JP2000171344A - Shock testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a piston rod and its screw part by separately constituting the joining part of a colliding body and the piston rod of a hydraulic cylinder for driving this body into a shock absorbing part and a rod connecting part. SOLUTION: The colliding body 1 of this shock testing device applied to a pseudo earthquake test is installed, for example, on the tip of a piston rod 61 for moving in a hydraulic cylinder 62 via piston land 67. The piston land 67 is freely slidably constituted in the shaft direction by fitting a rubber bellows- shaped first shock absorber 68 on an upper surface and a ring circular second shock absorber 71 on an under surface, and these are held to the colliding body 1 via a shock absorbing plate 72 by a flange 63. A shock of colliding body 1 at colliding is absorbed by the shock absorber 68, and the reaction energy is also given and received between the shock absorber 68 and the shock absorber 71. A shock wave to a flange joining bolt 75 is relieved by the shock absorbing plate 72.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact test apparatus for applying an impact force to a specimen to test the strength of the specimen.
In particular, the present invention relates to an impact test device applicable as a pseudo-earthquake test device capable of effectively applying a shocking stress wave similar to a direct earthquake.

[0002]

2. Description of the Related Art Conventionally, a seismic wave has two vibration components, a high-frequency component and a low-frequency vibration component similar to a shock wave. On the other hand, there are two types of earthquakes: oceanic earthquakes caused by the subduction of the oceanic plate, and direct earthquakes that occur directly below the land where active faults exist.In the case of the former oceanic earthquake, the land from the source of the earthquake is far from the land. High frequency components are attenuated and low frequencies are a major problem.

The conventional earthquake countermeasures are modeled on the Great Kanto Earthquake. For example, only earthquake disaster prevention in the Keihin district at an earthquake source caused by the sinking of the Sagami plate is considered. Prior to the Great Hanshin Earthquake, the earthquake was assumed to be an oceanic earthquake caused by the subduction of the oceanic plate, so a slow-period seismic waveform was assumed. The strength test was sufficient.

However, in the case of a direct earthquake such as the Great Hanshin Earthquake, high-frequency components have a large effect, the initial period is short (the period T is almost the same as or smaller than 0.1 s), and the speed is large (the speed υ is (Approximately equal to or greater than 10 cm / s), it is difficult to generate this waveform by a method other than solid collision.

In view of this problem, Japanese Patent Application Laid-Open No. 9-292304 discloses a test apparatus capable of performing a low-frequency vibration test continuously after an impact test. FIG. 3 shows an impact vibration test apparatus for generating an impact vibration similar to a known direct impact earthquake. A triaxial (の, Y, Z) exciter 101 having one end fixed to a foundation 100 via a bearing 102. A connected vibration transmission table 105 is provided, and a hole is formed in the vibration transmission table 105 so that the bearing 1
The impact transmission table 107 is inserted through the reference numeral 06. Reference numeral 111 denotes a hydraulic pressure source that applies vibration such as seismic waves to each of the vibrators 101.

The shock transmission table 107 is horizontally and rotationally constrained with respect to the vibration transmission table 105 via a bearing 106, and is configured to be movable only in the vertical direction.
10 is mounted on the impact transmission table 107. Below the impact transmission table 107, a collision body 109 for applying an impact force in a vertical direction is vertically suspended by a hydraulic cylinder so as to be able to move up at a high speed.

In this prior art, the impact body 1 is restrained except in the vertical direction where an impact force is applied.
09 to the shock transmission table 10
7 after applying a shock force to the specimen 110 through the shock transmission table 107 through the shock transmission table 107, and then continuously vibrating by the vibrator 101 via the shock and transmission tables 105 and 107, and then continuously lowering after the shock test. A frequency vibration test can be performed.

