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

Abstract

An exhaust gas purification device comprises a throttle valve located in a path through which exhaust gas emitted by an engine flows, the engine speed being controlled by operation of an accelerator pedal, a diesel oxidation catalyst device located on a downstream side of the throttle valve, a selective reduction catalyst device located on a downstream side of the diesel oxidation catalyst device, a fuel injection device injecting fuel on an upstream side of the diesel oxidation catalyst device, and a control device that inputs temperature data indicating an inlet temperature and an outlet temperature of the diesel oxidation catalyst device and controls the throttle valve and the fuel injection device.In a case of implementing throttle valve control, the control device changes an upper limit of a valve opening degree when a fully closed state of the throttle valve is set as a maximum value of the valve opening degree and a fully open state of the throttle valve is set as a minimum value of the valve opening degree, based on a determination result that is based on an accelerator pedal opening degree and operating conditions of one or more operating devices that differ from the accelerator pedal.

Description

Technical area

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

[0002] Priority is claimed to Japanese Patent Application No. 2022-140700, filed on September 5, 2022, the contents of which are incorporated herein by reference. State of the art

[0003] Patent Documents 1 to 3 disclose technologies for controlling an exhaust throttle valve (throttle valve) or the like provided in an exhaust path of a diesel engine to increase the temperature of an exhaust gas and reproduce an exhaust gas purification device. Citation listPatent documents Patent Document 1: Unexamined Japanese Patent Application, First Publication No. 2002-349239 Patent Document 2: PCT International Publication WO2016 / 068347 (Japanese Patent No. 5987133) Patent Document 3: Unexamined Japanese Patent Application, First Publication No. 2020-41461 Summary of the inventionTechnical problem

[0004] However, since the exhaust throttle valve is provided in a path through which exhaust gas discharged from the engine flows, as disclosed in Patent Document 3, the operating environment is unstable compared to an intake throttle valve provided in an intake path through which air is supplied to the engine. Therefore, the exhaust gas may have a high temperature and high pressure, for example, in conjunction with the throttling control of the opening degree of the exhaust throttle valve. Therefore, in controlling the throttling of the opening degree of the exhaust throttle valve, there is a problem that the opening degree must be appropriately controlled so as not to damage components such as the engine and an aftertreatment device.

[0005] 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 an opening degree of an exhaust throttle valve. Solution to the problem

[0006] To solve the above-described problem, according to one aspect of the present disclosure, there is provided an exhaust gas purification device comprising: a throttle valve configured to be provided in a path through which exhaust gas discharged from an engine flows, wherein a rotational speed of the engine is controlled according to an operation of an accelerator pedal; a diesel oxidation catalyst device configured to be disposed on a downstream side of the throttle valve; a selective reduction catalyst device configured to be disposed on a downstream side of the diesel oxidation catalyst device; a fuel injection device configured to inject fuel on an upstream side of the diesel oxidation catalyst device;an inlet temperature sensor configured to measure an inlet temperature of the diesel oxidation catalyst device; an outlet temperature sensor configured to measure an outlet temperature of the diesel oxidation catalyst device;and a control device configured to input temperature data measured by the intake temperature sensor and the exhaust temperature sensor and control the throttle valve and the fuel injection device. In a case of performing throttle valve throttling control, the control device changes an upper limit value of a valve opening degree when a fully closed state of the throttle valve is set as a maximum value of the valve opening degree and a fully open state of the throttle valve is set as a minimum value of the valve opening degree, based on a determination result based on an accelerator opening degree of the accelerator pedal and operating conditions of one or more operating devices other than the accelerator pedal.

[0007] Furthermore, according to another aspect of the present disclosure, an exhaust gas purification method is a control method of an exhaust gas purification device including a throttle valve configured to be provided in a path through which exhaust gas discharged from an engine flows, wherein a rotational speed of the engine is controlled according to an operation of an accelerator pedal, a diesel oxidation catalyst device configured to be arranged on a downstream side of the throttle valve, a selective reduction catalyst device configured to be arranged on a downstream side of the diesel oxidation catalyst device, a fuel injection device configured to inject fuel on an upstream side of the diesel oxidation catalyst device, an intake temperature sensor configuredto measure an inlet temperature of the diesel oxidation catalyst device, an outlet temperature sensor configured to measure an outlet temperature of the diesel oxidation catalyst device, and a control device configured to input temperature data measured by the inlet temperature sensor and the outlet temperature sensor and to control the throttle valve and the fuel injection device, wherein the exhaust gas purification method comprises: changing, in a case of performing the throttle valve throttling control, an upper limit value of a valve opening degree when a fully closed state of the throttle valve is set as a maximum value of the valve opening degree and a fully open state of the throttle valve is set as a minimum value of the valve opening degree, based on a determination result,which is based on an accelerator pedal opening degree of the accelerator pedal and operating conditions of one or more operating devices other than the accelerator pedal.

[0008] Furthermore, according to another aspect of the present disclosure, there is provided a control device in an exhaust gas purification device, including a throttle valve configured to be provided in a path through which exhaust gas discharged from an engine flows, wherein a rotational speed of the engine is controlled according to an operation of an accelerator pedal, a diesel oxidation catalyst device configured to be arranged on a downstream side of the throttle valve, a selective reduction catalyst device configured to be arranged on a downstream side of the diesel oxidation catalyst device, a fuel injection device configured to inject fuel on an upstream side of the diesel oxidation catalyst device, an inlet temperature sensor configured toto measure an inlet temperature of the diesel oxidation catalyst device and has an outlet temperature sensor configured to measure an outlet temperature of the diesel oxidation catalyst device, wherein the control device inputs temperature data measured by the inlet temperature sensor and the outlet temperature sensor and controls the throttle valve and the fuel injection device, and in a case of performing throttle valve throttling control, the control device changes an upper limit value of a valve opening degree when a fully closed state of the throttle valve is set as a maximum value of the valve opening degree and a fully open state of the throttle valve is set as a minimum value of the valve opening degree, based on a determination result based on an accelerator pedal opening degree of the accelerator pedal and operating conditions of one or more operating devices,which are different from the accelerator pedal. Advantageous effects of the invention,

[0009] According to aspects of the present disclosure, it is possible to appropriately control the opening degree of an exhaust throttle valve. Brief description of the drawings [ Fig. 1] A schematic configuration diagram of a work vehicle having an exhaust gas purification device according to an embodiment of the present disclosure. [ Fig. 2] A block diagram showing a configuration example of an operating device. [ Fig. 3] A block diagram showing a configuration example of a control device. [ Fig. 4] A flowchart showing the temperature increase control in the control device. [ Fig. 5] A schematic diagram showing an example of each control condition in temperature increase control. [ Fig. 6] A diagram showing an operation example of the exhaust gas purification device. [ Fig. 7] A diagram showing another operation example of the exhaust gas purification device. [ Fig. 8] A flowchart showing the automatic reproduction control in the control device. [ Fig. 9] A schematic representation of an example of the safety status of a vehicle. [ Fig. 10] A schematic diagram showing another example of the vehicle's safety status. [ Fig. 11] A schematic diagram showing another example of the vehicle's safety status. [ Fig. 12] A schematic diagram of an example of an ETV opening degree MAP1. [ Fig. 13] A schematic diagram of an example of an ETV opening degree MAP2. [ Fig. 14] A graphical representation showing another operation example of the exhaust gas purification device. Description of the embodiments

