JP2010038341A - Impact energy absorbing member and fabrication method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact energy absorbing member 1 superior in handling and capable of stably deforming a tublar body 2 in a tube axis Z direction without causing buckling deformation thereof. <P>SOLUTION: The body 2 is formed integrally with split deformable parts 3 and boundary parts 4. Each boundary part 4 is umbrella-shaped to be inclined to one side or the other side in the tube axis Z direction toward the radial outside of the body 2. The two boundary parts 4 adjacent to each other in the tube axis Z direction are inclined to mutually opposite sides toward the radial outside of the body 2. Additionally, each boundary part 4 plastically deforms the two split deformable parts 3 sandwiching the boundary part 4 to mutually opposite sides in the radial direction of the body 2 concurrently with its compression and plastic deformation in the tube axis Z direction while accelerating the shearing deformation of the boundary-side ends of the two split deformable parts 3 sandwiching the boundary part to mutually opposite sides in the radial direction of the body 2 when a certain or greater compressing load is input to the body 2 in the tube axis Z direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention belongs to a technical field related to an impact energy absorbing member suitable for a crash can of a vehicle and the like and a method for manufacturing the same, which absorbs a compressive load input in a cylindrical axis direction with respect to a cylindrical main body.

  Conventionally, for example, a crash can has been provided as an impact energy absorbing member at the front end of the front side frame or the rear end of the rear side frame of the vehicle. It is well known to absorb (load).

In the impact energy absorbing member such as the crash can, various proposals have been made to improve the impact energy absorbing performance. For example, in Patent Document 1, a cylindrical main body portion of an impact energy absorbing member is arranged with at least one short cylindrical first part and at least one short cylinder arranged concentrically with respect to the first part. As a configuration including a cylindrical second portion and a portion where the connection portion between the first portion and the second portion is inclined with respect to the concentric axis, a compressive load is applied to the main body portion in the cylindrical axis direction. When it is input, the first portion is pushed into the inner hollow portion of the second member by reducing the diameter of the first portion and expanding the second portion. With this configuration, the occurrence of an unstable buckling phenomenon is suppressed to stabilize the deformation mode, thereby improving the impact energy absorption performance.
International Publication No. 2006/025559 Pamphlet

  However, in the thing of the said patent document 1, when a compressive load is input with respect to the main-body part in the cylinder axial direction, the 1st part and the 2nd part are separated by the connection part, and the 1st member is made into the 2nd member. When the first member is pushed into the inner hollow portion of the first member, the first member or the second member may be buckled and deformed without being smoothly pushed into the inner hollow portion of the second member, thereby stabilizing the impact energy absorbing member. It becomes difficult to deform. In order to surely prevent this buckling deformation, the lengths of the first and second portions need to be considerably shortened. In this case, if it is attempted to cope with the compressive load generated in the vehicle, , The number of first and second parts is considerably increased. Further, in order to smoothly push the first member into the inner hollow part of the second member, even if the first part and the second part are simply in contact or fixed, the fixing force is reduced. However, if the number of the first and second parts becomes considerably large as described above, the first part or the second part may fall off when the impact energy absorbing member is transported or assembled to a vehicle or the like. There is a problem that it is difficult to handle.

  The present invention has been made in view of such a point, and an object of the present invention is to stably deform the cylindrical main body portion in the main body cylinder axis direction without causing buckling deformation. Another object of the present invention is to provide an impact energy absorbing member excellent in handleability.

  In order to achieve the above object, the invention of claim 1 is directed to an impact energy absorbing member that has a cylindrical main body portion and absorbs a compressive load that is input to the main body portion in the cylinder axis direction. The main body portion is made of metal and receives a compressive load of a predetermined value or more, and is subjected to compressive plastic deformation in the main body portion cylindrical axis direction, and is divided into three or more divided deformation portions in the main body portion cylindrical axis direction. A plurality of boundary portions respectively provided at a plurality of boundaries between two or more divided deformation portions are integrally formed, and the boundary portion is one side in the main body portion cylindrical axis direction toward the outer side in the main body portion radial direction. Alternatively, an arbitrary two boundary portions adjacent to each other in the main body portion cylindrical axis direction are inclined to opposite sides toward the outer side in the main body portion radial direction, and the boundary portions are When a compressive load greater than or equal to the predetermined value is input to the main body, The two split deformation portions sandwiching the boundary portion are plastically deformed to the opposite sides in the main body radial direction simultaneously with the compressive plastic deformation in the main body portion cylindrical axis direction, and the boundary between the two split deformation portions sandwiching the boundary portion It is assumed that the side end portions promote shear deformation to opposite sides of the main body portion in the radial direction.