[0008]

Now, a hydraulic cylinder / piston connected to a hydraulic source is used as a launching device for applying an impact force to the collision body. Since the acceleration at the time of impact is about 3000 G, the hydraulic pressure for obtaining such an impact acceleration is extremely large, and the diameter and overall length of the impact body itself are large, about 1 m, and the mass is also large. It is an iron rigid body of about several tons. For this reason, when such a weight-rigid body collides with a shock transmission table or specimen such as metal or concrete at a high speed, a large impact load is applied to the hydraulic piston rod supporting the collision body, and the piston rod is damaged. Leads to.

In particular, as described above, in the present test apparatus, since the acceleration at the time of impact is about 3000 G, a stress of about 70 kgf / mm 2 is generated on the piston rod, and even if the strength of the rod is increased, damage is not caused. is assumed.

As shown in FIG. 4, the piston rod generally has a female thread 112 formed by threading the tip of a rod 118 and a female thread threaded into a flange 114 provided on the lower surface of the collision body 103. After being screwed into the portion 115, it is locked by a lock nut 116. In addition,
117 is a hydraulic cylinder.

An excessive impact load due to the collision is applied to the coupling screw portion, and the collision screw may not be removed due to damage of the coupling screw portion. Further, since the collision body is fixed to the tip of the piston rod by the coupling screw portion, the parallelism between the upper surface of the collision body and the impact transmission table with which the collision body collides may not completely match. In such a case, there may be a case where the entire impact body does not collide with the impact transmission table, but only the corner thereof, and a bolt breakage or an accurate impact test cannot be performed.

In view of the above-mentioned problems, the present invention is directed to an impact test apparatus which requires a high impact force in order to be applied as a pseudo-earthquake test apparatus. Without any damage to the
It is an object of the present invention to provide an accurate and stable high impact force impact test device.

[0013]

According to the first aspect of the present invention,
In order to solve this problem, in an impact test apparatus for applying an impact force due to a collision to a specimen to test the strength of the specimen, an impact body for directly or indirectly biasing the impact force due to the collision to the specimen is provided. And between the piston rod of the hydraulic cylinder that imparts impact kinetic energy to the collision body,
Separately configured into a shock absorbing portion and a rod connecting portion, the shock absorbing portion is configured by interposing a shock buffer such as rubber or elastic resin between the collision body and the piston rod,
On the other hand, the rod connecting portion is characterized in that a flange for supporting the rod slidably in the axial direction is connected to a rear surface of the collision body by bolting.

More preferably, as set forth in claim 2,
The impact absorbing portion is configured by inserting a rod tip through the buffer in a concave portion formed in the rear surface of the collision body, while the rod connecting portion is configured to slide the rod in the axial direction. Is preferably connected to the rear surface of the collision body by bolting via an impact buffer plate such as rubber or elastic resin.

According to the present invention, since the space between the collision body and the piston rod is separated into the shock absorbing part and the rod connecting part, the function of the shock absorbing part and the function of the rod connecting part are respectively effective. And fully eliminate the disadvantages of the prior art shown in FIG.

In the prior art, FIG.
As shown in (1), since the collision body 103 is directly fixed to the tip of the rod 118 via a screw portion, the collision of the collision body 103 becomes impossible due to the damage of the rod 118 due to the collision and the damage of the coupling screw portion. .

On the other hand, according to the present invention, the impact absorbing portion and the rod connecting portion are separated, and the impact absorbing member is interposed between the impacting member and the piston rod as the impact absorbing portion. Even if a high impact load of about 3000 G is applied at the time of a collision, the impact force is absorbed by the buffer, and the rod can be completely prevented from being damaged. In addition, since the impact buffer is interposed in a plane perpendicular to the rod axis, even when the parallelism between the upper surface of the impactor and the impact transmission table does not completely match, the buffer reduces the parallelism. By adjusting, the entire impact body can collide with the shock transmission table at an equal pressure.

By changing the material, thickness, etc. of the shock buffer, it is possible to form an arbitrary shock waveform in which the high-frequency component of the shock waveform is dulled, and to adjust the operation time of the impact force to be applied to the specimen. It is possible to arbitrarily generate high-frequency waveforms (shock waveforms) and action times corresponding to the various earthquake waveforms described above, and effectively and accurately apply a shock wave similar to a direct earthquake. It is also possible to do.

