JP2008014457A - Device for reducing vehicle vibration - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce vehicle vibration in a relatively low speed/low shift stage region in a lockup-on condition, without changing the gear ratio of a gear shifter. <P>SOLUTION: The vehicle vibration reducing device is mounted with a fluid transmission device 51 having a lockup clutch 64, and the gear shifter 52 for stepwisely shifting gears with the selective fastening operation of friction fastening elements 67-71. It comprises a quasi-interlock means using a predetermined torque capacity for semi-fastening interlock elements 69, 71 as the other friction fastening elements to be interlocked with the fastening operation, than the friction fastening elements required to achieve a current shift stage, and a vibration detecting means 36 for detecting the vehicle vibration. When the vehicle vibration is at a predetermined value or greater, quasi-interlock is executed for a predetermined period to actuate the quasi-interlock means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle vibration reduction device. In particular, the present invention relates to a vibration reducing device that reduces single-shot vehicle vibration caused by rapid accelerator operation.

  Conventionally, a vehicle equipped with a fluid transmission device having a lock-up clutch is well known and widely used. The fluid transmission device is a device that transmits power via a fluid, such as a torque converter or a fluid coupling (fluid coupling). Since the fluid transmission device allows a speed difference to be generated between its input and output shafts, the fluid transmission device is frequently used as a device that is provided between an engine and a transmission and realizes a stopped state or an extremely low vehicle speed state, for example.

  In addition, the fluid transmission device has an action (buffer action) for smooth transmission by reducing rotational fluctuations and torque fluctuations between the input and output shafts. This buffering action is effective in reducing vehicle vibration and improving ride comfort.

  On the other hand, the fluid transmission device also has a side in which transmission efficiency is reduced due to fluid slip because of the structure in which power is transmitted via a fluid. A decrease in transmission efficiency is not preferable because it hinders improvement in fuel consumption. Therefore, as a countermeasure, a device having a lockup (L / U) mechanism is often used. The L / U mechanism is a mechanism that directly connects the input shaft and the output shaft of the fluid transmission device by an L / U clutch. When the L / U clutch is engaged, that is, when the L / U is on, torque is transmitted at a constant speed via the L / U clutch rather than fluid. Therefore, the reduction in the transmission efficiency is eliminated, and a great effect is exhibited in improving the fuel consumption.

  From the standpoint of improving fuel consumption, it is preferable that the L / U is on in the widest possible travel region other than the stopped state or the extremely low vehicle speed state. On the other hand, it is preferable that L / U is off from the viewpoint of improving vehicle comfort by reducing vehicle vibration. Conventionally, L / U is off in the low vehicle speed / low speed range where the vehicle vibration is relatively problematic, and L / U is on in the high vehicle speed / high speed range.

  However, in recent years, there has been an increasing demand for improvement in fuel consumption, and there is a strong demand to expand the L / U ON range to lower vehicle speed and lower gear position. In this case, there is a vibration called a chip-in / chip-out shock as described below.

  When the accelerator is operated rapidly, the output torque of the engine changes suddenly and impulse excitation occurs. This induces torsional resonance of the power transmission system (drive system) including the transmission. This torsional resonance causes longitudinal vibrations in the vehicle. In this specification, this type of vehicle vibration is referred to as a tip-in shock or a tip-out shock. A tip-in shock is generated during an operation for increasing the accelerator opening, and a tip-out shock is generated during an operation for decreasing the accelerator opening. The chip-in / chip-out shock is a general term for these.

  The chip-in / chip-out shock is a problem particularly in the low vehicle speed / low speed range regions, but conventionally it has been skillfully avoided by the L / U-off buffering action. However, it is necessary to reduce the tip-in / chip-out shock in the L / U on state in order to ensure a good riding comfort while expanding the L / U on region in response to the demand for fuel efficiency improvement.

As a technique for reducing the chip-in / chip-out shock in the L / U on state, for example, one disclosed in Patent Document 1 is known. This device feedback-controls engine output and a gear ratio in a direction in which vibration is canceled in a vehicle equipped with a continuously variable transmission (corresponding to an L / U on state) directly connected to an engine.
JP 2001-132501 A

  However, the technique disclosed in Patent Document 1 includes a vehicle not equipped with a continuously variable transmission, for example, an automatic transmission that selects and selects a specific shift speed from a plurality of fixed shift speeds (so-called multi-speed transmission). There is a problem that it is difficult to apply to a vehicle equipped with. This is because a multi-stage transmission cannot take an intermediate gear ratio between the respective gear stages, and the gear ratio cannot be finely adjusted.

  The present invention has been made in view of the above circumstances, and it is possible to detect vehicle vibration (chip-in / chip-out shock) in a relatively low vehicle speed / low gear range in the L / U on state, and to change the gear ratio of the transmission. It is an object of the present invention to provide a vehicle vibration reduction device that can be reduced without being changed.

  According to a first aspect of the present invention for solving the above-mentioned problem, a fluid transmission device having a lock-up clutch and one or more frictional engagement elements selected from a plurality of frictional engagement elements are fastened and shifted in stages. A vehicle equipped with a transmission, which reduces vibrations generated by a rapid change in input torque to the fluid transmission device when the vehicle is in a predetermined low vehicle speed state and the lockup clutch is in a power transmission state. In a vibration reduction device, a quasi-interlock that half-engages an interlock element, which is a frictional engagement element that becomes an interlock when engaged, other than the frictional engagement element necessary to achieve the current gear position at a predetermined torque capacity. And a vibration detecting means for detecting the vibration of the vehicle, and the quasi-interlock means is operated when the vibration of the vehicle is a predetermined value or more. And executes a predetermined period quasi interlock.

  Note that when the lockup (L / U) clutch is in the power transmission state, not only when the L / U clutch is completely engaged (complete L / U) but also a slight speed difference (slip) ) Including the case of the fastening state (weak L / U) that allows

  According to a second aspect of the present invention, in the vehicle vibration reducing device according to the first aspect, the torque capacity of the interlock element at the time of execution of the quasi-interlock increases as the input torque fluctuation to the transmission increases. It is set so that it may become.

  According to a third aspect of the present invention, in the vehicle vibration reduction device according to the first or second aspect, the vibration detection means is torque-related information detection means for detecting information related to transmission torque at a predetermined position on the power transmission system. The quasi-interlock period, which is a predetermined period during which the quasi-interlock is executed, is included in the period from the first torque trough to the next torque peak of the torque vibration based on the detection value of the torque-related information detecting means. It is set so that it may be set.

