JP2016125383A - Engine control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove ice around a throttle valve at the time of an engine start-up with improved reliability.SOLUTION: A throttle valve 36 is installed in an inclined passage 30b which is a portion of an intake passage 30 and inclined with respect to a vertical direction. An engine control device controls the throttle valve 36 in a manner that: maintains a valve opening at a first reference opening X when an engine is stopped; and fully closes the throttle valve 36 after increasing the valve opening from the first reference opening X to a second reference opening Y when the engine is started up.SELECTED DRAWING: Figure 6

Description

  The present invention includes an intake passage for introducing air into an engine, a throttle valve that opens and closes the intake passage, a throttle valve drive means that drives the throttle valve, and a control means that controls the throttle valve drive means. The present invention relates to an engine control device provided in an engine in which a throttle valve is in a state where a first reference opening that is set in advance is opened when the engine is stopped.

  Conventionally, there has been known a configuration in which a throttle valve is opened by a predetermined amount when the engine is stopped so that the engine can be started even if the throttle valve fails. In addition, a configuration for preventing the throttle valve from icing around the throttle valve and preventing the throttle valve from properly operating when the engine is started has been studied.

  For example, in Patent Document 1, when the engine is stopped, a predetermined amount of the throttle valve is opened. In order to remove ice around the throttle valve, the throttle valve is driven in the closing direction when the engine is started. A device that drives in the rear valve opening direction is disclosed.

JP 2006-249952 A

  If the throttle valve is opened and closed when the engine is started as in the device disclosed in Patent Document 1, the ice around the throttle valve can be removed by the vibration and impact. However, when the entire periphery of the throttle valve is frozen, the opening / closing operation of the throttle valve itself cannot be performed sufficiently and the ice may not be removed properly.

  The present invention has been made in view of the above circumstances, and provides an engine control device that can more reliably remove ice around a throttle valve.

  In order to solve the above problems, the present invention provides an intake passage for introducing air into an engine, a throttle valve for opening and closing the intake passage, a throttle valve driving means for driving the throttle valve, and a throttle valve drive Control means for controlling the means, and an engine control device provided in the engine in which the throttle valve is in a state of opening a first reference opening set in advance when the engine is stopped, wherein the throttle valve The control means is provided in an inclined passage that is inclined with respect to the vertical direction of the intake passage, and the control means opens the throttle valve with respect to the first reference opening by the throttle valve driving means when the engine is started. An engine control device is provided that performs freeze release control for opening the valve to the second reference opening and then fully closing the valve (claim 1).

  In this device, since the inclined passage provided with the throttle valve in the intake passage is inclined with respect to the vertical direction, the water present in the intake passage can be caused to flow toward one side (lower side) of the intake passage. it can. Therefore, it is possible to prevent the water and thus ice from adhering to the entire periphery of the throttle valve. When the engine is started, the throttle valve is more appropriately opened and closed, and the ice around the throttle valve can be removed by this opening and closing operation. it can.

  Moreover, in this device, when the engine is started, the throttle valve is first opened and then fully closed. Therefore, it is possible to more reliably remove the ice generated in the portion between the throttle valve and the inner surface of the intake passage (inclined passage) while the engine is stopped. Specifically, in this apparatus, the throttle valve side ice can be peeled off from the ice lump existing in the portion by first opening the throttle valve. Then, the throttle valve is then fully closed, so that the ice can be crushed by hitting the throttle valve against the ice remaining on the inner surface of the intake passage, and the ice around the throttle valve can be more reliably removed. In particular, since the throttle valve is moved to the fully closed position, ice generated between the first reference opening position and the fully closed position can be removed to ensure proper operation of the throttle valve.

  In the present invention, the throttle valve is disposed along a surface substantially orthogonal to the flow path of the inclined passage in the fully closed state, and the opening direction of the throttle valve is a portion that is the lower end in the fully closed state Is preferably set in the direction of moving downward (claim 2).

  According to this configuration, when the throttle valve is opened when the engine is started, the ice peeled off from the lump can be dropped below the intake passage, so that the ice can be more reliably removed from the periphery of the throttle valve. Can be removed.

