JP5445660B2 - Steering device - Google Patents

Description

  The present invention relates to a steering device, and more particularly to a steering device having a shaft coupling that connects shafts that transmit rotation of a steering shaft of the steering device.

  In a steering device that steers the front wheels of a vehicle, the movement of a steering shaft that is rotated by the operation of a steering wheel is transmitted to an input shaft of a steering gear through a universal joint.

  In such a steering device, when the shaft such as the intermediate shaft and pinion shaft connected to the universal joint is separated from the universal joint due to the layout of the vehicle body, it is between the universal joint and the intermediate shaft or freely. The joint and the pinion shaft are connected by an extension shaft and a shaft joint.

In a conventional shaft coupling, a plate portion is bent into a substantially cylindrical shape, and a coupling portion is formed. After press-fitting the extension shaft to the coupling portion, welding the extension shaft coupling portion. Next, the female serration coupling portion, after the male serration of the intermediate shaft engages serration engagement, reduced in diameter the female serration tighten the bolt to the coupling portion couples the coupling portion and the intermediate shaft.

In such a conventional shaft coupling, when press-fitting the extension shaft on the inner peripheral surface of the coupling portion, to open the slit of the coupling portion molded by bending a plate material, coupling portion is enlarged. Therefore, when the welding between the coupling portion and the extension shaft is insufficient, the coupling rigidity between the coupling portion and the extension shaft is lowered, and it is difficult to transmit the rotational torque of the steering shaft. .

As a shaft coupling in which a plate member is bent into a substantially cylindrical shape and a coupling portion is formed, there is a shaft coupling disclosed in Patent Document 1. In the shaft joint of Patent Document 1, the male serration of one shaft is serrated to the female serration of the inner peripheral surface of the shaft joint, and the cylindrical end portion of the other universal joint is press-fitted into the outer peripheral surface of the shaft joint. .

Therefore, even when press-fitting the cylindrical end portion of the universal joint on the outer peripheral surface of the shaft coupling, since only binding portion molded by bending a plate member is reduced in diameter, between the cylindrical end portion of the coupling portion and the universal joint The coupling rigidity does not decrease, and there is no problem in the transmission of the rotational torque of the steering shaft. However, the shaft coupling disclosed in Patent Document 1 cannot be applied to a shaft coupling in which a shaft is coupled to both ends of the inner peripheral surface of the coupling portion .

JP 2005-180698 A

The present invention provides a steering device having a shaft coupling in which a shaft is coupled to both ends of the inner peripheral surface of the coupling portion. Even when the weld coupling between the shaft and the shaft coupling is insufficient, the rotational torque of the steering shaft is reduced. It is an object of the present invention to provide a steering device capable of reliably transmitting.

The above problem is solved by the following means. That is, the first invention is a shaft coupling formed by bending a plate material, formed on one end side of the shaft coupling, and an arc-shaped coupling connecting a flange portion constituting a U-shaped parallel portion and a lower end of the flange portion. A U-shaped coupling portion having a connecting portion , a cylindrical coupling portion formed on the other end side of the shaft coupling and provided with a slit communicating with the inside, and penetrated through one of the U-shaped parallel portions A bolt hole formed through the other of the U-shaped parallel part, a female screw formed concentrically with the bolt hole, and inserted into the bolt hole and screwed into the female screw, thereby coupling the U-shaped A bolt that shrinks the U-shaped inner peripheral surface of the part , and a parallel surface and an arc surface that engage with the inner peripheral surface of the U-shaped coupling portion that is reduced in diameter by the bolt and transmit the rotational torque of the steering shaft. Has an outer peripheral surface First axis, is inserted from the other end side in the axial direction of the cylindrical coupling portion, a portion of the parallel surfaces for transmitting rotational torque of the steering shaft engages the inner peripheral surface of the parallel portion of the U-shaped welding a second shaft having a shaft portion of the circular, and the said circular shaft portion and the cylindrical coupling portion of the second shaft welded to tightly fit to the coupling portion of the outer peripheral surface and the cylinder having A steering apparatus including a coupling portion.

  A second invention is the steering device according to the first invention, wherein the first shaft is an intermediate shaft and the second shaft is an extension shaft.

