JP3435705B2 - Electromagnetic drive valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetically driven valve which is opened and closed by using electromagnetic force.

[0002]

2. Description of the Related Art Conventionally, an intake / exhaust valve arranged in a cylinder is opened and closed by a camshaft, a rocker arm, or the like that operates in response to the rotation of a crankshaft. Is narrow. for that reason,
Various electromagnetically driven valves have been developed that are opened and closed by using electromagnetic force. An example of this type of electromagnetically driven valve is disclosed in Japanese Patent Application Laid-Open No. 2-123210. This is a valve control device that uses a permanent magnet and an electromagnet to attract a magnetic pole attached to a valve stem to open and close the valve.

[0003]

In the valve control device disclosed in the above publication, the magnetic pole is attracted by the attraction force of the electromagnet when the valve is opened, but the electromagnet has a narrow range in which a practical attraction force can be obtained. There is a drawback that a large current is required to increase the working distance. In addition, there is a problem in that an effect of energy saving such as power regeneration or power generation cannot be obtained by simply attracting the magnetic pole. The present invention has been made in view of the above problems, and an object of the present invention is to provide an electromagnetically driven valve that increases a working distance and also regenerates electric power by using a two-stage moving coil. To provide.

[0004]

In order to achieve the above object, according to the present invention, an electromagnetic force generated by energizing a movable coil arranged in a magnetic field drives a valve stem having a valve portion below in a vertical direction. The electromagnetically driven valve has two upper and lower moving coils, and when the valve is opened and closed, the valve is thrust by sequentially energizing one moving coil to start energizing the other moving coil. Then, the braking force is applied to the valve by regenerating the moving coil which is finally energized. Alternatively, regeneration may be performed by the moving coil that is first energized.

[0005]

[Operation] A long stroke can be obtained because the movable coils are arranged in two stages, upper and lower, and the driving ranges are shared. Also, when the electromagnetically driven valve reaches a predetermined speed,
At the end of the stroke, the movable coil is made to generate electric power to regenerate electric power, which is used as the braking force of the electromagnetically driven valve.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a vertical sectional view of an embodiment of an electromagnetically driven valve according to the present invention. In FIG. 1, reference numeral 1 denotes an electromagnetically driven valve, which is a valve stem 1 made of a non-magnetic material.
The valve guide 12 is vertically reciprocally supported by a valve guide 12, and when the valve is closed, a valve portion 13 is in close contact with an intake / exhaust port to close the flow path. A non-magnetic cylindrical thick rod 14 is arranged at a predetermined portion in the middle of the valve stem 11, and a magnetic disk 15 having the same diameter as the thick rod 14 is adhered to the bottom thereof.

Reference numeral 2 denotes an upper magnetic field portion, and a casing 21 of the upper magnetic field portion 2 has a pair of annular permanent magnets 2 vertically arranged at a predetermined interval.
2 and 23 are stored. Between both magnets, a donut-shaped moving coil 2 wound corresponding to these magnet shapes
4 is arranged, and an inner ring 25 is fitted in the inner diameter portion of the movable coil 24. The permanent magnets 22 and 23 are similarly magnetized in the thickness direction as shown in the drawing, and the magnetic fluxes are linked in the height direction of the movable coil 24. Therefore, when the movable coil 24 is energized, the movable coil 24
Moves in the vertical direction, and when lowered, the lower surface of the inner ring 25 pushes down the upper surface of the thick rod 14 of the electromagnetically driven valve 1 and drives the valve in the valve opening direction.

Reference numeral 3 denotes a lower magnetic field portion, and a casing 31 thereof is attached below the upper magnetic field portion 2 and houses a pair of annular permanent magnets 32 and 33. Between both magnets,
A donut-shaped moving coil 3 also having an inner ring 35
4 is arranged so as to be vertically movable. Permanent magnet 3
Since the magnetizations of Nos. 2 and 33 are the same as those of the magnets in the above-mentioned upper field magnet unit 2, the movable coil 34 when energized moves in the vertical direction. When moving upward, the thick rod 14 of the electromagnetically driven valve 1 in the valve open position is pushed upward by the inner ring 35 to close the valve.

Reference numeral 16 denotes a spring, which holds the closed position of the electromagnetically driven valve 1 by its elastic force. The magnetic disk 15 is attracted to the movable coil 34 when the valve is opened,
Hold its position. Reference numeral 4 denotes a displacement sensor attached above the upper magnetic field portion 2. For example, a position sensor or a velocity signal is detected by a controller, which will be described later, by detecting the position or moving speed of a marker or the like attached to the valve stem 11. Is sent.