  In the present invention, the control means preferably performs the freeze release control only during a cold start.

  In this way, it is possible to ensure proper operation of the throttle valve by removing the ice around the throttle valve when there is a risk of icing around the throttle valve at the time of cold start. In addition, when the surroundings of the throttle valve are not frozen, the above-described freeze release control is not performed, so that the intake air amount can be prevented from fluctuating with the opening / closing operation of the throttle valve.

  As a configuration different from the above, the control means may be configured to perform the freeze release control only when the throttle valve is frozen (Claim 4).

  Even in this case, it is possible to remove the ice around the throttle valve to ensure proper operation of the throttle valve, and to avoid fluctuations in the intake air amount when the circumference of the throttle valve is not frozen. Can do.

  In the above configuration, it is preferable that the control means stops the freeze release control at least after a complete explosion of the engine.

  In this way, the ice around the throttle valve is removed when the engine is started, and the intake air amount fluctuates after the engine complete explosion, that is, after combustion is performed once in all the cylinders of the engine. It is possible to avoid instability of combustion.

  In the present invention, the control means is configured so that the driving force for driving the throttle valve in the valve closing direction is larger than the driving force for driving in the valve opening direction during execution of the freeze release control. It is preferable to control the driving means (claim 6).

  In this way, when the throttle valve is fully closed, the throttle valve can be struck against the ice remaining on the inner surface of the intake passage with a stronger force, and the ice can be crushed and removed more reliably. Can do.

  As described above, according to the engine control apparatus of the present invention, the ice around the throttle valve can be more reliably removed.

1 is a schematic configuration diagram of an engine system 100 to which an engine control device according to an embodiment of the present invention is applied. It is the schematic perspective view which showed a part of intake passage. It is the III-III sectional view taken on the line of FIG. It is a block diagram which shows the control system of an engine. (A) It is the figure which showed the state of the throttle valve at the time of an engine stop. (B) It is the figure which showed the state which the throttle valve opened to the 2nd reference opening degree. (C) It is the figure which showed the state which has a throttle valve in a fully closed position. It is the flowchart which showed the flow of the freeze release control. (A) It is the figure which showed a mode that ice was produced | generated around a throttle valve at the time of an engine stop. (B) It is the figure which showed the mode when the throttle valve was opened at the time of freezing release control implementation. (C) It is the figure which showed the mode when closing a throttle valve toward full closure at the time of freezing release control implementation. (D) It is the figure which showed a mode when a throttle valve was fully closed at the time of freezing release control implementation.

  Hereinafter, an engine control apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(1) Overall Configuration FIG. 1 is a schematic configuration diagram of an engine system 100 to which an engine control device according to the present invention is applied. The engine system 100 has an engine body 1 and is mounted on a vehicle. The engine body 1 is, for example, a gasoline engine.

  The engine body 1 includes a cylinder block 10 provided with a cylinder 11 and a cylinder head 12 disposed on the cylinder block 10. The engine body 1 has, for example, four cylinders 11 arranged in a direction orthogonal to the paper surface of FIG. In each cylinder 11, a piston 14 connected to a crankshaft via a connecting rod is fitted so as to be able to reciprocate. A crankcase 13 in which a crankshaft is accommodated is provided below the cylinder block 10, and an oil pan 19 is provided below the crankcase 13.

  The cylinder head 12 is provided with an injector 15 for injecting fuel into each cylinder 11 and an ignition plug (not shown) for igniting an air-fuel mixture in each cylinder 11.

  The cylinder head 12 is provided with an intake port 16 for introducing intake air into the cylinder 11 and an exhaust port 18 for discharging exhaust gas from the cylinder 11 for each cylinder 11. The intake port 16 and the exhaust port 18 are provided with these ports, specifically, an intake valve 21 and an exhaust valve 22 that open and close the openings of the ports 16 and 18 formed in the cylinder head 12, respectively. Yes.

  An intake passage 30 is connected to each intake port 16. Specifically, branch passages 30a (see FIG. 2) branching corresponding to the respective cylinders 11 are formed at the downstream end of the intake passage 30, and these branch passages 30a and the respective intake ports 16 are connected. Yes.

