Exhaust gas purification device, exhaust gas purification method, and control device

Abstract

This exhaust gas purification device is provided with: a throttle valve provided in a path through which exhaust gas discharged from an engine, the rotational speed of which is controlled according to the operation of an accelerator, flows; a diesel oxidation catalyst device disposed on the downstream side of the throttle valve; a selective reduction catalyst device disposed on the downstream side of the diesel oxidation catalyst device; a fuel injection device that injects fuel upstream of the diesel oxidation catalyst device; and a control device to which temperature data indicating the inlet temperature and the outlet temperature of the diesel oxidation catalyst device are input, and which controls the throttle valve and the fuel injection device. The upper limit value of the valve opening degree when the fully closed state of the throttle valve is set to the maximum value of the valve opening degree and the fully open state is set to the minimum value of the valve opening degree is changed in accordance with a determination result based on the accelerator opening degree of the accelerator and the operation state of one or more operation devices different from the accelerator.

Description

Technical Field

[0001] The present disclosure relates to an exhaust gas purification device, an exhaust gas purification method and a control device.

[0002] This application claims priority based on Japanese Patent Application No. 2022-140700 filed in Japan on September 5, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] Patent Documents 1 to 3 disclose a technology for regenerating an exhaust gas purification device by controlling an exhaust throttle valve (throttle valve) or the like provided in an exhaust passage of a diesel engine to raise the temperature of the exhaust gas.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: (Japanese) Patent Publication No. 2002-349239

[0007] Patent Document 2: International Publication No. 2016 / 068347 (Patent No. 5987133)

[0008] Patent Document 3: (Japanese) Patent Publication No. 2020-41461 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, as described in Patent Document 3, since the exhaust throttle valve is provided in the path through which the exhaust gas discharged from the engine flows, the use environment is unstable compared to the intake throttle valve provided in the intake path for supplying air to the engine. Therefore, when the exhaust throttle valve is controlled to reduce the opening degree, for example, the exhaust gas sometimes becomes high temperature and high pressure. Therefore, there is a technical problem that in the control of reducing the opening degree of the exhaust throttle valve, the opening degree needs to be appropriately controlled so that parts such as the engine or the after-treatment device are not damaged.

[0011] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide an exhaust gas purification device, an exhaust gas purification method, and a control device capable of appropriately controlling the opening degree of an exhaust throttle valve.

[0012] Technical solutions to solve problems

[0013] In order to solve the above-mentioned problems, one embodiment of the present disclosure provides an exhaust gas purification device, comprising: a throttle valve provided in a path through which exhaust gas discharged from an engine whose rotation speed is controlled according to an operation of an accelerator flows; a diesel oxidation catalyst device arranged on the downstream side of the throttle valve; a selective reduction catalyst device arranged on the downstream side of the diesel oxidation catalyst device; a fuel injection device that injects fuel on the upstream side of the diesel oxidation catalyst device; an inlet temperature sensor that measures an inlet temperature of the diesel oxidation catalyst device; an outlet temperature sensor that measures an outlet temperature of the diesel oxidation catalyst device; and a control device that receives temperature data measured by the inlet temperature sensor and the outlet temperature sensor and controls the throttle valve and the fuel injection device, wherein the control device changes an upper limit value of the valve opening when a fully closed state of the throttle valve is set to a maximum value of the valve opening and a fully open state is set to a minimum value of the valve opening, according to a determination result based on an accelerator opening of the accelerator and an operation state of one or more operation devices different from the accelerator, when performing control to reduce the throttle valve.

[0014] In addition, one aspect of the present disclosure provides a control method for an exhaust gas purification device, the exhaust gas purification device comprising: a throttle valve provided in a path through which exhaust gas discharged from an engine whose rotation speed is controlled according to an operation of an accelerator flows; a diesel oxidation catalyst device arranged on a downstream side of the throttle valve; a selective reduction catalyst device arranged on a downstream side of the diesel oxidation catalyst device; a fuel injection device that injects fuel on an upstream side of the diesel oxidation catalyst device; an inlet temperature sensor that measures an inlet temperature of the diesel oxidation catalyst device; an outlet temperature sensor that measures an outlet temperature of the diesel oxidation catalyst device; and a control device that receives temperature data measured by the inlet temperature sensor and the outlet temperature sensor and controls the throttle valve and the fuel injection device, wherein, when the control of narrowing the throttle valve is performed, the upper limit value of the valve opening when the fully closed state of the throttle valve is set to the maximum value of the valve opening and the fully open state is set to the minimum value of the valve opening is changed according to a determination result based on an accelerator opening of the accelerator and an operation state of one or more operation devices different from the accelerator.

[0015] In addition, one aspect of the present disclosure provides a control device, in an exhaust gas purification device, the control device receives temperature data measured by the inlet temperature sensor and the outlet temperature sensor, and controls the throttle valve and the fuel injection device, the exhaust gas purification device comprising: a throttle valve provided in a path through which exhaust gas discharged from an engine whose rotation speed is controlled according to an operation of an accelerator flows; a diesel oxidation catalyst device arranged on a downstream side of the throttle valve; a selective reduction catalyst device arranged on a downstream side of the diesel oxidation catalyst device; a fuel injection device that injects fuel on an upstream side of the diesel oxidation catalyst device; an inlet temperature sensor that measures an inlet temperature of the diesel oxidation catalyst device; and an outlet temperature sensor that measures an outlet temperature of the diesel oxidation catalyst device, wherein, when the control of narrowing the throttle valve is performed, the upper limit value of the valve opening when the fully closed state of the throttle valve is set to the maximum value of the valve opening and the fully open state is set to the minimum value of the valve opening is changed according to a determination result based on an accelerator opening of the accelerator and an operation state of one or more operation devices different from the accelerator.

[0016] Effects of the Invention

[0017] According to aspects of the present disclosure, the opening degree of the exhaust throttle valve can be appropriately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a construction vehicle equipped with an exhaust gas purification device according to an embodiment of the present disclosure.

[0019] Figure 2 This is a block diagram showing a configuration example of an operating device.

[0020] Figure 3 This is a block diagram showing a configuration example of a control device.

[0021] Figure 4 This is a flowchart showing the temperature increase control in the control device.

[0022] Figure 5 It is a schematic diagram showing an example of each control condition in the temperature increase control.

[0023] Figure 6 It is a graph showing an operation example of the exhaust gas purification device.

[0024] Figure 7 It is a graph showing an operation example of the exhaust gas purification device.

[0025] Figure 8 This is a flowchart showing the automatic regeneration control in the control device.

[0026] Fig. 9is a schematic diagram showing an example of a vehicle safety state condition.

[0027] Fig.10 is a schematic diagram showing an example of a vehicle safety state condition.

[0028] Fig.11 is a schematic diagram showing an example of a vehicle safety state condition.

[0029] Fig.12 Schematic diagram showing an example of the ETV opening degree MAP1.

[0030] Fig.13 Schematic diagram showing an example of the ETV opening degree MAP2.

[0031] Fig.14 It is a graph showing an operation example of the exhaust gas purification device. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Figure 1 This is a schematic structural diagram of a construction vehicle equipped with an exhaust gas purification device according to an embodiment of the present disclosure. Figure 2 This is a block diagram showing a configuration example of an operating device. Figure 3 This is a block diagram showing a configuration example of a control device. Figure 4 This is a flowchart showing the temperature increase control in the control device. Figure 5 It is a schematic diagram showing an example of each condition in the temperature increase control. Figure 6 and Figure 7 It is a graph showing an operation example of the exhaust gas purification device. Figure 8 This is a flowchart showing the automatic regeneration control in the control device. Figures 9 to 11 is a schematic diagram showing an example of a vehicle safety state condition.

