JPH0556424B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift method using an automatic transmission device that selects an optimum gear position based on vehicle information and automatically switches the transmission to the selected gear position.

(Prior art) Receiving input of various vehicle information, reading the optimum gear from a gear selection map based on the vehicle speed and accelerator opening, and operating the transmission to switch to that gear. An automatic transmission device is known that includes an automatic transmission controller that outputs an actuation signal to a gear shift unit. According to such a gear shifting method using an automatic transmission device, when a single gear selection map is used in all driving conditions, the shifting speed value is determined as a compromise in each driving condition. Otherwise, there was a problem that the engine braking characteristics could not be fully demonstrated. Therefore, as shown in Figure 3, there are two types: one for normal driving (only that pattern is shown in Figure 3a) and one for when only the exhaust brake is activated (only that pattern is shown in Figure 3b). , for when the main brake is activated in addition to the exhaust brake (only the pattern is shown in FIG. 3c)), and a method of selectively using a plurality of gear selection maps at a timely manner is known. In addition, here, it is assumed that the exhaust brake only means that the main brake (hydraulic brake, etc.) is not operating, and that the engine brake is operating at that time.

(Problem to be solved by the invention) By the way, when a vehicle enters a downhill slope and starts running at a speed that gradually accelerates compared to normal running (in the case of a loaded truck, etc.),
Operates only the exhaust brake. At this time, the map shown in Figure 3b will be used,
For example, the exhaust brake and engine brake work from point A to point B. However, if you move this point B further to around point C, you can get even more out of the engine brake.
It is also possible to delay air speed due to clutch disengagement during gear change (upshift). However, on the other hand, if the vehicle speed decreases when driving downhill with an empty vehicle, the pattern shown in Figure 3b will cause the vehicle to move from point D to point B.
Although the exhaust brake and engine brake work until this point, point B is reached relatively quickly and a downshift is performed. At this time, there is a problem in that the vehicle runs idle due to clutch switching, and the exhaust brake and engine brake are applied too hard, resulting in excessive braking force and deterioration of the braking feeling.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shift method using an automatic transmission device that can effectively apply engine braking and maintain good braking feeling.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a method for changing gears of an automatic transmission in which a gear position is determined according to the current vehicle speed and an accelerator opening. It also detects the operation of the main brake due to brake pedal operation, and when only the exhaust brake is activated, the shift speed value for shifting up in the accelerator opening range below a predetermined value is set to a higher vehicle speed than during normal driving. The present invention is characterized in that when the exhaust brake and the main brake are activated, the shift-up speed value and the shift-down speed value in the accelerator opening range below a predetermined value are changed to higher vehicle speeds than during normal driving.

(Function) According to the present invention, the state in which deceleration is required is determined by the presence or absence of exhaust brake or main brake operation, and the shift-up speed value is set to a higher vehicle speed than during normal driving in the accelerator opening range below a predetermined value. Since the engine brake is changed to the side, the engine braking force can be applied effectively.

In particular, if you change the downshift speed value to a higher vehicle speed in a situation where sufficient braking performance is obtained when only the exhaust brake is activated and the vehicle decelerates, the downshift will be performed early and the vehicle may be idle during the shift. However, in the present invention, when only the exhaust brake is activated,
Since only the shift speed for upshifting is changed, the above problem does not occur.

Furthermore, when the exhaust brake and main brake are activated, both the shift speed value for shift up and the shift speed value for shift down are changed to the higher vehicle speed side, so early shift up is prevented and downshift due to deceleration is prevented. carried out early,
Engine braking power can be used effectively. In this case, the main brake is operating, so
The above-mentioned problems regarding the feeling of empty running and discomfort do not occur.

(Example) In the method of the present invention, a pattern based on each shift speed value in each gear stage is set during normal driving (Fig. 1a,
d), when only the exhaust brake is activated (see Figure 1 b, e), and when the exhaust brake and main brake are activated (see Figure 1 c, f).
and during upshifts (see Figure 1 a, b, c) and downshifts (see Figure 1 d, d).
(see e and f). Then, based on each pattern, a gear stage selection map as shown in FIG. 2 is determined, for example, using the pattern shown in FIG. 1e when only the exhaust brake is activated during downshifting. Six types of such gear selection maps are created and built into an automatic transmission controller 1 of an automatic transmission as shown in FIG. That is, in FIG. 4, the automatic transmission controller 1 is composed of a microcomputer, which includes a transmission switch 2 having an automatic gear position for instructing automatic gear selection, a vehicle speed sensor 3, and an accelerator opening sensor 4. A solenoid valve 8 attached to the engine controller 5, gear shift unit 6, and clutch actuator 7 receives various signals from the engine controller 5, gear shift unit 6, and clutch actuator 7 to control starting, starting, and shifting of the vehicle (not shown) based on these signals. Outputs an activation signal to etc. The engine controller 5 receives a load signal from the automatic transmission controller 1 and operates the fuel supply amount adjusting actuator 9. In Fig. 4, numeral 10 indicates an air tank, numeral 1
1 is a solenoid valve for the gear shift unit, and 12 is an automatic transmission controller 1 that changes the current gear position from the gear position.
13 is a brake switch that is turned on when the main brake (hydraulic brake) is activated, and 14 is an exhaust brake switch that is turned on when the exhaust brake is activated.