  With the above configuration, when a compressive load greater than or equal to a predetermined value is input to the main body portion in the cylinder axis direction, the split deformation portion is simultaneously with the compressive plastic deformation in the main body portion cylinder axis direction by the umbrella-shaped boundary portion. The plastic deformation is performed to the outside or the inside in the main body radial direction, and the compressive load (impact energy) can be absorbed by the plastic deformation of the divided deformation portion. In addition, the two split deformable portions sandwiching the boundary portion are each plastically deformed so that the length in the main body portion cylindrical axis direction is shortened and spreads on the opposite sides of the main body portion radial direction, and plasticity is performed outward in the main body portion radial direction. Since the deformed split deformable part and the split deformable part plastically deformed inward in the main body radial direction are alternately arranged in the main body cylindrical axis direction, the main body part as a whole is stable in the cylindrical axis direction without causing buckling deformation. And deform. In addition, the boundary portion causes the boundary end portions of the two split deformation portions sandwiching the boundary portion to undergo shear deformation to opposite sides of the main body portion radial direction, respectively, so that the split deformation portion is moved outward or inward in the main body radial direction. It becomes easier to plastically deform. That is, when a compressive load greater than a predetermined value is input to the main body, the boundary side end portion of the split deformed portion is inclined relative to the boundary portion at or near the boundary portion due to the inclination of the boundary portion. A shearing force acting on the outer side or the inner side (in the two split deformed portions sandwiching the boundary portion is opposite to each other) acts. If the boundary portion is made of a material that makes the boundary-side end portion of the split deformation portion easily shear-deformed with respect to the boundary portion by the shearing force, the boundary side end of the split deformation portion by the shearing force. The portion undergoes shear deformation with respect to the boundary portion, and plastic deformation of the split deformation portion toward the outside or the inside in the main body portion radial direction is promoted.

  Therefore, even if a force is applied to the main body portion in the cylinder axis direction and a force that tilts the main body portion in the radial direction, the main body portion is unlikely to buckle and deform reliably in the cylinder axis direction. Thus, the compression load absorption performance can be enhanced. In addition, even if the number of split deformation portions and boundary portions increases, the split deformation portions and the boundary portions can be firmly and easily fixed to each other by integral molding. It is possible to improve the handleability when assembling.

  According to a second aspect of the present invention, in the first aspect of the invention, the split deformation portion is made of an aluminum alloy casting, and the boundary portion is made of a metal plate.

  This can reduce the weight of the impact energy absorbing member. In addition, with the umbrella-shaped metal plate at the boundary portion, the two split deformation portions sandwiching the boundary portion can be plastically deformed to the opposite sides in the main body radial direction, and different types of castings and metal plates can be used. In the joining, since the joining strength with respect to the shearing force becomes relatively small, the boundary side end portions of the two split deformable portions sandwiching the boundary portion can be shear-deformed to the opposite sides in the main body radial direction.

  According to a third aspect of the present invention, in the first aspect of the present invention, the split deformation portion is made of an aluminum alloy casting, and the boundary portion is made of an aluminum alloy casting containing reinforcing fibers.

  This can reduce the weight of the impact energy absorbing member. Further, since the reinforcing fiber is contained in the boundary portion, the two split deformation portions sandwiching the boundary portion can be plastically deformed to the opposite sides of the main body portion in the same manner as the metal plate, and the boundary By appropriately setting the volumetric fiber volume ratio of the part, it is possible to promote the shearing deformation of the boundary side end parts of the two split deformation parts sandwiching the boundary part to the opposite sides of the main body part in the radial direction. Become. That is, the content of metal (aluminum alloy) is small in the boundary portion by the amount of the reinforcing fiber, and the reinforcing fiber is usually disposed so as to extend substantially along the end face in the thickness direction of the boundary portion, so that the shear force As a result, the boundary-side end portions of the two split deformation portions sandwiching the boundary portion are easily shear-deformed with respect to the boundary portion. Therefore, it is possible to shear-deform the boundary side end portions of these two split deformation portions to the opposite sides in the main body radial direction.

  In the invention of claim 4, in the invention of claim 2 or 3, the aluminum alloy casting is an Al-Mn-Fe-Mg alloy casting.

  That is, the Al-Mn-Fe-Mg-based alloy can improve both castability and elongation at the same time while maintaining the strength of the aluminum alloy by appropriately setting the content of each component. It can be of high ductility with high elongation. Therefore, it is possible to improve the absorption performance of the compressive load while reducing the weight of the impact energy absorbing member.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the impact energy absorbing member is used for a front side frame or a crash can of a vehicle.

  This makes it possible to reliably absorb impact energy at the time of a frontal collision or a rearward collision of the vehicle and improve the safety of the vehicle. Further, by configuring the split deformed portion with, for example, an aluminum alloy casting, it is possible to improve safety while reducing the weight of the vehicle.

  The invention of claim 6 is an invention of a manufacturing method of an impact energy absorbing member that has a cylindrical main body portion and absorbs a compressive load input to the main body portion in the cylinder axial direction. The main body is made of metal and receives a compressive load of a predetermined value or more to undergo plastic plastic deformation in the main body cylinder axis direction, and is divided into three or more divided deformation parts in the main body cylinder axis direction. A plurality of boundary portions respectively provided at a plurality of boundaries between the divided deformation portions, and the boundary portions are inclined toward one side or the other side in the main body portion cylinder axis direction toward the outer side in the main body portion radial direction. The two boundary portions adjacent to each other in the main body portion cylinder axis direction are inclined toward opposite sides toward the outer side in the main body portion radial direction, and the boundary portions are further formed on the main body portion. Two that sandwich the boundary when a compressive load greater than a predetermined value is input The split deformation portion is plastically deformed to the opposite sides of the main body portion radial direction simultaneously with the compressive plastic deformation in the main body portion cylindrical axis direction, and the boundary side end portion of the two split deformation portions sandwiching the boundary portion is the main body portion. A step of forming a plurality of boundary portion forming members for forming the plurality of boundary portions, respectively, and a step of forming the boundary portion forming member, which promotes shear deformation to opposite sides in the radial direction. In the state set in the cavity of the mold, the molten metal is supplied into the cavity, thereby integrally forming the split deformed portion and the boundary portion.

