JPS61177507A - Duty control voltage generating device for automatic transmission - Google Patents

Abstract

PURPOSE:To calculate duty corresponding to a command duty control voltage accurately all the time even during variation in driving voltage and to hold a duty control voltage invariably at the command by correcting the driving duty of a solenoid according to the variation in driving voltage detected by a sensor. CONSTITUTION:A microcomputer 101 inputs the signal from an engine rotating speed sensor 14, the signal from a throttle opening extent sensor 15, the signal from a gear position sensor 16, the signal from a voltage sensor 17 which detects the driving voltage V of the solenoid 18 for generating the duty control voltage, and the signal from a oil temperature sensor 16 which detects the oil temperature T of an automatic transmission, thereby performing duty control over the solenoid 18 with output duty D based upon the arithmetic result of those signals. The solenoid 18 generates the command duty control voltage securely by correcting the duty in such a state that the duty control voltage deviates from the command owing to variation in the driving voltage V and performs the control accurately without any variance even during voltage variation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a duty control pressure generating device for an automatic transmission.

(Prior Art) Today, automatic transmissions are increasingly equipped with torque converter slip control devices, cooleep prevention devices, gear shift shock reduction devices, etc. in order to improve performance and quality. It is advantageous in terms of configuration to be electronically controlled.

When implementing electronic control, a duty control system is often considered in which a solenoid is driven under duty control using a drive voltage to generate duty control pressure, and this duty control pressure operates the above device. ing.

(Problem to be Solved by the Invention) However, in the conventional duty control pressure generating device, it is possible to obtain desired control according to control factors such as engine speed, throttle opening, and gear position. This system aims to generate the target duty control pressure by calculating the pressure and driving the solenoid with the corresponding duty, which has caused the following problems.

In other words, the driving voltage of the solenoid varies depending on whether the engine is warming up or after warming up, whether the temperature is high or low, whether the vehicle speed is high or low, whether the battery is new or old, etc. As shown in FIG. 7, the duty control pressures of the duty control pressures are also different (in this figure, eight types of drive voltages of 10V, 12V, and 14V are shown). Therefore, if the duty is determined based on the characteristics at a drive voltage of, for example, 12V, as in the past, the duty control pressure will be higher than the target when the drive voltage is 10V, and conversely, when the drive voltage is 14V, the duty control pressure will be higher than the target. The duty control pressure is made lower than the target, and in any case, the target duty control pressure cannot be obtained due to fluctuations in the drive voltage, resulting in five problems.

In the case of a torque converter slip control device, excessive or insufficient amount of torque converter slip causes deterioration of fuel efficiency, engine noise, and generation of vibration, and in the case of a creep prevention device, creep prevention cannot be prevented or start-up shock occurs, resulting in shift shock. In the case of a mitigation device, the engine may start racing or lose torque.

(Means for solving the problem) In order to solve this problem, the present invention generates duty control pressure by driving the solenoid 1 with a drive voltage 2 under duty control a, as shown in FIG. In an automatic transmission number controlled by this duty control pressure, a voltage sensor 5 detects the drive voltage 2, and a duty correction means 6 corrects the drive duty of the solenoid 1 according to fluctuations in the drive voltage. It is characterized by its configuration.

(Function) The means 6 corrects the drive duty of the solenoid 1 according to the fluctuation of the drive voltage 2 detected by the sensor 5.
Even when the drive voltage 2 fluctuates, a duty that accurately corresponds to the target duty control pressure can always be found, and the duty control pressure can always be kept at the target value.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows an embodiment in which the device of the present invention is constituted by a microcomputer. This is the normal one consisting of:

The micro/computer 10 includes a signal from an engine rotation speed station 14 that detects the engine rotation speed Ne, and a throttle opening sensor 1 that detects the engine throttle opening TH.
5, a signal from a gear position sensor 16 that detects the selected gear position G of the automatic transmission, and a voltage sensor 1? that detects the drive voltage V of the solenoid 18 that generates the duty control pressure. The signal from the oil temperature sensor 16 that detects the oil temperature T of the automatic transmission is input, respectively, and the output duty D based on these calculation results causes the solenoid 1 to be activated.
8 shall be subjected to duty control.

