JP2017115680A - Vehicular cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular cooling system, in which cooling water leakage and pump trouble are discriminated.SOLUTION: If a pump rotation number Np2 exceeds a threshold value Nth2 when a pump rotation number Np1 exceeds a threshold valve Nth1 and when a lapse time t is less than a threshold valve tth, it is decided (at steps S140 to S160) that a cooling water leak has occurred. If the pump rotation number Np2 is less than the threshold value Nth2 when the pump rotation number Np1 at the lapse time t exceeds the threshold value Nth1, it is decided (at steps S140, S170 and S180) that a trouble occurs in W/P26 but not in W/P28. If the pump rotation number Np2 is at or higher than Nth2 when the pump rotation number Np1 is at or higher than Nth1 and when the lapse time exceeds the threshold value tth, it is decided (at steps S140, S170 and S190) that a trouble has occurred in the W/P26 and 28.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicular cooling device.

  2. Description of the Related Art Conventionally, as this type of vehicular cooling device, an apparatus including a refrigerant flow path that circulates a refrigerant in a motor mounted on the vehicle and a pump that sends out the refrigerant has been proposed (for example, see Patent Document 1). . In this device, when the rotation speed of the pump exceeds the abnormality determination threshold, it is determined that the refrigerant is leaking in the refrigerant flow path.

JP 2013-110896 A

  In the vehicle cooling device described above, if the pump rotation speed exceeds the abnormality determination threshold, it is determined that the refrigerant has leaked, but the pump rotation speed also exceeds the abnormality determination threshold even if the pump fails. May exceed. Therefore, when the rotation speed of the pump exceeds the abnormality determination threshold value, it cannot be determined whether it is due to refrigerant leakage or a pump failure.

  The vehicular cooling device of the present invention is mainly intended to discriminate between coolant leakage and pump failure.

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

The vehicle cooling device of the present invention includes:
A cooling device for a vehicle equipped with a circulation channel through which cooling water circulates and mounted on a vehicle,
A first water pump for pumping the cooling water to the circulation flow path;
A second water pump disposed at a position lower than the first water pump and pumping the cooling water into the circulation flow path;
Failure determination means for determining failure; and
With
The failure determination means includes
The rotation speed of the first water pump is equal to or higher than the first rotation speed, and the rotation speed of the first water pump is equal to or higher than the first rotation speed before the predetermined time elapses. When the rotational speed is equal to or higher than the second rotational speed, it is determined that a cooling water leak has occurred,
The second water pump when the rotation speed of the first water pump becomes equal to or higher than the first rotation speed and the predetermined time elapses after the rotation speed of the first water pump becomes equal to or higher than the first rotation speed. When the rotational speed of the pump is less than the second rotational speed, it is determined that a failure has occurred in the first water pump and the second water pump has not failed,
The second water pump when the rotation speed of the first water pump becomes equal to or higher than the first rotation speed and the predetermined time elapses after the rotation speed of the first water pump becomes equal to or higher than the first rotation speed. When the rotational speed of the pump is equal to or higher than the second rotational speed, it is determined that a failure has occurred in the first and second water pumps.
This is the gist.

  In the vehicular cooling device of the present invention, the rotation speed of the first water pump is equal to or higher than the first rotation speed, and before the predetermined time has elapsed since the rotation speed of the first water pump is equal to or higher than the first rotation speed. When the rotational speed of the second water pump is equal to or higher than the second rotational speed, it is determined that a coolant leak has occurred. When the rotation speed of the first water pump is equal to or higher than the first rotation speed and a predetermined time elapses after the rotation speed of the first water pump is equal to or higher than the first rotation speed, the rotation speed of the second water pump is When the number of revolutions is less than two, it is determined that a failure has occurred in the first water pump and no failure has occurred in the second water pump. The rotation speed of the second water pump when a predetermined time has elapsed after the rotation speed of the first water pump is equal to or higher than the first rotation speed and the rotation speed of the first water pump is equal to or higher than the first rotation speed. Is greater than or equal to the second rotational speed, it is determined that a failure has occurred in the first and second water pumps. Thereby, it is possible to discriminate between a coolant leak, a failure of only the first water pump, and a failure of the first and second water pumps.

It is a block diagram which shows the outline of a structure of the cooling device 20 as one Example of this invention. It is a flowchart which shows an example of the failure determination routine repeatedly performed by ECU30 of an Example. It is explanatory drawing which shows an example of the relationship between the water quantity of the cooling water in the circulation flow path 24 when the cooling water leak arises in the radiator 22, and the state of operation | movement of W / P26,28.

