JP7650744B2 - Protective fence - Google Patents

Description

The present invention relates to a protective fence.

Conventionally, there is known a guardrail that is installed at a location adjacent to a road on which vehicles travel and that catches a vehicle if the vehicle deviates from the road. For example, an example of such a guardrail is disclosed in Patent Document 1 below.

The protective fence disclosed in the following Patent Document 1 is a movable protective fence that is configured to be movable from its installation location. This movable protective fence includes multiple movable side members, a beam, a fixed pipe, and multiple connecting members.

The multiple movable side members are each configured to be movable on a road from their installation location. Each movable side member has a cylindrical support that extends in the vertical direction. The beam extends across the supports of the multiple movable side members and connects them. The fixed pipe is fixed to the ground at the installation location.

The multiple connecting members are housed in the corresponding posts of the multiple movable side members so that they can move up and down. Each connecting member is arranged across the space in the post of the movable side member and the space in the fixed tube, and is movable up and down between a first height position where the connecting member connects the post of the movable side member to the fixed tube, and a second height position where the connecting member is inserted into the space in the post of the movable side member and moves upwardly out of the space in the fixed tube. The protective fence also has a holding portion that holds each connecting member at the second height position.

During normal use of the movable guard fence disclosed in Patent Document 1 below, each connecting member is placed at a first height position at the installation location, and the connecting members connect the support posts of each movable side member to each fixed tube, thereby fixing the movable side member to the installation location. Meanwhile, in an emergency, each connecting member is raised to a second height position and held at the second height position by the holding part, thereby releasing the connection between the support posts of each movable side member and each fixed tube by each connecting member. This makes each movable side member movable, and as a result, the movable guard fence can be moved from the installation location.

Patent No. 6014782

In recent years, there has been a demand for improving the ability of protective fences to absorb vehicle collision energy. In the movable protective fence disclosed in Patent Document 1, for example, by enlarging the inner diameter of the fixed tube, the horizontal movement distance of the connecting member inserted in the space inside the fixed tube and the tilt allowance of the connecting member can be secured, and it is possible to obtain the effect of absorbing collision energy caused by the horizontal movement of the movable protective fence upon impact with the vehicle, and the effect of absorbing collision energy caused by the movable protective fence collapsing by the amount of tilt of the connecting member in the space inside the fixed tube upon impact with the vehicle, and as a result, it is possible to improve the ability of the protective fence to absorb vehicle collision energy.

However, in this case, there is a problem that the stability of the protection fence's absorption performance against the collision energy of the vehicle cannot be ensured. Specifically, when the inner diameter of the fixed pipe is enlarged as described above, the horizontal position of the connecting member in the space inside the fixed pipe is not fixed, and when the connecting member is located closer to the road in the space inside the fixed pipe, the distance that the connecting member and the movable side member move horizontally when a vehicle collides with the protection fence from the road becomes large, resulting in high absorption performance of the protection fence against the collision energy of the vehicle. On the other hand, when the connecting member is located closer to the pipe wall on the side farther from the road in the space inside the fixed pipe, the distance that the connecting member and the movable side member move horizontally when a vehicle collides with the protection fence from the road becomes relatively small, and as a result, the improvement in the protection fence's absorption performance against the collision energy of the vehicle becomes relatively small. In this way, the absorption performance of the protection fence against the collision energy of the vehicle differs depending on the horizontal position of the connecting member in the space inside the fixed pipe, and the stability of the absorption performance of the protection fence cannot be ensured.

The objective of the present invention is to provide a safety fence that exhibits stable and high absorption performance against vehicle collision energy.

The present invention provides a guardrail that is installed at an installation location adjacent to a road on which vehicles travel and that catches a vehicle when the vehicle deviates from the road. The guardrail includes a guardrail body that is installed on the ground at the installation location so as to be movable from the installation location, and a fixing device for fixing the guardrail body at the installation location. The guardrail body has a support pipe that extends in the vertical direction. The fixing device includes a fixing pipe that is embedded in the ground at the installation location in an attitude that extends in the vertical direction, an insertion pipe that is inserted into the space within the support pipe and the space within the fixed pipe so as to span these spaces and connect the support pipe and the fixed pipe, and a positioning part that positions the horizontal position of the insertion pipe in the space within the fixed pipe. The fixed pipe has an inner diameter that can ensure a gap between the outer peripheral surface of the insertion pipe that is inserted into the space within the fixed pipe and the inner peripheral surface of the fixed pipe. The positioning portion is configured to position the horizontal position of the plug pipe at a predetermined position where a gap is formed between the plug pipe anti-road side portion, which is the portion of the outer surface of the plug pipe inserted into the space within the fixed pipe that faces away from the road, and the fixed pipe opposing portion, which is the portion of the inner surface of the fixed pipe that faces the plug pipe anti-road side portion, and is configured to allow the plug pipe to move horizontally to a position where the plug pipe anti-road side portion abuts against the fixed pipe opposing portion due to the collision load of the vehicle when a vehicle collides with the protective fence body from the road.

When a vehicle collides with the guardrail from the road, this guardrail is capable of absorbing the collision energy of the vehicle by tilting and horizontally moving the plug-in pipe and the guardrail body away from the road. Furthermore, the horizontal position of the plug-in pipe inserted into the space inside the fixed pipe is positioned by the positioning part at a predetermined position where a gap is formed between the part of the plug-in pipe facing the road and the part facing the fixed pipe. This ensures that the amount of collision energy absorbed by the horizontal movement of the plug-in pipe and the guardrail body away from the road is constant, allowing the guardrail to exhibit stable and high absorption performance against vehicle collision energy.