[0033] Fig.12 Schematic diagram showing an example of the ETV opening degree MAP1. Fig.13 Schematic diagram showing an example of the ETV opening degree MAP2. Fig.14 It is a diagram showing an operation example of the exhaust gas purification device. It should be noted that the same reference numerals are used for the same or corresponding structures in each figure, and the description thereof is appropriately omitted.

[0034] [Schematic structure of exhaust gas purification device]

[0035] Figure 1The schematic structure of an engineering vehicle 1 equipped with an exhaust gas purification device 10 of the present embodiment is shown. Here, the engineering vehicle 1 is, for example, an engineering machine that performs excavation, leveling, and other operations or transports sand and soil at a construction site such as a mine or a road, for example, a construction machine such as a hydraulic excavator, a wheel loader, a bulldozer, a motor grader, a crane, or a transport vehicle such as a dump truck or a forklift. It should be noted that the exhaust gas purification device 10 of the present embodiment is a device for purifying the exhaust gas of a diesel engine, so it is not limited to the engineering vehicle 1, and can be used for various vehicles or equipment equipped with a diesel engine. The engineering vehicle 1 is equipped with a diesel engine 2 (hereinafter also referred to as an engine), a turbocharger 3 that compresses the air supplied to the diesel engine 2 by rotating a turbine through the exhaust gas of the diesel engine 2, a control device 8, a monitor 9, a vehicle controller 73, an operating device 60, and an exhaust gas purification device 10.

[0036] The diesel engine 2 is provided with an engine speed detection device 6 for detecting the engine speed and a fuel injection device 7 for injecting fuel into the diesel engine 2. Detection data of the engine speed detection device 6 is output to the control device 8. The control device 8 controls the fuel injection device 7 according to accelerator operation and the like.

[0037] [Monitor]

[0038] The monitor 9 has a display unit and an input unit. The display unit is composed of a liquid crystal display or the like. The display unit displays various information, warnings, etc., such as cooling water temperature and remaining fuel. In the monitor 9 of the present embodiment, a notification unit 91 is provided for notifying the execution of the fixed manual regeneration described later, and the monitor 9 functions as a notification device for notifying the operator of various information. The input unit is composed of switches (buttons) and the like arranged around the display unit. In the display unit, the functions of each input unit are displayed by icons and the like. Therefore, the operator can easily understand which switch to press when executing fixed manual regeneration. It should be noted that if a touch panel monitor 9 is used, it is sufficient to touch the switch displayed on the touch panel. In the monitor 9 of the present embodiment, a switch (also referred to as a fixed manual regeneration switch) 92 indicating the execution of fixed manual regeneration is provided. It should be noted that the input unit is not limited to a switch integrally provided in the monitor 9, but may also be composed of a switch provided in a frame different from the monitor 9.

[0039] [Exhaust gas purification device]

[0040] The exhaust gas purification device 10 is a device that performs treatments such as trapping or reducing residual substances such as particulate matter (Particulate Matter; hereinafter referred to as "PM") or NOx (nitrogen oxides) in the exhaust gas, and is controlled by the control device 8. The exhaust gas purification device 10 is equipped with an exhaust throttle valve (hereinafter also referred to as "throttle valve" or "ETV" (Exhaust Throttle Valve)) 20, a fuel injection device 72, a DPF device 71, a urea water injection system 40, and a selective reduction catalyst (Selective Catalytic Reduction; hereinafter referred to as "SCR") device 50 in order from the upstream side in the flow direction of the exhaust gas discharged from the diesel engine 2. The DPF device 71 includes a diesel oxidation catalyst (Diesel Oxidation Catalyst; hereinafter referred to as "DOC") device 30 and a DPF (Diesel Particulate Filter; Diesel Particulate Filter) 70. These DPF device 71, urea water injection system 40, and SCR device 50 are arranged in the middle of the path 11 where the exhaust gas from the diesel engine 2 flows. The path 11 includes an inlet pipe 12 for introducing the exhaust gas from the turbocharger 3 connected to the diesel engine 2 into the DPF device 71, an outlet pipe 13 for connecting the DPF device 71 and the SCR device 50, and an outlet pipe 14 connected to the outlet of the SCR device 50. In addition, the outlet pipe 13 includes a mechanism for diffusing the urea water supplied from the urea water injection system 40.

[0041] [Throttle]

[0042] The throttle valve 20 is composed of a butterfly valve or the like disposed at the inlet pipe 12. The valve opening of the throttle valve 20 is controlled by the control device 8, and as described later, the temperature of the exhaust gas is adjusted by adjusting the valve opening. That is, if the valve opening is reduced, the exhaust gas is compressed in front of the throttle valve 20, and the pressure or temperature of the exhaust gas flowing through the exhaust flow path becomes higher. At this time, the control device 8 sets the torque target value of the engine based on the accelerator opening, for example, and uses a map (also called "MAP") data that sets the valve opening based on the set torque target value and the engine speed as factors to control the valve opening of the throttle valve 20. However, the map data may also be map data that sets the valve opening based on the fuel injection amount and the engine speed as factors. Specifically, when the torque is small, that is, when the load of the engine is small, the temperature of the exhaust gas also decreases. In addition, when the engine speed is low, the temperature of the exhaust gas also decreases. Here, as the valve opening of the throttle valve 20, when the fully closed state is set to 100% and the fully open state is set to 0%, in the region where the torque is less than the predetermined value, the valve opening of the throttle valve 20 is set to be larger as the torque is smaller, and the valve opening of the throttle valve 20 is smaller as the torque is larger, and the valve opening of the throttle valve 20 is set to be larger as the engine speed is smaller, and the valve opening of the throttle valve 20 is set to be smaller as the engine speed is larger. For example, when the torque is small and the engine speed is small, the valve opening is set to be about 90%, and when the torque is large and the engine speed is large, the valve opening is set to be small (for example, about 60%). Thus, in the state where the engine load is low, that is, the temperature is difficult to rise, the valve is slightly closed (the valve opening is increased) to increase the pressure difference resistance of the exhaust gas and increase the temperature of the exhaust gas. It should be noted that the throttle valve 20 has a structural gap even when the valve opening is set to 100%, so the inlet pipe 12 cannot be completely closed.

[0043] [DPF device]

[0044] The DPF device 71 includes the DOC device 30 and the DPF 70 , collects PM by the DPF 70 , and removes PM by oxidizing the PM collected downstream with nitrogen dioxide converted by the DOC device 30 to produce carbon dioxide.

[0045] [DOC device]

[0046] The DOC device 30 includes a housing, and a diesel oxidation catalyst is accommodated inside the housing. The DOC device 30 is a catalyst that oxidizes and generates heat from the fuel (hereinafter referred to as the metered fuel. In addition, the supplied metered fuel is referred to as the fuel metering) supplied to the exhaust gas as needed, so that the exhaust gas temperature rises to a predetermined high temperature range. By utilizing the exhaust gas after the temperature rise, for example, urea deposits accumulated on the outlet pipe 13 described later are decomposed and removed, and regeneration is performed. The metered fuel is, for example, the same light oil as the engine fuel. When the metered fuel is supplied to the engine cylinder, the metered fuel is supplied by post-injection using the fuel injection device 7 for injection into the engine cylinder. In addition, in the present embodiment, by means of the metered fuel injection device 72 provided on the inlet pipe 12, fuel can be supplied to the exhaust gas so that it flows into the DOC device 30 together with the exhaust gas. It should be noted that the fuel injection device disclosed in the present invention corresponds to at least one of the fuel injection device 7 and the fuel injection device 72.

