JP5921126B2 - Dual clutch transmission for vehicle - Google Patents

Description

  The present invention relates to a dual clutch transmission for a vehicle having two friction clutches that are mounted on a vehicle and can be switched between a connected state and a disconnected state, and more specifically, the temperature of the friction clutch is increased. Concerning the suppression of

  One type of vehicle transmission includes a dual clutch type including two clutches, two input shafts connected to the engine by each clutch, and a transmission mechanism provided between each input shaft and the output shaft. There is a transmission. The dual clutch transmission has an advantage that a transmission operation can be performed quickly without interrupting the transmission torque by performing a switching operation with two clutches. For each clutch, for example, a friction clutch that drives a plate having a friction material with a clutch actuator can be used. The speed change mechanism is normally composed of about 4 to 7 speed stages, and any of the speed stages can be selectively meshed and connected by a known synchronizer. In general, the clutch actuator and the synchronization device are controlled by an electronic control unit (ECU) to constitute a synchronous mesh type automatic transmission as a whole.

  In the friction clutch, generally, frictional heat is generated during the joining operation, and the temperature rises. This increase in temperature tends to be noticeable in dry friction clutches that do not use cooling oil, which may affect the durability performance. In particular, in a dual clutch transmission for a vehicle, torque transmitted by the clutch is large when the vehicle starts, and frictional heat also increases. Therefore, the temperature rise is likely to be large in one clutch that engages the first speed gear stage used for starting. An example of a technique for suppressing such a temperature rise of the clutch is disclosed in Patent Document 1.

  The pressure plate of the friction clutch disclosed in Patent Document 1 includes a pressure plate that rotates integrally with a drive member (drive side plate), and a clutch disk that can be rotated integrally by friction engagement with the drive side member and the pressure plate (driven side). In the friction clutch provided with the plate, at least a part of the surface of the pressure plate that does not frictionally engage with the clutch disk is a rough surface. Further, according to a third aspect of the present invention, the rough surface is formed in a substantially embossed shape, a heptagonal shape, or a substantially scale shape, or a plurality of grooves are provided in the rough surface. That is, unevenness is formed on the pressure plate, and the heat radiation surface area is increased. Thus, a pressure plate with high frictional heat radiation efficiency is provided, and overheating of the clutch disk is prevented.

JP-A-9-96320

  By the way, as exemplified in Patent Document 1, even if unevenness is provided on the constituent members of the friction clutch to increase the heat dissipation surface area, sufficient heat dissipation performance is not always obtained in consideration of factors such as the ambient temperature. . For example, when a friction clutch is disposed in an engine room, the air temperature around the clutch tends to be high due to the influence of heat radiation from the engine. For this reason, if the vehicle in motion is temporarily stopped and started, a lot of frictional heat is generated in a high temperature atmosphere, and the possibility that the temperature of the clutch will rise and affect the durability performance cannot be solved. Further, if the friction clutch component is provided with irregularities, the manufacturing cost increases accordingly.

  Further, in a dual clutch transmission for a vehicle, the temperature rise tends to be noticeable in one clutch that engages the first speed gear stage at the start, and the other clutch is rarely used for the start, and the temperature rises. Are often small. Here, the two clutches generally share a drive-side plate that is rotationally connected to a drive source, and a configuration that allows heat to move between the clutches is generally employed. Therefore, if heat is efficiently transferred from the one clutch on the high temperature side to the other clutch on the low temperature side, this is one measure for suppressing the temperature rise of the clutch.

  The present invention has been made in view of the above-mentioned problems of the background art, and is a low-cost dual clutch type for a vehicle that improves the heat dissipation characteristics of the friction clutch from the temporary stop to the start of the vehicle and suppresses temperature rise. Providing a transmission is an issue to be solved.

The dual clutch transmission for a vehicle of the present invention shares a drive side plate that is rotationally connected to a drive source, and pushes the driven side plate disposed opposite to the drive side plate and the driven side plate. Each having a pressure plate that slides on the driving side plate and an actuator that drives the pressure plate, and can be switched between a connected state that is rotationally connected to the driving source and a disconnected state that is disconnected from the driving source. A first friction clutch and a second friction clutch, and a first transmission mechanism that is rotationally connected to the drive source by the first friction clutch so as to be selectable and that can select one of a plurality of shift stages; A second speed change mechanism rotatably connected to the drive source by the second friction clutch and capable of selecting one of a plurality of speed stages; and the first friction clutch. And clutch temperature detecting means for actually measuring or estimating the temperature of one of the second friction clutches that engages from the disconnected state to the engaged state when the vehicle starts, the first friction clutch, the second friction clutch A control unit that controls the friction clutch, the first speed change mechanism, and the second speed change mechanism, and the control part sets the measured or estimated temperature of the one clutch to a specified value when the vehicle is temporarily stopped during travel. And a high temperature determination means for determining a high temperature state, and when the one clutch is in a high temperature state, the first transmission mechanism or the second transmission mechanism that is rotationally connected to the other clutch is in a neutral state, and continuing the engaged state of the temporary the other clutch from stop to start of the vehicle, the one clutch is at other than high temperature, cutting the other clutch Has a heat radiation promoting means to condition the.

  The control unit may further include a first heat radiation adjusting unit that adjusts the length of the operation time of the heat radiation promoting unit according to the magnitude of the high temperature state of the one clutch.

  Or the said control part may further have the 2nd heat radiation adjustment means which adjusts the operation | movement completion timing of the said heat radiation acceleration | stimulation means according to the change of the temperature of said one clutch.