  According to the present invention, an impact energy absorbing member that can be easily integrally formed with the split deformation portion and the boundary portion, can be stably deformed in the cylinder portion direction of the main body, and is excellent in handleability is easily manufactured. be able to.

  In the invention of claim 7, in the invention of claim 6, the metal is an aluminum alloy, and the boundary portion forming member is a metal plate.

  Thus, the impact energy absorbing member according to the invention of claim 2 can be easily manufactured.

  According to an eighth aspect of the present invention, in the sixth aspect of the present invention, the metal is an aluminum alloy, and the boundary portion forming member is made of a reinforcing fiber molded body.

  Thus, the impact energy absorbing member according to the invention of claim 3 can be easily manufactured.

  As described above, according to the impact energy absorbing member of the present invention, the main body portion is formed by integrally forming the split deformable portion and the boundary portion, and the boundary portion is directed toward the outer side in the main body portion radial direction. It forms an umbrella shape that is inclined to one side or the other side in the cylinder axis direction, and any two boundary portions adjacent to each other in the main body cylinder axis direction are inclined to opposite sides toward the outer side in the main body radial direction. When the boundary portion receives a compressive load greater than or equal to a predetermined amount in the cylinder axis direction with respect to the main body portion, the two split deformable portions sandwiching the boundary portion are compressed simultaneously with the compressive plastic deformation in the main body portion cylindrical axis direction. It is configured to plastically deform to the opposite sides in the radial direction, and to promote the shear deformation of the boundary side ends of the two split deformation portions sandwiching the boundary portion to the opposite sides in the main body radial direction. As a result, the main body is stabilized in the cylinder axis direction. Become deformed, it is possible to increase the absorption performance of the compression load, it is possible to improve the handling property at the time of assembling to the transportation or when the vehicle such as the impact energy absorbing member.

  Further, according to the manufacturing method of the impact energy absorbing member of the present invention, the step of producing the boundary portion forming member for forming the boundary portion, and the state where the produced boundary portion forming member is set in the cavity of the mold By supplying the molten metal into the cavity, the step of integrally forming the split deformation portion and the boundary portion is included, so that the main body portion is stabilized in the cylinder axis direction without causing buckling deformation. Thus, it is possible to easily manufacture an impact energy absorbing member that can be deformed and has excellent handleability.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 shows an impact energy absorbing member 1 according to Embodiment 1 of the present invention, and this impact energy absorbing member 1 has a cylindrical (cylindrical in this embodiment) body portion 2, and the body It absorbs a compressive load input to the portion 2 in the cylinder axis Z direction (vertical direction in FIG. 1).

  In the present embodiment, the impact energy absorbing member 1 includes front ends of left and right front side frames 91 provided to extend in the front-rear direction at both vehicle width direction positions in the front portion of the vehicle 100, as shown in FIG. The front bumper 93 is used as a crash can 92 interposed between left and right ends of a bumper reinforcement 93a extending in the vehicle width direction. In this case, the impact energy absorbing member 1 is disposed such that the direction of the cylinder axis Z coincides with the front-rear direction of the vehicle 100, and the collision energy (impact compression) input from the bumper reinforcement 93a at the time of a frontal collision of the vehicle 100. Absorbs load).

  The impact energy absorbing member 1 is not limited to the crash can 92 but extends in the front-rear direction at a part (particularly the front end portion) of the left and right front side frames 91 and at both sides in the vehicle width direction at the rear portion of the vehicle 100. A part of the left and right rear side frames (not shown) (particularly the rear end part) provided between the rear side frame and a bumper reinforcement (not shown) of the rear bumper 94. You may use for the crush can (not shown) provided. Further, the impact energy absorbing member 1 can be widely used in a portion where the impact energy needs to be absorbed in the vehicle 100 and can also be used for other than the vehicle 100.

  First and second fixing portions 7 for attaching and fixing the impact energy absorbing member 1 to the front end of the front side frame 91 and the bumper reinforcement 93a, respectively, at both ends of the main body portion 2 in the cylinder axis Z direction. , 8 are provided. The first fixing portion 7 has a plurality of bolt insertion holes 7a through which bolts for fastening and fixing the first fixing portion 7 to the front end of the front side frame 91 are formed. Are formed with a plurality of bolt insertion holes 8a through which bolts for fastening and fixing the second fixing portion 8 to the bumper reinforcement 93a are inserted. The shapes of the first and second fixing portions 7 and 8 differ depending on the application location of the impact energy absorbing member 1.

  When the impact energy absorbing member 1 is used for the crash can 92 as in this embodiment, the outer diameter D of the main body 2 is preferably 40 to 100 mm, the wall thickness t is preferably 2 to 8 mm, and the length L is 80 to 150 mm. Is preferred. In FIG. 1, the outer diameter D of the main body is constant throughout the cylinder axis Z direction of the main body 2, but is not strictly constant and is directed toward the second fixing portion 8. Gradually getting smaller. This is for facilitating release from the casting mold 30 after casting the impact energy absorbing member 1 with a casting mold 30 (see FIG. 7) described later.

