JP5454437B2 - Wastegate valve device - Google Patents

Description

  The present invention relates to a wastegate valve device that opens and closes a bypass passage that bypasses a turbine wheel of a supercharger.

  An internal combustion engine (hereinafter also referred to as an engine) mounted on a vehicle or the like is equipped with a supercharger (hereinafter also referred to as a turbocharger) using exhaust energy.

  A turbocharger is generally a turbine wheel that is rotated by exhaust gas flowing through an exhaust passage of an engine, a compressor impeller that forcibly feeds air in the intake passage to a combustion chamber, and a connection that connects the turbine wheel and the compressor impeller. And a shaft. In the turbocharger having such a structure, when exhaust gas is blown onto the turbine wheel and the turbine wheel rotates, the rotation is transmitted to the compressor impeller via the connecting shaft. Thus, the air in the intake passage is forcibly sent into the combustion chamber by the rotation of the compressor impeller.

  In the turbocharger, as a method for controlling the supercharging pressure, for example, a bypass passage that bypasses the turbine wheel is provided, and a wastegate valve that opens and closes the bypass passage is provided, and the opening of the wastegate valve is adjusted, and the turbine There is a method of controlling the supercharging pressure by adjusting the amount of exhaust gas that bypasses the wheel.

  Conventionally, a diaphragm actuator is used as an actuator for opening and closing such a waste gate valve. However, when the diaphragm type actuator is used, the opening degree of the waste gate valve depends on the supercharging pressure, and therefore the opening degree of the waste gate valve cannot be arbitrarily controlled in the entire use range. In view of these points, a device that opens and closes a wastegate valve using an electric motor as an opening / closing drive source (hereinafter, also referred to as “electric wastegate valve device”) is used (for example, see Patent Document 1). By using an electric motor as the open / close drive source in this way, the opening degree of the wastegate valve can be controlled (active control) regardless of the supercharging pressure in the entire use range, and the catalyst rise at the start of the engine can be controlled. It is possible to improve temperature, fuel consumption rate (fuel consumption), responsiveness, and the like.

JP 2006-274833 A

  By the way, in an electric waste gate valve device, a closing failure (sealing failure) may occur when the valve is fully closed. In other words, when the electric motor is controlled and the wastegate valve is fully closed, if the motor load is small, the target position when the valve is fully closed (the valve body is the turbine housing (valve seat)) due to mechanical variation or astringency. The position of the actual valve body may shift to the valve opening side with respect to the position where it strikes with an appropriate load on the valve. In such a situation, the valve does not close properly (a gap that creates a gap between the valve body and the valve seat) ) May occur, and exhaust gas leakage may occur. Conventionally, the valve is closed with full power when the valve is fully closed so that such a valve closing failure does not occur. For this reason, when a valve body hits a valve seat, a big electric current may flow into an electric motor and there is a concern that the lifetime of an electric motor may fall.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wastegate valve device capable of reducing the current flowing in the electric motor when the valve is fully closed.

The present invention includes a valve body that opens and closes a bypass passage (exhaust bypass passage) that bypasses the turbine wheel of the turbocharger, and an arm (oscillating arm) that moves the valve body in an opening and closing direction; It is premised on a wastegate valve device provided with an open / close mechanism that converts a rotational motion of an electric motor into a valve open / close motion and transmits the valve body to the valve body via the arm. In such a wastegate valve device, the valve The body is attached to the arm so as to be able to contact and separate in the valve opening / closing direction, and a spring is provided between the valve body and the arm to urge the valve body in a direction away from the arm. ing. And, as the opening / closing mechanism, a gear mechanism having a worm gear rotating by the rotational driving force of the electric motor, a worm wheel meshing with the worm gear, and a link mechanism connected between the gear mechanism and the waste gate valve. And an angle recognizing means for recognizing the rotation angle (gear angle) of the worm wheel, so that the rotation angle of the worm wheel becomes a target gear angle when the valve is fully closed when the wastegate valve is closed. And a control means for controlling the drive (energization) of the electric motor . In such a configuration, it is preferable to stop energization of the electric motor when the rotation angle of the worm wheel reaches the target gear angle when the valve is fully closed.

