Guard fence

Abstract

To provide a guard fence for suppressing the intrusion of snow into the inside space of the guard fence body without impairing accessibility to the inside space.SOLUTION: A guard fence 1 includes: a guard fence body 2; a roof structure including a roof part 50 connected to the guard fence body 2 and covering the upper side of the guard fence body 2; a maintenance opening 51c formed in the roof part 50; an opening / closing door 52 attached to the roof part 50 and configured to open the maintenance opening 51c by turning upward around a first predetermined axis from a closing position for closing the maintenance opening 51c; and a door holding mechanism 70 capable of holding the opening / closing door 52 at a predetermined opening position.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a protective fence installed at an installation location adjacent to a road on which a vehicle travels, and configured to receive the vehicle when the vehicle deviates from the road.

Background Art

[0002] Conventionally, a protective fence installed at an installation location adjacent to a road (such as a median strip, etc.) has been known (see, for example, Patent Document 1). This protective fence has a protective fence body configured to receive the vehicle when the vehicle deviates from the road. The protective fence body is fixed to the ground by a fixing device during normal times, while it is configured to be movable along the ground by releasing the fixing by the fixing device in case of an emergency such as a traffic accident. The protective fence body has two guard rails facing each other, and the guard rails are supported by a bottom plate. Casters for moving the protective fence body are attached to the lower surface of the bottom plate. The protective fence body has an inner space between the two guard rails. An operator can access this inner space to perform operations such as fixing the protective fence body to the ground.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the protective fence shown in Patent Document 1 is installed in a snow accumulation area, snow accumulates in the inner space of the protective fence body, and the corrosion of the steel material of the protective fence body progresses due to the moisture of this snow, or the casters on its lower surface are buried by the snow that has entered inside the protective fence body, making it difficult to move the protective fence body.

[0005] In order to avoid this problem, it is conceivable to provide a roof portion on the upper side of the protective fence body. However, if a roof portion is provided, the upper side of the protective fence body is covered by the roof portion, making it difficult for an operator to access the inner space of the protective fence body. For this reason, there is a problem that the workability of work (for example, work for fixing the protective fence body to the ground, etc.) performed by the operator accessing the inner space of the protective fence body deteriorates.

[0006] The present invention has been made to solve the above problems, and an object thereof is to suppress the entry of snow into the inner space of the protective fence body without impairing the accessibility to the inner space of the protective fence body.

Means for Solving the Problems

[0007] A protective fence according to a first invention is a protective fence installed at an installation location adjacent to a road on which a vehicle travels and configured to receive the vehicle when the vehicle deviates from the road, the protective fence including a protective fence body, a roof structure including a roof portion connected to the protective fence body and covering the upper side of the protective fence body, a maintenance opening formed in the roof portion, an opening / closing door attached to the roof portion and configured to be able to open the maintenance opening by rotating upward around a first predetermined axis from a closed position closing the maintenance opening, and a door holding mechanism capable of holding the opening / closing door at a predetermined open position.

[0008] According to this configuration, it is possible to suppress the entry of snow into the inner space of the protective fence body without impairing the accessibility to the inner space of the protective fence body. That is, according to this configuration, since the upper side of the protective fence body is covered by the roof portion, it is possible to prevent snow from entering the inner space of the protective fence body during snowfall. Further, since an opening / closing door is provided in the roof portion, an operator can easily access the inner space of the protective fence body from the maintenance opening by opening the opening / closing door.

[0009] Moreover, since the opening and closing door can be held at a predetermined open position by the door holding mechanism, when an operator accesses the inner space of the protective fence body, there is no need to support the opening and closing door by his own hand during work or to have another operator support the opening and closing door. Therefore, it is possible to efficiently access the inner space of the protective fence body with a small number of personnel and perform a predetermined operation.

[0010] In the protective fence according to the second invention, in the first invention, the door holding mechanism is rotatably attached to the back surface of the opening and closing door around a second predetermined axis, and has a door holding member displaceable between a holding position for holding the opening and closing door at a predetermined open position and a non-holding position rotated by a predetermined rotation angle around the second predetermined axis from the holding position. The door holding member, at the holding position, abuts one end portion thereof against a predetermined portion of the roof structure body, and thereby exerts a door holding function of holding the opening and closing door at the predetermined open position by stretching between the back surface of the opening and closing door at the predetermined open position and the predetermined portion of the roof structure body. On the other hand, in the non-holding position, the abutment is released and the door holding function is configured to be invalidated.

[0011] According to this configuration, by positioning the door holding member at the holding position, the door holding member functions like a tension member between the opening and closing door and the roof structure body, and the opening and closing door is held at the predetermined open position. Therefore, the configuration of the door holding mechanism can be simplified and the cost can be reduced. In addition, since a rotation space for the door holding member can be secured by using the space on the back surface of the opening and closing door, for example, the space efficiency can be improved as compared with the case where the door holding member is attached to the roof structure body.

[0012] In the protective fence according to the third invention, in the second invention, an engaged portion is provided on the roof structure, and the door holding member has a rotation restricting engagement portion that can engage with the engaged portion. In the state where the opening / closing door is held at the holding position, the rotation around the second predetermined axis is restricted by the rotation restricting engagement portion engaging with the engaged portion. On the other hand, when the opening / closing door is rotated upward from this state and the opening angle of the opening / closing door around the first predetermined axis reaches a preset angle, the engagement between the rotation restricting engagement portion and the engaged portion is released, and rotation around the second predetermined axis is allowed. It is preferably configured like this.

[0013] According to this configuration, in the state where the door holding member holds the opening / closing door at the holding position (hereinafter referred to as the door holding state), it is possible to prevent the door holding member from rotating around the second predetermined axis due to external forces such as wind or impact, thereby losing its door holding function. That is, according to this configuration, after the door holding member enters the door holding state, the engagement between the rotation restricting engagement portion of the door holding member and the engaged portion cannot be released unless the opening / closing door is rotated upward until its opening angle reaches a preset angle (for example, the maximum opening angle). In other words, the door holding member cannot be rotated around the second predetermined axis. Therefore, unless an external force sufficient to rotate the heavy opening / closing door to the preset angle acts on the opening / closing door, the door holding member will not rotate around the second predetermined axis. Thus, it is possible to prevent the door holding member from rotating unintentionally to the non-holding position side due to external forces such as wind or impact, and reliably maintain the door holding function of the door holding member.

[0014] In the protective fence according to the fourth invention, in the second or third invention, it is preferable that the first predetermined axis extends in the horizontal direction and the second predetermined axis extends in a direction orthogonal to the first predetermined axis.

[0015] According to this configuration, since the second predetermined axis, which is the rotation axis of the door holding member, is orthogonal to the first predetermined axis (the axis extending in the horizontal direction), which is the rotation axis of the opening / closing door that rotates up and down, it is possible to suppress the door holding member from rotating around the second predetermined axis due to its own weight (gravity).