Specifically, in this guardrail, the fixed pipe has an inner diameter that allows a gap to be secured between the outer circumferential surface of the plug-in pipe inserted into the space within the fixed pipe and the inner circumferential surface of the fixed pipe, so that the plug-in pipe inserted into the space within the fixed pipe can tilt away from the road. Therefore, when a vehicle collides with the guardrail main body from the road, the plug-in pipe and the guardrail main body can tilt away from the road to absorb the collision energy of the vehicle. In addition, in this protective fence, the horizontal position of the plug-in pipe inserted into the fixed pipe is positioned by the positioning unit at a predetermined position where a gap is formed between the part of the plug-in pipe facing the fixed pipe and the opposing part of the fixed pipe, and the positioning unit is configured to allow the plug-in pipe to move horizontally to a position where the part of the plug-in pipe facing the fixed pipe abuts due to the collision load of the vehicle when a vehicle collides with the protective fence main body from the road.Therefore, when a vehicle collides with the protective fence main body from the road, the plug-in pipe and the protective fence main body move horizontally to the side opposite the road to absorb the vehicle collision energy, and moreover, the distance of horizontal movement of the plug-in pipe and the protective fence main body to the side opposite the road is constant due to the positioning of the plug-in pipe by the positioning unit, so the amount of vehicle collision energy absorbed by the horizontal movement of the plug-in pipe and the protective fence main body can be kept constant. As described above, this guardrail can absorb the collision energy of a vehicle by tilting and horizontally moving the plug-in pipe and the guardrail body away from the road when the vehicle collides with the guardrail body, and can maintain a constant amount of vehicle collision energy absorption by horizontally moving the plug-in pipe and the guardrail body away from the road, providing stable and high absorption performance against vehicle collision energy.

The installation location where the protective fence is to be installed is a median strip located between a first road and a second road, the insertion pipe anti-road side portion includes a first anti-road side portion that faces the opposite side to the first road and a second anti-road side portion that faces the opposite side to the second road, the fixed pipe opposing portion includes a first opposing portion that faces the first anti-road side portion and a second opposing portion that faces the second anti-road side portion, and the positioning portion determines the horizontal position of the insertion pipe such that a gap is formed between the first anti-road side portion of the insertion pipe and the first opposing portion of the fixed pipe, It may be configured to be positioned at a predetermined position where a gap is formed between the second anti-road side portion of the plug-in pipe and the second opposing portion of the fixed pipe, and may be configured to allow the plug-in pipe to move horizontally to a position where the first anti-road side portion abuts against the first opposing portion due to the collision load of the vehicle when a vehicle collides with the protective fence main body from the first road, and to allow the plug-in pipe to move horizontally to a position where the second anti-road side portion abuts against the second opposing portion due to the collision load of the vehicle when a vehicle collides with the protective fence main body from the second road.

This configuration makes it possible to provide a protective fence that can stably and highly absorb the impact energy of both vehicle collisions from the first road and vehicle collisions from the second road in the median strip.

The positioning portion includes a top plate portion having an insertion hole through which the plug pipe is inserted and installed on the upper end of the fixed pipe, which positions the horizontal position of the plug pipe inserted into the insertion hole at the predetermined position, and a movement restriction protrusion that protrudes downward from the top plate portion into the space inside the fixed pipe at a position outside the insertion hole and radially inside the fixed pipe, and restricts the horizontal movement of the top plate portion by abutting against the inner peripheral surface of the fixed pipe. The movement restriction protrusion may have a strength that allows it to deform when it comes into contact with the fixed pipe so as to allow the plug pipe and the top plate portion to move horizontally to the opposite side of the road due to the collision load of the vehicle when the vehicle collides with the guardrail body from the road.

In this case, a positioning section can be specifically configured to position the horizontal position of the plug-in pipe at the specified position, and to allow the plug-in pipe to move horizontally to the opposite side of the road due to the collision load of a vehicle when the vehicle collides with the guardrail body from the road.

The protective fence main body further comprises a road side beam that faces the road and is arranged to extend along the road at a position on the road side relative to the support pipe when the protective fence main body is installed at the installation location, and a non-road side beam that is arranged to extend along the road at a position on the opposite side of the road side beam relative to the support pipe when the protective fence main body is installed at the installation location, and the insertion length of the plug pipe into the space within the fixed pipe, the difference between the inner diameter of the fixed pipe and the outer diameter of the plug pipe, and the distance from the lower end of the non-road side beam to the ground at the installation location are determined based on the forward impact force when a vehicle collides with the protective fence main body from above the road. After the plug-in pipe and the guardrail body move horizontally to a position where the opposite road side portion of the plug-in pipe abuts against the opposite fixed pipe portion, the plug-in pipe and the guardrail body tilt away from the road so that the lower end of the plug-in pipe abuts against the road side portion of the inner circumferential surface of the fixed pipe and the portion of the plug-in pipe that is above the lower end abuts against the upper end of the opposite fixed pipe portion, and then the plug-in pipe is bent and deformed, and the guardrail body further tilts away from the road until the lower end of the opposite road beam contacts the ground at the installation location. It is preferable that the plug-in pipe and the guardrail body are configured to operate in such a way that the plug-in pipe and the guardrail body tilt away from the road.

This configuration allows the insertion pipe and the guardrail body to perform the above-mentioned operation, which can effectively absorb the collision energy of a vehicle when it collides with the guardrail body from the road.

It is preferable that the difference between the inner diameter of the fixed pipe and the outer diameter of the plug pipe is set to be greater than the distance from the bottom end of the beam on the opposite side of the road to the ground at the installation location.

With this configuration, when a vehicle collides with the guardrail body, the lower end of the plug-in pipe abuts against the road side portion of the inner circumferential surface of the fixed pipe, and the portion of the plug-in pipe that is above the lower end abuts against the upper end of the opposing portion of the fixed pipe, causing the plug-in pipe and guardrail body to tilt away from the road, and then the plug-in pipe bends and deforms, causing the guardrail body to tilt further away from the road until the lower end of the non-road side beam comes into contact with the ground at the installation location. This prevents the lower end of the non-road side beam from coming into contact with the ground at the installation location before the plug-in pipe bends and deforms, preventing the bending deformation of the plug-in pipe from fully absorbing the vehicle collision energy.

As described above, the present invention provides a safety fence that exhibits stable and high absorption performance against vehicle collision energy.