[0047] [Urea water injection system]

[0048] The urea water injection system 40 adds a urea water solution as a reducing agent water solution to the exhaust gas. The urea water injection system 40 includes an injection nozzle 41 installed at the outlet pipe 13 of the DPF device 71 and injecting the urea water solution into the outlet pipe 13, a urea water tank 42 storing the urea water solution, and a pump unit 43 supplying the urea water solution from the urea water tank 42 to the injection nozzle 41. The control device 8 controls the injection nozzle 41 and the pump unit 43 to inject the urea water solution from the injection nozzle 41 into the outlet pipe 13. The urea water solution injected into the outlet pipe 13 is hydrolyzed by the heat of the exhaust gas to become ammonia.

[0049] [SCR device]

[0050] The SCR device 50 reduces and purifies nitrogen oxides in the exhaust gas by using ammonia obtained by hydrolyzing the urea aqueous solution as a reducing agent. Ammonia is supplied to the SCR device 50 together with the exhaust gas as a reducing agent. It should be noted that an ammonia oxidation catalyst can also be arranged on the downstream side of the SCR device 50. The ammonia oxidation catalyst is a catalyst that oxidizes unused ammonia by the SCR device 50 to make it harmless, further reducing the discharge of exhaust gas. If the urea aqueous solution is injected from the injection nozzle 41, there is a situation where urea crystallizes and precipitates in the outlet pipe 13. Therefore, it is necessary to perform a regeneration process by making the exhaust gas temperature high to decompose the precipitate (urea deposit) in the outlet pipe 13. As a regeneration process, there is an automatic regeneration control that is automatically performed when the engineering vehicle is working and a fixed manual regeneration performed by manual operation of the operator, which are switched and selected and controlled by the control device 8.

[0051] [sensor]

[0052] Various sensors for detecting the conditions of the diesel engine 2 and the exhaust gas purification device 10 are provided in the exhaust gas purification device 10. That is, in the inlet pipe 12, a NOx sensor 32 for detecting the concentration of nitrogen oxides (NOx) contained in the exhaust gas is arranged on the downstream side of the throttle valve 20. In the DPF device 71, an inlet temperature sensor 31 for measuring the inlet temperature of the DOC device 30, an outlet temperature sensor 45 for measuring the outlet temperature of the DOC device 30, and an outlet temperature sensor 74 for measuring the outlet temperature of the DPF 70 are arranged. In the SCR device 50, an SCR outlet temperature sensor 51 for measuring the outlet temperature of the SCR device 50 is arranged. In the outlet pipe 14 connected to the SCR device 50, a NOx sensor 52 for detecting the concentration of nitrogen oxides contained in the exhaust gas discharged from the SCR device 50 is arranged. These sensors are connected to the control device 8 via the Controller Area Network (CAN) 18, and the measurement data is output to the control device 8. It should be noted that the NOx sensor 32 is sometimes also arranged at the position of the DPF outlet. In addition, a temperature sensor may be provided at the SCR inlet. In addition, as an example of other sensors, there are differential pressure sensors provided before and after the DPF 70, etc.

[0053] The control device 8 measures the temperature of the exhaust gas on the inlet side of the DOC device 30 through the inlet temperature sensor 31, and controls the valve opening of the throttle valve 20 according to the measured temperature to adjust the temperature of the exhaust gas. The control device 8 obtains the engine speed Ne from the engine speed detection device 6, the temperature Tatin of the exhaust gas on the inlet side of the DOC device 30 from the inlet temperature sensor 31, and the nitrogen oxide concentration NOxin on the inlet side of the DOC device 30 from the NOx sensor 32. In addition, the control device 8 obtains the temperature Tatout of the exhaust gas on the outlet side of the DOC device 30 from the outlet temperature sensor 45, the SCR outlet temperature from the SCR outlet temperature sensor 51, and the nitrogen oxide concentration NOxout on the outlet side of the SCR device 50 from the NOx sensor 52. The control device 8 controls the operation of the fuel injection device 7, the fuel injection device 72, the throttle valve 20, the injection nozzle 41, and the pump unit 43 based on these obtained data or information such as the accelerator operation performed by the operator.

[0054] [Operation device]

[0055] like Figure 2 As shown in FIG. 1 , the operating device 60 includes various operating devices operated by the operator, such as an accelerator 61, a shift lever 62, a parking brake 63, a working device lever 64, a working device lock switch 65, and a travel lock switch 66. The operating device 60 also includes a brake, a steering gear, etc. However, depending on the specifications of the engineering vehicle 1, the operating device 60 may be omitted. Figure 2The accelerator 61 is a device for operating the rotation speed (rotation speed) (or acceleration degree) of the engine 2, and has the form of an accelerator pedal, an accelerator lever, etc. In the present embodiment, the operation amount of the accelerator 61 is referred to as the accelerator opening. In the present embodiment, the accelerator opening of 0% is the case where the operation amount is zero. The shift lever 62 is a device for operating the speed stage of the transmission. The shift lever 62 sets the transmission to, for example, neutral (hereinafter also referred to as "N"), forward, reverse, etc. The parking brake 63 is an operating device for switching the parking brake equipped with the engineering vehicle 1 to an operating state or a non-operating state. The working device lever 64 is a device for operating the working device equipped with the engineering vehicle 1. The working device lever 64 has a mechanism that automatically returns to the neutral position when the operator releases the lever, outputs a signal corresponding to the amount of the lever tilting forward and backward or forward and backward and left and right from the neutral position, and controls the operation of various actuators through the vehicle controller 73 (or the working device controller not shown) according to the signal. When the working device lock switch 65 is operated to the locked state, the operation of the working device stops. When the travel lock switch 66 is operated to the locked state, the travel device of the construction vehicle 1 stops.

[0056] [Vehicle Controller]

[0057] The vehicle controller 73 controls the various parts of the engineering vehicle 1 by inputting signals indicating the operation states (on state, off state, operation amount, etc.) of the various operation devices of the self-operating device 60 or transmitting and receiving predetermined data with other controllers (not shown) such as the control device 8. In the present embodiment, the vehicle controller 73 transmits data indicating the operation states of the accelerator 61, the shift lever 62, the parking brake 63, the working device lever 64, the working device lock switch 65, the driving lock switch 66, etc. or the determination results of the vehicle safety state conditions described later, etc. (hereinafter, these data are collectively referred to as "vehicle data") to the control device 8.

[0058] [Control device]

[0059] Next, the structure of the control device 8 will be described. Figure 3 As shown, the control device 8 includes a sensor data acquisition unit 81 , a vehicle data acquisition unit 82 , a temperature increase control execution unit 83 , a notification instruction unit 84 , and an engine speed increase control execution unit 85 .

[0060] [Sensor data acquisition unit]

[0061] The sensor data acquisition unit 81 repeatedly acquires measurement data of each sensor such as the engine speed detection device 6 , the NOx sensor 32 , the inlet temperature sensor 31 , the outlet temperature sensor 45 , and the NOx sensor 52 at a predetermined cycle.

[0062] [Vehicle data acquisition department]

[0063] The vehicle data acquisition unit 82 repeatedly acquires the above-mentioned vehicle data from the vehicle controller 73 at a predetermined cycle.

