JP2002115515A - Actuator for solenoid driving valve and valve system of internal combustion engine and electromagnetically driving method of valve element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate mounting on a vehicle, and reduce weight and a cost by making the constitution of an actuator for a solenoid driving valve compact. SOLUTION: Two movable pieces 65 and 67 are arranged to a single electromagnet 63. The electromagnet 63 can form a magnetic pole in upper and lower both end surfaces by winding a coil in the illustrated vertical direction on a core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for an electromagnetically driven valve, a valve gear for an internal combustion engine, and a method for electromagnetically driving a valve body. The present invention relates to a technology capable of mounting the device even in a narrow space, and further reducing the weight and cost.

[0002]

2. Description of the Related Art In recent years, in order to further improve the performance of an internal combustion engine, a so-called electromagnetically driven valve which enables more arbitrary valve operation instead of a valve train having a mechanical power source using a conventional cam mechanism. The adoption of is being considered. In general, a conventional electromagnetically driven valve has one movable element mounted on a drive shaft that can move integrally with a valve element, and two electromagnets are arranged, one on each of the upper and lower sides of the movable element. (See JP-A-11-81941).

[0003]

However, this has various problems as described below. The first is
This is a problem of mounting (storage) space. As described above, since the conventional electromagnetically driven valve incorporates two electromagnets, the overall length of the actuator is correspondingly increased, and when the internal combustion engine is mounted on a vehicle, a higher mounting space is required. Therefore, if this space is to be ensured, a considerable distance is required between the actuator mounting surface and the engine hood, which limits the vehicles that can be mounted.

[0004] In a vehicle such as a passenger car in which the distance between the actuator mounting surface and the engine hood is relatively short, it is difficult to change the shape of the engine hood from a design standpoint. There is a problem that we have to do it. The second problem is cost. The conventional electromagnetically driven valve is provided with two electromagnets each, so that the cost per actuator becomes high. Assuming that one valve corresponds to one actuator, a four-valve four-cylinder engine requires a total of 16 actuators, and a six-valve engine requires a total of 24 actuators. Become. Therefore, if such an actuator is employed in an actual engine, the cost is greatly increased.

Third, there is the problem of weight. Since the conventional electromagnetically driven valve is provided with two electromagnets each, the total weight as an actuator naturally increases. And
Considering the whole engine, as described above, a significant increase in weight is inevitable. Further, not only the weight increases, but also a problem in terms of vibration occurs. That is, when the actuator for the electromagnetically driven valve is mounted on the engine, the center of gravity of the engine becomes high, and the vibration of the engine whose center of gravity becomes high in this way is reduced to a sufficient vibration level by the mounting method of the base engine. Suppression is not always possible. And in order to solve this problem, the engine mounting method may have to be changed drastically.

In view of such circumstances, the present invention provides an unprecedented configuration of an electromagnetically driven valve actuator, a valve operating device for an internal combustion engine, and a method of electromagnetically driving a valve element. The goal is to eliminate all at once.

[0007]

An actuator for an electromagnetically driven valve according to the present invention is an actuator for an electromagnetically driven valve which electromagnetically drives a valve element which is urged in one direction by a valve spring. One electromagnet, a drive shaft that movably penetrates the electromagnet, and one end of which contacts the valve body; two movers attached to the drive shaft and opposed to both surfaces of the electromagnet; A spring for urging the shaft in a direction opposite to the urging direction of the valve spring, and for urging the valve body to a neutral position in cooperation with the valve spring (claim 1).

[0008] The coil, the electromagnet, the 2
It is preferable to be wound on each relative surface with two movers (claim 2). In the actuator for an electromagnetically driven valve according to the present invention, it is preferable that the valve is interposed in a fluid passage to open and close the passage (claim 3), and the valve is an intake valve or an exhaust valve of an internal combustion engine. It is particularly preferable that the valve spring urges the valve body in the valve closing direction to open and close the intake passage or the exhaust passage (claim 4).

A valve train for an internal combustion engine according to the present invention comprises a valve element constituting an intake valve or an exhaust valve, a first spring for urging the valve element in a valve closing direction, and a coil wound. One electromagnet, a drive shaft that movably penetrates the electromagnet, one end of which contacts the valve body, two movers attached to the drive shaft and opposed to both surfaces of the electromagnet, A second spring that urges the valve body in a valve opening direction and urges the valve body to a neutral position in cooperation with the first spring (claim 5). .