  According to a fourth aspect of the present invention, in the vehicle vibration reducing device according to the third aspect, the start time of the quasi-interlock period is a first predetermined time from a reference time that is a peak time of torque before the first torque trough. It is a point in time, and the release point is a point in time at which a second predetermined time has passed from the reference point.

  According to a fifth aspect of the present invention, in the vehicle vibration reducing device according to the third or fourth aspect, the quasi-interlock period is longer as the gear position is lower.

  According to a sixth aspect of the present invention, in the vehicle vibration reduction device according to any one of the third to fifth aspects, the torque-related information detecting means detects an input rotational speed for detecting the input rotational speed to the transmission. Including the detecting means, the time point of the trough of the torque vibration and the time point of the peak are calculated based on the input rotational acceleration which is the time change rate of the input rotational speed.

  According to the first aspect of the present invention, as described below, the vibration (chip-in / chip-out shock) in the relatively low vehicle speed / low speed range in the L / U on state is caused to change the gear ratio of the transmission. Can be reduced.

  The present invention appropriately controls a phenomenon called an interlock (sometimes called an internal lock or a double lock) in a general multi-stage transmission, and is used for vibration reduction. Interlock is a well-known phenomenon in which all or a part of the torque input to the transmission is internally circulated in the transmission and the output torque cannot be obtained or reduced from the original value. For example, the interlock occurs when the frictional engagement element that should be released at the selected gear position is engaged or semi-engaged. This frictional engagement element that becomes an interlock when fastened is referred to as an interlock element in this specification.

  If an interlock occurs during normal driving, the driving force cannot be obtained or decreased, which is not desirable. The present invention aims to reduce the vibration of the vehicle by utilizing the interlock, which is an originally undesirable phenomenon. In this specification, an appropriately controlled interlock that can be used to reduce vehicle vibration is referred to as a quasi-interlock to distinguish it from a normal interlock. Specifically, the quasi-interlock means that the interlock element is semi-fastened with a predetermined appropriate torque capacity, and that means is called quasi-interlock means in this specification.

  As described above, since the chip-in / chip-out shock is a vibration involving the torsional resonance of the drive system, the transmission torque of the drive system vibrates greatly during the occurrence of the chip-in / chip-out shock. In other words, it rapidly increases and decreases. According to the present invention, this rapid increase in transmission torque can be suppressed by the quasi-interlock. Accordingly, the torsional resonance of the drive system can be weakened and the damping can be promoted, so that the chip-in / chip-out shock can be effectively reduced.

  According to the second aspect of the present invention, as will be described below, a quasi-interlock having an appropriate strength can be performed according to the magnitude of vibration.

  The magnitude of the chip-in / chip-out shock (vibration amplitude) increases as the input torque fluctuation to the transmission increases. On the other hand, if the torque capacity of the interlock element at the time of executing the quasi-interlock is increased, the effect of the quasi-interlock is increased. That is, stronger quasi-interlock can be performed.

  From the above, according to the present invention, the stronger the quasi-interlock is performed when the input torque fluctuation to the transmission is large and the chip-in / chip-out shock is large, the appropriate vibration corresponding to the magnitude of the vibration A reduction effect can be obtained.

  According to the invention of claim 3, as described below, an effective vibration suppressing effect can be obtained.

  Since the quasi-interlock acts in the direction of reducing the transmission torque, in order to effectively suppress the vibration (repetition of increase and decrease) of the transmission torque, the quasi-interlock is being increased (torque trough). It is desirable to execute during the period from the peak of the torque to the next peak of the torque, and not during the decrease (the period from the peak of the torque to the next peak of the torque).

  In general, the chip-in / chip-out shock is a damped vibration, and the amplitude is larger as the vibration is started. Therefore, the transmission torque increases greatly from the first torque trough to the next torque peak.

  According to the present invention, since the quasi-interlock is performed during the period in which the transmission torque increase width is large, the transmission torque reduction allowance can be increased. That is, a great vibration reduction effect can be obtained.

  The most effective is to execute the quasi-interlock over the entire period from the torque valley to the next torque peak, but even if it is executed during a part of the period, a certain effect can be obtained. it can.

  Moreover, you may perform a semi-interlock in multiple times. In that case, the first quasi-interlock is executed from the first torque trough to the next torque peak, and then the quasi-interlock is stopped at least during the decrease of the transmission torque, and then from the next torque trough. The second quasi-interlock may be executed until the peak of the torque. The same applies to the third and subsequent times.

  According to the fourth aspect of the present invention, as will be described below, the quasi-interlock can be executed over as long a period as possible in the period from the valley of the torque to the next peak.

  As described above, the quasi-interlock is most desirably executed over the entire period from the torque valley to the next peak. However, even if the operation of the quasi-interlock is started at the same time when the torque valley is detected, there is a time lag until the operation of the quasi-interlock is actually obtained due to the operation delay of the quasi-interlock means. End up. Similarly, even if the quasi-interlock release operation is started at the same time as the torque peak is detected, a time lag actually occurs, and the quasi-interlock action is exerted until the transmission torque is reduced.

  Therefore, according to the present invention, even when there is such a time lag, the quasi-interlock period can be made as ideal as possible. In the present invention, the quasi-interlock is started after the first predetermined time has elapsed from the reference time, which is the peak time of the torque, and is released after the second predetermined time has elapsed. By setting the first predetermined time and the second predetermined time in advance to appropriate values (each time near the torque trough and the peak), the quasi-interlock start time is detected when the reference time is detected. And stop time can be set. Therefore, it is possible to substantially start and release the quasi-interlock at an optimal time, considering a time lag in advance.

  The optimal first predetermined time and second predetermined time may be set as follows specifically. The transmission torque of the drive system when a chip-in / chip-out shock occurs is damped and oscillated at a frequency unique to the gear position. Therefore, the vibration period can be obtained in advance by experiments or the like. The period from the peak of torque vibration to the next valley is half of the vibration period, that is, a half period. In order to make the starting point of the quasi-interlock a torque valley, this half cycle is set as the first predetermined time, and a correction considering a time lag or the like may be added as necessary.