[0064] [Temperature rise control execution unit]

[0065] The temperature rise control execution unit 83 executes control to raise the temperature of the exhaust gas when regenerating the exhaust gas purification device 10 (referred to as temperature rise control). In the temperature rise control, the temperature rise control execution unit 83 controls the valve opening of the throttle valve 20, and when the inlet temperature Tatin measured by the inlet temperature sensor 31 is above the set temperature (e.g., 250°C), for example, controls the fuel injection device 72 to supply a fixed amount of fuel. The set temperature is a temperature at which the DOC device 30 can be activated. The fixed amount of fuel is supplied to the DOC device 30 together with the exhaust gas, and chemically reacts with the oxidation catalyst of the DOC device 30 to generate heat. Therefore, the temperature of the exhaust gas that has been raised by controlling the valve opening of the throttle valve 20 further rises when flowing through the DOC device 30. That is, the outlet temperature Tatout of the exhaust gas measured by the outlet temperature sensor 45 becomes higher than the inlet temperature Tatin.

[0066] In addition, in the present embodiment, the temperature rise control includes automatic regeneration control and fixed manual regeneration control. Automatic regeneration control is a control that automatically performs temperature rise control when the temperature rise control execution unit 83 determines that regeneration is required. Fixed manual regeneration control is, for example, a control that stops the normal operation of the engineering vehicle 1 and performs temperature rise control with the permission of the operator when the automatic regeneration control is not completed within a specified time. In the fixed manual regeneration control, the control device 8 (notification instruction unit 84) first uses the monitor 9 to output to the operator that it is in a state where fixed manual regeneration can be performed and a request for fixed manual regeneration. In contrast, if the operator uses the monitor 9 to instruct the execution of fixed manual regeneration, the control device 8 fixes the engine speed to a certain speed, increases the exhaust temperature, and removes PM or urea deposits accumulated on the DPF or SCR, and releases HC or sulfur adsorbed on the DPF or SCR. It should be noted that in the present embodiment, the operation of the engineering vehicle 1 in the state of executing temperature rise control is referred to as regeneration operation. In addition, a specific example of temperature rise control will be described later.

[0067] [Notification and Instruction Department]

[0068] When it is determined that the temperature rise control execution unit 83 needs to execute the fixed manual regeneration control during the execution of the automatic regeneration control, the notification instruction unit 84 outputs the determination result from the monitor 9 and notifies the operator. The monitor 9 notifies the operator that the fixed manual regeneration control needs to be executed by flashing the notification unit 91 or sounding a buzzer. By notifying the monitor 9, the operator can understand that it is difficult to complete the regeneration process based on the automatic regeneration temperature rise control and that the fixed manual regeneration needs to be executed. Therefore, according to the notification of the monitor 9, if the operator presses the switch 92 of the monitor 9 to instruct the execution of the fixed manual regeneration, the fixed manual regeneration is executed by the temperature rise control execution unit 83.

[0069] In addition, after the initial notification (hereinafter referred to as the fixed manual regeneration control request L01), if the operator does not instruct the execution of the fixed manual regeneration within the fourth determination time T14 (for example, 30 minutes), the notification instruction unit 84 outputs the second notification, i.e., the fixed manual regeneration control request L03. The monitor 9 notifies the operator to urge the execution of the fixed manual regeneration again by accelerating the flashing speed of the notification unit 91 or increasing the volume of the notification sound of the buzzer in the fixed manual regeneration control request L03.

[0070] [Engine speed increase control execution unit]

[0071] When the accelerator opening exceeds a predetermined opening threshold after the automatic regeneration control is started, the engine speed increase control execution unit 85 executes control to increase the target value of the idle speed of the engine 2 from a normal speed (e.g., 600 to 700 rpm) to a predetermined value (e.g., 1000 rpm). Since the automatic regeneration control is a control automatically started by the control device 8, if the timing of increasing the setting of the idle speed coincides with the start timing of the automatic regeneration control, the operator may feel uncomfortable. In contrast, the operator can reduce discomfort by increasing the setting of the idle speed in coordination with the timing of operating the accelerator 61.

[0072] [Temperature rise control]

[0073] Next, refer to Figures 4 to 7 The temperature increase control according to the present embodiment will be described. Figure 4 The overall flow of the temperature increase control is shown. After the construction vehicle 1 is started, the control device 8 (temperature increase control execution unit 83) repeatedly determines whether the start condition of the automatic regeneration control is satisfied at a predetermined cycle (step S101).

[0074] like Figure 5As shown, the automatic regeneration control start condition is satisfied when the time elapsed since the last regeneration operation is completed is the first set time T1 or the denitration efficiency calculated based on the measurement data of the NOx sensors 32 and 52 is below the threshold value. Here, the first set time T1 can be set by taking into account the estimated accumulation amount of urea deposits accompanying long-term operation, catalyst poisoning caused by HC or sulfur adsorbed on the DPF or SCR, etc. Hereinafter, the estimated accumulation amount of urea deposits will be described as an example. For example, the accumulation amount of urea deposits per hour varies depending on the type of the engineering vehicle 1 or the diesel engine 2, the content of the work (operating conditions), etc., but can be estimated through experiments or simulations. In addition, the accumulation amount of urea deposits also affects the completion time of the temperature rise control. Therefore, the first set time T1 can be set by taking these into consideration. For example, when the automatic regeneration control is set to be completed within 15 minutes, the time required to reach the amount of urea deposit that can be removed within the time is 24 hours, 48 ​​hours, 72 hours, 96 hours, 120 hours, etc. depending on the type of the engineering vehicle. In these cases, the first set time T1 can be set to 24 hours, 48 ​​hours, 72 hours, 96 hours, 120 hours, etc. depending on the type of the engineering vehicle. In many engineering vehicles, the first set time T1 is set in the range of about 24 to 120 hours. In addition, the nitrogen oxide concentration NOxin measured by the NOx sensor 32 and the nitrogen oxide concentration NOxout measured by the NOx sensor 52 are used to obtain the denitration efficiency by (Noxin-Noxout) / Noxin×100. In this case, the automatic regeneration control is implemented even in the case where the denitration efficiency is below the threshold value before the first set time T1 passes. Furthermore, regardless of the automatic regeneration based on the denitration efficiency, the automatic regeneration control can be necessarily performed every first set time T1, and when the automatic regeneration based on the denitration efficiency is initiated, the first set time T1 can be reset.

[0075] When the automatic regeneration control start condition is satisfied (step S101: Yes), the temperature increase control execution unit 83 starts the automatic regeneration control (step S102). The details of the automatic regeneration control will be described later. Next, the temperature increase control execution unit 83 determines whether the automatic regeneration control end condition is satisfied (step S103). When the automatic regeneration control end condition is satisfied (step S103: Yes), the temperature increase control execution unit 83 ends the automatic regeneration control (step S104), and ends the temperature increase control.