[0010] In the electromagnet, the coil is a coil.
It is preferable to be wound on each relative surface with two movers (claim 6). The method of electromagnetically driving a valve body according to the present invention is directed to a single electromagnet in which a coil is wound so that magnetic poles can be formed on both end surfaces along a moving direction of the valve body biased to a neutral position.
The valve element is driven by arranging two movers opposed to the both end faces respectively, connecting the two movers integrally so as to be movable, and transmitting these movements to the valve element. (Chart 7).

Preferably, the coil is wound around both end faces of the electromagnet. The two movers,
It is preferable that the electromagnet be movably penetrated and connected via a drive shaft that comes into contact with the valve body.

[0012]

According to the first aspect of the present invention, the following effects (1) to (4) can be obtained. Although it is necessary to provide two movers in the electromagnetically driven valve actuator, on the other hand, only one electromagnet is required. The number of electromagnets occupied is reduced, and the overall length of the actuator for an electromagnetically driven valve can be shortened. (2) The number of electromagnets, which accounts for the majority of the cost of the actuator for an electromagnetically driven valve, has been reduced. The cost can be reduced, and (3) the total weight of the electromagnetically driven valve actuator can be reduced by reducing the number of electromagnets that account for a large proportion of the total weight of the electromagnetically driven valve actuator.

Along with the decrease in the number of electromagnets, (4) the required number of peripheral devices, such as amplifiers, is also reduced, so that the configuration can be simplified. According to the second aspect of the present invention, a conventional electromagnetically driven valve provided with two electromagnets for one mover by winding coils on each of the relative surfaces of the electromagnet and the two movers. (E.g., magnetic force that forms the attracting force of the mover) can be easily obtained.

According to the third aspect of the present invention, since the total length of the actuator for the electromagnetically driven valve is shortened, it can be stored in a relatively narrow storage space. According to the fourth aspect of the present invention, it is possible to facilitate mounting on a vehicle. According to the fifth aspect of the invention, the number of electromagnetic components constituting the valve train of the internal combustion engine, that is, the number of electromagnets and movers is different from the conventional one, and two movers need to be provided. Since only one electromagnet is required, as described above, (1) the valve operating device can be made compact and can be easily mounted on a vehicle.
(2) Significant cost reduction is possible, (3) The weight of the valve train, and hence the total weight of the internal combustion engine as a whole, can be reduced, and (4) Peripheral equipment such as an amplifier is also required. The number can be reduced and the configuration can be simpler.

According to the invention described in claim 6, it is possible to easily obtain the same performance as that of a conventional valve train of an internal combustion engine having two electromagnets for one mover. According to the seventh aspect of the present invention, two movable elements are required to drive the valve element, but only one electromagnet is required. The valve element can be driven with the configuration, (2) a great cost reduction can be achieved in realizing the present invention, and (3) the valve element can be driven with a low weight configuration. Also, (4)
The required number of peripheral devices such as amplifiers is also reduced.

According to the invention described in claim 8, the same performance as that of the conventional method using two electromagnets for one mover can be easily obtained. According to the ninth aspect of the invention, the two movers are connected via the drive shaft penetrating the electromagnet, so that a more compact configuration can be achieved.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the vicinity of a combustion chamber of an internal combustion engine (hereinafter, referred to as “engine”) including an electromagnetically driven valve actuator (hereinafter, simply referred to as “actuator”) 1 according to an embodiment of the present invention. First, an outline of the configuration of the gas exchange system of the engine will be described with reference to the drawing, and then the configuration of the actuator 1 will be described.

A piston 13 is inserted into the cylinder block 11 in a reciprocating manner, and an intake passage 19 and an exhaust passage 21 communicate with a combustion chamber 17 formed between the piston head and the cylinder head 15 so as to face each other. Gas exchange for introducing air from the intake passage 19 and exhausting the exhaust gas to the exhaust passage 21 is performed. Further, a valve body 23 is interposed in a port portion P communicating with the intake passage 19 and the exhaust passage 21, respectively, to constitute an intake valve 23a and an exhaust valve 23b of the engine.

