JPH0626353A - Switching control valve - Google Patents

Abstract

PURPOSE:To provide a switching control valve capable of preventing the degradation in control accuracy on the opening area of a fluid passage caused by the step-out of a step motor for driving the switching control valve of the fluid passage. CONSTITUTION:This switching control valve 14 is provided with a step motor 60 for rotating an output shaft according to an inputted pulse current, and a valve body part 44 for controlling the opening area of a fluid passage variably. When the valve body part 44 in the totally closed position is operated, the valve body part 44 opens the fluid passage 13 after the driving of the step motor 60 at least by the specified number of steps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-off control valve, and more particularly, to a step motor which rotates in response to an input pulse current and an opening area of a fluid passage which is driven by the step motor. The present invention relates to an opening / closing control valve having a valve body part that is variably controlled.

[0002]

2. Description of the Related Art An internal combustion engine such as a rotary engine is provided with a communication passage for connecting a cylinder in an intake stroke and a cylinder in a compression stroke to each other so as to reduce pumping loss caused by throttle of a throttle valve. There are known ones (for example, JP-A-63-90626). An opening / closing control valve is provided in the communication passage, and the opening / closing control valve opens the communication passage in a predetermined operation region to allow the two cylinders to communicate with each other.

An opening / closing control valve of this type is, for example, a rotary valve and has a valve body portion for variably controlling the opening area of the communication passage and a valve shaft portion integrally connected to the valve body portion. The valve shaft portion is operatively connected to the output shaft of the step motor. The step motor is energized by the pulse current by the engine control unit and rotates the valve shaft portion and the valve body portion by the rotation amount corresponding to the step set by the engine control unit, and the valve body portion opens the communication passage. The area is increased according to the amount of rotation.

[0004]

However, when the valve body portion in the fully closed position is rotated, a relatively large fluid resistance acts on the valve body portion in the low opening region of the opening / closing control valve, and the valve body portion is also rotated. The rotational moment due to the uniform acceleration motion of acts on the valve body. Therefore, when the on-off control valve is opened from the fully closed position in the low current region, the force acting on the valve body exceeds the torque of the step motor, resulting in step-out of the step motor and the fluid passage. However, there is a drawback that the control accuracy of the opening area is easily deteriorated.

The present invention has been made in view of the above point, and it is possible to prevent opening / closing control of the opening area of the fluid passage from deteriorating due to step-out of the step motor driving the opening / closing control valve of the fluid passage. To provide a valve.

[0006]

In order to achieve the above object, the present invention provides a step motor for rotating an output shaft according to an input pulse current and a valve for variably controlling an opening area of a fluid passage. An opening / closing control valve having a body portion, the valve body portion opens the fluid passage after the step motor has driven at least a predetermined number of steps when operating the valve body portion in a fully closed position. Provided is an opening / closing control valve characterized by the above.

According to the above configuration of the present invention, the valve body located at the closed position starts opening the fluid passage at least when the step motor is started and the step motor is driven for a predetermined number of steps. Therefore, the step-out of the step motor that may occur immediately after the step motor is started does not affect the control accuracy of the opening area of the fluid passage. In a preferred aspect of the present invention, the valve body portion includes a valve shaft portion rotated by the step motor, and a through hole that increases an opening area of the fluid passage as the rotation amount of the valve shaft portion increases. And the axis of the through-hole is oriented substantially orthogonal to the axis of the fluid passage in the fully closed position.

According to this structure, the through hole of the valve body is
Since it is orthogonal to the fluid passage at the fully closed position, the edge of the through hole and the inner wall of the communication passage are arranged with a slight distance in the rotation direction,
As a result, it is possible to delay the opening start timing of the fluid passage and ensure the sealing performance of the communication passage when fully closed. In a further preferred aspect of the present invention, the fluid passage is an inter-cylinder communication passage capable of mutually communicating a communication port formed in each cylinder of a rotary engine, and each of the communication ports is in one of the intake strokes. It is arranged so as to connect the working chamber of the cylinder and the working chamber of the other cylinder in the compression stroke, the valve body portion is arranged in the communication passage, and the opening area of the communication passage is reduced in order to reduce pumping loss. Variably controlled.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic vertical cross-sectional view of a rotary engine equipped with an opening / closing control valve according to an embodiment of the present invention. Wankel type rotary engine E is the first cylinder C
The first cylinder C1 and the second cylinder C2 have substantially the same structure. In each figure, the corresponding reference numeral is given to the element of each corresponding cylinder.

