JP2008215503A - Frictional engaging device of automatic transmission and control device of frictional engaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make both of improvement in responsiveness of engagement and reduction in dragging torque compatible. <P>SOLUTION: This frictional engaging device includes return springs 1 and 18 generating reaction to a piston 15 in the direction for expanding an interval between friction plates 13 and 14 until a position of the piston 15 becomes a position 1 of not applying pressing force to the friction plates 13 and 14 from a position where the friction plates 13 and 14 become a complete engaging state, and return springs 2 and 20 generating reaction to the piston 15 in the direction for expanding the interval until the position of the piston 15 becomes a position 2 on the direction side for narrowing the interval more than the position 1 from the position becoming the complete engaging state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a friction engagement device provided in an automatic transmission, and more particularly to a technique for suppressing the generation of drag torque without reducing responsiveness during engagement.

  Conventionally, an automatic transmission or the like is provided with a friction engagement device such as a clutch or a brake. As such a friction engagement device, for example, Japanese Patent Laid-Open No. 4-191530 (Patent Document 1) discloses a wet multi-plate clutch device that does not require a return spring. This wet multi-plate clutch device includes a plate group in which annular drive plates and driven plates are alternately arranged, and a piston chamber and a balance piston whose volumes are complementarily changed while moving a movable partition wall according to a difference in supply hydraulic pressure. A clutch piston that is integrally formed with the chamber and the movable partition wall and that can move along the arrangement direction of the plate group and moves in a predetermined direction when the volume of the piston chamber is enlarged, and press-engage the plate group; And an elastic body interposed between the plates and energizing the plates so as to widen the interval between the plates.

According to the wet multi-plate clutch device disclosed in the above-mentioned publication, the interval between the driven plates is widened by the biasing force of the elastic body, and dragging is suppressed by avoiding dragging. Further, the clutch piston is pushed back by the centrifugal hydraulic pressure and the urging force generated in the balance piston chamber, and a return force in place of the return spring is obtained.
Japanese Patent Laid-Open No. 4-191530

  By the way, in the friction engagement device, in order to improve the response when the friction member on the input side and the friction member on the output side are engaged, between the friction members on the input side and the output side in the released state. The distance may be reduced to the limit.

  However, if importance is attached to the improvement of responsiveness at the time of engagement and the distance between the friction members is reduced, a transmission torque may be generated between the friction members in the released state. For this reason, there is a possibility that the fuel consumption may deteriorate due to drag torque generated in the friction engagement device that is not involved in the shift.

  On the other hand, if the reduction in drag torque is emphasized and the distance between the friction members is increased to a distance at which drag torque does not occur, the moving distance of the piston that presses the friction member increases, and the responsiveness during engagement deteriorates. there is a possibility. Therefore, there is a problem that it is impossible to achieve both improvement in response during engagement and reduction in drag torque.

  In the wet multi-plate clutch device disclosed in the above-mentioned publication, no consideration is given to both improvement in responsiveness during engagement and reduction in drag torque, and this problem cannot be solved.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a frictional engagement device and a frictional engagement device for an automatic transmission that can achieve both improved response of engagement and reduction of drag torque. It is to provide a control device for a combined device.

  According to a first aspect of the present invention, there is provided a friction engagement device for an automatic transmission, wherein a first friction member on an input side and a second friction member on an output side are connected by a pressing force of a piston operated by a hydraulic pressure supplied from a supply source. It is a friction engagement device of an automatic transmission to be engaged. In this friction engagement device, the pressing force is not applied to the first friction member and the second friction member from the position where the piston is in a completely engaged state between the first friction member and the second friction member. The first reaction force generating means for generating a reaction force against the piston in the direction in which the distance between the first friction member and the second friction member is increased until the first position is reached, and the position of the piston is The second reaction force for generating the reaction force on the piston in the direction in which the interval is increased from the position where the engagement is completed to the second position on the direction side where the interval is narrower than the first position. Generating means.

  According to the first invention, when the position of the piston is the first position, the pressing force is not applied to the first friction member and the second friction member. Therefore, generation of drag torque can be suppressed between the first friction member and the second friction member. Thereby, deterioration of fuel consumption can be suppressed. Further, when the piston position is the second position, the piston position to the piston position at which the first friction member and the second friction member are completely engaged is more than that at the first position. The moving distance is shortened. Therefore, compared with the case where the piston moves from the first position to the fully engaged position, the response at the time of engagement between the first friction member and the second friction member can be improved. Further, the first reaction force generation means and the second reaction force generation means allow the reaction force characteristics with respect to the pressing force of the piston to be different from those in the case where the piston is at a position closer to the engagement side than the first position. It is possible to make the difference between the position 2 and the position on the engagement side. Thus, for example, if the reaction force is larger when the engagement position is closer to the second position, the distance from the first position to the second position depends on the movement distance. Therefore, the position of the piston can be accurately controlled up to the second position. In addition, when the piston is in the second position, the moving distance to the fully engaged position is shortened, so that the responsiveness can be improved and the first reaction force is generated at the time of hydraulic unloading. The distance between the first friction member and the second friction member can be increased with good responsiveness by the reaction force of the means and the second reaction force generation means. Therefore, it is possible to provide a friction engagement device for an automatic transmission that achieves both improvement in responsiveness during engagement and reduction in drag torque.

  In the friction engagement device for an automatic transmission according to the second invention, in addition to the configuration of the first invention, the second position is a position on the side in which the piston is narrower than the first position. In addition, there is a position where the transmission torque between the first friction member and the second friction member is equal to or lower than a predetermined torque.

  According to the second invention, the second position is set to a position where the transmission torque between the first friction member and the second friction member is equal to or less than a predetermined torque, thereby placing importance on responsiveness. However, the piston can be held at a position where unnecessary drag torque does not occur.

  In the frictional engagement device for an automatic transmission according to the third invention, in addition to the configuration of the first invention, the first reaction force generating means and the second reaction force generating means extend and contract in a direction in which the interval increases. It is an elastic member provided so that the urging | biasing force according to quantity may arise.

  According to the third invention, the position of the piston can be moved to the first position by the urging force corresponding to the expansion / contraction amount of the first reaction force generating means. Therefore, since no pressing force is applied to the first friction member and the second friction member, the generation of drag torque can be suppressed between the first friction member and the second friction member. Thereby, deterioration of fuel consumption can be suppressed. Further, the position of the piston can be moved to the second position by the urging force corresponding to the expansion / contraction amount of the second reaction force generating means. Therefore, the piston can be moved from the position where the first friction member and the second friction member are completely engaged to the second position with high responsiveness when the hydraulic pressure is unloaded.

  In the friction engagement device for an automatic transmission according to the fourth invention, in addition to the configuration of the third invention, the first reaction force generating means and the second reaction force generating means are springs having different spring constants. It is.

  According to the fourth invention, due to the winding springs having different spring constants, the characteristics of the reaction force with respect to the pressing force of the piston are different from those in the case where the piston is in the position closer to the engagement than the first position. Also, it can be made different depending on the position on the engagement side. Thus, for example, if the reaction force is larger when the engagement position is closer to the second position, the distance from the first position to the second position depends on the movement distance. Therefore, the position of the piston can be accurately controlled up to the second position. In addition, when the piston is in the second position, the moving distance to the fully engaged position is shortened, so that the response can be improved, and the reaction force of the winding spring during hydraulic unloading can be improved. The interval between the first friction member and the second friction member can be widened with good responsiveness.

  In the frictional engagement device for an automatic transmission according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, the first reaction force generating means and the second reaction force generating means, The characteristic of the reaction force with respect to the pressing force of the piston is made different between when the piston is located on the engagement side with respect to the first position and when the piston is located on the engagement side with respect to the second position.

  According to the fifth aspect of the invention, for example, when the reaction force is larger at the engagement side than at the second position, until the second position is reached from the first position, Since the reaction force to the piston generated according to the movement distance is weak, the position of the piston can be accurately controlled up to the second position. In addition, when the piston is in the second position, the moving distance to the fully engaged position is shortened, so that the responsiveness can be improved and the first reaction force is generated at the time of hydraulic unloading. The distance between the first friction member and the second friction member can be increased with good responsiveness by the reaction force of the means and the second reaction force generation means.