  Similarly, the period from the peak of torque vibration to the next peak after the passage of the next valley (first predetermined time) is one vibration period. In order to make the torque release peak when the quasi-interlock is released, this one period may be set as the second predetermined time, and correction may be made in consideration of a time lag as necessary.

  According to the fifth aspect of the present invention, as described below, an appropriate quasi-interlock period can be set according to the gear position. As described above, the transmission torque of the drive system when a chip-in / chip-out shock occurs attenuates and vibrates at a frequency unique to the gear position, but the frequency decreases as the gear position becomes lower. That is, the lower the gear position, the longer the vibration period. Therefore, the first predetermined time and the second predetermined time can be set to appropriate values according to the gear position by setting the longer time as the gear position is lower.

  According to the sixth aspect of the present invention, as will be described below, highly accurate torque-related information can be obtained with a simple structure. Further, in the case of a transmission originally provided with an input rotation speed detection means, the input rotation speed detection means can be used as a torque related information detection means without separately providing a new detection means.

  The torque related information detection means detects information related to the transmission torque at a predetermined position on the power transmission system. As this information, the most direct information is the transmission torque itself, and the torque related information detection means. For example, torque detecting means such as a torque sensor can be used. However, there are other means for detecting information related to transmission torque. For example, since torque and rotational acceleration are closely related, rotational acceleration detection means such as a rotational acceleration sensor can also be torque-related information detection means. Further, since the rotational acceleration is a rate of change of the rotational speed with time, the rotational acceleration can be detected by detecting the rotational speed and performing a time differentiation or processing corresponding thereto. That is, a rotational speed detecting means such as a rotational speed sensor can also be a torque related information detecting means.

  In the present invention, as the torque related information detecting means, an input rotational speed detecting means for detecting an input rotational speed to the transmission is used among the rotational speed detecting means. The input rotational speed becomes the highest rotational speed among the transmissions at a low gear position where a chip-in / chip-out shock is a problem. Therefore, it is easy to obtain high detection accuracy for the input rotation speed. Many transmissions are provided with highly accurate input rotation speed detection means (for example, a turbine rotation speed sensor) for the shift control. In such a case, according to the present invention, the existing input rotation speed detecting means can be used as the torque related information detecting means without separately providing new detecting means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a drive system including an automatic transmission according to an embodiment of the present invention. The input shaft 3 of the automatic transmission 50 is connected to an engine crankshaft (engine output shaft) (not shown). The automatic transmission 50 includes a torque converter 51 (fluid transmission) connected to the input shaft 3 and a multi-stage transmission mechanism 52 (transmission) connected to a turbine shaft 59 that is an output shaft of the torque converter 51. The plurality of friction elements 67 to 71 included therein are fastened in an appropriate combination to shift the speed stepwise (four forward steps and one reverse step).

  The torque converter 51 includes a pump cover 53 connected to the input shaft 3, a pump impeller 54 formed integrally with the pump cover 53, a turbine (turbine liner) 55 installed so as to face the pump impeller 54, In the meantime, a stator 58 attached to a case 57 via a one-way clutch 56 is provided. The space in the pump cover 53 is filled with oil (working oil, also referred to as ATF) as a working fluid, and the driving force of the pump impeller 54 is transmitted to the turbine 55 through the working oil. ing. The driving force is transmitted to the multi-stage transmission mechanism 52 via the turbine shaft 59 connected to the turbine 55.

  A disk-like lockup (L / U) clutch 64 is provided between the pump cover 53 of the torque converter 51 and the turbine 55. The L / U clutch 64 rotates integrally with the turbine shaft 59 and is movable in the axial direction thereof. A hollow disc-shaped friction material is affixed near the outer edge of the surface of the L / U clutch 64 facing the pump cover 53.

  When the L / U clutch 64 is moving away from the pump cover 53, the L / U clutch 64 is in a released state (L / U off). When L / U is off, relative rotation between the pump impeller 54 and the turbine 55 is allowed, and torque is transmitted from the pump impeller 54 to the turbine 55 via the internal ATF.

  On the other hand, when the L / U clutch 64 moves to the pump cover 53 side and the friction material of the L / U clutch 64 is pressed against the pump cover 53, the lockup clutch 64 is in the engaged state (L / U on). . When L / U is on, the L / U clutch 64 and the pump cover 53 rotate together, so the input shaft 3 and the turbine shaft 59 also rotate together. That is, the input shaft 3 and the turbine shaft 59 are directly connected.

  L / U on / off is controlled by the pressure difference of ATF acting on the plate surface of the L / U clutch 64. That is, the hydraulic pressure control mechanism 20 described later is controlled by the hydraulic pressure supplied to and discharged from the torque converter 51.

  A hollow rotary shaft 60 is connected to the pump impeller 54, and an oil pump 61 is attached to the rear end portion (end portion on the opposite side of the input shaft 3) of the shaft 60. The oil pump 61 is a hydraulic pressure generation source of the hydraulic mechanism of the automatic transmission 50.

  The multi-stage transmission mechanism 52 includes first and second planetary gear mechanisms 65 and 66 and a fastening element (a plurality of friction elements 67 to 71 such as a clutch plate and a band brake) for switching a power transmission path including the planetary gear mechanisms 65 and 66. And a one-way clutch 72), and a predetermined gear position is realized by a combination of fastening and releasing of these fastening elements 67 to 72.

  The first and second planetary gear mechanisms 65 and 66 are respectively arranged around the sun gears 65a and 66a and the sun gears 65a and 66a, and a plurality of (for example, three) planetary gears 65b, 66b, carriers 65c and 66c that support the planetary gears 65b and 66b, and ring gears 65d and 66d that are disposed so as to surround the planetary gears 65b and 66b and mesh with the planetary gears 65b and 66b. The ring gear 65d of 65 and the carrier 66c of the second planetary gear mechanism 66 are connected, and the carrier 65c of the first planetary gear mechanism 65 and the ring gear 66d of the second planetary gear mechanism 66 are connected, and each planetary gear mechanism. 65 and 66 can be interlocked.

