JPS60146948A - Automatic speed change control device - Google Patents

Abstract

PURPOSE:To obtain a comfortable running condition by switching a used speed change pattern from a standard pattern to an up-hill road speed change pattern on detecting a lowering of a car velocity exceeding a fixed speed reduction rate with a throttle opening larger than designated during running. CONSTITUTION:A computer 1 always detects a car velocity V and a throttle opening S. When the speed is reduced at the rate of 1km/h with the throttle opening S of more than 50%, the computer decides that it is an up-hill road and controls a car to use an up-hill road speed change pattern. The preset car velocity V obtained from a sensor 2 is compared with a speed change car velocity, and if speed change condition is satisfied, a speed change output is given to a speed change solenoid 6. When the throttle opening is more than 50%, and the speed reduction rate is below 1km/h, the computer decides that it is a slight gradient and controls the car to use a standard speed change pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to an automatic transmission control device that secures driving force by early downshifting on an uphill road.

Prior Art and Problems In general, in automatic transmissions (A/T) of automobiles, a reference shift pattern as shown in FIG. 1 is set based on vehicle speed, throttle opening, etc. This shift pattern is determined primarily based on the driving characteristics on flat roads, so it is difficult to handle on uphill and downhill roads. As a countermeasure, an auxiliary shift lever is installed, and by manually operating it in "D range" on flat roads and "2 range" or "L range" on slopes, it is possible to secure driving force on uphill roads and to maintain driving force on downhill roads. We are trying to ensure engine braking.

Figure 1 shows the basic shift pattern based on the auxiliary shift lever position, which is generally called the rD (drive) range.The solid line indicates the shift-up boundary when the vehicle speed increases, and the broken line indicates the shift-down boundary when the vehicle speed decreases. It shows. For example, if you accelerate while keeping the throttle opening at "4" (50%), the vehicle will shift up from 1st to 2nd gear at around 3Qkm/h, and then shift up from 2nd to 3rd at around 60km/h. . Once in 3rd gear, it will be further accelerated and shifted to 4th gear at a speed of 90km/h, or conversely it will remain in 3rd gear until it is decelerated to 33km/h or less and shifted down to 2nd gear. So, for example, if we consider a situation where the vehicle speed has decreased to 40 km/h in 3rd gear with a throttle opening of "4" (indicated by a ■ mark), if the road ahead is flat, we can expect it to accelerate again, but If it's on a road, the speed will drop even further.

One way to prevent this speed drop is to further depress the accelerator to increase the throttle opening and downshift from 2nd gear to 1st gear on the basic shift pattern shown in FIG. In this case, foot operation is required. Another method is to put the aforementioned auxiliary shift lever into the "2nd range", for example, and switch to the shift pattern shown in FIG. This "2 range"
mainly focuses on 2nd speed, and does not consider 4th speed, although it does have up to 3rd speed. For this reason, most of the gear is in 2nd gear, so when the throttle opening is "4" and the vehicle speed is 40 km/h, the symbol ■ immediately enters the 2nd gear range. This makes it possible to accelerate even on the slopes, but in this case manual operation is required.

If you do not use either of these methods, you will have to wait for the vehicle speed to drop below 33 km/h as shown in Figure 1 and automatically switch from 3rd gear to 2nd gear, but this will not allow for comfortable driving conditions. I can't get it.

Purpose of the Invention The present invention determines that if the throttle opening is greater than a predetermined throttle opening and the deceleration rate of the vehicle speed is above a certain value, it is determined that the road is uphill, and the shift pattern is automatically switched to that for uphill road, thereby automatically driving the uphill road. This makes it possible to secure power.

Structure of the Invention The present invention provides a standard shift pattern set based on flat road driving and a standard shift pattern set based on uphill road driving, in order to automatically switch the transmission of an automobile based on the relationship between throttle opening and vehicle speed. The uphill road shift pattern is stored in memory, and when a decrease in vehicle speed exceeding a certain deceleration rate is detected while driving at a predetermined throttle opening or more, the shift pattern in use is changed from the reference shift pattern to the uphill road shift pattern. This is characterized by switching to a shift pattern, which will be described in detail below with reference to the illustrated embodiment.

Embodiment of the Invention FIG. 3 is a flowchart showing an embodiment of the invention, and FIG. 4 is a block diagram showing the configuration of the device. First of all, the fourth
To explain from the figure, 1 is a microcomputer of a microcomputer-controlled automatic transmission control device (ECT).
The vehicle speed V from the vehicle speed sensor 2, the throttle opening S from the throttle sensor 3, the range designation signal R1 from the manual range (MR) switch linked to the auxiliary shift lever, and various other signals from other sensors are input here.

The vehicle speed V is km/h, the throttle opening S is expressed in %, and the range designation signal R indicates the D range, 2 range, etc.

The memory of the computer 1 stores at least the basic speed change pattern shown in FIG. 1 and the speed change pattern for the uphill road shown in FIG. A speed change output is given to the speed change solenoid 6 that drives the.

The operation will be described below with reference to the flowchart in FIG. The computer 1 constantly detects the vehicle speed V and the throttle opening S. This is also necessary for normal operation. For example, if the throttle opening S is 50% or more but the speed is decelerating at a rate of 1 km/h or more per second, it is determined that the road is uphill and the uphill road shift pattern ε shown in Fig. 2 is used. Switch. (Srono) Even if the small opening degree S is 50% or more, if the deceleration rate does not reach 1 km/h, it is determined that the slope is small and the basic shift pattern shown in Figure 1 is maintained.

Then, when switching to the uphill road shifting pattern, check the shifting vehicle speed. This shifting vehicle speed is the aforementioned boundary vehicle speed for downshifting (or upshifting). Then, the current vehicle speed (2) obtained from the sensor 2 is compared with the shifting vehicle speed, and if the shifting conditions are satisfied, a shifting output is given to the shifting solenoid 6. In this way, driving power is ensured while driving on the slope, and even if the throttle opening S decreases to 50% or less, the
When acceleration of more than km/h can be obtained, it is determined that the road has returned to a flat road, and the basic shift pattern shown in FIG. 1 is returned to. This is repeated below.

If the rate of change in speed is used to change the shift pattern, downshifts will be performed earlier on steep uphill roads. in this case,
More precise control becomes possible by changing the switching conditions of the shift pattern according to conditions such as the throttle opening S and the gear position.

Effects of the Invention As described above, according to the present invention, it is possible to easily detect the uphill road by simply changing the program of the ECT microcomputer without adding any special sensors, and it is also possible to automatically switch the shift pattern accordingly. There are some advantages.

[Brief explanation of the drawing]

FIGS. 1 and 2 are characteristic diagrams of different shift patterns, and FIGS. 3TIIJ and 4 are flowcharts and block diagrams showing one embodiment of the present invention. In the figure, 1 is a microcomputer, 2 is a vehicle speed sensor, and 3
is the throttle sensor, 4 is the manual range switch,
5 is a speed change gear, and 6 is a speed change solenoid. Applicant: Fujitsu Ten Ltd. Representative Patent Attorney Minoru Aoyagi Figure 3 Figure 4

Claims (1)

[Claims] ゛ In order to automatically switch the automobile transmission based on the relationship between throttle opening and vehicle speed, there is a standard shift pattern set based on flat road driving, and an uphill speed shift pattern set based on uphill road driving. The pattern is stored in memory, and when a decrease in vehicle speed that exceeds a certain deceleration rate is detected while driving at a predetermined throttle/nottle opening degree or more, the speed changer in use is changed from the reference speed changer to the uphill slope. An automatic shift control device characterized by switching to a road shift pattern.