  In the friction engagement device for an automatic transmission according to the sixth aspect of the invention, in addition to the configuration of the fifth aspect, the first position is when the piston is located closer to the engagement side than the second position. The reaction force generated by the first reaction force generation unit and the second reaction force generation unit is set to be larger than the case where the first reaction force generation unit and the second reaction force generation unit are located on the engagement side.

  According to the sixth aspect of the present invention, when the reaction force is larger when the engagement position is closer to the second position, the moving distance is from the first position to the second position. Since the reaction force to the piston generated in response to this is weak, it is possible to accurately control the position of the piston up to the second position. In addition, when the piston is in the second position, the moving distance to the fully engaged position is shortened, so that the responsiveness can be improved and the first reaction force is generated at the time of hydraulic unloading. The distance between the first friction member and the second friction member can be increased with good responsiveness by the reaction force of the means and the second reaction force generation means.

  A control device for a friction engagement device according to a seventh aspect is a control device for a friction engagement device provided in an automatic transmission. In the friction engagement device, the first friction member on the input side and the second friction member on the output side engaged by the pressing force of the piston operated by the hydraulic pressure supplied from the supply source, and the position of the piston are the first. The piston in the direction in which the distance between the first friction member and the second friction member is increased from the position where the friction member and the second friction member are completely engaged to the predetermined first position. Until the position of the first reaction force generating portion that generates the reaction force and the piston is in the fully engaged state and the second position on the side of the direction narrower than the first position, And a second reaction force generator that generates a reaction force against the piston in the direction in which the interval widens. The control device detects a physical quantity related to the shift state of the automatic transmission, and based on the detected physical quantity, shifts that require engagement between the first friction member and the second friction member. If it is determined that there is no possibility of shifting and a determination means for determining whether or not there is a possibility of shifting, the hydraulic pressure supplied to the piston is controlled so that the piston is in the first position. And a second hydraulic pressure for controlling the hydraulic pressure supplied to the piston so that the piston is in the second position when it is determined that there is a possibility of shifting. Control means.

  According to the seventh aspect, when there is no possibility of shifting, the hydraulic pressure supplied to the piston is controlled so that the position of the piston becomes the first position. In addition, when there is a possibility of shifting, the hydraulic pressure supplied to the piston is controlled so that the position of the piston becomes the second position. In addition, the second position has a shorter distance to the position where the first friction member and the second friction member are in a fully engaged state than the first position. As described above, when it is determined that there is no possibility of shifting, the piston is given to the first friction member and the second friction member by increasing the moving distance of the piston to the position where the engagement is complete. Therefore, the drag torque generated between the first friction member and the second friction member can be reduced. Therefore, deterioration of fuel consumption can be suppressed. Further, when it is determined that there is a possibility of shifting, the first friction member and the second friction member are completely engaged by shortening the moving distance of the piston to the position where the fully engaged state is achieved. It is possible to shorten the time until the state is reached and to improve the responsiveness at the time of engagement. Therefore, it is possible to provide a control device for a frictional engagement device that achieves both improvement in engagement responsiveness and reduction in drag torque.

  In the control device for a friction engagement device according to the eighth invention, in addition to the configuration of the seventh invention, the first position is a position where the pressing force is not applied to the first friction member and the second friction member. It is. The second position is a position closer to the direction narrower than the first position, and the first friction member and the second friction member are in a non-completely engaged state, and This is a position where the transmission torque between the first friction member and the second friction member is equal to or less than a predetermined torque.

  According to the eighth invention, when the position of the piston is the first position, the pressing force is not applied to the first friction member and the second friction member. Therefore, generation of drag torque can be suppressed between the first friction member and the second friction member. Thereby, deterioration of fuel consumption can be suppressed. Further, when the piston position is the second position, the piston position to the piston position at which the first friction member and the second friction member are completely engaged is more than that at the first position. The moving distance is shortened. Therefore, compared with the case where the piston moves from the first position to the fully engaged position, the response at the time of engagement between the first friction member and the second friction member can be improved.

  In the friction engagement device control device according to the ninth aspect of the invention, in addition to the configuration of the seventh or eighth aspect of the invention, the first hydraulic pressure control means has a reaction force generated by the first reaction force generator. Means are included for controlling the hydraulic pressure supplied to the piston so that a small pressing force is generated on the piston. The second hydraulic pressure control means has a pressing force that is greater than the reaction force generated by the first reaction force generator and less than the reaction force generated by the first reaction force generator and the second reaction force generator. Means for controlling the hydraulic pressure supplied to the piston such that is generated in the piston.

  According to the ninth invention, the first hydraulic pressure control means controls the hydraulic pressure supplied to the piston so that a pressing force smaller than the reaction force generated by the first pressure generating portion is generated in the piston. The position of the piston can be held at the first position. On the other hand, the second hydraulic pressure control means is larger than the reaction force generated by the first reaction force generation unit and more than the reaction force generated by the first reaction force generation unit and the second reaction force generation unit. By controlling the hydraulic pressure supplied to the piston so that a small pressing force is generated in the piston, the position of the piston can be held at the second position.

  In addition to the configuration of the ninth invention, the control device for the friction engagement device according to the tenth invention requires the engagement between the first friction member and the second friction member based on the detected physical quantity. Means for determining whether or not to shift, and if it is determined to shift, a pressing force larger than the reaction force generated by the first reaction force generation unit and the second reaction force generation unit is generated. And means for controlling the hydraulic pressure supplied to the piston.

  According to the tenth aspect of the invention, when it is determined to shift, the first friction member and the second friction member are engaged. At this time, since the position of the piston before the shift is the second position, the position of the piston when the first friction member and the second friction member are completely engaged with each other than the first position. The moving distance of the piston becomes shorter. Therefore, the response at the time of engagement can be improved.

  In the friction engagement device control device according to the eleventh aspect of the invention, in addition to the configuration of any of the seventh to tenth aspects of the invention, the automatic transmission has a combination of engagement and release of a plurality of friction engagement devices. This is a stepped automatic transmission in which any one of a plurality of shift stages is formed. The determination means includes a means for determining a shift stage that is likely to shift with the current shift stage based on the detected physical quantity, and a plurality of friction engagement devices based on the determined shift stage. Each includes means for determining whether there is a possibility of shifting that requires engagement between the first friction member and the second friction member.

  According to the eleventh aspect of the present invention, the friction that is determined that there is a possibility of performing a shift that needs to be engaged at the determined shift speed is determined based on the current shift speed. By setting the position of the piston of the engagement device to the second position, it is possible to improve the responsiveness of the engagement when shifting to the determined gear position. Thereby, the shift time can be shortened. On the other hand, the first position is the piston position of the friction engagement device that corresponds to the shift stage determined not to shift and that is determined not to shift requiring engagement. Thus, drag torque generated between the first friction member and the second friction member can be reduced. Therefore, deterioration of fuel consumption can be suppressed.

  In the friction engagement device control apparatus according to the twelfth aspect of the invention, in addition to the configuration of the eleventh aspect of the invention, the determination means is at most two gears from the first speed-increasing side based on the current speed. Means for determining that there is a possibility of shifting up to the shift speed on the speed reduction side is included.

  According to the twelfth aspect of the present invention, the friction that is determined that there is a possibility of performing a shift that needs to be engaged at the determined shift stage by determining a shift stage that is likely to shift based on the current shift stage. By setting the position of the piston of the engagement device to the second position, it is possible to improve the responsiveness of the engagement when shifting to the determined gear position. Thereby, the shift time can be shortened. On the other hand, the first position is the piston position of the friction engagement device that corresponds to the shift stage determined not to shift and that is determined not to shift requiring engagement. Thus, drag torque generated between the first friction member and the second friction member can be reduced. Therefore, deterioration of fuel consumption can be suppressed.

