KR102165415B1 - Apparatus and method for controlling continuously bariable transmission - Google Patents

Abstract

The present invention relates to a continuously variable transmission control apparatus and method.
A continuously variable transmission control apparatus according to an embodiment of the present invention is a device for controlling a continuously variable transmission in which a speed change is continuously performed by rotation of a driving pulley and a driven pulley according to a driving state of a vehicle, and the engine torque according to the rotation output of the engine The torque converter that transmits the signal to the continuously variable transmission, the pulley ratio detection unit that detects the pulley ratio as the rotational speed ratio of the drive pulley and the driven pulley included in the continuously variable transmission, and the difference between the pulley ratio and the target pulley ratio is greater than the set value. And a shift control unit for determining the sudden deceleration and releasing the hydraulic pressure of the forward clutch connected to the drive pulley until the continuously variable transmission is in a neutral state.

Description

Continuously variable transmission control device and method {APPARATUS AND METHOD FOR CONTROLLING CONTINUOUSLY BARIABLE TRANSMISSION}

The present invention relates to a continuously variable transmission control apparatus and method.

The transmission of a vehicle has a function of transmitting the rotational force of the engine to the driving wheels.These transmissions include a manual transmission in which the driver directly selects a gear position at the will of the driver, an automatic transmission in which the vehicle automatically shifts according to the driving conditions, It is classified as a continuously variable transmission in which there is no specific shift zone between each shift stage and continuously shifts continuously.

In the case of an automatic transmission, even if a sudden deceleration stops, it returns to the lowest gear stage, but in the case of a continuously variable transmission, the time to reach the lowest pulley ratio is longer than the time to stop by sudden deceleration, so it stops at the pulley ratio at the moment of stopping. Accordingly, in order to improve the performance to reach the lowest pulley ratio, if the time to stop is less than the time to reach the lowest pulley ratio, a method of immediately changing the target pulley ratio to the lowest pulley ratio is used, but eventually the lowest pulley ratio is not reached. In addition, in order to improve the performance to reach the lowest pulley ratio, the pulley ratio is forcibly reached to the lowest pulley ratio with a large hydraulic pressure in the D-stage stop state, but in this case, there is a problem that the durability is deteriorated and it takes a long time. In addition, there is a problem in that the re-start performance deteriorates (similar to the 2nd and 3rd gear start of an automatic transmission) when restarting is performed without reaching the lowest pulley ratio.

The above-described background technology is technical information possessed by the inventors for derivation of the present invention or acquired during the derivation process of the present invention, and is not necessarily known to be publicly known prior to filing the present invention.

Korean Patent Publication No. 2017-0113450

The present invention has been conceived to solve the above-described problems and/or limitations, and an object of the present invention according to one aspect is to improve the performance of reaching the lowest pulley ratio during rapid deceleration of a continuously variable transmission, thereby improving restart start performance. have.

A continuously variable transmission control apparatus according to an embodiment of the present invention is a device for controlling a continuously variable transmission in which a speed change is continuously performed by rotation of a driving pulley and a driven pulley according to a driving state of a vehicle, and the engine torque according to the rotation output of the engine A torque converter for transmitting the signal to the continuously variable transmission; A pulley ratio detector configured to detect a pulley ratio as a rotation speed ratio of the drive pulley and the driven pulley included in the continuously variable transmission; And a shift control unit determining a sudden deceleration of the vehicle when the difference between the actual pulley ratio and the target pulley ratio is greater than or equal to a set value, and releasing the hydraulic pressure of the forward clutch connected to the drive pulley until the continuously variable transmission is in a neutral state. Can include.

The shift control unit may reduce the engine torque below a set value in preparation for an accelerator pedal input in the neutral state.

When the difference between the actual pulley ratio and the target pulley ratio is less than a set value, the shift control unit may engage the hydraulic pressure of the forward clutch connected to the drive pulley and release the reduction of the engine torque.

