JPS62103234A - Speed change control of hydraulic type automatic transmission - Google Patents

Abstract

PURPOSE:To suppress the speed change shock by temporarily reducing the fuel feed quantity when a frictional engagement element of a hydraulic type automatic transmission is put into engagement state from nonengagement state through speed change operation. CONSTITUTION:A hydraulic type automatic transmission 9 transmits the output of an engine 11 to a driving wheel through the speed change treatment of the output of the engine 11, and supplies and discharges the hydraulic pressure into the frictional engagement elements such as clutch and brake, and the speed change ratio selection (speed change) is carried out automatically in correspondence with the driving state of a car by selecting the revolution elements such as arbitrary rotary drum and gear. When, in this automatic transmission 9, a frictional engagement element is put into engagement state from the nonengagement state (N range) through speed change operation by a shift lever 7, and an accelerating pedal 1 is stepped in, a throttle valve 5 is closed for a prescribed time by a controller 3. Therefore, the increase of the engine revolution is suppressed, and speed change shock can be prevented.

Description

[Detailed Description of the Invention] <Field of Application of Industrial Balls> The present invention relates to a shift control method capable of reducing shock during gear shifting in a hydraulic automatic transmission, and in particular,
It is effective when applied to select forward gear from neutral range or parking range.

<Prior art> As one of the automatic transmissions for vehicles, hydraulic pressure is supplied to frictional engagement elements such as clutches and brakes, and by selecting any rotating element such as a rotating drum or gear, the transmission ratio can be changed. ) is known, which automatically performs this function depending on the driving condition of the vehicle. Pressure oil is supplied to these frictional engagement elements in order to protect various devices and equipment and maintain a comfortable ride. teeth,
Normally, the shifting is carried out gradually, with predetermined characteristics consisting of the initial oil pressure supplied after the transmission of the shift start signal.

As shown in FIG. 3, which schematically shows the structure of a conventional general automatic transmission for vehicles, the crankshaft 12 of the engine 11, which is the power source of the vehicle, is a torque converter, which is one of the fluid connection means. The torque converter 13 is integrally connected to the pump] 4 of the conobark 13, and the torque converter 13 is connected to the pump 14 and the turbine 1.
5, a stator 16, and a one-way clutch 17,
The stator 16 is connected to the case 18 via the one-way clutch 17, and the one-way clutch 17 allows the stator 16 to rotate in the same direction as the crankshaft 12, but is not allowed to rotate in the opposite direction.

The torque transmitted to the turbine 15 is transmitted by an input shaft 19 to a gear transmission disposed at the rear thereof that achieves four forward gears and one reverse gear. It is basically the same even if a joint is used.

The gear transmission includes three sets of clutches 20, 21, 22, two sets of brakes 23, 24, and one one-way clutch 2.
5 and a set of Ravigneau type planetary gear mechanism 26. The Ravigneau planetary gear mechanism 26 rotatably supports a ring gear 27, a long pinion gear 28, a seat pinion gear 29, a front sun gear 30, a rear sun gear 31, and the pinion gears 28 and 29, and is rotatably fitted to the input shaft 19. The ring gear 27 is connected to the output shaft 33, the front sun gear 30 is connected to the input shaft 19 via the kickdown drum 34 and the front clutch 20,
The rear sun gear 31 connects to the input shaft 1 via the rear clutch 21.
9, and the carrier 32 is connected to the case 18 via a low reverse brake 24 and a one-way clutch 25, which are arranged in parallel with each other, and a four-speed clutch arranged at the rear end of this gear transmission. It is connected to the input shaft 19 via 22. In addition, kickdown drum 34
can be integrally connected to the case 18 by a kickdown brake 23, and the torque passing through the planetary gear mechanism 26 is transmitted from an output gear 35 fixed to an output shaft 33 to the drive shaft side of a drive wheel (not shown). be done.

