JPH0444903Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to shock absorbing technology, and in particular to an impact energy absorbing member that absorbs impact loads generated during accidents involving vehicles, aircraft, etc.

[Conventional technology]

Various types of shock absorbers have been used in the past, and for example, shock energy generated when an aircraft fails to land is absorbed by a shock absorber built into the fuselage. Furthermore, in the event of a collision, the collision energy is absorbed by a shock absorber provided between the bumper and the seat.

However, in the case of a failed landing of an aircraft or a collision of a motor vehicle, an impact load that exceeds the impact absorption capacity of the shock absorber may occur, and the excessive impact load is applied to the occupants. In order to absorb such impact energy, a cylindrical body made of a composite material of synthetic resin and carbon fiber is formed, and depending on the arrangement and blending ratio of the carbon fiber, the crushing load of the member absorbs energy. A chair was used in which the chair was fixed through an impact energy absorbing member that absorbed the impact energy.

[The problem that the idea attempts to solve]

However, according to the above-mentioned impact energy absorbing member, it is difficult to quantify the structure of the composite material of synthetic resin and carbon fiber in terms of physical properties, and the precision of the product varies, making production management difficult. Therefore, there was a problem in that the amount of absorbed energy could not be stably secured.

In addition, the conventional configuration has a structure in which energy is absorbed by the destruction of members, so there is a problem that fragments of the members fly away during operation, making it impossible to ensure safety.

The present invention was devised in view of the above-mentioned problems, and provides an impact energy absorbing member that has a simple structure, can obtain stable energy absorption, and can be particularly installed in seats of aircrafts, automobiles, etc. The purpose is to

[Means to solve the problem]

In order to achieve the above object, the impact energy absorbing member according to the present invention has an inner tube slidably inserted into a metal outer tube having a swollen portion in a part, and one end of the inner tube. A truncated cone or truncated pyramid having a maximum dimension larger than the inner diameter of the fixed outer tube,
A truncated cone-shaped expansion member of any shape is assembled so as to be inserted into the expanded diameter portion of the outer tube, and the outer tube and the inner tube are fixed via a rivet having an appropriate shear allowable stress, The structure is such that the impact force in the axial direction is absorbed by plastic deformation of the diameter of the outer tube due to the sliding displacement of the expansion member and shearing of the rivet.

Incidentally, the outer tube and the inner tube are normally structured so that the rivets provide a fixing force during normal use.

[Effect]

According to the above configuration, the impact energy absorbing member is used by being installed approximately in the axial direction of the impact direction to be absorbed, and when an impact load in the compression or tension direction is applied between the outer tube and the inner tube. First, the rivet having a shearing allowable stress is sheared, and at the same time, the expansion member slides in the axial direction while expanding the diameter of the outer tube by plastic deformation.
The impact energy applied between the outer tube and the inner tube is absorbed by the plastic deformation of the outer tube and the energy consumption associated with the shearing of the rivet.The amount of impact energy absorbed is Adjustments can be made depending on the maximum dimension of the expansion member relative to the inner diameter of the tube, the thickness of the outer tube, and the shape of the expansion member.

〔Example〕

Embodiments of the impact energy absorbing member according to the present invention will be described below with reference to the drawings.

1 to 5 show a tension-absorbing impact energy absorbing member.

In the drawings, reference numeral 1 denotes a cylindrical outer tube made of a rigid body such as steel or aluminum, for example, by drawing. D2) is integrally drawn and formed, and the enlarged diameter portion 3 and the narrow diameter cylindrical portion 2 have a continuous shape via the short tapered cylindrical portion 4. An inner tube 5 (outer diameter D3) is slidably inserted into the small diameter cylindrical portion 2 of the outer tube 1 with a slight gap, and is screwed into the inner end of the inner tube 5 by a screw structure 12. A fixed expansion member 6 is inserted into the expanded diameter portion 3 of the outer tube 1. As shown in FIG. 3, the expanding member 6 is an expanding member 6 that projects radially in the axial direction, has a trapezoidal side surface, and has an approximately cross-shaped axial cross-sectional shape that is inclined opposite to the tapered cylindrical portion 4. Opening ribs 7, 7...
The maximum dimension (L1) of the expansion member 6 is sufficiently larger than the inner diameter D1 of the narrow diameter cylindrical part 2 of the outer tube 1, and the inner diameter D2 of the expanded diameter part 3. It is sized to accommodate. The outer tube 1 is connected to the inner tube 5 via one or more connecting rivets 8.
The rivets 8 are temporarily fixed to each other, and the axial tensile force under normal conditions is supported by the sum of the allowable shear stress of each rivet 8.

Further, 9 and 10 are end fittings fixed to the end of the expanded diameter part 3 of the outer tube 1 and the outer end of the inner tube 5, and are firmly fixed through a number of rivets 11, 11, respectively. It is formed by sticking to.

Since the impact energy absorbing member having the above structure is of a tension absorbing type, both end fittings 9 and 10 are used as tensile support members for the portions receiving the impact load, respectively.

