JP3485072B2 - Abnormality detection device for electric water pump - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detecting device for an electric water pump that circulates a cooling liquid in a water-cooled intercooler for lowering the temperature of intake air supplied to an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, a supercharger installed in an internal combustion engine,
For example, there is known a water-cooled intercooler that increases the charging efficiency of an internal combustion engine and suppresses knocking to increase the output by lowering the temperature of intake air in the intake passage downstream of the turbocharger. In the abnormality detection device for the electric water pump for circulating the cooling liquid in this water-cooled intercooler, the voltage monitor circuit is connected to the drive circuit that drives the electric water pump, and the voltage value detected by this voltage monitor circuit is connected. Based on the above, the normality / abnormality of the electric water pump was determined.

[0003]

By the way, in the above-mentioned one, the voltage value applied to the electric water pump is detected by the voltage monitor circuit, and when the detected voltage value exceeds the predetermined range, the abnormality judgment is made. Therefore, the circuit configuration is required, which hinders cost reduction.

Therefore, the present invention has been made in order to solve such a problem, and it is possible to accurately determine the normality / abnormality of an electric water pump in a water-cooled intercooler with a simple configuration without using a voltage monitor circuit or the like. An object is to provide a possible abnormality detection device for an electric water pump.

[0005]

According to a first aspect of the invention, there is provided an abnormality detecting device for an electric water pump, wherein a cooling liquid disposed in the intake passage and circulated in the electric water pump is used to form the inside of the intake passage. A water-cooled intercooler for cooling the intake air is provided. The temperature difference between the temperature of the intake air on the upstream side of the water-cooled intercooler and the temperature of the intake air on the downstream side of the water-cooled intercooler indicates an abnormality in the electric water pump of the water-cooled intercooler. That is, if the cooling liquid is normally circulated by the electric water pump, a predetermined temperature difference is generated between the temperature of the intake air on the upstream side by the upstream temperature detecting means and the temperature of the intake air on the downstream side by the downstream temperature detecting means. Occurs. Here, the cooling capacity of the water-cooled intercooler during normal operation of the electric water pump is known in advance. Accordingly, the normality / abnormality of the electric water pump can be accurately determined with a simple configuration in which the temperature difference between the intake air before and after the water-cooled intercooler is detected.

In the pump abnormality detecting means in the abnormality detecting device for the electric water pump according to the second aspect, since the cooling capacity of the water-cooled intercooler is known in advance, the temperature of the intake air on the upstream side of the water-cooled intercooler is used as a parameter for electric driving. A judgment value for abnormality detection of the water pump is set in advance. As a result, the normal / abnormal condition of the electric water pump can be accurately determined with a simple configuration, for example, by making a table as a judgment value for detecting the normal / abnormal condition of the electric water pump based on the temperature difference between intake air before and after the water-cooled intercooler. Can be determined.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on Examples.

FIG. 1 is a schematic diagram showing an overall configuration of an internal combustion engine to which an abnormality detecting device for an electric water pump according to an embodiment of the present invention is applied.

In FIG. 1, an internal combustion engine 10 is provided with a turbocharger (supercharger) 20 for compressing intake air introduced from an air cleaner 11. The turbocharger 20 compresses intake air by a turbine side 21 in which a turbine (not shown) rotated by exhaust gas from the exhaust passage 13 of the internal combustion engine 10 is arranged and an impeller (not shown) coaxial with the turbine. It is composed of a compressor side 22 that supplies to the internal combustion engine 10 side.

Generally, when the intake air is compressed by the turbocharger 20, the temperature of the intake air rises due to adiabatic compression. For this reason, when the internal combustion engine 10 is, for example, a gasoline engine, the charging efficiency decreases, and the temperature of the air-fuel mixture rises, and knocking easily occurs. In order to deal with this, a water-cooled intercooler (cooler) 30 that cools intake air is provided in the middle of the intake passage 12 that connects the downstream side of the compressor side 22 of the turbocharger 20 and the intake port (not shown) of the internal combustion engine 10. is set up.

The water-cooled intercooler 30 includes an intake passage 12
An intercooler body 31, an intercooler sub-radiator 32, an electric water pump 33 for circulating a cooling liquid, a pipe 34, and the like are provided on the way. The water-cooled intercooler 30 lowers the temperature of the intake air introduced into the internal combustion engine 10 to increase the charging efficiency, suppress knocking, and increase the output.

Further, an upstream intake air temperature sensor 15 for detecting the temperature of intake air compressed by the compressor side 22 of the turbocharger 20 is arranged upstream of the intercooler body 31 of the water-cooled intercooler 30. A downstream intake air temperature sensor 16 is provided in the intake passage 12 on the downstream side of the intercooler body 31 of the water-cooled intercooler 30. The upstream intake air temperature detected by the upstream intake air temperature sensor 15 (hereinafter referred to as "upstream intake air temperature") and the downstream intake air temperature detected by the downstream intake air temperature sensor 16 (hereinafter The “downstream intake air temperature” is input to an ECU (Electronic Control Unit) 40.