  In the control device for a friction engagement device according to the thirteenth invention, in addition to the configuration of any of the seventh to twelfth inventions, the first reaction force generator and the second reaction force generator are spaced apart from each other. It is an elastic member provided so that the urging | biasing force according to the expansion-contraction amount arises in the spreading direction.

  According to the thirteenth invention, the position of the piston can be moved to the first position by the urging force according to the amount of expansion / contraction of the first reaction force generating portion. Therefore, since no pressing force is applied to the first friction member and the second friction member, the generation of drag torque can be suppressed between the first friction member and the second friction member. Thereby, deterioration of fuel consumption can be suppressed. In addition, the position of the piston can be moved to the second position by the urging force according to the amount of expansion and contraction of the second reaction force generator. Therefore, the piston can be moved from the position where the first friction member and the second friction member are completely engaged to the second position with high responsiveness when the hydraulic pressure is unloaded.

  In the control device for a friction engagement device according to the fourteenth aspect of the invention, in addition to the configuration of the thirteenth aspect, the first reaction force generator and the second reaction force generator are springs having different spring constants. .

  According to the fourteenth aspect of the present invention, due to the winding springs having different spring constants, the reaction force characteristics with respect to the pressing force of the piston are different from those in the case where the piston is in the position on the engagement side relative to the first position. Also, it can be made different depending on the position on the engagement side. Thus, for example, if the reaction force is larger when the engagement position is closer to the second position, the distance from the first position to the second position depends on the movement distance. Therefore, the position of the piston can be accurately controlled up to the second position. In addition, when the piston is in the second position, the moving distance to the fully engaged position is shortened, so that the response can be improved, and the reaction force of the winding spring during hydraulic unloading can be improved. The interval between the first friction member and the second friction member can be widened with good responsiveness.

  In the friction engagement device control device according to the fifteenth aspect of the invention, in addition to the configuration of any of the seventh to fourteenth aspects, the piston is constituted by the first reaction force generation means and the second reaction force generation means. The characteristic of the reaction force with respect to the pressing force is made different between when the piston is located on the engagement side with respect to the first position and when the piston is located on the engagement side with respect to the second position.

  According to the fifteenth aspect of the invention, for example, when the reaction force is larger at the engagement side than at the second position, until the second position is reached from the first position, Since the reaction force to the piston generated according to the movement distance is weak, the position of the piston can be accurately controlled up to the second position. In addition, when the piston is in the second position, the moving distance to the fully engaged position is shortened, so that the responsiveness can be improved and the first reaction force is generated at the time of hydraulic unloading. The distance between the first friction member and the second friction member can be increased with good responsiveness by the reaction force of the means and the second reaction force generation means.

  In the friction engagement device control device according to the sixteenth aspect of the invention, in addition to the configuration of the fifteenth aspect of the invention, the case where the piston is located closer to the engagement side than the second position is more than the first position. Also, the reaction force generated by the first reaction force generation means and the second reaction force generation means is made larger than that in the case of being positioned on the engagement side.

  According to the sixteenth aspect of the present invention, when the reaction force is larger when the engagement position is closer to the second position, the movement distance is from the first position to the second position. Since the reaction force to the piston generated in response to this is weak, it is possible to accurately control the position of the piston up to the second position. In addition, when the piston is in the second position, the moving distance to the fully engaged position is shortened, so that the responsiveness can be improved and the first reaction force is generated at the time of hydraulic unloading. The distance between the first friction member and the second friction member can be increased with good responsiveness by the reaction force of the means and the second reaction force generation means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, a vehicle equipped with a friction engagement device and a control device thereof according to an embodiment of the present invention will be described. This vehicle is an FF (Front engine Front drive) vehicle. A vehicle other than FF may be used.

  The vehicle includes an engine 1000, an automatic transmission 2000, a planetary gear unit 3000 constituting a part of the automatic transmission 2000, a hydraulic circuit 4000 constituting a part of the automatic transmission 2000, a differential gear 5000, a drive shaft 6000, Front wheel 7000 and ECU (Electronic Control Unit) 8000 are included. The control device for the friction engagement device provided in the automatic transmission according to the present invention is realized by the ECU 8000.

  Engine 1000 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 3200. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage.

  The output gear of automatic transmission 2000 is meshed with differential gear 5000. A drive shaft 6000 is connected to the differential gear 5000 by spline fitting or the like. Power is transmitted to the left and right front wheels 7000 via the drive shaft 6000.

  The ECU 8000 includes a vehicle speed sensor 8002, a position switch 8006 of a shift lever 8004, an accelerator opening sensor 8010 of an accelerator pedal 8008, a stroke sensor 8014 of a brake pedal 8012, a throttle opening sensor 8018 of an electronic throttle valve 8016, An engine speed sensor 8020, an input shaft speed sensor 8022, and an output shaft speed sensor 8024 are connected via a harness or the like.

  Vehicle speed sensor 8002 detects the speed of the vehicle from the rotational speed of drive shaft 6000 and transmits a signal representing the detection result to ECU 8000. The position of shift lever 8004 is detected by position switch 8006, and a signal representing the detection result is transmitted to ECU 8000. Corresponding to the position of the shift lever 8004, the gear stage of the automatic transmission 2000 is automatically formed. Further, a manual shift mode in which the driver can select an arbitrary gear stage may be selected according to the driver's operation.

  Accelerator opening sensor 8010 detects the opening of accelerator pedal 8008 and transmits a signal representing the detection result to ECU 8000. Stroke sensor 8014 detects the stroke amount of brake pedal 8012 and transmits a signal representing the detection result to ECU 8000.

  The throttle opening sensor 8018 detects the opening of the electronic throttle valve 8016 whose opening is adjusted by the actuator, and transmits a signal indicating the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Engine rotation speed sensor 8020 detects the rotation speed of the output shaft (crankshaft) of engine 1000 and transmits a signal representing the detection result to ECU 8000. Input shaft rotational speed sensor 8022 detects input shaft rotational speed (hereinafter also referred to as turbine rotational speed) NT of automatic transmission 2000, and transmits a signal representing the detection result to ECU 8000. Output shaft rotational speed sensor 8024 detects output shaft rotational speed NO of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000. Since the output shaft of engine 1000 is connected to the input shaft of torque converter 3200 and the output shaft of torque converter 3200 is connected to the input shaft of automatic transmission 2000, the rotational speed of the output shaft of engine 1000 is the torque. The rotational speed is the same as the rotational speed of the input shaft of converter 3200. Further, the input shaft rotation speed of automatic transmission 2000 is the same as the rotation speed of the output shaft of torque converter 3200.

  ECU 8000 is sent from vehicle speed sensor 8002, position switch 8006, accelerator opening sensor 8010, stroke sensor 8014, throttle opening sensor 8018, engine speed sensor 8020, input shaft speed sensor 8022, output shaft speed sensor 8024, and the like. Based on the received signal, a map and a program stored in a ROM (Read Only Memory), the devices are controlled so that the vehicle is in a desired running state.

  In the present embodiment, ECU 8000 has a 1st to 6th gear stage when D (drive) range is selected as the shift range of automatic transmission 2000 when shift lever 8004 is located at the D (drive) position. Automatic transmission 2000 is controlled so that one of these gears is formed. The automatic transmission 2000 can transmit the driving force to the front wheels 7000 by forming any one of the first to sixth gears.

  When the shift lever 8004 is in the N (neutral) position, when the N (neutral) range is selected as the shift range of the automatic transmission 2000, the automatic transmission 2000 is controlled so as to be in the neutral state (power transmission cut-off state). Is done.

  With reference to FIG. 2, planetary gear unit 3000 provided in automatic transmission 2000 will be described. Planetary gear unit 3000 is connected to a torque converter 3200 having an input shaft 3100 coupled to a crankshaft. Planetary gear unit 3000 includes a first set 3300 of planetary gear mechanisms, a second set 3400 of planetary gear mechanisms, an output gear 3500, a B1 brake 3610, a B2 brake 3620 and a B3 brake 3630 fixed to gear case 3600, and C1. Clutch 3640 and C2 clutch 3650, and one-way clutch F3660 are included. The friction engagement devices according to the present embodiment are a C1 clutch 3640, a C2 clutch 3650, a B1 brake 3610, a B2 brake 3620, and a B3 brake 3630.