  A sixth invention is characterized in that, in the steering device according to any one of the first and second inventions, the first shaft is a pinion shaft, and the second shaft is an extension shaft. It is a steering device.

In the steering device of the present invention, a non-circular inner peripheral surface is formed from one end of the connecting portion in the axial direction to the vicinity of the other end at the connecting portion of the shaft joint, and the non-circular inner peripheral surface of the reduced connecting portion is engaged. A first shaft having a non-circular outer peripheral surface that transmits rotational torque is inserted from one end of the coupling portion in the axial direction, and engaged with the non-circular inner peripheral surface of the coupling portion to transmit rotational torque. A second shaft having a non-circular outer peripheral surface is inserted from the other end in the axial direction of the joint portion , and the second shaft and the joint portion are joined by a weld joint portion.

Accordingly, the second axis, since the both engagement and welded connection between the non-circular inner circumferential surface of the coupling portion and the non-circular outer peripheral surface of the second shaft is coupled to the coupling section, welded Even if this is insufficient, the rotational torque can be reliably transmitted, so that the safety of the steering device is improved.

  Hereinafter, Example 1 to Example 2 of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall front view of a steering apparatus including a shaft coupling according to a first embodiment of the present invention. As shown in FIG. 1, the steering apparatus having the shaft coupling according to the first embodiment of the present invention includes a steering shaft 12 on which a steering wheel 11 can be mounted on the rear side of the vehicle body (the right side in FIG. 1), and the steering shaft 12 An inserted steering column 13, an assist device (steering assisting portion) 20 for applying an assist torque to the steering shaft 12, and a rack / pinion (not shown) on the front side of the vehicle body (left side in FIG. 1) of the steering shaft 12 And a steering gear 30 connected through a mechanism.

  The steering shaft 12 is spline-fitted between a female steering shaft 12A and a male steering shaft 12B so as to be able to transmit rotational torque and to be relatively movable in the axial direction. Therefore, when the female steering shaft 12A and the male steering shaft 12B collide, the spline fitting portion moves relative to each other so that the total length can be shortened.

  Further, the cylindrical steering column 13 inserted through the steering shaft 12 combines the outer column 13A and the inner column 13B so that they can be telescopically moved. It has a so-called collapsible structure in which the entire length is shortened while absorbing water.

  The vehicle body front side end portion of the inner column 13B is press-fitted and fixed to the vehicle body rear side end portion of the gear housing 21. Further, the front end portion of the male steering shaft 12B on the vehicle body is passed through the inside of the gear housing 21 and connected to the rear end portion of the assist device 20 on the rear side of the input shaft (not shown).

  The steering column 13 is supported by a support bracket 14 at a middle portion thereof on a part of the vehicle body 18 such as a lower surface of the dashboard. Further, a locking portion (not shown) is provided between the support bracket 14 and the vehicle body 18, and when an impact in a direction toward the front side of the vehicle body is applied to the support bracket 14, the support bracket 14 is locked to the locking bracket 14. It moves away from the vehicle and moves to the front side of the vehicle.

  The upper end portion of the gear housing 21 is also supported on a part of the vehicle body 18. In the case of this embodiment, by providing a tilt mechanism and a telescopic mechanism, the position of the steering wheel 11 in the longitudinal direction of the vehicle body and the height position can be freely adjusted. Such a tilt mechanism and a telescopic mechanism are well known in the art and are not characteristic features of the present invention, and thus detailed description thereof is omitted.

  The output shaft 23 protruding from the front end surface of the vehicle body of the gear housing 21 is connected to a universal joint (upper universal joint) 15, an extension shaft 4 coupled to the universal joint 15, and a shaft coupling 5 coupled to the extension shaft 4. The intermediate shaft 16 is connected to the rear end portion.

  Further, a pinion shaft (hereinafter referred to as a shaft) 31 of the steering gear 30 is connected to the front end portion of the intermediate shaft 16 via another universal joint (lower universal joint) 17. The intermediate shaft 16 is fitted on the vehicle body front side of the male intermediate shaft (male shaft) 16A on the vehicle body rear side of the female intermediate shaft (female shaft) 16B, so that rotational torque can be transmitted and relative movement in the axial direction is possible. Is fitted.

