JP3728557B2 - Manhole upper lid closing device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a manhole upper cover hole closing device for closing a jig insertion hole of a manhole upper cover exposed on a road surface.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, various devices for closing a hole serving as a clue for opening / closing a manhole upper cover are known so that the upper cover of a manhole is not opened / closed undesirably. For example, as a known example of such a device, actual fair 7-17768 or actual fair 7-54354 is disclosed, which uses a bolt having a head that can be operated only by a jig having a special tip shape. In this case, a closing bracket is fixed to the upper lid hole.
[0003]
Since the weight of the upper cover of the manhole is extremely large, an object such as a hand hook is inserted into the upper cover hole of the plane substantially elliptical shape, and its tip is hooked on the back side of the upper cover, thereby causing the upper cover to open. If this upper lid hole is closed, there is no clue for opening and closing, and the inconvenient opening and closing becomes impossible, which is the starting point of the known example.
[0004]
As described above, a specially shaped bolt is used as a means for closing the upper lid hole. However, in the case of the former known example, the nut that is moved by the rotation of the bolt is substantially the same shape as the upper lid hole. The nut that slides in the upper lid premises by tightening the bolt and approaches the bolt head deforms the elastic body interposed between the bolt head and the nut and presses the inner wall surface of the upper lid hole. Thus, the bolt is fixed by friction between the elastic body and the inner wall surface of the upper lid hole.
[0005]
Further, in the case of the latter known example, the nut itself also has a special shape, and the nut protruding from the upper lid hole to the rear surface of the upper lid stays on the rear surface of the upper lid by the rotation of the bolt, and by tightening the bolt The nut is brought into contact with the back surface of the upper lid and the upper lid is sandwiched and supported between the bolt head and the nut to fix the bolt.
[0006]
[Problems to be solved by the invention]
The problems that arise with such devices are that they are generally installed on outdoor roads for a considerable length of time and continue to receive the speed and weight of vehicles passing over them as well as outdoor weather conditions for long periods of time. It is to continue to undergo change. Such severe use conditions deteriorate the elastic body used for fixing in the former known example, gradually reduce the frictional force with the inner wall surface of the upper lid hole necessary for fixing, and the worst In some cases, the device may fall out of the top lid hole, and once the device is detached due to the necessity of work, the elastic body is in a state that cannot be reused, and a new closure device is applied. I have to do it.
[0007]
In the case of the latter known example, the nut is firmly in contact with the back surface of the upper lid by fixing. For example, when wheel pressure is applied to the bolt head when passing through the automobile, the bolt is supported at the upper end of the nut. If this is repeated over a long period of time, the bending of the bolt will be promoted, and the bolt will bend so that it cannot be turned to remove the device. Inevitable situation. The current products other than these known examples are generally fixed with a bolt inserted into the upper hole of the manhole, with a latch protruding on the back surface of the upper lid, and by firmly turning the bolt between the bolt and the latch by rotating the bolt. Therefore, when the wheel pressure is repeatedly applied to the bolt, the stronger the fixing, the more inevitable the bending of the bolt, resulting in the inconvenience that the bolt cannot be rotated.
[0008]
With respect to these known examples, the present invention aims to provide a novel occlusion device having high weather resistance and being able to cope with external physical pressure.
[0009]
[Means for Solving the Problems]
The use of a bolt head that can be operated with a special wrench is a desirable idea from the viewpoint of obtaining the high strength and simple structure required for this type of device. Further, from the viewpoint of preventing the deformation of the bolt, a form in which fixing is achieved by a frictional force is desirable. Furthermore, it is also important for the means for obtaining the frictional force not to be an elastic body but to be made of a metal block in order to counter changes with time in consideration of weather resistance.
[0010]
In order to realize such a device, in the present invention, a bolt having a deformed head is adopted, and the nut moves in the manhole upper lid hole and can be brought into close contact with the inner wall surface by changing the amount of movement. . Furthermore, the bolt is inserted into a main body having a flange covering the upper surface of the upper lid hole, and a long hole is formed so as to be movable only in one radial direction with respect to the axis of the bolt. The bolt head is accommodated in the container.
[0011]
The cross section of the main body and nut connected by a single bolt is shaped so that it can be inserted into the upper hole of the manhole with a slight margin, and the rotation of the bolt is free without affecting the main body. Yes, the nut is arranged so as to move inside the upper lid hole.
[0012]
The opposing surfaces of the main body and the nut are formed by slopes having the same angle as each other with respect to the axis of the bolt, and the nut is attracted to the main body by tightening the bolt. The nut that protrudes in the lateral direction from the main body due to the movement of the nut in the radial direction is pressed against the inner side wall of the upper lid hole. Arrange it.
[0013]
In this case, the movement of the nut in the radial direction also causes the movement of the bolt in the same direction, but the movement of the nut along the longitudinal direction of the long hole drilled in the main body and the slope of the nut By making the forming direction coincide with the longitudinal direction of the long hole, it is possible to secure room for movement of the bolt.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, an embodiment of the apparatus of the present invention will be described. In the figure, reference numeral 1 denotes a main body, 2 denotes a nut, and 3 denotes a bolt. The main body 1 is provided with a flange 4 at one end in the axial direction, and a long hole 5 having a substantially elliptical cross section is formed through the main body 1 in the longitudinal direction. At the same time, a recess 6 is formed around the long hole 5 that opens in the flange 4, and a bolt head 3 a having a deformed shape (pentagonal in the illustrated example) of the bolt 3 inserted into the long hole 5 is provided. It is accommodated in the recess of the recess 6. A washer 7 is installed between the bolt head 3 a and the main body 1.
