Work vehicle

Abstract

To provide a work vehicle in which the generation of exhaust gas odor is reduced.SOLUTION: A work vehicle includes a diesel engine, a heater to heat a gas to be supplied to a combustion chamber of the diesel engine, and a controller to execute an afterglow routine to cause the heater to operate. The controller is configured to execute the afterglow routine in response to the diesel engine being started, and an elapse of a predetermined stop time since an end of a previous execution of the afterglow routine, and the work vehicle being in a warming-up state.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] Patent Document 1 (Japanese Patent No. 3617572) discloses an intake air preheating device for a diesel engine. This device preheats the intake air before starting the diesel engine and then afterheats the intake air after starting the diesel engine. The afterheating ends when a predetermined time has elapsed or when the coolant temperature exceeds a set value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3617572 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have encountered the problem of strong exhaust gas odors from diesel-engine-mounted work vehicles, which is particularly noticeable in cold regions.

[0005] An object of the present invention is to realize a work vehicle that suppresses the generation of odorous exhaust gases. [Means for solving the problem]

[0006] As a means for solving the above-mentioned problems, the work vehicle of the present invention comprises a diesel engine, A traveling device and a working device, A work vehicle including a heater that heats gas supplied to a combustion chamber of the diesel engine, and a control device that executes an afterglow routine to operate the heater, wherein the control device is configured to: The traveling device is stopped and the working device is stopped.The afterglow routine is executed when

[0007] After extensive research, the inventors discovered that the generation of odor in exhaust gas can be suppressed by executing an afterglow routine that operates the heater not only when the diesel engine is started but also after a predetermined stop time has elapsed. According to the above features, a work vehicle that suppresses the generation of odor in exhaust gas can be realized. When the work vehicle is not traveling or performing work, the temperature of the diesel engine drops. In this case, the odor of the exhaust gas may be generated. According to the above feature, the afterglow routine is executed when the traveling device and the work device are stopped, so the odor of the exhaust gas can be effectively suppressed.

[0008]

[0009]

[0010] The present invention The work vehicle , Diesel engines and Running gear and 、 Work equipment and 、 Parking brake and A work vehicle comprising: a heater that heats gas supplied to a combustion chamber of the diesel engine; and a control device that executes an afterglow routine to operate the heater, When the traveling device is stopped, the working device is stopped, and the parking brake is activated The afterglow routine is executed.

[0011] When the work vehicle is not traveling or performing work, the temperature of the diesel engine drops. In this case, an odor of exhaust gas may be generated. According to the above feature, the afterglow routine is executed when the traveling device is stopped, the work device is stopped, and the parking brake is applied, so that the odor of exhaust gas can be effectively suppressed.

[0012] In the present invention, it is preferable that the control device counts the number of times the afterglow routine is executed, and does not execute the afterglow routine after the number of times the afterglow routine is executed reaches a predetermined upper limit.

[0013] According to the above feature, the execution of the afterglow routine is prohibited more than the upper limit number of times, so deterioration and breakdown of the heater are suppressed.

[0014] In the present invention, it is preferable that the present invention further includes a start switch, and that the control device resets the number of executions to zero when the start switch is turned off and when the diesel engine is stopped without operating the start switch.

[0015] According to the above feature, even when the diesel engine stops without operating the start switch, such as in the case of a so-called engine stall, the number of executions is reset to zero. Therefore, since the afterglow routine is executed until the upper limit number of times is reached after the diesel engine is restarted, the odor of exhaust gas can be reliably suppressed.

[0016] In the present invention ,before The control device is configured to execute midway termination of the afterglow routine when a predetermined termination condition is satisfied, and the termination condition preferably includes operation of the working device.

[0017] When the working device is activated, the temperature of the diesel engine rises. Therefore, the need for the afterglow routine is reduced. According to the above feature, when the working device is activated, the afterglow routine is terminated midway, thereby suppressing deterioration and failure of the heater.

[0018] In the present invention, the working device is preferably configured not to execute the midway termination before a predetermined elapsed time has elapsed since the diesel engine was started.

[0019] Since the temperature of the diesel engine is relatively low after starting, there is a high possibility of the exhaust gas smelling. Therefore, it is preferable not to terminate the afterglow routine midway. According to the above feature, the exhaust gas smell can be effectively suppressed.

