JP6716401B2 - Rotation transmission device - Google Patents

Description

The present invention relates to a rotation transmission device that switches between transmission and interruption of rotation from an input shaft to an output shaft.

The rotation transmission device is an input shaft (steering shaft) that rotates around an axis by a driver's steering operation and an output shaft connected to a steering device that steers the wheels to the left and right, as in a vehicle adopting a steer-by-wire system. It is often adopted as a mechanism that can switch the connection and disconnection with the (steering shaft).

For example, the configuration according to Patent Document 1 includes a clutch that switches between transmission and interruption of rotation between an input shaft and an output shaft, and a steering motor that drives a steering device to steer left and right wheels. ing. This clutch is normally disengaged, and the input shaft and the output shaft are mechanically disconnected. When the driver performs the steering operation in this state, the operation amount is detected by the steering angle sensor and the steering torque sensor provided on the input shaft, and the reaction force motor control unit is based on the detection amount by each sensor. Drive the reaction force motor to apply a steering reaction force to the input shaft to give the driver a natural steering feeling, and the steering motor control unit drives the steering motor to steer the left and right wheels. To do. When the reaction force motor or the like has some trouble, the clutch is switched to the connected state in which the rotation can be transmitted from the input shaft side to the output shaft side, and the steering operation of the driver is performed in the same manner as a normal steering device. It enables the steering of the wheels based on it.

Further, in the configuration according to Patent Document 2, the clutch and the reaction force motor are integrated so that the rotation transmission device as a whole is made compact.

JP, 2014-221588, A JP, 2005-189346, A

In the configurations according to Patent Documents 1 and 2, since the clutch and the reaction force motor are separate members, there is a problem that it is difficult to make the entire configuration sufficiently compact and lightweight. Further, it may be considered that the reaction force motor is directly incorporated in a part of the clutch mechanism, but in that case, it is necessary to incorporate a three-phase motor coil in the reaction force motor, and the wiring and the reaction force motor coil are There is a problem that the structure becomes complicated and the cost increases.

Therefore, it is an object of the present invention to reduce the size of a steer-by-wire type rotation transmission device and to apply a steering reaction force with a simple structure.

In order to solve this problem, in the present invention, a two-way clutch that switches transmission and interruption of rotation between an input shaft and an output shaft, an armature that performs a switching operation of the two-way clutch, and an armature that faces the armature. And a rotor provided to face the rotor, and an electromagnetic coil having a magnetic coil that applies a magnetic force that attracts the armature to the rotor, and a steering force of a driver by the magnetic force applied to the rotor. A rotation transmission device including a reaction force mechanism that generates a steering reaction force associated with an operation.

With this configuration, the rotor, which is a component of the electromagnetic clutch, can function as a part of the reaction force mechanism, and the number of components can be reduced compared to the case where the reaction force mechanism is individually provided in the electromagnetic clutch. You can Therefore, it is possible to reduce the size and weight of the entire configuration while ensuring the functions of both the electromagnetic clutch and the reaction mechanism.

In the above-mentioned structure, the reaction force mechanism has a power generation coil, generates an induced voltage in the power generation coil with the rotation of the rotor to which a magnetic force is applied, and generates power, and also generates a steering reaction force. It is preferable to have such a configuration. With this configuration, it is possible to apply a steering reaction force to the steering operation of the driver with a simple configuration, and it is possible to expect power generation associated with this steering. Therefore, it is possible to reduce the carry-out of electric power from the battery as much as possible, and it is possible to further reduce the weight of the vehicle by reducing the capacity of the battery.

In the configuration having the power-generating coil, the number of the power-generating coils is equal to the number of poles of the rotor, the circumferential distance between the adjacent power-generating coils, and the adjacent poles of the rotor. It is preferable that the circumferential intervals be uniform. With this configuration, a plurality of pairs of the power-generating coil and rotor poles that are radially opposed to the power-generating coil are formed, and a plurality of power-generating coil and rotor poles are formed in accordance with the steering operation of the driver. The pair of touches and separates simultaneously. Since the contact and separation occur at the same time, a large induced voltage can be generated in the power generation coil and a large steering reaction force can be obtained. The magnitudes of the induced voltage and the steering reaction force increase as the steering operation speed increases, that is, as the contact/separation speed between the power generation coil and the rotor pole increases.