According to the present invention, the valve body of the wastegate valve is attached to the arm so as to be able to contact and separate in the valve opening / closing direction, and the spring that biases the valve body between the valve body and the arm in a direction away from the arm. Therefore, when the valve is fully closed, the load applied when the valve body abuts against the valve seat (turbine housing) can be reduced by the spring, and the force applied to the electric motor can be reduced. As a result, it is possible to prevent a large current from flowing through the electric motor when the valve is fully closed, thereby extending the life of the electric motor. Furthermore, since the impact force when the valve body hits the valve seat when the valve is fully closed is reduced by the spring, the electric motor, the wastegate valve (valve body / valve seat, etc.), and the opening / closing mechanism (gear, link, etc.) ) And the like can be suppressed.

Furthermore, in the present invention, since the gear mechanism in which the worm gear and the worm wheel mesh with each other is connected to the opening / closing mechanism system between the electric motor and the wastegate valve, the energization to the electric motor is stopped after the valve is fully closed. However, the electric motor does not rotate in the opposite direction due to the exhaust pressure acting on the valve body or the force of the spring, that is, the valve body does not leave the valve seat and the valve is not opened. As described above, since it is possible to stop energization of the electric motor when the valve is fully closed, the power consumption can be reduced.

  Even when the valve fully closed position (actual closing position of the valve body) varies when the valve is closed to control the target gear angle when the valve is fully closed by energization control to the electric motor. Since it can be absorbed by a spring, the valve can always be closed reliably. Moreover, since a spring is provided between the valve body and the arm, even if the valve body is returned to the valve opening side by the backlash of the gear mechanism etc. due to the exhaust pressure etc., the return is absorbed by the spring. It is possible to maintain the valve fully closed state reliably.

  The rotation angle (gear angle) of the worm wheel may be detected directly by providing an angle sensor on the worm wheel, or an electric motor with an angle sensor is used and a detection signal (electric The rotation angle of the worm wheel may be recognized from the motor rotation angle detection signal).

  In the present invention, the target gear angle when the valve is fully closed used for control when the valve is closed is mechanical variation such as a waste gate valve or a link mechanism, gear backlash of the gear mechanism, exhaust pressure acting on the valve body, And it determines in consideration of the elastic force (spring force) of the spring.

  Specifically, the waste gate valve is closed from the fully open position by an experiment or the like in advance, and the motor load is `` target load '' in this valve closing process, specifically, the exhaust pressure is applied to the valve body of the waste gate valve. Measure the rotation angle (gear angle) of the worm wheel when the motor load (load that adds a predetermined amount of margin to [exhaust pressure + spring force]) that does not open the valve body even when applied. Then, by adding the gear angle corresponding to the mechanical variation (maximum amount of displacement of the valve body to the valve opening side) and the backlash of the gear mechanism etc. to the measured gear angle measurement value, the target gear is obtained. Determine the angle. Here, the motor load (power) when fully closed is a value larger by a predetermined margin than the force obtained by adding the exhaust pressure acting on the valve body of the wastegate valve and the force of the spring, as described above. (Because it does not have to be full power), when the wastegate valve is fully closed, the current value that flows to the electric motor is set to be greater than the limit current value (current value that does not shorten the life of the electric motor). Can be small.

  According to the present invention, the valve element of the wastegate valve is attached to the arm that moves the valve element so as to be able to contact and separate in the valve opening and closing direction, and a spring is provided between the valve element and the arm. The load when the valve body abuts against the valve seat when the valve is fully closed can be reduced by the spring, whereby the current flowing to the electric motor when the valve is fully closed can be reduced.

It is a schematic structure figure showing an example of an engine to which the present invention is applied. It is a figure which shows the structure of a wastegate valve apparatus. In FIG. 2, the valve is fully closed. It is a figure which shows the structure of a wastegate valve apparatus. FIG. 3 shows the valve fully open. It is XX sectional drawing of FIG. In FIG. 4, a part of the turbine housing is omitted. It is a perspective view which shows the structure of a part of waste gate valve | bulb and a link mechanism. It is a flowchart which shows an example of waste gate valve opening / closing control. It is a graph which shows the relationship between the gear angle of the worm wheel of a link mechanism, and a motor load.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, an engine (internal combustion engine) to which the present invention is applied will be described.

-Engine-
FIG. 1 is a diagram showing a schematic configuration showing an example of an engine 1 mounted on a vehicle.

