JPH11287351A - Proportional solenoid valve driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the control characteristics of a proportional solenoid valve when the full closed or the full open condition is approached while deterioration of hysteresis is kept in minimum. SOLUTION: When the amperage X fed to the solenoid of a proportional solenoid valve determined according to the engine operation situation is over the reference command amperage A at which a plunger moving intrudes into a certain proximity region near the limit of movement (NO at SA2), the frequency of the fed current is made a frequency HF higher than the frequency FL used when the plunger lies elsewhere than the proximity region (SA4), and a drive current to make fine motions at this frequency is supplied to the solenoid. In this proportional solenoid valve, fine motions of the valve element are lessened near the full open or full closed condition where the plunger approaches the limit of movement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proportional solenoid valve driving device used for driving a proportional solenoid valve used for line pressure control of an automatic transmission for an automobile, for example.

[0002]

2. Description of the Related Art Conventionally, in a proportional solenoid valve used for hydraulic control, a valve element (or a plunger integrated with the valve element) urged to an open position (or a closed position) by a spring force of a spring is connected to a solenoid. A device that adjusts the passage amount or pressure of a fluid by moving in proportion to a supplied drive current is generally used. Also, when using such a proportional solenoid valve, the valve body is finely vibrated by finely moving the value of the drive current supplied to the solenoid at a high frequency, thereby reducing friction at the time of operation of the valve body, reducing control accuracy, Improves responsiveness. further,
Hysteresis is reduced by lowering the frequency of the drive current.

On the other hand, in order to generate the driving current as described above, a method of superimposing a control current of a small number of pulses on a command current having a magnitude corresponding to a required valve opening (hereinafter, referred to as a dither method). , PWM method. The PWM method is
As shown in FIG. 8, a command current value having a magnitude corresponding to the valve opening is finely moved periodically by changing the pulse width of the drive voltage. Such a PWM method is called CP
If a pulse signal output from U is used, it is possible to generate a drive current with a relatively simple circuit, and there is an advantage that the control device of the proportional solenoid valve is less expensive than a dither type control device. For this reason, in recent years, the drive current is often performed by the PWM method.

[0004]

However, when the valve element is driven by the finely-moving drive current as described above, the valve element also slightly moves as described above, so that the valve element approaches the fully closed position (see FIG. 8 (P region 8), the valve element once contacting the valve seat rebounds and separates from the valve seat, and then immediately contacts the valve seat again. Will repeat.

For this reason, in the normally open type proportional solenoid valve, the static hydraulic characteristic in the fully closed state immediately before the fully closed state does not become the linear characteristic shown in FIG. The inflection characteristic shown in FIG. In the case of the normally closed type, the residual pressure characteristic in the fully open state becomes an inflection characteristic. Accordingly, although the hysteresis is improved, there is a problem that the control accuracy of the fluid is reduced. In addition, such a problem becomes more prominent as the operating resistance of the plunger decreases as the temperature of the hydraulic oil increases.

Needless to say, such a problem can be avoided by increasing the frequency of the drive current supplied to the solenoid, but in that case, another problem that the hysteresis of the control characteristics becomes large and the control accuracy is reduced thereby occurs. It was that.

The present invention has been made in view of such conventional problems, and provides a proportional solenoid valve driving device capable of improving control characteristics of a proportional solenoid valve while minimizing deterioration of hysteresis of the proportional solenoid valve. Aim.

[0008]

According to a first aspect of the present invention, there is provided a solenoid valve of a proportional solenoid valve which supplies a drive current whose current value periodically finely changes from a command value to a solenoid of a proportional solenoid valve. In a proportional solenoid valve driving device for controlling an operating position of a plunger of the proportional solenoid valve having an integrated body, the drive is performed while the plunger that moves upon excitation of the solenoid is in a predetermined proximity area close to a movement limit. Frequency control means for setting the frequency of the current higher than the frequency while the plunger is in the other area of the close area is provided.

In such a configuration, when a drive current is supplied to the solenoid during control of the proportional solenoid valve, the plunger of the proportional solenoid valve slightly moves to reciprocate. At this time, the frequency of the drive current is higher while the plunger is in a predetermined proximity area close to the movement limit than when the plunger is in another area. Becomes smaller. Therefore, the fine movement of the valve body near the fully open position or the fully closed position is reduced.

Further, according to the invention of claim 2, a drive current whose current value periodically fine-tunes from a command value is supplied to a solenoid of the proportional solenoid valve, and a drive current of the proportional solenoid valve integrated with a valve body is provided. A proportional solenoid valve driving device for controlling the operating position of the plunger, comprising frequency control means for increasing the fine movement frequency of the drive current in accordance with the temperature rise of the fluid controlled by the proportional solenoid valve.

