JPH06307483A - Energy absorber - Google Patents

Abstract

PURPOSE:To provide an energy absorber which has little influence of resistance upon the sealing degree of lead, and can take a countermeasure against the expansion of lead due to temperature change easily and design it precisely with desired characteristics. CONSTITUTION:This energy absorber 1 is provided with a cylinder 4 whose whose ends 2, 3 are closed, a rod 7 which can move relatively to the cylinder 4 and is disposed, passing through both ends 2, 3 of the cylinder 4, and a lead 8 which is extended to the recessed part 6 of the rod 7 and is disposed in the cylinder 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy absorbing device for absorbing vibration energy transmitted to a building due to a natural phenomenon such as earthquake, wind, or artificial crustal movement.

[0002]

2. Description of the Related Art As an energy absorbing device of this type, there is known one disclosed in Japanese Patent Publication No. 58-30470. The energy absorbing device described here is
It is equipped with a cylinder containing lead and a rod having a bulge portion arranged in this cylinder, and due to the plastic resistance of lead generated by the relative movement of the rod with respect to the cylinder, natural phenomena such as earthquakes and winds occur. It absorbs the vibration energy transmitted to the building due to. In the energy absorbing device described in this publication, when the rod moves relative to the cylinder, the lead plastically flows through the annular passage defined by the bulging portion of the rod and the inner peripheral surface of the cylinder. At this time, the cylinder internal pressure determined by the size of the annular passage acts on the one end closed surface of the cylinder and appears as a resistance force against the relative movement of the rod with respect to the cylinder.

[0003]

In the energy absorbing device, as described above, since the cylinder internal pressure is generated, the lead encapsulation degree has a resistance force characteristic (displacement-force history characteristic).
When air or the like is mixed in the cylinder or lead, for example, the displacement-force history characteristic curve does not become a left-right symmetrical rectangle but becomes a left-right asymmetrical distortion, and therefore the displacement-force history characteristic is The amount of energy absorption represented by the area surrounded by the curve becomes small, and the desired characteristics may not be obtained.

Further, since the above-mentioned energy absorbing device causes the plastic flow of lead in the cylinder, the resistance force generated thereby causes the lubrication state between the inner wall of the cylinder and lead and between the rod outer periphery and lead. Therefore, in order to obtain the designed resistance force for a long period of time, it is necessary to constantly maintain the lubrication state between them at a predetermined value.

Further, the resistance force F generated by the energy absorbing device is F = K.S.lnER + M (where K is
Is a constant obtained by an experiment, S is a pressure receiving area of the cylinder in the axial direction with respect to lead, ER is an area ratio that determines an annular passage through which lead flows, M is between the cylinder inner wall and lead, and between the rod outer circumference and lead. The resistance is determined by the frictional force), but as is clear from this equation, the determinants of the resistance are quite complicated, and it is difficult to obtain sufficiently high design accuracy.

On the other hand, since the iron-based material is used for the cylinder in relation to the strength, as a result of the fact that the amount of lead is larger than the thermal expansion of the cylinder, the lead escape means for coping with temperature changes is used as the cylinder. However, this lead escape means causes the same action as the above-mentioned aeration, and is not preferable.

The present invention has been made in view of the above points, and an object thereof is that the resistance characteristic is not so much influenced by the degree of encapsulation of lead, and a measure against expansion of lead due to temperature change is easy. Another object of the present invention is to provide an energy absorbing device which can be designed to have desired characteristics with high accuracy.

[0008]

According to the present invention, the above object is to provide a cylinder whose both ends are closed, and a cylinder which penetrates both ends of the cylinder so as to be movable relative to the cylinder. This is achieved by an energy absorbing device including a rod having a recess formed on the outer peripheral surface of the portion disposed in the cylinder, and lead extending to the recess of the rod and disposed in the cylinder.

Further, according to the present invention, the above object is to provide a cylinder having a recess formed in an inner peripheral surface thereof, a rod arranged in the cylinder so as to be movable relative to the cylinder, and attached to the rod. And a lid member fitted to both ends of the cylinder so as to be movable relative to the cylinder,
It is also achieved by an energy absorbing device with lead extending into the recess and arranged in the cylinder.