  In the intake passage 30, an air cleaner 31 for filtering intake air, a throttle valve (throttle valve) 36 for opening and closing the intake passage 30, and a surge tank 33 are arranged in this order from the upstream side.

  An exhaust passage 40 is connected to each exhaust port 18. Similar to the intake passage 30, branch passages branching corresponding to the cylinders 11 are formed at the upstream end of the exhaust passage 40, and these branch passages are connected to the respective exhaust ports 18.

  The exhaust passage 40 is provided with an exhaust purification device that purifies harmful components in the exhaust gas. In the present embodiment, an oxidation catalyst 41 and a lean NOx catalyst 42 are provided in order from the upstream side.

  Between the intake passage 30 and the exhaust passage 40, an EGR device 50 for returning a part of the exhaust gas to the intake air is provided. The EGR device 50 includes an EGR passage 51, an EGR cooler 52 for cooling gas (EGR gas) passing through the EGR passage 51, and an EGR valve 53 that opens and closes the EGR passage 51. The EGR passage 51 connects a portion of the intake passage 30 downstream of the throttle valve 36 (surge tank 33 in the present embodiment) and a portion of the exhaust passage 40 upstream of the oxidation catalyst 41. Yes.

  The engine body 1 also includes first and second ventilation hoses 65 and 66 for returning blow-by gas leaked from each cylinder 11 to the intake passage 30. The first ventilation hose 65 connects a portion of the intake passage 30 on the downstream side of the throttle valve 36 (surge tank 33 in this embodiment) and the crankcase 13. The first ventilation hose 65 is provided with a check valve (not shown), and the blow-by gas passes through the first ventilation hose 65 only when the pressure of the crankcase 13 is higher than the pressure of the intake passage 30. Flows into the intake passage 30. The second ventilation hose 66 connects a portion of the intake passage 30 immediately downstream of the air cleaner 31 and a portion between the upper portion of the cylinder head 12.

  Each of the above devices is centrally controlled by an ECU (engine control unit, control means) 70 shown in FIG. As is well known, the ECU 70 is a microprocessor including a CPU, a ROM, a RAM, and the like.

  The engine and the vehicle are provided with a plurality of sensors for detecting the state quantities of the respective parts, and information from each sensor is input to the ECU 70. For example, an engine speed sensor SN1 for detecting the engine speed, an accelerator opening degree sensor SN2 for detecting the opening degree of an accelerator pedal (not shown) operated by the driver, or downstream of the air cleaner 31 in the intake passage 30. An intake air temperature sensor SN3 that is provided on the side portion and detects the temperature of air (intake air) taken into the engine, a water temperature sensor SN4 that detects the temperature of engine cooling water that cools the engine body 1, and the like are provided. The ECU 70 is electrically connected to the sensors SN1 to SN4 and an ignition switch SW1 provided in the vehicle, and performs various determinations and calculations based on signals input from these sensors, Control each part.

(2) Detailed Structure of Intake Passage and Throttle Valve FIG. 2 is a schematic perspective view showing a part of the intake passage 30, and FIG. 3 is a sectional view taken along the line III-III in FIG.

  As shown in FIGS. 2 and 3, the intake passage 30 is connected to one side surface of the engine body 1. In the present embodiment, the intake passage 30 extends downward from one side surface of the engine body 1. Specifically, as described above, branch passages 30a that individually communicate with the intake ports 16 are provided at the downstream end of the intake passage 30, and these branch passages 30a are respectively provided from one side of the engine body 1. It extends diagonally downward. The surge tank 33 communicating with the branch passage 30a is positioned below the branch passage 30a, and a portion extending upstream from the surge tank 33 extends downward from the center of the surge tank 33. The throttle valve 36 is provided at a portion extending downward from the surge tank 33.

  As shown in FIG. 3, a portion 30 b of the intake passage 30 where the throttle valve 36 is disposed is inclined with respect to the vertical direction to form an inclined passage 30 b. Specifically, the portion 30b is inclined downward in a direction away from the engine body 1.