A method for controlling a continuously variable transmission according to an embodiment of the present invention is a method of controlling a continuously variable transmission in which a continuously variable transmission is performed by rotation of a driving pulley and a driven pulley according to a driving state of a vehicle, wherein the engine is rotated by a torque converter. Transferring engine torque according to the output to the continuously variable transmission; Detecting, by a pulley ratio detection unit, a pulley ratio as a rotational speed ratio of the drive pulley and the driven pulley included in the continuously variable transmission; And when the difference between the actual pulley ratio and the target pulley ratio is greater than or equal to a set value, the speed control control unit determines the rapid deceleration of the vehicle and releases the hydraulic pressure of the forward clutch connected to the drive pulley until the continuously variable transmission is in a neutral state. It may include;

The method may further include reducing, by the shift control unit, the engine torque below a set value in preparation for an accelerator pedal input in the neutral state.

The method includes the steps of, by the shift control unit, when a difference between the actual pulley ratio and the target pulley ratio is less than a set value, engaging the hydraulic pressure of the forward clutch connected to the driving pulley and releasing the reduction of the engine torque; It may further include.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to embodiments, when the continuously variable transmission is rapidly decelerated, the ability to reach the lowest pulley ratio may be improved, thereby improving restart start performance.

The effects of the present invention are not limited to those mentioned above, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a diagram schematically illustrating an apparatus for controlling a continuously variable transmission according to an exemplary embodiment of the present invention.
FIG. 2 is a diagram schematically illustrating a change in a pulley ratio and engine rotation speed according to a vehicle speed deceleration when a brake pedal is sensed among the continuously variable transmission control apparatus of FIG. 1.
3 is a flowchart illustrating a method of controlling a continuously variable transmission according to an embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described in detail together with the accompanying drawings. However, it should be understood that the present invention is not limited to the embodiments presented below, but may be implemented in various different forms, and includes all transformations, equivalents, or substitutes included in the spirit and scope of the present invention. . The embodiments presented below are provided to complete the disclosure of the present invention, and to fully inform a person of ordinary skill in the art to which the present invention belongs. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

The terms used in the present application are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance. Terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. These terms are used only for the purpose of distinguishing one component from another component.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, identical or corresponding components are assigned the same reference numbers, and redundant descriptions thereof are omitted. I will do it.

1 is a diagram schematically illustrating a continuously variable transmission control apparatus according to an embodiment of the present invention, and FIG. 2 is a pulley ratio according to a vehicle speed deceleration when a brake pedal is sensed among the continuously variable transmission control apparatus of FIG. It is a diagram schematically illustrating a change in engine speed. Referring to FIG. 1, the continuously variable transmission control apparatus 100 may include an engine 110, a continuously variable transmission 120, a hydraulic drive unit 130, a detection unit 140, and a shift control unit 150.

The engine 110 is a device that generates a driving force, and may include a cylinder (not shown) in which fuel is injected and ignited, and a piston (not shown) and a crank (not shown) that move by igniting fuel in the cylinder. .

The continuously variable transmission 120 is a device that automatically changes the pulley ratio under the control of the shift control unit 150 and shifts, and a torque converter 121, a clutch 122 including a forward clutch and a reverse clutch, a driving pulley and a driven drive It may include a pulley 123 including a pulley.

The torque converter 121 is a device that converts the output of the engine 110 and provides it to the clutch 122 and the pulley 123. In response to the rotational output of the engine 110, the clutch 122 and the pulley 123 It can be provided by converting the rotational force to the furnace. Such a torque converter 121 provides a torque value, that is, a torque value to the clutch 122 and the pulley 123 in response to the engine torque according to the rotation output of the engine 110, according to the control of the shift control unit 150 , The clutch 122 and the pulley according to the control of the shift control unit 150 may provide an engine torque value corresponding to the engine torque according to the rotation output of the engine 110 or a preset allowable torque value may be provided. It may include a structure in which the torque value provided by 123 can be varied. To this end, the torque converter 121 is configured by coupling between the independent driving bodies so that they can have different output torque values corresponding to the input torque values, and according to the combination of the interlocking driving bodies among the independent driving bodies. It is desirable to have a structure that can generate output (torque value) variably.

The clutch 122 may selectively transmit the output of the torque converter 121, that is, engine torque from the engine 110 to the driving pulley. The clutch 122 may include a forward clutch and a reverse clutch, and in the forward state of the vehicle (D-stage), the forward clutch is fastened to the drive pulley by a switching mechanism (not shown), and the vehicle is in a reversed state (R-stage). ), the reverse clutch is fastened to the driving pulley by a switching mechanism, and in the neutral state (neutral (N-level) or parking (P-level)), the forward clutch and the reverse clutch are released from the driving pulley together. Here, the engaged and released states of the clutch 122 may be controlled by the hydraulic pressure applied by the hydraulic drive unit 130 under the control of the shift control unit 150.