The valve bodies 23 are respectively inserted into valve guides 25 and held so as to be movable with respect to the cylinder head 15, and a retainer 27 is fixed to the upper end of the shaft. The valve spring (first spring) 29 is mounted in a compressed state between the retainer 27 and the cylinder wall facing the opening direction of the port P, so that the valve body 23 moves in the valve closing direction. Has been energized.

The lower end of the drive shaft 61 of the actuator 1 is in contact with the upper end of the shaft of the valve body 23. The drive shaft 61 reciprocates when the actuator 1 operates based on a command from an electronic control unit (hereinafter, referred to as “ECU”) 41, and causes the valve element 23 at the valve closing position to generate the elastic force of the valve spring 29. Pushed in opposition to open it. Then, when the drive shaft 61 is returned to the original position, the valve element 23 returns to the original valve closing position by the elastic force of the valve spring 29.

As described above, by controlling the position of the drive shaft 61 to control the position of the valve body 23, the intake passage 19 and the exhaust passage 21 are opened and closed, and gas exchange is achieved. In addition,
The ECU 41 receives an air flow meter 51, an accelerator opening sensor 53, a water temperature sensor 55,
Various operating conditions are input from the ₂ sensor 57, the crank angle sensor 59, and the like. The ECU 41 sets an optimal valve timing according to the actual operating conditions, and issues a valve opening / closing command to a controller 81 of the actuator 1 described later. Emits.

Next, the configuration of the actuator 1 will be described. FIG. 2 is a sectional view schematically showing the configuration of the actuator 1. As shown in the figure, the actuator 1 has one electromagnet 63 built therein. Drive shaft 61
The lower end thereof abuts on the upper end of the shaft of the valve body 23, and penetrates a substantially central portion of the electromagnet 63 vertically (in the moving direction of the valve body 23), and is guided so as to be able to reciprocate up and down.

Two soft magnetic plate-like members (hereinafter referred to as "movers") 65 and 67 are integrally attached to the drive shaft 61 so as to sandwich the electromagnet 63 from above and below. A retainer 69 is fixed to the portion. A spring (second spring) 71 is mounted in a compressed state between the retainer 69 and the case wall facing the port P direction.
7 in the valve opening direction of the valve body 23 and the valve spring 2
9, the valve element 23 is urged to the neutral position (the position of the mover 65 when the valve element 23 is in the neutral position is indicated by N).

The neutral position of the valve body 23 is slightly shifted in the opening direction or the closing direction from the middle between the fully open position and the fully closed position (the physical center in the pendulum movement of the movable portion) for the reason described later. However, the degree is not impaired, and more specifically, it is preferably about several millimeters.). In the present embodiment, the valve body 23 and the drive shaft 61
And the valve element 23 and the movers 65 and 67 are integrally movable. However, the valve element 23 and the drive shaft 61 are not limited to being separate members, and may be one continuous member. Is also good.

The upper end of the drive shaft 71 has a mover 6
Position sensors 73 so that the positions of 5 and 67 can be detected
Is provided, and its position information is stored in the controller 81.
Is output to The controller 81 sends an electromagnet 63 to the drive circuit 83 in response to a valve opening / closing command from the ECU 41.
Issue a power supply command to At this time, the controller 81
Controls the amount of energization to the electromagnet 63 using the position information. Then, the drive circuit 83 supplies a current from the power supply 85 to the electromagnet 63 according to a command from the controller 81.

Here, the electromagnet 63 will be further described with reference to FIG. FIG. 6A shows the electromagnet 63 according to the present embodiment, and FIG. 6B shows the electromagnet 263 used in the conventional electromagnetically driven valve actuator.
Is represented. Since the conventional electromagnets 263 are arranged one above and below one mover, the coils 26
5 is formed only on the side of the relative surface 267 to the mover as shown in the figure, and the magnetic pole is formed only on the relative surface 267. For this reason, the coil 265 is wound around the axis A indicating the moving direction of the valve element, and is formed concentrically with the insertion hole 269 of the drive shaft.