  In the dual clutch transmission for a vehicle according to the present invention, the temperature of one of the clutches that engages when the vehicle starts during a temporary stop is measured or estimated and compared with a specified value to determine a high temperature state. The engaged state of the other clutch is continued from the stop to the vehicle start. That is, when one clutch used for start-up is in a high temperature state, the other clutch is brought into a connected state. Thereby, the heat transfer from one clutch to the other clutch is promoted through the common drive side plate, and the heat radiation characteristic in the entire clutch portion is improved. Therefore, the temperature of the one clutch in the high temperature state can be quickly lowered during the temporary stop, and the temperature rise due to the frictional heat generated in the joining operation at the start can be suppressed. Further, it is not necessary to change the structure of the transmission when carrying out the present invention, and it is only necessary to change the control method of the control unit, so that the manufacturing cost does not increase.

  Further, in the aspect in which the control unit further includes the first heat radiation adjusting means, the length of the operation time of the heat radiation promoting means is adjusted according to the magnitude of the high temperature state of one clutch. In the present invention, it is impossible to use the speed change mechanism that is rotationally connected to the other clutch while the heat radiation promoting means is operating. Therefore, when the high temperature state is severe, the durability performance of the clutch can be ensured by operating the heat dissipating promotion means for a long time from the temporary stop to the vehicle start to give priority to the suppression of the temperature rise. Further, when the high temperature state is mild, the heat dissipation promoting means can be terminated early to enable a shift-up shift operation, and shift control giving priority to acceleration maneuverability can be performed.

  Alternatively, in an aspect in which the control unit further includes the second heat radiation adjustment unit, the operation end timing of the heat radiation promotion unit is adjusted according to a change in the temperature of one clutch used for starting. Therefore, when the temperature of one of the clutches has settled in a preferable range, it is possible to control the heat dissipation accelerating means so that it can cope with the shift-up shift operation, and it is possible to suppress the temperature rise of the clutch and to improve the acceleration maneuverability. It is possible to achieve both shift control.

1 is a skeleton diagram showing a dual clutch transmission for a vehicle according to an embodiment of the present invention. It is side surface sectional drawing explaining the detailed structure of a 1st and 2nd friction clutch. It is side surface sectional drawing explaining the joining operation | movement of a 1st friction clutch. It is side surface sectional drawing explaining the joining operation | movement of a 2nd friction clutch. It is side surface sectional drawing which illustrates and demonstrates the control action of the 1st and 2nd friction clutch by a heat dissipation promotion means. It is a figure which illustrates the change of the temperature of the clutch at the time of the temporary stop in a prior art. It is a figure which illustrates the change of the temperature of the clutch at the time of the temporary stop in embodiment. It is a figure which illustrates the speed change operation | movement from the time of the temporary stop in a prior art to the 2nd speed being established through the vehicle start by 1st speed. FIG. 6 is a diagram illustrating an example of a speed change operation from when the vehicle is temporarily stopped to when the second speed is established through vehicle start at the first speed in the embodiment.

  An embodiment for carrying out the present invention will be described with reference to FIGS. FIG. 1 is a skeleton diagram showing a dual clutch transmission 1 for a vehicle according to an embodiment of the present invention. The dual clutch transmission 1 for a vehicle is a device that selects one of five forward gears and one reverse gear and transmits the output torque of the engine 91 to the differential device 93 so that it can be disconnected. The vehicle dual clutch transmission 1 includes a first friction clutch 21 and a second friction clutch 22, a first input shaft 31, a second input shaft 32, an output shaft 4, a first transmission mechanism 5, a second transmission mechanism 6, The controller 7 and the clutch temperature detecting means 71 are included.

  The first friction clutch 21 and the second friction clutch 22 are portions that independently switch between a joint state that is rotationally connected to the output shaft 92 of the engine 91 that is a drive source and a disconnected state that is disconnected from the engine 91. The first friction clutch 21 and the second friction clutch 22 are respectively driven by a first clutch actuator 23 and a second clutch actuator 24 that operate according to a command from the control unit 7. The first and second friction clutches 21 and 22 are configured such that the frictional coupling force is adjusted independently of each other, and the transmitted clutch torques Tc1 and Tc2 are independently controlled.

  FIG. 2 is a side cross-sectional view illustrating the detailed configuration of the first and second friction clutches 21 and 22. The main body portions of the first and second friction clutches 21 and 22 have an axis line AX and are substantially axisymmetric. FIG. 2 shows the upper half of the clutches 21 and 22 in a disconnected state. FIG. 3 is a side sectional view for explaining the joining operation of the first friction clutch 21, and FIG. 4 is a side sectional view for explaining the joining operation of the second friction clutch 22. The first and second friction clutches 21 and 22 share the drive side plate 25. The first and second friction clutches 21 and 22 have driven plates 261 and 262 and pressure plates 271 and 272, respectively.

  First, the configuration of the first friction clutch 21 will be described in detail. The first friction clutch 21 includes a drive side plate 25 and is configured on one side (right side in the drawing) of the drive side plate 25 in the axis AX direction. The drive side plate 25 is a substantially annular member that is rotationally connected to the output shaft 92 of the engine 91. A bearing portion 95 is provided on the inner peripheral side of the drive side plate 25, and the first input shaft 31 penetrates the shaft center of the bearing portion 95 so as to be relatively rotatable.

  The driven plate 261 is a substantially annular member that is arranged on one side of the drive side plate 25 in the axis AX direction so as to be movable in the axis AX direction. The driven plate 261 is spline-coupled to the first input shaft 31 on the inner peripheral side, and is rotationally coupled so as to be movable in the direction of the axis AX. The driven side plate 261 has a friction material 281 on the surface facing the driving side plate 25 and also has a friction material 291 on the back surface thereof. The friction members 281 and 291 are also called facings and linings, and achieve friction and sliding synchronization when the rotational speeds of the driving side plate 25 and the driven side plate 261 are different, and also maintain synchronous rotation by frictional coupling. It is a member.

