JP2015222047A - Engine cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the erroneous determination of an abnormality of a valve.SOLUTION: When a prescribed time Tref1 elapses after performing control so that a valve attached to a communication flow passage which makes a clearance between an engine and a radiator and a bypass flow passage bypassing the engine communicate with each other is valve-opened, the valve attached to the communication flow passage temporarily determines a closed adhesion abnormality (S100, S110) when a cooling water temperature difference ΔTh being a difference between a cooling water temperature Thw at a downstream side immediately below the engine and a cooling water temperature Thb at a downstream side immediately below a merging position of the bypass flow passage and the communication passage is larger than a prescribed temperature difference Tdet. Furthermore, when it is determined that idling does not occur at an electric W/P, the closed adhesion abnormality of the valve is finally determined (S120, S130), and when it is determined that the idling occurs at the electric W/P, the temporary determination of the closed adhesion abnormality of the valve is released (S120, S140).

Description

  The present invention relates to an engine cooling device, and more specifically, a cooling circulation passage through which a cooling medium pumped by an electric pump circulates and circulates through the engine, and bypasses the engine by branching the cooling medium from the cooling circulation passage. The present invention relates to an engine cooling device including a bypass flow path that merges with a cooling circulation flow path and a valve that restricts the flow of a cooling medium to an engine by closing the valve.

  Conventionally, this type of engine cooling device includes a first cooling water circuit in which cooling water flows through the engine by an electric water pump, and a first cooling without branching from the first cooling water circuit and passing through the engine. A second cooling water circuit that joins the water circuit, and a valve that closes the valve to stop the flow of the cooling water inside the engine to the joining position of the first cooling water circuit and the second cooling water circuit. Has been proposed (see, for example, Patent Document 1). In this apparatus, when the valve is normally opened, the cooling water circulates through the first and second cooling water circuits, and the difference between the cooling water temperature inside the engine and the cooling water temperature of the second cooling water circuit is within a predetermined range. Therefore, if the difference between the cooling water temperature inside the engine and the cooling water temperature in the second cooling water circuit is equal to or higher than the abnormality determination value when the valve is controlled to open, a valve closing failure in the valve is detected. It is determined that it has occurred.

Japanese Patent No. 4883225

  In the above-described engine cooling device, when air is mixed in or generated in the first and second cooling water circuits, for example, when cooling water is injected, the air mixed or generated in the rotational drive portion of the electric water pump In some cases, so-called “air biting” is generated. When air is caught in the water pump, the discharge amount of the water pump is reduced, and the amount of cooling water circulating through the first and second cooling water circuits is reduced. Therefore, even if the valve is normally opened, the internal cooling of the engine The water temperature rises, the difference between the cooling water temperature inside the engine and the cooling water temperature in the second cooling water circuit exceeds the abnormality determination value, and it is erroneously determined that an abnormality (valve closing failure) has occurred in the valve. There is a case.

  The main purpose of the engine cooling device of the present invention is to suppress erroneous determination of valve abnormality.

  The engine cooling device of the present invention employs the following means in order to achieve the main object described above.

The engine cooling device of the present invention comprises:
A cooling circulation path through which the cooling medium pumped by the electric pump circulates and circulates through the engine, and a bypass in which the cooling medium branches from the cooling circulation path and bypasses the engine and joins the cooling circulation path A flow path, a valve that regulates the flow of the cooling medium that has flowed through the engine to the bypass flow path by closing the valve, and a first temperature sensor that is attached to the cooling circulation flow path immediately downstream of the engine, In an engine cooling device comprising: a second temperature sensor attached immediately downstream of a junction between the flow path from the valve and the bypass flow path,
After controlling the valve to open, the electric pump has a temperature difference between a first temperature detected by the first temperature sensor and a second temperature detected by the second temperature sensor being equal to or greater than a predetermined temperature. When it is determined that the valve is not idling, an abnormality determining means for determining that an abnormality has occurred in the valve;
It is a summary to provide.