In the rod connecting portion, since the collision body supports the rod via a flange so as to be slidable in the axial direction, even if the collision body receives a high impact force. The rod is prevented from being broken without being directly transmitted to the rod.

The flange is connected to the rear surface of the collision body by a flange connecting bolt. At this time, the flange is connected between the flange and the rear surface of the collision body via an impact buffer plate, whereby the upper surface of the collision body is connected. In the case where the parallelism between the impact transmission tables colliding with the colliding body does not completely coincide with each other, the parallelism is adjusted so that the entire collision body collides with the impact transmission table without colliding only at its corners. And
As a result, an accurate impact test can be performed without causing breakage of the flange connection bolt.

Further, by connecting the flange to the rear surface of the impact body via an impact buffer plate, the shock wave generated when the impact body collides is not directly applied to the flange connecting bolt. Breakage of the flange connection bolt can be eliminated.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

FIG. 2 shows an impact / vibration test apparatus applied to the present invention, in which a specimen 3 made of concrete is sandwiched between iron blocks 30 and 30 vertically to obtain a shock wave by reflection. After being set on the transmission table 2, a launching device 6 composed of a hydraulic cylinder for colliding the collision body 1 from below the impact transmission table 2 is provided, and the impact transmission table 2 is mounted on the vibration transmission table 7 having a hole 7 a in the center. It is mounted on.

On the other hand, the fixed bolt shaft 10 penetrates from the shock transmission table 2 to the vibration transmission table 7, the fixed cylinder 9 (hollow type) and the connecting ring 13, and has a fixed nut 2a at the upper end and a fixed nut 2b at the lower end. The screw is screwed to the lower surface of the connection ring 13 to be integrated.

The double-effect shock absorber 8 is
The upper end is on the vibration transmission table 7 and the lower end is the connecting ring 1
3 is screwed.

According to such a configuration, the shock transmission table 2 and the vibration transmission table 7 are fixedly held by the extension operation of the fixed cylinder 9, and conversely, the shock transmission table 2 and the vibration transmission table 7 are fixed by the contraction operation of the fixed cylinder 9. Is released from pinching fixation.

Thus, when the impact transmission table 2 is impacted by the collision body 1 and jumps or falls freely with the fixed cylinder 9 contracted, the connecting ring 13 moves in the same way, and the vibration transmitting table 7 and the connecting ring 13
Is mounted so as to act in both directions opposite to the direction of urging the impact force. The fluid pressure of the shock absorber 8 is adjusted only at the initial position of the piston stroke where the shock absorber 8 receives the cylinder operating oil pressure and moves so as not to generate a high pressure on the piston pressure receiving surface side.

Next, the launching device 6 of the collision body 1 is shown in FIG.
It will be described based on. FIG. 1 is an overall sectional view of the hydraulic firing device 6, in which a hydraulic cylinder 62 erected vertically from a cylinder mounting base 60 and a piston rod 61 are fitted in the hydraulic cylinder 62 so as to be able to expand and contract in the vertical direction. The hydraulic pressure supplied to the bottom of the hydraulic cylinder 62 is switched between high pressure and low pressure oil, so that the piston rod 61 is configured to be able to expand and contract. At the tip of the piston rod 61, the impact body 1 is inserted via a piston land 67 and a first impact buffer 68.
Is installed.

Hereinafter, the mounting structure will be described in detail. The impact body 1 has a rear surface (lower surface) having a central portion cylindrically recessed on the axis, a sleeve 66 fitted into the inner peripheral surface of the cylindrical recess 64, and a piston land attached to the tip of the piston rod 61. 67 is slidable in the axial direction. A rubber bellows-shaped first impact buffer 68 is fitted on the upper surface of the piston land 67, and a ring-shaped second impact buffer 71 is fitted on the lower surface.

