JP2005325751A - Throttle valve and control device of internal combustion engine having this throttle valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform normal operation of a throttle valve at a low temperature, by precisely detecting a deposit state and a freezing state of frost of the throttle valve. <P>SOLUTION: An ECU executes a program including a step (S100) of detecting a temperture state of an engine from an intake air temperature sensor and a water temperature sensor, a step (S110) of determining whether or not to be a low temperature condition reaching icing on the basis of the temperature state, a step (S130) of determining whether predetermined time passes after starting idling or the predetermined time passes from reversal operation of the last time when a measured air flow rate is a specified value or less to the minus side more than a flow rate generated to throttle opening when the throttle valve is a normal state (YES in S120), and a step (S140) of reversing the throttle valve by substantially 180 degrees when the predetermined time passes after starting the idling or the predetermined time passes after executing the reversal operation of the last time (YES in S130). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a throttle valve and a control device for an internal combustion engine including the throttle valve, and more particularly to a throttle valve and a device for controlling the internal combustion engine including the throttle valve that can operate normally even at low temperatures.

  Under extremely cold conditions, even when the engine is running, the water contained in the intake air in the intake pipe may freeze and freeze in the throttle valve and its surroundings. In the worst case, the throttle valve during steady running There is a risk that the shaft will freeze and the throttle valve will stop moving.

  As a countermeasure against this, there is one in which the periphery of the throttle valve is heated using cooling water (hot water) warmed by the engine to prevent icing of the throttle valve. However, if such a hot water heating device is provided, the configuration of the throttle system and the cooling water circulation system becomes complicated and the cost increases. In addition, in a high temperature environment, the high intake air temperature is further raised by the hot water heating device, so the cylinder air charge amount must be reduced, or the knocking limit must be reduced to retard the ignition timing. May occur, leading to a decrease in engine output.

  In consideration of such circumstances, Japanese Patent Laid-Open No. 2003-262178 (Patent Document 1) does not use a heating device such as hot water or an electric heater and does not adversely affect drivability. Disclosed is an internal combustion engine control device capable of enhancing the effect of preventing freezing. The control device for an internal combustion engine disclosed in this publication is a control device for an internal combustion engine that controls the opening degree of a throttle valve provided in an intake passage of the internal combustion engine to a target throttle opening degree, during operation of the internal combustion engine. A throttle anti-icing control unit that forcibly opens and closes the throttle valve in an opening range including the target throttle opening when a predetermined throttle anti-icing control execution condition is satisfied, and a throttle valve forcible drive by the throttle anti-icing control unit And an output fluctuation prevention control unit that corrects control parameters other than the throttle opening in a direction to cancel the output fluctuation of the internal combustion engine generated by the engine.

According to this control device for an internal combustion engine, the amount of forced drive when the throttle valve is forcibly opened / closed is increased to some extent to enhance the anti-icing effect of the throttle valve, while the internal combustion engine generated by the forced drive of the throttle valve The output fluctuation can be canceled by correcting control parameters other than the throttle opening. As a result, it is possible to effectively prevent icing of the throttle valve without adversely affecting drivability, and it is possible to prevent the throttle valve from icing and moving during driving. In addition, since it is not necessary to use a heating device such as hot water or an electric heater, the cost can be reduced, and a decrease in the output of the internal combustion engine due to an increase in intake air temperature by the heating device can be avoided.
JP 2003-262178 A

  However, in the control apparatus for an internal combustion engine disclosed in Patent Document 1, it is satisfied that the intake air temperature is equal to or lower than a predetermined temperature (the temperature at which icing of the throttle valve occurs) and that the throttle opening is almost in a steady state. Then, the opening degree of the throttle valve was periodically changed (hereinafter referred to as swinging). Since the temperature is the main condition, even if the possibility of actual icing is low, the throttle valve is swung, which causes unnecessary energy consumption.

  In a PCV (Positive Crankcase Ventilation) device (blow-by gas reduction device), when blow-by gas is supplied further upstream of the throttle valve through the PCV pipe, the following problems occur. That is, while the blow-by gas is a humid gas, in a low temperature atmosphere, the throttle valve and the throttle bore are in a cold state, so the blow-by gas directly hits the throttle valve and the throttle bore, resulting in dew condensation and frost. And accumulate.

