JP2002054759A - Controller for solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely open and close a valve by reduced consumption power and reduce impact at and noise generated when a needle collides against an electromagnet even if dynamic friction force fluctuates for a movable part. SOLUTION: A movable part speed estimate part 52 calculates a speed signal of the movable part based on a position signal of the movable part detected by a movable part position sensor 1. A loss energy calculation part 54 calculates loss energy of the movable part based on these position signal and speed signal. A current control amount computing part 51 calculates a current command value of the electromagnet based on these position signal, speed signal, and loss energy signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electromagnetically driven valve driven by an electromagnetic force and an elastic force, and more particularly to a control device for an electromagnetically driven valve suitable for intake and exhaust valves of an internal combustion engine.

[0002]

2. Description of the Related Art In a drive system of an intake / exhaust valve of an internal combustion engine, an electromagnetic drive valve which drives a valve by an electromagnetic force has been proposed instead of a conventional cam drive system in which a valve is driven by a cam. According to this electromagnetically driven valve, in addition to eliminating the need for a valve drive cam mechanism, the opening / closing timing of the intake / exhaust valve can be easily optimized according to the operating state of the internal combustion engine. It is possible to improve output and fuel efficiency.

[0003] Such an electromagnetically driven valve usually includes a mover of a soft magnetic material, a pair of opposing electromagnets for attracting the mover by electromagnetic force, and a spring for urging the mover to a neutral position of both electromagnets. , And the movable element is alternately attracted to the pair of electromagnets to open and close the valve body linked to the movable element.

[0004] In this motion system, the natural frequency f ₀ of the spring-mass system is given by assuming that the mass of the movable part such as the mover and the valve is m, the composite spring coefficient is k, and there is no in-cylinder pressure or dynamic friction. √ (k
/ M). Then, when the movable portion is attracted by the electromagnet at one of the two displacement ends and is stationary, the potential energy due to the spring force is maximum (or maximum), and the kinetic energy is minimum 0. When the energization of the electromagnet is stopped and the movable part starts moving from one displacement end to the other displacement end, the movable part accelerates while converting potential energy into kinetic energy, and the kinetic energy at the center of both displacement ends. And the speed is maximized, and the potential energy is minimized. Thereafter, the kinetic energy is decelerated while converting the kinetic energy into potential energy. When the kinetic energy reaches the other displacement end, the kinetic energy and the speed become zero.

[0005] On the other hand, in the cylinder of the internal combustion engine, in-cylinder pressure is generated by the combustion gas. The in-cylinder pressure varies depending on the engine speed and load. When the in-cylinder pressure fluctuates, the movement of the movable portion of the electromagnetically driven valve, in particular, the exhaust valve that opens to resist the in-cylinder pressure and the movement of the mover that drives the valve are affected. Change. It is desirable that the electromagnetically driven valve be reliably opened and closed with the minimum required power consumption.

For this reason, in the prior art disclosed in Japanese Patent Application Laid-Open No. H11-257036 (hereinafter referred to as a first prior art), the magnitude of the in-cylinder pressure is detected or estimated, and the magnitude of the in-cylinder pressure is reduced. The value of the current supplied to the electromagnet is determined based on the current value.

In an internal combustion engine using an electromagnetically driven valve,
If a part of the valve or the movable part violently collides with the electromagnet when the valve is closed and when the valve is fully opened, noise and vibration are generated, giving an occupant discomfort, and reducing the durability of the electromagnetically driven valve. Therefore, in Japanese Patent Application No. 10-35991 (hereinafter referred to as a second prior art), the speed of the movable portion of the electromagnetically driven valve is detected.
A technique has been disclosed in which the detected speed is fed back to current control to reduce the collision speed between the movable part and the electromagnet, thereby reducing impact and collision noise and increasing durability.

[0008]

However, in addition to the in-cylinder pressure, there is a dynamic friction force between the movable portion and the fixed portion that slidably supports the movable portion, as a force that affects the movement of the movable portion. Even when the dynamic frictional force fluctuates, the movement of the movable part changes, so that the minimum current value flowing to the electromagnet to attract the mover differs.

That is, when the dynamic frictional force fluctuates when the movable part moves from one stationary position to the other stationary position,
When the potential energy changes to kinetic energy, the energy amount changing to heat energy changes as an energy loss,
The kinetic energy of the movable part fluctuates. As a result, the position and speed of the movable portion change, and the minimum current value of the electromagnet for reliably drawing the movable portion to the other stationary position also changes. This dynamic frictional force changes due to the temperature of the movable portion, wear, viscosity of the lubricant, rattling of the shaft, and the like, and is difficult to detect.

As described above, in the first prior art, the current value of the electromagnet is determined by focusing only on the in-cylinder pressure without considering the dynamic frictional force. ) Can be compensated for, but cannot compensate for the change in the loss of mechanical energy when the dynamic friction force fluctuates.

