JP5679938B2 - 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 working 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 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 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.

There is a work vehicle disclosed in Patent Document 1 as a technique relating to such DPF regeneration.
The work vehicle disclosed in Patent Document 1 automatically activates the power supply of the work vehicle to the operator when the pressure difference between the pressure sensors immediately before the engine is stopped is detected to be a predetermined value or more, even after the engine is stopped. When the operator selects the regeneration mode with the selection switch, the engine is automatically started to regenerate the DPF at the idling rotational speed, and when the pressure sensor differential pressure becomes a predetermined value or less. The engine and power are automatically stopped.

JP 2010-77954 A

  The technique of Patent Document 1 is based on the premise that the operation of the work vehicle is stopped and the engine is stopped once when the DPF whose particulate matter accumulation amount is equal to or greater than a predetermined value is regenerated. As described above, Patent Document 1 discloses a DPF regeneration technique based on the premise that the engine is stopped. Therefore, depending on the technique of Patent Document 1, the operation cannot be continued during the regeneration of the DPF. That is, in order to regenerate the DPF, it is necessary to stop the operation of the work vehicle even when working with the work vehicle, which makes the work vehicle very inconvenient.

Furthermore, in the technique of Patent Document 1, since the DPF is regenerated at a very low engine speed, i.e., the idling speed, not only does it take time to regenerate the DPF, but it may not be possible to sufficiently regenerate the DPF. There is.
Therefore, an object of the present invention is to provide a working machine that can efficiently and sufficiently regenerate the DPF even when traveling or working.

In order to achieve the above object, the present invention has taken the following measures.
That is, technical means for solving the problems in the present invention include a diesel engine capable of increasing the rotational speed by an accelerator operation, and a filter for collecting 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 disposed on the filter. A first regeneration control mode for performing automatic regeneration for automatically burning and removing particulate matter deposited on the filter device when the amount of deposited particulate matter becomes equal to or greater than a first deposition amount threshold. when, in a case where performing the automatic regeneration, when the deposition amount of the particulate matter is equal to or greater than the higher second deposition amount threshold than the first deposition amount threshold , And having a second playback control mode that requests to increase the rotational speed of the diesel engine to the operator.

Here, the first regeneration control mode performs the automatic regeneration when the accumulation amount of the particulate matter is equal to or greater than a first accumulation amount threshold, and the second regeneration control mode includes the first regeneration control mode. of within a predetermined time from the start of the automatic reproduction by the reproduction control mode, unless falls below low warning release threshold than the deposition amount of the particulate matter is first deposited amount threshold, the diesel to the operator It is preferable to request that the engine speed be increased.

In the first regeneration control mode, the automatic regeneration is performed when the amount of the particulate matter deposited exceeds a first deposition amount threshold, and the second regeneration control mode is performed in the particulate regeneration. It is preferable to request that the rotation of the diesel engine be increased to a predetermined number of revolutions or more when the deposition amount of the substance reaches or exceeds a second deposition amount threshold value that is higher than the first deposition amount threshold value.
Further, when the accumulation amount of the particulate matter becomes equal to or higher than a third accumulation amount threshold value higher than the second accumulation amount threshold value at the stage where the request is made, the output is limited to the diesel engine. It is preferable to have a third reproduction control mode to instruct.
In the second regeneration control mode, the rotation speed of the diesel engine is increased when the accumulation amount of the particulate matter is not less than a second accumulation amount threshold value and the rotational speed of the diesel engine is less than a predetermined value. It is preferable to request that the number be increased.

  According to the first aspect, the DPF can be regenerated without stopping the work machine. At this time, since the worker is prompted to increase the engine speed by a warning, the worker who notices the warning can appropriately increase the engine speed even during the work. As a result, the temperature of the DPF increases due to a further increase in the exhaust gas temperature accompanying the increase in the engine speed, and the particulate matter burns. In this way, the amount of particulate matter deposited decreases, and the DPF can be regenerated efficiently.

