JP3405053B2 - Electromagnetic driven gas exchange device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to an electromagnetically driven gas exchange.
Related to a gas exchange device, in particular, driving a gas exchange valve of an internal combustion engine
The present invention relates to an electromagnetically driven gas exchange device suitable as a device. [0002] 2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 61-2485
No. 06, the gas exchange valve of the internal combustion engine
Devices driven by force are known. Such a device,
A magnetic plate connected to a gas exchange valve of an internal combustion engine and a magnetic plate
Elastic body biasing to neutral position, and arranged on both sides of magnetic plate
And two electromagnets for attracting the magnetic plate alternately.
You. In the gas exchange valve, the magnetic plate is attracted to one electromagnet
As a result, the valve is closed and the magnetic plate is attracted to the other electromagnet.
The valve is opened by being worn. Therefore, the above equipment
According to the configuration, it is necessary to appropriately control the current flowing through the electromagnet.
To open the gas exchange valve according to the operating condition of the internal combustion engine.
Can be closed. [0003] A constant current is supplied to the electromagnet.
The electromagnetic force acting between the electromagnet and the magnetic plate
Increases as the person approaches. Therefore, the above conventional
In the device, the gas exchange valve located near the neutral position
Relatively large to pull to open or closed position
Is required, but the gas exchange valve is
After reaching the closed position, the gas
The change valve can be held in the open or closed position.
Wear. [0004] For this reason, the above-mentioned conventional apparatus includes gas exchange.
When the valve is displaced between the open and closed positions,
Supply a large current to the gas and the gas exchange valve opens
After reaching the position or valve closed position,
A current control circuit that supplies a pulsed current at regular time intervals is installed.
It is listed. According to such a current control circuit,
The supplied current is controlled to the minimum necessary value. this
Therefore, according to the above-mentioned conventional device, excellent energy saving is achieved.
The gas exchange valve can be reliably driven while securing
You. [0005] SUMMARY OF THE INVENTION
When the current flowing through the magnetic coil changes, the electromagnetic coil:
An induced electromotive force is generated to suppress the change. Ma
In addition, the current flowing through the electromagnetic coil changes,
When the magnetic field generated in the stone changes, electromagnetic
The stones try to suppress the change of the magnetic flux flowing back inside
An eddy current is generated. For this reason, in the above-mentioned conventional apparatus,
After the current supply to the electromagnet is stopped,
Some delay before the body begins to separate from the electromagnet
Time occurs. [0006] Improving the control accuracy of the opening / closing timing of the gas exchange valve
Above, the shorter the delay time, that is, the electromagnetic
After the supply of current to the stone is stopped, the magnetic plate
It is advantageous to start moving away from the magnet. However,
In the above conventional device, the magnetic plate is quickly moved from the electromagnet.
No attention has been paid to the separation of
Did not. In this regard, the above-described conventional apparatus requires the opening of the gas exchange valve.
With an optimal configuration for controlling the closing timing accurately
There was no. The present invention has been made in view of the above points.
Electromagnetic holding the gas exchange valve at the end of movement
After the excitation current, which is the cause of the force, is cut off,
Valve can be quickly displaced away from the end of travel
An object of the present invention is to provide an electromagnetically driven gas exchange device. [0008] The above object is achieved by the present invention.
As described in, the plunger urged by the elastic body
The electric force that drives the gas exchange valve by applying electromagnetic force
Held at the end of movement in a magnetically driven gas exchange
Micro vibration applying means for applying micro vibration to the plunger;
Small displacement in the direction in which the plunger moves away from the end of movement
Supply of the exciting current causing the electromagnetic force
Exciting current stopping means for stopping theAnd the micro vibration
Motion imparting means, the excitation current, the elastic body and the
Natural frequency and substantial frequency of spring-mass system including plunger
Excitation current control means to make the amplitude equal to
Together with the exciting current stopping means,
Stop the excitation current based on the stateElectromagnetic drive
This is achieved by a switching device. In the present invention, the minute vibration applying means is provided.
