JPS5977165A - Automatic speed change gear fitted with lockup - Google Patents

Abstract

PURPOSE:To aim at improvements in drivability dependent on an engine brake effect as well as a reduction in fuel consumption, by making sure of whether a car is in deceleration running at a select range of a shift lever or not, while changing a lockup device over to a state of operation or stoppage selectively according to that ascertainment. CONSTITUTION:Receiving each output from an accelerator opening sensor and a select range sensor, a shift lever forcibly stops the operation of a lockup device when it is in a D range and an accelerator is in a state of being fully closed. On the other hand, when the shift lever is in a forward range other than the D range and the accelerator is in a state of being fully closed, a control unit is made up so as to cause the operation of the lockup device to keep its normal state. In this way, when the shift lever is in the D range, it is discriminated as normal running, thereby aiming at a reduction in fuel consumption with a torque converter, and when the shift lever is in the forward range other than the D range, it is discriminated as decelerated running so that an engine brake effect is raised with a directly connected clutch, thus drivability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an automatic transmission with a lockup, in which the rotational force of an engine is directly transmitted through a direct coupling clutch in a predetermined driving range of a vehicle.

In general, automatic transmissions with lock-up overcome the drawbacks of normal automatic transmissions (those without lock-up), namely, the driving force of the torque converter, etc. interposed between the output shaft of the engine and the input shaft of the transmission. It was developed to compensate for the disadvantages that vehicle drivability and fuel consumption increase due to transmission loss.For example, an accelerator opening sensor that detects accelerator opening, a vehicle speed sensor that detects vehicle speed, and It is equipped with a lock-up device that directly connects the input shaft of the transmission to the output shaft of the engine via a direct clutch, and locks up when the accelerator opening is below a predetermined opening and the vehicle speed is above a predetermined speed (lock-up region). The device is operated to connect the engine output shaft and the transmission input shaft together.

However, in this automatic transmission with a starter pull-up, there is a problem in that when the vehicle speed is out of the lock-up range when the vehicle is decelerating, the engine braking effect is small due to the lock-up device not operating.

In order to solve this problem, conventionally, for example,
As disclosed in JP-A No. 8757 and Japanese Patent Application Laid-open No. 50-82'730, when the vehicle is decelerating, the ON operation does not occur.
A proposal has been made to provide a retarder switch (deceleration switch) and to operate a lock-up device by turning the retarder switch on and off, thereby constantly operating the lock-up when driving at deceleration to obtain a sufficient engine braking effect. has been done.

However, with this proposal, on the other hand, when the vehicle is decelerating, the lock-up device always operates and the engine speed increases, resulting in a reduction in fuel consumption per hour even though the accelerator opening is fully closed. There is a tendency that the amount increases and the original fuel efficiency reduction effect is reduced.

For example, as disclosed in Japanese Unexamined Patent Publication No. 56-39353, when the accelerator opening is fully closed, the lock-up device is deactivated to lower the engine speed and reduce fuel consumption. It is difficult to obtain the above-mentioned sufficient engine braking effect.

Therefore, in view of the above points, the present invention has been devised so that when the accelerator opening detected by the accelerator opening sensor is in the fully closed state, K causes the vehicle to decelerate according to the select range of the shift lever operated by the driver. By determining whether driving is required or not, and selectively switching the lock-up device to an activated state or a deactivated state accordingly, it is possible to improve drivability through the engine braking effect and reduce fuel consumption. The aim is to achieve both.

In order to achieve this object, the present invention includes an accelerator opening sensor that detects the accelerator opening, a vehicle speed sensor that detects the vehicle speed, and an accelerator opening that detects when the accelerator opening is below a predetermined opening based on the outputs of both of the sensors. In an automatic transmission with a lockup device that directly connects the input shaft of the transmission to the output shaft of the engine via a direct clutch when the vehicle speed is in an operating range equal to or higher than a predetermined speed, the select range of the shift lever is changed. In response to the outputs of the select range sensor to be detected, the select range sensor, and the accelerator opening sensor, the operation of the lock-up device is forcibly stopped when the shift lever is in the D range and the accelerator opening is fully closed. On the other hand, by providing a control device that maintains the operation of the lock-up device when the shift lever is in a forward range other than the D range and the accelerator opening is in the fully closed state, when the accelerator pedal is released, the shift lever - is in the D range, the transmission is drive-connected to the engine by a torque converter, etc., and if it is in a forward range other than the D-range, the transmission is drive-connected to the engine by a direct clutch.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows a 4-speed overdrive automatic transmission with lockup and its hydraulic control circuit according to the present invention.
1 is a casing of the transmission; 2 is an input shaft of the transmission disposed on the same axis as the output shaft 3 of the engine at the inner front end of the core casing 1; A torque converter 4 is provided. The torque converter 4 is
It consists of a pump 4a attached to the engine output shaft 3, a turbine 4b attached to the input shaft 2 of the transmission, and a stator 4c supported by the input shaft 2, and the pump 4a is driven by the rotation of the engine output shaft 2. The rotating force of the engine output shaft 3 is transmitted to the transmission input shaft 2 by circulating the internal hydraulic oil from the pump 4a through the turbine 4b and the stator 4c and back to the pump 4a.

