JP2002013631A - Automatic speed-change controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems of the conventional ordinarily set control patterns that a car speed is increased due to delay in automatic speed changing operation for gear shift-down during traveling on a downward slope, and a rotating speed of an engine is not necessary a rotating speed suitable for engine brake in automatically executing the shifting-down. SOLUTION: Shifting-down is executed automatically, when the increase of a speed is determined on the basis of the car speed information in the traveling on the downward slope under the operation of an auxiliary brake by a driver, and a speed change gear is selected automatically, to obtain the rotating speed of the engine of high engine brake effect corresponding to the car speed at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a transmission of an automobile. The present invention relates to an improvement in a device for calculating an appropriate transmission gear to be selected by a program calculation circuit. The present invention is used only when the clutch pedal is required to perform a fine clutch operation, such as when starting, in addition to an automatic vehicle without a clutch pedal, and shifting during running is automatically performed without operating the clutch pedal each time. It can be used for semi-automatic vehicles. The present invention is an apparatus developed to be applied to a large towing vehicle having a dozen or more stages of forward speed change gears, but can be widely used in other automobiles.

[0002]

2. Description of the Related Art Automatic transmissions having a program operation circuit for large vehicles have been widely used. The automatic transmission can reduce the driver's fatigue, and can perform smooth running because the selection of the transmission gear is appropriate. Further, by using the automatic transmission, the fuel consumption does not greatly differ depending on the personality of the driver.

[0003] The automatic transmission takes in vehicle speed information, engine speed information, accelerator operation information and other driving operation information and, based on preset engine characteristics, determines the optimal transmission gear to be selected at that time. Is provided. If the program control circuit determines that it exceeds the range that can be covered by the currently selected transmission gear from the engine characteristics according to a change in vehicle speed, the program control circuit disconnects the clutch without any operation by the driver. Automatically execute a series of shifting operations such as reducing the amount of fuel supplied to the engine, changing the transmission gear to the optimal one by estimating calculation, connecting the clutch, increasing the amount of fuel supplied to the engine, etc. Control. Also, this program control circuit, according to the operation information of the shift instruction lever provided in the driver seat,
It is configured to execute and control shift operations such as forward, reverse, upshift, downshift, and neutral.

[0004] For example, when the driver attempts to decelerate using the engine brake and operates the shift instruction lever to shift down, the program control circuit executes the downshift in accordance with the driving operation. The same applies to upshifting. Further, in a transmission having an extremely large number of transmission gears (for example, 16 forward gears), when an automatic transmission operation is performed, the driver cannot know which transmission gear is currently selected, so that the driver is not provided with a driver's seat. 2. Description of the Related Art There is widely used a device that numerically displays the gear number of a currently selected transmission gear and displays the number of gears that can be shifted from the current traveling state by an upward arrow and a downward arrow in accordance with the display. When the driver operates the shift instruction lever to the “UP” side, for example, twice, while watching this display, a two-step upshift is executed, and when the driver operates the “DOWN” side once, a one-step downshift is executed. .

[0005] As a prior art, an automatic transmission which recognizes a driver's intention by operating an auxiliary brake and reflects it in control is disclosed in Japanese Patent Application Laid-Open Nos. 9-133209 and 9-133.
No. 133211 discloses this.

[0006]

SUMMARY OF THE INVENTION The inventor of the present invention has repeatedly performed various running tests to design a new automatic transmission. In such a situation, there is a case where the vehicle speed gradually increases even when the vehicle releases its foot from the accelerator pedal while traveling on a downhill and the engine is braked. At this time, the automatic transmission automatically shifts down,
Depending on the conditions such as the road surface gradient and the load capacity at that time, the automatic shifting operation may not be executed until the vehicle speed becomes considerably high.

This is because the range of vehicle speed that can be covered by one transmission gear is wide in reality, and the normal control pattern requires a large range in which the vehicle speed can be adjusted by operating the accelerator pedal during traveling. It is. Further, the normal control pattern for performing the automatic shifting is designed so that the shifting operation is not automatically executed every time the vehicle speed slightly changes. In other words, if the vehicle speed range covered by one transmission gear is narrowed and the downshift is executed finely, a smooth driving operation during normal traveling on a flat road surface is hindered, and conversely, the vehicle is covered by one transmission gear. If the vehicle speed range is designed to be wide, the vehicle speed increases on a long downhill without executing the speed change operation. Yet another reason is that
This is because, in the control based on the control pattern of the normal automatic shift, the rotation speed of the engine corresponding to the vehicle speed at that time by the shift gear newly selected by downshifting is not always the rotation speed optimal for engine braking.