  The first set 3300 is a single pinion type planetary gear mechanism. First set 3300 includes sun gear S (UD) 3310, pinion gear 3320, ring gear R (UD) 3330, and carrier C (UD) 3340.

  Sun gear S (UD) 3310 is coupled to output shaft 3210 of torque converter 3200. Pinion gear 3320 is rotatably supported by carrier C (UD) 3340. Pinion gear 3320 is in mesh with sun gear S (UD) 3310 and ring gear R (UD) 3330.

  Ring gear R (UD) 3330 is fixed to gear case 3600 by B3 brake 3630. Carrier C (UD) 3340 is fixed to gear case 3600 by B1 brake 3610.

  The second set 3400 is a Ravigneaux type planetary gear mechanism. The second set 3400 includes a sun gear S (D) 3410, a short pinion gear 3420, a carrier C (1) 3422, a long pinion gear 3430, a carrier C (2) 3432, a sun gear S (S) 3440, and a ring gear R. (1) (R (2)) 3450.

  Sun gear S (D) 3410 is coupled to carrier C (UD) 3340. Short pinion gear 3420 is rotatably supported by carrier C (1) 3422. Short pinion gear 3420 is in mesh with sun gear S (D) 3410 and long pinion gear 3430. Carrier C (1) 3422 is coupled to output gear 3500.

  Long pinion gear 3430 is rotatably supported by carrier C (2) 3432. Long pinion gear 3430 is in mesh with short pinion gear 3420, sun gear S (S) 3440, and ring gear R (1) (R (2)) 3450. Carrier C (2) 3432 is coupled to output gear 3500.

  Sun gear S (S) 3440 is coupled to output shaft 3210 of torque converter 3200 by C1 clutch 3640. Ring gear R (1) (R (2)) 3450 is fixed to gear case 3600 by B2 brake 3620 and connected to output shaft 3210 of torque converter 3200 by C2 clutch 3650. The ring gear R (1) (R (2)) 3450 is connected to the one-way clutch F3660 and cannot rotate when the first gear is driven.

  The one-way clutch F3660 is provided in parallel with the B2 brake 3620. That is, the outer race of the one-way clutch F3660 is fixed to the gear case 3600, and the inner race is connected to the ring gear R (1) (R (2)) 3450 via the rotation shaft.

  The ECU 8000 controls the hydraulic pressure supplied to the C1 clutch 3640, the C2 clutch 3650, the B1 brake 3610, the B2 brake 3620, and the B3 brake 3630 by transmitting control signals to various solenoid valves provided in the hydraulic circuit 4000.

  Specifically, hydraulic circuit 4000 is provided with an oil pump connected to the crankshaft of engine 1000. As the crankshaft rotates, the oil pump is driven to generate hydraulic pressure. The hydraulic pressure generated by the oil pump is supplied to various solenoid valves. Oil pressure supplied to the C1 clutch 3640, the C2 clutch 3650, the B1 brake 3610, the B2 brake 3620, and the B3 brake 3630 by various solenoid valves performing duty control on the hydraulic pressure generated by the oil pump based on a control signal from the ECU 8000. Is controlled. In the present embodiment, the “oil pump” corresponds to the “supply source” of hydraulic pressure.

  The C1 clutch 3640, the C2 clutch 3650, the B1 brake 3610, the B2 brake 3620, and the B3 brake 3630 are each composed of a multi-plate clutch, and include a plurality of input side friction plates and a plurality of output side friction plates. Thus, the engagement force between the friction plates is controlled by the pressing force of the piston.

  FIG. 3 shows an operation table showing the relationship between the respective shift speeds and the operation states of the clutch elements and the brake elements. By operating each brake element and each clutch element in the combination shown in this operation table, a forward gear of 1st to 6th speed and a reverse gear are formed.

  As shown in FIG. 3, the C1 clutch 3640 is engaged in all of the first to fourth gears. That is, it can be said that the C1 clutch 3640 is an input clutch in the first gear to the fourth gear. C2 clutch 3650 is engaged at the fifth speed and the sixth speed. That is, it can be said that C2 clutch 3650 is an input clutch at the fifth speed and the sixth speed.

  In the present embodiment, the description will be made on the assumption that the automatic transmission forms any one of a plurality of shift stages by a combination of engagement and release of a plurality of friction engagement devices. The number of engaging devices is not limited.

  FIG. 4 shows a cross-sectional view of an automatic transmission 2000 mounted on a vehicle. In the drawing, a part of the automatic transmission 2000 is shown. Referring to FIG. 4, automatic transmission 2000 includes a first set 3300 and a second set 3400 as a plurality of planetary gears. The automatic transmission 2000 outputs the rotation input from the internal combustion engine by decelerating or accelerating, or the reverse rotation by a combination of the first set 3300 and the second set 3400. First set 3300 and second set 3400 are housed in gear case 3600.

  FIG. 5 is a cross-sectional view showing a support structure of B1 brake 3610 according to the embodiment of the present invention. In the figure, a range surrounded by a two-dot chain line II in FIG. 4 is shown.

  Referring to FIGS. 4 and 5, automatic transmission 2000 includes B1 brake 3610. The B1 brake 3610 locks the rotation of the carrier C (UD) 3340 constituting the first set 3300 and the rotation of the sun gear S (D) 3410 constituting the second set 3400. The B1 brake 3610 includes friction plates 13 and 14, a back plate 21, a snap ring 31, a plurality of return springs (1) 18, and a plurality of return springs (2) 20 housed in a gear case 3600. . A plurality of friction plates 13 and a plurality of friction plates 14 are provided. In this embodiment, the B1 brake 3610 is listed as an example, and the friction engagement device according to the present invention will be described. However, the C1 clutch 3640, the C2 clutch 3650, the B2 brake 3620, and the like other than the B1 brake 3610 A similar structure is applied to the B3 brake 3630. Therefore, detailed description thereof will not be repeated.

  The gear case 3600 includes an inner peripheral surface 12 that extends around a central axis 201 that is a virtual axis. The central axis 201 is the rotation center of the first set 3300 and the second set 3400.

  The friction plate 13 is fixed to the gear case 3600. The friction plate 14 is fixed to the planetary gear side. The friction plate 13 and the friction plate 14 are fixed to the gear case 3600 and the planetary gear side, respectively, so that they can move in the axial direction of the central axis 201 and cannot rotate in the circumferential direction around the central axis 201. The friction plates 13 and 14 have a ring shape extending annularly inside the inner peripheral surface 12. The friction plates 13 and the friction plates 14 are arranged alternately in the axial direction of the central shaft 201.

  The B1 brake 3610 further includes a piston 15. The piston 15 is disposed adjacent to the friction plates 13 and 14 in the axial direction of the central shaft 201. A hydraulic chamber 16 is formed in the gear case 3600. The hydraulic chamber 16 is formed adjacent to the piston 15 in the axial direction of the central shaft 201. A piston 15 is disposed between the friction plates 13 and 14 and the hydraulic chamber 16.

  When hydraulic pressure is supplied to supply hydraulic pressure to the hydraulic chamber 16, the piston 15 strokes in the axial direction of the central shaft 201 and presses the friction plates 13 and 14. The friction plate 13 and the friction plate 14 are pressed against each other by friction due to the pressing force from the piston 15. As a result, the friction plate 13 and the friction plate 14 are engaged, and the rotation of the carrier C (UD) 3340 and the sun gear S (D) 3410 is locked.

  The back plate 21 is made of metal. The back plate 21 is disposed between the snap ring 31 and the friction plates 13 and 14. In the axial direction of the central shaft 201, the snap ring 31, the back plate 21, and the friction plates 13 and 14 are disposed so as to overlap each other. Back plate 21 is fixed to gear case 3600.