On the other hand, the electromagnet 6 according to the present embodiment
3 is disposed between the two movers 65 and 67 as described above, so that a magnetic pole can be formed on each of the facing surfaces 161 and 163 with these. Although various forms of forming the coil for this purpose are conceivable, in the electromagnet 63, the coil is formed parallel to a plane including the axis A indicating the moving direction of the valve element 23, and is wound on the relative surfaces 161 and 163. ing. Also, the coil is connected to the axis A (ie,
A total of two are formed, one on each side of the insertion hole 165) of the drive shaft 61, and a first coil 167 and a second coil 169 capable of forming a magnetic pole on each relative surface.

Next, the operation principle of the actuator 1 configured as described above will be described with reference to FIG.
FIG. 3A shows a state when the valve element 23 is in the fully closed position (hereinafter referred to as a “fully closed state”), and FIG. 2B shows a state in which the valve element 23 is in the fully open position. (Hereinafter referred to as “fully open state”). As described above, when the electromagnet 63 is not energized, the valve body 23 is urged by the valve spring 29 and the spring 71 and is stopped at the neutral position. First,
It moves to a predetermined initial position (here, a fully closed position) by an initialization method described later.

Here, the fully closed state will be described with reference to FIG. In the fully closed state, the lower movable element 67 (closer to the combustion chamber 17) approaches the lower end surface of the electromagnet 63, while the upper movable element 65 separates from the electromagnet 63 and moves to a position corresponding to the neutral position. Move to position C above N. At this time, since the two coils 167 and 169 of the electromagnet 63 are both energized, magnetic poles can be formed on both upper and lower end surfaces of the electromagnet 63. However, the upper movable element 65 is separated from the electromagnet 63, and conversely, Since the mover 67 on the side is close to the electromagnet 63, the mover 6 on the lower side
The poles are actually formed on the surface relative to 7. Then, a magnetic flux is formed using a part of the lower mover 67 as a magnetic circuit, and the electromagnetic force effectively acts on the lower mover 67.

Here, the direction of the current in the first coil 167 and the direction of the current in the second coil 169 are opposite (see the arrow symbol in the figure), and the dotted lines around the coils 167 and 169 are shown. Thus, the magnetic fluxes Φ1a and Φ
1b is formed. The valve body 23 is in the fully closed position and closes the intake passage 19 or the exhaust passage 21, the upper end of the shaft of the valve body 23 is separated from the lower end of the drive shaft 61, and a predetermined clearance Cr is provided between both end surfaces. Is formed.

Next, when opening the valve, first, the electromagnet 6
3 is shut off. At this time, the movers 65 and 67
Is moved by the energy stored in the spring 71, but the energy is lost due to the influence of friction acting on the outer peripheral surface of the drive shaft 61 and the like, and the energy cannot be reached to the fully open position only by the elasticity of the spring. For this reason, the distance (gap) between the coil 63 and the upper movable element 65 during the stroke (for example, 1)
(When it becomes about [mm]), the electromagnet 63 is energized to assist the movement by the electromagnetic force.

Then, this time, the upper movable element 65 is close to the electromagnet 63, and a magnetic pole is formed on the surface facing the upper movable element 65, so that the electromagnetic force works effectively. , And is stopped at the position O corresponding to the fully open position. The magnetic flux Φ2 formed at this time
a and Φ2b are as shown by the dotted lines in FIG.
A part of the upper mover 65 is included in the magnetic circuit and faces in the opposite direction.

Further, when closing the valve element 23, the power supply to the electromagnet 63 is cut off as described above, and the movable elements 65 and 6 are closed.
In the course of the upward movement of 7, electricity is supplied again to apply electromagnetic force to the lower electromagnet 67, and the lower mover 67 is attracted to the electromagnet 63. Here, the above-described initialization method will be described. As described above, the valve element 23 is
And a spring 71, which is biased to the neutral position, which is set slightly closer to the opening direction or the closing direction than the middle between the fully open position and the fully closed position. For this reason,
At the time of stop, one of the two movers 65 and 67 is closer to the electromagnet 63 than the other, and stops. When the electromagnet 63 is energized at the time of initialization, a difference is generated between the electromagnetic forces acting on the two, and The terminals 65 and 67 are attracted to one end face of the electromagnet 63. Here, if the energization is cut off, free oscillation can be performed with the energy stored in the springs 29 and 71. Then, each time the movers 65 and 67 approach, the electromagnet 63 is energized to gradually increase the amplitude of the movers 65 and 67. By repeating such intermittent energization, the valve element 23 can be moved to the initial position.