  The engine 1 of this example is, for example, a four-cylinder diesel engine, and an intake manifold 2 for distributing intake air to each cylinder and an exhaust manifold 3 for collecting exhaust gas discharged from each cylinder in a cylinder head. And are connected.

  An intake passage 4 is connected to the inlet of the intake manifold 2 for taking air from the atmosphere and guiding it to the intake manifold 2. An air cleaner 6 is attached to the inlet of the intake passage 4. A throttle valve 7 for adjusting the intake air amount of the engine is disposed upstream of the intake manifold 2 (upstream of the intake flow). The throttle valve 7 is driven by a throttle motor (not shown). The opening degree of the throttle valve 7 is detected by a throttle opening degree sensor 32. The throttle opening degree of the throttle valve 7 is controlled by an ECU (Electronic Control Unit) 300. On the other hand, an exhaust passage 5 is connected to the outlet of the exhaust manifold 3. A catalyst 9 is disposed in the middle of the exhaust passage 5.

  Further, the engine 1 of this example is equipped with a turbocharger (supercharger) 100 and an EGR device 120. These configurations will be described.

-Turbocharger-
The turbocharger 100 includes a turbine wheel 101 disposed in the exhaust passage 5, a compressor impeller 102 disposed in the intake passage 4, a connecting shaft 103 that integrally connects the turbine wheel 101 and the compressor impeller 102, and the like. The turbine wheel 101 arranged in the exhaust passage 5 is rotated by the energy of the exhaust, and the compressor impeller 102 arranged in the intake passage 4 is rotated accordingly. Then, the intake air is supercharged by the rotation of the compressor impeller 102, and the supercharged air is forcibly sent into the combustion chamber of each cylinder of the engine 1. In addition, an intercooler 8 that cools the air supercharged by the compressor impeller 102 is provided in the intake passage 4 on the downstream side of the compressor impeller 102 (downstream side of the intake flow).

  Further, in the turbocharger 100 of this example, as shown in FIGS. 2 and 3, an exhaust bypass passage 111 is formed in the turbine housing 110, and a wastegate valve 201 for opening and closing the exhaust bypass passage 111 is provided. It has been. Details of the wastegate valve device 200 including the wastegate valve 201 and its opening / closing drive system (electric motor 204, gear mechanism 203, link mechanism 202, etc.) will be described later.

-EGR device-
The EGR device 120 includes an EGR passage (exhaust gas recirculation passage) 121. One end of the EGR passage 121 is connected to the intake passage 4 between the intake manifold 2 and the throttle valve 7. The other end of the EGR passage 121 is connected to the exhaust manifold 3, and a part of the exhaust gas (EGR gas) is introduced into the intake passage 4 through the EGR passage 121. By introducing EGR gas (a gas having a higher specific heat than that of air and a smaller amount of oxygen) into the intake passage 4, the combustion temperature in the cylinder can be lowered and the amount of NOx produced can be reduced.

  An EGR valve 124 that opens and closes the EGR passage 121 is provided in the middle of the EGR passage 121. An EGR cooler 122 for cooling the EGR gas flowing in the EGR passage 121 is provided upstream (exhaust side) of the EGR passage 124 in the EGR passage 121. Cooling by the EGR cooler 122 increases the density of the EGR gas, and it is possible to improve the EGR rate while securing the intake air amount.

  Further, the EGR device 120 is provided with an EGR bypass passage 121a for bypassing the EGR cooler 122 and flowing EGR gas. A switching control valve 123 for adjusting the opening degree of the EGR passage 121 and the opening degree of the EGR bypass passage 121a is provided at a connection portion (a connection portion on the downstream side of the EGR gas flow) between the EGR bypass passage 121a and the EGR passage 121. Is provided.

-ECU-
The ECU 300 includes a CPU, a ROM, a RAM, a backup RAM, and the like.

  The ROM stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU executes various arithmetic processes based on various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores calculation results from the CPU, data input from each sensor, and the like. The backup RAM is a non-volatile memory that stores data to be saved when the engine is stopped, for example. It is memory.

  Various information indicating the engine operating state such as an engine speed sensor 31, a throttle opening sensor 32, and an accelerator opening sensor 33 that detects an accelerator pedal depression amount (accelerator opening) are acquired at an input unit of the ECU 300. For this purpose, various sensors are connected.