[0016] In the protective fence according to the fifth invention, in the fourth invention, it is preferable that the door holding mechanism further includes a bolt that penetrates the opening / closing door and the door holding member to form the second predetermined axis, and a nut that is screwed onto the bolt to hold the door holding member so as not to fall off from the opening / closing door.

[0017] According to this configuration, the second predetermined axis, which is the rotation axis of the door holding member, can be configured by using a fastening bolt.

[0018] In the protective fence according to the sixth invention, in the fifth invention, the door holding member includes a rotating plate portion that is disposed to face the back surface of the opening / closing door and has a through hole through which the bolt penetrates, a contact plate portion that stands on the side surface opposite to the surface of the rotating plate portion facing the opening / closing door and functions as the one end portion, and a reinforcing plate portion that stands on the side surface opposite to the rotating plate portion and is connected to the side surface of the contact plate portion opposite to the contact side surface with the roof structure. It is preferable to have.

[0019] According to this configuration, the reaction force received from the roof structure (predetermined location) acting on the contact plate portion when the door holding member is in the holding position can be received by the reinforcing plate portion connected to the back side of the contact plate portion. Therefore, the strength in the tension direction of the entire door holding member can be improved as much as possible, and the door holding function of the door holding member can be strengthened.

[0020] In the protective fence according to the seventh invention, in the fifth invention, it is preferable that the door holding mechanism further includes a first rotating seat plate and a second rotating seat plate that are disposed so as to sandwich the periphery of the penetrating portion of the bolt in the door holding member from both sides in the penetrating direction.

[0021] According to this configuration, an operator can smoothly perform the operation of rotating the door holding member around the second predetermined axis to switch between the non-holding position and the holding position. That is, when the first rotating seat plate and the second rotating seat plate are not provided, there is a possibility that the fastening load of the bolt concentrates around the bolt penetrating portion of the door holding member and the rotation of the door holding member is inhibited. However, in this embodiment, by sandwiching the periphery of the bolt penetrating portion of the door holding member between the first rotating seat plate and the second rotating seat plate, the concentration of the fastening load is prevented, and the switching operation between the non-holding position and the holding position by the rotation operation of the door holding member can be smoothly performed.

[0022] In the protective fence according to the eighth invention, in the fifth invention, it further includes a fastening member for fastening the opening and closing door to the roof structure. One end of the fastening member is connected to one of the fastening members of the bolt and the nut, and the other end is connected to the roof structure. It is preferable that the one fastening member has a fastening main body portion forming a screw portion and an annular portion connected to the fastening main body portion and engaging with one end of the fastening member.

[0023] According to this configuration, since the opening and closing door is fastened to the roof structure via the fastening member and the one fastening member, for example, it is possible to prevent the opening and closing door from flying off due to a sudden strong wind or the like. In addition, the one fastening member (bolt or nut) for connecting the fastening member is also used as a member for connecting the door holding member to the opening and closing door, so that the sharing of parts can be achieved and the cost can be reduced.

Effects of the Invention

[0024] According to the present invention, it is possible to suppress the entry of snow into the inner space without impairing the accessibility to the inner space of the protective fence body.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Mode for Carrying Out the Invention

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a protective fence 1 according to an embodiment of the present invention. FIG. 2 is a plan view showing a state in which the roof portion of the protective fence 1 is removed. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2.

[0027] [Overall Configuration] The protective fence 1 according to the present embodiment is installed on the ground of the median strip between two adjacent roads on an expressway or other roads. The protective fence 1 is installed along the extending direction (extension direction) of the roads on both sides of the median strip, and is configured to receive a vehicle when the vehicle traveling on the roads on both sides thereof deviates from the road. Further, in an emergency, it is possible to move the protective fence 1 from the installation location, and by moving the protective fence 1, a space can be secured for a vehicle to make a U-turn or enter from one road on both sides of the median strip to the other road.

[0028] In each figure, for the sake of facilitating the explanation of the protective fence 1, the longitudinal direction (extension direction) of the protective fence 1 is the front-rear direction, the width direction of the protective fence 1 is the left-right direction, and the height direction of the protective fence 1 is the up-down direction, and each direction is illustrated. This direction does not limit the protective fence 1 according to the present invention.

[0029] As shown in FIGS. 1 and 2, the protective fence 1 includes a protective fence body 2, a rolling element 22 that movably supports the protective fence body 2, a roof portion 50 (not shown in FIG. 2) that covers the upper side of the protective fence body 2, four opening / closing doors 52 provided at the four corners of the roof portion 50, and four door holding mechanisms 70 (see FIGS. 5A etc. described later) provided on the back side of each of the four opening / closing doors 52. When the protective fence 1 is in use, a plurality of the protective fences 1 are arranged adjacent to each other in a strip along an installation location (median strip) adjacent to the road. Adjacent protective fences 1 are connected to each other via a connecting member 4 (shown only in FIG. 2). Each protective fence 1 is fixed to the ground G by a protective fence fixing device 100 described later.

[0030] The protective fence body 2 extends in a specific longitudinal direction and is arranged along the road in that longitudinal direction. In the present embodiment, the protective fence bodies 2 of the plurality of protective fences 1 are arranged side by side along the extending direction of the roads on both sides of the median strip, and partition between one road and the road in the opposite lane. The protective fence body 2 of each protective fence 1 is movable on the ground G by the rolling member of the rolling element 22 described later rolling on the ground G.

[0031] The protective fence body 2 includes a plurality of bases 6 (see FIG. 2), a base reinforcing member 7 (see FIG. 2), a plurality of support pipes 8, a first beam 10 and a second beam 12, a plurality of connecting members 13, and a plurality of auxiliary connecting members 14.

[0032] The plurality of bases 6 are the base portions of the protective fence body 2 and are each configured to be movable on the ground G. In the present embodiment, the protective fence body 2 has two front and rear bases 6. As shown in FIG. 3, each base 6 has a base plate 20 (base material) and a plurality of rolling elements 22.

[0033] The base plate 20 is a flat plate arranged substantially horizontally. The base plate 20 is arranged at a position spaced upward from the ground between the first beam 10 and the second beam 12 in the left-right direction. The base plate 20 has a through hole 20a penetrating the base plate 20 in the vertical direction (the plate thickness direction of the base plate 20).

[0034] The plurality of rolling elements 22 are configured to be rollable on the ground G along the ground G, and are for enabling the base 6 to move on the ground G. The plurality of rolling elements 22 are each attached to the base plate 20. The rolling element 22 is a so-called caster. In the present embodiment, each base 6 has four rolling elements 22. The four rolling elements 22 (only two are shown in FIG. 3) are arranged in two on each side of the through hole 20a of the base plate 20. The four rolling elements 22 project downward from the base plate 20 and contact the ground G to support the base plate 20 from below.

[0035] The base reinforcing member 7 connects the pair of front and rear base plates 20 to each other. The base reinforcing member 7 has an H shape in plan view, and both ends thereof are respectively fixed to the inner ends of the base plate 20. Further, a plurality of auxiliary rolling elements (not shown) having the same structure and function as the rolling element 22 are attached to the lower surface portion of the base reinforcing member 7.