  The back plate 21 has a ring shape that extends annularly around the central axis 201. The back plate 21 includes an end surface 23 and an end surface 24. The end surface 23 and the end surface 24 face opposite directions in the axial direction of the central axis 201. The end faces 23 and 24 extend annularly about the central axis 201. The end face 23 faces the friction plates 13 and 14. The end surface 24 faces the snap ring 31. The end surfaces 23 and 24 extend in a plane orthogonal to the central axis 201.

  The position of the back plate 21 is limited to the gear case 3600 so that the back plate 21 can move in the axial direction of the central shaft 201 by spline fitting with the gear case 3600 and does not rotate in the circumferential direction around the central shaft 201. The back plate 21 is provided with a plurality of flange portions 27 extending in the radial direction around the central axis 201. The plurality of flange portions 27 are formed at predetermined intervals in the circumferential direction around the central axis 201.

  The return spring (1) 18 extends in the axial direction of the central shaft 201. The return spring (1) 18 includes one end 18m fixed to the piston 15 and the other end 18n fixed to the back plate 21. The other end 18n is fixed to the flange portion 27. The return spring (1) 18 is provided for each flange 27.

  The return spring (2) 20 extends in the axial direction of the central shaft 201. The return spring (2) 20 includes one end 20m that is a free end and the other end 20n that is fixed to the back plate 21. The other end 20 n is fixed to the flange portion 27. The return spring (2) 20 is provided for each flange portion 27 formed at substantially the same interval in the circumferential direction of the back plate 21. The return spring (2) 20 has a position where one end 20m can come into contact with the piston 15 when the piston 15 moves in a direction approaching the back plate 21 by supplying hydraulic pressure to the hydraulic chamber 16. If provided, the position is not particularly limited.

  In the present embodiment, it is assumed that a plurality of return springs (1) 18 and return springs (2) 20 are arranged on the same pitch circle around the central axis 201. It is not limited to such a configuration. For example, you may make it comprise with one winding spring larger than the diameter of the friction plates 13 and 14. FIG.

  In the present embodiment, the return spring (1) 18 and the return spring (2) 20 are both wound springs, and the winding radius of the return spring (2) 20 is the winding radius of the return spring (1) 18. Greater than radius. Further, the center axis of the return spring (1) 18 and the center axis of the return spring (2) 20 are provided so as to substantially coincide with each other. The positional relationship between the return spring (1) 18 and the return spring (2) 20 is not particularly limited to this. For example, the return spring (1) 18 and the return spring (2) 20 may be provided on circles having different pitches centered on the central axis 201 in the circumferential direction of the flange portion 27, respectively, or the same pitch. The center axis of the return spring (1) 18 and the center axis of the return spring (2) 20 may be provided at different positions.

  Furthermore, the fixing method of the other ends 18n and 20n to the back plate 21 and the fixing method of the one end 18m to the piston 15 may be any known technique and are not particularly limited. For example, it may be fixed to the back plate 21 or the piston 15 by a separately provided fixing member such as a bolt, or the other end 18n, 20n or one of the protrusion shape or groove shape formed on the back plate 21 or the piston 15. You may make it fix by fitting the edge 18m.

  Alternatively, an extendable shaft portion provided between the piston 15 and the back plate 21 or a shaft portion as a guide may penetrate the return spring (1) 18 or the return spring (2) 20.

  The length of the return spring (1) 18 is not particularly limited as long as it is larger than the distance from the back plate 21 to the piston 15 at the position (1) described later, but the weight of the piston 15 and the resistance during movement are not limited. It may be adapted by experiment etc. in consideration of the above. The length of the return spring (2) 20 is not particularly limited as long as it is larger than the distance from the back plate 21 to the piston 15 at the position (2) described later. It may be adapted by an experiment or the like in consideration of the resistance.

  Furthermore, the characteristics of the reaction force generated according to the distance between the piston 15 of the return spring (1) 18 and the return spring (2) 20 and the back plate 21, that is, the spring constant is not particularly limited, but preferably The return spring (1) 18 is preferably a spring constant that generates an elastic force that moves the piston 15 to the position (2) when no hydraulic pressure is supplied to the hydraulic chamber 16, and the return spring (2) 20 When the hydraulic pressure in the hydraulic chamber 16 is discharged from the fully engaged state, it is desirable that the spring constant be such that an elastic force that quickly moves the piston 15 away from the back plate 21 is generated. Preferably, the spring constant of the return spring (1) is smaller than the spring constant of the return spring (2). Furthermore, the spring constants of the return spring (1) 18 and the return spring (2) 20 may be calculated, for example, by design, or may be adapted by experiments or the like.

  Further, the snap ring 31 is positioned between the return spring (1) 18 and the return spring (2) 20 and the friction plates 13 and 14 in the radial direction about the central axis 201. The snap ring 31 restricts the movement of the friction plates 13 and 14 pressed by the piston 15.

  The direction in which the piston 15 moves away from the back plate 21 along the axial direction of the central axis 201 by the elastic force of the return spring (1) 18 and the return spring (2) 20 according to the supply state of the hydraulic pressure to the hydraulic chamber 16 The piston 15 is urged in the direction away from the back plate 21 along the axial direction of the central shaft 201 by the elastic force of the return spring (1) 18. The back plate 21 is pressed against the snap ring 31 by the elastic force of the return spring (1) 18 and the return spring (2) 20 or the elastic force of the return spring (1) 18.

  When the hydraulic pressure is unloaded to stop the hydraulic pressure supply to the hydraulic chamber 16, the piston 15 strokes in a direction away from the back plate 21 by the elastic force of the return spring (1) 18. Thereby, the engagement between the friction plate 13 and the friction plate 14 is released, and the rotation of the carrier C (UD) 3340 and the sun gear S (D) 3410 is allowed.

  In the friction engagement device according to the present embodiment having the above-described configuration, the pressing force is applied to the friction plates 13 and 14 from the position where the piston 15 is completely engaged with the friction plates 13 and 14. The first reaction force generating means for generating the reaction force against the piston 15 in the direction in which the distance between the friction plates 13 and 14 is increased and the position of the piston 15 are completely The second reaction force generation for generating the reaction force against the piston 15 in the direction in which the interval widens from the position in the combined state to the position (2) on the side of the direction narrower than the position (1). And a means.

  In the present embodiment, the “first reaction force generating means” corresponds to the return spring (1) 18 formed by the winding spring, but the urging force corresponding to the expansion / contraction amount is the friction plate 13. The elastic member is not particularly limited as long as the elastic member is provided so that the gap between the friction plate 14 and the friction plate 14 increases. The elastic member may be configured by a member having a spring structure different from that of rubber or the coil spring, in addition to the coil spring.

  In the present embodiment, the “second reaction force generating means” corresponds to the return spring (2) 20 formed by the winding spring, but the urging force according to the expansion / contraction amount is the friction plate 13. The elastic member provided so that it may arise in the direction where the space | interval with a friction plate 14 spreads may be used, and the electromagnet which generate | occur | produces the reaction force based on the electromagnetic force according to the electric power supply to a coil may be used.

  As shown in FIG. 6A, when the hydraulic pressure is unloaded to stop the hydraulic pressure supply to the hydraulic chamber 16, the piston 15 moves away from the back plate 21 by the elastic force of the return spring (1) 18. Stroke and hold at position (1). At this time, since no pressing force is applied to the friction plate 13 and the friction plate 14, the engagement is released, and the drag torque generated between the friction plate 13 and the friction plate 14 is small.

  As shown in FIG. 6 (B), at the time of preparation for engagement in which a predetermined hydraulic pressure is supplied to the hydraulic chamber 16, the piston 15 is pressed by a pressing force exceeding the elastic force from the return spring (1) 18. 6 (A) moves from the position (1) toward the back plate 21 and is held at the position (2) by the elastic force from the return spring (1) 18 and the return spring (2) 20. The At this time, the space between the friction plates 13 and 14 is reduced by the pressing force from the piston 15, and a transmission torque equal to or less than a predetermined torque is generated.