  The output portion of the ECU 300 is connected to an injector (not shown) of the engine 1, a throttle valve 7 (throttle motor), an EGR valve 124, a switching control valve 123, an electric motor 204 of the wastegate valve device 200, and the like. Yes.

  Then, the ECU 300 controls the drive of the injector (fuel injection valve) (fuel injection control), the drive control of the throttle motor of the throttle valve 7 (intake air amount control), and EGR based on the detection signals of the various sensors described above. Various control of the engine including control of the amount (control of the EGR valve 124 and the switching control valve 123, etc.) is executed. Further, the ECU 300 executes the following “waist gate valve opening / closing control”.

-Wastegate valve device-
Next, the waste gate valve device 200 will be described with reference to FIGS.

  The waste gate valve device 200 of this example includes a waste gate valve 201, a link mechanism 202, a gear mechanism 203, an electric motor (for example, a DC motor) 204, and the like.

  First, before describing the wastegate valve device 200, a part of the configuration of the turbine housing 110 will be described. As shown in FIGS. 1 to 4, an exhaust bypass passage 111 that bypasses the turbine wheel 101 is formed in the turbine housing 110 of this example. The exhaust bypass passage 111 includes a circular waste gate hole 111a penetrating the wall 110b of the turbine housing 110, and communicates with the upstream side (upstream side of the exhaust gas flow) of the turbine wheel 101 and the exhaust gas outlet passage 110a. doing. A valve seat (valve seat) 112 is provided at the peripheral portion of the waste gate hole 111a (peripheral portion on the exhaust gas outlet passage 110a side).

  The waste gate valve 201 is a circular valve body 211 that opens and closes the exhaust bypass passage 111 by being seated on or separated from the valve seat 112 provided in the turbine housing 110, and the valve body 211 is opened and closed (the valve seat 112). And a swing arm 212 that moves in the direction of contact with and away from the valve. The swing arm 212 swings the valve body 211 to close the exhaust bypass passage 111 (fully closed position: FIG. 2). ) And a position at which the exhaust bypass passage 111 is completely opened (fully opened position: FIG. 3). The valve seat 112 of the turbine housing 110 is also included in the constituent members of the wastegate valve 201.

  In the wastegate valve 201 of this example, a support pin 214 extending in a direction perpendicular to the swing arm 212 is provided at the tip of the swing arm 212, and a valve body is provided on the support pin 214. 211 is slidably provided. That is, the valve body 211 is attached to the tip of the swing arm 212 so as to be able to contact and separate in the valve opening / closing direction with respect to the swing arm 212. A spring (“belleville spring” in this example) 213 is sandwiched between them. Further, the movement of the valve body 211 in the direction away from the swing arm 212 is regulated by a stopper (for example, a retaining ring, a nut, etc.) 215, and external force (pushing toward the swing arm 212 side) is applied to the valve body 211. When the pressure is not applied, the valve body 211 comes into contact with the stopper 215 by the force of the spring 213.

  The stopper 215 may be provided by “caulking” the tip of the support pin 214. In this example, the inner diameter of the through hole 211 a of the valve body 211 is formed by a predetermined amount with respect to the outer diameter of the support pin 214, and the valve body 211 can tilt with respect to the support pin 214. .

  The swing arm 212 of the waste gate valve 201 is connected to the rotating shaft 241 of the electric motor 204 via the link mechanism 202 and the gear mechanism 203.

  The link mechanism 202 includes a link shaft 221, a drive arm 222, a drive rod 223, a crank arm 224, and the like.

  One end of the link shaft 221 is integrally attached to the end of the swing arm 212 of the wastegate valve 201 (the end opposite to the valve body 211). The link shaft 221 passes through the wall 110b of the turbine housing 110 and protrudes outside the housing. Further, the link shaft 221 is rotatably supported by the wall body 110b of the turbine housing 110.

  One end of the drive arm 222 is integrally attached to the other end of the link shaft 221 (the end opposite to the swing arm 212). The other end of the drive arm 222 is rotatably connected to one end of the drive rod 223 via a connection pin (link) 225. The other end of the drive rod is rotatably connected to the tip of the crank arm 224 via a connecting pin (link) 226, and the drive arm 222 is swung by the forward / backward movement of the drive rod 223 so that the link shaft. 212 rotates about its axis.

