JPH0392516A - Movable magnetic pole of solenoid valve - Google Patents

Abstract

PURPOSE:To reduce the weight of a movable magnetic pole and improve responsiveness of intake/discharge valves by providing projection magnetic poles composed of magnetic material which has a sectional area corresponding to that of a passage member, in the case that the intake/discharge valves are opened or closed by means of solenoid force of an electromagnet. CONSTITUTION:A movable magnetic pole of a solenoid valve is made up of a passage 2 for magnetism of magnetic line of force which has an insert hole 20 at the center thereof, first and second movable magnetic poles 21 and 22 composed of a plate-like magnetic body having even thickness and projected on the magnetic passage 2 in a radial direction. The magnetic passage 2 is actuated as the passage of the magnetic line of force applied to an outer peripheral part of a valve shaft by inserting the valve shaft into the inserting hole 20. In addition, ring-like projection magnetic poles are formed on the respective movable magnetic poles 21, 22. Non-magnetic reinforcing members, such as aluminum members 25, 26 are provided between the movable magnetic poles 21 and 22, and between the magnetic bodies which compose the movable magnetic poles 21, 22, so that the shape of the first movable magnetic pole is kept.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a movable magnetic pole of an electromagnetic valve used in a valve drive device that opens and closes intake and exhaust valves of an engine using electromagnetic force generated by an electromagnet.

(Prior Art) As a conventional intake/exhaust valve opening/closing drive device, a camshaft, in which intake and exhaust cams are arranged on a single wooden shaft, is disposed on the top or side of the engine. The camshaft is connected to the crankshaft, which is the rotating shaft of the engine, by a rotation transmission means such as a belt, and the camshaft is rotationally driven in synchronization with the rotational phase of the engine. The cam surface of the camshaft pushes the shaft end surface of the valve via a link mechanism such as a rocker arm or a bushing rod. The intake and exhaust valves are always held closed by springs, and are opened by pushing the end face of the valve shaft.

Alternatively, an intake camshaft with an intake cam and an exhaust camshaft with an exhaust cam are installed at the top of the engine, and the cam surface of the intake camshaft connects the shaft end of the intake valve, and then the exhaust camshaft. The intake and exhaust valves are opened by directly pushing the shaft end of the exhaust valve with the cam surface.

(Problem to be Solved by the Invention) Instead of the conventional valve drive using a camshaft, a system has been developed in which the opening and closing of the intake and exhaust valves of the engine are driven by electromagnetic force using electromagnets. . In this type of electromagnetic drive device, a movable magnetic pole is formed at the end of the valve shaft, and an electromagnetic force is applied between it and surrounding fixed magnetic poles based on the principle of a linear pulse motor. In this case, in order to drive the electromagnetic valve with high efficiency and high output, it is necessary to construct the valve and its shaft with ceramics, and to convert the lines of magnetic force acting on the valve into maximum effective force. However, the movable magnetic pole of such an electromagnetic valve is formed as a ring-shaped protruding magnetic pole on the outer periphery of the valve shaft.
It was constructed of homogeneous magnetically permeable material. In other words, the cross-sectional area of the magnetic field lines is small at the inner periphery of the ring, and increases toward the outer periphery.For this reason, the magnetic flux density of the protruding magnetic pole that effectively interacts with the fixed magnetic pole is small at the outer periphery in the radial direction of the shaft. Therefore, there was a problem in that the weight of the magnetic material constituting the protruding magnetic pole could not be sufficiently reduced to match the lines of magnetic force passing through it. The present invention was made to solve the above problems, and
The protrusion 1i is formed by a magnetic material with a cross-sectional area commensurate with the cross-sectional area of the passage member! 18l! The purpose of this invention is to provide a lightweight movable magnetic pole for an electromagnetic valve.