Is a plunge held at the end of movement by electromagnetic force
Micro vibration is applied to the keyer. Further, the exciting current stopping means
Is excited when the plunger is slightly displaced in the separation direction.
Cut off the current. The plunger is slightly displaced
Move the plunger away from the end of travel
And inertia is acting. Because of this,
To cut off the exciting current, and as a result, the electromagnetic force is attenuated.
When started, the plunger quickly moves away from the end of travel
Begins to displace in the direction. [0010] In the present invention, the exciting current control means
Is the characteristic of the spring-mass system
An amplitude substantially equal to the vibration frequency is provided. Excitation current
Is applied to the electromagnetic force
Is done. The amplitude generated by the electromagnetic force is determined by the spring including the plunger.
Is transmitted to the mass system. The frequency of the amplitude is unique to the spring-mass system
Since it substantially matches the vibration frequency,
Is excited by a minute vibration. Micro vibration generated in spring mass system
The movement responds to the amplitude period of the exciting current. The excitation current stop
The means is based on the amplitude period of the exciting current,
Excited when there is a slight displacement in the direction away from the end of movement
Cut off magnetic current. As a result, the spring mass system
Move away from the end of movement immediately after the flow is interrupted
Begins to displace in the direction. [0012] FIG. 1 shows an embodiment of the present invention.
Electromagnetically driven gas exchange device 10 (hereinafter simply referred to as gas exchange device)
10 (referred to as 10). Gas exchange
The device 10 includes a valve body 12. Valve element 12 is shown in the figure.
With the lower end exposed in the combustion chamber of the internal combustion engine,
This is a member that is installed in the
Construct a valve or exhaust valve. Cylinder head of internal combustion engine
Is provided with a port having a valve seat for the valve body 12.
ing. When the valve body 12 separates from the valve seat, or
The seating controls the conduction state of the port. A valve shaft 14 is fixed to the valve body 12.
You. The valve shaft 14 slides in the axial direction by the valve guide 16
It is kept possible. The valve guide 16 is a valve driving device.
It is supported by the lower cap 17 of the device 10. Valve shaft 14
A plunger holder 18 is fixed to the upper part of the plunger.
The plunger holder 18 is made of, for example, stainless steel or titanium.
High hardness and non-magnetic or low magnetic like alloys
It is made of a material exhibiting air characteristics. Plunger holder
18 is a cylindrical portion 18a extending in the axial direction of the valve shaft 14,
A ring portion formed substantially at the center in the axial direction of the cylindrical portion 18a
18b. The lower end of the plunger holder 18 has a lower
The retainer 20 is fixed. Lower retainer 20
There is a direction between the cap 17 and the cap 17 to separate them.
A lower spring 22 for generating power is provided.
The lower spring 22 holds the lower retainer 20, that is,
Attach the plunger holder 18 upward in FIG.
Generates a biasing force. On the other hand, at the upper end of the plunger holder 18
The upper retainer 24 is fixed. upper
At the top of the retainer, the lower end of the upper spring 26
Is in contact. Around the upper spring 26,
A cylindrical upper cap 2 surrounding the outer periphery
7 are provided. Further, the upper spring 26
The upper end is an adjuster screwed to the upper cap 27
It is in contact with the bolt 28. Upper spring 26
The upper retainer 24, that is, the plunger
An urging force for urging the rudder 18 downward in FIG.
Occurs. The ring portion 18b of the plunger holder 18
A plunger 30 is joined to the outer periphery of the plunger. plan
The jaw 30 is made of a soft material such as Fe, Ni, Co, or the like.
It is a donut-shaped member made of a magnetic material. plan
The jar 30 and the plunger holder 18 are connected to each other by electron beam fusion.
Welding, laser welding, brazing, caulking, bonding, etc.
Have been combined. Above the plunger 30, a first electromagnetic coil is provided.
And a first core 34 are provided. In addition,
A second electromagnetic coil 36 and a second core
A 38 is provided. First core 34 and second core
Numeral 38 is a member made of a magnetic material.
