JP2002266664A - Egr valve-integrated type electronic venturi - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a device and reduce the cost by mechanically integrally connecting a throttle valve to the actuator mechanism of an EGR valve through a drive motor shaft. SOLUTION: This venturi comprises the normally/reversely rotatable drive motor; the throttle valve rotatable on normal rotating side and reverse rotation side about the full open state; a first lever mechanically connected to the motor shaft so as not to transmit the rotation to the valve shaft of the throttle valve in a prescribed angle range; a second lever mechanically connected to the motor shaft so as not to transmit the rotation to the EGR valve shaft in a prescribed angle range; a rotating angle sensor fixed to a throttle valve-side reduction gear; two springs for retaining the throttle valve in the full open state by balancing; and a computer for controlling the normal/reverse rotation of the drive motor by use of the detection signal of the rotating angle sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic venturi, and more particularly to an EGR for controlling an EGR amount of an internal combustion engine with high efficiency.
The present invention relates to a valve-integrated electronic venturi.

[0002]

2. Description of the Related Art FIG. 10 is a block diagram of an example of the prior art. As a conventional technique, for example, Japanese Patent Application Laid-Open No. 10-11063
No. 3 (an intake throttle device for a diesel engine) is known. This document discloses a throttle valve (THRV) for opening and closing an intake passage, and an EGR for adjusting exhaust of EGR gas.
An intake throttle device including a valve (EGRV), a step motor (M) for controlling opening and closing of the throttle valve and the EGR valve, and a computer (ECU) for controlling the operation of the step motor is disclosed. In this example, 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 a detection signal to the ECU is provided.
The CU drives the step motor so that the current throttle valve is at a reference position that does not hinder the operation of the diesel engine, and performs step initialization of the step motor based on a detection signal from the position detecting means.

[0003]

As shown in the drawings, the above-mentioned prior art configuration has an actuator mechanism (A1) for controlling the opening and closing operation of a throttle valve and an actuator mechanism (A2) for controlling the opening and closing operation of an EGR valve. Are separately provided on the body body (B), and the step motor is an actuator mechanism (A
Only 1) is drive-controlled.

[0004] However, since the actuator mechanism for the throttle valve and the actuator mechanism for the EGR valve are separately provided, not only the entire device is enlarged by both actuator mechanisms, but also the cost of the device is increased. There is a problem to do. Further incidentally, E
Since the control of both actuator mechanisms and the opening and closing of both valves are required to be linked by the CU, there is a problem that the control amount by the ECU increases.

Accordingly, an object of the present invention is to reduce the size and cost of the apparatus by mechanically integrally connecting the actuator mechanism of the throttle valve and the actuator mechanism of the EGR valve via a drive motor. It is in.

[0006]

According to the present invention, the actuator mechanism of the throttle valve and the actuator mechanism of the EGR valve are mechanically integrally connected via a motor shaft of a drive motor. Therefore, it is possible to reduce the size of the actuator mechanism of the device, thereby not only reducing the cost of the device, but also reducing the control amount of the ECU and the burden.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the principle of an electronic venturi integrated with an EGR valve according to the present invention. In the figure, M is a drive motor, THRV is a throttle valve, EGRV is an EGR valve, L
1 is a first mechanically connecting the throttle valve and the drive motor.
L2, a second lever that mechanically couples the EGR valve and the drive motor, SPG1 and SPG2 are springs that hold the open / close position of the throttle valve, and SPG3 is an EGR
A spring that holds the open / close position of the valve.

In the present invention, as will be described in detail with reference to the following drawings (FIGS. 4 to 7), a motor shaft of a drive motor M capable of normal rotation and reverse rotation is provided with a lever 1 provided at an end of a throttle valve shaft. Mechanically coupled to the motor shaft,
It is mechanically connected to a bar 2 provided at the end of the valve shaft.
The throttle valve is rotatable in the normal rotation direction and the reverse rotation direction around the fully opened state, and is fully opened (in the state shown in the figure) at the neutral position. Closes. On the other hand, the EGR valve is fully closed at the illustrated position.