For this purpose, the microcomputer 10 is, for example, an eighth
The control program shown in the figure is executed, and first, in step 20, the engine rotation speed Ne s engine throttle opening TH
and read the gear position G. In the next step 21, the target duty control pressure is calculated based on these 8 pieces of information Ne5THsG, and in the next step 22, the reference duty d for the target duty control pressure is looked up from the table data corresponding to FIG. do. After that, in steps 28 and 24, the solenoid drive voltage V and oil temperature T are read, and in step 251C, the duty correction coefficient α is calculated from the voltage V, oil temperature T, and constants β and r using the following equation. Calculate.

αtan β・v−T+r In the next step 26, the duty is corrected by multiplying this correction coefficient α by the reference duty d to obtain a corrected duty D−α・d. output to solenoid 18. here,
By also including the oil temperature T, it is possible to eliminate the influence of oil viscosity and improve the response of the solenoid.

In this way, the solenoid 18 can reliably generate the target duty control pressure by correcting the duty even in a situation where the duty control pressure deviates from the target value due to fluctuations in the driving voltage V. Control can be performed accurately without variation even when voltage fluctuates.

FIG. 5 shows another example of the control program executed by the microcomputer IO, and in this example, Stella 7'80, 81
．． Steps 20, 21 and 28 in FIG.
Perform the same processing as . In the next step 88,
Based on the drive voltage V read in step 82, this is 1(I
When V or less, the table data corresponding to D1 in Figure 6 is
Table data corresponding to D2 in the same figure when the voltage is 10 to 12V, table data corresponding to D8 in the same figure when the voltage is 12 to 14V, and table data corresponding to D2 in the same figure when the voltage is 12V or more. search for. These table data are data for determining the five output duty control pressures that can be obtained so that the target duty control pressure calculated in step 81 falls within the allowable error range for each corresponding drive voltage section.

In step 84, an output duty D corresponding to the target duty control pressure is looked up from the single table data retrieved in this way, and this duty D is output to the solenoid 18 in step 85.

In this way, in this example as well, the drive duty of the solenoid 18 is corrected by the search of the table data as the drive voltage V fluctuates, so that the target duty control pressure can be generated accurately, and the control based on this pressure can be performed using the voltage. It can be executed accurately even when there are fluctuations.

(Effects of the Invention) As described above, since the device of the present invention is configured to correct the solenoid drive duty according to fluctuations in the solenoid drive voltage, the duty control pressure can always be maintained at the target value even when the drive voltage fluctuates. , it is possible to prevent the control from becoming unstable due to deviation of the duty control pressure from the target value.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of the duty control pressure generating device of the present invention, FIG. 2 is a system diagram showing an embodiment of the device of the present invention, FIG. 8 is a flowchart of the control program executed by the microcomputer of the same side device, and FIG. FIG. 4 is a change characteristic diagram of the reference duty, FIG. 5 is a flowchart showing another example of the control program, FIG. 6 is a change characteristic diagram of the output duty, and FIG. 7 is a change characteristic diagram of the duty control pressure. 1.18... Solenoid 2, V... Solenoid drive voltage 8... Duty control 4... Automatic transmission 5.1
7... Voltage sensor 6... Duty correction means 1
0...Microcomputer 11...Central processing (22) 12...Memory 18
... Input/output interface circuit 14 ... Engine speed sensor 15 ... 20 liter opening sensor 16 ... Gear position sensor Figure 4 Of 2 3 Eyes 1. - Tee rope 1 # pressure (sheer route □su Figure 5)

Claims (1)

[Claims] 1. An automatic transmission comprising a device configured to generate a duty control pressure by driving a solenoid under duty control with a drive voltage, and controlled by the duty control pressure, comprising: a voltage sensor for detecting the drive voltage; A duty control pressure generating device for an automatic transmission, comprising: duty correction means for correcting the drive duty of the solenoid according to fluctuations in drive voltage.