Therefore, according to the first prior art, when the dynamic friction force fluctuates and becomes larger than the dynamic friction force assumed when tuning the magnitude of the current of the electromagnet in accordance with the in-cylinder pressure, the movable element is moved to the electromagnet. There is a possibility that the electromagnetic force required for the displacement is not generated, and the opening and closing of the valve is not reliably performed. In order to reliably open and close the valve, even when the mover moves away from the electromagnet, it is necessary to attract the electromagnet again, which requires a large current to flow, resulting in a significant increase in power consumption. There was a problem. In addition, the size of the current control circuit increases, which causes a problem of securing a mounting space, an increase in weight, and an increase in cost.

When the dynamic friction force fluctuates and becomes smaller than the dynamic friction force assumed when tuning the magnitude of the current of the electromagnet in accordance with the in-cylinder pressure, it is necessary to displace the mover to the electromagnet. An electromagnetic force greater than the minimum electromagnetic force is generated, which may increase power consumption.

Further, there is a problem that an electromagnetic force larger than an electromagnetic force for bringing the mover into contact with the electromagnet at a low speed is generated, and the mover violently collides with the electromagnet, thereby causing vibration and noise. Was.

FIG. 12 shows the response of the speed, position, current and in-cylinder pressure when the movable part is controlled by the feedback control according to the second prior art. The feedback control is started when the movable section reaches the feedback control start position. The solid line in FIG. 12 is the response when the cylinder is misfired and no cylinder pressure is generated, and the broken line is the response when the cylinder pressure is generated.

For example, it is assumed that the parameters of the feedback control are tuned based on a state in which no in-cylinder pressure is generated. When the in-cylinder pressure is generated, the energy loss of the movable portion is larger than when no in-cylinder pressure is generated, and the speed of the movable portion at the start of the feedback control, that is, the kinetic energy is smaller. Therefore, a large amount of current flows to quickly compensate for the loss energy by the feedback function. Since the power consumption of the electromagnet is proportional to the square of the current, there has been a problem that the power consumption is significantly increased. In addition, since the current increases, the current control circuit increases in size, and there is a problem of securing mounting space, an increase in weight,
This leads to an increase in cost.

Alternatively, as shown in FIG. 13, when the parameters of the feedback control are tuned based on the case where there is an in-cylinder pressure (broken line), when the misfire is lost and the in-cylinder pressure disappears (solid line), the feedback control at the start of the feedback control is performed. Although the speed of the movable portion, that is, the kinetic energy is large, a current starts to flow to compensate for the energy lost when the in-cylinder pressure is generated. Although the value of this current is reduced by the feedback, the electromagnetic force does not act in the direction of pushing the mover, so that the valve may collide violently with the electromagnet.

Even if a current is applied to the electromagnet in accordance with the in-cylinder pressure before the feedback control is started by combining the first prior art and the second prior art, the movable part is lost because the dynamic friction force is not considered. The same problem occurs because the energy (loss energy) cannot be accurately compensated.

The first prior art also discloses a technique for detecting an in-cylinder pressure with an in-cylinder pressure sensor. If an inexpensive in-cylinder pressure sensor is used, the pressure detection accuracy will deteriorate. An in-cylinder pressure sensor with good detection accuracy is expensive. In the case where the cylinder pressure sensor is attached by making a hole in the cylinder, not only a problem concerning the sensor that processing is troublesome, but also a dynamic friction force cannot be taken into consideration by using the cylinder pressure sensor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and accurately compensates for lost energy due to in-cylinder pressure and dynamic frictional force during movement of a movable portion, thereby opening and closing a valve with low power consumption. It is an object of the present invention to provide a control device of an electromagnetically driven valve that can reliably perform the operation and control the speed at which the mover collides with the electromagnet to reduce the impact and noise of the collision between the mover and the electromagnet. .

[0020]

According to the first aspect of the present invention, there is provided an electromagnet, an elastic body, an electromagnetic force generated by the electromagnet, and an elastic force generated by the elastic body. An electromagnetically driven valve control device for controlling an electromagnetically driven valve comprising a movable element to be driven and a valve to be driven by the movable element, wherein the controller detects or estimates a position of a movable portion which is the movable element or the valve. Position detecting means, speed detecting means for detecting or estimating the speed of the movable part, and energy for calculating mechanical energy contained in the movable part based on the detected position and the detected speed. The gist of the present invention is to include a calculation unit and a current control unit that controls a current value to be supplied to the electromagnet based on the calculated mechanical energy.

According to a second aspect of the present invention, in the control apparatus for an electromagnetically driven valve according to the first aspect, the energy calculating means is configured such that the movable element is stationary at one stationary position. The movable part is lost while the movable part moves from one stationary position to the other stationary position due to the generated elastic force, based on the mechanical energy contained when the movable part is lost. The gist is that a loss energy is calculated from the detected position and the detected speed, and the current control means controls a current value to be supplied to the electromagnet based on the calculated loss energy. .

According to a third aspect of the present invention, in the control apparatus for an electromagnetically driven valve according to the first aspect, the energy calculating means is configured such that the movable element is stationary at one stationary position. The lost energy lost by the movable part during the movement of the movable part due to the generated elastic force, based on the potential energy of the movable part when And the current control means controls the value of the current supplied to the electromagnet based on the calculated energy loss.