[0010] Embodiments of the present disclosure will be described below with reference to the drawings. Fig. 1 is a schematic configuration diagram of a work vehicle having an exhaust gas purification device according to an embodiment of the present disclosure. Fig. 2 is a block diagram showing a configuration example of an operating device. Fig. 3 is a block diagram showing a configuration example of a control device. Fig. 4 is a flowchart illustrating the temperature increase control in the control device. Fig. Figure 5 is a schematic diagram showing an example of each condition in temperature increase control. Fig. 6 and Fig. 7 are diagrams showing operation examples of the exhaust gas purification device. Fig. Figure 8 is a flowchart illustrating the automatic reproduction control in the control device. Fig. Figures 9 to 11 are schematic diagrams illustrating examples of a vehicle safety condition. Fig. 12 is a schematic diagram showing an example of an ETV opening degree MAP1. Fig. Figure 13 is a schematic diagram showing an example of an ETV opening degree MAP2. Fig. 14 is a diagram showing an operation example of the exhaust gas purification device. In each figure, the same reference numerals are used for the same or corresponding configurations, and descriptions thereof are omitted where appropriate. [Schematic structure of an exhaust gas purification system]

[0011] Fig. 1 schematically shows the configuration of a work vehicle 1 having an exhaust gas purification device 10 according to the present embodiment. Here, the work vehicle 1 is, for example, a work machine that performs work such as excavation and leveling or transportation of soil and the like at a construction site such as a mine or a road, and corresponds, for example, to construction machinery such as a hydraulic excavator, a wheel loader, a bulldozer, a motor grader, and a crane, or transportation vehicles such as a dump truck and a forklift. Since the exhaust gas purification device 10 in the present embodiment purifies exhaust gas from a diesel engine, the exhaust gas purification device 10 can be applied not only to the work vehicle 1 but also to various diesel-engine-powered vehicles and equipment.The work vehicle 1 comprises a diesel engine 2 (also referred to as engine), a turbocharger 3 which rotates a turbine with the exhaust gas of the diesel engine 2 and compresses the air to be supplied to the diesel engine 2, a control device 8, a monitor 9, a vehicle controller 73, an operating device 60 and the exhaust gas purification device 10.

[0012] The diesel engine 2 is provided with an engine speed detecting device 6 that detects an engine speed, and a fuel injector 7 that injects fuel into the diesel engine 2. The detection data of the engine speed detecting device 6 is output to the control device 8. Furthermore, the control device 8 controls the fuel injector 7 according to an accelerator pedal operation or the like. [Monitor]

[0013] The monitor 9 includes a display unit and an input unit. The display unit is equipped with a liquid crystal display or the like. The display unit displays various types of information, such as a cooling water temperature and remaining fuel level, a warning, and the like. The monitor 9 in the present embodiment is provided with a notification unit 91 that executes notification for performing stationary manual reproduction, which will be described later. The monitor 9 functions as a notification device that informs an operator of various types of information. The input unit is configured by a switch (button) or the like arranged around the display unit. The functions of each input unit are displayed on the display unit by icons or the like.Therefore, the operator can easily determine which switch to press when performing stationary manual reproduction. When a monitor 9 with a touch panel is used, it suffices to touch a switch displayed on the touch panel. The monitor 9, in the present embodiment, is provided with a switch (also referred to as a stationary manual reproduction switch) 92 for instructing the execution of stationary manual reproduction. The input unit is not limited to a switch provided integrally with the monitor 9 and may be configured by a switch installed in a cabinet or the like different from the monitor 9. [Exhaust gas purification device]

[0014] The exhaust gas purification device 10 performs a process of capturing or reducing a residual substance such as particulate matter (hereinafter abbreviated as "PM") or nitrogen oxides (NOx) in the exhaust gas and is controlled by the control device 8. The exhaust gas purification device 10 includes, in order from an upstream side in a flow direction of the exhaust gas discharged from the diesel engine 2, an exhaust throttle valve (hereinafter also referred to as a "throttle valve" or "ETV") 20, a fuel injection device 72, a DPF device 71, a urea water injection system 40, and a selective catalytic reduction (hereinafter referred to as SCR) device 50. The DPF device 71 includes a diesel oxidation catalyst (hereinafter abbreviated as "DOC") 30 and a diesel particulate filter (DPF) 70.The DPF device 71, the urea water injection system 40, and the SCR device 50 are located in the center of a path 11 through which the exhaust gas of the diesel engine 2 flows. The path 11 includes an inlet pipe 12 that introduces exhaust gas from the turbocharger 3 connected to the diesel engine 2 into the DPF device 71, an outlet pipe 13 that connects the DPF device 71 and the SCR device 50, and an outlet pipe 14 that connects to the outlet of the SCR device 50. Furthermore, a mechanism for diffusing urea water supplied from the urea water injection system 40 is provided in the outlet pipe 13. [Throttle]

[0015] The throttle valve 20 is configured by a throttle body or the like arranged in the intake pipe 12. The valve opening degree of the throttle valve 20 is controlled by the control device 8, and the temperature of the exhaust gas is adjusted by adjusting the valve opening degree, as described later. That is, when the valve opening degree is reduced, the exhaust gas in front of the throttle valve 20 is compressed, and the pressure and temperature of the exhaust gas flowing through an exhaust flow passage are increased. At this time, the control device 8 sets, for example, a torque target of the engine based on an accelerator pedal opening degree or the like, and controls the valve opening degree of the throttle valve 20 using map data (also referred to as "MAP") in which the valve opening degree is adjusted using the set torque target and the engine speed as elements.However, the map data may be, for example, map data in which the valve opening degree is adjusted using a fuel injection amount and the engine speed as elements. In particular, in a case where the torque is small, that is, the load of the engine is small, the temperature of the exhaust gas is also reduced. Moreover, the exhaust gas temperature is also lowered at a low engine speed. In a case where the fully closed state is set to 100% and the fully open state is set to 0% as the valve opening degree of the throttle valve 20, in a range where the torque is equal to or less than a predetermined value, the valve opening degree of the throttle valve 20 is set to increase as the torque becomes smaller and decrease as the torque becomes larger, and to increase as the engine speed becomes smaller and decrease as the engine speed becomes larger.For example, when the torque is small and the engine speed is low, the valve opening degree only needs to be set to about 90%. When the torque is large and the engine speed is high, the valve opening degree only needs to be set to a small value (for example, about 60%). As a result, in a state where the engine load is light, that is, in a state where the temperature is difficult to rise, the valve is closed (the valve opening degree is increased) to increase the pressure resistance of the exhaust gas and raise the temperature of the exhaust gas. Since the throttle valve 20 has a gap in its structure even at a valve opening degree of 100%, the intake pipe 12 is not completely closed. [DPF device]

[0016] The DPF device 71 includes the DOC device 30 and the DPF 70, collects the PMs in the DPF 70, oxidizes the PMs collected downstream by nitrogen dioxide converted into carbon dioxide by the DOC device 30, and thereby removes the PMs. [DOC device]

[0017] The DOC device 30 includes a housing and a diesel oxidation catalyst housed in the housing. The DOC device 30 is a catalyst that oxidizes fuel supplied to an exhaust gas on demand (hereinafter referred to as metered fuel, and the supply of the metered fuel is referred to as fuel metering) and generates heat to raise an exhaust gas temperature to a predetermined high temperature range. By using the elevated-temperature exhaust gas, urea deposits or the like, which will be described later, accumulated in the exhaust pipe 13, for example, are decomposed and removed to be reproduced. The metered fuel is, for example, the same light oil as the engine fuel.In a case where the metered fuel is supplied to an engine cylinder, the metered fuel is supplied to the engine cylinder by post-injection with the fuel injection device 7. Furthermore, in the present embodiment, the fuel may be injected into the exhaust gas by the metered fuel injection device 72 provided in the intake pipe 12 and supplied to the DOC device 30 together with the exhaust gas. The fuel injection device according to the present disclosure corresponds to at least one of the fuel injection device 7 and the. Fuel injection device 72.[Urea water injection system]

