JPH07238518A - Impact absorber-integrated guard cable - Google Patents

Abstract

PURPOSE:To secure the function and safety of a guard cable by inserting semi- post-shaped resin or a rubber foam in a striding manner on the surface of a road and bonding the other end with a post. CONSTITUTION:A hollow semi-cylinder-shaped buffer metal plate 4 is fixed with a post 1 by means of a fixing tool 4a. The buffer metal plate 4 is provided with a function which absorbs collision-induced impact and hence relaxes the impact and has a required impact resistant strength with the post. The buffer metal plate 4 is installed to the side of a shoulder by way of a steel wire rope 2. A synthetic resin elastic member 6, which is to be directly subjected to the impact of a car, is installed to a road side in semi-cylindrical shape and inserted in such a fashion that it may step over the steel wire rope 2 and bonded with the buffer metal plate 4, thereby absorbing the impact to a satisfactory extent. To further enhance impact absorption efficiency, a plurality of reinforcing metal pieces 8 are integrally molded with the synthetic resin foam elastic member 6 and the reinforcing metal pieces 8 are cut from the center of the semi- cylindrical member to its central part so that they may be molded symmetrically or asymmetrically on both sides.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Road shoulders, especially curved guard cables.

[0002]

2. Description of the Related Art Regularly erected metal or concrete struts on a road shoulder and tightening a plurality of steel ropes in the lateral direction, or arranging metal or concrete struts in parallel and fixing metal plate pieces in the lateral direction. It was tied together to make a guard cable.

[0003]

The guard cable installed on the road shoulder, which is made of metal or concrete and is fastened with steel ropes or metal plate pieces, causes a great damage to the vehicle and the guard when the vehicle crashes at high speed. In many cases, the cable itself was damaged, affecting human life. There has been a demand for a guard cable that absorbs a vehicle kinetic energy of 1/2 mv ^{2 at} high speed (m: vehicle mass, v: vehicle speed).

[0004]

Means for Solving the Problems As a result of intensive research to solve the above problems, the present invention has been achieved. The present invention is a guard composed of metal columns and a plurality of steel ropes that are regularly juxtaposed on the road shoulder. In the cable, a metal buffer plate is fixed to the road surface of the pillar, and a synthetic resin foam elastic body made of a semi-cylindrical synthetic resin foam or rubber foam is laid across the steel rope on the road side corresponding to the pillar, and the composite is formed. A semi-cylindrical shock absorber made of resin foam or rubber foam is adhered and fixed to a metal cushion plate.For steel cushions and metal cushion plates that are regularly juxtaposed on the shoulder side of the road with steel ropes and fixed to the columns. On the road side, a semi-cylindrical curved surface of a synthetic resin foam elastic body made of a semi-cylindrical synthetic resin foam or rubber foam is set on the road surface, and a flat plate part of the synthetic resin foam or rubber foam is laid across the steel rope to form a metal. The semi-cylindrical shape is adhered to a shock-absorbing plate A fixing rod (made of mild steel or synthetic resin or synthetic resin elastomer with a high elastic modulus) that penetrates the road shoulder side from the steel rope of synthetic resin rubber is used to prevent falling off, and is a semi-cylindrical composite to improve shock absorption. A shock absorber integrated guard cable in which the surface (outer skin) of a resin elastomer (rubber) is a hard synthetic resin elastomer (rubber) and the inside is a soft synthetic resin foam or a rubber foam.

The present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a guard cable including a conventional metal strut 1 and a plurality of lateral steel ropes 2. 100k on the freeway now
About 4 kinetic energy alone when colliding with a pillar at m / hour
A shock of 0 G or more is transmitted to the driver. Including potential energy, it is about 80 G or more.

FIG. 2 is a side view of the shock absorbing material integrated guard cable of the present invention, and FIGS. 3 and 4 are enlarged sectional views taken along the line AA of FIG. A hollow semi-cylindrical buffer metal plate 4 is fixed to the support column 1 with a fixture 4a. The hollow semi-cylindrical buffer metal plate absorbs and absorbs the impact of collision.
It is necessary to have the strength to withstand the above impacts.

Now, the spring constant of the synthetic resin foamed elastic body 6 (having a synthetic resin foamed body or a rubber foamed body as a synonym of the synthetic resin foamed elastic body) having the cushioning property shown in FIG. 3 is described. It is considered that the intermediate portion containing the plate pieces 8, 8b, 8c absorbs most of the impact. In this case, assuming that the synthetic resin foam elastic body 6 is an infinitely long column of vibration-proof rubber (the correction of the apparent density of the foam will be described later, but the theory is advanced as a non-foam).

