JPH10274101A - Control device for pressure response type actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a pressure-response operation type actuator to improve durability of a position sensor. SOLUTION: A control device for a pressure-response operation type actuator 5 is provided with a pressure chamber 5a to which a variable pressure is fed, and a moving partition wall 5b displaced in response to a pressure in a pressure chamber, and drives an object 5A to be driven through displacement of the moving partition wall 5b. In this case, the control device comprises a non-contact type position sensor 15 to detect the displacement position P of the moving partition wall 5b; various sensors 14 to detect the control states Re, TW, and θof the object to be driven; pressure sources 19 and 20 to feed a variable pressure to the pressure chamber 5a; a first opening closing means 17 to regulate the feed time of a variable pressure; a second opening closing means 21 to regulate a variable pressure into an atmosphere pressure: and an ECU 13A to control opening and closing of the first and second opening closing means 17 and 21 in response to the displacement position of the moving partition wall 5b and the control state of the object to be driven.

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 a pressure-responsive actuator which is displaced in accordance with a pressure supplied to a pressure chamber, and more particularly to a pressure sensor having improved durability of a position sensor for feeding back a displacement position. The present invention relates to a control device for a responsive actuator.

[0002]

2. Description of the Related Art Conventionally, a pressure-responsive actuator which has a pressure chamber to which a variable pressure is supplied and a movable partition which is displaced in accordance with the pressure in the pressure chamber, and drives a driven object by the displacement of the movable partition is often used. Are known.

An object driven by this type of actuator is, for example, an EGR valve of an EGR pipe which bypasses an exhaust pipe and an intake pipe of an internal combustion engine. Further, a control device for purifying exhaust gas by controlling the EGR flow rate of an internal combustion engine is disclosed in Japanese Patent Publication No. 6-68282, Japanese Patent Publication No. 2-46787, Japanese Patent Publication No. 4-75388 or Japanese Patent Publication No. 5-69981. Reference can be made to gazettes and the like.

FIG. 8 is a block diagram showing a control device of a conventional pressure-responsive actuator disclosed in Japanese Patent Publication No. 6-68282, for example, in which an EGR valve of a diesel engine is used as the pressure-responsive actuator. Is shown.

In FIG. 8, an intake pipe 2 and an exhaust pipe 3 are connected to a cylinder 1 which is a main body of a diesel engine. The piston 1b driven by the ignition and explosion of the air-fuel mixture supplied to the combustion chamber 1a in the cylinder 1 rotates a crankshaft (not shown).

[0006] An air cleaner 2 a is provided at an intake port of the intake pipe 2, and an EGR pipe 4 branched from the exhaust pipe 3 and bypassed is connected to a downstream side of the intake pipe 2. The supplied air flows as shown by the arrow and is supplied to the cylinder 1.

At the connection between the EGR pipe 4 and the intake pipe 2, a pressure-responsive actuator 5 (hereinafter simply referred to as "actuator") and an object to be driven by the actuator 5, that is, an EGR valve 5A for adjusting the EGR flow rate, are provided. Is provided.

The actuator 5 urges the pressure chamber 5a to which the variable pressure is supplied, the movable partition wall 5b which is displaced according to the pressure in the pressure chamber 5a, and the movable partition wall 5a in a direction to close the EGR valve 5A. A movable partition 5b having a spring 5c;
The EGR valve 5A is driven by the displacement.

The pressure chamber 5 a of the actuator 5 is connected to a pressure regulating valve, that is, a solenoid valve 7 via a negative pressure passage 6. The solenoid valve 7 includes a coil 7a serving as an open / close drive source, a valve body 7b that is moved by excitation of the coil 7a, an open passage 12 opened to the atmosphere,
A spring 7c for urging the valve body 7b is provided on the open side of the open passage 12, and is connected to a pressure source, that is, a vacuum pump 9 via the other negative pressure passage 8.

The valve body 7b of the solenoid valve 7 is
In response to the excitation of the coil 7a, the negative pressure passage 8 or the open passage 12 is duty-driven, and the inside of the negative pressure passage 6 is set to a negative pressure when the negative pressure passage 8 is opened, and when the open passage 12 is opened (the coil 7a
When the pressure in the negative pressure passage 6 is set to the atmospheric pressure,
The supply pressure to the pressure chamber 5a is adjusted.