According to a fourth aspect of the present invention, there is provided a control device for an electromagnetically driven valve according to the first aspect, wherein the movable element is stationary at one of the stationary positions. With reference to the potential energy of the movable part when it is, the loss energy lost by the movable part from the start of movement of the movable part by the generated elastic force to the time when the electromagnet is energized is calculated. The gist of the invention is that the current control means calculates a current value to be supplied to the electromagnet based on the calculated energy loss based on the calculated position and the detected speed.

[0024]

According to the present invention, the dynamic energy contained in the movable part is calculated from the position of the movable part detected by the position detecting means and the speed of the movable part detected by the speed detecting means. Since the current value to be applied to the electromagnet is determined based on the dynamic energy, even if the motion of the movable portion changes due to the fluctuation of the dynamic frictional force, the change in the motion is reflected in the change in the dynamic energy and the current value is changed. Will be corrected. Therefore,
The mover is securely attracted to the electromagnet with minimal power consumption,
In addition, the speed at which the mover collides with the electromagnet is suppressed, the sound of collision between the mover and the electromagnet is reduced, and the valve can be stably opened and closed. Further, since the in-cylinder pressure sensor is not used, the control device can be simplified and the problem of increasing the sensor cost can be solved.

According to the second aspect of the present invention, the movable part is moved by the elastic force based on the dynamic energy contained before the movable part moves. Energy loss. The dynamic energy contained before the moving part moves is maximum, and the moving part starts to move from there, causing energy loss due to kinetic friction and the like. According to the present invention, most of the loss energy lost by the movable part can be calculated based on the mechanical energy contained before the movable part moves, so that the effect of the invention according to claim 1 can be obtained. In addition, the valve can be more stably opened and closed.

According to the third aspect of the present invention, the mechanical energy to be calculated is based on the potential energy of the movable part when the movable element is in contact with the electromagnet at one of the stationary positions or is held near the electromagnet. The loss energy lost by the movable part when the movable part is moved from one stationary position to the other stationary position by the elastic force. The potential energy when the movable part is in contact with or held near the electromagnet is the maximum, and the movable part starts to move from there, causing energy loss due to dynamic friction and the like. According to the present invention, since most of the loss energy lost by the movable portion can be calculated, the same effect as the effect of the second aspect of the invention can be obtained.

According to the present invention, the mechanical energy to be calculated is based on the potential energy of the movable portion when the movable element is in contact with the electromagnet at one of the stationary positions or is held near the electromagnet. The energy lost from when the movable portion starts moving from one stationary position to the other stationary position due to elastic force until the electromagnet is energized.
Calculating the energy loss immediately after the moving part starts moving,
Subsequent loss energy is not considered in the current control amount. Further, after the electromagnet is energized, the movement of the movable part is assisted by the electromagnetic force, so that it is difficult to calculate the loss energy. According to the present invention, since the energy loss immediately before the electromagnet is energized can be calculated, in addition to the effect of the second aspect, the valve can be more stably opened and closed.

[0028]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing an overall configuration in which a control device for an electromagnetically driven valve according to the present invention is applied to an internal combustion engine for a vehicle.

As shown in FIG.
A valve 23 (only a single valve is shown in FIG. 1) serving as an intake valve or an exhaust valve is provided on a cylinder head 20 fixed to an upper portion of the cylinder head 20. A retainer 17 is fixed to an upper portion of a valve shaft 19 extending upward from the valve 23.
A spring 15 for urging the valve 23 to the valve closing side is provided between the cylinder head 7 and the cylinder head 20.

A housing 25 serving as a case of the solenoid valve is provided upright on the upper part of the cylinder head 20. Inside the housing 25, the valve-closing electromagnet 11 and the valve-opening electromagnet 12 are fixed at positions facing each other up and down at a predetermined interval. A mover 13 is supported between the valve-closing electromagnet 11 and the valve-opening electromagnet 12 by a mover shaft 18 so as to be slidable up and down.

A retainer 16 is fixed to the armature shaft member 18 at a position above the valve-closing side electromagnet 11, and a movable element 13 is provided between the inner surface of the ceiling of the housing 25 and the retainer 16.
A spring 14 for urging the valve toward the valve opening side is provided.

A movable part position sensor 1 using a laser displacement meter or the like for detecting the position of the movable part and outputting a position signal is provided on the ceiling part of the housing 25. This position signal is transmitted to the electromagnetically driven valve. The information is transmitted to the control device 5 which is a control device.

The control device 5 further includes an engine control ECU
A valve opening command / valve closing command is transmitted from the controller 6, and the control device 5 controls the valve closing electromagnet current controller 2 and the valve opening electromagnet current controller 3.
, A current target value is output. The control device 5 is constituted by a microprocessor or the like.

The valve-closing-side electromagnet current control section 2 and the valve-opening-side electromagnet current control section 3 perform PWM control according to the input current target values from the power supply section 4 to the respective electromagnets 11 and 12.
The electromagnet can be controlled by supplying a current to the electromagnet.