[0020] In the present invention, the afterglow routine is a predetermined number of repetitions of a first process of activating the heater and a second process of setting the heater to a temperature lower than that of the first process, and it is preferable that the duration of the first first process is longer than the durations of the other first processes.

[0021] As a result of experiments, the inventors have found that the odor of exhaust gas can be reduced by making the duration of the first first process longer than the duration of the other first processes. According to the above-mentioned features, the odor of exhaust gas can be further suppressed. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. [Figure 2] FIG. 1 is a diagram illustrating a configuration of a diesel engine. [Figure 3] FIG. 2 is a diagram illustrating a configuration of a control device. [Figure 4] 10 is a graph showing an example of an afterglow routine. [Figure 5] 10 is a flowchart showing a main routine. [Figure 6] 10 is a flowchart showing an afterglow routine. [Figure 7] 4 is a flowchart showing a routine for detecting an engine stall. DETAILED DESCRIPTION OF THE INVENTION

[0023] A tractor, which is an example of a work vehicle according to the present invention, will be described below with reference to the drawings. The present invention is not limited to the following embodiments, and various modifications are possible within the scope of the present invention.

[0024] Unless otherwise specified, the front-rear and left-right directions in the description of this embodiment will be described as follows: The forward traveling direction when the tractor is traveling for work is defined as "front" and is indicated by arrow F in Fig. 1. The reverse traveling direction is defined as "rear" and is indicated by arrow B in Fig. 1. Arrow U in Fig. 1 indicates "up" and arrow D indicates "down."

[0025] [Overall structure] As shown in Figure 1, the running body of the tractor 1 includes a body frame 10 extending in the fore-and-aft direction, a wheeled running device 20, a motor unit 30, a driving unit 40, and a connection unit 60 to which a work device 50 can be connected.

[0026] The traveling device 20 has left and right front wheels 21 that can be steered and driven, and left and right rear wheels 22 that can be driven.

[0027] The motor unit 30 is supported on the front portion of the vehicle frame 10. The motor unit 30 includes a bonnet 31 and a diesel engine 32. The diesel engine 32 is disposed in an engine room formed by the bonnet 31.

[0028] A clutch housing 33 is connected to the rear of the diesel engine 32. A transmission case 35 is connected to the rear of the clutch housing 33 via an intermediate frame 34. An HST 36 (hydrostatic continuously variable transmission) is connected to the front of the transmission case 35.

[0029] Power from the diesel engine 32 is input to the input shaft of the HST 36 via a main clutch and the like inside the clutch housing 33. The power is transmitted from the output shaft of the HST 36 to a transmission inside the transmission case 35. The power is transmitted from the transmission to the front wheels 21 and rear wheels 22 of the traveling device 20.

[0030] The power of the diesel engine 32 is also transmitted to the working implement 50. The power from the HST 36 is transmitted to a work drive system inside the transmission case 35 and supplied to the working implement 50 via a PTO shaft (not shown).

[0031] The engine 30 is equipped with a battery 37 (FIG. 3) that supplies power to the diesel engine 32 and the electrical system. The speed change device inside the transmission case 35 is equipped with a parking brake 38 (FIG. 3).

[0032] The driver's section 40 is supported on the rear portion of the vehicle frame 10. The driver's section 40 includes a seat 41, a steering wheel 42, and a rope 43.

[0033] The driving section 40 also includes a start switch 44 (FIG. 3) that accepts operations to start and stop the diesel engine 32. The start switch 44 can be operated to OFF, ON, and start states.

[0034] The driving unit 40 is equipped with operating tools (not shown) that accept manual operations on the traveling device 20, the parking brake 38, the working device 50, etc. Examples of the operating tools include a main speed change lever, an auxiliary speed change lever, a parking brake pedal, and a PTO switch.

[0035] The work implement 50 is, for example, a rotary tillage implement or a chemical spraying implement.

[0036] The connection portion 60 is configured to support the working device 50 and to be connectable to the traveling machine body. In this embodiment, the connection portion 60 includes a link mechanism 61 that raises and lowers the working device 50 .

[0037] [Diesel engine] 2 shows a schematic configuration of the diesel engine 32. The diesel engine 32 includes an air cleaner 71, a turbocharger 72, an intake passage 73, a combustion chamber 74, an exhaust passage 75, a DPF 76, a heater 77, and the like.

[0038] Air taken in through an air cleaner 71 is compressed by a turbocharger 72 and sent to a combustion chamber 74 through an intake passage 73. Exhaust gas generated in the combustion chamber 74 passes through an exhaust passage 75, drives the turbocharger 72, is purified by a DPF 76, and is then exhausted.