  In the engine cooling device of the present invention, after controlling the valve to open, the temperature difference between the first temperature detected by the first temperature sensor and the second temperature detected by the second temperature sensor is equal to or greater than a predetermined temperature. When it is determined that the electric pump is not idling, it is determined that an abnormality has occurred in the valve. If air engagement occurs in the electric pump, the discharge amount of the electric pump decreases and the amount of cooling water circulating in the circulation flow path decreases. Therefore, even if the valve opens normally, the cooling water temperature immediately downstream of the engine increases. In some cases, the difference between the first temperature from the first temperature sensor and the second temperature from the second temperature sensor is equal to or greater than a predetermined temperature, and it is erroneously determined that an abnormality has occurred in the valve. When the electric pump is air-engaged, idling occurs in the electric pump. Therefore, when it is determined that the temperature difference between the first temperature and the second temperature is equal to or higher than the predetermined temperature and the electric pump is not idling, By determining that an abnormality has occurred in the valve, erroneous determination of valve abnormality can be suppressed.

  In such an engine cooling device of the present invention, the abnormality determination means is configured such that the valve malfunctions when a difference in rotational speed between the target rotational speed of the electric pump and the actual rotational speed of the electric pump is less than a predetermined rotational speed. It is also possible to determine that the valve is malfunctioning when the actual rotational speed of the electric pump is lower than a predetermined rotational speed.

  In the engine cooling device of the present invention, the cooling circulation channel is a channel that circulates in the order of the electric pump, the engine, the radiator, the thermostat, and the electric pump, and the bypass channel is connected to the electric pump. A flow path branched from the cooling circulation flow path to the engine and joined to the cooling circulation flow path by the thermostat, and the valve is disposed between the engine and the radiator in the cooling circulation flow path. It can also be attached to a communication channel that communicates with the bypass channel.

It is a block diagram which shows the outline of a structure of the engine cooling device 20 as one Example of this invention mounted in the vehicle which drive | works with the motive power from the engine 10 which has an EGR system (not shown) which performs exhaust gas recirculation. It is explanatory drawing which shows the flow path through which cooling water circulates when the thermostat 32 is closing. 3 is a flowchart showing an example of a valve abnormality determination routine executed by an electronic control unit 50. It is explanatory drawing which shows the relationship between the target pump rotation speed Nwp * of electric W / P34, and W / P drive duty D. FIG. It is a flowchart which shows an example of the valve abnormality determination routine of a modification. It is a flowchart which shows an example of the valve abnormality determination routine of another modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 shows an engine cooling apparatus 20 according to an embodiment of the present invention mounted on a vehicle that travels with power from an engine 10 having an EGR system (not shown) that performs exhaust gas recirculation for supplying exhaust gas to an intake system. It is a block diagram which shows the outline of a structure. The engine cooling device 20 includes an electric water pump (W / P) 34, an engine 10, a radiator 30, a thermostat 32, an electric water pump (W / P) 34, a circulation passage 22 through which cooling water circulates, and an electric W / P The P34 and the engine 10 are branched from the circulation flow path 22 and joined to the circulation flow path 22 by the thermostat 32 to bypass the engine 10 and the radiator 30 and the EGR cooler 36 and the heater 38 of the air conditioner (not shown) A bypass flow path 24 through which the coolant flows, a communication flow path 26 communicating between the engine 10 and the radiator 30 of the circulation flow path 22 and an upstream side of the EGR cooler 36 of the bypass flow path 24, and a communication flow path A valve 40 that is attached to the valve 26 and closes the valve to restrict the flow of the cooling water flowing through the engine 10 to the bypass flow path 24; Comprising an electronic control unit 50 for controlling the driving of the opening and closing electric W / P34 0, the. Here, in the embodiment, the circulation channel 22 corresponds to the “cooling circulation channel” of the present invention.

  The thermostat 32 is a cooling water temperature flowing from the bypass flow path 24 to the thermostat 32 (cooling water temperature immediately downstream of the heater 38) as a cooling water temperature flowing from the bypass flow path 24 to the thermostat 32 when the engine 10 is warmed up. The valve is opened when the temperature is equal to or higher than a predetermined bypass water temperature T1 (for example, 80 ° C., 82 ° C., 84 ° C., etc.) at the completion of warm-up, and the cooling water temperature flowing from the bypass passage 24 is less than the bypass water temperature T1 at the completion of warm-up. It is configured to close at certain times.

