JPH10138950A - Shock absorbing member and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity, to reduce parts cost and manufacturing cost, to reduce the weight of a car body, and to prevent the stress of a shock load or a fatigue load from concentrating on a part between a plastically deformed part and an original shape keeping part when the shock load is applied to them. SOLUTION: This is a cylindrical front side member 10 for constituting a car body frame 1 and has a shock absorbing part 11 which is plastically deformed when it receives an axial shock load and an original shape keeping part 12 which is integrally formed with the shock absorbing part 11 continuously in the direction of the length thereof and nearly keeps an original shape when it receives the axial shock load. Thickness of a part connecting the shock absorbing part 11 to the original shape keeping part 12 is gradually changed and the thickness T1 of the original shape keeping part 12 is made larger than the thickness t1 of the shock absorbing part 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is used, for example, as a front side member constituting a body frame,
The present invention relates to a shock absorbing member that absorbs shock energy at the time of a collision to minimize damage to a passenger cabin.

[0002]

2. Description of the Related Art Conventionally, as a shock absorbing member constituting the above-mentioned body frame, for example, there have been a front side member 101 shown in FIG. 30 and a front side member 201 shown in FIG.

A front side member 101 shown in FIG.
Has a cylindrical shape, a shock absorbing portion 102 disposed in the front and rear direction of the vehicle body in a lower portion of an engine room (not shown), and a passenger compartment which is continuous with the shock absorbing portion 102 and curves downward toward the rear of the vehicle body. An original shape maintaining portion 103 connected to a structural member on the front floor is provided.

In the front side member 101, a reinforcing member 104 is attached to the original shape maintaining portion 103 by arc welding, laser welding, or the like so that plastic deformation is unlikely to occur in the original shape maintaining portion 103. Upon receiving the shock, the shock absorbing portion 102 is largely plastically deformed to absorb shock energy, and the original shape maintaining portion 103, which almost maintains the original shape, maintains the passenger compartment space.

A front side member 201 shown in FIG. 31 has a shock absorbing cylinder 202 having a high absorption rate of impact energy and having a concave bead 202a serving as a starting point of plastic deformation, and a corner for suppressing plastic deformation. A cylinder 203;
A connecting member 204 located between each end of the shock absorbing cylinder 202 and the rectangular cylinder 203, and a structural member on the front floor of the passenger cabin located at the end of the rectangular cylinder 203 opposite to the impact absorbing cylinder 202. A connection member 205 to be fixed,
Each of the connecting members 204 and 205 is made of a casting, to which a suspension mount and a dash panel are respectively attached.

The shock absorbing cylinder 202 and the rectangular cylinder 203 of the front side member 201 are connected by fitting their ends to a connecting member 204 and fixing them by welding, respectively. The portion is fitted to the connecting member 205 and fixed by welding to be connected to the structural member on the front floor of the passenger compartment.

[0007]

However, conventionally, in the case of the front side member 101 shown in FIG. 30, a reinforcing member 104 is attached to the original shape maintaining portion 103 by arc welding, laser welding, or the like. It is necessary to provide a process for correcting deformation caused by welding heat, and in order to prevent the original shape maintaining portion 103 from being plastically deformed by an axial impact load, the entire periphery of the reinforcing member 104 must be welded. As a result, there is a problem that productivity cannot be said to be good because the welding length becomes long and welding requires a lot of time.

Further, in the case of the front side member 201 shown in FIG. 31, as apparent from the above description, in addition to requiring many parts, the shock absorbing cylinder 20 is required.
Since the total welding length when connecting the components of the square tube 203 and the connecting members 204 and 205 to each other becomes long, there is a problem that the cost of parts and the manufacturing cost are increased.

Further, the front side member 201
In this case, it is difficult to reduce the thickness of the connecting members 204 and 205 made of casting, so that it is not possible to contribute to the reduction of the weight of the vehicle body. In addition, the wall thickness of these connecting members 204 and 205 changes suddenly. However, there is a problem that the stress of the impact load or the stress of the fatigue load is not concentrated, and it has been a conventional problem to solve these problems.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. It is possible to improve the productivity and to reduce the cost of parts and the production cost. Impact absorption that contributes to weight reduction and prevents the stress of impact load and the stress of fatigue load from concentrating between the part that undergoes plastic deformation under impact load and the part that maintains its original shape An object is to provide a member and a method for manufacturing the member.

[0011]

A shock absorbing member according to a first aspect of the present invention is a cylindrical shock absorbing member constituting a vehicle body frame, the shock absorbing member being plastically deformed by receiving an axial shock load. An absorbing portion, and a shape maintaining portion that is formed integrally and continuously with the shock absorbing portion in the longitudinal direction and substantially maintains an original shape in a state of receiving the impact load in the axial direction, wherein the shock absorbing portion and the original shape maintaining portion are provided. The thickness of the original shape maintaining portion is made thicker than the thickness of the shock absorbing portion by gradually changing the thickness in a continuous portion of the shock absorbing portion. And

Further, in the shock absorbing member according to claim 2 of the present invention, the shock absorbing portion has a substantially circular cross section, and the original shape maintaining portion has a polygonal cross section. In the shock absorbing member according to the present invention, the shock absorbing portion and the original shape maintaining portion are configured such that a substantially circular cross section of the shock absorbing portion is substantially inscribed in a polygonal cross section of the original shape maintaining portion, and according to claim 4 of the present invention, The shock absorbing member according to the present invention is configured such that the outer circumferential circumference of the shock absorbing portion and the outer circumferential circumference of the original shape maintaining portion are substantially the same, and in the shock absorbing member according to claim 5 of the present invention,
The shock absorbing portion and the original shape maintaining portion are configured such that a substantially circular cross-section of the shock absorbing portion is substantially in contact with opposing sides of the polygonal cross section of the original shape maintaining portion that are parallel to each other.

Further, the shock absorbing member according to claim 6 of the present invention has a structure in which a concave or convex bead serving as a starting point of plastic deformation is provided in the shock absorbing portion, and the shock absorbing member according to claim 7 of the present invention. The member has a configuration in which a plane for mounting components is provided on the shock absorbing portion.

Further, according to a method of manufacturing a shock absorbing member according to claim 8 of the present invention, when manufacturing the shock absorbing member according to claim 3, with respect to one end side of the cylindrical material. After performing the uneven thickness processing and performing at least one of the cylinder reduction processing on one end side of the material and the cylinder expansion processing on the other end side, a shock absorbing portion forming a substantially circular cross section is formed. The material is put into a shock absorbing member forming mold having a cavity for forming an original shape maintaining portion forming a polygonal cross section and subjected to liquid pressure bulging, and one end side of the material is substantially circular in cross section. And the other end side of the material is formed as an original shape maintaining portion having a polygonal cross section, and the structure of the method for manufacturing the shock absorbing member is a means for solving the conventional problems. age There.

Further, in the method of manufacturing a shock absorbing member according to claim 9 of the present invention, when manufacturing the shock absorbing member according to claim 4 or 5, the method of manufacturing a shock absorbing member according to claim 4 or 5 includes: After the wall is subjected to uneven thickness processing, the material is put into a shock absorbing member forming mold having a cavity for forming a shock absorbing portion having a substantially circular cross section and a cavity for forming an original shape maintaining portion having a polygonal cross section, and hydraulic pressure is applied. By performing bulging by, one end of the material is formed as a shock absorbing portion having a substantially circular cross section, and the other end of the material is formed as a shape maintaining portion having a polygonal cross section, The configuration of the method for manufacturing the shock absorbing member is used as means for solving the conventional problems.

Further, according to a method of manufacturing a shock absorbing member according to claim 10 of the present invention, when manufacturing the shock absorbing member according to claim 6, the method of manufacturing a shock absorbing member according to claim 6 is performed with respect to one end side of a cylindrical material. After performing the uneven thickness processing, the material is formed into a shock absorbing member molding die having a shock absorbing portion forming cavity having a substantially circular cross section and a bead forming portion and a prototype shape maintaining portion forming cavity having a polygonal cross section. Injected and formed overhang by hydraulic pressure, one end side of the material is formed as a shock absorbing portion having a bead having a substantially circular cross section and a starting point of plastic deformation, and the other end side of the material is formed. The method for manufacturing a shock absorbing member according to claim 11 is configured to be formed as an original shape maintaining portion having a polygonal cross section, and when manufacturing the shock absorbing member according to claim 7, one of a cylindrical material of It was subjected to polarization meat against part side,
The material is put into a shock absorbing member molding die having a cavity for forming a shock absorbing portion having a substantially circular cross section and having a plane forming portion for mounting parts and a cavity for forming an original shape maintaining portion having a polygonal cross section, and applying hydraulic pressure. By performing bulging, one end side of the material is formed as a shock absorbing portion having a substantially circular cross section and a component mounting plane,
The other end of the material is formed as an original shape maintaining portion having a polygonal cross section.