[0018] The urea water injection system 40 adds an aqueous urea solution to the exhaust gas as an aqueous reducing agent solution. The urea water injection system 40 includes an injection nozzle 41 attached to the outlet pipe 13 of the DPF device 71 and injecting an aqueous urea solution into the outlet pipe 13, a urea water tank 42 storing the aqueous urea solution, and a pump unit 43 supplying the aqueous urea 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 aqueous urea solution from the injection nozzle 41 into the outlet pipe 13. The aqueous urea solution injected into the outlet pipe 13 is hydrolyzed by the heat of the exhaust gas and converted into ammonia. [SCR device]

[0019] The SCR device 50 reduces and purifies nitrogen oxides in the exhaust gas by using ammonia obtained by hydrolysis of an aqueous urea solution as a reducing agent. Ammonia is supplied to the SCR device 50 along with the exhaust gas as a reducing agent. An ammonia oxidation catalyst may be provided downstream of the SCR device 50. The ammonia oxidation catalyst oxidizes and detoxifies ammonia not used in the SCR device 50, further reducing exhaust emissions. When the aqueous urea solution is injected from the injection nozzle 41, the urea may crystallize and deposit in the exhaust pipe 13. Therefore, it is necessary to perform a reproduction process to decompose the precipitate (urea deposit) in the exhaust pipe 13 by raising the exhaust gas temperature.The reproduction process includes automatic reproduction control, which is performed automatically when the work vehicle is in operation, and stationary manual reproduction, which is performed by manual operation by the operator. The reproduction method is switched, selected, and controlled by the control device 8. [Sensor]

[0020] The exhaust gas purification device 10 is equipped with various sensors for detecting the state of the diesel engine 2 or the exhaust gas purification device 10. For example, a NOx sensor 32 is arranged in the intake pipe 12 on the downstream side of the throttle valve 20. This sensor detects the concentration of nitrogen oxides (NOx) contained in the exhaust gas. The DPF device 71 is provided with an inlet temperature sensor 31 that measures the inlet temperature of the DOC device 30, an outlet temperature sensor 45 that measures the outlet temperature of the DOC device 30, and an outlet temperature sensor 74 that measures the outlet temperature of the DPF 70. The SCR device 50 is provided with an SCR outlet temperature sensor 51 that measures the outlet temperature of the SCR device 50. A NOx sensor 52 is arranged in the outlet pipe 14 connected to the SCR device 50 and measures the concentration of nitrogen oxides contained in the exhaust gas of the SCR device 50.These sensors are connected to the control device 8 via a Controller Area Network (CAN) 18 and output measurement data to the control device 8. The NOx sensor 32 can be installed at a location on the DPF outlet. Furthermore, a temperature sensor can be installed at the SCR inlet. Other sensors include, for example, a differential pressure sensor installed before and after the particulate filter 70.

[0021] The control device 8 measures the temperature of the exhaust gas on the inlet side of the DOC device 30 with the inlet temperature sensor 31 and controls the valve opening degree of the throttle valve 20 according to the measured temperature to adjust the exhaust gas temperature. The control device 8 detects the engine speed Ne from the engine speed detection device 6, detects the temperature Tatin of the exhaust gas on the inlet side of the DOC device 30 from the inlet temperature sensor 31, and detects 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 detects the temperature Tatout of the exhaust gas on the outlet side of the DOC device 30 from the outlet temperature sensor 45, detects the SCR outlet temperature from the SCR outlet temperature sensor 51, and detects 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 injector 7, the fuel injector 72, the throttle valve 20, the injection nozzle 41 and the pump unit 43 based on the detected data and information such as an accelerator pedal operation by the operator. [Operating device]

[0022] As in Fig. 2, the operating device 60 includes various devices that are operated by the operator, such as an accelerator pedal 61, a shift lever 62, a parking brake 63, a work machine lever 64, a work machine lock switch 65, and a travel lock switch 66. In addition, the operating device 60 includes a brake, a steering, and the like. Some of the devices shown in Fig. However, the operating devices shown in Fig. 2 may be omitted depending on the specifications of the work vehicle 1. The accelerator pedal 61 is a device that controls the rotational speed (or acceleration degree) of the engine 2 and is in the form of an accelerator pedal, a throttle lever, or the like. In the present embodiment, the operation degree of the accelerator pedal 61 is referred to as the accelerator opening degree. In the present embodiment, the accelerator opening degree of 0% corresponds to the case where the operation amount is zero. The shift lever 62 is a device that operates a gear stage of a transmission. The shift lever 62 sets the transmission to, for example, neutral (hereinafter also abbreviated to "N"), forward, reverse, or the like. The parking brake 63 is an operating device that switches a parking brake provided in the work vehicle 1 between an operating state and a non-operating state.The work machine lever 64 is a device that operates a work machine provided in the work vehicle 1. The work machine lever 64 includes a mechanism that automatically returns to a neutral position when the operator releases their hand and outputs a signal corresponding to a forward / backward or forward / backward / left / right tilt amount from the neutral position of the lever. The operation of the various actuators is controlled by the vehicle controller 73 (or a work machine controller (not shown)) according to the signal. When the work machine lock switch 65 is operated in a locked state, the operation of the work machine is stopped. When the travel lock switch 66 is operated in a locked state, a travel device of the work vehicle 1 is stopped. [Vehicle control]

[0023] The vehicle controller 73 controls each unit of the work vehicle 1 by inputting a signal representing an operating state (an on state, an off state, an operation amount, and the like) of each operating device from the operating device 60, or by transmitting and receiving predetermined data to and from another controller (not shown), such as the control device 8. In the present embodiment, the vehicle controller 73 transmits data indicating the operating states of the accelerator pedal 61, the shift lever 62, the parking brake 63, the work machine lever 64, the work machine lock switch 65, the travel lock switch 66, and the like, a determination result of a vehicle safety state described later, and the like (these data are hereinafter collectively referred to as "vehicle data") to the control device 8. [Control device]

[0024] Next, the configuration of the control device 8 is described. As shown in Fig. 3, 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. [Sensor data acquisition unit]

[0025] The sensor data acquisition unit 81 repeatedly acquires measurement data from each sensor such as the engine speed detection device 6, the NOx sensor 32, the intake temperature sensor 31, the exhaust temperature sensor 45, and the NOx sensor 52 in a predetermined cycle. [Vehicle data acquisition unit]

[0026] The vehicle data acquisition unit 82 repeatedly acquires the above-described vehicle data from the vehicle controller 73 in a predetermined cycle. [Temperature increase control implementation unit]

[0027] The temperature increase control execution unit 83 controls (referred to as temperature increase control) the increase in exhaust gas temperature when the exhaust gas purification device 10 is reproduced. During temperature increase control, the temperature increase control execution unit 83 controls the valve opening degree of the throttle valve 20 and, for example, controls the fuel injector 72 to supply the metered fuel when the intake temperature Tatin measured by the intake temperature sensor 31 is equal to or higher than a target temperature (e.g., 250°C). The target temperature is a temperature at which the DOC device 30 can be activated. The metered fuel is supplied to the DOC device 30 along with the exhaust gas and generates heat through a chemical reaction with the oxidation catalyst of the DOC device 30.Therefore, the exhaust gas temperature, which is increased by controlling the valve opening degree of the throttle valve 20, continues to rise as the exhaust gas flows through the DOC device 30. That is, the exhaust gas outlet temperature Tatout measured by the exhaust temperature sensor 45 is higher than the intake temperature Tatin.

