JP4226540B2 - Active anti-vibration support device - Google Patents

Description

  The present invention relates to an active vibration isolating support device that supports a load of a vibrating body and suppresses vibration by periodically expanding and contracting an actuator with a current according to a vibration state of the vibrating body by a control unit.

  In order to drive the movable member of the active vibration isolating support device that suppresses the transmission of engine vibration to the vehicle body with a sinusoidal vibration waveform, the drive cycle of the actuator is divided into a number of minute time regions, Patent Document 1 below discloses that a sinusoidal target current is supplied to an actuator by individually controlling a duty ratio in a minute time region.

Also, in the case of supplying a sinusoidal current to the solenoid coil to perform the suction and release operations periodically, the influence of the counter electromotive force when the power supply to the coil is cut off is eliminated and the sinusoidal actual current is removed. Japanese Patent Application Laid-Open No. 2004-228688 discloses a circuit including a counter electromotive force absorption circuit combining a diode and a Zener diode and a counter electromotive force return circuit combining a diode and a transistor.
JP 2002-139095 A JP 2004-134510 A

  By the way, even if an attempt is made to supply a sinusoidal excitation current to the actuator coil of the active vibration isolating support device, the change in the resistance value of the coil due to the temperature change and the characteristics of the back electromotive force absorption circuit and the back electromotive force return circuit Due to the change, the waveform of the excitation current may deviate from the target waveform, and the active vibration isolating support device may not be accurately controlled.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to make it possible to accurately control a waveform of a current for driving an actuator of an active vibration isolating support device to a target waveform.

In order to achieve the above object, according to the first aspect of the present invention, the load of the vibrating body is supported, and the actuator is periodically expanded and contracted with a current according to the vibration state of the vibrating body by the control means. In the active vibration isolating support device that suppresses vibration, the control means performs feedback control so that the actual current that drives the actuator matches the target current according to the vibration state of the vibrating body. There is proposed an active vibration isolating support device characterized in that the feedback gain is changed between rising and falling at each cycle .

  According to the second aspect of the present invention, the active type that supports the load of the vibration body and that suppresses vibration by periodically extending and contracting the actuator with a current according to the vibration state of the vibration body by the control means. In the anti-vibration support device, the control means includes a counter electromotive force absorption circuit that absorbs the counter electromotive force generated by the actuator, and a counter electromotive force that bypasses the counter electromotive force generated by the actuator so as not to pass through the counter electromotive force absorption circuit. A feedback circuit for feedback control so that the actual current for driving the actuator matches the target current corresponding to the vibration state of the vibrating body, and the back electromotive force return circuit during operation of the back electromotive force absorption circuit An active vibration isolating support device is proposed in which the feedback gain is changed depending on whether the operation is performed.

According to the invention described in or claim 3, as well as supporting the load of the vibrating body, suppress vibration actuator periodically stretch driven by a current corresponding to the vibration state of the vibrating body by the control means actively In the anti-vibration support device, the control means includes a counter electromotive force absorption circuit that absorbs the counter electromotive force generated by the actuator, and a reverse circuit that bypasses the counter electromotive force generated by the actuator so as not to pass through the counter electromotive force absorption circuit. It is equipped with an electromotive force return circuit and performs feedback control so that the actual current that drives the actuator matches the target current according to the vibration state of the vibrating body. At the rise and fall of each cycle of the target current And the feedback gain is changed, and in the above-mentioned falling region of the target current, it is switched between when the back electromotive force absorption circuit is operated and when the back electromotive force recirculation circuit is operated. The active vibration isolation support system is proposed which is characterized in that Mochikaeru the over-back gain.

  The electronic control unit U and the actuator drive circuit C of the embodiment correspond to the control means of the present invention.

According to the configuration of the first aspect, the control means for performing feedback control so that the actual current that drives the actuator of the active vibration isolating support device matches the target current according to the vibration state of the vibrating body includes each period of the target current. Since the feedback gain is switched between rising and falling at, the actuator of the active anti-vibration support device is driven with high accuracy by compensating for changes in the waveform of the actual current due to temperature changes, etc., to enhance the anti-vibration effect be able to.