Finally, effects obtained by the actuator 1 according to this embodiment will be described. According to the actuator 1, all of (1) effects in terms of performance, (2) effects in terms of dimensions, (3) effects in terms of weight, and (4) effects in terms of cost can be obtained. Therefore, each item will be described below. (1) Effect on Performance In order to evaluate the performance of the actuator 1, the electromagnet 63
The magnitude of the attracting force (electromagnetic force) of the mover obtained by the above is theoretically examined.

The following expression (1) is a general expression of the magnetic flux Φ.
It shows the magnitude of the suction force. Φ = μInA / L = F / R (1) μ: magnetic permeability [H / m] I: current [A] n: number of turns of coil  A: Cross-sectional area of magnetic circuit (here, core of electromagnet 63)
[M^TwoL: Average length of magnetic circuit [m] F: Magnetomotive force (= IN) R: Magnetic resistance (= L · (μA)^-1Here, the electromagnet 63 according to the present embodiment and a conventional electromagnetic drive
Electromagnet 2 used in valve actuation actuator
Compare with 63. First, the magnetic permeability μ is the same for both materials.
The same value can be attained by forming with. Ko
The number of turns n of the coil is such that the coil is wound at two positions of the electromagnet 63.
The first coil 167 and the second coil 169
And the same number. The cross-sectional area A is the core of the electromagnet 63
By properly designing (iron core), the same value can be easily obtained.
can do. For the average length L of the magnetic circuit,
Next, a description will be given with reference to FIG.

FIG. 5 shows the magnetic flux Φ formed in the fully open state.
FIG. 3A shows the case where the electromagnet 63 is used (Φ2a, Φ2b), and FIG. 3B shows the case where the conventional electromagnet 263 is used (Φ3). .
In the conventional electromagnet 263, the magnetic circuit is formed over the entire core, whereas in the electromagnet 63 according to the present embodiment, the magnetic circuit is formed only on the upper portion of the core. The average length L is shorter than before.

Accordingly, if the current I flowing through the coil is the same, it is possible to obtain an attractive force greater than that of the conventional electromagnet, and in this respect, the performance can be improved. (2) Dimensional Effect FIG. 6 shows a comparison of dimensions between the actuator 1 according to the present embodiment and the conventional actuator 101 for an electromagnetically driven valve. The former is shown in FIG. 6A and the latter is shown in FIG. Figure (b)
Is shown in

The conventional actuator 101 has a height H2
Two electromagnets 263a and 263b and one mover 2
71 (thickness t). Here, the mover 271
Is W2, and the dimension of the mounting portion (including the retainer 69 ') of the spring 71' is B2, the total length of the actuator 101 is approximately L2 + B2 = 2 * H2 + W.
2 + B2.

On the other hand, the actuator 1 according to the present embodiment
Are one electromagnet 63 of height H1 and two movers 6
5 and 67 (thickness t), the stroke width of the mover is set to W1, and the mounting portion of the spring 71 (the retainer 6).
9 inclusive. ) Is B1, the actuator 1
Is approximately L1 + B1 = H1 + 2 × W1 + B1.

Here, the difference between the total lengths of the two is calculated as (L2 +
B2)-(L1 + B1).
Since 1 and B2 can generally be the same, this difference can be represented substantially by D = L2-L1.
Accordingly, in the actuator 1, although the number of movers is increased, the number of electromagnets, which occupy a relatively large proportion of the entire length of the actuator, is reduced. Can be.

A preferred example of each of the above dimensions (unit is [mm]) is as follows: H1 = 26.0, W1 = 12.0.
5, H2 = 26.0, W2 = 12.5, and the overall length of the actuator 1 is reduced by D = 13.5 compared to the conventional actuator 101. (3) Weight Effect The electromagnet (particularly the core) is a component that accounts for a large proportion of the total weight of the actuator for the electromagnetically driven valve. Therefore, it goes without saying that the reduction in the number leads to a significant reduction in the total weight of the actuator for the electromagnetically driven valve. (4) Cost Effect The electromagnet is an expensive component that accounts for most of the cost in the actuator for the electromagnetically driven valve. Therefore, it goes without saying that a reduction in the number leads to a significant cost reduction.

