JP5063753B2 - Body front structure - Google Patents

Description

  The present invention relates to a vehicle body front structure in which a front side frame is extended in a longitudinal direction of a vehicle body, and a bumper beam extension joined to a bumper beam is provided at a front end of the front side frame.

  The vehicle body front structure is provided with a crushing member (bumper beam extension) that buckles and deforms due to an impact load applied from the bumper beam at the time of a front collision of the vehicle and absorbs energy. Some are set in an arc shape pointing outward in the vehicle width direction.

  According to this vehicle body front part structure, it is possible to absorb impact energy even when the object with which the vehicle body collides at the time of a vehicle body front collision has a tilt angle outside in the vehicle width direction (for example, patents) Reference 1).

  The front body frame has a front side frame extending in the longitudinal direction of the vehicle body, an upper member is disposed on the outer side of the front side frame, and inner and outer shock absorbing portions (bumpers) are provided at the front end portions of the front side frame and the upper member, respectively. It is known that a beam extension is provided and a bumper beam is provided at the front end of the inner and outer shock absorbing parts.

  According to this vehicle body front part structure, it is possible to prevent the inner and outer shock absorbing parts from being bent and deformed toward the center of the vehicle body by an impact load acting obliquely from the front of the vehicle body (see, for example, Patent Document 2). ).

JP 2009-107445 A JP 2009-137359 A

In the vehicle body front part structure of Patent Document 1, the axis of the crushing member (bumper beam extension) is set in an arc shape that is directed outward in the vehicle width direction. Therefore, when the front impact load acts from the front without the bumper beam tilt angle, the crushing member collapses in a bellows shape with respect to the axial load and absorbs energy, so that the arc shape is bent and the energy absorption is reduced. To do.
In addition, since there is a crushing member in the width range of the front side frame, the amount of energy absorption is insufficient for an oblique collision with an inclination angle.

  In the vehicle body front part structure of Patent Document 2, an inner shock absorbing portion (bumper beam extension) is provided at the front end portion of the front side frame, and an outer shock absorbing portion (bumper beam extension) is provided at the front end portion of the upper member. It has been. In addition, the inner and outer shock absorbing parts are formed in a straight line, so that bellows deformation due to buckling of the inner and outer shock absorbing parts (bumper beam extension) against a load with an inclination angle. Is difficult to occur and the crushing mode cannot be stabilized.

  An object of the present invention is to provide a vehicle body front structure that can reduce transmission loss of a load transmitted from a bumper beam to a front side frame. It is another object of the present invention to provide a vehicle body front structure that can increase the amount of energy absorbed during an oblique collision. Furthermore, it aims at providing the vehicle body front part structure which can stabilize the collapsing aspect of a bumper beam extension.

According to a first aspect of the present invention, there is provided a vehicle body front structure including a front side frame extending in a longitudinal direction of a vehicle body, a bumper beam extension provided at a front end of the front side frame, and a bumper beam provided at a front end of the bumper beam extension. The bumper beam extension is provided with a connecting plate attached to the front end of the front side frame at the rear end of the bumper beam extension. has a curved shape that curves are welded butt on the front face of the connecting plate, Rutotomoni ridgeline of the polygonal cross-section is grounded to the connecting plate, the front end is intended to be closed by a lid member, the vehicle body rear side of the lid member The lid member side flange that is folded back is the bumper beam extension. The bumper beam extension is welded to one of the upper and lower surfaces of the cover, and the rear part of the lid member side flange is connected to the bumper beam via the connecting bracket, and the connecting bracket is deformed near the fastening portion fastened to the bumper beam extension. A bead is provided to prevent this .

  The invention according to claim 2 includes an outer bumper beam extension in which an upper member curved upward toward the rear of the vehicle body is arranged outside the front side frame, and a central axis is linear in the vehicle longitudinal direction at the front end of the upper member. The outer bumper beam extension is set shorter than the bumper beam extension provided at the front end of the front side frame.

The invention according to claim 3 is characterized in that the bumper beam extension and the outer bumper beam extension are integrated by a connecting plate.