FIG. 2 is a basic structural view of the EGR valve-integrated electronic venturi 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 integrally connected via a motor shaft of a drive motor. As a result, the actuator mechanism of the apparatus can be made smaller, thereby not only reducing the cost of the apparatus, but also reducing the EC cost.
Since the control amount of U also controls the drive motor, the load can be reduced. That is, based on the detection signal of the rotation angle sensor, as shown in FIG. 8, which will be described later, the throttle valve (see the solid line) is fully opened at the time of forward rotation of the drive motor M at the neutral point. A small amount of EGR control is performed when the EGR valve (see the dashed line) starts to open, and then a large amount of EGR gas is controlled by closing the throttle valve. Further, when the drive motor rotates in the reverse direction, only the throttle valve is controlled.

FIG. 3 is a detailed structural view of a main part of the EGR valve-integrated electronic venturi shown in FIG. In the figure, SPG1, SP
G2 is a spring that holds (biases) 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 provided on the reduction gear of the throttle valve and rotating with the motor shaft. As described above, THRV is a throttle valve, EGRV is an EGR valve, L1 is a lever (gear) provided at an end of a throttle valve shaft, and does not transmit rotation of a motor shaft to the throttle valve shaft within a predetermined angle range. Having a structure. L2 is a lever (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.

An actuator mechanism A according to the present invention includes an actuator mechanism (see SPG1 and L1) for a throttle valve (THRV) and an actuator mechanism (see L2) for an EGR valve (EGRV) via a motor shaft of a drive motor M. This is a configuration in which the components are combined. Since the throttle valve and the EGR valve are not integrally provided with an actuator mechanism as in the above-described conventional apparatus, they are mechanically integrated, so that the actuator mechanism can be reduced in size, thereby reducing the cost of the apparatus. Can be planned. Further, the ECU can control the drive motor based on the detection signal from the rotation angle sensor S to simultaneously control the lever L1 and the lever L2.

FIG. 4 is an explanatory view (part 1) for explaining the positional relationship between the two levers L1 and L2 in the EGR valve-integrated electronic venturi shown in FIG. As shown, the motor shaft of the drive motor is mechanically coupled to levers L1 and L2 via its gear (G). Lever L1 and L shown
The position 2 is a state where the throttle valve is fully open and the EGR valve is fully closed.

[0013] Such a state occurs when no power is supplied to the drive motor, when a failure occurs (when an abnormality occurs), and when the drive motor is supplied with power and the required EGR amount is zero during engine operation.
It is. At the time of non-energization and at the time of failure, the throttle valve (THRV) is fixed at a substantially full open position by the balance between the springs SPG1 and SPG2. Further, the EGR valve (EGRV) is fixed to the fully closed position by the spring SPG3. When the required EGR amount is zero during the operation of the engine, the drive motor is energized, and THRV is fully opened.
The angle at which the RV is fully closed is maintained.

FIG. 5 is an explanatory view (part 2) for explaining the positional relationship between the two levers L1 and L2 in the EGR valve-integrated electronic venturi shown in FIG. The illustrated positions of the levers L1 and L2 are such that THRV is fully open and EGRV is half open. Such a state is caused by the demand E during engine operation.
This is when the GR amount is small. In this case, the drive motor is energized to rotate in the normal rotation direction (arrow direction). By this rotation, the lever L2 coupled to the gear G rotates in the direction of the arrow,
Open the EGR valve halfway. On the other hand, the motor shaft and the lever L1 of the throttle valve are not engaged and are in an idle swing state, and are held at the fully opened position by the springs SPG1 and SPG2.

FIG. 6 is an explanatory view (part 3) for explaining the positional relationship between the two levers L1 and L2 in the EGR valve-integrated electronic venturi shown in FIG. The illustrated positions of the levers L1 and L2 are such that THRV is closed and EGRV is fully opened. Such a state is caused by the demand EG during engine operation.
This is when the amount of R is large. In this case, the drive motor is energized to further rotate in the normal direction (arrow direction). Due to this rotation, the lever L2 connected 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 lever L1 of the throttle valve are engaged to close the THRV. T
If the HRV is fully closed, the EGR rate can be set to 100%. The EGR rate is represented by {(EGR gas flow rate) / (intake air amount + EGR gas flow rate)} × 100 (%).