  The friction element includes a forward clutch 67 interposed between the turbine shaft 59 and the sun gear 65a of the first planetary gear mechanism 65, and a reverse clutch 68 interposed between the turbine shaft 59 and the sun gear 66a of the second planetary gear mechanism 66. A 3-4 clutch 69 interposed between the turbine shaft 59 and the carrier 66c of the second planetary gear mechanism 66, a 2-4 brake 70 for fixing the sun gear 66a of the second planetary gear mechanism 66, and the first planetary gear. A ring gear 65d of the gear mechanism 65 and a low reverse brake 71 for fixing the carrier 66c of the second planetary gear mechanism 66. Further, the one-way clutch 72 only allows rotation in one direction (the driving direction of the input shaft 3) of the ring gear 65d and the carrier 66c (unlocking), and locks it so as not to rotate in the reverse direction. These fastening elements 67 to 72 are intermittently connected, and the power transmission path connected to the output gear 73 is changed or disconnected.

  As the output gear 73 rotates, the driving force is transmitted to the left and right axles 78 and 79 via the driving wheel side, that is, the transmission gears 74, 75 and 76 and the differential mechanism 77. . The axles 78 and 79 are configured to rotate integrally with a wheel (drive wheel) (not shown).

  In addition, fixing here means integrating with the fixed member (case 57 or what was integrated with this).

  The case 57 is provided with a turbine rotation speed sensor 36 (input rotation speed detection means) that detects the rotation speed of the turbine shaft 59 (turbine rotation speed). Specifically, the turbine rotation speed sensor 36 is provided in a state of facing the outer peripheral surface of the forward clutch 67 that rotates integrally with the turbine shaft 59, and is a spline-like shape provided on the drum outer peripheral surface of the forward clutch 67. The turbine rotation speed is detected by detecting a periodic change of the induced voltage caused by the unevenness being displaced by the rotation of the drum.

  FIG. 2 is a schematic control block diagram of the automatic transmission 50. The automatic transmission 50 is controlled by electrically controlling a hydraulic control mechanism 20 that directly supplies and discharges hydraulic pressure to and from the torque converter 51 and the friction elements 67 to 71 and a plurality of solenoid valves 25 included in the hydraulic control mechanism 20. The control unit 2 to be used is a core part. The control unit 2 includes a computer having a CPU, a ROM, a RAM, and the like. Specifically, a program stored in advance in the ROM (or RAM) is executed by the CPU, so that the hydraulic control mechanism 20 The solenoid valve 25 and the like are controlled. In addition to the turbine rotational speed sensor 36 described above, the control unit 2 includes an engine rotational speed sensor 30 that detects the engine rotational speed, a vehicle speed sensor 38 that detects the vehicle speed, and an accelerator opening sensor 40 that detects the amount of accelerator depression by the driver. A signal from a throttle opening sensor 42 for detecting the throttle opening of the engine is input. A signal from an oil temperature sensor 27 that is provided in the hydraulic control mechanism 20 and detects the temperature of the hydraulic oil (ATF temperature) is input.

  In the control unit 2, for example, a shift schedule for determining whether or not there is a gear position and L / U is set and stored using parameters such as vehicle speed, accelerator opening, or ATF temperature as a parameter. The control unit 2 refers to the shift schedule and various detection signals, and determines the optimum gear position for the driving state. A predetermined drive signal is output to each solenoid valve 25 of the hydraulic control mechanism 20 in order to achieve the gear position.

  Further, the control unit 2 sets the working hydraulic pressure (line pressure) of the hydraulic control mechanism 20 to an optimum value according to the operating state, and outputs a drive signal to the line pressure control solenoid valve 25.

  Furthermore, the control unit 2 functionally includes a semi-interlock control unit 10. The semi-interlock control unit 10 performs semi-interlock control, which will be described in detail later, as necessary.

  In addition to the solenoid valve 25 and the oil temperature sensor 27 shown in the figure, the hydraulic control mechanism 20 incorporates various pressure regulating valves and switching valves not shown. The hydraulic control mechanism 20 regulates the pressure of the ATF supplied from the oil pump 61 with a line pressure regulating valve so that the pressure of the ATF becomes a predetermined line pressure. This line pressure is adjusted to a height corresponding to the pilot pressure (signal pressure) from the solenoid valve 25 for line pressure described above. Therefore, the optimum line pressure corresponding to the operating state can be obtained.

  The hydraulic control mechanism 20 selectively supplies and discharges the line pressure to and from the friction elements 67 to 71 by a switching valve that is switched by driving the solenoid valve 25 for shifting. The friction elements 67 to 71 are fastened or released by the supply / discharge of the line pressure, and the speed determined by the control unit 2 is achieved.

  The hydraulic control mechanism 20 also supplies ATF to the torque converter 51. There are at least two modes for supplying ATF to the torque converter 51. One mode is a mode in which the hydraulic pressure on the front surface (surface facing the pump cover 53) of the L / U clutch 64 is lower than the hydraulic pressure on the rear surface side. It is. If this supply form is taken, the L / U clutch 64 moves to the low pressure side, that is, the pump cover 53 side and is pressed. Therefore, the torque converter 51 is in the L / U on state. Further, the pressure difference of the ATF acting on the plate surface of the L / U clutch 64 may be adjusted as appropriate so that a weak L / U that allows a certain rotational speed difference (slip) while transmitting power may be achieved. .

  The other form is a form in which the oil pressure on the front side of the L / U clutch 64 is higher than the oil pressure on the back side. If this supply form is taken, the L / U clutch 64 moves in the direction away from the low pressure side, that is, the pump cover 53. Therefore, the torque converter 51 is in the L / U off state.

  Switching of the ATF supply mode to the torque converter 51 is performed by a solenoid valve 25 for L / U control included in the hydraulic control mechanism 20 and a switching valve (not shown).

  FIG. 3 is a diagram showing the relationship between the intermittent state of the fastening elements 67 to 72 and the gear position. FIG. 3 shows the D range first speed to fourth speed. A circle indicates a state in which the friction elements 67 to 71 are fastened. (○) indicates that the one-way clutch 72 is locked during driving (when the driving force from the engine is directed toward the driving wheel) and can transmit the driving force, and during reverse driving (reverse driving force from the driving wheel). Indicates that the reverse drive force is not transmitted. No mark indicates a state in which each fastening element 67 to 72 is released or unlocked.

  As shown in this figure, the forward clutch 67 is engaged and the one-way clutch 72 is in the drive side locked state and the reverse drive side unlocked state at the first speed of the D range. The 2-4 brake 70 is engaged, the forward clutch 67 and the 3-4 clutch 69 are engaged at the third speed, and the 3-4 clutch 69 and the 2-4 brake 70 are engaged at the fourth speed. Although not shown in the drawing, the reverse clutch 68 and the low reverse brake 71 are engaged during reverse (R range).

