JP2008106625A - Temperature raising device for throttle body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature raising device for a throttle body quickly melting icing, by effectively supplying cooling water to the throttle body. <P>SOLUTION: The temperature raising device for a throttle body is suitably used for increasing the temperature of the throttle body by using the cooling water for cooling an engine. Concretely, the temperature raising device for the throttle body determines whether or not the icing is generated in the throttle body, and performs a control for increasing a flow rate of an electric pump circulating the cooling water when the icing is generated. Since the temperature of the throttle body can be quickly increased, a part of the throttle valve where the icing is generated can be effectively melted. Therefore, the throttle valve is early restored from the icing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a temperature raising device for a throttle body that raises the temperature of a throttle body using cooling water for cooling an engine.

  2. Description of the Related Art Conventionally, techniques have been proposed for taking measures against icing (hereinafter also referred to as “icing”) in a throttle valve. For example, Patent Document 1 describes a technique for raising the temperature of a throttle body by flowing cooling water to the throttle body of a throttle valve.

Japanese Utility Model Publication No. 63-190542

  However, in the technique described in Patent Document 1 described above, the temperature of the throttle body cannot be sufficiently increased, and icing may not be properly eliminated. This is because a sufficient amount of cooling water for eliminating icing may not be supplied to the throttle body when the engine is started.

  The present invention has been made to solve the above-described problems, and a temperature raising device for a throttle body capable of quickly eliminating icing by effectively supplying cooling water to the throttle body. The purpose is to provide.

  In one aspect of the present invention, a temperature increasing device for a throttle body that circulates cooling water for cooling an engine by an electric pump and raises the temperature of the throttle body by supplying the cooling water to the throttle body. Determining means for determining whether or not icing has occurred in the throttle body, and electric pump control means for performing control to increase the flow rate of the electric pump when it is determined by the determining means that the icing has occurred And comprising.

  The above-described temperature increasing device for the throttle body is preferably used for increasing the temperature of the throttle body using the cooling water for cooling the engine. Specifically, the temperature raising device for the throttle body determines whether or not icing has occurred in the throttle body, and executes control to increase the flow rate of the electric pump that circulates cooling water when icing has occurred. To do. Thereby, the temperature of the throttle body can be quickly raised, and the portion of the throttle valve where icing is generated can be effectively melted. Therefore, the throttle valve can be returned from icing at an early stage.

  One aspect of the temperature increasing device for the throttle body further includes an exhaust heat recovery device for exchanging heat between the cooling water passing through the inside and the exhaust gas.

  In this aspect, the temperature increasing device for the throttle body has an exhaust heat recovery device that performs heat exchange between the cooling water and the exhaust gas. The exhaust heat recovery device can effectively raise the temperature of the cooling water by exchanging heat between the cooling water passing through the inside and the exhaust gas. Thereby, it becomes possible to efficiently raise the temperature of the throttle body by supplying the raised cooling water to the throttle body.

  In another aspect of the temperature increasing device for the throttle body, the electric pump control means further includes a cooling water supply unit that supplies the cooling water to an EGR system that recirculates exhaust gas to the intake system. When the EGR rate in the EGR system is high, control is performed to increase the flow rate of the electric pump.

  In this aspect, the temperature increasing device for the throttle body supplies cooling water to a part of the EGR system to cool the EGR system. The electric pump control means performs control to increase the flow rate of the electric pump when the EGR rate is high. Thus, by increasing the flow rate of the electric pump, the amount of cooling water supplied to the EGR system can be increased, and the EGR system can be effectively cooled. Therefore, the temperature of the EGR gas can be effectively reduced, so that fuel consumption can be improved.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram showing a schematic configuration of a cooling system 100 to which a temperature increasing device for a throttle body according to a first embodiment of the present invention is applied. In FIG. 1, solid line arrows indicate an example of the flow of gas or cooling water, and broken line arrows indicate signal input / output. A solid line indicated by a bold line indicates a passage (cooling water passage) through which the cooling water flows.

  The cooling system 100 according to the first embodiment basically cools the engine 1 and the like using cooling water, and performs heat exchange between the cooling water and the exhaust gas, thereby generating exhaust heat. This is a system that is recovered and used for warming up the engine 1 and for the heat source of the heater. In this case, the cooling water passes through the cooling water passages 7a, 7b, 7c, and 7d. The exhaust heat recovery device 2 is provided on the cooling water passage 7a, and the radiator 3 is provided on the cooling water passage 7b. An electric pump 5 is provided on the cooling water passage 7c, and a throttle valve 10 is provided on the cooling water passage 7d. In the following description, when the cooling water passages 7a to 7d are not distinguished, they are simply used as the cooling water passage 7.