In the above configuration, when tension is applied between the end fittings 9 and 10, a tensile load is generated in the direction of arrow A on the expansion member 6 with respect to the outer tube 1, as shown in FIG. When this tensile load exceeds the total shearing allowable stress of the connecting rivet 8 connecting the outer tube 1 and the inner tube 5, the connecting rivet 8 is cut. Therefore, the expanding member 6 moves from the enlarged diameter section 3 to the narrow diameter cylindrical section 2 (see FIGS. 4 and 5), and the maximum dimension (L1) of the expanding member 6 becomes equal to that of the narrow diameter cylindrical section 2. Since it is configured to be sufficiently larger than the inner diameter D1, the narrow diameter cylindrical portion 2 slides while being plastically deformed into a rectangular cylindrical shape by the expanding ribs 7, 7, . . . . The energy consumption associated with this diameter-expanding plastic deformation contributes to the absorption of displacement energy and acts as an energy absorber. Since the plastic deformation occurs continuously up to the end of the outer tube 1, it provides a smooth impact energy absorbing effect. demonstrate.

Further, in the above configuration, since the expansion member 6 is screwed to the end of the inner tube 5 via the screw structure 12, the attachment length between the expansion member 6 and the end fitting 10 can be finely adjusted. I can do it.

Next, FIG. 6 shows a compressive force absorbing type impact energy absorbing member, and a structure different from the tension absorbing type described above will be explained.

The expanded diameter portion 3 of the outer tube 1 is connected to the narrow diameter cylindrical portion 2.
A guide member 13 is screwed to the outer end of the guide member 13 using a screw structure 14, and an inner tube 5 is slidably inserted into the shaft hole 15 of the guide member 13. An expansion member 6 is screwed onto the inner end of the inner tube 5 in a direction opposite to that of the above embodiment, and the maximum dimension (L1) of the expansion member 6 is as follows:
It is configured to have a size that is sufficiently larger than the inner diameter D1 of the narrow diameter cylindrical portion 2 of the outer tube 1 and can be accommodated in the inner diameter D2 of the expanded diameter portion 3. Further, the inner tube 5 is temporarily fixed to the guide member 13 fixed to the outer tube 1 through one or more connecting rivets 8, and each rivet 8
The guide member 13 supports the normal axial compressive force by the sum of the allowable shear stress of The structure is such that it is formed at a sufficient distance from the support part to prevent buckling during shock absorption.

Since the impact energy absorbing member having the above structure is a compressive force absorbing type, the both end fittings 9 and 10 are used as compressive support members for the portions receiving the impact load, and similarly to the tensile force absorbing type described above. When the expansion member 6 moves from the enlarged diameter section 3 to the narrow diameter cylindrical section 2, the energy consumption accompanying the plastic deformation of the narrow diameter cylindrical section 2 to expand its diameter acts to absorb impact energy.

In the above embodiment, the expansion member 6 has a substantially cross-shaped cross-sectional shape in the direction transverse to the axis, but the cross-sectional shape of this portion may be circular, square, triangular, star-shaped, etc. It can be configured into a truncated pyramid shape.

[Effect of idea]

Since the impact energy absorbing member according to the present invention is configured as described above, it has a structure that absorbs and converts impact energy by the energy consumed when the rivet shearing and expanding member plastically deforms the outer tube to expand its diameter. Therefore, it exhibits a continuous and smooth impact energy absorption effect, and can be easily constructed by, for example, drawing processing, so there is little variation in energy absorption power due to the processing precision of the product, and it can be provided at a low cost. can do.

In addition, since the expansion member is screwed onto the end of the inner tube via a screw structure, the installation length between the expansion member and the end fitting fixed to the outer end of the inner tube is small. The practical effects such as being able to make adjustments are extremely large.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front cross-sectional view showing an embodiment of the tension-absorbing impact energy absorbing member according to the present invention, FIG. 2 is a cross-sectional view taken along the line -- in FIG. 1, and FIG. A perspective view, FIG. 4 is an explanatory diagram showing the operating state of the impact-absorbing energy member, FIG. 5 is a cross-sectional view taken along the - line in FIG. 4, and FIG. 6 is a part showing an embodiment of the compression-type impact energy-absorbing member. FIG. 3 is a cutaway front sectional view. 1...Outer tube, 2...Small diameter cylinder part, 3
... Expanded diameter portion, 4... Tapered tube portion, 5... Inner tube, 6... Expansion member, 7... Expansion rib, 8
...Connection rivet, 9,10...End mounting bracket,
13... Guide member.

Claims (1)

[Claims for Utility Model Registration] An inner tube is slidably inserted into a metal outer tube having a swollen portion in part, and a diameter larger than the inner diameter of the outer tube is attached at one end of the inner tube. Screwing and fixing an expansion member of any shape, such as a truncated cone or a truncated pyramid, which has a maximum dimension part and has an expansion rib that protrudes radially in the axial direction and has an approximately cross-shaped shaft cross-section; The expansion member is assembled so as to be inserted into the enlarged diameter portion of the outer tube, and the outer tube and the inner tube are fixed via a rivet having an appropriate shear allowable stress, and the expansion member slides. An impact energy absorbing member characterized in that it is configured to absorb impact force in the axial direction by expanding plastic deformation of an outer tube due to dynamic displacement and shearing of a rivet.