JP4380072B2 - EGR valve integrated electronic venturi - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic venturi, and more particularly to an EGR valve-integrated electronic venturi that controls the EGR amount of an internal combustion engine with high efficiency.
[0002]
[Prior art]
FIG. 10 is a block diagram of the main part of an example of the prior art. As a prior art, for example, there is JP-A-10-110633 (intake throttle device for a diesel engine). This document includes a throttle valve (THRV) that opens and closes an intake passage, an EGR valve (EGRV) that adjusts exhaust of EGR gas, a step motor (M) that controls the opening and closing of these throttle valve and EGR valve, An intake throttle device that includes a computer (ECU) that controls the operation of a step motor is disclosed. In this example, there is provided position detection means (PD) for detecting a predetermined position of the throttle valve within a high opening range of the throttle valve where the intake flow rate hardly changes and outputting the detection signal to the ECU. The step motor is driven so that the throttle valve is at a reference position that does not interfere with the operation of the diesel engine, and the step motor is initialized by the detection signal from the position detecting means.
[0003]
[Problems to be solved by the invention]
As shown in the figure, the above prior art configuration includes an actuator mechanism (A1) for controlling the opening / closing operation of the throttle valve and an actuator mechanism (A2) for controlling the opening / closing operation of the EGR valve in the body body (B). Each of the step motors is disposed separately, and the step motor drives and controls only the actuator mechanism (A1) of the throttle valve.
[0004]
However, since the actuator mechanism of the throttle valve and the actuator mechanism of the EGR valve are separately provided as described above, the entire apparatus is increased by both actuator mechanisms, and the cost of the apparatus is increased accordingly. is there. In addition, there is a problem that the amount of control by the ECU increases because the ECU requires control that links the control of both actuator mechanisms and the opening and closing of both valves.
[0005]
Accordingly, an object of the present invention is to reduce the size of the apparatus and reduce the cost by mechanically coupling the actuator mechanism of the throttle valve and the actuator mechanism of the EGR valve integrally through a drive motor. .
[0006]
[Means for Solving the Problems]
According to the first to seventh aspects of the present invention, since the actuator mechanism of the throttle valve and the actuator mechanism of the EGR valve are mechanically and integrally coupled via the motor shaft of the drive motor, the actuator mechanism of the device is made small. Therefore, not only the device cost can be reduced, but also the control amount of the ECU can be reduced, and the burden can be reduced.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a principle view of an EGR valve integrated electronic venturi according to the present invention. In the figure, M is a drive motor, THRV is a throttle valve, EGRV is an EGR valve, L1 is a first lever that mechanically couples the throttle valve and the drive motor, and L2 is a first lever that mechanically couples the EGR valve and the drive motor. The second lever, SPG1 and SPG2, are springs that hold the opening / closing position of the throttle valve, and SPG3 is a spring that holds the opening / closing position of the EGR valve.
[0008]
In the present invention, as will be described in detail in the following drawings (FIGS. 4 to 7), the motor shaft of the drive motor M capable of normal rotation and reverse rotation is mechanically coupled to the lever 1 provided at the end of the throttle valve shaft. Further, the motor shaft is mechanically coupled to the bar 2 provided at the end of the EGR valve shaft. The throttle valve can rotate to the forward rotation side and the reverse rotation side around the fully open state, and is fully opened at the neutral position (the state shown in the figure). Closed. On the other hand, the EGR valve is fully closed at the illustrated position.
[0009]
FIG. 2 is a basic configuration diagram of the EGR valve integrated electronic venturi having the configuration shown in FIG. As shown in the figure, in the present invention, an actuator mechanism A in which an actuator mechanism of a throttle valve (see L1) and an actuator mechanism of an EGR valve (see L2) are mechanically coupled together via a motor shaft of a drive motor. As a result, the actuator mechanism of the device can be reduced, thereby reducing the cost of the device, and the control amount of the ECU also controls the drive motor, thereby reducing the burden. be able to. That is, based on the detection signal of the rotation angle sensor, the ECU opens the throttle valve (see the solid line) fully open when the drive motor M is rotating forward from the neutral point as shown in FIG. A small amount of EGR control is performed when the EGR valve (see the alternate long and short dash line) begins to open, and then the throttle valve is closed to control a large amount of EGR gas. Furthermore, only the throttle valve is controlled when the drive motor rotates in reverse.
[0010]
FIG. 3 is a detailed configuration diagram of a main part of the EGR valve-integrated electronic venturi having the configuration shown in FIG. In the figure, SPG1 and SPG2 are springs that hold (bias) the throttle valve in a fully open state by balancing, and SPG3 is a spring that holds the EGR valve in a fully closed state. S is a rotation angle sensor that is provided in the reduction gear of the throttle valve and rotates together with the motor shaft. As described above, THRV is a throttle valve, EGRV is an EGR valve, L1 is a lever ( hereinafter referred to as a gear) provided at the end of the throttle valve shaft, and the rotation of the motor shaft is controlled to the throttle valve shaft within a predetermined angle range. It has a structure that does not transmit. L2 is a lever ( hereinafter referred to as a gear) provided at the end of the EGR valve shaft, and has a structure that does not transmit the rotation of the motor shaft to the EGR valve shaft within a predetermined range.
[0011]
The actuator mechanism A of the present invention mechanically couples the actuator mechanism (see SPG1 and L1) of the throttle valve (THRV) and the actuator mechanism (see L2) of the EGR valve (EGRV) via the motor shaft of the drive motor M. This is the configuration. Since the throttle valve and the EGR valve are not mechanically connected to each of the throttle valve and the EGR valve as in the conventional apparatus described above, the actuator mechanism can be made smaller, thereby reducing the cost of the apparatus. Can be planned. Further, ECU can control the drive motor for controlling the gear L1 and gear L2 simultaneously based on the detection signal from the rotation angle sensor S.
[0012]
FIG. 4 is an explanatory view (No. 1) for explaining the positional relationship between both gears L1, L2 in the EGR valve integrated electronic venturi having the configuration shown in FIG. As shown, the motor shaft of the drive motor is mechanically coupled to gears L1 and L2 via its gear (G). The positions of the illustrated gears L1 and L2 are in a state where the throttle valve is fully open and the EGR valve is fully closed.
[0013]
Such a state is when the drive motor is energized when the drive motor is not energized, at the time of failure (when abnormal), and when the engine is running and when the required EGR amount is zero. At the time of non-energization and at the time of failure, the throttle valve (THRV) is almost fixed at the fully open position by the balance of the springs SPG1 and SPG2. The EGR valve (EGRV) is fixed at the fully closed position by a spring SPG3. Further, when the required EGR amount is zero during engine operation, the drive motor is energized and maintained at an angle at which THRV is fully open and EGRV is fully closed.
[0014]
FIG. 5 is an explanatory diagram (No. 2) for explaining the positional relationship between both gears L1, L2 in the EGR valve integrated electronic venturi having the configuration shown in FIG. The positions of the illustrated gears L1 and L2 are such that THRV is fully open and EGRV is half open. Such a state is when the required EGR amount is small during engine operation. In this case, the drive motor is energized and rotated in the forward direction (arrow direction). By this rotation, the gear L2 coupled to the gear G rotates in the direction of the arrow, and the EGR valve is half-opened. On the other hand, the motor shaft and the gear L1 of the throttle valve are not engaged and are swung, and are held in the fully open position by the springs SPG1 and SPG2.
[0015]
FIG. 6 is an explanatory view (No. 3) for explaining the positional relationship between both gears L1, L2 in the EGR valve-integrated electronic venturi of FIG. The positions of the illustrated gears L1 and L2 are such that THRV is closed and EGRV is fully open. Such a state is when the required EGR amount is large during engine operation. In this case, the drive motor is energized and further rotated in the forward direction (arrow direction). By this rotation, the gear L2 coupled to the gear G rotates in the direction of the arrow, and the EGR valve is fully opened. On the other hand, the motor shaft and the gear L1 of the throttle valve are engaged to close THRV. If THRV is fully closed, the EGR rate can be set to 100%. The EGR rate is
{(EGR gas flow rate) / (intake air amount + EGR gas flow rate)} × 100 (%)
It is represented by
[0016]
FIG. 7 is an explanatory view (No. 4) for explaining the positional relationship between both gears L1, L2 in the EGR valve-integrated electronic venturi of FIG. The positions of the gears L1 and L2 shown in the figure are such that THRV is closed to an appropriate opening and EGRV is fully closed (when the engine is started), or THRV is fully closed and EGRV is fully closed (when the engine is stopped). . At the time of starting the engine, if the drive motor is energized and rotated in the reverse direction, the rotation of the motor shaft is transmitted to THRV through the gear L1, and therefore the THRV can be closed to an appropriate opening degree at the time of starting the engine. it can. On the other hand, when the latter engine is stopped, when the drive motor is energized and rotated in the reverse direction, the rotation of the motor shaft is transmitted to THRV via the gear L1, and THRV can be fully closed. At this time, the EGR valve is held in the fully closed position regardless of the motor shaft.