  The electronic control unit 50 is configured as a microprocessor centered on a CPU (not shown). In addition to the CPU, none is shown, but a ROM for storing a processing program and a RAM for temporarily storing data. , With input / output ports. The electronic control unit 50 is mounted immediately downstream of the cooling water temperature Thw and the junction of the bypass flow path 24 and the communication flow path 26 from the water temperature sensor 60 that is mounted immediately downstream of the engine 10 and detects the temperature of the cooling water. The coolant temperature Thb from the water temperature sensor 62 that detects the temperature of the water temperature, the pump rotation speed Nwp from the rotation speed sensor (not shown) that detects the rotation speed of the electric W / P 34, and the like are input via the input port. The electronic control unit 50 outputs a drive signal to the valve 40, a drive signal to the electric W / P 34, and the like.

  In the engine cooling device 20 of the embodiment configured as described above, the cooling water is pressure-fed to the circulation flow path 22 by the electric W / P 34, and the flow of the cooling water to the radiator 30 is regulated when the thermostat 32 is closed. When the engine 10 is warmed up and the thermostat 32 is open, the cooling water is circulated to the radiator 30 and the cooling water heated by the engine 10 is radiated by the radiator 30 and circulated through the circulation passage 22. To cool the engine 10.

  FIG. 2 is an explanatory diagram showing a flow path through which cooling water circulates when the thermostat 32 is closed. In the figure, a broken line indicates a portion of the circulation channel 22 where the cooling water does not circulate when the thermostat 32 is closed. When the thermostat 32 is closed, the valve 40 is opened / closed according to the cooling water temperature Thw from the water temperature sensor 60. More specifically, when the thermostat 32 opens, that is, when the temperature of the cooling water flowing from the bypass passage 24 to the thermostat 32 is the bypass water temperature T1 when the warm-up is completed, the temperature is lower than the temperature detected by the water temperature sensor 60. When the temperature is lower than a predetermined temperature T2 (for example, 70 ° C., 72 ° C., 74 ° C., etc.), the valve 40 is controlled to close. By closing the valve 40 in a state where the thermostat 32 is closed, the flow of the cooling water flowing through the engine 10 to the bypass flow path 24 is regulated, and the cooling water bypasses the engine 10 and bypasses the bypass flow path 24. The electric W / P 34, the EGR cooler 36, the heater 38, and the thermostat 32 are circulated. Since the cooling water stays inside the engine 10, the temperature rise of the cooling water inside the engine 10 can be promoted along with the warm-up operation of the engine 10, and the warm-up of the engine 10 can be promoted.

  Then, when the warm-up of the engine 10 is promoted and the coolant temperature Thw becomes equal to or higher than the predetermined temperature T2, the valve 40 is controlled to open. At this time, since the thermostat 32 is closed, the cooling water bypasses the radiator 30, passes through the bypass flow path 24 and the communication flow path 26, the engine 10, the EGR cooler 36, the heater 38, the thermostat 32, and the electric motor. Circulate W / P34. Since the cooling water circulates bypassing the radiator 30, the engine 10 continues to be warmed up.

  If the engine 10 continues to be warmed up in this way, the temperature of the cooling water that passes through the bypass flow path 24 and the communication flow path 26 and circulates through the engine 10, the EGR cooler 36, the heater 38, the thermostat 32, and the electric W / P 34 increases. The temperature of the cooling water flowing from the bypass passage 24 to the thermostat 32 becomes equal to or higher than the bypass water temperature T1 when the warm-up is completed, and the thermostat 32 opens. When the thermostat 32 is opened, the cooling water passes through the circulation flow path 22, the bypass flow path 24, and the communication flow path 26, and the engine 10, the radiator 30, the thermostat 32, the electric W / P 34, the valve 40, the EGR cooler 36, and the heater 38. Circulate. Thus, the cooling water heated by the engine 10 is radiated by the radiator 30 and the cooling water is circulated to cool the engine 10.

  Further, in the engine cooling device 20 of the embodiment, the electric W / P 34 is controlled so that the cooling water is discharged at a target flow rate corresponding to the output of the engine 10 and the cooling water temperature Thw, and more specifically, the output of the engine 10. The target discharge amount of the electric W / P 34 is set so as to increase as the cooling water temperature Twh increases and as the cooling water temperature Twh increases, and the electric W / P 34 rotates at the target pump rotation speed Nwp * corresponding to the target discharge amount. Electric W / P 34 is controlled using drive duty ratio D (hereinafter referred to as “W / P drive duty D”). In the embodiment, the W / P drive duty D is increased as the target pump speed Nwp * increases.

