JP2019049289A - transmission - Google Patents

Abstract

A transmission capable of suppressing an increase in size in the radial direction is provided. An input shaft to which a rotational force of a drive source is input, a speed reduction mechanism for transmitting the rotational force of the input shaft to a differential mechanism, and one of the rotational forces divided into two by the differential mechanism are input. The first variable displacement pump motor and the second variable displacement pump motor to which the other is input are connected in a closed circuit, and the rotational force of the input / output shaft of the first variable displacement pump motor A stepped transmission having a first engagement mechanism capable of outputting the output to the output shaft, and a second engagement mechanism capable of outputting the rotational force of the input / output shaft of the second variable displacement pump motor to the output shaft; , And the input / output shaft of the first variable displacement pump motor is arranged coaxially with the input shaft. [Selection] Figure 1

Description

  The present invention relates to a transmission.

  Conventionally, a hydromechanical continuously variable transmission (hydromechanical transmission: HMT) combining a hydrostatic continuously variable transmission (hydrostatic transmission: HST) and a differential mechanism is known (for example, Patent Document 1) See). Patent Document 1 discloses a so-called "input split type" HMT in which driving force from an engine is divided by a planetary gear mechanism and input to two hydraulic pump motors.

Patent No. 2522219 gazette

  In the HMT described in Patent Document 1, one hydraulic pump motor is connected to a first output element of a planetary gear mechanism via a first reduction mechanism, and a second output element of a planetary gear mechanism is The other hydraulic pump motor is connected via the reduction gear mechanism 2.

  Therefore, it is necessary to arrange both hydraulic pump motors on an axis different from the output shaft of the engine, and there is a problem that the whole becomes a three-axis structure and the size increases in the radial direction.

  An object of the present invention is to provide a transmission capable of suppressing an increase in radial size.

  The transmission according to the present invention comprises an input shaft to which a rotational force of a drive source is input, a reduction mechanism for transmitting the rotational force of the input shaft to a differential mechanism, and the two divided by the differential mechanism. A hydraulic transmission unit in which one variable displacement pump motor to which one of the rotational forces is input and the other variable displacement pump motor to which the other is input are connected by a closed circuit, and the input of the one variable displacement pump motor A first engagement mechanism capable of outputting the rotational force of the output shaft to the output shaft, and a second engagement mechanism capable of outputting the rotational force of the input / output shaft of the other variable displacement pump motor to the output shaft And an input / output shaft of said one variable displacement pump motor is disposed coaxially with said input shaft.

  According to the transmission according to the present invention, it is possible to suppress the transmission from being enlarged in the radial direction.

A skeleton diagram showing an overall configuration of a vehicle according to an embodiment of the present invention Skeleton diagram showing the first transmission state Skeleton diagram showing the second transmission state Skeleton diagram showing the third transmission state Diagram showing the relationship between speed ratio and displacement volume

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiment described below is an example, and the present invention is not limited by this embodiment.

  First, with reference to FIG. 1, an overall configuration of a vehicle 1 equipped with a hydraulic mechanical transmission according to the present embodiment will be described. The longitudinal direction of the vehicle 1 is depicted in FIG. In the following description, the front side of the vehicle may be simply referred to as "front" and the rear side of the vehicle may be simply referred to as "rear".

  The vehicle 1 includes a drive source 10, a damper 20, a differential mechanism 30, a hydraulic transmission unit 40, and a stepped transmission unit 50. A drive wheel 64 is coupled to the output side of the stepped transmission unit 50 via a propeller shaft 61, a differential 62 and a drive shaft 63 so that power can be transmitted.

  The drive source 10 is, for example, a diesel engine. The drive source 10 may be a gasoline engine, an electric motor or the like. The input side member 21 of the damper 20 is connected to the output shaft 11 of the drive source 10.

  The damper 20 includes an input side member 21, an output side member 22, and an elastic connecting member 23 that elastically connects the input side member 21 and the output side member 22. The output side member 22 of the damper 20 is connected to the input shaft 22a. The damper 20 has a function of suppressing transmission of rotational vibration generated by the drive source 10 to the differential mechanism 30. The structure of the damper 20 is the same as that of a general damper, and thus the detailed description is omitted.