  At the time of engagement in which the hydraulic pressure supplied to the hydraulic chamber 16 further increases, the piston 15 moves from the position (2) in a direction closer to the back plate 21 due to the increase in hydraulic pressure. As the hydraulic pressure supplied to the hydraulic chamber 16 increases, the transmission torque between the friction plates 13 and 14 increases. When slip does not occur between the friction plates 13 and 14, or when the slip amount is equal to or less than a predetermined amount, the friction plates 13 and 14 are completely engaged.

  When the hydraulic pressure supplied to the hydraulic chamber 16 is discharged, the pressing force of the piston 15 decreases, so that the piston 15 is moved back by the elastic force from the return spring (1) 18 and the return spring (2) 20. Move away from. When a hydraulic pressure is generated that causes a pressing force larger than the elastic force from the return spring (1) 18 and smaller than the elastic force of the return spring (1) 18 and the return spring (2) 20, the piston 15 is positioned. It will be held in (2). When the hydraulic pressure supplied to the hydraulic chamber 16 is completely discharged, the piston 15 moves to the position (1) by the elastic force of the return spring (1) 18.

  Further, according to the present invention, there is a possibility that the ECU 8000 may perform a shift that requires engagement between the friction plates 13 and 14 based on a physical quantity related to the shift state of the automatic transmission 2000 in the above-described friction engagement device. It is characterized by determining whether or not and controlling the hydraulic pressure supplied to the piston 15 in accordance with the possibility of shifting.

  Specifically, ECU 8000 determines a gear stage that is likely to shift based on the current gear stage based on a physical quantity related to the gear shift state of automatic transmission 2000. For example, ECU 8000 determines that there is a possibility of shifting at most from the shift stage on the first speed increase side to the shift stage on the second speed reduction side based on the current shift speed.

  ECU 8000 performs a shift that requires engagement of friction plates 13 and 14 in each of C1 clutch 3640, C2 clutch 3650, B1 brake 3610, B2 brake 3620, and B3 brake 3630, based on the determined shift speed. Determine whether there is a possibility. The friction engagement device that is engaged when the determined shift speed is formed is determined based on the operation table shown in FIG.

  When the ECU 8000 determines that there is no possibility of shifting that requires engagement of the friction plates 13 and 14, the ECU 8000 generates a pressing force smaller than the reaction force generated in the return spring (1) 18 (that is, the piston 15). The hydraulic pressure supplied to the hydraulic chamber 16 of the piston 15 is controlled so that the hydraulic pressure supplied to the hydraulic chamber 16 received by the piston 15 is discharged. Accordingly, the piston 15 is hydraulically controlled by the ECU 8000 so as to be in the position (1).

  Further, when ECU 8000 determines that there is a possibility of shifting, it is larger than the reaction force generated by return spring (1) 18, and return spring (1) 18 and return spring (2) 20 are generated. The hydraulic pressure supplied to the hydraulic chamber 16 of the piston 15 is controlled so that a pressing force smaller than the resultant force of the reaction force is generated. Accordingly, the piston 15 is hydraulically controlled by the ECU 8000 so as to be in the position (2).

  Further, the ECU 8000 determines whether or not the friction plates 13 and 14 perform a shift requiring engagement based on a physical quantity related to the shift state of the automatic transmission 2000. The hydraulic pressure supplied to the hydraulic chamber 16 of the piston 15 is controlled so that a pressing force larger than the resultant force of the reaction force generated by the spring (1) 18 and the return spring (2) 20 is generated. Therefore, the piston 15 is moved to the back plate 21 side from the position (2) by the ECU 8000.

  In the present embodiment, the “physical quantity related to the shift state of the automatic transmission 2000” is the throttle opening of the electronic throttle valve 8016 and the output shaft rotational speed NO of the automatic transmission 2000, but is particularly limited to this. Instead, for example, the accelerator opening of the accelerator pedal and the rotational speed of the front wheel 7000 may be used.

  FIG. 7 shows a functional block diagram of ECU 8000 which is a control device for the friction engagement device according to the present embodiment.

  ECU 8000 includes an input interface (hereinafter referred to as an input I / F) 300, an arithmetic processing unit 400, a storage unit 500, and an output interface (hereinafter referred to as an output I / F) 600.

  The input I / F 300 includes an engine speed signal from the engine speed sensor 8020, a turbine speed signal from the input shaft speed sensor 8022, an output shaft speed signal from the output shaft speed sensor 8024, and an accelerator opening. The accelerator opening signal from the degree sensor 8010 and the throttle opening signal from the throttle opening sensor 8018 are received and transmitted to the arithmetic processing unit 400.

  Arithmetic processing section 400 includes a shift speed determination section 402, an engagement element determination section 404, a minute pressure control section 406, a shift determination section 408, a release control section 410, and an engagement control section 412.

  The shift speed determination unit 402 determines the current shift speed based on the turbine speed signal and the output shaft speed signal received via the input I / F 300. Specifically, gear stage determination unit 402 calculates a gear ratio based on the ratio between turbine rotational speed NT and output shaft rotational speed NO, and determines the current gear stage based on the calculated gear ratio. .

  The engagement element determination unit 404 determines a gear stage that is likely to shift based on the current gear stage, and determines a friction engagement device that is engaged when the determined gear stage is formed. Specifically, the engagement element determination unit 404 uses a current shift speed as a reference, and at most, a shift speed that may shift from the first speed increase speed to the second speed reduction speed. judge. The engagement element determination unit 404 determines a friction engagement device to be engaged when the determined shift speed is formed.

  For example, when the shift speed determination section 402 determines that the current shift speed is the fourth speed, the engagement element determination section 404 determines whether the current shift speed is the second speed, the third speed, and the fifth speed. It is determined that there is a possibility of shifting. At the fourth speed, as shown in the operation table of FIG. 3, the C1 clutch 3640 and the C2 clutch 3650 are engaged. At the second speed, the C1 clutch 3640 and the B1 brake 3610 are engaged. At the third speed, the C1 clutch 3640 and the B3 brake 3630 are engaged. At the fifth speed, the C2 clutch 3650 and the B3 brake 3630 are engaged. Therefore, the B1 brake 3610 and the B3 brake 3630 are determined as the friction engagement devices that are engaged when a gear stage that is likely to shift is formed. The C1 clutch 3640 and the C2 clutch 3650 are friction engagement devices that are engaged at the current shift speed. For example, the engagement element determination unit 404 may turn on a flag corresponding to the determined friction engagement device.

  The micro pressure control unit 406 controls the hydraulic circuit 4000 so that a predetermined hydraulic pressure A is supplied to the hydraulic chamber 16 of the determined friction engagement device. Specifically, the micro pressure control unit 406 generates control signals for various solenoid valves provided in the hydraulic circuit 4000, and transmits the generated control signals via the output I / F 600. Note that the minute pressure control unit 406 is, for example, hydraulic pressure so that a predetermined hydraulic pressure A is supplied to the hydraulic chamber 16 of the friction engagement device corresponding to the flag turned on in the engagement element determination unit 404. The circuit 4000 may be controlled.

  The “predetermined hydraulic pressure A” is such that the pressing force of the piston 15 toward the back plate 21 exceeds the elastic force of the return spring (1) 18, and the return spring (1) 18 and the return spring (2). The hydraulic pressure is less than the elastic force of 20, and is the hydraulic pressure at which the piston 15 is held at the position (2), and is adapted by experiments or the like. The predetermined oil pressure A is preferably an oil pressure that generates a transmission torque equal to or less than a predetermined torque that does not affect the deterioration of fuel consumption between the friction plates 13 and 14.

  The shift determination unit 408 determines whether or not to shift based on the throttle opening signal, the output shaft rotational speed signal received via the input I / F 300, and the shift diagram stored in the storage unit 500. To do. Specifically, in the shift diagram, a downshift line and an upshift line to each shift stage adjacent to each shift stage are set in advance. The shift determination unit 408 identifies a position on the shift diagram based on the throttle opening and the output shaft rotational speed, and determines the shift when the identified position crosses the downshift line or the upshift line. Note that the shift determination unit 408 determines to shift to a shift stage corresponding to the position specified on the shift diagram.