Normally, the inner diameter of each passage 6, 8 and 12 is 2
In this case, the inner diameters of the negative pressure passage 8 and the open passage 12 are reduced to about 0.8 mm in order to give priority to pressure controllability over control response.

An ECU (Electronic Control Unit) 13 composed of a microcomputer is provided with driving information from various sensors,
That is, the cooling water temperature TW from the water temperature sensor 14, the engine rotation speed Re from a rotation sensor (not shown),
A control signal C for exciting the coil 7a of the solenoid valve 7 based on a lever opening θ from a lever opening sensor (not shown) for detecting the opening θ of the lever for adjusting the injection amount of the fuel pump. Generate

Next, the operation of the conventional control device for a pressure-responsive actuator shown in FIG. 8 will be described. First,
When the coil 7a is excited by the control signal C from the ECU 13 and the valve body 7b closes the negative pressure passage 8, the negative pressure passage 6 communicates with the open passage 12, and the pressure chamber 5a of the actuator 5 becomes the atmospheric pressure. .

As described above, when the pressure chamber 5a is set to the atmospheric pressure, the movable partition 5b moves by the urging force of the spring 5c, and drives the EGR valve 5A in the closing direction. Therefore, the EGR pipe 4 is closed, and the EGR flow from the exhaust pipe 3 is suppressed to zero.

On the other hand, when the coil 7a is excited by the control signal C from the ECU 13 and the valve body 7b of the solenoid valve 7 closes the open passage 12, the negative pressure passage 8 is connected to the negative pressure passage 6 and the actuator 5 Negative pressure is supplied to the pressure chamber 5a.

As described above, when the pressure in the pressure chamber 5a is set to a negative pressure, the movable partition 5b moves against the urging force of the spring 5c, and drives the EGR valve 5A in the opening direction. Thereby, the EGR pipe 4 is opened according to the amount of movement of the movable partition 5b, and the EGR flow from the exhaust pipe 3 to the intake pipe 2 increases.

Accordingly, the duty of the coil 7a is controlled by changing the excitation duty (excitation ratio within a predetermined cycle) of the coil 7a, so that the negative pressure from the vacuum pump 9 and the pressure from the open passage 12 are changed according to the duty value. Since the atmospheric pressure is intermittently supplied to the negative pressure passage 6, the pressure in the negative pressure passage 6 can be set to a predetermined value. Also, E
The CU 13 determines the duty control amount of the coil 7a based on the map data according to the operation state.

However, as shown in FIG.
When the feedback control of the displacement position of b is not performed, cylinder 1
The control error of the EGR flow rate (EGR rate) with respect to the intake air amount to the air can be suppressed only to about 13%.

Therefore, as disclosed in Japanese Patent Publication No. 4-75388 or Japanese Patent Publication No. 5-69981, a position sensor (not shown) for detecting the displacement position of the movable partition 5b is provided, and the position sensor of the EGR valve 5A is provided. A device for feedback controlling the opening has also been proposed.

However, in the conventional apparatuses described in the above publications, all use a contact type position sensor, so that the durability of the sliding portion in the position sensor is limited.

In particular, in the case of a diesel engine, since the engine temperature is lowered by controlling the EGR flow rate from a high-temperature combustion state, the operation frequency of the position sensor is high, and wear of the sliding portion cannot be ignored.

In the case of a commercial vehicle such as a truck or a bus using a diesel engine, the practical mileage is 50
It is about 10,000km to 1,000,000km, and for passenger cars (100,000km)
), The durability is required for a long use period, but this durability cannot be realized.

When the solenoid valve 7 is duty-driven, the pressure of the pressure source is constantly consumed, so that the pump must be driven to maintain the pressure source. Further, since the vacuum pump 9 (negative pressure source) is used as the pressure source, the control width of the pressure supplied to the pressure chamber 5a is a maximum of 1 atm (the difference between the atmospheric pressure and the vacuum) even if the pressure is reduced in vacuum. And cannot be set large.

[0024]

As described above, the conventional pressure-responsive actuator control apparatus performs feedback control of the amount of movement of the movable partition 5b corresponding to the opening of the EGR valve 5A to be driven. Since the contact-type position sensor is used, there is a problem that the durability of the sliding portion in the position sensor is low and not practical.