Further, 5 is a direct coupling clutch disposed close to the torque converter 4, and the direct coupling clutch 5 has an operating chamber (
(not shown), and by introducing pressure oil into the working chamber, the turbine 4b is connected to the pump 4a portion of the torque converter 4.
It operates so that M minutes are connected Mf, that is, the output shaft 3 of the engine and the input shaft 2 of the transmission are directly connected.

Note that 6 is an overdrive mechanism provided on the rear side of the torque converter 4 inside the casing 1, and 7 is an auxiliary transmission mechanism provided on the rear side of the overdrive mechanism 6. Both include planetary gears 8, 8 . as gear transmissions. . . . and multi-plate clutches 9, 9, which serve as transmission elements for switching and driving the gear transmission. ..., brake band (not shown), one-way clutch 10,1
0. . . . etc., and the rotational speed of the input shaft 2 is varied in various ways.

On the other hand, 1'1 is an oil pump, 12 is a regulator valve that adjusts the discharge pressure of the oil pump 11 to a pressure (line pressure) suitable for the driving condition of the automobile, and 13 is a shift lever on the driver's seat.
(not shown) is a manual valve that switches and controls the supply direction of pressurized oil adjusted to the line pressure.

Further, 14 is a lock-up control valve, which selectively supplies pressure oil from the oil pump 11 to either the torque converter 4 or the working chamber of the direct coupling clutch 5, and controls the engine output shaft 3. The connection between the transmission input shaft 2 and the transmission input shaft 2 is controlled via the torque converter 4 or the direct coupling clutch 5. In addition, 15
is a diaphragm device 16 operated by the engine's intake negative pressure.
This is a throttle valve that is driven by the throttle valve to obtain a throttle pressure that corresponds to the accelerator opening, that is, the engine output. 17 is still the throttle backup valve. 18 is 3-4 speed shift valve, 19 is 1-
The 2-speed shift valve, 2Qi;j2-3 speed shift valve, automatically switches the oil path to the speed change element in the casing 1 according to the pressure of the pressure oil. Also, 21
and 22, a band servo, which drives the brake band among the above-mentioned speed change elements.

FIG. 2 shows a control system for controlling the operation of the lock-up control valve 14 in the hydraulic control circuit, where 23 is a vehicle speed sensor that detects the vehicle speed, and 24 is an accelerator that detects the accelerator opening (engine output direction). It is an opening sensor. Reference numeral 25 denotes a first determiner that determines whether or not the vehicle driving range is in the lock-up range based on the output signals from both sensors 23 and 24. As shown in the figure, when the accelerator opening is below a predetermined opening and the vehicle speed is above a predetermined speed, an H level signal is output, while an L level signal is output when the accelerator is outside the lock up area. It is something. The output of the first determiner 25 is connected via a first multiplier 26 to a solenoid 27 that controls the lock-up control valve 14, and is passed through the solenoid 27 when the operating range of the vehicle is in the lock-up range. ! lock-up control valve 14
A lock-up device 28 is configured to directly connect the transmission input shaft 2 to the engine output shaft 3 via the direct coupling clutch 5 by operating the lock-up device 28 .

Further, 29 is a second determiner which receives the output from the accelerator opening sensor 24 and determines whether or not the accelerator opening is in the fully closed state.
It outputs a level signal, and an L level signal at other times. 30 is a select range sensor that detects the select range of the shift lever; 31 is a third determiner that determines whether the shift lever is in the D range based on the output signal from the select range sensor 30; Therefore, the third determiner 31 determines whether the H level signal is in the D range when the shift lever is in the D range (normal driving range).
When the vehicle is in a forward range (low speed range) other than the range, an L level signal is output.

Further, 32 is a second multiplier that outputs an H level signal when the output signals of the second and third determiners 29 and 31 are both at H level, and 33 is an inverter for inverting the output signal of the second multiplier 32. The output of the inverter 33 is input to the other input section of the first multiplier 26. As described above, upon receiving the outputs of the accelerator opening sensor 24 and the select range sensor 30, when the shift lever is in the D range and the accelerator opening is fully closed, the output signal of the first multiplier 26 is set to L level. to forcibly stop the operation of the lock-up device 28, and when the shift lever is in a forward range other than the D range and the accelerator opening is fully closed, the output signal of the first multiplier 26 is maintained at H level to lock-up. A control device 34 is configured to control the operation of the device 28 in a normal state.

Next; the operation of the control device 34 will be explained with reference to the control flowchart shown in FIG. It is determined whether or not the is in the lockup area, and when it is not in the lockup area (in the blank area in Figure 3), the first determiner 2
When the output signal of 5 becomes L level, the solenoid 2
7 and the lock-up control valve 14 do not operate, and as a result, the engine output shaft 3 and the transmission input shaft 2
and is connected via a torque converter 4.