In such a configuration, when a drive current is supplied to the solenoid during control of the proportional solenoid valve, the plunger of the proportional solenoid valve slightly moves to reciprocate. Here, since the fine movement frequency of the drive current increases as the temperature of the fluid rises, the fine movement amount of the plunger, that is, the valve body even if the viscosity of the fluid decreases with the temperature rise and the operating resistance of the plunger decreases. It is prevented from growing.

According to the third aspect of the present invention, a drive current whose current value periodically fine-tunes from a command value is supplied to a solenoid of a proportional solenoid valve, and the solenoid valve of the proportional solenoid valve integrated with a valve element is provided. In the proportional solenoid valve driving device for controlling the operating position of the plunger, a value of a voltage applied to the solenoid while the plunger moving at the time of exciting the solenoid is in a predetermined proximity region close to a movement limit is set in the proximity region. And a voltage control means for reducing the value of the voltage applied to the solenoid while in an operation region other than the above.

In such a configuration, when a drive current is supplied to the solenoid during control of the proportional solenoid valve, the plunger of the proportional solenoid valve slightly moves to reciprocate. At this time, the applied voltage of the solenoid becomes smaller while the plunger is in a predetermined proximity area close to the movement limit than when the plunger is in another area. Therefore, when the plunger is approaching the movement limit, the operating force is reduced, and the amount of fine movement of the plunger is reduced. Therefore, the fine movement of the valve body near the fully open position or the fully closed position is reduced.

Further, according to the invention of claim 4, a drive current whose current value periodically fine-tunes from the command value is supplied to the solenoid of the proportional solenoid valve, and the solenoid valve of the proportional solenoid valve having an integrated valve element is provided. The proportional solenoid valve driving device for controlling the operating position of the plunger is provided with voltage control means for reducing the value of the voltage applied to the solenoid in accordance with the temperature rise of the fluid controlled by the proportional solenoid valve.

In this configuration, when a drive current is supplied to the solenoid during control of the proportional solenoid valve, the plunger of the proportional solenoid valve slightly moves to reciprocate. Here, since the applied voltage of the solenoid decreases as the temperature of the fluid increases, the operating force of the plunger decreases as the viscosity of the fluid decreases and the operating resistance of the plunger decreases as the temperature increases. For this reason, even if the temperature of the fluid increases, the amount of fine movement of the plunger, that is, the valve body, is prevented from increasing.

According to the fifth aspect of the present invention, a drive current whose current value periodically fine-tunes from a command value is supplied to a solenoid of a proportional solenoid valve, and the proportional solenoid valve having an integrated valve body is provided. In the proportional solenoid valve driving device for controlling the operating position of the plunger, the upper part of the waveform of the driving current is maintained at a constant level while the plunger moving at the time of energizing the solenoid is in a predetermined proximity region close to a movement limit. Waveform shaping means for shaping the waveform to be cut was provided.

In such a configuration, when a drive current is supplied to the solenoid during control of the proportional solenoid valve, the plunger of the proportional solenoid valve slightly moves to reciprocate. At this time, while the plunger is in a predetermined proximity region close to the movement limit, the upper part of the waveform of the drive current is cut off at a certain level. For this reason, while the plunger is near the movement limit, the amplitude force generated in the plunger in the movement limit direction is small. Therefore, the fine movement of the valve body near the fully open position or the fully closed position is reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a proportional solenoid valve driving device 1 according to the first embodiment of the present invention. The proportional solenoid valve driving device 1 specifically performs various controls related to an automatic transmission, and uses a vehicle battery (not shown) as a power source to generate a driving current whose value periodically fine-tunes as described in the related art. It is generated by the PWM method described above and supplied to the solenoid 3 of the proportional solenoid valve 2 to control the opening / closing operation of the proportional solenoid valve 2 according to the operating condition of the engine.

FIG. 2 is a view showing an example of the proportional solenoid valve 2. The proportional solenoid valve 2 is used for line pressure control of an automatic transmission, and has an output port 21 connected to the line pressure side and a nozzle block 23 provided with a drain port 22. The solenoid 3, the core 24 and the yoke 25 are caulked and fixed to the nozzle block 23 by a cylindrical cover 26 made of a magnetic material. The plunger 27 is connected to bearings 31, 3 via a connecting shaft 28.
2 slidably supported by the plunger 2.
7, a valve body 29 is integrated via a connecting shaft 28.

