JP5542652B2 - Shock absorbing member for vehicle - Google Patents

Description

  The present invention relates to a vehicle impact absorbing member provided in a front end of an automobile, for example, and a related technology.

  Conventionally, a tow hook is used when towing a vehicle or fixing at the time of transportation, and a tow hook detachable vehicle in which the tow hook is attached as necessary is well known.

  In a tow hook detachable automobile, a nut (female screw member) for attaching a tow hook is attached to the vehicle body. When necessary, the tow hook can be fixed to the vehicle body by screwing a male screw provided at the end of the tow hook into the nut on the vehicle body side.

  In such an automobile, it is well known that a nut for attaching a tow hook is fixed to a bumper beam.

  For example, in the bumper beam shown in Patent Document 1, a bumper stay that also serves as a hook attachment member is attached to a base end (rear end) of a crash box by bolting, and a nut for attaching a tow hook is fixed to the bumper stay. Further, in this document, a bumper stay having a complex shape and serving as a hook mounting member is fixed by electromagnetic forming at the base end of the crash box, and a nut for mounting a tow hook is fixed to the bumper stay.

  In the bumper beam shown in Patent Document 2, a plate member (hook attachment member) is fixed to a base end (rear end) of a bumper arm corresponding to a crash box by bolts, and a nut for attaching a tow hook is attached to the plate member. It is fixed.

JP 2008-37220 A JP 2009-292175 A

  However, in the conventional bumper beam in which the hook mounting member is incorporated, for example, a process for assembling the hook mounting member is separately required, and the number of processes is increased or troublesome bolting work is required, so that workability is lowered. As a result, there is a problem that productivity is reduced and cost is increased. Further, in the conventional bumper beam, parts such as a bumper stay that also serves as a hook mounting member have a complicated structure, and thus have a problem that the structure is complicated and may increase in weight.

  Needless to say, when a hook mounting member is incorporated into an impact absorbing member such as a crash box, the incorporation of the hook surely ensures that the original function of the impact absorbing member, that is, an impact absorbing characteristic is adversely affected. It is necessary to avoid it.

  The present invention has been made in view of the above-described problems, and can improve productivity, reduce costs and reduce weight, and can further obtain excellent shock absorbing characteristics. And its related technology.

  In order to solve the above problems, the present invention comprises the following means.

[1] A vehicle impact absorbing member to which a tow hook can be attached,
A cylindrical crash box,
A bumper stay having a mounting hole;
A hook mounting member formed in a cup shape having a peripheral wall along the outer peripheral edge of the bottom wall, and provided with a female screw for attaching a tow hook on the bottom wall;
Each of the peripheral walls of the crash box and the hook mounting member in a state where the hook mounting member is fitted on the base end portion of the flash box and the peripheral wall of the hook mounting member penetrates the mounting hole of the bumper stay. In the front and rear of the mounting hole peripheral portion of the bumper stay, a convex portion protruding in the outer diameter direction is formed by tube expansion processing using a tube expansion die, so that the hook mounting member and the bumper stay are attached to the crash box. A shock absorbing member for a vehicle characterized by being fixed.

  [2] The vehicle impact absorbing member according to [1], wherein a partition wall for partitioning the interior of the crash box is formed continuously along the axial direction.

  [3] The vehicle impact absorbing member according to the above item 1 or 2, wherein the convex portion is provided so as to extend along a circumferential direction.

  [4] The vehicle impact absorbing member according to any one of the preceding items 1 to 3, wherein the convex portions are provided intermittently at intervals in the circumferential direction.

  [5] Any one of items 1 to 4 above, wherein a mold interference prevention hole for avoiding interference with a mold at the time of pipe expansion processing is formed in a region where the female screw is not located in the bottom wall of the hook mounting member. The impact absorbing member for a vehicle according to the item.

  [6] The vehicle impact absorbing member according to any one of the preceding items 1 to 5, wherein a nut having the female screw is provided on an outer surface of a bottom wall of the hook mounting member.

[7] A bumper reinforcement having a mounting hole is further provided,
With the front end portion of the crash box penetrating through the mounting hole of the bumper reinforcement, in the outer diameter direction by tube expansion processing using a tube expansion mold before and after the bumper reinforcement mounting hole peripheral portion of the peripheral wall of the crash box 7. The vehicle impact absorbing member according to any one of the preceding items 1 to 6, wherein the bumper reinforcement is fixed to the crash box by forming a projecting portion projecting into the crash box.

[8] A vehicle bumper beam to which a tow hook can be attached,
A cylindrical crash box,
Bumper reinforcement,
A bumper stay having a mounting hole;
A hook mounting member formed in a cup shape having a peripheral wall along the outer peripheral edge of the bottom wall, and provided with a female screw for attaching a tow hook on the bottom wall;
While the bumper reinforcement is attached to the tip of the crash box,
Each of the peripheral walls of the crash box and the hook mounting member in a state where the hook mounting member is fitted on the base end portion of the flash box and the peripheral wall of the hook mounting member penetrates the mounting hole of the bumper stay. In the front and rear of the mounting hole peripheral portion of the bumper stay, a convex portion protruding in the outer diameter direction is formed by tube expansion processing using a tube expansion die, so that the hook mounting member and the bumper stay are attached to the crash box. A bumper beam for vehicles characterized by being fixed.