  The pressure plate 271 is a substantially annular member arranged side by side on one side of the driven plate 261 in the axis AX direction. The pressure plate 271 rotates integrally with the drive side plate 25 and moves to the other side in the axis AX direction (left side in the drawing) to perform the joining operation. The first clutch actuator 23 is a part that drives the pressure plate 271. For the first clutch actuator 23, various known mechanisms such as a servo motor and a hydraulic drive mechanism can be used.

  When an operating force is generated on one end side of the first clutch actuator 23 as indicated by an arrow F11 in FIG. 3, the pressure plate 271 is operated toward the other side in the axis AX direction (leftward in the figure) indicated by the arrow F12. Power is added. As a result, the pressure plate 271 moves to the other side in the axis AX direction, first presses against the friction material 291 on the back surface of the driven side plate 261, and further moves to push the driven side plate 261 toward the driving side plate 25. To do. Then, the friction material 281 of the driven side plate 261 comes into contact with the driving side plate 25 and frictional sliding is started. Finally, the pressure plate 271 moves to the complete joining point, and the three of the pressure plate 271, the driven side plate 261, and the driving side plate 25 are strongly pressed against each other to rotate synchronously, thereby achieving the joined state. .

  The second friction clutch 22 has a structure obtained by reversing the first friction clutch 21 substantially in the axis AX direction, and is configured on the other side (left side in the drawing) of the drive side plate 25 in the axis AX direction. In other words, the driven side plate 262 is arranged on the other side in the axis AX direction of the drive side plate 25 so as to be movable in the axis AX direction, and is splined to the second input shaft 32 on the inner peripheral side, and is in the axis AX direction. It is rotationally connected so as to be movable. The driven side plate 262 has friction materials 282 and 292 on the surface and the back surface facing the driving side plate 25. The pressure plate 272 is arranged side by side on the other side in the axis AX direction of the driven side plate 261, rotates integrally with the drive side plate 25, and moves to one side (right side in the figure) in the axis AX direction. Perform the splicing operation. The second clutch actuator 24 is a part that drives the pressure plate 272.

  When an operating force is generated on one end side of the second clutch actuator 24 as indicated by an arrow F21 in FIG. 4, the pressure plate 272 is operated toward one side (right side in the drawing) in the axis AX direction indicated by the arrow F22. Power is added. As a result, the pressure plate 272 moves to one side in the axis AX direction, first presses against the friction material 292 on the back surface of the driven side plate 262, and further moves to push the driven side plate 262 toward the driving side plate 25. To do. Then, the friction material 282 of the driven side plate 262 comes into contact with the driving side plate 25 and friction sliding is started. Finally, the pressure plate 272 moves to the complete joining point, and the pressure plate 272, the driven side plate 262, and the driving side plate 25 are in strong pressure contact with each other and rotate synchronously to achieve the joined state. .

  In the first and second friction clutches 21 and 22, frictional heat is generated during the joining operation, and the temperature of each member (25, 261, 262, 271, 272, etc.) constituting the clutch rises. The magnitude of the temperature rise value varies depending on the work amount that the clutches 21 and 22 have done during the joining operation. Moreover, since the temperature of each member is not necessarily uniform, for example, the temperatures T1 and T2 of the first and second friction clutches 21 and 22 are set by the temperatures of the pressure plates 271 and 272 as representative members. However, the present invention is not limited to this, and the temperature may be obtained using another member as a representative member, or the average temperature of all members may be obtained.

  The temperature increase value of the first friction clutch 21 can be obtained by the following calculation. First, the work to be done is obtained by multiplying the torque transmitted when the first friction clutch 21 is engaged and the rotational speed difference between the input and output, and the total work is calculated by integrating this work over the engagement time. To do. Then, the total work amount is converted into a calorific value, and the temperature rise value is calculated by dividing by the heat capacity of the first friction clutch 21. The temperature rise value of the second friction clutch 22 can also be obtained by the same calculation.

  However, since it is difficult to actually measure the torque and the calculation is complicated, in the present embodiment, the temperature rise values in a list form using the operating conditions when the first and second friction clutches 21 and 22 are engaged as parameters as parameters. Use a map. As parameters, for example, the throttle opening of the engine 91, the engine speed Ne of the engine 91, the speed N1 of the first input shaft 31, and the speed N2 of the second input shaft 32 are used. The throttle opening is a parameter governing the magnitude of the output of the engine 91, and corresponds to using the torque as a parameter. Further, (Ne−N1) and (Ne−N2) can be easily calculated as the rotational speed difference between the input and output. The temperature increase value map is obtained in advance by a basic experiment or simulation, and is stored in the control unit 7.

  Further, in the connected state of the first and second friction clutches 21 and 22, the driven plates 261 and 262 including the pressure plates 271 and 272, the friction materials 281, 282, 291 and 292, and the driving plate 25 are provided. One is strongly pressed against each other. Therefore, heat transfer is performed very well from the high temperature side member to the low temperature side member. On the other hand, in the cut state, these three parties are opposed to each other with a minute interval, and heat transfer is lower than that in the joined state. The heat transfer characteristics of the first and second friction clutches 21 and 22 in the connected state and the disconnected state are also quantitatively obtained in advance by basic experiments or simulations and stored in the control unit 7.

  Furthermore, these three people dissipate heat to the atmosphere air, and the temperature decreases. The heat dissipation characteristics of the first and second friction clutches 21 and 22 in the connected state and the disconnected state are also quantitatively obtained in advance and stored in the control unit 7. The above-described temperature rise value map, the heat transfer characteristic, and the heat dissipation characteristic are used by a clutch temperature detecting means 71 described later.