The first and second cylinders C1 and C2 respectively include a rotor 2 arranged in a rotor housing 1.
The housing 1 and the rotor 2 provide three working chambers 3,
Nos. 4, 5 are formed in the cylinders C1, C2, respectively, and the working chambers 3, 4, 5 are sucked and compressed by the revolution of the rotor 2.
A cycle consisting of expansion and exhaust strokes is periodically repeated.
Each of the cylinders C1 and C2 is provided with first and second spark plugs 6 and 7 on the peripheral wall of the trochoid.
Is the advancing side of the rotor rotation direction with respect to the trochoid short axis,
That is, the second spark plug 7 is arranged on the leading side.
Is the delay side of the rotor rotation direction with respect to the trochoid axis,
That is, it is arranged on the trailing side.

Intake ports 11 are formed in the side housings of the first and second cylinders C1 and C2, respectively. The intake port 11 communicates with an intake passage 21 via a branch intake passage 20 having a fuel injection valve 9. Intake passage 21
Communicate with intake system components (not shown) such as a turbocharger and an air cleaner via a throttle valve 15.

An exhaust port 31 is formed in each side housing of the first and second cylinders C1 and C2, and each exhaust port 31 communicates with an exhaust branch passage 32. The exhaust branch passages 32, 32 merge to form an exhaust passage 33,
The exhaust passage 33 communicates with exhaust system components (not shown) such as a supercharger and a catalytic converter. First and second
A communication port 12 is formed in each of the side housings of the cylinders C1 and C2, and the communication ports 12 and 12 communicate with each other via a communication passage 13 having an opening / closing control valve 14. Each of the communication ports 12 is disposed at a position which is closed later than the intake port 11, and when one communication port 12 is open to the working chamber of the intake stroke, the other communication port 12 is in the compression stroke. It is positioned so as to open into the working chamber.

2 and 3 show the opening / closing control valve 1 shown in FIG.
It is a longitudinal cross-sectional view and a cross-sectional view showing a structure around four. The communication passage 12 (FIG. 3) is formed in the intermediate housing 40 arranged between the cylinders C1 and C2. The valve case 41 of the opening / closing control valve 14 is embedded in the intermediate housing 40, and the openings 42, 42 (shown by phantom lines) of the paired valve cases 41 are aligned with the communication passage 12. The opening / closing control valve 14 is of a rotary type, the valve body portion 44 (FIG. 2) is arranged in the valve case 41, and the gear box 50 is fixed to the upper portion of the valve case 41. The rod portion 45 of the rotary valve is the casing 51 of the gearbox 50.
The rod portion 45,
The input gear 52 is fixed to the upper end of the. A torsion coil spring 54 is provided between the casing 51 and the input gear 52, and the coil spring 54 urges the rod portion 45 and the valve body portion 44 in the closing direction via the input gear 52.

The valve body portion 44 is rotatably supported on the valve case 41 by bearings 46 and 47, and the rod portion 45.
Are rotatably supported on the casing 51 by bearings 53. A through hole 48 that allows fluid communication with the communication passage 12 is formed in the valve body portion 44, and the through hole 48 is aligned with the communication passage 12 as described above when the opening / closing control valve 14 is fully opened. The receiving portion 44 a is formed concentrically with the rod portion 45 on the upper portion of the valve body portion 44, and the discharge passage 44 b communicating with the receiving portion 44 a is bored in the valve body portion 44. From the communication passage 12 to the valve case 4
The air-fuel mixture blown into 1 is liquefied in the valve case 41 and becomes droplet fuel. If this is left unattended, it adheres to the inner wall of the valve case 41 and the valve body portion 44 and causes malfunction, so it must be quickly discharged. The receiving portion 44a and the discharge passage 44b are for receiving and discharging such droplet fuel, and the discharge passage 44b is arranged substantially parallel to the communication passage 12 as shown in FIG. 14
Is aligned with the communication passage 12 when fully opened. Therefore, the receiving portion 44a
The liquid droplet fuel accumulated in is discharged from the valve case 41 into the communication passage 12 when the opening / closing control valve 14 is opened.

