JPH0567828B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a line pressure control device for an automatic transmission for an automobile.

<Conventional technology> In conventional automatic transmissions for automobiles, the oil discharged from the oil pump is adjusted to the optimal line pressure according to the throttle opening (or accelerator opening) of the engine, and is then applied to each hydraulic circuit. supplying.

An example of an electronically controlled automatic transmission will be explained with reference to FIG. Reference numeral 1 denotes an oil pump, which is driven by the output shaft of the engine via a torque converter, that is, driven by the input shaft of the transmission. 2 is an electromagnetic valve whose duty is controlled by a control unit 32 to which a signal from a throttle sensor 31 that detects the opening degree of the throttle valve 16 in the engine intake passage is input, and the discharge of the oil pump 1 is guided through the orifice 3. Based on the pressure, a pilot pressure (throttle pressure) proportional to the throttle opening is obtained. 4 is a pressure modifier valve that increases the pilot pressure. 5
is a pressure regulator valve that regulates the discharge pressure from the oil pump 1 to a line pressure proportional to the pilot pressure from the pressure modifier valve 4, and is used for torque converter (power transmission) 6.
It is sent to each of the hydraulic circuits 7 for lubrication, 8 for cooling, 9 for generating hydraulic pressure, and 10 others. Note that a valve is provided at the end of the circuit 9 for generating hydraulic pressure to operate the clutch, brake, etc. in combination according to the gear position.

<Problems to be Solved by the Invention> By the way, the line pressure, which is the source of the working oil pressure of the automatic transmission, needs to be adjusted to an appropriate oil pressure according to the engine output, and if it is higher than the appropriate oil pressure, the torque transmission rate is high, engine vibration,
Since the gear shifting shock is transmitted to the axle, noise and vibration increase. Furthermore, if the oil pressure is lower than the appropriate oil pressure, the engagement force of the gears etc. will be weakened, unnecessary slips will occur, the transmission efficiency will be significantly reduced, and in the worst case, the clutch etc. will be damaged due to friction.

However, in the past, the throttle opening was used as a parameter for engine output, and the line pressure was adjusted according to the throttle opening.Since the throttle opening did not necessarily reflect the engine output accurately, the engine output There was a problem that the corresponding line pressure was not the same.

For example, when the throttle valve changes from fully closed to fully open, the intake air flow rate increases with a slight delay relative to the change in throttle opening, and the engine speed increases with an even later delay. This is because even in the same fully open state, the engine output fluctuates during transient periods, and the line pressure does not follow this fluctuation.

SUMMARY OF THE INVENTION In view of these conventional problems, it is an object of the present invention to provide a line pressure control device for an automatic transmission for an automobile that can appropriately adjust line pressure in accordance with engine output.

<Means for Solving the Problems> In order to achieve the above object, the present invention, as shown in FIG. In a line pressure control device for an automatic transmission for an automobile, which includes a pressure regulator valve 5 that sends pressure to the circuit, and an electromagnetic valve 2 that changes the pilot pressure under duty control, the line pressure control device synchronizes with the rotation of the engine 13. A fuel injection amount detection means A detects the amount of fuel injected and supplied to the engine 13 from the fuel injection valve 17; an engine rotation speed detection means B detects the rotation speed of the engine 13; a storage means C that stores data on duty values for obtaining line pressures corresponding to the numbers;
a retrieval means D for retrieving a corresponding duty value from the storage means C based on the fuel injection amount and engine rotation speed detected from each of the detection means A and B, and driving the electromagnetic valve 2 according to the duty value. The configuration is such that a drive means E is provided.

<Function> With this configuration, the fuel injection amount (pulse width of the drive pulse signal to the fuel injection valve) can be adjusted to the fourth level.
As shown in the figure, the engine output is almost proportional to the engine shaft torque, and therefore the engine output can be more closely approximated by the fuel injection amount and engine speed, so by controlling the engine based on the fuel injection amount and engine speed, Appropriate line pressure matched to output can be obtained.

<Example> An example of the present invention will be described below based on FIGS. 2 and 3. However, in FIG. 2, the same parts as in FIG. 5 are designated by the same reference numerals, and their explanation will be omitted.