  The main body 2 receives three or more predetermined compressive loads in the cylinder axis Z direction with respect to the main body 2 and undergoes plastic plastic deformation in the cylinder axis Z direction, and at least three in the cylinder axis Z direction (six in this embodiment). The divisional deformation part 3 divided into three and a plurality of boundary parts 4 (one less than the divisional deformation part 3 and five) provided at the boundary between the three or more divisional deformation parts 3 are integrated. Molded. The split deformation portion 3 positioned at the end of the main body 2 on the first fixing portion 7 side is formed integrally with the first fixing portion 7 and is split at the end of the main body portion 2 on the second fixing portion 8 side. The part 3 is formed integrally with the second fixing part 8.

  In addition, although the division | segmentation deformation | transformation part 3 should just be 3 or more (the boundary part 4 becomes 2 or more), it is preferable that the number of the division | segmentation deformation | transformation parts 3 is an even number of about 4-8. In this way, as will be described later, the number of the split deformation portions 3 that plastically deform outward in the radial direction of the main body portion 2 and the number of split deformation portions 3 that plastically deform inward of the radial direction of the main body portion 2 are the same. Can do.

  The boundary portion 4 has an umbrella shape that is inclined toward one side or the other side in the cylinder axis Z direction toward the outer side in the main body portion 2 radial direction. As a result, the boundary portion 4 moves the two split deformation portions 3 sandwiching the boundary portion 4 in the cylinder axis Z direction when a compressive load of a predetermined value or more is input to the main body portion 2 in the cylinder axis Z direction. At the same time as the compressive plastic deformation, the plastic deformation is forcibly plastically deformed to the opposite sides in the main body 2 radial direction.

  And the arbitrary two boundary parts 4 adjacent to the cylinder axis Z direction incline in the mutually opposite side toward the outer side of the main-body part 2 radial direction. As a result, the split deformation part 3 (three split deformation parts 3 positioned at odd numbers from the end of the main body part 2 on the second fixing part 8 side) that plastically deforms outward in the radial direction of the main body part 2 and the main body part Split deformable portions 3 that are plastically deformed inward in the two radial directions (three divided deformable portions 3 that are even-numbered when counted from the end of the main body portion 2 on the second fixing portion 8 side) are alternately arranged in the cylinder axis Z direction. Will be lined up. The odd-numbered divisional deformation portion 3 has a shape in which the length in the cylinder axis Z direction increases toward the outer side in the main body 2 radial direction, and the even-numbered divisional deformation portion 3 is The length in the cylinder axis Z direction is reduced toward the outer side in the radial direction of the main body 2.

  In addition, the boundary portion 4 is configured such that when a predetermined or more compressive load is input to the main body portion 2 in the cylinder axis Z direction, the boundary side end portions of the two divided deformation portions 3 sandwiching the boundary portion 4 are the main body portions. It plays a role of promoting shear deformation to the opposite sides of the part 2 radial direction. That is, when a predetermined or more compressive load is input to the main body 2, the boundary portion 4 or the vicinity thereof has the boundary side end portion of the split deformation portion 3 with respect to the boundary portion 4 due to the inclination of the boundary portion 4. A shearing force acting to shift to the outer side or the inner side of the main body part 2 in the radial direction (the two split deformation parts 3 sandwiching the boundary part 4 are opposite to each other) acts. Due to this shearing force, the boundary side end portion of the split deformation portion 3 undergoes shear deformation with respect to the boundary portion 4, and plastic deformation of the split deformation portion 3 to the outside or the inside in the main body radial direction is promoted.

  The boundary portion 4 has an inclination angle θ (an inclination angle with respect to a plane perpendicular to the cylinder axis Z direction) of preferably 30 ° to 60 °, and particularly preferably 40 ° to 50 °. The inclination angle of the boundary portion 4 inclined to one side in the cylinder axis Z direction toward the outer side in the radial direction of the main body portion 2 is preferably the same as the inclination angle of the boundary portion 4 inclined to the other side. May be different.

  It is preferable that all of the shape and size of the split deformation portion 3 are substantially the same. This is to prevent the compression weight from acting uniformly on all of the divisional deformation units 3 and concentrating on the specific divisional deformation unit 3.

  In the present embodiment, the split deformation portion 3 is made of an aluminum alloy casting, and the boundary portion 4 is made of an aluminum alloy casting containing reinforcing fibers. The split deformation portion 3 and the boundary portion 4 are integrally formed by combining a molten aluminum alloy and a preformed body 15 (see FIG. 4) made of a reinforcing fiber molded body, as will be described later.

  The aluminum alloy is preferably an Al—Mn—Fe—Mg alloy. This Al-Mn-Fe-Mg-based alloy is high in casting as it can improve the castability and elongation at the same time while maintaining the strength of the aluminum alloy by appropriately setting the content of each component. It can be of high ductility with elongation. Specifically, 0.5 to 2.5% Mn component, 0.1 to 1.5% Fe component, 0.01 to 1.2% Mg component, and the balance contains inevitable impurities The aluminum alloy is composed of an Al component (the numerical value of the content is a mass percentage).

  In addition, to the Al-Mn-Fe-Mg based alloy having the above respective component contents, 0.1 to 0.2% Ti component by mass percentage, 0.01 to 0.1% B component by mass percentage, And it is more preferable to add at least one of Be components of 0.01 to 0.2% by mass percentage. That is, the Ti component, the B component and the Be component can improve the casting cracking property by refining the crystal grains of the casting, but if the content is too large, a coarse compound is generated. As a result, the elongation decreases. Then, each content of Ti component, B component, and Be component is set to the said range, and cast cracking property is made further favorable, preventing the fall of elongation.

