JPS63266260A - Electronic line pressure controller for automatic transmission - Google Patents

Abstract

PURPOSE:To suppress operational noise of solenoid by disabling a duty ratio control solenoid valve for hydraulic clutch or brake until complete combustion state of engine is achieved even if ignition switch is turned ON. CONSTITUTION:A control unit 10 sets a duty ratio corresponding to line pressure for clutch or brake through a duty ratio determining circuit 11 based on throttle valve opening and turbine rotation, and provides a signal 12a through an AND gate 12, a drive element 13 and a solenoid 14 to a duty ratio control solenoid valve 3 so as to control the solenoid valve 3, then a pilot hydraulic pressure proportional to the duty ratio is fed to a pressure regulation valve 4 so as to feed a predetermined line pressure L1. Since output A from an alternator is L until complete combustion state of engine is achieved even if an ignition switch is turned ON, the AND gate 12 does not produce the signal 12a and disables the solenoid valve 3. Consequently, operational noise of solenoid is suppressed before the engine is started, resulting in prevention of noise and improvement of durability.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides line pressure to be supplied to hydraulic clutches, brakes, etc. for setting gears in an automatic transmission.
The present invention relates to a line pressure control device adjusted by a duty ratio control solenoid valve.

(Prior Art) In an automatic transmission, a power transmission path of the transmission is switched according to driving conditions, etc., and a gear stage is appropriately set according to the driving conditions. This switching of the power transmission path is often performed by operating a hydraulically operated clutch, brake, etc. The hydraulic pressure used to operate this clutch, brake, etc. is line pressure, and usually the engine The oil supplied from the hydraulic pump driven by the pump is adjusted to a predetermined pressure using a pressure regulator valve.

This line pressure only needs to be the pressure necessary to engage the clutches, brakes, etc., but in this case, setting the maximum pressure necessary for the engagement as the line pressure is not sufficient for the hydraulic pump. Since the power required for driving becomes too large, the line pressure is normally adjusted according to the driving situation so as to keep the line pressure to the minimum necessary according to the torque transmitted by the clutch and brake. This line pressure is adjusted according to engine load, output rotation, etc., and a duty ratio control solenoid pulp is sometimes used for this adjustment. Duty ratio control solenoid pulp repeatedly turns the pulp on and off in extremely short cycles, and by changing the on-time ratio (duty ratio) in each cycle, the oil pressure on the upstream side of this pulp is controlled. For example, as a device for performing speed change control using such a duty ratio control pulp,
There is a control device disclosed in Japanese Patent No. 2349.

(Problems to be Solved by the Invention) By using the duty ratio control solenoid valve as described above, line pressure can be controlled electrically, and R
The power to drive this pulp solenoid is supplied to the solenoid at the same time as the ignition switch is turned on.For example, when the ignition switch is turned on to start the vehicle, the engine starts. There is a problem in that the solenoid pulp is driven even if it has not been started yet, and the operating sound of this solenoid pulp causes noise. In particular, before the engine is started, there is no engine noise, so the noise inside the car is small, but the operating noise of the solenoid pulp is relatively loud, and it can be said that the problem of noise inside the car is serious at this time. Furthermore, before the engine is started, the hydraulic pump is not driven, and there is no need to drive the duty ratio control solenoid pulp.
There is a problem in that the durability of this solenoid pulp and, by extension, the durability of the control unit that controls the drive of this solenoid pulp are reduced, and the life of the battery is also reduced.

(Means for Solving the Problems) The present invention solves problems such as generation of noise due to solenoid operation, deterioration of durability of solenoid pulp, etc., which are problems when using a duty ratio control solenoid pulp as in the conventional manner, and problems caused by battery life. In order to solve the above problem, the line piezoelectric control device of the present invention provides a hydraulically operated clutch for setting gears, a hydraulically operated clutch for setting a gear, a brake, etc. line pressure,
The duty ratio control solenoid valve is controlled by the duty ratio control solenoid valve, but even if the ignition switch is on, the duty ratio control solenoid valve is prohibited from operating until the engine reaches full combustion. I try to do that. Note that a complete explosion state here refers to a state in which the engine has been cranked and is in a normal operating state, for example, when the engine rotation is 40 Orr.
The judgment is made based on whether or not the pm has been exceeded.