The present invention has the following effects.
The invention according to claim 1 includes a front side frame extending in the longitudinal direction of the vehicle body, a bumper beam extension provided at the front end of the front side frame, and a bumper beam provided at the front end of the bumper beam extension.
A connecting plate attached to the front end of the front side frame is provided at the rear end of the bumper beam extension.
The bumper beam extension has a polygonal cross section in cross section, and has a curved shape that curves from the inside of the vehicle body to the outside of the vehicle body as it extends forward, and is butt welded to the front surface of the connecting plate. Since it is grounded to the connecting plate, the transmission loss of the load transmitted from the bumper beam to the front side frame can be reduced, and the energy can be absorbed by collapsing into a bellows shape from the beginning of the oblique collision. For example, by setting the bumper beam extension to a plate thickness of 1 mm, general MIG welding can be performed, and productivity can be improved.
In addition, in the invention according to claim 1, the bumper beam extension is such that the front end is closed by the lid member, and the lid member side flange that is folded back to the vehicle body of the lid member is one of the upper surface and the lower surface of the bumper beam extension. Welded to.
The welded side is less crushed because it has higher strength and rigidity than the non-welded side. When the bumper beam rotates upward or downward due to the front collision, the unwelded side is bent first, and the starting point of the crushing action can be made. As a result, the bumper beam extension can be stably crushed into a bellows shape.
Furthermore, in the invention according to claim 1, the rear portion of the flange on the lid member side of the bumper beam extension is connected to the bumper beam via the connection bracket, so that the vibration of the bumper beam can be reduced. Since the rear part of the lid member side flange is connected to the bumper beam via the connection bracket, the influence on the crushing mode can be minimized.
In addition, in the invention according to claim 1, since the bead for preventing deformation is provided in the vicinity of the fastening portion fastened to the bumper beam extension of the connection bracket, deformation of the connection bracket during transportation can be prevented.

In the invention according to claim 2, the upper member that is curved upward toward the rear of the vehicle body is juxtaposed on the outside of the front side frame.
An outer bumper beam extension having a central axis that is linear in the longitudinal direction of the vehicle body is provided at the front end of the upper member, and the outer bumper beam extension is set shorter than the bumper beam extension provided at the front end of the front side frame.
In the vehicle body front structure, by curving the shape of the bumper beam extension provided at the front end of the front side frame, the crushing mode can be fixed and the collision performance can be stably controlled. That is, it is provided at the front end of the front side frame, and only the bumper beam extension that is long in the front-rear direction and has an unstable collapse state at the time of an oblique collision is curved to stabilize the collapse state, and the initial collapse of the bumper beam extension is the starting point. The short straight outer bumper beam extension was crushed. Thereby, the energy absorption amount at the time of an oblique collision can be increased.
Further, in the case of a front collision without an inclination angle, the outer bumper beam extension supports the bumper beam on the outer side, so that the (inner) bumper beam extension is not bent.

In the invention according to claim 3 , since the bumper beam extension and the outer bumper beam extension are integrated by the connecting plate, the collapse mode can be further stabilized.

It is a top view which shows the vehicle body front part structure which concerns on this invention. It is a bottom view of the vehicle body front part structure shown by FIG. FIG. 3 is a view taken in the direction of arrow 3 in FIG. 1. It is a perspective view from the left rear of the vehicle body front part structure shown by FIG. It is a perspective view from the right rear of the vehicle body front part structure shown by FIG. It is a front view of the vehicle body front part structure shown by FIG. FIG. 2 is a perspective view of a bumper beam extension of the vehicle body front structure shown in FIG. 1. FIG. 2 is a perspective view of the vehicle body front structure shown in FIG. 1 with a bumper beam extension lid member removed.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

  As shown in FIGS. 1 to 5, a front side frame 16 extending in the front-rear direction of the vehicle body and a front side frame 16 are arranged in parallel at the front portion of the vehicle body 10, and upward toward the rear of the vehicle body. A curved upper member 17, a bumper beam extension (inner bumper beam extension) 21 that is provided at the front end of the front side frame 16 and is curved inside the vehicle body, and provided outside the bumper beam extension 21 and at the front end of the upper member 17. The outer bumper beam extension 22 whose central axis is linear in the longitudinal direction of the vehicle body, the bumper beam extension 21 and the outer bumper beam extension 22 are connected in the vehicle width direction, the bumper beam extension 21 and the outer bumper beam extension. 2, a bumper beam 24 provided at the front end, a connecting bracket 25 that connects the bumper beam 24 and the bumper beam extension 21, a front end side wall (front end outer wall) 46 of the front side frame 16, and a front end side wall (front end inner wall) 47 of the upper member 17. And a connecting member 28 for connecting the two.

