JP2000303861A - Intake control valve device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an intake control valve device capable of reducing fluid torque acting a throttle valve in a closing valve direction, even if flow velocity of intake air flowing in the vicinity of the throttle valve is not constant, and of having no necessity for use of a large-sized motor generating large driving torque. SOLUTION: In an intake control valve device of an engine, a throttle valve 4 is constituted of a first fluid receiving part A and a second fluid receiving part B in which intake air collides by defining a throttle shaft 3 as a boundary. The throttle valve 4 is fixed to a throttle shaft 3 at a position deviated from a center line C, extending in the radial direction and fluid torque acting on each of the first fluid receiving part A and the second fluid receiving part B is regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake control valve device for an engine having a return spring which biases a throttle valve for opening and closing an intake passage in a valve opening or valve closing direction.

[0002]

2. Description of the Related Art For example, as a conventional intake control valve device for a diesel engine, Japanese Utility Model Laid-Open Publication No. 63-198458 discloses a system in which an engine cooling water temperature, fuel injection amount, engine Control unit (EC based on engine operating conditions such as number of rotations)
An intake control valve device for a diesel engine that varies the opening area of an intake passage by adjusting the opening degree of a throttle valve using a stepper motor in response to a control signal from U). In addition, the intake control valve device of the diesel engine reduces the engine vibration and noise by closing the throttle valve during idling or deceleration to restrict the intake to the engine, or by reducing the pressure in the intake passage. Adjust the EGR gas recirculation rate. In addition, in order to stop the engine without vibration when the engine is stopped, it is necessary to shut off intake air to the engine by fully closing the throttle valve.

In the conventional intake control valve device for a diesel engine, when the throttle valve is in the vicinity of the fully closed state, for example, during idling operation, the stepper motor or the ECU breaks down due to disconnection or the like, and the stepper motor cannot operate. When the engine runs out, the throttle valve is fully closed by the fluid torque of the intake fluid, the intake to the engine is shut off, the continuous operation of the diesel engine cannot be performed, and the vehicle cannot run.

In order to solve such a problem, a conventional intake control valve device for a diesel engine uses a throttle valve even if a stepper motor or an ECU breaks down due to disconnection or the like and the stepper motor cannot operate. A return spring that is normally urged in the valve opening direction is provided so that the valve can be opened.

[0005] By the way, since the intake control valve device of a general diesel engine is interposed between the bent or curved intake passages due to the layout of the engine, the intake air (intake fluid) flowing near the throttle valve drifts. Due to the state or the non-constant flow velocity, the intake fluid receives the force of the fluid in the direction to close or open the throttle valve depending on the shape of the intake passage. That is, the fluid torque acts. The value of the fluid torque varies depending on the operating state of the diesel engine. For example, at high speeds, the amount of intake air to the engine increases, so that the fluid torque acting on the throttle valve also increases.

In the conventional intake control valve device for a diesel engine, the center line of the throttle valve that opens and closes the intake passage extends in the radial direction of the throttle valve regardless of the shape of the intake passage. Installed to match. In this case, when the shape of the intake passage is such that the intake pipe downstream of the throttle valve 104 is curved to the left in the figure as shown in FIG. 16, for example, the flow of intake air as intake fluid to the engine is reduced. Accordingly, the fluid torque acting on the throttle valve 104 acts in the direction in which the throttle valve 104 is closed (clockwise in the figure). That is, in FIG. 16, since the intake pipe 112b downstream of the throttle valve 104 is curved to the left in the drawing, the intake air flowing in the vicinity of the throttle valve 104 has a flow velocity (indicated by an arrow and proportional to the size of the arrow). Is not constant, and the fluid torque acting on the first fluid receiving portion b of the throttle valve 104 in the clockwise direction with respect to the throttle shaft 200 is caused by the second fluid receiving portion b acting in the counterclockwise direction. Greater than the required fluid torque. Therefore, the throttle valve 1
Fluid torque applied to the entire valve 04 acts in a direction to close the throttle valve 104 (clockwise in the drawing).