  Next, the operation of the engine cooling device 20 of the embodiment configured as described above, particularly, the operation when determining abnormality of the valve 40 will be described. FIG. 3 is a flowchart showing an example of a valve abnormality determination routine executed by the electronic control unit 50. This routine is repeatedly executed every predetermined time (for example, every several msec) when the cooling water temperature Thw from the water temperature sensor 60 is low and the thermostat 32 is closed.

  When this routine is executed, the CPU (not shown) of the electronic control unit 50 passes the predetermined time Tref1 after the valve 40 is controlled to open, and from the cooling water temperature Thw from the water temperature sensor 60 to the water temperature sensor 62. A process of determining whether or not the cooling water temperature difference ΔTh obtained by subtracting the cooling water temperature Thb exceeds a predetermined temperature difference Tdet is executed (step S100). Here, the predetermined time Tref1 is a predetermined time (for example, 8 sec) from when the valve 40 is opened until the cooling water in the engine 10 is replaced after the circulation of the cooling water to the engine 10 is started. , 10 sec, 12 sec, etc.). The predetermined temperature difference Tdet is a threshold value for determining whether or not there is a possibility of occurrence of a closed adhering abnormality (abnormality in which the valve 40 is not opened even if the valve 40 is opened). The maximum value (for example, 18 ° C., 20 ° C., 22 ° C., etc.) that the cooling water temperature difference ΔTh can take when the valve 40 is normally opened is assumed to be set. Here, the comparison of the cooling water temperature difference ΔTh and the predetermined temperature difference Tdet is based on the following reason. When the electric W / P 34 is normal, when the valve 40 is normally opened, the cooling water warmed by the engine 10 passes through the communication flow path 26 and merges with the bypass flow path 24. Therefore, the cooling water temperature difference ΔTh However, when the valve 40 is closed and stuck abnormally, the cooling water stays in the upstream of the valve 40, the cooling water temperature Thw rises due to the heat of the engine 10, and the cooling water temperature difference ΔTh increases and becomes predetermined. The temperature difference Tdet is exceeded. Therefore, by comparing the cooling water temperature difference ΔTh and the predetermined temperature difference Tdet, it can be determined that there is a possibility that the valve 40 has a closed adhesion abnormality. For these reasons, the cooling water temperature difference ΔTh and the predetermined temperature difference Tdet are compared.

  When the valve 40 is controlled to open, the cooling water temperature difference ΔTh is less than the predetermined temperature difference Tdet, or when the valve 40 is controlled to close, it is determined that the valve 40 is normal. (Step S150), and this routine ends.

  When the cooling water temperature difference ΔTh exceeds the predetermined temperature difference Tdet when the valve 40 is controlled to be opened and the predetermined time Tref1 has elapsed, the closed fixing temporary abnormality determination is temporarily determined. (Step S110), and then, it is determined whether or not the electric W / P 34 is idling (Step S120). This determination is made by comparing the target pump speed Nwp * of the electric W / P 34 with the actual pump speed Nwp of the electric W / P 34, and the difference between the target pump speed Nwp * and the pump speed Nwp is a predetermined rotation. When the number difference is Ndet (for example, 500 rpm, 600 rpm, 700 rpm) or more, it is determined that the electric W / P 34 is idling. In the embodiment, the predetermined rotational speed difference Ndet is set to a value that can reliably determine the idling of the electric W / P 34 in consideration of an error of the rotational speed sensor. FIG. 4 shows the relationship between the target pump speed Nwp * of the electric W / P 34 and the W / P drive duty D. In the figure, the broken line indicates the relationship between the pump rotation speed Nwp (hereinafter referred to as idling pump rotation speed Nwp_s) and the W / P drive duty D when idling occurs in the electric W / P 34. As shown in the drawing, the difference between the target pump speed Nwp * and the idling pump speed Nwp_s increases as the W / P drive duty D increases. Here, the reason for determining whether or not the electric W / P 34 is idling will be described.