  The vehicle body front structure shown in FIG. 1 is a structure of a part composed of a bumper beam 24, a bumper beam extension (inner bumper beam extension) 21, an outer bumper beam extension 22, a connecting plate 23, a front side frame 16, and an upper member 17. It is. Details will be described below.

  A frame-side mounting plate 48 is provided at the front end of the front side frame 16, and the bumper beam extension 21 is provided on the frame-side mounting plate 48 via the connecting plate 23. A plurality of nuts 51 for bolting the connecting plate 23 are welded to the frame side mounting plate 48 (see FIG. 4).

  The rear end of the front side frame 16 is connected to a side sill (not shown) and a tunnel frame (not shown) that extend in the longitudinal direction of the vehicle body via a side frame extension (not shown).

  The upper member 17 is juxtaposed on the outside of the front side frame 16 and is curved upward toward the rear of the vehicle body. A member-side mounting plate 49 is provided at the front end of the upper member 17, and an outer bumper beam extension 22 having a central axis that is linear in the longitudinal direction of the vehicle body is provided on the member-side mounting plate 49 via the connecting plate 23. A plurality of nuts 52 for bolting the connecting plate 23 are welded to the member side mounting plate 49 (see FIG. 4).

  The bumper beam 24 is provided with a central impact absorbing member (safety plate) 54 and an end impact absorbing member (safety plate) 55 that absorb an impact on a pedestrian from the front in the center of the front surface.

The rear end of the bumper beam 24 is attached to the front ends of the bumper beam extension 21 and the outer bumper beam extension 22. Specifically, it is attached to the lid front surfaces 63 and 73 of the lid members 59 and 69 of the bumper beam extension 21 and the outer bumper beam extension 22.
Further, the rear surface of the bumper beam 24 is connected to the bumper beam extension 21 via a connection bracket 25.

  As shown in FIGS. 6 to 8, the bumper beam extension 21 is formed in a cylindrical shape having a polygonal cross section in cross section. Specifically, the bumper beam extension 21 is formed in a cylindrical shape having an octagonal cross section in cross section when the outer piece 57 and the inner piece 58 are combined.

  Further, it is formed in a curved shape that curves from the inside of the vehicle body to the outside of the vehicle body as indicated by a one-dot chain line A1 (see FIG. 1) as it extends forward of the vehicle body. Further, the front end is closed by the lid member 59. The rear end is butt welded to the front surface 23 a of the connection plate 23, and the ridge line 61 having a polygonal cross section is grounded to the connection plate 23. That is, the bumper beam extension 21 employs a curved structure (or banana structure) whose tip is directed outward of the vehicle body.

  Further, the bumper beam extension 21 is formed by bending an inner flange 62 from a cylindrical shape with a polygonal cross section in the connection plate 23 side and the outer bumper beam extension 22 side, and the inner flange 62 is a joining flange of the outer bumper beam extension 22. (Outer flange) 72a is coupled.

  The bumper beam extension 21 employs a steel plate having a thickness of 1 mm. Thereby, MIG welding can be performed directly on the connecting plate 23. That is, the end portion 21a on the connecting plate 23 side of the bumper beam extension 21 is brought into contact with the front surface 23a of the connecting plate 23, and substantially the entire circumference of the cylindrical end portion 21a having a polygonal cross-sectional view of the bumper beam extension 21 is formed. The connecting plate 23 is MIG welded (except for the portion where the inner flange 62 is formed). Thereby, the curved ridgeline 61 can be landed on the front surface 23 a of the connecting plate 23. As a result, it is possible to reduce the load transmission loss.

The lid member 59 includes a lid front surface 63 to which the bumper beam 24 is attached, and a lid member side flange 64 that is folded back to the vehicle body of the lid front surface 63.
The lid member side flange 64 positioned on the upper side includes extended flanges 65 and 66 extending rearward of the vehicle body. The ends of the extending flanges 65 and 66 are welded to the upper surface 21b of the bumper beam extension 21 (a cylindrical shape with a polygonal cross section in cross section).