FIG. 17 shows the fluid torque acting on the entire throttle valve 104 in the conventional device having the shape of the intake passage shown in FIG. 16, and a large fluid flows in the direction of closing the throttle valve 104 over the full opening. It can be seen that the torque is acting. In FIG. 17, the horizontal axis represents the throttle valve opening θ (°), and the vertical axis represents the fluid torque Ta (N · N) acting on the throttle valve 104 by the intake air.
m).

FIG. 19 shows the fluid torque acting on the throttle valve 104 when the opening direction of the throttle valve 104 is clockwise as shown in FIG. 18 in the conventional intake control valve device for a diesel engine. It can be seen that a large fluid torque is acting in the direction in which the throttle valve 104 is opened over the full opening.

FIG. 20 shows a case in which the shape of an intake passage of a conventional intake control valve device for a diesel engine is different from that shown in FIGS. 16 and 18, and an intake pipe 112a upstream of the throttle valve 104 is located on the left side in the figure. It shows a case in which it is curved. It can be seen that a large fluid torque acts in the direction in which the throttle valve 104 is closed (clockwise) because the intake air mainly drifts and collides with the first fluid receiving portion b of the throttle valve 104 mainly.

[0010]

In a conventional intake control valve device for a diesel engine, a large fluid torque in a valve opening direction or a valve closing direction over a full opening degree is caused by a throttle valve 10.
17, for example, in the case of the example shown in FIG.
A large motor having a large driving torque capable of opening the valve 04 is required. This leads to an increase in cost, a problem that not only the vibration resistance is deteriorated due to the deterioration of vehicle mountability and weight increase, but also the control response is deteriorated due to an increase in inertial weight of the motor.

Also, as shown in FIG.
Fluid torque over the full opening of the throttle valve 10
In the intake control valve device acting in the direction to close the valve 4, the throttle valve 104 is opened to continue the diesel engine even when the stepper motor or the ECU fails due to disconnection or the like and the stepper motor cannot operate. A return spring that is normally urged in the valve opening direction is provided so as to perform a proper operation. In addition, the setting of the elastic force of the return spring has to be equal to or greater than the fluid torque described above. For this reason, in the case of an intake control valve device of a diesel engine provided with a return spring having a large elastic force in the valve opening direction, when the throttle valve 104 is rotated at a low speed such as during idling, that is, when the opening of the throttle valve 104 is near 0 °, the fluid torque Is small, a large motor having a large driving torque capable of overcoming the elastic force of the return spring and closing the throttle valve 104 is required.

Further, the increase in the size of the motor leads to an increase in detent torque (stop torque applied to the output shaft of the motor when the stepper motor is not energized), and the elastic force of the return spring must be further increased. There was also the problem of falling into a vicious circle. Furthermore, in the case of a return spring set to a large valve opening torque, the stress applied to the return spring is large and there is a problem in reliability. If the return spring breaks, for example, the fluid torque is applied to the valve closing side of the throttle valve 104. Has a problem that the throttle valve 104 fully closes the intake passage, shuts off intake air to the engine, and makes it impossible to continuously operate the diesel engine.

The output shaft of the motor and the throttle shaft 20
When the drive torque is amplified by adding a gear reduction mechanism between 0 and 0, the detent torque further increases in proportion to the gear ratio. Responsibility of opening and closing 104 is deteriorated, and the number of parts is increased, resulting in an increase in cost.

As shown in FIG. 19, in the intake control valve device in which the fluid torque acts in the direction of opening the throttle valve 104 over the full opening of the throttle valve, the fluid torque overcomes the fluid torque and the valve opening torque by the return spring. Therefore, a large motor having a large driving torque capable of closing the throttle valve is required, and thus the same problem as described above has been encountered.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems. Even if the flow rate of the intake fluid flowing in the vicinity of the throttle valve is not constant, the throttle valve is closed or closed. Can reduce the fluid torque acting in the valve opening direction, does not require the use of a large motor having a large driving torque, is small and light, and has the effect of improving vehicle mountability and vibration resistance. An apparatus is provided.