An O-ring 62 is inserted between the upper edge of the valve case 41 and the casing 51 in order to ensure a tight seal between the valve case 41 and the gearbox 50. Further, in order to ensure the tight sealing between the intermediate housing 40 and the valve case 41, the O-ring 61 is installed in the intermediate housing 40.
And a curved seal member 63 (FIG. 3) that is interposed between the intermediate housing 40 and the lower portion of the valve case 41. Seal member 63
As shown in FIG. 4, is a linear member 64 that is rotated in a substantially rectangular shape.
And the seal member 6 provided at a predetermined position of the linear member 64.
It is composed of a plurality of protrusions 65 that enhance the adhesion of
It is generally curved with a degree of curvature. The seal members 63 are respectively inserted between the left and right inner wall surfaces of the intermediate housing 40 and the left and right outer wall surfaces of the lower portion of the valve case 41 to prevent the air-fuel mixture from passing through the communication passage 12 to the outside of the intermediate housing 40. To do. Further, in the opening / closing control valve 14 of this example, the bearing 46 that supports the valve body portion 44 and the rod portion 45,
As the bearings 47, 53, so-called sealed bearings that prevent fluid communication before and after the bearings are used.
Leakage of air-fuel mixture is prevented.

A step motor 60 for rotating the rod portion 45 and the valve body portion 44 is fixed to the upper portion of the gear box 50. The output shaft (not shown) of the step motor 60 is
It is operatively connected to the input gear 52 via an intermediate gear (not shown). FIG. 5 is a schematic cross-sectional view around the valve body portion 44. FIG. 6 is a diagram showing the relationship between the rotation angle and the opening area of the opening / closing control valve 14.

In FIG. 5, the valve body portion 44 has a communication passage 12
It is located in the fully closed position, which blocks the fluid communication of. The axis of the through hole 48 is substantially orthogonal to the communication passage 12, and the through hole 4
Both ends of 8 are closed by the peripheral wall of the valve case 41. When the opening / closing control valve 14 is opened, the valve body portion 44 is rotated in the direction indicated by the arrow, and both ends of the through hole 48 are opened to the communication passage 12. The through hole 48 is provided with a taper 49 that widens the edge portion on the front side in the rotation direction. Valve body 4
4 in the fully closed position, the edge of the taper 49 and the communication passage 12
The inner wall is slightly separated from the inner wall in the rotation direction, and this distance is set to a distance corresponding to a rotation angle of about 10 degrees of the opening / closing control valve 14 shown in FIG.

FIG. 7 is a flowchart showing a method of controlling the opening / closing control valve 14 by the control unit ECU. As shown in FIG. 1, a control unit ECU for controlling the operation of the engine E is provided, and the control unit ECU includes various sensors such as a cooling water temperature sensor 101, a throttle opening sensor 102, and an engine speed sensor 103. The detection result is input. The control unit ECU reads the cooling water temperature T detected by the cooling water temperature sensor 101, the throttle opening TVO detected by the throttle opening sensor 102, the engine speed N detected by the engine speed sensor 102, and the like ( S1). The control unit ECU is
When the cooling water temperature T is lower than the predetermined value T1, it is determined that the current operating state of the engine E is not within the predetermined operating range in which the opening / closing control valve 14 should be opened, or that the vehicle is accelerating / decelerating (S2). 3, 4), the open / close control valve 14 is held at the fully closed position (S7). The operating state of the engine E is determined by, for example, the throttle opening TVO and the engine speed N.

On the other hand, the cooling water temperature T is equal to or higher than the predetermined value T1, the current operating state of the engine E is within the predetermined operating range, and the vehicle is not accelerated or decelerated. If it is determined (S2, 3, 4), the opening of the opening / closing control valve 14 is determined based on the throttle opening TVO and the engine speed N, and the fuel injection amount and the ignition timing are corrected (S5, 6). ).