On the other hand, the shock absorbing member according to claim 12 of the present invention is a cylindrical shock absorbing member constituting a vehicle body frame, has a substantially circular cross section, and is plastically deformed by receiving an axial shock load. A deformable shock absorbing portion, and a prototype maintaining portion having a polygonal cross-section and substantially maintaining the original shape in a state of receiving the impact load in the axial direction, wherein ends of the shock absorbing portion and the prototype maintaining portion are connected to each other. The configuration is such that they are fitted and connected, and the configuration of the shock absorbing member is a means for solving the conventional problems.

Further, the shock absorbing member according to claim 13 of the present invention has a structure in which the thickness of the shock absorbing portion is smaller than the thickness of the original shape maintaining portion, and the shock absorbing member according to claim 14 of the present invention. The shock absorbing portion and the original shape maintaining portion have a dimensional relationship such that the substantially circular cross section of the shock absorbing portion is substantially inscribed in the polygonal cross section of the original shape maintaining portion, and is fitted into the end of the original shape maintaining portion and the end of the shock absorbing portion. The shock absorbing member according to claim 15 of the present invention includes a shock absorbing portion and an original shape maintaining portion, wherein the substantially circular cross section of the shock absorbing portion has an original shape maintaining portion. A configuration in which the dimensional relationship is substantially in contact with opposing sides of the polygonal cross section that are parallel to each other, and a connection fitting portion having a substantially circular cross section fitted to the end of the shock absorbing portion is provided at the end of the original shape maintaining portion. The shock absorbing member according to claim 16 of the present invention comprises: And the outer circumference, and the outer peripheral circumference of the connecting fitting portion is configured is substantially the same.

Further, the shock absorbing member according to claim 17 of the present invention has a structure in which a concave or convex bead serving as a starting point of plastic deformation is provided in the shock absorbing portion.
The shock absorbing member according to 8 has a structure in which a plane for mounting components is provided on the shock absorbing portion.

Further, in the method of manufacturing a shock absorbing member according to the nineteenth aspect of the present invention, when manufacturing the shock absorbing member according to the fourteenth aspect, the end of a cylindrical material is subjected to a contraction process. After that, the material is put into an original shape maintaining portion forming mold having a cavity for forming an original shape maintaining portion having a portion for forming a connection fitting portion having a substantially circular cross section at an end portion, and overhanging by hydraulic pressure is performed. The end portion of the material is formed as a connection insertion portion having a substantially circular cross section, and the main body portion of the material is formed as an original shape maintaining portion having a polygonal cross section, and the connection fitting portion of the original shape maintaining portion is maintained at the original shape. The impact absorbing portion is formed to be thinner than the portion and is fitted and connected to an end portion of the impact absorbing portion. The configuration of the method of manufacturing the impact absorbing member is a means for solving the conventional problems.

Further, in the method of manufacturing a shock absorbing member according to claim 20 of the present invention, when manufacturing the shock absorbing member according to claim 17, the end of a cylindrical material is subjected to contraction processing. After that, the material is put into an original shape maintaining portion forming mold having a cavity for forming an original shape maintaining portion having a portion for forming a connection fitting portion having a substantially circular cross section at an end portion, and overhanging by hydraulic pressure is performed. Performing, the end portion of the material is formed as a connecting insertion portion having a substantially circular cross section, and the main body portion of the material is formed as an original shape maintaining portion having a polygonal cross section, and further, a bead forming portion having a substantially circular cross section is formed. A shock absorbing portion forming mold having a shock absorbing portion forming cavity having a thinner material than the cylindrical material is put into the shock absorbing portion forming mold and subjected to liquid pressure bulging, and the thin material is formed into a substantially circular cross section and Initiation of plastic deformation It formed as a shock absorbing portion having a bead serving as a connecting fitting portion of the original holding section is configured to be connected is fitted on the end portion of the shock absorbing unit according to claim 21 of the present invention
The manufacturing method of the shock absorbing member according to the above, when manufacturing the shock absorbing member according to claim 18, after performing a contraction processing on the end portion of the cylindrical material, the cross section is substantially circular in the end portion The raw material is put into a mold for maintaining the original shape having a cavity for forming an original shape maintaining portion having a portion for forming a connection fitting portion to be formed, and overhanging by hydraulic pressure is performed. And a shock absorbing portion forming cavity having a substantially circular cross section and having a component mounting flat forming portion, wherein the main body portion of the material is formed as an original shape maintaining portion having a polygonal cross section. A shock absorbing part having a thinner material than the tubular material and a liquid pressure bulge formed in a shock absorbing part forming mold, and the thin material having a substantially circular cross section and a flat surface for mounting parts. Formed as Has a configuration that connects to the connecting fitting portion of the original holding section is fitted to an end portion of the shock absorber.

In the shock absorbing member according to claim 22 of the present invention, the shock absorbing portion and the original shape maintaining portion are both formed by extruded aluminum members, and the shock absorbing member according to claim 23 of the present invention. In the member, both the shock absorbing portion and the original shape maintaining portion are made of a steel pipe or a high-tensile steel pipe.

[0023]

In the shock absorbing member according to the first aspect of the present invention, for example, when the shock absorbing member is used as a front side member constituting a body frame, at the time of a collision, the thin shock absorbing portion receives an axial shock load. While the plastic deformation deforms and absorbs the collision energy, the thick original shape maintaining portion almost keeps its original shape, so that the damage to the passenger cabin is reduced to a small extent. At this time, the shock absorbing portion and the original shape maintaining portion In the continuous portion, the thickness is gradually changed, so that the stress of the impact load and the stress of the fatigue load are prevented from being concentrated between the shock absorbing portion and the original shape maintaining portion.

Further, since the reinforcing member is not attached to the original shape maintaining portion by welding as in the prior art, there is no need to provide a welding step and a step of correcting deformation caused by welding heat, thereby improving productivity. At the same time, parts costs and manufacturing costs are reduced.

In the shock absorbing member according to the second aspect of the present invention, the cross section of the shock absorbing portion is substantially circular and the cross section of the original shape maintaining portion is polygonal. According to the third aspect of the present invention, the collision energy is efficiently absorbed, and the original shape maintaining section surely maintains the original shape.
In the shock absorbing member according to the above, the collision energy that could not be absorbed by the shock absorbing portion is efficiently transmitted to the original shape maintaining portion, and the reaction force from the original shape maintaining portion due to this is also efficiently transmitted to the shock absorbing portion. Therefore, the concentration of the stress of the impact load and the stress of the fatigue load between the shock absorbing portion and the original shape maintaining portion can be more reliably avoided.

In the shock absorbing member according to the fourth aspect of the present invention, since the shock absorbing member has the above-described structure, the shock absorbing member having a substantially circular cross section and the original shape maintaining portion having a polygonal cross section are formed. The step of performing the contraction processing and the expansion processing on the material of the member is omitted, and in the shock absorbing member according to claim 5 of the present invention, for example, the portion where the original shape maintaining portion curves downward is used. When the cross section of the original shape maintaining portion has a rectangular shape, the opposite sides of the shock absorbing portion and the original shape maintaining portion located above and below the rectangular cross section of the original shape maintaining portion are substantially circular cross sections of the shock absorbing portion. If the lengths of the opposing sides are made shorter than the opposing sides located on both sides of the rectangular cross section, the second moment of area of the original shape maintaining portion increases, and as a result, the original shape maintaining portion Is curved In the event of a collision, the thin-walled shock absorbing part receives the impact load in the axial direction and plastically deforms to absorb the collision energy, while the thick-walled original shape retaining part retains its original shape without significant plastic deformation. In addition, collision energy and reaction force that could not be completely absorbed by the shock absorbing portion are efficiently transmitted to each other between the shock absorbing portion and the original shape maintaining portion. Therefore, deformation can be avoided.

In the shock absorbing member according to claim 6 of the present invention, the bead serves as a starting point of plastic deformation at the time of a collision, and the initial load is reduced. In the shock absorbing member according to claim 7 of the present invention, for example, When the shock absorbing member is a front side member, other components such as a bumper stay, a first cross member, and an engine mount can be easily attached to the shock absorbing portion.

In the method for manufacturing a shock absorbing member according to claim 8 of the present invention, since there is no welding step of attaching a reinforcing material to the original shape maintaining portion by welding, a step of correcting thermal distortion due to welding heat is omitted. As a result, productivity is improved, and parts costs and manufacturing costs are reduced.

In the method of manufacturing a shock absorbing member according to the ninth aspect of the present invention, the step of performing the contraction or expansion of the material of the shock absorbing member is omitted, and the impact according to the tenth aspect of the present invention is eliminated. In the manufacturing method of the shock absorbing member, a bead is formed in the shock absorbing portion at the same time as the formation of the shock absorbing portion, thereby improving the productivity, and manufacturing the shock absorbing member according to claim 11 of the present invention. According to the method, a flat surface for mounting a component is formed on the shock absorbing portion at the same time as the formation of the shock absorbing portion, so that productivity is improved as in the method of manufacturing a shock absorbing member according to claim 10. Become.