  The rear end of the input shaft 22a is pivotally supported by a second input / output shaft 42a (described later) via a bearing (not shown). The input shaft 22a and the second input / output shaft 42a are coaxially arranged.

  A reduction gear 22b is provided on the rear end side of the input shaft 22a so as to rotate integrally with the input shaft 22a. The reduction gear 22 b meshes with a differential input gear 31 a provided on the outer periphery of the input member 31 of the differential mechanism 30. The reduction gear 24 b and the differential input gear 31 a constitute a reduction mechanism 24. The rotation of the drive source 10 transmitted to the input shaft 22 a is decelerated by the reduction mechanism 24 and input to the differential mechanism 30.

  The differential mechanism 30 is provided with a plurality of bevel gears 32, a first differential output gear 33 and a second differential output gear 34 provided equidistantly in the circumferential direction. As shown in FIG. 1, the bevel gear 32 is axially supported by the input member 31 so as to be relatively rotatable. The first differential output gear 33 is provided at the front end of the first input / output shaft 41 a of the first pump motor 41. The second differential output gear 34 is provided at the front end of the differential output shaft 35.

  The differential output shaft 35 is a cylindrical member coaxial with the first input / output shaft 41 a and provided on the outer peripheral side of the first input / output shaft 41 a. A first gear 36 is provided at the rear end of the differential output shaft 35. The differential output shaft 35 is pivotally supported by the first input / output shaft 41 a via a bearing (not shown). The first gear 36 meshes with a second gear 37 provided on the front end side of the second input / output shaft 42 a of the second pump motor 42.

  In the present embodiment, the number of teeth of the first differential output gear 33 is the same as the number of teeth of the second differential output gear 34. Further, the number of teeth of the first gear 36 is the same as the number of teeth of the second gear 37. The structure of the differential mechanism 30 is the same as that of a general bevel gear type differential mechanism, and thus the detailed description is omitted.

  Here, the reason why the output shaft 11 of the drive source 10 is not connected directly to the differential mechanism 30 via the damper 20 but connected via the reduction gear mechanism 24 including the reduction gear 22 b and the differential input gear 31 a is simple. Explain to.

  As described above, in the present embodiment, the power of the drive source 10 is input to the input member 31 for supporting the bevel gear 32 and is output from the first differential output gear 33 and the second differential output gear 34. Therefore, any of the first differential output gear 33 and the second differential output gear 34 except in the case where the rotational speeds of the input member 31, the first differential output gear 33 and the second differential output gear 34 are the same. One rotation speed exceeds the rotation speed of the input member 31.

  Therefore, when the output shaft 11 of the drive source 10 is directly connected to the input member 31 of the differential mechanism 30, the upper limit of the rotational speed of the drive source 10 corresponds to the first pump motor 41 and the second pump motor 42 of the hydraulic transmission unit 40 It may be limited by the upper limit number of rotations of (described later).

  On the other hand, in the present embodiment, the rotational speed of the output shaft 11 of the drive source 10 is reduced and transmitted to the input member 31 of the differential mechanism 30. Therefore, the upper limit of the rotational speed of the drive source 10 can be suitably suppressed from being limited by the upper limit rotational speeds of the first pump motor 41 and the second pump motor 42.

  A reduction mechanism is provided between the first and second differential output gears 33 and 34 and the first and second pump motors 41 and 42, respectively, to rotate the first and second differential output gears 33 and 34. It is conceivable to reduce the number and transmit it to the first and second pump motors 41, 42.

  However, in such a case, it is necessary to provide an additional shaft on an axis different from the first and second input / output shafts 41a and 42a in order to provide the speed reduction mechanism, and the transmission increases in size in the radial direction. Also, two reduction mechanisms are required.

  On the other hand, in the present embodiment, the input shaft 22a is disposed coaxially with the second input / output shaft 42a, and the axis of the differential mechanism 30 is made to coincide with the first input / output shaft 41a. Therefore, the transmission as a whole has a two-shaft structure, and an increase in size of the transmission in the radial direction can be suitably suppressed. Also, there is one reduction mechanism.

  The hydraulic transmission unit 40 includes a first pump motor 41, a second pump motor 42, and a closed circuit 43 hydraulically connecting the first pump motor 41 and the second pump motor 42. Since the configuration of the closed circuit 43 is the same as a general HST closed circuit, components (charge pump, charge oil passage, relief oil passage, bypass oil passage, etc.) in the closed circuit 43 are omitted in FIG. doing.