[0039] The heater 77 is provided in the intake passage 73. The heater 77 heats gas (air) supplied to the combustion chamber 74 of the diesel engine 32. The heater 77 is, for example, an element that generates heat when energized.

[0040] As shown in FIG. 3, the diesel engine 32 is provided with a water temperature sensor 78 that detects the temperature of the cooling water, and an exhaust temperature sensor 79 that detects the temperature of the exhaust gas.

[0041] [Control device] The tractor 1 includes a control device 80. In this embodiment, the control device 80 includes a main ECU 81, an engine ECU 82, and a relay 83, as shown in FIG.

[0042] The main ECU 81 and the engine ECU 82 each include a memory such as an HDD or nonvolatile RAM, and a CPU (both not shown). The CPU executes a program stored in the memory, thereby realizing the control of the tractor 1 described below.

[0043] The relay 83 is controlled by the engine ECU 82 to turn on and off the supply of electricity to the heater 77 of the diesel engine 32 .

[0044] The main ECU 81 is configured to be able to detect the state of the traveling device 20. For example, the main ECU 81 can detect whether the HST 36 is in neutral, whether the transmission is in neutral, etc. The state of the traveling device 20 may be detected based on the output of a sensor provided in the control system or operation system of the HST 36 or other transmissions.

[0045] The main ECU 81 is configured to be able to detect the state of the battery 37. For example, the main ECU 81 can detect the voltage of the battery 37.

[0046] The main ECU 81 is configured to be able to detect the state of the parking brake 38. For example, the main ECU 81 can detect whether the parking brake 38 is activated or not. The state of the parking brake 38 may be detected based on the output of a sensor provided in the control system or operation system of the parking brake 38.

[0047] The main ECU 81 is configured to be able to detect the state of the start switch 44. For example, the main ECU 81 can detect the operation state (OFF, ON, start) of the start switch 44.

[0048] The main ECU 81 is configured to be able to detect the state of the working implement 50. For example, the main ECU 81 can detect whether the PTO shaft is being driven (i.e., whether the working implement 50 is operating). The state of the working implement 50 may be detected based on the output of a sensor provided in the control system or operation system of the working implement 50.

[0049] Temporary parameters and permanent parameters are stored in the memory of the main ECU 81. The memory of the main ECU 81 also stores the number of times an afterglow routine, which will be described later, is executed.

[0050] The engine ECU 82 is configured to be able to detect the temperature of the cooling water of the diesel engine 32 based on the output of the water temperature sensor 78 .

[0051] The engine ECU 82 is configured to be able to detect the temperature of the exhaust gas from the diesel engine 32 based on the output of the exhaust temperature sensor 79 .

[0052] The engine ECU 82 is configured to be able to detect other conditions of the diesel engine 32 (such as the rotation speed).

[0053] The main ECU 81 and the engine ECU 82 are connected to each other via an in-vehicle network such as a CAN so as to be able to communicate with each other.

[0054] [Afterglow Routine] The control device 80 is configured to execute an afterglow routine, which is a routine for operating the heater 77.

[0055] An example of an afterglow routine is shown in Fig. 4. The afterglow routine in the illustrated example is a predetermined number of repetitions of a first process P1 for activating the heater 77 and a second process P2 for setting the heater 77 to a temperature lower than that of the first process P1. In the illustrated example, the first process P1 is repeated nine times, with eight second process P2s interposed therebetween.

[0056] In the first process P1, the voltage applied to the heater 77 is voltage V1. In the second process P2, the voltage applied to the heater 77 is voltage V2. The control device 80 is configured so that the absolute value of voltage V2 is smaller than the absolute value of voltage V1. As a result, the temperature of the heater 77 in the second process P2 is lower than the temperature of the heater 77 in the first process P1.

[0057] In this embodiment, voltage V2 is zero and voltage V1 is a non-zero positive voltage. In this embodiment, the first process P1 is realized by relay 83 energizing heater 77. The second process P2 is realized by relay 83 cutting off energization to heater 77.

[0058] In FIG. 4, the duration of the first process P1 is indicated by T1, T2,...T9. The duration of the second process P2 is indicated by U1, U2,...U8. In the illustrated example, the duration T1 of the first first process P1 is longer than the durations T2, T3,...T9 of the other first processes P1. In the illustrated example, the durations T2, T3,...T9 are the same. The durations U1, U2,...U8 are the same.