The control unit ECU opens the opening / closing control valve 14 to the opening thus determined,
The step motor 60 is energized, the output shaft of the step motor 60 is rotated until a predetermined step, and the valve body portion 44 is rotated in the arrow direction shown in FIG. The through hole 48 does not open in the communication passage 12 until the valve body portion 44 rotates about 10 degrees, and after the valve body portion 44 rotates about 10 degrees, the through hole 48 is formed in the communication passage 12 according to the rotation amount of the valve body portion 44. Open.

As described above, the engine E of the present embodiment has the cylinder C
1 and C2 is provided with a communication passage 12, and a rotary type opening / closing control valve 14 is disposed in the communication passage 12.
The fourth valve body 44 is rotated by the step motor 60. The through hole 48 of the valve body portion 44 communicates with the communication passage 12 in accordance with the amount of rotation thereof, and variably controls the substantial opening area of the communication passage 12. Here, the through hole 48 continues to close the communication passage 12 until the step motor 60 rotates the valve body portion 44 by a predetermined rotation amount, and after the valve body portion 44 is rotated by the rotation amount, the valve body portion. Communication passage 12 depending on the amount of rotation of 44
Increase the opening area of. Therefore, the opening / closing control valve 14 is
The opening area of the communication passage 12 can be accurately and variably controlled without being affected by the step-out of the step motor 60 in the initial stage of rotation.

The axis of the through hole 48 has the opening / closing control valve 1
The taper 49, which is substantially orthogonal to the communication passage 12 and is provided on the front side in the rotation direction when the valve 4 is fully closed, is slightly separated from the inner wall of the communication passage 12 in the rotation direction. Therefore, the sealing performance of the opening / closing control valve 14 when fully closed is improved. Although the preferred embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above embodiments and various modifications and changes can be made. For example, although the above embodiments relate to a rotary engine, the present invention may be applied to a reciprocating engine equipped with a reciprocating piston.

[0023]

According to the above configuration of the present invention, the opening / closing control valve is configured such that the valve body opens the fluid passage after the step motor constituting the drive source has driven at least a predetermined number of steps. Accordingly, it is possible to prevent deterioration of control accuracy of the opening area due to step-out of the step motor.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a rotary engine including an opening / closing control valve according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing the structure around the opening / closing control valve shown in FIG.

FIG. 3 is a cross-sectional view showing the structure around the opening / closing control valve shown in FIG.

FIG. 4 is a front view and a plan view of a seal member inserted between an intermediate housing and a valve case.

5 is a schematic cross-sectional view around the valve body similar to FIG.

FIG. 6 is a diagram showing a relationship between a rotation angle and an opening area in the opening / closing control valve.

FIG. 7 is a flowchart showing a method of controlling an opening / closing control valve by an engine control unit.

[Explanation of symbols]

 E engine C1, C2 cylinder ECU engine control unit 2 rotor 3, 4, 5 working chamber 6, 7 spark plug 8, 9 fuel injection valve 11 intake port 13 communication passage 14 opening / closing control valve 20 branch intake passage 21 intake passage 40 intermediate housing 41 valve case 42 opening 44 valve body 45 rod 50 gearbox 60 step motor ECU engine control unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Naito 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (3)

[Claims] 1. An on-off control valve comprising a step motor for rotating an output shaft according to an input pulse current and a valve body portion for variably controlling an opening area of a fluid passage, wherein the valve is in a fully closed position. An opening / closing control valve, wherein the valve body opens the fluid passage after the step motor has driven at least a predetermined number of steps when operating the body. 2. The valve body portion includes a valve shaft portion rotated by the step motor, and a through hole that increases an opening area of the fluid passage as the rotation amount of the valve shaft portion increases. The opening / closing control valve according to claim 1, wherein the axis of the through hole is oriented so as to be substantially orthogonal to the axis of the fluid passage in the fully closed position. 3. The fluid passage is an inter-cylinder communication passage capable of mutually communicating a communication port formed in each cylinder of a rotary engine, and each of the communication ports is a working chamber of one cylinder in an intake stroke. , The valve body portion is arranged in the communication passage so as to communicate with the working chamber of the other cylinder in the compression stroke, and the opening area of the communication passage is variably controlled to reduce pumping loss. Claim 1 characterized by the above-mentioned.
Or the opening / closing control valve according to 2.