  The first pump motor 41 is a so-called double swing pump motor capable of changing the displacement volume from zero to positive and negative directions. The first input / output shaft 41 a of the first pump motor 41 penetrates the first pump motor 41 from the front to the rear. As such a first pump motor 41, various types such as an axial piston type and a radial piston type can be adopted. The first pump motor 41 corresponds to the “other variable displacement pump motor” in the present invention.

  The second pump motor 42 is a so-called double swing pump motor capable of changing the displacement volume from zero to positive and negative directions. The second input / output shaft 42 a of the second pump motor 42 penetrates the second pump motor 42 from the front to the rear. As such a second pump motor 42, various types such as an axial piston type and a radial piston type can be adopted. The second pump motor 42 corresponds to "one variable displacement pump motor" in the present invention.

  In the present embodiment, the first pump motor 41 and the second pump motor 42 use the same type. Also, the maximum displacement volume of the first pump motor 41 is equal to the maximum displacement volume of the second pump motor 42.

  The stepped transmission unit 50 includes a first input / output shaft 41a, a second input / output shaft 42a disposed parallel to the first input / output shaft 41a, a sub shaft 51, and an output shaft 52. The first input / output shaft 41 a corresponds to the “input / output shaft of the other variable displacement pump motor” in the present invention. The second input / output shaft 42a corresponds to "the input / output shaft of one variable displacement pump motor" of the present invention.

  As described above, the first differential output gear 33 of the differential mechanism 30 is provided at the front end of the first input / output shaft 41a. In addition, a first input hub 41b is provided at the rear end of the first input / output shaft 41a so as to rotate integrally with the first input / output shaft 41a.

  The countershaft 51 is a cylindrical member coaxial with the first input / output shaft 41a and provided on the outer peripheral side of the first input / output shaft 41a. A first auxiliary gear 53 is provided at the front end of the auxiliary shaft 51, and a second auxiliary gear 54 is provided at the rear end of the auxiliary shaft 51.

  The first input gear 55 is provided on the outer peripheral side of the first input / output shaft 41a so as to be rotatable relative to the first input / output shaft 41a. The first input gear 55 is provided between the countershaft 51 and the first input hub 41b.

  As described above, the second gear 37 of the differential mechanism 30 is provided on the front end side of the second input / output shaft 42a. In addition, a second input hub 42b is provided at the rear end of the second input / output shaft 42a so as to rotate integrally with the second input / output shaft 42a.

  The second input gear 56 is provided to rotate integrally with the second input / output shaft 42a. The second input gear 56 is provided between the second pump motor 42 and the second input hub 42 b. The second input gear 56 meshes with the first auxiliary gear 53.

  An output hub 57 is provided at the front end of the output shaft 52 so as to rotate integrally with the output shaft 52. The first output gear 58 is provided on the outer peripheral side of the output shaft 52 so as to be rotatable relative to the output shaft 52. The first output gear 58 is provided on the rear side of the output hub 57. The first output gear 58 meshes with the second auxiliary gear 54.

  The second output gear 59 is provided to rotate integrally with the output shaft 52. The second output gear 59 is provided on the rear side of the first output gear 58. The second output gear 59 is in mesh with the first input gear 55.

  The stepped transmission portion 50 is provided with a first connection mechanism 71 that selectively and integrally connects the first input / output shaft 41 a and the first input gear 55. The first connection mechanism 71 includes a first input hub 41 b, a first clutch gear 55 a integrally provided with the first input gear 55, and a first sleeve 72.

  The first sleeve 72 is provided on the outer peripheral side of the first input hub 41 b so as to be integrally rotatable with the first input hub 41 b and to be relatively movable in the axial direction. When the first sleeve 72 is in the rear position shown in FIG. 1, the first input / output shaft 41 a and the first input gear 55 can rotate relative to each other.

  By setting the first sleeve 72 to the front position, the first input gear 55 rotates integrally with the first input / output shaft 41 a. In this embodiment, a general synchronizer system is used as the first connection mechanism 71. Since a synchronizer type connection mechanism is known, the detailed description is omitted. The first connection mechanism 71 corresponds to the "second engagement mechanism" in the present invention.