FIG. 2 is a block diagram of a drive circuit for an electromagnetically driven valve in this embodiment. In FIG. 2, reference numeral 51 is a power source for converting AC power into DC power, and 52 is an upper coil driver for supplying power to the movable coil 24 of the upper magnetic field portion 2 or for supplying regenerative power of the movable coil 24 to the capacitor C. It is a guide. Reference numeral 53 is a lower coil driver, and the lower field magnet portion 3
Power is supplied to the movable coil 34 and the regenerated power is guided to the capacitor C ′.

Reference numeral 5 is a controller which is a moving coil control means, and is provided with, for example, a differentiator 5a, a controller 5b, a current controller 5c and the like. Then, when the position signal or the velocity signal from the displacement sensor 4 is input, predetermined calculation or processing is performed, and the control signal is sent to the upper coil driver 52 and the lower coil driver 53 based on the control map. . Then, the movable coil 24 and the movable coil 34 are configured to control energization and electric power regeneration to lift the electromagnetically driven valve 1.

Next, the operation of this embodiment thus constructed will be described. When the electromagnetically driven valve 1 is in the closed state and is about to be opened, the upper coil driver 52 is instructed to pass the current so that the magnetic flux generated in the movable coil 24 is in a direction to repel the permanent magnet 22. Moving coil 24
Moves down, pushes down the thick rod 14, and the drive of the electromagnetically driven valve 1 is started. Then, if it is known from the signal from the displacement sensor 4 that the descending speed of the valve stem 11 has reached a predetermined value, the power supply to the movable coil 24 is cut off. However, since the moving coil 24 continues to descend due to inertia and generates an electromotive force, the moving coil 24 is braked by regenerating the electromotive force to the power supply side.

The thick rod 14 of the electromagnetically driven valve 1 eventually reaches the movable coil 34 of the lower magnetic field portion 3. At that time, the movable coil 34 is energized to lower the disc 15 while attracting the disc 15. When the descending speed reaches a predetermined value, the lower coil driver 53 is instructed to regenerate the electromotive force of the movable coil 34 to the power supply side to provide a braking force, and the electromagnetically driven valve 1 reaches the target lift amount. Then, at the valve opening position of the electromagnetically driven valve 1, the movable coil 34 is energized to attract the disk 15 at the lower end of the thick rod 14 and hold the valve open state as shown in FIG.

Next, in order to drive the electromagnetically driven valve 1 from the valve open position to the valve closed state, the upper and lower movable coils 24 and 34 and the magnets of the upper field magnet portion 2 and the lower field magnet portion 3 in the above-described operation. It is only necessary to read the upper and lower parts of the above and operate according to the above. Note that the spring 1 is used to maintain the closed valve position.
The elastic force of 6 is used. FIG. 3 shows the valve lift amount when the valve is opened and closed, the movable coil 24, and
It is a curve diagram showing the timing of the current of 34. The current in the negative direction in FIG. 3 indicates the regenerative current. FIG. 5 is a process flow chart showing an example of the operation of this embodiment.

[0015]

As described above, according to the present invention, when the electromagnetically driven valve is driven, the movable coils having short strokes are arranged in the upper and lower two stages, and the energization is performed only for a short time of the initial operation and a short time in the middle. In addition to applying the driving thrust, when the speed of the electromagnetically driven valve reached a predetermined value or at the end of the stroke, the electromotive force of the moving coil that moved in the magnetic field was regenerated as the braking force. Therefore, a long stroke can be obtained by the two-stage movable coil, and an effect that power consumption can be saved by regenerative operation of electric power can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment of an electromagnetically driven valve according to the present invention.

FIG. 2 is a block diagram of a drive circuit for an electromagnetically driven valve according to the present embodiment.

FIG. 3 is a curve diagram showing a valve lift amount and a moving coil current timing during valve opening and closing operations in the present embodiment.

FIG. 4 is a vertical sectional view when the valve is opened.

FIG. 5 is a process flow chart showing an example of the operation of the present embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic drive valve, 2 ... Upper field part, 3 ... Lower field part, 5
... Controller, 14 ... Thick rod, 22, 23 ... Permanent magnet,
24 ... Moving coil, 32, 33 ... Permanent magnet, 34 ... Moving coil

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F01L 9/04 F16K 31/06 385

Claims (2)

(57) [Claims] 1. An electromagnetically driven valve for vertically driving a valve stem having a valve portion downward by an electromagnetic force generated by energizing a movable coil arranged in a magnetic field, the valve having two upper and lower movable coils. When opening and closing the valve, apply a thrust to the valve by sequentially energizing the moving coil so that the energizing of the other moving coil is started after the energization of one moving coil is completed, and then regenerate with the moving coil that is energized last. An electromagnetically driven valve characterized by applying a braking force to the valve. 2. The electromagnetically driven valve according to claim 1, wherein braking is performed by regenerating with a movable coil which is first energized.