  The engine (internal combustion engine) 1 is a device that generates power by burning a mixture of supplied fuel and air. For example, the engine 1 is configured by a gasoline engine, a diesel engine, or the like. The engine 1 is mounted on a hybrid vehicle or the like. The engine 1 is controlled by the control signal S1 supplied from the ECU 50, such as the ignition timing and the fuel injection amount.

  The throttle valve 10 is a valve that adjusts the amount of intake air supplied to the engine 1. Cooling water is supplied to the body of the throttle valve 10 (hereinafter referred to as “throttle body”) via the cooling water passage 7d. The throttle valve 10 and the cooling water passage 7d are configured so that cooling water does not enter the intake air. By supplying the cooling water to the throttle body in this way, the temperature of the throttle body is increased to a temperature at which the icing can be eliminated when icing (hereinafter also referred to as “icing”) occurs in the throttle valve 10. It becomes possible to make it.

  The exhaust heat recovery device 2 is provided on an exhaust passage (not shown) through which exhaust gas from the engine 1 passes. The exhaust heat recovery unit 2 recovers exhaust heat by allowing cooling water to pass through and exchanging heat between the cooling water and the exhaust gas.

  In the radiator 3, the cooling water passing through the inside thereof is cooled by outside air. In this case, cooling of the cooling water in the radiator 3 is promoted by the wind introduced by the rotation of the electric fan (not shown). The electric pump (hereinafter referred to as “electric WP”) 5 includes an electric motor, and the cooling water is circulated in the cooling water passage 7 by driving the motor. Specifically, electric WP5 is supplied with electric power from a battery, and the number of rotations and the like are controlled by a control signal S5 supplied from ECU 50.

  The thermostat 4 is configured by a valve that opens and closes according to the temperature of the cooling water. Basically, the thermostat 4 opens when the temperature of the cooling water becomes high. In this case, the cooling water passes through the radiator 3. Thereby, the cooling water is cooled and, for example, overheating of the engine 1 is suppressed. On the other hand, when the temperature of the cooling water is relatively low, the thermostat 4 is closed. In this case, the cooling water does not pass through the radiator 3. Thereby, since the temperature fall of a cooling water is suppressed, for example, the overcool of the engine 1 etc. are suppressed.

  The ECU (Engine Control Unit) 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown). In the first embodiment, the ECU 50 determines whether or not icing has occurred in the throttle body, and performs control to increase the flow rate of the electric WP 5 when icing has occurred. Thus, by increasing the flow rate of the electric WP5, the amount of cooling water supplied to the throttle body can be increased, and the temperature of the throttle body can be quickly raised. Therefore, according to the control described above, by quickly raising the temperature of the throttle body, the portion where the icing is generated in the throttle valve 10 can be effectively melted, and the throttle valve 10 is returned to normal early. It becomes possible. As described above, the ECU 50 operates as the determination unit and the electric pump control unit in the present invention.

(Control method of electric WP)
Here, with reference to FIG. 2, the control method of the electric WP 5 according to the first embodiment will be described.

  FIG. 2 is a flowchart showing a control process of the electric WP 5 according to the first embodiment. This process is performed to quickly eliminate icing generated in the throttle body. Specifically, when icing occurs in the throttle body, the throttle valve 10 is not set to a desired opening, and thus a malfunction may occur. Therefore, in the first embodiment, in order to prevent the occurrence of such a problem caused by icing, control is performed to quickly eliminate the icing generated in the throttle body and return it to normal. This process is repeatedly executed by the ECU 50 described above at a predetermined cycle.

  First, in step S101, the ECU 50 determines whether icing has occurred in the throttle body and an abnormality in operation (hereinafter referred to as "freezing abnormality") has occurred. In one example, the ECU 50 determines whether or not an abnormality in freezing has occurred in the throttle body according to the operating state of the engine 1, the rotational speed, and the like. In this case, the ECU 50 determines that the icing abnormality has occurred when the engine speed is greatly reduced from the assumed speed. In another example, the ECU 50 determines whether or not an icing abnormality has occurred based on the output of a throttle opening sensor that detects the opening of the throttle valve 10 (throttle opening). In this case, the ECU 50 determines whether or not icing abnormality has occurred by comparing the throttle opening corresponding to the control signal supplied to the throttle valve 10 with the throttle opening detected by the throttle opening sensor. To do. If it is determined that an icing abnormality has occurred (step S101; Yes), the process proceeds to step S102. If it is determined that an icing abnormality has not occurred (step S101; No), the process proceeds with the flow. Exit.