(Means for Solving the Problems) According to the present invention, the valve shaft is provided on the valve shaft of the intake and exhaust valve of the engine, and a magnetic field path is formed in a stepped manner by the action of magnetic force, thereby controlling the reciprocating motion of the pulp shaft. In the movable magnetic pole of the electromagnetic valve, there is a passage member for the lines of magnetic force formed on the outer periphery of the valve shaft, and a plurality of plate-like plates of the same thickness connected to the passage member at the end of the valve shaft and protruding in the radial direction thereof. It is possible to provide a movable magnetic pole for an electromagnetic valve, which is composed of a magnetic material and a reinforcing member made of a non-magnetic material that is lighter than these magnetic materials and fills the space between them.

(Function) In the movable magnetic pole of the electromagnetic valve of the present invention, a plurality of protruding magnetic poles connected to the passage member for magnetic lines of force on the end side of the valve shaft are formed of a plurality of plate-shaped magnetic bodies having the same thickness and protruding in the radial direction of the valve shaft. By filling the gap between these magnetic materials with a lighter non-magnetic material, the weight of the part that reciprocates together with the valve is reduced in proportion to the lines of magnetic force that pass through it.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view showing the overall structure of the movable magnetic pole of the 1t magnetic valve of the present invention.

This possible B iff & is a magnetic passage body 2 for the lines of magnetic force, in which an insertion hole 20 for a valve shaft, which will be described later, is formed in the center.
A plurality of first flexible wJ magnetic poles 21 are provided protruding in the radial direction of the magnetic passage body 2 and are made of a plate-shaped magnetic body having the same thickness.
, a second movable magnetic pole 22.

By inserting the pulp shaft tia portion on the opposite side from the umbrella portion of the intake and exhaust pulp of the engine into the insertion hole 20, the magnetic passage body 2 becomes a passage for the lines of magnetic force acting on the outer peripheral portion of the pulp shaft, and the above-mentioned The first movable magnetic pole 21 and the second movable magnetic pole 8i22 are connected to the outer circumferential surface of the magnetic passage body 2 at the end of the valve shaft, respectively, and constitute a ring-shaped protruding magnetic pole.

Note that the area of the first movable magnetic pole 21 and the second movable magnetic pole 22 connected to the magnetic passage body 2 is the same as that of the magnetic passage body 2.
The passage capacity of the magnetic lines of force of the ring-shaped protruding magnetic pole is made equal to the passage capacity of the magnetic passage body 2. Electromagnetic force acts on the first movable magnetic pole 21 and the second movable magnetic pole 22 with a predetermined gap between them and the fixed magnetic pole described later.

Next, the cross-sectional shape of the first flexible wJ magnetic pole 21 will be explained. Note that the cross-sectional shape of the second movable magnetic pole 22 is similar to that of the first movable magnetic pole 21.
Since the cross-sectional shape is the same as that of , the explanation will be omitted.

FIG. 2 is a partial sectional view of the first movable magnetic pole 21. FIG.

Between the 1i [11iii pole 21 and the 2nd flexible 8 magnetic pole 22,
In the gaps between the plurality of plate-shaped magnetic bodies constituting both movable magnetic poles, for example, aluminum 25, which is lighter than the plate-shaped magnetic bodies, is interposed. ill6fl pole 2
1 is formed to have a predetermined length in its movable direction (vertical direction in the figure). This aluminum 25 is integrated through a casting hole 26 drilled in the center of the plate-shaped magnetic material constituting the first movable magnetic pole 21 and the second movable magnetic pole 22, and is integrated with the ring-shaped first It acts as a reinforcing member that maintains the shape of the flexible J magnetic pole 21.

FIG. 3 is a block diagram showing a drive device having a movable magnetic pole according to the present invention. In addition, the following explanation applies to the intake and exhaust valves.
This will be explained using an intake valve as an example. In addition, the first wJ magnetic pole 21
In order to clarify the second movable magnet Vi122, the description of the aluminum 25 is omitted.

Reference numeral 1 denotes an intake valve made of a lightweight, high-strength material such as ceramics, and the shaft portion of the intake valve 1 is connected to a valve guide 1.
1 and is freely supported in the axial direction. Further, the magnetic passage body 2 made of a magnetic material is fitted into the shaft end of the intake valve 1. The first movable magnet f! is located at the axial end of the magnetic passage body 2. 21 and S2 movable magnetic poles 22 are provided around the periphery. Then, the first coil 23 is placed in a position surrounding the first movable magnetic pole 21 when the intake valve 1 is in the closed state.
is installed. In addition, a spring 24 is provided to prevent the intake valve 1 from falling when the engine is stopped.
It is provided between the valve guide 11 and the magnetic passage body 2.