According to claim 2, it is determined whether or not it is necessary to increase the engine speed by observing the decreasing tendency of the accumulation amount after a predetermined time from the start of the automatic regeneration (whether it is less than the warning cancellation threshold). (It is determined whether or not to prompt the operator to regenerate the DPF). As a result, the DPF can be regenerated at an early stage (a stage where the amount of deposition is not so large).
According to the third aspect of the present invention, after the automatic regeneration is started, it is determined whether or not it is necessary to increase the engine speed by looking at the increasing tendency of the accumulation amount (whether or not the second accumulation amount threshold is exceeded). Whether or not to prompt the worker). Thus, only when the accumulation amount increases to some extent (when the accumulation amount is equal to or greater than the second accumulation amount), regeneration of the DPF can be promoted by increasing the engine speed. As a result, it is possible to suppress the fuel consumption due to the regeneration of the DPF while suppressing the accumulation amount from becoming larger than the second accumulation amount.

  According to claim 4, when the accumulation amount is equal to or higher than the third accumulation amount threshold value higher than the second accumulation amount threshold value, the output is limited to the diesel engine, and the third accumulation amount threshold value is set. The increase in the particulate matter after exceeding can be suppressed. That is, since the warning for increasing the engine speed while continuing the engine output is continued, the operator can increase the engine speed before the accumulation amount becomes excessive.

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. 1 is a block diagram showing a schematic configuration of a filter regeneration unit, an engine ECU, and a display device of a main ECU in a first embodiment of the present 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 elapsed time in 1st Embodiment of this invention. It is a flowchart which shows the operation | movement after a reproduction | regeneration control level is determined by the accumulation amount acquisition means. It is a figure which shows the display mode of the display apparatus in each reproduction | regeneration control level. It is a block diagram which shows schematic structure of the filter reproduction | regeneration means of main ECU, engine ECU, and a display apparatus in 2nd 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 elapsed 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. 8 is a side view showing a schematic configuration of the backhoe 1. As shown in FIG. 8, 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. A dozer 5 is provided at the front of the traveling device 2.
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 around a swivel axis in the vertical direction, and a working 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 is swung by expansion and contraction of a swing cylinder provided in the swivel base 12. The boom 15 is swung by the expansion and contraction of a boom cylinder 18 interposed between the boom 15 and the swing bracket 14. The arm 16 is swung by the expansion and contraction of an arm cylinder 19 interposed between the arm 16 and the boom 15. The bucket 17 is squeezed and dumped by expansion and contraction of the bucket cylinder 20 interposed 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. 2, 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. 2, 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. 2, in the center of the liquid crystal panel 112, an icon A indicating that the automatic regeneration of the DPF is currently being performed and character information for calling attention regarding the regeneration of the DPF (diesel particulate filter) are displayed. ing. 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 a certain warning has been issued, a hydraulic LED display unit 113b indicating a warning of engine oil pressure, and a battery LED display unit 113c indicating a warning of the state of charge of the battery There are a speed LED display 113d for indicating a speed warning, an exhaust LED display for indicating an exhaust temperature warning, 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.

2 shows the display device 11 including the liquid crystal panel 112, the display device 11 is not limited to the one displayed on the liquid crystal panel 112 as long as the above display is possible. .
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, 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 the gas after combustion (combustion gas) is stored in the cylinder 34. An exhaust port 36, which is an opening for discharging from 34, 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 purification device 31 collects and purifies particulate matter (PM) contained in the passing combustion gas. That is, the combustion gas 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 exhaust 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 in 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 a plurality of control devices (ECUs). For example, the engine ECU 32 that controls the diesel engine 9 and the main that controls the operation of the backhoe 1 as a whole. ECU33. 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 provided around the driver's seat 10 is operated (by performing the accelerator operation), the engine ECU detects the operation amount (opening) of the accelerator and increases the fuel injection amount. In this way, the engine speed of the diesel engine 9 can be increased.

  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.

FIG. 2 is a block diagram showing the configuration of the filter regeneration means 47. As shown in FIG. 2, 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 fuel injection amount is obtained, and the amount of particulate matter deposited on the DPF 41 is calculated and acquired.