On the other hand, in the shock absorbing member according to the twelfth aspect of the present invention, at the time of a collision, the shock absorbing portion having a substantially circular cross section having a high absorption rate of the collision energy is subjected to an axial impact load to undergo plastic deformation. While absorbing the collision energy, the original shape maintaining portion, which has a polygonal cross-section and is less likely to be plastically deformed, substantially retains its original shape, so that damage to the passenger cabin is reduced.

Further, in this shock absorbing member, the ends of the shock absorbing portion and the original shape maintaining portion are fitted and connected to each other, so that a connecting member made of a casting is used or this connecting member is connected to the shock absorbing portion and the shock absorbing portion. There is no need to weld to each end of the original shape maintaining part.In addition, since the original shape maintaining part does not have a structure in which a reinforcing material is attached by welding unlike the conventional one, deformation caused by the welding process and welding heat is corrected. Therefore, it is not necessary to provide a step for performing the above-mentioned steps, and therefore, productivity is improved, parts costs and manufacturing costs are reduced, and the weight of the vehicle body is greatly reduced.

Further, even if the ends of the shock absorbing portion and the original shape maintaining portion are fitted to each other and then the ends are more firmly connected by welding, the total welding length is short and the shock absorbing portion is not damaged. By fitting the end portions of the portion and the original shape maintaining portion to each other, a step of correcting thermal distortion caused by welding heat is omitted, so that productivity is also improved in this case.

In the shock absorbing member according to the thirteenth aspect of the present invention, at the time of a collision, the shock absorbing portion having a small thickness efficiently absorbs the collision energy, and the original shape maintaining portion having a large thickness surely maintains the original shape. Thus, in the shock absorbing member according to claim 14 of the present invention, the collision energy that could not be absorbed by the shock absorbing portion is efficiently transmitted to the original shape maintaining portion, and the reaction force from the original shape maintaining portion due to this is also reduced. Since the shock is efficiently transmitted to the shock absorbing portion, the deformation between the shock absorbing portion and the original shape maintaining portion is avoided.

In the shock absorbing member according to the fifteenth aspect of the present invention, for example, when the original shape maintaining portion has a portion curved downward and the cross section of the original shape maintaining portion has a rectangular shape, And the original shape maintaining portion are in a dimensional relationship in which the upper and lower opposing sides of the rectangular cross section of the original shape maintaining portion are substantially in contact with the substantially circular cross section of the shock absorbing portion, and the lengths of the opposing sides are both sides of the rectangular cross section. When the original shape maintaining portion is curved, the impact absorbing portion having a small thickness is not affected by the impact even if the original shape maintaining portion is curved as described above. Plastic deformation under the impact load in the direction to absorb the collision energy, and the thick original shape maintaining part keeps its original shape almost without large plastic deformation.In addition, it cannot be absorbed by the shock absorbing part Collision energy and Since the force is efficiently transmitted between the shock absorbing portion and the original shape maintaining portion, deformation is prevented from occurring between the shock absorbing portion and the original shape maintaining portion. Since the shock absorbing member according to the above is configured as described above, the step of reducing the size of the material of the original shape maintaining portion when forming the connection fitting portion in the original shape maintaining portion is omitted.

In the shock absorbing member according to the seventeenth aspect of the present invention, at the time of collision, the bead serves as a starting point of plastic deformation, and the initial load is reduced.
In the shock absorbing member according to 8, for example, when the shock absorbing member is a front side member, other components such as a bumper stay, a first cross member, and an engine mount can be easily attached to the shock absorbing portion.

In the method for manufacturing a shock absorbing member according to the nineteenth aspect of the present invention, since the ends of the shock absorbing portion and the original shape maintaining portion are fitted and connected to each other, a connecting member made of casting is used or this connection is used. There is no need to weld members to each end of the shock absorbing part and the original shape maintaining part, and there is no need to attach a reinforcing material to the original shape maintaining part by welding, so it is necessary to provide a step to correct deformation caused by welding heat Therefore, the productivity is improved, the parts cost and the manufacturing cost are reduced, and the weight of the vehicle body is greatly reduced.

Even if the ends of the shock absorbing portion and the original shape maintaining portion are fitted to each other and then the ends are connected more firmly by welding, the total welding length is short and the shock absorbing portion is not damaged. In addition, since the end portions of the original shape maintaining portions are fitted to each other, the step of correcting thermal distortion caused by welding heat is omitted, so that the productivity is also improved in this case.

In the method of manufacturing a shock absorbing member according to claim 20 of the present invention, a bead is formed in the shock absorbing portion at the same time as the formation of the shock absorbing portion, so that productivity is improved. In the method of manufacturing a shock absorbing member according to claim 21 of the present invention, a flat surface for mounting parts is formed on the shock absorbing portion at the same time as the formation of the shock absorbing portion. The productivity is improved as in the case of the manufacturing method.

In the shock absorbing member according to claim 22 of the present invention, the weight of the vehicle body is reduced. On the other hand, in the shock absorbing member according to claim 23 of the present invention, the strength of the vehicle body frame is increased. It will be.

[0040]

According to the first aspect of the present invention, the shock absorbing member has the above-described structure, so that the productivity can be greatly improved, and the cost of parts and manufacturing can be reduced. Sometimes, it is possible to prevent the stress of the impact load and the stress of the fatigue load from concentrating between the shock absorbing part and the original shape maintaining part, and it is possible to reduce the damage to the cabin. Brought.

Further, in the shock absorbing member according to the second aspect of the present invention, at the time of a collision, the shock absorbing portion efficiently absorbs the collision energy and the original shape maintaining portion securely retains the original shape, so that the damage to the passenger cabin is reduced. In the shock absorbing member according to the third aspect of the present invention, the collision energy that could not be absorbed by the shock absorbing portion can be efficiently transmitted to the original shape maintaining portion, and thereby the impact energy from the original shape maintaining portion can be reduced. Since the force can also be efficiently transmitted to the shock absorbing portion, it is possible to more reliably avoid the concentration of the stress of the impact load and the stress of the fatigue load between the shock absorbing portion and the original shape maintaining portion. Excellent effect is obtained.

Further, since the shock absorbing member according to the fourth aspect of the present invention has the above-described structure, it is possible to reduce or expand the material of the shock absorbing member when forming the shock absorbing portion and the original shape maintaining portion. In the shock absorbing member according to claim 5 of the present invention, for example, even if the original shape maintaining portion has a curved portion, the second moment of area of the original shape maintaining portion can be reduced. Since it is possible to increase the size, it is possible to prevent the original shape maintaining portion from undergoing large plastic deformation at the time of a collision, and additionally, the collision energy and reaction force that could not be completely absorbed by the impact absorbing portion are transferred between the impact absorbing portion and the original shape maintaining portion. Can efficiently transmit each other, so that a very excellent effect of preventing deformation from occurring between the shock absorbing portion and the original shape maintaining portion is brought about.

Further, in the shock absorbing member according to claim 6 of the present invention, the initial load can be reduced. In the shock absorbing member according to claim 7 of the present invention, for example, the shock absorbing member is a front side member. In some cases, there is an extremely excellent effect that other components such as a bumper stay, a first cross member, and an engine mount can be easily attached to the shock absorbing portion.

Further, in the method of manufacturing an impact absorbing member according to claim 8 of the present invention, since the above-described configuration is employed, productivity can be significantly improved, and parts costs and manufacturing costs can be reduced. A very good effect that can be achieved is brought about.

Further, the method of manufacturing a shock absorbing member according to the ninth aspect of the present invention provides the same effect as the method of manufacturing a shock absorbing member according to the eighth aspect of the present invention, and also provides the effect of the shock absorbing member. The step of performing the contraction processing and the expansion processing of the raw material can be omitted, and the method of manufacturing an impact absorbing member according to claim 8 of the present invention can also be applied to the method of manufacturing an impact absorbing member according to claims 10 and 11 of the present invention. The same effect as described above is obtained, and in addition, a very excellent effect that further improvement in productivity can be realized is brought about.

On the other hand, in the shock absorbing member according to the twelfth aspect of the present invention, since the above structure is adopted, productivity can be greatly improved, and parts and manufacturing costs can be reduced, and vehicle body weight can be reduced. Can be realized,
In addition, at the time of a collision, a very excellent effect that it is possible to reduce the damage to the passenger cabin is provided.