The recess in the present invention may be an annular recess extending annularly in a direction orthogonal to the movable direction of the rod, in which case the recess is a vertical side wall orthogonal to the movable direction of the rod. May be defined by, or may be defined by an inclined side wall that obliquely intersects the movable direction of the rod. The width or diameter of the recess may be gradually increased toward the outside, or conversely, the width or diameter may be gradually decreased toward the outside.
Further, the wall defining the recess at the open end of the recess may be tapered and formed smoothly. The recess may be a circular, elliptical or rectangular recess instead of the annular recess as described above, or may be a plurality of annular recesses or a plurality of circular, oval or rectangular recesses, It may be a continuous spiral recess. As a measure against thermal expansion, the inside may be opened to the outside to form a cylinder.

[0011]

In the energy absorbing device of the present invention, when the rod is moved in the axial direction with respect to the cylinder, the lead arranged in the cylinder also extends into the recess, so that the opening surface of the recess is reduced. At, a virtual shear plane for lead is formed, and shear deformation occurs in the lead at this virtual shear plane, and the shear deformation of lead absorbs the energy of the axial movement of the rod. Part of the absorbed energy is immediately released as heat, and the rest is stored in sheared lead and contributes to its recovery and recrystallization. Here, the shear resistance force from lead in the virtual shear plane mainly appears as a resistance force against the axial movement of the rod.

The present invention will be described in more detail below based on the preferred embodiments shown in the drawings. The present invention is not limited to these specific examples.

[0013]

SPECIFIC EXAMPLE In FIG. 1, an energy absorbing device 1 of this example
Are arranged so as to penetrate through both ends 2 and 3 of the cylinder 4 such that the cylinder 4 has both ends 2 and 3 closed and the cylinder 4 is movable relative to the cylinder 4 in the axial direction A. The rod 7 has a recess 6 formed on the outer peripheral surface 5 of the open portion, and the lead 8 extending to the recess 6 of the rod 7 and arranged in the cylinder 4.

The cylinder 4 of this example comprises a cylinder-shaped cylinder body 11 and disc-shaped lids 12 and 13 integrally formed at both ends of the cylinder body 11, and is made of an iron-based material. Has been done. A steel rod 7 slidably penetrating the lid portions 12 and 13 of both ends 2 and 3 of the cylinder 4 is a large diameter portion 15 and 16 and a small diameter portion sandwiched between the large diameter portions 15 and 16. 17 and the small diameter portion 17 forms the recess 6. The recess 6 of this example is formed as an annular recess that extends annularly in the movable direction of the rod 7, that is, in the direction orthogonal to the axial direction A. The lead 8 is densely arranged in the cylinder 4 in this example.

In the energy absorbing device 1 of the present example formed as described above, for example, the cylinder 4 is fixed to the ground and the rod 7 is connected to the structure to operate so as to absorb the vibration energy generated in the structure. To do. That is, when the structure is vibrated due to an earthquake or the like, the rod 7 moves against the cylinder 4.
Is also vibrated in the axial direction A, and when the rod 7 is moved in this way, the lead 8 arranged in the cylinder 4 also extends to the recess 6, so that at the annular opening surface 21 of the recess 6. A virtual shear plane for the lead 8 is formed, shear deformation occurs in the lead 8 in this virtual shear plane, and the shear deformation of the lead 8 absorbs the energy of movement of the rod 7 in the axial direction A, and a part of the absorbed energy. Is immediately released as heat, and the rest is stored in the sheared lead 8 and contributes to its recovery and recrystallization. The shear resistance force from the lead 8 on the virtual shear plane mainly appears as a resistance force against the movement of the rod 7 in the axial direction A.

In the energy absorbing device 1, when the lead 8 is sheared and deformed, a bearing pressure is generated in the recess 6 to cause some plastic flow in the lead 8 in the recess 6, but this plastic flow is a resistance force. As described above, lead 8 does not substantially contribute to the annular opening surface 21.
Is mainly used as a resistance against the movement of the rod 7 in the axial direction A, in other words, the internal pressure of the cylinder 4 that causes the plastic flow of the lead 8 is not mainly used as a resistance. The degree of encapsulation of the lead 8 does not significantly affect the resistance characteristic of the movement of the rod 7 in the axial direction A,
Even if the lead 8 is not tightly sealed and sealed in the cylinder 4, desired characteristics can be obtained. Then, in the energy absorbing device 1, the resistance force F is F = π · d · L · σ (where d
Can be represented by the diameters of the large diameter portions 15 and 16 of the rod 7, L is the width of the recess 6, and σ is the yield load of lead 8. As is clear from this equation, the principle of resistance force generation is Since it is extremely simple, the design accuracy is extremely high. Further, since it is not always necessary to tightly enclose and seal the lead 8 in the cylinder 4, it is possible to easily take measures against temperature changes, especially thermal expansion of the lead 8 at high temperatures, and in addition, simple processing is performed. The recess 6 can be easily formed in the rod 7 only by itself.