The reduction in the number of electromagnets to be controlled also leads to simplification of peripheral devices. For example, if the number of electromagnets is reduced from two to one, the number of amplifiers and control circuits can be reduced by half. In addition to the above effects, the actuator 1 has various effects. For example, a decrease in the number of electromagnets and a decrease in the number of control targets can lead to another effect of facilitating control.

In addition, winding the coils 167 and 169 on the surface facing the mover leads to a reduction in the number of manufacturing steps of the electromagnet 63 and simplification of manufacturing. This is because the coils 167 and 169 according to the present embodiment can be formed by directly winding a conductive wire around the core while supporting the core.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view around a combustion chamber of an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically showing a configuration of an actuator for an electromagnetically driven valve according to the embodiment.

FIG. 3 is a perspective view of an electromagnet provided in the actuator.

FIG. 4 is a view for explaining the operation principle of the actuator.

FIG. 5 is a diagram showing a magnetic flux formed in the electromagnet of the actuator in comparison with a conventional one.

FIG. 6 shows dimensions of various components of the actuator.
Figure shown in comparison with the conventional one

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Actuator for electromagnetically driven valves 19 ... Intake passage 21 ... Exhaust passage 23 ... Valve 27 ... Retainer 29 ... Valve spring 61 ... Drive shaft 63 ... Electromagnet 65 ... Mover 67 ... Mover 69 ... Retainer 71 ... Spring 73 ... Position Sensor 167: coil 169: coil

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3G018 AB09 CA12 DA36 DA38 DA41 EA02 EA11 EA16 EA17 FA01 FA06 FA07 GA14 GA18 GA32 3H106 DA05 DA22 DA25 DB02 DB13 DB19 DB26 DB32 DB38 DC02 DD03 EE34 5H633 BB10 GG02 GG04 GG07 GG13 JA02

Claims (9)

[Claims] 1. An electromagnetically driven valve actuator for electromagnetically driving a valve element biased in one direction by a valve spring, comprising: one electromagnet formed by winding a coil; and movably penetrating the electromagnet; A drive shaft having one end contacting the valve body, two movers attached to the drive shaft and opposed to both surfaces of the electromagnet, and biasing the drive shaft in a direction opposite to a biasing direction of the valve spring. A spring for urging the valve body to a neutral position in cooperation with the valve spring. 2. The electromagnet according to claim 2, wherein said coil is
The actuator for an electromagnetically driven valve according to claim 1, wherein the actuator is wound on each relative surface with one of the movers. 3. The electromagnetically driven valve actuator according to claim 1, wherein the valve element is interposed in a fluid passage to open and close the passage. 4. The valve body constitutes an intake valve or an exhaust valve of an internal combustion engine, and the valve spring biases the valve body in a valve closing direction to open and close an intake passage or an exhaust passage. The actuator for an electromagnetically driven valve according to claim 3, wherein 5. A valve element constituting an intake valve or an exhaust valve, a first spring for urging the valve element in a valve closing direction, one electromagnet formed by winding a coil, and the electromagnet being movable. Penetrates into
A drive shaft having one end in contact with the valve body, two movers attached to the drive shaft and opposed to both surfaces of the electromagnet, and biasing the drive shaft in a valve opening direction of the valve body; A second spring for urging the valve body to a neutral position in cooperation with a first spring. 6. The electromagnet according to claim 6, wherein said coil is
6. The valve train for an internal combustion engine according to claim 5, wherein the valve train is wound on each surface of the movable element. 7. An electromagnet having a coil wound so that magnetic poles can be formed on both end faces along a moving direction of a valve body biased to a neutral position, wherein two movable magnets are respectively opposed to said both end faces. An electromagnetic drive method for a valve element, comprising: arranging a movable element, connecting the two movable elements so as to be integrally movable, and transmitting the movement to the valve element to drive the valve element. . 8. The method according to claim 7, wherein the coil is wound around both end faces of the electromagnet. 9. The valve body according to claim 7, wherein the two movers are movably penetrated through the electromagnet and connected via a drive shaft that abuts on the valve body. Electromagnetic drive method.