[0016]

According to a first aspect of the present invention, there is provided an intake control valve device for an engine, wherein the housing has an intake passage through which intake fluid flows, and the housing is rotatably supported via a bearing. A throttle shaft, a throttle valve fixed to the throttle shaft and opening and closing the intake passage by rotating, a return spring for urging the throttle valve in a valve opening or valve closing direction, and rotating the throttle shaft. And a motor for opening and closing the throttle valve. The throttle valve includes a first fluid receiving portion and a second fluid receiving portion against which the intake fluid collides with the throttle shaft as a boundary line. At the same time, the first fluid receiving portion and the second fluid receiving portion are caused to have different collision areas of the intake fluid with the first fluid receiving portion and the second fluid receiving portion. Fluid torque acting respectively on the receiving part is adapted to be adjusted.

In the engine intake control valve device according to a second aspect of the present invention, the throttle valve is fixed to the throttle shaft at a position deviated from a center line extending in the radial direction.

In the intake control valve device for an engine according to a third aspect of the present invention, the throttle valve is fixed to a center line extending in a radial direction, and the first fluid receiving portion and the second fluid receiving portion are provided. The areas of the parts are different.

According to a fourth aspect of the present invention, in the engine intake control valve device, the throttle valve is provided with a positioning portion for the throttle shaft.

In the intake control valve device for an engine according to the fifth aspect of the present invention, the fluid torque acting on the throttle valve by the intake fluid acts in the valve opening direction below the minimum opening of the throttle valve capable of continuous operation. It has become.

In the intake control valve device for an engine according to a sixth aspect of the present invention, the fluid torque acting on the throttle valve due to the intake fluid is less than the minimum opening degree (θ2) of the throttle valve capable of continuous operation. And the valve opening direction fluid torque at the minimum opening degree (θ2) is Ta (θ2), the maximum value of the detent torque when the motor is not energized is Td (max),
When the maximum value of the stopping torque for preventing the rotation of the throttle shaft due to friction around the bearing is Tf (max), Ta
The relationship of (θ2)> (Td (max) + Tf (max)) is established.

In the engine intake control valve device according to a seventh aspect of the present invention, when the throttle valve is at or below the minimum opening degree (θ2) of the throttle valve capable of continuous operation, the fluid torque acting on the throttle valve by the intake fluid changes the valve opening direction. And the valve opening direction fluid torque at the minimum opening degree (θ2) is Ta (θ2), the maximum value of the detent torque when the motor is not energized is Td (max),
The maximum value of the blocking torque for preventing rotation of the throttle shaft due to friction around the bearing is Tf (max), the minimum value of the torque of the motor is Tm (min), and the return spring is opened at the minimum opening (θ2). Assuming that the valve torque is Ts (θ2), Ta (θ2)> Td (max) + Tf (max), Tm (min)>
The relationship Ta (θ2) + Ts (θ2) + Tf (max) is established.

In the engine intake control valve device according to claim 8 of the present invention, the motor is a stepper motor directly connected to the throttle shaft.

In the engine intake control valve device according to the ninth aspect of the present invention, the engine is a diesel engine.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a sectional view of a main part of an intake control valve device for a diesel engine according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. 1 is a housing interposed in the intake pipes 12a and 12b, 2 is an intake passage, 3 is a throttle shaft rotatably supported via a bearing, 4 is a throttle valve for opening and closing the intake passage 2, and 5 is a throttle shaft. Step 3a formed at one end of 3
Is a stopper lever fixed by a nut 6, and forms bent portions 5a and 5b. The bent portion 5a stops the throttle valve 4 at the fully open position by contacting the stopper surface 1a of the housing 1, and prevents further rotation in the valve opening direction. Further, the bent portion 5b is brought into contact with the stopper screw 7 screwed to the housing 1 so that
The throttle valve 4 is stopped at the fully closed position, and further rotation in the valve closing direction is prevented. The fully closed position of the throttle valve 4 can be adjusted by moving the stopper screw 7 forward or backward.