  In step S102, the ECU 50 performs control to increase the idle speed and control to increase the flow rate of the electric WP5. The control for increasing the idling speed is performed to secure a heat source. The reason why the flow rate of the electric WP 5 is increased is to increase the amount of cooling water supplied to the throttle body and to quickly raise the temperature of the throttle body. That is, this is because the throttle valve 10 can be returned early by effectively melting the portion of the throttle valve 10 where icing has occurred. When the above process ends, the process proceeds to step S103.

  In step S103, the ECU 50 counts up a timer. Then, the process proceeds to step S104. In step S104, the ECU 50 determines whether or not the timer is equal to or longer than a predetermined time. The predetermined time used for this determination is a preset time, and roughly corresponds to the time required for the portion of the throttle valve 10 where icing is generated to melt. If the timer is equal to or longer than the predetermined time (step S104; Yes), the process proceeds to step S105. In step S105, the ECU 50 performs processing for clearing the icing abnormality. This is because it is considered that the icing abnormality in the throttle body has been resolved. Then, the process exits the flow.

  On the other hand, when the timer is less than the predetermined time (step S104; No), the process returns to step S103. In this case, in step S103, the timer is further counted up. Thus, by repeating the process of step S103 and the determination of step S104, the control for increasing the idle speed and the control for increasing the flow rate of the electric WP5 until the timer reaches a predetermined time or more (step S104; Yes). continue.

  According to the control process of the electric WP 5 according to the first embodiment described above, when the icing abnormality occurs in the throttle body, the temperature of the throttle body can be quickly raised, and icing occurs in the throttle valve 10. The part which is present can be effectively melted. As a result, the throttle valve 10 can be quickly restored from the icing abnormality. In addition, since the exhaust heat recovery device 2 is provided on the cooling water passage 7, the temperature of the cooling water can be effectively raised by heat exchange between the exhaust gas and the cooling water, so that the temperature rise By supplying water to the throttle body, it is possible to efficiently raise the temperature of the throttle body.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in that control is performed to increase the flow rate of the electric WP 5 when the temperature of the exhaust gas is high. Specifically, in the second embodiment, control is performed to increase the flow rate of the electric WP 5 in order to promote heat exchange in the exhaust heat recovery device 2 using high-temperature exhaust gas. That is, in the first embodiment, control is performed for the purpose of raising the temperature of the throttle body, but in the second embodiment, control is performed for the purpose of promoting heat exchange in the exhaust heat recovery device 2. The reason for promoting heat exchange in the exhaust heat recovery unit 2 is to warm up the engine 1 early.

  Specifically, the control according to the second embodiment is executed by the ECU 50 in the cooling system 100 described above (see FIG. 1). In this case, the ECU 50 controls the electric WP 5 based on the temperature of the exhaust gas obtained from the sensor or the temperature of the exhaust gas obtained by estimation. In other words, the ECU 50 changes the flow rate of the electric WP 5 depending on the temperature of the exhaust gas. Specifically, the ECU 50 performs control to increase the flow rate of the electric WP 5 when the temperature of the obtained exhaust gas is higher than a predetermined temperature.

  By increasing the flow rate of the electric WP 5 in this way, the amount of cooling water passing through the exhaust heat recovery device 2 can be increased, and therefore heat exchange in the exhaust heat recovery device 2 can be promoted. In other words, the amount of heat recovered by the exhaust heat recovery device 2 can be increased. Therefore, according to the control according to the second embodiment, it is possible to effectively warm up the engine 1 using the cooling water heated by the heat exchange in the exhaust heat recovery device 2.

  In addition, it is not limited to performing only the control which concerns on 2nd Embodiment, You may perform control which concerns on 2nd Embodiment in combination with the control which concerns on 1st Embodiment mentioned above. That is, it is possible to perform control to increase the flow rate of the electric WP 5 in both the situation where the temperature of the throttle body should be raised (the situation where icing has occurred) and the situation where heat exchange in the exhaust heat recovery device 2 should be promoted. .