  If air is mixed in or generated in the circulation flow path 22 during cooling water injection, so-called “air biting” may occur in which the mixed or generated air stays in the rotational drive portion of the electric W / P 34. is there. When air entrainment occurs in the electric W / P 34, the discharge amount of the electric W / P 34 decreases, the amount of cooling water circulating in the circulation flow path 22 decreases, and the engine 10 passes through the engine 10 even if the valve 40 is normally opened. Then, the cooling water temperature Thw from the water temperature sensor 60 detected increases, and the cooling water temperature difference ΔTh, which is the difference between the cooling water temperature Thw and the cooling water temperature Thb, increases. For this reason, if it is determined whether or not the closed adhering abnormality of the valve 40 is caused only by the cooling water temperature difference ΔTh, there is a possibility of erroneous determination. In the embodiment, in order to suppress such an erroneous determination, if the electric W / P 34 is air-engaged, the electric W / P 34 idles, so whether or not the electric W / P 34 is idle in the process of step S120. It was determined whether or not. Therefore, the process of step S120 is a process of determining whether or not there is a high possibility that an erroneous determination will occur when the closed adhering abnormality is determined based on the cooling water temperature difference ΔTh.

  When it is determined that the electric W / P 34 is not idling (step S120), it is determined that the closed sticking abnormality may be determined based on the cooling water temperature difference ΔTh, and the closed sticking abnormality occurs in the valve 40. This routine is terminated and it is determined that the electric W / P 34 is idling (step S120), based on the cooling water temperature difference ΔTh. When it is determined that the closed adhering abnormality is determined, it is determined that there is a high possibility of erroneous determination, the closed adhering temporary abnormality determination is canceled (step S140), and this routine is terminated. As described above, when the closed adhering abnormality is determined based on the cooling water temperature difference ΔTh, and it is determined that the electric W / P 34 is not idling, the closed adhering abnormality is determined, whereby the closed adhering abnormality is determined. An erroneous determination of abnormality can be suppressed.

  According to the engine cooling device 20 of the embodiment described above, when the valve 40 is controlled to open, the cooling water temperature difference ΔTh that is the difference between the cooling water temperature Thw and the cooling water temperature Thb is greater than the predetermined temperature difference Tdet, and When it is determined that the difference between the target pump rotation speed Nwp * of the electric W / P 34 and the pump rotation speed Nwp of the electric W / P 34 is less than the predetermined rotation speed Ndet and the electric W / P 34 is idling, By determining that an abnormality has occurred in the valve 40, it is possible to suppress erroneous determination of the abnormality of the valve 40.

  In the engine cooling apparatus 20 of the embodiment, when the difference between the target pump speed Nwp * and the pump speed Nwp is equal to or greater than the predetermined speed difference Ndet in the process of step S120 of the valve abnormality determination routine illustrated in FIG. Although it is determined that the electric W / P 34 is idling, the pump rotation speed Nwp of the electric W / P 34 is greater than or equal to a determination threshold value that can be determined that the electric W / P 34 is idling due to air engagement. Sometimes, it may be determined that the electric W / P 34 is idling due to air biting. As shown in FIG. 4, the determination threshold value tends to increase as the W / P drive duty D increases because the idling pump rotation speed Nwp_s tends to increase as the W / P drive duty D increases. It may be determined.

  In the engine cooling apparatus 20 of the embodiment, the valve abnormality determination routine shown in FIG. 3 is executed when the thermostat 32 is closed. However, the thermostat 32 is closed and the electric W / P 34 is operated. Is executed when the difference between the target pump speed Nwp * and the idling pump speed Nwp_s is relatively large (for example, 82%, 85%, 87%, etc.). Also good. In this way, it is possible to more accurately determine whether or not the electric W / P 34 is idling, and it is possible to further suppress erroneous determination of abnormality of the valve 40.