  The filter regeneration control means 60 divides the regeneration operation for regenerating the DPF 41 into a plurality of modes (modes) step by step. Specifically, the first regeneration control mode 51 and the second regeneration are performed. The reproduction operation is performed step by step in three modes: a control mode 52 and a third reproduction control mode 53. That is, the filter regeneration control unit 60 determines the regeneration control mode to be operated from among the first regeneration control mode 51 to the third regeneration control mode 53 in accordance with the PM accumulation amount acquired by the accumulation amount acquisition unit 50. The DPF 41 is regenerated in each regeneration control mode.

  For example, the filter regeneration control means 60 has four threshold values as predetermined values serving as a reference for determining the regeneration control mode in accordance with the PM accumulation amount. These four threshold values are a warning release threshold value, a threshold value TH1 (first deposition threshold value), a threshold value TH2 (second deposition threshold value), and a threshold value TH3 (third deposition threshold value) in descending order. These four threshold values correspond to the regeneration control level corresponding to the content of the regeneration operation of the DPF 41 to be executed. The filter regeneration control means 60 compares the PM accumulation amount calculated by the accumulation amount acquisition means 50 with the above four threshold values, and determines which threshold the current PM accumulation amount is between. Determine the appropriate playback control level.

FIG. 3 is a graph showing an example of a change in the amount of particulate matter deposited (PM deposition amount) with respect to elapsed time. The regeneration of the DPF 41 will be described in detail with reference to FIG.
When the diesel engine 9 of the backhoe 1 is started, the accumulation amount acquisition unit 50 continuously calculates and acquires the PM accumulation amount of the DPF 41. In the graph of FIG. 3, the PM accumulation amount increases as the operating time of the diesel engine 9 starts from the origin side.

First, when the accumulation amount acquisition unit 50 calculates the PM accumulation amount, the filter regeneration control unit 60 compares the acquired PM accumulation amount with the four threshold values of the warning cancellation threshold value, the threshold value TH1, the threshold value TH2, and the threshold value TH3. Do.
When the PM accumulation amount is less than the threshold TH1, the filter regeneration control means 60 sets the regeneration control level to Level 0, and when it is Level 0, determines that the regeneration of the DPF 41 is not required, and does not perform the regeneration of the DPF 41 (DPF 41). Does not start playing).

  Next, when the PM accumulation amount is equal to or greater than the threshold value TH1 and less than the threshold value TH2, the filter regeneration control unit 60 shifts (shifts) the regeneration control level from Level0 to Level1. Level 1 or higher indicates that the PM accumulation amount is such that the automatic regeneration of the DPF 41 must be started. The filter regeneration control means 60 selects the first regeneration control mode 51 for performing the automatic regeneration of the DPF 41 in response to the regeneration control level becoming Level 1, and automatically reproduces in the first regeneration control mode 51. Is output to the control unit 46 and the like, and the DPF 41 is regenerated. As an automatic regeneration operation, for example, the intake throttle of the diesel engine 9 is throttled, and the exhaust temperature rises due to the throttle of the intake throttle.

In the first regeneration control mode 51, automatic regeneration of the DPF 41 is started and the particulate matter deposited on the filter is combusted when the amount of particulate matter accumulated exceeds the threshold TH1 (regeneration control level is Level 1). To remove.
Further, in the first reproduction control mode 51, an icon A indicating that automatic reproduction is being performed is displayed on the display device 11, and a continuous warning sound is generated.

As described above, the automatic regeneration is a regeneration operation that does not require a special operation for the operator operating the backhoe 1, and is automatically performed when the backhoe 1 is uniquely, that is, viewed from the operator. In this operation, the temperature of the DPF 41 is raised to burn the deposited particulate matter.
Next, after the start of the automatic regeneration, when the PM accumulation amount becomes equal to or higher than the threshold value TH2 and lower than the threshold value TH3 in spite of the execution of the first regeneration control mode 51 in Level 1, the exhaust temperature is raised and the automatic regeneration of the DPF 41 is performed. Therefore, the filter regeneration control means 60 shifts (shifts) the regeneration control level from Level 1 to Level 2 and transitions to the second regeneration control mode 52.