The ECU 40 calculates various control amounts based on various sensor signals, and controls an injector, an igniter, and the like (not shown) so that the operating state of the internal combustion engine 10 is optimized according to the calculation result. Further, the electric water pump 33 is driven by the drive signal from the ECU 40, and the cooling liquid in the intercooler body 31 is circulated through the pipe 34 and the sub radiator 32.

The ECU 40 includes a CPU as a central processing unit for executing various known arithmetic processes, a ROM storing a control program, a RAM storing various data, and a B / U.
It is configured as a logical operation circuit including a (backup) RAM, an input / output circuit, and a bus line connecting them.

Next, FIG. 3 will be described based on the flowchart of FIG. 2 showing the processing procedure of the pump abnormality detection in the ECU 40 used in the abnormality detection device for the electric water pump according to one example of the embodiment of the present invention. It will be described with reference to FIG. Here, FIG. 3 is a table showing the determination value δ for the upstream intake air temperature [° C.] for detecting the pump abnormality in FIG. 2. The pump abnormality detection routine is about 1-2.
It is repeatedly executed by the ECU 40 every [sec: second].

In FIG. 2, first, in step S101, it is determined whether the internal combustion engine 10 is in a steady operation state after warming up. When the determination condition of step S101 is satisfied, the process proceeds to step S102, and the post-warm counter that indicates the elapsed time after warm-up is incremented. Next, the routine proceeds to step S103, where the post-warm counter incremented at step S102 exceeds a predetermined value α, and
It is determined whether the vehicle speed exceeds a predetermined value β. When the determination condition of step S103 is satisfied, step S10
4, the steady operation state after warming up is the predetermined value α, and
After the vehicle speed exceeds a predetermined value β and a stable operating state continues for a predetermined time, monitoring is started and the electric water pump 3 described later is started.
The delay timer for executing the normal / abnormal determination for 3 is incremented.

Next, in step S105, it is determined whether the delay timer incremented in step S104 exceeds a predetermined value γ. When the determination condition of step S105 is satisfied, the process proceeds to step S106,
From the downstream intake air temperature detected by the intake air temperature sensor 16 disposed downstream of the intercooler body 31 of the water-cooled intercooler 30 that cools the intake air passing through the intake passage 12, to the intercooler body 31 of the water-cooled intercooler 30. It is determined whether the intake air temperature difference obtained by subtracting the upstream intake air temperature detected by the intake air temperature sensor 15 arranged on the upstream side exceeds the determination value δ for detecting the pump abnormality. This predetermined value δ is
As shown in the table of FIG. 3, it is set for the upstream intake air temperature [° C.] and is stored in advance in the ROM of the ECU 40.

Since the determination condition of step S106 is not satisfied,
That is, when the intake air temperature difference between the downstream intake air temperature and the upstream intake air temperature of the intercooler body 31 of the water-cooled intercooler 30 arranged in the intake passage 12 of the internal combustion engine 10 is smaller than a predetermined value δ, the process proceeds to step S107. After it is determined that the electric water pump 33 is normal, this routine ends.

On the other hand, when the determination condition of step S106 is satisfied, that is, when the difference in intake air temperature between the downstream intake air temperature of the intercooler body 31 of the water-cooled intercooler 30 and the upstream intake air temperature exceeds the predetermined value δ, the process proceeds to step S108. Then, the abnormality counter is incremented. Next, the process proceeds to step S109, and it is determined whether the abnormality counter incremented in step S108 exceeds a predetermined value ε. When the determination condition of step S109 is satisfied, the process proceeds to step S110, and the water-cooled intercooler 3
After it is determined that the electric water pump 33 is abnormal at 0, this routine is ended.

Here, when the determination condition of step S101 is not satisfied, that is, when the internal combustion engine 10 is cold, in the middle of warming up, or in a transient operation state, it is not possible to accurately determine whether the electric water pump 33 is normal or abnormal. This routine ends without doing anything. Further, even when the determination condition of step S103 is not satisfied, that is, when the post-warming counter is as small as a predetermined value α or less or when the vehicle speed is as low as a predetermined value β or less, the normality / abnormality of the electric water pump 33 is accurately determined. If the determination cannot be made, the routine is terminated without doing anything. Then, the determination condition of step S105 is not satisfied,
That is, even when the delay timer is as short as the predetermined value γ or less, it is determined that the normality / abnormality of the electric water pump 33 cannot be accurately determined, and this routine is ended without doing anything. Furthermore,
When the determination condition of step S109 is not satisfied, that is, when the abnormality counter is smaller than or equal to the predetermined value ε, the routine is terminated without doing anything in order to prevent erroneous determination of normality / abnormality of the electric water pump 33.