  In particular, when an abnormality occurs in which the PCV pipe downstream from the throttle valve is blocked for some reason, the engine is lightly loaded, the throttle valve opening is small, and the throttle valve clearance is small. Then, since the PCV pipe line to the downstream side is blocked, the reduced humid blow-by gas passes through the PCV pipe line upstream from the throttle valve and becomes a throttle valve cooled in a low temperature atmosphere. Direct hit. At this time, condensation may occur and accumulate as frost. In particular, since the clearance of the throttle valve is small, even if the accumulation of frost is small, the throttle valve may stick or the clearance may be frosted. This increases the possibility that the intake pipe will be blocked due to the cover.

  More specifically, when a humid gas flows in, frosty water adheres to the surface of the throttle valve, or the attached frosty water blocks the clearance between the throttle valve and the throttle bore, This means that there may be a decrease in engine speed or engine stall.

  Under such circumstances, when the temperature of the throttle valve freezes or the throttle opening is almost in a steady state as in Patent Document 1, the throttle valve is swung. If you do, there are the following problems. That is, in the swing start condition disclosed in Patent Document 1, not only frost is actually accumulated nor frozen, but not only is unnecessary energy consumption caused by swinging the throttle valve, but also generation of frost is caused. Since it cannot be accurately detected only by temperature, it may be possible to swing the throttle valve after frost accumulates and the throttle valve freezes. This causes the swing timing to be too late, causing the throttle valve to swing. Even so, the accumulated frost and further freezing cannot be removed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a throttle valve and a control device for an internal combustion engine including the throttle valve, which realize normal operation of the throttle valve at a low temperature. Is to provide.

  A throttle valve according to a first aspect of the present invention is provided in an intake pipe of an internal combustion engine and controls an intake amount to the internal combustion engine. This throttle valve includes a valve body supported by a rotating shaft, a bore having a shape matching the outer shape of the valve body, and a rotating means for rotating the rotating shaft by approximately 180 degrees or more.

  According to the first invention, for example, when an abnormality occurs in which the PCV pipe downstream of the throttle valve in the PCV device is blocked for some reason, the blow-by gas is returned to the upstream side of the throttle valve, and the humid blow-by gas There is a case where dew condensation occurs and directly accumulates as frost by directly hitting the cooled throttle valve. In such a case, when the throttle valve starts to condense, frost begins to accumulate on the throttle valve, the throttle valve begins to freeze, or when the throttle valve opening is small and the clearance is small, the intake pipe (air passage) When the valve starts to close, the throttle valve that can rotate about 180 degrees or more (or 360 degrees) may be rotated about 180 degrees around the rotation axis. That is, the front and back are reversed when the throttle valve is viewed from the upstream side. In this way, frost-like moisture adhering to the surface of the valve body of the throttle valve is not further grown by the blow-by gas, so that the throttle valve can be prevented from freezing. Moreover, there is a possibility that the accumulated frost and the frozen frost may be blown off to the internal combustion engine side by the intake air. As a result, it is possible to provide a throttle valve that realizes normal operation of the throttle valve at a low temperature.

  A control device for an internal combustion engine according to a second invention controls the opening of a throttle valve provided in an intake pipe of the internal combustion engine. The throttle valve controlled by the control device of the internal combustion engine includes a valve body supported by a rotating shaft, a bore having a shape that matches the outer shape of the valve body, and a rotating means for rotating the rotating shaft by approximately 180 degrees or more. including. The control device for an internal combustion engine includes a detecting means for detecting occurrence or possibility of occurrence of malfunction of the throttle valve due to at least one of frost and ice adhering to the throttle valve, and a throttle by means of the detecting means. And a control means for controlling the rotating means so as to reverse the valve body by approximately 180 degrees when the occurrence of the valve malfunction or the possibility of occurrence thereof is detected.