[0036] As shown in FIG. 3, the plurality of support pipes 8 are fixed to the respective bases 6 so as to stand upright from the respective bases 6 at a plurality of positions arranged in the longitudinal direction of the guard fence body 2. In the present embodiment, the guard fence body 2 has two support pipes 8. Each support pipe 8 has a cylindrical shape, is inserted into the through hole 20a of the base plate 20 of each base 6, penetrates the base plate 20, and is fixed to the base plate 20 in a posture extending upward from the base plate 20.

[0037] As shown in FIGS. 3 and 4, the first beam 10 and the second beam 12 are arranged at intervals in the width direction of the guardrail body 2 (the direction orthogonal to both the longitudinal direction (front-rear direction) and the height direction (up-down direction) of the guardrail body 2), so as to sandwich the inner space S from both sides. In other words, the inner space S is the space between the first beam 10 and the second beam 12. Further, the first beam 10 and the second beam 12 are arranged on both sides of the plurality of support pipes 8 and are respectively fixed to the plurality of support pipes 8 via connecting members 13. The first beam 10 and the second beam 12 are located at the outermost positions on both sides in the width direction of the guardrail body 2 and can receive the impact of a vehicle.

[0038] Specifically, the first beam 10 faces the first road, which is one of the roads on both sides of the guardrail 1, and constitutes a surface for receiving the impact of a vehicle when the vehicle traveling on this first road deviates from the first road onto the median strip. As shown in FIG. 3, the first beam 10 is composed of a first upper beam 10A and a first lower beam 10B arranged vertically. The first upper beam 10A is made of a thin plate with a corrugated cross-section in the vertical direction and extends along the longitudinal direction of the guardrail body 2. The first lower beam 10B has the same shape as the first upper beam 10A and extends parallel to the first upper beam 10A below the first upper beam 10A.

[0039] The second beam 12 faces the second road, which is the road located on the opposite side of the first road across the guardrail 1, and constitutes a surface for receiving the impact of a vehicle when the vehicle traveling on this second road deviates from the second road onto the median strip. In other words, the second beam 12 is arranged on the opposite side of the first beam 10 in the left-right direction. 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 symmetric with the first upper beam 10A and extends along the longitudinal direction of the guardrail body 2. The second lower beam 12B has the same shape as the second upper beam 12A and is symmetric with the first lower beam 10B, and extends parallel to the second upper beam 12A below the second upper beam 12A.

[0040] As shown in FIG. 2, the plurality of connecting members 13 and the plurality of auxiliary connecting members 14 are arranged at different positions in the front-rear direction, and each connects the first beam 10 and the second beam 12 to each other along the left-right direction.

[0041] As shown in FIG. 2, the plurality of connecting members 13 are arranged so as to sandwich the support pipe 8 from the front and rear on both sides in the front-rear direction of the guardrail main body 2. Further, as shown in FIG. 3, the plurality of 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. In particular, the connecting member 13 interposed between the first upper beam 10A and the second upper beam 12A connects the first upper beam 10A and the second upper beam 12A in the width direction of the guardrail main body 2 and connects these first upper beam 10A and second upper beam 12A to the support pipe 8. Further, the connecting member 13 interposed between the first lower beam 10B and the second lower beam 12B connects the first lower beam 10B and the second lower beam 12B in the width direction of the guardrail main body 2 and connects these first lower beam 10B and 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 the connecting member 13 that connects them. Further, the first lower beam 10B and the second lower beam 12B are connected to the support pipe 8 via the connecting member 13 that connects them.

[0042] On the other hand, as shown in FIG. 2, the plurality of auxiliary connecting members 14 are arranged outside the connecting members 13 in the front-rear direction. Although not shown, the plurality of auxiliary connecting members 14 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. In particular, the auxiliary connecting member 14 interposed between the first upper beam 10A and the second upper beam 12A connects the first upper beam 10A and the second upper beam 12A in the width direction of the guardrail main body 2. Further, the auxiliary connecting member 14 interposed between the first lower beam 10B and the second lower beam 12B connects the first lower beam 10B and the second lower beam 12B in the width direction of the guardrail main body 2.

[0043] [Configuration of the protective fence fixing device] Next, with reference to FIG. 3, the protective fence fixing device 100 will be described. The protective fence fixing device 100 is for fixing the protective fence 1 at its installation position when the protective fence 1 is installed at the installation location (the median strip in this embodiment). The protective fence fixing device 100 is provided for each of the plurality of protective fences 1 arranged in a strip shape at the installation location. That is, the protective fence fixing device 100 is installed at the installation locations of the plurality of protective fences 1 so as to be arranged at intervals along the extending direction of the first and second roads.

[0044] Each protective fence fixing device 100 includes two fixing pipes 30 buried in the ground (only one is shown in FIG. 3), the support pipes 8 (only one is shown in FIG. 3) respectively provided on the two bases 6 of the protective fence main body 2, and insertion pipes 32 respectively inserted into the inner spaces of each fixing pipe 30 and each support pipe 8.

[0045] The protective fence fixing device 100 is configured to be switched between a fixed state in which the protective fence main body 2 is fixed to the ground G at its installation position and a fixed release state in which the fixing is released and the movement of the protective fence main body 2 on the ground G is allowed by inserting and removing the insertion pipe 32 by an operator. Specifically, in the fixed state, the protective fence fixing device 100 fixes the base 6 connected to the support pipe 8 to be immovable relative to the ground G at its installation position by the insertion pipe 32 inserted into the support pipe 8 and the fixing pipe 30, and in the fixed release state, the fixing of the base 6 is released to allow the movement of the base 6 relative to the ground G.

[0046] The two fixing pipes 30 are arranged at intervals in the extending direction of the first and second roads. Each fixing pipe 30 is buried and fixed under the ground G at the installation location of the protective fence 1. Each fixing pipe 30 is in a hollow cylindrical shape and is buried in the ground in a posture extending in the vertical direction to secure a space for receiving the insertion pipe 32 inside. Each fixing pipe 30 is arranged such that the position of its upper end coincides with the position of the ground G. The upper end of each fixing pipe 30 is open.

[0047] As shown in Fig. 3, the insertion tube 32 is inserted into the inner spaces of the support tube 8 and the fixed tube 30 so as to straddle them in the fixed state, connecting the support tube 8 and the fixed tube 30 to each other, and fixing the base 6 of the protective fence body 2 provided with the support tube 8 immovably to the ground G. In the unlocked state, the insertion tube 32 is pulled upward from the inner spaces of the fixed tube 30 and the support tube 8, releasing the fixation of the base 6 provided with the support tube 8 to the ground G and allowing the base 6 to move on the ground G.

[0048] In other words, the insertion tube 32 is configured to be vertically displaceable between a fixed position and a non-fixed position. The fixed position is the position where the lower end of the insertion tube 32 is inserted into the ground G of the median strip, and the non-fixed position is the position where the lower end of the insertion tube 32 is detached upward from the ground G of the median strip.