[9] A method of manufacturing a shock absorbing member for a vehicle to which a tow hook can be attached,
A cylindrical crash box,
A bumper stay having a mounting hole;
A hook mounting member that is formed in a cup shape with a peripheral wall provided along the outer peripheral edge of the bottom wall, and that has a female screw for attaching a tow hook on the bottom wall;
The hook mounting member is externally fitted to the base end portion of the flash box, and the peripheral wall of the hook mounting member is passed through the mounting hole of the bumper stay, and the crash box and the peripheral wall of the hook mounting member are The hook mounting member and the bumper stay are fixed to the crash box by forming convex portions projecting in the outer diameter direction by tube expansion processing using a tube expansion die around the periphery of the mounting hole peripheral portion of the bumper stay. A method of manufacturing a shock absorbing member for a vehicle, characterized by

[10] A method for manufacturing a vehicle bumper beam to which a tow hook can be attached,
A cylindrical crash box,
Bumper reinforcement,
A bumper stay having a mounting hole;
A hook mounting member that is formed in a cup shape with a peripheral wall provided along the outer peripheral edge of the bottom wall, and that has a female screw for attaching a tow hook on the bottom wall;
While attaching the bumper reinforcement to the tip of the crash box,
The hook mounting member is externally fitted to the base end portion of the flash box, and the peripheral wall of the hook mounting member is passed through the mounting hole of the bumper stay, and the crash box and the peripheral wall of the hook mounting member are The hook mounting member and the bumper stay are fixed to the crash box by forming convex portions projecting in the outer diameter direction by tube expansion processing using a tube expansion die around the periphery of the mounting hole peripheral portion of the bumper stay. A method for manufacturing a bumper beam for a vehicle.

  According to the vehicle impact absorbing member of the invention [1], since the hook mounting member and the bumper stay can be simultaneously fixed to the crash box, the number of work steps can be reduced, and the troublesome bolting and welding are not used. The cost can be reduced. Furthermore, since the hook attachment member has a simple cup-like configuration, the structure can be simplified and reduced in weight.

  Input is input to the towing hook attached to the hook attaching member by towing the other vehicle or the like. In the present invention, the tensile force applied to the traction hook acts on the end face of the crash box, so that the crash box is not inadvertently deformed. Further, the pressing force for pushing the traction hook does not act on the crash box, but is directly received by the vehicle structure via the hook mounting member. Therefore, the crash box, bumper reinforcement, and the like are not inadvertently deformed by the force applied to the tow hook, and a desired shock absorption characteristic can be reliably obtained.

  In addition, since the crash box is supported by the vehicle structure through the hook mounting member and the bumper stay, the impact energy applied to the bumper reinforcement can be reliably absorbed by the deformation of the crash box, and excellent shock absorption characteristics can be obtained. it can.

  According to the vehicle impact absorbing member of the invention [2], the amount of energy absorption can be adjusted more appropriately, and the impact absorbing characteristics can be further improved.

  According to the vehicle impact absorbing member of the invention [3] or [4], the hook mounting member and the bumper stay can be more reliably fixed to the crash box.

  According to the vehicle impact absorbing member of the invention [5], the projection can be reliably formed by the crash box and the hook mounting member, and the hook mounting member and the bumper stay can be more securely fixed to the crash box.

  According to the vehicle impact absorbing member of the invention [6], the nut is not disposed inside the crash box, and the tube expansion mold can be reliably inserted into the crash box. For this reason, a convex part can be formed in the desired position of a crash box and a hook attachment member, and a hook attachment member and a bumper stay can be more reliably fixed to a crash box.

  According to the shock absorbing member for a vehicle of the invention [7], the bumper reinforcement is fixed to the crash box by the pipe expansion process using the pipe expansion die. The member and the bumper stay can be fixed to the crash box at the same time, and the productivity can be further improved.

  According to the bumper beam for a vehicle of the invention [8], the productivity can be improved, the cost can be reduced, and the weight can be reduced as described above.

  According to the method for manufacturing a shock absorbing member for a vehicle of the invention [9], productivity can be improved, cost can be reduced, and weight can be reduced as described above.

  According to the method for manufacturing a bumper beam for a vehicle of the invention [8], it is possible to improve the productivity, reduce the cost, and reduce the weight as described above.

FIG. 1 is a plan view showing a vehicle bumper beam according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing the bumper beam of the embodiment. FIG. 3 is a rear view showing the bumper beam of the embodiment. FIG. 4 is a side cross-sectional view showing the vicinity of one side of the crash box in the bumper beam of the embodiment in a state in which a tow hook is attached. FIG. 5 is an exploded perspective view showing the periphery of one side of the crush box in the embodiment in a state before tube expansion processing. FIG. 6 is a plan view showing the bumper beam of the embodiment in a state where a tube expansion die is inserted. FIG. 7 is a front view showing the bumper beam of FIG. 8A is a cross-sectional view taken along line AA in FIG. 8B is a cross-sectional view taken along line BB in FIG. FIG. 9 is a perspective view showing a hook mounting member used in a modification of the present invention. FIG. 10 is a cross-sectional view showing the bumper beam to which the hook attachment member of the modification is applied in a state immediately after inserting the tube expansion die, and is a cross-sectional view corresponding to the cross section taken along the line BB of FIG.