  The throttle valve 36 is a so-called butterfly valve that rotates about a predetermined axis. The throttle valve 36 extends along a plane orthogonal to the flow path of the inclined passage 30b in the fully closed state and passes through the center of the throttle valve 36. The shaft 36a is configured to rotate about the shaft 36a by rotating the shaft 36a. Here, as described above, the inclined passage 30b is inclined with respect to the vertical direction. Therefore, as shown in FIG. 3, the throttle valve 36 is inclined with respect to the horizontal direction in the fully closed state. Further, in this embodiment, the shaft 36a of the throttle valve 36 is provided so as to extend horizontally when fully closed, that is, to extend in a direction perpendicular to the paper surface of FIG. Note that the fact that the throttle valve 36 is orthogonal to the flow path of the inclined passage 30b includes not only those that are strictly orthogonal but also those that are slightly displaced from the orthogonal position.

  Specifically, the inclined passage 30b is a circular pipe, and the throttle valve 36 has a disk shape and has a shaft 36a extending horizontally through the center of the circle.

  The throttle valve 36 (the shaft 36a of the throttle valve 36) configured as described above is driven by an electric motor (throttle valve driving means, hereinafter referred to as a throttle motor) 38 provided in the inclined passage 30b. The throttle motor 38 rotates the shaft 36a of the throttle valve 36 based on a command from the ECU 70 to open and close the throttle valve 36.

  In the present embodiment, the opening direction of the throttle valve 36 is set in a direction in which a lower end portion (hereinafter simply referred to as a lower end portion) A moves downward as shown in the arrow of FIG. The throttle valve 36 is opened and closed between a fully closed position orthogonal to the flow path of the inclined passage 30b and a fully open position extending along the flow path.

(3) Control of throttle valve The control contents of the throttle motor 38 (throttle valve 36) will be described with reference to FIGS. 5 (a) to 5 (c) schematically show the movement of the throttle valve 36. FIG. In addition, the broken line of Fig.5 (a) has shown the throttle valve of a fully closed state.

  The ECU 70 is functionally provided with a throttle valve control unit 71 for controlling the throttle motor 38 (throttle valve 36). The throttle motor 38 (throttle valve 36) is controlled by the throttle valve control unit 71. Be controlled.

  During normal operation (except when the engine is stopped and when the engine is started), the throttle valve control unit 71 detects the engine speed detected by the engine speed sensor SN1 and the accelerator position detected by the accelerator position sensor SN2 (engine load). ) And the like, the throttle motor 38 is controlled so that the opening degree of the throttle valve 36 becomes an appropriate opening degree corresponding to the driving condition.

  In addition, when the engine is stopped, the throttle valve control unit 71 controls the throttle motor 38 so that the throttle valve 36 is opened only by the first reference opening X set in advance, as shown in FIG. To do. In the present embodiment, the throttle valve control unit 71 controls the throttle motor 38 so that the opening degree of the throttle valve 36 becomes the first reference opening degree X when the engine speed becomes a predetermined value or less. The engine is stopped with the throttle valve 36 opened at the first reference opening X.

  In this way, when the engine is stopped, the throttle valve 36 is opened by a predetermined amount even if the throttle valve 36 fails and does not operate. This is to enable starting. Specifically, the valve is opened to such an extent that an air amount necessary for idle operation can be secured.

  In addition, the throttle valve control unit 71 performs freeze release control that is control for removing ice around the throttle valve 36 when the engine is started.

  Specifically, when the ambient temperature decreases when the engine is stopped, water present in the intake passage 30, for example, moisture contained in EGR gas introduced into the intake passage 30 or blow-by gas introduced into the intake passage 30. The contained water may freeze around the throttle valve 36, and the throttle valve 36 may not be operated properly when the engine is started.

  Here, in the present embodiment, as described above, the inclined passage 30b in which the throttle valve 36 is disposed extends in the vertical direction, and the throttle valve 36 is opened when the engine is stopped. . Therefore, most of the water present in the portion of the intake passage 30 above (downstream side) the throttle valve 36 flows down through the gap between the throttle valve 36 and the inner surface of the inclined passage 30b. However, some water may accumulate in the vicinity of the gap due to surface tension and become ice, which may hinder the operation of the throttle valve 36. In particular, as described above, when the engine is stopped, the throttle valve 36 is opened with the first reference opening X, so that ice is generated in the region between the position where the first reference opening X is opened and the fully closed position. As a result, the throttle valve 36 may not be fully closed.

