JP2538194Y2 - Variable air duct - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake duct of an engine having a variable sectional area.

[0002]

2. Description of the Related Art An intake air duct of an engine, that is, an inlet pipe of an air cleaner or an outside air introduction pipe connected to the air duct secures a passage cross-sectional area in accordance with an amount of intake air, and on the other hand, a useless wide passage cross-sectional area. High noise emissions must be avoided.
Therefore, there is a configuration in which the passage cross-sectional area is reduced when the intake air amount is small. For example, Japanese Unexamined Utility Model Publication No. 59-27146 discloses an air cleaner in which an inlet pipe is divided into two in the axial direction, and a plate-like opening / closing valve is provided on one of the two to open only in a high flow rate region of intake air. It has been disclosed. Japanese Utility Model Laid-Open Publication No. 55-149553 discloses an air cleaner in which a valve plate is provided in an inlet pipe to reduce the cross-sectional area of an air inflow passage. As is known in these examples, such conventional valve devices are:
The plate valve which rotates in opposition to the intake air is driven by a negative pressure motor.

[0003]

The valve device provided in the above air duct has the following problems. a. Since the plate valve is structured to rotate in opposition to the flow of the inflow air, the plate valve is pushed by the inflow air and the wobble flow rate becomes unstable. b. Since the operation is performed by changing the negative pressure, the opening / closing operation is unclear, and it is difficult to stabilize the operation in the completely closed position. c. Since the level of the negative pressure serving as the driving source is based on the suction pipe negative pressure, it does not always have a proportional relationship with the rotational speed, and it is difficult to obtain an accurate opening / closing operation of the valve according to the intake air amount. d. Since the valve is driven by transmission of a negative pressure, delay in opening and closing occurs, resulting in poor responsiveness. e. Installation and maintenance are troublesome because a space for piping the pipe for negative pressure guidance is required, and the piping must be kept airtight.

[0004]

The variable air duct of the present invention is divided into two suction passages by providing a partition wall in the axial direction, and one of the suction passages is provided with a valve element that closes in a direction transverse to the suction passages. By providing the valve body with magnetism and fixing an electromagnet in the vicinity of the valve body, control means for changing the polarity of the electromagnet according to the engine speed, by changing the polarity of the electromagnet to attract or repel the valve body This opens and closes the shutoff valve.

[0005]

In the variable air duct of the present invention, the shutoff valve is set to the closed position, and when the engine speed exceeds a predetermined value, the polarity is changed and the valve is set to the open position. Since the amount of intake air is proportional to the engine speed, opening and closing the shut-off valve accurately corresponds to the amount of intake air, ensuring a wide passage cross-sectional area corresponding to the amount of intake air at high rotations, and reducing the amount of intake air at low rotations. When the number is small, the cross-sectional area of the passage is narrowed to prevent the noise from being largely dissipated from an unnecessary wide opening. In the low rotation speed region, the noise is on the low frequency side, but the reduction in the passage cross-sectional area shifts the silencing action to the low frequency side, and is adapted to the generated noise.

[0006] The switching of the passage cross-sectional area is performed quickly and accurately because the magnetic force is attracted or repelled, and the valve body slides in the transverse direction, so that the flow of the intake air does not fluctuate.

[0007]

1 and 2 show an embodiment. The air duct 1 is an inlet pipe made of a synthetic resin and attached to the air cleaner main body 2 for an internal combustion engine. The air duct 1 is provided with a cut wall 3 in the axial direction to form the suction passages 4 and 5. A bulging portion 6 is provided on the pipe wall of the air duct 1, and the inside of the bulging portion 6 communicates with the suction passage 4 in a door pocket shape, and the valve body 8 of the shutoff valve 7 is stored. The valve body 8 is made of a steel plate and forms a permanent magnet, and synthetic rubber cushion members 9a and 9b are attached to the front and rear edges of the valve body. A slide bar 10 traversing the suction passage 4 and reaching the inside of the bulging portion 6 is provided, and the valve body 8 advances and retreats from the inside of the bulging portion 6 slidably along the slide bar, and closes the suction passage 4.
Open. An electromagnet 11 is attached to the outer surface of the bulging portion 6 in the vicinity of the retreat position of the valve 8, and the coil 12 is connected to the control means 13. The control means 13 switches the current direction of the coil 12 according to the signal input of the engine speed sensor 14 and
To change the polarity.