  A pinion (not shown) is formed at the lower end (the front end portion of the vehicle body) of the pinion shaft 31. A rack (not shown) meshes with the pinion, and the rotation of the steering wheel 11 moves the tie rod 32 to steer a wheel (not shown).

  A case 261 of an electric motor 26 is fixed to the gear housing 21 of the assist device 20, and a worm is coupled to a rotating shaft (not shown) of the electric motor 26. A worm wheel (not shown) is attached to the output shaft 23, and the worm of the rotating shaft of the electric motor 26 is engaged with the worm wheel.

  A torque sensor (not shown) is provided around the intermediate portion of the output shaft 23. The direction and magnitude of the torque applied from the steering wheel 11 to the steering shaft 12 is detected by a torque sensor, and the electric motor 26 is driven in accordance with the detected value via a reduction mechanism comprising a worm and a worm wheel. Then, the output shaft 23 is caused to generate auxiliary torque with a predetermined magnitude in a predetermined direction. The assist device that generates the auxiliary torque is not limited to an electric type, and may be a hydraulic assist device.

  2 to 3 show the shaft coupling of the first embodiment of the present invention, FIG. 2 is a component diagram showing the shaft coupling of the first embodiment of the present invention, and FIG. 2 (1) is a diagram of FIG. 2 (2). AA sectional view, FIG. 2 (2) is a front view of a part of the shaft coupling, and FIG. 2 (3) is a BB sectional view of FIG. 2 (2).

  3 shows a coupling state of the shaft coupling and the shaft according to the first embodiment of the present invention, FIG. 3 (1) is a component diagram of the extension shaft coupled to the shaft coupling, and FIG. 3 (2) is a diagram illustrating coupling of the extension shaft to the shaft coupling. FIG. 3 (3) is a cross-sectional view showing a state where an extension shaft and an intermediate shaft are coupled to the shaft coupling.

The shaft coupling according to the first embodiment of the present invention is an example in which the shaft coupling is applied to a coupling portion between the extension shaft (second shaft) 4 and the male intermediate shaft (first shaft) 16A shown in FIG.

As shown in FIG. 2, the shaft coupling 5 according to the first embodiment of the present invention is formed with a coupling portion 51 formed by bending a plate material into a substantially cylindrical shape, and a noncircular shape is formed on the inner peripheral surface of the coupling portion 51. A female serration 52 is formed as an inner peripheral surface. The female serration 52 is formed from one end (left end in FIG. 2 (2)) 511 of the coupling portion 51 to the vicinity of the other end (right end in FIG. 2 (2)) 512 in the axial direction.

A fitting hole 53 having a larger diameter than the female serration 52 is formed concentrically with the female serration 52 on the inner peripheral surface of the other end 512 in the axial direction of the coupling portion 51. The coupling portion 51 is formed with a pair of left and right flange portions 54A and 54B extending from the coupling portion 51 in the tangential direction (downward in FIG. 2 (1)) and then folded inward.

Flanges 54A, 54B from one end 511 of the coupling portion 51 is formed to a length of approximately half of the axial length of the coupling portion 51. A slit 55 communicating with the female serration 52 is formed between the flange portions 54A and 54B. The slit 55 is formed to extend to the other end 512 of the coupling portion 51 (see FIG. 2 (3)).

In addition, a bolt hole 541A is formed through the flange portion 54A in the left-right direction in FIG. 2A (the direction perpendicular to the axis of the coupling portion 51). Further, a female screw 541B is formed through the flange portion 54B concentrically with the bolt hole 541A. When a bolt (not shown) is inserted into the bolt hole 541A from the left side of FIG. 2A and screwed into the female screw 541B, the flange portions 54A and 54B are elastically deformed, the width of the slit 55 is reduced, and the female serration 52 is reduced in diameter.

  As shown in FIG. 3 (1), a male serration 41 capable of serration engagement with the female serration 52 is formed on the outer peripheral surface of the left end of the extension shaft (second shaft) 4. Further, the extension shaft 4 is formed with a shaft portion 42 having a diameter larger than that of the male serration 41 from the right end of the male serration 41 and closely fitting into the fitting hole 53 and having a circular cross section. ing.

As shown in FIG. 3 (2), the extension shaft 4 is inserted from the other end 512 of the coupling portion 51, and the male serration 41 formed on the extension shaft 4 is serrated and engaged with the female serration 52. The shaft portion 42 is closely fitted into the fitting hole 53.