  As shown in FIG. 3, when a front collision load acts on the bumper beam 24 as shown by an arrow b1, the bumper beam 24 can rotate upward as shown by an arrow b2, and becomes a starting point of bellows deformation. An extended flange is not formed on the cylindrical lower surface 21c having a polygonal cross section in cross section. In addition, the lengths of the extending flanges 65 and 66 are the lengths extended to the position where the polygonal cross-section in the cross-sectional view is broken when the bumper beam 24 rotates.

When the bumper beam 24 is set to rotate downward, an extension flange may be extended to the rear surface of the vehicle body on the lower surface of the lid member side flange 64. You may weld to the cylindrical lower surface 21c of a square cross section.
That is, in the vehicle body front part structure shown in FIG. 3, the bumper beam extension 21 is closed at the front end by the lid member 59, and the lid member side flange 64 is disposed at the rear of the lid member 59 in the vehicle body. 21 is welded to one of the upper surface 21b and the lower surface 21c. Further, the lid member side flange 64 may be welded to the left and right side surfaces of the bumper beam extension 21.

  As shown in FIGS. 6 to 8, the outer bumper beam extension 22 is formed in a cylindrical shape having a polygonal cross section as viewed in cross section. Specifically, the outer bumper beam extension 22 is formed in a cylindrical shape having an octagonal cross section in cross section in which the outer piece 67 and the inner piece 68 are combined and the four corners of the rectangular cross section are chamfered.

  In the outer bumper beam extension 22, a steel plate having a thickness of 1 mm or less is employed. Accordingly, a plurality of joining flanges 72 a to 72 f are formed on the connecting plate 23 side, and the plurality of joining flanges 72 a to 72 f are spot welded to the connecting plate 23. Among the plurality of joining flanges 72a to 72f, the inner flange 62 of the bumper beam extension 21 is joined to a joining flange (outer flange) 72a formed on the bumper beam extension 21 side.

In addition, since several joining flange 72a-72f is formed in the connection plate 23 side of the outer side bumper beam extension 22, in order to form the joining flange 72a-72f, the notch for bending escape generate | occur | produces. Since the outer bumper beam extension 22 starts to be crushed and deformed while the inner bumper beam extension 21 is being crushed, in the outer bumper beam extension 22, each ridge line 71 may not be grounded to the front surface 23 a of the connecting plate 23.
Furthermore, since the cost of spot welding the joining flanges 72a to 72f is lower than the cost of MIG welding the end faces, for example, it contributes to a reduction in manufacturing cost.

  By joining the inner flange 62 of the inner bumper beam extension 21 and the joining flange (outer flange) 72a of the outer bumper beam extension 22, it contributes to stabilization of the collapse mode of the inner bumper beam extension 21 and the outer bumper beam extension 22. be able to.

  Further, the outer bumper beam extension 22 is formed such that the central axis is linear in the longitudinal direction of the vehicle body. It is set shorter than the bumper beam extension 21 along the design of the vehicle body front corner portion. Further, the front end is closed by the lid member 69. Joining flanges 72 a to 72 f formed by bending at the rear end are grounded (spot welded) to the connecting plate 23.

The lid member 69 includes a lid front surface 73 to which the bumper beam 24 is attached, and a lid member side flange 74 that is folded back to the vehicle body rear side of the lid front surface 73.
The lid member side flange 74 includes a plurality of extending flanges 75a to 75g extending rearward of the vehicle body. The tips of the plurality of extending flanges 75a to 75g are welded into a cylindrical shape having a polygonal cross section in cross section.

  In the vehicle body front structure shown in FIGS. 1 and 2, the bumper beam extension (inner bumper beam extension) 21 and the outer bumper beam extension 22 are inner bumpers that are long in the front-rear direction and have an unstable crushing state at the time of a front collision. Only the beam extension 21 was curved to stabilize the crushing mode. Starting from the initial crushing of the inner bumper beam extension 21, the short outer bumper beam extension 22 is crushed, for example, to increase the amount of energy absorbed during an oblique collision from the front of the vehicle body and from the outside of the vehicle body.

