JP3070355B2 - Solenoid drive control device for automatic transmission - Google Patents

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 driving a solenoid in a hydraulic control device of an automatic transmission in a stable state with good responsiveness and without vibration.

[0002]

2. Description of the Related Art Conventionally, in an automatic transmission, in order to maintain shift characteristics better, a hydraulic pressure applied to a friction engagement device at the time of shifting is feedback-controlled to an optimal oil pressure by a linear solenoid. (Eg, JP-A-2-80852).

[0003] In this case, the linear solenoid is required to have a performance that follows the target value quickly, that is, a fast response, when the target value changes in order to achieve good feedback control.

[0004] Generally, in order to ensure a quick response, the size, the driving force, and the lap amount of the valve (all ports are required for pressure adjustment) so that the linear solenoid itself has a quick response. There is a method of determining hardware specifications such as the amount of overlap when the is closed). Another method is to improve the driving software such that a large current is applied temporarily (for a certain period of time immediately after the start of driving) when the target value changes greatly, and then the current is reduced to the target current value. It has been proposed (JP-A-2-142966).

[0005]

However, no matter which method is used to improve the responsiveness, for example, in a hydraulic control device using a linear solenoid,
If the responsiveness is to be improved, there is a problem that the linear solenoid itself is more likely to vibrate. The vibration of the linear solenoid not only makes the pressure adjustment value of the hydraulic pressure unstable, but also reduces the durability of the linear solenoid. Therefore, in general, the valve wrap amount is increased to a level that does not vibrate under the operating environment (mechanical adjustment),
Alternatively, a method of softening the change of the target value so that the change of the target value does not occur so rapidly (soft adjustment)
Must be adopted.

However, this is not an adjustment that sacrifices the responsiveness that would otherwise be improved. That is, conventionally, in order to avoid the occurrence of vibration, the actual response cannot be further improved in some cases.

However, recently, the level of demands on the response of the hydraulic control system has been increasing, and the specifications do not generate vibrations in the operating environment (specifications that allow a certain margin before the vibrations are generated). When a linear solenoid is designed, there are cases where the demand for responsiveness cannot be satisfied.

The present invention has been made in view of such a conventional problem, and it is possible to always drive a solenoid at a vibration limit, and as a result, it is possible to maximize responsiveness without vibration. It is an object of the present invention to provide a solenoid drive control device for an automatic transmission as described above, and to maintain the shift characteristics of the automatic transmission more favorably.

[0009]

SUMMARY OF THE INVENTION As shown in FIG. 1, the present invention relates to a solenoid drive control apparatus for an automatic transmission which drives a solenoid by an electric command and thereby controls a hydraulic pressure. Means for detecting a current flowing through the solenoid, means for detecting whether or not the solenoid is vibrating based on the detected current, and a solenoid for suppressing the vibration when the vibration of the solenoid is detected. And a means for driving the motor.

The term "current flowing through the solenoid" includes a concept such as a voltage corresponding thereto.

[0011]

In the present invention, attention is paid to the fact that when vibration is generated in the solenoid, the current flowing through the solenoid is also oscillating due to the back electromotive force generated from the solenoid by the vibration. By detecting the flowing current, the vibration of the solenoid itself is detected, and when the vibration is detected, the solenoid is driven in such a manner that the vibration is suppressed.

That is, the present invention detects whether or not the solenoid is actually vibrating and drives the solenoid so as to suppress the vibration only when the vibration is actually occurring. The response can be maximized within the vibration limit. As a result, both the vibration resistance and the responsiveness of the solenoid can be achieved at a higher level than before.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 shows a linear solenoid in an automatic transmission to which the present invention is applied.

In the drawing, reference numeral 2 denotes a linear solenoid, 4
Is a coil, 6 is a case, 8 is a cover, 10 is a pin, 12
Is a plunger, 14 is a core, 16 is a spool, 18 is a sleeve, and 20 is a spring.

The linear solenoid 2 is known per se, and the plunger 12 slides in the axial direction (the direction of the arrow X) in response to the current flowing through the coil 4, and is connected to the plunger 12 by this sliding. The pin 10 slides in the axial direction X, and the spool 16 pressed against the pin 10 by the spring 20 is moved and positioned in the axial direction. As a result, the drain amount from the port 24 is increased / decreased with respect to the line pressure input from the port 22, and a hydraulic pressure corresponding to the current passed through the coil 4 is output from the port 26.

FIG. 3 shows a coil 4 of the linear solenoid 2.
Shows a circuit for supplying a current to the circuit. Automatic transmission CP
A duty signal for the coil 4 is output from U30. This duty signal is, specifically, a rectangular wave of 300 Hz as shown in FIG. 4, and by changing the on-time and off-time within 1 Hz as shown in (A) to (C), for example. The increase and decrease of the current (average current) supplied to the coil 4 is controlled.

Reference numeral 32 in FIG. 3 denotes a transistor.
The switching function of applying the battery voltage to the coil 4 is performed only when the duty signal is turned on.

In this embodiment, in order to detect a current flowing through the coil 4, a resistor 34 is arranged on the ground side of the coil 4, and a voltage (battery voltage) Vb on the hot side of the transistor 32 and a hot The voltage Vio on the side is detected. This voltage Vio is averaged in the increase and decrease due to the duty on and off of 300 Hz through the ripple elimination filter 35, and the averaged voltage Vi is input to the analog-digital converter 36 together with the battery voltage Vb. A digital signal output from the analog-to-digital converter 36 is input to the CPU 30 and processed.