  According to the configuration of the second aspect, the control means for performing feedback control so that the actual current for driving the actuator of the active vibration isolating support device matches the target current corresponding to the vibration state of the vibrating body is the reverse generated by the actuator. Equipped with a back electromotive force absorption circuit that absorbs the electromotive force and a back electromotive force return circuit that bypasses the back electromotive force generated by the actuator so that it does not pass through the back electromotive force absorption circuit. Since the feedback gain is switched between when the back electromotive force recirculation circuit is activated, the actuator of the active anti-vibration support device is driven accurately by compensating for the change in the actual current waveform due to temperature changes, etc. Can be increased.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 6 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an active vibration isolating support device, FIG. 2 is an enlarged view of a part 2 in FIG. 1, and FIG. 3 is a circuit of an actuator drive circuit. 4 is a timing chart for explaining the control of the excitation current of the actuator, FIG. 5 is a flowchart for explaining a method for determining the excitation current of the actuator, and FIG. 6 is a flowchart for explaining a method for selecting a feedback gain of the excitation current of the actuator. is there.

As shown in FIGS. 1 and 2, an active anti-vibration support device M (active control mount) used for elastically supporting an automobile engine on a body frame is substantially axisymmetric with respect to an axis L. A substantially cup-shaped actuator case having an open upper surface between a flange portion 11a at the lower end of the substantially cylindrical upper housing 11 and a flange portion 12a at the upper end of the generally cylindrical lower housing 12. The outer peripheral flange portion 13a, the outer peripheral portion of the annular first elastic body support ring 14, and the outer peripheral portion of the annular second elastic body support ring 15 are overlapped and joined by caulking. At this time, the annular first floating rubber 16 is interposed between the flange portion 12a of the lower housing 12 and the flange portion 13a of the actuator case 13, and the upper portion of the actuator case 13 and the inner surface of the second elastic body support member 15 By interposing the annular second floating rubber 17 therebetween, the actuator case 13 is floatingly supported so as to be movable relative to the upper housing 11 and the lower housing 12.

  The lower end and the upper end of the first elastic body 19 formed of thick rubber are joined to the first elastic body support ring 14 and the first elastic body support boss 18 disposed on the axis L by vulcanization adhesion. Is done. A diaphragm support boss 20 is fixed to the upper surface of the first elastic body support boss 18 with bolts 21, and the outer peripheral portion of the diaphragm 22, which is joined to the diaphragm support boss 20 by vulcanization adhesion, is added to the upper housing 11. Joined by sulfur adhesion. An engine mounting portion 20a integrally formed on the upper surface of the diaphragm support boss 20 is fixed to an engine (not shown). In addition, the vehicle body attachment portion 12b at the lower end of the lower housing 12 is fixed to a vehicle body frame (not shown).

  A flange portion 23a at the lower end of the stopper member 23 is coupled to the flange portion 11b at the upper end of the upper housing 11 by bolts 24 ... and nuts 25 ..., and a diaphragm support boss 20 is attached to a stopper rubber 26 attached to the upper inner surface of the stopper member 23. The engine mounting portion 20a that protrudes from the upper surface of the upper and lower surfaces faces each other so as to be able to come into contact therewith. When a large load is input to the active vibration isolating support device M, the engine mounting portion 20a abuts against the stopper rubber 26, thereby suppressing excessive displacement of the engine.

  The outer peripheral portion of the second elastic body 27 formed of a film-like rubber is joined to the second elastic body support ring 15 by vulcanization adhesion, and the movable member 28 is added so as to be embedded in the central portion of the second elastic body 27. Joined by sulfur adhesion. A disk-shaped partition wall member 29 is fixed between the upper surface of the second elastic body support ring 15 and the outer periphery of the first elastic body 19, and the first partition partitioned by the partition wall member 29 and the first elastic body 19. The liquid chamber 30 and the second liquid chamber 31 partitioned by the partition member 29 and the second elastic body 27 communicate with each other through a communication hole 29 a formed at the center of the partition member 29.

  An annular communication path 32 is formed between the first elastic body support ring 14 and the upper housing 11, and one end of the communication path 32 communicates with the first liquid chamber 30 through the communication hole 33. The other end communicates with the third liquid chamber 35 defined by the first elastic body 19 and the diaphragm 22 through the communication hole 34.