[0049] The insertion tube 32 has a cylindrical insertion tube body 32A inserted into the inner spaces of the support tube 8 and the fixed tube 30, a flange portion 32B attached to the upper end of the insertion tube body 32A so as to project radially outward from the upper end thereof, and a gripping portion 32C attached to the upper end of the insertion tube body 32A. The flange portion 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 the height position where the insertion tube 32 connects the support tube 8 and the fixed tube 30 to each other. Further, the gripping portion 32C is a portion that is gripped by an operator during the operation of inserting and removing the insertion tube 32 into and from the inner spaces of the support tube 8 and the fixed tube 30.

[0050] [Configuration of the roof portion] Returning to FIG. 1, the roof portion 50 is disposed above the guardrail main body 2 and extends in the front-rear direction so as to cover the inner space S from above. The roof portion 50 is supported by the plurality of connecting members 13 and the plurality of auxiliary connecting members 14 via two first support frames 61 and two second support frames 62. Bracket plates 15 (see FIG. 2) for fixing the base end portions of the respective support frames 61 and 62 are provided on the upper surfaces of the respective connecting members 13 and the respective auxiliary connecting members 14. The roof portion 50 and the connecting members (in this example, the first support frame 61 and the second support frame 62) that connect the roof portion 50 to the guardrail main body 2 constitute a roof structure.

[0051] As shown in FIG. 1, the roof portion 50 is an inclined roof having an isosceles triangular shape that protrudes upward when viewed from the front-rear direction of the guardrail 1, and is composed of two sheet metal members 51.

[0052] Specifically, each of the two sheet metal members 51 has a roof plate portion 51a that forms a roof surface and an upper end plate portion 51b that extends upward from the upper end edge of the roof plate portion 51a. The two sheet metal members 51 are connected by bolts 101 in a state where their respective upper end plate portions 51b are overlapped with each other. The connection portion of the two sheet metal members 51 forms the top portion 50T of the roof portion 50.

[0053] The roof plate portion 51a of each sheet metal member 51 extends downward from the top portion 50T of the roof portion 50. The tip end portion of each roof plate portion 51a is disposed above the adjacent beam. Thus, each roof plate portion 51a is configured to prevent snow from entering the inner space S of the guardrail main body 2 during snowfall, and to guide the snow accumulated on the roof portion 50 along the upper surface of each roof plate portion 51a to both sides of the median strip by causing the snow to fall.

[0054] In addition, rectangular maintenance openings 51c that open toward the eaves side and the outside in the front-rear direction are respectively formed at both end portions in the front-rear direction of each roof panel portion 51a. That is, a total of four maintenance openings 51c are formed in the roof portion 50, and each maintenance opening 51c is closable by an opening / closing door 52 in an openable manner. Each opening / closing door 52 is configured to be able to open and close the maintenance opening 51c by rotating up and down with its upper end portion as a fulcrum. An operator can access the inner space S through the maintenance opening 51c by rotating each opening / closing door 52 upward from the closed position, and can perform various operations (for example, the insertion / removal operation of an insertion pipe 32 described later).

[0055] [Configuration of the opening / closing door] Next, with reference to FIGS. 4 to 7, the details of each opening / closing door 52 provided in the roof portion 50 and the schematic configuration of the door holding mechanism 70 will be described. FIG. 4 is a left side view showing an enlarged periphery of the opening / closing door 52 provided at the left rear end portion of the roof portion 50. FIG. 5A is a side view showing a state where the opening / closing door 52 is opened to a predetermined open position from the state of FIG. 4 and a door holding member 71 described later is positioned at the holding position. FIG. 5B is a side view showing the state of FIG. 5A with the door holding member 71 omitted. FIG. 6 is a side view of the roof portion 50 of the protective fence 1 as viewed from the rear side in the front-rear direction, showing a state where all the opening / closing doors 52 are in the closed position, and FIG. 7 is a side view of the roof portion 50 of the protective fence 1 as viewed from the rear side in the front-rear direction, showing a state where one of the four opening / closing doors 52 (the opening / closing door 52 at the left rear end portion in the example of FIG. 7) is positioned at the predetermined open position. Since the basic configuration of each opening / closing door 52 provided in the roof portion 50 is the same, hereinafter, the configuration of the opening / closing door 52 at this left rear end portion will be described as a representative. In addition, in the following description, unless otherwise specified, the description will be made assuming that the opening / closing door 52 is in the closed position.

[0056] As shown in FIG. 4, the opening / closing door 52 has a door main body plate portion 52a, an upper end bent plate portion 52b connected to the upper end edge of the door main body plate portion 52a, and a rectangular plate-shaped contact plate portion 52f connected to the inner edge in the roof transverse direction of the door main body plate portion 52a. The contact plate portion 52f abuts on the upper surface of the roof plate portion 51a when the opening / closing door 52 is in the closed position. A bent piece 52e protruding toward the back surface side is connected to the side edge of the contact plate portion 52f. The bent piece 52e engages with a rectangular hole 57 formed in the roof plate portion 51a when the opening / closing door 52 is in the closed position.

[0057] The door main body plate portion 52a has a substantially rectangular plate shape corresponding to the outer edge shape of the maintenance opening 51c. A lower end plate portion 52g hanging vertically downward is connected to the lower end edge of the door main body plate portion 52a. A side plate portion 52h hanging vertically downward is connected to the outer edge in the roof transverse direction of the door main body plate portion 52a. The side plate portion 52h also functions as a regulating plate portion for regulating excessive rotation around a door holding member 71 described later.

[0058] The upper end bent plate portion 52b is formed over the entire edge in the front-rear direction of the upper end edge of the door main body plate portion 52a. As shown in FIG. 6, the upper end bent plate portion 52b has a bent plate shape with a top portion bent at an acute angle. Specifically, the upper end bent plate portion 52b has a protruding plate portion 52c standing perpendicular to the upper surface of the door main body plate portion 52a, and an inclined plate portion 52d extending from the upper end edge of the protruding plate portion 52c so as to approach the roof plate portion 51a. A nut 103 for attaching a hinge base 53 described later is accommodated in the space sandwiched between the protruding plate portion 52c and the inclined plate portion 52d.

[0059] Referring to Fig. 6, a pair of hinge bases 53 (only one is shown in Fig. 6) are attached to the lower surface of the inclined plate portion 52d at intervals in the front-rear direction. The pair of hinge bases 53 are respectively fastened and fixed to both ends of the inclined plate portion 52d in the front-rear direction by two bolts 102 (only one is shown in Fig. 6) and nuts 103 (see Fig. 6) screwed thereto. Each hinge base 53 has a cylindrical shaft support cylinder portion 53a extending in the front-rear direction. Each hinge base 53 is rotatably connected to the roof-side hinge base 54 via a hinge shaft 55 inserted into the shaft support cylinder portion 53a. In this example, the hinge shaft 55 extends in the front-rear direction (an example of the horizontal direction).