  In the engine cooling device 20 of the embodiment, it is determined whether or not the electric W / P 34 is idling after performing the closed fixed temporary abnormality determination of the valve 40 (steps S110 and S120), as shown in FIG. Since the difference between the target pump speed Nwp * and the idling pump speed Nwp_s increases as the W / P drive duty D increases, as shown in the valve abnormality determination routine of the modified example of FIG. Duty D2 (for example, 82%, 85%, 87%, etc.) in which the difference between the target pump rotation speed Nwp * and the idling pump rotation speed Nwp_s becomes relatively large after the closed stuck temporary abnormality determination is performed in the process of step S110. ) When the W / P drive duty D of the electric W / P 34 is small, the W / P drive duty D is increased until the duty D2 is reached (step S1). 2) When a predetermined time Tref2 (for example, 8 sec, 10 sec, 12 sec, etc.) determined in advance as a time during which the W / P drive duty D is stabilized has elapsed (step S114), the process of step S120 is executed to execute the electric W / It may be determined whether or not P34 is idling. To determine whether or not the electric W / P 34 is idling after increasing the W / P drive duty D until the difference between the target pump speed Nwp * and the idling pump speed Nwp_s becomes a relatively large duty D1. Thus, it can be determined with higher accuracy whether or not the electric W / P 34 is idling, and erroneous determination of abnormality of the valve 40 can be further suppressed.

  In the engine cooling apparatus 20 of the embodiment, the cooling water temperature difference ΔTh exceeds the predetermined temperature difference Tdet when the predetermined time Tref1 has elapsed since the valve 40 was controlled to open in the valve abnormality determination routine of FIG. If it is determined that the valve 40 is closed and stuck abnormally, a temporary sticking and temporary abnormality determination is performed (step S110), and then it is determined whether or not the electric W / P 34 is idling (step S120). However, as illustrated in the valve abnormality determination routine of the modification of FIG. 6, first, it is determined whether or not the electric W / P 34 is idling by the same process as step S120 of FIG. 3 (step S50). When it is determined that the W / P is idling, this routine is terminated. When it is determined that the electric W / P is not idling, the valve 40 is opened so as to open. It is determined whether or not the predetermined time Tref1 has passed and the cooling water temperature difference ΔTh exceeds the predetermined temperature difference Tdet (step S100), and the valve 40 is controlled to pass the predetermined time Tref1. When it is determined that the cooling water temperature difference ΔTh exceeds the predetermined temperature difference Tdet, a closed sticking abnormality determination is performed (step S130), and the valve 40 is controlled so that the predetermined time Tref1 has not elapsed, or the cooling water temperature difference When it is determined that ΔTh does not exceed the predetermined temperature difference Tdet, normality determination may be performed (step S150).

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the electric W / P 34 corresponds to the “electric pump”, and the flow path through which the cooling water pumped by the electric W / P 34 circulates through the engine 10 corresponds to the “cooling circulation flow path”. The flow path 24 corresponds to a “bypass flow path”, the valve 40 corresponds to a “valve”, the water temperature sensor 60 corresponds to a “first temperature sensor”, and the water temperature sensor 62 corresponds to a “second temperature sensor”. The electronic control unit 50 corresponds to “abnormality determination means”. Further, the circulation passage 22 that circulates in the order of the electric W / P 34, the engine 10, the radiator 30, the thermostat 32, and the electric W / P 34 also corresponds to the “cooling circulation passage”, and the communication passage 26 becomes the “connection passage”. Equivalent to.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of engine cooling devices.

  10 engine, 20 engine cooling device, 22 circulation flow path, 24 bypass flow path, 26 communication flow path, 30 radiator, 32 thermostat, 34 electric water pump (W / P), 36 EGR cooler, 38 heater, 40 valve, 50 Electronic control unit, 60, 62 Water temperature sensor.

Claims (1)

A cooling circulation path through which the cooling medium pumped by the electric pump circulates and circulates through the engine, and a bypass in which the cooling medium branches from the cooling circulation path and bypasses the engine and joins the cooling circulation path A flow path, a valve that regulates the flow of the cooling medium that has flowed through the engine to the bypass flow path by closing the valve, and a first temperature sensor that is attached to the cooling circulation flow path immediately downstream of the engine, In an engine cooling device comprising: a second temperature sensor attached immediately downstream of a junction between the flow path from the valve and the bypass flow path,
After controlling the valve to open, the electric pump has a temperature difference between a first temperature detected by the first temperature sensor and a second temperature detected by the second temperature sensor being equal to or greater than a predetermined temperature. When it is determined that the valve is not idling, an abnormality determining means for determining that an abnormality has occurred in the valve;
An engine cooling device comprising:

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