In each of the above configurations, it is preferable that a claw pole type magnetic pole pair is formed on a surface of the rotor that faces the electromagnetic coil. As described above, by forming the claw pole type magnetic pole pairs in the rotor, the magnetic poles corresponding to the number can be formed with a high density, and the size of the rotor can be reduced.

In each of the above configurations, it is preferable that the reaction force mechanism is disposed outside the electromagnetic coil in the radial direction. By arranging the reaction force mechanism in this way, the axial length becomes compact, and the rotation transmission device can be easily mounted in a small passenger vehicle such as a light vehicle.

The rotation transmission device shown in each of the configurations switches transmission and interruption of rotation between the input shaft that rotates integrally with the steering shaft and the output shaft that is connected to the steering device, and also applies a steering reaction force to the input shaft. The present invention can be applied to an automobile steer-by-wire device that can provide

In the rotation transmission device according to the present invention, the magnetic force applied to the rotor, which is a component of the electromagnetic clutch, is used to generate the steering reaction force associated with the steering operation by the driver. The number of parts can be reduced as compared with the case where the reaction force mechanism for making it is configured as a separate member. Therefore, the rotation transmission device can be made compact and lightweight, and the steering reaction force can be applied with a simple structure.

1 is a longitudinal sectional view showing an embodiment of a rotation transmission device according to the present invention. Front view showing a steering mechanism that employs the rotation transmission device shown in FIG. (A) is sectional drawing which follows the III-III line in FIG. 1, and is a free state of a two-way clutch, (b) is a standby state of a two-way clutch. Sectional drawing which follows the IV-IV line in FIG. FIG. 5 is a cross-sectional view taken along the line VV in FIG. 4, where (a) is a state where the ball is located at the deepest position of the cam groove, and (b) is a groove depth where the ball is in the cam groove. The state of rolling toward a shallow place Sectional drawing which follows the VI-VI line in FIG. Sectional drawing which follows the VII-VII line in FIG. 1 is a perspective view of a rotor used in the rotation transmission device shown in FIG. 1A is a cross-sectional view taken along line IX-IX in FIG. 1, and FIG. 1B is a cross-sectional view of a main part of FIG. 2A and 2B are vertical cross-sectional views showing a main part of the rotation transmission device shown in FIG. 1, in which FIG.

An embodiment of the rotation transmission device 1 according to the present invention will be described with reference to FIGS. 1 to 10. As shown in FIGS. 1 and 2, this rotation transmission device 1 is an output connected to an input shaft 3 (steering shaft) that rotates integrally with a steering shaft 2 and a steering device 5 that steers wheels 4 left and right. It is used in a steer-by-wire device for an automobile, which can switch transmission and interruption of rotation with the shaft 6 (steering shaft) and can apply a steering reaction force to the input shaft 3.

The rotation transmission device 1 mainly includes a two-way clutch 10, an electromagnetic clutch 30, and a reaction force mechanism 40. The two-way clutch 10, the electromagnetic clutch 30, and the reaction force mechanism 40 are housed in a housing 50.

As shown in FIGS. 1 and 3, the two-way clutch 10 is provided at the shaft end portion of the output shaft 6 and has an outer ring 11 having a cylindrical surface 11 a formed on the inner periphery thereof and the shaft end portion of the input shaft 3. An inner ring 12 provided on the outer periphery of which a plurality of cam surfaces 12a are formed at equal intervals in the circumferential direction, a pair of rollers 13 and 13 as an engaging element arranged between the cylindrical surface 11a and the cam surface 12a, and a pair of rollers. Is provided between the rollers 13 and 13, and includes a biasing member 14 that biases the pair of rollers 13 and 13 in opposite circumferential directions, and a retainer 15 that holds each roller.

The cam surface 12a is composed of inclined surfaces 12a ₁ and 12a ₁ formed at both ends in the circumferential direction and a flat surface 12a ₂ formed along the tangent line of the inner ring 12 formed between the inclined surfaces 12a ₁ and 12a _1. Has been done. Posts 15a ₂ and 15b _{2 of} a cage 15 to be described later are arranged on the outer sides in the circumferential direction of the inclined surfaces 12a ₁ and 12a ₁ . A wedge space is formed between the outer ring 11 and the inner ring 12 such that the radial gap between the cylindrical surface 11a and the cam surface 12a becomes narrower on both sides as compared with the central portion in the circumferential direction.