On the other hand, when the driving region of the vehicle is in the lock-up region (in the upper right shaded area in FIG. 3), the output signal of the first determiner 25 becomes H level, and then Based on the output signal from the accelerator opening sensor 24, it is determined whether the accelerator opening is in the fully closed state.

When the accelerator opening is not fully closed, the second
The output signal of the determiner 29 becomes L level, and accordingly, the output signal of the second multiplier 32 also becomes L level, and the inverter 3
When the output signals of 3 go to H level, the 1st
The multiplier 26 outputs an H level signal, which activates the lockup device 28 and locks the engine output shaft.
3 and the transmission input shaft 2 are directly connected via a direct coupling clutch 5, thereby improving the drivability of the vehicle and reducing fuel consumption.

On the other hand, when the accelerator opening is fully closed, the second
The determiner 29 outputs an H level signal, and in this state, the third determiner 31 determines whether or not the shift lever is in the D range. When the shift lever is not in the D range but in a forward range other than the D range, it is determined that the vehicle is in a decelerating state based on the fully closed state of the accelerator opening, and in that case, the output signal of the third determiner 31 is As the output signal of the inverter 33 becomes the L level and the output signal of the inverter 33 becomes the H level, the operation of the lock-up device 28 is maintained, and the engine output shaft 3 and the transmission input shaft 2 are directly connected in the same way as above. Therefore, the engine braking effect can be efficiently obtained.

Conversely, when the shift lever is in the D range, the output signal of the third determiner 31 becomes H level, the output signal of the second multiplier 32 becomes H level, and the output signal of the inverter 33 becomes L level. As a result, the lock-up device 28 as shown in the upper left diagonal shaded area of FIG.
operation is stopped and the engine output shaft 3 and transmission input shaft 2
and is connected via a torque converter 4. As a result, the engine speed is kept low due to the sliding action in the torque converter 4, and the fuel consumption per hour is reduced.

Therefore, in this way, when the accelerator opening is in the fully closed state and the shift lever is in the D register, it is determined that the vehicle is in the normal driving state and the torque converter 4 is operated to reduce fuel consumption, while the shift lever is - is in a forward range other than D range, it is determined that the vehicle is in a decelerating state, and the direct coupling clutch 5 is activated to enhance the engine braking effect, so the driver can operate the vehicle according to each range of the shift lever selected by the driver. It is possible to achieve both improvement in performance and reduction in fuel consumption.

In the above embodiment, the case where the application is applied to a 4-speed overdrive type automatic transmission has been described, but the present invention also has other features.
Needless to say, the invention can also be applied to two-speed or three-speed automatic transmissions.

As explained above, according to the present invention, the operating range of the vehicle is detected based on the vehicle speed and the accelerator opening, and when the vehicle is in the lock-up range, the lock-up device is activated to connect the output shaft of the engine to the input of the transmission. In an automatic transmission with a lockup that is directly connected to the shaft, the select range of the shift lever when the accelerator opening is fully open is detected, and when the shift lever is in the D range, the lockup device is activated. While the system is forced to stop, the lock-up device remains in operation when in a forward range other than D range.
According to the selection range of the shaft lever selected by the driver, it is possible to achieve both improved drivability and reduced fuel consumption.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a hydraulic control circuit diagram, FIG. 2 is an explanatory diagram of the operation control mechanism of the lock-up device,
FIG. 3 is an explanatory diagram showing the operating range of the lock-up device, and FIG. 4 is a flowchart of the control device. 2...Transmission input shaft, 3...Engine output shaft, 4...Torque converter, 5...Direct clutch, 14...Lockup control valve, 23...Vehicle speed sensor, 24
・・Accelerator opening sensor, 27・・Solenoid, 28・
・Lockup device, 30...Select range sensor,
34...control device. Figure 2 Figure 3 Vehicle speed →9 Figure 4

Claims (1)

[Claims] +1+ When the accelerator opening sensor detects the accelerator opening degree, the vehicle speed sensor detects the vehicle speed, and the output of both of the above sensors is received, the accelerator opening degree is below a predetermined opening degree and is in a driving range where the accelerator opening is at single speed or above a predetermined speed. In an automatic transmission with a lockup, the automatic transmission is equipped with a lockup device that directly connects an input shaft of a transmission to an output shaft of an engine via a direct clutch, a select range sensor that detects a select range of a shift lever, and a select range sensor that detects a select range of a shift lever. In response to each output of the accelerator opening sensor, when the shift lever is in the D range and the accelerator opening is fully closed, the operation of the lock-up device is forcibly stopped, and when the shift lever is in the forward range other than the D range. 1. An automatic transmission with a lock-up, comprising: a control device for controlling the lock-up device to maintain operation when the accelerator opening is in a fully closed state;