Further, since the pressure supplied to the pressure chamber 5a is duty-controlled, there is a problem in that the pressure consumption of the pressure source increases. Further, since the vacuum pump 9 is used as the pressure source, there is a problem that the pressure control width supplied to the pressure chamber 5a of the actuator 5 cannot be set large.

The present invention has been made to solve the above problems, and has as its object to provide a control device for a pressure-responsive actuator with improved durability of a position sensor.

Another object of the present invention is to provide a control device for a pressure-responsive actuator in which the durability of a position sensor is improved and the pressure consumption of a pressure source is suppressed.

Another object of the present invention is to provide a pressure-responsive actuator control device that improves the durability of a position sensor and realizes high-speed response of the actuator.

[0029]

A control device for a pressure-responsive actuator according to the present invention has a pressure chamber to which a variable pressure is supplied, and a movable partition which is displaced according to the pressure in the pressure chamber. A pressure-responsive actuator control device that drives a driven object by the displacement of a non-contact type position sensor that detects a displacement position of a movable partition, various sensors that detect a control state of the driven object, and a pressure chamber. A pressure source for supplying the variable pressure, a first opening / closing means for adjusting the supply time of the variable pressure, a second opening / closing means for adjusting the variable pressure to the atmospheric pressure, a displacement position and driving of the movable partition An ECU that controls opening and closing of the first and second opening / closing means according to the control state of the target.

Further, in the control device for the pressure-responsive actuator according to the present invention, the ECU keeps the first and second opening / closing means closed when the displacement position of the movable partition reaches the target value. Things.

In the control device for a pressure-responsive actuator according to the present invention, the pressure source supplies a positive pressure higher than the atmospheric pressure.

The position sensor by the pressure-responsive actuator control device according to the present invention includes a bridge circuit using an MR element, a movable magnet opposed to the MR element, and differentially amplifying the output voltage of the bridge circuit. And a differential amplifier circuit.

The control device for a pressure-responsive actuator according to the present invention employs, as a drive target, an EGR valve of an EGR pipe that bypasses an exhaust pipe and an intake pipe of an internal combustion engine.

Further, the control device for the pressure-responsive actuator according to the present invention includes third opening / closing means having an air passage having a larger sectional area than the air passage of the second opening / closing means, and the ECU includes an EGR valve. When closing,
The third opening / closing means is opened to close the EGR valve.

Further, the control device for a pressure-responsive actuator according to the present invention is applied to a diesel engine as an internal combustion engine, in which the EGR valve is closed, for the acceleration state of the diesel engine. .

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. Elements similar to those described above are designated by the same reference numerals and will not be described in detail.

In this case, the movable partition 5b is provided with the movable partition 5
A non-contact type position sensor 15 for detecting the displacement position P of b is connected. The pressure chamber 5 a of the actuator 5 is connected to a solenoid valve 17 through a positive pressure passage 16.
(First opening / closing means) and the solenoid valve 21 (second
Opening / closing means).

The solenoid valve 17 is connected to a pressure source, that is, a positive pressure pump 19 and a positive pressure tank 20 via the other positive pressure passage 18, and is moved by a coil 17a serving as an open / close drive source and an excitation of the coil 17a. And a spring 17c for urging the valve body 17b to the closing side. The positive pressure from the positive pressure tank 20 is adjusted to, for example, 6 to 10 atm, and may be branched and supplied to other in-vehicle loads (not shown) such as a brake.

The solenoid valve 21 includes a coil 21a serving as an open / close drive source, a valve body 21b that is moved by excitation of the coil 21a, a spring 21c for urging the valve body 21b to the open side, and a positive pressure passage 16. And an open passage 22 that is open to the atmosphere.

The valve bodies 17b and 21b of the solenoid valves 17 and 21 respond to the excitation of the coils 17a and 21a by the control signals C1 and C2 from the ECU 13A.
The supply pressure to the pressure chamber 5a is adjusted by supplying a positive pressure or atmospheric pressure from the pressure chamber 5a. In this case, the inside diameter of each of the passages 16, 18, and 22 is designed to be about 2 mm.