[Equation 1] Eap / Gr = 4 + 3.29S ₁ ² Eap = apparent elastic modulus Gr = transverse elastic modulus of rubber material

[Equation 2] Now, a synthetic resin elastic body has a hardness of 90 A (JIS6301KA
Shape) is used, Gr = 52 kg / cm ²

[Equation 3] Eap = {4 + 3.29 (0.66) ² } × 52≈28
2 kg / cm ² The spring constant Kc in this case is

[Equation 4] h ₁ , h ₂ : rubber thickness: 3 cm

[Equation 5] Becomes

The speed Vo at the moment of collision of an automobile is 60k.
Assuming m / hr, Vo = 60 km / hr≈17 m / sec Acceleration α given to the shock absorber by the car (from the relationship between speed and displacement)

[Equation 6] Vo: Initial velocity V: Velocity after t seconds S: Amount of movement of buffer and support column According to the law of conservation of momentum

[Equation 7] W ₁ , W ₂ : weight of two objects (kg) V ₁ , V ₂ : initial velocity of each object U ₁ , U ₂ : velocity of each object t seconds later. Now, W _2: weight of the car 1200kg W _1: the weight of the shock absorber 14kg + support force 30000kg
(It will be the supporting force of the columns and steel ropes)

[Equation 8] U _1, U _2: the _{V 2 = 0 V 1 = 17m} / sec with W _1, speed U ₁ of the W _2, U ₂ = U after the collision.

The speed at which the automobile and the shock absorber / plastic elastic body move

[Equation 9] Is. Acceleration α (acceleration to stop) is

[Equation 10]

[Equation 11]

[Equation 12] So, the resistance of the columns and steel ropes is

[Equation 13]

[Equation 14]

[Equation 15] Is.

The greater the amount of movement of the shock absorber and the pillar until the automobile stops, the smaller the resistance of the pillar becomes.

[Table 1]

[Table 2] It is considered that S can be used up to about 0.0145 (m) = 1.45 cm 2, that is, up to a load of 46200 kg when the deflection amount of the synthetic resin elastic body is 2 cm (between the reinforcing metal plate pieces). However, in the deflection of the synthetic resin elastic body, it is necessary to consider the thickness h ₁ and the thickness h ₂ of the synthetic resin elastic body on the outer circumference and the inner circumference.

The thickness h of the synthetic resin elastic body having a cushioning property
₁ (outer circumference) and thickness h ₂ (inner circumference)

[Table 3] Shown in. Since the deformable amount of the synthetic resin elastic body portion is about 70%, the synthetic resin elastic body layer (3 + 3) c on the outer and inner circumferences
Seen from the SS curve of Graph 3 from m, the load is 300
It becomes 00 kg. Since the amount of deflection of the synthetic resin elastic body (between the reinforcing metal plate pieces) at this time is 1.3 cm, the load 3000
The total amount of deflection at 0 is 4.1 + 1.3 =
It will be 5.4 cm. Therefore, the diameter of the semi-cylindrical synthetic resin elastic body is 5.4 cm × 2≅11.0 cm, and about 11 cm or more is required.

Kinetic energy at the time of car collision and energy absorption amount of synthetic resin elastic body are 1) Kinetic energy at the time of car speed 60 km / hr

[Equation 16]

[Equation 17] = 1.76 × 10 ⁶ kg · cm 2. 2) Maximum energy absorption of synthetic resin elastic body is load 30
Approximately 5,000 kg Tawami 5.4 cm, the spring constant in the case of high-speed collision is about twice that of static data.

[Equation 18] Becomes 3) The vehicle speed and the energy absorption rate of the synthetic resin elastic body are the vehicle speed energy absorption rate 30 km / hr 40.0% 60 km / hr 9.2%.

Actually, the energy absorption rate is almost doubled by the deformation of the synthetic resin foam elastic body 6c and the buffer metal plate 4 after the steel rope 2. In the above theory, the synthetic resin elastic body was discussed as a non-foamed body, but as the foamed body, for example, the non-foamed body has a total deflection of 5.4c under a load of 30,000.
When converted into a cylindrical diameter, 5.4 × 2≈11.m.
0 cm, and when applied to a synthetic resin foam elastic body,
The diameter of the synthetic resin foam elastic body is

11.0 / Synthetic resin foam elastic body apparent density is applied. For example, when the apparent density of the synthetic resin foamed elastic body is 0.5 g / cm ³ , it is 22.0 cm, which is inversely proportional to the apparent density. Desirable apparent density of synthetic resin foam is 0.5
~ 1.0 is desirable. When the amount is 0.5 g / cm ³ or less, the buffering effect is large, but a buffering absorber having a diameter twice or more that of the non-foamed body is required, and it greatly protrudes on the road surface. When the apparent density of the foam becomes 0.01 g / cm ³ , the shock absorber needs to have a diameter 10 times or more that of the non-foam.