  In place of the Al—Mn—Fe—Mg alloy, for example, an Al—Si alloy may be used (in the case of this alloy, casting is performed by a high vacuum die casting method). The metal may be used.

  As the reinforcing fiber of the boundary portion 4, alumina fiber, silica fiber, silicon carbide fiber, or the like is preferable. In the case of alumina fibers and silica fibers, for example, those having an average fiber diameter of 3 μm to 5 μm and a fiber length of 5 mm to 10 mm are used. In the case of silicon carbide fibers, for example, the average fiber diameter of 10 μm to 15 μm, the fiber length is used. The thing of 5 mm-10 mm should just be used.

  The reinforcing fiber volume ratio of the boundary portion 4 is normally 5 to 10%, but is larger than this in the present embodiment. Further, from the manufacturing method described later, the reinforcing fibers are arranged so as to extend substantially along the end face in the thickness direction of the boundary portion 4, and in combination with the large reinforcing fiber volume ratio, the split deformation with respect to the shearing force is performed. The joint strength between the portion 3 and the boundary portion 4 is lowered, and as a result, the boundary side end portions of the two split deformation portions 3 sandwiching the boundary portion 4 are easily shear-deformed with respect to the boundary portion 4. That is, the boundary side end portions of these two split deformable portions 3 are easily shear-deformed to opposite sides of the main body portion 2 in the radial direction. In order to promote this shear deformation, a preferable range of the reinforcing fiber volume ratio of the boundary portion 4 is 20 to 25%. This is because, if it is less than 20%, the shear deformation cannot be sufficiently promoted, whereas if it exceeds 25%, the pores in the preform 15 are reduced and the filling property of the molten metal is deteriorated.

  As shown in FIG. 3, the split deformation portion 3 undergoes compressive plastic deformation in the cylinder axis Z direction when a predetermined or greater compressive load is input to the body portion 2 in the cylinder axis Z direction. Further, due to the boundary portion 4, the odd-numbered divided deformable portions 3 counted from the end of the main body portion 2 on the second fixing portion 8 side are compressed and plastically deformed in the cylinder axis Z direction, and at the same time outside the main body portion 2 in the radial direction. The even-numbered divided deformation portion 3 is plastically deformed inward in the radial direction of the main body portion 2 simultaneously with the compressive plastic deformation in the cylinder axis Z direction. Will do. In addition, the boundary portion 4 shears and deforms the boundary side end portions of the two split deformation portions 3 sandwiching the boundary portion 4 in opposite directions in the main body portion 2 radial direction. That is, the boundary-side end portion of the odd-numbered divided deformation portion 3 is shear-deformed outward in the main body 2 radial direction with respect to the boundary portion 4, and the even-numbered divided deformation portion 3 is deformed relative to the boundary portion 4. Thus, the main body part 2 is sheared inward in the radial direction. As a result, the odd-numbered divided deformation portion 3 is more easily plastically deformed outward in the radial direction of the main body portion 2, and the even-numbered divided deformation portion 3 is further plasticized inward of the main body portion 2 in the radial direction. It becomes easy to deform. The compression load is absorbed by the plastic deformation of the divided deformation portion 3. At this time, the split deformation portion 3 spreads outward or inward in the radial direction of the main body 2 while its length in the cylindrical axis Z direction is shortened, so that the main body 2 as a whole is not buckled and deformed. Deforms stably in the direction. The split deformation portion 3 is slightly plastically deformed to the side opposite to the side that is plastically deformed by the boundary portion 4 in the radial direction of the main body portion 2 along with the compressive plastic deformation in the cylinder axis Z direction. The amount of plastic deformation to the opposite side is considerably smaller than the amount of plastic deformation to the side forcedly deformed by the boundary portion 4.

  As the plastic deformation of the split deformation portion 3 proceeds, the inclination angle θ of the boundary portion 4 decreases, but the boundary portion 4 allows the split deformation portion 3 to be connected to the cylinder until the inclination angle θ becomes zero. Simultaneously compressive plastic deformation in the axis Z direction and plastic deformation outward or inward in the main body 2 radial direction, and the boundary side end of the split deformation portion 3 with respect to the boundary portion 4 in the outer or inner side of the main body 2 radial direction Plays a role of shear deformation. And even if the inclination angle θ becomes 0, the plastic deformation amount of the split deformation portion 3 is already considerably large at that time, and as a result, even if the compression load continues to act after that time, The main body 2 as a whole is deformed in the cylinder axis Z direction without causing buckling deformation.

  In addition, there is a possibility of breaking (shear failure) at the interface between the split deformable portion 3 and the boundary portion 4 when the compression load greater than the predetermined value is input to the main body portion 2, but even if it breaks, the split portion The deformable portion 3 remains plastically deformed outward or inward in the main body portion 2 radial direction by the boundary portion 4. Rather, the deformable portion 3 is easily plastically deformed outward or inward in the main body portion 2 radial direction by breakage.