The ECU 13A controls the coils 17a and 21a of the solenoid valves 17 and 21 based on not only the coolant temperature TW, the engine speed Re and the lever opening θ but also the displacement position P fed back from the position sensor 15. Control signals C1 and C2 for exciting are generated.

FIG. 2 is an enlarged sectional view showing a specific configuration example of the position sensor 15 in FIG. In FIG. 2, the position sensor 15 includes a movable partition 5 at one end 23a.
b (see FIG. 1) is connected to the slidable sensor body 23
And a magnet 24 provided on a side end surface of the sensor body 23,
A spring 25 for urging the sensor body 23 toward one end 23a;
An MR element 26 is provided on the holding portion of the sensor main body 23 so as to face the magnet 24, and a signal processing circuit 27 that forms a bridge circuit (described later) with the MR element 26.

FIG. 3 is a circuit diagram showing a specific configuration of the signal processing circuit 27 in FIG. 3, the signal processing circuit 27 includes a bridge circuit 28 inserted between the power supply voltage VCC and the ground GND, and a differential amplifier circuit 29 for differentially amplifying a pair of output voltages of the bridge circuit 28. I have.

The bridge circuit 28 includes an MR element 26 inserted between the power supply voltage VCC and the ground GND,
Series resistors R3 and R4 connected in parallel with element 26
The MR element 26 includes a movable magnet 2
4 includes a series resistor R1 and R2 whose resistance value changes according to the position.

The voltage at the junction of resistors R1 and R2 is
A voltage is applied to one input terminal of the differential amplifier 29, and a resistor R
The voltage at the connection point between 3 and R4 is applied to the other input terminal of the differential amplifier 29.

As a result, the differential amplifier 29 responds to the resistance value of the resistors R1 and R2, which change according to the position of the movable magnet 24 (corresponding to the displacement of the movable partition 5b), and changes the displacement of the movable partition 5b. The position P is generated as an output voltage.

FIG. 4 is a characteristic diagram showing the relationship between the displacement amount of the magnet 24 of the position sensor 15 and the output voltage. The horizontal axis represents the linear position [mm] of the magnet 24, and the vertical axis represents the output voltage corresponding to the displacement position P. [V]. In FIG. 4, the output voltage (displacement position P) of the position sensor 15 is
It changes in a linear function in proportion to the amount of change in the linear displacement of the (movable partition 5b).

FIG. 5 is an explanatory diagram showing a control mode of the solenoid valves 17 and 21 according to control signals C1 and C2 from the ECU 13A. In FIG. 5, the solenoid valves 17 and 21 are not duty-controlled according to the pressure holding mode, the pressure increasing mode and the pressure decreasing mode, but are controlled to be either open or closed, respectively. The pressure in the pressure chamber 5a is variably controlled by the supply time of each pressure to the pressure chamber 5a.

Next, the operation of the first embodiment of the present invention shown in FIG. 1 will be described with reference to the flowchart of FIG. 6 together with FIGS. First, the ECU 13A
Indicates various sensor information indicating the operating state (cooling water temperature TW,
Based on the engine rotation speed Re and the lever opening θ), EG is referred to by referring to map data stored in advance.
The target position Po of the R valve 5A is read (step S
1).

Subsequently, the ECU 13A determines a control mode corresponding to the target position Po and generates control signals C1 and C2 for the solenoid valves 17 and 21 in order to supply a target pressure to the pressure chamber 5a. As a result, the coils 17a of the solenoid valves 17 and 21 are
And 21a are excited according to each control mode (see FIG. 5).

That is, in the pressure increasing mode, the solenoid valve 17 is opened and the positive pressure through the positive pressure passage 18 is supplied to the pressure chamber 5a.
Moves against the urging force of the spring 5c, and the EGR valve 5
A is driven in the opening direction.

In the pressure drop mode, since the solenoid valve 21 is opened and the atmospheric pressure is supplied to the pressure chamber 5a, the movable partition wall 5b is moved by the urging force of the spring 5c to close the EGR valve 5A. Drive in the forming direction.

At this time, the ECU 13A determines the displacement position P detected by the position sensor 15 as feedback.
Is read as the actual position of the movable partition 5b (step S
2) A deviation ΔP (= P−Po) from the target position Po is calculated (step S3), and it is determined whether or not the absolute value of the deviation ΔP is equal to or smaller than a predetermined value K (step S4).