[0060] As shown in Fig. 4, the roof-side hinge base 54 is attached to the upper surface of the roof plate portion 51a of the sheet metal member 51 via two bolts 105. The roof-side hinge base 54 has a shaft support cylinder portion 54a into which the hinge shaft 55 is inserted, similar to the door-side hinge base 53.

[0061] The opening / closing door 52 is configured to be rotatable between a closed position (see Fig. 6) for closing the maintenance opening 51c and a maximum open position (the position shown in Fig. 14 described later) rotated upward by a maximum opening angle θ2 with the hinge shaft 55 as a fulcrum from the closed position. And the axis of the hinge shaft 55 functions as a first predetermined axis.

[0062] Also, the opening / closing door 52 is configured to be held at a predetermined open position (the position shown in Fig. 7) by a door holding mechanism 70 provided on the back surface side thereof. The predetermined open position is a position where each opening / closing door 52 is rotated upward by a predetermined angle θ1 with the hinge shaft 55 as a fulcrum from the closed position. In this example, this predetermined angle θ1 is set smaller than the maximum opening angle θ2, but it is not limited to this, and for example, it may be set equal to the maximum opening angle θ2.

[0063] As shown in FIG. 5B, an engagement hole 51e (an example of an engaged portion) with which an engagement plate portion 71e of a door holding member 71 described later engages is formed in a roof plate portion 51a of the sheet metal member 51. The engagement hole 51e is formed at a location adjacent to a maintenance opening 51c in the roof plate portion 51a and below the hinge shaft 55 (see FIG. 6).

[0064] [Configuration of Door Holding Mechanism] FIG. 8 is a side view showing the door holding mechanism 70 in an enlarged manner, corresponding to a view taken in the direction of arrow VIII in FIG. 4. FIG. 9 is a view taken in the direction of arrow IX in FIG. 8, and FIG. 10 is an exploded view of the door holding mechanism shown in FIG. 8.

[0065] As shown in FIGS. 8 to 10, the door holding mechanism 70 includes a long door holding member 71 attached to the back surface of the door main body plate portion 52a, a first rotating seat plate 72 and a second rotating seat plate 73 arranged to sandwich one end portion of the door holding member 71 from both the upper and lower sides, a bolt 74 passing through the door holding member 71, each rotating seat plate 72, 73, and the door main body plate portion 52a vertically, a washer 77 provided on the upper surface of the door main body plate portion 52a through which the bolt 74 is inserted, and a lock nut 76 and an eye nut 75 screwed onto the threaded portion of the bolt 74.

[0066] The door holding member 71 is configured to be rotatable along the back surface (lower surface) of the door main body plate portion 52a with the bolt 74 as a fulcrum. The axis of this bolt 74 functions as a second predetermined axis. And the door holding member 71 is configured to be displaceable between a holding position for holding the opening / closing door 52 at the predetermined open position and a non-holding position (see the two-dot chain line in FIG. 5A) rotated 180° (an example of a predetermined rotation angle) around the bolt 74 with reference to the holding position. As shown in FIG. 7, in the holding position, the door holding member 71 is configured to be able to hold the opening / closing door 52 at the predetermined open position by stretching between the back surface of the door main body plate portion 52a and the upper surface of the roof plate portion 51a against the weight of the opening / closing door 52.

[0067] FIG. 11 is a component diagram showing the door holding member 71 based on the triangulation method. (a) is a plan view of the door holding member 71 viewed from above, (b) is a side view of the door holding member 71 viewed from one side in its width direction, and (c) is a plan view of the door holding member viewed from below.

[0068] The door holding member 71 has a rotating plate portion 71a, a contact plate portion 71b, a pair of reinforcing plate portions 71c, and an engaging plate portion 71e (an example of a rotation restricting engaging portion). Note that the door holding member 71 may be formed, for example, by metal welding a plurality of plate materials, or may be integrally formed by casting or the like. Further, the door holding member 71 is not limited to being made of metal and may be constituted by other materials such as ceramics.

[0069] The rotating plate portion 71a is made of a long plate material having a through hole 71d at one end. The bolt 74 is inserted into this through hole 71d. At the other end of the rotating plate portion 71a, a convex plate-shaped engaging plate portion 71e protruding outward in the longitudinal direction is formed. The engaging plate portion 71e is formed at the center in the width direction of the other end of the rotating plate portion 71a. The plate width of the engaging plate portion 71e is smaller than the plate width of the rotating plate portion 71a.

[0070] The contact plate portion 71b is connected to the opposite side surface 71f of the rotating plate portion 71a from the side surface facing the opening and closing door 52. The tip of the contact plate portion 71b is inclined so as to be located outside (the left side in FIG. 11) in the longitudinal direction (corresponding to the stretching direction) of the rotating plate portion 71a from the base end portion (the connection portion with the rotating plate portion 71a).

[0071] The pair of reinforcing plate portions 71c are vertically connected to the opposite side surface 71f of the rotary plate portion 71a and extend in its longitudinal direction. The pair of reinforcing plate portions 71c are arranged at intervals in the width direction of the rotary plate portion 71a. The through hole 71d is located between the pair of reinforcing plate portions 71c. One end surface in the longitudinal direction of the pair of reinforcing plate portions 71c is connected to the back surface of the contact plate portion 71b (the surface opposite to the contact side surface with the roof plate portion 51a). Thus, the pair of reinforcing plate portions 71c are connected to both the rotary plate portion 71a and the contact plate portion 71b and function as a reinforcing member for reinforcing the strength (rigidity) of the contact plate portion 71b.

[0072] Next, with reference to FIGS. 12 and 13, the first rotary seat plate 72 and the second rotary seat plate 73 will be described. FIG. 12 is a longitudinal sectional view along the axis showing the first rotary seat plate 72, and FIG. 13 is a longitudinal sectional view along the axis showing the second rotary seat plate 73.

[0073] As shown in FIG. 12, the first rotary seat plate 72 has a base plate portion 72a, a circular seat portion 72b, and a through hole 72c. The base plate portion 72a is a square plate-shaped portion, and the upper surface is a contact surface that contacts the back surface of the door main body plate portion 52a. The circular seat portion 72b is a flat cylindrical portion protruding from the lower surface of the base plate portion 72a. The end surface on the protruding side of the circular seat portion 72b contacts the periphery of the through hole 71d in the rotary plate portion 71a of the door holding member 71 with low friction from above. The through hole 72c is an insertion hole for a bolt 74 (see FIG. 10) and is formed so as to penetrate the central portions of both the base plate portion 72a and the circular seat portion 72b. The first rotary seat plate 72 is arranged such that its through hole 72c is coaxial with the through hole 71d (see FIG. 10) of the door holding member 71.

