JPH0565902A - Fluid pressure actuator device - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the response of the fluid pressure actuator device. [Structure] An actuator body 12 for changing the opening degree of a valve body 5 of an EGR device of a vehicle, a negative pressure tank 13, a communication passage 19 for communicating these, a passage 23 branched from the communication passage 19, The second electromagnetic opening / closing valves 14 and 15, the opening sensor 21, and the controller 16 that selects one of the electromagnetic opening / closing valves 14 and 15 to open / close by duty ratio control.
The negative pressure actuator device 10 is provided with the above. The controller 16 controls the target opening degree L _t supplied from the CU 4,
Which solenoid on-off valve is operated is determined based on the magnitude relationship with the measured opening L _m supplied from the opening sensor 21, and the duty factor at the time of operation is set to the measured opening L _m and the target opening. It is determined according to the difference from L _t and the volume V of the pressure chamber 18. Therefore, the duty factor can be set as large as possible, and the opening degree of the valve body 5 can be changed quickly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure actuator device for opening and closing an on-off valve and the like by utilizing the pressure of fluid.

[0002]

2. Description of the Related Art A control valve of an exhaust gas recirculation device (hereinafter referred to as an EGR device) mounted on a vehicle is
It is operated to open and close by a fluid pressure actuator device that uses the negative pressure of the engine intake system. A conventional fluid pressure actuator device includes, for example, an actuator main body having a negative pressure chamber partitioned by a belofrum, a communication passage for supplying the negative pressure of an intake manifold to the negative pressure chamber, and an atmosphere opening branching from the middle of the communication passage. First opening and closing the road and the open air path
Of the electromagnetic on-off valve, a second electromagnetic on-off valve that opens and closes the communication passage at a position between the atmosphere open path and the intake manifold, and a controller that selectively operates each electromagnetic on-off valve. There is.

The actuator body is formed integrally with the control valve of the EGR device, and the valve body of the control valve is attached to the bellows. Therefore, when the controller selectively operates each electromagnetic on-off valve to change the pressure in the negative pressure chamber, the bellows is displaced and the opening degree of the control valve is changed. The negative pressure chamber is set to a small size so that the bellows can be quickly displaced by a slight pressure change.

The controller monitors the current opening of the valve based on a signal from an opening sensor attached to the control valve. And this current opening L
Deviation Δ between _m and the target opening L _t calculated by the EGR device
L is calculated and each electromagnetic on-off valve is feedback-controlled. That is, when the target opening L _t is larger than the current opening L _{m and the} deviation ΔL is positive, the controller opens the second electromagnetic opening / closing valve to introduce the negative pressure into the negative pressure chamber, and the target Opening L
_{When t} is smaller than the present opening L _m and the deviation ΔL is negative, the first electromagnetic on-off valve is opened to introduce the atmospheric pressure into the negative pressure chamber.

Then, when the absolute value of the deviation ΔL is larger than the predetermined value ε ₁ , the controller fully opens one of the solenoid on-off valves to rapidly drive the actuator main body to change the opening of the control valve at once. Then, when the absolute value of the deviation ΔL becomes equal to or less than the predetermined value ε ₁ , one of the solenoid on-off valves is duty ratio controlled with a predetermined duty coefficient, and the actuator body is gently driven to finely adjust the opening of the control valve.

This duty factor is set in consideration of the displacement characteristics of the belofram. That is, the change characteristic between the pressure change amount in the pressure chamber and the displacement amount of the bellows is not linear. For example, when the volume V of the pressure chamber increases by β, the volume V _a changes to the volume (V _a + β). When it changed
When the volume V _b changes to the volume (V _b + β),
The amount of change in the opening of the control valve is different. This tendency becomes more remarkable because the negative pressure chamber is set to be small.

For this reason, the duty factor is set to a small value, the rate of change of the volume V is made gentle, and the opening of the control valve is made gentle. As a result, the opening degree of the control valve can be finely adjusted over the entire range from the fully closed position to the fully opened position of the control valve, and the reliability of the opening operation of the control valve is improved.

Further, when the absolute value of the deviation ΔL becomes smaller than the predetermined value ε ₂ , the controller considers that the current opening L _m and the target opening L _t match each other and fully closes the electromagnetic opening / closing valve. Stop the actuator body.

[0009]

However, in the above conventional fluid pressure actuator device, since the duty factor is set to a small value, when the absolute value of the deviation ΔL becomes smaller than the predetermined value ε _2. In addition, there is a problem that the change speed of the opening degree of the control valve is extremely slow and the fluid pressure actuator device is inferior in responsiveness.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a fluid pressure actuator device having excellent responsiveness while maintaining the reliability of operation.

