JP2657361B2 - Energization control method for linear solenoid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling energization of a linear solenoid.

[0002]

2. Description of the Related Art Conventionally, a valve in which a valve is driven by using a linear solenoid is disclosed in, for example, Japanese Patent Application Laid-Open No. 64-121.
No. 89, JP-A-1-247228 and JP-A-4-50550.

[0003]

SUMMARY OF THE INVENTION In the above prior art,
The thrust exerted by the linear solenoid is changed by controlling the energization of the linear solenoid, and the thrust is applied to the valve so that the hydraulic pressure corresponding to the thrust is output from the valve. However, when controlling the energization of the linear solenoid, the energization current is continuously changed, so the energization amount is affected by the residual magnetic flux when the energization amount is large. There is a difference in thrust.
However, if hysteresis occurs in the thrust exerted by the linear solenoid, it becomes difficult to accurately control a valve or the like using the linear solenoid.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for controlling the energization of a linear solenoid which minimizes the occurrence of thrust hysteresis.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, when controlling the energizing current of the linear solenoid, the energizing is performed to a current value lower than the current energizing current value. in reducing current after the energization of the linear solenoid and zero for a predetermined time, to increase the amount of current to said lower current value.

According to the invention, the predetermined time is set to 10 to 300 msec.

[0007]

An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show one embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a hydraulic control device having a linear solenoid, FIG. 2 is a flow chart showing a procedure for controlling energization of the linear solenoid, FIG. 3 is a diagram showing a current change accompanying the energization control.

First, in FIG. 1, the hydraulic pressure output from a high hydraulic pressure source 1 is controlled by a hydraulic pressure control device 3 and applied to a hydraulic pressure operating section 2, and this hydraulic pressure control device 3 It comprises a solenoid 4 and a spool valve 5 driven by the linear solenoid 4.

The inner housing 6 of the linear solenoid 4 has a structure in which both ends of a non-magnetic cylinder 9 are liquid-tightly fitted and connected to a magnetic cylinder 7 and a fixed core 8. In addition, the outer housing 10 has a flange 10 that engages the inner peripheral edge with the fixed core 8.
is formed in a cylindrical shape from a magnetic material having one end at one end, and a magnetic ring 11 engaged with and connected to the magnetic cylinder 7 at the other end of the outer housing 10; And a cover 12 made of a synthetic resin that covers the cover. A coil 14 wound around a bobbin 13 is disposed in the outer housing 10 so as to surround the inner housing 6 coaxially between the magnetic ring 11 and the flange 10a. Thus, the cover 12 is provided with a connection coupler 12a that faces the connection terminal 15 connected to the coil 14.

Both ends of a movable core 16 are slidably fitted to the magnetic cylinder 7 and the fixed core 8, and a plunger 17 that penetrates the fixed core 8 movably in the axial direction. Are coaxially caulked.

Such a linear solenoid 4 attracts the movable core 16 to the fixed core 8 with an attraction force corresponding to the current flowing through the coil 14, and therefore has an axial thrust corresponding to the current flowing through the coil 14. Is provided to the plunger 17, and the plunger 17 is driven in a direction protruding from the fixed core 8.

The valve housing 20 of the spool valve 5 is connected to the linear solenoid 4 so that the fixed core 8 is fitted at one end. The valve housing 20 has a large-diameter sliding hole 21, a small-diameter sliding hole 22, and a screw hole 23 provided sequentially and coaxially from the fixed core 8 side. An adjusting screw 25 screwed into a screw hole 23 and a spool valve element 24 are slidably fitted in the sliding hole 22 with a spool valve element 24 having one end contacting the plunger 17 protruding from the fixed core 8. A valve spring 26 is contracted between them. A locking nut 27 is screwed into a portion of the adjusting screw 25 protruding from the valve housing 20.
The set load of the valve spring 26 can be adjusted by tightening the lock nut 27 while the adjusting screw 25 is advanced or retracted.

In the valve housing 20, a release chamber 28 is formed between one end of the spool valve element 24 and the fixed core 8, and a reaction force chamber 29 is formed between the other end of the spool valve element 24 and the adjusting screw 25. . Thus, on the inner surface of the large-diameter sliding hole 21, the first annular concave portion 30, the second annular concave portion 31, and the third annular concave portion 31 are formed.
An annular concave portion 32 is provided at an axial interval from the release chamber 28 side, and the large-diameter sliding hole 21 and the small-diameter slide are provided at axially spaced positions from the third annular concave portion 32 to the reaction force chamber 29 side. A fourth annular recess 33 is provided between the inner surfaces of the moving holes 22. Thus, the release chamber 28, the third annular recess 32, and the fourth annular recess 33 communicate with the reservoir 34, the first annular recess 30 communicates with the high hydraulic pressure source 1, and the second annular recess 31 communicates with the hydraulic operating section. 2, the reaction force chamber 29 is communicated with the hydraulic operating section 2 via the orifice 35.

An annular groove 36 is provided on the outer surface of the spool valve element 24. The annular groove 36 is provided in the second annular concave portion 31, that is, when the spool valve element 24 is in the advanced position as shown in FIG. The pressure operating portion 2 is communicated with the third annular concave portion 32, that is, the reservoir 34.
When the second annular recess 31 is retracted to the right of the first annular recess 3,
0, that is, connected to the high hydraulic pressure source 1.