  The ▲ mark indicates that the frictional engagement element is an interlock element at the gear position. An interlock element refers to a frictional engagement element that becomes an interlock when fastened. Interlock is a well-known phenomenon, and all or a part of the torque input to the multi-stage transmission mechanism 52 is internally circulated in the multi-stage transmission mechanism 52, and the output torque cannot be obtained or reduced from the original value. It is a phenomenon.

  Thus, the interlock is an inherently undesirable phenomenon, but the automatic transmission 50 can reduce the vibration of the vehicle by using the interlock. Here, an appropriately controlled interlock that can be used to reduce vehicle vibration is referred to as a quasi-interlock to distinguish it from a normal interlock. Specifically, the quasi-interlock means that the interlock element is semi-fastened with a predetermined moderate torque capacity. The above-described quasi-interlock control unit 10, the hydraulic control mechanism 20, and each interlock element shown in FIG. 3 constitute quasi-interlock means for realizing quasi-interlock.

  As shown in FIG. 3, at the first speed, the 3-4 clutch 69 and the low reverse brake 71 are interlocking elements. Therefore, in the quasi-interlock control at the first speed, the forward clutch 67 is engaged, and the 3-4 clutch 69 and the low reverse brake 71 are semi-engaged so as to have an appropriate torque capacity.

  At the second speed, the 3-4 clutch 69 serves as an interlock element. Therefore, in the semi-interlock control at the second speed, the forward clutch 67 and the 2-4 brake 70 are engaged, and the 3-4 clutch 69 is semi-engaged so as to have an appropriate torque capacity.

  In addition to this, there are friction engagement elements that serve as interlock elements, but in this embodiment, the interlock elements shown in FIG. 3 are set in consideration of controllability. For example, in the first speed, the 2-4 brake 70 can be used as an interlock element instead of the 3-4 clutch 69. However, since the 3-4 clutch 69 that is a multi-plate clutch has better controllability than the 2-4 brake 70 that is a brake band, the 3-4 clutch 69 is employed. In the second speed, the low reverse brake 71 can be used as an interlock element instead of the 3-4 clutch 69. However, as shown in FIG. 1, the 3-4 clutch 69 is a smaller-diameter multi-plate clutch than the low-reverse brake 71, and the controllability is better. Therefore, the 3-4 clutch 69 is employed.

  Although there are interlocking elements for the third speed and the fourth speed, they are omitted in this embodiment because the quasi-interlock control is performed at the second speed and lower.

  Next, a driving force transmission form of the multi-stage transmission mechanism 52 will be described. First, a normal case where quasi-interlock control is not performed will be described.

  FIG. 4 is a schematic diagram showing the driving force transmission state of the multi-stage transmission mechanism 52 at the first speed of the D range, that is, the torque transmission path and the rotation direction of each part. In this figure, when viewed from the left front side, the left rotation is the forward rotation direction, and the right rotation is the reverse rotation direction. When the engine is in a normal operating state, the turbine shaft 59 rotates in the forward direction. Further, when the vehicle is in the forward traveling state, the transmission gear 76 rotates in the forward rotation direction together with the axles 78 and 79.

  At the first speed shown in FIG. 4, the turbine shaft 59 rotates in the forward rotation direction, and the rotation and torque are transmitted to the sun gear 65 a via the forward clutch 67. Further, it is transmitted to the planetary gear 65b, and this planetary gear 65b rotates in the reverse direction. Here, since the one-way clutch 72 is locked (indicated by a path β), the rotation of the ring gear 65d in the reverse rotation direction is restricted, so that the planetary gear 65b rotates in the reverse rotation direction around the support shaft (carrier 65c). While rotating, the periphery of the sun gear 65a is rotated in the forward rotation direction integrally with the carrier 65c. That is, the carrier 65c rotates in the forward rotation direction. The forward rotation and torque force of the carrier 65c are transmitted to the output gear 73 and the transmission gears 74, 75, and 76. 1 is transmitted to the axles 78 and 79 through the differential mechanism 77 as shown in FIG.

  Since the carrier 66c integrated with the ring gear 65d locked by the one-way clutch 72 is fixed and the ring gear 66d integrated with the carrier 65c rotates in the forward rotation direction, the planetary gear 66b rotates forward with the shaft stopped. Accordingly, the sun gear 66a meshing with the planetary gear 66b rotates in the reverse direction. The reverse rotation of the sun gear 66a is permitted by the reverse clutch 68 and the 2-4 brake 70 being in the released state.

  FIG. 5 is a schematic diagram showing a driving force transmission state of the multi-stage transmission mechanism 52 at the second speed of the D range. The definition of the rotation direction conforms to FIG.

  As shown in FIG. 3, the D range second speed is obtained by further engaging the 2-4 brake 70 from the D range first speed in which the forward clutch 67 is engaged. As described above, in the D range first speed, the sun gear 66a rotates in the reverse direction. When the 2-4 brake 70 is engaged from this state, the sun gear 66a stops. For this reason, the planetary gear 66b rotates around the sun gear 66a in the forward direction integrally with the carrier 66c while rotating in the forward direction around the support shaft (carrier 66c). That is, at the first speed in the D range, the one-way clutch 72 restricts the rotation in the reverse direction, and the stopped carrier 66c rotates in the normal direction. The rotation speed of the carrier 66c is lower than the rotation speed of the turbine shaft 59 (turbine rotation speed).

  At this time, the planetary gear 65b rotates around the sun gear 65a in the forward rotation direction integrally with the carrier 65c while rotating in the reverse rotation direction around the carrier 65c as in the first speed. In this case, unlike the first speed, since the ring gear 65d rotates in the forward direction, the rotational speed of the carrier 65c is relatively higher than that in the first speed. However, it is decelerated from the rotational speed of the turbine shaft 59. Thereafter, as in the first speed, the rotation and driving force of the carrier 65c in the forward rotation direction are transmitted to the output gear 73 and the transmission gears 74, 75, and 76.

  In the case of the D range 3rd speed, although not shown in particular, the driving force transmission state is as follows. When the forward clutch 67 and the 3-4 clutch 69 are engaged, the driving force of the turbine shaft 59 is transmitted in parallel from the sun gear 65a and the carrier 66c. Accordingly, the sun gears 65a and 66a, the planetary gears 65b and 66b, the carriers 65c and 66c, and the ring gears 65d and 66d rotate integrally with the turbine shaft 59. That is, torque equal to the torque input from the turbine shaft 59 is output to the output gear 73 at the same speed as the rotational speed of the turbine shaft 59 (directly connected state).