FIG. 2 is a block diagram showing an embodiment of a control device for an electromagnetically driven valve according to the present invention. In the figure, the control device 5 is based on a position signal output by the movable portion position sensor 1, a current signal output by the electromagnet current controllers 2 and 3, and a valve opening command and a valve closing command output by the engine control ECU 6. A generated electromagnetic force estimating unit 53 for estimating the electromagnetic force generated by the electromagnets 11 and 12, and a movable unit for estimating a moving speed of the movable unit based on the position signal and the electromagnetic force signal output from the generated electromagnetic force estimating unit 53. A speed estimating unit 52, a loss energy calculating unit 54 that calculates a loss energy of the movable unit based on the position signal and the speed signal output by the movable unit speed estimating unit 52, a loss energy, a position signal, a speed signal, and engine control. ECU6
A current control amount calculating section 51 for calculating a command value of a current to be supplied to the valve-closing-side electromagnet current control section 2 or the valve-opening-side electromagnet current control section 3 according to the valve opening command and the valve closing command output by the controller. ing.

Movable part position sensor 1, valve closing side electromagnet current control unit 2, valve opening side electromagnet current control unit 3, engine control EC
U6 is the same component as the component described in FIG.

The correspondence between the components of claims 1 to 4 and the components of FIG. 2 is as follows. The position detecting means for detecting the position of the movable part, which is a mover or a valve, corresponds to the movable part position sensor 1. Speed detecting means for detecting or estimating the speed of the movable portion corresponds to the movable portion speed estimating portion 52 and the generated electromagnetic force estimating portion 53. Energy calculating means for calculating the mechanical energy of the movable section from the detected position and the estimated speed corresponds to the loss energy calculating section 54. Further, based on the calculated energy, the current control means for controlling the value of the current supplied to the electromagnet is controlled by the current control amount calculating section 5.
1, a valve closing side electromagnet current control unit 2 and a valve opening side electromagnet current control unit 3.

Next, the operation of the electromagnetically driven valve and the control device for the electromagnetically driven valve will be described with reference to FIGS. The mover 13 is suspended by springs 14 and 15 and is positioned approximately at the center of the valve-closing electromagnet 11 and the valve-opening electromagnet 12 when the valve-closing electromagnet 11 and the valve-opening electromagnet 12 are not energized. As described above, the dimensions of the springs 14 and 15 are set. Further, the spring coefficients of the respective springs 14 and 15 are set so that the time required for closing and opening the valve becomes a desired time.

Here, the natural frequency f ₀ of the spring-mass system composed of the springs 14 and 15 and the movable portion including the valve 23 and the movable element 13 is represented by the composite spring coefficient of the spring 14 and the spring 15. Assuming that k and the total inertial mass of the movable part are m, f ₀ = √
(K / m).

Now, in the initial operation before starting the engine,
The valve-closing-side electromagnet 11 has a period corresponding to the natural frequency f _0.
And the valve-opening side electromagnet 12 is energized alternately. Then, by resonating the movable portion, the amplitude of the movable portion is gradually increased. At the final stage of the initial operation, the movable element 13 is attracted to, for example, the valve-closing electromagnet 11, and the attracted state is maintained.

Next, when the engine is started or in normal operation, for example, when the valve is opened, the current of the valve-closing electromagnet 11 is first turned off, and the movable portion starts moving downward by the force of the spring. Due to energy loss due to in-cylinder pressure, dynamic frictional force, and the like in the cylinder 21, the mover 13 cannot be moved to the valve fully open position only by the force of the spring. Therefore, mover 1
3 approaches the valve-opening electromagnet 12, at a position z ₁ where the electromagnetic force is effective, the loss energy of the movable portion is calculated by the loss energy calculation section 54, and the current value based on the loss energy is calculated by the current control amount calculation section 51. Is energized to the valve-opening electromagnet 12 to assist the movement of the mover 13.

Next, from the position z ₂ near the position where the mover 13 contacts the valve-opening electromagnet 12, the current control amount calculating section 51 is used to reduce the impact of the mover 13 colliding with the valve-opening electromagnet 12. , A target speed of the movable portion is generated according to the position of the movable portion, and feedback control for causing the speed of the movable portion to follow the target speed is started. The target speed of the movable part is the mover 1
3 is generated so as to become smaller as it approaches the valve-opening-side electromagnet 12. The speed of the moving part is calculated by the moving part speed estimating part 52.
Estimate by The movable section speed estimating section 52 is configured as an observer.

FIG. 9 is a flowchart showing the overall flow of the embodiment. The routine shown in this flowchart is executed for each control cycle.

First, the position of the movable section is detected by the movable section position sensor 1 (step S10), and the moving speed of the movable section is detected by the movable section speed estimating section 52 as an observer (step S20). Then, it is determined whether the movable portion reaches the position z ₁ (step S31).