  According to the second invention, for example, when an abnormality occurs in which the PCV pipe downstream of the throttle valve in the PCV device is blocked for some reason, the blow-by gas is returned to the upstream side of the throttle valve, and the humid blow-by gas There is a case where dew condensation occurs and directly accumulates as frost by directly hitting the cooled throttle valve. In such cases, when the throttle valve starts to condense, frost begins to accumulate on the throttle valve, the throttle valve begins to freeze, or when the throttle valve opening is small and the clearance is small, the intake pipe (air passage) When the valve starts to be closed, the detection means detects the occurrence or the possibility of occurrence of malfunction of the throttle valve due to at least one of frost and ice adhering to the throttle valve. In such a case, the throttle valve that can rotate approximately 180 degrees or more (or 360 degrees) about the rotation axis is rotated approximately 180 degrees. In this way, frost-like moisture adhering to the surface of the valve body of the throttle valve is not further grown by the blow-by gas, so that the throttle valve can be prevented from freezing. Further, there is a possibility that the accumulated frost and further the frozen frost are blown off to the internal combustion engine side by the intake air. As a result, it is possible to provide a control device for an internal combustion engine that realizes normal operation of the throttle valve at a low temperature. Note that the malfunction of the throttle means that frost adheres to the throttle valve and its support shaft and a desired opening cannot be obtained, frost adheres to the throttle valve and its vicinity, When the clearance is small and the clearance is small, the intake pipe (air passage) is blocked.

  In the internal combustion engine control apparatus according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the detection means sets the value of the physical quantity representing the target state of the internal combustion engine corresponding to the open / close state of the throttle valve to the first value. Means for detecting the measured value of the physical quantity as a second value, comparing means for comparing the first value and the second value, and the result of the comparison And means for detecting the occurrence or possible occurrence of throttle valve malfunction.

  According to the third aspect of the present invention, when no frost is accumulated on the throttle valve and no icing is formed, an actual measured value of a physical quantity representing the target state of the internal combustion engine corresponding to the open / closed state when the throttle valve is normal ( This is because, for example, the inflow air amount as the second value and the internal combustion engine speed, etc., are normal values, but the second value is normal when frost is accumulated or frozen on the throttle valve. It is not a correct value. A physical quantity value representing a target state when the throttle valve of the internal combustion engine is in a normal state corresponding to the opening / closing state of the throttle valve is detected as a first value, and is a measured value that is an actually measured value rather than the first value. If the second value is lower than the first value, for example, the occurrence of malfunction of the throttle valve due to the adhesion of at least one of frost and ice to the throttle valve or The possibility of occurrence can be detected.

  In the control apparatus for an internal combustion engine according to the fourth aspect of the invention, in addition to the configuration of the third aspect of the invention, the detection means detects the throttle valve when the second value is lower than the first value as a result of comparison. Means for detecting the occurrence or potential for malfunctions.

  According to the fourth invention, when the second value (inflow air amount or internal combustion engine speed) is lower than the first value, at least one of frost and ice adheres to the throttle valve. It is possible to detect the occurrence or the possibility of occurrence of malfunctions. That is, if frost is accumulated on the throttle valve or is frozen, it will not open to its opening even when a control signal for opening the throttle valve is received. In a situation where the surface of the throttle valve is frosted, the intake air amount does not satisfy the target even if the throttle valve opening is at the target position. For this reason, the inflow air amount and the internal combustion engine speed are lower than when the throttle valve is in a normal state. Based on this, it is possible to detect the occurrence or the possibility of occurrence of malfunction of the throttle valve due to at least one of frost and ice adhering to the throttle valve.

  In the control device for an internal combustion engine according to the fifth invention, in addition to the configuration of the third or fourth invention, the physical quantity is the amount of air flowing into the internal combustion engine.

  According to the fifth aspect of the present invention, the malfunction of the throttle valve is caused by detecting the amount of inflow air having a strong relationship with the opening degree of the throttle valve with the air flow meter and attaching at least one of frost and ice to the throttle valve. Occurrence or the possibility of occurrence can be detected.

  In the control device for an internal combustion engine according to the sixth invention, in addition to the configuration of the third or fourth invention, the physical quantity is the rotational speed of the internal combustion engine.

  According to the sixth aspect of the invention, the operation of the throttle valve is performed by detecting the rotational speed of the internal combustion engine having a strong relationship with the opening degree of the throttle valve by the rotational speed sensor and attaching at least one of frost and ice to the throttle valve. It is possible to detect the occurrence or possibility of occurrence of defects.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
With reference to FIGS. 1 and 2, a cross section of engine 100 mounted with a PCV device, which is controlled by the engine control system according to the present embodiment, will be described. FIG. 1 shows a state when the engine 100 is lightly loaded, and FIG. 2 shows a state when the engine 100 is heavily loaded.