FIG. 7 is an explanatory view (part 4) for explaining the positional relationship between the two levers L1 and L2 in the EGR valve-integrated electronic venturi shown in FIG. The illustrated positions of the levers L1 and L2 are such that THRV is closed to an appropriate opening and EG
RV is fully closed (when the engine is started) or THR
V is fully closed and EGRV is fully closed (when the engine is stopped). At the time of the former engine start, when the drive motor is energized and rotated in the reverse direction, the rotation of the motor shaft is controlled by the lever L.
1, the THRV is transmitted to the THRV, so that the THRV can be closed to an appropriate opening when the engine is started. On the other hand, when the engine is stopped, when the drive motor is energized and rotated in the reverse direction, the rotation of the motor shaft is controlled by the lever L1.
To the THRV, and the THRV can be fully closed. At this time, the EGR valve is held at the fully closed position regardless of the motor shaft.

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 according to the present invention. As shown in the figure, in the section (A), the throttle valve (THRV) reversely rotates and controls only THRV,
In the section (B), THRV controls a small amount of EGR when fully opened, and in the section (C), THRV rotates forward and a large amount of EG
Control R.

The operation of the THRV and the EGRV has been described along the engagement relationship between the levers L1 and L2 in FIGS. 4 to 7 described above. Here, the operation will be described at each time point of the operation. That is, the operations of THRV and EGRV are as follows: (1) when power is not supplied to the drive motor, when power is not supplied, and when failure occurs,
At the time of starting the engine, (3) at the time of operating the engine, and (4) at the time of stopping the engine, it can be roughly classified. Further, during the engine operation of (3), when the required EGR amount is zero, the required EG
When the R amount is small, and when the required EGR amount is large, it is divided into: (1) When no power is supplied to the drive motor, and when a failure occurs, the throttle valve opens both springs (SPG1, SPG1).
By the balance of PG2), it is fixed to the almost fully open position,
The EGR valve is fixed at the fully closed position by a spring (SPG3). (2) At the start of the engine, when the drive motor is energized and rotated in the reverse direction, the rotation of the drive motor is controlled by the lever (L
The throttle valve is transmitted to the throttle valve via 1), so that the throttle valve can be closed to an opening suitable for starting the engine. At this time, the EGR valve is maintained at the fully closed position regardless of the drive motor shaft. In this way, by reversing the drive motor, it is possible to open and close only the throttle valve. As described above, only the THRV can be operated by reversing the motor. (3) During engine operation, when the required EGR amount is zero, the drive motor is energized, the throttle valve is fully opened, and E
The GR valve is held at an angle at which it is fully closed. Also, the required EGR
When the amount is small, the drive motor is energized to rotate in the forward direction. By this rotation, one end of the drive motor shaft is connected to the shaft of the EGR valve via the lever (L2) to open the EGR valve. However, at this time, the other end of the drive motor shaft and the lever (L1) of the throttle valve shaft ) Is not connected, and the throttle valve is held at a substantially full 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 normal rotation direction. Due to this rotation, one end of the drive motor shaft is connected to the lever (L
2) coupled to the shaft of the EGR valve via
Further, the other end of the drive motor shaft and the lever (L1) of the throttle valve shaft are connected, and 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 to rotate in the reverse direction. Drive motor rotation lever (L1)
And the throttle valve is fully closed. At this time, the EGR valve is maintained at the fully closed position regardless of the drive motor shaft. As a result, there is no intake,
Since the exhaust gas does not recirculate, the engine stops.

FIG. 9 is a block diagram of a main part of the ECU according to the present invention. The required EGR amount determination means 1
It is determined whether the R amount is zero, the required EGR amount is small, or the required EGR amount is large, and a determination result is output. The throttle valve opening and EGR valve opening determining means 2 determines a throttle valve opening based on a detection signal of a rotation angle sensor S provided on a gear of the throttle valve shaft, and outputs a determination result. The motor energization determining means 3 determines whether or not the drive motor is energized and outputs a determination result. The engine operating state determining means 4 determines whether the engine is running, whether the engine is running,
Determines whether the engine is stopped and outputs the determination result. EGR
The amount control means 5 receives the determination results of the respective means 1 to 4, determines the forward rotation / 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 direction and amount of rotation.

[Brief description of the drawings]

FIG. 1 is a principle view of an EGR valve-integrated electronic venturi according to the present invention.