[0045] Until the movable portion reaches the position z _1, the movable portion moves by the force of the spring. When the time when the movable part reaches the position z ₁ is determined (step S31, S30), calculates the energy loss of the movable portion from the position and speed of the moving part (Step S40), the current command value based on the energy loss Is determined (step S60).

[0046] Then, it is determined whether the position of the movable portion _{z 2} or more (step S70). Position of the movable portion position z ₁ or more, and when less than the predetermined position z _2, and outputs a current command value based on energy loss in the electromagnet current controlling section (step S100). The electromagnetic force of the electromagnet is generated by the current control to control the movable part (step S110).

[0047] When the position of the movable part is equal to or higher than a predetermined position z _2, and generates a target speed according to the position (step S8
0), the electromagnetic force command value of the electromagnet for feedback-controlling the speed of the movable portion to the target speed is calculated by the current control amount calculating portion 51
And a current command value is calculated from the electromagnetic force command value and the position of the movable portion by nonlinear compensation, and the electromagnet current control portion 2
3 (step S90). The electromagnetic force of the electromagnets 11 and 12 is generated by the current control to control the movable part (step S110).

Hereinafter, the method of calculating the loss energy, the current control based on the loss energy, the generation and feedback control of the target speed, and the estimation of the movable portion speed by the observer will be described in detail.

[Method of Calculating Loss Energy] Loss energy, which is mechanical energy lost by the movable portion due to in-cylinder pressure and dynamic frictional force, is calculated by the loss energy calculating section 54.

The dynamic energy E of the movable part is calculated from the position z of the movable part and the velocity V of the movable part as shown in equation (1).
The dynamic energy E of the movable part is the sum of the kinetic energy and the potential energy. Hereinafter, mechanical energy is also simply abbreviated as energy.

[0051]

(Equation 1) Here, z ₀ is the neutral position of the mover 13. The coordinates of the position z of the movable part are such that the position of the movable element in contact with the valve-closing electromagnet is the origin, and the valve-opening electromagnet direction is positive. m is the total inertial mass of the movable part, and k is the composite spring coefficient.

Although the composite spring coefficient k may change with time, it can also be determined by initializing the electromagnetically driven valve based on the attenuation rate of the amplitude of the movable part.

The total inertia mass m is equal to the armature member 18 and the valve shaft 1.
When 9 separates, it becomes smaller. In order to prevent the valve from closing due to thermal expansion of the valve shaft 19 and the like, the movable member 18 and the valve shaft 19 are formed as separate bodies, and the movable member 18
A gap called a valve clearance is provided between the valve shaft 19 and the valve shaft 19. When the valve 23 is seated on the valve seat 24,
The mover member 18 and the valve shaft 19 are separated, and the mover further moves by the length of the gap to contact the electromagnet. The length of the gap is about several hundred μm, and the stroke of the movable part is about 1 cm.
It is about. The movable member 18 and the valve shaft 1 are moved while the movable portion is moving.
9 is separated only slightly in one stroke, and there is almost no error in calculating the energy of the movable part.

When the valve is opened, the movable member 18 and the valve shaft 19 are united while the movable portion is moving, and the energy of the movable portion changes due to the impact. In the present invention, the energy after the energy is changed by this impact is calculated. Therefore, the energy of the movable part can be accurately calculated by the equation (1) and the following equation.

Before the movable portion starts to move, the energy E ₀ contained in the movable portion in the state where the movable element 13 is in contact with the electromagnet is only potential energy.

(Equation 2) Equation (2) is obtained. When the mover 13 moves from the state in which the mover 13 is in contact with the electromagnet, the total energy E _pc lost by the movable portion due to the in-cylinder pressure and the kinetic friction force is given by the following equations (1) and (2).

[Number 3] _{E PC = E 0 -E ... (} 3) becomes (3).

FIG. 3 is a diagram showing the relationship between the position of the movable part and the speed. When the speed in the position z ₁ with a movable part and V _1, the total energy E of the movable portion at a position z ₁ there is loss
_{pc 1}

(Equation 4) Becomes

As described above, the loss energy calculating section 54 receives the position z ₁ and the speed V ₁ of the movable section and outputs the total energy E _pc1 (loss energy) lost by the movable section.

Z ₁ is a position where the loss energy is calculated, and is selected to be equal to the energization start position in the present invention. Z ₁ which is a power distribution start position, the electromagnetic force exceeds the neutral position z ₀ as shown in FIG. 3 is set to a position becomes effective. The electromagnetic force is applied to the gap between the mover and the electromagnet (the position of the movable part when the valve is closed and z ₁
Is not effective if the difference is large. Therefore, z ₁ which is a power distribution start position is set in a range where the electromagnetic force is enabled.

FIG. 4 is a flowchart for explaining the operation of the loss energy calculating section 54. The routine shown in this flowchart is executed for each control cycle.

First, the position of the movable part is detected (step S).
10), the moving speed of the movable part is detected by the observer (step S20). Position of the movable part to determine whether reached a predetermined position z ₁ (step S30), by substituting the velocity detection value to V ₁ upon reaching (step S40),
calculating the energy loss of the movable portion on the basis of z ₁ and _{V 1} to (4) below (step S50).

