JPS5935651Y2 - Manhole opening closing structure - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a manhole opening closing structure that is attached to a manhole on a general road or the like.

Manhole covers, which are generally attached to manholes such as roads, often shift from the manhole or come off.

Therefore, it is not only unsafe for cars and people passing on the road, but also extremely dangerous.

The proposer of the present application considered that the above-mentioned movement phenomenon of the manhole cover was due to the following reasons.

That is, as shown in FIG. 1, a conventional manhole cover 1 has a rectangular cross section and is placed on a manhole stand 2.

For this reason, assuming that the car tire 3 rotates in the direction of the arrow \\ and applies force to the manhole cover 1 without slipping, the moment the tire 3 touches the outer circumferential upper edge 1a of the manhole cover, the tire 3 Contact point 1c between 1b and manhole stand 2
is the fulcrum, and the contact point 1d between the tire 3 and the outer peripheral wall 1b is the point of force, and due to the rotation of the tire, the force in the circumferential direction of the tire outer peripheral portion 3a causes the manhole cover 1 to move around the contact point 1C by the action of a lever. As shown in the imaginary line,
be lifted up.

The effect of lifting the manhole cover 1 is to
It was hypothesized that this would occur when various factors such as the thickness of the tire, the speed of the car, the type and size of the tires, etc., met certain conditions.

The present invention was devised in view of the above circumstances, and aims to provide a safe manhole opening closing structure that exhibits sufficient mounting effect and does not slip or come off from the manhole. It is.

Hereinafter, embodiments of this invention will be described in detail based on the drawings.

FIGS. 2 and 3 show an embodiment of this invention, in which the upper outer periphery 10a of the plate-shaped body 10 is formed with an inclined portion 10c that slopes downward toward the peripheral end 10b. - An outer peripheral wall 10d extending vertically downward is formed on the peripheral end portion 10b.

The size of the inclined portion 10c and the outer peripheral wall 10d are as follows:
The plate-like body 10 is set so as not to be lifted up when the tire comes into contact with the peripheral end portion 10b of the plate-like body 10.

On the other hand, the cylindrical manhole stand 11 on which the plate-shaped body 10 is placed is provided at the periphery of the opening of the manhole,
A convex portion 11a is provided on the upper surface of the manhole base 11 and extends around the inner periphery of the manhole base 11, and a flange portion 15 is provided on the upper outer periphery of the manhole base 11 so as to come into contact with the lower surface of the plate-shaped body 10. It is being

The circular plate-shaped body 10 is formed such that its outer circumferential wall 10d is located inside the outer circumferential portion of the flange portion 15 of the manhole base 11, and a fitting hole formed concentrically with the outer circumferential wall 10d is formed on its inner surface 10e. It has a concave groove 10f, and a manhole stand 1
The inner circumferential surface 10e is fitted into the convex portion 11a of the manhole base 11, and the manhole table 11 is placed on the manhole base 11.

Further, as shown in FIG. 4, the thickness T of the inner peripheral side wall 10g of the fitting groove 10f is formed to be larger than the thickness t of the outer peripheral side wall 10h, so that the lid can sit well on the manhole base 11. It has become.

Incidentally, a V-shaped groove 13 as shown in FIG. 7 and a semicircular protruding anti-slip 13 as shown in FIG. 8 are provided at appropriate locations on the upper surface 10g of the plate-like body.

As explained above, according to this invention, the following excellent effects can be achieved.

■ Since the manhole cover has a sloped part where the upper part of the outer periphery of the plate-shaped body slopes downward as it goes outward, if the manhole cover of this invention is used on general roads,
Even if a car tire comes into contact with this, there is no point to focus on, so there is no large force acting on the manhole cover like in the past, and the manhole cover maintains a stable state without moving from above. Become.

Therefore, the present invention provides a manhole cover which is free from danger and has a safe installation effect.

■ Since the plate-shaped body is placed on the flange of the manhole stand, even if the road surface is uneven and the manhole stand and the road surface are not flush, the work will be carried out under the influence of such road surface. To prevent a plate-like body from shaking in a lid state and to be able to reliably and safely attach it to an opening of a manhole.

This means that as automobiles become larger and have higher horsepower, the lid (plate) lifts up due to rattling (in other words, the rattling of the lid forms a point of force and a fulcrum on the lid,
This completely prevents the lid from lifting when a large torque is applied, increasing safety.

■ A fitting groove is provided on the lower surface of the plate-like body, and the inner circumferential side wall of this fitting groove is made longer than the outer circumferential side wall, so that the plate-like body can be easily fitted, and the lid can be easily seated. Furthermore, even if the plate-shaped body and the manhole base are formed of cast metal, they can be easily manufactured and the cost can be reduced.

In addition, since the inner peripheral side wall of the fitting groove on the inner surface of the plate-like body is made large, the strength is strong and can sufficiently cope with large loads (for example, torque from automobile tires).

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing how a conventional manhole cover is attached. Fig. 2 is a partial sectional view showing one embodiment of the manhole cover of this invention, Fig. 3 is a plan view, Fig. 4 is a sectional view showing the installed state of the manhole cover of this invention, and Fig. 5 is a manhole stand. 6 is a plan view, FIG. 7 is an enlarged view of the part 2 in FIG. 2, and FIG. 8 is an enlarged view of another slip stop. 1... Manhole cover, 10... Plate-shaped body, 10a... Upper outer periphery, 10c... Inclined portion, 10d... Outer peripheral wall , 10f...
・Mating groove, 10g... Inner peripheral side wall, 10h...
...Outer peripheral side wall, 11... Manhole stand, l
la... Convex portion, 15... Flange portion.

Claims (1)

[Scope of utility model registration request] In a manhole opening closing structure in which a plate-like body 10 is placed on two sides of a cylindrical manhole stand 11 provided at the periphery of the manhole opening to close the manhole opening, the manhole stand 11 A convex portion 11a is provided on the upper surface of the 11a to extend around the inner periphery of the 11a.
A flange portion 15 that comes into contact with the lower surface of the plate-like body 10 is provided on the upper outer circumference of the manhole base 11, and on the other hand, the outer circumferential wall 10b of the plate-like body 10 is located inside the outer circumferential portion of the flange portion 15. The lower surface of the plate-like body 10 has a fitting groove 10f that fits into the convex portion 11a.
is formed, and the thickness T of the inner peripheral side wall 10g of the fitting groove 10f is formed to be larger than the thickness t of the outer peripheral side wall 10h. Therefore, a manhole opening closing structure is characterized in that the opening is sloped downward.