  When it is determined that the gear shift is to be performed, the release control unit 410 is hydraulically operated so that the friction engagement device corresponding to the current gear position and not corresponding to the gear position after the gear shift is released. To control. Specifically, the release control unit 410 controls the various solenoid valves included in the hydraulic circuit 4000 so that the hydraulic pressure supplied to the hydraulic chamber of the friction engagement device that does not correspond to the gear stage after the shift is lowered. A signal is generated, and the generated control signal is transmitted via the output I / F 600. The release control unit 410 may be lowered until the piston 15 reaches the hydraulic pressure held at the position (2), and the friction engagement device may be required to be engaged at the shift stage after the shift. If it is determined that there is no possibility, the hydraulic pressure supplied to the hydraulic chamber 16 may be discharged. At this time, the piston 15 may be held at the position (1), and the mode of the hydraulic pressure reduction control at the time of release is not particularly limited. Also good.

  The engagement control unit 412 controls the hydraulic pressure supplied to the hydraulic chamber 16 so that the friction engagement device corresponding to the determined gear position after the shift is engaged. Specifically, the engagement control unit 412 is provided in the hydraulic circuit 4000 so that the hydraulic pressure supplied to the hydraulic chamber 16 of the friction engagement device corresponding to the determined gear position after the shift is further increased. Control signals for the various solenoid valves to be generated are generated, and the generated control signals are transmitted via the output I / F 600. In the present embodiment, the manner of increasing the hydraulic pressure during engagement is not particularly limited, but may be controlled linearly, for example.

  In the present embodiment, the shift speed determination unit 402, the engagement element determination unit 404, the minute pressure control unit 406, the shift determination unit 408, the release control unit 410, and the engagement control unit 412 are: In any case, the CPU (Central Processing Unit), which is the arithmetic processing unit 400, will be described as functioning as software realized by executing a program stored in the storage unit 500. May be. Such a program is recorded on a storage medium and mounted on the vehicle.

  Various information, programs, threshold values, maps, and the like are stored in the storage unit 500, and data is read or stored from the arithmetic processing unit 400 as necessary.

  Hereinafter, with reference to FIG. 8, a control structure of a program executed by ECU 8000 which is the control device of the friction engagement device according to the present embodiment will be described.

  In step (hereinafter, step is referred to as S) 100, ECU 8000 determines the current gear position. In step S102, the ECU 8000 determines a gear stage that is likely to shift based on the current gear stage, and determines a friction engagement device that may be engaged at the next gear shift.

  In step 104, the ECU 8000 sends a control signal indicating a predetermined control value corresponding to the predetermined hydraulic pressure A to the hydraulic circuit for the friction engagement device that has been determined to be engaged. Output to various solenoid valves provided at 4000.

  In S106, ECU 8000 determines whether or not a shift is performed based on the throttle opening, output shaft rotational speed NO, and shift diagram. If a shift is performed (YES in S106), the process proceeds to S108. If not (NO in S106), the process returns to S106.

  In S108, ECU 8000 performs release control on the friction engagement device released by the shift. In S110, ECU 8000 performs engagement control on the friction engagement device engaged by the shift.

  The operation of ECU 8000, which is the control device for the friction engagement device according to the present embodiment, based on the above-described structure and flowchart will be described.

  For example, if it is determined that the current gear position is the fourth gear (S100), the gears that are likely to shift next are based on the operation table shown in FIG. It is determined that the fifth gear is selected. Therefore, it is determined that the friction engagement devices that may be engaged next are the B1 brake 3610 and the B3 brake 3630 (S102). Therefore, the minute pressure control is performed so that the predetermined hydraulic pressure A is supplied to the hydraulic chamber 16 of the B1 brake 3610 and the B3 brake 3630 (S104). Therefore, the pistons 15 in the B1 brake 3610 and the B3 brake 3630 are moved to the position (2). Further, since no hydraulic pressure is supplied to the B2 brake 3620, the piston 15 of the B2 brake 3620 is held at the position (1). Furthermore, hydraulic pressure is supplied to the hydraulic chamber 16 so that the C1 clutch 3640 and the C2 clutch 3650 are maintained in the engaged state.

  If it is determined based on the throttle opening, the output shaft rotational speed, and the shift diagram that downshifting to the third gear (YES in S106), the C2 clutch 3650 is controlled to be released (S108). ), The B3 brake 3630 is controlled to be engaged (S110). Before the shift, the B3 brake 3630 is held at the position (2), so that the moving distance of the piston 15 at the time of engagement is shorter than that at the position (1). Further, since the piston 15 of the B2 brake 3620 is held at the position (1), the drag torque generated in the B2 brake 3620 is reduced as compared with the case of the position (2).

  As described above, according to the friction engagement device and the control device thereof according to the present embodiment, the position of the piston is moved to the position (1) by the urging force according to the expansion / contraction amount of the return spring (1). Can do. When the position of the piston is the position (1), no pressing force is applied to the friction plate. Therefore, the generation of drag torque between the friction plates can be suppressed. Thereby, deterioration of fuel consumption can be suppressed.

  Further, the position of the piston can be moved to the position (2) according to the hydraulic control supplied to the hydraulic chamber by the biasing force according to the expansion / contraction amount of the return spring (1) and the return spring (2). When the position of the piston is the position (2), the moving distance of the piston to the position of the piston where the friction plates are in the fully engaged state is shorter than when the position is the position (1). Therefore, compared with the case where the piston moves from the position (1) to a position where the piston is completely engaged, the responsiveness when the friction plate is engaged can be improved.

  Further, due to the return spring (1) and the return spring (2), the characteristics of the reaction force against the pressing force of the piston can be obtained when the piston is at a position closer to the engagement side than the position (1) and from the position (2). Also, it can be made different depending on the position on the engagement side. That is, since the reaction force is larger when it is on the engagement side than the position (1), until the position (1) is changed to the position (2), the piston is moved according to the moving distance. Since the reaction force is weak, the position of the piston can be accurately controlled up to position (2). Further, when the position of the piston reaches the position (2), the moving distance to the position where the piston is completely engaged is shortened, so that the response can be improved and the return spring (1) and The space between the friction plates can be widened with good responsiveness by the reaction force of the return spring (2). Therefore, it is possible to provide a friction engagement device for an automatic transmission that achieves both improvement in responsiveness during engagement and reduction in drag torque.

  Further, by setting the position (2) to a position where the transmission torque between the friction plates is equal to or less than a predetermined torque, the piston is held at a position where unnecessary drag torque is not generated while emphasizing responsiveness. Can do.

  Further, when there is no possibility of shifting, the hydraulic pressure supplied to the piston is controlled so that the position of the piston becomes the position (1). Becomes longer. At this time, since the pressing force applied from the piston to the friction plate is reduced, the drag torque generated between the friction plates can be reduced. Therefore, deterioration of fuel consumption can be suppressed.

  Further, when there is a possibility of shifting, the hydraulic pressure supplied to the piston is controlled so that the position of the piston becomes the position (2). Becomes shorter. At this time, since the time until the friction plate is brought into the fully engaged state is shortened, the response at the time of engagement can be improved.

  Therefore, it is possible to provide a control device for a frictional engagement device that achieves both improvement in engagement responsiveness and reduction in drag torque.

  Furthermore, the piston of the friction engagement device is determined based on the current shift speed as a reference and a shift speed that is likely to shift is determined, and it is determined that there is a possibility of performing a shift that requires engagement at the determined shift speed. By setting the position of the position to position (2), it is possible to improve the responsiveness of engagement when shifting to the determined shift speed. Thereby, the shift time can be shortened. On the other hand, the piston position of the frictional engagement device that corresponds to the shift stage determined not to shift and that is determined not to shift requiring engagement is set to position (1). Thus, drag torque generated between the friction plates can be reduced. Therefore, deterioration of fuel consumption can be suppressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic block diagram which shows the power train controlled by ECU which is a control apparatus which concerns on embodiment of this invention. It is a skeleton figure which shows the gear train in an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a figure which shows the cross section of an automatic transmission. It is sectional drawing which shows the structure of the friction engagement apparatus which concerns on this Embodiment. It is a figure which shows operation | movement of the friction engagement apparatus which concerns on this Embodiment. It is a functional block diagram of ECU which is a control apparatus of the friction engagement apparatus which concerns on this Embodiment. It is a flowchart which shows the control structure of the program performed with ECU which is a control apparatus of the friction engagement apparatus which concerns on this Embodiment.