When it is determined in step S110 that the electric water pump 33 is abnormal, the driver is notified by a warning lamp or the like, and the diagnosis (Di
agnosis: Failure diagnosis).

As described above, the abnormality detecting apparatus for the electric water pump of this embodiment is provided with the air cleaner 11 of the internal combustion engine 10.
A turbocharger 20 that compresses intake air introduced from the side and supplies it to an intake port (not shown) of the internal combustion engine 10.
And a water-cooled intercooler which is disposed in the intake passage 12 up to the intake port on the downstream side of the turbocharger 20 and cools the intake air in the intake passage 12 using the cooling liquid circulated by the electric water pump 33. 30 and an upstream side temperature detecting means comprising an upstream side intake air temperature sensor 15 for detecting the upstream side intake air temperature of the intake passage 12 in which the water cooling type intercooler 30 is arranged, and the intake passage 12 in which the water cooling type intercooler 30 is arranged. Downstream side intake air temperature sensor 1 for detecting the downstream side intake air temperature
6, the downstream side temperature detecting means, and the upstream side intake temperature detected by the upstream side intake temperature sensor 15 and the downstream side intake temperature sensor 1
It is provided with a pump abnormality detecting means that is achieved by the ECU 40 that detects an abnormality of the electric water pump 33 based on the temperature difference from the downstream side intake air temperature detected in 6.

That is, the water-cooled intercooler 30 which is disposed in the intake passage 12 on the downstream side of the turbocharger 20 and cools the intake air in the intake passage 12 using the cooling liquid circulated by the electric water pump 33. The water-cooled intercooler 30 based on the difference in intake temperature between the upstream intake air temperature by the upstream intake air temperature sensor 15 arranged on the upstream side and the downstream intake air temperature by the downstream intake air temperature sensor 16 arranged downstream thereof.
The abnormality of the electric water pump 33 is known. That is, if the cooling water is normally circulated by the electric water pump 33, a predetermined intake air temperature difference occurs between the upstream intake air temperature by the upstream intake air temperature sensor 15 and the downstream intake air temperature by the downstream intake air temperature sensor 16. is there. Here, the water-cooled intercooler 3 during normal operation of the electric water pump 33
The cooling capacity of 0 is known in advance. As a result, a voltage monitor circuit or the like is not required for the drive circuit of the electric water pump 33, and the normality / abnormality of the electric water pump 33 can be accurately detected by the simple configuration of detecting the intake temperature difference before and after the water-cooled intercooler 30. Can be determined.

Further, the pump abnormality detecting means achieved by the ECU 40 of the abnormality detecting apparatus for the electric water pump according to the present embodiment uses the judgment value δ for detecting the abnormality of the electric water pump 33 in advance with the upstream intake air temperature as a parameter. It is something to set. Here, the cooling capacity of the water-cooled intercooler 30 with respect to the upstream intake air temperature flowing into the water-cooled intercooler 30 is known in advance. Therefore, the electric water pump 33 is based on the difference in intake air temperature before and after the water-cooled intercooler 30.
As the determination value δ for normality / abnormality detection of the electric water pump 33, for example, with a simple configuration in which a table is prepared.
The normality / abnormality of can be accurately determined.

By the way, in the above embodiment, the turbocharger is provided as the supercharger. However, the present invention is not limited to this, and a supercharger is provided instead of the turbocharger. It can also be applied to the configuration.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall configuration of an internal combustion engine to which an abnormality detecting device for an electric water pump according to an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing a processing procedure for pump abnormality detection in an ECU used in the abnormality detection device for an electric water pump according to an example of an embodiment of the present invention.

FIG. 3 is a table showing a determination value for an upstream intake air temperature for detecting a pump abnormality in FIG.

[Explanation of symbols]

10 Internal combustion engine 11 Air cleaner 12 Intake passage 15 Upstream intake air temperature sensor 16 Downstream intake air temperature sensor 20 Turbocharger (supercharger) 30 Water-cooled intercooler (cooler) 33 Electric water pump 40 ECU (electronic control unit)

Claims (2)

(57) [Claims] 1. A water-cooled intercooler that cools intake air in the intake passage by using a cooling liquid that is disposed in the intake passage and circulated by an electric water pump.
A cooler), upstream temperature detection means for detecting the temperature of intake air upstream of the intake passage in which the water-cooled intercooler is disposed, and downstream side of the intake passage in which the water-cooled intercooler is disposed. A downstream temperature detecting means for detecting the temperature of the intake air, and a temperature of the intake air on the upstream side detected by the upstream temperature detecting means and an intake air on the downstream side detected by the downstream temperature detecting means. And a pump abnormality detecting means for detecting abnormality of the electric water pump based on a temperature difference from the temperature of the electric water pump. 2. The electric motor according to claim 1, wherein the pump abnormality detecting means presets a determination value for abnormality detection of the electric water pump by using a temperature of intake air on the upstream side as a parameter. Water pump abnormality detection device.