An upper fixed magnetic pole 31 facing the upper end surface of the first movable magnet 8i21 and a second coil 32 wound around the upper fixed magnetic pole 31 are disposed above the magnetic passage body 2. The yoke member of the upper fixed magnet 8i31 extends along the side surface of the magnetic path body 2 to the lower end of the side surface of the magnetic path body 2, and forms a lower magnetic pole 33 facing the lower end of the side surface. The lower magnetic pole 33 is provided with a lower coil 34 surrounding the magnetic passage body 2 . Also, from the upper fixed magnetic pole 31 to the lower magnetic pole 3
3, the first movable magnetic pole 2 is moved while the magnetic path body 2 is moving.
An intermediate 6ii pole 41 facing the first and second movable magnetic poles 22.
42 and 43 protrude, and each intermediate magnetic pole 41, 42, and 4
3C has coils 44, 45, and 46 wound thereon.

The lower coil 34 is connected to the power supply device 4, and is constantly energized in a direction that generates an upward magnetic flux in the magnetic path body 2. Further, the first coil 23, the second coil 32, and the coils 44, 45, and 46 are also connected to the power supply device 4, and power is supplied to each of them.

The power supply device 4 is connected to an input/output interface 54 of the control unit 5, and is opened/closed by a signal from the input/output interface 54. The control unit 5 includes an input/output interface 54 as well as a ROM 52 that stores programs and various relationship maps in advance.
, a CPU 51 that performs calculations based on the program stored in the ROM 52, and a CPU 51 that temporarily stores calculation results and data.
It is composed of an AM 53, a control memory 55 that controls the flow of signals within the control unit, and the like. In addition to the power supply device 4, the human output interface 54 also includes the engine speed and crank angle θ.
A rotation sensor 6 is connected to detect the rotation.

Next, the operation of the intake valve drive device according to the present invention will be explained.

The lower coil 34 is normally supplied with electricity from the power supply device 4 in a direction that generates magnetic flux upward in the figure with respect to the magnetic passage body 2, and the magnetic flux is transmitted from the upper end surface of the magnetic passage body 2 to the lower part through the upper fixing 6flti31. A closed circuit is formed from the magnetic pole 33 to the side surface of the magnetic passage body 2 again, and the suction is caused by the attractive force acting between the N pole appearing on the upper end surface of the magnetic passage body 2 and the S pole appearing on the upper fixed magnetic pole 31. Valve 1 remains closed.

When the crank angle θ detected by the rotation sensor 6 reaches a preset opening timing for the intake valve 1, a signal is output from the input/output interface 54 to the power supply device 4,
Power is supplied to the second coil 32 in the direction in which downward magnetic flux in the figure is generated in the upper fixed magnet 8i31.

Similarly, current is supplied to the first coil 23 in a direction that causes the magnetic path body 2 to generate an upward magnetic flux. An upward magnetic flux is already generated in the magnetic passage body 2 by the lower coil 34, and a magnetic flux with a high density is generated in the magnetic passage body 2.

As mentioned above, since the directions of the magnetic flux generated in the upper fixed magnet 8i31 and the magnetic path body 2 are opposite directions, a strong repulsive force acts between the upper end surface of the magnetic path body 2 and the upper fixed magnetic pole 31. The magnetic passage body 2 and the intake valve 1 rapidly move downward, that is, in the opening direction.

By the way, the coils 44, 45, and 46 are supplied with pulsed currents having mutually different phases from the power supply 4h according to a command from the control unit 5, and the magnetic pole 41
- The magnetic flux from 42 and 43 forms an upward traveling magnetic field.