The present invention has been made in such a background, and in a situation where the vehicle speed is still increasing when the driver intends to decelerate by operating the auxiliary brake by the driving operation. It is an object of the present invention to provide a device that can automatically shift down to a transmission gear for which engine braking is effective and avoid the vehicle from accelerating downhill. SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic transmission in which a downshift is performed early on a downhill slope without losing the smoothness of a driving operation under normal traveling. SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic transmission that can perform a downshift by reflecting a driver's intention to decelerate. SUMMARY OF THE INVENTION It is an object of the present invention to provide a device capable of appropriately applying an engine brake to give a sense of security to a driver when the driver indicates intention to decelerate.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a driver intends to decelerate a vehicle by operating an auxiliary brake, and further increases the vehicle speed for a predetermined period of time without performing a shift operation. Is automatically downshifted to a transmission gear that can effectively apply engine braking on a downhill by identifying the vehicle speed information from the vehicle speed information.

That is, the present invention provides vehicle speed information (1), engine rotation speed information (2), accelerator operation information (4), auxiliary brake operation information (5), and shift instruction lever operation information (6). In the automatic transmission control device including a control means (10) for automatically selecting and controlling the optimum transmission gear, the control means (10) includes: 1) an auxiliary brake is operated in a braking state, and 2) a predetermined time ( When the condition that the vehicle speed increases over t) and the increase exceeds the set value is simultaneously satisfied, means for shifting down the shift gear even if the shift instruction lever is not operated by the driving operation is included. I do.

The numerals in the parentheses are reference numerals in the drawings of the embodiment device to be described later. This is added so that the configuration of the invention can be easily understood, and is not intended to limit the configuration of the invention to the embodiment apparatus.

During the predetermined time (t), time measurement is started when the automatic shift operation is not being performed, the auxiliary brake is operated in the braking state, and the increase in vehicle speed exceeds a set value. In the device of the present invention, during the execution of the timing, if a shift is instructed by operating the shift instruction lever before the predetermined time (t) elapses, the shift operation is executed with priority given to the driving operation, and The timing of the predetermined time (t) is reset when the shift instruction lever is operated. Thereby, consistency between the driving operation and the automatic shift operation is ensured.

With this configuration, when traveling downhill,
When the vehicle speed is increasing, the downshift is performed automatically so that the engine brake becomes effective. This downshift can avoid a phenomenon in which the vehicle accelerates on a downhill. Although the control logic added by the present invention is simple, the results of various tests have shown that it is effective to satisfy experienced drivers.

[0014] The prior art disclosed in the above-mentioned publication is common to the present invention in that the driver's intention is recognized by operating the auxiliary brake, but the present invention is based on complicated elements such as engine load and loading status. The feature is that simple control is executed based on time and vehicle speed, instead of calculating and controlling by adopting the above.

[0015] The means for downshifting is characterized in that the engine speed after downshifting is adjusted to the optimum engine speed for engine braking (for example, 1700-rpm in a truck diesel engine) set and held in advance in this program control circuit. It is desirable to include a means for selecting a transmission gear (in the range of 2400 rpm). With this configuration, after the shift operation is automatically performed, the engine brake is in the most effective state, and there is no need for the driver to give another instruction to perform the shift operation. By performing the control as expected, it is possible to give the driver a sense of security.

[0016]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. This device has a program control circuit 10
The program control circuit 10 includes a vehicle speed information 1, an engine rotation speed information 2, an accelerator operation information 4, an auxiliary block operation information 5, a shift instruction lever operation information 6, and a transmission Gear position information 7 is input. This program control circuit 10
Is supplied with a power supply current from a battery B mounted on the vehicle via a key switch. The auxiliary brake is an exhaust brake that closes the exhaust passage of the engine, a retarder that performs electric braking on axle rotation, a retarder that performs fluid braking on the axle,
This is one or a combination of retarders that make effective use of the compression resistance of the engine, and is controlled on / off by the driver operating a switch attached near the steered wheels.