  The geared transmission unit 50 is provided with a second connection mechanism 73 for selectively and integrally rotatably connecting the second input / output shaft 42a and the output shaft 52, or the first output gear 58 and the output shaft 52. ing. The second connection mechanism 73 includes a second input hub 42 b, an output hub 57, an output clutch gear 58 a integrally provided with the first output gear 58, and a second sleeve 74.

  The second sleeve 74 is provided on the outer peripheral side of the output hub 57 so as to be integrally rotatable with the output hub 57 and relatively movable in the axial direction. When the second sleeve 74 is at the center position shown in FIG. 1, the second input / output shaft 42a and the output shaft 52 can be rotated relative to each other. When the second sleeve 74 is at the center position shown in FIG. 1, the first output gear 58 and the output shaft 52 can rotate relative to each other.

  By setting the second sleeve 74 to the front position, the output shaft 52 rotates integrally with the second input / output shaft 42a. Further, by setting the second sleeve 74 to the rear position, the output shaft 52 rotates integrally with the first output gear 58. The second connection mechanism 73 corresponds to the "first engagement mechanism" in the present invention.

  Here, the first sleeve 72 is in the rear position, the second sleeve 74 is in the rear position, and the rotation of the second input / output shaft 42a is performed by the second input gear 56, the first auxiliary gear 53, and the second auxiliary gear 54. The state transmitted to the output shaft 52 via the first output gear 58 is referred to as "first transmission state" (see FIG. 2).

  In addition, the first sleeve 72 is at the front position, the second sleeve 74 is at the center position, and the rotation of the first input / output shaft 41 a is transmitted via the first input gear 55 and the second output gear 59 to the output shaft 52. The state transmitted to the vehicle is referred to as "second transmission state" (see FIG. 3).

  In addition, the state in which the first sleeve 72 is in the rear position and the second sleeve 74 is in the front position, and the rotation of the second input / output shaft 42a is directly transmitted to the output shaft 52 is referred to as "third transmission state" or It is called “direct connection state” (see FIG. 4).

  In the present embodiment, the number of teeth of the second input gear 56, the first sub gear 53, the second sub gear 54, and the first output gear 58 reduces the rotation of the second input / output shaft 42a in the first transmission state. Is set to be transmitted to the output shaft 52. Further, the number of teeth of the first input gear 55 and the second output gear 59 is set such that the rotation of the first input / output shaft 41a is decelerated and transmitted to the output shaft 52 in the second transmission state. .

  The gear ratio in the first transmission state (rotational speed of the second input / output shaft 42a / rotational speed of the output shaft 52) is α1, the transmission gear ratio in the second transmission state (rotational speed of the first input / output shaft 41a / output shaft 52 Assuming that the rotation speed is α2, α1> α2> 1. The relationship between α1, α2 and 1 (direct connection) is not limited to this. Specifically, for example, it is possible to set α1 <α2 <1.

  Next, the gear change operation will be described with reference to FIGS. 2 to 4 are skeleton diagrams in each transmission state. FIG. 5 is a diagram showing the relationship between the speed ratio and the displacement volume.

  The start of the vehicle 1 is performed in the first transmission state shown in FIG. In this case, the first pump motor 41 operates as a pump, and the second pump motor 42 operates as a motor. In the following description, “operate as a pump” and “operate as a motor” refer to the first pump when the vehicle 1 is driven by the drive source 10 (that is, when the tire is performing positive work) The role of the motor 41 and the second pump motor 42 is referred to. When the vehicle 1 is driven from the wheel side (i.e., when the engine brake is applied), the roles of the pump and the motor are reversed.

  In order to start the vehicle 1, the displacement volume of the first pump motor 41 operating as a pump is gradually increased from zero while holding the displacement volume of the second pump motor 42 at a maximum. By doing this, as shown in FIG. 5, the speed ratio (the rotation number Nout of the output shaft 52 / the rotation number Nin of the drive source 10) rises from zero.

  At this time, when the engine torque is controlled so that the discharge pressure from the first pump motor 41 to the second pump motor 42 becomes constant (that is, the engine torque is increased according to the increased pump-side displacement volume) (In the case where it is made), the torque generated by the second pump motor 42 becomes constant. Further, the torque transmitted from the differential gear to the second input / output shaft 42a of the second pump motor 42 is increased. Therefore, the torque transmitted to the output shaft 52 is increased.