[0028] Furthermore, the temperature increase control in the present embodiment includes automatic reproduction control and stationary manual reproduction control. Automatic reproduction control is the control of automatically executing the temperature increase control in a case where the temperature increase control execution unit 83 determines that reproduction is necessary. Stationary manual reproduction control is the control of executing the temperature increase control by stopping the normal operation of the work vehicle 1 with the operator's permission, for example, in a case where the automatic reproduction control is not completed within a predetermined time.In the stationary manual reproduction control, the control device 8 (notification / instruction unit 84) first issues a request to establish a state where the stationary manual reproduction can be performed using the monitor 9 and a request to perform the stationary manual reproduction to the operator. On the other hand, when the operator issues an instruction to perform the stationary manual reproduction using the monitor 9, the control device 8 sets the engine speed to a predetermined speed, increases the exhaust gas temperature, removes PM or urea deposits accumulated in the DPF or SCR, and releases HC, sulfur, or the like adsorbed in the DPF or SCR. In the present embodiment, the operation of the work vehicle 1 in a state where the temperature increase control is performed is referred to as a reproduction operation.In addition, a specific example of temperature increase control will be described later. [Notification / Instruction Unit]

[0029] In a case where the temperature increase control execution unit 83 determines that stationary manual reproduction control must be performed during the execution of automatic reproduction control, the notification / instruction unit 84 outputs the determination result from the monitor 9 to inform the operator. The monitor 9 notifies the operator that stationary manual reproduction control must be performed by flashing the notification unit 91 or sounding an audible signal, etc. Through the notification from the monitor 9, the operator can determine that completing the reproduction process by automatic reproduction temperature increase control is difficult and stationary manual reproduction must be performed.Therefore, when the operator presses the switch 92 of the monitor 9 to instruct the execution of the stationary manual reproduction in response to the notification of the monitor 9, the stationary manual reproduction is executed by the temperature increase control execution unit 83.

[0030] If the operator does not issue an instruction to perform stationary manual reproduction within a fourth determination time T14 (for example, 30 minutes) after the first notification (hereinafter referred to as stationary manual reproduction control request L01), the notification / instruction unit 84 issues a stationary manual reproduction control request L03, which is a second notification. In the stationary manual reproduction control request L03 for stationary manual reproduction, the monitor 9 performs notification to prompt the operator to perform stationary manual reproduction again by increasing the flashing speed of the notification unit 91 or increasing the volume of a notification sound such as the buzzer. [Engine speed increase control execution unit]

[0031] In a case where the accelerator pedal opening degree exceeds a predetermined opening degree threshold after the start of the automatic reproduction control, the engine speed increase control execution unit 85 performs control to increase the target idle speed of the engine 2 from a normal speed (for example, 600 to 700 rpm) to a predetermined value (for example, 1000 rpm). The automatic reproduction control is automatically started by the control device 8. Therefore, if the timing of increasing the idle speed coincides with the start timing of the automatic reproduction control, there is a possibility that the operator may feel uncomfortable. In this regard, the operator can reduce the feeling of discomfort by increasing the idle speed setting according to the timing at which the operator depresses the accelerator pedal 61. [Temperature increase control]

[0032] Hereinafter, the temperature increase control in the present embodiment will be explained with reference to the Fig. 4 to 7. Fig. Figure 4 shows the overall flow of the temperature increase control. After the work vehicle 1 is started, the control device 8 (temperature increase control execution unit 83) repeatedly determines whether a start condition for the automatic reproduction control is satisfied or not in a predetermined cycle (step S101).

[0033] As in Fig. As shown in Figure 5, the start condition for the automatic reproduction control is satisfied in a case where the elapsed time since the end of the previous reproduction operation reaches a first setting time T1, in a case where the denitrification efficiency calculated from the measurement data of the NOx sensors 32 and 52 is equal to or less than a threshold value, or the like. Here, the first setting time T1 only needs to be set taking into account the estimated accumulation amount of urea deposition, the poisoning by HC or sulfur adsorbed on the DPF or SCR, and the like in connection with the long-term operation. The estimated accumulation amount of urea deposition is described below as an example.For example, the amount of urea deposit accumulation per hour varies depending on the type of work vehicle 1 or diesel engine 2, the work content (operating condition), and the like, but can be estimated through experiments or simulations. In addition, the amount of urea deposit accumulation is also affected by the completion time of the temperature increase control. Therefore, the initial setting time T1 needs to be determined only by considering these factors.For example, if the automatic reproduction control is set to be completed in 15 minutes, and the time until the accumulation amount of urea deposit that can be removed in this time varies depending on the type of work vehicle, such as 24 hours, 48 ​​hours, 72 hours, 96 hours, and 120 hours, the first setting time T1 only needs to be set to 24 hours, 48 ​​hours, 72 hours, 96 hours, 120 hours, and the like, depending on the type of work vehicle. In many work vehicles, the first setting time T1 is set in a range of approximately 24 to 120 hours. In addition, the denitrification efficiency is obtained by (NOxin-NOxout) / NOxin × 100 using the nitrogen oxide concentration NOxin measured by the NOx sensor 32 and the nitrogen oxide concentration NOxout measured by the NOx sensor 52.In this case, automatic reproduction control is performed in a case where the denitrification efficiency is in a state equal to or less than the threshold even before the first setting time T1 elapses. Furthermore, regardless of the denitrification efficiency-based automatic reproduction, automatic reproduction control can always be performed for each first setting time T1, and in a case where the denitrification efficiency-based automatic reproduction is started, the first setting time T1 can be reset.

[0034] If the start condition for automatic reproduction control is satisfied (step S101: Yes), the temperature increase control execution unit 83 starts automatic reproduction control (step S102). Details of the automatic reproduction control will be described later. Then, the temperature increase control execution unit 83 determines whether the end condition for automatic reproduction control is satisfied (step S103). If the end condition for automatic reproduction control is satisfied (step S103: Yes), the temperature increase control execution unit 83 ends the automatic reproduction control (step S104) and ends the temperature increase control.

[0035] As in Fig. As shown in Fig. 5, the end condition for automatic reproduction control is satisfied in a case where a time in which the DOC outlet temperature Tatout measured by the outlet temperature sensor 45 is equal to or higher than a reproduction determination temperature θ1 (for example, 450°C) is integrated as a first integration time (reproduction time), and the first integration time is equal to or longer than a first determination time T11 (for example, 15 minutes). The reproduction determination temperature θ1 is set based on a reproduction target temperature θ2. The reproduction target temperature θ2 is a target value of the outlet temperature Tatout set to recover from performance deterioration due to the removal of urea deposits, poisoning by HC or sulfur adsorbed on the DPF or SCR, and the like in conjunction with long-term operation.The estimated accumulation amount of urea deposit is described below as an example. Then, the control device 8 mainly increases the supply amount of the metered fuel to raise the outlet temperature Tatout when the outlet temperature Tatout is lower than the reproduction target temperature θ2, and the control device 8 mainly decreases the supply amount of the metered fuel to lower the outlet temperature Tatout when the outlet temperature Tatout is higher than the reproduction target temperature θ2. Thus, the outlet temperature Tatout fluctuates near the reproduction target temperature θ2 during the reproduction process for removing urea deposits.Then, since it is determined that the reproduction process for moving the outlet temperature Tatout up and down is in progress near the reproduction target temperature θ2, the reproduction determination temperature θ1 is set to be a predetermined temperature lower than the reproduction target temperature θ2. In the present embodiment, since the reproduction target temperature θ2 is set to, for example, 500°C and the predetermined temperature is -50°C, the reproduction determination temperature θ1 is set to 450°C. The reproduction determination temperature θ1 is set so as not to fall below the lower limit of the temperature range in which the urea deposit can be removed.

