JPS6196248A - Vehicle speed change gear - Google Patents

Abstract

PURPOSE:To prevent the speed of a vehicle from abruptly increasing upon creep running, by providing such an arrangement that when a vehicle is in a stop condition, a gear ratio is controlled to a value corresponding to the first shift stage, and when an idle-up device is actuated, the gear ration is changed over from the value corresponding to the first shift stage to a value corresponding to the second stage. CONSTITUTION:An output from a load sensor 13 is delivered to an idle-up device 14 while an output from a vehicle speed sensor 15 is delivered to a vehicle stop detecting means 16. Further, outputs from the idle-up device 14 and the vehicle stop detecting means 16 are delivered to a speed ratio change- over means 17 so that the gear ratio is set to a value corresponding to the first gear stage when the vehicle is in its stop condition, and the gear ratio is changed over from the value corresponding to the first gear stage to a value corresponding to the second gear stage when the idle-up device is operated. With this arrangement, when the idle-up device 14 is operated upon creep con trol, the torque of the engine is decreased, and therefore, it is possible to prevent the speed of the vehicle from abruptly increasing when the vehicle is introduced in a garage, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic transmission for a vehicle that transmits engine output to a transmission mechanism via a torque converter.

(Prior art) In the case of the above-mentioned automatic transmission, when the vehicle is stopped, the crinib phenomenon occurs and the vehicle starts to move, so as a means to prevent this, there is a means to set the gear shift position to a high gear (for example, Publication No. 109752/1983).

However, if the above-mentioned creep phenomenon is utilized, for example, the operation of parking the vehicle in the garage can be simplified by only operating the brake, and there is an advantage that the operation of moving the vehicle to the side is also simplified.

By the way, in engine idle link control, when an engine load such as a cooler is applied, in order to prevent engine output from decreasing and stalling, engine idle up is performed to increase the minimum engine output value by a predetermined value. However, when the idle up device is activated when the vehicle is running under creep control as described above, the engine output suddenly increases and the vehicle speed suddenly increases.
Correct problems that may cause accidents or make drivers feel uncomfortable.

(Object of the invention) The object of the invention is to prevent the vehicle speed from suddenly increasing during creep driving by switching the gear ratio from 1st gear to 2nd gear and reducing torque when the idle up device is operating. The purpose of the present invention is to provide an automatic transmission for a vehicle that can perform the following functions.

(Structure of the Invention) The present invention includes a detection means for detecting a stopped state of the vehicle, and when the vehicle is stopped, the gear ratio achieved by the transmission is controlled to 1st speed, and the idle up device is activated. The present invention is characterized in that the automatic transmission for a vehicle is equipped with a gear ratio switching means for switching the gear ratio from 1st speed to 2nd speed.

That is, as shown in FIG. 1, the engine 10 inputs its output to the transmission @ 12 via the torque converter 11, and the engine load of the cooler etc. on the engine 10 is detected by the load sensor 13 etc. An idle-up device 14 is provided to increase the minimum output value of the engine 10 to a set value, and a detection means 16 is provided to detect a stopped state of the vehicle based on a signal from a vehicle speed sensor 15 or the like. ), when this detection means 16 detects a stopped state of the vehicle, it controls the gear ratio achieved by the transmission mechanism 12 to 1st speed, and when the idle up device 1/I is operating, it controls the gear ratio to be changed to 1st speed. The automatic transmission for a vehicle is characterized in that it is provided with a gear ratio switching means 17 that changes the ratio from 1st speed to 2nd speed and reduces torque.

(Effect of the invention) According to the invention, when performing creep control,
When the idle up device operates, the gear ratio changes from 1st to 2nd gear.
Since the torque is reduced, the vehicle speed 1 will not suddenly increase when pulling into the garage or pulling over, allowing safe driving and ensuring the safety of the driver. The driving feeling can be improved without causing any discomfort.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows an automatic transmission for a vehicle, and in FIG. 2, the output of an engine 10 is input to a transmission mechanism 12 via a torque converter 11.

The above-mentioned transmission mechanism 12 includes first to fourth gears in the forward direction, and switching between each gear is performed by switching gears (not shown) combined in a shift cylinder group 18. Further, the combination operation of the shift cylinder group 18 is performed by the combination operation of the shift valve group 19, and the combination operation of the shift valve group 19 is performed by the combination operation of the three lock-up solenoid valves SL1.812.
.

The speed change is performed by the combined control operation of SL3, and as a result, the speed change by the combined operation of these valves SL1-813 is as shown in the table below.

(The following margin continues on the next page) -5= The engine 10 described above is equipped with an idle-up device 14 that increases the minimum output value (output during idling) of the engine 10 to a set value when an engine load such as a cooler is applied. [I'm being beaten.

Note that the output from the transmission mechanism 12 is transmitted to an output shaft 20, and this output shaft 20 drives a front wheel, a rear wheel, or both front and rear wheels.

The controller 21 is composed of a CPU, memory, etc., and includes the aforementioned lock-up solenoid valves SL1 and SL2.
, SL3 and the idle up device 14, and this controller 21 receives engine loads such as a signal indicating the accelerator opening from the accelerator opening sensor 22, a signal indicating the vehicle speed from the vehicle speed sensor 15, and a cooler from the load sensor 13. A signal indicating the shift range position of the shift sensor 23, that is, P range (parking), R range (
There are signals indicating the shift positions of (reverse), N range (neutral), D range (automatic shifting up to 4th gear), 2 range (automatic shifting up to 3rd gear), and Lunge (automatic shifting up to 2nd gear). is input.