  Therefore, in the present embodiment, as described above, the freeze release control for removing ice around the throttle valve 36 is performed at the time of starting the engine so that the throttle valve 36 can operate properly during the subsequent normal operation. .

  The freeze release control is performed so that the throttle valve 36 opens and closes to the fully closed position after the throttle valve 36 is opened to the second reference opening Y set to the opening side with respect to the first reference opening X. Control for driving the throttle motor 38, that is, the throttle valve 36 is opened to the second reference opening Y as shown in FIG. 5 (b), and then fully closed as shown in FIG. 5 (c). The control is to close the valve to the position. In this embodiment, when the engine starts (when the ignition key is turned on and a predetermined signal is output from the ignition switch SW1, or when the idle stop control is performed, the engine is restarted. Until the engine is completely detonated, that is, until combustion is performed once in each cylinder 11, until the engine is completely opened and closed. Let it continue. Therefore, when starting the engine, the throttle valve 36 opens from the first reference opening X to the second reference opening Y, and then closes to the fully closed position. Thereafter, the throttle valve 36 is repeatedly opened and closed between the position of the second reference opening Y and the fully closed position.

  In the present embodiment, the throttle valve control unit 71 is configured such that the driving force for driving the throttle valve 36 in the closing direction is the driving force in the opening direction when performing the freeze release control (when performing the opening / closing operation at the start). The throttle motor 38 is driven so as to be larger.

  In the present embodiment, the throttle valve control unit 71 performs the freeze release control only during the cold start of the engine start, and in other cases, the throttle valve 36 is set for start. Control to a predetermined opening. Specifically, the throttle valve control unit 71 performs the freeze release control only when the engine is started under the condition that the temperature of the engine coolant detected by the water temperature sensor SN4 is not more than a predetermined value.

  The flow of the above freeze release control is shown in FIG.

  First, in step S1, the throttle valve control unit 71 determines whether or not it is a cold start time. If this determination is NO and not cold start, the process proceeds to step S5. In step S5, the throttle valve control unit 71 sets the opening of the throttle valve 36 to a predetermined idle opening set for idle operation (normal start).

  On the other hand, if the determination in step S1 is YES and the cold start is in progress, the process proceeds to step S2, and the throttle valve control unit 71 opens the throttle valve 36 to the second reference opening Y by the throttle motor 38. Let As described above, at the start of engine start, the throttle valve 36 opens from the first reference opening X to the second reference opening Y.

  After step S2, the process proceeds to step S3. In step S3, the throttle valve controller 71 causes the throttle motor 38 to close the throttle valve 36 until it is fully closed. Further, the throttle valve control section 71 makes the driving force of the throttle motor 38 at this time larger than that at the time of step S2.

  After step S3, the process proceeds to step S4, and the throttle valve control unit 71 determines whether or not the engine has completely exploded, that is, whether or not combustion has been performed once in all the cylinders 11. In the present embodiment, it is determined that the engine has completely exploded when the engine speed exceeds a predetermined value. If this determination is YES, the throttle valve control unit 71 proceeds to step S5.

  On the other hand, if the determination in step S4 is NO and the engine has not yet completely exploded, the throttle valve control unit 71 returns to step S2 and performs the processes in steps S2 to S4. That is, the throttle valve control unit 71 repeats the processes of steps S2 and S3 until the determination of step S4 becomes YES, and opens the throttle valve 36 to the second reference opening Y and then closes it to the fully closed state. Repeat the opening and closing operation at the start. In the second and subsequent steps S2, the throttle valve 36 is opened from the fully closed position to the position of the second reference opening X.

(4) Operation The operation of the engine control apparatus according to the present embodiment configured as described above will be described with reference to FIGS.

  First, FIG. 7A is a diagram showing how ice I is generated around the throttle valve 36 when the engine is stopped. In FIG. 7A, the broken line indicates the throttle valve 36 in the fully closed state.