In the second regeneration control mode 52, a warning requesting to increase the rotational speed of the diesel engine 9 is issued while the automatic regeneration is continued. Here, 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 rotational speed of the engine 9 to twice or more the idling rotational speed. .
Specifically, in the second regeneration control mode 52, the display device 11 is displayed intermittently with an icon B instructing the operator to increase the engine speed to, for example, 1800 revolutions or more. Generate a warning sound. When in the second regeneration control mode 52, the operator operates the accelerator according to this display and warning sound, and the engine speed is equal to or higher than a predetermined speed (higher than the idling speed, for example, If it is increased to 1800 revolutions or more), the exhaust temperature further increases, and the combustion of particulate matter deposited on the DPF 41 is promoted to reduce the PM deposition amount. If the PM accumulation amount falls below the warning cancellation threshold value, the filter regeneration control unit 60 returns the regeneration control level to Level 0, and ends the automatic regeneration of the DPF 41 and the display of the icons A and B on the display device 11.

When the PM accumulation amount further increases and the PM accumulation amount becomes equal to or greater than the threshold TH3, such as when the engine speed is not increased, the filter regeneration control means 60 shifts the regeneration control level from Level 2 to Level 3. (Shift) and shift to the third reproduction control mode 53.
In the third regeneration control mode 53, when the PM accumulation amount becomes equal to or higher than the threshold value TH3 higher than the threshold value TH2 at the stage where the warning is issued in the second regeneration control mode 52, the output is output to the diesel engine 9 within a predetermined range. This is a reproduction operation instructing to limit to. In the third regeneration control mode 53, the engine output is limited while continuing automatic regeneration.

In the third regeneration control mode 53, the filter regeneration control means 60 instructs the engine ECU 32 to limit the horsepower that restricts the maximum output of the diesel engine 9 to a predetermined value or less (for example, 50% or less of the specified maximum output). At the same time, an icon indicating that the amount of accumulated PM is too large is displayed on the display device 11 to generate a continuous warning sound.
In Level 3, as with Level 2, an icon B for instructing to increase the engine speed is displayed on the display device 11. When the operator increases the engine speed in accordance with this warning and the PM accumulation amount falls below the warning cancellation threshold, the filter regeneration control means 60 returns the regeneration control level to Level 0, the automatic regeneration of the DPF 41 and the display device 11 End the display of each icon.

In this way, in any of Level 1 to Level 3, if the PM accumulation amount falls below the warning cancellation threshold, the accumulation amount acquisition unit 50 returns the regeneration control level to Level 0, the automatic regeneration of the DPF 41 and the display device 11 End the display of each icon.
The above-described regeneration control of the DPF 41 will be further described with reference to FIGS. FIG. 4 is a flowchart showing the operation after the regeneration control level is determined by the filter regeneration control means 60, and FIG. 5 is a diagram showing the display mode of the display device 11 at each regeneration control level.

In FIG. 4, when the regeneration control level is Level 1 (in the first regeneration control mode 51), the filter regeneration control means 60 causes the engine ECU 32 to perform automatic regeneration as a combustion process (S1) and automatic regeneration. Is displayed on the display device 11 by the main ECU 33 (S2).
As shown in FIG. 5, in the first regeneration control mode 51, the display device 11 displays an icon (DPF burning lamp) A on the liquid crystal panel 112 in accordance with a command from the filter regeneration control means 60 and “DPF “Reproducing” and “Exhaust temperature rise” messages are displayed. At this time, the display device 11 causes the warning LED display portion 113a provided at the uppermost portion of the LED display portion 113 to blink orange.