Accommodates the first electromagnetic coil 32 or the second electromagnetic coil 36
Annular grooves 34a, 38a for
And through holes 34b and 38b penetrating in the axial direction.
You. One end of the through hole 34b of the first core 34 (FIG. 1)
A first bearing 40 is disposed at the upper end of the first bearing 40).
You. Also, one end of the through hole 38b of the second core 38 (see FIG. 1)
A second bearing 42 is disposed at the lower end of the second bearing 42).
You. Plunger holder inserted into through holes 34b, 38b
The cylindrical portion 18a of the die 18 has these first bearings 40 and
And slidably held by the second bearing 42
I have. On the outer periphery of the first core 34 and the second core 38
Is provided with an outer cylinder 44. The first core 34 and the
The two cores 38 have a predetermined space therebetween.
And is held by an outer cylinder 44. In addition,
The upper cap 27 is fixed to the upper end surface of the first core 34.
Have been. On the other hand, the lower cap 17 described above is
It is fixed to the lower end surface of the door 38. Then,
When the neutral position of the plunger 30 is
Adjusted so as to be an intermediate point between the first core 34 and the second core 38.
It is arranged. First electromagnetic coil provided in gas exchange device 10
32 and the second electromagnetic coil 36 are connected to the electronic control unit 4.
6 (hereinafter, referred to as ECU). ECU4
6 is a power cycle at a cycle corresponding to the engine speed NE of the internal combustion engine.
An NE sensor 48 that emits a loose signal is connected. E
The CU 46 is a pulse signal output from the NE sensor 48
The engine speed NE is detected based on the
When the rotation angle reaches the reference crank angle (hereinafter referred to as the reference
) Is detected. The ECU 46 determines the engine speed NE and
And the valve body 12 at an appropriate timing based on the
The first electromagnetic coil 32 and the second
A current is alternately supplied to the magnetic coils 36. The following
In the description of the first electromagnetic coil 32 and the second electromagnetic coil 32
The current supplied to the coil 36 is called an exciting current. In the gas exchange device 10 of the present embodiment,
Excitation current to the first electromagnetic coil 32 and the second electromagnetic coil 36
Is not supplied, the plunger 30 is in its neutral position.
Position, ie, between the first core 34 and the second core 38
Maintained in the department. Plunger 30 is maintained in the neutral position
The exciting current flows through the first electromagnetic coil 32
Then, a magnetic field that circulates between the inner and outer circumferences of the first electromagnetic coil 32
appear. This magnetic field is generated by the first core 34, the plunger 3
0, and air between the first core 34 and the plunger 30
Generates magnetic flux flowing through the magnetic circuit consisting of the gap
You. The magnetic flux generated as described above causes the plunger 30 to
The suction force for suction to the 1 core 34 side, that is, the valve body 12
In FIG. 1, a suction force for displacing upward is generated. The above-mentioned suction force acts on the plunger 30.
When used, the plunger 30, the plunger holder 18,
Partainer 24, lower retainer 20, valve shaft 14, and
Valve element 12 (hereinafter, these are collectively referred to as movable section 50)
In FIG. 1 against the urging force of the upper spring 26.
Displaces upward. And the displacement is the plan
The operation is continued until the jaw 30 contacts the first core 34. Less than
Below, the position where the plunger 30 contacts the first core 34,
Termed the upper moving end of the plunger 30 or the movable part 50
You. The plunger 30 is held at the upper moving end.
From the state of being supplied to the first electromagnetic coil 32.
When the exciting current is interrupted, it acts on the plunger 30
The electromagnetic force disappears. As a result, the upper spring 2
6, the movable portion 50 moves downward in FIG.
Begins to displace towards. The displacement amount of the movable part 50 reaches a predetermined value.
At that point, an appropriate exciting current is applied to the second electromagnetic coil 36.
When circulating, the plunger 30 is now placed on the second core 38 side.