[0061]

[Current Control Based on Loss Energy and Generation of Target Speed and Feedback Control] Next, referring to FIGS. 5, 6, and 7, current control based on loss energy, generation of a target speed, and feedback will be described. The control will be described.
FIG. 5 shows a current command value I ₁ based on the loss energy E _pc1 .
It is an example of a calculation method of. As shown in FIG. 5, the current command value is determined substantially in proportion to the energy loss.

FIG. 6 is a block diagram for explaining the operation of the current control amount calculating section 51.

In FIG. 6, the current control amount calculating section 51
A position signal switching SW 101 for switching a position signal according to the direction of movement of the mover depending on whether the operation of opening or closing the valve is controlled, a current command value calculation unit 103 for calculating a current command value based on the loss energy, , Current command value switching SW for switching the current command value for each area where the mover is located
105, an energizing electromagnet switching switch 107 for switching whether to output the current command value to the valve closing side or the valve opening side electromagnet current control unit, a target speed generation unit 109 for generating a target speed of the movable unit, a target speed Subtractor 111 for calculating the difference between the signal and the speed signal, and an electromagnetic force command value switch SW 113 for switching the direction of the electromagnetic force acting on the valve opening operation and the valve closing operation.
An electromagnetic force nonlinearity compensator 115 for compensating for the nonlinearity of the electromagnetic force according to the gap between the mover and the electromagnet; a multiplier 117 for multiplying the reciprocal of the number of turns of the coil; and a gap for switching the gap direction by opening / closing the valve. And a signal switching SW 119.

A valve opening command and a valve closing command are input from the engine control ECU 6 to the current control amount calculating section 51, and a position signal from the movable section position sensor, a speed signal from the movable section speed estimating section 52, a loss energy calculating section 54 are provided. Respectively, the loss energy values are input. Then, the current control amount calculation unit 51
Outputs a current command value to the valve-closing electromagnet current control unit 2 or the valve-opening electromagnet current control unit 3.

The current command value switch SW 105 switches the current command value according to the section of the position signal z of the mover. That is, 0 in ≦ z <z ₁ interval, the current command value until the moving part reaches the position z ₁ from starting to move 0
And no current flows through the electromagnet. In the section of z ₁ ≦ z <z ₂ , that is, from the time when the movable part reaches the position z ₁ to the position z ₂ where the speed control of the mover is started, the current command value I ₁ proportional to the loss energy is output. is, by an electromagnet current control unit, a current value to be supplied to the electromagnet is controlled to the current command value I _1.

After reaching the section z ₂ ≦ z, that is, the position z ₂ near the position where the mover 13 comes into contact with the electromagnet, the control is switched to the speed feedback control in order to control the speed of the movable portion with high accuracy. The target speed r (z) of the movable unit is generated by the target speed generator 109 according to the position z.

Estimation of the generated target speed and movable portion speed
Multiplying the difference from the speed signal output by the unit 52 by a control gain
Electromagnetic force command value f^*Is calculated. When the control gain is open
Is K _{i *}, -K when valve is closed_{i *}Becomes Open / close valve size
Disconnection is a valve opening command output by the engine control ECU 6, a valve closing finger.
Made by decree.

The electromagnetic force nonlinear compensator 115 calculates a target ampere-turn value _AT from the calculated electromagnetic force command value f ^* and the gap between the mover and the electromagnet, and calculates the target ampere-turn value _AT as the number of coil turns. Dividing by nt results in a current command value i ^* .

Whether the current command value is transmitted to the valve-opening electromagnet current control unit 3 or the valve-closing electromagnet current control unit 2 in response to the valve opening command and the valve closing command output by the engine control ECU 6 Is selected. Since the position coordinates of the movable part are such that the direction of the valve-opening electromagnet is positive with respect to the position where the movable element contacts the valve-closing-side electromagnet, the gap between the movable element and the electromagnet is a value obtained by subtracting the position signal z of the movable portion from the stroke S _t from the valve-opening electromagnet to the valve-closing electromagnet. Also, contrary to when the valve is open,
The gap between the mover and the electromagnet when the valve is closed is the position of the movable part.

FIG. 7 is a diagram for explaining a method of generating a target speed by the target speed generating section 109 in FIG. On the plane indicating the position and velocity of the movable part, points movable portion reaches the position _{z 2 a} from _{(z 2, V} 2), in terms of position _{z r} to stop the movable portion _b (z _{r, V} r) The trajectory connecting up to a straight line is the target speed. That is, the target speed is given by the following equation (5). V ₂ is the speed at which the movable portion reaches the position z _2, using the velocity estimates of the observer.

[0072]

(Equation 5) For example, the _{z r} mover 13 is chosen equal to the position in contact with the electromagnet and choosing _{V r} and 0.02 m / s, the target speed at which the movable element is in contact with the electromagnet becomes 0.02 m / s. Further, the z _r select equal to the previous position of the movable element 13 comes into contact with the electromagnet, when the V _r is set to 0, the mover is performed controlled with the goal to be held in a position away from the electromagnet, The sound of collision of the mover 13 with the electromagnet is eliminated.