The controller 21 according to the present invention controls the gear of the transmission mechanism to the first gear when the vehicle is stopped, and changes the gear from the first gear when the idle up device 1/1 is activated at the same time. Switch control to 2nd speed.

The processing operation of the controller 21 will be explained below with reference to FIG.

In a first step 31, the system is initialized, in a second step 32, a timer is set for a predetermined time, in a third step 33, a signal indicating the shift range of the shift sensor 23 is read, and in a fourth step 3/l. , and when other ranges are determined, it is determined in a fifth step 35 whether or not the range is 2, and when these 2 ranges are determined, in a sixth step 36, lockup is determined. Then, in a seventh step 37, a shift process to the second speed is executed.

That is, O is applied to the first lock-up solenoid valve SL1.
By outputting an N signal and an OFF signal to the second and third lock-up solenoid valves SL2.8L3, the transmission mechanism 12 operates as shown in the table above through one shift valve group and shift cylinder group 18. As shown in FIG. 3, the gear is shifted to the second speed, and at the eighth step 38, after a sufficient time has elapsed to complete the gear shifting process, the process returns to the second step 32.

If a lunge is determined in the fourth step 34 described above, the lockup is released in the ninth step 39, and
) In a tenth step 40, it is calculated whether the engine 10 will overrun when downshifting to first gear.

That is, the current vehicle speed is read from the vehicle speed sensor 15, a first speed cut line is map searched, and in an eleventh step 41, it is determined whether or not there will be an overrun.

If the above-mentioned determination indicates that there is an overrun, the gear is shifted to the second speed in a twelfth step 42. That is, the shift process to the second speed similar to that in the seventh step 37 described above is performed, and the shift process to the eighth speed is performed.
Skip to step 38.

Further, in the judgment at the 11th step/11 described above, if there is no overrun, the gear is shifted to the 1st speed at the 13th step 43. That is,
All lock-up solenoid valves SL1 to 51-3 are OFF
By outputting the signal, the transmission mechanism 12 is shifted to the first speed via the shift valve group 19 and the shift cylinder group 18 as shown in the table above.

When the D range is determined as a result in the fifth step 35 described above, creep control, which will be described later, is performed in a fourteenth step 44. At the 16th step 45.46, shift up,
Control of downshifting is performed.

That is, the optimum gear position is determined based on the vehicle speed signal from the vehicle speed sensor 15 and the accelerator opening signal from the accelerator opening sensor 22, and the gear shifting process for this gear position is executed.

After lockup control is performed at the 17th step 47, the process skips to the 8th step 38.

FIG. 4 shows the creep control in the fourteenth step 44 described above. In this creep control, when the vehicle is stopped, the transmission mechanism 12 is controlled to the first gear, and at the same time the idle up device 14 is controlled to the first gear. When the engine is in operation, the gear is controlled to the second gear.

That is, in a twenty-first step 51, a signal indicating the vehicle speed is read from the vehicle speed sensor 15, and in a twenty-second step 52, the speed is changed to 4. km/h or less, and when it is determined that the vehicle is in a stopped state, the accelerator distance signal from the accelerator distance sensor 22 is read in a twenty-third step 53, and in a twenty-fourth step 54. , determine whether the accelerator is fully open or not,
When it is determined that the accelerator is fully open, in a twenty-fifth step 55,
Read the valve signal for idle correction. That is, based on the load sensor 13 detecting an engine load such as a cooler, the controller 21 outputs an idle correction valve signal to operate the idle up device 14, so the output of this valve signal is read. By doing so, it can be determined whether or not the idle up device 14 is in an operating state.

In a twenty-sixth step 56, based on the above-mentioned valve signal,
It is determined whether or not the idle up device 14 is in operation, and when the idle up device 14 is not in operation,
Creep control is executed at the first gear set in the shift map.

However, when it is determined that the idle up device 140 has been activated, at step 27, a shift process to the second speed is executed in the same manner as step 37 described above, and the creep control is ended. .

As described above, when the idle up device 14 is in operation, the output of the engine 10 is increased by a predetermined value, so if the vehicle creeps in this state, the vehicle speed increases.

Therefore, when shifting to the second gear as described above, the output torque is smaller than that of the first gear, so even if the vehicle creeps, the vehicle speed will not suddenly increase. Things will go away.

Incidentally, if the determination in the above-mentioned 22nd and 24th steps 52 and 54 is ON, the creep control is ended.

In the correspondence between the configurations of this invention and the embodiments described above, the detection means of the invention has the following features:
Similarly, the gear ratio switching means is the second one of the controller 21.
The steps 5 to 27 correspond to the processes 55 to 57, and the other parts correspond to the same part names in the embodiment.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a block diagram of an automatic transmission for a vehicle according to the present invention, FIG. 2 is a block diagram of the automatic transmission for a vehicle according to an embodiment, and FIG. Flowchart of the speed change process. FIG. 4 is a flowchart of the creep control. 10...Engine 11...Torque converter 12...Transmission mechanism 13...Load sensor 14.
... Idle up device 15 ... Vehicle speed sensor 21 ... Controller 22
...Accelerator distance sensor diagram 1

Claims (1)

[Claims] 1. An idle up device is provided which increases the minimum engine output value to a set value when an engine load such as a cooler is applied, and the engine output is transmitted to the transmission mechanism via a torque converter. The automatic transmission for a vehicle is equipped with a detection means for detecting a stopped state of the vehicle, and when the vehicle is in a stopped state, the gear ratio achieved by the transmission mechanism is controlled to 1st speed, and an idle-up device is activated. An automatic transmission for a vehicle, characterized in that it is provided with a gear ratio switching means for switching the gear ratio from first speed to second speed when the automatic transmission is in operation.