Reference numeral 8 denotes a return spring fitted on the outer periphery of the throttle shaft 3, which urges the throttle valve 4 in the valve opening direction. 9 is an engine control computer (EC
U) A stepper motor that rotates in accordance with a command of 13. A concave portion 9b is formed at the distal end of the output shaft 9a so as to fit with the convex portion 3b formed at the distal end of the throttle shaft 3. Is transmitted directly to the throttle shaft 3, and the throttle valve 4 is opened and closed to a predetermined opening in accordance with a command from the ECU 13. Reference numeral 10 denotes a throttle position sensor, which is connected to a connection lever 11 fixed to the other end of the throttle shaft 3, detects a rotation angle of the throttle shaft 3, that is, an opening of the throttle valve 4, and transmits the rotation angle to the ECU 13. You.

FIG. 3 is a sectional view taken along the line BB of FIG. In FIG. 3, the intake pipe 12b downstream of the throttle valve 4 is curved to the left in the drawing.
The flow rate of the intake fluid flowing in the vicinity of the arrow (indicated by an arrow and assumed to be proportional to the size of the arrow) is not constant, and the fluid torque is in the direction of closing the throttle valve 4 (clockwise in FIG. Direction). In this passage configuration, the slot valve 4 is attached to the throttle shaft 3 with the center line c extending in the radial direction of the throttle valve 4 shifted downstream with respect to the rotation center of the throttle shaft 3 (C <D in the figure). The projected area (area receiving the fluid force) of the second fluid receiving portion b on the downstream side of the valve 4 is made larger than the projected area (area receiving the fluid force) of the first fluid receiving portion b on the upstream side, Even if a difference occurs in the flow velocity at which the intake fluid collides between the first fluid receiving portion A and the second fluid receiving portion B, the first fluid receiving portion A and the second fluid receiving portion B of the throttle valve 4 The balance of the fluid torques acting on each is optimized, and the closing force of the intake air as intake fluid is reduced.

FIG. 4 shows the fluid torque acting on the throttle valve 4 according to the first embodiment of the present invention.
The horizontal axis indicates the throttle valve opening θ (°), and the vertical axis indicates the fluid torque Ta (N
M). In FIG. 4, the fluid torque acting on the throttle valve 4 is switched from the valve closing direction to the valve opening direction with the opening degree θ1 as a branch point.

Embodiment 2 FIG. 5 is a diagram for explaining the fluid torque acting on the throttle valve according to the second embodiment of the present invention. In this embodiment, as shown in FIG. 5, the opening θ1 serving as the branch point of the fluid torque is adjusted to be more open (θ1> θ2) than the minimum opening θ2 of the throttle valve capable of continuously operating the diesel engine. It was done. Minimum opening θ
If the opening is lower than 2, fluid torque acts on the throttle valve in the valve opening direction, so that when the stepper motor or the ECU breaks down due to disconnection or the like and the stepper motor cannot operate, the throttle valve capable of continuous operation can be operated. The vehicle can be driven without closing the throttle valve below the minimum opening degree θ2, for example, even if the return spring for opening the valve is broken.

More specifically, the valve opening direction fluid torque at the minimum opening θ2 of the throttle valve capable of continuously operating the diesel engine is Ta (θ2), and the maximum value of the detent torque when the stepper motor is not energized is Td (max). ), Assuming that the maximum value of the torque for preventing rotation of the throttle shaft 3 due to friction around the bearings of the stepper motor and the throttle shaft (hereinafter simply referred to as shaft friction) is Tf (max), Ta (θ2)>
By satisfying the condition of Td (max) + Tf (max), even when the stepper motor cannot operate, the throttle valve does not rotate below the minimum opening degree θ2 and the continuous operation is possible.