FIG. 2 is a front view of a safety fence according to one embodiment of the present invention. FIG. 2 is a top view of a safety fence according to one embodiment of the present invention. 3 is a cross-sectional view of the safety fence shown in FIG. 1 taken along the line III-III in FIG. 1. This is a partial view showing the engagement state between the fixed pipe and positioning portion of the protective fence and the plug-in pipe inserted inside them, with the fixed pipe and positioning portion cut away. This is a cross-sectional view of the fixed tube, positioning portion, and plug-in tube of the protective fence at the VV position in Figure 4. FIG. FIG. FIG. 13 is a diagram for explaining the operation of the safety fence when a vehicle collides against the safety fence, showing the state before the vehicle collides. FIG. FIG. 10 is a diagram for explaining the operation of the safety fence when a vehicle collides against it, showing the state in which the safety fence has been hit by the vehicle and moved horizontally in the direction of the collision from the state shown in FIG. 9 . FIG. 11 is a diagram for explaining the operation of the safety fence when a vehicle collides against the safety fence, showing a state in which the safety fence has tilted from the state shown in FIG. 10 due to the collision load of the vehicle. This figure explains the operation of the protective fence when a vehicle collides against it, and shows the state in which the insertion pipe has been bent and deformed by the vehicle collision load from the state shown in Figure 11, causing the protective fence to tilt further.

The following describes an embodiment of the present invention with reference to the drawings.

The guardrail 1 according to one embodiment of the present invention is installed on the ground of the median strip of a highway or other road so as to extend along the direction of the roads on both sides of the median strip, and is designed to catch vehicles traveling on the roads on both sides if they deviate from the road. In addition, in the event of an emergency, the guardrail main body 2, which is part of the guardrail 1 and will be described later, can be moved from the installation location, and by moving the guardrail main body 2, it is possible to secure space for vehicles to make a U-turn or enter from one of the roads on either side of the median strip to the other.

The protective fence 1 comprises multiple protective fence bodies 2 (see Figure 1), multiple fixing devices 3 (see Figure 1), and multiple connecting members 4 (see Figure 2).

Each of the multiple protective fence bodies 2 extends in a specific longitudinal direction and is arranged so as to follow the road in that longitudinal direction. In this embodiment, the multiple protective fence bodies 2 are arranged side by side along the extension direction of the road on both sides of the median strip, separating one road from the road on the opposite lane. The protective fence body 2 can move on the ground G by the rolling members of the rolling bodies 22 described below rolling on the ground G. The protective fence body 2 comprises multiple bases 6, multiple support pipes 8, a first beam 10, a second beam 12 (see Figure 2), and multiple beam connecting members 13.

The multiple bases 6 are the bases of the protective fence main body 2, and each is configured to be movable on the ground G. In this embodiment, the protective fence main body 2 has two bases 6. Each base 6 has a base plate 20 and multiple rolling elements 22, as shown in FIG. 3.

The base plate 20 is a flat plate arranged approximately horizontally. This base plate 20 has a through hole that passes through the base plate 20 in the vertical direction (thickness direction of the base plate 20).

The multiple rolling elements 22 are configured to be able to roll on the ground G along the ground G, allowing the base 6 to move on the ground G. Each of the multiple rolling elements 22 is attached to the base plate 20. The rolling elements 22 are so-called casters. In this embodiment, each base 6 has four rolling elements 22. The four rolling elements 22 are arranged two on each side of the through hole of the base plate 20. The four rolling elements 22 protrude downward from the base plate 20 and contact the ground G to support the base plate 20 from below.

As shown in FIG. 1, the multiple support pipes 8 are fixed to the multiple bases 6 at multiple positions aligned in the longitudinal direction of the protective fence main body 2 so as to stand upright from each of the multiple bases 6. In this embodiment, the protective fence main body 2 has two support pipes 8. Each support pipe 8 is cylindrical, inserted into a through hole in the base plate 20 of each base 6, penetrating the base plate 20, and fixed to the base plate 20 in a position extending upward from the base plate 20.

As shown in Figures 2 and 3, the first beam 10 and the second beam 12 are arranged on both sides of the multiple support pipes 8 in the width direction of the protective fence main body 2, which is perpendicular to both the longitudinal direction and the height direction of the protective fence main body 2, and are fixed to the multiple support pipes 8 via beam connecting members 13. The first beam 10 and the second beam 12 are located on the outermost sides of the protective fence main body 2 in the width direction. When a vehicle collides with the protective fence main body 2 from the first road, the first beam 10 is an example of a road side beam in this invention, and the second beam 12 is an example of a non-road side beam in this invention. Also, when a vehicle collides with the protective fence main body 2 from the second road, the second beam 12 is an example of a road side beam in this invention, and the first beam 10 is an example of a non-road side beam in this invention.

The first beam 10 faces the first road, which is one of the roads located on both sides of the protective fence 1, and constitutes the surface that receives the collision of a vehicle traveling on this first road if the vehicle deviates from the first road onto the central reservation. As shown in FIG. 3, the first beam 10 consists of a first upper beam 10a and a first lower beam 10b arranged side by side one above the other. The first upper beam 10a is made of a thin plate whose vertical cross section is corrugated, and extends along the longitudinal direction of the protective fence body 2. The first lower beam 10b has the same shape as the first upper beam 10a, and extends below the first upper beam 10a in parallel with the first upper beam 10a.

The second beam 12 faces the second road, which is the road located on the opposite side of the guardrail 1 from the first road, and constitutes the surface that receives the collision of a vehicle traveling on the second road when the vehicle deviates from the second road onto the central reservation. As shown in FIG. 3, the second beam 12 is composed of a second upper beam 12a and a second lower beam 12b arranged vertically. The second upper beam 12a is symmetrical to the first upper beam 10a and extends along the longitudinal direction of the guardrail main body 2. The second lower beam 12b has the same shape as the second upper beam 12a and is symmetrical to the first lower beam 10b, and extends below the second upper beam 12a in parallel with the second upper beam 12a.

2 and 3, the beam connecting members 13 are respectively interposed between the first upper beam 10a and the second upper beam 12a and between the first lower beam 10b and the second lower beam 12b. The beam connecting members 13 interposed between the first upper beam 10a and the second upper beam 12a connect the first upper beam 10a and the second upper beam 12a in the width direction of the protective fence main body 2 and connect the first upper beam 10a and the second upper beam 12a to the support pipe 8. The beam connecting members 13 interposed between the first lower beam 10b and the second lower beam 12b connect the first lower beam 10b and the second lower beam 12b in the width direction of the protective fence main body 2 and connect the first lower beam 10b and the second lower beam 12b to the support pipe 8. Therefore, the first upper beam 10a and the second upper beam 12a are connected to the support pipe 8 via a beam connecting member 13 that connects them. Also, the first lower beam 10b and the second lower beam 12b are connected to the support pipe 8 via a beam connecting member 13 that connects them.