In such a hydraulic pressure control device 3, when a thrust acts on the spool valve element 24 from the plunger 17 due to energization of the linear solenoid 4, the spool valve element 24 connects the hydraulic operating section 2 to the reservoir 34, but the hydraulic pressure control device 3 is high. It is pressed to the side that is shut off from the hydraulic pressure source 1. On the other hand, the spool valve element 24 has
A spring force opposing the thrust is given by the valve spring 26 and the hydraulic pressure in the reaction force chamber 29, which is communicated to the hydraulic pressure operating section 2 through the orifice 35, acts on the spool valve body 24. Will be given in opposition to Accordingly, the spool valve element 24 causes the hydraulic pressure operating unit 2 to move the reservoir 34 so that the thrust given from the linear solenoid 4 and the hydraulic force of the valve spring 26 and the hydraulic pressure of the reaction force chamber 29 are balanced. The hydraulic fluid moves axially between a forward position for communication and a retracted position for communicating the hydraulic operating section 2 to the high hydraulic pressure source 1. The output hydraulic pressure of the high hydraulic pressure source 1 depends on the amount of electricity supplied to the linear solenoid 4. As the pressure increases, the pressure is reduced so as to increase the degree of pressure reduction, and the pressure is applied to the hydraulic operating unit 2.

The energization amount of the coil 14 in the linear solenoid 4 is controlled by an electronic control unit ECU. In the electronic control unit ECU, a control procedure as shown in FIG. Is set.

In FIG. 2, in a first step S1, it is determined whether or not the current command value I _{C is} to be changed.
_{When C} is changed, it is determined in a second step S2 whether or not the current command value I _C is changed to a decrease side. When it is determined that the current command value I _{C is} to be increased, the process proceeds from the second step S2 to the third step S3, and the energization amount is increased to the current command value I _C changed in the third step S3. I do.

In the second step S2, the current command value I
When it is determined that _{C is} to be decreased, the process proceeds from the second step S2 to a fourth step S4, in which the energization of the linear solenoid 4 is cut off. When it is confirmed in the fifth step S5 that a predetermined time T _OFF, for example, 10 to 300 msec has elapsed after the energization cutoff,
In the third step S3, the energization amount is increased to the current command value I _C to be changed.

That is, when controlling the energizing current of the linear solenoid 4 to reduce the energizing current to a current value lower than the current energizing current value , the energizing amount of the linear solenoid 4 is set to zero for a predetermined time T _OFF. After that , the amount of current is increased to the low current value. On the other hand, when the energizing current is increased to a higher current value, the energizing amount is increased as it is. That is, the current supplied to the linear solenoid 4 is always controlled on the increasing side.

[0021] Next, to explain the action of this embodiment, in controlling the energization amount of the linear solenoid 4, when the current command value I _C changes as shown in FIG. 3 (a), energization of the linear solenoid 4 The amount will change as shown in FIG. That is, the energization command value I _C
When changing the reduction side, the operation delay time T _D from the time of change is interrupted the current to the linear solenoid 4 has elapsed (i.e., the energization amount is zero), the elapsed its current blocking state for a predetermined time period T _OFF from to, it will increase the amount of current to the current command value I _C after the change.

As described above, when the energizing current is changed to the decreasing side, the energizing amount is increased to the current value after the energizing amount is increased after the energizing amount is increased to the changed current value after the energizing amount is cut _off for the predetermined time T _OFF. When the magnetic flux is reduced and the energizing current is continuously reduced, the influence of the residual magnetic flux which becomes large can be suppressed as much as possible. As a result, it is possible to minimize the occurrence of hysteresis in the thrust generated by the linear solenoid 4 when the energizing current increases and when the energizing current decreases, and it is possible to accurately control the spool valve 5.

[0023] Moreover the interruption of energization current over a long time, but in which pulsation in the thrust generated by the linear solenoid 4 is generated when increasing the applied current after its blocking, the predetermined time T _OFF to cut off the electric current 10 By setting the time to そ の 300 msec, such a pulsation can be prevented, and the thrust can be changed moderately.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, the present invention is widely applicable not only to a linear solenoid that drives the spool valve 5, but also to a linear solenoid that causes a working portion to act on a thrust according to the amount of electricity.

[0026]

As described above, according to the first aspect of the present invention, when controlling the energizing current of the linear solenoid, the energizing current is reduced to a current value lower than the current energizing current value. For a predetermined time, the linear solenoid
After the coulometric zero, since increasing the amount of current to said lower current value, the so that increasing the amount of current to a lower current value after decreasing the residual magnetic flux when electric current was large
When the energizing current is continuously reduced,
Suppressed as much as possible can Rukoto the influence of Kunar residual magnetic flux, it
Thus, it is possible to minimize the occurrence of hysteresis in the thrust generated by the linear solenoid when the current is increased and when the current is decreased .

According to the second aspect of the present invention, since the predetermined time is set to 10 to 300 msec, it is possible to prevent pulsation from being generated in the thrust generated by the linear solenoid due to interruption of the energizing current, and to reduce the linear solenoid. Can be changed moderately.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a hydraulic control device having a linear solenoid.

FIG. 2 is a flowchart showing a procedure for controlling energization of a linear solenoid.

FIG. 3 is a diagram showing a change in current according to energization control.

[Explanation of symbols]

 4 Linear solenoid

Claims (2)

(57) [Claims] When controlling an energizing current of a linear solenoid (4) to reduce the energizing current to a current value lower than a current energizing current value, a linear time is controlled for a predetermined time.
A method for controlling the energization of a linear solenoid, characterized in that , after the amount of energization of the solenoid (4) is reduced to zero, the amount of energization is increased to the low current value. 2. The method according to claim 1, wherein the predetermined time is set to 10 to 300 msec.