As shown in FIG. 1, the cage 15 includes a control cage 15a and a rotary cage 15b. Control retainer member 15a is on one side an outer peripheral portion of the annular flange 15a _1, equally spaced pillars portion 15a ₂ of the same number of cam surfaces 12a in the circumferential direction, between the column portions _15a 2, 15a ₂ adjacent its to, and forming an arc-shaped long holes 15a _3, it has a configuration in which a cylindrical portion 15a ₄ in the opposite direction to the column portion 15a ₂ on the outer periphery. Rotation retainer 15b is on the outer periphery of the annular flange 15b _1, has a configuration in which equally spaced pillars portion 15b ₂ of the same number of cam surfaces 12a in the circumferential direction.

The control cage 15a and the rotary cage 15b are controlled as shown in FIGS. 3(a) and 4 by inserting the pillar portion 15b ₂ of the rotary cage 15b into the elongated hole 15a ₃ of the control cage 15a. column portion 15a ₂ and the rotation retainer 15b column portion 15b ₂ of the retainer 15a are combined so as to align alternately in the circumferential direction. Then, the distal end portion of the pillar portion _15a 2, 15b ₂ are arranged between the outer ring 11 and inner ring 12 in the combination state, the flange 15b ₁ of the flange 15a ₁ and the rotation retainer 15b of the control retainer 15a, the input shaft 3 It is incorporated between the outer ring 11 and the support ring 16 fitted on the outer periphery.

By incorporating this control retainer 15a and the rotation retainer 15b, between the column portions 15a ₂ of the control retainer 15a and the column portion 15b ₂ of the rotary cage 15b, the pocket 17 is formed. The pocket 17 radially faces the cam surface 12a formed on the inner ring 12. The pair of rollers 13, 13 are arranged in the pocket 17, and the biasing member 14 is arranged between the pair of rollers 13, 13.

As shown in FIG. 1, the flange 15a ₁ of the control cage 15a is slidably supported along a slide guide surface 3a formed on the outer circumference of the input shaft 3. A thrust bearing 18 is incorporated between the flange 15b ₁ of the rotary cage 15b and the support ring 16 fitted to the input shaft 3. The thrust bearing 18 prevents the rotary retainer 15b from moving toward the electromagnetic clutch 20 and also rotatably supports the rotary retainer 15b.

As shown in FIGS. 1 and 5, and rotation flange 15a ₁ of the control retainer 15a is between the flanges 15b ₁ of the rotation retainer 15b, a linear motion in the axial direction of the control retainer 15a, a control retainer 15a A torque cam 19 is provided as a motion converting mechanism that converts the cage 15b into a relative rotational motion. The torque cam 19 are each opposing surface of the flange 15b ₁ of the flange 15a ₁ and the rotary retainer 15b of the control retainer 15a, deep in the circumferential direction of the central portion, increases toward both ends shallows pair of cam grooves 19a, 19b are The ball 19c is incorporated between the pair of cam grooves 19a and 19b.

When an external force in a direction of approaching the flange 15b ₁ of the rotary cage 15b acts on the flange 15a ₁ of the control cage 15a to move the control cage 15a in the axial direction, as shown in FIG. 5(a). First, the ball 19c rolls toward the deepest groove depth of the cam grooves 19a and 19b. At this time, the rotary cage 15b rotates in one direction relative to the control cage 15a. This relative rotation, the distance between the bar portion 15b ₂ of the pillar portion 15a ₂ and the rotation retainer 15b of the control retainer 15a is narrowed, a pair of rollers 13, 13 against the biasing force of the biasing member 14 Approach each other. Then, the pair of rollers 13, 13 moves to a place where the radial gap of the wedge space formed in the pocket 17 is wide (near the center in the circumferential direction), and at least one of the roller 13 and the cylindrical surface 11a or the cam surface 12a. (A gap between the cylindrical surface 11a and the cylindrical surface 11a in FIG. 3(a)). Due to this gap, rotation transmission between the input shaft 3 and the output shaft 6 is blocked.