  When the displacement volume of the first pump motor 41 is maximum, the displacement volume of the second pump motor 42 operating as a motor is gradually directed toward zero while maintaining the displacement volume of the first pump motor 41 at a maximum. Reduce it to By doing this, the speed ratio is further increased.

  When the displacement volume of the second pump motor 42 is gradually decreased and the displacement volume of the second pump motor 42 becomes Q1, the rotational speed of the first input hub 41b (ie, the rotation of the first input / output shaft 41a Number) and the rotational speed of the first input gear 55 match.

  At this timing, the gear change in the stepped transmission unit 50 is performed. Specifically, the first sleeve 72 is moved to the front position, and the second sleeve 74 is moved from the rear position to the central position. Thus, in the stepped transmission unit 50, the shift from the first transmission state to the second transmission state is performed. In addition, at the time of such a shift, torque shortage does not occur.

  When the shift from the first transmission state to the second transmission state is completed in the stepped transmission unit 50, the first pump motor 41 operating as a pump in the first transmission state operates as a motor and operates as a motor. The second pump motor 42 that has been operating operates as a pump.

  Subsequently, in a state where the displacement volume of the first pump motor 41 is held at the maximum, the displacement volume of the second pump motor 42 operating as a pump is gradually increased from Q1. By doing this, the speed ratio is further increased.

  When the displacement volume of the second pump motor 42 is maximum, the displacement volume of the first pump motor 41 operating as a motor is gradually directed toward zero while maintaining the displacement volume of the second pump motor 42 at a maximum. Reduce it to By doing this, the speed ratio is further increased.

  When the displacement volume of the first pump motor 41 is gradually decreased and the displacement volume of the first pump motor 41 becomes Q2, the rotational speed of the second input hub 42b (ie, the rotation of the second input / output shaft 42a) And the number of rotations of the output hub 57 (that is, the number of rotations of the output shaft 52).

  At this timing, the gear change in the stepped transmission unit 50 is performed. Specifically, the second sleeve 74 is moved to the front position, and the first sleeve 72 is moved from the front position to the rear position. In this manner, gear change from the second transmission state to the third transmission state is performed in the stepped transmission unit 50. In addition, at the time of such a shift, torque shortage does not occur.

  When the shift from the second transmission state to the third transmission state is completed in the stepped transmission unit 50, the second pump motor 42 operating as a pump in the second transmission state operates as a motor and operates as a motor. The first pump motor 41 which has been operating operates as a pump.

  Subsequently, in a state where the displacement volume of the second pump motor 42 is maintained at a maximum, the displacement volume of the first pump motor 41 operating as a pump is gradually increased from Q2. By doing this, the speed ratio is further increased.

  When the displacement volume of the first pump motor 41 is maximum, the displacement volume of the second pump motor 42 operating as a motor is gradually directed toward zero while maintaining the displacement volume of the first pump motor 41 at a maximum. Reduce it to By doing this, the speed ratio is further increased. Then, the speed ratio increases until the displacement volume of the second pump motor 42 becomes substantially zero.

  As described above, according to the present embodiment, the rotational force of the drive source 10 can be input from the input shaft 22a coaxially arranged with the second input / output shaft 42a to the input of the differential mechanism 30 via the reduction mechanism 24. It was made to transmit to the member 31. Thereby, the transmission can be made into a two-shaft structure. Therefore, it becomes possible to suppress the enlargement in the radial direction.

  In particular, when the transmission is mounted on a so-called FR vehicle in which the engine is disposed on the front side of the vehicle and the rear wheel is a driving wheel, the radial dimension is often restricted on the vehicle. In this embodiment, since the transmission as a whole has a two-shaft structure, the mountability to the FR vehicle is improved. Further, when the transmission is disposed vertically with respect to the vehicle, the radial dimension of the transmission is often restricted in relation to the space in which the transmission is mounted (in particular, the space in the vehicle width direction). In particular, when the side PTO is added to the transmission or when the vehicle is four-wheel driven, the restriction of the radial dimension of the transmission is large. According to the transmission of the present embodiment, since the transmission has a two-shaft structure, enlargement in the radial direction can be suppressed, and when the transmission is vertically mounted to the vehicle, the mountability to the vehicle is improved. Do.