  That is, as shown in FIG. 1, when the collision barrier 79 enters from the oblique direction of the vehicle body as indicated by a plurality of arrows a1, the shape of the bumper beam extension (inner bumper beam extension) 21 is changed to the direction in which the collision barrier 79 enters. By curving (orienting), the crushing mode can be stabilized, and the collision performance can be stably controlled.

  The connecting plate 23 is a single plate integrally formed and is a plate member that connects (attaches) the bumper beam extension (inner bumper beam extension) 21 and the outer bumper beam extension 22.

  The connecting plate 23 to which the bumper beam extension (inner bumper beam extension) 21 and the outer bumper beam extension 22 are attached is bolted to the frame side mounting plate 48 of the front side frame 16 and the member side mounting plate 49 of the upper member 17.

  The connection bracket 25 is formed on the bracket body 81 passing to the bumper beam 24 and the bumper beam extension 21, bent on the bumper beam 24 side of the bracket body 81, attached on the bumper beam 24, and formed on the bumper beam extension 21 side. A fastening portion 83 fastened to the bumper beam extension 21, a bead 84 that is formed across the bracket body 81 and the fastening portion 83 and prevents deformation of the connecting bracket 25 during transportation, and a side of the bracket body 81. The bracket body 81 is intentionally directed when a front impact load is applied in a mounting direction attached to the reinforcing portions 85, 85 for reinforcing the bracket body 81 and the bumper beam 24 and the bumper beam extension 21. Stress absorbing part 86 for bending deformation , It is formed.

The connecting bracket 25 is a member that regulates vibrations in the vehicle width direction in the bumper beam 24, and suppresses uncomfortable sounds (sounds in the engine room) by reducing the vibrations, thereby improving the quietness in the vehicle interior. To play a role.
Further, the connecting bracket 25 is coupled to the rear of the extending flanges 65 and 66 of the lid member 59 that does not affect the collision performance of the bumper beam extension 21.

In the vehicle body front structure shown in FIG. 1, a front side frame 16 extending in the longitudinal direction of the vehicle body, a bumper beam extension 21 provided at the front end of the front side frame 16, and a bumper beam 24 provided at the front end of the bumper beam extension 21. And comprising.
A connecting plate 23 attached to the front end of the front side frame 16 is provided at the rear end of the bumper beam extension 21.

  The bumper beam extension 21 has a polygonal cross section in cross section, and has a curved shape that curves from the inside of the vehicle body to the outside of the vehicle body as it extends forward of the vehicle body. Since the ridge line 61 is grounded to the connecting plate 23, transmission loss of the load transmitted from the bumper beam 24 to the front side frame 16 can be reduced, and energy can be absorbed by collapsing into a bellows shape from the beginning of the oblique collision. . For example, by setting the plate thickness of the bumper beam extension 21 to 1 mm, general MIG welding becomes possible, and productivity can be improved.

In the vehicle body front structure shown in FIGS. 1 and 2, an upper member 17 that is curved upward toward the rear of the vehicle body is provided outside the front side frame 16.
An outer bumper beam extension 22 whose central axis is linear in the longitudinal direction of the vehicle body is provided at the front end of the upper member 17, and the outer bumper beam extension 22 is set shorter than the bumper beam extension 21 provided at the front end of the front side frame 16. .

In the vehicle body front structure shown in FIG. 1 and FIG. 2, the crushing mode can be fixed by curving the shape of the bumper beam extension 21 provided at the front end of the front side frame 16, and the collision performance can be stably performed. Can be controlled. In other words, only the bumper beam extension 21 which is provided at the front end of the front side frame 16 and is long in the front-rear direction and unstable in the crushing mode at the time of an oblique collision is curved to stabilize the crushing mode. The short linear outer bumper beam extension 22 is crushed from the starting point. Thereby, the energy absorption amount at the time of an oblique collision can be increased.
Further, at the time of a front collision without an inclination angle, the outer bumper beam extension 22 supports the bumper beam 24 on the outer side, so that the (inner) bumper beam extension 21 is not bent.

  As shown in FIG. 3, in the vehicle body front structure, the bumper beam extension 21 is closed at the front end by the lid member 59, and the lid member side flange 64 is provided on the rear side of the lid member 59 with respect to the vehicle body. It is welded to one of the upper surface 21b or the lower surface 21c of the extension.