Next, the configuration of a feedback control system for causing the speed of the movable portion to follow the target speed r (z) will be described.

[0074]

(Equation 6) A current command value is obtained by electromagnetic force non-linear compensation from the electromagnetic force command value f ^* according to the equation (6) and the gap between the mover and the electromagnet. The electromagnetic force nonlinear compensation outputs a target ampere turn value _AT according to the electromagnetic force and the gap. By dividing the target ampere turn value _AT by the number of coil turns nt, the current command value i ^*
Becomes The current supplied to the electromagnet is controlled by the electromagnet current control unit to the calculated current command value.

[0075]

(Equation 7) The electromagnetic force non-linear compensation outputs an ampere-turn value according to the electromagnetic force and the gap between the mover and the electromagnet. The electromagnetic force nonlinear compensation can be created as an inverse function of the input and output of the electromagnetic force map. As shown in FIG. 10, the electromagnetic force map outputs an electromagnetic force according to an ampere turn value (current × the number of coil turns nt) and a gap between the mover and the electromagnet.
The electromagnetic force map is a map determined by the shapes and materials of the electromagnet and the mover, and is created by actually measuring the electromagnetic force. The electromagnetic force map can also be created by means such as a magnetic field analysis.

[Estimation of Moving Part Speed by Observer] Next, a method of estimating the moving part speed by the observer will be described.

The speed of the movable part necessary for the calculation of the loss energy and the feedback control is determined by the generated electromagnetic force estimating section 53.
From the estimated value of the electromagnetic force generated by the electromagnet and the position of the movable part by the movable part speed estimation 52.

The generated electromagnetic force estimating unit 53 performs the engine control E
The electromagnetic force signal is output according to the valve opening command and the valve closing command output by the CU 6 and the position signal of the movable unit. Generated electromagnetic force estimation unit 5
3 uses the electromagnetic force map described above. The electromagnetic force map outputs an electromagnetic force according to an ampere turn value (current × the number of coil turns) and a gap between the mover and the electromagnet.
Here, the gap between the armature and the electromagnet is comprised of a stroke S _t from the open valve electromagnet of the movable element to the valve-closing electromagnet and the value obtained by subtracting the position signal z of the movable portion when the valve is opened. When the valve is closed, the gap between the mover and the electromagnet is at the position of the movable portion. The ampere-turn value is obtained by multiplying the current value by the number of coil turns nt. When the valve is opened, the current signal of the current control unit of the valve-opening electromagnet is used as the current value, and when the valve is closed, the current signal of the current control unit of the valve-closing electromagnet is used.

An observer is used for the movable section speed estimating section 52. The equation of motion of the moving part is

(Equation 8) Can be expressed as Here, f is the electromagnetic force, z is the position of the movable part, m
Is the synthetic inertial mass, k is the synthetic spring coefficient, c is the viscosity coefficient, d
Is a disturbance. When equation (8) is converted into a state equation,

(Equation 9) FIG. 8 shows a time chart of the control of the embodiment. In time t ₁ in which the movable portion reaches the position z _1, to calculate the energy loss E _pc1 of the movable portion from the position and speed. Next, a current command value I ₁ is determined for the loss energy, and the current is set to the command value I ₁
To control. From the time t ₂ the movable part reaches the position z _2, feedback control of the speed of the movable portion of the target speed as r (z).

Next, effects of the embodiment will be described.

According to the embodiment of the present invention, in a control device of an electromagnetically driven valve for driving a valve for intake and exhaust of an internal combustion engine by an elastic force and an electromagnetic force, a valve when a movable element is in contact with an electromagnet is used. Based on the potential energy of the movable part, the loss energy that the movable part has lost due to the in-cylinder pressure and the kinetic frictional force between the time when the movable part moves by the elastic force and the time when the electromagnet is energized is calculated, and based on the loss energy, The determined current is applied to the electromagnet, and immediately before the mover contacts the electromagnet,
Since the feedback control for causing the speed of the movable portion to follow the target speed is started, the following effects can be obtained.

(1) Since the dynamic friction force is not taken into account in the first prior art, when the dynamic friction force fluctuates, the response of the position and speed of the movable part changes, and in order to prevent the valve from being reliably opened and closed. In some cases, a large current control circuit for passing a large current was required, or the mover and the electromagnet violently collided with each other, generating noise. However, since the current value of the electromagnet is determined based on the loss energy, not only the in-cylinder pressure but also the kinetic energy of the movable portion consumed by the kinetic friction force can be accurately compensated, and the movable element and the electromagnet do not collide violently. The valve can be reliably opened and closed.