Next, the other end 512 of the joint portion 51 and the outer periphery of the shaft portion 42 of the extension shaft 4 are welded and joined to form a weld joint portion 56. Subsequently, the male intermediate shaft 16 </ b> A (first shaft) is coupled to the shaft coupling 5 integrally coupled to the extension shaft 4.

  As shown in FIG. 3 (3), a male serration 61 capable of serration engagement with the female serration 52 is formed on the outer peripheral surface of the right end of the male intermediate shaft 16A. Further, a semicircular annular groove 62 is formed in the male intermediate shaft 16A at an intermediate position in the axial length of the male serration 61.

The male intermediate shaft 16A is inserted from one end 511 of the coupling portion 51, and the male serration 61 formed on the male intermediate shaft 16A is serrated to the female serration 52. Thereafter, when the bolt 81 is inserted into the bolt hole 541A of the shaft coupling 5 and screwed into the female screw 541B, the flange portions 54A and 54B are elastically deformed, the width of the slit 55 is reduced, and the female serration 52 is reduced in diameter.

  When the female serration 52 is reduced in diameter, the male serration 61 of the male intermediate shaft 16 </ b> A is strongly tightened to the female serration 52. Further, the outer periphery of the bolt 81 screwed into the shaft coupling 5 engages with the semicircular annular groove 62 of the male intermediate shaft 16A. Therefore, even if a force is applied in the direction in which the male intermediate shaft 16A is pulled out from the shaft coupling 5 (the left direction in FIG. 3 (3)), the annular groove 62 abuts on the outer periphery of the bolt 81. 5, the male intermediate shaft 16 </ b> A does not come out of the shaft coupling 5 while being held at a predetermined axial assembly position.

In the first embodiment, since the extension shaft 4 is coupled to the coupling portion 51 by both the serration engagement and the weld coupling portion 56, even if the welding coupling is insufficient, the rotational torque of the steering shaft 12 is reduced. Since it becomes possible to transmit reliably through serration engagement, the safety of the steering device is improved.

  Next, a second embodiment of the present invention will be described. FIG. 4 is a component diagram showing a shaft coupling of Embodiment 2 of the present invention, (1) is a left side view of (2), and (2) is a front view of the shaft coupling. FIG. 5 is a component diagram of the extension shaft coupled to the shaft coupling of the second embodiment. (1) is a left side view of (2), and (2) is a front view of the extension shaft.

  FIG. 6 shows a coupling state of the shaft coupling and the shaft according to the second embodiment of the present invention, (1) is a front view showing a state in which the extension shaft is coupled to the shaft coupling, and (2) is a cross-sectional view taken along the line CC of (1). FIG. 3 (3) is a sectional view taken along the line DD of (1). FIG. 7 is a front view showing a state in which an extension shaft and an intermediate shaft are coupled to the shaft coupling of Embodiment 2 of the present invention. In the following description, only structural portions and operations different from those of the first embodiment will be described, and overlapping descriptions will be omitted. Further, the same parts will be described with the same numbers.

In Example 1, female serrations were formed as noncircular inner peripheral surfaces on the inner peripheral surface of the coupling portion , but in Example 2, a pair of substantially parallel flat surfaces were formed as noncircular inner peripheral surfaces. It is.

As shown in FIG. 4, the shaft coupling 7 according to the second embodiment of the present invention is formed by bending a plate material, and a coupling portion 71 having a U-shaped cross section is formed on the left side of FIG. On the right side of the connecting portion 71, a cylindrical connecting portion 72 is integrally formed.

The U-shaped coupling portion 71 includes flange portions 73A and 73B that constitute substantially U-shaped parallel portions, and an arc-shaped coupling portion 74 that couples the lower ends of the flange portions 73A and 73B. The flange portions 73 </ b> A and 73 </ b> B form an opening 75 on the opposite side (upper side in FIG. 4) of the connecting portion 74.

As shown in FIG. 4 (1), the flange portions 73A and 73B that are arranged substantially parallel to each other are provided with flat surfaces 731A and 731B parallel to each other as noncircular inner peripheral surfaces. Is formed. In addition, circular bolt holes 732A and 732B pass through the flange portions 73A and 73B concentrically in the left-right direction of FIG. 4A (the direction perpendicular to the axis of the coupling portions 71 and 72). Is formed.