  Next, the structure of the actuator 41 that drives the movable member 28 will be described.

  The fixed core 42, the coil assembly 43, and the yoke 44 are sequentially attached to the inside of the actuator case 13 from the bottom to the top. The coil assembly 43 includes a bobbin 45 disposed on the outer periphery of the fixed core 42, a coil 46 wound around the bobbin 45, and a coil cover 47 that covers the outer periphery of the coil 46. The coil cover 47 is integrally formed with a connector 48 that extends through the openings 13b and 12c formed in the actuator case 13 and the lower housing 12 and extends to the outside.

A seal member 49 is disposed between the upper surface of the coil cover 47 and the lower surface of the yoke 44, and a seal member 50 is disposed between the lower surface of the bobbin 45 and the upper surface of the fixed core 42. These seal members 49 and 50 can prevent water and dust from entering the internal space 61 of the actuator 41 from the openings 13 b and 12 c formed in the actuator case 13 and the lower housing 12.

  A thin cylindrical bearing member 51 is fitted to the inner peripheral surface of the cylindrical portion 44a of the yoke 44 so as to be vertically slidable. An upper flange 51a bent radially inward is formed at the upper end of the bearing member 51. A lower flange 51b that is bent radially outward is formed at the lower end. A set spring 52 is disposed in a compressed state between the lower flange 51b and the lower end of the cylindrical portion 44a of the yoke 44. The elastic force of the set spring 52 causes the lower flange 51b to be fixed to the fixed core 42 via the elastic body 53. The bearing member 51 is supported by the yoke 44 by being pressed against the upper surface of the yoke 44.

  A substantially cylindrical movable core 54 is fitted to the inner peripheral surface of the bearing member 51 so as to be slidable up and down. A rod 55 extending downward from the center of the movable member 28 penetrates the center of the movable core 54 loosely, and a nut 56 is fastened to the lower end thereof. A set spring 58 in a compressed state is disposed between a spring seat 57 provided on the upper surface of the movable core 54 and the lower surface of the movable member 28, and the movable core 54 is pressed against the nut 56 by the elastic force of the set spring 58. Fixed. In this state, the lower surface of the movable core 54 and the upper surface of the fixed core 42 face each other via the conical air gap g. The rod 55 and the nut 56 are loosely fitted into an opening 42 a formed at the center of the fixed core 42, and the opening 42 a is closed by a plug 60 through a seal member 59.

  The electronic control unit U, to which a crank pulse sensor Sa for detecting a crank pulse output as the crankshaft of the engine rotates, is connected to the actuator 41 of the active vibration isolating support device M via the actuator drive circuit C. Control. The engine crank pulse is output 24 times per revolution of the crankshaft, that is, once every 15 ° of the crank angle.

  As shown in FIG. 3, the actuator drive circuit C excites the coil 46 of the actuator 41 based on a signal from the electronic control unit U, and includes a first field effect transistor 71, a first diode 72, and a second field effect. A counter electromotive force return circuit 74 configured by a transistor 73 and a counter electromotive force absorption circuit 77 configured by a second diode 75 and a zener diode 76 are provided.

  The first field effect transistor 71 has a source connected to a power source (not shown), a drain connected to the positive electrode 46 a of the coil 46, and a base connected to the electronic control unit U. In the back electromotive force return circuit 74, the cathode of the first diode 72 is connected to the positive electrode 46 a of the coil 46, the anode is connected to the drain of the second field effect transistor 73, and the source of the second field effect transistor 73 is the coil 46. The base is connected to the electronic control unit U, and is connected to the grounded negative electrode 46b. In the back electromotive force absorption circuit 77, the cathode of the second diode 75 is connected to the positive electrode 46a of the coil 46, the anode is connected to the anode of the Zener diode 76, and the cathode of the Zener diode 76 is connected to the grounded negative electrode 46b. Connected.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

When low-frequency engine shake vibration is generated while the vehicle is running, the first elastic body 19 is deformed by a load input from the engine via the diaphragm support boss 20 and the first elastic body support boss 18, and the first liquid When the volume of the chamber 30 changes, the liquid goes back and forth between the first liquid chamber 30 and the third liquid chamber 35 connected via the communication path 32. When the volume of the first liquid chamber 30 is enlarged / reduced, the volume of the third liquid chamber 35 is reduced / expanded accordingly, but the volume change of the third liquid chamber 35 is absorbed by the elastic deformation of the diaphragm 22. At this time, the shape and size of the communication path 32 and the spring constant of the first elastic body 19 are set so as to exhibit a low spring constant and a high damping force in the frequency region of the engine shake vibration. The vibration transmitted to can be effectively reduced.