On the other hand, when an external force acting on the control retainer member 15a is released by the biasing force of the biasing member 14, a pair of rollers 13 and 13, the control retainer 15a of the pillar portion 15a ₂ and the rotary cage 15b of move in opposite directions so as to widen the distance between the bar portion 15b _2, the rotation retainer 15b is the control retainer 15a, relative rotation in the opposite direction to the one direction. With this relative rotation, as shown in FIG. 5( b ), the ball 19 c rolls toward the position where the groove depth of the cam grooves 19 a, 19 b is shallow, and the control cage 15 a becomes the rotary cage 15 b. Move axially away from each other. At this time, the pair of rollers 13, 13 move in opposite directions to each other at a location where the radial gap of the wedge space is narrow (near both ends in the circumferential direction). By this movement, the roller 13 and the cylindrical surface 11a and the cam surface 12a are engaged with each other (hereinafter, referred to as a standby state, see FIG. 3B).

In this standby state, when the input shaft 3 (inner ring 12) is rotated in one direction, one of the pair of rollers 13, 13 (roller 13 arranged on the opposite side to the rotation direction) has a cylindrical surface. The rotation of the input shaft 3 can be transmitted to the output shaft 6 (outer ring 11) by being firmly bitten between the cam surface 11a and the cam surface 12a. Further, when the input shaft 3 is rotated in the opposite direction, the other roller 13 of the pair of rollers 13, 13 is strongly caught between the cylindrical surface 11a and the cam surface 12a, and similarly, the rotation of the input shaft 3 is prevented. It can be transmitted to the output shaft 6.

As shown in FIGS. 1 and 7, a cylindrical holder fitting surface 3b having a diameter larger than that of the slide guide 3a surface is formed at the intersection of the axial end surface of the inner ring 12 and the slide guide 3a surface. The spring holder 20 is fitted to the holder fitting surface 3b. The spring holder 20 is prevented from rotating with respect to the holder fitting surface 3b and is supported immovably in the axial direction.

Its outer periphery, as shown in FIG. 6, a plurality of detent piece 20a which is disposed between the pillar portion 15b ₂ of the pillar portion 15a ₂ and the rotation retainer 15b of the control retainer 15a is formed. The rotation locking pieces 20a, when the control retainer 15a and rotating the retainer 15b are relatively rotated in a direction to reduce the circumferential width of the pocket 17, the control retainer 15a of the pillar portion 15a ₂ and the rotary cage 15b of The pillar portion 15b ₂ is received by both side edges to hold the pair of rollers 13, 13 facing each other at the neutral position.

As shown in FIGS. 6 and 7, a spring holding piece 20b is provided on the outer peripheral portion of the spring holder 20 so as to project to the outer diameter side of each biasing member 14. The spring holding piece 20b prevents the biasing member 14 from escaping to the outer diameter side between the pair of rollers 13, 13.

Bearings 21 and 22 are provided between the tip of the input shaft 3 and the output shaft 6, and between the output shaft 6 and the housing 50, respectively. The bearings 21 and 22 allow the input shaft 3 and the output shaft 6, and the output shaft and the housing 50 to rotate relative to each other about the shaft.

As shown in FIG. 1, the electromagnetic clutch 30 includes an armature 31, a rotor 32 provided axially opposite the armature 31, and an electromagnetic coil 33 provided opposite the rotor 32. The inner peripheral edge of the armature 31 is fitted to the outer periphery of the support ring 16 and is supported so as to be rotatable around the axis and movable in the axial direction. Further, the outer peripheral edge of the armature 31 is fitted into the control holder 15a, and the armature 31 and the control holder 15a are configured to move integrally in the axial direction.

As shown in FIG. 1, the rotor 32 is arranged coaxially with a tubular fitting tubular portion 32a that fits with the input shaft 3 and radially outside the fitting tubular portion 32a. Is a member having a U-shaped cross section in the circumferential direction, which includes a large-diameter tubular yoke 32b and a disc portion 32c that connects the fitting tubular portion 32a and the yoke 32b. As shown in FIG. 8, a claw pole type magnetic pole pair is formed on the surface (yoke 32b) of the rotor 32 that faces the reaction force mechanism 40. This claw pole type magnetic pole pair is composed of two yoke constituent members 32b ₁ and 32b _{2 which} face each other in the axial direction.