(Function) When using the line piezoelectric control I device as described above, the line pressure is adjusted by the duty ratio control solenoid pulp, so the line pressure is adjusted to the minimum necessary value according to the transmission torque of each clutch, brake, etc. It is easy to make
Furthermore, since the solenoid pulp is not operated when the engine is not being driven, the solenoid operating noise that has conventionally been a problem before starting the engine is eliminated, and the problem of noise is eliminated. moreover,
Since the solenoid is not activated before the engine starts, the durability of the solenoid pulp is improved, and the durability of the control unit that controls the operation of this solenoid pulp is also improved, preventing over-discharge of the battery and extending its lifespan. do.

(Example) Preferred examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a part of a hydraulic circuit for controlling an automatic transmission having a line piezoelectric control device according to the present invention. This control circuit controls the hydraulic pump 1 driven by the engine and the hydraulic pressure in a first line L1 connected to the discharge port of the hydraulic pump 1 to a desired line pressure P1 necessary for the gear shifting clutch and brake (not shown). A pressure regulator valve 4 to be adjusted, a pressure reducing valve 2 to reduce the hydraulic pressure of the first hydraulic line L1 in order to obtain a pilot pressure P2 for adjusting the hydraulic pressure by the pressure regulator valve 4, and this pressure reducing valve. The hydraulic pressure of the second hydraulic line L2 lowered by F
It has a duty ratio control solenoid valve 3 that adjusts A and produces a pilot pressure P2. The pressure regulator valve 4 operates based on the pilot pressure P2 of the second hydraulic line L2 created by the solenoid valve 3.
The first hydraulic line Li corresponds to this pilot pressure P2.
Adjust the line pressure P1. The line pressure P1 of the first hydraulic line L1 is selectively supplied to a clutch, a brake, etc. for shifting. Therefore, in the above circuit, the line pressure PK can be controlled by controlling the pilot pressure P2 of the second hydraulic line L2 using the duty ratio control solenoid pulp 3.

Next, the adjustment of the pilot pressure P2 by the duty ratio control solenoid pulp 3 will be explained.

The device shown in the circuit diagram of FIG. 2 controls the energization of the solenoid of the solenoid valve 3, and this circuit consists of a duty value determining circuit 1 that determines the duty ratio.
1, an AND circuit 12 that receives an output signal from the duty value determining circuit 11, a transistor 13 that receives the output signal of the AND circuit 12 at its base electrode, and a line 13a connected to the emitter of the transistor. The solenoid coil 14 of the solenoid valve 3 is connected to the solenoid coil 14 of the solenoid valve 3. Various signals are input to the control unit 10, such as a throttle opening detection signal, a torque converter turbine rotation speed detection signal, and a range signal obtained by detecting the position of the gear shift lever. Based on this, a signal for controlling the operation of the gear shifting clutch and brake is output to the gear shifting solenoid valve, etc. In addition, this control unit 10 calculates a desired line pressure PI for the clutch and brake based on the throttle opening signal and the turbine rotation speed signal, and the duty value determining circuit 11 calculates the desired line pressure PI for the clutch and brake. Line pressure P! The first hydraulic line L1
The duty ratio required to obtain the pilot pressure P2 required to create the same is determined, and a signal having this duty ratio is output to the AND circuit 12 via the line 12a. An "A" signal is input to this AND circuit 12 via a line 12b.

This “A” signal is either a 00” signal or a “1” signal, and when the “A” signal is 0, the AND circuit 1
The output of the transistor 2 is "0", the transistor 13 is not energized, and the solenoid 14 is also not energized and is not energized.
” signal is “1”, the duty value determining circuit 11
A signal having a predetermined duty ratio output from AN
The signal is outputted to the base of the transistor 13 via the D circuit 12, and the solenoid 14 repeatedly turns on and off based on the duty ratio.

Here, the operation of the duty ratio control solenoid pulp 3 when ON/OFF is repeated at a predetermined duty ratio will be explained with reference to FIGS. 3A and 3B. As shown in FIG. 3, the duty ratio is 1.0% during 1 hour on 1 cycle. It refers to the proportion of the on signal in the signal that is repeated with the on signal for a certain period of time. For example, when the duty ratio of the duty ratio control solenoid pulp 3 in the circuit of FIG. 1 is changed from 0% to 100%, the 3B As shown in the figure, the pilot pressure P2 changes to 0 as shown by the dotted line, and the line pressure PK changes as shown by the solid line. As can be seen from this, the line pressure P1 can be adjusted by changing the duty ratio.