  In the frequency region of the engine shake vibration, the actuator 41 is kept in an inoperative state.

  When vibration having a higher frequency than the engine shake vibration, that is, vibration during idling or vibration during cylinder deactivation caused by rotation of the crankshaft of the engine occurs, the first liquid chamber 30 and the third liquid chamber 35 are connected. Since the liquid in the communication path 32 is in a stick state and cannot exhibit the anti-vibration function, the actuator 41 is driven to exhibit the anti-vibration function.

  The electronic control unit U controls the energization of the coil 46 based on the signal from the crank pulse sensor Sa in order to operate the actuator 41 of the active vibration isolating support device M to exhibit the vibration isolating function.

That is, in the flowchart of FIG. 5, first, in step S1, a crank pulse output from the crank pulse sensor Sa every 15 ° of the crank angle is read, and in step S2, the read crank pulse is used as a reference crank pulse (specific cylinder). And the time interval of the crank pulse is calculated. In the next step S3, the crank angular velocity ω is calculated by dividing the crank angle of 15 ° by the time interval of the crank pulse, and in step S4, the crank angular velocity ω is time differentiated to calculate the crank angular acceleration dω / dt. In the following step S5, the torque Tq around the engine crankshaft is set as I, and the moment of inertia around the engine crankshaft is set as I.
Tq = I × dω / dt
Calculate by This torque Tq is zero assuming that the crankshaft is rotating at a constant angular velocity ω, but in the expansion stroke, the angular velocity ω increases due to acceleration of the piston, and in the compression stroke, the angular velocity ω decreases due to deceleration of the piston. Since the crank angular acceleration dω / dt is generated, a torque Tq proportional to the crank angular acceleration dω / dt is generated.

  In the subsequent step S6, the maximum value and the minimum value of the temporally adjacent torque are determined, and in step S7, the active vibration isolation support device M that supports the engine as a deviation between the maximum value and the minimum value of the torque, that is, the amount of torque fluctuation. The amplitude at the position of is calculated. In step S8, the duty waveform and timing (phase) of the current applied to the coil 46 of the actuator 41 are determined.

  Thus, when the engine moves downward with respect to the vehicle body frame and the first elastic body 19 is deformed downward to reduce the volume of the first liquid chamber 30, the coil 46 of the actuator 41 is excited in accordance with the timing. Then, the movable core 54 moves downward toward the fixed core 42 by the suction force generated in the air gap g, and is pulled by the movable member 28 connected to the movable core 54 via the rod 55, so that the second elastic body 27. Deforms downward. As a result, since the volume of the second liquid chamber 31 increases, the liquid in the first liquid chamber 30 compressed by the load from the engine passes through the communication hole 29a of the partition wall member 29 and flows into the second liquid chamber 31. The load transmitted from the engine to the vehicle body frame can be reduced.

Subsequently, when the engine moves upward with respect to the vehicle body frame and the first elastic body 19 is deformed upward to increase the volume of the first liquid chamber 30, the coil 46 of the actuator 41 is demagnetized in accordance with the timing. Since the attracting force generated in the air gap g disappears and the movable core 54 can move freely, the second elastic body 27 deformed downward is restored upward by its own elastic restoring force. As a result, since the volume of the second liquid chamber 31 decreases, the liquid in the second liquid chamber 31 passes through the communication hole 29a of the partition wall member 29 and flows into the first liquid chamber 30, and the engine is in contact with the vehicle body frame. It can be allowed to move upward.

  In this way, by exciting and demagnetizing the coil 46 of the actuator 41 according to the engine vibration cycle, it is possible to generate an active damping force that prevents the engine vibration from being transmitted to the vehicle body frame. .