  In the present embodiment, as described above, the inclined passage 30b in which the throttle valve 36 is disposed is inclined in the vertical direction. Therefore, as shown by the arrows in FIG. 7A, the water in the intake passage 30 mainly connects the lower portion (the left inner surface in FIG. 7A) of the inner surface of the inclined passage 30b. It flows down. Therefore, the water flowing down from above the throttle valve 36 is mainly directed to the gap between the lower portion of the inner side surface of the inclined passage 30b and the throttle valve 36.

  In the present embodiment, as shown by the solid line in FIG. 7A, the throttle valve 36 is perpendicular to the horizontal direction of the inclined passage 30b when the engine is stopped and the valve is opened by the first reference opening X. It is inclined in the same direction as the inclination direction with respect to the direction. That is, the lower end A of the throttle valve 36 is opposed to the lower part of the inclined passage 30b. Therefore, the water on the throttle valve 36 also flows down the throttle valve 36 toward the lower end A.

  In this way, the water flowing down toward the throttle valve 36 mainly passes near the lower end portion A of the throttle valve 36. At this time, a part of water collects in the vicinity of the lower end A of the throttle valve 36 due to surface tension. Then, ice is generated unevenly between the lower end A of the throttle valve 36 and the lower portion of the inner side surface of the inclined passage 30b.

  As described above, in the present embodiment, ice is generated by moving toward one side of the throttle valve 36.

  In this state, when a cold start is performed, the freeze release control is performed. That is, the throttle valve 36 is opened from the position of the first reference opening X indicated by the broken line in FIG. 7B to the position of the second reference opening Y indicated by the solid line. At this time, the ice on the throttle valve 36 side of the ice block generated in the vicinity of the lower end A is pulled by the throttle valve 36 and peeled off from the inner surface of the inclined passage 30b. Further, a part of the ice is crushed by the impact applied with the displacement of the throttle valve 36. A part of the crushed ice and a part of the peeled ice fall below the throttle valve 36. Here, in the present embodiment, in a state where the valve is opened to the second reference opening degree Y, the throttle valve 36 is in a posture in which the lower end portion A is directed downward. Therefore, at this time, a lot of ice falls from the throttle valve 36.

  Thus, in this embodiment, a part of ice is removed from the periphery of the throttle valve 36 by further opening the throttle valve 36 when the engine is stopped.

  However, in this state, ice may still remain on the inner surface of the inclined passage 30b. In other words, the ice on the inner side surface of the inclined passage 30b among the ice generated between the throttle valve 36 and the inclined passage 30b may remain frozen on the inner side surface.

  In this embodiment, in this state, the throttle valve 36 is closed toward the fully closed position as shown by the solid lines in FIGS. FIG. 7C shows a state in which the throttle valve 36 is being closed toward the fully closed state, and FIG. 7D shows a state in which the throttle valve 36 is fully closed. 7 (c) and 7 (d), the broken line indicates the throttle valve 36 that is opened by the second reference opening Y.

  As shown in FIGS. 7C and 7D, while the throttle valve 36 is being closed toward the fully closed position, the throttle valve 36 hits ice remaining on the inner surface of the inclined passage 30b. As a result, the ice remaining on the inner surface of the inclined passage 30 b is crushed and falls below the throttle valve 36.

  In particular, as shown in FIG. 7D, the throttle valve 36 is driven to a fully closed position that is a position closer to the closing side than the position of the first reference opening X that is a position when the engine is stopped. Therefore, the ice between the position of the first reference opening X and the fully closed position is crushed, and the ice is removed from the movable region of the throttle valve 36.

  As described above, in the engine system 100 according to the present embodiment, the inclined passage 30b is inclined with respect to the vertical direction, so that ice is generated toward one side of the throttle valve 36. Therefore, it is possible to prevent ice from adhering to the entire periphery of the throttle valve 36, and the throttle valve 36 can be appropriately opened and closed when the engine is started. In addition, when starting the engine, first, the throttle valve 36 is opened to the second reference opening Y, and then fully closed, so that ice can be more reliably removed from the movable region of the throttle valve 36. Appropriate operation of the throttle valve 36 can be ensured.