  Moreover, in this embodiment, the boundary part 4 is strengthened by the composite of the aluminum alloy that is the constituent material of the split deformation part 3 and the reinforcing fiber, and the split deformation part 3 is more resistant to the compressive load in the cylinder axis Z direction. However, the boundary portion 4 is compressed in the cylinder axis Z direction with respect to the main body portion 2 although it is difficult to be plastically deformed and hard to break (that is, the strength and rigidity with respect to the compression load are higher than those of the split deformation portion 3). Even if a compressive load having such a magnitude as to cause plastic deformation is inputted, since the thickness of the boundary portion 4 is small, the change in the inclination angle θ due to the compressive plastic deformation of the boundary portion 4 is small. Play a role.

  In order to manufacture the impact energy absorbing member 1, first, as shown in FIG. 4, a plurality of preforms capable of forming the plurality of boundary portions 4 by compounding with the molten aluminum alloy, respectively. 15 (corresponding to a plurality of boundary portion forming members for forming the plurality of boundary portions 4 respectively) is formed. Each of the preforms 15 has an umbrella shape similar to the boundary portion 4.

  Each preform 15 is produced as follows. That is, first, the reinforcing fiber, water, and the additive are put in a container (not shown) and mixed by stirring to prepare a slurry 24 (see FIG. 5). The additive includes a reinforcing agent (for example, granular alumina sol) for securing the strength of the preform 15, an adhesion promoter (for example, ammonium sulfate) for promoting adhesion of the reinforcing agent to the reinforcing fibers, and a reinforcing material. It is a dispersing agent (for example, polyamide) for improving the dispersibility of the fiber.

  Subsequently, as shown in FIG. 5, the liquid component such as water in the slurry 24 is removed by the filtration device 20. The filtration device 20 includes a container 21 in which a porous filter 22 is disposed, and a suction device (not shown) connected to the bottom of the container 21. A protrusion 22a (not functioning as a filter) projecting upward is formed at the center of the porous filter 22, and the peripheral portion (functioning as a filter) of the protrusion 22a is inclined by the boundary 4 It is inclined with respect to the horizontal to correspond to. Then, the slurry 24 is introduced into the container 21 above the peripheral portion of the protrusion 22a of the porous filter 22, and then the liquid such as water in the slurry 24 is passed through the porous filter 22 by the suction device. Remove components (suction dehydration).

  Next, as shown in FIG. 6, the liquid removal member 25 obtained by removing the liquid component in the slurry 24 is compressed. That is, the shape of the preform 15 is formed by pressurizing the liquid removal member 25 from above with the punch 27 while the liquid removal member 25 is disposed in the container 21 above the peripheral portion of the protrusion 22a of the porous filter 22. Compression molding is performed. A fitting hole 27a into which the protrusion 22a is fitted is formed at the center of the lower surface of the punch 27, and the peripheral portion of the fitting hole 27a is horizontal with respect to the inclination of the boundary portion 4. Inclined.

  Subsequently, the demolded liquid removal member 25 is dried and then sintered. This sintering is performed at 640-840 degreeC for 1.5 hours, for example. In this way, the preform 15 made of the reinforcing fiber molded body is completed.

  Next, the impact energy absorbing member 1 is manufactured (cast) using a casting mold 30 as shown in FIG. The casting mold 30 is attached to a fixed mold 32 attached and fixed to a fixed mold plate 31 and a movable mold plate 33 supported so as to be movable in the left-right direction in FIG. A fixed movable mold 34 is provided. The fixed mold 32 is formed with a recessed portion 32a that opens to the movable mold 34 side, while the movable mold 34 is formed with a projecting portion 34a that enters the recessed portion 32a, and these recessed portions 32a. And a cavity 35 is formed between the protrusions 34a. A plurality of grooves (not shown) for supporting the plurality of preforms 15 are formed on the outer peripheral surface of the protrusion 34a. Further, the fixed mold 32 is provided with a plurality of pins 32 b for forming a plurality of bolt insertion holes 8 a of the second fixed portion 8. The movable mold 34 has the first fixed portion 7. A plurality of pins 34b for forming a plurality of bolt insertion holes 7a are provided.

  The casting mold 30 is provided with an injection sleeve 37 for supplying a molten aluminum alloy into the cavity 35. The injection sleeve 37 is formed with a hot water supply port 37a for the molten metal. In addition, an injection plunger 38 slidably fitted to the injection sleeve 37 is provided in the injection sleeve 37. By moving the injection plunger 38 to the left side in FIG. 8, a hot water supply port 37a is provided. The molten metal supplied into the injection sleeve 37 is injected into the cavity 35.

  In order to manufacture the impact energy absorbing member 1 using the casting mold 30, first, in the mold open state, the plurality of preformed moldings are formed in the plurality of grooves formed in the protrusions 34 a of the movable mold 34. Each of the bodies 15 is supported, and then the movable mold 34 is moved to the fixed mold 32 side to close the mold. As a result, the plurality of preforms 15 are set in the cavity 15 of the casting mold 30.

  Subsequently, a molten aluminum alloy (a molten metal temperature of about 700 ° C.) is supplied into the injection sleeve 37 from the hot water supply port 37 a, and this molten metal is injected into the cavity 35 by the injection plunger 38 and supplied. Thereby, in the part in which the preform 15 in the cavity 35 does not exist, the split deformable portion 3 and the first and second fixing portions 7 and 8 are integrally formed, and the molten metal is formed in the holes in each preform 15. Is filled with the preform 15 and the molten metal, whereby the boundary portion 4 is integrally formed with the split deformable portion 3. When the molten metal in the cavity 15 is solidified, the casting of the impact energy absorbing member 1 is completed.