  The gear mechanism 203 includes a worm gear 231 and a worm wheel (flat gear) 232 that meshes with the worm gear 231. The worm gear 231 is attached to the distal end portion of the rotating shaft 241 of the electric motor 204 and rotates by the rotational driving force of the electric motor 204. A crank arm 224 of the link mechanism 202 is attached to one surface of the worm wheel 232 (a surface orthogonal to the gear rotation axis). The crank arm 224 rotates integrally with the worm wheel 232. An angle sensor (for example, a rotary encoder) 233 for detecting the rotation angle (gear angle) of the worm wheel 232 is provided on the back side of the worm wheel 232 (the side opposite to the crank arm 224). An output signal (angle detection signal) of the angle sensor 233 is input to the ECU 300. The configurations of the gear mechanism 203 and the link mechanism 202 correspond to an “opening / closing mechanism”.

  In the wastegate valve device 200 having such a configuration, the rotating shaft 241 of the electric motor 204 rotates (forward or reverse) by energizing the electric motor 204 from the state shown in FIG. 3 (valve fully opened state). When the worm gear 231 rotates, the worm wheel 232 rotates. The rotation of the worm wheel 232, that is, the rotation of the crank arm 224 moves the drive rod 223 forward (moves toward the wastegate valve 201 side), and the drive arm 222 swings. Move. As the drive arm 222 swings, the link shaft 221 rotates, and accordingly, the swing arm 212 of the wastegate valve 201 swings and the valve body 211 is seated on the valve seat 112 of the turbine housing 110. As a result, the exhaust bypass passage 111 is closed (the valve is fully closed as shown in FIG. 2).

  In this example, when the valve is fully closed, as shown in FIG. 2, the valve body 211 of the wastegate valve 201 is separated from the stopper 215 by a predetermined amount, and the valve body 211 springs against the valve seat 112 of the turbine housing 110. It hits in the state pressed by the force of 213.

  On the other hand, in the state shown in FIG. 2 (valve fully closed state), when a current in the direction opposite to that when the valve is closed is supplied to the electric motor 204, the worm wheel 232 (crank arm 224) rotates in the direction opposite to that when the valve is closed. Then, the drive rod 223 moves backward, the drive arm 222 swings, and the link shaft 221 rotates in the direction opposite to that when the valve is closed. As a result, the valve body 211 of the wastegate valve 201 is separated from the valve seat 112 and the exhaust bypass passage 111 is opened (the valve is fully opened as shown in FIG. 3). In addition, as operation | movement when opening the wastegate valve 201, as mentioned later, the operation | movement which makes a fully open state according to a use range (engine speed and required torque), and the opening degree of the wastegate valve 201 are engine speed. In addition, there is an operation of adjusting according to the required torque or the like.

-Wastegate valve opening / closing control-
Next, waste gate valve opening / closing control executed by the ECU 300 will be described with reference to FIGS.

  First, the target gear angle when the valve is fully closed used for wastegate valve opening / closing control will be described. Here, the gear angle is the rotation angle (gear angle) of the worm wheel (flat gear) 232 of the gear mechanism 203 described above, and the target gear angle when the valve is fully closed is, for example, the waste gate valve 201. With the fully open position as a reference (angle = 0), this is the angle from the reference to the valve fully closed position. The valve fully closed position (fully closed angle) is measured in advance by experiments or the like. The specific measuring method will be described with reference to FIG.

  As shown in FIG. 7, when the waste gate valve 201 is closed from the valve fully open position (gear angle = 0), the motor load starts to increase from the point P <b> 1 when the valve body 211 hits the valve seat 112 of the turbine housing 110. . In the process of increasing the load, the motor load is the “target load”. Specifically, even when exhaust pressure is applied to the valve body 211 of the wastegate valve 201, the fully closed load F ([exhaust pressure] + The force of the spring 213]), and the rotation angle (gear angle) of the worm wheel 232 is measured. Then, by adding the gear angle corresponding to the mechanical variation (maximum amount of displacement of the valve body 211 to the valve opening side) and the backlash of the gear mechanism 203 and the like to the measured gear angle measurement value, the target is obtained. The gear angle θgt is determined.

  Here, as described above, the motor load F (power) when fully closed is obtained by adding the exhaust pressure in the turbine housing 110 (exhaust pressure acting on the valve body 211) and the force of the spring 213. Can be set to a value that is larger by a predetermined amount (margin) (since it is not necessary to make full power), the current value that flows through the electric motor 204 when the wastegate valve 201 is fully closed is set to the limit current value ( Current value that does not shorten the life of the electric motor 204).