  Returning to FIG. 1, the first input shaft 31 is a shaft member that is rotatably connected to the engine 91 by the first friction clutch 21 so as to be able to be connected and disconnected. The second input shaft 32 is a shaft member that is rotatably connected to the engine 91 by the second friction clutch 22 so as to be able to be connected and disconnected. The first input shaft 31 has a rod shape, and the second input shaft 32 has a cylindrical shape and is arranged on the inside and outside of the same axis. The right end of the first input shaft 31 in the drawing is connected to the output side member of the first friction clutch 21, and the left end in the drawing protrudes through the second input shaft 32 and is supported by the ball bearing 36. The right end of the second input shaft 32 in the drawing is connected to the output side member of the second friction clutch 22, and the central portion is pivotally supported by the ball bearing 37.

  The output shaft 4 is a shaft member that is rotationally coupled to a drive wheel (not shown), and is arranged in parallel to the lower side of the first input shaft 31 and the second input shaft 32 in the drawing. The output shaft 4 is pivotally supported at both ends by tapered roller bearings 46 and 47. An output gear 48 is fixedly provided in the vicinity of one tapered roller bearing 46 of the output shaft 4, and the output gear 48 meshes with a differential device 93. Therefore, the output shaft 4 transmits torque to the drive wheels via the differential device 93.

  The first speed change mechanism 5 is provided between the first input shaft 31 and the output shaft 4, and constitutes an odd speed shift stage of the first speed, the third speed, and the fifth speed and selectively selects one set. This is a mechanism having three gear sets 51, 53, and 55 that can be meshed with each other. Specifically, in order from the left side of the first input shaft 31 in the figure, the first speed drive gear 51A is fixed, the third speed drive gear 53A is provided so as to be freely rotatable, and the fifth speed drive gear 55A is idle. It is provided to be able to roll. On the other hand, a first speed driven gear 51P is rotatably provided at a position where the output shaft 4 faces, a third speed driven gear 53P is fixed, and a fifth speed driven gear 55P is fixed.

  The first speed drive gear 51A and the first speed driven gear 51P are always meshed with each other to form the first speed gear set 51 that constitutes the first speed gear stage. When the first speed driven gear 51P is rotationally connected to the output shaft 4 by the sleeve S1 of the first speed synchromesh mechanism 81 (synchronizer), the first speed gear set 51 is meshed and coupled to transmit torque. It becomes possible. Similarly, the third speed drive gear 53A and the third speed driven gear 53P are always meshed with each other to form a third speed gear set 53 that constitutes the third speed gear stage. When the third speed drive gear 53A is rotationally connected to the first input shaft 31 by the sleeve S35 of the 3-5 speed synchromesh mechanism 82, the third speed gear set 53 is meshed and coupled to transmit torque. It becomes possible. Further, the fifth speed drive gear 55A and the fifth speed driven gear 55P are always meshed with each other to form a fifth speed gear set 55 constituting the fifth speed gear stage. When the fifth speed drive gear 55A is rotationally connected to the first input shaft 31 by the sleeve S35 of the third to fifth speed synchromesh mechanism 82, the fifth speed gear set 55 is meshed and coupled to transmit torque. It becomes possible. Only one set of the first speed gear set 51, the third speed gear set 53, and the fifth speed gear set 55 is selectively meshed by an interlock mechanism (not shown).

  The second speed change mechanism 6 is provided between the second input shaft 32 and the output shaft 4, constitutes an even speed shift stage of the second speed and the fourth speed, and can selectively mesh and couple one set. This mechanism has two sets of gears 62 and 64. More specifically, the fourth speed drive gear 64 and the second speed drive gear 62A are fixed in order from the left side of the second input shaft 32 in the drawing. On the other hand, a fourth speed driven gear 64 </ b> P and a second speed driven gear 62 </ b> P are provided so as to be free to rotate at locations facing the output shaft 4.

  The fourth speed drive gear 64A and the fourth speed driven gear 64P are always meshed with each other to form a fourth speed gear set 64 constituting the fourth speed gear stage. When the fourth speed driven gear 64P is rotationally connected to the output shaft 4 by the sleeve S24 of the second to fourth speed synchromesh mechanism 83, the fourth speed gear set 64 is meshed and coupled to transmit torque. Become. Similarly, the second speed drive gear 62A and the second speed driven gear 62P are always meshed with each other to form the second speed gear set 62 that constitutes the second speed gear stage. When the second-speed driven gear 62P is rotationally connected to the output shaft 4 by the sleeve S24 of the second-fourth speed synchromesh mechanism 83, the second speed gear set 62 is meshed and can transmit torque. Become. Only one of the fourth speed gear set 64 and the second speed gear set 62 is selectively meshed.

  Although not shown in the figure, a conventional gear set configuration can be used as appropriate for the reverse gear.

  When the vehicle starts, the first speed gear stage of the first speed change mechanism 5 is usually used. At this time, the first friction clutch 21 is engaged to perform a large amount of work and heat generation is increased. Therefore, the temperature T1 of the first friction clutch 21 tends to be higher than the temperature T2 of the second friction clutch 22, and the first friction clutch 21 is likely to fall into a higher temperature state.