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

   FIG. 1 is a configuration diagram showing an outline of a configuration of a cooling device 20 as an embodiment of the present invention. The cooling device 20 is configured as a device that cools a transaxle (hereinafter referred to as “T / A”) 12 and a power control unit (hereinafter referred to as “PCU”) 14 in the hybrid vehicle 10. A flow path 24, electric water pumps (W / P) 26 and 28, a reservoir tank 29, and an electronic control unit (hereinafter referred to as “ECU”) 30 are provided. The cooling device 20 may be mounted on an electric vehicle or the like together with a motor and a PCU.

  The radiator 22 is disposed near the front opening (grill) 16 and exchanges heat between cooling water (LLC (long life coolant)) and outside air. The circulation channel 24 circulates cooling water in this order through the radiator 22, the PCU 12, and the T / A 12. The electric water pumps (W / P) 26 and 28 are arranged between the radiator 22 and the PCU 10 in the circulation flow path 24 so as to pump the cooling water from the PCU 10 side to the T / A 12 and the radiator 22 side. W / P28 is arrange | positioned in the position lower than W / P26. The reservoir tank 29 stores cooling water.

Although not shown, the ECU 30 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors necessary for driving and controlling the electric W / Ps 26 and 28 are input to the ECU 30 via an input port. Examples of the signal input to the ECU 30 include the following.
・ Cooling water temperature Tw from a temperature sensor (not shown) that detects the cooling water temperature
-Pump rotation speeds Np1, Np2 from rotation speed sensors 26a, 28a for detecting the rotation speeds of the electric water pumps (W / P) 26, 28

  From the ECU 30, a control signal and the like necessary for driving and controlling the electric W / Ps 26 and 28 are output via an output port.

  In the cooling device 20 of the embodiment thus configured, the ECU 30 sets the target outputs Pout1 * and Pout2 * of the W / Ps 26 and 28 according to the coolant temperature Tw, and the outputs Pout1 and Pout2 of the W / Ps 26 and 28 are set. The target drive duty ratio D * of the drive signal (ratio of the time when the drive signal rises with respect to the cycle of the drive signal) is set so that the target outputs Pout1 * and Pout2 * are obtained, and the drive signal of the target drive duty ratio D * Is used to drive the W / Ps 26 and 28.

  Next, the operation of the cooling device 20 of the embodiment configured as described above, particularly the operation when determining a failure will be described. FIG. 2 is a flowchart illustrating an example of a failure determination routine that is repeatedly executed by the ECU 30 of the embodiment.

  When this routine is executed, the ECU 30 executes a process of inputting the pump rotation speed Np1 from the rotation speed sensor 26a (step S100). Subsequently, whether or not the input pump rotation speed Np1 is greater than or equal to a threshold value Nth1. Is determined (step S110). The threshold value Nth1 is a threshold value for determining whether or not the W / P 26 is idling. When the pump speed Np1 is less than the threshold value Nth1, this routine ends.

  When the pump speed Np1 is greater than or equal to the threshold value Nth1 (step S110), it is determined that the W / P 26 is idling and measurement of the elapsed time t is started (step S120).

  Subsequently, the pump rotational speed Np2 of the W / P 28 is input from the rotational speed sensor 28a (step S130), and it is determined whether or not the elapsed time t exceeds the threshold value tth (step S140). Here, the threshold value tth is a threshold value for determining whether or not the coolant leaks in the radiator 22. FIG. 3 is an explanatory diagram showing an example of the relationship between the amount of cooling water in the radiator 22 when the coolant leaks in the radiator 22 and the state of operation of the W / Ps 26 and 28. When cooling water leaks in the radiator 22 (time t1), first, the W / P 26 arranged at a higher position starts idling and becomes a high rotation speed (time t2), and then W / P 28 idling. It starts and becomes a high rotation speed (time t3). Considering the relationship between the amount of cooling water and the state of operation of the W / Ps 26 and 28, the threshold value tth is set to a predetermined value as a time obtained by subtracting the time t2 from the time t3.

  If the elapsed time t does not exceed the threshold value tth, it is determined whether or not the input pump speed Np2 is equal to or greater than the threshold value Nth2 (step S150). The threshold value Nth2 is a threshold value for determining whether or not the W / P 28 is idling.