In FIG. 1, the suction force for sucking
An attraction force displaced downward is generated. The above-mentioned suction force acts on the plunger 30.
When used, the movable part 50 exerts the urging force of the lower spring 22.
Until the plunger 30 contacts the second core 38
Displace. Hereinafter, the plunger 30 contacts the second core 38.
To the position below the plunger 30 or the movable part 50.
This is called the end of movement. Therefore, as described above,
The first electromagnetic coil 32 and the second electromagnetic coil 36 alternately.
When the exciting current is supplied, the movable section 50 is moved upward.
It reciprocates repeatedly between the end and the lower moving end. Moth
The movable body 50 of the valve body 12 of the switching device 10 moves upward.
Valve seat at one end of the port when located at the end
To sit down. For this reason, according to the gas exchange device 10,
At the appropriate timing according to the operating state of the fuel engine,
Can be opened and closed. Incidentally, the first electromagnetic coil 32 and the second
The electromagnetic coils 34 are converted into electric currents flowing through them.
When a change occurs, the induction
Power is generated. Therefore, the first electromagnetic coil 32 and the second
The exciting current flowing through the electromagnetic coil 34 is
It does not disappear immediately after its suspension. Furthermore, the first
The excitation flowing through the electromagnetic coil 32 and the second electromagnetic coil 34
When the magnetic current decreases, the first core 34 and the second core 38
Direction to suppress the reduction of magnetic flux flowing inside them
Eddy current flows through Therefore, the first core 34 and the plan
Between the second core 38 and the plunger 30.
In between, the excitation current is stopped by the ECU 46.
After that, the electromagnetic force remains for a certain period. The gas exchange device 10 opens the valve body 12.
To control the closing timing with high accuracy, the first electromagnetic
Excitation electricity supplied to the coil 32 and the second electromagnetic coil 36
After the flow is stopped, until the movable part 50 begins to displace
It is advantageous that the delay time required is shorter. In this embodiment,
The exchange device 10 controls the exciting current according to the process described below.
By doing so, the delay time has been reduced.
It is characterized by the fact that Hereinafter, refer to FIGS. 2 and 3.
The control executed by the ECU 46 to realize the above functions
The contents of your request will be described. FIG. 2 shows that the valve body 12 is moved from the open position to the closed position.
To explain the operation of the gas exchange device 10 when displacing to
3 shows a time chart. FIG. 2A shows whether the ECU 46
Of the exciting current generated toward the first electromagnetic coil 32 from the
(The waveform shown by the solid line in the figure) and the actual
The measured value of the exciting current flowing through the electromagnetic coil 32 (in FIG.
(A waveform indicated by a chain line). FIG. 2B shows the ECU 4
Excitation current generated from 6 to the second electromagnetic coil 36
Command value (the waveform shown by the solid line in the figure) and the actual
The measured value of the exciting current flowing through the second electromagnetic coil 36 (see FIG.
The waveform shown by the dashed line is shown in FIG. FIG. 2 (C)
Indicates a displacement position of the valve body 12. In addition, in FIG.
2B, the horizontal axis in FIG. 2B, and FIG.
The horizontal axis represents the exciting current of the first electromagnetic coil 32, respectively.
The first conversion time and the second electromagnetic
The second variable set for controlling the exciting current of the
The switching time and the reference time T are set. As shown in FIG. 2C, the valve element 12 is
Time T in time₀(Hereafter, the reference time T₀)
Previously, it was held in the valve open position. As shown in FIG.
Command value of the exciting current supplied to the second electromagnetic coil 36
Is the reference time T₀Previously, at the second conversion time
Time t_TwoBefore + hold, it oscillates at a predetermined cycle Δt.
Is controlled as follows. Below, the command value in the amplitude
The center value is represented by the holding current Ih, and its amplitude is represented by δ.
The second conversion time is determined by the rotation angle of the internal combustion engine,
A predetermined time when the supply of the exciting current to the
This is the time that is reset each time the turning angle is reached. By the way, the gas exchange device 10 has
Pa spring 26, lower spring 22, and movable part
50 is a spring mass system having a predetermined natural vibration frequency F.