Further, in the shock absorbing member according to the thirteenth aspect of the present invention, at the time of a collision, the shock absorbing portion efficiently absorbs the collision energy and the original shape maintaining portion securely retains the original shape. With the shock absorbing member according to claim 14 of the present invention, it is possible to efficiently transmit the collision energy that could not be absorbed by the shock absorbing portion to the original shape maintaining portion, and further reduce the impact energy from the original shape maintaining portion. Can be efficiently transmitted to the shock absorbing portion, so that a very excellent effect that deformation can be prevented between the shock absorbing portion and the original shape maintaining portion is provided.

Further, in the shock absorbing member according to the fifteenth aspect of the present invention, for example, even when the original shape maintaining portion has a curved portion, the second moment of area of the original shape maintaining portion can be increased. Thus, the same effect as the shock absorbing member according to claim 5 of the present invention can be obtained, and claim 16 of the present invention.
Since the shock absorbing member according to (1) is configured as described above, it is possible to omit the contraction processing of the material of the original shape maintaining portion when forming the connection fitting portion in the original shape maintaining portion, and according to claim 17 of the present invention. With the shock absorbing member, the initial load at the time of collision can be reduced.
For example, when the shock absorbing member is a front side member, other parts such as a bumper stay, a first cross member, and an engine mount can be easily attached to the shock absorbing portion. A very good effect is brought.

Furthermore, in the method of manufacturing a shock absorbing member according to the nineteenth aspect of the present invention, since the above-described configuration is employed, productivity can be improved, and parts and manufacturing costs can be reduced. Thus, a very excellent effect that it is possible to greatly contribute to the reduction of the weight of the vehicle body is brought about, and in the method of manufacturing the shock absorbing member according to claims 20 and 21 of the present invention, the productivity is improved. This is a very excellent effect that further improvement can be realized.

The shock absorbing member according to claim 22 of the present invention can contribute to reducing the weight of the vehicle body, while the shock absorbing member according to claim 23 of the present invention realizes an improvement in the strength of the vehicle body frame. It has a very good effect of being able to do it.

[0051]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

[First Embodiment] FIGS. 1 to 5 show an embodiment of a shock absorbing member according to claims 1 to 3 and 22 of the present invention. In this embodiment, a shock absorbing member according to the present invention is used. The case where a member is a front side member which constitutes a body frame is shown.

As shown in FIG. 1, a front side member 10 constituting the vehicle body frame 1 is formed of a cylindrical extruded aluminum alloy material.
A shock absorbing portion 11 positioned in the front and rear direction of the vehicle body in the front engine room 3, and provided integrally and continuously with the shock absorbing portion 11 and curved downward toward the rear so as to be bent downward and to the floor of the passenger compartment 4. It has an original shape maintaining portion 12 connected to the cross member 5 located at the front portion. In the event of a collision, while the shock absorbing portion 11 receives an axial impact load and plastically deforms to absorb the collision energy, The retainer 12 substantially retains its original shape while receiving the impact load in the axial direction, and retains the space of the passenger compartment 4.

In this case, as shown in FIGS. 2 and 3, the shock absorbing portion 11 has a circular cross section, while the original shape maintaining portion 12 has a square cross section. A dash panel and a suspension mount are attached to each flat surface 12a.

The shock absorbing portion 11 and the original shape maintaining portion 12 have a dimensional relationship such that the circular cross section of the shock absorbing portion 11 is substantially inscribed in the square cross section of the original shape maintaining portion 12, that is, the diameter d1 of the shock absorbing portion 11 And the width w1 of each plane of the original shape maintaining unit 12
Are approximately the same length, and the shock absorbing portion 11
The thickness T1 of the original shape maintaining portion 12 is made thicker than the thickness t1 of the shock absorbing portion 11 by gradually changing the thickness in a continuous portion between the original shape maintaining portion 12 and the original shape maintaining portion 12. 12 has a thickness T1 of 3 to 7 mm, and the shock absorbing portion 11 has a thickness t1 of 2 to 4 mm.

In manufacturing the front side member 10, first, a cylindrical material 10A (extruded aluminum alloy) having a diameter d1 and a thickness T1 shown in FIG. 4A is prepared. While gradually changing the thickness in the middle part of the raw material 10A, one end side (left end side in the drawing) is subjected to uneven thickness processing, and as shown in FIG. 4 (b), one end side of the raw material 10A Is set to a thickness t1 smaller than the thickness T1 at the other end (right end in the drawing).

Next, at least one of a cylinder reduction process on one end side and a tube expansion process on the other end side of the material 10A is performed. In this embodiment, the cylinder expansion process on the other end side is performed. After processing, the material 10A is
After the shape shown in FIG. 4C, the other end of the material 10A is bent to form the material 10A into the shape shown in FIG.

Next, as shown in FIG. 5, a shock absorbing member forming die 80 having a fixed die 81 and a movable die 82.
The raw material 10A is put into the container, and overhanging by hydraulic pressure is performed.

In this shock absorbing member molding die 80,
When the movable mold 82 is closed, the impact absorbing portion forming cavity 83 having a circular cross section and the original shape maintaining portion forming cavity having a square cross section having the same width w1 as the diameter d1 of the shock absorbing portion forming cavity 83 are formed. 84 is formed, and the other end side of the expanded material 10A is fixed to the fixed mold 81 in the original shape maintaining portion forming cavity 84, as shown in FIG. 5B. 5A, and is pressed by the movable mold 82, and in this state, the fluid pressure applied to the inside of the raw material 10A is used to make close contact with the pressing surfaces of the fixed mold 81 and the movable mold 82 as shown in FIG. The other end of the material 10A has a flat width w.
In this case, one end of the raw material 10A is molded as the shock absorbing portion 11 having the diameter d1 while maintaining its shape in the shock absorbing portion forming cavity 83. So that
The front side member 10 having the shock absorbing portion 11 and the original shape maintaining portion 12 integrally formed continuously with the shock absorbing portion 11 in the longitudinal direction is obtained.

In the front side member 10 manufactured in this manner, at the time of collision, the impact energy absorption rate of the front side member 10 is made to be about 2 times that of the original shape maintaining portion 12 by making the cross section circular.
Since the shock absorbing portion 11 having the thickness t1 increased by 0% receives the impact load in the axial direction and undergoes plastic deformation to absorb the collision energy, the original shape maintaining portion 12 having the thickness T1 substantially maintains its original shape. The damage to the guest rooms will be reduced,
At this time, the wall thickness is gradually changed in a continuous portion between the shock absorbing portion 11 and the original shape maintaining portion 12, and the diameter d1 of the shock absorbing portion 11 and the width w1 of each plane of the original shape maintaining portion 12 are set.
Are approximately the same length, so that the collision energy that could not be completely absorbed by the shock absorbing portion 11 is efficiently transmitted to the original shape maintaining portion 12, and the reaction force from the original shape maintaining portion 12 by this also absorbs the impact energy. The stress is transmitted to the portion 11 efficiently, so that the stress of the impact load or the stress of the fatigue load is reliably prevented from being concentrated between the shock absorbing portion 11 and the original shape maintaining portion 12.

Further, since the original shape maintaining portion 12 does not have a structure in which a reinforcing material is attached by welding as in the related art, the cost of parts and the manufacturing cost can be reduced, and when the front side member 10 is manufactured, ,
Since there is no need to provide a welding step and a step of correcting deformation caused by welding heat, productivity is improved.

In this embodiment, the cross section of the shock absorbing portion 11 of the front side member 10 is circular.
On the other hand, the cross section of the original shape maintaining portion 12 is square, but as shown in FIGS. 6 and 7, the cross section of the shock absorbing portion 11A is elliptical, and the cross section of the original shape maintaining portion 12A is
A rectangular shape having a height (long side) H and a width (short side) D substantially the same as the major axis a and minor axis b of the elliptical cross section in 1A may be used.

As shown in FIGS. 8 and 9, the cross section of the shock absorbing portion 11B may have a circular shape, and the cross section of the original shape maintaining portion 12B may have a trapezoidal shape having a long upper side substantially inscribed by the circular cross section of the shock absorbing portion 11B. Often, in this case, a large dash panel mounting surface can be secured.

Further, as shown in FIGS. 10 and 11,
The cross section of the shock absorbing portion 11C has a circular shape, and the original shape maintaining portion 1
The cross section of 2C may be a hexagonal shape having a long upper side where the circular cross section of the shock absorbing portion 11C is substantially inscribed. In this case, the same wide dash panel mounting surface as described above can be secured, and the front side member in the above embodiment can be secured. Similarly to 10, the collision energy not absorbed by the shock absorbing portion 11C can be efficiently transmitted to the original shape maintaining portion 12C, and the reaction force from the original shape maintaining portion 12C can be efficiently transmitted to the shock absorbing portion 11C. Becomes

[Second Embodiment] FIGS. 12 to 15 show an embodiment of a shock absorbing member according to the first, second, fourth and fifth aspects of the present invention. A case where the front side member is arranged at the same position as the side member 10 will be exemplified.