[0059] As will be discussed below, the form of the afterglow routine may differ from the example of FIG.

[0060] The control device 80 may be configured so that the voltage V1 and the voltage V2 are variable.

[0061] The voltages V1 and V2 may change during the afterglow routine. For example, the voltage V1 of the first process P1 the first time and the voltage V1 of the first process P1 the second time may be different.

[0062] The durations T1, ...T9 may be the same. The durations T2, T3, ...T9 may be different from each other. The durations U1, U2, ...U8 may be different from each other.

[0063] The afterglow routines executed multiple times may all have the same form (voltage and / or duration) or may differ from one another.

[0064] When the afterglow routine is executed, the control device 80 operates as follows. The main ECU 81 transmits a heater relay request signal requesting output to the engine ECU 82. Upon receiving the heater relay request signal requesting output, the engine ECU 82 controls the relay 83 to energize the heater 77. After the duration T1 has elapsed, the main ECU 81 transmits a heater relay request signal requesting stop to the engine ECU 82. Upon receiving the heater relay request signal requesting stop, the engine ECU 82 controls the relay 83 to stop energizing the heater 77.

[0065] [Afterglow routine start process] The process for starting the afterglow routine (referred to as the "main routine") will be described with reference to the flowchart of Fig. 5. This process starts when the start switch 44 is turned ON.

[0066] The control device 80 resets the number of times the afterglow routine has been executed to zero (step #01).

[0067] The control device 80 determines whether or not the diesel engine 32 has started (step #02). The process of step #02 is repeated until it is determined that the diesel engine 32 has started (step #02: No).

[0068] Whether or not the diesel engine 32 has started is determined based on, for example, the rotation speed of the diesel engine 32 and whether or not the battery 37 is being charged.

[0069] When it is determined that the diesel engine 32 has started (step #02: Yes), an afterglow routine is executed (step #03). The processing during the execution of the afterglow routine will be described later with reference to FIG.

[0070] When the afterglow routine is completed, the control device 80 counts up the number of times the afterglow routine has been executed (step #04). That is, the number of times the routine has been executed is incremented by one. In this embodiment, the counting up of the number of times the routine has been executed is performed not only when the afterglow routine has been completed normally, but also when the routine has been terminated midway. Note that the control device 80 may be configured not to count up the number of times the routine has been executed when the afterglow routine has been terminated midway.

[0071] The control device 80 waits until a predetermined stop time has elapsed since the afterglow routine ended (step #05: No). Specifically, the control device 80 measures the time that has elapsed since the afterglow routine ended, compares it with the predetermined stop time, and waits until the elapsed time exceeds the stop time. The stop time is, for example, 50 minutes.

[0072] When the stop time has elapsed (Step #05: Yes), the control device 80 determines whether the tractor 1 is in a warm-up state (Step #06). The process of Step #06 is repeated until it is determined that the tractor 1 is in a warm-up state (Step #06: No).

[0073] In this embodiment, the control device 80 determines that the tractor 1 is in a warm-up state when a state in which all of the following conditions (warm-up state conditions) are satisfied continues for a predetermined time (for example, 10 minutes).

[0074] (Warm State Condition 1) The traveling device 20 is stopped. The control device 80 determines whether the traveling device 20 is stopped based on the detected state of the traveling device 20. For example, the control device 80 determines that warm state condition 1 is satisfied when both the HST 36 and the transmission are in neutral. The control device 80 may be configured to determine that warm state condition 1 is satisfied when one of the HST 36 and the transmission is in neutral.

[0075] (Warm State Condition 2) The working device 50 is stopped. Based on the detected state of the working device 50, the control device 80 determines whether the working device 50 is stopped.

[0076] (Warm-up state condition 3) The parking brake 38 is applied (locked state). Based on the detected state of the parking brake 38, the control device 80 determines whether the parking brake 38 is applied.

[0077] That is, the control device 80 determines that the tractor 1 is in a warm-up state when the traveling device 20 is stopped, the work device 50 is stopped, and the parking brake 38 is applied.

[0078] The control device 80 may be configured to determine that the tractor 1 is in a warm-up state when some of the warm-up state conditions are satisfied. For example, the control device 80 may be configured to determine that the tractor 1 is in a warm-up state when the traveling gear 20 is stopped and the work implement 50 is stopped.