By the way, in the above-mentioned example, the recess 6 is defined by the annular vertical side walls 22 and 23 orthogonal to the movable direction of the rod 7 and has a constant width L. However, as shown in FIG. The slanted side wall 3 obliquely crossing the movable direction of 7
1 and 32, the width L may be gradually increased toward the outside, and as shown in FIG. The width L may be defined by 42, and the width L may be gradually reduced toward the outside.
Furthermore, as shown in FIG. 2, the slanted wall 31 is formed at the opening end of the recess 6.
And 32 may be tapered 51 and 52 to form smoothly.

The energy absorbing device 1 as described above can be formed as follows. First, a rod 7 having a recess 6 as shown in FIG. 4 formed by cutting or the like is prepared, and then, as shown in FIG. 5, lead 8 is cast around the rod 7 using the rod 7 as a core. . After the lead 8 is cast, half halves 61 and 62 of the cylinder 4 as shown in FIG. 6 are prepared, which is covered with the lead 8 cast around the rod 7, and finally the half halves 61.
The energy absorbing device 1 can be obtained by integrally forming the cylinder 4 by fastening bolts and 62 by bolting or welding.

Large diameter holes 71 and 7 as shown in FIG.
2 and a small-diameter hole 73 that communicates the large-diameter holes 71 and 72 with each other. Prepared is a cast lead 8, and then a rod member having a screw hole 74 formed at one end as shown in FIG. 75 is inserted into the large diameter hole 71, a rod member 78 having a threaded portion 77 formed on the small diameter portion 76 at one end is inserted into the large diameter hole 72, and the small diameter portion 76 is inserted into the small diameter hole 73 to project from the small diameter hole 73. The threaded portion 77 is screwed into the threaded hole 74, and the rod members 75 and 78 are integrated to form the rod 7, as shown in FIG. 9, and then the halves 61 and 62 of the cylinder 4 are formed. The lead 8 around the rod 7 and finally the halves 61 and 62.
It is also possible to obtain the energy absorbing device 1 by integrally forming the cylinder 4 by bolting or welding.

Further, the lead 8 shown in FIG. 7 is prepared, and then the lead 8 shown in FIG.
A small-diameter rod 83 having screws 81 and 82 formed at two positions on the outer peripheral surface as shown in FIG. 0 is inserted into the large-diameter hole 71, the small-diameter hole 73 and the large-diameter hole 72, and then screwed as shown in FIG. 8
Internal cylinders 86 and 87 having internal threads 84 and 85 respectively screwed into 1 and 82 are formed in the large diameter holes 71 and 72, and screws 81 and 82 and internal threads 84 and 8 are inserted.
5 are screwed together to integrally form the rod 83 and the cylindrical bodies 86 and 87 to form the rod 7, and the cylinder 4 is formed as shown in FIG. 6 or FIG. It is also possible to obtain the absorber 1.

As is clear from the above, the energy absorbing device of the present invention can be manufactured by a very simple method. The method for manufacturing the energy absorbing device of the present invention is not limited to the above.

In the energy absorbing device 1 shown in FIG. 1, the recess 6 is provided in the rod 7, but instead of this, as shown in FIG. 12, the recess 111 is provided in the cylinder 113 to form the energy absorbing device 100. May be. That is, the energy absorbing device 100 shown in FIG.
1 is formed, a rod 114 disposed inside the cylinder 113 so as to be relatively movable in the axial direction A with respect to the cylinder 113, and attached to the rod 114 by screwing through screws 115 and 116. The lid members 119 and 120 are fitted to the inner peripheral surfaces 112 of both ends 117 and 118 of the cylinder 113 so as to be relatively movable in the axial direction A with respect to the cylinder 113, and extend to the recess 111. And a lead 121 arranged in the cylinder 113. In this example, the cylinder 113 includes the collar portions 125 and 12
A pair of cylindrical bodies 127 and 128 with 6 are formed on the collar portion 12.
They are abutted at 5 and 126 and connected to each other by a bolt 129 and a nut 130 to be integrally formed. In the energy absorbing device 100, the rod 1
When 14 is moved in the axial direction A, lids 119 and 120
In addition to the lead 121, the lead 121 is also moved in the axial direction A.
Of the axial direction A relative to the cylinder 113 of
A virtual shear plane for the lead 121 is formed on the annular opening surface 135 of the recess 111, and the lead 1
21 is sheared, and the lead 121 is sheared by the rod 1
The energy of the movement of 14 in the A direction is absorbed, and the shear resistance force from the lead 121 in the virtual shear plane is generated by the rod 1
It mainly appears as a resistance force against the movement of A in the A direction, and therefore the same effect as that of the energy absorbing device 1 can be obtained.