The multiple fixing devices 3 (see FIG. 1) are for fixing each protective fence main body 2 at its installation position when the protective fence main body 2 is placed at the installation position. The fixing devices 3 are configured to be switchable between a fixed state in which the protective fence main body 2 is fixed to the ground G at its installation position, and an unlocked state in which the lock is released and the protective fence main body 2 is allowed to move on the ground G. Specifically, in the fixed state, the fixing devices 3 fix the corresponding base 6 of the protective fence main body 2 to the ground G at its installation position, and in the unlocked state, the lock is released from the corresponding base 6 and the base 6 is allowed to move on the ground G.

The multiple fixing devices 3 are installed at the installation location of the protective fence 1 (the median strip in this embodiment) so as to be lined up at intervals along the extension direction of the first and second roads. Each fixing device 3 has a fixing pipe 30, an insertion pipe 32, and a positioning part 42.

The fixed pipe 30 is buried and fixed under the ground G at the installation location of the protective fence 1. The fixed pipe 30 is hollow and cylindrical, and is buried in the ground in an up-down orientation to secure a space inside to receive the plug-in pipe 32. The fixed pipe 30 is positioned so that the position of its upper end coincides with the position of the ground G. The upper end of the fixed pipe 30 is open. The inner surface of the fixed pipe 30 has a first opposing portion 30a, which is a portion facing the first anti-road portion 32d of the plug-in pipe 32 inserted into the space inside the fixed pipe 30 as described below, and a second opposing portion 30b, which is a portion facing the second anti-road portion 32e of the plug-in pipe 32. The first opposing portion 30a and the second opposing portion 30b are examples of fixed pipe opposing portions in the present invention.

As shown in Figures 1 and 3, when the fixing device 3 is in the fixed state, the plug-in pipe 32 is inserted into the space within the support pipe 8 and the space within the fixed pipe 30 so as to span these spaces, interconnecting the support pipe 8 and the fixed pipe 30, thereby fixing the support pipe 8 and the protective fence body 2 having it to the installation location. When the fixing device 3 is in the released state, the plug-in pipe 32 is pulled upward from the space within the fixed pipe 30 and the space within the support pipe 8, releasing the base 6 from its fixation to the ground G and allowing the base 6 to move on the ground G.

The insertion tube 32 has a cylindrical insertion tube body 32a that is inserted into the space in the support tube 8 and the space in the fixed tube 30, a flange 32b attached to the upper end of the insertion tube body 32a so as to protrude radially outward from the upper end of the insertion tube body 32a, and a handle 32c attached to the upper end of the insertion tube body 32a. The flange 32b has an outer diameter larger than the outer diameter of the support tube 8, and abuts against the upper end of the support tube 8 in the fixed state, thereby holding the insertion tube 32 at a height position (see Figure 3) where the insertion tube 32 connects the support tube 8 and the fixed tube 30 to each other. The handle 32c is the part that is held by the worker when inserting and removing the insertion tube 32 into and from the space in the support tube 8 and the space in the fixed tube 30.

The plug-in pipe body 32a has a first anti-road side portion 32d, which is a portion of the outer surface of the plug-in pipe body 32a facing away from the first road, and a second anti-road side portion 32e, which is a portion of the outer surface of the plug-in pipe body 32a facing away from the second road. The first anti-road side portion 32d and the second anti-road side portion 32e are examples of anti-road side portions in the present invention.

The positioning unit 42 (see FIG. 4) is attached to the upper end of the fixed tube 30 and positions the horizontal position of the plug-in tube 32 inserted into the space inside the fixed tube 30. Specifically, the positioning unit 42 is configured to position the horizontal position of the plug-in tube 32 at a predetermined position where a gap is formed between the first anti-road side portion 32d and the first opposing portion 30a of the fixed tube 30 and a gap is formed between the second anti-road side portion 32e and the second opposing portion 30b of the fixed tube 30. More specifically, the positioning unit 42 positions the horizontal position of the plug-in tube 32 at a predetermined position where a gap is formed between the outer peripheral surface of the plug-in tube 32 and the inner peripheral surface of the fixed tube 30 over the entire circumferential direction. That is, the positioning unit 42 positions the horizontal position of the insertion pipe 32 in the space inside the fixed pipe 30 in the direction perpendicular to the extension direction of the first and second roads, and the horizontal position of the insertion pipe 32 in the space inside the fixed pipe 30 in the direction along the extension direction of the first and second roads. The positioning unit 42 is also configured to allow the insertion pipe 32 to move horizontally to a position where the first anti-road side portion 32d of the insertion pipe 32 abuts against the first opposing portion 30a of the fixed pipe 30 due to the collision load of the vehicle when a vehicle collides with the protective fence main body 2 from the first road, and to allow the insertion pipe 32 to move horizontally to a position where the second anti-road side portion 32e of the insertion pipe 32 abuts against the second opposing portion 30b of the fixed pipe 30 due to the collision load of the vehicle when a vehicle collides with the protective fence main body 2 from the second road.

The positioning portion 42 has a top plate portion 44, an extension portion 46, and multiple movement restriction protrusions 48.

The top plate portion 44 is installed on the upper end of the fixed pipe 30. This top plate portion 44 has an insertion hole 44a through which the insertion pipe 32 is inserted. This insertion hole 44a is a round hole with a diameter slightly larger than the outer diameter of the insertion pipe 32, and penetrates the top plate portion 44 in the vertical direction. When the top plate portion 44 is installed on the upper end of the fixed pipe 30, the insertion hole 44a is arranged so that its center is located on the axis of the fixed pipe 30. The top plate portion 44 positions the horizontal position of the insertion pipe 32 inserted into the insertion hole 44a at the predetermined position. In addition, the top plate portion 44 covers the gap between the inner edge of the upper end of the fixed pipe 30 and the outer circumferential surface of the insertion pipe 32, and also has the function of suppressing the falling of foreign objects such as gravel and garbage into the space inside the fixed pipe 30 through the gap.