[0079] If it is determined that the tractor 1 is in a warm-up state (step #06: Yes), the control device 80 determines whether the number of times the afterglow routine has been executed has reached a predetermined upper limit (step #07). The upper limit is set to, for example, 3.

[0080] If the number of times the afterglow routine has been executed has not reached the predetermined upper limit (step #07: No), the afterglow routine is executed (step #03), and the processing from step #04 onwards is executed.

[0081] If the number of times the afterglow routine has been executed reaches the predetermined upper limit (step #07: Yes), the control device 80 ends the main routine. In other words, the control device 80 counts the number of times the afterglow routine has been executed, and does not execute the afterglow routine after the number of times the afterglow routine has been executed reaches the predetermined upper limit.

[0082] [Afterglow Routine Details] The processing performed in the afterglow routine will be described with reference to the flowchart of FIG.

[0083] The control device 80 starts controlling the heater 77 (step #11). Specifically, the control device 80 starts operating the heater 77 (powering the heater 77). In this embodiment, the control device 80 operates the heater 77 in the manner shown in FIG.

[0084] From the start of control of the heater 77 (step #11) until the heater operation is completed a predetermined number of times (step #17: No), the processing from step #12 to step #16 is repeatedly executed.

[0085] In the processing from step #12 to step #16, it is determined whether or not the termination condition is satisfied, and if the termination condition is satisfied (step #12-16: Yes), the control device 80 terminates the afterglow routine. If the termination condition is not satisfied (step #12-16: No), the processing is repeated until the heater operation is performed a predetermined number of times (step #17: No).

[0086] The control device 80 determines whether the temperature of the exhaust gas from the diesel engine 32 has risen above a predetermined threshold temperature (step #12). Specifically, the control device 80 compares the output of the exhaust temperature sensor 79 with the threshold temperature (e.g., 230°C), and determines Yes if the state in which the temperature exceeds the threshold temperature continues for a predetermined time (e.g., 10 seconds) or more.

[0087] The control device 80 determines whether or not intake throttling due to DPF regeneration is being performed (step #13). The intake throttling is performed by the engine ECU 82 when the cooling water temperature of the diesel engine 32 exceeds a predetermined threshold (e.g., 55°C) during DPF regeneration for a predetermined period of time or more.

[0088] The control device 80 determines whether the coolant temperature of the diesel engine 32 has risen above a predetermined threshold temperature (step #14). Specifically, the control device 80 compares the output of the water temperature sensor 78 with the threshold temperature (e.g., 90°C), and determines Yes if the state in which the temperature exceeds the threshold temperature continues for a predetermined time (e.g., 3 seconds) or more.

[0089] The control device 80 determines whether the voltage of the battery 37 has dropped below a predetermined threshold voltage (step #15). Specifically, the control device 80 compares the voltage of the battery 37 with the threshold voltage (e.g., 10.0 V), and determines Yes if the voltage remains below the threshold voltage for a predetermined period of time (e.g., 5 seconds) or more.

[0090] The control device 80 determines whether the tractor 1 is in a working state (step #16). In this embodiment, the control device 80 determines that the tractor 1 is in a working state when a state in which all of the following conditions (working state conditions) are satisfied continues for a predetermined time (for example, one minute).

[0091] (Working state condition 1) The traveling gear 20 is operating. The control device 80 determines whether the traveling gear 20 is operating based on the detected state of the traveling gear 20. For example, the control device 80 determines that working state condition 1 is met when both the HST 36 and the transmission are not in neutral. The control device 80 may be configured to determine that working state condition 1 is met when one of the HST 36 and the transmission is not in neutral.

[0092] (Working State Condition 2) The working device 50 is operating. Based on the detected state of the working device 50, the control device 80 determines whether the working device 50 is operating.

[0093] (Working State Condition 3) The parking brake 38 is released (unlocked state). Based on the detected state of the parking brake 38, the control device 80 determines whether the parking brake 38 is released or not.

[0094] The control device 80 may be configured to determine that the tractor 1 is in a working state when some of the working state conditions are met.

[0095] When the heater operation is completed a predetermined number of times (9 times in the example of FIG. 4) (Step #17: Yes), the control device 80 normally ends the afterglow routine.

[0096] [Engine Stall Detection Routine] The engine stall detection routine will be described with reference to the flowchart of Figure 7. The engine stall detection routine starts after the diesel engine 32 is started (step #02 of the main routine).