(2) In FIG. 11, when the movable portion is controlled only by the feedback control according to the second prior art (broken line), the electromagnet is energized according to the energy loss before the feedback control is started according to the present invention. The comparison in the case where the movable part is controlled (solid line) is shown. The feedback control is started when the movable section reaches a predetermined position. In the present invention, the peak value of the current is low, and the current is supplied for a longer time (because the current is supplied even before the feedback control is started). That is, the kinetic energy of the movable portion consumed by the in-cylinder pressure and the dynamic frictional force is gradually supplemented. In the second prior art, the peak value of the current is high, and the current is supplied for a shorter time. That is, the kinetic energy of the movable portion consumed by the in-cylinder pressure and the dynamic frictional force is rapidly supplemented. Therefore, in the present embodiment, the peak value of the current flowing through the electromagnet is smaller than the peak value of the current in the second related art, so that the current control circuit can be reduced and simplified. Even if the feedback control start point is the same time, in the second related art, since the current does not flow before the feedback control starts, the peak value of the current at the time of the feedback control increases.

(3) In the second prior art, a large current flows through the electromagnet. Since the power consumption is proportional to the square of the current, the power consumption increases when a large current flows. In the present embodiment, since the current flowing through the electromagnet is small, power consumption can be reduced.

(4) In the first prior art, an in-cylinder pressure sensor was used. However, in this embodiment, a control device is configured without using an in-cylinder pressure sensor as in the second prior art.
The control device can be reduced in size and cost.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of an electromagnetically driven valve to which the present invention is applied.

FIG. 2 is a configuration diagram of an embodiment.

FIG. 3 is a graph showing a trajectory of a movable part on a position / velocity phase plane for explaining a method of calculating a loss energy in the embodiment.

FIG. 4 is a flowchart of a loss energy calculation unit according to the embodiment.

FIG. 5 is a graph illustrating a method for determining a current command value based on loss energy according to the embodiment.

FIG. 6 is a block diagram of a current control amount calculation unit according to the embodiment.

FIG. 7 is a diagram illustrating generation of a target speed according to the embodiment.

FIG. 8 is a response diagram illustrating a flow of control according to the embodiment.

FIG. 9 is an overall flowchart of the embodiment.

FIG. 10 is a block diagram of a generated electromagnetic force estimating unit of the embodiment.

FIG. 11 is a diagram illustrating the effect of the embodiment.

FIG. 12 is a diagram illustrating a problem of the second conventional technique.

FIG. 13 is a diagram illustrating a problem of the second conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Movable part position sensor 2 Valve closing side electromagnet current control part 3 Valve opening side electromagnet current control part 5 Control device 6 Engine control ECU 51 Current control amount calculation part 52 Movable part speed estimation part 53 Generated electromagnetic force estimation part 54 Loss energy calculation Department

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F16K 37/00 F16K 37/00 Z F term (reference) 3G018 AB09 AB19 BA38 CA12 DA35 DA41 DA45 EA22 EA31 EA32 FA01 FA06 FA07 GA01 GA03 GA14 GA18 GA31 GA33 GA37 3G092 AA11 DA01 DA02 DA03 DF05 DG09 EA01 EA02 EA03 EA04 EA22 EC02 EC06 FA06 FA11 FA12 FA13 FA14 FA25 GA01 GA03 GA08 HA13X HA13Z 3H065 AA01 BA01 BA04 BB11 CA01 CA03 CA07 3DB106 DB07 DA07 FB46 KK17

Claims (4)

[Claims] An electromagnetic device comprising an electromagnet, an elastic body, a movable element driven by an electromagnetic force generated by the electromagnet and an elastic force generated by the elastic body, and a valve driven by the movable element. A control device for an electromagnetically driven valve that controls a drive valve, comprising: a position detection unit that detects or estimates a position of a movable unit that is the mover or the valve; and a speed detection unit that detects or estimates a speed of the movable unit. Energy calculating means for calculating mechanical energy contained in the movable portion based on the detected position and the detected speed; and energizing the electromagnet based on the calculated mechanical energy. A control device for an electromagnetically driven valve, comprising: current control means for controlling a current value. 2. The energy calculation means according to claim 1, wherein said movable part is configured to generate one of said movable parts based on said generated elastic force based on mechanical energy contained when said movable part is stationary at one stationary position. Calculating the loss energy lost by the movable unit from the detected position and the detected speed while moving from the stationary position to the other stationary position; and The control device for an electromagnetically driven valve according to claim 1, wherein a current value to be supplied to the electromagnet is controlled based on the loss energy. 3. The energy calculating means according to claim 1, wherein said movable portion is moving by said generated elastic force with reference to a potential energy of said movable portion when said movable member is stationary at one stationary position. Detecting the loss energy lost by the movable portion from the detected position and the detected speed, the current control means calculates a current value to be supplied to the electromagnet based on the calculated loss energy. The control device for an electromagnetically driven valve according to claim 1, wherein the control is performed. 4. The energy calculating means according to claim 1, wherein the movable element moves with the generated elastic force based on a potential energy of the movable section when the movable element is stationary at one of the stationary positions. Calculating the loss energy lost by the movable part from the start to the time when the electromagnet is energized from the detected position and the detected speed; the current control unit calculates the loss energy The control device for an electromagnetically driven valve according to claim 1, wherein a value of a current supplied to the electromagnet is controlled based on the control value.