The first movable magnetic pole 21 and the second movable magnetic pole 22 are made of Ni.
If so, immediately after the valve is opened, the magnetic pole 8i41 becomes the south pole to promote the valve opening operation, and then the magnetic pole 42 becomes the south pole to sequentially move the intake valve 1 in the opening direction. After opening, the intake valve 1 is moved upward, that is, in the closing direction, after reaching the maximum lift point by performing the reverse operation of the opening operation described above.

Next, just before the intake valve 1 is seated, a strong repulsive force is applied again between the upper end surface of the magnetic passage body 2 and the upper fixed magnetic pole 31 in the same manner as described above, thereby increasing the closing direction speed of the intake valve 1. is decelerated, and the impact when the intake valve 1 is seated is alleviated. After seating, the repulsive force is extinguished, and the magnetic flux generated by the lower coil 34 holds the intake pulp 1 in a closed state until the tying for the next time.

By the way, at the end of engine operation, the power supply to the lower coil 34 disappears, and the M. Since the magnetic force disappears, the intake valve 1 is held closed by the spring 24. The holding force of the spring 1 is set to be sufficiently small with respect to the driving force in the opening direction generated by the driving device according to the present invention.

In this way, the weight of the movable magnetic pole is reduced commensurate with the magnetic flux passing through it, so that the amount of electric power required to generate the magnetic flux required for driving can be reduced, and the responsiveness of operation can be improved.

In addition to aluminum, it is also possible to use hard plastic as the reinforcing member, and a map of the relationship between engine speed and intervalve timing is stored in advance in the ROM 52, so that changes in engine speed can be monitored. By changing the valve opening timing accordingly, the output and efficiency of the engine can be improved over the entire engine speed range. It is also possible to perform cylinder control to increase or decrease the number of operating cylinders by increasing or decreasing the engine speed (accordingly, by driving or stopping the intake valve for each cylinder).

Although one embodiment of the present invention has been described above, mainly regarding an intake valve, it is obvious that the drive device according to the present invention can be similarly applied to an exhaust valve. Since embodiments may be readily constructed, the invention is not limited to specific embodiments, other than the limitations set forth in the appended claims.

(Effects of the Invention) As explained above, the movable magnetic pole of the present invention can cut the passage member when the opening and closing of the intake and exhaust valves of the engine is driven by the electromagnetic force of the electromagnet instead of the camshaft. Since it has a protruding magnetic pole made of a magnetic material with a cross-sectional area commensurate with the area k, if the intake and exhaust valves themselves are made of lightweight and high-strength ceramic material, they can be opened and closed with minute electromagnetic force, resulting in highly efficient and It is possible to provide an electromagnetic force valve drive device with good responsiveness.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an example of the entire configuration of a moving magnetic pole of an electromagnetic valve according to the present invention, FIG. 2 is a partial cross-sectional view thereof, and FIG. 3 is a valve drive having a movable magnetic pole according to the present invention. FIG. 2 is a block diagram showing the device. DESCRIPTION OF SYMBOLS 1... Intake valve, 2... Magnetic passage body, 4... Power supply device, 5... Control unit, 6... Rotation sensor, 21... First movable magnetic pole, 22... No. 2 movable magnetic pole, 23...first coil, 25...aluminum, 32...second coil.

Claims (3)

[Claims] (1) At the movable magnetic pole of an electromagnetic valve that is provided on the valve shaft of an intake and exhaust valve of an engine, a magnetic field path is formed in a stepped manner by the action of magnetic force, and the reciprocating motion of the valve shaft is controlled. A channel member for magnetic lines of force formed in the section, a plurality of plate-shaped magnetic bodies of the same thickness connected to the channel member at the end of the valve shaft and protruding in the radial direction, and a plurality of plate-shaped magnetic bodies that are lighter than these magnetic bodies. A movable magnetic pole of an electromagnetic valve, comprising a reinforcing member made of a non-magnetic material and filling the gap between the magnetic poles. (2) The movable magnetic pole of an electromagnetic valve according to claim (1), wherein the reinforcing member is made of aluminum. (3) The movable magnetic pole of the electromagnetic valve according to claim (1), wherein the reinforcing member is made of hard plastic.