In step S4, if | ΔP | ≦
K (ie, YES), the displacement position P
Assuming that the (actual position) has reached the target position Po, the solenoid valves 17 and 21 are closed to execute the pressure holding mode (step S5).

In step S4, | ΔP |>
If it is determined to be K (that is, NO), the displacement position P (actual position) has not reached the target position Po, and subsequently, it is determined whether the deviation ΔP is a positive value (step S).
6). Here, the upward direction in FIG. 1 (the direction in which the EGR valve 5A is closed) is defined as the positive direction of the displacement position P.

In step S6, if ΔP> 0
If it is determined (YES), since the actual position (displacement position P) is on the positive side (upper side in FIG. 1) of the target position Po, the movable partition 5b is moved in the direction to open the EGR valve 5A. In order to perform the downward movement, the solenoid valve 17 is opened to execute the pressure increasing mode (step S
7).

In step S6, ΔP ≦ 0
If it is determined as NO, the actual position (displacement position P) is on the negative side (lower side in FIG. 1) than the target position Po, so that the movable partition wall is moved in the direction to close the EGR valve 5A. 5b is moved upward by the solenoid valve 2
1 is released to execute the pressure drop mode (step S
8).

Each control mode step S5, S7 or S
After the execution of step 8, the process returns to step S1, and the processing routine of FIG. 6 is repeatedly executed. In this way, the feedback control of the displacement position P allows the opening of the EGR valve 5A to be appropriately controlled in accordance with the operating state.

That is, although the opening degree of the EGR valve 5A, that is, the EGR flow rate does not completely correspond to the opening degree of the EGR valve 5A, it can be made substantially coincident with the target position Po by the feedback control of the displacement position P. , Can be adjusted with high accuracy within a few percent error.

Further, since the position sensor 15 is a non-contact type position sensor having no sliding portion, the position sensor 15 does not wear due to aging, and can secure sufficient durability.

In particular, when the present invention is applied to a position sensor 15 for detecting a displacement position P of an actuator 5 for driving an EGR valve of a diesel engine, durability corresponding to a traveling distance of 1,000,000 km or more can be realized.

Since a positive pressure was used as the pressure source,
The pressure can be controlled in the range of 6 to 10 atmospheres, and the driving force of the movable partition wall 5b can be sufficiently secured.

Since the solenoid valves 17 and 21 are controlled to open and close based on feedback control, it is not necessary to adjust the positive pressure supplied from the positive pressure tank 20 with high precision. Of the regulator (not shown) can be omitted.

When the displacement position P of the movable partition 5b reaches the target position Po, the mode is set to the pressure holding mode (step S5), and the solenoid valves 17 and 21 are closed.
Since the consumption of the positive pressure from the positive pressure tank 20 is suppressed, other in-vehicle loads (such as brakes) from the positive pressure tank 20 are reduced.
The function of supplying the positive pressure to is not impaired.

Embodiment 2 In the first embodiment, only the single solenoid valve 21 is provided for closing the EGR valve 5A. However, in consideration of a case where the present invention is applied to a diesel engine for an automobile, the EGR valve 5A is closed. In order to increase the closing ability of the EGR valve 5A in the case of (for example, in an accelerated state), a third opening / closing means for rapidly releasing the pressure in the pressure chamber 5a to the atmospheric pressure may be provided.

FIG. 7 is a block diagram showing a second embodiment of the present invention. Elements similar to those described above are given the same reference numerals and will not be described in detail. In this case, the positive pressure passage 16 is provided with a solenoid valve 30 (third opening / closing means) for supplying atmospheric pressure, and the sectional area of the air passage of the solenoid valve 30 is equal to that of the air passage of the solenoid valve 21. It is set larger than the cross-sectional area.

That is, the solenoid valve 30 includes a coil 30a serving as an open / close drive source, a valve body 30b which is moved by exciting the coil 30a, a spring 30c for urging the valve body 30b to the closing side, and a positive pressure passage 16 And an open passage 32 for opening the air to the atmosphere.