As shown in FIGS. 12 and 13, in the front side member 20, the cross section of the shock absorbing portion 21 has a circular shape with a diameter d 2, while the cross section of the original shape maintaining portion 22 has short sides (opposite to each other). Side) 22a A rectangular shape having a long side 22b perpendicular to the side 22a, and the circular cross section of the shock absorbing portion 21 is made to substantially contact the short side 22a of the original shape maintaining portion 22, ie, the diameter of the circular cross section in the shock absorbing portion 21 d2 and the long side 22 of the rectangular cross section in the original shape maintaining portion 22
b and the length h2 are made substantially the same size,
1 and the outer circumference of the original shape maintaining portion 22 are substantially the same, and the other configuration is the same as the front side member 10 of the previous embodiment.

When manufacturing the front side member 20, first, a cylindrical material 20A having a diameter d2 and a thickness T1 shown in FIG.
While gradually changing the wall thickness in the middle part of 0A, one end side (left end side in the figure) is subjected to uneven thickness processing, and FIG.
As shown in (b), the thickness of one end of the material 10A is set to a thickness t1 that is smaller than the thickness T1 of the other end (the right end in the drawing), and then the thickness of the other end of the material 20A is reduced. The material 20A is bent into the shape shown in FIG.

Next, as shown in FIG.
And a movable mold 92, and in a state where the movable mold 92 is tightened, a cavity 93 for forming the shock absorbing portion having the same circular cross section as the shock absorbing portion 21 and an original shape maintaining portion having the same rectangular cross section as the original shape maintaining portion 22. The raw material 20A is put into a shock absorbing member molding die 90 in which the cavity 94 is formed, and overhang molding is performed by hydraulic pressure.

At this time, the other end of the raw material 20A is pressed against the fixed mold 91 and the movable mold 92 by the original shape maintaining portion forming cavity 94 as shown in FIG. Due to the liquid pressure applied to the inside of the raw material 20A, as shown in FIG. 15C, it protrudes so as to be in close contact with the pressing surfaces of the fixed mold 91 and the movable mold 92, and is formed as the original shape maintaining portion 22, One end side of the material 20A is formed as a shock absorbing portion 21 having a diameter d2 while its shape is maintained in the shock absorbing portion forming cavity 93,
Thereby, the front side member 20 is obtained.

In the front side member 20 manufactured in this manner, since the second moment of area of the original shape maintaining portion 22 is large, even if the original shape maintaining portion 22 is curved, it is thin at the time of collision. The impact absorbing portion 21 receives the impact load in the axial direction and plastically deforms to absorb the collision energy, and the thick original shape maintaining portion 22 substantially maintains its original shape without undergoing large plastic deformation. By making the cross section of the absorbing portion 21 circular, the original shape maintaining portion 2 is formed.
Since the impact energy absorption rate is set to be about 20% higher than 2, the impact energy is efficiently absorbed.

The thickness of the continuous portion between the shock absorbing portion 21 and the original shape maintaining portion 22 is gradually changed, and the diameter d2 of the circular cross section of the shock absorbing portion 21 and the length of the rectangular cross section of the original shape maintaining portion 22 are changed. Length h2 of side 22b
Are substantially equal in size, so that the collision energy and the reaction force that could not be completely absorbed by the shock absorbing portion 21 are efficiently transmitted to each other between the shock absorbing portion 21 and the original shape maintaining portion 22. Deformation due to stress concentration is prevented from occurring between 21 and the original shape maintaining portion 22.

Further, also in this embodiment, since the reinforcing material is not attached to the original shape maintaining portion 22 by welding, the cost of parts and the manufacturing cost can be reduced. It is not necessary to provide a process for correcting deformation caused by welding heat, and the outer peripheral circumference of the shock absorbing portion 21;
By making the outer peripheral circumference of the original shape maintaining portion 22 substantially the same, the step of performing the contraction processing and the expansion processing on the raw material 20A is omitted, so that the productivity is improved.

[Third Embodiment] FIGS. 16 to 18 show an embodiment of a shock absorbing member according to the first to third, sixth, seventh aspects of the present invention. The member 30 differs from the front side member 10 in the first embodiment in that
As shown in (1), the shock absorbing portion 31 is provided with a concave bead 33 serving as a starting point of plastic deformation, and flat surfaces 34 and 35 for mounting parts P such as a bumper stay, a first cross member or an engine mount. Other configurations such as the cross-sectional shape of the original shape maintaining portion 32 are the same as those of the front side member 10 in the first embodiment.

When manufacturing the front side member 30, first, the same processing as in the first embodiment is sequentially performed until the original shape maintaining portion 32 is bent.

Next, as shown in FIG.
1A and a movable mold 82A for forming a shock absorbing portion having the same circular cross-section as the shock absorbing portion 31 and having a bead forming portion B and a component mounting flat forming portion F when the movable mold 82A is fastened. The raw material 30A is put into a shock absorbing member molding die 80A in which a cavity (not shown) for forming an original shape maintaining portion having the same square cross section as the cavity 83A and the original shape maintaining portion 32 is formed, and overhanging by hydraulic pressure is performed. The other end of the material 30A subjected to the tube expansion is formed as the original shape maintaining portion 32 having a square cross section in the same manner as in the first embodiment, and one end of the material 30A is subjected to impact. The material is pressed by the bead forming portion B and the component mounting flat forming portion F while maintaining its shape in the absorbing portion forming cavity 83A.
One end side is a concave bead 33 and a flat surface 34,
Thus, the front side member 30 is obtained as a shock absorbing portion 31 having a diameter d1 and having the integral 35.

In this front side member 30,
As in the case of the front side member 10 in the first embodiment, at the time of collision, damage to the passenger cabin is reduced, and at this time, the shock absorbing portion 31 and the original shape maintaining portion 3
In the meantime, the concentration of the stress of the impact load or the stress of the fatigue load is reliably avoided during the period 2, and the bead 33 and the flat surfaces 34 and 35 are provided in the shock absorbing portion 31. And at the same time,
Parts P such as a bumper stay, a first cross member, and an engine mount can be easily attached.

Further, since no reinforcing material is used in the original shape maintaining portion 32, the cost of parts and the manufacturing cost can be reduced. In addition, when the front side member 30 is manufactured, the welding process and welding heat are reduced. It is not necessary to correct the accompanying thermal distortion, and at the same time that the shock absorbing portion 31 is formed, the beads 33 and the planes 34 and 35 for attaching components are formed in the shock absorbing portion 31, so that productivity is improved. .

[Fourth Embodiment] FIGS. 19 to 22 show an embodiment of the shock absorbing member according to claims 12 to 14 of the present invention. Is a front side member constituting a vehicle body frame.

As shown in FIG. 19, the front side member 40 has a cylindrical shape as a whole, has a circular cross section, and has an impact absorbing portion 41 which is plastically deformed by receiving an axial impact load. As shown in FIG. 20, the original shape maintaining portion 42 which has a square cross section and has a thickness T4 greater than the thickness t4 of the shock absorbing portion 41 and substantially maintains the original shape in a state where it receives an axial impact load. It has.

The end of the original shape maintaining portion 42 has a shock absorbing portion 4
A connection fitting portion 42a having a circular cross section whose diameter is reduced by the thickness t4 from 1 is provided. The shock absorbing portion 41 and the original shape maintaining portion 42 connect the connecting fitting portion 42a to the end of the shock absorbing portion 41. In this case, the shock absorbing portion 41 and the original shape maintaining portion 42
Has a dimensional relationship in which the circular cross section of the shock absorbing portion 41 is substantially inscribed in the square cross section of the original shape maintaining portion 42, that is,
The diameter d4 of the shock absorbing portion 41 and the width w4 of each plane of the original shape maintaining portion 42 are substantially the same length.

In manufacturing the front side member 40, first, a cylindrical material 40A having a thickness T4 shown in FIG. 21A is prepared, and the end of the material 40A is subjected to a contraction process. 21B, and the material 40A is bent to form the shape shown in FIG.
The shape is as shown in the figure.

Next, as shown in FIG.
1B and a movable mold 82B, and in a state where the movable mold 82B is fastened, has a portion C having the same square cross section as the original shape maintaining portion 42 and having a circular cross section forming a connection fitting portion 42a at an end portion. Cavity 8 for forming original shape maintaining part
Impact-absorbing member molding die 80 in which 4B is formed
The raw material 40A is put in B, and overhang forming by hydraulic pressure is performed.