When discussing the relationship between the column diameter R and the buffer metal plate buffer distance B, it is desirable that B = 0.5R to 1.5R. If it is 0.5R or less, the cushioning effect is small, and if it is 1.5R or more, the cushioning effect is excellent, but it has a drawback that it takes up space and reduces the traveling width of the road. Further, the installation position of the buffer metal plate 4 is provided on the road shoulder side through the steel rope. The synthetic resin elastic body 6 which receives the impact of the automobile directly is installed in the semi-cylindrical shape on the road side, is inserted and placed so as to straddle the steel rope 2, and is bonded to the buffer metal plate to completely absorb the impact. . The semi-cylindrical synthetic resin elastic body uses a fixing rod in a through hole formed in the road shoulder side of the steel rope in a direction perpendicular to the road surface to prevent falling off.

The synthetic resin foam used in the present invention is preferably polyurethane, polystyrene or rubber. The hardness of the rubber is preferably 35 to 70 ° (JIS K6301 hardness A type). If it is less than 35 °, it is too soft and the impact absorption effect is too short to reach the column, resulting in damage to the body of the synthetic resin foam. When the hardness is 70 ° or more, the time required to reach the column is delayed, but the impact absorption effect is reduced. Synthetic resin foam alone is an irreversible change in the case of a car collision, whereas the reversible change is a reversible change. 8 is integrally molded.

The reinforcing metal plate piece is installed on the steel rope at an angle of 10 ° to 14 ° with respect to the center of the semi-cylindrical synthetic resin foam. Below 10 ° the impact effect is small, and above 14 ° there is no effect as a reinforcing material. In addition, it is possible to freely design whether the reinforcing metal plate piece is divided from the center of the semi-cylindrical part to the center to be formed symmetrically (see FIG. 3) or asymmetrical (see FIG. 4). Is. If it is not divided, the buffering effect will be drastically reduced. The dividing angle at the central portion is preferably 25 ° to 35 °. Below 25 °, there is a reinforcing effect, but the cushioning effect decreases. There is a buffering effect if it is cut at 35 ° or more,
The effect of reinforcement is reduced. The thickness of the reinforcing metal plate piece is 2.8.
mm-3.6 mm is desirable. If it is 2.8 mm or less, it is easily deformed by impact, and if it is 3.6 mm or more, the shock absorbing effect is reduced.

6 and 7 are front views of the reinforcing metal plate piece 8. In order to mold the reinforcing metal plate piece into the semi-cylindrical synthetic resin foam 6, the plurality of stabilizing holes 8a are preliminarily drilled. The stable hole may be drilled at any position, but a position corresponding to the steel rope is desirable. Drilling hole diameter is 2 mm
~ 6 mm is desirable.

The relationship between the diameter R of the column and the radius H of the semi-cylindrical synthetic resin foam is preferably H = 1.5R to 2.5R.
If it is 1.5R or less, the buffer effect is small, and if it is 2.5R or more, the buffer effect is provided, but the occupied area of the road is large, which is not desirable.

FIG. 4 is another example of the AA sectional view of FIG. 2 of the present invention. The reinforcing metal plate pieces are two and three semi-cylindrical synthetic resin foams. Now, when the collision occurs in the direction of the arrow, the reinforcing metal plate pieces 8c and 8d and the reinforcing metal plate piece 8 in the opposite direction.
There is a buffering effect by shifting in the direction between d and 8b.

FIG. 5 is another example of the AA sectional view of FIG. 2 of the present invention. The outer cover of the semi-cylindrical synthetic resin elastic body 6 is a synthetic resin hard elastic body 7, and the inside is a soft synthetic resin foam 6a, which is a shock absorber. Providing the synthetic resin hard elastic body on the outer skin absorbs the intended impact and the soft synthetic resin foam absorbs the collision energy. The hardness of the synthetic resin hard elastic body is preferably 85 to 95 ° (JIS K6301 hardness A type). To obtain hardness, glass fiber, aromatic polyamide fiber, etc. are added to the synthetic resin. The hardness of the soft synthetic resin foam is preferably 35 to 70 °.