  For the valve fully open position (gear angle = 0) serving as a reference for the target gear angle θgt, the valve body 211 of the wastegate valve 201 and the swing arm 212 (or the drive arm 222 of the link mechanism 202, etc.) are fully opened. The valve fully closed position (actually closed position of the valve body 211) is always set to an appropriate position by learning the detected value of the gear angle sensor 233 when it hits (not shown) as the reference angle output value. It becomes possible to control, and the controllability at the time of valve closing can be improved.

  Next, an example of waste gate valve opening / closing control will be described with reference to the flowchart of FIG. The control routine of FIG. 6 is repeatedly executed by the ECU 300 every predetermined time.

  When the control routine of FIG. 6 is started, first, in step ST101, it is determined based on the map whether or not it is a region where the waste gate valve 201 is closed. Specifically, the engine speed and the required torque are used as parameters, for example, a full supercharging region (valve fully closed region), a supercharging pressure adjusting region (valve opening adjusting region), and a non-supercharging region (valve fully open region). Based on the required torque and the current engine speed, it is determined whether or not the operating region is in the “full supercharging region” and the “full supercharging region” is set. If it is present (the region where the valve is closed and the determination result in step ST101 is affirmative (YES)), the process proceeds to step ST102. If the determination result in step ST101 is negative (NO), the process returns.

  In step ST102, the electric motor 204 is energized to close the waste gate valve 201. In this valve closing process, the gear angle θgr (actual gear angle from the valve fully open position (gear angle = 0)) obtained from the output signal of the angle sensor 233 and the target gear angle when the valve is fully closed. When the actual gear angle θgr matches the target gear angle θgt (when the determination result in step ST103 is affirmative (YES)), the wastegate valve 201 is fully closed. It is determined that the power supply to the electric motor 204 is stopped (step ST104). In this valve closing control, energization of the electric motor 204 is continued until the actual gear angle θgr matches the target gear angle θgt.

  Next, in step ST105, it is determined whether or not it is an area where the waste gate valve 201 is opened. Specifically, when the operating state changes and the region transitions to the “supercharging pressure adjustment region” or “no supercharging region” (the valve is opened, the determination result in step ST105 is affirmative (YES) ), The electric current is applied to the electric motor 204 in the direction opposite to that when the valve is closed to open the wastegate valve 201 (step ST106). At this time, when the operation region is the above-described supercharging pressure adjustment region (valve opening adjustment region), energization control to the electric motor 204 is performed so that the supercharging pressure according to the engine speed and the required torque is obtained. Then, the opening degree of the waste gate valve 201 is adjusted. Further, when the operation region is the above-described supercharging-free region (valve fully open region), the wastegate valve 201 is opened to the fully open position (gear angle = 0). Note that energization of the electric motor 304 may be stopped after the waste gate valve 201 is fully opened.

  As described above, in the opening / closing control of this example, when the waste gate valve 201 is fully closed from the opened state, the processing of steps ST101 to ST104 is executed, and the waste gate valve 201 is opened from the fully closed state. When opening, the process of step ST105-ST106 is performed.

  As described above, according to the wastegate valve device of this example, the valve body 211 of the wastegate valve 201 is attached to the swing arm 212 that moves the valve body 211 so as to be able to contact and separate in the valve opening / closing direction. Since the spring 213 is provided between the valve body 211 and the swing arm 212, the load when the valve body 211 hits the valve seat 112 of the turbine housing 110 when the valve is fully closed is reduced by the spring 213. The force applied to the electric motor 204 can be reduced. As a result, a large current can be prevented from flowing through the electric motor 204 when the valve is fully closed, and the life of the electric motor 204 can be extended. Furthermore, since the impact force when the valve body 211 hits the valve seat 112 when the valve is fully closed can be reduced by the spring 213, the electric motor 204, the wastegate valve 201 (the valve body 211, the valve seat 112, etc.) The wear of each part of the gear mechanism 203 and the link mechanism 202 can be suppressed.

  In addition, even when the valve fully closed position (actual closed position of the valve body 211) varies when the valve is closed to control the target gear angle θgt when the valve is fully closed by energization control to the electric motor 204, Since the variation can be absorbed by the spring 213, the valve can always be closed reliably.