Embodiment 3 FIG. 6 is a diagram illustrating fluid torque acting on a throttle valve according to Embodiment 3 of the present invention. In this embodiment, as shown in FIG. 6, in the case where a return spring for valve opening is provided, the valve opening torque of the return spring at the minimum opening degree θ2 of the throttle valve capable of continuously operating the diesel engine is represented by Ts. (θ
2) When the minimum value of the torque of the stepper motor is Tm (min), Ta (θ2)> Td (max) + described in the second embodiment.
Along with the relationship of Tf (max), Tm (min)> Ta (θ2) + T
It has a relationship of s (θ2) + Tf (max). In this embodiment, even when the stepper motor cannot operate, the throttle valve has the minimum opening degree θ2 as in the second embodiment.
With the above, continuous operation is possible, and when the engine is stopped, the valve closing torque of the stepper motor exceeds the valve opening torque of the return spring and the like, and the throttle valve is opened to the minimum opening θ.
The engine can be shut down completely without vibrating by fully closing it to 2 or less.

Embodiment 4 FIG. FIG. 7 shows an intake control valve device according to a fourth embodiment of the present invention, which is different from the intake control valve device according to the first embodiment shown in FIG. The direction (clockwise) is the case of reverse rotation. In this embodiment, the throttle valve 44 is attached to the throttle shaft 3 so that the center line c of the throttle valve 44 is shifted upstream with respect to the rotation center of the throttle shaft 3,
(C> D in the figure), the first upstream side of the throttle valve 44
Is larger than the projected area (area receiving fluid force) of the second fluid receiving section B on the downstream side. Therefore, even if there is a difference in the flow rate of the intake air that collides between the first fluid receiving portion A and the second fluid receiving portion B, the first
The balance between the fluid torques acting on the fluid receiving portion A and the second fluid receiving portion B is optimized, and the valve opening force by the intake air as the intake fluid is reduced.

Embodiment 5 FIG. FIG. 8 is a front view of a throttle valve 4A of an intake control valve device according to a fifth embodiment of the present invention. Only the shape of the throttle valve 4 according to the first embodiment shown in FIG. . That is, the throttle shaft 3 is fixed to the throttle valve 4A so that the center line c extending in the radial direction of the throttle valve 4A coincides with the center of rotation of the throttle shaft 3, and a part of the upstream side of the throttle valve 4A is cut. By making the projected area (area receiving the fluid force) of the lacked first fluid receiving section a smaller than the projected area (area receiving the fluid force) of the second fluid receiving section b on the downstream side, the first fluid Even if a difference in flow velocity occurs between the intake air colliding between the receiving portion A and the second fluid receiving portion B, the fluid torque acting on the first fluid receiving portion A and the second fluid receiving portion B The balance is optimized, and as a result, the valve closing action force due to the intake air is reduced, and the same effect as in the first embodiment can be obtained.

The notched shape of the throttle valve 4A is not limited to the shape shown in FIG. 8, but may be, for example, a notched upper end as shown in a throttle valve 4B in FIG. 9 or a cut out shape as shown in a throttle valve 4C in FIG. The same effect can be obtained even if the upper end is made elliptical.

Embodiment 6 FIG. FIG. 11 is a front view of a throttle valve of an intake control valve device according to a sixth embodiment of the present invention. The throttle valve 44 according to the fourth embodiment shown in FIG. Only the position is different. That is, the throttle valve 44A is fixed to the throttle shaft 3 so that the center line C extending in the radial direction of the throttle valve 44A coincides with the rotation center of the throttle shaft 3, and a part of the throttle valve 44A on the downstream side is cut. The projected area (area receiving the fluid force) of the missing second fluid receiving section B is made smaller than the projected area (area receiving the fluid force) of the first fluid receiving section b on the upstream side, and the first fluid receiving section Balance of fluid torque acting on the first fluid receiving portion a and the second fluid receiving portion b even if a difference in flow velocity occurs between the intake air colliding between the portion a and the second fluid receiving portion b. , And as a result, the valve closing action force due to the intake air is reduced, and the same effect as that of the fourth embodiment can be obtained.