  Next, when the regeneration control level is Level 2 (in the second regeneration control mode 52), the filter regeneration control means 60 continues automatic regeneration as a combustion process for the engine ECU 32 (S3), and automatic regeneration is performed. An icon (DPF burning lamp) A indicating that the engine is being executed and an icon (Eng rotation speed increase request lamp) B instructing to increase the engine speed are turned on the display device 11 by the main ECU 33 (S4). . Further, when in the second regeneration control mode 52, the filter regeneration control means 60 determines whether or not the engine speed acquired from the engine ECU 32 is, for example, 1800 revolutions or more (S5), and 1800 revolutions or more. If there is (S5: YES), the display device 11 is instructed to turn off the Eng speed increase request lamp B (S6). If the engine speed is less than 1800 rpm (S5: NO), the filter regeneration control means 60 instructs the display device 11 to blink the Eng speed increase request lamp B (S7).

  As shown in FIG. 5, in the second regeneration control mode 52, the display device 11 displays a screen for displaying the DPF burning lamp (icon) A and the Eng rotation speed increase request lamp in the second regeneration control mode 52. A screen displaying (icon) B is alternately displayed on the liquid crystal panel 112. At this time, the display device 11 blinks the warning LED display portion 113a provided at the top of the LED display portion 113 in orange.

  When the operator increases the engine speed in accordance with the displayed instruction and the engine speed acquired from the engine ECU 32 is 1800 or more, the filter regeneration control means 60 increases the Eng speed relative to the display device 11. An instruction is given to display only the screen for displaying the DPF burning lamp (icon) A without displaying the screen for displaying the request lamp (icon) B.

  Subsequently, when the regeneration control level is Level 3 (in the third regeneration control mode 53), the filter regeneration control means 60 continues automatic regeneration as a combustion process for the engine ECU 32 (S8) and automatic regeneration. Is displayed (DPF burning lamp) A and an icon (Eng rotation speed increase request lamp) B for instructing to increase the engine speed is lit on the display device 11 (S9). Further, when in the third regeneration control mode 53, the filter regeneration control means 60 determines whether or not the engine speed acquired from the engine ECU 32 is, for example, 1800 revolutions or more (S10), and 1800 revolutions or more. If there is (S10: YES), the display device 11 is instructed to turn off the Eng speed increase request lamp B (S11). If the engine speed is less than 1800 (S10: NO), the filter regeneration control means 60 instructs the display device 11 to blink the Eng speed increase request lamp B (S12), and the LED display unit. The main ECU 33 instructs the display device 11 to blink the warning LED display 113a provided at the top of 113 in red (S13).

  As shown in FIG. 5, the display device 11 in Level 3 displays a screen for displaying a DPF burning lamp (icon) A and an Eng rotation speed increase request lamp (icon) B in accordance with an instruction from the filter regeneration control means 60. The screen is alternately displayed on the liquid crystal panel 112. In Level 3, since the horsepower of the backhoe 1 is limited, a message “output is being limited” is displayed at the bottom of the screen displaying the Eng rotation speed increase request lamp (icon) B. At this time, the display device 11 blinks the warning LED display portion 113a provided at the top of the LED display portion 113 in red.

  When the operator increases the engine speed in accordance with the displayed instruction and the engine speed acquired from the engine ECU 32 is 1800 or more, the filter regeneration control means 60 increases the Eng speed relative to the display device 11. On the screen displaying the request lamp (icon) B, it is instructed not to display the message “Please increase the engine speed”. Accordingly, when the engine speed is 1800 rpm or more, the display device 11 displays a screen for displaying the DPF burning lamp (icon) A in accordance with an instruction from the filter regeneration control means 60, and “increases the engine speed”. The screen displaying the Eng rotational speed increase request lamp (icon) B on which the message “Please do” is not displayed is alternately displayed on the liquid crystal panel 112. At this time, the display device 11 changes the warning LED display unit 113a provided at the uppermost part of the LED display unit 113 from flashing red to flashing orange.

  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 prompted to perform an operation for backing up the automatic regeneration (increase in the engine speed), so that the reduction of the PM accumulation amount can be promoted and the regeneration of the DPF 41 can be efficiently performed. Can be done well.