[0074] As shown in FIG. 13, the second rotation seat plate 73 has a base plate portion 73a, a circular seat portion 73b, and a through hole 73c. The base plate portion 73a is a flat disk-shaped portion, and its lower surface constitutes the seat surface of the lock nut 76 (see FIG. 10). The circular seat portion 73b is a flat cylindrical portion projecting coaxially from the upper surface of the base plate portion 73a. The end face on the protruding side of the circular seat portion 73b abuts against the rotating plate portion 71a of the door holding member 71 with low friction from below. The through hole 73c is an insertion hole for the bolt 74, and is formed so as to penetrate the central portions of both the base plate portion 73a and the circular seat portion 73b. The second rotation seat plate 73 is arranged such that its through hole 73c is coaxial with the through hole 71d (see FIG. 10) of the door holding member 71.

[0075] Returning to FIG. 10, the lock nut 76 and the eye nut 75 are arranged coaxially with the first rotation seat plate 72 and the second rotation seat plate 73 and are screwed onto the threaded portion of the bolt 74.

[0076] The eye nut 75 has a nut main body portion 75a (corresponding to the fastening main body portion) and an annular portion 75b connected to the nut main body portion 75a. This eye nut 75 is connected to a wire 80 (see FIG. 5A) for preventing the opening / closing door 52 from scattering.

[0077] In FIG. 5A described above, an example of the routing path of this wire 80 is shown by a two-dot chain line. Rings 80a and 80b are respectively formed at both ends of the wire 80. The ring 80a at one end of the wire is engaged with the annular portion 75b of the eye nut 75. The ring 80b at the other end of the wire 80 is engaged with the annular portion 79a of an eye bolt 79 attached to the side surface of the second support frame 62 (an example of a roof structure). The eye bolt 79 is a bolt having a head formed by the annular portion 79a, and is fixed to the second support frame 62 by a nut 104. The eye bolt 79 is arranged such that its annular portion 79a is located inside the outer edge of the maintenance opening 51c when the opening / closing door 52 is opened. Thereby, the workability when engaging the ring 80b at the other end of the wire 80 with the annular portion 79a can be improved.

[0078] Further, the middle portion of the wire 80 is inserted into and supported by an annular portion 78a of an eye nut 78 fixed to the back surface of the opening / closing door 52. As the eye nut 78, the same component as the eye nut 75 for fixing the door holding member 71 to the opening / closing door 52 can be used. By supporting the middle portion of the wire 80 with the eye nut 78 in this way, slack of the wire 80 can be prevented. Thereby, it is possible to prevent the wire 80 from getting in the way when an operator accesses the inner space S from the maintenance opening 51c.

[0079] [Description of working procedure] Next, with reference to FIGS. 6, 7, and 14 to 16, a working procedure for holding the opening / closing door 52 at a predetermined open position by the door holding mechanism 70 will be described. FIG. 14 is a side view showing a state where the opening / closing door 52 is opened from the state of FIG. 6 to the maximum open position and the door holding member 71 is rotated to the holding position. FIG. 15 is an enlarged view showing an enlarged portion XV in FIG. 14. FIG. 16 is a view corresponding to FIG. 14 showing a state where the opening / closing door 52 is rotated from the state of FIG. 15 (the state where the opening / closing door 52 is at the maximum open position) to the predetermined open position.

[0080] Basically, this operation can be performed by a single operator. Specifically, the operator first rotates the opening / closing door 52 from the closed position (the position shown in FIG. 6) to the maximum open position (see FIG. 14) once. Then, while holding the opening / closing door 52 at the maximum open position with one hand, the operator grips the door holding member 71 with the other hand and rotates the door holding member 71 180° around the bolt 74 from the non-holding position (the position shown by the two-dot chain line in FIG. 14) to the holding position (the position shown by the solid line in FIG. 14). Then, as shown in FIG. 15, the engaging plate portion 71e formed at the tip of the door holding member 71 moves to a position facing the engaging hole 51e formed in the roof plate portion 51a. From this state, when the opening / closing door 52 is rotated downward with the hinge shaft 55 as the fulcrum to be positioned at a predetermined open position, as shown in FIG. 16, the engaging plate portion 71e of the door holding member 71 engages with the engaging hole 51e, and the abutting plate portion 71b of the door holding member 71 abuts against a predetermined portion (in this example, the portion adjacent to the lower side of the engaging hole 51e) on the upper surface of the roof plate portion 51a. As a result, as shown in FIG. 7, the door holding member 71 is stretched between the back surface of the opening / closing door 52 (specifically, the connecting portion with the door holding member 71 on the back surface of the opening / closing door 52 (that is, the fastening portion by the bolt 74)) and the predetermined portion of the roof plate portion 51a to hold the opening / closing door 52 at the predetermined open position. Therefore, after that, even if the operator releases the hand from the opening / closing door 52, the opening / closing door 52 is held at the predetermined open position by the door holding member 71. Thus, the operator can access the inner space S of the protective fence body 2 from the maintenance opening 51c alone and perform a predetermined operation (for example, the insertion / extraction operation of the insertion pipe 32, etc.) without having the door holding member 71 held by another person.

[0081] When returning the opening / closing door 52 from the predetermined open position (the position shown in FIG. 7) to the closed position, the reverse procedure of the above-described operation may be followed. That is, the operator first rotates the opening / closing door 52 from the predetermined open position to the maximum open position (see FIG. 14) once to release the engagement between the engagement plate portion 71e of the door holding member 71 and the engagement hole 51e (see FIG. 15). Then, the door holding member 71 is rotated 180° around the bolt 74 to move the door holding member 71 to the non-holding position (the position of the two-dot chain line in FIG. 14). After releasing the door holding function by the door holding member 71, the opening / closing door 52 is rotated to the closed position.

[0082] [Operational Effects] As described above, in the present embodiment, the protective fence 1 includes a protective fence main body 2, a roof structure including a roof portion 50 connected to the protective fence main body 2 and covering the upper side of the protective fence main body 2, a maintenance opening 51c formed in the roof portion 50, an opening / closing door 52 attached to the roof portion 50 and configured to be able to open the maintenance opening 51c by rotating upward about a first predetermined axis from a closed position closing the maintenance opening 51c, and a door holding mechanism 70 capable of holding the opening / closing door 52 at a predetermined open position.

[0083] According to this configuration, it is possible to suppress the entry of snow into the inner space S of the protective fence main body 2 without impairing the accessibility to the inner space S of the protective fence main body 2. That is, according to this configuration, since the upper side of the protective fence main body 2 is covered by the roof portion 50, it is possible to prevent snow from entering the inner space S of the protective fence main body 2 during snowfall. In addition, since the opening / closing door 52 is provided in the roof portion 50, when the operator performs an operation such as inserting and removing the insertion pipe 32, for example, the operator can easily access the inner space S of the protective fence main body 2 through the maintenance opening 51c by opening the opening / closing door 52. Moreover, since the opening / closing door 52 can be held at the predetermined open position by the door holding mechanism 70, it is not necessary for the operator to hold the opening / closing door 52 by hand when accessing the inner space S to perform an operation. Therefore, the accessibility of the operator to the inner space S can be improved as much as possible.