The shape of the notch of the throttle valve 44A is not limited to that shown in FIG. 11, and for example, the lower end may be cut away as shown in FIG.
Similar effects can be obtained even if the lower end is made elliptical as in the throttle valve 44C of No. 3.

Embodiment 7 FIG. 14 is a front view of a throttle valve of an intake control valve device according to a seventh embodiment of the present invention, and FIG. 15 is a sectional view taken along line EE in FIG. In the seventh embodiment, the throttle valve 4 of the first embodiment is provided with a cylindrical projection 14 which is a positioning portion that comes into contact with the outer diameter of the throttle shaft 3. The accuracy is improved, and the balance of the fluid torque acting on each of the first fluid receiving portion A, which is the upstream surface of the throttle valve 4, and the second fluid receiving portion B, which is the downstream surface, is more accurately adjusted. You. Note that the protrusions are the throttle valves 44, 44A, 4
4B, 4A, and 4B, and the shape of the protrusion 14 is not limited to a columnar shape, and may be a square shape or the like. further,
The positions of the protrusions 14 are not limited to the two positions shown in FIG. 14, and may be provided on either the upstream side or the downstream side, or may be provided at one or a plurality of positions.

In each of the above embodiments, the intake control valve device for a diesel engine has been described.
The present invention can be applied to, for example, an intake control valve device of a gasoline engine in which a return spring biases a throttle valve in a valve closing direction.

[0039]

As described above, according to the intake control valve device for an engine according to the first aspect of the present invention, a housing having an intake passage through which intake fluid flows, and the housing is rotatable via a bearing. A throttle shaft fixed to the throttle shaft, and opening and closing the intake passage by rotating the throttle shaft; a return spring for urging the throttle valve in a valve opening or valve closing direction; And a motor that opens and closes the throttle valve by rotating the throttle valve. The throttle valve is provided with a first fluid receiving portion and a second fluid receiving portion with which the intake fluid collides with the throttle shaft as a boundary line. The first fluid receiving portion is configured to have different collision areas of the intake fluid with the first fluid receiving portion and the second fluid receiving portion. And the fluid torque acting on the second fluid receiving portion is adjusted. Therefore, even if the flow rate of the intake fluid flowing near the throttle valve is not constant, the throttle valve is closed, or Can reduce the fluid torque acting in the valve opening direction. As a result, it is possible to reduce the torque of the motor and the return spring, and it is not necessary to amplify the driving torque by decelerating the motor or use a large motor that generates a large driving torque.
In addition to being small and light, the vehicle mountability and vibration resistance can be improved.

According to the intake control valve device for an engine according to the second aspect of the present invention, the throttle valve is fixed to the throttle shaft at a position deviated from the center line extending in the radial direction. The fluid torque acting on each of the fluid receiving portion and the second fluid receiving portion can be easily adjusted.

According to the intake control valve device for an engine according to the third aspect of the present invention, the throttle valve is fixed to the center line extending in the radial direction, and the first fluid receiving portion and the second Since the areas of the fluid receiving portions are different, the fluid torque acting on each of the first fluid receiving portion and the second fluid receiving portion can be easily adjusted.

According to the intake control valve device for an engine according to the fourth aspect of the present invention, since the throttle valve is provided with the positioning portion for positioning with respect to the throttle shaft, the mounting position accuracy of the throttle shaft with respect to the throttle valve is improved, First
The balance between the fluid torques acting on the fluid receiving portion and the second fluid receiving portion can be more properly adjusted.

According to the intake control valve device for an engine according to the fifth aspect of the present invention, the fluid torque acting on the throttle valve due to the intake fluid in the valve opening direction is less than the minimum opening of the throttle valve capable of continuous operation. When the motor, the ECU, and the like fail due to disconnection or the like and the motor cannot operate, the vehicle can run without, for example, a return spring for opening the valve.

According to the intake control valve device for an engine according to the sixth aspect of the present invention, the fluid torque acting on the throttle valve due to the intake fluid is opened when the throttle valve which can be continuously operated is less than the minimum opening (θ2). Acting in the valve direction, the valve opening direction fluid torque at the minimum opening degree (θ2) is Ta (θ2), and the maximum value of the detent torque when the motor is not energized is Td (ma).
x), when the maximum value of the blocking torque for blocking the rotation of the throttle shaft due to friction around the bearing is Tf (max),
Since the relationship of Ta (θ2)> (Td (max) + Tf (max)) is established, continuous operation can be reliably performed even when the motor cannot operate.

According to the intake control valve device for an engine according to the seventh aspect of the present invention, the fluid torque acting on the throttle valve due to the intake fluid is opened when the throttle valve which can be continuously operated has a minimum opening degree (θ2) or less. Acting in the valve direction, the valve opening direction fluid torque at the minimum opening degree (θ2) is Ta (θ2), and the maximum value of the detent torque when the motor is not energized is Td (ma).
x), the maximum value of the blocking torque for preventing rotation of the throttle shaft due to friction around the bearing is Tf (max), the minimum value of the motor torque is Tm (min), and the minimum opening (θ2)
Where Ts (θ2) is the valve opening torque of the return spring at the time of Ta (θ2)> Td (max) + Tf (max), Tm (min)
> Ta (θ2) + Ts (θ2) + Tf (max), so that even if the motor or the ECU breaks down due to disconnection or the like and the motor cannot operate, the engine continues to operate. In addition to the above, when the engine is stopped, the throttle valve is fully closed, so that the engine can be stopped without vibration.

According to the engine intake control valve device of the present invention, since the motor is a stepper motor directly connected to the throttle shaft, the detent torque can be reduced and the torque of the return spring can be reduced. It is possible to reduce the size, improve the opening / closing response of the throttle valve, and reduce the number of parts.

According to the intake control valve device for an engine according to the ninth aspect of the present invention, since this intake control valve device is applied to a diesel engine, it is small and lightweight and can be mounted on a vehicle and improved in vibration resistance. Thus, a diesel engine that is inexpensive and has improved control response can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an intake control valve device for a diesel engine according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is an explanatory diagram of fluid torque acting on the throttle valve according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of a fluid torque acting on a throttle valve according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a fluid torque acting on a throttle valve according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a main part of an intake control valve device for a diesel engine according to a fourth embodiment of the present invention.

FIG. 8 is a front view of a throttle valve according to a fifth embodiment of the present invention.

FIG. 9 is a front view of another throttle valve according to the fifth embodiment of the present invention.

FIG. 10 is a front view of still another throttle valve according to the fifth embodiment of the present invention.

FIG. 11 is a front view of a throttle valve according to a sixth embodiment of the present invention.

FIG. 12 is a front view of another throttle valve according to the sixth embodiment of the present invention.

FIG. 13 is a front view of still another throttle valve according to the sixth embodiment of the present invention.

FIG. 14 is a front view of a throttle valve according to a seventh embodiment of the present invention.

FIG. 15 is a sectional view taken along the line EE in FIG. 14;

FIG. 16 is a sectional view of a main part of a conventional intake control valve device for a diesel engine.

FIG. 17 is an explanatory diagram of fluid torque acting on the throttle valve of FIG.

FIG. 18 is a cross-sectional view of a main part of a conventional intake control valve device for a diesel engine in which a throttle valve rotates in a reverse direction.

FIG. 19 is an explanatory diagram of fluid torque acting on the throttle valve of FIG.

FIG. 20 is a cross-sectional view of a main part of a conventional intake control valve device for a diesel engine having a different shape of an intake passage.

[Explanation of symbols]

1 housing, 2 intake passage, 3 throttle shaft,
4,44 Throttle valve, 8 Return spring, 9
Stepper motor, 14 protrusions (positioning portion), (a) first fluid receiving portion, (b) second fluid receiving portion, (c) center line.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) F02D 41/20 360 F02D 41/20 360 (72) Inventor Takeshi Sugiyama 2-3-2 Marunouchi, Chiyoda-ku, Tokyo No. Mitsubishi Electric Corporation F-term (reference) 3G065 AA01 CA00 DA05 DA06 GA41 HA09 HA21 HA22 KA02 KA12 3G301 HA02 JA00 LA01 LC04 PA11Z

Claims (9)

[Claims] 1. A housing having an intake passage through which an intake fluid flows, a throttle shaft rotatably supported by a bearing in the housing, and a throttle shaft fixed to the throttle shaft to open and close the intake passage. A throttle valve that opens and closes the throttle valve by rotating the throttle shaft, and a throttle spring that urges the throttle valve in a valve opening or closing direction. And a first fluid receiving portion and a second fluid receiving portion against which the intake fluid collides with a boundary line, and the suction of the first fluid receiving portion and the second fluid receiving portion is performed. By making the collision areas of the fluids different, the fluid torques acting on the first fluid receiving portion and the second fluid receiving portion are adjusted. Intake control valve unit of engine. 2. The intake control valve device for an engine according to claim 1, wherein the throttle valve is fixed to a throttle shaft at a position deviated from a center line extending in a radial direction. 3. The intake air for an engine according to claim 1, wherein the throttle valve is fixed to a center line extending in a radial direction, and the first fluid receiving portion and the second fluid receiving portion have different areas. Control valve device. 4. The intake control valve device for an engine according to claim 1, wherein a positioning portion for the throttle shaft is provided on the throttle valve. 5. The fluid valve according to claim 1, wherein the fluid torque acting on the throttle valve by the intake fluid acts in the valve opening direction when the throttle valve is at or below the minimum opening of the throttle valve capable of continuous operation. An intake control valve device for an engine according to any of claims 1 to 3. 6. When the throttle valve is at or below the minimum opening (θ2) of the throttle valve capable of continuous operation, the fluid torque acting on the throttle valve by the intake fluid acts in the valve opening direction, and the minimum opening of the throttle valve.
The fluid torque in the valve-opening direction at (θ2) is Ta (θ2), the maximum value of the detent torque when the motor is not energized is Td (max), and the maximum blocking torque that prevents rotation of the throttle shaft due to friction around the bearings. When the value is Tf (max), Ta (θ
The engine intake control valve device according to any one of claims 1 to 4, wherein a relationship of (2)> (Td (max) + Tf (max)) is satisfied. 7. When the throttle valve is at or below the minimum opening (θ2) of the throttle valve capable of continuous operation, the fluid torque acting on the throttle valve by the intake fluid acts in the valve opening direction, and the minimum opening thereof.
The fluid torque in the valve-opening direction at (θ2) is Ta (θ2), the maximum value of the detent torque when the motor is not energized is Td (max), and the maximum blocking torque that prevents rotation of the throttle shaft due to friction around the bearings. When the value is Tf (max), the minimum value of the motor torque is Tm (min), and the valve opening torque of the return spring at the minimum opening (θ2) is Ts (θ2),
Ta (θ2)> Td (max) + Tf (max), Tm (min)> Ta
5. The intake control valve device for an engine according to claim 1, wherein a relationship of (θ2) + Ts (θ2) + Tf (max) is established. 8. The intake control valve device for an engine according to claim 1, wherein the motor is a stepper motor directly connected to a throttle shaft. 9. The intake control valve device for an engine according to claim 1, wherein the engine is a diesel engine.