  Further, at any time during traveling of the vehicle, one of the first and second friction clutches 21 and 22 is engaged, and one of the first and second transmission mechanisms 5 and 6 is selected. The timing of the shift speed switching operation is usually determined by determining the conditions of the shift line and the preshift line. That is, when the operating point indicating the running state of the vehicle crosses a predetermined shift line, the shift condition is established, and the shift stage switching operation is started. In the switching operation, both the first and second friction clutches 21 and 22 are in a half-clutch state, and a torque switching operation from one of the first and second input shafts 31 and 32 to the other is performed. Further, when the operating point crosses a predetermined preshift line, the preshift condition is established and the preshift operation is started. In the pre-shift operation, one of the first and second friction clutches 21 and 22 that is not transmitting torque is disengaged, and one of the first and second transmission mechanisms 5 and 6 that is rotationally connected to the one clutch. The next expected gear is engaged.

  The control unit 7 is a part that controls the first friction clutch 21, the second friction clutch 22, the first transmission mechanism 5, and the second transmission mechanism 6. The control unit 7 acquires various information such as the operating state of the engine 91 and the vehicle speed, and controls the first and second clutch actuators 23 and 24 in association with the three synchromesh mechanisms 81, 82, and 83. The control part 7 can be comprised using the electronic control apparatus (ECU) which incorporates a microcomputer and operate | moves with software. Moreover, the control part 7 can also be comprised so that a some electronic control apparatus (ECU) may cooperate and perform cooperative control. The control unit 7 includes four functional units, that is, a clutch temperature detection unit 71, a high temperature determination unit 72, a heat release promotion unit 73, and a first heat release adjustment unit 74.

  The clutch temperature detecting means 71 is a means for actually measuring or estimating the temperature of one of the first friction clutch 21 and the second friction clutch 22 that is engaged from the disconnected state to the connected state when the vehicle starts. In the present embodiment, the clutch temperature detection means 71 is realized by software of the control unit 7 and estimates the temperatures T1 and T2 of both the first and second friction clutches 21 and 22. Hereinafter, a method for estimating the temperature T1 of the first friction clutch 21 will be described as an example.

  The first friction clutch 21 is disposed in the engine room together with the engine 9. Therefore, the clutch temperature detection means 71 acquires the detection information of the intake air temperature sensor attached to the engine 91 and sets the intake air temperature as the ambient temperature of the first friction clutch 21. Moreover, the clutch temperature detection means 71 can obtain | require the temperature rise value when the 1st friction clutch 21 engages using the above-mentioned temperature rise value map. Further, the clutch temperature detecting means 71 quantitatively grasps the heat transfer characteristics and the heat dissipation characteristics in the engaged state and the disconnected state of the first friction clutch 21. Therefore, the clutch temperature detecting means 71 can estimate a time-series change in the temperature T1 of the first friction clutch 21 using the above-described ambient temperature, temperature rise value map, heat transfer characteristic, and heat dissipation characteristic. Note that a dedicated temperature sensor may be provided in the vicinity of the first friction clutch 21 to actually measure the temperature T1 instead of estimation.

  The high temperature determination means 72 is a means for determining the high temperature state by comparing the temperature of one of the clutches that are engaged from the disconnected state to the connected state when the vehicle starts, during a temporary stop while the vehicle is running. . Since the vehicle starts normally at the first speed, the temperature T1 of the first friction clutch 21 that is rotationally connected to the first speed gear set 51 is compared with a specified value T0. The specified value T0 is appropriately set within a range in which the thermal stress during the joining operation does not affect the durability performance of the first friction clutch 21. The high temperature determination means 72 determines that the temperature is high when the temperature T1 exceeds the specified value, and calculates an excess ΔT1 (= T1-T0). In the case of starting at the second speed based on the judgment of the control unit 7 referring to the vehicle state or the driver's instruction, the temperature T2 of the second friction clutch 22 is compared with the specified value T0, and the excess ΔT2 (= T2− T0) is calculated.

  The heat release promoting means 73 rotates to the other clutch when one of the first friction clutch 21 and the second friction clutch 22 that is engaged from the disconnected state to the connected state when the vehicle starts is in a high temperature state. The first transmission mechanism 5 or the second transmission mechanism 6 to be connected is in a neutral state, and is a means for continuing the engagement state of the other clutch from the time of the temporary stop to the start of the vehicle.

  FIG. 5 is a side cross-sectional view illustrating the control operation of the first and second friction clutches 21, 22 by the heat dissipation promoting means 73. FIG. 5 shows a control operation when the first friction clutch 21 to be engaged when starting at the first speed is in a high temperature state. The heat radiation promoting means 73 is first in a temporarily stopped state, generates an operating force on one end side of the second clutch actuator 24 as indicated by an arrow F23, applies an operating force indicated by an arrow F24 to the pressure plate 272, The friction clutch 22 is engaged. At the same time, the second to fourth speed synchromesh mechanism 83 of the second transmission mechanism 6 is set to the neutral state.

  Next, the control proceeds to start control, the first speed gear set 51 is meshed and coupled, an operating force (indicated by arrow F13) is generated at one end of the first clutch actuator 23, and an operating force (indicated by arrow F14) is applied to the pressure plate 271. The first friction clutch 21 is engaged. With this start control, the vehicle starts at the first speed. In the first friction clutch 21, frictional heat is generated and the temperature T1 rises. The heat dissipation promoting means 73 maintains the engaged state of the second friction clutch 22 from the time of temporary stop to the start of the vehicle as necessary.

  Here, the reason why the second friction clutch 22 is engaged is not to transmit torque but to improve heat transfer characteristics. Therefore, it is not necessary to move the pressure plate 272 to the complete joining point, the pressure plate 272, the driven side plate 262, and the driving side plate 25 are in contact with each other, and the heat transfer characteristics are better than in the cut state. It only has to be. As a result, the high heat of the pressure plate 271 and the driven plate 261 of the first friction clutch 21 on the high temperature side quickly moves to the driven plate 262 and the pressure plate 272 on the low temperature side via the drive side plate 25. As a result, the surface area of the high temperature side member is equivalently increased, heat dissipation to the atmosphere is promoted, and the temperature T1 of the first friction clutch 21 is rapidly reduced.