  As shown in FIGS. 1 and 2, the engine 100 mainly includes a cylinder 104, a piston 106, a crankcase 102, and a cylinder head 116. The blow-by gas is a mixed gas that leaks from the gap between the piston ring and the cylinder 104 to the crankcase 102. The blow-by gas contains a large amount of hydrocarbons and is very acidic, so it is too much. This can cause deterioration of engine oil and rust inside the engine. Moreover, since it contains hydrocarbons, it is not good for the environment to release it to the atmosphere as it is. Therefore, the blow-by gas is forcibly returned to the intake system using the negative pressure of the intake manifold through the PCV line 122A (at light load), the PCV line 122A and the PCV line 122B (at high load). Become. The flow of this blow-by gas and fresh air is indicated by arrows.

  A throttle valve 118 is provided in the intake system. The amount of intake air supplied to engine 100 is adjusted by throttle valve 118, and the intake air whose amount has been adjusted passes through intake pipe 112 and is supplied from intake valve 108 to a combustion chamber inside engine 100. Fuel is combusted by the supplied intake air, and combustion gas is discharged to the outside of the engine through the exhaust valve 110 and the exhaust pipe 114.

  Blow-by gas generated in the gap between the piston ring and the cylinder 104 passes through the inside of the cylinder head 116, passes through the PCV conduit 122A at a light load, and intakes through the PCV conduit 122A and the PCV conduit 122B at a high load. Guided to tube 112. A PCV valve 123 is provided in the PCV conduit 122A. The PCV valve 123 is a flow rate regulating valve that regulates the flow rate with the strength of the negative pressure of the intake manifold. That is, as shown in FIGS. 1 and 2, the flow rate of the PCV conduit 122 </ b> A is adjusted by the PCV valve 123 to reduce the blow-by gas downstream of the throttle valve 118. PCV pipe line 122B reduces blow-by gas upstream of throttle valve 118 when engine 100 is under a high load.

  When such an operation is performed, a case where the following abnormality occurs is assumed. Assume that an abnormality occurs in which the downstream PCV pipe line 122A is blocked for some reason. When the engine 100 is lightly loaded, the opening of the throttle valve 118 is small, and the clearance between the throttle valve 118 and the intake pipe 112 is small. In such a state, when the downstream PCV pipe 122A is blocked, the reduced humid blow-by gas directly passes through the PCV pipe 122B and directly hits the throttle valve 118 that has been cooled in a low temperature atmosphere to cause condensation. It may occur and accumulate as frost. In particular, since the clearance between the throttle valve 118 and the intake pipe 112 is small at this time, even if the accumulation of frost is small, the throttle valve 118 is fixed or the clearance is covered with frost and the intake pipe line Is likely to occur. The present invention provides a throttle valve and a control device that solve such problems.

  With reference to FIG. 3, the throttle valve 118 according to the present embodiment, which is controlled by the engine control system, of engine 100 will be described.

  As shown in FIG. 3, the throttle valve 118 has a disc-like valve body 118A having the same diameter as the bore of the throttle valve 118, and the valve body 118A is fully closed (the throttle opening is 0 degrees). 180 degrees or more (or 360 degrees may be included), including from a fully open state (a state where the valve body 118A is substantially vertical) to a fully opened state (a state where the throttle body 118A is substantially horizontal). A motor 118B for rotating operation, a throttle position sensor 118C for detecting the opening degree of the valve body 118A, and a rotational force by a gear provided on the rotation shaft of the motor 118B are decelerated and provided on the rotation shaft of the valve body 118A. Including a reduction gear 118D and a reduction gear 118E that transmit the rotational force to the other gears.

  The motor 118B is constituted by a DC motor, for example. Further, as shown in FIG. 3, the throttle valve 118 according to the present embodiment is configured so that the valve body 118A of the throttle valve 118 rotates between 0 degrees and approximately 180 degrees or more in order to rotate the valve body 118A. The reduction gear 118E provided in the is engraved with gears of at least about 180 degrees (1/2 circumference). (In FIG. 3, the maximum 360 degree gear is carved). Further, the throttle valve 118 is provided with a return spring that generates a force that is contrary to the force for opening the valve body 118A by the motor 118B. By this return spring, a force acts in the direction in which the valve body 118A of the throttle valve 118 is always closed. The motor 118B opens the valve body 118A of the throttle valve 118 by a predetermined opening against the force of the return spring via the reduction gear 118D and the reduction gear 118E.

  Further, an inversion signal (inversion flag) is transmitted as a control signal from the ECU to the motor 118B. Upon receiving this signal from the ECU, the motor 118B reverses the front and back of the valve body 118A of the throttle valve 118 (rotates the valve body 118A by approximately 180 degrees).

