regeneration when the temperature index related to the diesel engine 9 becomes less than the first temperature within the period during which the automatic regeneration in the first regeneration control mode is performed. Implement the control mode.
As described above, any one of the intake air temperature, the exhaust gas temperature, and the cooling water temperature of the diesel engine 9 may be adopted as the temperature index.

  For example, when the exhaust temperature is selected as the temperature index, only one reference temperature (for example, 250 degrees) with respect to the exhaust temperature needs to be set. For example, two or more temperatures such as the exhaust temperature and the cooling water temperature are selected. In this case, a reference temperature for the exhaust temperature and a reference temperature (for example, 70 degrees) for the cooling water temperature are set. In addition, the second regeneration control mode may be performed when the exhaust gas temperature and the cooling water temperature are both lower than the reference temperature set for each. Further, the second regeneration control mode may be performed when either one of the exhaust temperature and the cooling water temperature is lower than the reference temperature.

The “DPF regeneration operation” by the filter regeneration means 47 will be summarized with reference to FIGS.
When the operator starts the diesel engine 9 of the backhoe 1, the accumulation amount acquisition means 50 of the filter regeneration means 47 receives from the engine ECU 32 the differential pressure of the exhaust gas purification device 31, the exhaust temperature, the coolant temperature, and the intake air. Information such as oxygen concentration and temperature, fuel injection amount, and the like is obtained, and the amount of particulate matter deposited on the DPF 41 (PM deposition amount) is calculated and acquired.

  When the low load operation is continued for a long time by the backhoe 1, the PM accumulation amount calculated by the accumulation amount acquisition means 50 increases with time, and at time T1 in the graph of FIG. It becomes more than the threshold value TH. At this time, the filter regeneration control means 60 determines that regeneration of the DPF 41 is necessary, first executes the first regeneration control mode, and starts automatic regeneration of the DPF 41.

Since the operator does not notice the start of this automatic regeneration, the filter regeneration control means 60 displays the icon A shown in FIG. 3A on the display device 11 and generates a continuous warning sound, so that the current automatic regeneration is performed. Inform the operator that
At this time, the filter regeneration control means 60 compares the exhaust gas temperature, which is one of the temperature indexes related to the diesel engine 9, with the first temperature. If the exhaust gas temperature is lower than the first temperature, the filter regeneration control means 60 implements the second regeneration control mode in order to further increase the exhaust gas temperature to assist and promote the automatic regeneration of the DPF 41.

  The filter regeneration control means 60 implements the second regeneration control mode, thereby causing the display 11 to alternately display the icon B requesting an increase in the rotational speed as shown in FIG. A warning sound different from the warning sound generated when the icon A is displayed in the first reproduction control mode is generated on the display 11. The operator recognizes that it is necessary to increase the rotational speed of the diesel engine 9 based on the display of the icon B and the warning sound, and operates the accelerator lever at any timing, such as between work, to set the rotational speed of the engine. Raise.

  At this time, the filter regeneration control unit 60 continuously or intermittently determines whether or not the exhaust gas temperature acquired by the accumulation amount acquisition unit 50 is equal to or higher than the second temperature. As shown in FIG. 2, when the engine speed increases, the exhaust temperature starts to rise accordingly. When the exhaust temperature becomes equal to or higher than the second temperature at time T2, the filter regeneration control means 60 continuously increases the exhaust temperature. The timing of the duration P that is equal to or higher than the second temperature is started.

  That is, the filter regeneration control means 60 performs both the determination as to whether or not the exhaust gas temperature is equal to or higher than the second temperature at time T2 and the time duration P. Even if the exhaust gas temperature becomes equal to or higher than the second temperature and starts measuring the duration P, if the exhaust temperature falls below the second temperature, the timing of the duration P is stopped and the duration P is returned to zero. Reset. When the exhaust gas temperature becomes equal to or higher than the second temperature again, the measurement of the duration P is started again.

  When the time duration P thus counted is, for example, 10 minutes, that is, at time T3 in FIG. 2, the filter regeneration control means 60 stops the second regeneration control mode and the icon B to the display 11 is displayed. Is stopped and the warning sound is stopped. Accordingly, the display device 11 returns to the state in which the icon A shown in FIG. 3A is continuously displayed, and only the warning sound related to the icon A is emitted. It is determined that it is no longer necessary to raise the accelerator, and the accelerator lever is returned to the idle position.

