JP5892966B2 - Shock absorber - Google Patents

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, the present invention is configured such that a plurality of resin cylinders having cylindrical side walls are overlapped and integrally connected so as to be continuous in the axial direction of the cylindrical shape. An impact absorbing device that absorbs an applied impact by deformation of the cylindrical body, and (a) is provided continuously in the axial direction of the impact absorbing device, and is respectively provided on a surface along the axial direction of the plurality of cylindrical bodies. It has a resin connection member to be fused, the plurality of cylinders are integrally connected to each other through the connection member , and (b) on the outer peripheral surface of the plurality of cylinders, A groove is provided along each axial direction, and the connecting member is constituted by a resin material filled in the groove .

In the impact absorbing device of the present invention , the resin coupling 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 integrated with each other via the coupling members. Therefore, 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.

Moreover, since the groove | channel is each provided in the outer peripheral surface of several cylinders along the axial direction, and the connection member is comprised by the resin material with which the groove | channel was filled , the groove width, groove depth, groove shape The connection strength can be easily adjusted by, for example.

It is a front view which shows the crash box for vehicles demonstrated as a reference example . 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 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. 10, and is sectional drawing of the XI-XI 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 FIG. 12 from upper direction. 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.

  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. Reinforcing fibers may be contained as necessary, the content thereof is desirably reduced as the distal end side of the cylindrical body shock is inputted. 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.

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 described as a reference example . 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 reference example , when a compressive load is applied from the axial direction, it is compressed and deformed (collapsed) in a bellows shape from the tip side of the crash box 10, and the impact energy is absorbed by this deformation, and the impact applied to the vehicle body is reduced. 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. 15 ) 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. 11 , the reinforcing ribs 32 of the adjacent inner members 12 can be prevented from overlapping by shifting the phase around the center line S by, for example, 30 °.

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 reference example , when an impact load is applied from the bumper, the inner member located on the tip side close to the bumper so that compression deformation proceeds from the tip side. 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. 15 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.

Figure 15 (a) is a state in which the movable mold 204 is opened mold is driven upwardly, the inner member 12-3,12-2,12 which is preformed as shown in its state (b) -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. (B) in FIG. 15 is a case where phase matching is performed such that the position 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 of the present reference example is provided so that the resin-made outer members 18 are respectively 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 reference example that compresses and deforms in a bellows shape and absorbs impact energy, the plurality of inner members 12 do not necessarily have to be displaced relative to each other (laterally shifted), and 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 as respectively welded to the outer peripheral surfaces of the plurality of inner members 12, a cylindrical outer member 18 is provided on the outer circumferential side of the plurality of inner members 12, prepared as shown in FIG. 15 According to the method, the crash box 10 can be manufactured with high productivity and low cost.

Next, the actual施例of the present invention. In the following embodiments, parts that are substantially the same as those in the reference example are given the same reference numerals, and detailed descriptions thereof are omitted.

Figure 10 is a perspective view of a crash box 180 according to an embodiment of the present invention, FIG 11 is a longitudinal sectional view, i.e. a sectional view of XI-XI palm portion 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. 12 is a front view showing one inner member 182 alone, FIG. 13 is a plan view, and FIG. 14 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. Accordingly, in a state in which a plurality of inner members 182 are overlapped in the axial direction, a plurality of vertical grooves 194 and a plurality of annular grooves 196 are connected so as to intersect the outer peripheral surface thereof, as a whole as shown in FIG. 10 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.

Incidentally, omitted reinforcing ribs 32 of the inner member 12, 182 may be constituted by only the side walls 30,190 cylindrical, it is also possible to provide other reinforcing ribs of the flat plate shape.

  As mentioned above, although the Example of this invention was described in detail based on drawing, these are one Embodiment to the last, 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.

1 80: Crash box (shock absorber) 1 82, 182-1, 182-2, 182-2: Inner member (tubular body) 1 84: Outer member (connecting member) 1 94: Vertical groove ( groove)

Claims (1)

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 The bodies are connected together ,
An impact is characterized in that grooves are provided along the axial direction on the outer peripheral surfaces of the plurality of cylindrical bodies, and the connecting member is constituted by a resin material filled in the grooves. Absorber.

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