JPS6111323Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a support structure for a square lid for underground structures and a lid holder frame.

In this specification, square lids for underground structures refer to large iron lids, mounting lids, and manhole iron lids that serve to open and close underground underground objects such as water supply and sewage systems, and openings that communicate with underground structural facilities and above ground. Lid and underground facility equipment,
Iron lids and mounting lids that serve to protect and open and close wiring, etc., as well as fire hydrant lids and water control valve lids that serve as opening and closing doors that connect conduits buried under roads and their auxiliary equipment to the ground. Refers to square-shaped gate valve lids, air valve lids, gas pipe lids, and water meter lids.

Conventional lid support structures for square lids for underground structures include flat-receiver support structures in which only a protruding edge is provided on the lower surface of the periphery of the lid, and flat-receiver support structures in which the inner surface of the receptacle frame is sloped linearly or curved. There is a slope receiving type lid support structure in which the outer circumferential surface of the protruding edge of the lid fits into the sloped inner surface.

In the former flat support type lid support structure, the load on the lid is directly received by the horizontal step as a vertical load, and as the lid becomes larger, the lid bends and the generated stress increases, so the strength of the lid is strengthened by thick ribs. This has the disadvantage that it is heavy, expensive, difficult to handle, and generates noise due to rattling vibration caused by the gap between the lid and the receiving frame.

In addition, the latter type of lid support structure in which only one side has a slope support has the disadvantage that the support frame deforms into a bulging shape when a load is applied from above, especially in the case of a square lid, and concentrated stress occurs particularly at the corners. It was hot.

The present invention provides a new rectangular lid frame structure for underground structures that eliminates these drawbacks.

Hereinafter, the present invention will be explained using an example in which the present invention is applied to a large iron lid consisting of a plurality of lids shown in the attached FIGS. 1 and 2.

In these figures, reference numeral 1 indicates a rectangular lid for an underground structure in which a steeply sloped trapezoidal protrusion 2 with linearly inclined inner and outer sides is provided along the lower surface periphery of two opposing sides. Reference numeral 3 denotes a lid receiving frame having a fitting groove 4 on its inner peripheral surface for fitting and supporting the trapezoidal protruding edge 2 of the lid 1.

As shown in FIG. 2, the fitting groove 4 of the lid receiving frame 3 has an inclined surface that is the same on both the inner and outer sides of the trapezoidal projection 2 and a bottom surface that is narrower than the width of the top of the trapezoidal projection 2. When the lid 1 is mounted on the lid holder frame 3, only both inner and outer surfaces of the trapezoidal protrusion 2 of the lid 1 are connected to both inner surfaces of the fitting groove 4 of the lid holder frame 3. A gap is provided between the top of the trapezoidal edge 2 of the lid 1 and the bottom of the fitting groove 4 of the lid holder frame 3. The fitting groove 4, which is a receiving frame support structure for receiving the projecting edge 2 of the lid 1, is composed of a pair of opposing receiving plates 5, 5'.

Reference numeral 6 indicates a rib on the lower surface of the lid 1, 7 indicates a rib on the receiving frame 3, and 8 indicates a pivot portion of the lid 1 relative to the receiving frame 3.

In this invention, the projecting edge 2 of the lid 1 is used by fitting into the fitting groove 4 of the receiving frame 3. When a load P is applied to the lid 1, the trapezoidal projecting edge 2 slides down the fitting groove 4. The projecting edge 2 presses the receiving plates 5, 5', respectively, and the receiving plates 5, 5' have reaction forces R, R', respectively, and the pressing force is applied by both sides of the projecting edge 2. The lid 1 stops at a position where the load P and the vertical components of the reaction forces R and R' are balanced.

Even in this state, the lower surface of the protrusion 2 does not come into contact with the bottom surface of the fitting groove 4, and there is a gap between them, so there is no load transmission through the bottom surface of the fitting groove 4, and the lid 1 is supported only by the inclined side surfaces of the receiving plates 5, 5'. In this way, the trapezoidal projecting edge 2 is fitted and supported in the fitting groove 4 formed by the receiving plates 5, 5', and the lid 1 and the receiving frame 3 are in a semi-fixed state. Therefore, the stress and strain on the lid 1 are influenced by the reaction forces R, R' and the resistance moment of the receiving frame 3, the apparent strength of the lid 1 increases, and the stress value and strain on the lid 1 are significantly reduced. At the same time, since it is in a semi-fixed state, no noise caused by rattling vibration is generated.

The horizontal component force that the receiving frame 3 receives from the lid 1, that is, the horizontal component force that is received at each receiving frame peripheral edge position, is opposite in direction, so the reaction forces R and R' cancel each other out and decrease. This is significantly smaller than the horizontal component force (in the case of only reaction force R). Therefore, acceptance slot 3
It is possible to greatly reduce the horizontal deformation (displacement) experienced by This effect is remarkable in rectangular lid receiving frames where concentrated stress acts at the corners and bulge-like deformation is likely to occur at the non-corner periphery. The reaction forces R and R' are generated by the projecting edge 2, the receiving plate 5,
This can be adjusted by changing the inclination angle of the fitting surface 5'.

In the embodiment shown in the accompanying drawings, the present invention was applied to two opposing sides, but of course, in a rectangular type with two lids, three sides excluding mutually adjacent sides were explained. Moreover, in the case of a rectangular type having a single lid, the structure of the present invention can be provided on each side.

As described above, according to the present invention, the apparent strength of the lid 1 is increased by making the projecting edge part 2 into a trapezoidal shape and receiving it by a pair of opposing receiving plates 5, 5'. The lid 1 can be obtained by using a light material, making it inexpensive and easy to handle, and the tightening by the receiving frame 3 can prevent the generation of noise caused by rattling vibrations of the lid 1. Moreover, the outer receiving plate 5
The horizontal force acting on the receiving frame 3 is significantly reduced by receiving the load twice by the inner receiving plate 5'.
This has the effect that deformation of the receiving frame 3 can be suppressed to a large extent.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing an embodiment of the lid structure for underground structures of the present invention, and FIG. 2 is an enlarged vertical sectional view taken along the line shown in FIG. 1. 1: Lid, 2: Trapezoidal edge, 3: Receiving frame, 4: Fitting groove, 5, 5': Receiving plate.

Claims (1)

[Scope of utility model registration request] A rectangular lid 1 for an underground structure having a steeply sloped trapezoidal ridge 2 with linearly inclined inner and outer sides along the periphery of the lower surface, and a fitting that fits and supports the trapezoidal ridge 2 of the lid. In a rectangular lid frame structure for an underground structure consisting of a lid receiving frame 3 provided with a groove 4 on the inner peripheral surface, the fitting groove 4 of the lid receiving frame 3 is the same on both the inner and outer sides of the trapezoidal protrusion 2. and a bottom surface narrower than the width of the top of the trapezoidal protrusion 2, and the lid receiving frame 3 of the lid 1
When the lid 1 is placed on a shelf, the trapezoidal protrusion 2 of the lid 1
Only the inner and outer surfaces of the lid receiving frame 3 are fitted and supported by the inner and outer surfaces of the fitting groove 4 of the lid receiving frame 3, and the top of the trapezoidal protrusion 2 of the lid 1 and the bottom of the fitting groove 4 of the lid receiving frame 3 are connected to each other. A rectangular lid frame structure for underground structures, characterized by having a gap between the ends.