  The welded side is less crushed because it has higher strength and rigidity than the non-welded side. When the bumper beam 24 rotates upward or downward due to the front collision, the unwelded side is bent first, and the starting point of the crushing action can be created. As a result, the bumper beam extension 21 can be stably crushed into a bellows shape.

  As shown in FIG. 7, in the vehicle body front structure, the bumper beam extension 21 and the outer bumper beam extension 22 are integrated by the connecting plate 23, so that the collapse mode can be further stabilized.

  As shown in FIGS. 1 and 5, in the vehicle body front structure, the rear part of the lid member side flange 64 of the bumper beam extension 21 is connected to the bumper beam 24 via the connection bracket 25, so that the bumper beam 24 Vibration can be reduced. Since the rear portion of the lid member side flange 64 is connected to the bumper beam 24 via the connection bracket 25, the influence on the crushing mode can be minimized.

  As shown in FIGS. 1 and 5, in the vehicle body front structure, a bead 84 for preventing deformation is provided in the vicinity of the fastening portion 83 fastened to the bumper beam extension 21 of the connection bracket 25. It is possible to prevent deformation during transportation.

As shown in FIGS. 1 and 5, the connecting member 28 is divided into a frame side connecting member 91 connected to the front side frame 16 side and a member side connecting member 92 connected to the upper member 17 side. Is done. The connecting member 28 is formed in a substantially U-shaped cross section in a side view.
The frame side connecting member 91 is connected to the front end side wall 46 of the front side frame 16, the member side connecting member 92 is connected to the front end side wall 47 of the upper member 17, and the frame side connecting member 91 and the member side connecting member 92 are connected to each other. Is done.

  In the vehicle body front structure according to the present invention, as shown in FIG. 8, the bumper beam extension 21 employs a steel plate having a plate thickness of 1 mm, and the connecting plate 23 has a cylindrical end portion having a polygonal cross-sectional view. 21a is MIG welded to the connecting plate 23, and the outer bumper beam extension 22 is made of a steel plate having a thickness of 1 mm or less, and a plurality of joining flanges 72a to 72f are formed on the connecting plate 23 side. Although the flanges 72a to 72f are spot welded to the connecting plate 23, a steel plate having a thickness of 1 mm is adopted as the outer bumper beam extension 22, and this does not prevent the entire periphery of the connecting plate 23 from being MIG welded.

  The vehicle body front structure according to the present invention is suitable for use in passenger cars such as sedans and wagons.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 16 ... Front side frame, 17 ... Upper member, 21 ... Bumper beam extension (inner bumper beam extension), 22 ... Outer bumper beam extension, 23 ... Connection plate, 23a ... Front, 24 ... Bumper beam, 25 ... Connection bracket 59 ... Lid member, 61 ... Ridge line, 83 ... Fastening part, 84 ... Bead.

Claims (3)

In a vehicle front structure comprising a front side frame extending in the longitudinal direction of the vehicle body, a bumper beam extension provided at the front end of the front side frame, and a bumper beam provided at the front end of the bumper beam extension,
At the rear end of the bumper beam extension, a connecting plate to be attached to the front end of the front side frame is provided,
The bumper beam extension has a polygonal cross section in cross section, and has a curved shape that curves from the inside of the vehicle body to the outside of the vehicle body as it extends forward of the vehicle body, and is butt welded to the front surface of the connecting plate, are those ridgeline of Rutotomoni is grounded to the connecting plate, the front end is closed by a lid member,
The lid member side flange that is folded back to the vehicle body of the lid member is welded to one of the upper surface or the lower surface of the bumper beam extension,
In the bumper beam extension, a rear part of the lid member side flange is connected to the bumper beam via a connection bracket,
The vehicle body front structure , wherein the connection bracket is provided with a bead for preventing deformation in the vicinity of a fastening portion fastened to the bumper beam extension .   An upper member that is curved upward toward the rear of the vehicle body is provided outside the front side frame, and an outer bumper beam extension having a central axis that is linear in the longitudinal direction of the vehicle body is provided at the front end of the upper member. The vehicle body front part structure according to claim 1, wherein the bumper beam extension is set shorter than a bumper beam extension provided at a front end of the front side frame. The bumper beam extension and the outer bumper beam extension, front body structure of claim 2 Symbol mounting, characterized in that it is integrated in the connection plate.

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