The extension portion 46 is a cylindrical portion that extends downward from the edge of the insertion hole 44a of the top plate portion 44 into the space inside the fixed tube 30. The extension portion 46 is positioned so that its axis coincides with the axis of the fixed tube 30. The extension portion 46 has an inner diameter slightly larger than the outer diameter of the insertion tube 32, and the insertion tube 32 is inserted into its inside. In other words, the insertion tube 32 is inserted into the space inside the fixed tube 30 through the insertion hole 44a of the top plate portion 44 and the inside of the extension portion 46.

The multiple movement restriction protrusions 48 each protrude downward from the top plate portion 44 into the space inside the fixed tube 30 at a position outside the insertion hole 44a and radially inside the fixed tube 30. The multiple movement restriction protrusions 48 restrict the horizontal movement of the top plate portion 44 by abutting against the inner peripheral surface of the fixed tube 30. As shown in Figures 5 and 6, the multiple movement restriction protrusions 48 are arranged at equal intervals in the circumferential direction of the insertion hole 44a and the extension portion 46, i.e., in the circumferential direction of the fixed tube 30. In this embodiment, each movement restriction protrusion 48 is made of a rivet driven into the top plate portion 44.

The movement restriction protrusions 48 have a strength that allows the insertion pipe 32 and the top plate 44 to move horizontally to the opposite side of the first road due to the collision load of the vehicle when the vehicle collides with the guardrail body 2 from the first road, and has the strength to deform when it hits the fixed pipe 30 so as to allow the insertion pipe 32 and the top plate 44 to move horizontally to the opposite side of the second road due to the collision load of the vehicle when the vehicle collides with the guardrail body 2 from the second road. In other words, each movement restriction protrusion 48 is capable of being crushed when it hits the fixed pipe 30 due to the collision load of the vehicle, and by being crushed in this manner, the insertion pipe 32 and the top plate 44 are allowed to move horizontally to the opposite side of the first and second roads.

9 and 10, in this embodiment, the insertion length L of the plug-in pipe 32 into the space within the fixed pipe 30, the difference 2x between the inner diameter of the fixed pipe 30 and the outer diameter of the plug-in pipe 32, and the distance y from the lower end of the first lower beam 10b to the ground G are determined based on the following relationship: when a vehicle collides with the protective fence main body 2 from above the first road, the plug-in pipe 32 and the protective fence main body 2 move horizontally to a position where the first anti-road side portion 32d of the plug-in pipe 32 abuts against the first opposing portion 30a of the fixed pipe 30, and then the lower end of the plug-in pipe 32 is located on the first road side of the inner surface of the fixed pipe 30. The plug-in pipe 32 and the guard fence body 2 tilt away from the first road so that the part above the lower end of the plug-in pipe 32 abuts against the upper end (support part A) of the first opposing part 30a of the fixed pipe 30, and then the plug-in pipe 32 bends and deforms at the position where it abuts against the upper end (support part A) of the first opposing part 30a of the fixed pipe 30, causing the guard fence body 2 to tilt further away from the first road until the lower end of the second lower beam 12b contacts the ground G.

In addition, the insertion length L of the plug pipe 32 into the space within the fixed pipe 30, the difference 2x between the inner diameter of the fixed pipe 30 and the outer diameter of the plug pipe 32, and the distance y from the lower end of the second lower beam 12b to the ground G are determined based on the following relationship: when a vehicle collides with the protective fence main body 2 from above the second road, the plug pipe 32 and the protective fence main body 2 move horizontally to a position where the second anti-road side portion 32e of the plug pipe 32 abuts against the second opposing portion 30b of the fixed pipe 30, and then the lower end of the plug pipe 32 abuts against the second road side portion of the inner surface of the fixed pipe 30. The plug-in pipe 32 and the guard fence body 2 tilt away from the second road so that the portion of the plug-in pipe 32 that is above the lower end of the plug-in pipe 32 abuts against the upper end of the second opposing portion 30b of the fixed pipe 30, and then the plug-in pipe 32 bends and deforms at the position where it abuts against the upper end of the second opposing portion 30b of the fixed pipe 30, causing the guard fence body 2 to tilt further away from the second road until the lower end of the first lower beam 10b contacts the ground G.

In addition, the distance from the lower ends of the first and second lower beams 10b, 12b to the ground G is set to be greater than the difference 2x between the inner diameter of the fixed pipe 30 and the outer diameter of the insertion pipe 32.

The multiple connection members 4 are each a member that connects adjacent ends of adjacent protective fence bodies 2. Each connection member 4 is detachable from the end of the protective fence body 2 in the extension direction, and is attached to adjacent ends of adjacent protective fence bodies 2 when multiple protective fence bodies 2 are installed side by side at the installation location, thereby connecting those ends.

Next, we will explain the operation of this embodiment when a vehicle collides with the safety fence 1 and the safety fence 1 absorbs the collision energy of the vehicle.

First, before a vehicle collides with the safety fence 1, as shown in FIG. 9, the insertion pipe 32 is inserted into the space inside the support pipe 8 of the safety fence main body 2, and is positioned coaxially with the fixed pipe 30 by the positioning part 42. In other words, a uniform gap x is formed between the outer circumferential surface of the insertion pipe 32 and the inner circumferential surface of the fixed pipe 30 around the entire circumference of the outer circumferential surface and the inner circumferential surface.

Then, the vehicle collides with the protective fence body 2 of the protective fence 1. At this time, for example, a vehicle traveling on the first road deviates from the first road toward the center divider and collides with the protective fence body 2. At this time, the protective fence body 2 receives the collision load P of the vehicle, and the protective fence body 2 and the plug-in pipe 32 move horizontally to the opposite side of the first road as shown in FIG. 10. Specifically, the plug-in pipe 32 and the protective fence body 2 move horizontally to the opposite side of the first road (the second road side) until the first opposite side portion 32d of the plug-in pipe 32 inserted into the space inside the fixed pipe 30 abuts against the first opposite portion 30a of the fixed pipe 30. At this time, among the multiple movement restriction protrusions 48 (see FIG. 7 and FIG. 8) of the positioning portion 42, the one located on the far side from the first road hits the pipe wall at the upper end of the fixed pipe 30 and is crushed by the collision load P, so that the horizontal movement of the plug-in pipe 32 positioned by the positioning portion 42 to the opposite side of the first road is permitted. A portion of the vehicle collision energy is absorbed by the resistance force generated when the movement-restricting protrusion 48 is crushed and the horizontal movement of the protective fence body 2, which is a heavy object.