From the control circuit 10, a fuel supply amount control signal 8 for the engine governor 11, a control signal 9 for the clutch actuator 12, and a transmission actuator control signal 14 for the transmission actuator 13 serve as interfaces. Sent out via This device also has a display 15 in the driver's seat, and this display 15 is connected to the program control circuit 10 via an interface. The display 15 displays the number of gears of the currently used transmission gear by numbers, the number of possible upshifts at the current time by an upward arrow, and the number of possible downshifts by a downward arrow. Is done. Incidentally, this embodiment is an example in which the present invention is applied to a large towing vehicle, and this transmission is equipped with 16 forward gears and 2 reverse gears.

In the device configured as described above, when the driver intends to start from a stopped state, the driver steps on the clutch and shifts the shift instruction lever from the neutral position (N) to the drive position (D). Program control circuit 1
0 selects a transmission gear suitable for starting. When the driver confirms on the display 15 that the start gear has been set, the driver can perform the start operation in the same manner as a normal manual shift vehicle by slowly releasing the clutch pedal while depressing the accelerator pedal.

When the vehicle starts moving, the automatic transmission determines acceleration based on vehicle speed information, engine rotation information, accelerator operation information, and the like, and performs acceleration while sequentially shifting up the transmission gear automatically. In this case, the driver does not have to depress the clutch pedal each time. The clutch actuator 12 automatically disengages the clutch under the control of the program control circuit 10, the transmission actuator 13 automatically selects and sets the transmission gear under the control of the program control circuit 10, and the clutch actuator 12 automatically The clutch is set to the engaged state. There is no need to adjust the accelerator pedal depression according to the shift operation, and the program control circuit 10 automatically controls the engine governor 11 in accordance with the shift operation.

FIG. 2 is a flow chart for explaining the main control logic of the program control circuit of the apparatus according to the embodiment of the present invention. When it is detected that the auxiliary brake operation has been performed by the driving operation while the vehicle is traveling with the shift instruction lever in the D position, a vehicle speed increase per time (Δv) is calculated from the vehicle speed information at that time, When this exceeds a predetermined value, a shift gear at which the engine rotational speed (in this example, 2000 rpm) at which the engine brake is most effective is selected, and downshifting to that shift gear is executed.

[0021]

By adopting such a configuration, it is possible to avoid a disadvantage that the vehicle speed gradually increases without downshifting while traveling downhill. The logic of the present invention does not include complicated arithmetic control, detects the current state, and simply executes downshifting, so that the operation is stable and in a situation where the driver expects downshifting while traveling downhill. Since the downshift is performed reliably,
A skilled driver can be given a sense of security.

[Brief description of the drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining a main part of a control logic implemented in a control circuit of the device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle speed information 2 Engine rotation speed information 4 Accelerator operation information 5 Auxiliary block operation information 6 Gear shift operation lever operation information 7 Gear position information 8 Fuel supply amount control signal 9 Clutch actuator control signal 10 Program control circuit 11 Engine governor 12 Clutch Actuator 13 Transmission actuator 14 Transmission actuator control signal 15 Indicator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) F16H 59:54 F16H 59:54 59:66 59:66 F term (reference) 3J552 MA01 MA13 NA04 NB01 PA33 RB18 RB23 SB02 SB10 UA03 VA62W VA76W VB01W VB04W VB16W VB18Z VD02W VE04W

Claims (2)

[Claims] 1. Automatically selecting and controlling an optimal transmission gear by taking in vehicle speed information, engine rotation speed information, gradient sensor output information, accelerator operation information, auxiliary brake operation information, and shift instruction lever operation information. In the automatic transmission control device including control means for controlling the vehicle, the control means includes: 1) when the auxiliary brake is operated in the braking state, and 2) when the vehicle speed increases for a predetermined time (t) and the increase exceeds a set value. An automatic transmission control device including means for shifting down a transmission gear even when a shift instruction lever is not operated. 2. The automatic transmission control device according to claim 1, wherein said means for downshifting includes means for selecting a transmission gear at which the rotational speed of the engine after downshifting becomes an optimal engine rotational speed for engine braking.