[0036] The first determination time T11 is set according to the first setting time T1. The first determination time T11 is a time required to remove the urea deposit by the temperature increase control. Therefore, the first determination time T11 depends on the amount of accumulating urea deposit. The accumulated amount of urea deposit is affected by a time interval in which the temperature increase control is performed, that is, the first setting time T1. Therefore, the first determination time T11 can be set according to the first setting time T1. For example, since the first setting time T1 is 48 hours in the present embodiment, the first determination time T11 is set to 15 minutes. If the first setting time T1 is longer than 48 hours, the first determination time T11 should preferably also be longer.If the first setting time T1 is shorter than 48 hours, the first determination time T11 can also be set shorter. Thus, the first determination time T11 only needs to be set within a range of, for example, approximately 10 minutes to 60 minutes according to the first setting time T1.

[0037] In a case where the end condition for the automatic reproduction control is not satisfied (step S103: No), the temperature increase control execution unit 83 determines whether or not a first condition for the stationary manual reproduction control request is satisfied (step S105).

[0038] As in Fig. As shown in FIG. 5, the first condition for the stationary manual reproduction control request is satisfied in a case where the first integration time (reproduction time), obtained by integrating a time during which the measured temperature (outlet temperature Tatout) of the outlet temperature sensor 45 is equal to or higher than the reproduction determination temperature θ1, is shorter than the first determination time T11, and the elapsed time from the start of the reproduction process is equal to or longer than the second determination time T12 (for example, 120 minutes) during the execution of the automatic reproduction control. When the first condition for the stationary manual reproduction control request is satisfied, the temperature increase control execution unit 83 determines that the condition for notifying the operator that the stationary manual reproduction must be performed is satisfied.The first condition for the stationary manual reproduction control request is not limited to this example. For example, a case where the PM accumulation amount in the DPF is estimated from a differential pressure sensor value before and after the DPF (not shown), and the estimated value is equal to or greater than a predetermined threshold, can be included in the first condition for the stationary manual reproduction control request as an OR condition.

[0039] As described above, the first determination time T11 is a time at which the automatic reproduction control is completed. The second determination time T12 is set to a time for which the work vehicle 1 is allowed to continue working while the automatic reproduction control is being performed. When the second determination time T12 elapses in a state where the automatic reproduction control is not completed, a notification is issued to prompt the execution of stationary manual reproduction. During stationary manual reproduction, it is not possible to continue working with the work vehicle 1. Therefore, the second determination time T12 is set as a grace period during which the operator can continue working until the notification is issued.In a case where the grace period can be set shorter, the second determination time T12 can be shortened to, for example, 60 to 90 minutes. If the grace period should be longer, the second determination time T12 can be set longer, for example, 150 to 180 minutes.

[0040] For example, in Fig. As shown in FIG. 6, in a state where the automatic reproduction control is performed, in a case where the load of the diesel engine 2 is low and the outside air temperature is under a low-temperature environment (for example, -25°C or lower), for example, in a case where the diesel engine 2 is stopped in an idling state, the temperature of the exhaust gas may be low, and the intake temperature Tatin measured by the intake temperature sensor 31 may be equal to or lower than the target temperature (250°C). Therefore, the supply of the metered fuel, which is performed only in a case where the intake temperature Tatin is equal to or higher than the target temperature, is hardly performed, and the reproduction time during which the outlet temperature Tatout measured by the outlet temperature sensor 45 is equal to or higher than the reproduction determination temperature θ1 is also shortened. Fig. 6 illustrates an example of a temporal change of the DOC inlet temperature Tatin, the DOC outlet temperature Tatout, the reproduction time, the metered fuel flow rate, and the valve opening degree of the throttle valve 20, with a horizontal axis serving as a time axis.

[0041] In a case where the first condition for the stationary manual reproduction control request is met (step S105: Yes), the notification / instruction unit 84 issues the stationary manual reproduction control request (step S106). In step S106, the notification / instruction unit 84 first issues the stationary manual reproduction control request L01, and then, if the operator does not issue the instruction to perform the stationary manual reproduction within the fourth determination time T14 (for example, 30 minutes), the notification / instruction unit 84 issues the stationary manual reproduction control request L03.

[0042] In a case where the first condition for the stationary manual reproduction control request is not satisfied (step S105: No) or after the notification / instruction unit 84 issues the stationary manual reproduction control request (step S106), the temperature increase control execution unit 83 determines whether or not a second condition for the stationary manual reproduction control request is satisfied (step S107).

[0043] As in Fig. 5, the second condition for the stationary manual reproduction control request is that, during execution of the automatic reproduction control, the second integration time obtained by integrating the time during which the measured temperature (outlet temperature Tatout) of the outlet temperature sensor 45 is lower than the reproduction determination temperature θ1 is equal to or longer than the third determination time T13 (for example, 60 minutes) while the reproduction time is lower than the first determination time T11 (15 minutes) and the metering fuel is supplied (that is, while the inlet temperature Tatin is equal to or higher than the target temperature (250°C)).Even in a case where the second condition for the stationary manual reproduction control request is satisfied, the temperature increase control execution unit 83 determines that the stationary manual reproduction execution condition is satisfied.

[0044] The third determination time T13 is set as a grace period for continuing a state in which the exhaust gas temperature does not increase even though the metered fuel is supplied and the reproduction process does not operate normally. A case corresponding to the second condition for the stationary manual reproduction control request is a case where there is a possibility that the DOC device 30 does not operate normally, or a case where there is a possibility that the operator performs a special operation of repeatedly operating and stopping the work machine in a short period of time. Therefore, it is advantageous to determine that the second condition for the stationary manual reproduction control request is satisfied in a time shorter than the second determination time T12 of the first condition for the stationary manual reproduction control request.Therefore, the third determination time T13 is set to a time shorter than the second determination time T12, namely half the time. The time of the third determination time T13 can also be set according to the second determination time T12. For example, in a case where the second determination time T12 is set to 90 minutes, the third determination time T13 can be set to approximately 40 to 60 minutes. If the second determination time T12 is set to 150 minutes, the third determination time T13 can be set to approximately 60 to 80 minutes.

[0045] For example, as in Fig. 7, in a state where the automatic reproduction control is performed, the measured temperature (outlet temperature Tatout) of the outlet temperature sensor 45 may not rise to the reproduction determination temperature θ1 or higher depending on the use of the work vehicle 1 even though the metered fuel is supplied, and the second integration time obtained by integrating the time in which the outlet temperature Tatout is lower than the reproduction determination temperature θ1 may be equal to or longer than the third determination time T13. The second integration time is obtained by integrating all the times of the arrows A1 to A6 in Fig. 7. In Fig. 7, the first integration time (reproduction time) is the reproduction time in which the outlet temperature Tatout is equal to or higher than the reproduction determination temperature θ1, as in the first condition for the stationary manual reproduction control request. In a case where the second condition for the stationary manual reproduction control request is satisfied, a state in which the automatic reproduction control end condition is not satisfied continues even though the metered fuel is supplied. Thus, it can be determined that the stationary manual reproduction must be performed earlier than the first condition for the stationary manual reproduction control request. Fig. 7 shows an example of a temporal change of the DOC inlet temperature Tatin, the DOC outlet temperature Tatout, the reproduction time, the metered fuel flow rate, and the valve opening degree of the throttle valve 20, with the horizontal axis serving as a time axis.