(5) Modification In the above embodiment, the opening direction of the throttle valve 36 is described as the direction in which the lower end A moves downward. However, the opening direction of the throttle valve 36 is such that the lower end A is upward. It is good also as a direction to move. However, if this valve opening direction is set as in the above embodiment, more ice can be dropped from the throttle valve 36 when the throttle valve 36 is opened to the second reference opening.

  Even when the opening direction of the throttle valve 36 is the direction in which the lower end A moves upward, the first reference opening X and the second reference opening Y are inclined with respect to the horizontal direction. Is preferably set. In this way, in the state where the throttle valve 36 is at the first reference opening X when the engine is stopped, the water on the throttle valve 36 can be collected in the lower part of the inner side surface of the inclined passage 30b. Ice can be biased to a portion of the valve 36 that faces the lower portion. Further, when the throttle valve 36 is opened to the position of the second reference opening Y, the ice on the throttle valve 36 can be more reliably dropped from the throttle valve 36 downward.

  Further, the operating condition for performing the above-described freeze release control is not limited to the cold start. For example, the freeze release control may be performed only under the condition that the throttle valve 36 is frozen. Whether or not the throttle valve 36 is frozen may be determined, for example, based on whether or not the intake air temperature detected by the intake air temperature sensor SN3 is equal to or lower than a predetermined value (if it is equal to or lower than the predetermined value, it is frozen). Determined). Further, the freeze release control may always be performed regardless of whether the engine is cold-started and whether the throttle valve 36 is frozen. However, if the freeze release control is performed only during cold start, that is, when the possibility that the throttle valve 36 is frozen or when the throttle valve 36 is frozen, the freeze is released and the throttle valve 36 is While ensuring proper operation, when the throttle valve 36 is not frozen, it is possible to avoid the intake air amount from fluctuating due to the opening / closing operation of the throttle valve 36 associated with the execution of the freeze release control.

  Further, in the above embodiment, the case where the opening / closing operation at the time of starting the throttle valve 36 is continued until the engine completes explosion has been described. This operation may be terminated at an earlier time than when the engine is completely detonated. Further, this operation may be continued after the complete explosion of the engine. However, after the engine completes explosion, combustion becomes unstable due to fluctuations in the intake air amount associated with the opening / closing operation of the throttle valve. To ensure combustion stability, the opening / closing operation at the start must be performed before the engine completes explosion. It is preferable to stop.

30 Intake passage 30b Inclination passage 36 Throttle valve (throttle valve)
38 Throttle motor (throttle valve drive means)
70 ECU (control means)
100 Engine control device

Claims (6)

An engine is provided with an intake passage for introducing air into the engine, a throttle valve for opening and closing the intake passage, a throttle valve driving means for driving the throttle valve, and a control means for controlling the throttle valve driving means, and stopping the engine An engine control device provided in an engine in which a throttle valve is sometimes opened in a preset first reference opening,
The throttle valve is provided in an inclined passage that is inclined with respect to a vertical direction in the intake passage,
The control means is a freeze release control for causing the throttle valve driving means to open the throttle valve to the second reference opening on the valve opening side with respect to the first reference opening and then to fully close the engine when starting the engine. The engine control apparatus characterized by implementing. The engine control device according to claim 1,
The throttle valve is disposed along a surface substantially orthogonal to the flow path of the inclined passage in the fully closed state,
The engine control device according to claim 1, wherein the opening direction of the throttle valve is set to a direction in which a lower end portion of the throttle valve moves downward in the fully closed state. The engine control apparatus according to claim 1 or 2,
The engine control apparatus, wherein the control means performs the freeze release control only during a cold start. The engine control apparatus according to claim 1 or 2,
The engine control apparatus according to claim 1, wherein the control means performs the freeze release control only when the throttle valve is frozen. The engine control apparatus according to any one of claims 1 to 4,
The engine control apparatus according to claim 1, wherein the control means stops the freeze release control at least after the complete explosion of the engine. The engine control apparatus according to any one of claims 1 to 5,
The control means controls the throttle valve driving means so that the driving force for driving the throttle valve in the valve closing direction is larger than the driving force for driving in the valve opening direction during execution of the freeze release control. An engine control device.

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