  A sinusoidal current for exciting the coil 46 of the actuator 41 is generated by an actuator drive circuit C controlled by the electronic control unit U. FIG. 4 shows one cycle of the exciting current of the actuator 41, and the one cycle is divided into, for example, 22 minute periods. The first duty for each minute period supplied from the electronic control unit U to the first field effect transistor 71 of the actuator drive circuit C in the first half (region a) and the first half (region b) of one period of the excitation current The signal D1 gradually decreases from 100% to 0%, and the first duty signal D1 is held at 0% in the region c. Further, the second duty signal D2 for each minute period supplied from the electronic control unit U to the second field effect transistor 73 of the actuator drive circuit C in the region a and the region b in FIG. The second duty signal D2 gradually decreases from 100% to 0%. Meanwhile, the current of the coil 46 rises in the region a, and the current of the coil 46 falls in the region b and the region c, and changes in a sine wave shape.

  In the region a and the region b, the second field effect transistor 73 is held conductive by the 100% second duty signal D2, so that the back electromotive force return circuit 74 functions. Accordingly, the first duty signal D1 supplied to the first field effect transistor 71 is periodically turned on and off, and the negative electromotive force generated at the moment when the exciting current supplied to the coil 46 is cut off is the negative electrode of the coil 46. 46b side becomes a high potential and the positive electrode side becomes a low potential. At this time, the current due to the back electromotive force bypasses the back electromotive force absorption circuit 77 and passes through the first diode 72 of the back electromotive force recirculation circuit 74 as the return current Ib. By refluxing, the exciting current of the coil 46 is quickly raised.

  In the region c in FIG. 4, that is, when the first duty signal D1 supplied to the first field effect transistor 71 becomes 0% and the exciting current to the coil 46 is cut off, it is supplied to the second field effect transistor 73. The second duty signal D2 gradually decreases from 100% to 0%. As the exciting current supplied to the coil 46 is interrupted, the coil 46 generates a counter electromotive force, so that the negative electrode 46b side of the coil 46 has a high potential and the positive electrode side has a low potential.

  At this time, if the second duty signal D2 is OFF and the second field effect transistor 73 is in the cut-off state, the counter electromotive force absorption circuit 77 is returned to when the counter electromotive voltage exceeds the breakdown voltage of the Zener diode 76. When the outflow flow Ia flows, the back electromotive force of the coil 46 is limited to a constant value. Thus, the Zener diode 76 absorbs a part of the counter electromotive force of the coil 46, so that damage to the first field effect transistor 71 due to the counter electromotive force is reduced.

  When the second duty signal D2 is on and the second field effect transistor 73 is in a conducting state, the current caused by the back electromotive force bypasses the back electromotive force absorption circuit 77 and flows back through the back electromotive force recirculation circuit 74. Reflux as current Ib. As a result, the ratio of the back electromotive force of the coil 46 borne by the Zener diode 76 can be reduced, and the back electromotive force can be gently absorbed by the second diode 65 to gradually decrease the exciting current of the coil 46. At that time, wasteful power consumption and harmful heat generation by the Zener diode 76 can be suppressed.

  Accordingly, by appropriately controlling the first duty signal D1 supplied to the first field effect transistor 71 and the second duty signal D2 supplied to the second field effect transistor 73, a sinusoidal excitation current is supplied to the coil 46. can do.

  The electronic control unit U performs feedforward control on the excitation current (target current) supplied to the coil 46 of the actuator 41 according to the engine vibration state estimated from the crank pulse signal, and the actual current flowing in the coil 46 is Feedback control is performed to match the target current. At that time, the waveform of the actual current supplied to the coil 46 due to a change in the resistance value of the coil 46 and the power supply voltage accompanying a temperature change, or due to a change in the characteristics of the counter electromotive force return circuit 74 and the counter electromotive force absorption circuit 77. May change, and the anti-vibration function of the active anti-vibration support device M may deteriorate. Therefore, in this embodiment, the feedback gain of the P term, the I term, and the D term in the feedback control is changed according to the operating state of the back electromotive force return circuit 74 and the back electromotive force absorption circuit 77, thereby The change of the current waveform is suppressed.