The valve body 30b of the solenoid valve 30
Is a coil 30 based on a control signal C3 from the ECU 13B.
In response to the excitation of a, the positive pressure passage 16 is opened to the atmospheric pressure,
The pressure in the pressure chamber 5a is quickly adjusted to the atmospheric pressure.

Therefore, in order to improve the responsiveness of the pressure control, the inner diameter of each of the air passage connecting the solenoid valve 30 and the positive pressure passage 16 and the inner diameter of the open passage 32 to the atmosphere are designed to be larger than 2 mm. I have.

When the ECU 13B determines the acceleration state of the internal combustion engine based on, for example, a lever opening degree θ equal to or greater than a predetermined value, the ECU 13B generates a control signal C3 to excite the coil 30a, and the solenoid valve 30 having a large air passage. To quickly close the EGR valve 5A. As a result, the movable partition 5b of the actuator 5 drives the EGR valve 5A to close upward, so that the amount of EGR taken into the cylinder 1 is rapidly reduced, the amount of intake air is increased, and the combustion state in the cylinder 1 is increased. Is improved.

At this time, the ECU 13B outputs the control signal C2
, The coil 21a of the solenoid valve 21 may be demagnetized to open the solenoid valve 21 at the same time. However, most of the air in the positive pressure passage 16 is supplied to the solenoid valve 3 having a smaller fluid resistance component than the solenoid valve 21.
It passes through the zero side and escapes into the atmosphere.

As described above, by realizing the high-speed response of the actuator 5 when the EGR valve 5A is closed, for example, during engine acceleration, the EGR flow rate is immediately suppressed, and the intake air supplied to the cylinder 1 is reduced. The amount increases quickly, preventing black smoke emissions and
The output torque increases and the acceleration performance improves.

In particular, in the case of a diesel engine automobile,
If the decrease in the EGR flow rate is delayed during acceleration, the amount of harmful carbon particles contained in the exhaust gas increases, so that the effect of increasing the control response speed when the EGR valve 5A is closed is remarkable.

In each of the first and second embodiments, the actuator 5 is an actuator for opening and closing the EGR valve of a diesel engine. However, the same operation and effect can be obtained with any other actuator. Needless to say.

As a pressure source connected to the pressure chamber 5a of the actuator 5, a positive pressure pump 1 for generating a positive pressure is used.
9 and the positive pressure tank 20 are applied, but it goes without saying that any pressure source that generates a negative pressure can be applied.

Although the solenoid valves 17, 21 and 30 are used as the opening and closing means for pressure adjustment, it goes without saying that other opening and closing means can be applied.

Although the MR element 26 is used for the signal processing circuit 27 in the position sensor 15, any other position sensor can be used.

[0078]

As described above, according to the first aspect of the present invention, there is provided a pressure chamber to which a variable pressure is supplied, and a movable partition which is displaced in accordance with the pressure in the pressure chamber. A control device for a pressure-responsive actuator that drives a driven object, a non-contact type position sensor that detects a displacement position of a movable partition, various sensors that detect a control state of a driven object, and a variable pressure in a pressure chamber. Pressure source for supply, first opening / closing means for adjusting the supply time of the variable pressure, second opening / closing means for adjusting the variable pressure to the atmospheric pressure, control of the displacement position of the movable partition and the driven object ECU for controlling opening and closing of first and second opening / closing means according to the state
Therefore, there is an effect that a control device for a pressure-responsive actuator in which the durability of the position sensor is improved can be obtained.

According to a second aspect of the present invention, in the first aspect, the ECU changes the closed state of the first and second opening / closing means when the displacement position of the movable partition reaches the target value. Since the pressure is held, there is an effect that a control device for a pressure-responsive actuator in which the pressure consumption of the pressure source is suppressed can be obtained.

According to a third aspect of the present invention, in the first aspect, since the pressure source supplies a positive pressure higher than the atmospheric pressure, a pressure responsive device capable of sufficiently generating a driving force. There is an effect that a control device of the type actuator is obtained.

According to a fourth aspect of the present invention, in the first aspect, the position sensor includes a bridge circuit using the MR element, a movable magnet opposed to the MR element, and an output voltage of the bridge circuit. Since a differential amplifier circuit for differential amplification is included, a control device for a pressure-responsive actuator that effectively realizes a non-contact position sensor is obtained.