At this time, the main body of the material 40A is
As shown in (b), the original shape maintaining portion forming cavity 84 is formed.
B is pressed by the fixed mold 81B and the movable mold 82B,
In this state, due to the hydraulic pressure applied inside the material 40A,
As shown in FIG. 22 (c), it protrudes so as to be in close contact with the pressing surfaces of the fixed mold 81B and the movable mold 82B, and is molded as the original shape maintaining portion 42. The end of the material 40A is formed as shown in FIG. As shown in a), a fixed die 81B is formed at a portion C having a circular cross section of the original shape maintaining portion forming cavity 84B.
And the movable mold 82B presses the material 40 in this state.
Due to the hydraulic pressure applied to the inside of A, it is formed as a connection fitting portion 42a having a circular cross section and a diameter smaller than the shock absorbing portion 41 by the thickness t4.

Then, the connection fitting portion 42a of the original shape maintaining portion 42 is fitted into the end of the shock absorbing portion 41 having the thickness t4, and the ends are connected by welding (or caulking, an adhesive, or a rivet). The front side member 4
0 will be obtained.

In the front side member 40,
At the time of collision, the cross section is made circular so that the
Thickness t4 with about 20% higher impact energy absorption rate than
The impact absorbing portion 41 receives the impact load in the axial direction and plastically deforms to absorb the collision energy, while the original shape maintaining portion 42 having the thickness T4 almost maintains its original shape, so that the damage to the passenger cabin is reduced. At this time, the shock absorber 4
Since the diameter d4 and the width w4 of each plane of the original shape maintaining portion 42 are substantially the same length, the collision energy that could not be absorbed by the shock absorbing portion 41 is efficiently transmitted to the original shape maintaining portion 42. Thus, the reaction force from the original shape maintaining portion 42 is also efficiently transmitted to the shock absorbing portion 41, so that deformation between the shock absorbing portion 41 and the original shape maintaining portion 42 is avoided. .

Further, in the front side member 40, since the ends of the shock absorbing portion 41 and the original shape maintaining portion 42 are fitted and connected to each other, it is not necessary to use a connecting member made of a casting. Since the original shape maintaining portion 42 does not have a structure in which a reinforcing material is attached by welding as in the related art, the cost of parts and the manufacturing cost can be reduced, and further, the weight of the vehicle body can be greatly reduced.

Further, when manufacturing the front side member 40, the shock absorbing portion 41 and the original shape maintaining portion 4
After fitting the ends of each other to each other, as described above, even if the ends are connected more firmly by welding, the total welding length is short and the original shape maintaining portion 42 is attached to the end of the shock absorbing portion 41. The step of correcting the thermal distortion caused by the welding heat is omitted by fitting the connecting fitting portion 42a of the above, so that it is not necessary to provide a welding process for attaching a reinforcing material, and thus productivity is improved. Will be done.

[Fifth Embodiment] FIGS. 23 to 26 show one embodiment of the shock absorbing member according to the twelfth, thirteenth, fifteenth, and sixteenth aspects of the present invention. The case where the shock absorbing member concerned is a front side member constituting a body frame is shown.

As shown in FIGS. 23 and 24, in the front side member 50, the cross section of the shock absorbing portion 51 has a circular shape with a diameter d5, while the cross section of the original shape maintaining portion 52 has the short side (the opposite side) positioned vertically. Side) 52c As a rectangular shape having a long side 52b orthogonal to the side 52c, the circular section of the shock absorbing section 51 has a relationship substantially in contact with the short side 52c of the original shape maintaining section 52, that is, the circular section diameter d5 And the long side 52 of the rectangular cross section in the original shape maintaining portion 52
b is substantially equal to the length h5, and furthermore, a connection fitting portion 52a having a circular cross section provided at the end of the original shape maintaining portion 52 is provided.
Is substantially the same as the outer circumference of the main body of the original shape maintaining portion 52, and the other configuration is the same as the front side member 40 of the fourth embodiment.

In manufacturing the front side member 50, first, a cylindrical material 50A having a thickness T5 shown in FIG. 25A is prepared, and the end of the material 50A is bent. To the shape shown in FIG.

Next, as shown in FIG.
1B and a movable mold 92B, and in a state where the movable mold 92B is fastened, a portion E having the same rectangular cross-section as the original shape maintaining portion 52 and having a circular cross-section forming a connecting fitting portion 52a at an end portion. Shock-absorbing member molding die 9 having the original shape maintaining portion forming cavity 94B formed therein
The raw material 50A is put in 0B, and bulging by hydraulic pressure is performed.

At this time, the main body of the material 50A is
As shown in (b), the original shape maintaining portion forming cavity 94 is formed.
B is pressed by the fixed mold 91B and the movable mold 92B,
In this state, due to the hydraulic pressure applied inside the material 50A,
As shown in FIG. 26C, it protrudes so as to be in close contact with the pressing surfaces of the fixed mold 91B and the movable mold 92B, and is formed as the original shape maintaining portion 52. The end of the material 50A is formed as shown in FIG. As shown in a), a fixed mold 91B is formed at a portion E having a circular cross section of the original shape maintaining portion forming cavity 94B.
And the movable mold 92B presses the material 50 in this state.
Due to the hydraulic pressure applied to the inside of A, a circular cross section having a diameter smaller than the shock absorbing portion 51 by the thickness t5 and having substantially the same outer circumferential length as the outer circumferential length of the main body portion of the original shape maintaining portion 52. It is molded as the fitting portion 52a.

Then, the connecting fitting portion 52a of the original shape maintaining portion 52 is fitted into the end of the shock absorbing portion 51 having the thickness t5, and the ends are connected by welding (or caulking, an adhesive, or a rivet). As a result, the front side member 5
0 will be obtained.

In the front side member 50 manufactured as described above, since the second-order moment of area of the original shape retaining portion 52 is large, even if the original shape retaining portion 52 is curved, it is thin at the time of collision. The shock absorbing portion 51 receives the impact load in the axial direction and plastically deforms to absorb the collision energy, and the thick original shape maintaining portion 52 substantially maintains its original shape without undergoing large plastic deformation. By making the cross section of the absorbing portion 51 circular, the original shape maintaining portion 5 is formed.
Since the impact energy absorption rate is set to be about 20% higher than 2, the impact energy is efficiently absorbed.

In the connecting portion between the shock absorbing portion 51 and the original shape maintaining portion 52, the diameter d5 of the circular cross section of the shock absorbing portion 51 and the length h5 of the long side 52b of the rectangular cross section of the original shape maintaining portion 52 are substantially the same. Because it is sized,
Since the collision energy and the reaction force that could not be completely absorbed by the shock absorbing portion 51 are efficiently transmitted to each other between the shock absorbing portion 51 and the original shape maintaining portion 52, a stress is applied between the shock absorbing portion 51 and the original shape maintaining portion 52. Deformation due to concentration is avoided.

Further, in the front side member 50, since the ends of the shock absorbing portion 51 and the original shape maintaining portion 52 are fitted and connected to each other, it is not necessary to use a connecting member made of casting, and the original shape is not required. Since the reinforcing member is not attached to the holding portion 52 by welding, the cost of parts and the manufacturing cost can be reduced, and in addition, the weight of the vehicle body can be greatly reduced.
It is not necessary to provide a welding process and a process for correcting deformation caused by welding heat in the manufacture of the base material 0. In addition, the outer circumference of the connection fitting portion 52a provided at the end of the original shape maintaining portion 52 and the original shape maintaining portion 52 Since the outer peripheral length of the main body portion is substantially the same, the step of performing the cylinder reduction processing on the material 50A is omitted, so that the productivity is improved.

[Sixth Embodiment] FIGS. 27 to 29 show an embodiment of a shock absorbing member according to claims 12 to 14, 17 and 18 of the present invention. The member 60 is different from the front side member 40 in the fourth embodiment as shown in FIGS. 27 and 28 in that a shock-absorbing portion 61 has a concave bead 63 serving as a starting point of plastic deformation, a bumper stay and a first bumper. The point is that flat surfaces 64 and 65 for mounting components P such as a cross member or an engine mount are provided, and other configurations such as the cross-sectional shape of the original shape maintaining portion 62 are the same as those of the front side member 60 in the fourth embodiment. .

In manufacturing the front side member 60, first, the original shape maintaining portion 62 is formed in the same manner as in the fourth embodiment.

Next, as shown in FIG.
1C and a movable mold 82C for forming a shock absorbing portion having the same circular cross section as the shock absorbing portion 61 and having a bead forming portion B and a component mounting flat forming portion F when the movable mold 82C is fastened. The material 60 is inserted into the shock absorbing member forming die 80C in which the cavity 83C is formed.
A, and overhanging by hydraulic pressure is performed, the material 60
A is pressed by the bead forming portion B and the component mounting flat forming portion F while its shape is maintained in the shock absorbing portion forming cavity 83C, so that the raw material 60A integrates the concave bead 63 and the flat surfaces 64 and 65 into one piece. Having diameter d
4 is formed as the shock absorbing portion 61.