[0046] In a case where the second condition for the stationary manual reproduction control request is satisfied (step S107: Yes), the notification / instruction unit 84 issues the stationary manual reproduction control request (step S108). In step S108, the notification / instruction unit 84 first issues the stationary manual reproduction control request L01, and then, if the operator does not issue the instruction to execute the stationary manual reproduction within the fourth determination time T14 (for example, 30 minutes), the notification / instruction unit 84 issues the stationary manual reproduction control request L03. Then, the temperature increase control execution unit 83 terminates the automatic reproduction control (step S109).

[0047] If it is determined that the first condition for the stationary manual reproduction control request is met (step S105: Yes), the temperature increase control execution unit 83 continues to execute the automatic reproduction control. Therefore, the automatic reproduction control process continues even after notification from the notification / instruction unit 84. In a case where the reproduction time reaches the first determination time T11 (15 minutes) and the reproduction process in the automatic reproduction control is completed before the stationary manual reproduction execution is started (step S103: Yes), the notification / instruction unit 84 stops issuing the stationary manual reproduction control request L01 or L03 in step S104 and terminates the notification on the monitor 9.On the other hand, if it is determined that the second condition for the stationary manual reproduction control request is met (step S107: Yes), the temperature increase control execution unit 83 stops executing the automatic reproduction control (step S109). Therefore, notification by the notification / instruction unit 84 continues until the operator no longer requests the stationary manual reproduction execution.

[0048] In a case where the second condition for the stationary manual reproduction control request is not satisfied (step S107: No) or after the temperature increase control execution unit 83 has finished executing the automatic reproduction control (step S109), the temperature increase control execution unit 83 determines whether or not the stationary manual reproduction control start condition is satisfied (step S110).

[0049] As in Fig. 5, the condition for starting stationary manual reproduction is satisfied in a case where the stationary manual reproduction switch 92 is pressed by the operator and the work vehicle is in a state where stationary manual reproduction can be performed. Here, the state where stationary manual reproduction can be performed is, for example, a state where the work vehicle is stopped and not operated, such as a state where the parking brake is applied, the accelerator pedal is in an off state, and the lever of the work machine is in a neutral position.

[0050] In a case where the start condition for the stationary manual reproduction control is satisfied (step S110: Yes), the temperature increase control execution unit 83 ends the automatic reproduction control (step S111) and starts the stationary manual control (step S112). In a case where the automatic reproduction control is ended in step S109, the temperature increase control execution unit 83 does nothing in step S111. Then, it is determined whether or not the end condition for the stationary manual reproduction control is satisfied (step S113). In a case where the end condition for the stationary manual reproduction control is satisfied (step S113: Yes), the temperature increase control execution unit 83 ends the stationary manual reproduction control (step S114) and ends the temperature increase control.

[0051] The temperature increase control execution unit 83 executes the steady-state manual reproduction control, for example, in the following manner. That is, the temperature increase control execution unit 83 acquires the adjustment valve opening degree ETVffo specified by the engine speed Ne and the target torque (or the fuel injection amount Qf) from the steady-state manual reproduction map, and performs control so that the valve opening degree of the throttle valve 20 becomes the adjustment valve opening degree ETVffo. During steady-state manual reproduction, the valve opening degree of the throttle valve 20 and the metered fuel supply amount are controlled so that the exhaust gas temperature is likely to be higher than during automatic reproduction control, and thus, it is possible to efficiently resolve the performance deterioration of the DPF or SCR.The stationary manual reproduction control is automatically terminated when the first integration time in which the outlet temperature Tatout is equal to or higher than the reproduction determination temperature θ1 is equal to or longer than the first determination time T11, as in the automatic reproduction control.

[0052] At the Fig. 4, the determination process of step S103 is not executed thereafter in a case where the automatic reproduction control is terminated in step S109. Furthermore, the determination process of step S105 is not executed thereafter in a case where the second condition for the stationary manual reproduction control request is satisfied in step S107. [Automatic reproduction control]

[0053] Next, the automatic reproduction control in the present embodiment will be described with reference to the Fig. 8 to 14. The Fig. The automatic reproduction control process shown in Fig. 8 is repeated in a predetermined cycle from the beginning (step S102) to the end (step S104 or step S111) of the automatic reproduction control in the manner described with reference to Fig. 4 described temperature increase control is carried out.

[0054] In a case where the Fig. 8 is started, the temperature increase control execution unit 83 first determines whether the vehicle safety state condition is satisfied or not (step S201). In the present embodiment, the vehicle safety state means a state in which the work vehicle 1 is not operating (for example, a state in which the engine 2 is operating at low idle and there is a low probability that the operation of the work vehicle 1 that increases the output torque from this state is immediately executed). Moreover, in the present embodiment, the operation means operating the work vehicle 1 except for an operation of operating the engine 2 in the idle state.

[0055] The Fig. Figures 9 to 11 show examples of the vehicle safety condition. In the Fig. In the example shown in Figure 9, the vehicle safety state condition (Example 1) is that condition (1) is satisfied and condition (2-1) is satisfied. In condition (1), the accelerator pedal opening degree is equal to or less than the accelerator pedal opening degree threshold for safety state determination (for example, the accelerator pedal opening degree is approximately 0%, or 0% or more, and 5% or less). Condition (2-1) is that the shift lever is in N and the parking brake is applied. In the example shown in Fig. In the example shown in Figure 10, the vehicle safety state condition (Example 2) is designed such that condition (1) is satisfied and condition (2-2) is satisfied. In state (1), the accelerator pedal opening degree is equal to or less than an accelerator pedal opening degree threshold for safety state determination. Condition (2-2) is that the travel lock is engaged and the work machine lock is engaged. A state in which condition (2-2) is satisfied corresponds to a state in which neither travel nor work is being performed. In the Fig. In the example shown in Figure 11, the vehicle safety state condition (Example 3) is configured such that Condition (1) is satisfied and Condition (2-3) is satisfied. In Condition (1), the accelerator pedal opening degree is equal to or less than an accelerator pedal opening degree threshold for safety state determination. Condition (2-3) is that the work machine lock is turned on. These are examples, and for example, conditions such as all levers of the work machine being in the neutral position may be combined. In addition, the vehicle safety state condition of the vehicle may vary depending on, for example, the type or specification of the work vehicle 1. For example, the vehicle safety state condition (Example 1) may be used for a vehicle such as a wheel loader, a dump truck, or a passenger car.For example, the vehicle safety condition (Example 2) can be used for a vehicle such as a bulldozer that moves a work machine while driving. Furthermore, the vehicle safety condition (Example 3) can be used for a vehicle such as a hydraulic excavator that moves a work machine with almost no movement.

[0056] In a case where the vehicle safety condition is not satisfied (step S201: No), the temperature increase control execution unit 83 determines the ETV opening degree (throttle opening degree) based on an ETV opening degree MAP1 (throttle opening degree Map1) for a case where the vehicle safety condition is not satisfied (step S202). In a case where the vehicle safety condition is satisfied (step S201: Yes), the temperature increase control execution unit 83 determines the ETV opening degree (throttle opening degree) based on an ETV opening degree MAP2 (throttle opening degree Map2) for a case where the vehicle safety condition is satisfied (step S203). The ETV opening degree MAP1 is a configuration of a first map according to the present disclosure, and the ETV opening degree MAP2 is a configuration of a second map according to the present disclosure.