Further, a flange 63 is provided on the lower surface of the collision body 1 via a donut plate-shaped shock absorbing plate 72 so that these functional products inserted in the cylindrical concave portion 64 do not jump out of the collision body 1. They are connected by flange connection bolts 75.

As shown in FIG. 1B, twelve flange connecting bolts 75 are provided, and the shock absorbing plate 72 is provided with twelve mounting holes 72a for mounting the flange connecting bolts 75.

According to this embodiment, the flange 63 is connected to the lower surface of the collision body 1 by the flange connecting bolt 75 via the shock absorbing plate 72, but the piston rod 61
Are slidably penetrated. Therefore, the piston rod 61 responds to the impact when the collision body 1 collides.
Is absorbed by the first shock buffer 68, and the energy due to the reaction is also transferred to and from the second shock buffer 71. Thus, the piston rod 6
No. 1 is prevented from being damaged without receiving a large impact load.

The flange 63 and the flange connecting bolt 75 also reduce the shock wave propagation by the shock absorbing plate 72 against the shock when the collision body 1 collides, thereby preventing breakage.

Then, the piston rod 61, the collision body 1,
Since the first impact buffer 68, the second impact buffer 71, and the impact buffer plate 72 are interposed between the respective connections of the flanges 63, the impact between the upper surface of the impact body 1 and the impact body 1 collides. Even when the parallelism between the transmission tables 2 does not completely match, the parallelism is adjusted so that the entire impact body 1 collides with the impact transmission table 2 without colliding only at its corners,
As a result, an accurate impact test can be performed without any bolt breakage.

[0035]

According to the first aspect of the present invention, it is possible to effectively prevent the piston rod from being damaged,
According to the second aspect of the present invention, it is possible to effectively prevent a bolt from being damaged due to the impact and reaction of a collision body, and particularly to an impact test apparatus which requires a high impact force to be applied as a pseudo-earthquake test apparatus. An accurate and stable high impact force impact test apparatus can be provided without causing damage to a piston rod for lifting and supporting the collision body 1 and damage to a thread portion thereof.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a hydraulic firing device of an impact vibration test device according to an embodiment of the present invention, in which (A) is an overall cross-sectional view, and (B) is a cross-sectional view along AA of (A).

FIG. 2 is an impact vibration test apparatus applied to the present invention.

FIG. 3 is an impact vibration test apparatus that generates impact vibration similar to a direct impact earthquake.

FIG. 4 is a hydraulic firing device according to the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impactor 3 Specimen 6 Launcher 60 Cylinder mounting base 61 Piston rod 62 Hydraulic cylinder 63 Flange 64 Cylindrical recess 66 Sleeve 67 Piston land 68 First impact buffer 71 Second impact buffer 72 Impact buffer plate 75 Flange connection bolt

Continued on the front page (72) Inventor Go Kato 1200, Higashi-Tanaka, Komaki City, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Nagoya Guidance and Propulsion System Works (72) Inventor Kazuo Asada 2-1-1 Shinama, Araimachi Takasago-shi, Hyogo Mitsubishi Heavy Industries Co., Ltd. Takasago Research Laboratory

Claims (2)

[Claims] An impact test apparatus for testing the strength of a test piece by applying an impact force from a collision to the test piece, comprising: an impact body for directly or indirectly applying an impact force from a collision to the test piece; The space between the piston rod of the hydraulic cylinder that imparts impact kinetic energy to the collision body is configured to be separated into a shock absorption section and a rod connection section, and the shock absorption section is provided between the collision body and the piston rod. The shock absorber such as rubber or elastic resin is interposed, and the rod connecting part is connected to the rear surface of the collision body by bolting a flange for supporting the rod slidably in the axial direction. An impact test apparatus characterized by the following. 2. The shock absorbing portion is configured by inserting a rod tip through a buffer in a concave portion formed in a rear surface of the collision body, and the rod connecting portion is configured to connect the rod to a shaft. 2. The impact test apparatus according to claim 1, wherein a flange slidably supported in the direction is connected to a rear surface of the collision body by bolting via an impact buffer plate made of rubber or elastic resin.