[0076] like Figure 5As shown, the automatic regeneration control end condition is satisfied when: the time during which the DOC outlet temperature Tatout measured by the outlet temperature sensor 45 is above the regeneration determination temperature θ1 (e.g., 450° C.) is accumulated and obtained as a first accumulated time (regeneration time), and the first accumulated time is above the first determination time T11 (e.g., 15 minutes). The regeneration determination temperature θ1 is set based on the regeneration target temperature θ2. The regeneration target temperature θ2 is a target value of the outlet temperature Tatout set for the purpose of removing urea deposits and recovering the performance degradation caused by HC or sulfur adsorbed on the DPF or SCR during long-term operation. Hereinafter, the estimated accumulation amount of urea deposits will be described as an example. Moreover, as far as the control device 8 is concerned, when the outlet temperature Tatout is lower than the regeneration target temperature θ2, the supply amount of the dosing fuel is mainly increased to increase the outlet temperature Tatout, and when the outlet temperature Tatout is higher than the regeneration target temperature θ2, the supply amount of the dosing fuel is mainly reduced to decrease the outlet temperature Tatout. Therefore, in the regeneration process for removing urea deposits, the outlet temperature Tatout fluctuates around the regeneration target temperature θ2. Furthermore, since it is determined that the regeneration process is in which the outlet temperature Tatout fluctuates around the regeneration target temperature θ2, a regeneration determination temperature θ1 is set to a predetermined temperature lower than the regeneration target temperature θ2. In the present embodiment, since the regeneration target temperature θ2 is set to 500° C. and the predetermined temperature is set to −50° C. as an example, the regeneration determination temperature θ1 is set to 450° C. The regeneration determination temperature θ1 is set to be not lower than the lower limit of the temperature range in which urea deposits can be removed.

[0077] The first determination time T11 is set according to the first set time T1. The first determination time T11 is the time required to remove the urea deposit by the temperature rise control. Therefore, it is affected by the accumulation amount of the urea deposit. The accumulation amount of the urea deposit affects the time interval for performing the temperature rise control, that is, the first set time T1. Therefore, the first determination time T11 only needs to be set according to the first set time T1. In the present embodiment, since the first set time T1 is 48 hours as an example, the first determination time T11 is set to 15 minutes. If the first set time T1 is longer than 48 hours, the first determination time T11 is also preferably set longer, and if the first set time T1 is shorter than 48 hours, the first determination time T11 can also be set shorter. Therefore, the first determination time T11 only needs to be set in the range of about 10 minutes to 60 minutes according to the first set time T1, for example.

[0078] When the automatic regeneration control end condition is not satisfied (step S103 : No), the temperature increase control execution unit 83 determines whether the fixed manual regeneration control request first condition is satisfied (step S105 ).

[0079] like Figure 5 As shown, the first condition for the fixed manual regeneration control request is satisfied in the following cases, etc.: during the execution of the automatic regeneration control, the first cumulative time (regeneration time) obtained by accumulating the time when the measured temperature (outlet temperature Tatout) of the outlet temperature sensor 45 is above the regeneration judgment temperature θ1 is less than the first judgment time T11, and the elapsed time from the start of the regeneration process is more than the second judgment time T12 (for example, 120 minutes). If the first condition for the fixed manual regeneration control request is met, the temperature rise control execution unit 83 determines that the condition for notifying the operator that the fixed manual regeneration needs to be performed is met. It should be noted that the first condition for the fixed manual regeneration control request is not limited to this example. For example, the situation where the PM accumulation amount in the DPF is estimated based on the differential pressure sensor value before and after the DPF (not shown) and the estimated value is above a specified threshold value can be included in the first condition for the fixed manual regeneration control request as an OR condition.

[0080] As described above, the first judgment time T11 is the time when the automatic regeneration control is completed. The second judgment time T12 is set as the time that allows the work performed by the engineering vehicle 1 to continue while the automatic regeneration control is executed. If the second judgment time T12 has passed in a state where the automatic regeneration control is not completed, a notification is made to prompt the execution of fixed manual regeneration. In fixed manual regeneration, the work cannot be continued by the engineering vehicle 1. Therefore, the second judgment time T12 is set as a grace time for the operator to continue the work until the notification. Therefore, in the case where the grace time can be set shorter, the second judgment time T12 can be shortened to, for example, about 60 minutes to 90 minutes. In addition, in the case where the grace time is desired to be set longer, the second judgment time T12 can be extended to, for example, about 150 minutes to 180 minutes.

[0081] For example, Figure 6 As shown, in the state of automatic regeneration control, when the load of the diesel engine 2 is low and the outside temperature is low (e.g., below -25°C), for example, when the diesel engine 2 is about to stop in an idling state, the exhaust gas temperature is low, and the inlet temperature Tatin measured by the inlet temperature sensor 31 is below the set temperature (250°C). Therefore, the quantitative fuel supply that is performed only when the inlet temperature Tatin is above the set temperature is almost not performed, and the regeneration time when the outlet temperature Tatout measured by the outlet temperature sensor 45 is above the regeneration judgment temperature θ1 is also shortened. It should be noted that Figure 6 An example of time changes of the DOC inlet temperature Tatin, the DOC outlet temperature Tatout, the regeneration time, the metered fuel flow rate, and the valve opening of the throttle valve 20 is shown when the horizontal axis is the time axis.

[0082] When the first condition of the fixed manual regeneration control request is satisfied (step S105: Yes), the notification instruction unit 84 outputs the fixed manual regeneration control request (step S106). In step S106, the notification instruction unit 84 first outputs the fixed manual regeneration control request L01, and then outputs the fixed manual regeneration control request L03 if the operator does not instruct execution of the fixed manual regeneration within the fourth determination time T14 (e.g., 30 minutes).

[0083] When the fixed manual regeneration control request first condition is not satisfied (step S105: No) or after the notification instruction unit 84 outputs the fixed manual regeneration control request (step S106), the temperature increase control execution unit 83 determines whether the fixed manual regeneration control request second condition is satisfied (step S107).

[0084] like Figure 5 As shown, the second condition for the fixed manual regeneration control request is as follows: during the execution of the automatic regeneration control, when the regeneration time is less than the first judgment time T11 (15 minutes), during the supply of the fixed fuel (i.e., during the period when the inlet temperature Tatin is above the set temperature (250° C.)), the second cumulative time obtained by accumulating the time during which the measured temperature (outlet temperature Tatout) of the outlet temperature sensor 45 is less than the regeneration judgment temperature θ1 is greater than the third judgment time T13 (e.g., 60 minutes). When the second condition for the fixed manual regeneration control request is met, the temperature increase control execution unit 83 also determines that the execution condition for the fixed manual regeneration is met.

[0085] The third judgment time T13 is set as a grace time for a state where the temperature of the exhaust gas does not rise even if a fixed amount of fuel is supplied, and the regeneration process continues to operate normally. The situation that meets the second condition of the fixed manual regeneration control request is a situation where the DOC device 30 may not operate normally, or the operator may perform a special operation such as repeatedly operating and stopping the working device in a short period of time. Therefore, it is preferred to determine that the second condition of the fixed manual regeneration control request is met within a time shorter than the second judgment time T12 of the first condition of the fixed manual regeneration control request. Therefore, the third judgment time T13 is set to a time shorter than the second judgment time T12, specifically half the time. The time of the third judgment time T13 can also be adjusted according to the second judgment time T12. For example, when the second judgment time T12 is set to 90 minutes, the third judgment time T13 can also be set to about 40 minutes to 60 minutes. When the second judgment time T12 is set to 150 minutes, the third judgment time T13 can also be set to about 60 minutes to 80 minutes.