  Although not shown in the case of the D range 4th speed, the 3-4 clutch 69 and the 2-4 brake 70 are engaged, and the driving force input from the turbine shaft 59 is faster than the rotational speed of the turbine shaft 59. Then, it is output to the output gear 73 via the carrier 65c.

  Next, the driving force transmission state at the time of executing the semi-interlock control will be described. First, the case of the first gear will be described with reference to FIG. In the first-speed quasi-interlock control, first, the low reverse brake 71 is semi-engaged (in this case, it may be completely engaged). As a result, the ring gear 65d and the carrier 66c act in a direction to be fixed to the case 57 (path α), but these elements are locked by the one-way clutch 72 at the first speed in the originally driven state. Therefore, the interlock does not occur only when the low reverse brake 71 is engaged or semi-engaged.

  In the first-speed semi-interlock control, the 3-4 clutch 69 is further semi-engaged. Thereby, a part of the input torque from the turbine shaft 59 is transmitted to the carrier 66c. Accordingly, the carrier 66c tries to rotate in the forward rotation direction. However, the rotation of the carrier 66c is blocked by the engagement (half-engagement) of the low reverse brake 71 (in other words, the torque capacity of the low reverse brake 71 in the quasi-interlock control is set to such an extent that the rotation of the carrier 66c can be blocked. ing). Therefore, the torque input from the carrier 66c circulates internally without contributing to the output. On the other hand, the torque input from the turbine shaft 59 to the sun gear 65a via the forward clutch 67 is reduced by the amount that flows to the carrier 66c via the 3-4 clutch 69. For this reason, the torque transmitted from the sun gear 65a to the output gear 73 is also reduced as a whole, and finally the output torque transmitted to the axles 78 and 79 is also reduced.

  Next, the driving force transmission state at the time of executing the semi-interlock control in the second speed will be described with reference to FIG. In the second-speed semi-interlock control, the 3-4 clutch 69 is semi-engaged. As a result, part of the torque of the turbine shaft 59 is transmitted to the carrier 66c via the 3-4 clutch 69. That is, there is an effect of trying to rotate the carrier 66c at the turbine rotation speed. However, as described above, at the second speed, the carrier 66c rotates at a lower speed than the turbine rotation speed. Therefore, the torque input from the 3-4 clutch 69 circulates internally as a resistance that hinders the smooth operation of the carrier 66c. On the other hand, the torque input from the turbine shaft 59 to the sun gear 65a via the forward clutch 67 is reduced by the amount that flows to the carrier 66c via the 3-4 clutch 69. For this reason, the torque transmitted from the sun gear 65a to the output gear 73 is also reduced as a whole, and finally the output torque transmitted to the axles 78 and 79 is also reduced.

  In both the first speed and the second speed, as the torque capacity of the 3-4 clutch 69 is larger, the amount of decrease in the output torque is larger, and the effect of the quasi-interlock is increased.

  FIG. 6 is a time chart showing that vehicle vibration is reduced by the quasi-interlock. This time chart is a simulation result of the quasi-interlock in the second speed. The horizontal axis indicates time t, and the upper vertical axis indicates output torque (drive shaft torque) to the axles 78 and 79. The lower vertical axis indicates the input torque to the input shaft 3 and the torque capacity of the 3-4 clutch 69 by the quasi-interlock control.

  A lower characteristic 105 is an input torque to the input shaft 3. This characteristic is a single fluctuation of input torque that rises steeply in a short time. For example, when the driver depresses the accelerator pedal rapidly while driving near the accelerator opening fully closed and L / U is on. This corresponds to the fluctuation of the engine torque.

  The upper characteristics 101 and 102 are output torques with respect to the input torque 105. The characteristic 101 indicated by the solid line indicates the case of the prior art in which quasi-interlock control is performed, and the characteristic 102 indicated by the broken line indicates the case of the prior art in which quasi-interlock is not performed. Each is shown. In either case, no shift is caused by fluctuations in the input torque 105.

  When the quasi-interlock control is not performed, the output torque (characteristic 102) first increases as the input torque 105 increases. However, since the increase in the input torque 105 is steep, it greatly overshoots (time point ta). . After that, it shakes back greatly by the reaction and overshoots in the decreasing direction (time point ta + ts). Thereafter, the damped vibration is repeated at a period of 2 ts, and finally converges to the output torque (about 1000 N · m) corresponding to the torque after the change of the input torque 105 (about 185 N · m). This large torque fluctuation becomes vehicle vibration called chip-in shock. The main factor causing such torque fluctuation is torsional resonance of the drive system in the automatic transmission 50.

  On the other hand, the output torque (characteristic 101) when the quasi-interlock control is executed is the same as the characteristic 102 until the time point ta + ts, but the subsequent convergence of the damped vibration is much faster than the characteristic 102. . This is because the semi-interlock control is executed from the time point ta + ts to the time ta + 2ts (length ts) and the hydraulic pressure is supplied to the 3-4 clutch 69 to be in a semi-engaged state as shown in the lower stage characteristic 107. It is an effect. By providing an appropriate torque capacity Ta (≈80 N · m) to the 3-4 clutch 69 as an interlock element during this period, the multi-stage transmission mechanism 52 enters a quasi-interlock state, and an increase in transmission torque is suppressed. The second torque peak (time point ta + 2ts) is much smaller. For this reason, the damped vibration converged rapidly.

  In order to perform effective quasi-interlocking, it is necessary to consider the following three points. The first point is the torque capacity (necessary torque Ta) to be given to the quasi-interlock element, the second point is the quasi-interlock execution period (quasi-interlock period), and the third point is quasi-interlock execution This is the number of times (necessary number Na).

  The required torque Ta, which is the first point, will be described. As described above, the strength of the quasi-interlock (the magnitude of the quasi-interlock action) increases as the torque capacity of the 3-4 clutch 69 that is the quasi-interlock element increases. If the quasi-interlock is too weak, the effect of suppressing vibration is small, and if it is too strong, the vibration is suppressed and the output torque is reduced too much (the action of the interlock, which has been considered undesirable in the past, appears on the surface). Therefore, the necessary torque Ta is preferably set so that the larger the input torque, the larger the torque capacity, according to the magnitude of the input torque.