  Thereafter, the filter regeneration control means 60 stops the automatic regeneration in the first regeneration control mode when the PM accumulation amount calculated by the accumulation amount acquisition means 50 becomes less than a predetermined value. However, when the temperature index relating to the diesel engine 9 falls below the first temperature within the period during which the automatic regeneration in the first regeneration control mode is performed, the filter regeneration control means 60 again performs the second regeneration. Implement the control mode.

  In this embodiment, it has been described that at least one of the three temperatures of the intake air temperature, the exhaust gas temperature, and the cooling water temperature of the diesel engine 9 is used as the temperature index related to the diesel engine 9. As described above, these temperatures are continuously acquired by the accumulation amount acquisition means 50 (engine ECU or the like) and are temperature indexes directly related to the calculation of the PM accumulation amount. Therefore, if these related temperature indicators are used, simply by monitoring changes in the temperature indicators over time, it is necessary to simply and accurately increase the rotational speed of the diesel engine at an appropriate timing according to the increase / decrease in the amount of accumulated PM. And can be stopped.

  According to the present embodiment, since a warning is issued to the worker and an increase in the engine speed is urged, the worker who notices the warning appropriately increases the rotational speed of the diesel engine 9 even during the work and exhausts the engine. The temperature can be raised. As a result of the rise in the exhaust temperature, the temperature of the DPF 41 that has been raised by automatic regeneration such as the throttle of the intake throttle further rises, and the particulate matter deposited on the DPF 41 burns. As described above, according to the present embodiment, the operator can be urged to assist (back up) automatic regeneration (increase in the engine speed), so that the decrease in the amount of accumulated PM can be promoted. Regeneration can be performed efficiently.

In addition, the operator can increase the engine speed, which is a backup operation for automatic regeneration, by the accelerator operation even when the backhoe 1 is traveling or when the operation lever is operated. Therefore, it is not necessary to stop the backhoe 1 to interrupt the work only for the regeneration of the DPF 41.
For example, the backhoe 1 may be run to move within the work site or to evacuate from the work site. In that case, the operator operates the operation lever provided around the driver's seat 10 to drive the backhoe 1. Since such traveling is often repeated intermittently during work, the accelerator operation is manually performed at an arbitrary timing of the worker in the idle time between repeated traveling to increase the engine speed. To increase the exhaust temperature.

  Further, at the work site, an operator operates a work device or the like by operating an operation lever different from that used for traveling the backhoe 1, and performs, for example, excavation work. Normally, work performed at a work site is a series of multiple units of work, so an operator can choose any amount of free time between the end of one unit of work and the start of the next unit of work. The accelerator operation can be performed manually at this timing to increase the engine speed and raise the exhaust temperature.

  Further, unlike a vehicle (automobile) such as a passenger car or a truck, the diesel engine 9 of the backhoe 1 generally powers various devices such as a hydraulic motor and a hydraulic pump mounted on the backhoe 1. It is possible to increase the engine speed even during work or running. Thus, the operator can increase the engine speed at any time, not just between work and travel.

  That is, according to the present embodiment, the warning informs the user that the engine speed needs to be increased in order to further promote the regeneration of the DPF 41. The engine speed can be increased and the exhaust temperature can be raised by operation. As a result, as in the prior art, the backhoe 1 must be stopped at a safe place only for the regeneration of the DPF 41 to increase the engine speed, and during that time, neither running nor work can be performed. No longer occurs.

  Further, according to the present embodiment, after the PM accumulation amount becomes equal to or higher than the threshold value TH and automatic regeneration is started, and when the exhaust gas temperature is lower than the first temperature, an increase in engine speed is requested, and automatic Encourage combustion of DPF 41 by regeneration. In addition, if the exhaust temperature is maintained at the second temperature or higher for a predetermined duration P, the request for increasing the engine speed is stopped. As a result, an increase in engine speed at an inappropriate timing can be avoided, and as a result, fuel deterioration accompanying an increase in engine speed can be prevented.

