JP2697052B2 - Electromagnetic drive valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetically driven valve that controls opening and closing of intake and exhaust ports of an engine.

(Prior Art) A valve operating mechanism such as a camshaft is conventionally used for opening and closing an intake valve and an exhaust valve of a cylinder in an engine. However, instead of such a mechanical mechanism, an electric means such as a solenoid is used. Japanese Patent Application Laid-Open No. 58-183805 discloses a proposal for operating a valve.

When the valve is opened and closed by the electric means as described above, the impact at the time of seating is large, causing problems in noise, durability, and the like. Therefore, the valve of an engine that controls the impact by applying an applied pulse immediately before the valve is seated. The control device is
It is proposed in 61-76713.

(Problems to be Solved by the Invention) In the above-described proposal of the valve control device for the engine,
Since the mass of the valve and the movable part of the valve operating mechanism is heavy, control means for reducing the impact when the bubble is seated is required.If the movable part including the valve is lightweight, the above-mentioned control means is unnecessary. It is what becomes.

The present invention has been made in view of the above, and an object of the present invention is to provide an electromagnetically driven valve that solves the conventional problems by reducing the weight of a movable portion of an intake / exhaust valve and its valve operating mechanism. .

(Means for Solving the Problems) According to the present invention, there is provided a ceramic material intake / exhaust valve having a disk-shaped permanent magnet, which is covered with a thin protective member and is fitted in a diametrical direction, at a stem end portion, An electromagnet having magnetic poles corresponding to the magnetic pole positions of the permanent magnets for attracting / separating the permanent magnets and controlling valve operation of intake / exhaust valves, and energization control for controlling energization of the electromagnets based on a combustion cycle of the engine Means are provided.

(Function) A disk-shaped permanent magnet covered with a thin protective member is fixed to the stem end of a lightweight intake / exhaust valve made of a ceramic material, and has a magnetic pole corresponding to the magnetized magnetic pole position of the permanent magnet. Since the electromagnet of the deformed U-shaped core is energized to control the separation / attraction of the permanent magnet, the light intake / exhaust valve is light in weight, so the impact at the time of its seating is reduced, so that the opening / closing operation is smooth and the strength is brittle. The permanent magnet is protected by the protection member, thereby preventing a breakage accident.

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

FIG. 1 is a configuration block diagram showing one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an engine, which drives a vehicle with an engine output based on the combustion energy of fuel, and controls a fuel injection device 11 for controlling fuel supplied to the engine 1.
Is mounted with a load sensor 12 for measuring the fuel flow and detecting the engine load. 13 is a position sensor,
It detects the position of the piston performing reciprocating motion,
It generates a signal that is the basis for setting the timing of opening and closing the intake and exhaust valves in the combustion cycle of the engine. Reference numeral 14 denotes a rotation sensor, which is disposed on the output shaft of the engine 1 and detects the number of revolutions of the engine 1. Detection signals from these various sensors are sent to a controller described later.

Reference numeral 2 denotes an intake valve, which is made of a lightweight material made of a ceramic material, is slidably held in a vertical direction by a valve guide 31, and an umbrella portion 21 of the intake valve 2 comes into contact with / separates from a valve seat 32 provided on a cylinder. The air flow flowing from the intake passage 33 into the cylinder is controlled to be closed / open.

Reference numeral 22 denotes a valve seat provided on the stem end portion 23 of the intake valve 2, and in this embodiment, a magnetic material is employed because an electromagnetic valve mechanism is used. The details are shown in FIG. 2, and the valve seat 22 includes a hollow disk portion 221 and a cylindrical portion 222, and the hollow disk portion 221 uses a rare earth element inside, for example, using a samarium cobalt magnet as shown in the drawing. Has a permanent magnet 22A that is magnetized. Also permanent magnet 2
The outer wall of the hollow disk portion 221 covering the 2A and the cylindrical portion 222 are integrated using, for example, SUS (stainless steel) made of a titanium alloy or a nonmagnetic material to cover and protect the permanent magnet 22A that is brittle against impact force, The portion 222 is firmly fixed to the stem end portion 23 of the intake valve 2. Numeral 24 denotes a coil spring, which is mounted between the upper surface of the cylinder and the valve seat 22, and which is normally closed by its elastic force.

