Technical Field

The present invention relates a dual-clutch coupling system which is used in dual clutch systems in vehicles and which can perform two functions together by using just one activation drive.

Prior Art

In automatic transmission vehicles, recently more efficient clutching methods are used instead of conventional torque converter clutching methods. In this way, the fuel consumption is not negatively affected. The said dry clutching methods are used as two different clutch applications such as a single clutch and dual clutch.

In the single-clutch method, which is one of the dry clutching methods, engaging or releasing of the conventional clutch disc and pressure plate is realized by a control unit using an electronically controlled mechanism instead of performing the same operation through a driver using a pedal. However, the single clutch method used here causes to feel the motor-clutch movement during gear shifts and the gear change takes a longer time. To overcome this lack of comfort of a single clutch method, the dual clutch method is preferred and used more frequently in current applications. In dual clutch automatic transmission vehicles, especially two methods are used to engage each clutch. In one of the said methods, a pressurized hydraulic fluid is directed to the piston that should move the respective lever arm to engage the preferred clutch disc via electronically controlled valves. The hydraulic fluid used in this application is continuously to use by means of the drive originated from the vehicle motor as well as the said fluid has to be hold at a certain pressure level continuously. The other one of the said methods is the electromechanical control system. The respective lever arm is pushed by using the elektromechanical control system and the preferred clutch disc is activated. In this method, a servo-motor assembly is provided for each clutch. The servo-motor connected to the corresponding lever arm pushes the clutch pressure plate with the incoming current, thus provides engaging of the preferred clutch.

The above mentioned dual clutch automatic transmission vehicles fail frequently because of the complicated control systems. Particularly in dense traffic, due to frequent gear changes, the systems with hydraulic valves and electromechanical control activate and deactivate various valves or servomotors continuously to activate the corresponding clutch pressure plate and deactivate the other. However, this fact triggers then overheating of the working components. In such a case it is important to avoid the activation of two clutch pressure plates of the both clutches at the same time and to control the activation mechanisms well during switching from one clutch to another. This necessity renders also the system for vehicles with dual-clutch transmissions too complicated. The more complex the system becomes, the greater the risk of failures and errors. Simplifying the mechanisms will both reduce production complexity and minimize the risk of failure.

In the known state of the art, a dual clutch system is disclosed in the US document US6012561 (A). In this application, clutch sets are activated by means of two electromechanic motors. The electric motor is on the cam plate and offers selective features by rotating the activation links. In addition, the other motor is used to provide the gear shifts. In this application is a system that activates the engagement parts. However, in the invention of the patent application, there is an activation member. Said activation member is linked with a first transfer element as well as a second transfer element. In the case that the activation member is driven rotationally, the first transfer element or the second transfer element moves with respect to the position of activation member in an axial direction and thus applying pressure force to the first spring or to the second spring.

In the US Patent Application US2007240530 (Al), which is in the known state of the art, a double clutch system is provided. In this document, the cam forms driven by the electric motor are provided by the plate on which the clutch sets are shifted. Rotation is achieved by using a worm gear. Thanks to these forms, the clutches are not activated at the same time and thus the system is simplified. In this system, the engine moves the clutch sets with a single link. However, in the invention according to the application, pressure force is applied to the first spring by the first transfer element and to the second spring by the second transfer element. First transfer element and second transfer element are linked with the activation member on their other sides, on which there are no springs. By means of this link, the first transfer element and the second transfer element apply pressure to first spring or to second spring, by moving in the axial direction, when activation member rotates around its own axis.

In the International patent document WO2017041405 (Al), which is in the known state of the art, a double clutch system is disclosed. The lever that is moved by means of a motor provides the transition between the clutch sets. The lever end which moves in a slot receives the motion transmitted from the motor and activates the clutch sets by moving in a hollow tube at the other end. This invention, which represents the prior art, is quite different from the invention according to the application in technical terms. In the invention according to the application, there is an activation member by means of which a force is applied to the first clutch lining or to the second clutch lining and thus a shift to preferred gear stage is provided.

Thanks to the invention according to the application, a simpler control mechanism is used instead of complex activation and deactivation methods. The activator in the application does not require a continuous electrical current or continuous hydraulic pressure assistance.

Objectives of the Invention

The object of the present invention is to realize a dual-clutch coupling system that is more cost-effective in practice than the clutches used with two servomotors, especially since one servomotor is used.

A further object of the present invention is to realize a dual clutch coupling system which can operate by a simpler software instead of a complicated software controlling the both servomotors. Another object of the present invention is to realize a dual-clutch coupling system that does not use hydraulic fluid that increases fuel consumption since it does not require a hydraulic drive system and further contributes to fuel economy because it only requires power for the gear shift.