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In the third embodiment, the first embodiment and the first embodiment are different in that control is performed to effectively reduce the temperature of exhaust gas recirculated to the intake system (hereinafter referred to as “EGR gas”) with cooling water. Different from the second embodiment. Specifically, in the third embodiment, when the EGR rate is high (when the amount of EGR gas is large), the temperature of the EGR gas is decreased by performing control to increase the flow rate of the electric WP5. That is, in the first embodiment, control is performed to increase the flow rate of the electric WP5 for the purpose of raising the temperature of the throttle body. In the third embodiment, however, the electric WP5 is used for the purpose of reducing the temperature of the EGR gas. Control to increase the flow rate.

  FIG. 3 is a diagram illustrating a schematic configuration of the cooling system 103 according to the third embodiment. In FIG. 3, a solid line arrow indicates an example of the flow of gas or cooling water, and a broken line arrow indicates signal input / output. The cooling system 103 is applied to a system (exhaust gas recirculation (EGR) system) that improves fuel efficiency by recirculating exhaust gas to the intake system. In addition, the same code | symbol is attached | subjected to the component same as the cooling system 100 shown in FIG. 1, and the description is abbreviate | omitted.

  Specifically, in the cooling system 103 according to the third embodiment, the cooling water passage 7e is connected to the cooling water passage 7a. An EGR cooler 12 is provided in the cooling water passage 7e. The EGR cooler 12 is provided on an EGR passage (not shown) through which the EGR gas passes and is used to cool the EGR gas. Further, cooling water is supplied to the EGR cooler 12 via the cooling water passage 7e. The EGR cooler 12 and the cooling water passage 7e are configured so that the cooling water is not mixed into the EGR gas. By supplying the cooling water to the EGR cooler 12 in this way, the EGR cooler 12 can be cooled by the cooling water, and the temperature of the EGR gas can be effectively lowered. The cooling water passage 7e corresponds to the cooling water supply unit in the present invention.

  The ECU 53 includes a CPU, ROM, RAM, and the like (not shown). In the third embodiment, the ECU 53 executes control to increase the flow rate of the electric WP5 when the EGR rate is high. By increasing the flow rate of the electric WP 5 in this way, the amount of cooling water supplied to the EGR cooler 12 can be increased, and the EGR cooler 12 can be effectively cooled. Therefore, the temperature of the EGR gas passing through the EGR cooler 12 can be effectively reduced.

  Therefore, according to the control according to the third embodiment, the temperature of the EGR gas can be effectively reduced, so that the fuel consumption of the engine 1 can be improved.

  In addition, although the example which supplies cooling water to the EGR cooler 12 and reduces the temperature of EGR gas was shown above, it is not limited to this. In another example, the temperature of the EGR gas can be lowered by supplying cooling water to components other than the EGR cooler 12 in the EGR system.

  Moreover, it is not limited to performing only the control according to the third embodiment, and at least one of the control according to the third embodiment, the control according to the first embodiment and the control according to the second embodiment described above. , May be executed in combination. For example, in a situation where the temperature of the throttle body should be raised (a situation where icing has occurred), a situation where heat exchange in the exhaust heat recovery device 2 should be promoted, and a situation where the temperature of the EGR gas should be lowered, the flow rate of the electric WP 5 is reduced. Increased control can be performed.

It is a figure which shows schematic structure of the cooling system which concerns on 1st Embodiment. It is a flowchart which shows the control processing of the electric WP which concerns on 1st Embodiment. It is a figure which shows schematic structure of the cooling system which concerns on 3rd Embodiment.

Explanation of symbols

1 engine (internal combustion engine)
2 Exhaust heat recovery unit 3 Radiator 5 Electric pump (Electric WP)
7 Cooling water passage 9 Intake passage 10 Throttle valve 12 EGR cooler 50 ECU
100 Cooling system

Claims (3)

A temperature raising device for a throttle body that circulates cooling water for cooling the engine by an electric pump and raises the temperature of the throttle body by supplying the cooling water to the throttle body,
Determination means for determining whether icing has occurred in the throttle body;
An electric pump control unit that performs control to increase the flow rate of the electric pump when the determination unit determines that the icing has occurred.   The temperature increasing device for a throttle body according to claim 1, further comprising an exhaust heat recovery device for exchanging heat between the cooling water passing through the interior and the exhaust gas. A cooling water supply unit that supplies the cooling water to an EGR system that recirculates exhaust gas to the intake system;
The temperature increasing device for a throttle body according to claim 1 or 2, wherein the electric pump control means performs control to increase the flow rate of the electric pump when the EGR rate in the EGR system is high.

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