Make up. The natural frequency F is determined by
Assuming that the spring constant of the quantity system is K and the weight of the movable part is M, F =
(1 / 2π) √ (K / M). Real truth
In the embodiment, while the valve body 12 is held at the valve open position,
To the command value of the exciting current for the second electromagnetic coil 36
The predetermined frequency f is set so that f = F is substantially satisfied.
That is, the spring mass system of the gas exchange device 10 has
Set to substantially match the natural vibration frequency F
I have. Excitation current supplied to second electromagnetic coil 36
Is amplitude at the natural vibration frequency F as described above.
Between the second core 38 and the plunger 30.
The magnetic force also has an amplitude due to its natural vibration frequency F.
The amplitude of the electromagnetic force is transmitted through the plunger 30.
Is transmitted to the movable part 50, and the natural frequency F
Generates minute vibrations. For this reason, FIG.
As shown in the figure, the displacement position of the valve element 12 is₀Before
At a predetermined period Δt. As shown in FIG. 2B, the second electromagnetic coil 3
The command value of the excitation current supplied to 6 changes from the amplitude state to “0”.
When the command value is changed to the
The time coincides with the time when the small value becomes “Ih−δ”. 2nd electromagnetic
After the supply of the exciting current to the coil 36 is stopped, the second
Electromagnetic remaining between the electromagnetic coil 36 and the plunger 30
To extinguish the force quickly, stop supplying the exciting current.
At the time when the current is flowing through the second electromagnetic coil 36.
The smaller the magnetic current, the more advantageous. Therefore, as described above,
At the time when the command value of the magnetic current becomes “Ih−δ”, the second
To stop supplying the exciting current of the electromagnetic coil 36,
Is advantageous for quickly eliminating the remaining electromagnetic force.
The situation can be shaped. The gas exchange device 10 includes a valve body 12
It has the characteristic that the excitation current command value and the
You. Therefore, the exciting current supplied to the second electromagnetic coil 36
At the time when the command value of the valve body 12 becomes “Ih−δ”,
Is the largest from the valve-opening position to the valve-closing side during the amplitude process.
It exists at the displaced position. And under such circumstances
Indicates that inertia toward the valve closing side acts on the valve body 12.
You. Therefore, as described above, the second electromagnetic coil 36
When the supply of the excitation current command value to the
h−δ ″, then the second
A Even if electromagnetic force remains between plunger 30 and plunger 30
Regardless, the valve body 12 is quickly displaced toward the valve closing position.
You can begin to let. Therefore, the gas exchange device of this embodiment is
According to the position 10, the valve body 12 is moved from the valve opening position to the valve closing position.
Excellent controllability when displacing
Wear. Reference time T₀The valve body 12 is closed
From the valve opening position side by a predetermined distance from
As shown, an excitation current command is issued to the first electromagnetic coil 32.
The value starts to be supplied. In the present embodiment,
Time at which supply of the command value to first electromagnetic coil 32 is started
At time t in the first conversion time₀Called. Note that the first conversion
During the time, the supply of the command value to the first electromagnetic coil 32 is open.
Every time it starts₀It is time to be reset to Excitation current supplied to first electromagnetic coil 32
At the time t₀Held at the maximum value for a predetermined time after
Then, the time t in the first conversion time₁From time t_TwoTo
At a predetermined rate of change. First core 34 and plunge
The electromagnetic force acting between the first electromagnetic coil 32 and the
Is constant, the plunger 30
While being away from the first core 34, the plunger 3 is small.
0 is increased as approaching the first core 34. this
Therefore, when driving the gas exchange device 10, the first electromagnetic
It is assumed that the maximum exciting current always flows through the coil 34.
If the movable part 50 approaches the upper moving end,
The displacement speed of the moving part 50 will be increased. The movable part 50 maintains a high displacement speed.