[0011]

In order to achieve the above object, according to the present invention, there is provided means for detecting the current position of a driven member, and the driven member is moved to a target position while performing feedback control. In the fluid pressure actuator device, the actuator main body having a pressure chamber partitioned by a movable film and an output transmission member connecting the driven member and the movable film, the pressure source, and the pressure chamber and the pressure source are communicated with each other. Fluid passage, an atmosphere opening passage provided in the middle of the fluid passage, a first electromagnetic opening / closing valve for opening and closing the atmosphere opening passage, and a position between the pressure source and the atmosphere opening passage in the middle of the fluid passage. A second electromagnetic on-off valve, a volume detecting means for detecting the volume of the pressure chamber, and one of the first and second electromagnetic on-off valves to select and open / close by duty ratio control, Pressure chamber And a controller for changing the product, and the controller selects which one of the first and second electromagnetic on-off valves to operate based on the magnitude relationship between the current position of the driven member and the target position. In addition, the duty factor for operating the selected solenoid valve is determined according to the difference between the current position and the target position and the volume of the pressure chamber.

[0012]

By selectively controlling the duty ratio of the first and second electromagnetic on-off valves, the atmospheric pressure or the pressure of the pressure source is introduced into the pressure chamber of the actuator body, and the movable membrane is displaced. When the movable film is displaced, the output transmission member moves the driven member. The controller selects whether to operate the first electromagnetic on-off valve or the second electromagnetic on-off valve based on the magnitude relationship between the current position of the driven member and the target position. Thereby, the driven member can be driven toward the target position. Then, the duty coefficient for controlling the duty ratio of the electromagnetic opening / closing valve is determined according to the difference between the current position and the target position and the size of the volume of the pressure chamber. Therefore, the duty factor can be set large in accordance with the difference between the current position and the target position and the size of the volume of the pressure chamber, the rate of change of the volume of the pressure chamber becomes large, and the movable membrane,
That is, the displacement speed of the driven member increases.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a fluid pressure actuator device to which the present invention is applied. The fluid pressure actuator device 10 is a negative pressure actuator device and is attached to, for example, an EGR device.

The EGR device includes an exhaust gas recirculation passage 2 for connecting an exhaust pipe and an intake pipe (both not shown), and a control valve unit (hereinafter simply referred to as a valve unit) interposed in the exhaust gas recirculation passage 2. 3) and an EGR control unit 4 for calculating a target opening (target position) L _t of the valve unit 3 based on signals from various sensors. The valve unit 3 includes a valve body 5 that adjusts the flow rate of exhaust gas in the exhaust gas recirculation path 2, an actuator body 12 that is a component of a fluid pressure actuator device 10, and the like, as will be described later. Also, EG
The R control unit (hereinafter referred to as CU) 4 supplies the target opening _Lt to the controller 16 of the fluid pressure actuator device 10 each time the calculated target opening _Lt is updated.

A fluid pressure actuator device (hereinafter referred to as a negative pressure actuator device) 10 includes an actuator body 12, a negative pressure tank 13, and first and second solenoid on-off valves 1.
4, 15, a controller 16 and the like. The negative pressure actuator device 10 changes the measured opening L _m of the valve unit 3, more specifically, the valve body 5, toward the target opening L _t supplied from the CU 4 by performing feedback ratio control.

The actuator body 12 is a so-called bellows-type actuator, and defines a negative pressure chamber 18 with a beloflam 12b arranged in a casing 12a. The casing 12a is interposed at a predetermined position of the exhaust gas recirculation passage 2. A port 12c facing the negative pressure chamber 18 is formed at a predetermined position of the casing 12a,
One end 19a of the communication passage 19 is connected to the port 12c.

A valve shaft 12e is connected to the bellows 12b.
Has been done. The valve shaft 12e is integrally formed with the valve body 5.
Is shaped. Therefore, this bellofram 12b is displaced.
Then, the opening degree of the valve body 5 changes. Also, belofram 12
b is the valve unit due to the return spring 12d.
It is always urged in the direction to close g. Also, act
An opening sensor 21 is attached to the user body 12.
ing. The opening sensor 21 measures the opening of the valve body 5 with an electric resistance.
Measured opening L detected by using resistance _mAs controller
Supply to 16. The valve body 5 is fitted with a bellows via a valve shaft 12e.
Since it is connected to the ram 12b, the controller 16
Is the measured opening L of the valve body 5._mNegative pressure chamber 18
When the volume V is large, the actual measured opening L of the whole 5_mBut
When it is large, it is determined that the volume V of the negative pressure chamber 18 is small.
It That is, the opening sensor 21 measures the valve unit 3
Opening L_mAnd a negative pressure chamber.
It is also a volume detecting means for detecting the volume V of 18.