Based on the signal of the rotation speed sensor 14, if the rotation speed is equal to or higher than a specific rotation speed, the control means 13 causes the electromagnet 11 to have N and S poles as shown in FIGS. 8. Aspirate 8. If the rotation speed is lower than the specific rotation speed,
Reverse the polarity. Therefore, the valve body 8 repels and is pushed out along the slide bar 10 to close the suction passage 5. In this manner, the suction passages 4 and 5 are opened in the high rotation range to secure the amount of air required for high rotation, and the suction passage 5 is closed in the low rotation range to emit more noise to unnecessary openings. prevent.

FIGS. 3 and 4 show another embodiment. The air duct 21 is made of a synthetic resin and is for intake air of an internal combustion engine. An air duct 21 is provided with a partition wall 23 in the axial direction to form suction passages 24 and 25. A bulging portion 26 is provided on the pipe wall of the air duct 21, and the inside thereof communicates with the suction passage 24 in a door pocket shape, and the valve body 28 of the shutoff valve 27 is stored. Valve body 28
Is a rod-shaped permanent magnet 28 attached to a synthetic resin plate-shaped valve member 28a.
b is fixed. A slide bar 30 traversing the suction passage 24 and reaching the inside of the bulging portion 26 is provided, and synthetic rubber cushion members 29a, 29
b is attached. The valve body 28 is slidably moved along the slide bar 30 to close the suction passage 24 at the advanced position, and is housed in the bulging portion 26 at the retracted position to open the suction passage 24. The permanent magnet 28b is provided on the retreating side edge of the valve body 28 in a direction perpendicular to the slide bar 30. Electromagnets 31 and 33 are fixed in parallel to the slide bar 30 and near one end and the other end of the permanent magnet 28b, respectively.
34 is provided with the winding direction changed. Coil 32, 34
Is connected to the control means 35, and an engine speed sensor 36 is connected to the control means 35.

The permanent magnet 28b of the valve body 28 has an N-pole and an S-pole specified as shown in FIG. The electromagnets 31, 3
Numeral 3 denotes an S pole and an N pole at one end on the retreat position side, respectively, as shown in FIG. 4, and sucks the valve body 28 to the retreat position.
When the current direction of the coils 32, 34 changes, the electromagnets 31, 3,
3, the permanent magnet 28b is repelled, the valve body 28 is pushed out along the slide bar 30, and the permanent magnet 28b is attracted to the forward pole at the other end of the electromagnets 31,33. For the change of the polarity, the control means 35 is set so that the valve body 28 is opened at a high rotational speed equal to or higher than a specific value and closed at a high rotational speed less than the specific value in accordance with a signal from the rotational speed sensor 36.

[0010]

The air duct of the present invention reduces the passage cross-sectional area of the air duct in the low rotation range where the amount of intake air is small and the noise is on the low frequency side, while preventing large noise from being emitted from unnecessary wide openings. The silencing effect is shifted to the lower frequency side to increase the silencing effect. This switching operation is extremely quick and accurate because of the attraction and repulsion of the magnetic force, and has excellent responsiveness. Further, a driving fluid conduit is not required, and the space and labor for piping are saved. Further, since the valve element blocks the air flow in the transverse direction, the air amount is not unstable due to the fluctuation of the valve due to the inflow pressure, and the reliability is high.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment.

2 is a view of the shut-off valve in the direction of the arrow in FIG.

FIG. 3 is a sectional view showing another embodiment.

4 is a view of the shut-off valve in the direction of the arrow in FIG. 3;

[Explanation of symbols]

 3, 23 partition wall 4, 5, 24, 25 suction passage 6, 26 bulging portion 7, 27 shut-off valve 8, 28 valve plate 11, 31, 33 electromagnet 13, 35 control circuit

Claims (1)

(57) [Scope of request for utility model registration] An axial partition wall is provided in an intake air duct of an engine to form a divided intake passage, and one intake passage is closed in a transverse direction with a magnetic valve element. A shut-off valve is provided, an electromagnet is fixed in the vicinity of the shut-off valve, and a control means for changing the polarity of the electromagnet in accordance with the engine speed is provided. A variable air duct designed to be used.