[0086] For example, Figure 7As shown, in the state of executing automatic regeneration control, according to the use method of the engineering vehicle 1, even if a fixed amount of fuel is supplied, the measured temperature of the outlet temperature sensor 45 (outlet temperature Tatout) does not rise above the regeneration determination temperature θ1, and the second cumulative time obtained by accumulating the time when the outlet temperature Tatout is lower than the regeneration determination temperature θ1 is sometimes longer than the third determination time T13. Figure 7 In the example, the second accumulated time is the time obtained by accumulating the times of arrows A1 to A6. Figure 7 The first accumulated time (regeneration time) in is the same as the first condition of the fixed manual regeneration control request, and the outlet temperature Tatout is the regeneration time above the regeneration determination temperature θ1. When the second condition of the fixed manual regeneration control request is met, even if a fixed amount of fuel is supplied, the state that does not meet the automatic regeneration control end condition continues. Therefore, it can be determined that the fixed manual regeneration needs to be performed earlier than the first condition of the fixed manual regeneration control request. It should be noted that Figure 7 An example of time changes of the DOC inlet temperature Tatin, the DOC outlet temperature Tatout, the regeneration time, the metered fuel flow rate, and the valve opening of the throttle valve 20 is shown when the horizontal axis is the time axis.

[0087] When the second condition of the fixed manual regeneration control request is satisfied (step S107: Yes), the notification instruction unit 84 outputs the fixed manual regeneration control request (step S108). In step S108, the notification instruction unit 84 first outputs the fixed manual regeneration control request L01, and then, when the operator does not instruct the execution of the fixed manual regeneration within the fourth determination time T14 (for example, 30 minutes), the notification instruction unit 84 outputs the fixed manual regeneration control request L03. Then, the temperature increase control execution unit 83 ends the automatic regeneration control (step S109).

[0088] When it is determined that the first condition of the fixed manual regeneration control request is met (step S105: Yes), the temperature rise control execution unit 83 continues the execution of the automatic regeneration control. Therefore, after the notification instruction unit 84 has made a notification, the automatic regeneration control process continues. Moreover, when the regeneration time reaches the first determination time T11 (15 minutes) before the execution of the fixed manual regeneration starts and the regeneration process of the automatic regeneration control is completed (step S103: Yes), the notification instruction unit 84 stops the output of the fixed manual regeneration control request L01 or L03 in step S104, and ends the notification in the monitor 9. On the other hand, when it is determined that the second condition of the fixed manual regeneration control request is met (step S107: Yes), the temperature rise control execution unit 83 stops the execution of the automatic regeneration control (step S109). Therefore, as long as the operator does not operate the execution of the fixed manual regeneration, the notification by the notification instruction unit 84 continues.

[0089] When the fixed manual regeneration control request second condition is not satisfied (step S107: No) or after the temperature increase control execution unit 83 ends the execution of the automatic regeneration control (step S109), the temperature increase control execution unit 83 determines whether the fixed manual regeneration control start condition is satisfied (step S110).

[0090] like Figure 5 As shown, the fixed manual regeneration control start condition is satisfied when the fixed manual regeneration switch 92 is pressed by the operator and the construction vehicle is in a state where fixed manual regeneration can be performed. Here, the state where fixed manual regeneration can be performed is, for example, a state where the construction vehicle is stopped and not in motion, such as when the parking brake is actuated, the accelerator is in the off state, and the working implement lever is in the neutral position.

[0091] When the fixed manual regeneration control start condition is satisfied (step S110: Yes), the temperature rise control execution unit 83 ends the automatic regeneration control (step S111) and starts the fixed manual control (step S112). It should be noted that, when the automatic regeneration control ends in step S109, the temperature rise control execution unit 83 does not perform any action in step S111. Next, it is determined whether the fixed manual regeneration control end condition is satisfied (step S113). When the fixed manual regeneration control end condition is satisfied (step S113: Yes), the temperature rise control execution unit 83 ends the fixed manual regeneration control (step S114) and ends the temperature rise control.

[0092] It should be noted that the temperature rise control execution unit 83 performs the fixed manual regeneration control as follows, for example. That is, the temperature rise control execution unit 83 obtains the set valve opening ETVffo specified according to the engine speed Ne and the target torque (or the fuel injection amount Qf) from the map for fixed manual regeneration, and controls the valve opening of the throttle 20 to become the set valve opening ETVffo. Compared with the automatic regeneration control, the fixed manual regeneration controls the valve opening of the throttle 20 or the supply amount of the quantitative fuel so that the temperature of the exhaust gas is easily increased, thereby being able to efficiently recover the performance degradation of the DPF or SCR. Similar to the automatic regeneration control, as long as the first accumulated time when the outlet temperature Tatout is above the regeneration judgment temperature θ1 becomes above the first judgment time T11, the fixed manual regeneration control automatically ends.

[0093] It should be noted that in Figure 4 In the temperature rise control shown, if the automatic regeneration control ends in step S109, the determination process of step S103 is not executed thereafter. Also, if the second condition for the fixed manual regeneration control request is satisfied in step S107, the determination process of step S105 is not executed thereafter.

[0094] [Automatic regeneration control]

[0095] Next, refer to Figure 8 to Figure 14 The automatic regeneration control of this embodiment will be described. Figure 4 In the temperature rise control described above, the automatic regeneration control is repeatedly executed in a predetermined cycle from the start (step S102) to the end (step S104 or step S111). Figure 8 The process of automatic regeneration control is shown.

[0096] if Figure 8 The process shown in FIG. 1 starts, and first, the temperature rise control execution unit 83 determines whether the vehicle safety state condition is satisfied (step S201). In the present embodiment, the vehicle safety state refers to a state in which the engineering vehicle 1 is not in operation (for example, a state in which the possibility of the engineering vehicle 1 immediately causing the engine 2 to operate at low speed idling and increase the output torque from this state is low). In addition, in the present embodiment, operation refers to causing the engineering vehicle 1 to operate except for the operation of operating the engine 2 at an idle state.

[0097] Figures 9 to 11 Indicates an example of a safe state condition for a vehicle. Fig. 9 In the example shown, the vehicle safety state condition (Example 1) is that condition (1) is satisfied and condition (2-1) is satisfied. Condition (1) is that the accelerator opening is below the accelerator opening threshold for safety state determination (for example, the accelerator opening is almost 0% or below 0% to 5%). Condition (2-1) is that the shift lever is in N and the parking brake is in action. Fig.10 In the example shown, the vehicle safety state condition (Example 2) is that condition (1) is satisfied and condition (2-2) is satisfied. Condition (1) is that the accelerator opening is below the accelerator opening threshold for safety state determination. Condition (2-2) is that the driving lock is ON (connected) and the working device lock is ON. The state in which condition (2-2) is satisfied corresponds to a state in which the vehicle is neither driving nor working. Fig.11 In the example shown, the vehicle safety state condition (Example 3) is that condition (1) is satisfied and condition (2-3) is satisfied. Condition (1) is that the accelerator opening is below the accelerator opening threshold for safety state determination. Condition (2-3) is that the working device is locked ON. It should be noted that these are only examples, and for example, all working device levers can be combined in a neutral position. In addition, the vehicle safety state condition can be different, for example, depending on the type or specification of the engineering vehicle 1. For example, the vehicle safety state condition (Example 1) can be used for vehicles such as wheel loaders, dump trucks, or passenger cars. In addition, the vehicle safety state condition (Example 2) can be used for vehicles such as bulldozers that operate the working device while driving. In addition, the vehicle safety state condition (Example 3) can be used for vehicles such as hydraulic excavators that operate the working device without driving.