[0017]
FIG. 8 is a graph showing the relationship between the throttle valve opening, the EGR valve opening, and the forward / reverse rotation of the drive motor in the present invention. As shown in the figure, in the section (A), the throttle valve (THRV) is reversely controlled and only THRV is controlled. In the section (B), THRV is fully opened and a small amount of EGR is controlled. In the section (C), THRV is normal and controls a large amount of EGR.
[0018]
The operation of THRV and EGRV has been described along the engagement relationship between the gears L1 and L2 in FIGS. 4 to 7 described above. Here, the operation will be described along each time point of operation. In other words, the operation of THRV and EGRV is roughly divided into (1) when no power is supplied to the drive motor and when it fails, (2) when the engine is started, (3) when the engine is operating, and (4) when the engine is stopped. Can do. Furthermore, the engine operation of (3) is divided into when the required EGR amount is zero, when the required EGR amount is small, and when the required EGR amount is large.
(1) At the time of non-energization and failure when the drive motor is not energized, the throttle valve is fixed at the fully open position by the balance of both springs (SPG1, SPG2), and the EGR valve is at the fully closed position by the spring (SPG3). Fixed.
(2) When the engine is started, when the drive motor is energized and rotated in the reverse direction, the rotation of the drive motor is transmitted to the throttle valve via the gear (L1). It can be closed to the opening. At this time, the EGR valve is kept in the fully closed position regardless of the drive motor shaft. Thus, by opening and closing the drive motor, only the throttle valve can be opened and closed. Thus, only THRV can be operated by reversing the motor.
(3) When the required EGR amount is zero during engine operation, the drive motor is energized, and the throttle valve is fully opened and held at an angle at which the EGR valve is fully closed. When the required EGR amount is small, the drive motor is energized and rotated in the forward rotation direction. By this rotation, one end of the drive motor shaft is coupled with the shaft of the EGR valve via the gear (L2), and the EGR valve is opened. However, at this time, the other end of the drive motor shaft and the gear (L1 ) Are not coupled, and the throttle valve is held in the fully open position by both springs (SPG1, 2). Further, when the required EGR amount is large, the drive motor is energized and further rotated in the forward rotation direction. By this rotation, one end of the drive motor shaft is coupled to the shaft of the EGR valve via the gear (L2), the EGR valve is opened, and the other end of the drive motor shaft is coupled to the gear (L1) of the throttle valve shaft. Then, the throttle valve is closed. If the throttle valve is fully closed, the EGR rate can be 100%.
(4) When the engine is stopped, the drive motor is energized and rotated in the reverse direction. The rotation of the drive motor is transmitted to the throttle valve via the gear (L1), and the throttle valve is fully closed. At this time, the EGR valve is kept in the fully closed position regardless of the drive motor shaft. As a result, there is no intake air and no exhaust gas recirculation occurs, so the engine stops.
[0019]
FIG. 9 is a block diagram of the main part of the ECU according to the present invention. The requested EGR amount determination unit 1 determines whether the requested EGR amount is zero, the requested EGR amount is small, or the requested EGR amount is large, and outputs a determination result. The throttle valve opening and EGR valve opening determining means 2 determines the throttle valve opening based on the detection signal of the rotation angle sensor S provided on the gear of the throttle valve shaft, and outputs the determination result. The motor energization determining means 3 determines whether or not the drive motor is energized and outputs a determination result. The engine operation state determination means 4 determines whether the engine is starting, the engine is operating, or the engine is stopped, and the determination result is output. The EGR amount control means 5 receives the determination results of these means 1 to 4, determines the forward / reverse rotation and the rotation amount of the drive motor, and outputs the rotation direction and the rotation amount. The drive motor forward / reverse drive means 6 drives the drive motor based on the rotation direction and the rotation amount.