Further, in the above, the rod 7 or the cylinder 11
Although the single recess 6 or 111 is provided on the rod 3, instead of this, a plurality of parallel recesses 6 may be provided on the rod 7 as shown in FIG. 13, for example, and as shown in FIG. The rod 7 may be provided with a plurality of circular recesses 141 separated from each other. The recess 6 and the circular recess 141 shown in FIGS. 13 and 14 may be provided in the cylinder 113, or the various recesses described above may be provided in the rod 7 or the cylinder 113 in combination with each other. Assuming that the depth of the recess is constant, as the width L of the recess increases, the bearing pressure acting on the side wall defining the recess increases, which facilitates the flow of lead in the recess. When a plurality of recesses are provided in, the stable shearing resistance above a certain level can be obtained without increasing the width L of each recess.

[0024]

According to the present invention, the resistance characteristic is not so much influenced by the degree of lead encapsulation, and the thermal expansion of lead due to temperature change can be easily taken, and the desired characteristic can be obtained with high accuracy. It is possible to provide an energy absorbing device that can be designed by

[Brief description of drawings]

FIG. 1 is a sectional view of a preferred embodiment of the present invention.

FIG. 2 is an explanatory view of another example of a recess according to the present invention.

FIG. 3 is an explanatory diagram of still another example of the recess according to the present invention.

FIG. 4 is an explanatory diagram of one method for manufacturing the specific example shown in FIG.

5 is an explanatory view of one method for manufacturing the one specific example shown in FIG. 1. FIG.

FIG. 6 is an explanatory diagram of one method for manufacturing the specific example shown in FIG.

FIG. 7 is an explanatory diagram of another method for manufacturing the specific example shown in FIG. 1.

FIG. 8 is an explanatory view of another method for manufacturing the specific example shown in FIG.

FIG. 9 is an explanatory diagram of another method for manufacturing the specific example shown in FIG. 1.

10 is an explanatory view of still another method of manufacturing the one specific example shown in FIG. 1. FIG.

FIG. 11 is an explanatory view of still another method of manufacturing the specific example shown in FIG. 1.

FIG. 12 is a cross-sectional view of another preferred embodiment of the present invention.

FIG. 13 is an explanatory diagram of another example of the recess according to the present invention.

FIG. 14 is an explanatory diagram of still another example of the recess according to the present invention.

[Explanation of symbols]

 1 Energy Absorbing Device 4 Cylinder 6 Recess 7 Rod 8 Lead

Claims (9)

[Claims] 1. A cylinder whose both ends are closed, and a cylinder which is arranged so as to be movable relative to the cylinder and penetrates both ends of the cylinder, and a recess is formed on an outer peripheral surface of a part arranged in the cylinder. Energy-absorbing device comprising a rod provided with a lead and a lead extending into a recess of the rod and arranged in a cylinder. 2. A cylinder having a recess formed on the inner peripheral surface thereof,
A rod arranged in the cylinder so as to be movable relative to the cylinder, and attached to the rod,
An energy absorbing device comprising: a lid member fitted to both ends of a cylinder so as to be movable relative to the cylinder; and lead extending to a recess and arranged in the cylinder. 3. The energy absorbing device according to claim 1, wherein the recess is an annular recess extending annularly in a direction orthogonal to the movable direction of the rod. 4. The energy absorbing device according to claim 3, wherein the recess is defined by a vertical side wall orthogonal to the movable direction of the rod. 5. The energy absorbing device according to claim 3, wherein the recess is defined by an inclined side wall that obliquely intersects with the movable direction of the rod. 6. The energy absorbing device according to claim 1, wherein the recess has a width or a diameter that gradually increases toward the outside. 7. The energy absorbing device according to claim 1, wherein the recess has a width or a diameter that gradually decreases toward the outside. 8. The wall defining the recess at the open end of the recess is tapered and smoothly formed.
7. The energy absorbing device according to any one of items 7 to 7. 9. The energy absorbing device according to claim 1, wherein a plurality of recesses are provided.