Then, the connection fitting portion 62a of the original shape maintaining portion 62 is fitted into the end of the shock absorbing portion 61 having the thickness t4, and the ends are connected by welding (or caulking, an adhesive, or a rivet). Then, the front side member 60
Is obtained.

In the front side member 60,
As in the case of the front side member 40 in the fourth embodiment, at the time of collision, damage to the passenger cabin is reduced, and at this time, the shock absorbing portion 61 and the original shape maintaining portion 6
In the meantime, the concentration of the stress of the impact load and the stress of the fatigue load is reliably avoided during the period 2, and the bead 63 and the flat surfaces 64 and 65 are provided in the shock absorbing portion 61. In addition to the reduction,
Parts P such as a bumper stay, a first cross member, and an engine mount can be easily attached.

Further, in the front side member 60, since the ends of the shock absorbing portion 61 and the original shape maintaining portion 62 are fitted and connected to each other, it is not necessary to use a connecting member made of a casting. Since the original shape maintaining portion 62 does not have a structure in which a reinforcing material is attached by welding as in the related art, the cost of parts and the cost of manufacturing can be reduced, and the weight of the vehicle body can be greatly reduced.

Further, when manufacturing the front side member 60, it is not necessary to correct the thermal distortion caused by the welding process and welding heat, and at the same time when the shock absorbing portion 61 is formed, a bead 63 is attached to the shock absorbing portion 61. In addition, since the planes 64 and 65 for mounting components are formed, productivity is improved.

In each of the above-described embodiments, the case where the shock absorbing member according to the present invention is the front side member constituting the body frame is shown. However, the present invention is not limited to this. The shock absorbing member according to the present invention is not limited to this. Can naturally be applied to, for example, a rear side member constituting a body frame.

Further, in the above-described fourth and sixth embodiments, the connection fitting portions 42a and 62a are provided at the ends of the original shape maintaining portions 42 and 62. However, the present invention is not limited to this. Instead, as another configuration, for example, a configuration may be adopted in which the connection fitting portion is formed by performing a contraction process or an expansion process on the end portions of the impact absorbing portions 41 and 61. Further, the impact absorbing member may be formed of a steel pipe. Alternatively, it may be configured to be made of a high-tensile steel pipe.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a vehicle body frame showing an arrangement state of a front side member according to an embodiment of a shock absorbing member according to claims 1 to 3 of the present invention, and FIG. b).

FIG. 2 is an explanatory side view of the front side member shown in FIG. 1;

3A is a cross-sectional explanatory view of an impact absorbing portion of the front side member shown in FIG. 1, FIG. 3B is a cross-sectional explanatory view of an original shape maintaining portion, and FIG.

4 (a), (b), (c) and (d) are explanatory diagrams of the manufacturing process of the front side member shown in FIG.

FIGS. 5A and 5B are cross-sectional explanatory views of the front side member shown in FIG. 1 after the shock absorbing portion is formed in a state where the material of the front side member is placed in the metal mold for forming the shock absorbing member, (C) is a cross-sectional explanatory view after molding of the original shape maintaining portion.

FIG. 6 is an explanatory side view showing another configuration example of the front side member in FIG. 1;

7A is a cross-sectional explanatory view of the shock absorbing portion of the front side member shown in FIG. 6, FIG. 7B is a cross-sectional explanatory view of the original shape maintaining portion, and FIG.

FIG. 8 is an explanatory side view showing still another configuration example of the front side member in FIG. 1;

9A is a cross-sectional explanatory view of the shock absorbing portion of the front side member shown in FIG. 8, FIG. 9B is a cross-sectional explanatory view of the original shape maintaining portion, and FIG.

FIG. 10 is an explanatory side view showing still another configuration example of the front side member in FIG. 1;

11A is a cross-sectional explanatory view of the shock absorbing portion of the front side member shown in FIG. 10, FIG. 11B is a cross-sectional explanatory view of the original shape maintaining portion, and FIG.

FIG. 12 is an explanatory side view of a front side member according to an embodiment of a shock absorbing member according to claims 1, 2, 4, and 5 of the present invention.

13A is a cross-sectional explanatory view of the shock absorbing portion of the front side member shown in FIG. 12, FIG. 13B is a cross-sectional explanatory view of the original shape maintaining portion, and FIG.

14 (a), (b), and (c) are explanatory views of the manufacturing process of the front side member shown in FIG.

15 (a) is a cross-sectional explanatory view of the front side member shown in FIG. 12 after the shock absorbing portion is formed in a state where the material of the front side member is placed in the metal mold for forming the shock absorbing member, and FIG. (C) is a cross-sectional explanatory view after molding of the original shape maintaining portion.

FIG. 16 is an explanatory side view of a front side member according to an embodiment of the shock absorbing member according to the first to third, sixth, seventh aspects of the present invention.

FIG. 17 is a cross-sectional explanatory view of a front side flat forming portion in the shock absorbing portion of the front side member shown in FIG. 16, a cross-sectional explanatory view of a bead forming portion in the shock absorbing portion, and FIG. (C) of FIG.

18 (a) is a cross-sectional explanatory view of a front side flat forming portion in a shock absorbing portion, showing a state in which a material of a front side member in FIG. 16 is put into a shock absorbing member forming die, and a bead in the shock absorbing portion. It is sectional explanatory drawing in a formation part (b), and sectional explanatory drawing in a center plane formation part in a shock absorption part (c).

FIG. 19 is an exploded view from the side of a front side member according to one embodiment of the shock absorbing member according to claims 12 to 14 of the present invention.

20A is a cross-sectional explanatory view of the shock absorbing portion of the front side member shown in FIG. 19, FIG. 20B is a cross-sectional explanatory view of the original shape maintaining portion, and FIG.

FIGS. 21 (a), (b), and (c) are explanatory views of the manufacturing process of the original shape maintaining portion of the front side member shown in FIG.
It is.

22 (a) is a cross-sectional explanatory view of the front side member shown in FIG. 19 after the connection fitting portion is formed in a state where the material of the original shape maintaining portion is placed in the mold for forming the shock absorbing member, and FIG. It is sectional explanatory drawing (b) and sectional explanatory drawing (c) after an original shape maintenance part shaping | molding.

FIG. 23 is an exploded view from the side of the front side member according to one embodiment of the shock absorbing member according to claims 12, 13, 15, and 16 of the present invention.

24A is a cross-sectional explanatory view of the shock absorbing portion of the front side member shown in FIG. 23, FIG. 24B is a cross-sectional explanatory view of the original shape maintaining portion, and FIG.

25 (a) and 25 (b) are explanatory views of the manufacturing process of the original shape maintaining portion in the front side member shown in FIG. 23.

26 (a) is a cross-sectional view of the front side member shown in FIG. 23 after the connection fitting portion is formed in a state where the material of the original shape maintaining portion is placed in the mold for forming the shock absorbing member, and FIG. It is sectional explanatory drawing (b) and sectional explanatory drawing (c) after an original shape maintenance part shaping | molding.

FIG. 27 is an exploded view from the side of a front side member according to an embodiment of the shock absorbing member according to claims 12 to 14, 17 and 18 of the present invention.

28 (a) is a cross-sectional explanatory view of a front side flat forming portion of the shock absorbing portion of the front side member shown in FIG. 27, FIG. 28 (b) is a cross-sectional explanatory view of a bead forming portion of the shock absorbing portion, and FIG. (C) of FIG.

29 (a) is a cross-sectional view of the impact absorbing portion of the front side member shown in FIG. 27, in a state where the material of the impact absorbing portion is put into a mold for molding an impact absorbing member and is formed at a front-side flat forming portion. FIG. 3B is an explanatory cross-sectional view of a bead forming portion of the shock absorbing portion, and FIG. 3C is an explanatory cross-sectional view of a central flat forming portion of the shock absorbing portion.

FIG. 30 is an exploded perspective view showing a conventional shock absorbing member.

FIG. 31 is an overall perspective explanatory view showing another conventional shock absorbing member.