Then, after the insertion pipe 32 and the protective fence main body 2 have moved horizontally as described above, as shown in Fig. 11, the insertion pipe 32 tilts away from the first road, with support part A, which is the upper end of the first opposing part 30a of the fixed pipe 30, as a fulcrum, until the lower end of the insertion pipe 32 hits the part of the inner circumferential surface of the fixed pipe 30 on the first road side (the second opposing part 30b), and the protective fence main body 2 tilts away from the first road. At this time, the inclination angle _θ1 of the insertion pipe 32 and the protective fence main body 2 with respect to the embedding direction of the fixed pipe 30 into the ground (the axial direction of the fixed pipe 30) is about 5°. This tilting of the insertion pipe 32 and the protective fence main body 2 absorbs a further part of the vehicle collision energy.

After the insertion pipe 32 and the protective fence main body 2 have tilted in this way, the collision load P causes the protective fence main body 2 to further tilt away from the first road, while bending and deforming the insertion pipe 32 so as to bend at the position where it hits the support part A, as shown in Fig. 12. At this time, the protective fence main body 2 tilts until the lower end of the second lower beam 12b contacts the ground G. When the protective fence main body 2 has tilted in this way until the lower end of the second lower beam 12b contacts the ground G, the inclination angle _θ2 of the protective fence main body 2 with respect to the embedding direction of the fixed pipe 30 into the ground (the axial direction of the fixed pipe 30) is approximately 8°. This tilting of the protective fence main body 2 and the bending deformation of the insertion pipe 32 further absorb a part of the vehicle collision energy.

By performing the above operations, the protective fence 1 of this embodiment absorbs the collision energy of the vehicle. Furthermore, if a vehicle collides with the protective fence main body 2 from the second road, the above operations are performed in the same manner, but with the first road side replaced by the second road side, and the collision energy caused by the vehicle colliding from the second road is similarly absorbed.

In the protective fence 1 of this embodiment, when a vehicle collides with the protective fence main body 2 from the first road, the collision energy of the vehicle can be absorbed by the tilting and horizontal movement of the plug-in pipe 32 and the protective fence main body 2 to the opposite side of the first road, and when a vehicle collides with the protective fence main body 2 from the second road, the collision energy of the vehicle can be absorbed by the tilting and horizontal movement of the plug-in pipe 32 and the protective fence main body 2 to the opposite side of the second road. Moreover, in this guardrail 1, the horizontal position of the plug-in pipe 32 inserted into the space inside the fixed pipe 30 is determined by the positioning unit 42 at a predetermined position where a gap is formed between the first anti-road portion 32d of the plug-in pipe 32 and the first opposing portion 30a of the fixed pipe 30, and a gap is formed between the second anti-road portion 32e of the plug-in pipe 32 and the second opposing portion 30b of the fixed pipe 30. This ensures that the amount of collision energy absorbed by the horizontal movement of the plug-in pipe 32 and the guardrail main body 2 toward the opposite side of the first road is constant, and that the amount of collision energy absorbed by the horizontal movement of the plug-in pipe 32 and the guardrail main body 2 toward the opposite side of the second road is constant. This allows the guardrail 1 to stably exhibit high absorption performance against vehicle collision energy.

Specifically, in the protective fence 1 according to this embodiment, the fixed pipe 30 has an inner diameter that allows a gap to be secured between the outer circumferential surface of the plug-in pipe 32 inserted into the space within the fixed pipe 30 and the inner circumferential surface of the fixed pipe 30, so that the plug-in pipe 32 inserted into the space within the fixed pipe 30 can tilt toward the opposite side of the first road or the opposite side of the second road. Therefore, when a vehicle collides with the protective fence main body 2 from the first road, the plug-in pipe 32 and the protective fence main body 2 can tilt toward the opposite side of the first road to absorb the collision energy of the vehicle, and when a vehicle collides with the protective fence main body 2 from the second road, the plug-in pipe 32 and the protective fence main body 2 can tilt toward the opposite side of the second road to absorb the collision energy of the vehicle.

In addition, in this protective fence 1, the horizontal position of the plug-in pipe 32 inserted into the fixed pipe 30 is determined by the positioning unit 42 at a predetermined position where a gap is formed between the first anti-road side portion 32d of the plug-in pipe 32 and the first opposing portion 30a of the fixed pipe 30, and where a gap is formed between the second anti-road side portion 32e of the plug-in pipe 32 and the second opposing portion 30b of the fixed pipe 30. The positioning unit 42 is configured to allow the plug-in pipe 32 to move horizontally to a position where the first anti-road side portion 32d abuts against the first opposing portion 30a when a vehicle collides with the protective fence main body 2 from the first road, due to the collision load of the vehicle, and to allow the plug-in pipe 32 to move horizontally to a position where the movement restriction protrusion 48 abuts against the first opposing portion 30a when a vehicle collides with the protective fence main body 2 from the second road, due to the collision load of the vehicle, and to allow the plug-in pipe 32 to move horizontally to a position where the second anti-road side portion 32e abuts against the second opposing portion 30b. Therefore, when a vehicle collides with the guardrail body 2 from the first road, the plug-in pipe 32 and the guardrail body 2 move horizontally to the opposite side of the first road to absorb the collision energy of the vehicle, and when a vehicle collides with the guardrail body 2 from the second road, the plug-in pipe 32 and the guardrail body 2 move horizontally to the opposite side of the second road to absorb the collision energy of the vehicle. Moreover, the distance of the horizontal movement of the plug-in pipe 32 and the guardrail body 2 in these cases is constant due to the positioning of the plug-in pipe 32 by the positioning unit 42, so the amount of vehicle collision energy absorbed by the horizontal movement of the plug-in pipe 32 and the guardrail body 2 can be constant.

As described above, the guardrail 1 according to this embodiment can absorb the collision energy of the vehicle by tilting and horizontally moving the plug-in pipe 32 and the guardrail main body 2 when the vehicle collides with the guardrail main body 2, and can maintain a constant amount of vehicle collision energy absorbed by the horizontal movement of the plug-in pipe 32 and the guardrail main body 2, so it can exhibit stable and high absorption performance against the collision energy of the vehicle. Moreover, the guardrail 1 according to this embodiment can exhibit stable and high absorption performance against the collision energy of the vehicle when it collides with the vehicle from both the first road and the second road on the central median strip.