As shown in FIG. 8, each of the yoke constituent members 32b ₁ and 32b ₂ is formed with a mountain-shaped claw portion 32d that is continuous in the circumferential direction, and the claws formed on one of the yoke constituent members 32b ₁ and 32b ₂ are formed. The portion 32d is arranged so as to face the other yoke constituent members 32b ₁ and 32b ₂ while maintaining a gap between the claw portions 32d. When the electromagnetic coil 33 is energized, N-pole and S-pole magnetic poles are alternately formed in the circumferential direction on the claw portions 32d arranged in the circumferential direction of the yoke constituent members 32b ₁ and 32b ₂ . In this embodiment, each of the yoke constituting members 32b ₁ and 32b ₂ is provided with eight claw portions 32d, whereby the rotor 32 as a whole has 16 poles (8 pole pairs).

Both of the yoke constituent members 32b ₁ and 32b ₂ are continuously provided by a bridge portion 32e formed on the peripheral surface of the yoke 32b at a predetermined interval. As long as the bridge portion 32e has the strength for connecting both the yoke constituent members 32b ₁ and 32b ₂ in series, the smaller the number and the smaller the width in the circumferential direction, the closer the bridge 32e is to the magnetic pole formed on the yoke 32b. It is preferable because the influence is small.

The electromagnetic coil 33 generates a magnetic force in the rotor 32 by the energization, and as shown in FIG. 1, the magnetic force attracts the armature 31 to the rotor 32. When the armature 31 is attracted by the magnetic force, the control holder 15a of the two-way clutch 10 fitted to the armature 31 also moves in the same direction. When the control cage 15a moves in the axial direction (leftward in FIG. 1), the input shaft 3 and the output shaft 6 are disengaged by the action of the two-way clutch 10 as described above. A bearing 34 is provided between the electromagnetic coil 33 and the input shaft 3 so that the input shaft 3 and the electromagnetic coil 33 can relatively rotate around the shaft.

As shown in FIG. 1, the reaction force mechanism 40 is arranged outside the electromagnetic coil 33 in the radial direction so as to surround the yoke 32 b of the rotor 32. By arranging the reaction force mechanism 40 radially outside in this manner, the axial length becomes compact, and the rotation transmission device 1 can be easily mounted on a small automobile such as a light automobile. You can

In this reaction force mechanism 40, a power generation coil 42 is wound around a core 41, and as shown in FIGS. 9A and 9B, the tip of the core 41 faces the yoke 32b. The number of power generation coils 42 of the reaction force mechanism 40 and the number of poles of the rotor 32 can be appropriately determined, but both the number of power generation coils 42 and the number of poles of the rotor 32 are, for example, 16 poles (see FIG. It is preferable that the same number be used, and the circumferential distance between the adjacent power generating coils 42 and the circumferential distance between the adjacent poles of the rotor 32 be equal.

In this way, the number of power generation coils 42 and the number of poles of the rotor 32 are made equal, and the intervals in the circumferential direction are made uniform, so that the coils 42 for power generation and the poles of the rotor 32 radially opposed to the coils 42 for power generation. A plurality of pairs are formed. Then, as the driver operates the steering wheel, a plurality of pairs of the power generation coil 42 and the poles of the rotor 32 come into contact with and separate from each other at the same time. Since the contact and separation occur at the same time, a large induced voltage can be generated in the power generation coil 42 and a large steering reaction force can be obtained. The magnitudes of the induced voltage and the steering reaction force increase as the steering speed or steering angle of the steering increases, that is, the contact/separation speed between the power generation coil 42 and the pole increases, and the number of times of contact/separation increases.

If the number of poles of the power generation coil 42 and the rotor 32 is increased, the pair of the power generation coil 42 and the pole of the rotor 32 is brought close to or separated from each other even when the steering operation speed is low or the operation angle is small. It can be done reliably. Therefore, a sufficient amount of power generation can be obtained by the steering operation of the driver, and a steering reaction force having an appropriate amount can be generated.

Since this reaction force mechanism 40 does not have a motor function, it cannot positively apply a rotational force (steering reaction force) to the rotor, but it does not function as a reaction force mechanism (reaction force motor) having a motor function. In comparison, the structure can be simplified and the cost can be reduced.