  The first heat radiation adjustment means 74 is a means for adjusting the length of the operation time of the heat radiation promotion means 73 corresponding to the magnitude of the high temperature state. In other words, the first heat release adjusting means 74 corresponds to the magnitude of the excess ΔT1 (= T1-T0) from the specified value T0 of the temperature T1 of the first friction clutch 21 in the engaged state of the second friction clutch 22. Adjust the time. However, the time when the speed change condition to the second speed or the pre-shift condition is established after the vehicle starts is limited, and at this time, the engagement state of the second friction clutch 22 is terminated and returned to the disconnected state, and the speed change to the second speed is made. It shall be prepared for operation.

  Next, the operation and action of the vehicle dual clutch transmission 1 according to the embodiment configured as described above will be described in comparison with the prior art. FIG. 6 is a diagram illustrating the change in the temperature of the clutch at the time of a temporary stop in the prior art. FIG. 7 is a diagram illustrating the change in the temperature of the clutch at the time of temporary stop in the embodiment. 6 and 7, in each of the three graphs, the upper stage shows the number of revolutions, the middle stage shows the temperature T1 of the first friction clutch, the lower stage shows the torque Tc of the clutch, and the horizontal axis is the common time t, A range of time zones t1 to t3 during the stop is shown.

  In the upper part of FIG. 6 showing the prior art, the engine rotational speed NE is kept constant at the idle rotational speed NEi through the time zones t1 to t3 during the temporary stop, and the rotational speed N1 of the first and second input shafts 31 and 32, N2 is zero. Moreover, as shown in the lower stage, the first and second friction clutches 21 and 22 are in a disconnected state, and the torques Tc1 and Tc2 that can be transmitted are zero. As shown in the middle stage, the temperature T1old of the first friction clutch 21 is a high temperature T1H at time t1, and gradually decreases with the passage of time.

  In the upper part of FIG. 7 showing the embodiment, the engine rotational speed NE is constant at the idle rotational speed NEi, and the rotational speeds N1 and N2 of the first and second input shafts 31 and 32 are zero. Further, as shown in the lower stage, the first friction clutch 21 is disconnected through the temporarily stopped time zones t1 to t3, and the torque Tc1 that can be transmitted is zero. On the other hand, the second friction clutch 22 is engaged from the time t1 during the temporary stop to the time t2 in the middle, and a torque Tc2 (≠ 0) that can be transmitted is generated. As described above, this joint state is not for transmitting torque but for improving heat transfer characteristics.

  Therefore, as shown in the middle stage, during the period from t1 to t2, the temperature T1 of the first friction clutch 21 decreases from the high temperature T1H more rapidly (steeply) than the prior art shown by the broken line. Further, since the second friction clutch 22 is disengaged between the times t2 and t3, the decreasing tendency of the temperature T1 of the first friction clutch 21 is almost the same as that of the conventional technique. As a result, the temperature T1 of the first friction clutch 21 at time t3 is improved by a decrease ΔTgood as compared with the temperature T1old of the prior art.

  Next, the operation and effect when the second friction clutch 22 is kept engaged until the vehicle starts will be described in comparison with the prior art. FIG. 8 is a diagram illustrating the speed change operation from the time of a temporary stop in the prior art to the establishment of the second speed through vehicle start at the first speed. FIG. 9 is a diagram illustrating the speed change operation from the time of the temporary stop to the establishment of the second speed through the vehicle start at the first speed in the embodiment. In each of FIGS. 8 and 9, three graphs show the rotational speed at the upper stage, the torque Tc of the clutch at the middle stage, the state of the second transmission mechanism 6 at the lower stage, and the common time t on the horizontal axis. Further, the vehicle is temporarily stopped at time t11, start control is started at time t12, the first speed is established at time t13, the speed change condition to the second speed is established at time t14, and the second speed at time t15. The case where is established is illustrated.

  In the upper part of FIG. 8 showing the prior art, at the time t11 during the temporary stop, the engine speed NE is the idle speed NEi, and the speeds N1 and N2 of the first and second input shafts 31 and 32 are zero. . Further, as shown in the middle stage, the first and second friction clutches 21 and 22 are in a disconnected state, and the torques Tc1 and Tc2 that can be transmitted are zero. As shown in the lower stage, the second speed change mechanism 6 is already engaged with the second speed gear set 62 in preparation for the upshift operation after starting.

  Then, when the start control is started at time t12 by the accelerator operation of the driver, the torque Tc1 that can be transmitted through the engagement of the first friction clutch 21 increases. Further, the first input shaft 31 starts rotating by the joining operation, and the rotational speed N1 increases to approach the engine rotational speed NE. When the rotational speed N1 of the first input shaft 31 substantially matches the engine rotational speed NE at time t13, the first speed is established, and thereafter the rotational speeds NE and N1 gradually increase. During this time, the second input shaft 32 is driven from the output shaft 4 side via the second speed gear set 62, and a rotational speed N2 (indicated by a broken line) corresponding to the second speed is generated.

  When the speed change condition to the second speed is established at time t14, the first friction clutch 21 is disengaged and the second friction clutch 22 is engaged, and the torque Tc1 of the first friction clutch 21 is changed to the second friction clutch 22. To the torque Tc2 (indicated by a broken line). When the first friction clutch 21 is disconnected and the second friction clutch 22 is engaged at time t15, the second speed is established.