[Second Embodiment]
The second embodiment is different from the first embodiment described above in terms of determination criteria for starting and stopping the second regeneration control mode by the filter regeneration control means 60.
The filter regeneration control unit 60 according to the present embodiment determines whether to start and stop the second regeneration control mode based on the PM accumulation amount calculated by the accumulation amount acquisition unit 50. Since the configuration and effects other than this point are almost the same as those of the first embodiment, only differences from the first embodiment will be described with reference to FIG.

In the first embodiment, the filter regeneration control unit 60 has started and stopped the second regeneration control mode based on the exhaust gas temperature. However, the filter regeneration control unit 60 according to the present embodiment performs the second regeneration control mode. The control mode is started and stopped based on the PM deposition amount.
First, when the diesel engine 9 is started, the filter regeneration control unit 60 continuously or intermittently acquires the PM accumulation amount from the accumulation amount acquisition unit 50, and compares the acquired PM accumulation amount with the second accumulation amount. When the PM accumulation amount becomes equal to or greater than the second accumulation amount, the filter regeneration control unit 60 starts the first regeneration control mode.

  Even after the start of the first regeneration control mode, the PM deposition amount calculated by the deposition amount acquisition means 50 is the time when the low load operation by the backhoe 1 continues for a long time and the exhaust temperature does not rise. As shown in the graph of FIG. 4, there is a case where the first deposition amount is larger than the second deposition amount. In other words, the PM accumulation amount may not increase so much by the automatic regeneration in the first regeneration control mode, but may increase beyond the first accumulation amount. The first accumulation amount is a value set to a value that is about 60% to about 70% with respect to the upper limit amount of the particulate matter that can be collected by the DPF 41, for example. The state where the PM deposition amount exceeds the first deposition amount is a stage where the PM deposition amount must be reduced as soon as possible by improving the efficiency of automatic regeneration in the first regeneration control mode. For this reason, when the PM accumulation amount becomes equal to or greater than the first accumulation amount, the second regeneration control mode is performed to assist and promote the automatic regeneration of the DPF 41.

When the operator operates the accelerator according to the display on the display 11 and the warning sound in the second regeneration control mode to increase the engine speed to a predetermined speed or higher, the exhaust temperature further increases, and the DPF 41 Combustion of the particulate matter deposited on the substrate is promoted, and the amount of PM deposition decreases.
Here, when the PM deposition amount decreases steadily and becomes less than the second deposition amount, which is a criterion for determining whether or not to implement the first regeneration control mode, that is, the particulate matter is steadily performed by automatic regeneration. The filter regeneration control means 60 ends the second regeneration control mode at the stage where the PM accumulation amount has decreased due to combustion (less than the second accumulation amount).

  According to the present embodiment, an increase in the engine speed is requested based on the PM accumulation amount, and combustion of the DPF 41 by automatic regeneration is promoted. Then, when the automatic regeneration is advanced and the amount of accumulated PM is surely reduced, the request for increasing the rotational speed is appropriately stopped. As a result, it is possible to request an increase in the engine speed only for an appropriate period until the PM accumulation amount reaches a predetermined value, thereby preventing an inadvertent increase in the engine speed and suppressing fuel consumption due to automatic regeneration. .

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-described embodiment, the automatic regeneration has been described by taking “intake throttle throttle” as an example. However, automatic regeneration is not limited to “intake throttle throttle”, and regeneration of DPF by fuel post-injection is automatically regenerated. You may add to. Post-injection is an operation that promotes the temperature rise of the DPF 41 by injecting fuel into the gas after combustion.

  In the automatic regeneration performed in each regeneration control mode, “throttle intake throttle” or “post-injection” may be appropriately combined. For example, in the first regeneration control mode, the intake throttle is throttled. In addition, in the second regeneration control mode 52, when the water temperature or the exhaust temperature is sufficiently increased, the intake throttle is throttled. You may start injection.