  1 is a plan view showing a bumper beam for a vehicle according to an embodiment of the present invention, FIG. 2 is a schematic perspective view, FIG. 3 is a rear view, and FIG. 4 is a side view showing the periphery of one crash box in the bumper beam of the embodiment. FIG. 5 is an exploded perspective view showing the vicinity of one side crush box in a state before tube expansion processing.

  As shown in these drawings, this bumper beam is provided at the front end of an automobile for absorbing shock at the time of a collision, and includes a bumper reinforcement 1, a pair of left and right crash boxes 2, and a pair of left and right bumpers. Stays 3 and 4 and a hook mounting member 5 provided in one of the crash boxes 2 arranged on the right side of FIG.

  In the present embodiment, the bumper reinforcement 1 is constituted by, for example, an extrusion molded product or a pultruded molded product made of aluminum or an alloy thereof.

  The bumper reinforcement 1 in the present embodiment is formed such that the intermediate portion slightly protrudes forward by bending both sides in the vehicle width direction backward.

  The bumper reinforcement 1 includes a peripheral wall 11 formed in a vertically long rectangle in a cross-sectional shape when cut along a plane orthogonal to the length direction, and a front and rear wall at an intermediate position in the height direction of the peripheral wall 11. And a partition wall 12 integrally formed so as to be bridged therebetween. In other words, the bumper reinforcement 1 is formed in a so-called “day” cross-sectional shape. The partition wall 12 is formed continuously in the length direction (vehicle width direction) of the bumper reinforcement 1 except for a portion where a mounting hole 51 described later is formed.

  Furthermore, attachment holes 15 and 15 penetrating in the front-rear direction are formed in the front wall and the rear wall of the peripheral wall 11 at both end portions in the length direction of the bumper reinforcement 1.

  The inner peripheral shape of the mounting hole 15 is formed corresponding to the outer peripheral shape of the tip portion of the crash box 2, and the tip portion of the crash box 2 can be loosely inserted into the mounting hole 15.

  Similarly to the above, the crash box 2 is constituted by an extrusion molded product or a pultruded product made of aluminum or an alloy thereof.

  The crush box 2 includes a hollow cylindrical peripheral wall 21 having both ends of the distal end and the proximal end opened. The peripheral wall 21 is formed in a substantially regular hexagonal shape that is rounded in a cross-sectional shape cut by a plane perpendicular to the axial direction.

  Further, six reinforcing partition walls 22... Extending in the radial direction (radially) from the center in the sectional view are integrally formed in the crash box 2 at equal intervals in the circumferential direction.

  The partition wall 22 is formed continuously in the axial direction (front-rear direction) of the crash box 2. Therefore, the front end (front end) opening and the base end (rear end) opening of the crush box 2 communicate with each other through each of the partition walls 22.

  With the tip portion (front end portion) of the crash box 2 configured as described above penetratingly disposed in the mounting holes 15 of the front and rear walls of the bumper reinforcement 1, the peripheral wall 21 of the crash box 2 is expanded by tube expansion described in detail later. Are formed on the front and rear of the mounting holes 15 and 15, respectively, so as to protrude radially outward (outer radial direction). As a result, the convex portions 25 are brought into pressure contact with the peripheral portions of the mounting holes 15, 15 in the bumper reinforcement 1, and the crash box 2 is connected and fixed to the bumper reinforcement 1.

  In the present embodiment, the convex portions 25 are provided along the circumferential direction over substantially the entire circumference of the crash box 2 except for the positions corresponding to the partition walls 22. In other words, six convex portions 25... Extending in the circumferential direction are formed at equal intervals in the circumferential direction at the front and rear positions of the mounting holes 15, 15 on the outer circumferential surface of the crash box 2.

  As shown in FIGS. 4 and 5, the hook attachment member 5 for attaching the tow hook 6 is made of aluminum, an alloy thereof, a steel material, or the like. Furthermore, the hook attachment member 5 is configured by a molded product such as press molding, die casting, or forging.

  The hook attachment member 5 has a cup-like shape, and includes a cylindrical peripheral wall 51 and a bottom wall 52 integrally formed so as to close a base end side (rear end side) opening of the peripheral wall 51. It has.

  The peripheral wall 51 of the hook attachment member 5 is formed in a substantially regular hexagonal shape corresponding to the inner peripheral shape of the base end portion of the crash box 2. And the base end part of the crush box 2 can be loosely inserted in the surrounding wall 51 from the front end side (front end side) opening. In other words, the peripheral wall 51 of the hook attachment member 5 can be fitted on the base end portion of the crash box 2.

  On the outer surface (rear surface) of the bottom wall 52 of the hook attachment member 5, a nut 53 for attaching a tow hook is provided so that the axial center direction coincides with the axial center direction of the hook attachment member 5. The front end opening (front end opening) of the screw hole 54 in the nut 53 is open to the inner surface of the bottom wall 51 of the hook mounting member 5, that is, the inner side of the peripheral wall 51 of the hook mounting member 5. Accordingly, the male screw 63 of the pulling hook 6 inserted from the front end side (front end side) opening of the hook mounting member 5 can be screwed into the screw hole 54 of the nut 53.

  In the present embodiment, a female screw is constituted by the screw hole 54 of the nut 53.

  A wedge insertion hole 55 is formed at the center of the bottom wall 52 except for the attachment region of the nut 53. As will be described later in detail, the wedge insertion hole 55 is provided to prevent the wedge 83 from interfering with the bottom wall 52 of the hook attachment member 5 during tube expansion processing.