  Therefore, in the present embodiment, the main body portion 2 of the impact energy absorbing member 1 is formed by integrally forming the split deformation portion 3 and the boundary portion 4, and this boundary portion 4 is directed outward in the radial direction of the main body portion 2. It forms an umbrella shape that is inclined to one side or the other side in the cylinder axis Z direction, and any two boundary portions 4 adjacent to each other in the cylinder axis Z direction are inclined to opposite sides toward the outer side in the radial direction of the main body portion 2. Further, when the boundary portion 4 receives a compressive load of a predetermined value or more in the cylinder axis Z direction with respect to the main body portion 2, the two divided deformable portions 3 sandwiching the boundary portion 4 are compressed in the cylinder axis Z direction. Simultaneously with plastic deformation, plastic deformation is performed to the opposite sides of the main body portion 2 in the radial direction, and the boundary end portions of the two split deformation portions 3 sandwiching the boundary portion are respectively sheared to opposite sides of the main body portion 2 in the radial direction. Since it is comprised so that it may accelerate | stimulate, the division | segmentation deformation | transformation part 3 is While the length in the cylinder axis Z direction becomes shorter, the split deformation part 3 that spreads outward or inward in the radial direction of the main body 2 and plastically deforms outward in the radial direction of the main body 2, and inward in the radial direction of the main body 2. The split deformation portions 3 that are plastically deformed are alternately arranged in the cylinder axis Z direction, whereby the main body portion 2 as a whole is stably deformed in the cylinder axis Z direction without causing buckling deformation. Moreover, the shear deformation promoting function by the boundary portion 4 makes the split deformation portion 3 more easily plastically deformed outward or inward in the main body portion 2 radial direction. As a result, even if a force is applied to the main body 2 simultaneously with the compressive load in the cylinder axis Z direction and the main body 2 is tilted in the radial direction, the main body 2 is hardly buckled and deformed. It is possible to reliably deform in the Z direction, thereby improving the compression load absorption performance. Further, even if the number of the split deformable portions 3 and the boundary portions 4 increases, the split deformable portions 3 and the boundary portions 4 can be firmly and easily fixed to each other by integral molding, and the impact energy absorbing member 1 can be transported. It is possible to improve handling at the time of installation to a vehicle or a vehicle.

(Embodiment 2)
In the present embodiment, the material of the boundary portion 4 is different from that of the first embodiment.

  That is, in the present embodiment, the boundary portion 4 is made of a metal plate (in the present embodiment, a steel plate) that is less likely to be compressively plastically deformed and harder to break than an aluminum alloy casting against a compressive load in the cylinder axis Z direction.

  With the boundary portion 4 made of such a steel plate, the two split deformation portions 3 sandwiching the boundary portion 4 can be plastically deformed in opposite directions in the radial direction of the main body portion 2. In addition, when joining different types of aluminum alloy castings and steel plates, the joint strength against shearing force is relatively small, so the boundary side end portions of the two split deformable portions 3 sandwiching the boundary portion 4 are in the body portion 2 radial direction. It is possible to cause shear deformation to opposite sides of each other.

  In order to manufacture the impact energy absorbing member 1 of the present embodiment, first, a plurality of boundary portion forming members for forming the plurality of boundary portions 4 are prepared. Specifically, the steel plate is processed and finished to have the same shape as the boundary portion 4. And the several through-hole penetrated to the thickness direction with respect to this steel plate is formed. Thus, the boundary portion forming member is completed.

  The through holes are provided in order to allow the molten metal to flow in the direction of the cylinder axis Z in the cavity 15 and to integrate the split deformable portion 3 and the boundary portion 4 together, but the number thereof is too large. And the shear deformation promotion function by the boundary part 4 falls, Therefore The number of through-holes is set in consideration of them.

  Note that the through hole is not necessarily formed. When the through hole is not formed, a flow groove through which the molten metal flows may be formed in the fixed mold 32 so that the molten metal flows in the direction of the cylinder axis Z in the cavity 15. What is necessary is just to remove the protrusion part shape | molded corresponding to this distribution | circulation groove | channel after casting.

  In the state where the produced boundary portion forming member is set in the cavity 15 of the casting mold 30 as in the preform 15 of the first embodiment, the molten aluminum alloy is supplied into the cavity 30. The split deformation portion 3, the boundary portion 4 (boundary portion forming member), and the first and second fixing portions 7 and 8 are integrally formed. At this time, since the through hole is formed in the boundary portion forming member, the molten metal flows in the cavity 15 in the direction of the cylinder axis Z through the through hole, and the divided deformable portion 3 and the boundary portion 4 are surely connected by the through hole. Will be integrated.

  Therefore, also in the present embodiment, the same effects as those of the first embodiment can be obtained, and when a predetermined or more compressive load is input to the main body 2 in the direction of the cylinder axis Z, the main body 2 is connected to the cylinder shaft. It is possible to reliably deform in the Z direction and enhance the compressive load absorption performance.

  In the second embodiment, a steel plate is used for the boundary portion 4. However, other various metal plates can be used, for example, an aluminum plate can be used. The material of the boundary portion 4 is preferably higher in strength and rigidity against the compressive load in the cylinder axis Z direction than the split deformation portion 3, but is not limited thereto, and is not less than a predetermined amount in the cylinder axis Z direction with respect to the main body portion 2. When two compressive loads are input, the two split deformation portions 3 sandwiching the boundary portion 4 are plastically deformed to the opposite sides of the main body portion 2 in the radial direction simultaneously with the compressive plastic deformation in the cylinder axis Z direction. As long as the boundary side end portions of the two split deformation portions 3 sandwiching the boundary portion have a function of promoting shear deformation to opposite sides of the main body portion 2 in the radial direction, any Also good.