The pulley 123 includes a driving pulley that receives power from the engine 110 through the torque converter 121 and a driven pulley that transmits power to the wheels, and the two pulleys are connected by belts. The driving pulley may receive power from the engine and transmit power to the belt, and the driven pulley may receive power from the belt and transmit power to the output side of the continuously variable transmission 120.

The hydraulic drive unit 130 may provide hydraulic pressure so that hydraulic pressure can be formed in the clutch 122 and the pulley 123 according to the driving state and transmission ratio of the vehicle under the control of the shift controller 150.

The detection unit 140 may generate various detection values so that the shift control unit 150 can control the continuously variable transmission 120 according to the driving state of the vehicle and output them to the shift control unit 150. In this embodiment, the detection unit 140 may include a vehicle speed detection unit 141, a pulley ratio detection unit 142, an engine rotation speed detection unit 143, and a turbine rotation speed detection unit 144. The vehicle speed detection unit 141 may detect the speed of the vehicle, the pulley ratio detection unit 142 may detect a pulley ratio as a rotational speed ratio of the driving pulley and the driven pulley, and the engine speed detection unit 143 may detect the engine speed. The rotation speed of 110) may be detected, and the turbine rotation speed detection unit 144 may detect the turbine rotation speed of the torque converter 121.

The shift control unit 150 may control the hydraulic drive unit 130 according to the state of the vehicle to output the controlled hydraulic pressure to the continuously variable transmission 120. The shift control unit 150 may determine a sudden deceleration of the vehicle when the difference between the actual pulley ratio and the target pulley ratio is greater than or equal to a set value. Referring to FIG. 2, the shift control unit 150 receives a brake pedal detection signal (brake ON) in the driving state (D stage) of the vehicle, the vehicle speed is less than a set value, and the difference between the actual pulley ratio and the target pulley ratio is set. If it is more than the value, it is possible to determine the sudden deceleration of the vehicle. Here, the set values may be variously designed and stored in advance based on the vehicle specifications and the designer's experimental results. When determining the sudden deceleration of the vehicle, the shift control unit 150 may control the hydraulic drive unit 130 to release the hydraulic pressure of the forward clutch connected to the drive pulley until the continuously variable transmission 120 is in a neutral state (N-stage). have. The shift control unit 150 may determine a neutral state when a difference between the engine speed from the engine speed detection unit 143 and the turbine speed from the turbine speed detection unit 144 reaches a set value. This is due to the fact that in the neutral state, the engine speed and turbine speed become the same. In addition, when the signal for detecting the accelerator pedal in the neutral state is received, the shift control unit 150 may reduce the engine torque below a set value in preparation for the occurrence of large slips and shocks during starting.

The shift control unit 150 continuously determines the difference between the actual pulley ratio and the target pulley ratio, and when the difference between the actual pulley ratio and the target pulley ratio is less than a set value, determines the normal driving state (D stage) of the vehicle, and drives By engaging the hydraulic pressure of the forward clutch connected to the pulley, it is possible to release the reduction of engine torque.

In this way, it is possible to improve the restart start performance by improving the performance to reach the lowest pulley ratio during rapid deceleration of the continuously variable transmission.

3 is a flowchart illustrating a method of controlling a continuously variable transmission according to an embodiment of the present invention. In the following description, portions overlapping with the descriptions of FIGS. 1 and 2 will be omitted.

Referring to FIG. 3, in steps S310 and S320, the continuously variable transmission control apparatus 100 determines a sudden deceleration of the vehicle when the difference between the actual pulley ratio and the target pulley ratio is greater than or equal to a set value.

In step S330, when determining the rapid deceleration of the vehicle, the continuously variable transmission control apparatus 100 releases the hydraulic pressure of the forward clutch connected to the drive pulley, and reduces the engine torque below the set value.

In steps S340 and S350, the continuously variable transmission control device 100 determines the difference between the actual pulley ratio and the target pulley ratio after a certain period of time has elapsed, and when the difference between the actual pulley ratio and the target pulley ratio is less than the set value, It judges the normal driving state (D stage).