  In this embodiment, the wedge insertion hole 55 forms a mold interference prevention hole.

  The hook mounting member 5 having the above configuration is fitted on the base end portion of the crash box 3 on one side (the right side in FIG. 1). That is, the base end portion of the crash box 3 on one side is inserted into the peripheral wall 51 of the hook attachment member 5 from the opening on the front end side, and the bottom wall 52 of the hook attachment member 5 closes the base end side opening of the crash box 3. Arranged in the embodiment.

  Further, when the hook mounting member 5 is externally fitted to the base end portion of the crash box 3 in this way, the nut 53 of the hook mounting member 5 is located between any two adjacent partition walls 22 and 22 in the crash box 2. It is arranged corresponding to. Therefore, the nut 53 communicates with the opening at the front end of the crash box 2 through any one of the two partition walls (predetermined partition walls) 22 and 22 of the crash box 2.

  The means for fixing the hook attachment member 5 to the crash box 3 will be described later.

  The bumper stays 3 and 4 are formed of a plate-shaped molded product made of aluminum or an alloy thereof.

  At the center of the bumper stays 3 and 4, mounting holes 36 and 36 are formed. The inner peripheral shape of the mounting hole 36 of the bumper stay 3 on the one side (the right side in FIG. 1) is formed corresponding to the inner peripheral shape of the peripheral wall 51 of the hook mounting member 5. 5 peripheral walls 51 can be loosely inserted.

  As described above, the peripheral wall 51 of the hook mounting member 5 that is externally fitted to the base end portion of the one-side crash box 2 is disposed through the mounting hole 36 of the one-side bumper stay 3. In this state, convex portions 26, 26, 56, 56 projecting in the outer diameter direction are formed on the front and rear of the mounting holes 36 in the peripheral wall 21 of the crash box 2 and the peripheral wall 51 of the hook mounting member 5 by tube expansion processing described later. Is done. Thereby, the convex portions 26 and 26 of the crash box 2 are press-fitted inside the convex portions 56 and 56 of the hook attachment member 5, and the hook attachment member 5 is fixed to the crash box 2. Further, the convex portions 56 of the hook attachment member 5 are brought into pressure contact with the peripheral edge portion of the attachment hole 36 in the bumper stay 3, and the bumper stay 3 is fixed to the hook attachment member 5. Thus, the hook mounting member 5 and the bumper stay 3 are connected and fixed to the crash box 2.

  In addition, in this embodiment, the convex parts 26 and 56 are provided along the circumferential direction over substantially the perimeter of the crash box 2 and the hook attachment member 5 except the position corresponding to the partition walls 22. In other words, six convex portions 26 and 56 extending in the circumferential direction are formed at equal intervals in the circumferential direction at the front and rear positions of the mounting hole 36 on the outer peripheral surface of the crash box 2.

  The bumper stay 4 on the other side arranged on the left side of FIG. 1 has an inner peripheral shape of the mounting hole 36 corresponding to the outer peripheral shape of the base end portion of the crash box 2 on the other side (left side of FIG. 1). It is formed in a regular hexagon shape, and the base end portion of the crash box 2 can be loosely inserted into the mounting hole 36.

  Then, with the base end portion of the crash box 2 on the other side penetrating through the mounting hole 36 of the bumper stay 4 on the other side, the tube expansion process described later is performed before and after the mounting hole 36 on the peripheral wall 21 of the crash box 2. Convex portions 26, 26 projecting in the outer diameter direction are formed. Thus, the convex portions 26 and 26 are brought into pressure contact with the peripheral edge portion of the mounting hole 36 in the bumper stay 4 on the other side, and the other bumper stay 4 is connected and fixed to the crash box 2.

  In the present embodiment, the convex portion 26 of the crash box 2 on the other side is provided along the circumferential direction over substantially the entire circumference of the crash box 2 except for the position corresponding to the partition walls 22. In other words, six convex portions 26 extending in the circumferential direction are formed at equal intervals in the circumferential direction at front and rear positions of the mounting hole 36 on the outer peripheral surface of the crash box 2.

  In the present embodiment, the operation of connecting and fixing the bumper reinforcement 1 to the crash boxes 2 and 2 and the operation of connecting and fixing the hook mounting member 5 and the bumper stays 3 and 4 to the crash box 2 are expanded die (expanding die). It is performed by tube expansion processing (expanding processing) using

  Furthermore, in the present embodiment, one side (right side in FIG. 1) of the bumper reinforcement 1 is connected and fixed to the crash box 2 on one side, and the hook mounting member 5 and The operation of connecting and fixing the bumper stay 3 on one side (expansion processing) is performed simultaneously. In this embodiment, this pipe expansion process is referred to as one-side pipe expansion process.

  Further, the work of connecting and fixing the other side (left side in FIG. 1) of the bumper reinforcement 1 to the crash box 2 on the other side (expansion processing), and the work of connecting and fixing the bumper stay 4 on the other side to the crash box 2 on the other side. (Tube expansion processing) is performed at the same time. In this embodiment, this pipe expansion process is referred to as the other pipe expansion process.

  6 is a plan view showing the bumper beam of the embodiment in a state in which the expansion die is inserted, FIG. 7 is a front view thereof, FIG. 8A is a cross-sectional view taken along the line AA in FIG. 7, and FIG. It is line sectional drawing. In order to facilitate understanding of the invention, the front view of FIG. 7 is shown upside down.