Brief Description of the Invention

There is an activation member which is realized in order to achieve the object of the present invention and which is a characterizing element in the dual clutch system defined in the first claim and in the other dependent claims. The activation member can be rotated at a preferred rate and speed around its axis by means of an activator. The contact of the activation member with the activator is provided by means of a drive gear. In the activation member, there is further a first transfer element cam activator and a second drive except the drive gear. Said first transfer element cam activator and second drive are respectively in connection with the first transfer element and the second transfer element. In the case where the extensions located in the first transfer element cam activator overlap with the extensions contained in the first drive cam profiles, the first transfer element moves in the axial direction to apply pressure force to the first spring, and in the event that the extensions located in the second drive overlap with the extensions located in the second drive cam profiles, the second transfer element moves in the axial direction to apply pressure force to the second spring. By means of said pressure forces, the preferred gear shift is performed.

Detailed Description of the Invention

The dual-clutch coupling system for achieving the object of the present invention is shown in the attached figures, wherein:

Figure 1 is a sectional side view of the dual-clutch coupling system.

Figure 2 is a schematic view of the dual-clutch coupling system wherein one of the clutches is activated. Figure 3 is a schematic view of the dual-clutch coupling system wherein the other one of the clutches is activated.

Figure 4 is a perspective view of the activation member, the first transfer element and the second transfer element, wherein the second transfer element is in a forward position.

Figure 5 is a sectional perspective view of the activation member, the first transfer element and the second transfer element, wherein the second transfer element is in a forward position.

Figure 6 is a perspective view of the activation member, the first transfer element and the second transfer element, wherein the first transfer element is in a forward position.

Figure 7 is a sectional perspective view of the activation member, the first transfer element and the second transfer element, wherein the first transfer element is in a forward position.

Figure 8 is an exploded perspective view of the activation member, the first transfer element and the second transfer element.

Figure 9 is a perspective view of the activation member.

Figure 10 is a perspective view of the activation member from another viewpoint. Figure 11 is a perspective view of the second transfer element. Figure 12 is a perspective view of the first transfer element.

The parts in the figures are numbered individually and the correspondences of these numbers are given below.

1. Dual-clutch coupling system

2. First clutch

3. Second clutch

4. First clutch pressure plate 5. Second clutch pressure plate

6. First spring

7. Second spring

8. Activation member

8.1. Body

8.2. Drive gear

8.3. First transfer element cam activators 8.4. Second transfer element cam activators

9. Activator

10. Sensor

11. First transfer element

11.1. First drive cam profiles

11.2. Inner channel

11.3. Outer channel

12. Second transfer element

12.1. Second drive cam profiles

12.2. Channel counterpart

13. Inner shaft

14. Outer shaft

15. Antirotation element

16. Intermediate disc The dual clutch coupling system (1) which is used in dual clutch systems in vehicles and which can perform two functions together by using just one activation drive, comprises in its most basic form; at least one first clutch (2) to perform torque transfer to the gears preferred in the gearbox, at least one second clutch (3) for transmitting torque to the other gears in the gearbox to which the first clutch (2) does not transmit torque. at least a first clutch pressure plate (4) for fixing the first clutch (2) to the engine flywheel and for transmitting the engine torque to the traction wheels from the first clutch (2),

at least a second clutch pressure plate (5) for fixing the second clutch (3) to the engine flywheel and for transmitting the engine torque to the traction wheels from the second clutch (3),

at least one first spring (6) for engagement of the first clutch pressure plate (4), at least one second spring (7) for engagement of the second clutch pressure plate

(5),

at least one activation member (8), which can rotate around its own axis in clockwise or in counter clockwise direction with preferred speeds and which according to its rotating position forces the first transfer element (11) or the second transfer element (12) to move along the central axis of the first transfer element (11) or the second transfer element (12) wherein the first transfer element (11) transmits drive to the first spring (6) and the second transfer element (12) to the second spring (7).

In the dual-clutch coupling system (1) in one embodiment of the invention, there is a first clutch (2) and a second clutch (3). Said first clutch (2) transmits torque only to particular gears in the gearbox (eg. gears 1-3-5-7). The first clutch (2) in this embodiment of the invention is preferably a clutch disc. In this embodiment of the invention, there is also a second clutch (3). This second clutch (3) engages the gears that are not engaged by the first clutch (2) (eg 2-4-6-R gears) and transmits in this way the torque. The second clutch (3) in this embodiment of the invention is preferably also a clutch disc.