[0098] When the vehicle safety state condition is not satisfied (step S201: No), the temperature increase control execution unit 83 calculates the temperature increase control execution unit 83 based on the ETV opening MAP1 (throttle opening) for when the vehicle safety state condition is not satisfied. Figure 1 ), determines the ETV opening (throttle opening) (step S202). When the vehicle safety state condition is satisfied (step S201: Yes), the temperature increase control execution unit 83 determines the ETV opening MAP2 (throttle opening) used when the vehicle safety state condition is satisfied. Figure 2 ), and determine the ETV opening (throttle opening) (step S203). It should be noted that the ETV opening MAP1 is a component of the first map of the present disclosure, and the ETV opening MAP2 is a component of the second map of the present disclosure.

[0099] Fig.12 The following is an example of the configuration of the ETV opening MAP1: Fig.13 A configuration example of the ETV opening degree MAP2 is shown. Fig.12 The ETV opening MAP1 and Fig.13 The ETV opening MAP2 shown is a diagram that determines the valve opening based on the engine speed and torque. Fig.12 The upper limit value of the ETV opening in the ETV opening MAP1 shown is 86%. Fig.13 The ETV opening MAP2 shown is different in that the upper limit of the ETV opening is 95%. Fig.13 The ETV opening MAP2 shown is set to the valve opening ratio in the region where the torque is less than 400. Fig.12 The ETV opening MAP1 shown is large. Fig.13 The ETV opening MAP2 shown is set to the valve opening ratio in the region below 1200 rpm. Fig.12 The ETV opening MAP1 shown is large. In this case, Fig.13 The ETV opening MAP2 shown is a state in which the valve opening is further reduced from the ETV opening MAP1 in a region where the torque is approximately close to zero and the engine speed is in an idle engine speed region (engine speed region from low speed idling to idle state).

[0100] Next, the temperature increase control execution unit 83 determines whether the DOC inlet temperature is greater than a predetermined temperature threshold value (e.g., 250° C., the temperature at which the DOC device 30 is activated) (step S204). If the DOC inlet temperature is not greater than the predetermined temperature threshold value (step S204: No), the temperature increase control execution unit 83 determines the ETV opening by feedback control with the DOC inlet temperature as a target value (e.g., 250° C.) (step S205). In this case, in step S205, when the ETV opening MAP2 (second map) is selected, the temperature increase control execution unit 83 may determine the valve opening so as to exceed the upper limit value determined in the ETV opening MAP2 (second map) so that when the DOC inlet temperature is less than the predetermined threshold value, the deviation between the DOC inlet temperature and the predetermined target value becomes smaller.

[0101] Next, the temperature rise control execution unit 83 controls the ETV opening based on the ETV opening determined in step S202, S203 or S205 (step S206). Next, the temperature rise control execution unit 83 starts the fuel injection control for the automatic regeneration control when the DOC inlet temperature is greater than a predetermined temperature threshold (e.g., 250°C, the temperature at which the DOC device 30 is activated) (step S207: Yes), and ends the fuel injection control for the automatic regeneration control when the DOC inlet temperature is less than the predetermined temperature threshold (step S207: No). Here, the fuel injection control for the automatic regeneration control is a fuel quantitative control performed by the fuel injection device 72, etc., for example, by Figure 8 The control performed by the repetitive processing separately executed by the processing shown in the figure, for example, controls the fuel injection amount using a coefficient or a map for automatic regeneration control according to the inlet temperature measured by the inlet temperature sensor 31 or the outlet temperature measured by the outlet temperature sensor 45. It should be noted that in step S208 and step S209, no processing is performed when it has been started or ended.

[0102] Next, the engine speed increase control execution unit 85 determines whether the accelerator opening is greater than a predetermined opening threshold (step S210), and sets the idle speed to be used for automatic regeneration control when the accelerator opening is greater than the predetermined opening threshold (step S211). Once the idle speed is set to be used for automatic regeneration control, it will not be changed until the automatic regeneration control ends. The idle speed for automatic regeneration control is, for example, a speed set to be higher than the normal speed by a predetermined value or a predetermined ratio.

[0103] The operation of the automatic regeneration control based on the above processing is shown in FIG. Fig.14 . Fig.14An example of time changes of the DOC inlet temperature Tatin, the DOC outlet temperature Tatout, the regeneration time, the metered fuel flow rate, and the valve opening of the throttle valve 20 is shown when the horizontal axis is the time axis. Fig.14 This is an example of an operation when the vehicle safety state condition is satisfied. Fig.13 The example shown is the case. Fig.14 In the example shown, the throttle opening is 95% immediately after the automatic regeneration control starts, and then the throttle opening increases from 95% until the DOC inlet temperature reaches 250°C. At time t1, the DOC inlet temperature exceeds 250°C, and the throttle opening becomes 95% again. At time t2, the DOC outlet temperature becomes above the regeneration determination temperature θ1, the regeneration time increases, and at time t3, the automatic regeneration control ends.

[0104] [Effects of Embodiment]

[0105] According to the present embodiment, when a control is requested to increase the exhaust temperature in the exhaust path, a state in which the vehicle is not running (for example, a state in which the vehicle is not running immediately during low-speed idling operation) is detected, and only when the state in which the vehicle is not running is detected, the opening of the exhaust throttle valve is further reduced than before the detection. According to this configuration, when the use environment of the exhaust throttle valve is stable, control is performed to further reduce the opening. Therefore, when control is performed to reduce the throttle valve 20, the temperature can be efficiently increased while avoiding performance deterioration. That is, according to the present embodiment, the opening of the exhaust throttle valve can be appropriately controlled. In addition, because the temperature can be efficiently increased in the automatic regeneration control, the frequency of fixed manual regeneration can be reduced.

[0106] The embodiments of the present invention have been described above with reference to the accompanying drawings, but the specific configuration is not limited to the above embodiments and includes design changes within the scope of the present invention. Fig.12 The ETV opening MAP1 and Fig.13 The ETV opening MAP2 shown may also be a map that determines the valve opening using the engine speed and the fuel injection amount (the fuel injection amount of the fuel injection device 7) as factors. In addition, the control device 8 may be configured using a computer, and part or all of the program executed by the computer may be distributed via a computer-readable recording medium or a communication line.

[0107] [Note]

[0108] The exhaust gas purification device 10 described in the embodiment can be understood as follows.

[0109] (1) A first aspect of the present disclosure provides an exhaust gas purification device 10, comprising: a throttle valve 20, which is provided in a path 11 through which exhaust gas discharged from an engine 2 whose speed is controlled according to an operation of an accelerator 61 flows; a diesel oxidation catalyst device 30, which is arranged on the downstream side of the throttle valve 20; a selective reduction catalyst device 50, which is arranged on the downstream side of the diesel oxidation catalyst device 30; a fuel injection device 72 (7), which injects fuel on the upstream side of the diesel oxidation catalyst device 30; an inlet temperature sensor 31, which measures the inlet temperature of the diesel oxidation catalyst device 30; and an outlet temperature sensor 45, which measures the diesel oxidation catalyst device 30. The outlet temperature of the catalyst device; the control device 8, which is input with the temperature data measured by the inlet temperature sensor 31 and the outlet temperature sensor 45, controls the throttle valve 20 and the fuel injection device 72. When the control of reducing the throttle valve 20 is performed, the control device 8 changes the upper limit value of the valve opening when the fully closed state of the throttle valve 20 is set to the maximum value of the valve opening and the fully open state is set to the minimum value of the valve opening, based on the judgment result based on the accelerator opening of the accelerator 61 and the operation state of one or more operation devices (62 to 66) different from the accelerator 61. According to this aspect and the following aspects, the opening of the exhaust throttle valve can be appropriately controlled.