[0057] Fig. 12 shows a configuration example of the ETV opening degree MAP1, and Fig. 13 shows a configuration example of the ETV opening degree MAP2. Both the Fig. 12 shown ETV opening degree MAP1 as well as the one in Fig. The ETV opening degree MAP2 shown in Figure 13 are maps that define the valve opening degree using engine speed and torque as elements. Fig. The ETV opening degree MAP1 shown in Figure 12 differs from that shown in Fig. 13 shown ETV opening degree MAP2 in that the upper limit of the ETV opening degree in ETV opening degree MAP1 is 86%, but the upper limit of the ETV opening degree in ETV opening degree MAP2 is 95%. In addition, the Fig. 13 is set so that the value of the flap opening degree is greater than that of the Fig. 12 shown ETV opening degree MAP1 in a range where the torque is less than 400. In addition, the Fig. 13 is set so that the value of the flap opening degree is greater than that of the Fig. 12 shown ETV opening degree MAP1 in a range of less than 1200 rpm. In this case, the valve opening degree in the Fig. 13, in a range where the torque is almost zero, and in a range where the speed is an idle speed (speed range in a state from low idle to high idle), a state in which the valve opening degree of the ETV opening degree MAP1 is further throttled.

[0058] Then, the temperature increase control execution unit 83 determines whether the DOC inlet temperature is higher than a predetermined temperature threshold (for example, 250°C, which is the temperature at which the DOC device 30 is activated) (step S204). In a case where the DOC inlet temperature is not higher than the predetermined temperature threshold (step S204: No), the temperature increase control execution unit 83 determines the ETV opening degree by feedback controlling the setting of the DOC inlet temperature to a target value (for example, 250°C) (step S205).In this case, in a case where the ETV opening degree MAP2 (second map) is selected in step S205 when the DOC inlet temperature is equal to or lower than the predetermined threshold, the temperature increase control execution unit 83 may also determine the valve opening degree to exceed the upper limit value defined in the ETV opening degree MAP2 (second map) so that the deviation between the DOC inlet temperature and the predetermined target value is reduced.

[0059] Then, the temperature increase control execution unit 83 controls the ETV opening degree based on the ETV opening degree determined in step S202, S203, or S205 (step S206). Then, in a case where the DOC inlet temperature is higher than a predetermined temperature threshold (for example, 250°C, which is a temperature at which the DOC device 30 is activated) (step S207: Yes), the temperature increase control execution unit 83 starts the fuel injection control for automatic reproduction control. In a case where the DOC inlet temperature is equal to or lower than the predetermined temperature threshold (step S207: No), the temperature increase control execution unit 83 ends the fuel injection control for automatic reproduction control.Here, the fuel injection control for the automatic reproduction control is a fuel metering control by the fuel injection device 72 or the like, and is a control performed, for example, by the repetition process separate from that shown in FIG. Fig. 8 is executed. The fuel injection amount is controlled by using a coefficient or a map for automatic reproduction control from, for example, the intake temperature measured by the intake temperature sensor 31 or the exhaust temperature measured by the exhaust temperature sensor 45. In step S208 and step S209, no process is executed in a case where the process has already been started or has already been completed.

[0060] Then, the engine speed increase control execution unit 85 determines whether the accelerator opening degree is greater than a predetermined opening degree threshold (step S210), and sets the idle speed for automatic reproduction control in a case where the accelerator opening degree is greater than the predetermined opening degree threshold (step S211). In a case where the idle speed for automatic reproduction control is set once, the idle speed is not changed until the automatic reproduction control is completed. The idle speed for automatic reproduction control is, for example, a speed set higher than the normal speed by a predetermined value or a predetermined ratio.

[0061] Fig. 14 shows an operation example of automatic reproduction control by the above methods. Fig. 14 illustrates an example of a temporal change of the DOC inlet temperature Tatin, the DOC outlet temperature Tatout, the reproduction time, the metered fuel flow rate, and the valve opening degree of the throttle valve 20, where the horizontal axis is a time axis. Fig. Figure 14 is an operation example when the vehicle safety condition is met. Furthermore, the ETV opening degree MAP2 is a case where the Fig. 13 is used. In the example shown in Fig. In the example shown in Figure 14, the throttle opening degree is 95% immediately after the start of automatic reproduction control. Then, the throttle opening degree increases from 95% until the DOC inlet temperature reaches 250°C, and at time t1, when the DOC inlet temperature exceeds 250°C, the throttle opening degree is again 95%. At time t2, the DOC outlet temperature is equal to or higher than the reproduction determination temperature θ1, and the reproduction time is extended. At time t3, the automatic reproduction control is terminated. [Effects of the embodiment]

[0062] According to the present embodiment, in a case where control of increasing the exhaust gas temperature in the exhaust path is required, a state where the vehicle is not running (for example, a state where the vehicle is not immediately running due to low idle operation) is detected, and the opening degree of the exhaust throttle valve is further throttled compared to the opening degree before detection only in a case where the condition is detected. According to this configuration, the control of further throttling the opening degree is performed in a case where the operating environment of the exhaust throttle valve is stable. Thus, in a case where the throttling control of the throttle valve 20 is performed, it is possible to efficiently increase the temperature while avoiding deterioration in performance or the like.That is, according to the present embodiment, it is possible to appropriately control the opening degree of the exhaust throttle valve. Furthermore, since it is possible to efficiently increase the temperature in the automatic reproduction control, it is possible to reduce the frequency of stationary manual reproduction.

[0063] Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to the above embodiment, and design changes and the like are included within the scope of the gist of the present invention. For example, the Fig. 12 shown ETV opening degree MAP1 and the Fig.13 may be maps that define the valve opening degree using the engine speed and the fuel injection amount (fuel injection amount of the fuel injector 7) as elements. Furthermore, the control device 8 may be configured using a computer, and part or all of a program executed by the computer may be distributed via a computer-readable recording medium or a communication line. [Additional information]

[0064] The exhaust gas purification device 10 described in the embodiment can be determined as follows.

[0065] (1) An exhaust gas purification device 10 according to a first aspect of the present disclosure includes a throttle valve 20 configured to be provided in a path 11 through which exhaust gas discharged from an engine 2 flows, a rotational speed of the engine 2 being controlled according to an operation of an accelerator pedal 61; a diesel oxidation catalyst device 30 configured to be disposed on a downstream side of the throttle valve 20; a selective reduction catalyst device 50 configured to be disposed on a downstream side of the diesel oxidation catalyst device 30; a fuel injection device 72 (7) configured to inject fuel on an upstream side of the diesel oxidation catalyst device 30; an inlet temperature sensor 31 configured to measure an inlet temperature of the diesel oxidation catalyst device 30;an outlet temperature sensor 45 configured to measure an outlet temperature of the diesel oxidation catalyst device, and a control device 8 configured to input temperature data measured by the inlet temperature sensor 31 and the outlet temperature sensor 45 and to control the throttle valve 20 and the fuel injection device 72. In a case of performing throttle control of the throttle valve 20, the control device 8 changes an upper limit value of a valve opening degree when a fully closed state of the throttle valve 20 is set as a maximum value of the valve opening degree and a fully open state of the throttle valve 20 is set as a minimum value of the valve opening degree, based on a determination result based on an accelerator pedal opening degree of the accelerator pedal 61 and operating conditions of one or more operating devices (62 to 66).which are different from the accelerator pedal 61. According to the present aspect and each of the following aspects, it is possible to appropriately control the opening degree of the exhaust throttle valve.