In the dual-clutch coupling system (1) in one embodiment of the invention, there is a first clutch pressure plate (4) and a second clutch pressure plate (5). Said first clutch pressure plate (4) is in contact with the first clutch (2) and fixes the first clutch (2) to the engine flywheel such that the engine torque is transmitted to the traction wheels by means of the first clutch (2). In this embodiment of the invention, there is also a second clutch pressure plate (5). Said second clutch pressure plate (5) is connected with the second clutch (3) in a manner similar to the first clutch pressure plate (4). The second clutch pressure plate (5) is connected to the second clutch (3) and fixes the second clutch (3) to the engine flywheel so that the engine torque is transmitted to the traction wheels via the second clutch (3). In this embodiment of the present invention, in addition to the first clutch pressure plate (4) and the second clutch pressure plate (5), there is also a first spring (6) and a second spring (7). The first spring (6) mentioned in this embodiment of the present invention, is connected to the first clutch pressure plate (4) and allows the first clutch pressure plate (4) to be gripped. Similarly, the second spring (7) is connected to the second clutch pressure plate (5) and allows the gripping of the second clutch pressure plate (5).

In the dual-clutch coupling system (1) in one embodiment of the invention, there is an activation member (8) which allows the first spring (6) and the second spring (7) to be moved in preferred situations. The body (8.1) of said activation member (8) preferably consists of a cylindrical form with a hollow central part. The activation member (8) can only perform a rotational motion and does not move axially in any way. Through the central part of the activation member (8) the inner shaft (13) and the outer shaft (14) is passed. In this embodiment of the present invention, drive gears (8.2) are located around the activation member (8). These drive gears (8.2) located around the activation member (8) are in contact with the activator (9). The geometry, form and number of the drive gear (8.2) is similar to that of the geometry, form and number of the activator (9), with the drive gear (8.2) and activator (9) being similar in form. Thus, the drive gear (8.2) and the activator (9) can operate synchronously and a moment formed in the activator (9) can be transmitted to the activation member (8) via drive gear (8.2). In the activation member (8), in addition to the drive gear (8.2) there is also a first transfer element cam activators (8.3) and a second transfer element cam activator (8.4). Said first transfer element cam activator (8.3) and second transfer element cam activator (8.4) are located on the side of the body (8.1) facing the first spring (6) and the second spring (7). The first transfer element cam activators (8.3) is in contact with the first spring (6) via first transfer element (11) and the second transfer element cam activator (8.4) is in contact with the second spring (7) via second transfer element (12). The first transfer element cam activator (8.3) consists of one or more extensions as well as of cavities between the extensions, which are located in a circular strip on the surface of the body (8.1) facing the first spring (6) and the second spring (7) and extending from the inside of said circular strip parallel to the central axis of the body in a direction to the first spring (6). The length of said extensions is able to be changed in a preferred ratio according to the size of the axial travel. In the activation member (8) according to one embodiment of the invention, in addition to the first transfer element cam activator (8.3) there is also a second transfer element cam activator (8.4). Said second transfer element cam activator (8.4) is located in the circular strip on the surface of the body (8.1) facing the first spring (6) and the second spring (7) in a manner similar to that of the first transfer element cam activator (8.3). In said strip there is one or more extensions extending from the strip towards the second spring (7) so as to be parallel to the central axis of the body (8.1). The length of said extensions can be changed in a preferred ratio according to the size of the axial travel. The remaining sections between the extensions of the first transfer element cam activator (8.3) and the second transfer element cam activators (8.4) are empty.

In the dual-clutch coupling system (1) in one embodiment of the invention, there is a first transfer element (11) and a second transfer element (12) in order to transfer the movement formed by means of the activation member (8). Said first transfer element (11) and also the second transfer element (12) can only move axially and cannot move rotationally in any way. One side of the first transfer element (11) mentioned in this embodiment of the invention is connected with the activation member (8) and the other side thereof is connected with the first spring (6). Similarly, the one side of the second transfer element (12) is connected with the activation member (8) and the other side thereof is connected with the second spring (7). In the first transfer element (11), there is preferably a first drive cam profile (11.1), an inner channel (11.2) and an outer channel (11.3). Said first drive cam profiles (11.1) are connected directly to the first transfer element cam activator (8.3). The first drive cam profiles (11.1) have extensions and cavities of similar construction as the first transfer element cam activator (8.3). The inner channel (11.2) and the outer channel (11.3) found in the first transfer element (11) are formed in the first transfer element (11) for such a reason that the first transfer element

(11) moves only in axial direction, with other words for preventing the rotational motion. The second transfer element (12) in this embodiment of the invention has a second drive cam profiles (12.1) and channel counterpart (12.2). The channel counterpart (12.2) found in the second transfer element (12) is formed to allow the second transfer element (12) to move only in axial direction and in the inner channel (11.2) found in the first transfer element (11). The second drive cam profiles (12.1) found in the second transfer element

(12) is connected with the second transfer element cam activator (8.4). In the second drive cam profiles (12.1) there are also extensions and cavities of similar structure like in the first drive cam profiles (11.1) and in the second transfer element cam activator (8.4). During the rotation of the activation member (8) around its own axis the first transfer element (11) moves axially when the extensions in the activation member (8) and the extensions in the first transfer element (11) overlap, however the second transfer element (12) moves in an axial direction when the extensions in the second transfer element (12) overlap. In other respects, if the extensions in the activation member (8) are located in the cavities between the extensions found in the first transfer element (11), this time the first transfer element (11) comes back to its initial position, but if said extensions are located in the cavities between the extensions found in the second transfer element (12), similarly the second transfer element (12) comes back to its initial position.