The plunger 27 is constantly urged in the opening direction by a coil spring 30 loosely inserted into the connecting shaft 28. Then, when the solenoid 3 is excited, the plunger 27 moves against the coil spring 30 and the output port pressure, and the valve element 29 moves the output port 2 in the nozzle block 23.
1 to control the line pressure.

On the other hand, the proportional solenoid valve driving device 1 includes a CPU 4 serving as frequency control means of the present invention, a ROM 5 storing a control program of the CPU 4 and various parameters,
RAM 6, which stores various data in accordance with the operation of PU 4, A
It has an input / output device (not shown) including a / D converter, a D / A converter, and the like, and a drive circuit 7 including a power transistor (not shown) that supplies predetermined power to the solenoid 3 based on a command from the CPU 4. . The proportional electromagnetic valve driving device 1 is connected to an oil temperature sensor 8 and the like for detecting the temperature of hydraulic oil of the automatic transmission controlled by the proportional electromagnetic valve 2.

As shown in FIG. 3, the ROM 5 includes a driving current value of the solenoid 3 as a parameter used for controlling the proportional solenoid valve 2, and a plunger 27 which moves upon excitation is in a proximity region where the plunger 27 approaches the movement limit. That is, a reference command current value A indicating a drive current value falling within a region corresponding to P in FIG. 8 described in the related art, and two types of frequencies which are pulse signal frequencies to be sent to the drive circuit 7, that is, the first A frequency FL and a higher frequency second frequency F
H are stored.

Next, the operation of the present embodiment having the above configuration will be described with reference to the flowchart of FIG.

That is, in the proportional solenoid valve driving device 1, when the proportional solenoid valve 2 is controlled, the CPU 4 outputs a command value corresponding to the operating condition of the engine, that is, the current supplied to the solenoid 3 of the proportional solenoid valve 2. The value X is determined (SA1).
Next, it is determined whether or not the command value X is smaller than the reference command current value A (SA2). If the command value X has not reached the reference command current value A, the frequency F of the pulse signal sent to the drive circuit 7 is set to the first frequency FL (SA
3) If the command value X is equal to or greater than the reference command current value A, the frequency F of the pulse signal sent to the drive circuit 7 is set to the second frequency FH (SA4). Then, the pulse signal of the determined frequency and the command signal S indicating the command value X determined in step SA1 are sent to the drive circuit 7, and accordingly, the drive circuit 7 sends the command signal and the pulse signal , And supplies a drive current to the solenoid 3 of the proportional solenoid valve 2 (SA5).

Therefore, in the proportional solenoid valve 2, the plunger 27 slightly moves so as to reciprocate at the time of its operation, but while the plunger 27 is in a predetermined proximity region close to the movement limit, the drive current of the Since the frequency becomes the second frequency FH higher than before, the amount of the fine movement is reduced. Therefore, in the proportional solenoid valve 2, the fine movement of the valve body 29 near the fully closed position is reduced.

Therefore, control characteristics can be improved while minimizing deterioration of hysteresis in the proportional solenoid valve 2. Further, in the normally open type proportional solenoid valve 2 as shown in the present embodiment, the seating sound of the valve body 29 is reduced and the quietness is improved. At the same time, the degree of wear between the valve element 29 and the valve seat decreases with the lapse of the use period, so that stable control characteristics can be obtained over a long period of time.

In the present embodiment, CUP4
Switches the frequency of the drive current supplied to the proportional solenoid valve 2 from the low frequency FL to the higher frequency FH when the supply current value X according to the operating condition of the engine is equal to or more than the reference command current value A. However, while the supply current value X is equal to or more than the reference command current value A, the frequency of the drive current is increased stepwise or continuously according to the increase of the supply current value X. You may.

Next, a second embodiment of the present invention will be described. That is, in the present embodiment, in the proportional solenoid valve driving device 1 shown in FIG. 1, the ROM 5 stores the aforementioned reference command current value A and the drive circuit 7 in the proportional solenoid valve 2 as shown in FIG. While two kinds of voltage values to be applied to the solenoid 3 are stored, that is, a first voltage value VL and a second voltage value VH higher than the first voltage value VL, the drive circuit 7 is controlled by the voltage control means of the present invention. In addition, the configuration is such that the voltage applied to the solenoid 3 can be controlled.

The operation of this embodiment having the above configuration will be described with reference to the flowchart of FIG.

That is, in the proportional solenoid valve driving device 1 according to the present embodiment, when the proportional solenoid valve 2 is controlled, the CPU 4 issues a command value corresponding to the operating condition of the engine, that is, the solenoid of the proportional solenoid valve 2 3 is determined (SB1). Next, it is determined whether or not the command value X is smaller than the reference command current value A (SB2). If the command value X is smaller than the reference command current value A, the voltage value to be applied to the solenoid 3 is set to the second voltage value VH (SB3). The voltage value to be applied to the solenoid 3 is a first voltage value V
L (SB4).