[0097] The control device 80 continuously determines whether an engine stall (stop) has occurred in the diesel engine 32 (step #21: No). Specifically, the control device 80 determines whether an engine stall has occurred based on the detected rotation speed of the diesel engine 32.

[0098] If it is determined that an engine stall has occurred (step #21: Yes), the control device 80 stops the supply of electricity to the heater 77 (step #22). Then, the control device 80 proceeds to A of the main routine (FIG. 5) and executes step #01.

[0099] As described above, the control device 80 executes the afterglow routine (step #03) when the diesel engine 32 is started (step #02: Yes), and when a predetermined stop time has elapsed since the previous afterglow routine ended (step #05: Yes) and the tractor 1 is in a warm-up state (step #06: Yes).

[0100] When the start switch 44 is turned OFF and then turned ON, the main routine (FIG. 5) is started and the number of times the afterglow routine has been executed is reset to zero (step #03). Also, when an engine stall occurs (step #21: Yes), the number of times the afterglow routine has been executed is reset to zero (step #03). That is, when the start switch 44 is turned OFF and when the diesel engine 32 stops without operating the start switch 44, the control device 80 resets the number of times the afterglow routine has been executed to zero.

[0101] The control device 80 is configured to execute an intermediate termination of the afterglow routine when predetermined termination conditions are met (steps #12-16: Yes), and the termination conditions include the operation of the working device 50 (step #16: Yes).

[0102] Other Embodiments (1) In the above-described embodiment, the tractor 1 is a cabless machine that does not have a cabin. The tractor 1 may have a cabin that covers the driver's section 40.

[0103] (2) The working implement 50 may be driven by another power source. For example, the working implement 50 may be driven by hydraulic oil from a hydraulic pump driven by the diesel engine 32.

[0104] (3) The control device 80 may be configured not to terminate the afterglow routine midway before a predetermined time has elapsed since the diesel engine 32 was started. After the diesel engine 32 is started, the temperature of the diesel engine 32 is relatively low, so there is a high possibility that the odor of the exhaust gas will be generated. Therefore, it is preferable not to terminate the afterglow routine midway. According to this embodiment, the odor of the exhaust gas can be effectively suppressed. [Industrial Applicability]

[0105] The present invention can be applied to work vehicles equipped with diesel engines, such as tractors, harvesters such as normal combine harvesters and head-feeding combine harvesters, agricultural machinery such as rice transplanters and cultivators, and construction machinery. [Explanation of symbols]

[0106] 1: Tractor (work vehicle) 20: Running gear 32: Diesel engine 38: Parking brake 44: Start switch 50: Work equipment 74: Combustion chamber 77: Heater 80: Control device P1: First process T1-9: Duration (duration of the first process)

Claims

1. Diesel engines and Running gear and A working device; a heater for heating gas supplied to a combustion chamber of the diesel engine; A control device that executes an afterglow routine to operate the heater, The control device executes the afterglow routine when the diesel engine is started and when a predetermined stop time has elapsed since the previous afterglow routine ended and the traveling device and the work device are stopped.

2. Diesel engines and Running gear and A working device; Parking brake and a heater for heating gas supplied to a combustion chamber of the diesel engine; A control device that executes an afterglow routine to operate the heater, The control device executes the afterglow routine when the diesel engine is started, and when a predetermined stop time has elapsed since the previous afterglow routine ended, the traveling device has stopped, the work device has stopped, and the parking brake is applied.

3. 3. The work vehicle according to claim 1, wherein the control device counts the number of times the afterglow routine is executed, and does not execute the afterglow routine once the number of times the afterglow routine is executed reaches a predetermined upper limit.

4. A start switch is further provided, 4. The work vehicle according to claim 3, wherein the control device resets the number of executions to zero when the start switch is turned off and when the diesel engine is stopped without operating the start switch.

5. The control device is configured to terminate the afterglow routine when a predetermined termination condition is satisfied, The work vehicle according to claim 1 or 2, wherein the termination condition includes an operation of the work implement.

6. 6. The work vehicle according to claim 5, wherein the work device is configured not to execute the mid-operation termination before a predetermined elapsed time has elapsed since the diesel engine was started.

7. 3. The work vehicle according to claim 1, wherein the afterglow routine is a predetermined number of repetitions of a first process of activating the heater and a second process of setting the heater to a temperature lower than that of the first process, and the duration of the first first process is longer than the durations of the other first processes.

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