Note that in the circuit of FIG. 2, A
The "A"A" signal input to the ND circuit 12 causes or prohibits the driving of the solenoid pulp 3 based on the above-mentioned duty ratio. This "A" signal will be explained below.

Figure 4A shows how the 'A#' signal is connected to the alternator terminal 21.
An example of setting by the voltage from

The voltage at this L terminal 21 is +12■ when the engine is in a normal operating state (when the engine is in a complete explosion state), but when the engine is not running or has not reached a complete explosion, it is approximately +12■. Ov, so when the L terminal voltage is approximately OV, a "0" signal is output as the "'A" signal by a circuit configured as shown in the figure with a resistor 22.23iB and a capacitor 24, and the L terminal voltage is 12V. When this happens, a signal of ``1''1'' is generated.

FIG. 4B shows a second example of setting the "A" signal, in which the output waveform of the ignition coil 31 is shaped by the waveform shaping circuit 32 to detect the engine rotation speed, and the engine rotation speed is detected by the rotation speed determination circuit 33. This rotation speed is 400 rpm
It is determined whether or not the engine rotation is greater than 400 rpm, and if it is greater than 400 rpm, a "1" signal is output as the "A" signal, and if it is smaller, a 0 signal is output. That is, in this case, the engine rotation is 400 rpm When it becomes larger, it is determined that it has reached a complete explosion state.

FIG. 4C is a flowchart showing a third embodiment of setting the "A" signal. In this case, when the ignition is turned on, the "A" signal is first set to "O".

There is an interrupt step in the step after this, but
After this interrupt is made, it is determined whether the "A" signal is "1" or not, and if it is "1", this flow ends and the next flow starts from the above interrupt step. , the same flow follows. If it is determined that the "A'A" signal is 0 in the above determination, the turbine rotation speed of the torque converter is detected, and it is determined whether or not this rotation speed is 400 rpm or more. If the rpm is less than 400 rpm, this flow is ended as it is, while if it is more than 400 rpm, "A"
" signal is set to "1" to end this flow. When the current flow ends, the next flow starts from the above interrupt step, and the same flow is performed thereafter.

That is, in this example, the complete explosion of the engine is determined from the turbine rotation speed, which is approximately the same as the engine rotation.

Although three examples of detecting the complete combustion state of the engine have been described above, it goes without saying that the method for detecting the complete combustion state of the engine is not limited to these.

(Effects of the Invention) As described above, according to the present invention, the line pressure for operating the hydraulic clutch, brake, etc. for gear setting is controlled by the duty ratio control solenoid pulp, and the even pressure control Even if the switch is on, driving of this duty ratio control solenoid pulp is prohibited until the engine reaches a complete explosion state, so the line pressure is adjusted by the duty ratio control solenoid pulp, and the line pressure is adjusted by the duty ratio control solenoid pulp. It is easy to set the pressure to the minimum required value according to the transmission torque of each clutch, brake, etc. On the other hand, when the engine is not in a complete combustion state or is not yet driven, the solenoid pulp is not operated. This eliminates the generation of solenoid operating noise before starting the engine, which was a problem in the past, and can suppress the noise problem. . Furthermore, since the solenoid is not operated before the engine starts, the durability of the solenoid pulp can be improved, and the operation of this solenoid pulp can be reduced to 1 liter.
The durability of the control unit can also be improved, and over-discharge of the battery can be prevented and its lifespan can be extended.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram for controlling an automatic transmission having a line piezoelectric control device according to the present invention, FIG. 2 is a circuit diagram showing a device for controlling energization of a solenoid of a duty ratio control solenoid pulp, and FIG. 3B and 3B are graphs showing the duty ratio and the relationship between the duty ratio and the line pressure, and FIGS. 4A to 4C are circuit diagrams and flow charts showing examples of determining the "A"A" signal. 1...Hydraulic pump 2...Press chassis reducing valve 3...Duty ratio control solenoid valve 4...Pressure regulator valve 10...Control unit 12...AND circuit 13...Transistor 14 ...Solenoid coil 21...L terminal 31.
... Ignition coil 32 ... Waveform shaping circuit 33 ... Rotation speed judgment circuit O

Claims (1)

[Claims] 1) In an automatic transmission in which line pressure for operating a hydraulically operated clutch, brake, etc. for gear setting is controlled by a duty ratio control solenoid valve, when the ignition switch is in the on state. 1. A line piezoelectric control device for an automatic transmission, characterized in that driving of the duty ratio control solenoid valve is prohibited until the engine is in a complete explosion state.