At the negative pressure tank 13, the other end 1 of the communication passage 19 is provided.
9b is connected. Therefore, the negative pressure tank 13 and the negative pressure chamber 18 of the actuator body 12 are communicated with each other through the communication passage 19. The negative pressure tank 13 has a predetermined volume, is connected to a negative pressure source, for example, an intake manifold (not shown) via a check valve 20, and stores a predetermined negative pressure. Therefore, the negative pressure tank 13 can supply a predetermined negative pressure to the negative pressure chamber 18.

A passage 23 is branched from the middle of the communication passage 19, and its tip 23a is open to the atmosphere. The first electromagnetic opening / closing valve 14 is attached in the middle of the passage 23. The first electromagnetic on-off valve 14 is a normally closed on-off valve, and when the controller 16 excites the solenoid 14a, the valve body 14b opens the passage 23. When the passage 23 is opened, the atmosphere is supplied into the negative pressure chamber 18 through the communication passage 19. The amount of the atmosphere supplied into the negative pressure chamber 18, that is, the magnitude of the pressure is determined by the opening time of the electromagnetic opening / closing valve 14.

The second solenoid opening / closing valve 15 is provided in the middle of the communication passage 19 and between the passage 23 and the negative pressure tank 13. The solenoid on-off valve 15 is a normally closed on-off valve, and when the controller 16 excites the solenoid 15a, the valve body 15
b opens the communication passage 19. When the communication passage 19 is opened, a predetermined negative pressure is supplied from the negative pressure tank 13 into the negative pressure chamber 18.
The amount of the negative pressure supplied into the negative pressure chamber 18, that is, the magnitude of the negative pressure is determined by the opening time of the electromagnetic opening / closing valve 14.

The controller 16 has a microcomputer. The opening sensor 21 and the CU 4 are electrically connected to the input side of the controller 16, and the electromagnetic on-off valves 14 and 15 are electrically connected to the output side. The controller 16 follows the procedure described below and
4, 15 are excited to adjust the pressure in the negative pressure chamber 18, and the measured opening L _m of the valve body 5 is changed to the target opening L _t supplied from the CU 4.
Change the direction to match. The controller 16 feedback-controls the opening degree of the valve body 5 by repeating this procedure.

Further, the memory in the controller 16 includes
A valve opening control routine described later, a predetermined value ε ₀ , a predetermined rate α,
The control map of FIG. 4 and the like are stored in advance. Next, a procedure for the negative pressure actuator device 10 to change the valve opening degree of the valve body 5 will be described in detail with reference to FIGS. 2 and 3.
2 and 3 are flowcharts of the valve opening control routine stored in the memory of the controller 16. This routine is repeatedly executed at a predetermined time T _C cycle when the ignition switch (not shown) of the vehicle is in the ON state. Then, one execution of this routine ends within time T _C which is a time cycle for repeating this routine.

First, in step S31 of FIG.
The target opening L _t supplied from the CU 4 and the opening sensor 21
The actual measurement opening L _m supplied from is read. Then, in step S32, from the target opening L _t to the actual opening L _m
To obtain the deviation ΔL. In step S33, it is determined whether the absolute value of the deviation ΔL is smaller than the predetermined value ε ₀ . When the absolute value of the deviation ΔL is small and smaller than the predetermined value ε ₀ , it can be considered that the opening degree of the controller 3 matches the target opening degree L _t . Therefore,
In this case, after proceeding to step S34 and initializing the flag F, the routine immediately exits from this routine without operating the electromagnetic on-off valves 14 and 15, and this routine is repeatedly executed at a predetermined time T _C cycle.

The flag F is also initialized when the ignition switch is turned on to start the vehicle. On the other hand, if the absolute value of the deviation ΔL is greater than or equal to the predetermined value ε ₀ in step S33, step S33
Proceed to 35. In step S35, the electromagnetic on-off valve to operate is determined. That is, when the deviation ΔL is positive, that is, when the target opening L _t is larger than the actual opening L _m , step S
Proceed to 36, and operate the electromagnetic on-off valve
Set to 5. Thereby, negative pressure can be supplied to the negative pressure chamber 18, the volume V of the negative pressure chamber 18 can be reduced, and the opening degree of the valve body 5 can be increased.

On the other hand, in step S35, the deviation ΔL
Is negative, that is, when the target opening L _t is smaller than the actual opening L _m , the process proceeds to step S37, and the electromagnetic opening / closing valve to be operated is set to the first electromagnetic opening / closing valve 14. This allows
The atmospheric pressure can be supplied to the negative pressure chamber 18, the volume V of the negative pressure chamber 18 can be increased, and the opening degree of the valve body 5 can be reduced.

Then, in step S38, the controller
Control map stored in the memory of LA16
Based on the above, the predetermined value of the electromagnetic on-off valve determined as described above
Time T_CBasic valve opening rate T for₀Ask for. This control
The concept of the roll map is shown in FIG. Area where the deviation ΔL is positive
Then, the basic opening rate T of the second solenoid opening / closing valve 15₀Represents the bias
In the region where the difference ΔL is negative, the basic opening of the first solenoid opening / closing valve 15 is performed.
Rate T₀Is represented. Basic valve opening rate T₀Is the deviation ΔL
It is set to increase as the logarithmic value increases. So
Then, for each volume V of the negative pressure chamber 18, the basic valve opening rate T₀Set up
Each has a fixed line and the volume V is V₁, V ₂
... V_nThe slope of each setting line increases as
When the deviation ΔL is the same, the volume V becomes large.
Basic valve opening rate T₀Is set to a large value.

The basic valve opening rate T ₀ is a value of 100% or less. The size of the volume V of the negative pressure chamber 18 affects the amount of change in the opening degree of the valve body 5 and the like. Detailed description. The amount of deformation (the amount of displacement) of the bellows 12b of the actuator body 12 and the amount of change of the volume V of the negative pressure chamber 18 are not proportional. That is,
The amount of change in the volume V of the negative pressure chamber 18 differs depending on whether the bellows 12b is stretched by a predetermined amount X from a state where it is not stretched or when it is further stretched by a predetermined amount X after being stretched to some extent. In other words, when a certain amount of atmospheric pressure or negative pressure is introduced into the negative pressure chamber 18, the volume V is relatively small volume V ₁ and V larger than the volume V _1.
The amount of deformation of the bellofram 12b is different from when it is ₂ .

In the valve body 5, the bellows drum 12b is deformable.
Since it is opened and closed with, the amount of deformation of the bellofram 12b is different.
Then, the displacement distance of the valve body 5, that is, the valve opening amount also differs. others
Therefore, the volume of the negative pressure chamber 18 changes depending on the size of the volume V.
If the volume is adjusted, the volume V becomes V ₁And V₂In case of
The valve opening amount of the valve body 5 can be set to be the same. Negative pressure chamber
The volume V in 18 changes as the pressure in the negative pressure chamber 18 changes.
Change. The magnitude of the pressure supplied into the negative pressure chamber 18 is
As mentioned above, the opening time of each solenoid valve 14, 15
It is determined. Therefore, the volume V of the negative pressure chamber 18 is V₁, V₂
... V _nAs the number of solenoid valves 14 and 15 increases
Opening time, that is, basic opening rate T₀If you set a large
The valve body 5 is not affected by the magnitude of the pressure in the pressure chamber 18.
The change amount of the opening becomes constant.

Then, in step S38, after obtaining the basic valve opening ratio T ₀ , the process proceeds to step S40 shown in FIG. In step S40, it is determined whether or not the flag F is 0, and the solenoid opening / closing valve 1
It is determined whether or not 4 or 15 has been excited. When the solenoid opening / closing valve 14 or 15 is operated in the execution of the previous routine, the flow of the atmospheric pressure or the negative pressure has already been formed in the communication passage 19, and the solenoid opening / closing valve 14 or 1
It is not necessary to consider the time such as the response delay from the time when the valve 5 is excited until the opening degree of the valve body 5 actually starts changing. on the other hand,
The solenoid on-off valve 14 or 15
When the opening of the valve body 5 is maintained without being operated, it is necessary to consider the time such as the response delay.

If it is determined in step S40 that the flag F is 0 and the solenoid opening / closing valve 14 or 15 is not operated in the execution of the previous routine, step S40 is performed.
Proceed to 41. Then, in step S41, a predetermined rate α considering the time such as the response delay is substituted for the correction rate T _D. Then, it progresses to step S43. On the other hand, in step S40, when the flag F is not 0 and it is determined that the solenoid opening / closing valve 14 or 15 is operated in the execution of the previous routine, the process proceeds to step S42, and the correction factor T _{D is set} to 0.
Is substituted. Then, the process proceeds to step S43.

In step S43, the valve opening rate T is set. That is, the valve opening rate T is obtained by adding the basic valve opening rate T ₀ obtained in step S38 to the correction rate T obtained in steps S41 and S42.
Calculated by adding _D. Then, in step S44, the excitation timer T _S is calculated. The excitation timer T _S obtains a time T _S by multiplying a predetermined time T _C that determines the repetition cycle of this routine by the valve opening rate T. Therefore, the excitation timer T _S is the same or shorter than the predetermined time T _C.

In step S45, there is step S36.
Or the solenoid on-off valve 14 or 15 set in S37
Excitation is started and the opening of the valve body 5 is changed to the target opening L._tWeird towards
Be transformed. Then, in step S46, the excitation timer T_S
This time T _SUntil the
Loop up. Therefore, the solenoid on-off valve 14 or 1
5 is time T_SIt is excited and opens the valve.

When the time T _S has elapsed in step S46, the process proceeds to step S47, in which the electromagnetic opening / closing valve 14 being excited is
Alternatively, the excitation of 15 is stopped and this is closed. Therefore, the electromagnetic on-off valves 14 and 15 are closed, and the pressure and volume V in the negative pressure chamber 18 are maintained. Since this routine is repeatedly executed at a predetermined time period T _C , the excitation timers T _s1 , T _S2 ... _Are calculated each time the routine is executed. Therefore, as shown in FIG.
Is opened by being excited by time T _s1 , T _S2, ... For each time T _C. That is, the solenoid on-off valve 14 or 15
Is duty ratio controlled with a duty factor T _S / T _C.

Next, in step S48, the flag F is set to 1
Is set, and at the next execution of this routine, it is set so as to proceed from step S40 to step S42. Then, the routine exits from this routine and this routine is repeatedly executed every time a predetermined time T _C has elapsed, and the opening degree of the valve body 5 is feedback-controlled. In the negative pressure actuator device 10 of the present embodiment, the valve body 5 of the valve unit 3 of the EGR device mounted on the vehicle is opened and closed. However, the invention is not limited to this. The negative pressure actuator device 10 may be used to open / close the throttle valve of the traction control system.

Further, in the present embodiment, the case where it is applied to the negative pressure actuator device 10 having the negative pressure chamber 18 has been described, but the present invention is not limited to this, and it is applied to the positive pressure actuator device having the positive pressure chamber. May be. Further, in the present embodiment, instead of the beloflam 12b,
A simple diaphragm or beloze may be used.

[0036]

As described above, according to the present invention, the controller controls the first position in accordance with the relationship between the current position of the driven member and the target position and the size of the pressure chamber.
Alternatively, the duty factor for operating the second solenoid opening / closing valve is determined. Therefore, the duty factor can be set as large as possible, and the responsiveness of the fluid pressure actuator device is improved. Further, since the duty coefficient reflects the volume of the pressure chamber, there is an excellent effect that the displacement accuracy of the driven member can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a fluid pressure actuator device to which the present invention is applied.

2 is a flow chart of the front part of the process of the operation of the fluid pressure actuator device of FIG. 1;

FIG. 3 is a flowchart of a process following that of FIG.

FIG. 4 is a conceptual diagram of a control map for obtaining a basic valve opening rate T ₀ .

5 is a diagram showing opening / closing timings of the electromagnetic opening / closing valve of FIG. 1. FIG.

[Explanation of symbols]

 3 Control Valve Unit 10 Negative Pressure Actuator Device 12 Actuator Main Body 13 Negative Pressure Tank 14 First Electromagnetic On-off Valve 15 Second Electromagnetic On-off Valve 16 Controller 18 Negative Pressure Chamber 19 Communication Passage 21 Opening Sensor

Claims (1)

[Claims] 1. A fluid pressure actuator device having means for detecting the current position of a driven member and moving the driven member to a target position while performing feedback control, having a pressure chamber defined by a movable membrane. At the same time, an actuator body having an output transmission member that connects the driven member and the movable film, a pressure source, a fluid passage that connects the pressure chamber and the pressure source, and an atmosphere opening passage provided in the middle of the fluid passage. And a first electromagnetic on-off valve that opens and closes the atmosphere opening passage,
A second electromagnetic opening / closing valve provided in the middle of the fluid passage between the pressure source and the atmosphere opening passage, a volume detecting unit for detecting the volume of the pressure chamber, and first and second electromagnetic opening / closing valves. A controller for selecting one of the valves and opening / closing the valve by duty ratio control to change the volume of the pressure chamber is provided. It is selected which one of the second electromagnetic on-off valves is to be operated, and the duty factor for operating the selected electromagnetic on-off valve is set to the difference between the current position and the target position, and A fluid pressure actuator device characterized by being determined according to the size of the volume of a pressure chamber.