  A control block diagram of the engine control system according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 4, the engine control system according to the present embodiment controls engine 100. In particular, hereinafter, the control of the opening degree of the throttle valve 118 that controls the amount of intake air to the engine 100 and the control that prevents the throttle valve 118 from freezing will be described.

As shown in FIG. 4, this engine control system includes an ECU (Electronic Control Unit) 1000 that controls engine 100 and throttle valve 118, and engine 100.
An intake air temperature sensor 1010 for detecting the intake air temperature of the intake air sucked into the engine 100, a water temperature sensor 1020 for detecting the coolant temperature of the engine 100, an engine speed sensor 1030 for detecting the engine speed, and the engine 100 And an intake air amount sensor 1040 for detecting the amount of intake air taken into the air. The intake air temperature sensor 1010, the water temperature sensor 1020, the engine speed sensor 1030, and the intake air amount sensor 1040 are connected to the ECU 1000, and signals representing the detected physical quantities (intake air temperature, water temperature, engine speed, intake air amount) are sent to the ECU 1000. Send to.

  An accelerator opening sensor 1050 for detecting the opening of the accelerator pedal is provided, and a signal indicating the opening of the accelerator pedal is input to the ECU 1000. Further, a signal indicating the opening of the throttle valve 118 and an inversion signal (inversion flag) are input from the throttle position sensor 118C to the ECU 1000.

  A signal indicating the opening degree of the valve body 118A of the throttle valve 118 is output from the ECU 1000 to the motor 118B of the throttle valve 118. When the motor 118B rotates, the valve body 118A is set to a predetermined value via the reduction gear 118D and the reduction gear 118E. Or the valve body 118A is controlled so as to reverse approximately 180 degrees.

  As described above, blow-by gas is supplied on the intake air amount sensor 1040 side (upstream side) of the throttle valve 118 shown in FIG. This blow-by gas is humid air, and when the throttle valve 118 is at a low temperature, such as when it is cold, condensation occurs to generate moisture. This moisture is often frosty.

ECU 1000 includes a CPU (Central Processing Unit) and a drive circuit provided therein. ECU 1000 transmits an inversion signal (inversion flag) to motor 118B so that throttle valve 118 does not freeze based on a physical quantity representing the state of engine 100 input from various sensors, so that valve body 118A of throttle valve 118 is Force inverting to prevent icing.

  FIG. 5 illustrates a map representing the relationship between the throttle opening and the flow rate stored in the memory of ECU 1000. The map shown in FIG. 5 is also referred to as a flow characteristic curve, and shows how much air amount is detected by the intake air amount sensor 1040 with respect to the throttle opening when the throttle valve 118 is normal. is there.

  That is, the map shown in FIG. 5 is a map showing how much intake air flows with respect to the throttle opening when the throttle valve 118 is operating normally.

  The flow characteristic curve of the throttle valve 118 changes over time due to wear of the valve body 118A of the throttle valve 118, wear of the bore, and deposits such as oil. The flow rate characteristic curve shown in FIG. 5 may be learned and corrected so as to calculate the flow rate with respect to the throttle opening in consideration of the influence of such throttle valve body and bore wear and oil and other deposits. Good.

  A control structure of a program executed by ECU 1000 will be described with reference to FIG.

  In step (hereinafter, step is abbreviated as S) 100, ECU 1000 detects the temperature of the intake air taken into engine 100 from intake air temperature sensor 1010 and water temperature sensor 1020 and the temperature of cooling water in engine 100. In S110, ECU 1000 determines whether or not the low temperature condition is such that throttle valve 118 reaches icing. If the temperature is low enough to cause icing of throttle valve 118 (YES in S110), the process proceeds to S120. If not (NO in S110), the process proceeds to S150.

  In S120, ECU 1000 determines whether or not the air flow rate is equal to or less than a specified value on the minus side compared to the flow rate map (FIG. 5). That is, it is determined whether or not the intake air amount detected by the intake air amount sensor 1040 has decreased to a predetermined value or less on the negative side with respect to the flow rate that would flow based on the current throttle opening command signal. Is done. This determines whether or not malfunction of the throttle valve 118 has occurred or is likely to occur due to at least one of frost and ice adhering to the throttle valve 118. If the air flow rate detected by intake air amount sensor 1040 has decreased to a predetermined value or less on the negative side as compared to the flow rate calculated from the map shown in FIG. 5 (YES in S120), the process proceeds to S130. Moved. If not (NO in S120), the process proceeds to S150.