[0110] (2) The exhaust gas purification device 10 of the second embodiment of the present disclosure is the exhaust gas purification device 10 according to (1), wherein the control device 8 determines the valve opening by selecting either a first map (ETV opening MAP1) that determines the valve opening based on the rotation speed and torque of the engine 2 and a second map (ETV opening MAP2) whose upper limit value of the valve opening is larger than that of the first map, thereby changing the upper limit value of the valve opening. According to this embodiment, the opening of the exhaust throttle valve can be appropriately controlled with a simple structure.

[0111] (3) The exhaust gas purification device 10 of the third aspect of the present disclosure is the exhaust gas purification device 10 according to (2), wherein the second figure is set to a value greater than the first figure in the region where the torque is smaller than the specified value. According to this method, it is possible to control the valve opening to be further reduced in a stable region where the torque, i.e., the load, is small.

[0112] (4) The exhaust gas purification device 10 of the fourth embodiment of the present disclosure is the exhaust gas purification device 10 according to (2) or (3), wherein the second map is set to a value greater than the first map in the region where the rotation speed is smaller than the specified value. According to this aspect, control can be performed to further reduce the valve opening in a stable region where the rotation speed is small.

[0113] (5) The exhaust gas purification device 10 of the fifth embodiment of the present disclosure is the exhaust gas purification device 10 according to (2) to (4), wherein the control device 8 controls the valve opening to exceed the upper limit value determined in the second diagram when the second diagram is selected, so that when the inlet temperature is below a predetermined threshold value, the deviation between the inlet temperature and the predetermined target value becomes smaller. According to this embodiment, the opening can be further reduced.

[0114] Industrial Applicability

[0115] According to the above aspect, the opening degree of the exhaust throttle valve is appropriately controlled.

[0116] Description of Reference Numerals

[0117] 1 Engineering Vehicles

[0118] 2 Diesel Engine

[0119] 3 Turbocharger

[0120] 6 Engine speed detection device

[0121] 7 Fuel injection device

[0122] 8 Control device

[0123] 9 Monitor

[0124] 10 Exhaust gas purification device

[0125] 11 Path

[0126] 20 Throttle

[0127] 30 Diesel Oxidation Catalytic Device (DOC Device)

[0128] 31 Inlet temperature sensor

[0129] 32 NOx sensor

[0130] 40 Urea water injection system

[0131] 41 Injection Nozzle

[0132] 42 Urea water tank

[0133] 43 Pump unit

[0134] 45 Outlet temperature sensor

[0135] 50 Selective Catalytic Reduction Device (SCR Device)

[0136] 52 NOx sensor

[0137] 60 Operating device

[0138] 61 Accelerator

[0139] 62 Gear lever

[0140] 63 Parking brake

[0141] 64 Working device rod

[0142] 65 Working device lock switch

[0143] 66 Driving lock switch

[0144] 70DPF

[0145] 71 DPF device

[0146] 72 Fuel injection device

[0147] 73 Vehicle Controller

[0148] 74 Outlet temperature sensor

[0149] 81 Sensor data acquisition unit

[0150] 82 Vehicle Data Acquisition Department

[0151] 83 Temperature rise control execution unit

[0152] 84 Notification and Instruction Department

[0153] 85 Engine speed increase control execution unit

[0154] 91 Notification Department

[0155] 92 switch (fixed manual regeneration switch)

Claims

1. An exhaust gas purification device, characterized in that: have: a throttle valve provided on a path through which exhaust gas discharged from an engine whose rotation speed is controlled according to an operation of an accelerator flows; a diesel oxidation catalyst device, which is arranged on the downstream side of the throttle valve; Selecting a reduction catalyst device, which is arranged on the downstream side of the diesel oxidation catalyst device; a fuel injection device that injects fuel on the upstream side of the diesel oxidation catalyst device; an inlet temperature sensor for measuring an inlet temperature of the diesel oxidation catalyst device; an outlet temperature sensor for measuring the outlet temperature of the diesel oxidation catalyst device; a control device which receives the temperature data measured by the inlet temperature sensor and the outlet temperature sensor and controls the throttle valve and the fuel injection device, When the control device performs control to reduce the throttle valve, based on a determination result based on an accelerator opening of the accelerator and an operation state of one or more operation devices different from the accelerator, The upper limit value of the valve opening when the fully closed state of the throttle valve is set to the maximum value of the valve opening and the fully open state is set to the minimum value of the valve opening is changed.

2. The exhaust gas purification device according to claim 1, characterized in that: The control device determines the valve opening by selecting either a first map that determines the valve opening based on the engine speed and torque and a second map whose upper limit of the valve opening is larger than that of the first map, thereby changing the upper limit of the valve opening.

3. The exhaust gas purification device according to claim 2, characterized in that: The second map is configured such that the valve opening degree has a value larger than that in the first map in a region where the torque is smaller than a predetermined value.

4. The exhaust gas purification device according to claim 3, characterized in that: The second map is configured such that the valve opening degree is set to a value larger than that in the first map in a region where the rotation speed is lower than a predetermined value.

5. The exhaust gas purification device according to any one of claims 2 to 4, characterized in that: When the second map is selected, the control device controls the valve opening to exceed the upper limit value determined in the second map so that when the inlet temperature is equal to or lower than a predetermined threshold value, a deviation between the inlet temperature and a predetermined target value becomes small.

6. A method for controlling an exhaust gas purification device, the exhaust gas purification device comprising: a throttle valve provided in a path through which exhaust gas discharged from an engine whose rotation speed is controlled according to an operation of an accelerator flows; a diesel oxidation catalyst device, which is arranged on the downstream side of the throttle valve; Selecting a reduction catalyst device, which is arranged on the downstream side of the diesel oxidation catalyst device; a fuel injection device that injects fuel on the upstream side of the diesel oxidation catalyst device; an inlet temperature sensor for measuring an inlet temperature of the diesel oxidation catalyst device; an outlet temperature sensor for measuring the outlet temperature of the diesel oxidation catalyst device; A control device, which receives the temperature data measured by the inlet temperature sensor and the outlet temperature sensor and controls the throttle valve and the fuel injection device, is characterized in that: When executing control to narrow the throttle, the upper limit value of the valve opening when the fully closed state of the throttle is set to the maximum value of the valve opening and the fully open state is set to the minimum value of the valve opening is changed according to a judgment result based on the accelerator opening of the accelerator and the operating state of one or more operating devices different from the accelerator.

7. A control device, in an exhaust gas purification device, wherein the control device receives temperature data measured by the inlet temperature sensor and the outlet temperature sensor and controls the throttle valve and the fuel injection device, the exhaust gas purification device comprising: a throttle valve provided in a path through which exhaust gas discharged from an engine whose rotation speed is controlled according to an operation of an accelerator flows; a diesel oxidation catalyst device, which is arranged on the downstream side of the throttle valve; Selecting a reduction catalyst device, which is arranged on the downstream side of the diesel oxidation catalyst device; a fuel injection device that injects fuel on the upstream side of the diesel oxidation catalyst device; an inlet temperature sensor for measuring an inlet temperature of the diesel oxidation catalyst device; An outlet temperature sensor is used to measure the outlet temperature of the diesel oxidation catalyst device. The control device is characterized in that: When the throttle control is executed, based on a determination result based on an accelerator opening of the accelerator and an operation state of one or more operation devices different from the accelerator, The upper limit value of the valve opening when the fully closed state of the throttle valve is set to the maximum value of the valve opening and the fully open state is set to the minimum value of the valve opening is changed.

Images