A circular fitting hole (see FIG. 6 (3)) 721 is formed on the inner peripheral surface of the coupling portion 72 concentrically with the coupling portion 72. The coupling portion 72 is formed with a slit 722 that communicates with the opening 75 and communicates with the fitting hole 721. The slit 722 extends to the right end 723 of the coupling portion 72.

  When a bolt (not shown) is inserted into the bolt hole 732A from the left side of FIG. 4 (1) and a nut is screwed into the bolt from the right side of FIG. 4 (1), the flange portions 73A and 73B are elastically deformed and flat surfaces 731A and 731B are obtained. The width of is narrowed.

  As shown in FIG. 5, a shaft portion 42 having a diameter dimension that fits closely into the fitting hole 721 and a circular section is formed on the outer peripheral surface of the left end of the extension shaft (second shaft) 4. . The left end outer peripheral surface of the shaft portion 42 has a substantially oval shape and is formed with a pair of parallel flat surfaces 43A and 43B that can be engaged with the flat surfaces 731A and 731B.

As shown in FIG. 6 (1), the extension shaft 4 is inserted from the right end 723 of the coupling portion 72, and the flat surfaces 43A and 43B formed on the extension shaft 4 are engaged with the flat surfaces 731A and 731B. The shaft portion 42 of the shaft 4 is closely fitted into the fitting hole 721.

Next, the right end 723 of the joint portion 72 and the outer periphery of the shaft portion 42 of the extension shaft 4 are welded and joined to form a weld joint portion 76. Subsequently, the male intermediate shaft (first shaft) 16 </ b> A is connected to the shaft coupling 7 integrally coupled with the extension shaft 4.

  As shown in FIG. 7, on the outer peripheral surface of the right end of the male intermediate shaft 16A, a pair of parallel flat surfaces 63A and 63B that can be engaged with the flat surfaces 731A and 731B (in FIG. 7, only one flat surface 63B is provided). Is formed). A semicircular groove 64 is formed above the outer peripheral surface of the male intermediate shaft 16A at a substantially intermediate position in the axial length of the flat surfaces 63A and 63B.

The male intermediate shaft 16A is inserted from the left end 711 of the coupling portion 71, and the pair of flat surfaces 63A and 63B formed on the male intermediate shaft 16A are engaged with the flat surfaces 731A and 731B. Thereafter, when the bolt 82 is inserted into the bolt holes 732A and 732B of the shaft coupling 7 and a nut (not shown) is screwed into the bolt 82, the flange portions 73A and 73B are elastically deformed, and the flat surfaces 731A and 731B are narrowed.

  When the flat surfaces 731A and 731B are narrowed, the flat surfaces 63A and 63B of the male intermediate shaft 16A are strongly tightened to the flat surfaces 731A and 731B. Further, the eccentric outer periphery of the bolt 82 inserted into the shaft coupling 7 engages with the semicircular groove 64 of the male intermediate shaft 16A. Therefore, even if a force is applied in the direction in which the male intermediate shaft 16A is pulled out from the shaft coupling 7 (the left direction in FIG. 7), the groove 64 abuts the outer periphery of the bolt 82. The male intermediate shaft 16 </ b> A does not come out of the shaft coupling 7 while being held at a predetermined axial assembly position.

In the second embodiment, the extension shaft 4 is coupled to the coupling portion 72 by both the engagement of the flat surfaces 43A and 43B and the flat surfaces 731A and 731B and the weld coupling portion 76. Therefore, even if the welding connection is insufficient, the rotational torque of the steering shaft 12 can be reliably transmitted through the engagement between the flat surfaces 43A and 43B and the flat surfaces 731A and 731B. The safety of the steering device is improved.

  In the above embodiment, the case where the noncircular inner peripheral surface is the serration engagement between the female serration and the male serration and the pair of flat surfaces substantially parallel to each other has been described. Torque may be transmitted.