According to a fifth aspect of the present invention, in the first aspect, since the EGR valve of the EGR pipe that bypasses the exhaust pipe and the intake pipe of the internal combustion engine is applied as a driving target, the durability of the position sensor is improved. There is an effect that a control device for a pressure-responsive actuator with particularly improved performance can be obtained.

According to a sixth aspect of the present invention, in the fifth aspect, a third opening / closing means having an air passage having a larger cross-sectional area than the air passage of the second opening / closing means is provided.
U opens the third opening / closing means and closes the EGR valve when the EGR valve is closed, so that the control device of the pressure-responsive actuator realizing the high-speed response of the actuator is provided. There is an effect that can be obtained.

According to a seventh aspect of the present invention, in the sixth aspect, a diesel engine is applied as the internal combustion engine and the EGR valve is closed, and the acceleration state of the diesel engine is targeted. In addition, there is an effect that a control device for a pressure-responsive actuator which particularly effectively realizes high-speed response of the actuator can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a specific configuration of a position sensor in FIG.

FIG. 3 is a circuit diagram illustrating a configuration example of a signal processing circuit in FIG. 2;

FIG. 4 is a characteristic diagram showing a relationship between an output voltage and a displacement amount of a position sensor in FIG.

FIG. 5 is an explanatory diagram illustrating a relationship between a pressure control mode and an open / close state of an opening / closing unit according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating a pressure control operation according to the first embodiment of the present invention.

FIG. 7 is a configuration diagram showing a second embodiment of the present invention.

FIG. 8 is a configuration diagram showing a conventional pressure-responsive actuator control device.

[Explanation of symbols]

1 cylinder, 2 intake pipe, 3 exhaust pipe, 4 EGR pipe, 5
A EGR valve, 5 pressure responsive actuator, 5a
Pressure chamber, 5b movable partition, 13A, 13BECU, 1
4 water temperature sensor, 15 position sensor, 16, 18
Positive pressure passage, 17, 21, 30 solenoid valve, 1
9 positive pressure pump, 20 positive pressure tank, 24 magnets, 26
MR element, 28 bridge circuit, 29 differential amplifier circuit, P displacement position, Po target value, Re engine speed, TW cooling water temperature, θ lever opening.

Claims (7)

[Claims] 1. A control device for a pressure-responsive actuator, comprising: a pressure chamber to which a variable pressure is supplied; and a movable partition that is displaced in accordance with the pressure in the pressure chamber, wherein a drive target is driven by the displacement of the movable partition. A non-contact type position sensor for detecting a displacement position of the movable partition, various sensors for detecting a control state of the driven object, a pressure source for supplying a variable pressure to the pressure chamber, First opening / closing means for adjusting the supply time of the variable pressure, second opening / closing means for adjusting the variable pressure to the atmospheric pressure, and a displacement position of the movable partition and a control state of the driven object, A control device for a pressure-responsive actuator, comprising: an ECU that controls opening and closing of the first and second opening / closing means. 2. The ECU according to claim 1, wherein the ECU keeps the first and second opening / closing means closed when the displacement position of the movable partition reaches a target value. Pressure-responsive actuator control device. 3. The control device according to claim 1, wherein the pressure source supplies a positive pressure higher than the atmospheric pressure. 4. The position sensor includes: a bridge circuit using an MR element; a movable magnet opposed to the MR element; and a differential amplifier circuit for differentially amplifying an output voltage of the bridge circuit. The control device for a pressure-responsive actuator according to claim 1, wherein: 5. The control device for a pressure-responsive actuator according to claim 1, wherein the drive target is an EGR valve of an EGR pipe that bypasses an exhaust pipe and an intake pipe of the internal combustion engine. 6. An air conditioner comprising: a third opening / closing means having an air passage having a larger cross-sectional area than an air passage of the second opening / closing means; wherein the ECU sets the EGR valve to a closed state when closing the EGR valve. The control device for a pressure-responsive actuator according to claim 5, wherein the opening / closing means (3) is opened to close the EGR valve. 7. The pressure-responsive actuator according to claim 6, wherein the internal combustion engine is a diesel engine, and when the EGR valve is closed, the diesel engine is in an accelerated state. Control device.