  As shown in these drawings, the tube expansion die 7 that performs tube expansion processing on one side includes a plurality of (six) split dies 71 that are respectively inserted between the partition walls 22 in the crash box 2. . The sectional shape of each split mold 71 is formed in a substantially fan shape corresponding to the inner peripheral shape between the partition walls 22. Each split mold 71 has the same cross-sectional shape.

  Further, on the outer peripheral surface of each split mold 71..., Tip side molding convex portions 75 and 75 are formed corresponding to the positions where the bumper reinforcement 1 side convex portions 25 and 25 are formed in the crash box 2. Further, on the outer peripheral surface of each split mold 71..., Corresponding to the position where the convex portions 26, 26 (convex portions 56, 56) on the bumper stay 3 side (hook attachment member 5 side) are formed, Protrusions 76 are formed.

  Further, each split mold 71 is provided with wedge insertion portions 73 along the axis. Each wedge insertion part 73 is formed in a substantially 1/6 hexagonal pyramid shape so that the wedge insertion parts 73 of each split mold 71.

  Further, the mandrel 8 for expanding the diameter of the tube expansion die 7 has wedges 83 corresponding to the wedge insertion portions 73 of the split dies 71. Each wedge 83 is formed in a tapered shape on the tip side (insertion direction side), and is formed corresponding to the inner peripheral shape of each wedge insertion portion 73. That is, each wedge 83 is formed in a substantially 1/6 regular hexagonal pyramid shape so that the wedges 83 are formed in a substantially regular hexagonal pyramid shape when all the wedges are combined. The taper angle at the outer peripheral surface of each wedge 83 is set equal to the taper angle of the inner peripheral surface at each wedge insertion portion 73.

  Further, among the plurality (six) of wedges 83, the wedge 83 corresponding to the position of the nut 53 of the hook mounting member 5 is, in other words, the wedge insertion hole 55 is not formed in the bottom wall 52 of the hook mounting member 5. The wedge 83 corresponding to the region where the bottom wall 52 remains is formed such that its tip (insertion side end) is cut out and shorter than the other wedges 83. This is to prevent the wedge 83 of the tube expansion mold 7 from interfering with the bottom wall 52, as will be described in detail later.

  When the tube expansion mold 7 having this configuration is used, when one side of the tube expansion processing is performed, the tip portion of the crash box 2 on one side is disposed through the mounting hole 15 on one side of the bumper reinforcement 1, The hook attachment member 5 is fitted on the base end portion of the crash box 2 on one side, and the peripheral wall 51 of the hook attachment member 5 is disposed through the attachment hole 36 of the bumper stay 3 on the one side. In this state, as shown in FIGS. 6 to 8, the split dies 71 of the pipe expansion die 7 are inserted between the partition walls 22 in the crash box 2 from the front end (front end) opening side, respectively. In this case, the forming convex portions 75 and 76 of each split mold 71 are arranged in regions (projection forming scheduled regions) where the convex portions 25, 26 and 56 of the crash box 2 and the hook attachment member 5 are to be formed.

  In this state, by pressing the mandrel 8 in the axial direction, the wedges 83 are forcibly pushed into the wedge insertion portions 73 of the split dies 71. As a result, the split dies 71 are moved in the outer diameter direction, and the projection forming regions of the crash box 2 and the hook attachment member 5 are expanded (expanded).

  In this pipe expansion processing, the projected portion formation regions of the crash box 2 and the hook mounting member 5 are locally pushed and expanded in the radial direction, and the above-described convex portions 25, 26, 56 are applied to the crash box 2 and the hook mounting member 5. Is formed. In this way, the connection and fixing operation of one side of the crash box 2 on one side and the bumper reinforcement 1 and the operation of connecting and fixing the crash box 2, the hook mounting member 5 and the bumper stay 3 on one side are performed simultaneously.

  In the present embodiment, when the mandrel 8 is pushed in, the wedges 83 can be reliably prevented from interfering with the bottom wall 52 of the hook mounting member 5. That is, as described above, of the plurality (six) wedges 83 of the mandrel 8, the wedge 83 disposed at a position corresponding to the nut 53 of the hook mounting member 5 is cut at the tip thereof, and the other It is formed shorter than the wedge 83. Further, a wedge insertion hole 55 is formed in a region of the bottom wall 52 of the hook attachment member 5 where the nut 53 is not attached. For this reason, when the mandrel 8 is pushed in, the wedge 83 corresponding to the nut 53 does not reach the bottom wall 52 to which the nut 53 is attached, and interferes with the bottom wall 52 and the nut 53 of the hook attachment member 5. Can be prevented. Further, the other wedges 83 can be prevented from interfering with the bottom wall 52 of the hook mounting member 5 by being inserted into the wedge insertion hole 55.

  After forming the convex portions 25, 26, and 56, the mandrel 8 is extracted, the diameter of the tube expansion mold 7 is reduced, and the crush box 2 is extracted.

  The pipe expansion process on the other side is performed in substantially the same manner as the pipe expansion process on the one side. As the tube expansion die 7 used in the tube expansion processing on the other side, a plurality of split dies 83 are all of the same length. The other configuration of the tube expansion mold 7 on the other side is substantially the same as that of the tube expansion mold 7 on the one side described above.