As shown in FIG. 10A, in the energized state of the electromagnetic coil 33 (the state where the armature 31 is attracted to the rotor 32), the magnetic path (see the arrow in FIG. 10A) is inside the rotor 32. The magnetic path is formed and a part of this magnetic path is in a state of entering the armature 31 and the core 41 of the reaction force mechanism 40. In this state, when the steering (input shaft) is rotated around the axis by the driver's operation force, the interaction between the magnetic path and the reaction force mechanism 40 causes an induced voltage in the power generation coil 42 and the power generation. A braking force is generated by controlling the amount, and a steering reaction force opposite to the rotation acts on the rotor 32 side. In other words, the electromagnetic coil 33 can obtain a reaction force function with the current used to cut off the transmission as the two-way clutch 10.

This induced voltage can minimize the carry-out of electric power from the battery, and can reduce the size and weight of the battery. In addition, the steering reaction force allows the driver to obtain a steering feeling equivalent to that of a normal steering device that mechanically steers the wheels by the steering force of the driver.

Normally, the electromagnetic coil 33 is energized, and the two-way clutch 10 mechanically disconnects the input shaft 3 and the output shaft 6. However, when the electromagnetic coil 33 is de-energized due to some trouble, the rotor 32 and the armature 31 are separated from each other as shown in FIG. 10B, and as described above, the input shaft 3 and the output shaft 6 are separated from each other. It is mechanically connected via a directional clutch 10. As a result, a normal steering operation can be performed in which the left and right wheels are steered by the rotational force based on the driver's steering operation.

In this embodiment, the reaction force mechanism 40 is arranged radially outward of the electromagnetic coil 33 along the circumferential direction, but the reaction force mechanism 40 is arranged coaxially with the electromagnetic coil 33. It is also possible (not shown). By disposing the reaction force mechanism 40 in this manner, it is possible to reduce the size of the rotation transmission device 1 in the radial direction. In this case, the shape of the rotor 32 is appropriately changed so that the core 41 of the reaction force mechanism 40 and the yoke 32b of the rotor 32 face each other. Whether the disposition of the reaction force mechanism 40 is located radially outside or coaxial with the electromagnetic coil 33 can be appropriately determined according to the shape of the mounting space of the vehicle.

The rotation transmission device according to the above-described embodiment is merely an example in all respects, and aims at downsizing the rotation transmission device of the steer-by-wire system and imparts a steering reaction force with a simple structure. As long as the above can be solved, the shape, arrangement, etc. of each component can be appropriately changed.

2 Steering shaft 3 Input shaft 5 Steering device 6 Output shaft 10 Two-way clutch 30 Electromagnetic clutch 31 Armature 32 Rotor 33 Electromagnetic coil 40 Reaction force mechanism 42 Power generation coil

Claims (6)

A two-way clutch (10) for switching between transmission and interruption of rotation between the input shaft (3) and the output shaft (6),
An armature (31) for switching the two-way clutch (10), a rotor (32) provided so as to face the armature (31), and an rotor (32) provided so as to face the rotor (32). 32) an electromagnetic clutch (30) having an electromagnetic coil (33) for applying a magnetic force that attracts the armature (31),
A reaction force mechanism (40) for generating a steering reaction force due to a steering operation of a driver by a magnetic force applied to the rotor (32);
A rotation transmission device. The reaction force mechanism (40) has a power generation coil (42) and generates an induced voltage in the power generation coil (42) in accordance with the rotation of the rotor (32) to which a magnetic force is applied to generate power. The rotation transmission device according to claim 1, wherein a steering reaction force is also generated. The number of the power generating coils (42) and the number of poles of the rotor (32) are the same, and the circumferential spacing between the adjacent power generating coils (42) and the adjacent rotors (32). The rotation transmission device according to claim 2, wherein the poles are arranged at equal intervals in the circumferential direction. The rotation transmission device according to claim 1, wherein a claw pole type magnetic pole pair is formed on a surface of the rotor (32) facing the electromagnetic coil (33). The rotation transmission device according to any one of claims 1 to 4, wherein the reaction mechanism (40) is arranged radially outside the electromagnetic coil (33). The input shaft (3) is switched between transmission and cutoff of rotation between the input shaft (3) that rotates integrally with the steering shaft (2) and the output shaft (6) connected to the steering device (5). 6. The rotation transmission device according to claim 1, wherein the rotation transmission device is used in a steer-by-wire device for an automobile, which can apply a steering reaction force to the vehicle.

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