In addition, in the protective fence 1 according to this embodiment, the insertion length L of the plug-in pipe 32 into the space within the fixed pipe 30, the difference 2x between the inner diameter of the fixed pipe 30 and the outer diameter of the plug-in pipe 32, and the distance y from the lower end of the second lower beam 12b to the ground G at the installation location of the protective fence 1 are such that, when a vehicle collides with the protective fence main body 2 from above the first road, the plug-in pipe 32 and the protective fence main body 2 move horizontally until the first anti-road side portion 32d of the plug-in pipe 32 abuts against the first opposing portion 30a of the fixed pipe 30, and then the lower end of the plug-in pipe 32 abuts against the first road side portion of the inner surface of the fixed pipe 30 (the The insertion pipe 32 and the protective fence main body 2 tilt away from the first road so that the insertion pipe 32 abuts against the upper end (support portion A) of the first opposing portion 30a of the fixed pipe 30 and the portion of the insertion pipe 32 located upward from the lower end abuts against the upper end (support portion A) of the first opposing portion 30a of the fixed pipe 30, and then the insertion pipe 32 bends and deforms at the position where it abuts against the upper end (support portion A) of the first opposing portion 30a, causing the protective fence main body 2 to tilt further away from the first road until the lower end of the second lower beam 12b contacts the ground G. In addition, in the protective fence 1 according to this embodiment, the insertion length L of the plug-in pipe 32 into the space within the fixed pipe 30, the difference 2x between the inner diameter of the fixed pipe 30 and the outer diameter of the plug-in pipe 32, and the distance y from the lower end of the first lower beam 10b to the ground G at the installation location of the protective fence 1 are set so that, when a vehicle collides with the protective fence main body 2 from above the second road, the plug-in pipe 32 and the protective fence main body 2 move horizontally until the second anti-road side portion 32e of the plug-in pipe 32 abuts against the second opposing portion 30b of the fixed pipe 30, and then the lower end of the plug-in pipe 32 is located within the second road area of the inner circumferential surface of the fixed pipe 30. The insertion pipe 32 and the guard fence body 2 tilt away from the second road so that the insertion pipe 32 abuts against the part (first opposing part 30a) on the side of the second road and the part above the lower end of the insertion pipe 32 abuts against the upper end of the second opposing part 30b of the fixed pipe 30, and then the insertion pipe 32 bends and deforms at the position where it abuts against the upper end of the second opposing part 30b, and the guard fence body 2 further tilts away from the second road until the lower end of the first lower beam 10b contacts the ground G. In order to realize such an operation of the insertion pipe 32 and the guard fence body 2, the distance y from the lower ends of the first and second lower beams 10b, 12b to the ground G at the installation location of the guard fence 1 is set to be greater than the difference 2y between the inner diameter of the fixed pipe 30 and the outer diameter of the insertion pipe 32.

When a vehicle collides with the guardrail body 2, the above-described operation of the plug-in pipe 32 and the guardrail body 2 is performed, and the collision energy of the vehicle can be effectively absorbed. Specifically, in conventional guardrails, a gap is not provided between the inner circumferential surface of the fixed pipe and the outer circumferential surface of the plug-in pipe to allow the plug-in pipe to move horizontally and tilt in the space inside the fixed pipe, so that the horizontal movement and tilt of the plug-in pipe and the guardrail body cannot absorb the collision energy of the vehicle when the vehicle collides. However, in the guardrail 1 according to this embodiment, the plug-in pipe 32 and the guardrail body 2 first move horizontally to the opposite side of the road when the vehicle collides, and then the plug-in pipe 32 and the guardrail body 2 tilt to the opposite side of the road to absorb the collision energy of the vehicle. Furthermore, if the plug-in pipe 32 and the protective fence main body 2 tilt away from the road and the lower end of the first lower beam 10b or the lower end of the second lower beam 12b contacts the ground G before the plug-in pipe 32 is bent, the tilting of the protective fence main body 2 stops at that point, and the vehicle collision energy absorption effect due to the bending deformation of the plug-in pipe 32 is not obtained. In contrast, with the protective fence 1 of this embodiment, when a vehicle collides from the first road, the plug-in pipe 32 bends and the protective fence main body 2 tilts away from the first road until the lower end of the second lower beam 12b contacts the ground G, and when a vehicle collides from the second road, the plug-in pipe 32 bends and the protective fence main body 2 tilts away from the second road until the lower end of the first lower beam 10b contacts the ground G, and therefore the vehicle collision energy absorption effect due to the bending deformation of the plug-in pipe 32 can be fully obtained. As a result of the above, the protective fence 1 according to this embodiment can realize the operation of the plug-in pipe 32 and the protective fence main body 2 that can effectively absorb the collision energy of a vehicle when the vehicle collides with the protective fence main body 2.

The protective fence of the present invention is not necessarily limited to the configuration described above. For example, the following configurations can be adopted for the protective fence of the present invention.

The positioning section in the protective fence of the present invention is not necessarily limited to that used in the above embodiment, and various configurations can be used as long as it is capable of positioning the horizontal position of the plug-in pipe inserted into the space inside the fixed pipe.

For example, the movement restriction protrusion of the positioning portion in the present invention may be a bolt screwed into and fixed to the disc portion so as to protrude downward from the disc portion, or a piece of round steel welded to the disc portion so as to protrude downward from the disc portion, or a portion of the disc portion bent up so as to protrude downward from the disc portion.

The positioning portion in the present invention may be an annular plate welded to the upper end of the fixed tube, with the plug-in tube inserted inside. The positioning portion may be formed by subjecting the fixed tube to a drawing process or the like, so that a portion of the wall of the fixed tube protrudes radially inward.

The positioning portion according to the present invention may also be provided on the plug-in tube. In this case, the positioning portion may be a plate-like member or a protrusion provided on the portion of the plug-in tube that is inserted into the space inside the fixed tube so as to protrude radially outward. The positioning portion provided on the plug-in tube may also be a portion of the plug-in tube that has been bent so as to protrude radially outward. The positioning portion provided on such a plug-in tube determines the horizontal position of the plug-in tube in the space inside the fixed tube by contacting the inner peripheral surface of the fixed tube.