The automatic transmission controller 1 always receives input signals in sequence and determines whether the current driving is normal driving, only the exhaust brake is being operated, or whether the main brake is being activated in addition to the exhaust brake. Furthermore, it is determined whether to shift up or down based on whether the vehicle speed increases or decreases over time.
Based on one gear selection map selected through such judgment, the vehicle speed, accelerator opening degree, and more optimal gear are determined. When the current gear position and the optimum gear position are different, the clutch actuator 7, gear shift unit 6, and engine controller 5 are controlled to switch the gear train according to the gear change program.

Among these, a method of changing gears when the vehicle enters downhill driving from normal driving will be explained.

First, assume that the vehicle is traveling down a relatively gentle downhill slope when loading a vehicle. As a result, when the vehicle speed increases, the exhaust brake is immediately turned on and shift control is started based on the gear selection map having the pattern shown in FIG. 1b. Assume that the vehicle speed at this time is the P1 value, and that the vehicle speed has increased from this value even though both the exhaust brake and engine brake are acting. In this case, the time it takes to reach the P2 value as the shift speed value for upshifting exceeds the conventional value shown as the P3 value and has a more sufficient time width. For this reason, engine braking can be applied for a longer period of time than before, the shift-up timing can be delayed, and depending on the situation, it is possible to continue driving without changing gears.

Next, let's assume that the exhaust brake and engine brake decelerate even though the vehicle speed is downhill when the vehicle is empty. In this case, shift control is performed according to a gear selection map as shown in FIG. 2 based on the pattern of FIG. 1e. At this time, it is assumed that the vehicle speed is the P5 value, and that the vehicle speed is decelerated from this value by the action of the exhaust brake and engine brake. In this case as well, in order to reach the P4 value as the shift speed value for downshifting, it is necessary to have a sufficient time range beyond the conventional value shown as the P6 value.
By sufficiently delaying the downshift timing, it is possible to continue driving without changing gears in some cases.

Next, in shift control when the downhill slope is relatively steep and the main brake (hydraulic brake) is activated in addition to the exhaust brake, if the vehicle speed further increases, the pattern shown in Figure 1 c will occur. Conversely, when the vehicle speed is decreasing, the gear selection map based on the pattern shown in FIG. 1f is used to perform shift-up and downshift control. In this case, since the main brake is activated in both cases, it is possible to prevent the vehicle from running idle during gear shifting, and there is no need to delay the downshift timing in the vicinity of zero accelerator opening. Therefore, the patterns in FIG. 1c and FIG. 1f are similar, with the difference being that the downshift side is generally slower than the upshift side.

(Effects of the Invention) According to the method of the present invention, by changing the shift speed value according to the operating status of the exhaust brake and the main brake, engine braking force can be applied effectively without causing a feeling of dry running or discomfort. It has the effect of making it possible.

[Brief explanation of the drawing]

Fig. 1 is a comparison diagram of patterns consisting of shift speed values for upshifting and downshifting used in the method of the present invention, and Fig. 2 is a gear selection map based on the pattern shown in Fig. 1e. FIG. 3 is a comparative diagram of patterns consisting of conventional shifting speed values, and FIG. 4 is a block diagram of an automatic transmission used in the method of the present invention. 1... automatic gear shift controller, 2... gear change switch, 3... vehicle speed sensor, 4... accelerator opening sensor, 13... brake switch, 14... electric brake switch.

Claims (1)

[Scope of Claims] 1. In an automatic transmission shifting method that determines the gear position according to the current vehicle speed and accelerator opening, the operation of the exhaust brake is detected as well as the operation of the main brake due to the operation of the brake pedal. However, when only the exhaust brake is activated, only the shift-up speed value in the accelerator opening range below a predetermined value is changed to a higher vehicle speed than during normal driving, and when the exhaust brake and main brake are activated, the accelerator opening is below the predetermined value. The shift-up speed value and shift-down speed value in the range are changed to higher vehicle speeds than during normal driving. A gear shifting method using an automatic transmission characterized by the following.