  The operation procedure of the tube expansion process is substantially the same. That is, the front end portion of the crash box 2 on the other side is disposed through the mounting hole 15 on the other side portion of the bumper reinforcement 1, and the base end portion of the crash box 2 on the other side is disposed in the mounting hole for the bumper stay 4 on the other side. 36 is disposed through. In this state, the split molds 71 of the tube expansion mold 7 are inserted and arranged between the partition walls 22 of the crush box 2 and the mandrel 8 is pushed in. As a result, the projection forming region of the crush box 2 is locally expanded to form the projections 25 and 26 protruding in the outer diameter direction. In this way, the connecting and fixing work of the bumper reinforcement 1 of the crash box 2 and the connecting and fixing work of the bumper stay 4 of the crash box 2 are simultaneously performed.

  In the present invention, the tube expansion molds 7 and 7 are disposed in the crush boxes 2 and 2 on the one side and the other side, and the mandrel 8 and 8 are simultaneously press-fitted, thereby expanding the tube on the one side, The pipe expansion process on the other side can be performed simultaneously. In this case, productivity can be further improved.

  As described above, the bumper reinforcement 1, the bumper stays 3 and 4, and the hook mounting member 5 are connected and fixed to the crash box 2 to assemble the bumper beam (vehicle impact absorbing device).

  The bumper beam is assembled to the vehicle body via bumper stays 3 and 4. That is, the bumper stays 3 and 4 are fixed to the ends of both side frames (both side members) (not shown) as a vehicle structure by bolting, welding, or the like, and the bumper beam is assembled to the vehicle body.

  In an automobile in which the bumper beam is assembled, when an impact is applied to the bumper reinforcement 1 due to a collision, the crash box 2 is compressed and deformed in the axial direction (vehicle longitudinal direction), and the impact energy is absorbed by the deformation. It is like that.

  On the other hand, as shown in FIGS. 4 and 5, the tow hook 6 is cut into the shaft portion 61, the hook main body 62 provided at the tip of the shaft portion 61, and the base end portion (insertion side end portion) of the shaft portion 61. A male screw 63 is provided.

  And when attaching the traction hook 6 to the automobile to which the bumper beam is assembled, the shaft portion 61 of the traction hook 6 is inserted with the male screw 63 side as the insertion side through the tip side opening of the crash box 2 on one side. It is inserted between the predetermined partition walls 22 and 22 in the crash box 2. When the male screw 63 of the traction hook 6 reaches the nut 53, the traction hook 6 is rotated and the male screw 63 is screwed into the screw hole 54 of the nut 53 and fixed. As a result, the tow hook 6 is assembled to the vehicle body with the hook main body 62 disposed in front of the tip (front end) of the crash box 2.

  Moreover, what is necessary is just to perform operation contrary to the above, when removing the tow hook 6. FIG. That is, the traction hook 6 is rotated to loosen the screw, the male screw 63 is removed from the nut 53, and then the traction hook 6 is extracted from the front end side opening of the crash box 2.

  As described above, according to the bumper beam of the present embodiment, the convex portions 26 and 56 are formed on the front and rear of the peripheral portion of the mounting hole 36 in the crash box 2 and the hook mounting member 5 by the pipe expanding process using the pipe expanding die 7. By forming, the hook mounting member 5 and the bumper stay 3 are fixed to the crash box 2. For this reason, the hook attachment member 5 and the bumper stay 3 can be simultaneously fixed to the crash box 2, and it is not necessary to separately perform an assembly operation for assembling the hook attachment member 5, and the number of work steps can be reduced. . Therefore, the assembling work can be easily performed, and the productivity can be improved and the cost can be reduced.

  Furthermore, since the hook attachment member 5 for attaching the tow hook 6 has a simple structure in which a nut 53 is provided on the bottom wall 52 with a cup shape, the structure can be simplified and the weight can be reduced. Can do.

  In the present embodiment, the crush box 2 is expanded to be connected and fixed to the bumper reinforcement 1, the hook mounting member 5, and the bumper stays 3, 4. Shapes can be used. That is, the bumper reinforcement 1, the bumper stays 3, 4 and the hook mounting member 5 can be reliably connected and fixed even in the crash box 2 in which a plurality of reinforcing partition walls 22 are formed as in this embodiment. it can. For this reason, the strength of the crash box 2 can be increased by changing the shape of the partition wall 22 or increasing the number thereof. Therefore, it is not necessary to increase the thickness and size of the crash box, and the crash box 2 can be reduced in size and weight and the cost can be further reduced.

  Furthermore, by adjusting the shape and number of the partition walls 22, it is possible to appropriately control the behavior (crushing method) at the time of crushing deformation (compression deformation) of the crash box 2 due to a collision. For this reason, for example, the difference between the initial maximum load at the time of collision and the average load after the initial load can be reduced, and the EA efficiency can be improved while increasing the amount of energy absorption (EA). The shock absorbing property can be obtained with certainty.

  In the present embodiment, the base end (rear end) of the crash box 2 is opposed to the bottom wall surface of the hook mounting member 5, so that a pulling force that pulls the pulling hook 6 attached to the hook mounting member 5 is not generated. The base end surface of the crash box 2 is pushed forward through the bottom wall 52 of the hook mounting member 5. Since this tensile force acts in the axial direction of the crash box 2, it is possible to reliably prevent a problem that the crash box 2 is deformed. Further, the pushing force that pushes the tow hook 6 does not directly act on the crash box 2 but is directly received by the vehicle side frame (structure) via the hook mounting member 5 and the crash box 2 is deformed. Can be reliably prevented. As described above, the force applied to the pulling hook 6 can surely prevent a problem such that the crash box 2 and the bumper reinforcement 1 are deformed. Therefore, it is possible to reliably perform the towing work or the vehicle body fixing work using the tow hook 6 without any trouble.

  In the present embodiment, the crash box 2 is supported by a side frame as a vehicle structure via the hook attachment member 5 and the bumper stay 3, so that the impact load applied to the bumper reinforcement 1 by the collision is the crash box. The impact energy can be reliably absorbed by the compression deformation (crush deformation) of the crash box 2. For this reason, it is possible to reliably prevent a problem that the hook mounting member 5 is inadvertently deformed by an impact load and fluctuates the desired EA amount, and excellent shock absorption characteristics can be reliably maintained. .

  In the present embodiment, the bumper beam constituent members 1 to 5 are connected and fixed by tube expansion processing. In other words, they are not fixed by welding or bolting. Therefore, an increase in costs associated with welding can be prevented, costs can be further reduced, and inadvertent shear failure at the time of collision caused by bolting and a reduction in assembly workability can be prevented, resulting in a further excellent impact. Absorption characteristics can be obtained, and productivity can be further improved.

  In the above-described embodiment, the hook mounting member 5 is a member in which the nut 53 is disposed on the rear surface (outer surface) of the bottom wall 52. However, the present invention is not limited to this, and in the present invention, as shown in FIG. In addition, the nut 53 may be disposed on the front surface (inner surface) of the bottom wall 52 of the hook mounting member 5.

  In this case, as the tube expansion die 7 used for connecting and fixing the hook mounting member 5 to the crash box 2 together with the bumper stay 3, the one shown in FIG. 10 may be used.

  That is, since the nut 53 disposed on the inner surface of the bottom wall 52 of the hook mounting member 5 is disposed inside the crash box 2, the split mold 71 of the tube expansion die 7 interferes with the nut 53, thereby There is a possibility that the mold 71 cannot be inserted. For this reason, in this modified example, among the plurality of split dies 71... Of the pipe expansion die 7, a short one with the tip (insertion side end) cut off is used as the split mold 71 corresponding to the nut 53.

  If this pipe expansion die 7 is used, the pipe expansion processing can be performed without any trouble without causing the split mold 71 to interfere with the nut 53.

  In the tube expansion die 7, since the split mold 71 does not exist in the portion corresponding to the nut 53, the connection fixing convex portion 26, the portion corresponding to the nut 53 in the crash box 2 and the hook mounting member 5, is provided. 56 cannot be formed. However, the portions where the convex portions 26 and 56 are not formed are only a part in the circumferential direction, and the connecting convex portions 26 and 56 can be formed without any trouble in many remaining portions. Therefore, the hook mounting member 5 and the bumper stay 3 can be reliably connected and fixed to the crash box 2 in the same manner as described above.

  Moreover, in the said embodiment, although the push-type thing which pushes a mandrel into a metal mold | die is used as a pipe expansion mold, it is not restricted only to this, As long as pipe expansion processing is possible, what kind of pipe expansion is possible. A mold may be used. For example, a pull-type tube expansion die that pulls the mandrel from the die may be used.

  In the above embodiment, a crush box having a substantially regular hexagonal cross section is used as the crush box. However, the present invention is not limited to this, and a crush box having another cross sectional shape may be used in the present invention. For example, the cross section may be circular, elliptical, oval, polygonal other than hexagonal, or irregular.

  In the above embodiment, the case where six partition walls are formed in the crush box has been described as an example. However, in the present invention, the number of partition walls is not limited, and the partition walls are not necessarily limited. There is no need to provide it.

  Furthermore, the shape of the partition wall is not particularly limited, and may be formed in any shape. For example, the partition wall is not necessarily formed radially along the radial direction in a cross-sectional view, and may be formed so as not to pass through the axis.

  In the above embodiment, the screw hole of the nut provided in the bottom wall of the hook mounting member is configured as a female screw. However, the present invention is not limited to this, and in the present invention, the screw hole is cut into the bottom wall of the hook mounting member. Thus, the threaded hole may be configured as a female screw.

  Moreover, in the said embodiment, although the cross-section of a surrounding wall is a rectangular thing as a bumper reinforcement, it is not restricted to it, In this invention, you may use the bumper reinforcement of another cross-sectional shape. For example, the cross section may be triangular, pentagonal or more polygonal, circular, elliptical, oval, or irregular.

  Furthermore, the partition walls provided in the bumper reinforcement are not limited to one, and two or more partition walls may or may not be provided.

  In the present embodiment, the bumper reinforcement is formed by an extrusion-molded product, a pultruded product, or the like. However, the present invention is not limited thereto, and in the present invention, the bumper reinforcement is formed by, for example, a metal plate press-formed product. Is also possible.

  In the above embodiment, the case where the bumper beam of the present invention is used as a structure inside the bumper has been described as an example. However, the present invention is not limited thereto, and the bumper beam of the present invention is also applied to a front underlamp protector of a large vehicle. Can be applied. In this case, the front end side of the crash box is the vehicle rear side, and the base end side of the crash box is the vehicle front side.