The guardrail of the present invention is not limited to being installed on a median strip, but may also be installed on the side of a road on which vehicles pass. In this case, it is preferable that the positioning portion positions the horizontal position of the insertion pipe in a position close to the portion of the pipe wall of the fixed pipe that is closer to the road. This ensures a greater distance for the insertion pipe to move horizontally in the space within the fixed pipe when a vehicle collides with the guardrail body from the road, and further improves the guardrail's ability to absorb vehicle collision energy.

In the above embodiment, the protective fence has a first upper beam and a first lower beam aligned vertically, and a second upper beam and a second lower beam aligned vertically, but the protective fence may also have a single first beam and a single second beam.

The protective fence body is not necessarily limited to one that can be moved on the ground by the rolling elements shown in the above embodiment. For example, the protective fence body of the present invention may not have rolling elements and may be one that is installed by being placed on the ground at the installation location, or one that can be moved on the ground by dragging or pushing it along the ground or lifting it off the ground.

1 Guard fence 2 Guard fence body 3 Fixing device 8 Support pipe 10 First beam (road side beam, opposite road side beam)
12 Second beam (road side beam, anti-road side beam)
30 Fixed pipe 30a first opposing part (fixed pipe opposing part)
30b Second opposing part (fixed tube opposing part)
32 Insertion pipe 32d first opposite road side portion (insertion pipe opposite road side portion)
32e Second opposite side of road (opposite side of plug pipe)
42 Positioning portion 44 Top plate portion 44a Insertion hole 48 Movement restriction protrusion

Claims (4)

A protective fence that is installed at a location adjacent to a road on which vehicles travel and that receives a vehicle when the vehicle deviates from the road,
A protective fence body that is installed on the ground at the installation location so as to be movable from the installation location;
A fixing device for fixing the protective fence body at the installation site,
The protective fence body has a support pipe extending in the vertical direction,
The fixing device includes a fixing pipe that is embedded in the ground at the installation site in a vertically extending position, an insertion pipe that is inserted into a space within the support pipe and a space within the fixing pipe so as to span these spaces and connect the support pipe and the fixing pipe, and a positioning portion that determines a horizontal position of the insertion pipe in the space within the fixing pipe,
the fixed pipe has an inner diameter capable of securing a gap between an outer circumferential surface of the insertion pipe inserted into a space within the fixed pipe and an inner circumferential surface of the fixed pipe,
the positioning portion is configured to position the horizontal position of the plug-in pipe in a direction perpendicular to the extension direction of the road at a predetermined position where a gap is formed between a plug-in pipe anti-road side portion, which is a portion of the outer circumferential surface of the plug-in pipe inserted into the space within the fixed pipe that faces away from the road, and a fixed pipe opposing portion, which is a portion of the inner circumferential surface of the fixed pipe that faces the plug-in pipe anti-road side portion, and is configured to allow the plug-in pipe to move horizontally due to the collision load of the vehicle when a vehicle collides with the protective fence main body from the road to a position where the plug-in pipe anti-road side portion abuts against the fixed pipe opposing portion ,
the positioning portion includes a top plate portion having an insertion hole through which the insertion tube is inserted and installed on the upper end portion of the fixed tube, which positions the horizontal position of the insertion tube inserted into the insertion hole at the predetermined position, and a movement restricting protrusion that protrudes downward from the top plate portion into the space within the fixed tube at a position outside the insertion hole and radially inside the fixed tube, and abuts against an inner circumferential surface of the fixed tube to restrict horizontal movement of the top plate portion,
The movement-restricting protrusion has a strength that allows it to deform when it comes into contact with the fixed tube so as to allow the insertion tube and the top plate portion to move horizontally to the side opposite the road due to the collision load of a vehicle when the vehicle collides with the protective fence main body from the road . The installation location where the protective fence is installed is a median strip located between a first road and a second road,
The plug-in pipe opposite-road side portion includes a first opposite-road side portion that faces the opposite side to the first road and a second opposite-road side portion that faces the opposite side to the second road,
the fixed pipe opposing portion includes a first opposing portion that is an opposing portion to the first opposite-road-side portion and a second opposing portion that is an opposing portion to the second opposite-road-side portion,
The protective fence of claim 1, wherein the positioning portion is configured to position the horizontal position of the insertion pipe at a predetermined position where a gap is formed between the first anti-road side portion of the insertion pipe and the first opposing portion of the fixed pipe and where a gap is formed between the second anti-road side portion of the insertion pipe and the second opposing portion of the fixed pipe, and is configured to allow the insertion pipe to move horizontally to a position where the first anti-road side portion abuts against the first opposing portion due to the collision load of the vehicle when a vehicle collides with the protective fence main body from the first road, and to allow the insertion pipe to move horizontally to a position where the second anti-road side portion abuts against the second opposing portion due to the collision load of the vehicle when a vehicle collides with the protective fence main body from the second road. The protective fence main body further includes a road-side beam that faces the road and is arranged to extend along the road at a position on the road side relative to the support pipe when the protective fence main body is installed at the installation location, and an anti-road-side beam that is arranged to extend along the road at a position opposite to the road-side beam relative to the support pipe when the protective fence main body is installed at the installation location,
3. The protective fence of claim 1 or 2, wherein the insertion length of the plug-in pipe into the space within the fixed pipe, the difference between the inner diameter of the fixed pipe and the outer diameter of the plug-in pipe, and the distance from the lower end of the anti-road side beam to the ground at the installation location are set so that, when a vehicle collides with the protective fence main body from above the road, the plug-in pipe and the protective fence main body move horizontally to a position where the anti-road side portion of the plug-in pipe abuts against the opposing portion of the fixed pipe, and then the plug-in pipe and the protective fence main body tilt away from the road so that the lower end of the plug-in pipe abuts against the portion of the inner surface of the fixed pipe that faces the road and a portion upwardly from the lower end of the plug-in pipe abuts against the upper end of the opposing portion of the fixed pipe, and then the plug-in pipe bends and deforms, causing the protective fence main body to tilt further away from the road until the lower end of the anti-road side beam contacts the ground at the installation location. The protective fence according to claim 3 , wherein the distance from the lower end of the anti-road side beam to the ground at the installation location is set to be greater than the difference between the inner diameter of the fixed pipe and the outer diameter of the insertion pipe.