In the above embodiment, an example of applying the binding portion of the extension shaft 4 and the intermediate shaft 16, applied such union of the extension shaft and the pinion shaft 31, the coupling portion of any axis of the steering device can do.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall front view of a steering apparatus including a shaft coupling according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is component drawing which shows the shaft coupling of Example 1 of this invention, (1) is AA sectional drawing of (2), (2) is the front view which cut down a part of shaft coupling, (3) is ( It is BB sectional drawing of 2). The coupling | bonding state of the shaft coupling and shaft of Example 1 of this invention is shown, (1) is a component drawing of the extension shaft couple | bonded with a shaft coupling, (2) is a part which shows the state which couple | bonded the extension shaft to the shaft coupling. FIG. 3 is a cross-sectional front view, and FIG. 3 (3) is a cross-sectional view showing a state in which an extension shaft and an intermediate shaft are coupled to a shaft coupling. It is component drawing which shows the shaft coupling of Example 2 of this invention, (1) is a left view of (2), (2) is a front view of a shaft coupling. It is a component figure of the extension shaft couple | bonded with the shaft coupling of Example 2, (1) is a left view of (2), (2) is a front view of an extension shaft. The coupling | bonding state of the shaft coupling and shaft of Example 2 of this invention is shown, (1) is a front view which shows the state which couple | bonded the extension shaft to the shaft coupling, (2) is CC sectional drawing of (1), ( 3) is a sectional view taken along the line DD of (1). It is a front view which shows the state which couple | bonded the extension shaft and the intermediate shaft with the shaft coupling of Example 2 of this invention.

DESCRIPTION OF SYMBOLS 11 Steering wheel 12 Steering shaft 12A Female steering shaft 12B Male steering shaft 13 Steering column 13A Outer column 13B Inner column 14 Support bracket 15 Universal joint (upper universal joint)
16 Intermediate shaft 16A Male intermediate shaft 16B Female intermediate shaft 17 Universal joint (lower universal joint)
DESCRIPTION OF SYMBOLS 18 Car body 20 Assist device 21 Gear housing 23 Output shaft 26 Electric motor 261 Case 30 Steering gear 31 Pinion shaft 32 Tie rod 4 Extension shaft 41 Male serration 42 Shaft portion 43A, 43B Flat surface 5 Shaft joint 51 Joint portion 511 One end 512 Other end 52 female serration 53 fitting holes 54A, 54B flange portion 541A bolt hole 541B internal thread 55 slit 56 welded connection 61 male serration 62 annular groove 63A, 63B of the flat surface 64 groove 7 shaft coupling 71 U-shaped coupling portion 711 left 72 cylindrical Joint portion 721 Fitting hole 722 Slit 723 Right end 73A, 73B Flange portion 731A, 731B Flat surface 732A, 732B Bolt hole 74 Connection portion 75 Open portion 76 Welded joint portion 81 Bolt 82 volts

Claims (3)

A shaft coupling formed by bending a plate material,
A coupling portion having a U-shaped cross section including a flange portion that forms a U-shaped parallel portion and an arc-shaped coupling portion that connects a lower end of the flange portion, formed on one end side of the shaft coupling;
A cylindrical coupling part formed on the other end side of the shaft coupling and provided with a slit communicating with the inside,
A bolt hole formed through one of the U-shaped parallel parts;
An internal thread penetrating the other of the U-shaped parallel parts and formed concentrically with the bolt hole;
A bolt that is inserted into the bolt hole and screwed into the female screw, thereby shrinking the U-shaped inner peripheral surface of the U-shaped coupling portion;
A first shaft having an outer peripheral surface constituted by a parallel surface and an arc surface that engages with the inner peripheral surface of the U-shaped coupling portion reduced in diameter by the bolt and transmits the rotational torque of the steering shaft;
An outer peripheral surface having a parallel surface portion inserted from the other axial end of the cylindrical coupling portion and engaged with the inner peripheral surface of the U-shaped parallel portion to transmit the rotational torque of the steering shaft, and A second shaft having a circular shaft portion that fits closely into the cylindrical coupling portion;
A steering apparatus comprising a welded joint portion in which the circular shaft portion of the second shaft and the cylindrical joint portion are welded. The steering apparatus according to claim 1, wherein
The first shaft is an intermediate shaft;
A steering apparatus, wherein the second shaft is an extension shaft. In the steering device according to claim 1 or 2,
The first axis is a pinion shaft;
A steering apparatus, wherein the second shaft is an extension shaft.

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