  In S130, ECU 1000 determines whether or not a predetermined time has elapsed after the start of idling (N position) or after the reverse operation of valve body 118A of throttle valve 118 is executed. If a predetermined time has elapsed after the start of idling or the execution of the reversing operation of valve body 118A of throttle valve 118 (YES in S130), the process proceeds to 140. If not (NO in S130), the process returns to S100.

  In S140, ECU 1000 operates to reverse the front and back of valve body 118A of throttle valve 118. At this time, ECU 1000 transmits an inversion signal (inversion flag) to motor 118B. The motor 118B operates to rotate approximately 180 degrees from the current angle. Thereafter, the process returns to S100.

  In S150, ECU 1000 executes normal control.

  The operation of the engine control system according to the present embodiment based on the above-described structure and flowchart will be described.

  While the engine 100 is operating, the intake air temperature and the engine cooling water temperature detected by the intake air temperature sensor 1010 and the water temperature sensor 1020 are detected (S100). If it is determined based on these temperatures that the temperature is low enough to cause icing on throttle valve 118 (YES in S110), the air flow rate detected by intake air amount sensor 1040 is shown in FIG. It is determined whether or not the value is equal to or more than a specified value on the minus side compared to the flow rate map (S120). If the air flow rate actually detected by the intake air amount sensor 1040 is equal to or less than the specified value on the negative side of the flow rate obtained from the throttle opening shown in FIG. 5 (YES in S120), icing actually occurs. If it is determined that the valve body 118A of the throttle valve 118 satisfies the condition of S130, the operation of reversing the front and back of the valve body 118A of the throttle valve 118 is performed.

  When a predetermined time has elapsed since the start of idling or when a predetermined time has elapsed since the previous reversal operation of throttle valve 118 (YES in S130), the valve body of throttle valve 118 It is operated so that the front and back of 118A are reversed. On the other hand, until a predetermined time elapses after the start of idling or until a predetermined time elapses after execution of the reverse operation of the previous throttle valve 118 (NO in S130), the throttle valve 118 Inversion operation is not performed. This is preferable because the reverse operation of the throttle valve 118 in the idling region has a small influence on the behavior of the vehicle, but the processing in S130 is performed in order to avoid performing this indefinitely.

  FIG. 7A shows a state in which the valve body 118A is fully closed with the front side of the valve body 118A facing the upstream side of the intake air, and the valve body 118A is fully oriented with the back side of the valve body 118A facing the upstream side of the intake air. The closed state is shown in FIG. 7C, and the throttle valve 118 is fully opened in FIG. 7B.

  In the state shown in FIG. 7A, it is assumed that frost has begun to accumulate on the surface of the valve body 118A. When an inversion signal (inversion flag) is received from ECU 1000, the state shown in FIG. 7C is obtained after the state shown in FIG. 7B. In this process, the frost that has been accumulated is likely to be blown off by the intake air in the state of FIG. Moreover, even if it is not blown away, the backside that has not been deposited is switched to the surface that is exposed to the high-humidity blowby gas, so that it is possible to avoid further accumulation of frost on the surface.

  As described above, according to the throttle valve and the engine control system according to the present embodiment, it is possible that the malfunction of the throttle valve occurs or occurs when the ECU attaches at least one of frost and ice to the throttle valve. This is detected by comparing the amount of intake air with the flow rate obtained from the map. When the occurrence or the possibility of occurrence of malfunction of the throttle valve is detected, the throttle valve that can rotate about 180 degrees or more around the rotation shaft is rotated about 180 degrees. In this way, frost-like moisture adhering to the surface of the valve body of the throttle valve is not further grown by the blow-by gas, so that the throttle valve can be prevented from freezing. Further, there is a possibility that the accumulated frost and further the frozen frost are blown off to the internal combustion engine side by the intake air. As a result, normal operation of the throttle valve at low temperatures can be realized.

<Second Embodiment>
Hereinafter, an engine control system according to a second embodiment of the present invention will be described. The engine control system according to the present embodiment differs only in the control structure of a program executed by ECU 1000, and the other control structures and flowcharts are the same as those in the first embodiment. Therefore, detailed description thereof will not be repeated here.

  With reference to FIG. 8, a control structure of a program executed by ECU 1000 of the engine control system according to the present embodiment will be described. In the flowchart shown in FIG. 8, the same steps as those in the flowchart shown in FIG. The processing for them is the same. Therefore, detailed description thereof will not be repeated here.

  In S220, ECU 1000 determines whether or not the difference between the actual engine speed detected by engine speed sensor 1030 and the target engine speed at idling is equal to or greater than the specified engine speed on the minus side. This determines whether or not a malfunction of the throttle valve 118 has occurred or is likely to occur due to at least one of frost and ice adhering to the throttle valve 118. That is, if throttle valve 118 is operating normally (if it is not icing), a control signal for opening throttle valve 118 from ECU 1000 to motor 118B so as to reach a preset target rotational speed at idling. The output is output and feedback control is performed so that the deviation between the actual value detected by the throttle position sensor 118 and the target value is eliminated with the opening degree as a target value.

  Therefore, if the throttle valve 118 is normal, the difference between the engine speed and the target speed at idling should not be large. However, if the throttle valve 118 is frozen, even if a control signal is output from the ECU 1000 to the motor 118B, an opening corresponding to the control signal cannot be obtained. Therefore, the engine speed actually measured with respect to the target engine speed of engine 100 is reduced by more than the specified engine speed. This is detected and it is determined that the throttle valve 118 is frozen or possibly frozen, and the reversing operation of the throttle valve 118 is executed.

  As described above, also in the engine control system according to the present embodiment, the same operational effects as those of the first embodiment described above can be expressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing (the 1) of the engine which has a PCV apparatus controlled with the engine control system which concerns on embodiment of this invention. It is sectional drawing (the 2) of an engine which has a PCV apparatus controlled with the engine control system which concerns on embodiment of this invention. It is a disassembled perspective view of a throttle valve. It is a control block diagram of an engine control system. It is a figure which shows the relationship between a throttle opening and a flow volume. It is a flowchart which shows the control structure of the program performed by ECU of the engine control system which concerns on the 1st Embodiment of this invention. It is a figure showing the state of the valve body of a throttle valve seen from the throttle valve upstream side. It is a flowchart which shows the control structure of the program performed by ECU of the engine control system which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  100 Engine, 102 Crankcase, 104 Cylinder, 106 Piston, 108 Intake valve, 110 Exhaust valve, 112 Intake pipe, 114 Exhaust pipe, 116 Cylinder head, 118 Throttle valve, 118A Valve body, 118B Motor, 118C Throttle position sensor, 118D , 118E Reduction gear, 122A, 122B PCV line, 123 PCV valve.

Claims (6)

A throttle valve that is provided in an intake pipe of an internal combustion engine and controls an intake air amount to the internal combustion engine,
The throttle valve is
A valve body supported by a rotating shaft;
A bore having a shape matching the outer shape of the valve body;
A throttle valve including rotation means for rotating the rotation shaft by approximately 180 degrees or more. A control device for an internal combustion engine that controls the opening degree of a throttle valve provided in an intake pipe of the internal combustion engine,
The throttle valve includes a valve body supported by a rotating shaft, a bore having a shape that matches the outer shape of the valve body, and a rotating means for rotating the rotating shaft by approximately 180 degrees or more,
The control device includes:
Detecting means for detecting occurrence or possibility of occurrence of malfunction of the throttle valve due to adhesion of at least one of frost and ice to the throttle valve;
Control means for controlling the rotation means so as to reverse the valve body approximately 180 degrees when the detection means detects the occurrence or possibility of malfunction of the throttle valve. Control device for internal combustion engine. The detection means includes
Means for detecting a value of a physical quantity representing a target state of the internal combustion engine corresponding to an open / closed state of the throttle valve as a first value;
Means for detecting the measured value of the physical quantity as a second value;
A comparison means for comparing the first value and the second value;
The control device for an internal combustion engine according to claim 2, further comprising means for detecting occurrence or possibility of malfunction of the throttle valve based on the result of the comparison.   The detection means includes means for detecting the occurrence or possibility of malfunction of the throttle valve when the second value is lower than the first value as a result of the comparison. Item 4. The control device for an internal combustion engine according to Item 3.   The control device for an internal combustion engine according to claim 3 or 4, wherein the physical quantity is an amount of air flowing into the internal combustion engine.   The control device for an internal combustion engine according to claim 3 or 4, wherein the physical quantity is a rotational speed of the internal combustion engine.

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