If the movable end 50 reaches the upper moving end,
Loud collision sound is generated when reaching the end of the one side movement
You. Therefore, as the movable part 50 approaches the end of movement,
The above phenomenon that the displacement speed of the gas exchange device is increased
Phenomenon unfavorable for obtaining excellent quietness at 0
It is. Therefore, in this embodiment, the first electromagnetic
In supplying the exciting current to the coil 32, the plunger 3
Time t when 0 is away from the first core 34₀~Times of Day₁Between
Maintains the command value of the exciting current at the maximum value,
T reaches the vicinity of the first core 34_TwoAfter that,
The command value was gradually reduced. With such control
If the movable part 50 is separated from the first core 34
Generates a large electromagnetic force, and the movable part 50
A To reduce the electromagnetic force when it is close to
Can be. Therefore, according to the gas exchange device 10 of the present embodiment,
If the movable part 50 reaches the upper end of the movement,
Excellent quietness can be realized. The exciting current supplied to the electromagnetic coil is always maximum.
The problem of collision noise that occurs when the value is
When displacing from the side end of movement to the end
This also occurs in any case. Therefore, the gas exchange device 1
In the case of 0, the movable section 50 is moved downward from the upper end of the movement.
The plunger 30 is also moved to the second
A) While away from 38, set the excitation current command value to the maximum value.
The plunger 30 reaches the vicinity of the second core 38,
After that, the command value is gradually reduced.
You. Therefore, according to the gas exchange device 10, the movable unit 50
Is displaced from the upper moving end to the lower moving end,
And the movable part 50 is moved from the lower end to the upper end.
Excellent quietness when moving to the edge
can do. As shown in FIG. 2A, the first electromagnetic coil 3
The command value of the excitation current supplied to the second conversion time
Time t₁To time t_TwoAfter being reduced to
In the period Δt, the amplitude is controlled to be within the range of Ih ± δ.
You. Then, the exciting current supplied to the first electromagnetic coil 32
At the time t_TwoAfter that, the command value becomes “Ih−δ”
Time t_TwoIt is switched to "0" at + hold.
It should be noted that the time hold depends on the operation state of the internal combustion engine and the valve element 1
2 is set as the time to hold in the closed position
Time. As in the case of the second electromagnetic coil 36 described above.
The command value of the exciting current supplied to the first electromagnetic coil 32
Is "Ih-δ" and its supply is stopped,
Remains between the first electromagnetic coil 32 and the plunger 30
The electromagnetic force can be quickly eliminated. Also heel
If the excitation current is stopped at a certain timing,
Prior to stopping the magnetic current, the valve body 12 is opened to the valve opening position side.
Inertia can be applied. For this reason, according to the gas exchange device 10,
The command value of the exciting current supplied to one electromagnetic coil 32 is
After being switched to “0”, the first core 34 and the plunger
Despite the remaining electromagnetic force between the valve body 12 and
Can be quickly displaced toward the valve opening position.
You. Therefore, according to the gas exchange device 10 of the present embodiment, the valve
When the body 12 is displaced from the valve closing position to the valve opening position,
Or excellent controllability can be obtained. FIG. 3 shows the first electromagnetic coil 32 and the second
E to control the exciting current supplied to the magnetic coil 36
Flowchart of an example of a control routine executed by the CU 46
Show In the routine shown in FIG.
The supply of the exciting current to the first electromagnetic coil 32 should be started.
Angle CA₁And the second electromagnetic coil 3
6 at which to start supplying the exciting current to_TwoReached
Fired when it reaches. The ECU 46 controls the rotation of the internal combustion engine.
Corner is CA₁After reaching, a series of processing shown in FIG. 3 is executed.
The excitation electric power supplied to the first electromagnetic coil 32
Control the flow. Also, when the rotation angle of the internal combustion engine is CA_TwoReach
After that, the series of processes shown in FIG.
(2) The exciting current supplied to the electromagnetic coil 32 is controlled. Less than
Below, the contents of a series of processes shown in FIG.