Then, a first command signal S1 indicating the determined command value X, a second command signal S2 indicating the determined voltage value, and a pulse signal of a predetermined frequency are sent to the drive circuit 7, Accordingly, the drive circuit 7 generates a drive current based on the transmitted first and second command signals S1 and S2 and the pulse signal, supplies the drive current to the solenoid 3, and determines the applied voltage value at a predetermined voltage value. To control.

Therefore, in the proportional solenoid valve 2, the plunger 27 slightly moves so as to reciprocate at the time of its operation, but the solenoid 3 is applied while the plunger 27 is in a predetermined proximity area close to the movement limit. The voltage is
The first voltage value VL is lower than before. For this reason, the operating force when the plunger 27 is approaching the movement limit is reduced, the amount of the fine movement is reduced, and the fine movement of the valve body 29 near the fully open position or the fully closed position is reduced. Therefore, the same effect as in the first embodiment can be obtained.

In the present embodiment, CUP4
When the supply current value X according to the operating condition of the engine is equal to or more than the reference command current value A, the applied voltage of the solenoid 3 is changed from the second voltage value VH to the first voltage value V
Although the switching to L has been described, while the supply current value X is equal to or more than the reference command current value A, the applied voltage of the solenoid 3 is changed stepwise or continuously according to the increase of the supply current value X. May be lowered.

On the other hand, in the first and second embodiments described above, the CUP 4
The frequency of the drive current may be set higher in accordance with the temperature rise of the hydraulic oil detected by the oil temperature sensor 8. In this case, even if the viscosity of the hydraulic oil decreases with an increase in temperature and the operating resistance of the plunger 27 decreases, the amount of fine movement of the plunger 27, that is, the valve body 29, is prevented from increasing.

Therefore, even in such a configuration, it is possible to improve the control characteristics of the proportional solenoid valve 2 while minimizing deterioration of the hysteresis. This effect can be obtained even when the control for setting the frequency of the drive current higher according to the rise in the temperature of the hydraulic oil is performed independently of the control in the first and second embodiments.

Next, a third embodiment of the present invention will be described. That is, in this embodiment, in the proportional solenoid valve driving device 1 shown in FIG.
The above-mentioned reference command current value A alone is stored (not shown) as a parameter to be used for the control of the above. On the other hand, the drive circuit 7 is the waveform shaping means of the present invention, and the upper part of the waveform of the finely moving drive current is stored. At a predetermined fixed level.

The operation of the present embodiment having the above configuration will be described with reference to the flowchart of FIG.

That is, in the proportional solenoid valve driving device 1 according to the present embodiment, when the proportional solenoid valve 2 is controlled, the CPU 4 issues a command value according to the operating condition of the engine, that is, the solenoid of the proportional solenoid valve 2 3 is determined (SC1). Next, it is determined whether or not the command value X is smaller than the reference command current value A (SC2). Here, if the command value X is smaller than the reference command current value A, a first command signal S1 indicating the command value X determined in step SC1 and a pulse signal of a predetermined frequency are sent to the drive circuit 7. Accordingly, the drive circuit 7 generates a drive current based on the transmitted first command signal S1 and pulse signal, and supplies the drive current to the solenoid 3 (SC3).

On the other hand, if the decision result in the above-mentioned step SC2 is YES and the command value X is not less than the reference command current value A, the first command signal S1 and the pulse signal of a predetermined frequency are In addition, a second command signal S2 for causing the drive circuit 7 to perform the above-described waveform shaping is sent to the drive circuit 7, and accordingly, the drive circuit 7 sends the first command signal S1 and the pulse signal And the drive current generated based on
A drive current obtained by cutting the upper part of the waveform at a predetermined constant level is supplied to the solenoid 3 (SC
4).

Therefore, in the proportional solenoid valve 2, the plunger 27 slightly moves so as to reciprocate at the time of its operation, but while the plunger 27 is in a predetermined proximity area close to the movement limit, the drive current of the The top of the waveform is cut off at a certain level. For this reason, the plunger 27
Is near the travel limit, the plunger 27
, The amplitude force in the movement limit direction decreases, and the fine movement of the valve body 29 near the fully open position or the fully closed position decreases. Therefore, effects similar to those of the first and second embodiments can be obtained.

In each of the embodiments described above, the present invention is mainly applied to the normally open proportional solenoid valve 2. However, the present invention is not limited to this. May be applied. In that case, it is possible to suppress a slight movement in the opening / closing direction of the valve element that occurs when the valve element is located near the fully closed position. Therefore, the residual pressure in the control can be reduced, and the control characteristics on the valve closing side can be improved.