[Brief description of the drawings]
FIG. 1 is a principle view of an electronic venturi integrated with an EGR valve according to the present invention.
2 is a basic configuration diagram of an EGR valve-integrated electronic venturi configured as shown in FIG. 1;
3 is a detailed configuration diagram of a main part of an electronic Venturi integrated with an EGR valve configured as shown in FIG. 1;
4 is an explanatory view (No. 1) for explaining the positional relationship between both gears in the EGR valve-integrated electronic venturi having the configuration shown in FIG. 1; FIG.
5 is an explanatory diagram (No. 2) for explaining the positional relationship between both gears in the EGR valve-integrated electronic venturi having the configuration shown in FIG. 1; FIG.
6 is an explanatory diagram (No. 3) for explaining the positional relationship between both gears in the EGR valve-integrated electronic venturi having the configuration shown in FIG. 1; FIG.
7 is an explanatory diagram (No. 4) for explaining the positional relationship between both gears in the EGR valve-integrated electronic venturi having the configuration shown in FIG. 1; FIG.
FIG. 8 is a graph showing the relationship between the throttle valve opening, the EGR valve opening, and the forward / reverse rotation of the drive motor in the present invention.
FIG. 9 is a block diagram of a main part of an ECU according to the present invention.
FIG. 10 is a configuration diagram of a main part of an example of a conventional technique.
[Explanation of symbols]
THRV ... throttle valve EGRV ... EGR valve L1 ... first gear L2 ... second gear SPG ... spring 1 ... required EGR amount determining means 2 ... throttle valve opening and EGR valve opening determining means 3 ... motor energization determining means 4 ... Engine operation state determination means 5 ... EGR amount control means 6 ... Drive motor forward / reverse drive means

Claims (7)

An EGR valve integrated electronic venturi for controlling the EGR amount of an internal combustion engine,
A forward / reverse drive motor,
The mechanically decelerate coupled with the motor shaft of the driving motor, a first gear having a structure which does not transmitted to the throttle valve axis rotated at a predetermined angular range of said motor shaft,
A second gear having a structure that does not transmit the EGR valve shaft by said motor shaft and is mechanically decelerate binding a predetermined angle range rotation of the motor shaft,
Equipped with,
The throttle valve shaft and the EGR valve shaft are parallel.
EGR valve integrated electronic venturi.   2. The EGR valve-integrated electronic venturi according to claim 1, wherein the throttle valve has a structure capable of rotating on both the forward rotation side and the reverse rotation side with a fully opened state as a center. The EGR valve integrated electronic venturi according to claim 1 or 2 , further comprising a rotation angle sensor for detecting a rotation angle of the throttle valve at an end of the throttle valve shaft . The EGR valve-integrated electronic venturi according to claim 1 or 2 , further comprising a plurality of springs for holding the throttle valve in a fully opened state . The EGR valve-integrated electronic venturi according to claim 1 or 2 , further comprising a spring for holding the EGR valve in a fully closed state . The EGR valve integrated electronic venturi according to any one of claims 1 to 5 , further comprising a computer that controls forward / reverse rotation of the drive motor using a detection signal of the rotation angle sensor . An EGR valve integrated electronic venturi for controlling the EGR amount of an internal combustion engine,
A forward / reverse drive motor,
A throttle valve that can rotate on both the forward and reverse sides around the fully open state;
A first gear that is mechanically decelerated and coupled to a motor shaft of the drive motor and has a structure that does not transmit rotation of the motor shaft to a valve shaft of the throttle valve within a predetermined angle range;
A second gear that is mechanically decelerated and coupled to the motor shaft of the drive motor and has a structure that does not transmit the rotation of the motor shaft to the EGR valve shaft within a predetermined angular range ;
A rotation angle sensor fixed to the reduction gear on the throttle valve side;
Two springs that hold the throttle valve in a fully open state by balancing;
A spring for holding the EGR valve shaft on the fully closed side;
A computer for controlling forward / reverse rotation of the drive motor using a detection signal of the rotation angle sensor;
EGR valve integrated electronic venturi comprising:

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