Explanation of symbols

  12 Inner circumferential surface, 13, 14 Friction plate, 15 Piston, 16 Hydraulic chamber, 18, 20 Return spring, 21 Back plate, 23, 24 End face, 27 Hook, 31 Snap ring, 201 Central axis, 300 Input I / F , 400 arithmetic processing unit, 402 shift speed determination unit, 404 engagement element determination unit, 406 micro pressure control unit, 408 shift determination unit, 410 release control unit, 412 engagement control unit, 500 storage unit, 600 output I / F , 1000 engine, 2000 automatic transmission, 3000 planetary gear unit, 3100 input shaft, 3200 torque converter, 3210 output shaft, 3300 1st set, 3310 sun gear S (UD), 3320 pinion gear, 3330 ring gear R (UD), 3340 carrier C UD), 3400 2nd set, 3410 Sun gear S (D), 3420 Short pinion gear, 3422 Carrier C (1), 3430 Long pinion gear, 3432 Carrier C (2), 3440 Sun gear S (S), 3450 Ring gear R (1) (R (2)), 3500 output gear, 3600 gear case, 3610 B1 brake, 3620 B2 brake, 3630 B3 brake, 3640 C1 clutch, 3650 C2 clutch, 3660 one-way clutch F, 4000 hydraulic circuit, 5000 differential gear, 6000 drive shaft 7000 Front wheel, 8000 ECU, 8002 Vehicle speed sensor, 8004 Shift lever, 8006 Position switch, 8008 Accelerator pedal, 8010 Accelerator position Sa, 8012 brake pedal, 8014 stroke sensor, 8016 electronic throttle valve, 8018 throttle opening sensor, 8020 engine speed sensor, 8022 input shaft rotational speed sensor, 8024 output shaft speed sensor.

Claims (16)

A friction engagement device for an automatic transmission for engaging a first friction member on an input side and a second friction member on an output side by a pressing force of a piston operated by hydraulic pressure supplied from a supply source,
Since the position of the piston is such that the pressing force is not applied to the first friction member and the second friction member from the position where the first friction member and the second friction member are completely engaged. First reaction force generating means for generating a reaction force against the piston in a direction in which the distance between the first friction member and the second friction member is increased until the position becomes 1.
The position of the piston is a reaction force against the piston in the direction in which the interval is increased until the piston is moved to the second position closer to the direction in which the interval is narrower than the first position. And a second reaction force generating means for generating the friction engagement device for an automatic transmission.   The second position is a position between the first friction member and the second friction member in addition to the position where the piston is narrower than the first position. The friction engagement device for an automatic transmission according to claim 1, wherein the transmission torque is a position that is equal to or less than a predetermined torque.   2. The automatic according to claim 1, wherein the first reaction force generation unit and the second reaction force generation unit are elastic members provided so that an urging force corresponding to an amount of expansion and contraction is generated in a direction in which the interval is widened. A friction engagement device for a transmission.   The friction engagement device for an automatic transmission according to claim 3, wherein the first reaction force generation means and the second reaction force generation means are springs having different spring constants.   The characteristic of the reaction force with respect to the pressing force of the piston by the first reaction force generation means and the second reaction force generation means is that the piston is located closer to the engagement side than the first position. The frictional engagement device for an automatic transmission according to any one of claims 1 to 4, wherein the frictional engagement device is different between the first position and the second position.   When the piston is located closer to the engagement side than the second position, the first reaction force generating means and the second position are more likely to be located closer to the engagement side than the first position. 6. The friction engagement device for an automatic transmission according to claim 5, wherein a reaction force generated by the reaction force generating means is increased. A control device for a friction engagement device provided in an automatic transmission, wherein the friction engagement device is engaged by an input side first friction member engaged by a pressing force of a piston operated by a hydraulic pressure supplied from a supply source. And the position of the second friction member on the output side and the piston changes from the position where the first friction member and the second friction member are completely engaged to a first position determined in advance. The first reaction force generator that generates a reaction force against the piston in the direction in which the distance between the first friction member and the second friction member is increased, and the position of the piston A second reaction force generation that generates a reaction force against the piston in a direction in which the interval widens from a position in a combined state to a second position closer to the direction in which the interval is narrower than the first position. Including
Detecting means for detecting a physical quantity related to a shift state of the automatic transmission;
Determination means for determining whether or not there is a possibility of shifting that requires engagement between the first friction member and the second friction member based on the detected physical quantity;
A first hydraulic control means for controlling the hydraulic pressure supplied to the piston so that the piston is in a first position when it is determined that there is no possibility of shifting;
And a second hydraulic control means for controlling the hydraulic pressure supplied to the piston so that the piston is in the second position when it is determined that there is a possibility of shifting. Control device of combined device. The first position is a position where the pressing force is not applied to the first friction member and the second friction member,
The second position is a position closer to the direction in which the gap is narrower than the first position, and the first friction member and the second friction member are not fully engaged. The friction engagement device control device according to claim 7, wherein the control device is a position where a transmission torque between the first friction member and the second friction member is equal to or less than a predetermined torque. . The first hydraulic pressure control means includes means for controlling the hydraulic pressure supplied to the piston such that a pressing force smaller than the reaction force generated by the first reaction force generator is generated in the piston. ,
The second hydraulic pressure control means is larger than a reaction force generated by the first reaction force generation unit and more than a reaction force generated by the first reaction force generation unit and the second reaction force generation unit. 9. The control device for a friction engagement device according to claim 7, further comprising means for controlling a hydraulic pressure supplied to the piston so that a smaller pressing force is generated in the piston. The controller is
Means for determining whether or not to perform a shift that requires engagement between the first friction member and the second friction member based on the detected physical quantity;
When it is determined that the speed is changed, the hydraulic pressure supplied to the piston is increased so that a pressing force larger than the reaction force generated by the first reaction force generation unit and the second reaction force generation unit is generated. 10. The control device for a friction engagement device according to claim 9, further comprising means for controlling. The automatic transmission is a stepped automatic transmission in which any one of a plurality of shift stages is formed by a combination of engagement and release of a plurality of friction engagement devices,
The determination means includes
Means for determining a gear stage that is likely to shift based on the current gear stage based on the detected physical quantity;
Whether or not there is a possibility of performing a shift requiring engagement between the first friction member and the second friction member in each of the plurality of friction engagement devices based on the determined shift speed. The control device for a friction engagement device according to any one of claims 7 to 10, further comprising means for determining   The determination means includes means for determining, from the current gear position as a reference, at most a gear position on the first speed increasing side to a gear position on the second speed reducing side as the gear speed that is likely to shift. The control device for a friction engagement device according to claim 11.   The said 1st reaction force generation part and the said 2nd reaction force generation part are any elastic members provided so that the urging | biasing force according to the expansion-contraction amount may arise in the direction where the said space | interval expands. A control device for the frictional engagement device according to claim 1.   The control device for a friction engagement device according to claim 13, wherein the first reaction force generation unit and the second reaction force generation unit are springs having different spring constants.   The characteristic of the reaction force with respect to the pressing force of the piston by the first reaction force generation means and the second reaction force generation means is that the piston is located closer to the engagement side than the first position. The controller for a frictional engagement device according to any one of claims 7 to 14, wherein the control unit is configured to be different from a case where it is positioned closer to the engagement side than the second position.   When the piston is located closer to the engagement side than the second position, the first reaction force generating means and the second position are more likely to be located closer to the engagement side than the first position. The control device for a frictional engagement device according to claim 15, wherein a reaction force generated by the reaction force generating means is increased.

Images