Reference numeral 11 denotes a control unit with a built-in microcomputer that controls the duty of the electromagnetic valve 2, and includes a drive pulse signal from the control unit 12 for fuel injection control and a rotation speed sensor 14 that detects the rotation speed of the engine 13. A signal is input.

Control unit 12 for fuel injection control
is the throttle valve 16 of the intake passage 15 of the engine 13.
The engine 1 is connected to the electromagnetic fuel injection valve 17 provided downstream.
The fuel injection amount is controlled by intermittently outputting a drive pulse signal with a pulse width corresponding to the intake air amount in synchronization with the rotation of 3.
Ti is the intake air amount Q detected by the air flow meter 18 provided in the intake passage 15 of the engine 13 and the engine rotation speed N detected by the rotation speed sensor 14.
From that, the basic pulse width Tp = K・Q/N (K is a constant)
Calculate this and correct it with various correction coefficients COEF such as water temperature and voltage correction Ts to get Ti=Tp・COEF+
Defined as Ts.

The control unit 11 is controlled by a built-in microcomputer according to the flowchart shown in FIG.

Explaining according to the flowchart in Figure 3,
In step 1 (denoted as S1 in the figure), a shift range position (Drive, Manual, 1st speed, 2nd speed, etc.) is detected based on a signal from a shift range position sensor (not shown). Next, in step 2, the control unit 12 for controlling fuel injection controls the fuel injection valve 17.
The pulse width Ti of the drive pulse signal outputted from the engine is read as the fuel injection amount, and then the engine speed N is read based on the signal from the rotation speed sensor 14. Here, step 2 corresponds to the fuel injection amount detection means,
Step 3 corresponds to the engine rotation speed detection means.

On the other hand, a map in which duty values corresponding to the pulse width Ti and the engine speed N are stored is prepared in advance in the ROM in the microcomputer as a storage means for each shift range position. Note that the duty value is set to obtain the line pressure corresponding to the engine output calculated from the pulse width Ti and the engine rotation speed N. For the same pulse width, the engine rotation speed and line pressure are almost proportional, and the same engine The rotation speed is determined so that the pulse width and line pressure are approximately proportional.

Therefore, in step 4, a map corresponding to the shift range position is selected, and a duty value corresponding to the pulse width Ti and engine speed N is searched from the map, and in step 4, the duty value is set by interpolation calculation. do. These steps 4 and 5 correspond to the search means.

Then, in step 5, a duty control output is generated at this duty value to drive the electromagnetic valve 2. This part corresponds to the driving means.

Thereby, it is possible to obtain a line pressure that corresponds to the engine output.

<Effects of the Invention> As explained above, according to the present invention, it is possible to generate line pressure according to the engine output based on the fuel injection amount and the engine speed, and even during transients, the gear etc. The effect is that noise and vibration can be reduced without weakening the fastening force.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the configuration of the present invention.
FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is a flowchart, FIG. 4 is a diagram showing an engine performance curve, and FIG. 5 is a block diagram showing a conventional example. 1...Oil pump, 2...Solenoid valve, 4...
...Pressure modifier valve, 5...Pressure regulator valve, 11...Control unit, 12...Control unit for fuel injection control, 13...Engine, 14...Rotational speed sensor, 17... Fuel injection valve, 18... air flow meter.

Claims (1)

[Claims] 1 An automobile automatic machine comprising a pressure regulator valve that regulates the discharge pressure of an oil pump to a line pressure proportional to the pilot pressure and sends it to each hydraulic circuit, and an electromagnetic valve that changes the pilot pressure under duty control. A line pressure control device for a tick transmission includes a fuel injection amount detection means for detecting the injection amount of fuel injected and supplied to the engine from a fuel injection valve in synchronization with the engine rotation, and an engine rotation detection means for detecting the engine rotation speed. a storage means that stores duty value data for obtaining a line pressure corresponding to the fuel injection amount and engine speed; and a fuel injection amount and engine speed detected by each of the detection means. A line pressure control device for an automatic transmission for an automobile, comprising: a retrieval means for retrieving a corresponding duty value from the storage means; and a driving means for driving the electromagnetic valve in accordance with the duty value.