CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2020-136400 filed on Aug. 12, 2020, incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The disclosure relates to an abnormality diagnosis device for a blower system.

2. Description of Related Art

Blower systems, such as air conditioning systems for vehicles, which send air to air receiving objects are known in the art (see Japanese Unexamined Patent Application Publications No. 09-286223 (JP 09-286223 A), No. 2009-083672 (JP 2009-083672 A), and No. 10-291407 (JP 10-291407 A), for example). In particular, a fault diagnosis device that performs fault diagnosis on actuators for air conditioning used in an air conditioning system is disclosed in JP 09-286223A. The fault diagnosis device described in JP 09-286223 A performs fault diagnosis, by controlling the actuators for air conditioning to operating states corresponding to a fault diagnosis pattern, and having an inspector check if the state of the air conditioning system at this time matches the state corresponding to the fault diagnosis pattern.

SUMMARY

With the fault diagnosis device as described in JP 09-286223 A, the actuators for air conditioning are controlled to the operating states corresponding to the fault diagnosis pattern, and then, the inspector finally checks the states of the actuators, so as to make fault diagnosis on the actuators. Accordingly, the fault diagnosis device as described in JP 09-286223 A cannot detect an abnormality in the blower system including the actuators for air conditioning, by itself.

The disclosure provides an abnormality diagnosis device that can automatically detect an abnormality in a blower system, without depending on an inspector.

The gist of the disclosure is as follows.

(1) An abnormality diagnosis device that performs an abnormality diagnosis on a blower system that sends air to a plurality of air receiving objects is provided. The abnormality diagnosis device includes an operating state obtaining unit that obtains a target operating state of an airflow control device that controls flow of air to the air receiving objects, a temperature obtaining unit that obtains a temperature detected by a temperature sensor that detects a first temperature as a temperature of air fed to a first air receiving object as one of the air receiving objects or a temperature of the first air receiving object, a temperature estimating unit that estimates the first temperature, based on the target operating state of the airflow control device, and an abnormality diagnosing unit that performs an abnormality diagnosis on the airflow control device. The abnormality diagnosing unit determines that there is an abnormality in the airflow control device, when a difference between the first temperature obtained by the temperature obtaining unit and the first temperature estimated by the temperature estimating unit is equal to or larger than a predetermined first reference value.

(2) In the abnormality diagnosis device as described in the above paragraph (1), the airflow control device may comprise a first airflow control device and a second airflow control device which control a flow rate of air fed to the first air receiving object. The abnormality diagnosing unit may perform an abnormality diagnosis on the second airflow control device, based on a parameter other than the first temperature. The abnormality diagnosing unit may determine, when determining that there is no abnormality in the second airflow control device, that there is an abnormality in the first airflow control device, when the difference between the first temperature obtained by the temperature obtaining unit and the first temperature obtained by the temperature estimating unit is equal to or larger than the first reference value.

(3) In the abnormality diagnosis device as described in the above paragraph (2), the first air receiving object may be an air passage located downstream of the airflow control device, and the first temperature may be a temperature of air in the air passage. The abnormality diagnosing unit may determine that there is an abnormality in the first airflow control device, when the difference between the first temperature obtained by the temperature obtaining unit and the first temperature estimated by the temperature estimating unit is equal to or larger than the first reference value, in the case where air that flows toward the first air receiving object is heated or cooled by a temperature controller that heats or cools the air flowing toward the first air receiving object.

(4) In the abnormality diagnosis device as described in the above paragraph (3), the air passage as the first air receiving object may communicate with a vent that is open to a vehicle cabin.

(5) In the abnormality diagnosis device as described in any one of the above paragraphs (2) to (4), the blower system may include a first air passage and a second air passage which lead to the first air receiving object, and the first airflow control device may be an air conditioning door that controls an opening of the second air passage. The second airflow control device may be a blower that blows air to the first air passage and the second air passage, or an air mixing door that controls a ratio of openings of the first air passage and the second air passage.

(6) In the abnormality diagnosis device as described in the above paragraph (1) or (2), the first air receiving object may be a heat generating device, and the first temperature may be a temperature of the heat generating device.

(7) In the abnormality diagnosis device as described in the above paragraph (6), the temperature estimating unit may estimate the temperature of the heat generating device, based on an amount of heat released from the heat generating device, and the amount of heat released from the heat generating device may be calculated, based on a flow rate of air fed to the heat generating device calculated based on the target operating state of the airflow control device, and a difference between the temperature of the heat generating device and a temperature of the air fed to the heat generating device.

(8) In the abnormality diagnosis device as described in the above paragraph (7), the heat generating device may be a battery.

(9) In the abnormality diagnosis device as described in the above paragraph (2), the first airflow control device may be a battery door that controls an opening of a branch air passage that communicates with a battery as the first air receiving object, and the second airflow control device may be a blower that blows air into the branch air passage.

(10) The abnormality diagnosis device as described in any one of the above paragraphs (1) to (9) may further include a warning sending unit that sends a signal to a warning device to generate a warning to a user of the blower system, when the abnormality diagnosing unit determines that there is an abnormality in the airflow control device.

(11) In the abnormality diagnosis device as described in any one of the above paragraphs (1) to (10), the temperature obtaining unit may obtain a temperature detected by a temperature sensor that detects a second temperature as a temperature of air fed to a second air receiving object as one of the air receiving objects that is different from the first air receiving object, or a temperature of the second air receiving object, and the temperature estimating unit may estimate the second temperature, based on the target operating state of the airflow control device. The abnormality diagnosing unit may determine that there is an abnormality in the airflow control device, when a difference between the second temperature obtained by the temperature obtaining unit and the second temperature estimated by the temperature estimating unit is equal to or larger than a predetermined second reference value.

According to the disclosure, the abnormality diagnosis device can automatically detect an abnormality in the blower system, without depending on the inspector.