[0042]

As described above, in the proportional solenoid valve driving device according to the first, third, and fifth aspects, the valve body in the vicinity of the fully open position or the fully closed position is used for controlling the proportional solenoid valve. To reduce the micromotion.

Therefore, when controlling the proportional solenoid valve,
Control characteristics can be improved while minimizing deterioration of hysteresis. In particular, in the normally open proportional solenoid valve, the seating noise is reduced and the quietness is improved, and at the same time, the degree of wear between the valve body and the valve seat with the lapse of the use period is reduced, so that it is stable for a long time. Control characteristics are obtained.

Further, in the proportional solenoid valve driving device according to the second and fourth aspects, when controlling the proportional solenoid valve, when the viscosity of the fluid decreases as the temperature rises and the operating resistance of the plunger decreases. Thus, the amount of fine movement of the plunger, that is, the valve body, can be prevented from increasing.

Therefore, it is possible to improve the control characteristics of the proportional solenoid valve while minimizing the deterioration of the hysteresis.

[0046]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a proportional solenoid valve driving device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a proportional solenoid valve, in which a left half shows a non-energized state and a right half shows a energized state.

FIG. 3 is a diagram showing parameters stored in a ROM of the embodiment.

FIG. 4 is a flowchart showing an operation of the embodiment.

FIG. 5 is a diagram showing parameters stored in a ROM according to the second embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of the embodiment.

FIG. 7 is a flowchart illustrating an operation of the third exemplary embodiment of the present invention.

FIG. 8 is a diagram showing a correspondence relationship between a drive current, a valve operation, and an output pressure of a PWM method in the related art.

9A and 9B are characteristic diagrams of a proportional solenoid valve, in which FIG. 9A shows required characteristics and FIG. 9B shows characteristics of a proportional solenoid valve according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Proportional solenoid valve drive device 2 Proportional solenoid valve 3 Solenoid 4 CPU 7 Drive circuit 27 Plunger 29 Valve element

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahito Yamaguchi 2-215 Aobudai, Zama City, Kanagawa Prefecture Tosok Corporation

Claims (5)

[Claims] 1. A proportional solenoid valve for supplying a drive current whose current value periodically fine-tunes from a command value to a solenoid of a proportional solenoid valve to control an operating position of a plunger of the proportional solenoid valve having an integrated valve body. In the driving device, the frequency of the drive current when the plunger moving at the time of exciting the solenoid is in a predetermined proximity region close to a movement limit is set to be higher than the frequency while the plunger is in another region of the proximity region. A proportional solenoid valve driving device comprising frequency control means for setting a high value. 2. A proportional solenoid valve for supplying a drive current whose current value periodically fine-tunes from a command value to a solenoid of the proportional solenoid valve to control an operation position of a plunger of the proportional solenoid valve having an integrated valve body. In a drive device, a proportional electromagnetic valve drive device characterized by comprising frequency control means for increasing the frequency of the drive current in accordance with an increase in the temperature of the fluid controlled by the proportional electromagnetic valve. 3. A proportional solenoid valve for supplying a drive current whose current value periodically fine-tunes from a command value to a solenoid of the proportional solenoid valve to control an operating position of a plunger of the proportional solenoid valve having an integrated valve body. In the driving device, the value of the voltage applied to the solenoid while the plunger moving at the time of excitation of the solenoid is in a predetermined proximity area close to a movement limit is changed while the plunger is in another operation area other than the proximity area. A proportional solenoid valve driving device comprising a voltage control means for making the voltage applied to the solenoid smaller than the value of the voltage applied to the solenoid. 4. A proportional solenoid valve for supplying a drive current whose current value periodically fine-tunes from a command value to a solenoid of the proportional solenoid valve to control an operating position of a plunger of the proportional solenoid valve integrated with a valve element. The drive device according to claim 1, further comprising a voltage control unit configured to reduce a value of a voltage applied to the solenoid according to a temperature rise of a fluid controlled by the proportional solenoid valve. 5. A proportional solenoid valve for supplying a drive current whose current value periodically fine-tunes from a command value to a solenoid of the proportional solenoid valve to control an operating position of a plunger of the proportional solenoid valve having an integrated valve body. The drive device, further comprising: a waveform shaping unit configured to perform a waveform shaping that cuts an upper part of a waveform of the drive current at a certain level while the plunger that moves upon excitation of the solenoid is in a predetermined proximity area close to a movement limit. A proportional solenoid valve driving device.