In the dual-clutch coupling system (1) in one embodiment of the invention, rotation of the activation member (8) around its axis in a preferred ratio and speed is provided by means of the activator (9). The activator (9) in this embodiment of the present invention is preferably a servo-motor. In the dual-clutch coupling system (1) in one embodiment of the invention, there is a sensor (10) which detects the position of the activation member (8). Said sensor is a sensing element which detects the actual position of the activation member (8) and continuously measures the position of the activation member (8).

In one embodiment of the invention, the operation of the dual-clutch coupling system (1) is carried out as follows; said dual-clutch coupling system (1) is designed to realize two functions using a drive from only one activator (9) for dual clutch systems used in automotive industry. Activation member (8) performs a rotation movement by being connected to the activator (9) via drive gear (8.2) in order to be able to perform these two functions together. Since the activation member (8) is fixed to body of the gearbox so that it cannot perform an axial movement, when the activator (9) is actuated the activation member (8) performs only a rotational movement. As a result of the rotational movement, the extensions in the first transfer element cam activator (8.3) located on the activation member (8) and the second transfer element cam activator (8.4) are following a circular route. The first transfer element (11) and the second transfer element (12) are positioned and these have a first drive cam profiles (11.1) and a second drive cam profiles (12.1) which correspondence the first transfer element cam activator (8.3) and the second transfer element cam activator (8.4) of the activation member (8). This first transfer element (11) and the second transfer element (12), unlike the activation member (8) are positioned by means of the antirotation element (15) such that they are able to perform an axial movement but cannot perform a rotational movement. When the activation member (8) rotates, the extensions in the first transfer element cam activator (8.3) and the second transfer element cam activator (8.4) overlap with the extensions in the first drive cam profiles (11.1) and the second drive cam profiles (12.1) and they push the first transfer element (11) or the second transfer element (12) and thus allow the first spring (6) or the second spring (7) to be compressed which are in contact with the first transfer element (11) or the second transfer element (12). When the activation member (8) is positioned such as to push the first transfer element (11) by rotation, the first transfer element (11) that was pushed allows the first spring (6) to be tensed with which it is in contact. The tensed first spring (6) urges the first clutch (2) to rotate at the same speed as the engine by compressing it between the intermediate disk (16) directly linked to engine and the first clutch pressure plate (4). The first clutch (2) that starts rotating at the same speed as the engine, rotates the inner shaft (13) to ensure that also the gears (e.g. 1, 3, 5, 7) to which it is connected rotate at the same speed as the engine. The appropriate one of these gears is selected by the control unit, thus the preferred torque convertion is made.

A similar operation is performed when the activation member (8) is positioned such as to push the second transfer element (12) by rotation, thus the second transfer element that is pushed allows the second spring (7) to be tensed. The tensed second spring (7) urges the second clutch (3) to rotate at the same speed as the engine by compressing it between the intermediate disk (16) directly linked to engine and the second clutch pressure plate (5). The second clutch (3) that starts rotating at the same speed as the engine, rotates the outer shaft (14) to ensure that also the gears (e.g. 2,4,6, R), to which it is connected, rotate at the same speed as the engine. Thanks to this connection, the torque is transmitted to the gearbox via the second clutch (3) by means of the outer shaft (14) and the appropriate one of the gears on the outer shaft (14) is selected by the control unit, thus the preferred torque convertion is realized. In order to interrupt the electrical current supplied to the activator (9) according to the predetermiend reference points in the activation member (8) to fix the extensions on the activation member (8) to the preferred position, a feedback signal is sent to the control unit by means of the sensor (10).

In the dual-clutch coupling system (1) in this embodiment of the invention the shift speed varies depending on the turn of the activator (9), gear ratio between the activator (9) and the activation member (8) and the number of designs of the extensions in the activation member (8). The next gear engagement is available even before the gear shift if the gear is to be increased or decreased, and the gear shift takes place during the transition period from one clutch (eg the first clutch (2)) to another clutch (eg the second clutch (3)). This period can be reduced or increased by a proportion depending on the number of extensions in the activation member (8) as mentioned above.