  Further, in each of the embodiments described above, automatic regeneration (first regeneration control mode) is started as a trigger when the PM deposition amount becomes equal to or greater than a predetermined deposition amount. However, the trigger for starting automatic regeneration is the PM deposition amount. May not be used as a reference. For example, the difference between the exhaust pressures on the inlet side and the outlet side of the DPF 41 (or the exhaust gas purification device 31), that is, the differential pressure detected by the differential pressure sensor 44 may be used as a reference. If the differential pressure detected by the differential pressure sensor 44 is equal to or greater than a predetermined pressure, it can be considered that the PM accumulation amount in the DPF 41 is equal to or greater than the predetermined accumulation amount as described above. The detected differential pressure can be used as a trigger for starting automatic regeneration.

Similarly, in the second embodiment, the operation for issuing a warning requesting the operator to increase the rotational speed of the diesel engine 9 (second regeneration control mode) is not the PM accumulation amount but the DPF 41 (or You may start on the basis of the difference (differential pressure) of the exhaust pressure on the entrance side and exit side of the exhaust gas purification device 31).
In the second embodiment, a difference (differential pressure) between the exhaust pressures on the inlet side and the outlet side of the DPF 41 (or the exhaust gas purification device 31) is employed as a trigger for starting automatic regeneration (first regeneration control mode). Even in this case, the second regeneration control mode is started after the first regeneration control mode is started, as in the case where the PM accumulation amount is employed. At this time, the temperature index when starting the first regeneration control mode is often a value equal to or lower than the temperature index when starting the second regeneration control mode.

  In addition to the backhoe 1, the regeneration control of the DPF 41 of the present invention can also be applied to construction machines and agricultural machines that perform operations such as compact truck loaders (CTLs) and tractors.

DESCRIPTION OF SYMBOLS 1 Backhoe 2 Traveling device 3 Revolving body 4 Traveling body 5 Dozer 6 Swivel bearing 7 Swivel stand 8 Working device 9 Diesel engine 10 Driver's seat 11 Display device 12 Cabin 13 Support bracket 14 Swing bracket 15 Boom 16 Arm 17 Bucket 18 Boom cylinder 19 Arm Cylinder 20 Bucket cylinder 30 Exhaust manifold 31 Exhaust gas purification device 32 Engine ECU
33 Main ECU
34 Cylinder 35 Intake port 36 Exhaust port 37 Intake valve 38 Exhaust valve 39 Intake manifold 40 Silencer 41 DPF
42 Inlet pressure sensor 43 Outlet pressure sensor 44 Differential pressure sensor 45 Exhaust temperature sensor 46 Control unit 47 Filter regeneration means 50 Deposit amount acquisition means 60 Filter regeneration control means A, B icon

Claims (6)

A diesel engine capable of increasing the number of revolutions by an accelerator operation, an exhaust gas purification device including a filter for collecting particulate matter contained in the exhaust gas exhausted from the diesel engine, and the exhaust gas purification device A working machine comprising filter regeneration means for burning and removing particulate matter deposited on the filter,
Said filter regeneration means, said had row AutoPlay removal by burning the particulate matter deposited in the filter by raising the temperature of the exhaust gas automatically, during the automatic reproduction, the rotation of the diesel engine A work machine that requests a worker who performs the accelerator operation to increase the number by the accelerator operation . Said filter regeneration means, wherein in a state in which the automatic regeneration is being performed, and when the temperature indicator of the diesel engine is equal to or less than the first temperature, the rotational speed of the accelerator operation to raise by the accelerator operation of the diesel engine The work machine according to claim 1, wherein the work machine is requested to a worker who performs the operation .   The filter regeneration means stops the request when a temperature index related to a diesel engine is equal to or higher than a second temperature higher than the first temperature for a predetermined time or longer in the state where the request is made. The working machine according to claim 2. Said filter regeneration means, in a state in which the automatic regeneration is being performed, and when the deposition amount of the particulate matter becomes first deposit amount or more, to increase the rotational speed of the diesel engine by the accelerator operation 2. The work machine according to claim 1, wherein a request is made to a worker who performs the accelerator operation .   The filter regeneration unit stops the request when the amount of the particulate matter deposited becomes equal to or less than a second deposition amount smaller than the first deposition amount in the state where the request is made. The working machine according to claim 4.   The work machine according to claim 2 or 3, wherein the temperature index is at least one of an intake air temperature, an exhaust gas temperature, and a cooling water temperature of the diesel engine.