  Actually, a suitable required torque Ta based on the tip-in shock generation conditions (driving state before accelerator operation, accelerator operation amount, accelerator operation speed, change amount of throttle opening TVO, change rate of TVO, etc.) is determined in advance by experiments or the like. The optimum required torque Ta is set by obtaining the map and storing it in the semi-interlock control unit 10 and reading the required torque Ta corresponding to the chip-in shock occurrence condition from the map. It ’s fine.

  The quasi-interlock period that is the second point will be described. The quasi-interlock is executed while the transmission torque is increasing (the period from the torque valley to the next torque peak) and not during the decrease (the period from the torque peak to the next torque valley). Is desirable. This is because the quasi-interlock acts in the direction of reducing the transmission torque, so that if it is executed while the torque is increasing, its suppression effect is exhibited, but if it is executed while the torque is decreasing, vibration may be promoted.

  Further, as shown in FIG. 6, the tip-in shock is a damped vibration, and the amplitude is larger as the vibration is in the initial stage. Therefore, it is desirable to execute at a time when the amplitude is large, that is, as early as possible. This is because, as described above, stronger quasi-interlock can be appropriately performed as the torque fluctuation is larger, and a large vibration suppressing effect can be obtained.

  In this regard, the quasi-interlock period in the characteristic 107 covers the entire period from the first torque trough (time ta + ts) to the next torque peak (time ta + 2ts) of the torque vibration. Therefore, it meets the conditions of the desirable quasi-interlock period.

  By the way, in executing the semi-interlock, even if the operation of the semi-interlock is started at the time when the torque valley is detected (ta + ts), the operation delay of the semi-interlock means (for example, the clutch piston of the 3-4 clutch 69) For example, there is a concern that a time lag may occur before the quasi-interlock action is actually obtained. Similarly, even if the quasi-interlock release operation is started at the time when a torque peak is detected (ta + 2ts), there is a concern that a time lag will actually occur, and the quasi-interlock will be exerted until the transmission torque is reduced. There is.

  In order to dispel such concerns, the semi-interlock control unit 10 executes the following control. First, the quasi-interlock control unit 10 first detects a time point when the torque shows a peak, and sets it as a reference time point ta.

  Specifically, the semi-interlock control unit 10 obtains the reference time ta as follows. The control unit 2 receives a signal from a turbine rotational speed sensor 36 that is an input rotational speed detection means. The semi-interlock control unit 10 uses the turbine rotation speed sensor 36 as a torque related information detection unit. First, the quasi-interlock control unit 10 calculates an input rotational acceleration that is a degree of change (time differentiation) from a turbine rotational speed that is a detection value of the turbine rotational speed sensor 36. Since the input rotational acceleration is positive while the transmission torque is increasing and negative when the transmission torque is decreasing, the semi-interlock control unit 10 defines the reference time ta based on the time when the input rotational acceleration changes from positive to negative.

  By obtaining the reference time point ta, which is the peak time of the torque, by using the high-precision turbine rotational speed sensor 36 that has been conventionally used for shift control, a simple torque sensor or the like can be provided. High-precision detection can be performed with the structure.

  Next, the semi-interlock control unit 10 sets the time after the first predetermined time (ta + ts) from the reference time ta as the start time of the semi-interlock and sets the time after the second predetermined time (ta + 2ts) as the release time. Here, the period ts is preferably set to a half cycle of torque vibration as shown in FIG. The period 2ts of torque vibration is a period inherent to the gear position (longer as the gear position is lower). Accordingly, this can be obtained and memorized in advance by experiments or the like.

  Thus, the semi-interlock control unit 10 sets the semi-interlock start time (ta + ts) and the release time (ta + 2ts) when the reference time ta is detected. When performing correction in consideration of a time lag or the like, the control may be executed with a necessary correction amount advanced from these points.

  By performing such control, the effective period of the quasi-interlock can be brought closer to an ideal period (from the torque valley to the peak).

  The required number Na, which is the third point, will be described. In the example shown in FIG. 6, a sufficient effect can be obtained by one quasi-interlock control (characteristic 107). However, since the interlock period is limited to the maximum ts, one quasi-interlock is not always sufficient depending on the input torque fluctuation value. In such a case or when it is assumed to be such, the quasi-interlock may be performed a plurality of times. In this case, the second quasi-interlock may be started after the time ts has elapsed after the first quasi-interlock is released, as indicated by the characteristic 108 indicated by a two-dot chain line in FIG. The same applies to the third and subsequent times.

  As for the required number of times of quasi-interlock, a value based on the chip-in shock occurrence condition is obtained in advance by experiments or the like, as in the above-described required torque Ta, and the mapped value may be read.

  FIG. 6 shows the case of the tip-in shock, but the same applies to the tip-out shock in the direction of rapidly decreasing the accelerator opening. In this case, the torque starts to decrease, but the time point at which the torque peak is first reached through the torque valley is set as the reference time point ta, and the subsequent time point ta + ts is set as the quasi-interlock start time point.

  As described above, according to the vehicle vibration reduction device of this embodiment, by performing the quasi-interlock control, the torsional resonance of the drive system can be weakened and the damping can be promoted. Chip-in / chip-out shocks at the first speed and the second speed) can be effectively suppressed without changing the gear ratio. Therefore, it is possible to expand the L / U on region to these low gear stages while suppressing the deterioration of the riding comfort, and to further improve the fuel consumption.

  FIG. 7 is a schematic flowchart of control including semi-interlock control. When this flowchart starts, first, data from various sensors is read (step S1), and then it is determined whether or not L / U is on (step S2). If L / U is on (YES in step S2), it is next determined whether or not the changing speed of the throttle opening TVO (detected value of the throttle opening sensor 42) is larger than a predetermined value (step S3). In the case of YES in step S3, it is further determined whether or not the amount of fluctuation of the engine torque accompanying the change in the throttle opening TVO is greater than a predetermined value (step S4). In the case of YES in step S4, it is further determined whether or not the change in the accelerator opening that causes the change in the throttle opening TVO is accompanied by a shift (step S5).