FIG. 2 is a basic configuration diagram of the EGR valve-integrated electronic venturi of the configuration of FIG. 1;

FIG. 3 is a detailed configuration diagram of a main part of the EGR valve-integrated electronic venturi shown in FIG. 1;

FIG. 4 is an explanatory view (part 1) illustrating the positional relationship between both levers in the EGR valve-integrated electronic venturi of FIG. 1;

FIG. 5 is an explanatory view (part 2) illustrating the positional relationship between both levers in the EGR valve-integrated electronic venturi shown in FIG. 1;

6 is an explanatory view (part 3) illustrating the positional relationship between both levers in the EGR valve-integrated electronic venturi shown in FIG. 1;

FIG. 7 is an explanatory view (part 4) illustrating the positional relationship between both levers in the EGR valve-integrated electronic venturi of FIG. 1;

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 according to 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 an example of a main part of a conventional technique.

[Explanation of symbols]

 THRV: Throttle valve EGRV: EGR valve L1: First lever L2: Second lever SPG: Spring 1: Requested EGR amount determining means 2: Throttle valve opening and EGR valve opening determining means 3: Motor energizing determining means 4 ... Engine operating state determination means 5 ... EGR amount control means 6 ... Drive motor forward / reverse drive means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 21/08 301 F02D 21/08 301A F02M 25/07 550 F02M 25/07 550R 580 580F F-term (Reference) 3G062 BA06 CA01 CA06 DA01 DA02 EA11 FA02 FA05 FA23 GA04 GA06 3G065 CA23 DA05 DA06 DA15 EA01 EA06 EA07 GA10 GA41 HA06 HA21 HA22 KA02 KA15 KA16 3G092 AA17 BA01 DC03 DC08 DG08 EA01 EA02 HA03 GA03 GA03 GA03

Claims (9)

[Claims] 1. An electronic venturi integrated with an EGR valve for controlling an EGR amount of an internal combustion engine, comprising: a drive motor capable of normal / reverse rotation; and a mechanically coupled motor shaft of the drive motor and a throttle valve shaft. An electronic venturi integrated with an EGR valve, comprising: a first lever; and a second lever that mechanically couples the motor shaft and an EGR valve shaft. 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 around a fully open state. 3. The EGR valve-integrated electronic venturi according to claim 1, wherein the first lever has a structure that does not transmit the rotation of the motor shaft to the throttle valve shaft within a predetermined angle range. 4. The EGR valve-integrated electronic venturi according to claim 1, wherein the second lever has a structure not transmitting the rotation of the motor shaft to the EGR valve shaft within a predetermined angle range. 5. The EGR valve-integrated electronic venturi according to claim 1, further comprising a rotation angle sensor for detecting a rotation angle of the throttle valve at an end of the throttle valve shaft. 6. The apparatus according to claim 1, further comprising a plurality of springs for holding said throttle valve in a fully open state.
An electronic venturi integrated with an EGR valve according to any one of the above. 7. The electronic venturi integrated with an EGR valve according to claim 1, further comprising a spring for holding said EGR valve in a fully closed state. 8. The EGR according to claim 1, further comprising a computer that controls forward / reverse rotation of said drive motor using a detection signal of said rotation angle sensor.
Electronic venturi with integrated valve. 9. An electronic venturi integrated with an EGR valve for controlling an EGR amount of an internal combustion engine, comprising: a drive motor capable of forward / reverse rotation; and a throttle valve capable of rotating both forward and reverse sides around a fully open state. A first lever mechanically coupled to a motor shaft of the drive motor and having a structure that does not transmit rotation of the motor shaft to the valve shaft of the throttle valve within a predetermined angle range; and a motor shaft of the drive motor. A second lever mechanically coupled to the second shaft, the second lever having a structure not transmitting the rotation of the motor shaft to the EGR valve shaft within a predetermined angle range; a rotation angle sensor fixed to a reduction gear on the throttle valve side; Two springs that hold the throttle valve in a fully open state by balancing; a spring that holds the EGR valve shaft on a fully closed side; and a spring using the detection signal of the rotation angle sensor. EGR valve integrated electronic venturi comprising a computer for controlling the forward / reverse rotation of the drive motor.