[0084] Further, in the present embodiment, the door holding member 71 is rotatably attached around a bolt 74 to the back surface of the opening / closing door 52. The door holding member 71 is configured to be displaceable between a holding position where it can hold the opening / closing door 52 with the bolt 74 as a fulcrum and a non-holding position rotated 180° (an example of a predetermined rotation angle) around the bolt 74 from the holding position. And, in the holding position, one end portion of the door holding member 71 abuts on a predetermined position on the upper surface of the roof plate portion 51a (a position adjacent to the lower side of the engagement hole 51e in this example), thereby exerting a door holding function of holding the opening / closing door 52 in the predetermined open position by stretching between the back surface of the opening / closing door 52 in the predetermined open position and the predetermined position of the roof plate portion 51a. On the other hand, in the non-holding position (the position of the two-dot chain line in FIG. 14), the abutment (the mutual abutment between one end portion of the door holding member 71 and the roof plate portion 51a) is released and the door holding function is configured to be invalidated.

[0085] According to this configuration, the door holding mechanism 70 of the opening / closing door 52 can be configured with a simple configuration of rotating the door holding member 71 around the bolt 74, so that the configuration of the door holding mechanism 70 can be simplified and the cost can be reduced. Also, since a rotation space for the door holding member 71 can be secured by utilizing the space on the back surface of the opening / closing door 52, the space efficiency can be improved compared to, for example, the case where the door holding member 71 is attached to the roof structure.

[0086] Further, in the present embodiment, the door holding member 71 has an engagement plate portion 71e that can be engaged with an engagement hole 51e formed in the roof plate portion 51a. In the door holding state (the state in FIG. 6), the rotation of the door holding member 71 around the bolt 74 is restricted by the engagement plate portion 71e engaging with the engagement hole 51e. On the other hand, when the opening / closing door 52 is rotated upward from the door holding state (the state in FIG. 6) and the opening angle around the hinge axis 55 of the opening / closing door 52 reaches a preset angle (the maximum opening angle θ2 in the above embodiment), the engagement between the engagement plate portion 71e and the engagement hole 51e is released and the rotation of the door holding member 71 around the bolt 74 is configured to be allowed.

[0087] According to this configuration, after the door holding member 71 enters the door holding state (the state shown in FIG. 6), the door holding member 71 cannot be rotated around the bolt 74 unless the opening / closing door 52 is once rotated to the maximum open position. Therefore, unless an external force sufficient to rotate the heavy opening / closing door 52 to the maximum open position acts on the opening / closing door 52, the door holding member 71 will not rotate around the bolt 74. Thus, it is possible to prevent, as much as possible, the door holding member 71 from unintentionally rotating around the bolt 74 due to an external force such as wind or impact when the door holding member 71 is in the holding position, thereby losing the door holding function of the door holding member 71.

[0088] Also, in the present embodiment, the axis of the bolt 74 extends in a direction orthogonal to the axis of the hinge shaft 55 of the opening / closing door 52.

[0089] According to this configuration, since the axis of the bolt 74 is orthogonal to the axis of the hinge shaft 55 of the opening / closing door 52, it is possible to suppress the door holding member 71 from rotating around the bolt 74 due to its own weight (gravity). That is, for example, when the axis of the bolt 74 is parallel to the axis of the hinge shaft 55 of the opening / closing door 52, the door holding member 71 is likely to rotate around the bolt 74 due to its own weight (gravity). However, in the present embodiment, by arranging the axis of the bolt 74 to be orthogonal to the axis of the hinge shaft 55 of the opening / closing door 52, the door holding member 71 can be sandwiched and fastened and held from both sides in the rotation direction of the opening / closing door 52 by the bolt 74 and the nut. Therefore, it is possible to suppress the door holding member 71 from rotating around the bolt 74 due to its own weight. Thus, it is possible to prevent the door holding member 71 from unintentionally rotating due to some external force (such as wind or impact) from the holding position where the door holding member 71 holds the opening / closing door 52 and losing its door holding function.

[0090] In addition, in the present embodiment, the door holding member 71 has a rotating plate portion 71a, a contact plate portion 71b, and a reinforcing plate portion 71c. The rotating plate portion 71a has a through hole 71d through which the bolt 74 passes and is arranged to face the opening / closing door 52. The contact plate portion 71b is erected on the opposite side surface 71f of the rotating plate portion 71a from the surface facing the opening / closing door 52, and in the door holding state (the state in FIG. 6), it contacts the predetermined position on the upper surface of the roof plate portion 51a. The reinforcing plate portion 71c is erected on the opposite side surface 71f of the rotating plate portion 71a and is connected to the opposite side surface of the contact plate portion 71b from the contact side surface with the roof plate portion 51a.

[0091] According to this configuration, when the door holding member 71 is in the holding position for holding the opening / closing door 52, the reaction force from the roof plate portion 51a acting on the contact plate portion 71b can be received by the reinforcing plate portion 71c arranged on the back side thereof. Therefore, the strength in the tension direction (longitudinal direction) of the entire door holding member 71 can be improved as much as possible, and the door holding function by the door holding member 71 can be strengthened.

[0092] In the present embodiment, the door holding member 71 further includes a first rotating seat plate 72 and a second rotating seat plate 73 arranged to sandwich the periphery of the penetrating portion of the bolt 74 in the door holding member 71 from both sides in the penetrating direction.

[0093] According to this configuration, an operator can smoothly perform the operation of rotating the door holding member 71 around the bolt 74 to switch between the non-holding position and the holding position. That is, when the first rotating seat plate 72 and the second rotating seat plate 73 are not provided, there is a possibility that the fastening load of the bolt 74 concentrates around the through hole 71d of the rotating plate portion 71a of the door holding member 71 and the rotation of the door holding member 71 is hindered. However, in the present embodiment, by sandwiching the periphery of the through hole 71d in the rotating plate portion 71a with the first rotating seat plate 72 and the second rotating seat plate 73, the concentration of the fastening load is prevented, and the switching operation between the non-holding position and the holding position by the rotation of the door holding member 71 can be smoothly performed.

[0094] In addition, in the present embodiment, the protective fence 1 further includes a wire 80 (an example of a locking member) for locking the opening / closing door 52. One end of the wire 80 is engaged and connected to an annular portion 75b of an eye nut 75 provided on the back surface of the opening / closing door 52, and the other end of the wire 80 is engaged and connected to an annular portion 79a of an eye bolt 79 attached to the side surface of the second support frame 62 (an example of a roof structure).

[0095] According to this configuration, since the opening / closing door 52 is locked to the second support frame 62 (roof structure) via the wire 80, it is possible to prevent the opening / closing door 52 from flying off due to a storm or the like. In addition, since the eye nut 75 for connecting the wire 80 is also used as a fastening member for connecting the door holding member 71 to the opening / closing door 52, the cost can be reduced by making parts serve multiple purposes.

[0096] (Other embodiments) As described above, the protective fence 1 according to the embodiment of the present invention has been described. However, the present invention is not limited to this, and for example, the following modified embodiments can be adopted.