  When the pump rotation speed Np2 is less than the threshold value Nth2 (step S150), the process returns to step S130, and steps S130 to S150 are repeated until the elapsed time t exceeds the threshold value tth or the pump rotation speed Np2 becomes equal to or greater than the threshold value Nth2. Repeat the process. When the elapsed time t is less than the threshold value tth and the pump rotation speed Np2 is greater than or equal to the threshold value Nth2 (steps S140 and S150), it is determined that cooling water leakage has occurred in the radiator 22 (step S160). This routine ends. When it is determined that a coolant leak has occurred in the radiator 22, the coolant leak can be notified by turning on a cooling system abnormality warning lamp (not shown) for notifying that the coolant is abnormal. it can.

  When the elapsed time t exceeds the threshold value tth (step S140), it is subsequently determined whether or not the pump speed Np2 is equal to or greater than the threshold value Nth2 (step S170). When the pump speed Np2 is less than the threshold value Nth2, it is determined that the W / P 28 is not idling and has not failed, that is, the W / P 26 has failed but the W / P 28 has not failed (step). S180) When the pump rotation speed Np2 is equal to or greater than the threshold value Nth2, it is determined that both W / P 26 and 28 are idling and malfunctioning (step S190), and this routine is terminated. By such processing, it is possible to determine whether W / P 26 has failed but W / P 28 has not failed, and W / P 26, 28 has failed. It should be noted that when W / P 26 has failed but W / P 28 has not failed, or when W / P 26, 28 has failed, water pump abnormality has occurred. It is possible to notify that at least one of W / P 26 and 28 has a failure by turning on the W / P abnormality warning lamp that is not to be operated.

  According to the cooling device 20 of the embodiment described above, when the pump rotation speed Np1 is equal to or greater than the threshold value Nth1, and when the pump rotation speed Np2 is equal to or greater than the threshold value Nth2 when the elapsed time t is less than the threshold value tth, cooling is performed. When it is determined that water leakage has occurred, the pump rotation speed Np1 is equal to or greater than the threshold value Nth1, and when the elapsed time t exceeds the threshold value tth, the pump rotation speed Np2 is less than the threshold value Nth2, W / P26 is set. It is determined that a failure has occurred and W / P 28 has not failed, the pump rotation speed Np1 is equal to or greater than the threshold value Nth1, and the pump rotation speed Np2 is equal to or greater than the threshold value Nth2 when the elapsed time t exceeds the threshold value tth. In some cases, it is determined that a failure has occurred in W / P 26.28, so that a cooling water leak has occurred and a failure has occurred in W / P 26. Flip and are can be determined and that no cause failure W / P28, and that a failure in W / P26,28 occurs, the.

  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 circulation channel 24 corresponds to the “circulation channel”, the water pump (W / P) 26 corresponds to the “first water pump”, and the water pump (W / P) 28 corresponds to the “second water pump”. The ECU 30 corresponds to “pump” and the “failure determination means”.

  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 vehicle cooling devices.

10 power control unit (PCU), 12 transaxle, 14 PCU, 16 opening, 20 cooling device, 22 radiator, 24 circulation flow path, 26, 28 electric water pump (W / P), 26a, 28a rotation speed sensor, 29 Reservoir tank, 30 Electronic control unit (ECU).

Claims (1)

A cooling device for a vehicle equipped with a circulation channel through which cooling water circulates and mounted on a vehicle,
A first water pump for pumping the cooling water to the circulation flow path;
A second water pump disposed at a position lower than the first water pump and pumping the cooling water into the circulation flow path;
Failure determination means for determining failure; and
With
The failure determination means includes
The rotation speed of the first water pump is equal to or higher than the first rotation speed, and the rotation speed of the first water pump is equal to or higher than the first rotation speed before the predetermined time elapses. When the rotational speed is equal to or higher than the second rotational speed, it is determined that a cooling water leak has occurred,
The second water pump when the rotation speed of the first water pump becomes equal to or higher than the first rotation speed and the predetermined time elapses after the rotation speed of the first water pump becomes equal to or higher than the first rotation speed. When the rotational speed of the pump is less than the second rotational speed, it is determined that a failure has occurred in the first water pump and the second water pump has not failed,
The second water pump when the rotation speed of the first water pump becomes equal to or higher than the first rotation speed and the predetermined time elapses after the rotation speed of the first water pump becomes equal to or higher than the first rotation speed. When the rotational speed of the pump is equal to or higher than the second rotational speed, it is determined that a failure has occurred in the first and second water pumps.
Vehicle cooling device.

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