In step S360, the continuously variable transmission control device 100 engages the hydraulic pressure of the forward clutch connected to the drive pulley, and releases the reduction of engine torque.

The embodiment according to the present invention described above may be implemented in the form of a computer program that can be executed through various components on a computer, and such a computer program may be recorded in a computer-readable medium. In this case, the medium is a magnetic medium such as a hard disk, a floppy disk, and a magnetic tape, an optical recording medium such as a CD-ROM and a DVD, a magneto-optical medium such as a floptical disk, and a ROM. A hardware device specially configured to store and execute program instructions, such as, RAM, flash memory, and the like.

Meanwhile, the computer program may be specially designed and configured for the present invention, or may be known and usable to those skilled in the computer software field. Examples of the computer program may include not only machine language codes produced by a compiler but also high-level language codes that can be executed by a computer using an interpreter or the like.

In the specification of the present invention (especially in the claims), the use of the term "above" and a similar reference term may correspond to both the singular and the plural. In addition, when a range is described in the present invention, the invention to which an individual value falling within the range is applied (unless otherwise stated), and each individual value constituting the range is described in the detailed description of the invention. Same as

If there is no explicit order or contradictory description of the steps constituting the method according to the present invention, the steps may be performed in an appropriate order. The present invention is not necessarily limited according to the order of description of the steps. The use of all examples or illustrative terms (for example, etc.) in the present invention is merely for describing the present invention in detail, and the scope of the present invention is limited by the above examples or illustrative terms unless limited by the claims. It does not become. In addition, those skilled in the art can recognize that various modifications, combinations, and changes may be configured according to design conditions and factors within the scope of the appended claims or their equivalents.

Therefore, the spirit of the present invention is limited to the above-described embodiments and should not be determined, and all ranges equivalent to or equivalently changed from the claims to be described later as well as the claims to be described later are the scope of the spirit of the present invention. It will be said to belong to.

100: continuously variable transmission control device
110: engine
120: continuously variable transmission
130: hydraulic drive unit
140: detection unit
150: shift control unit

Claims (6)

As a device for controlling a continuously variable transmission in which a speed change is made steplessly by rotation of a driving pulley and a driven pulley according to the driving condition of the vehicle,
A torque converter for transmitting engine torque according to the rotational output of the engine to the continuously variable transmission;
A pulley ratio detector configured to detect a pulley ratio as a rotation speed ratio of the drive pulley and the driven pulley included in the continuously variable transmission; And
When the difference between the actual pulley ratio and the target pulley ratio is greater than or equal to a set value, a shift control unit determines a rapid deceleration of the vehicle and releases the hydraulic pressure of the forward clutch connected to the drive pulley until the continuously variable transmission is in a neutral state. And
The shift control unit, when the accelerator pedal detection signal is received in the neutral state, reduces the engine torque to a preset value or less so that a large slip and shock are not generated when the vehicle starts.
delete The method of claim 1, wherein the shift control unit,
When the difference between the actual pulley ratio and the target pulley ratio is less than a set value, the hydraulic pressure of the forward clutch connected to the drive pulley is engaged and the reduction of the engine torque is canceled.
As a method of controlling a continuously variable transmission in which a speed change is made continuously by rotation of a driving pulley and a driven pulley according to the driving state of a vehicle,
Transmitting, by a torque converter, engine torque according to the rotational output of the engine to the continuously variable transmission;
Detecting, by a pulley ratio detection unit, a pulley ratio as a rotation speed ratio of the driving pulley and the driven pulley included in the continuously variable transmission;
When the difference between the actual pulley ratio and the target pulley ratio is greater than or equal to a set value, the shift control unit determines a sudden deceleration of the vehicle, and releases the hydraulic pressure of the forward clutch connected to the drive pulley until the continuously variable transmission is in a neutral state. ; And
And reducing, by the shift control unit, the engine torque below a set value so that a large slip and shock does not occur when the vehicle starts when the accelerator pedal detection signal is received in the neutral state.
delete The method of claim 4,
When the difference between the actual pulley ratio and the target pulley ratio is less than a set value, by the shift control unit, engaging the hydraulic pressure of the forward clutch connected to the drive pulley and releasing the reduction of the engine torque; further comprising , Continuously variable transmission control method.

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