[Explanation of symbols]

1 Body frame 10, 20, 30, 40, 50, 60 Front side member (shock absorbing member) 10A, 20A, 30A, 40A, 50A, 60A Material 11, 11A, 11B, 11C, 21, 31, 41, 5
1,61 Shock absorber 12,12A, 12B, 12C, 22,32,42,5
2,62 Original shape maintaining portions 22a, 52c Short sides (opposed sides parallel to each other in polygonal cross section of original shape maintaining portions) 33,63 Beads 34,35,64,65 Planes 42a, 52a, 62a for attaching parts Connection fitting portion 80, 80A, 80B, 80C, 90, 90B Shock absorbing member forming die 83, 83A, 83C, 93 Shock absorbing portion forming cavity 84, 84B, 94, 94B Original shape maintaining portion forming cavity B Bead forming Part E A part forming a fitting part for connection F Plane forming part for component mounting T1, T4, T5 Thickness of original shape maintaining part t1, t4, t5 Thickness of shock absorbing part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B62D 25/08 B62D 25/08

Claims (23)

[Claims] 1. A shock absorbing member having a cylindrical shape constituting a vehicle body frame, the shock absorbing portion being plastically deformed by receiving an axial shock load, and integrally formed with the shock absorbing portion continuously in a longitudinal direction. A shape maintaining portion that is formed and substantially maintains an original shape in a state of receiving the impact load in the axial direction, and that a thickness of the shock absorbing portion is gradually changed at a continuous portion between the shock absorbing portion and the original shape maintaining portion. An impact absorbing member, characterized in that the thickness of the original shape maintaining portion is thicker than that of the original shape maintaining portion. 2. The shock absorbing member according to claim 1, wherein the shock absorbing portion has a substantially circular cross section, and the original shape maintaining portion has a polygonal cross section. 3. The shock absorbing member according to claim 2, wherein the shock absorbing portion and the original shape maintaining portion have a dimensional relationship such that a substantially circular cross section of the shock absorbing portion is substantially inscribed in a polygonal cross section of the original shape maintaining portion. 4. The shock absorbing member according to claim 1, wherein an outer peripheral length of the impact absorbing portion is substantially the same as an outer peripheral length of the original shape maintaining portion. 5. The shock absorbing portion and the original shape maintaining portion are in a dimensional relationship such that a substantially circular cross section of the shock absorbing portion is substantially in contact with mutually parallel sides of the polygonal cross section of the original shape maintaining portion.
Or the shock absorbing member according to 4. 6. The shock absorbing member according to claim 1, wherein a concave or convex bead serving as a starting point of plastic deformation is provided in the shock absorbing portion. 7. The shock-absorbing member according to claim 1, wherein a plane for mounting components is provided on the shock-absorbing portion. 8. When manufacturing the shock absorbing member according to claim 3, one end side of a cylindrical material is subjected to uneven thickness processing, and a reduced cylinder is formed on one end side of the material. After performing at least one of the processing and the expanding processing on the other end side, a cavity for forming a shock absorbing portion having a substantially circular cross section and a cavity for forming an original shape maintaining portion having a polygonal cross section are provided. The material is put into a shock absorbing member forming mold and subjected to liquid pressure bulging to form one end side of the material as a shock absorbing portion having a substantially circular cross section and the other end side of the material. A method for manufacturing a shock absorbing member, wherein the method is formed as a shape maintaining part having a polygonal cross section. 9. When manufacturing the shock absorbing member according to claim 4 or 5, the shock absorbing member having a substantially circular cross-section after subjecting one end side of the cylindrical material to a thickness unevenness process. The material is put into a shock-absorbing member molding die having a cavity for forming a portion and a cavity for forming an original shape maintaining a polygonal cross-section, and overhanging by hydraulic pressure is performed, and one end side of the material is cross-sectioned. A method for manufacturing a shock absorbing member, wherein the shock absorbing member is formed as a substantially circular shock absorbing portion, and the other end side of the material is formed as a shape maintaining portion having a polygonal cross section. 10. A method of manufacturing the shock absorbing member according to claim 6, wherein after one end of the cylindrical material is subjected to uneven thickness processing, the bead forming portion has a substantially circular cross section. The material is placed in a shock absorbing member forming mold having a shock absorbing portion forming cavity having a cavity and an original shape maintaining portion forming cavity having a polygonal cross section, and is subjected to liquid pressure bulging to form one end of the material. The shock absorbing portion is characterized in that the portion side is formed as a shock absorbing portion having a substantially circular cross section and a bead which is a starting point of plastic deformation, and the other end side of the material is formed as a shape maintaining portion having a polygonal cross section. Manufacturing method of the member. 11. A method for manufacturing the shock absorbing member according to claim 7, wherein after one end side of the cylindrical material is subjected to uneven thickness processing, the material has a substantially circular cross section and is used for mounting parts. The material is put into a shock absorbing member forming mold having a cavity for forming a shock absorbing portion having a flat surface forming portion and a cavity for forming an original shape maintaining portion having a polygonal cross section, and bulging is performed by hydraulic pressure to form the material. Shock absorption characterized in that one end side is formed as a shock absorbing portion having a substantially circular cross section and a flat surface for mounting parts, and the other end side of the material is formed as a shape maintaining portion having a polygonal cross section. Manufacturing method of the member. 12. A cylindrical shock-absorbing member constituting a vehicle body frame, having a substantially circular cross-section, a shock-absorbing portion which is plastically deformed by receiving an axial shock load, and a polygonal cross-section. And an original shape maintaining portion for substantially maintaining the original shape under the impact load in the axial direction, wherein the end portions of the impact absorbing portion and the original shape maintaining portion are fitted and connected to each other. Element. 13. The shock absorbing member according to claim 12, wherein the thickness of the shock absorbing portion is smaller than the thickness of the original shape maintaining portion. 14. The shock absorbing portion and the original shape maintaining portion have a dimensional relationship in which a substantially circular cross section of the shock absorbing portion is substantially inscribed in a polygonal cross section of the original shape maintaining portion. The shock absorbing member according to claim 12 or 13, further comprising a connection fitting portion having a substantially circular cross section fitted into the end portion. 15. The shock absorbing portion and the original shape maintaining portion have a dimensional relationship in which a substantially circular cross section of the shock absorbing portion is substantially in contact with mutually parallel sides of the polygonal cross section of the original shape maintaining portion. 14. The shock absorbing member according to claim 12, wherein a connection fitting portion having a substantially circular section is fitted to an end of the shock absorbing portion. 16. The shock absorbing member according to claim 15, wherein an outer peripheral circumference of the original shape maintaining portion is substantially equal to an outer peripheral circumference of the connection fitting portion. 17. The shock absorbing member according to claim 12, wherein a concave or convex bead serving as a starting point of plastic deformation is provided in the shock absorbing portion. 18. The shock absorbing member according to claim 12, wherein a plane for mounting a component is provided on the shock absorbing portion. 19. A manufacturing method for manufacturing a shock-absorbing member according to claim 14, wherein after reducing the end portion of the cylindrical material, the connecting portion has a substantially circular cross-section at the end portion. The raw material is put into a mold for maintaining the original shape having a cavity for forming an original shape having a portion for forming the material, and overhanging is performed by hydraulic pressure, and the end of the material is inserted into the connecting portion having a substantially circular cross section. And the main body of the material is formed as an original shape maintaining portion having a polygonal cross section, and the connection fitting portion of the original shape maintaining portion is fitted into the end of the shock absorbing portion formed thinner than the original shape maintaining portion. A method for manufacturing a shock absorbing member, comprising connecting. 20. A manufacturing method for manufacturing the shock absorbing member according to claim 17, wherein after the end of the cylindrical material is subjected to a contraction process, the end is formed with a connection fitting having a substantially circular cross section. The raw material is put into a mold for maintaining the original shape having a cavity for forming an original shape having a portion for forming the material, and overhanging is performed by hydraulic pressure, and the end of the material is inserted into the connecting portion having a substantially circular cross section. In addition to the above, the main body portion of the material is formed as an original shape maintaining portion having a polygonal cross section, and further, a shock absorbing portion forming mold having a shock absorbing portion forming cavity having a substantially circular cross section and having a bead forming portion. The thin material is formed as a shock absorbing portion having a bead having a substantially circular cross-section and a starting point of plastic deformation by inserting a thinner material than the cylindrical material and performing bulging by hydraulic pressure. Connection of maintenance unit A method for manufacturing a shock absorbing member, wherein a fitting portion for fitting is fitted to and connected to an end of the shock absorbing portion. 21. In manufacturing the shock absorbing member according to claim 18, after the end of the cylindrical material is subjected to the contraction processing, the connection fitting portion having a substantially circular cross section at the end. The raw material is put into a mold for maintaining the original shape having a cavity for forming an original shape having a portion for forming the material, and overhanging is performed by hydraulic pressure, and the end of the material is inserted into the connecting portion having a substantially circular cross section. And forming a main body portion of the material as an original shape maintaining portion having a polygonal cross section, and further having a shock absorbing portion forming cavity having a substantially circular cross section and having a plane forming portion for mounting components. A thinner material than the cylindrical material is put in a mold and bulging is performed by hydraulic pressure to form the thin material as a shock absorbing portion having a substantially circular cross section and a flat surface for mounting components. Connection of maintenance unit A method for manufacturing a shock absorbing member, wherein a fitting portion for fitting is fitted to and connected to an end of the shock absorbing portion. 22. The shock absorbing portion and the original shape maintaining portion are each formed of an extruded aluminum material.
19. The shock absorbing member according to any one of 7, 12 to 18. 23. The shock absorbing portion and the original shape maintaining portion are each made of a steel pipe or a high-tensile steel pipe.
19. The shock absorbing member according to any one of 7, 12 to 18.