Since the increase in engine speed, which is a backup operation for automatic regeneration as described above, is performed by an accelerator operation by an operator, the backhoe 1 is stopped only for regeneration of the DPF 41 as in the prior art. This eliminates the need to interrupt work.
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 engine speed is increased by manually performing the accelerator operation at any timing of the worker during idle time between repeated traveling. The exhaust temperature can be raised.

  Further, in the work site, an operator may operate a work device or the like by operating an operation lever different from that used for traveling the backhoe 1, for example, excavation work. Since the work performed at the work site is a series of multiple work units, the worker can set an arbitrary timing in the idle time between the end of one work unit and the start of the next work unit. By manually operating the accelerator, the exhaust temperature can be raised by increasing the engine speed in the same way as during traveling.

  Further, according to the present embodiment, when it is necessary to further promote the regeneration of the DPF 41 even during traveling or during work, first, the operator is notified by a warning that the engine speed will be increased. In addition, the engine speed can be arbitrarily increased by an accelerator operation. Therefore, unlike the prior art, it is not necessary to stop the backhoe 1 at a safe place just for the regeneration of the DPF 41, and the DPF 41 can be easily reproduced.

  Further, according to the present embodiment, after the PM accumulation amount becomes equal to or greater than the threshold value TH1 and automatic regeneration starts, the rotation of the diesel engine 9 is determined based on the increasing tendency of the PM accumulation amount (whether or not it is equal to or greater than the threshold value TH2). The necessity of increasing the number (whether or not to prompt the operator to regenerate the DPF 41) is determined. That is, it is necessary to increase the engine speed only when the PM accumulation amount further increases (when the threshold value is TH2 or more) because a sufficient regeneration effect cannot be obtained even though the automatic regeneration is started. The operator is notified by an alarm.

That is, when the regeneration effect is sufficient (less than the threshold value TH2), the warning for increasing the engine speed is not performed, so that an unnecessary increase in the engine speed can be avoided. It is possible to prevent the deterioration of the fuel accompanying the increase.
In addition, according to this embodiment, when the regeneration control level becomes Level 3, the output (horsepower) of the diesel engine 9 is limited. This Level 3 is a stage in which the current PM accumulation amount is increasing with respect to the PM accumulation amount that can be collected by the DPF 41, but this level is increased by limiting the horsepower of the diesel engine 9 at this stage. It is possible to reduce the amount of accumulated PM.

That is, at the stage of limiting the horsepower of the diesel engine 9, the PM accumulation amount is also reduced (reduced by combustion) by automatic regeneration, and further, the exhaust amount of exhaust gas is suppressed by this horsepower limitation to reduce the PM accumulation amount. An increase in the amount of accumulated PM is suppressed from both aspects of reducing the amount of accumulated PM due to combustion and reducing the amount of accumulated PM by suppressing the amount of exhaust gas emitted. . In addition, in the horsepower limitation of the diesel engine 9, since the diesel engine 9 is rotating, the operation can be continued if the load is light.
In the present embodiment, even if the PM accumulation amount is equal to or higher than the threshold TH3, the warning for continuously increasing the engine speed is continuously issued. The rotational speed of the engine 9 can be increased and the exhaust temperature can be increased.

[Second Embodiment]
The second embodiment is different from the first embodiment described above in terms of the standard for shifting the playback control level from Level 1 to Level 2.

Differences from the first embodiment will be described with reference to FIGS. 6 and 7.
Referring to FIG. 6, the regeneration control level is Level 1 when the PM accumulation amount is equal to or greater than the threshold value TH1. After that, even if the PM accumulation amount is not equal to or greater than the threshold TH2, the PM accumulation amount after a predetermined time T seconds (sec) from the time when the level becomes Level 1 is not less than the warning cancellation threshold smaller than the threshold TH1. If it is equal to or higher than the warning cancellation threshold, the playback control level is shifted from Level 1 to Level 2. Hereinafter, differences from the first embodiment will be described in detail.