  Further, according to the present embodiment, the second connecting mechanism 73 is provided to shift the rotation of the second input / output shaft 42 a of the second pump motor 42 and transmit the rotation to the output shaft 52. Therefore, high-speed travel of the vehicle becomes possible.

  Further, according to the present embodiment, the first connection mechanism 71 and the second connection mechanism 73 are mechanical engagement mechanisms by the engagement of the hub and the sleeve. Therefore, loss of transmission efficiency can be reduced.

  In the above-described embodiment, the input shaft 22a is disposed coaxially with the second input / output shaft 42a, and the axis of the differential mechanism 30 is aligned with the first input / output shaft 41a. However, the present invention is not limited thereto. The input shaft 22a may be disposed coaxially with the first input / output shaft 41a, and the axis of the differential mechanism 30 may be aligned with the second input / output shaft 42a.

  Moreover, in the above-mentioned embodiment, although the differential mechanism was a bevel gear type differential mechanism, it is not limited to this. A well-known structure can be suitably adopted as a differential mechanism. Specifically, for example, a planetary gear mechanism can be used as a differential mechanism.

  Further, in the above-described embodiment, although the stepped transmission is configured such that the first input / output shaft side is one stage and the second input / output shaft side is two stages, a total of three stages are provided, the present invention is not limited thereto. Specifically, for example, the first input / output shaft may have two stages, and the first input / output shaft may have one stage.

  Further, in the present embodiment, although the number of shift speeds in the stepped transmission unit is three, the present invention is not limited to this. Specifically, for example, a transmission mechanism that shifts the rotational force of the first input / output shaft and transmits it to the output shaft is provided, and the first input / output shaft side has two stages, and the second input / output shaft side has two stages. It may be In this case, each gear ratio is set to alternately use the first input / output shaft and the second input / output shaft. Furthermore, it is also possible to make the number of shift stages from each input / output shaft to the output shaft 3 or more, and to achieve further multistage.

  The continuously variable transmission according to the present invention is suitably used in a vehicle in which the transmission is placed vertically with respect to the vehicle, in particular, a so-called FR vehicle in which an engine is disposed on the front side of the vehicle and a rear wheel is a driving wheel.

Reference Signs List 1 vehicle 10 drive source 11 output shaft 20 damper 21 input side member 22 output side member 22a input shaft 22b reduction gear 23 elastic connection member 24 speed reduction mechanism 30 differential mechanism 31 input member 31a differential input gear 32 bevel gear 33 first differential Output gear 34 second differential output gear 35 differential output shaft 36 first gear 37 second gear 40 hydraulic transmission unit 41 first pump motor 41 a first input / output shaft 41 b first input hub 42 second pump motor 42 a second Input / output shaft 42b Second input hub 43 Closed circuit 50 Stepped transmission unit 51 Secondary shaft 52 Output shaft 53 First minor gear 54 Second minor gear 55 First input gear 55a First clutch gear 56 Second input gear 57 Output hub 58 1st output gear 58a output clutch gear 59 2nd output gear 61 propeller shaft 62 differential Le 63 drive shaft 64 drive wheel 71 first connecting mechanism 72 first sleeve 73 second coupling mechanism 74 the second sleeve

Claims (3)

An input shaft to which the rotational force of the drive source is input;
A reduction mechanism for transmitting the rotational force of the input shaft to a differential mechanism;
A hydraulic transmission unit in which one variable displacement pump motor into which one of the rotational force divided into two by the differential mechanism is input and the other variable displacement pump motor into which the other is input are connected by a closed circuit When,
The first engagement mechanism capable of outputting the rotational force of the input / output shaft of the one variable displacement pump motor to the output shaft, and the rotational force of the input / output shaft of the other variable displacement pump motor to the output shaft And a geared transmission having a second engagement mechanism capable of outputting.
The input / output shaft of the one variable displacement pump motor is disposed coaxially with the input shaft,
transmission. The first engagement mechanism is capable of changing the rotational force of the input / output shaft of the one variable displacement pump motor at a plurality of transmission ratios and outputting it to the output shaft.
The transmission according to claim 1. The first and second engagement mechanisms are mechanical engagement mechanisms.
The transmission according to claim 1 or 2.

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