  INDUSTRIAL APPLICABILITY The present invention is useful for an impact energy absorbing member that absorbs a compressive load that is input to a cylindrical main body in the cylinder axis direction, and a method for manufacturing the same. This is useful when applied to left and right front side frames and left and right rear side frames.

It is sectional drawing which shows the impact energy absorption member which concerns on Embodiment 1 of this invention. It is the side view which fractured | ruptured the front part of the vehicle which shows the crash can to which an impact energy absorption member is applied. It is sectional drawing which shows the deformation | transformation state of this main-body part when a predetermined or more compressive load is input with respect to the main-body part of an impact energy absorption member in a cylinder axial direction. It is sectional drawing which shows a preforming body. It is sectional drawing of the container of the filtration apparatus which shows the state which has removed the liquid component in a slurry. FIG. 6 is a view corresponding to FIG. 5, illustrating a state where a liquid removal member obtained by removing a liquid component in a slurry is compressed. It is sectional drawing which shows a casting mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Impact energy absorption member 2 Main body part 3 Division deformation part 4 Boundary part 15 Preliminary body (boundary part formation member)
30 Casting mold 35 Cavity 91 Front side frame 92 Crash can

Claims (8)

An impact energy absorbing member that has a cylindrical main body portion and absorbs a compressive load that is input to the main body portion in the cylinder axis direction,
The main body is made of metal and receives a compressive load of a predetermined value or more to undergo plastic plastic deformation in the main body cylinder axis direction, and is divided into three or more divided deformation parts in the main body cylinder axis direction. A plurality of boundary portions respectively provided at a plurality of boundaries between the above-described divided deformation portions are integrally formed,
The boundary portion has an umbrella shape inclined toward one side or the other side in the main body cylinder axis direction toward the outer side in the main body portion radial direction,
Any two boundary portions adjacent to each other in the main body portion cylinder axis direction are inclined to the opposite sides toward the outer side in the main body portion radial direction,
Further, the boundary portion is configured such that, when a compressive load greater than or equal to the predetermined value is input to the main body portion, the two split deformation portions sandwiching the boundary portion are subjected to the main body portion diameter simultaneously with the compressive plastic deformation in the main body portion cylindrical axis direction. And plastically deforming in opposite directions to each other and promoting shear deformation of the boundary-side end portions of the two split deformable portions sandwiching the boundary portions in opposite directions in the main body radial direction. A characteristic impact energy absorbing member. The impact energy absorbing member according to claim 1,
The split deformation part is made of an aluminum alloy casting,
The said boundary part consists of a metal plate, The impact energy absorption member characterized by the above-mentioned. The impact energy absorbing member according to claim 1,
The split deformation part is made of an aluminum alloy casting,
The said boundary part consists of an aluminum alloy casting containing the reinforced fiber, The impact energy absorption member characterized by the above-mentioned. The impact energy absorbing member according to claim 2 or 3,
The impact energy absorbing member, wherein the aluminum alloy casting is an Al-Mn-Fe-Mg alloy casting. In the impact energy absorption member according to any one of claims 1 to 4,
An impact energy absorbing member used for a front side frame or a crash can of a vehicle. A method for manufacturing an impact energy absorbing member that has a cylindrical main body part and absorbs a compressive load input in the cylinder axis direction with respect to the main body part,
The main body is made of metal and receives a compressive load of a predetermined value or more to undergo plastic plastic deformation in the main body cylinder axis direction, and is divided into three or more divided deformation parts in the main body cylinder axis direction. It consists of a plurality of boundary portions respectively provided at a plurality of boundaries between the above-described divided deformation portions,
The boundary portion has an umbrella shape inclined toward one side or the other side in the main body cylinder axis direction toward the outer side in the main body portion radial direction,
Any two boundary portions adjacent to each other in the main body portion cylinder axis direction are inclined to the opposite sides toward the outer side in the main body portion radial direction,
Further, the boundary portion is configured such that, when a compressive load greater than or equal to the predetermined value is input to the main body portion, the two split deformation portions sandwiching the boundary portion are subjected to the main body portion diameter simultaneously with the compressive plastic deformation in the main body portion cylindrical axis direction. And plastically deforming the opposite sides of each direction, and promoting the boundary side end portions of the two split deformation portions sandwiching the boundary portion to each other opposite to each other in the main body radial direction,
Producing a plurality of boundary portion forming members for forming the plurality of boundary portions, respectively,
Including the step of integrally forming the divided deformable portion and the boundary portion by supplying the molten metal into the cavity in a state where the produced boundary portion forming member is set in the cavity of the mold. A method for producing an impact energy absorbing member. In the manufacturing method of the impact energy absorption member according to claim 6,
The metal is an aluminum alloy,
The said boundary part formation member is a metal plate, The manufacturing method of the impact energy absorption member characterized by the above-mentioned. In the manufacturing method of the impact energy absorption member according to claim 6,
The metal is an aluminum alloy,
The said boundary part formation member consists of a reinforced fiber molded object, The manufacturing method of the impact energy absorption member characterized by the above-mentioned.

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