The filter regeneration means 47 includes a timer 54. The timer 54 starts counting from the time when the regeneration control level becomes Level 1 and measures the elapsed time from the time when Level 1 is reached.
The filter regeneration control unit 60 determines whether or not the PM accumulation amount is equal to or greater than the threshold value TH2. If the PM accumulation amount is equal to or greater than the threshold value TH2, the regeneration control level is shifted to Level2.

  Further, even if it is determined that the PM accumulation amount is less than the threshold value TH2, the filter regeneration control means 60 shifts the regeneration control level to Level 2 if the PM accumulation amount after a predetermined time is not less than the warning cancellation threshold value. That is, if the PM accumulation amount is not less than the warning release threshold after a predetermined time T seconds (sec) from the time when Level 1 is reached, the regeneration control level is shifted to Level 2.

As described above, the filter regeneration control means 60 according to the second embodiment can obtain a sufficient regeneration effect only by reducing the intake throttle in the automatic regeneration operation when the regeneration control level at Level 1 is equal to or longer than the predetermined time T seconds (sec). Since it can be determined that it is not, the process proceeds to the next playback control level.
The filter regeneration means 47 having the accumulation amount acquisition means 50 that performs such an operation can issue a warning to the operator to increase the engine speed without waiting for an increase in the PM accumulation amount. Therefore, DPF regeneration can always be executed early.

  According to the present embodiment, the diesel engine 9 is based on the decreasing tendency of the PM accumulation amount after the elapsed time (predetermined time T seconds) from the start of the automatic regeneration (whether it is less than the warning cancellation threshold). The necessity of increasing the rotational speed (whether or not to prompt the operator to regenerate the DPF 41) is determined. That is, after the start of automatic regeneration, when the PM accumulation amount is less than the warning cancellation threshold value and tends to decrease, it is not necessary to increase the rotation speed of the engine 9. If there is no tendency to decrease, the operator is notified that the number of revolutions of the engine 9 is to be increased so that automatic reproduction backup can be performed as soon as possible. In other words, since the DPF can be regenerated by backing up the automatic regeneration at an early stage (a stage where the PM accumulation amount is not so much), it is possible to suppress the deterioration and deterioration of the initial performance of the DPF.

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.
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 DPF regeneration by fuel post-injection is added to automatic regeneration. May be. 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 51 to the third regeneration control mode 53, the intake throttle is all throttled, and then, in the second regeneration control mode 52, the water temperature and the exhaust temperature are the first regeneration control. When it becomes higher than that in the mode 51, the post injection may be started in addition to the throttle of the intake throttle. In this case, it is preferable to continue the post injection even in the third regeneration control mode 53. In addition to the backhoe 1, the control of the DPF 41 can be applied to a construction machine or an agricultural machine that performs operations such as a compact truck loader (CTL) and a tractor.

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 51 First regeneration control mode 52 Second regeneration control mode 53 Third regeneration control Mode 54 Timekeeping part A, B icon

Claims (3)

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,
The filter regeneration means includes
When the amount of particulate matter deposited on the filter becomes equal to or greater than a first deposition amount threshold, automatic regeneration is performed to automatically burn and remove particulate matter deposited on the filter device. Playback control mode,
In the case where the automatic regeneration is performed, when the accumulation amount of the particulate matter becomes equal to or higher than a second accumulation amount threshold value that is higher than the first accumulation amount threshold value , the rotational speed of the diesel engine is set. And a second regeneration control mode for requesting to be raised.   If the amount of the particulate matter accumulated exceeds a third accumulation amount threshold higher than the second accumulation amount threshold at the stage where the request is made, the output of the diesel engine is limited to a predetermined range. The work machine according to claim 1, further comprising a third regeneration control mode instructing to. In the second regeneration control mode, the rotation speed of the diesel engine is increased when the accumulation amount of the particulate matter is not less than a second accumulation amount threshold value and the rotational speed of the diesel engine is less than a predetermined value. The work machine according to claim 1 or 2, wherein the number is required to be increased .