  As shown in FIG. 4, in the present embodiment, the P-term gain is 8.0, the I-term gain is 4.5, and the region a and the region b where the first duty signal D1 is turned on and the second duty signal D2 is turned off. In the region c where the D term gain is set to 1.2 and the first duty signal D1 is turned off and the second duty signal D2 is turned on, the P term gain is 7.0, the I term gain is 4.0, and the D term gain is set. Is set to 1.2.

  The above operation will be further described based on the flowchart of FIG.

  First, when the coil 46 of the actuator 41 is energized and suction of the movable core 54 is started in step S11, the counter electromotive force return circuit 74 is selected and operated in step S12, and the region a (see FIG. 4) is operated in step S13. Feedback gain is selected. When the release of the coil 46 of the actuator 41 is started in the following step S14, the feedback gain of the region b (see FIG. 4) is selected in step S15. In the embodiment, the feedback gain in the region a and the feedback gain in the region b are set to be the same.

  When the duty ratio of the first duty signal D1 (see FIG. 4) for exciting the coil 46 is decreased to a predetermined value or less in the subsequent step S16, the back electromotive force reflux circuit 74 determines that the excitation current does not sufficiently decrease, and step S17. Thus, instead of the back electromotive force return circuit 74, the back electromotive force absorption circuit 77 is selected and operated, and the feedback gain of the region c (see FIG. 4) is selected in step S18. When one drive cycle of the active vibration isolating support device M is completed in step S19, the process returns to step S11.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, the actuator 41 of the embodiment is applied to an active vibration isolation support device M that supports an automobile engine, but the actuator 41 can be applied to an active vibration isolation support device M for other uses.

  In the embodiment shown in FIG. 4, the P term gain and the I term gain are not changed in the region a and the region b. However, they may be changed in the region a and the region b, and the D term gain is a constant value. However, it may be changed according to the areas a, b, and c.

Longitudinal section of active vibration isolator 2 enlarged view of FIG. Circuit diagram of actuator drive circuit Timing chart explaining the control of the excitation current of the actuator Flow chart explaining the method for determining the excitation current of the actuator Flowchart explaining a method for selecting feedback gain of excitation current of actuator

Explanation of symbols

41 Actuator 74 Back electromotive force return circuit 77 Back electromotive force absorption circuit C Actuator drive circuit (control means)
U Electronic control unit (control means)

Claims (3)

In an active vibration isolating support device for supporting a load of a vibrating body and periodically driving the actuator (41) to extend and contract with a current corresponding to the vibration state of the vibrating body by a control means (U, C). ,
The control means (U, C) performs feedback control so that the actual current for driving the actuator (41) matches the target current corresponding to the vibration state of the vibrating body, and the rising of the target current at each cycle. An active anti-vibration support device characterized in that the feedback gain is changed between the time and the fall. In an active vibration isolating support device for supporting a load of a vibrating body and periodically driving the actuator (41) to extend and contract with a current corresponding to the vibration state of the vibrating body by a control means (U, C). ,
The control means (U, C) includes a counter electromotive force absorption circuit (77) that absorbs counter electromotive force generated by the actuator (41), and a counter electromotive force absorption circuit ( 77) having a counter electromotive force return circuit (74) that bypasses the actuator so that it does not pass through, and performs feedback control so that the actual current that drives the actuator (41) matches the target current according to the vibration state of the vibrator An active type anti-vibration support device, wherein the feedback gain is switched between when the back electromotive force absorption circuit (77) is operated and when the back electromotive force return circuit (74) is operated. In an active vibration isolating support device for supporting a load of a vibrating body and periodically driving the actuator (41) to extend and contract with a current corresponding to the vibration state of the vibrating body by a control means (U, C). ,
The control means (U, C) includes a counter electromotive force absorption circuit (77) that absorbs counter electromotive force generated by the actuator (41), and a counter electromotive force absorption circuit ( 77) having a counter electromotive force return circuit (74) that bypasses the actuator so that it does not pass through, and performs feedback control so that the actual current that drives the actuator (41) matches the target current according to the vibration state of the vibrator The feedback gain is changed at the rising and falling times in each cycle of the target current, and the reverse of the target current in the falling region.
An active vibration isolating support device, wherein the feedback gain is switched between when the electromotive force absorption circuit (77) is operated and when the counter electromotive force return circuit (74) is operated.

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