Reference numeral 4 denotes an electromagnet, which is composed of a core portion 41 and a coil portion 42, and separates or attracts the permanent magnet 22A of the valve seat 22 of the intake valve 2 according to a command from the controller 5,
The opening and closing of the intake valve 2 is controlled. The core portion 41 is formed by using a ferromagnetic material such as a silicon steel sheet laminated in a deformed U-shape so that the magnetic resistance is small, and when the valve seat 22 is attracted, the magnetic pole of the core portion 41 and the valve seat 22 are separated. The magnetic poles are arranged so as to be in close contact with each other without any gap, so that an efficient magnetic circuit can be obtained.

The controller 5 is composed of a microcomputer, and includes a central controller for performing arithmetic processing, various memories for storing arithmetic processing procedures and control procedures, input / output ports, and the like. , The process according to the stored procedure is performed, and the electromagnet 4 is operated so that the valve operation corresponding to the combustion cycle is performed.
Is energized. Reference numeral 6 denotes a battery that supplies power to the controller 5, the electromagnet 4, and the like.

The operation of the present embodiment configured as described above will be described below.

When each detection signal from the load sensor 12, the position sensor 13, and the rotation sensor 14 arranged in the engine 1 is input to the controller 5, predetermined memory contents are searched from various memories stored in the controller 5. The opening / closing timing of the valve operation corresponding to the input detection signal is read. Then, a control current corresponding to the opening / closing timing is supplied from the battery 6 to the coil portion 42 of the electromagnet 4 via the controller 5, and for example, the first
When the core 41 is magnetized to the polarity shown in the figure, the valve seat
22 is sucked, the intake valve 2 closes the intake passage 33, and when the core portion 41 is magnetized to the polarity opposite to the polarity shown in FIG. 1, the valve seat 22 presses the coil spring 23, and the intake valve 2 The valve opening operation is performed, and the valve opening / closing is repeated according to the combustion cycle of the engine.

In the above description, the present embodiment has been described with respect to the intake valve. However, it is needless to say that the exhaust valve can be applied according to the intake valve of the present embodiment only with different opening and closing timings.

As described above, the present invention has been described using the above-described embodiment, but various modifications are possible within the scope of the present invention, and these modifications are not excluded from the scope of the present invention.

(Effects of the Invention) According to the present invention, a strong permanent magnet covered with a thin protective member is fixed to the stem end of a lightweight intake / exhaust valve made of a ceramic material, and the magnet is positioned at the magnetized position of the permanent magnet. The energization timing of the electromagnet provided with the deformed U-shaped core having the corresponding magnetic poles is controlled in accordance with the combustion cycle of the engine, and the opening and closing of the intake and exhaust valves is performed by separating / attracting the permanent magnet. The impact at the time of seating of the valve is reduced in weight so that the opening and closing operation can be smoothly performed, and the permanent magnet is covered with a tough protective member, so that the permanent magnet is protected from damage.

In the present invention, the magnetic resistance of the corresponding permanent magnet is reduced by using a deformed U-shaped core material for the magnetic path of the electromagnet,
In addition, since the permanent magnet is made of a magnetic material containing a rare earth element with a large residual magnetic force, the magnetic attraction and repulsion of the corresponding magnetic poles can be obtained strongly during valve operation, resulting in quick responsive valve operation. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG.
The figure is an explanatory view showing details of the valve seat in the present embodiment. 1 ... engine, 2 ... intake valve, 4 ... electromagnet, 5
…… Controller, 12… Load sensor, 13… Position sensor, 14… Rotation sensor, 22 …… Valve seat, 23
…… Stem end, 41 …… Core part.

Claims (4)

(57) [Claims] An intake / exhaust valve made of a ceramic material, which has a disk-shaped permanent magnet covered by a thin protective member and magnetized in a diameter direction at a stem end portion, and a magnetic pole corresponding to a magnetic pole position of the permanent magnet. An electromagnet provided to control the valve operation of the intake / exhaust valve by attracting / separating the permanent magnet and energization control means for controlling energization of the electromagnet based on a combustion cycle of the engine. Drive valve. 2. The electromagnetically driven valve according to claim 1, wherein an oxide permanent magnet containing a rare earth element and having a remanence is used for said permanent magnet. 3. An electromagnetically driven valve according to claim 1, wherein said electromagnet has a core portion formed in a deformed U-shape and having a small magnetic resistance. 4. The electromagnetically driven valve according to claim 1, wherein said protection member is made of a titanium alloy or a non-magnetic stainless steel.