  On the other hand, in the embodiment shown in FIG. 9, the engaged state of the second friction clutch 22 is continued from the temporary stop to the vehicle start. (1) in FIG. 9 shows that the engagement state of the second friction clutch 22 is canceled by the start of the start control, and (3) shows that the engagement condition of the second friction clutch 22 is satisfied for the second speed. (2) shows an intermediate case, respectively. The state at time t11 during the temporary stop of (1) to (3) in FIG. 9 is the same, and as shown in the upper stage, the engine speed NE is the idle speed NEi, the first and second input shafts 31, The rotational speeds N1 and N2 of 32 are zero. Further, as shown in the middle stage, the torque Tc1 that can be transmitted when the first friction clutch 21 is in the disconnected state is zero, and the torque Tc2 (≠ 0) that can be transmitted when the second friction clutch 22 is in the connected state. It has occurred. As shown in the lower stage, the second transmission mechanism 6 is in a neutral state.

  In (1) of FIG. 9, when start control is started at time t12, the torque Tc1 that can be transmitted by the first friction clutch 21 is increased, and the rotation of the first input shaft 31 is increased by the engagement operation. The number N1 also increases and approaches the engine speed NE. Further, the second friction clutch 22 is released from the engaged state, and shifts to a disconnected state by a cutting operation. Thereby, since the 2nd input shaft 22 will be in a free state, the 2nd speed gear set 62 of the 2nd transmission mechanism 6 can be meshed | engaged, and the rotation speed N2 (shown with a broken line) commensurate with 2nd speed generate | occur | produces. When the rotational speed N1 of the first input shaft 31 substantially matches the engine rotational speed NE at time t13, the first speed is established, and thereafter the rotational speeds NE and N1 gradually increase. Thereafter, the operation up to time t15 is the same as in the prior art.

  In this case, during the period from time t11 to t12, the second friction clutch 22 is engaged and the heat transfer characteristics are improved, and the high temperature T1H of the first friction clutch 21 is rapidly reduced. In addition, since the heat dissipation promotion means 73 is terminated early after the vehicle starts to enable the shift-up shift operation, shift control giving priority to acceleration maneuverability can be performed.

  Next, in (3) of FIG. 9, when start control is started at time t12, the torque Tc1 that can be transmitted by the first friction clutch 21 is increased, and the first input shaft is increased by the engagement operation. The rotational speed N1 of 31 also increases and approaches the engine rotational speed NE. When the rotational speed N1 of the first input shaft 31 substantially matches the engine rotational speed NE at time t13, the first speed is established, and thereafter the rotational speeds NE and N1 gradually increase. At this time, the rotational speed N2 of the second input shaft 32 is synchronized with the engine rotational speed NE according to the engaged state of the second friction clutch 22.

  When the condition for shifting to the second speed is satisfied at time t14, the second friction clutch 22 is released from the engaged state and is shifted to the disconnected state by the disconnection operation. As a result, the second input shaft 22 enters a free state, so that the second speed gear set 62 of the second transmission mechanism 6 can be meshed, and the second input shaft 32 has a rotational speed N2 (indicated by a broken line) corresponding to the second speed. Occurs). Further, the first friction clutch 21 is disconnected and the second friction clutch 22 is engaged, and the torque Tc1 of the first friction clutch 21 is replaced with the torque Tc2 of the second friction clutch 22. When the first friction clutch 21 is disconnected and the second friction clutch 22 is engaged at time t15, the second speed is established.

  In this case, for a long period from time t11 to t14, the second friction clutch 22 is engaged and the heat transfer characteristics are improved, and the high temperature T1H of the first friction clutch 21 is rapidly and significantly reduced. Further, the frictional heat generated by the joining operation of the first friction clutch 21 is also efficiently radiated. That is, since the heat radiation promotion means 73 is operated for a long time after the start at the first speed and priority is given to the suppression of the temperature rise, the durability performance of the first friction clutch 21 can be made more reliable.

  Further, in FIG. 9B, when the start control is started at time t12, the torque Tc1 that can be transmitted by the first friction clutch 21 is increased, and the first input shaft 31 is increased by the engagement operation. The engine speed N1 also increases and approaches the engine speed NE. When the rotational speed N1 of the first input shaft 31 substantially matches the engine rotational speed NE at time t13, the first speed is established, and thereafter the rotational speeds NE and N1 gradually increase. At this time, the rotational speed N2 of the second input shaft 32 is synchronized with the engine rotational speed NE according to the engaged state of the second friction clutch 22.

  Next, at time tm before the condition for shifting to the second speed is established at time t14, the second friction clutch 22 is released from the engaged state, and shifts to the disconnected state by the cutting operation. As a result, the second input shaft 22 enters a free state, so that the second speed gear set 62 of the second transmission mechanism 6 can be meshed, and the second input shaft 32 has a rotational speed N2 (indicated by a broken line) corresponding to the second speed. Occurs). At time t14, the first friction clutch 21 is disconnected and the second friction clutch 22 is engaged, and the torque Tc1 of the first friction clutch 21 is replaced with the torque Tc2 of the second friction clutch 22. When the first friction clutch 21 is disconnected and the second friction clutch 22 is engaged at time t15, the second speed is established.

  In this case, the second friction clutch 22 is engaged with an intermediate length from the time t11 to t1m to improve the heat transfer characteristics, and the high temperature T1H of the first friction clutch 21 is quickly and intermediate. Decreases by size.

  Note that the first heat dissipation adjustment means 74 determines the length of the duration of the engaged state of the second friction clutch 22 when it is determined that the temperature is high. Thereby, the dual clutch transmission 1 for a vehicle according to the embodiment operates in any one of (1) to (3) in FIGS. 7 and 9.