Is CA₁Will be described by way of an example in which the value has been reached. As described above, the rotation angle of the internal combustion engine is equal to the predetermined angle C.
A₁Is reached, the routine shown in FIG. 3 is started.
When the routine shown in FIG.
0, the timer t is t₀Is reset. The above
The timer value t reset as described above is used in this routine.
The time corresponds to the time in the first conversion time. When the above processing is completed, the process proceeds to step 1
At 02, a process of turning on the exciting current is executed.
In this routine, the first electromagnetic command
The command value of the excitation current supplied to the file 32 is set to the maximum value
Is done. In step 102, the excitation current command value
If the value is set to a large value, then at step 104
The time t is the time t at which the seating control of the exciting current should be started.₁Reached
It is determined whether or not it has been reached. As a result, t ≧ t
₁Is not satisfied, the above conditions are met.
The determination process of step 104 is repeatedly executed until the
It is. And t ≧ t₁If it is determined that
Then, the process of step 106 is executed. In step 106, the seating control of the exciting current is performed.
Process to reduce the excitation current to achieve
Is done. Then, in step 108, the conversion time t is
When to end the excitation current reduction process by seating control
Time t_TwoIs determined. as a result,
Still t ≧ t_TwoIf it is determined that is not established,
Until the condition is satisfied.
Is executed. While such processing is repeated,
The command value of the exciting current supplied to the first electromagnetic coil 32 is:
At a predetermined reduction rate, the value is reduced to a predetermined value Ih. So
And t ≧ t_TwoIf it is determined that
Step 110 is executed. In step 110, the command value of the exciting current
At a center value Ih, an amplitude δ, and a frequency f.
Dither control is started. The median Ih is
As described above, the movable unit 50 is held at the upper end of the movement.
Current to be supplied to the first electromagnetic coil 32
You. The amplitude δ is the port sealing performance when the valve is closed.
Is installed to cause the valve body 12 to vibrate minutely without damaging the
It is a specified amplitude value. Further, the frequency f depends on the gas exchange device.
The natural vibration frequency F of the spring mass system provided in the device 10 is substantially
Have the same value. When the process of step 110 is completed,
Then, in step 112, the valve body 12 is maintained at the valve closing position.
The time to hold, that is, the basis for the hold time hold
Hold time₀Is calculated. The valve body 12 is closed.
Depending on the time to be held in the
The time during which a closed port should be kept closed is
It changes according to the operating state of the fuel engine. In this routine,
Based on the engine speed NE, which is a representative value of the operating state of the internal combustion engine,
Then, the most ideal holding time f (NE) is calculated,
The value is the reference hold time hold₀Is stored as Reference hold time hold₀When the calculation of
Next, in step 114, the hold time hold is calculated.
You. The hold time hold is determined by the oscillation period Δt by dither control.
The reference hold time hold of the integer n times Δt₀
It is assumed to be a value close to The hold time hold is assumed to be such a value
Time t_TwoAfter the hold time elapses
In this case, the command value of the exciting current is always “Ih−δ”. When the processing of step 114 is completed,
Next, at step 116, the conversion time t is set to
At which to switch the command value to “0”,
1 When the supply of the exciting current to the electromagnetic coil 32 should be stopped
Time t_TwoIt is determined whether or not + hold has been reached. The result
As a result, t ≧ t_TwoWhen it is determined that + hold is not established
In this case, step 11 is repeated until such a condition is satisfied.
6 is performed. And t ≧ t_Two+ Hold
If it is determined that the condition is satisfied, the process proceeds to step 118.
After the excitation current command value is switched to “0” by
The routine ends. According to the above processing, the movable part 50 is
The first or second
The command value of the exciting current supplied to the electromagnetic coils 32 and 36 is
Stop supplying the command value when “Ih-δ” is reached
As well as prior to stopping the supply of command values.
Thus, the inertia toward the other end of movement is given to the movable portion 50.
can do. For this reason, the gas exchange device of the present embodiment
According to FIG. 10, it is possible to make the ECU 46 execute the above processing.