Each of the clutches 20 to 22 and the brakes 23 and 24, which are IWA engagement elements, is composed of a hydraulic device equipped with an engagement piston device or a servo device, etc.
Although it is operated via a hydraulic control device by pressure oil generated by an oil pump (not shown) connected to the pump 14 of the torque converter 13, its detailed configuration and operation ζ are disclosed in Japanese Patent Laid-Open No. 58-46258, etc. That's exactly what it says. These clutches 20 to 22 and brake 23
．． By the combination of 24 operations, a gear stage of 4 forward speeds and 1 reverse speed as shown in Table 1 is achieved.
shows the engaged state.

<Problems to be Solved by the Invention> In the conventional hydraulic automatic transmission as shown in FIG. is selected, all frictional engagement elements are in a non-engaged state. Therefore, when the driver operates the shift 1 lever and selects the forward automatic shift range (D range) or the reverse range (R range) from 1st to 4th gear, the respective predetermined frictional engagement elements are activated. As a result of shifting to the engaged state, rotational power from the engine is transmitted to the driving wheels, and the vehicle begins to travel forward or backward depending on the amount of depression of the accelerator pedal.

However, when the driver depresses the accelerator pedal and switches the shift lever from the N or P range to the D or R range, a large rotational force is suddenly transmitted when the frictional engagement element engages, resulting in excessive rotational force. There are problems such as shift shock, which impairs riding comfort, and unreasonable force is applied to the gear transmission, which is undesirable in terms of durability.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with conventional hydraulic automatic transmissions, it is an object of the present invention to provide a shift control method that can reduce the shift shock at the time of starting even if the driver continues to press the accelerator pedal. do.

Means for Solving the Problems> The gear change control method for a hydraulic automatic transmission of the present invention operates hydraulically and selects an arbitrary rotating element, so that the rotational power of the engine is transmitted through the fluid connection means. In a hydraulic automatic transmission equipped with a plurality of frictional engagement elements that change the gear ratio between the input shaft that receives the input and the output shaft that outputs this rotational power to the drive wheels, the frictional engagement element is non-switching. When either of them shifts from the engaged state to the engaged state, the rotation of the engine is reduced for a certain period of time regardless of the amount of depression of the accelerator pedal, and then the rotation of the engine is reduced in accordance with the amount of depression of the accelerator pedal. It is characterized by being made to return to its original state.

Function> When a signal is input that causes all of the giI friction engagement elements to shift from a disengaged state to an engaged state, the amount of fuel supplied, for example, will change regardless of the amount of depression of the accelerator pedal by the driver. After reducing the amount of fuel for a certain period of time to about the idling speed, the amount of fuel supplied is returned to a state corresponding to the amount of depression of the accelerator pedal.

This suppresses the increase in engine speed and reduces unpleasant shocks because there is only a small torque fluctuation when the frictional engagement element engages.

Embodiment Example FIG. 1 shows the concept of an embodiment of the shift control method for a hydraulic automatic transmission according to the present invention, and FIG. 2 shows the relationship between the shift lever position, the accelerator pedal depression amount, the throttle opening, and the transmitted torque. As shown in the figure, the amount of depression of the accelerator pedal 1 (detected by the potentiometer 2 and sent to the control device 3, and the opening degree of the throttle valve 5 provided in the middle of the air supply passage 4 of the engine 1) controls this control. The throttle actuator 6 can be changed based on the control v!!J signal from the device 3.The operation of the throttle actuator 6 is set in accordance with the amount of depression of the accelerator pedal 1, and will be described later. When the conditions are met, the opening degree of the throttle valve 5 is controlled to be close to the opening degree corresponding to idling rotation, regardless of the amount of depression of the accelerator pedal 1, based on a preset time chart 1. In other words, the soft range position is changed by the knot lever 7 from the N range to the D position by the inhibitor switch 8.
When it is detected that the range has been changed to range or R range, or that the P range has been changed to R range, the control device 3 changes the throttle opening degree to t2 time (for example, after a quim lag of L time (for example, 025 seconds)). After 0.35 seconds), the throttle actuator unique 6 is activated so that the throttle opening corresponds to the detected value of potentiometer 2 again. is designed to be controlled.