  In the case of NO in step S5, there is a concern about a large chip-in / chip-out shock. Therefore, the following quasi-interlock control is executed. First, the peak time ta of the shock torque is detected from the detected value of the turbine rotation speed sensor 36 (step S6). Next, the required torque Ta and the required number Na of quasi-interlock control are set (step S7). Then, 1 is input to the execution count i (step S8). Next, using the half cycle value ts at the current gear position, whether or not the current time t is greater than or equal to ta + (2 · i−1) · ts (when i = 1, t is greater than or equal to ta + ts). Determine (step S9). If NO in step S9, the process waits until YES.

  If “YES” in the step S9, a torque trough has elapsed and a torque increasing phase has been reached. Therefore, a hydraulic pressure corresponding to the required torque Ta is supplied to the semi-interlock element corresponding to the gear position (step S10). As a result, quasi-interlocking is performed, and torque increase is suppressed.

  Next, it is determined whether or not the current time t is equal to or greater than ta + 2 · i · ts (when i = 1, whether t is equal to or greater than ta + 2ts) (step S11). If NO in step S11, the quasi-interlock is continued until YES.

  If YES in step S11, the torque peak has passed and the torque has fallen. Therefore, the hydraulic pressure of the semi-interlock element is released, and the semi-interlock is released (step S12).

  Next, it is determined whether or not the effective number i = the required number Na (step S13). If NO in step S13, 1 is added to the number of executions i (step S14), and the process proceeds to the next quasi-interlock (to step S9). In this way, the routine of steps S9 to S14 is repeated until YES is obtained in step S13 (until the required number of times Na quasi-interlock is completed). If “YES” is determined in the step S13, since all necessary quasi-interlocks are completed, the process returns.

  Going back, if NO in any of step S2, step S3, or step S4 and if YES in step S5, there is less concern about a chip-in / chip-out shock, so the quasi-interlock is not executed and the process returns. To do.

  The above flowchart is for the case where the time from the supply of hydraulic pressure until the interlock element actually has a predetermined torque capacity is not taken into consideration. In consideration of this, the conditional expressions in steps S9 and S11 may be corrected, and the supply of hydraulic pressure may be advanced as appropriate.

  As mentioned above, although embodiment of this invention was described, these embodiment can be suitably changed in the range which does not deviate from the summary of this invention. For example, the interlock elements are not limited to those indicated by ▲ in FIG. 3, and other frictional engagement elements may be applied.

  In this embodiment, torque related information detecting means for detecting information related to transmission torque at a predetermined position on the power transmission system is used as vibration detecting means, and turbine rotational speed sensor 36 (input rotational speed detection) is used as the torque related information detecting means. However, for example, a torque sensor or the like may be used as the torque related information unit, and a vehicle acceleration sensor (G sensor) or the like may be used as the vibration detection unit.

  The semi-interlock control may be executed at the third speed or the fourth speed. However, it is more effective to execute at a low speed (first speed or second speed), which is disadvantageous to a chip-in / chip-out shock when L / U is on.

  Further, the quasi-interlock control of this embodiment may be used in combination with other vibration reduction means (for example, engine torque control, vibration reduction by weak L / U, etc.).

1 is a schematic configuration diagram of a drive system including an automatic transmission according to an embodiment of the present invention. It is a schematic control block diagram of the automatic transmission. It is a figure which shows the relationship between the intermittent state of each fastening element, and a gear stage. It is a schematic diagram which shows the drive force transmission state of the multi-stage transmission mechanism in D range 1st speed stage. It is a schematic diagram which shows the drive force transmission state of the multistage transmission mechanism in D range 2nd speed. It is a time chart which shows that vehicle vibration is reduced by a quasi interlock. It is a schematic flowchart of control including quasi-interlock control.

Explanation of symbols

10 Semi-interlock control unit (quasi-interlock means)
20 Hydraulic control mechanism (quasi-interlocking means)
36 Turbine rotation speed sensor (input rotation speed detection means, torque related information detection means, vibration detection means)
51 Torque converter (fluid transmission)
52 Multi-speed transmission mechanism (transmission)
64 Lock-up clutch 67 Forward clutch (friction engagement element)
68 Reverse clutch (friction engagement element)
69 3-4 clutch (friction engagement element, interlock element, quasi-interlock means)
70 2-4 Brake (Friction engagement element)
71 Low reverse brake (friction engagement element, interlock element, semi-interlock means)
ta Reference point ta
ts first predetermined time 2ts second predetermined time

Claims (6)

A vehicle equipped with a fluid transmission device having a lock-up clutch and a transmission that engages one or more frictional engagement elements selected from a plurality of frictional engagement elements to shift in stages, and is in a predetermined low vehicle speed state and In a vehicle vibration reduction device for reducing vibration generated by a rapid change in input torque to the fluid transmission device when the lockup clutch is in a power transmission state,
Quasi-interlock means for semi-engaging an interlock element, which is a friction engagement element that becomes an interlock when engaged, other than the friction engagement element necessary to achieve the current gear position, and a predetermined torque capacity;
Vibration detecting means for detecting the vibration of the vehicle,
An apparatus for reducing vibration of a vehicle, comprising: performing a semi-interlock for operating the semi-interlock means for a predetermined period when the vibration of the vehicle is equal to or greater than a predetermined value.   2. The vehicle vibration reduction according to claim 1, wherein the torque capacity of the interlock element when the quasi-interlock is executed is set so as to increase as the input torque fluctuation to the transmission increases. apparatus. The vibration detection means is torque related information detection means for detecting information related to transmission torque at a predetermined position on the power transmission system,
The quasi-interlock period, which is a predetermined period during which the quasi-interlock is executed, is included in the period from the first torque trough to the next torque peak of the torque vibration based on the detection value of the torque-related information detecting means. The vehicle vibration reduction device according to claim 1, wherein the vehicle vibration reduction device is set as follows.   The start time of the quasi-interlock period is a time when a first predetermined time has elapsed from a reference time that is a peak time of torque before the first torque valley, and the release time is a second predetermined time from the reference time. 4. The vehicle vibration reducing device according to claim 3, wherein the time has elapsed.   5. The vehicle vibration reduction apparatus according to claim 3, wherein the quasi-interlock period is longer as the gear position is lower. The torque related information detection means includes an input rotation speed detection means for detecting an input rotation speed to the transmission,
The time point of the trough of the torque vibration and the time point of the peak are calculated based on an input rotational acceleration that is a time change rate of the input rotational speed. Vehicle vibration reduction device.

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