With this, the valve element 12 is opened and closed with excellent controllability.
be able to. By the way, in the above embodiment, the gas
The exchange device 10 sets the valve body 12 in phase with the excitation current command value.
Since it has the characteristic to make it swing,
When the value becomes “Ih−δ”, that is, when the exciting current
When the command value reaches the minimum value during amplitude, the excitation current
Command value is switched to “0”.
Ming is not limited to this. That is, gas exchange
The switching device 10 moves the valve body 12 to a position different from the excitation current command value.
In case of amplitude in phase, take this phase difference into account
To change the timing of switching the excitation current command value to "0".
It may be set. Also, in the above embodiment, one of
The movable part 50 sucked and held at the end of movement
Due to the largest displacement towards the other end of travel
At this point, the supply of the excitation current is to be stopped.
The invention is not limited to this.
Excited at the time of displacement at the highest speed toward the other end of movement
The supply of current may be stopped. Further, in the above embodiment, the first and the second
Of the exciting current supplied to the first and second electromagnetic coils 32 and 36
Micro vibration is applied to the movable part 50 by vibrating the value
However, the present invention is not limited to this.
Instead, for example, a fine mechanism is
A small vibration may be given. Incidentally, in the above embodiment, the
The ring (26) and the lower spring (22) described above.
The gas exchange according to claim 1, wherein the valve body (12) is mounted on the elastic body.
Each corresponds to a valve. Also, in the above embodiment,
In other words, the ECU 46 executes the processing of step 110 described above.
The micro vibration applying means according to claim 1,
YoEncouragementThe magnetic current control means performs steps 112 to 118 described above.
Claims by executing the processing of1 noteExcitation electricity
Flow stop means are respectively realized. [0055] As described above, according to the first aspect of the present invention,
IfThe excitation current is substantially equal to the natural vibration frequency of the spring-mass system.
By giving equal amplitudes, the spring mass system can be made more efficient
It can vibrate very finely. This allowsOf electromagnetic force
Before attempting to stop the excitation current,
Imparting inertia in a direction away from the end of movement to the
In other words, in a situation where the plunger is easily separated from the end of movement.
Can be placed.Also, due to its vibration,
If the quantity system is slightly displaced away from the end of movement
In this case, the exciting current can be cut off.For this reason, books
According to the electromagnetically driven gas exchange device according to the invention, the exciting current
Stop the gas exchange valve immediately from the end of movement.
Can be separated. [0056]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating an overall configuration of an electromagnetically driven gas exchange device according to one embodiment of the present invention. FIG. 2A is a time chart of a command value of an exciting current supplied to a first electromagnetic coil. FIG. 2B is a time chart of the command value of the exciting current supplied to the second electromagnetic coil. FIG. 2C is a time chart showing the displacement position of the valve element. FIG. 3 is a flowchart of an example of a control routine executed in the electromagnetically driven gas exchange device shown in FIG. DESCRIPTION OF SYMBOLS 10 Electromagnetic driven gas exchange device 12 Valve element 18 Plunger holder 30 Plunger 32 First electromagnetic coil 34 First core 36 Second electromagnetic coil 38 Second core 40 First bearing 42 Second bearing 46 Electronic control unit (ECU)

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Claims (1)

(57) [Claim 1] In an electromagnetically driven gas exchange device that drives a gas exchange valve by applying an electromagnetic force to a plunger urged by an elastic body, the plunger is held at a moving end. Micro-vibration applying means for applying micro-vibration to the plunger; excitation-current stopping means for stopping supply of excitation current caused by the electromagnetic force when the plunger is slightly displaced away from the end of movement When, wherein the micro-vibrating means, said excitation current, the elastic member
And natural frequency of spring-mass system including plunger
Excitation current control means to oscillate at a frequency substantially equal to the number
A step, and wherein the exciting current stopping means is based on an amplitude state of the exciting current.
And stopping the exciting current .