Since the coil 4 and the resistor 34 are arranged in series, the currents I flowing through the two become equal.
The relationship I = Vi / Ri = (Vb-Vi) / Rsol is established. Here, Ri is the resistance value of the resistor 34, Rsol
Is the resistance value of the coil 4. Now, since Ri is constant, the current I flowing through the coil 4 is eventually proportional to the average voltage Vi, and it is possible to obtain an operation equivalent to detecting the current of the coil 4 by detecting the average voltage Vi. it can.

FIG. 5 is a block diagram showing a control algorithm for detecting the vibration of the linear solenoid using the circuit configuration shown in FIG. 3 and for suppressing the vibration when the vibration is detected.

In FIG. 5, a portion indicated by a chain line A in the figure corresponds to a basic solenoid drive control system. That is, first, the average voltage Vi corresponding to the drive current applied to the coil 4 is taken. This average voltage V
Since i includes the effect of the back electromotive force generated by the vibration of the linear solenoid, first, it was passed through a valve vibration frequency removal filter 50 to remove the (high frequency) component, and the influence of the vibration of the linear solenoid was removed. Take it out as a signal.

This signal is compared with a voltage (target voltage) Vtarg corresponding to a drive current for obtaining a hydraulic pressure to be generated at a summing point 52, and a deviation e between the respective voltages Vi and Vtarg is extracted. . This deviation e is output as a duty signal to the transistor 32 of FIG. 3 via a known PID controller 54.

Here, a portion surrounded by a two-dot chain line B corresponds to a control system for detecting and suppressing valve vibration according to the present invention.

First, since the average voltage Vi contains a frequency component of valve vibration, an output obtained by removing this component by the valve vibration frequency removing filter 50 and an output obtained by bypassing this component are compared at a summing point 56. As a result, a component close to direct current that fluctuates with the fluctuation of the target voltage Vtrag is removed.

That is, a (high-frequency) component Vli generated by the vibration of the linear solenoid is located downstream of the summing point 56.
Only p will be extracted. This vibration component Vlip
Is multiplied by the vibration suppression gain Klip by the multiplier 58,
After the phase is substantially inverted by the phase correction circuit 60, the sum is matched with the output of the PID controller 54 at the summation point 62. As a result, the voltage component generated by the vibration of the linear solenoid can be reduced from the output of the PID controller 54, and the vibration that is actually occurring is canceled by outputting the duty signal from which the voltage component of the vibration is subtracted. You.

Therefore, the phase correction in the phase corrector 60 not only reverses the plus / minus direction of the signal, but also takes into account the delay of the entire system and considers the voltage generated by the vibration of the linear solenoid that is actually occurring. There is a time delay so that fluctuations are most effectively offset.

The time delay is set by experimentally finding a value that effectively cancels the vibration when the linear solenoid actually has such a fast response that the vibration occurs.

In this circuit, Vlip is provided downstream of the summation point 56.
Has occurred, the subsequent vibration suppression system in the multiplier 58 and the phase correction circuit 60 (because the vibration has been detected) substantially functions. When no vibration is generated, Vlip becomes zero, and the vibration suppression system does not substantially function.

In this embodiment, the current (voltage) generated based on the vibration of the linear solenoid in real time
Vlip is detected, and the solenoid is driven so as to constantly suppress vibration based on the current (voltage) Vlip. However, in FIG. 2, the time when the absolute value of the voltage component Vlip exceeds a certain value continues for a predetermined time or more. A block is provided for determining whether or not the determination has been made.
And 60 may be configured to be matched.

With this configuration, when the vibration is small enough to cause no particular problem, the phase inversion / correction circuit of the vibration suppression system does not function, and the phase inversion / correction does not function as intended. It is possible to prevent the occurrence of a disadvantage that the vibration component is promoted.

Further, in the above embodiment, the configuration is adopted in which the voltage component generated by the vibration is used to cancel out the voltage component actually generated by the vibration, but the present invention suppresses the vibration. The method of driving the solenoid in such a manner is not limited to this. For example, if a slight decrease in responsiveness can be recognized, it is assumed that the time when the absolute value of Vlip exceeds a certain value continues for a predetermined time or more. In such a case, a configuration may be adopted in which the target voltage Vtarg passes through a block that obstructs the rise (a block that slightly sacrifices response). Generally, vibration is also suppressed when responsiveness is sacrificed.

[0033]

As described above, according to the present invention,
Since the vibration of the solenoid is detected from the current flowing through the solenoid and the drive can be performed so that the vibration is suppressed, the response can be maximized, and the generation of the vibration can be suppressed. An excellent effect is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention.

FIG. 2 is a sectional view of a linear solenoid to which the present invention is applied.

FIG. 3 is a circuit diagram for supplying a current to a coil of the linear solenoid.

FIG. 4 is a diagram showing an example of a duty signal output from a CPU.

FIG. 5 is a block diagram showing a control algorithm for detecting vibration of the linear solenoid and suppressing the vibration.

[Explanation of symbols]

2: Linear solenoid 4: Coil Vi: Average voltage (voltage corresponding to the drive current of the linear solenoid) Vlip: Voltage component of the average voltage Vi due to the vibration of the linear solenoid Vtarg: (obtains the hydraulic pressure to be generated Target voltage corresponding to the drive current for

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-50550 (JP, A) JP-A-63-43081 (JP, A) JP-A-2-199384 (JP, A) 164181 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00-63/48 F16K 31/06 H01F 7/18

Claims (1)

(57) [Claims] 1. A solenoid is driven by an electric command,
Thus, in the solenoid drive control device of the automatic transmission for controlling the hydraulic pressure, a means for detecting a current flowing through the solenoid, a means for detecting whether or not the solenoid is vibrating based on the detected current, Means for driving a solenoid so as to suppress the vibration when the vibration is detected. A solenoid drive control device for an automatic transmission, comprising: