JP2014181799A - Shock absorber device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a shock absorber device having a plurality of cylinders integrally connected and overlapped while being axially connected to each other to assure a sufficient rigidity through the connection and to adjust their connecting strength in an easy manner.SOLUTION: Each of resin outer members 18 is arranged to be fused to outer peripheral surfaces of a plurality of inner members (cylinder) 12 and a plurality of inner members 12 are integrally connected through the outer members 18. Due to this fact, relative loads of the plurality of inner members 12 in lateral displacement direction can be appropriately accepted by the outer members 18 and an entire rigidity of a crush box 10. In addition, a wall thickness of the outer member and a contact area between it and the outer peripheral surface of the inner member 12 are changed to enable a connecting strength in a lateral displacing direction, i.e. a load to cause a plurality of inner members 12 to be displaced to each other (lateral displacement) to be easily adjusted, so that a degree of freedom in setting a characteristic of shock absorption is increased.

Description

  The present invention relates to an impact absorbing device, and more particularly to an improvement of an impact absorbing device in which a plurality of resin cylinders are overlapped and connected integrally in an axial direction.

  A plurality of resin cylinders having a cylindrical side wall are overlapped and integrally connected so as to be continuous in the axial direction of the cylindrical shape, and the impact applied from the axial direction is absorbed by deformation of the cylindrical body. An impact absorbing device is used in, for example, a mounting portion of a vehicle bumper. The apparatus described in Patent Document 1 is an example, and a tapered inclined surface is provided on the end faces of a plurality of cylinders, and each cylinder is deformed by expanding or contracting along the inclined surfaces. It is proposed that the end faces of a plurality of cylinders are stacked so that they abut each other, and that the abutting portions are bonded with an adhesive or the like as means for integrally connecting them. Yes.

International Publication No. 2006/0255559

  However, when bonding the abutting portions of a plurality of cylinders with an adhesive or the like, there is a limit because the connection strength in the lateral displacement direction intersecting the axial direction depends on the contact area of the abutting portion, and the shock absorbing device as a whole In some cases, sufficient rigidity cannot be obtained, and it is difficult to adjust the connection strength, which may limit the shock absorption performance.

  The present invention has been made against the background of the above circumstances. The object of the present invention is to provide a shock absorber in which a plurality of cylinders are overlapped so as to be continuous in the axial direction and connected integrally. It is to ensure sufficient rigidity and to easily adjust the connection strength.

  In order to achieve such an object, according to the first aspect of the present invention, a plurality of resin cylinders having a cylindrical side wall are overlapped and integrally connected so as to be continuous in the axial direction of the cylindrical shape. An impact absorbing device that absorbs the impact applied from the cylinder by deformation of the cylindrical body, and is continuously provided in the axial direction of the impact absorbing apparatus, and is fused to the surfaces along the axial direction of the plurality of cylindrical bodies. The plurality of cylinders are integrally connected to each other through the connecting member.

  According to a second aspect of the present invention, in the shock absorber of the first aspect, the connecting member is provided on the outer peripheral side of the plurality of cylindrical bodies, and is a cylindrical outer member that is fused to the outer peripheral surface of the plurality of cylindrical bodies. It is characterized by being.

  According to a third aspect of the present invention, in the impact absorbing device of the first or second aspect, (a) a gap is provided in an axial boundary portion of the plurality of cylindrical bodies, and (b) the connecting member is It is characterized in that a part of the gap penetrates into the gap and is also fused to the surface forming the gap.

  According to a fourth aspect of the present invention, in the impact absorbing device according to any one of the first to third aspects, at least one of the plurality of cylindrical bodies is made of fiber reinforced resin, and the impact is input to the side. The cylindrical body is characterized in that it has a lower fiber content than the cylindrical body on the side opposite to the input side.

  According to a fifth aspect of the present invention, in the impact absorbing device according to any one of the first to fourth aspects, grooves are provided along the axial direction on the outer peripheral surfaces of the plurality of cylinders, and resin is provided in the grooves. The connecting member is formed by filling a material.

  According to a sixth aspect of the present invention, (a) a plurality of resin inner members having cylindrical side walls are superposed so as to be continuous in the axial direction of the cylindrical shape, and (b) the outer peripheral side of the plurality of inner members A cylindrical outer member made of resin that is continuously provided in the axial direction, covers the outer peripheral surface of the plurality of inner members and is fused to the outer peripheral surface of the plurality of inner members, and (c) A method of manufacturing an impact absorbing device in which the plurality of inner members are integrally connected to each other via the outer member and absorbs an impact applied from the axial direction by deformation of the inner member, and (d) the plurality A setting step in which the inner members of the inner member are overlapped so as to be continuous in the axial direction and arranged in the first molding die, (e) a second molding die having a molding surface having an inner diameter larger than the outer diameter of the inner member, and the first molding die 1 mold A mold clamping step of clamping the mold relatively close to each other and forming a cylindrical cavity corresponding to the outer member between the molding surface and the outer peripheral surface of the inner member; and (f) the outer member An injection step of melting the resin material at a temperature higher than the melting temperature of the inner member and injecting the resin material into the cavity, molding the outer member, and simultaneously fusing the outer member to the outer peripheral surface of the inner member. It is characterized by that.

  In the impact absorbing device of the first to fifth inventions, the resin-made connecting members are provided so as to be fused to the surfaces along the axial direction of the plurality of cylinders, and the plurality of cylinders are interposed via the connecting members. Since the bodies are integrally connected to each other, the load in the lateral displacement direction between the cylinders can be appropriately received by the connecting member, and the rigidity of the entire shock absorbing device can be appropriately ensured. Also, by changing the contact area with the surface along the axial direction of the cylinder and the thickness of the connecting member, the connection strength in the lateral displacement direction, that is, the load that causes the multiple cylinders to be displaced relative to each other (lateral displacement) can be easily achieved. Since it can be adjusted, the degree of freedom in setting the shock absorption characteristics is increased.

  2nd invention is a case where a cylindrical outer member is provided in the outer peripheral side of the some cylinder so that it may fuse | fuse to the outer peripheral surface of a some cylinder as said connection member, for example of 6th invention The shock absorbing device can be manufactured with high productivity and low cost by a manufacturing method or the like.

  In the third invention, a gap is provided in the axial boundary portion of the plurality of cylindrical bodies, and the connecting member enters the gap and is fused, so that the joining area by the fusion is increased and the coupling strength is increased. Further improve.

  In the fourth invention, at least one of the plurality of cylinders is made of fiber reinforced resin, and the cylinder on the side to which the impact is input has a fiber as compared with the cylinder on the opposite side to the input side. Since the content is reduced and the strength is low, the deformation can be appropriately advanced from the input side, and a predetermined shock absorbing performance can be stably obtained.

  In the fifth invention, grooves are provided along the axial direction on the outer peripheral surfaces of the plurality of cylinders, and the connecting material is formed by filling the grooves with a resin material. The connection strength can be easily adjusted by the groove shape or the like.

  According to a sixth aspect of the present invention, the cylindrical member includes an inner member, and a resin-cylindrical outer member is provided on the outer peripheral side as the connecting member, and is fused to the outer peripheral surface of each inner member. The present invention relates to the connected shock absorbing device, that is, the manufacturing method of the shock absorbing device of the second invention, and the same effects as the second invention can be obtained. Further, in this manufacturing method, after a plurality of inner members are overlapped in the axial direction and arranged in the first mold, the first mold and the second mold are brought relatively close to each other to clamp the mold. By forming a cylindrical cavity on the outer peripheral side of the inner member and injecting the molten resin material of the outer member into the cavity, the outer member is molded and simultaneously fused to the outer peripheral surface of the inner member Therefore, the impact absorbing device can be manufactured with high productivity and at low cost.

It is a front view which shows the crash box for vehicles which is one Example of this invention. It is a longitudinal cross-sectional view of the crush box of FIG. 1, and is sectional drawing of the II-II arrow part in FIG. It is sectional drawing of the boundary part of the several inner member of the crush box of FIG. 1, and is an expanded sectional view of the III section in FIG. It is a cross-sectional view of the crush box of FIG. 1, and is a cross-sectional view taken along the line IV-IV in FIG. It is sectional drawing of the flange part of the crush box of FIG. 1, and is sectional drawing of the VV arrow part in FIG. It is a front view which shows independently one inner member which comprises the crash box of FIG. It is a cross-sectional view of the inner member of FIG. 6, and is a cross-sectional view taken along the line VII-VII in FIG. It is a longitudinal cross-sectional view of the inner member of FIG. 6, and is a cross-sectional view taken along the line VIII-VIII in FIG. It is a perspective view of the inner member of FIG. It is a figure explaining the other Example of this invention, and is sectional drawing corresponding to FIG. It is a figure explaining another Example of this invention, and is sectional drawing corresponding to FIG. It is a figure explaining another Example of this invention, and is sectional drawing corresponding to FIG. It is a figure explaining another Example of this invention, and is sectional drawing corresponding to FIG. It is a figure explaining another Example of this invention, and is a longitudinal cross-sectional view corresponding to FIG. It is sectional drawing of the boundary part of the some inner member of the Example of FIG. 14, It is an expanded sectional view of the XV part in FIG. It is a figure explaining another Example of this invention, and is a longitudinal cross-sectional view corresponding to FIG. It is sectional drawing of the boundary part of the some cylinder of the Example of FIG. 16, and is an expanded sectional view of the XVII part in FIG. It is a perspective view which shows independently the one cylinder in the Example of FIG. It is a figure explaining another Example of this invention, and is sectional drawing corresponding to FIG. FIG. 20 is a perspective view independently showing one inner member in the embodiment of FIG. 19. It is a figure explaining another Example of this invention, and is a perspective view of the crash box for vehicles. It is a longitudinal cross-sectional view of the Example of FIG. 21, It is sectional drawing of the XXII-XXII arrow part in FIG. It is a front view which shows independently one inner member in the Example of FIG. It is the top view which looked at the inner member of Drawing 23 from the upper part. It is a perspective view of the inner member of FIG. It is process drawing explaining an example of the manufacturing method at the time of manufacturing the crush box of FIG. It is process drawing explaining an example of the manufacturing method at the time of manufacturing the crash box of the Example of FIG.

  The impact absorbing device of the present invention is preferably applied to a crash box disposed between a vehicle body and a bumper, but can also be applied to other impact absorbing devices for other vehicles. The number of the plurality of cylinders is at least 2 or more, but about 2 to 5 is appropriate. A cylindrical shape is appropriate as the shape of the cylindrical body, but it may be a polygonal rectangular tube shape such as a quadrangular section or an octagonal section. Various aspects are possible, such as the corners of the polygon can be rounded, or a tapered shape with a smaller cross section on the tip side in the axial direction. The inside of the cylindrical body may be a complete space, but a flat reinforcing rib, a reinforcing rib in which a large number of cylinders or square cylinders are continuously connected, and the like may be provided as necessary. The entire inside of the cylindrical body may be a reinforcing rib structure such as a honeycomb.

  When the plurality of cylinders are stacked so as to be continuous in the axial direction, fitting portions that are fitted to each other can be provided at end portions in the axial direction so that they are positioned substantially concentrically with each other. The end faces in the direction may simply be abutted. Further, by providing a plurality of locking claws around the shaft center and being locked to the other member, the axial detachment can be restricted.

  The plurality of cylinders are each deformed by applying a compressive load from the axial direction and absorb impact energy, but the deformation mode is not only crushing in the axial direction and compressing and deforming in a bellows shape, As described in Patent Document 1, various modes such as a diameter expansion deformation toward the outer peripheral side and a diameter reduction deformation toward the inner peripheral side are possible. For example, polypropylene or polyamide is preferably used as the resin material for the plurality of cylinders, and glass fiber, carbon fiber, aramid fiber, or the like is preferably used as the reinforcing fiber. The reinforcing fiber may be contained as necessary, and the content thereof is preferably as small as the cylindrical body on the tip side to which an impact is inputted as in the fourth invention. The content of reinforcing fibers in the most advanced cylindrical body may be 0, and a predetermined amount of reinforcing fibers may be included in other cylindrical bodies. The resin material of the connecting member is preferably the same resin material as the cylinder for fusing to the cylinder, and polypropylene, polyamide, etc. are preferably used, but other thermoplastic elastomers or the like are used. You can also

  In the manufacturing method of the second invention or the sixth invention, a cylindrical outer member is provided as a connecting member. However, when implementing another invention, a cylindrical connecting member is provided on the inner peripheral side of the cylindrical body, It can also be made to be fused to the inner peripheral surface of the cylinder. Also, through-holes vertically passing in the axial direction are provided in the side walls of the plurality of cylindrical bodies, and a connecting member is formed by pouring molten resin into the through-holes, and a plurality of fusion holes are fused to the inner peripheral surface of the through-holes. Various modes are possible, such as the cylindrical bodies can be connected together. It is desirable to form a plurality of through holes around the axial center and provide a connecting member for each of the plurality of through holes. These connecting members can also be fused to a plurality of cylindrical bodies at the same time as injection molding as in the manufacturing method of the sixth invention.

  The first molding die in which a plurality of inner members are arranged so as to be continuous in the axial direction has positioning pins, positioning grooves and the like so that the inner member is arranged at a predetermined position of the first molding die. It is desirable to provide a part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view showing a crash box 10 for a vehicle to which the present invention is applied. FIG. 2 is a longitudinal sectional view of the crash box 10 and is a sectional view taken along the line II-II in FIG. 3 is an enlarged sectional view of a portion III in FIG. 2, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1, and FIG. 5 is a sectional view taken along the line VV in FIG. As can be seen from these drawings, the crash box 10 has three cylindrical inner members 12-1, 12-2, 12-3 that are overlapped so as to be continuous in the axial direction. Member 12) and a cylindrical outer member 18 provided on the outer peripheral side of the inner members 12-1, 12-2, 12-3, and the base end of the outer member 18. A flat plate-like flange 20 that extends to the outer peripheral side substantially at a right angle to the center line S is provided integrally with the portion (the lower end portion in FIGS. 1 and 2).

  In the crash box 10, the flange 20 side of the outer member 18 is integrally fixed to the vehicle body via a mounting plate (not shown), while a mounting plate (not shown) is provided on the tip (upper end in FIGS. 1 and 2) side. A bumper is mounted via the bumper, and an impact applied from the axial direction via the bumper is absorbed by deformation of the inner member 12 and the like. In this embodiment, when a compressive load is applied from the axial direction, the crush box 10 is compressed and deformed (collapsed) in a bellows shape from the tip side, and the impact energy is absorbed by this deformation and an impact applied to the vehicle body is applied. Alleviated. As shown in FIG. 5, the flange 20 is provided with a plurality of insertion holes 22 through which mounting bolts and the like for fixing to the vehicle body are inserted. The crash box 10 corresponds to an impact absorbing device, the three inner members 12 correspond to cylinders, and the outer member 18 corresponds to a connecting member.

  The three inner members 12 have the same shape, and as shown in FIGS. 6 to 9, each has a cylindrical side wall 30 and a plurality of reinforcements radially provided around the center line S inside the side wall 30. The ribs 32 are formed integrally with a resin material such as polypropylene. 6 is a front view showing the inner member 12 alone, FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6, FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 3 is a perspective view of a member 12. FIG. As is clear from these figures, the side wall 30 has a tapered shape with a slightly smaller diameter toward the tip side, but as is clear from FIG. 3, the outer diameter of the small diameter end 30a of the side wall 30 is large. These end surfaces, which are larger than the inner diameter of the radial end 30b and are substantially perpendicular to the center line S, are brought into contact with each other and overlapped in the axial direction.

  The reinforcing ribs 32 have a shape in which hexagonal cross-section cylinders are aligned in a row so as to be in close contact with each other and joined together, and have the same length as the axial length of the inner member 12 and are radially formed. Six pieces are provided, and are integrally joined to the inner wall surface of the cylindrical side wall 30. A centering hole of these reinforcing ribs 32, that is, a portion coinciding with the center line S is provided with a positioning hole 34 having a circular cross section, and a positioning pin 208 (see FIG. 26) is inserted during manufacture. Thus, the three inner members 12 are positioned concentrically. For example, the three inner members 12 are overlapped so that the reinforcing ribs 32 coincide with each other around the center line S. However, the phases around the center line S can be overlapped without any particular limitation. Further, as shown in FIG. 22, the phase around the center line S may be shifted by, for example, 30 degrees so that the reinforcing ribs 32 of the adjacent inner members 12 do not overlap.

  The inner member 12 is reinforced with a resin material containing reinforcing fibers such as carbon fibers. The content of this reinforcing fiber may be the same, but in this embodiment, the inner member located on the tip side close to the bumper so that compression deformation proceeds from the tip side when an impact load is applied from the bumper. The content of the reinforcing fiber is reduced toward the 12-1 side. Specifically, the content of the reinforcing fibers in the innermost member 12-1 at the most distal end is about 15 wt%, the content of the reinforcing fibers in the inner member 12-2 at the intermediate position is about 30 wt%, and the inner end on the proximal end side The reinforcing fiber content of the member 12-3 is about 50 wt%. This content is appropriately determined according to the type of reinforcing fiber and the like.

  On the other hand, the outer member 18 is provided continuously over the entire length of the crash box 10 in the axial direction, and is brought into close contact with the surfaces along the axial direction of the three inner members 12, that is, the outer peripheral surfaces thereof. The three inner members 12 are integrally connected to each other with a predetermined connection strength via the outer member 18 by this fusion. The outer member 18 is made of the same resin material (not including reinforcing fibers) as the inner member 12, and the molten resin material is injected to the outer peripheral side of the inner member 12, thereby simultaneously forming the inner member 12. Are integrally fused to each outer peripheral surface. The connection strength can be adjusted by the thickness of the outer member 18 and the contact area with the inner member 12, and the lateral displacement of the inner members 12 is limited according to the connection strength.

  FIG. 26 is a process diagram illustrating an example of a method for manufacturing the crash box 10. The manufacturing apparatus 200 is an injection molding apparatus having a fixed mold 202 and a movable mold 204. The fixed mold 202 is provided with a shallow recess 206 for molding the flange 20, and a positioning pin 208 at the center. Is standing vertically. The positioning pin 208 has a length dimension substantially the same as the axial dimension of the crash box 10 and is inserted through the positioning holes 34 of the inner members 12-1, 12-2, 12-3. Etc. are positioned concentrically with each other. The movable mold 204 is vertically driven so as to be moved closer to and away from the fixed mold 202 and has a molding surface 210 having an inner diameter larger than the outer diameter of the inner member 12 and substantially equal to the outer diameter of the outer member 18. A circular hole is provided. A shallow recess 212 for forming the flange 20 is formed together with the recess 206 at the opening end of the circular hole. The fixed mold 202 corresponds to a first mold, and the movable mold 204 corresponds to a second mold.

  FIG. 26A shows a state in which the movable mold 204 is driven upward and the mold is opened. In this state, the inner members 12-3, 12-2, and 12 formed in advance as shown in FIG. -1 are arranged on the fixed mold 202 so that the positioning pins 208 can be inserted into the positioning holes 34 in that order. At this time, phase alignment around the center line S of each inner member 12 is performed as necessary. FIG. 26B shows a case where the phase alignment is performed so that the positions of the reinforcing ribs 32 coincide with each other. Thereafter, the movable mold 204 is lowered as shown in (c), is brought close to the fixed mold 202, and is clamped. Thereby, a cylindrical cavity 214 corresponding to the outer member 18 is formed between the molding surface 210 of the movable mold 204 and the outer peripheral surface of the inner member 12. Then, as shown in (d), the resin material of the outer member 18 is melted at a temperature higher than the melting temperature of the inner member 12 and injected into the cavity 214, thereby simultaneously forming the outer member 18. The plurality of inner members 12 are integrally fused to each outer peripheral surface. Thus, the target crash box 10 is obtained, and after the outer member 18 is cooled and hardened, the movable mold 204 is raised and taken out.

  As described above, the crash box 10 according to the present embodiment is provided so that the resin outer member 18 is fused to the outer peripheral surfaces of the plurality of inner members 12, and the plurality of inner members 12 are interposed via the outer members 18. Are integrally connected to each other. For this reason, it is possible to appropriately receive the loads in the lateral displacement directions of the plurality of inner members 12 by the outer member 18, and it is possible to appropriately ensure the rigidity of the crash box 10 as a whole.

  Further, by changing the wall thickness of the outer member 18 and the contact area with the outer peripheral surface of the inner member 12, it is possible to easily increase the connection strength in the lateral displacement direction, that is, the load that causes the plurality of inner members 12 to be displaced relative to each other (lateral displacement). Since it can be adjusted, the degree of freedom in setting the shock absorption characteristics is increased. In the case of the crash box 10 of this embodiment that compresses and deforms in a bellows shape and absorbs impact energy, it is not always necessary that the plurality of inner members 12 be displaced relative to each other, and they are connected with a relatively high connection strength. It ’s fine.

  Each of the plurality of inner members 12 is made of a fiber reinforced resin, and the strength of the reinforcing fibers is reduced as much as the inner member 12-1 on the tip side to which an impact is input, so that the strength is low. Therefore, compression deformation (crushing) can be appropriately advanced from the input side, and a predetermined shock absorbing performance can be stably obtained.

  Further, in the present embodiment, since the cylindrical outer member 18 is provided on the outer peripheral side of the plurality of inner members 12 so as to be fused to the outer peripheral surfaces of the plurality of inner members 12, the manufacturing shown in FIG. According to the method, the crash box 10 can be manufactured with high productivity and low cost.

  Next, another embodiment of the present invention will be described. In the following embodiments, parts that are substantially the same as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 10 is a cross-sectional view corresponding to FIG. 3 and relates to the crash box 40 shown in FIG. The crush box 40 includes three inner members 42-1, 42-2, and 42-3 (which are simply referred to as an inner member 42 unless otherwise specified), and the outer peripheral surfaces thereof. It is comprised from the cylindrical outer member 48 closely_contact | adhered to and fused. An annular fitting step 50 is provided on the outer peripheral side of the small-diameter end 44a of the side walls 44 of the three inner members 42, and an annular fitting step 52 is provided on the inner peripheral side of the large-diameter end 44b. The three inner members 42 are positioned substantially concentrically with each other by fitting the small-diameter end 44a and the large-diameter end 44b to each other. Further, the axial length of the fitting step 50 is larger than the axial length of the fitting step 52, and the fitting step 50 forms a gap 54 that is spaced apart from the large diameter end 44 b in the axial direction. Accordingly, when the outer member 48 is injection-molded as in the above-described embodiment, a part of the outer member 48 enters the gap 54 and solidifies, so that the outer surface of the large-diameter end 44b, the end surface of the fitting step 50, etc. As a result of the fusion, the bonding area is increased. Thereby, coupled with the fitting of the small-diameter end 44a and the large-diameter end 44b, the connection strength against the lateral displacement of the plurality of inner members 42 is further improved.

  On the other hand, since the inner member 42 does not include the reinforcing rib 32, the positioning hole 34 cannot be provided, and positioning by the positioning pin 208 is impossible. Therefore, as in the manufacturing apparatus 220 shown in FIG. 27, an annular positioning groove 222 into which the large-diameter end 44 b is fitted is provided in the fixed mold 202, and the inner member 42 with respect to the fixed mold 202 is formed by the positioning groove 222. Perform positioning. FIG. 27 is a manufacturing process diagram corresponding to FIG. 26. In this example, in order to mold the flange 56 of the outer member 48, a recess 224 is provided only on the movable mold 204 side. In the mold closing step (c), a cylindrical cavity 226 corresponding to the outer member 48 is formed on the outer peripheral side of the three inner members 42, and melted in the cavity 226 as shown in (d). By injecting the resin, the outer member 48 is molded and simultaneously fused to the outer peripheral surfaces of the plurality of inner members 42, whereby the target crash box 40 is obtained. Therefore, also in the present embodiment, the crash box 40 can be manufactured with high productivity and at low cost as in the above-described embodiment.

  FIG. 11 is a cross-sectional view corresponding to FIG. 3, that is, two inner members 60-2 and 60-3 on the base end side among the three inner members 60 of the same shape overlapped in the axial direction (in particular, It is sectional drawing which shows the boundary part of only the inner member 60 when not distinguishing. These inner members 60 are constituted by only cylindrical side walls 62 as in the case of the inner member 42 in the embodiment of FIG. 10, and a cylindrical outer member 64 is integrally fused to the outer peripheral side thereof. Yes. An annular fitting step 66 is provided on the outer peripheral side of the small diameter end 62a of the side wall 62 of the inner member 60, while an annular fitting step 68 is provided on the inner peripheral side of the large diameter end 62b. The small-diameter end 62a and the large-diameter end 62b are fitted to each other, whereby the plurality of inner members 60 are positioned substantially concentrically with each other. An annular step 70 having a larger diameter than the fitting step 68 is further provided on the large-diameter end 62b side, and a gap 72 that is radially separated from the outer peripheral surface of the small-diameter end 62a is formed. It has become. Therefore, when the outer member 64 is injection-molded as in the above-described embodiment, a part of the outer member 64 penetrates into the gap 72 and solidifies, thereby increasing the bonding area by fusion. Thereby, coupled with the fitting of the small-diameter end 62a and the large-diameter end 62b, the connection strength against the lateral displacement of the plurality of inner members 60 is further improved.

  12 is a cross-sectional view corresponding to FIG. 3, that is, two inner members 80-2 and 80-3 on the proximal end side among the three inner members 80 having the same shape overlapped so as to be continuous in the axial direction (in particular, It is sectional drawing which shows the boundary part of only the inner member 80 when not distinguishing. These inner members 80 are composed of only a cylindrical side wall 82 as in the case of the inner member 42 in the embodiment of FIG. 10, and a cylindrical outer member 84 is integrally fused to the outer peripheral side thereof. Yes. Annular grooves 86 and 88 are provided on the end surfaces of the small-diameter end 82a and the large-diameter end 82b of the side wall 82 of the inner member 80, respectively, and an annular fitting formed on the inner peripheral side of the large-diameter end 82b. By fitting the projection 90 into the annular groove 86 of the small diameter end 82a, the plurality of inner members 80 are positioned substantially concentrically with each other. Further, the annular annular protrusion 92 formed on the outer peripheral side of the small diameter end 82a is smaller than the annular groove 88 of the large diameter end 82b as a whole, and an axial direction is provided between the annular groove 88 and the annular protrusion 92. In addition, an inverted V-shaped or inverted U-shaped gap 94 that is separated in the radial direction is formed. Therefore, when the outer member 84 is injection-molded as in the above-described embodiments, a part of the outer member 84 enters into the gap 94 and solidifies, so that the bonding area by fusion increases, and the fitting protrusion 90 and Coupled with the fitting with the annular groove 86, the connection strength against the lateral displacement of the plurality of inner members 80 is further improved.

  FIG. 13 is a cross-sectional view corresponding to FIG. 3, that is, two inner members 100-2 and 100-3 on the base end side among the three inner members 100 of the same shape stacked so as to be continuous in the axial direction (in particular, It is sectional drawing which shows the boundary part of only the inner member 100 when not distinguishing. These inner members 100 are constituted by only cylindrical side walls 102 as in the case of the inner member 42 in the embodiment of FIG. 10, and a cylindrical outer member 104 is integrally fused to the outer peripheral side thereof. Yes. An annular groove 106 is provided on the outer peripheral surface of the side wall 102 of the inner member 100 on the side of the small diameter end 102a, while the inner peripheral portion of the large diameter end 102b has a reverse V-shaped or reverse U-shaped spring portion. 108 is provided, and an engaging claw 110 to be fitted into the annular groove 106 is provided at an inner peripheral end edge which is a tip of the spring portion 108. In this case, the spring portion 108 is elastically deformed so that the locking claw 110 is fitted in the annular groove 106 and locked to the edge thereof, thereby positioning the plurality of inner members 100 substantially concentrically with each other. At the same time, the axial displacement is limited. Further, when a part of the outer member 104 enters and solidifies into the gap 112 formed in the vicinity of the locking claw 110, the deformation of the spring portion 108 is suppressed, and the locking claw 110 is more locked. In addition to being reliably maintained, an increase in bonding area due to fusion, coupled with positioning by the locking claws 110, further improves the connection strength of the plurality of inner members 100 against lateral displacement.

  FIG. 14 is a cross-sectional view corresponding to FIG. 2, that is, a vertical cross-sectional view of the crush box 120. The crush box 120 includes three cylindrical inner members 122-1, 122-2, and 122-3 (which are simply referred to as an inner member 122 unless otherwise distinguished) that are overlapped in an axial direction. It is comprised from the cylindrical outer member 124 integrally melt | fused by the outer peripheral side of the inner members 122-1, 122-2, and 122-3. The three inner members 122 have the same taper shape and are alternately stacked in the opposite directions in the axial direction, and the intermediate inner member 122-2 has a small diameter end side as a base end side. In this case, the small-diameter ends and the large-diameter ends are brought into contact with each other, but as is clear from FIG. V-shaped annular grooves 126 and 128 are provided, and the outer circumferential groove walls 130 and 132 of these annular grooves 126 and 128 are smaller than the inner circumferential groove wall and are abutted in the axial direction. In this state, a gap 134 that is separated in the axial direction is formed. Therefore, when the outer member 124 is injection-molded as in the above embodiments, a part of the outer member 124 enters the annular grooves 126 and 128 from the gap 134 and solidifies, thereby being fused. As the joining area increases, the outer member 124 is locked in the annular grooves 126 and 128, and the connection strength against the lateral displacement of the plurality of inner members 122 is further improved.

  FIG. 16 is a cross-sectional view corresponding to FIG. 2, that is, a vertical cross-sectional view of the crush box 140. The crush box 140 has three cylindrical cylinders 142-1, 142 that are stacked so as to be continuous in the axial direction. -2 and 142-3 (if not particularly distinguished, simply referred to as a cylinder 142). 17 is an enlarged cross-sectional view of a portion XVII in FIG. 16, and FIG. 18 is a perspective view showing one cylindrical body 142 alone. The cylinders 142-1, 142-2, and 142-3 have a diameter as small as that of the cylinder 142-1 on the distal end side so as to form a smooth taper shape in which the diameter continuously changes at a constant taper angle as a whole. Has been. Further, a plurality of through holes 144 (four in the embodiment) are provided at equal angular intervals around the center line S in the side wall of each cylindrical body 142, and these through holes 144 are provided. They are overlapped in the axial direction so as to coincide with each other around the center line S. Then, a predetermined molten resin is filled and solidified so as to pass through the through-holes 144 provided in the three cylinders 142, so that they are integrally fused to the inner wall surfaces of those through-holes 144. The connecting member 146 is configured. That is, in this embodiment, the three cylindrical bodies 142 are connected with the predetermined connection strength by the four rod-like connection members 146, and the number, thickness, and width dimensions of the connection members 146, that is, through holes The connection strength can be easily adjusted by the number of 144, the width dimension, and the length dimension.

  An annular fitting protrusion 148 protrudes from the inner periphery of the small diameter end of the cylindrical body 142 so as to protrude in the axial direction, while the fitting protrusion 148 protrudes from the inner periphery of the large diameter end. An annular fitting step 150 to be fitted to 148 is provided, and the plurality of cylindrical bodies 142 are positioned substantially concentrically with each other by being fitted to each other.

  FIG. 19 is a cross-sectional view corresponding to FIG. 3, that is, two inner members 160-2 and 160-3 on the base end side among three inner members 160 having the same shape overlapped in an axial direction (in particular, FIG. 20 is a perspective view showing one inner member 160 by itself. The inner member 160 is mainly composed of a cylindrical side wall 162, and a cylindrical outer member 164 is integrally fused to the outer peripheral side thereof. In the vicinity of the small-diameter end 162a of the side wall 162 of the inner member 160, a plurality of (four in the embodiment) through-holes 166 penetrating in the radial direction are provided at equal angular intervals around the center line S. A plurality of locking claws 168 are provided on the 162b so as to protrude in the axial direction corresponding to the through holes 166 thereof. Therefore, the plurality of locking claws 168 are elastically deformed and fitted into the through holes 166, respectively, and locked to the end portions of the through holes 166, so that the plurality of inner members 160 are substantially concentric with each other. As well as being positioned, axial withdrawal is limited. Further, a part of the outer member 164 enters the gap 170 formed in the vicinity of the locking claw 168, solidifies, and is integrally fused, so that the deformation of the locking claw 168 is suppressed. The locking state of the pawl 168 is more reliably maintained, and due to the increase in the bonding area due to fusion, the coupling strength against mutual lateral displacement of the plurality of inner members 160 is further improved in combination with the positioning by the locking pawl 168. .

  21 is a perspective view of a crash box 180 according to an embodiment of the present invention, and FIG. 22 is a longitudinal sectional view, that is, a sectional view taken along the line XXII-XXII in FIG. The crush box 180 includes three cylindrical inner members 182-1, 182-2, 182-2 (which are simply referred to as an inner member 182 unless otherwise specified), which are overlapped so as to be continuous in the axial direction, A cylindrical outer member 184 that is integrally fused to the outer peripheral side of the inner members 182-1, 182-2, and 182-3, and a disc that is integrally fixed by an adhesive or the like so as to cover the tip. The outer member 184 is integrally provided with a disk-shaped flange 188. FIG. 23 is a front view showing one inner member 182 alone, FIG. 24 is a plan view, and FIG. 25 is a perspective view. This inner member 182 is similar to the inner member 12 in FIGS. A plurality of reinforcing ribs 32 are provided radially. A fitting projection 192 is provided at the small-diameter end of the cylindrical side wall 190 of the inner member 182, and the inner members 182 are positioned concentrically with each other by being fitted inside the large-diameter end. Is done.

  On the outer peripheral surface of the side wall 190, a plurality of longitudinal grooves 194 extending in the axial direction are provided at equal angular intervals around the center line S, specifically, six at substantially the same position as the reinforcing ribs 32. The inner member 182 is overlapped so that the position of the longitudinal groove 194 around the center line S is shifted by 30 °. Further, the protrusion dimension of the fitting protrusion 192 is longer than the fitting length with the large-diameter end, and the outer periphery of the fitting protrusion 192 is overlaid so that the plurality of inner members 182 are continuous in the axial direction. An annular groove 196 is formed on the side. Therefore, in a state where the plurality of inner members 182 are overlapped in the axial direction, a plurality of longitudinal grooves 194 and a plurality of annular grooves 196 are connected to the outer peripheral surface so as to intersect with each other, as shown in FIG. A rectangular mesh groove is formed. Then, a molten resin constituting the outer member 184 is filled in the grooves 194 and 196 and solidified to be solidified, so that a mesh-patterned outer part partially fused to the outer peripheral surface of the plurality of inner members 182 is obtained. A member 184 is provided integrally. In this embodiment, the three inner members 182 are connected with a predetermined connection strength by the mesh-shaped outer member 184, and the number, depth, width dimension of the longitudinal grooves 194, or the annular grooves 196 The connection strength can be easily adjusted by the depth and width.

  The inner members 42, 60, 80, 100, 122, 160 and the cylindrical body 142 can be reinforced by providing reinforcing ribs 32 or the like as necessary. Conversely, the reinforcing ribs 32 of the inner members 12 and 182 can be omitted, and the inner side members 12 and 182 can be configured by only the cylindrical side walls 30 and 190, or other reinforcing ribs such as a flat plate shape can be provided.

  As mentioned above, although the Example of this invention was described in detail based on drawing, these are one embodiment to the last, and this invention is implemented in the aspect which added the various change and improvement based on the knowledge of those skilled in the art. be able to.

  10, 40, 120, 140, 180: Crash box (shock absorber) 12, 12-1, 12-2, 12-3, 42-1, 42-2, 42-3, 60-2, 60-3 80-2, 80-3, 100-2, 100-3, 122-1, 122-2, 122-3, 160, 160-2, 160-3, 182, 182-1, 182-2, 182 -3: Inner member (tubular body) 18, 48, 64, 84, 104, 124, 164, 184: Outer member (connecting member) 54, 72, 94, 112, 134, 170: Clearance 142, 142-1, 142-2, 142-3: cylinder 146: connecting member 194: longitudinal groove (groove) 202: fixed mold (first molding mold) 204: movable mold (second molding mold) 210: molding surface 214 and 226: mold tea

Claims (6)

A plurality of resin cylinders having a cylindrical side wall are stacked and connected integrally so as to be continuous in the axial direction of the cylindrical shape, and the impact applied from the axial direction is absorbed by deformation of the cylindrical body. A shock absorbing device that
A resin-made connecting member that is provided continuously in the axial direction of the shock absorbing device and that is fused to a surface along the axial direction of the plurality of cylinders, and the plurality of cylinders via the connecting members An impact absorbing device characterized in that the bodies are integrally connected to each other. 2. The impact according to claim 1, wherein the connecting member is a cylindrical outer member that is provided on an outer peripheral side of the plurality of cylindrical bodies and is fused to an outer peripheral surface of the plurality of cylindrical bodies. Absorber. A gap is provided in an axial boundary portion of the plurality of cylindrical bodies,
The impact absorbing device according to claim 1 or 2, wherein a part of the connecting member is also fused to a surface of which a part of the connecting member enters the gap to form the gap. At least one of the plurality of cylinders is made of fiber reinforced resin, and the cylinder on the side to which the impact is input has a fiber content as compared to the cylinder on the side opposite to the input side. The impact absorbing device according to any one of claims 1 to 3, wherein the impact absorbing device is small. The outer peripheral surface of the plurality of cylinders is provided with a groove along the axial direction, respectively, and the connecting member is formed by filling the groove with a resin material. The impact absorbing device according to any one of -4. A plurality of resin inner members having a cylindrical side wall are superimposed so as to be continuous in the axial direction of the cylindrical shape,
A resin cylindrical outer member that is continuously provided in the axial direction on the outer peripheral side of the plurality of inner members, covers the outer peripheral surface of the plurality of inner members, and is fused to the outer peripheral surface of the plurality of inner members. Having a member,
The plurality of inner members are integrally connected to each other via the outer member, and a method of manufacturing an impact absorbing device that absorbs an impact applied from the axial direction by deformation of the inner member,
A setting step of superposing the plurality of inner members so as to be continuous in the axial direction and disposing them in the first mold;
The second molding die having a molding surface having an inner diameter larger than the outer diameter of the inner member is clamped with the first molding die relatively close to each other, and the molding surface and the outer circumferential surface of the inner member are A mold clamping step for forming a cylindrical cavity corresponding to the outer member in between,
An injection process in which the resin material of the outer member is melted at a temperature higher than the melting temperature of the inner member and injected into the cavity, and the outer member is molded and simultaneously fused to the outer peripheral surface of the inner member; ,
A method of manufacturing an impact absorbing device, comprising:

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