[0097] In the above embodiment, the rotation axis of the door holding member 71 (the axis of the bolt 74 in the above embodiment) extends in a direction perpendicular to the axis of the hinge shaft 55. However, the present invention is not limited to this, and for example, it may extend in a direction parallel to the hinge shaft 55. In this case, the door holding member 71 will rotate up and down, but even with such a configuration, the same operational effects as those of the above embodiment can be obtained. However, in this case, it is preferable to separately provide a holding mechanism for holding the door holding member 71 in the non-holding position.

[0098] In the above-described embodiment, the wire 80 is connected to the eye nut 75 which is a fastening member for fastening the door holding member 71 to the opening / closing door 52. However, the present invention is not limited to this, and the bolt 74 may be replaced with an eye bolt, and the wire 80 may be connected to the annular portion of this eye bolt. In this case, the threaded portion of the eye bolt corresponds to the fastening main body portion, and the annular portion of the eye bolt corresponds to the annular portion connected to the fastening main body portion. Also in this case, it is preferable to penetrate the eye bolt from the back side to the front side of the opening / closing door 52. By doing so, the annular portion of the eye bolt can be positioned on the lower surface side of the opening / closing door 52.

[0099] In the above-described embodiment, the wire 80 which is a latching member is connected to the second support frame 62 (an example of a roof structure). However, the present invention is not limited to this, and it may be connected to the protective fence main body 2.

[0100] In the above-described embodiment, an example in which the rotation restricting engaging portion is constituted by the engaging plate portion 71e and the engaged portion is constituted by the engaging hole 51e has been described. However, the present invention is not limited to this. For example, the rotation restricting engaging portion may be constituted by an engaging hole, and the engaged portion may be constituted by an engaging plate portion that engages with the engaging hole. Also, the shapes of the engaged portion and the rotation restricting engaging portion may be any shape.

[0101] In the above-described embodiment, the door holding member 71 is configured to abut on one end portion thereof at a position adjacent to the lower side of the engaging hole 51e (an example of a predetermined location) in the holding position for holding the opening / closing door 52. However, the present invention is not limited to this. That is, the predetermined location on the roof structure where the door holding member 71 abuts may be at any position as long as it is located below the rotation axis (axis of the hinge shaft 55) of the opening / closing door 52 in the example of the above-described embodiment.

[0102] In the above-described embodiment, the roof structure is configured to include the roof portion 50, the first support frame 61, and the second support frame 62. However, the present invention is not limited to this, and any configuration may be used as long as it is a structure including the roof portion 50.

[0103] In the above-described embodiment, the door holding mechanism 70 is configured to cause the door holding member 71 to function as a strut member. However, the present invention is not limited to this, and any configuration may be used as long as it can hold the opening / closing door 52 at a predetermined open position.

[0104] In the above-described embodiment, the protective fence 1 has the protective fence fixing device 100. However, the protective fence fixing device 100 is not necessarily required. That is, the present invention is also applicable to the protective fence 1 that does not have the protective fence fixing device 100.

Explanation of Reference Numerals

[0105] 1: Protective fence 2: Protective fence main body 50: Roof part 51a: Roof board part (roof part, roof structure) 51c: Maintenance opening 51e: Engagement hole (engaged part) 52: Opening / closing door 61: First support frame (roof structure) 62: Second support frame (roof structure) 70: Door holding mechanism 71: Door holding member 71a: Rotating plate part 71b: Contact plate part 71c: Reinforcing plate part 71d: Through hole 71e: Engagement plate part (rotation restricting engagement part) 72: First rotating seat plate 73: Second rotating seat plate 74: Bolt 75: Eye nut (one fastening member, nut) 75a: Nut main body part (fastening main body part) 75b: Annular part

Claims

1. A protective fence installed at an installation location adjacent to a road on which a vehicle travels and configured to receive the vehicle when the vehicle deviates from the road, comprising a protective fence body, a roof structure connected to the protective fence body and including a roof portion that covers the upper side of the protective fence body, a maintenance opening formed in the roof portion, an opening / closing door attached to the roof portion and configured to be able to open the maintenance opening by rotating upward about a first predetermined axis from a closed position where the maintenance opening is closed, and a door holding mechanism capable of holding the opening / closing door at a predetermined open position. The protective fence is provided with these components.

2. In the protective fence according to Claim 1, the door holding mechanism has a door holding member that is rotatably attached to the back surface of the opening / closing door about a second predetermined axis and is displaceable between a holding position for holding the opening / closing door at the predetermined open position and a non-holding position rotated by a predetermined rotation angle about the second predetermined axis from the holding position, and the door holding member, at the holding position, exerts a door holding function of holding the opening / closing door at the predetermined open position by abutting one end portion thereof against a predetermined portion of the roof structure and stretching between the back surface of the opening / closing door at the predetermined open position and the predetermined portion of the roof structure, while at the non-holding position, the abutment is released and the door holding function is invalidated. The protective fence is configured in this way.

3. In the protective fence according to Claim 2, the roof structure is provided with an engaged portion, and the door holding member has a rotation restricting engagement portion engageable with the engaged portion. In a state where the opening / closing door is held at the holding position, rotation about the second predetermined axis is restricted by the rotation restricting engagement portion engaging with the engaged portion. On the other hand, when the opening / closing door is rotated upward from this state and the opening angle of the opening / closing door about the first predetermined axis reaches a preset angle, the engagement between the rotation restricting engagement portion and the engaged portion is released and rotation about the second predetermined axis is allowed. The protective fence is configured in this way.

4. In the protective fence according to Claim 2 or 3, the first predetermined axis extends in the horizontal direction, and the second predetermined axis extends in a direction orthogonal to the first predetermined axis. The protective fence is configured in this way.

5. In the protective fence according to Claim 4, the door holding mechanism includes a bolt that penetrates the opening / closing door and the door holding member and constitutes the second predetermined axis, A protective fence further having a nut that engages with the bolt to hold the door holding member in a non-detachable manner from the opening and closing door.

6. In the protective fence according to claim 5, the door holding member includes a rotating plate portion disposed to face the back surface of the opening and closing door and having a through hole through which the bolt passes, a contact plate portion standing on the side opposite to the surface of the rotating plate portion facing the opening and closing door and functioning as the one end portion, a reinforcing plate portion standing on the opposite side surface of the rotating plate portion and connected to the side surface of the contact plate portion opposite to the contact side surface with the roof structure. A protective fence having.

7. In the protective fence according to claim 5, the door holding mechanism further includes a first rotating seat plate and a second rotating seat plate disposed so as to sandwich the periphery of the penetrating portion of the bolt in the door holding member from both sides in the penetrating direction. A protective fence.

8. In the protective fence according to claim 5, further provided with a locking member for locking the opening and closing door to the roof structure, one end of the locking member is connected to one of the fastening members of the bolt and the nut, and the other end is connected to the roof structure, the one fastening member has a fastening main body portion forming a screw portion and an annular portion connected to the fastening main body portion and engaged with the one end portion of the locking member. A protective fence.

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