[0066] (2) An exhaust gas purification device 10 according to a second aspect of the present disclosure is the exhaust gas purification device 10 in (1), in which the control device 8 selects a first map (ETV opening degree MAP1) that defines the valve opening degree using the rotational speed and a torque of the engine 2 as elements, or a second map (ETV opening degree MAP2) in which the upper limit value of the valve opening degree is greater than the upper limit value of the first map, and determines the valve opening degree to change the upper limit value of the valve opening degree. According to this aspect, it is possible to appropriately control the opening degree of the exhaust throttle valve with a simple configuration.

[0067] (3) An exhaust gas purification device 10 according to a third aspect of the present disclosure is the exhaust gas purification device 10 in (2), in which the second map is set so that a value of the valve opening degree is larger than that of the first map in a range where the torque is smaller than a predetermined value. According to this aspect, it is possible to perform the control of further throttling the valve opening degree in a stable range where the magnitude of the torque, that is, the magnitude of the load, is relatively small.

[0068] (4) An exhaust gas purification device 10 according to a fourth aspect of the present disclosure is the exhaust gas purification device 10 in (2) or (3), in which the second map is set so that a value of the valve opening degree is larger than that of the first map in a range where the rotational speed is lower than a predetermined value. According to this aspect, it is possible to perform control for further restricting the valve opening degree in a stable range where the rotational speed magnitude is relatively small.

[0069] (5) An exhaust gas purification device according to a fifth aspect of the present disclosure is the exhaust gas purification device 10 in (2) to (4), in which, when the intake temperature is equal to or lower than a predetermined threshold in a case where the second map is selected, the control device 8 controls the valve opening degree to exceed the upper limit value defined in the second map so that a deviation between the intake temperature and a predetermined target value is small. According to this aspect, it is possible to further throttle the opening degree. Industrial applicability

[0070] According to the aspect described above, the opening degree of the exhaust throttle valve is appropriately controlled. List of reference symbols 1 work vehicle 2 diesel engines 3 turbochargers 6 Engine speed detection device 7 Fuel injection device 8 Control device 9 monitors 10 Exhaust gas purification device 11 Way 20 Throttle valve 30 Diesel Oxidation Catalyst Device (DOC Device) 31 Inlet temperature sensor 32 NOx sensor 40 Urea water injection system 41 Injector nozzle 42 Urea water tank 43 Pump unit 45 Outlet temperature sensor 50 Selective Reduction Catalyst Device (SCR Device) 52 NOx sensor 60 Operating device 61 Accelerator pedal 62 gear levers 63 Parking brake 64 work machine levers 65 Machine lock switch 66 drive lock switch 70 DPF 71 DPF device 72 Fuel injection device 73 Vehicle control 74 Outlet temperature sensor 81 Sensor data acquisition unit 82 Vehicle data acquisition unit 83 Temperature increase control implementation unit 84 Notification / Instruction Unit 85 Engine speed increase control implementation unit 91 Notification unit 92 switches (switches for stationary manual reproduction) QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-140700

[0002] JP 2002-349239

[0003] WO 2016 / 068347

[0003] JP 5987133

[0003] JP 2020-41461

[0003]

Claims

[1] Exhaust gas purification device comprising: a throttle valve configured to be provided in a path through which exhaust gas discharged from an engine flows, wherein a rotational speed of the engine is controlled according to an operation of an accelerator pedal; a diesel oxidation catalyst device configured to be disposed on a downstream side of the throttle valve; a selective reduction catalyst device configured to be disposed on a downstream side of the diesel oxidation catalyst device; a fuel injection device configured to inject fuel on an upstream side of the diesel oxidation catalyst device; an inlet temperature sensor configured to measure an inlet temperature of the diesel oxidation catalyst device; an outlet temperature sensor configured to measure an outlet temperature of the diesel oxidation catalyst device; and a control device configured to input temperature data measured by the intake temperature sensor and the exhaust temperature sensor and to control the throttle valve and the fuel injector, wherein, in a case of performing throttle valve throttling control, the control device changes an upper limit value of a valve opening degree when a fully closed state of the throttle valve is set as a maximum value of the valve opening degree and a fully opened state of the throttle valve is set as a minimum value of the valve opening degree, based on a determination result based on an accelerator pedal opening degree of the accelerator pedal and operating conditions of one or more operating devices other than the accelerator pedal. [2] The exhaust gas purification device according to claim 1, wherein the control device selects any one of a first map defining the valve opening degree using the rotational speed and a torque of the engine as elements, or a second map in which the upper limit value of the valve opening degree is larger than the upper limit value of the first map, and determines the valve opening degree to change the upper limit value of the valve opening degree. [3] An exhaust gas purification device according to claim 2, wherein the second map is set so that a value of the valve opening degree is larger than that of the first map in a range where the torque is smaller than a predetermined value. [4] An exhaust gas purification device according to claim 3, wherein the second map is set so that a value of the valve opening degree is larger than that of the first map in a range where the rotational speed is smaller than a predetermined value. [5] An exhaust gas purification device according to any one of claims 2 to 4, wherein, when the intake temperature is equal to or lower than a predetermined threshold value in a case where the second map is selected, the control device controls the valve opening degree to exceed the upper limit value defined in the second map so that a deviation between the intake temperature and a predetermined target value is small. [6] An exhaust gas purification method which is a control method for an exhaust gas purification device comprising: a throttle valve configured to be provided in a path through which an exhaust gas discharged from an engine flows, wherein a rotational speed of the engine is controlled according to an operation of an accelerator pedal, a diesel oxidation catalyst device configured to be disposed on a downstream side of the throttle valve; a selective reduction catalyst device configured to be disposed on a downstream side of the diesel oxidation catalyst device, a fuel injection device configured to inject fuel on an upstream side of the diesel oxidation catalyst device; an inlet temperature sensor configured to measure an inlet temperature of the diesel oxidation catalyst device, an outlet temperature sensor configured to measure an outlet temperature of the diesel oxidation catalyst device, and a control device configured to input temperature data measured by the intake temperature sensor and the exhaust temperature sensor and to control the throttle valve and the fuel injector, wherein the exhaust gas purification process comprises: Changing, in a case of performing throttle throttling control, an upper limit value of a valve opening degree when a fully closed state of the throttle valve is set as a maximum value of the valve opening degree and a fully opened state of the throttle valve is set as a minimum value of the valve opening degree, based on a determination result based on an accelerator opening degree of the accelerator pedal and operating conditions of one or more operating devices other than the accelerator pedal. [7] Control device in an exhaust gas purification device, comprising: a throttle valve configured to be provided in a path through which an exhaust gas discharged from an engine flows, wherein a rotational speed of the engine is controlled according to an operation of an accelerator pedal, a diesel oxidation catalyst device configured to be disposed on a downstream side of the throttle valve; a selective reduction catalyst device configured to be disposed on a downstream side of the diesel oxidation catalyst device, a fuel injection device configured to inject fuel on an upstream side of the diesel oxidation catalyst device; an inlet temperature sensor configured to measure an inlet temperature of the diesel oxidation catalyst device, and an outlet temperature sensor configured to measure an outlet temperature of the diesel oxidation catalyst device, wherein the control device inputs temperature data measured by the inlet temperature sensor and the outlet temperature sensor and controls the throttle valve and the fuel injection device, and in a case of performing throttle valve throttling control, the control device changes an upper limit value of a valve opening degree when a fully closed state of the throttle valve is set as a maximum value of the valve opening degree and a fully opened state of the throttle valve is set as a minimum value of the valve opening degree, based on a determination result based on an accelerator pedal opening degree of the accelerator pedal and operating conditions of one or more operating devices other than the accelerator pedal.

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