  In addition, in this example, the gear mechanism 203 in which the worm gear 231 and the worm wheel 232 are engaged is connected to the opening / closing mechanism system between the electric motor 204 and the wastegate valve 201. The electric motor 204 rotates in the opposite direction due to the exhaust pressure acting on the valve body 211 of the wastegate valve 201 or the force of the spring 213, that is, the valve body 211 is separated from the valve seat 112 even if the energization of the valve is stopped. This prevents the valve from opening. As described above, when the valve is fully closed, it is possible to stop energization of the electric motor 204, thereby reducing power consumption. Further, since the spring 213 is provided between the valve body 211 and the swing arm 212, even if the valve body 211 is returned to the valve opening side by the backlash of the gear mechanism 203 or the like due to the exhaust pressure or the like, The return amount can be absorbed by the spring 213, and the valve fully closed state can be reliably maintained.

  In the waste gate valve device 200 of this example, since the driving force source for opening and closing the waste gate valve 201 is the electric motor 204, active control of the waste gate valve 201 is possible, and the catalyst temperature rise performance at the time of engine start-up is possible. Moreover, the effect that improvement of a fuel consumption, responsiveness, etc. can be aimed at can also be achieved.

-Other embodiments-
In the above example, a disc spring is used as a spring provided between the valve element 211 and the swing arm 212 of the wastegate valve 201. Instead of this, for example, a spring of another form such as a compression coil spring is used. It may be used.

  In the above example, the angle sensor 233 is provided in the worm wheel 232 so as to directly detect the gear angle of the worm wheel 232. However, the present invention is not limited to this. For example, the electric motor 204 with an angle sensor is used. You may make it recognize the gear angle (rotation angle) of the worm wheel 232 from the detection signal (rotation angle detection signal of the electric motor 204) of the angle sensor.

  As an engine (internal combustion engine) to which the present invention is applied, in addition to a four-cylinder diesel engine, for example, a diesel engine having any other number of cylinders such as six or eight cylinders may be used. A gasoline engine may be used. In addition to the engine (internal combustion engine) alone, the vehicle power source may be a hybrid power source including both an engine and an electric motor.

  INDUSTRIAL APPLICABILITY The present invention can be used for an apparatus that opens and closes a wastegate valve that opens and closes a bypass passage that bypasses a turbine wheel of a supercharger using an electric motor.

1 Engine 5 Exhaust passage 100 Turbocharger (supercharger)
DESCRIPTION OF SYMBOLS 101 Turbine wheel 110 Turbine housing 111 Exhaust bypass passage 112 Valve seat 200 Waste gate valve apparatus 201 Waste gate valve 211 Valve body 212 Oscillating arm 213 Spring 202 Link mechanism 203 Gear mechanism 231 Worm gear 232 Warm wheel 233 Angle sensor 204 Electric motor 300 ECU

Claims (3)

A wastegate valve having a valve body that opens and closes a bypass passage that bypasses the turbine wheel of the supercharger, and an arm that moves the valve body in an opening and closing direction;
In a wastegate valve device comprising an opening / closing mechanism that converts a rotational movement of an electric motor into a valve opening / closing movement and transmits it to the valve body via the arm,
The valve body is attached to the arm so as to be able to contact and separate in a valve opening / closing direction, and a spring that biases the valve body in a direction away from the arm between the valve body and the arm. Provided ,
The opening / closing mechanism includes a gear mechanism having a worm gear rotating by a rotational driving force of the electric motor, a worm wheel meshing with the worm gear, and a link mechanism connected between the gear mechanism and the waste gate valve. And
Angle recognition means for recognizing the rotation angle of the worm wheel, and control for controlling the driving of the electric motor so that the rotation angle of the worm wheel becomes a target gear angle when the valve is fully closed when the wastegate valve is closed. waste gate valve apparatus characterized by comprising a means. The wastegate valve device according to claim 1,
Target gear angle of the valve is fully closed, the mechanical variation, the gear backlash of the gear mechanism, the exhaust pressure acting on the valve body, and, characterized that you determined in consideration of the elastic force of the spring A wastegate valve device. The wastegate valve device according to claim 1 or 2,
A wastegate valve device , wherein energization of the electric motor is stopped when a rotation angle of the worm wheel becomes a target gear angle when the valve is fully closed .

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