  Needless to say, the bumper beam of the present invention can also be used for a bumper provided at the rear end of an automobile.

  The vehicle impact absorbing member of the present invention can be applied to the structure inside the bumper of an automobile.

1: bumper reinforcement 15: mounting hole 2: crash box 21: peripheral wall 22: partition wall 25, 26: convex part 3, 4: bumper stay 36: mounting hole 5: hook mounting member 51: peripheral wall 52: bottom wall 53: nut 54: Screw hole (female thread)
55: Wedge insertion hole (mold interference prevention hole)
56: Convex part 6: Tow hook 7: Tube expansion mold

Claims (10)

A shock absorbing member for a vehicle to which a tow hook can be attached,
A cylindrical crash box,
A bumper stay having a mounting hole;
A hook mounting member formed in a cup shape having a peripheral wall along the outer peripheral edge of the bottom wall, and provided with a female screw for attaching a tow hook on the bottom wall;
Each of the peripheral walls of the crash box and the hook mounting member in a state where the hook mounting member is fitted on the base end portion of the flash box and the peripheral wall of the hook mounting member penetrates the mounting hole of the bumper stay. In the front and rear of the mounting hole peripheral portion of the bumper stay, a convex portion protruding in the outer diameter direction is formed by tube expansion processing using a tube expansion die, so that the hook mounting member and the bumper stay are attached to the crash box. A shock absorbing member for a vehicle characterized by being fixed.   The impact absorbing member for a vehicle according to claim 1, wherein a partition wall for partitioning the interior of the crash box is formed continuously along the axial direction.   The vehicle impact absorbing member according to claim 1 or 2, wherein the convex portion is provided so as to extend along a circumferential direction.   The impact-absorbing member for a vehicle according to any one of claims 1 to 3, wherein the convex portions are provided intermittently at intervals in the circumferential direction.   The mold interference prevention hole for avoiding interference with a metal mold | die at the time of pipe expansion processing is formed in the area | region where the said internal thread is not located in the bottom wall of the said hook attachment member. The vehicle impact absorbing member as described.   The impact absorbing member for a vehicle according to any one of claims 1 to 5, wherein a nut having the female screw is provided on an outer surface of a bottom wall of the hook mounting member. It further comprises a bumper reinforcement having a mounting hole,
With the front end portion of the crash box penetrating through the mounting hole of the bumper reinforcement, in the outer diameter direction by tube expansion processing using a tube expansion mold before and after the bumper reinforcement mounting hole peripheral portion of the peripheral wall of the crash box The impact absorbing member for a vehicle according to any one of claims 1 to 6, wherein the bumper reinforcement is fixed to the crash box by forming a projecting portion that protrudes into the crash box. A bumper beam for a vehicle to which a tow hook can be attached,
A cylindrical crash box,
Bumper reinforcement,
A bumper stay having a mounting hole;
A hook mounting member formed in a cup shape having a peripheral wall along the outer peripheral edge of the bottom wall, and provided with a female screw for attaching a tow hook on the bottom wall;
While the bumper reinforcement is attached to the tip of the crash box,
Each of the peripheral walls of the crash box and the hook mounting member in a state where the hook mounting member is fitted on the base end portion of the flash box and the peripheral wall of the hook mounting member penetrates the mounting hole of the bumper stay. In the front and rear of the mounting hole peripheral portion of the bumper stay, a convex portion protruding in the outer diameter direction is formed by tube expansion processing using a tube expansion die, so that the hook mounting member and the bumper stay are attached to the crash box. A bumper beam for vehicles characterized by being fixed. A method of manufacturing a shock absorbing member for a vehicle to which a tow hook can be attached,
A cylindrical crash box,
A bumper stay having a mounting hole;
A hook mounting member that is formed in a cup shape with a peripheral wall provided along the outer peripheral edge of the bottom wall, and that has a female screw for attaching a tow hook on the bottom wall;
The hook mounting member is externally fitted to the base end portion of the flash box, and the peripheral wall of the hook mounting member is passed through the mounting hole of the bumper stay, and the crash box and the peripheral wall of the hook mounting member are The hook mounting member and the bumper stay are fixed to the crash box by forming convex portions projecting in the outer diameter direction by tube expansion processing using a tube expansion die around the periphery of the mounting hole peripheral portion of the bumper stay. A method of manufacturing a shock absorbing member for a vehicle, characterized by A method of manufacturing a bumper beam for a vehicle to which a tow hook can be attached,
A cylindrical crash box,
Bumper reinforcement,
A bumper stay having a mounting hole;
A hook mounting member that is formed in a cup shape with a peripheral wall provided along the outer peripheral edge of the bottom wall, and that has a female screw for attaching a tow hook on the bottom wall;
While attaching the bumper reinforcement to the tip of the crash box,
The hook mounting member is externally fitted to the base end portion of the flash box, and the peripheral wall of the hook mounting member is passed through the mounting hole of the bumper stay, and the crash box and the peripheral wall of the hook mounting member are The hook mounting member and the bumper stay are fixed to the crash box by forming convex portions projecting in the outer diameter direction by tube expansion processing using a tube expansion die around the periphery of the mounting hole peripheral portion of the bumper stay. A method for manufacturing a bumper beam for a vehicle.

Images