On the other hand, the hydraulic automatic transmission 9 attached to the engine 11 has the same structure as shown in FIG. Based on the signal, the control device 3 indicates the most favorable gear position of this hydraulic automatic transmission 9.

By the way, the above-mentioned t1 time and L2 time can be changed as appropriate depending on the depression state of the accelerator pedal 1, the operating state of the engine, etc. Generally speaking, the shorter the 7 hours and the longer the t2 hours per month, the more severe the shock will be. becomes less. Note that there is no problem in setting the 2 hour period before or after the engagement completion time of the friction engagement element, and by setting the t2 time, it is possible to notify the driver that the accelerator response has decreased by 1 degree. However, if the accelerator pedal l has been depressed before changing the shift range position, it is also effective to set t to 0 and set only the time t2.

Therefore, for example, when the driver changes the shift lever 7 from the N range to the D range and depresses the accelerator pedal 1, the throttle opening will increase in accordance with the amount of depression of the accelerator pedal 1, but after t1 hours, the driver will press the accelerator pedal 1. Throttle valve 5 is t
It is closed for only two hours to prevent the engine speed from increasing. As a result, the transmission torque becomes a fluctuation curve as shown by the solid line in FIG. 2, and it can be seen that the fluctuation amount of the transmission torque is smaller than the fluctuation amount of the conventional transmission torque shown by the broken line in which no control is performed as shown in FIG. The two-dot chain line in the figure shows the case of idling, and the same applies when the shift lever 7 is changed from the N range to the R range or from the P range to the R range.

In this embodiment, the accelerator opening degree is controlled as a means for reducing the rotation of the engine 11, but it is of course possible to control the ignition timing, fuel supply, etc. in addition to this.

<Effects of the Invention> According to the method of the present invention, when the driver selects a gear shifting operation in which all the friction engagement elements of the hydraulic automatic transmission shift from a disengaged state to an engaged state. In this case, the system temporarily reduces the amount of fuel supplied to suppress the increase in engine speed regardless of how much the accelerator pedal is pressed, reducing the shift shock even when the driver is strongly pressing the accelerator pedal. There is no risk of deterioration in durability or ride comfort.

[Brief explanation of drawings]

FIG. 1 is a conceptual control diagram showing one embodiment of the present invention, and FIG. 2 shows the shift range position and accelerator pedal depression amount,
A graph showing the relationship between throttle opening and transmitted torque, and FIG. 3 is a conceptual diagram of the mechanism of the hydraulic automatic transmission to which the present invention is applied. Also, in the symbols in the figure, 1 is the accelerator pedal, 3 is the control device,
5 is a throttle valve, 7 is a shift lever, 19 is a hydraulic automatic transmission, 11 is an engine, 13 is a torque converter, 1
9 is an input shaft, 20 is a front clutch, 21 is a rear clutch, 22 is a 4-speed clutch, 23 is a kick down brake, 24 is a low reverse brake, and 33 is an output shaft. Patent application: Mitsubishi Motors Corporation Company agent

Claims (1)

[Claims] By selecting an arbitrary rotating element operated by hydraulic pressure, the gear ratio between the input shaft, into which the rotational power of the engine is input via the fluid connection means, and the output shaft, which outputs this rotational power to the drive wheels, can be adjusted. In a hydraulic automatic transmission equipped with a plurality of frictional engagement elements to be switched, when any of the frictional engagement elements transitions from a disengaged state to an engaged state, the engine speed changes regardless of the amount of depression of the accelerator pedal. A speed change control method characterized in that, after the rotation of the engine is reduced for a certain period of time, the rotation of the engine is returned in accordance with the amount of depression of the accelerator pedal.