  According to the vehicle dual clutch transmission 1 of the embodiment, the temperature of the first friction clutch 21 to be engaged when the vehicle starts during a temporary stop is measured or estimated, and compared with a specified value to determine a high temperature state. In the state, the engaged state of the second friction clutch 22 is continued from the temporary stop to the vehicle start. Thereby, the heat transfer from the first friction clutch 21 to the second friction clutch 22 is promoted via the common drive side plate 25, and the heat dissipation characteristics of the entire clutch portion are improved. Accordingly, the temperature of the first friction clutch 21 in the high temperature state can be quickly lowered during the temporary stop, and the temperature increase due to the frictional heat generated in the joining operation at the start can be suppressed. Further, it is not necessary to change the structure of the transmission 1 when implementing the present invention, and only the control method of the control unit 7 needs to be changed, so that the manufacturing cost does not increase.

  Further, the first heat radiation adjusting means 74 is further provided, and the length of the operation time of the heat radiation promoting means 73 is adjusted according to the magnitude of the high temperature state. Therefore, when the high temperature state is severe, the durability performance of the second friction clutch 21 can be ensured by operating the heat radiation promoting means 73 for a long time from the temporary stop to the vehicle start to give priority to the suppression of the temperature rise. In addition, when the high temperature state is mild, the heat radiation promoting means 73 is terminated early to enable the shift-up shift operation to the second speed, and shift control giving priority to acceleration maneuverability can be performed.

  In addition, the 1st heat radiation adjustment means 74 of the control part 7 can also be replaced with the 2nd heat radiation adjustment means. The second heat radiation adjustment means adjusts the operation end timing of the heat radiation promotion means 73 according to the temperature change of one of the first friction clutch 21 and the second friction clutch 22 determined to be in the high temperature state. For example, the second friction clutch 22 is engaged when the temperature T1 of the first friction clutch 21 is compared with the specified value T0 during the temporary stop and is determined to be in a high temperature state, and thereafter, the first friction clutch 21 is sequentially increased. The temperature T1 is estimated. Then, when the temperature T1 decreases to a specified value T0 or less, the engaged state of the second friction clutch 22 is canceled.

  In the aspect having the second heat radiation adjusting means, the operation end timing of the heat radiation promoting means 73 is adjusted according to the change in the temperature T1 of the first friction clutch 21. Therefore, when the first friction clutch 21 temperature T1 has settled within a preferred range, for example, a specified value T0 or less, the heat radiation promoting means 73 can be terminated and controlled so as to be able to cope with the upshifting operation. Thereby, it is possible to achieve both the suppression of the temperature rise of the first friction clutch 21 and the shift control with good acceleration controllability.

  In addition, the present invention can be variously applied and modified.

1: Dual clutch transmission 21 for vehicle 21: First friction clutch 22: Second friction clutch 23: First clutch actuator 24: Second clutch actuator 25: Drive side plate 261, 262: Drive side plate 271, 272: Pressure Plates 281, 282, 291, 292: Friction material 31: First input shaft 32: Second input shaft 4: Output shaft 5: First transmission mechanism 51, 53, 55: First speed, third speed, fifth speed Gear set 6: 2nd speed change mechanism 62, 64: 2nd speed, 4th speed gear set 7: Control unit
71: Clutch temperature detection means 72: High temperature determination means
73: Heat radiation promoting means 74: First heat radiation adjusting means 81: First speed synchromesh mechanism 82: Third to fifth speed synchromesh mechanism 83: Second to fourth speed synchromesh mechanism 91: Engine 92: Output shaft 93: Differential device NE: Engine speed NEi: Idle speed N1, N2: Speeds of first and second input shafts Tc1, Tc2: Torque that can be transmitted by first and second friction clutches T1, T2; Second friction clutch temperature T1H: High temperature

Claims (3)

A driven side plate that is rotationally connected to a driving source, a driven side plate disposed opposite to the driven side plate, a pressure plate that pushes the driven side plate and slides on the driven side plate; And a first friction clutch and a second friction clutch each having an actuator for driving the pressure plate and capable of switching between a joint state rotationally connected to the drive source and a disconnected state disconnected from the drive source ,
A first speed change mechanism rotatably connected to the drive source by the first friction clutch and capable of selecting one of a plurality of speed stages;
A second speed change mechanism that is rotatably connected to the drive source by the second friction clutch and that allows one of a plurality of shift speeds to be selected;
Clutch temperature detecting means for actually measuring or estimating the temperature of one of the first friction clutch and the second friction clutch that is engaged from the disengaged state to the engaged state when the vehicle starts.
A controller for controlling the first friction clutch, the second friction clutch, the first transmission mechanism, and the second transmission mechanism;
The controller is
High temperature determination means for comparing the measured or estimated temperature of the one clutch with a specified value at the time of a temporary stop in the middle of running the vehicle to determine a high temperature state;
When the one clutch is in a high temperature state, the first transmission mechanism or the second transmission mechanism that is rotationally connected to the other clutch is set to the neutral state, and the engagement of the other clutch is performed from the time of the temporary stop to the start of the vehicle. A heat dissipation facilitating means for continuing the state and disengaging the other clutch when the one clutch is not in a high temperature state ;
A dual clutch transmission for a vehicle.   2. The vehicle-use vehicle according to claim 1, wherein the control unit further includes first heat radiation adjusting means that adjusts the length of the operation time of the heat radiation promoting means in accordance with the magnitude of the high temperature state of the one clutch. Dual clutch transmission.   2. The dual clutch transmission for a vehicle according to claim 1, wherein the control unit further includes a second heat radiation adjustment unit that adjusts an operation end timing of the heat radiation promotion unit according to a change in temperature of the one clutch.

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