[0015]
The bolt 3 inserted into the long hole 5 is allowed to move along the longitudinal direction in the long hole 5. The main body 1 is dimensioned so that it can be inserted into the manhole upper cover hole and does not rattle after insertion. When the manhole upper cover hole has a substantially elliptical plane, the cross section of the main body 1 is also substantially elliptical as shown in the figure. It becomes a shape. The other end of the main body 1 is formed with an inclined surface 8 cut at right angles to the longitudinal side surface of the main body 1 having an elliptical cross section.
[0016]
A nut 2 is screwed to the end of the bolt 3 in which the bolt head 3a is inserted into the elongated hole 5 inside the recess 6. A split pin 9 is inserted into the protruding end of the bolt 3 through a washer. The nut 2 is prevented from falling off. Further, the nut 2 is provided with an inclined portion 10 cut in parallel with the inclined surface 8 of the main body 1.
[0017]
The operation will be described. First, the main body 1 and the nut 2 having a substantially elliptical cross section are inserted into the upper cover hole of the manhole with the bolt 3 sufficiently loosened (state shown in FIG. 1). As described above, the main body 1 can be inserted into the upper lid hole, but its backlash is slight, and the flange 4 of the main body 1 covers the opening of the upper lid hole.
[0018]
Next, when the deformed bolt head 3a is rotated by a wrench or the like adapted thereto, the bolt 3 is tightened and the nut 2 screwed on the bolt 3 is attracted to the main body 1. As a result, the inclined portion 10 of the nut 2 comes into contact with the inclined surface 8 of the main body 1. When the bolt 3 is further tightened, the nut 2 is pushed out along the inclined surface 8 of the main body 1 in a direction perpendicular to the axial direction of the bolt 3. It is. This increases the longitudinal diameter of the main body 1 and the nut 2 having a substantially elliptical cross section, the side surface of the nut 2 (the lower portion in FIG. 2) abuts the inner surface of the upper lid hole, and the bolt 3 As a result, the side surface of the nut 2 is strongly pressed against the inner surface of the upper lid hole. When the nut 2 is pressed strongly against the inner side surface of the upper lid hole, a large frictional force is generated between the two, thereby closing the manhole upper lid hole.
[0019]
In order for the nut 2 to move in the longitudinal direction of the cross section of the main body 1 by tightening the bolt 3, the bolt 3 is inserted into the long hole 5 having a substantially elliptical diameter as described above. It is allowed to move the distance in the longitudinal direction of the substantially elliptical diameter.
[0020]
In order to remove the apparatus of the present invention installed as described above from the manhole upper lid hole, the bolt 3 is loosened using the same wrench as that used for installation, but the nut 2 is placed inside the upper lid hole by tightening during installation. Since a wedge is entered between the side surface and the slope 8 of the main body 1 to maintain a large frictional force, the nut 2 does not move due to the loosening of the bolt 3, and the bolt 3 is moved from the nut 2 in the fixed state. It comes out and protrudes from the collar part 4 of the main body 1. Since this protrusion amount is limited by the retaining split pin 9 installed at the tip of the bolt 3, the projection of the bolt 3 is performed within the limited range, and the split pin 9 is attached to the nut 2 via the washer. Stops when it comes into contact.
[0021]
If the bolt head 3a protrudes from the flange 4 and stops, if the bolt head 3a is lightly driven into the recess 6 of the flange 4, the frictional force between the inclined surface 8 of the main body 1 and the inner surface of the upper lid hole can be obtained. The nut 2 that has been maintained moves after its friction is released, and can return to the starting position before the installation of the device. If the screwed state of the bolt 3 and the nut 2 does not proceed smoothly due to a change during use, if the bolt 3 is loosened and the bolt head 3a is driven several times, the nut 2 The position can be applied suddenly, and when the nut 2 returns to the old position, the upper lid hole can be opened by removing the whole from the upper lid hole with the flange 4.
[0022]
The material of the device of the present invention is preferably a metal having high rust prevention properties, but it is of course possible to use reinforced synthetic resin or the like if the strength problem is solved.
[0023]
【The invention's effect】
As described above, according to the present invention, since the bolt used for fixing is accommodated in the elongated hole of the main body, even if an external force acts on the main body, particularly the collar portion, the force directly affects the bolt. It is released in the range of the margin of the long hole without any possibility, so that there is no possibility that the unremovable state of the device due to the deformation of the bolt that was often seen in the conventional device, and the structure is simple but the effect is reliable There is.
[Brief description of the drawings]
FIG. 1 is a side view of an embodiment of the present invention in a non-installed state.
FIG. 2 is a side view of the installed state of the embodiment of the present invention.
FIG. 3 is a plan view of the embodiment of the present invention in a non-installed state. FIG. 4 is a plan view of the embodiment of the present invention in an installed state.
FIG. 5 is a plan view of a main body portion of an embodiment of the present invention.
FIG. 6 is a bottom view of the main body portion of the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Nut 3 Bolt 3a Bolt head 4 Gutter part 5 Long hole 6 Recess 7 Washer 8 Slope 9 Split pin 10 Slanted part

Claims (1)

A long hole in which a bolt is drilled in a main body in a manhole upper cover hole closing device comprising a main body that can be inserted into a manhole upper cover hole, a bolt having a deformed head that can be inserted into the main body, and a nut screwed to one end of the bolt. The bolt head is accommodated in the recess of the collar portion installed at one end of the main body, and the oblique portion is installed along the longitudinal direction of the long hole at the other end of the main body, and the one end of the nut is the main body A manhole upper lid hole closing device having a slope corresponding to the slanted portion of the bolt and a nut stopper on the end of the bolt adjacent to the other end.

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