FIG. 8 shows the compression load and the compression load displacement of the present invention.
FIG. Diameter of synthetic resin (non-foamed) elastic body is 1
When set to 1.0 cm, non-foam A, apparent density 0.5 g
/ Cm ³B, apparent density 0.25 g / cm³Compression for C
The load curve is shown. Apparent density 0.5g / cm³When
When it is about half of non-foamed elastic body, the compression load displacement is about twice
become. Apparent density is 0.25g / cm³And non-foamed elastic body
When it becomes about 1/4 of that, the compression load displacement becomes about 4 times.
Shows.

[0022]

[Function] A hollow buffer metal plate is fixed to a metal or concrete pillar, a semi-cylindrical synthetic resin foam or a rubber foam is laid across a steel rope on the road surface, and the semi-cylindrical synthetic resin foam or The other end of the rubber foam is adhered to a metal buffer metal plate so that it does not cause human life damage even if the vehicle collides with the guard cable.

[0023]

The pillar, the buffer metal plate, the semi-cylindrical synthetic resin foam or the rubber foam are integrally molded, and the semi-cylindrical synthetic resin foam or the rubber foam has a plurality of reinforcing metal plate pieces. By improving the cushioning effect by collision, the semi-cylindrical synthetic resin foam or rubber foam is prevented from falling off by inserting the fixing rod through the road shoulder side of the steel rope. Maintain performance and safety.

[Brief description of drawings]

FIG. 1 is a perspective view of a conventional guard cable.

FIG. 2 is a side view of the shock absorbing material integrated guard cable of the present invention.

3 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 4 is another AA enlarged cross-sectional view of FIG.

FIG. 5 is a cross-sectional view of a shock absorbing material integrated guard cable having a semi-cylindrical hard synthetic resin elastomer (rubber) elastic body of the present invention and a synthetic resin foam or rubber foam inside.

FIG. 6 is a front view of an outer metal plate piece of the present invention.

FIG. 7 is a front view of the inner metal plate piece of the present invention.

FIG. 8 is a compression load curve of the shock absorber integrated guard cable of the present invention.

[Explanation of symbols]

1 Strut 2 Steel rope 3 Steel rope stopper 4 Buffer metal plate 4a Buffer metal plate fixture 5 Fixing rod 6 Synthetic resin foam elastic body 6a Synthetic resin foam elastic body (inside) 6b Synthetic resin foam elastic body (road side) 6c Synthetic resin foam Elastic body (road shoulder side) 6d Synthetic resin foam elastic body flat plate portion 6e Synthetic resin foam elastic body half curved surface portion 7 Synthetic resin hard elastic body (outer skin) 8 Reinforcing metal plate piece 8a Metal plate piece stabilizing hole 8b Outside metal plate piece 8c Inner metal plate piece 8d Middle metal plate piece B Buffer metal plate Buffer distance E Road G Guard cable H Synthetic resin foam elastic body radius R Strut diameter h ₁ Synthetic resin foam elastic metal sheet space / Outermost h ₂ Between synthetic resin foam elastic metal plate pieces, thickness (middle side) h _{3 Between} synthetic resin foam elastic metal plate pieces, thickness (innermost side)

Claims (4)

[Claims] 1. A guard cable composed of metal columns and a plurality of steel ropes, which are regularly juxtaposed on the shoulders of a road, has a metal buffer plate fixed to the road-facing surface of the columns, and has a semi-cylindrical shape on the road side corresponding to the columns. Impact characterized in that a synthetic resin foam elastic body made of synthetic resin foam or rubber foam is laid across a steel rope, and the synthetic resin foam or rubber foam semi-cylindrical shock absorber is adhesively fixed to a metal buffer plate. Absorber integrated guard cable. 2. A synthetic resin foam made of a synthetic resin foam or a rubber foam which has a semi-columnar shape on the road side with respect to the steel rope and a metal buffer plate which is regularly juxtaposed to the road shoulder side via steel ropes and fixed to the support. The semicircular curved surface of the elastic body is used as the road surface, and the flat plate portion of the synthetic resin foam or rubber foam is attached to the metal buffer plate by straddling the steel rope, and the semicylindrical synthetic resin foam or rubber foam steel rope is attached. 2. The shock absorbing material integrated guard cable according to claim 1, wherein a fixing rod penetrating more toward the road shoulder side prevents the falling off. 3. A semi-cylindrical synthetic resin foam or rubber foam straddling a steel rope, wherein a plurality of metal plate pieces are incorporated in a portion located on the road side. Shock absorber integrated guard cable. 4. A semi-cylindrical synthetic resin foam or rubber foam whose surface (outer skin) is a hard synthetic resin elastomer (rubber) elastic body and whose inside is a soft synthetic resin foam elastic body or rubber foam elastic body. The shock absorbing material integrated guard cable according to claim 1, claim 2 or claim 3.