JP3308500B2 - Lock structure of manhole cover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lock structure for a manhole cover. More specifically, the present invention relates to a lock structure for preventing unauthorized opening of a manhole cover that closes a manhole that leads to an underground channel through sewage, communication, and power cables.

[0002]

2. Description of the Related Art FIG. 15 shows a lock structure of a manhole cover for closing a manhole leading to an underground trench through which sewage and communication cables are passed. In this conventional lock structure for a manhole cover, a hinge 5a is provided at one end of the manhole cover 5, and a key member 5 is provided at the other opposite end.
b is provided. The hinge 5a is penetrated into the hole 4a of the manhole opening 4 so as not to be pulled out, and the tip of the key member 5b has the same protrusion 4b of the manhole opening 4.
Are engaged using the weight of the key member 5b. Also,
A spring 5c is provided to prevent the engagement from being released.

[0003]

However, the lock structure of the conventional manhole cover described above has a problem that the manhole cover 5 can be relatively easily removed. That is, for example, a bur or the like is inserted from a hole formed in the manhole cover 5 above the key member 5b, and the tip of the key member 5b is pressed against the elasticity of the spring 5c. As a result, the manhole cover 5 is relatively easily removed by lifting the manhole cover 5 after releasing the engagement between the tip of the key member 5b and the projection 4b.

In the conventional manhole cover 5, since the key member 5b is fixedly attached to the manhole cover 5, the structure of the manhole cover 5 is complicated.
There is also the problem that its manufacture and assembly is cumbersome.

It is an object of the present invention to provide a locking structure for a manhole cover which is not illegally removed from the manhole opening frame.

It is another object of the present invention to provide a lock structure for a manhole cover which has a simple structure and is easy to manufacture and assemble.

[0007]

According to a first aspect of the present invention, there is provided a lock structure for a manhole cover, comprising: a manhole opening frame (1); and a manhole opening frame (1). A lock structure for a manhole cover, comprising: a manhole cover (2) to be closed; and a lock member (3) attached to the manhole opening frame (1) to prevent unauthorized opening of the manhole cover (2). A storage recess (1a) in which a support groove (1b) is formed on both side walls and a stop projection (1d) is formed at an entrance portion is formed at one location on the inner peripheral surface of the manhole opening frame (1). A hole (1c) is formed in the other portion of the inner peripheral surface facing the recess (1a), and both ends of the lock member (3) are inserted into support grooves (1b) formed in both side walls. It is integrated with the support rod (3c) attached so as to be fitted. Forward and reverse rotation to the hook portion (3b)
The hook (3b) has a heavy base (3d) projecting outward and downward from the support rod (3c), and a base (3d).
d) and an abutting projection (3e) projecting inward and downward from the support rod (3c).
f) and the abutting projection (3g) projecting upward from the abutting projection (3f), the side surface of the manhole cover (3c) is substantially H-shaped, and the manhole cover (3c) is formed. At one place on the lower surface of the outer peripheral end of 2), the engagement protrusion (3) of the lock member (3) is provided.
e) is formed with an engaging projection piece (2a) to be engaged with, and withdrawn into the hole (1c) of the manhole opening frame (1) at the other location on the lower surface of the outer peripheral end opposite to the engaging projection piece (2a). In the state where the hinge member (2b) which cannot be fitted and assembled is provided, and the manhole cover (2) is opened, the locking member (3) has the base (3d) whose stop (3d) is stopped by the weight of the base (3d). (1d) until it comes into contact with the manhole cover (3h). The assembly opening (3h) formed between the engagement protrusion (3e) and the contact protrusion (3g) opens upward to cover the manhole cover (3d). 2) Engagement projection (2a)
When the manhole cover (2) is started to be closed, the engaging projection (2a) of the manhole cover (2) presses the contact protruding portion (3g) of the lock member (3). The locking member (3) rotates in reverse with the support rod (3c) as a fulcrum, and the engaging projection (2a) of the manhole cover (2).
When the tip of the engagement protrusion (3e) of the lock member (3) comes into contact with the tip of the lock member (3) and the manhole cover (2) is further closed, the lock member is engaged by the engagement protrusion (2a) of the manhole cover (2). When the contact protruding portion (3g) of (3) is pushed down, the locking member (3) rotates in reverse with the tip of the engaging protruding portion (3e) as a fulcrum, and further closes the manhole cover (2). The engagement projection (2a) of the manhole cover (2) pushes the contact projection (3g) of the lock member (3) further downward, and the tip of the engagement projection (2a) is attached to the assembly opening. (3
h), when the manhole cover (2) is completely closed, the abutting projection (3f) of the lock member (3) abuts the stop projection (1d) of the manhole opening frame (1),
The lock member (3) rotates in reverse with the tip of the abutting protrusion (3f) as a fulcrum, and then rotates forward with the weight of the base (3d), whereby the manhole cover (2) is closed and locked. When the manhole cover (2) is to be opened from this locked state, the lock member (3) rotates forward around the support bar (3c) by the weight of the base (3d), and the lock member (3) is rotated. The engaging projection (2a) of the manhole cover (2) is sandwiched between the engaging projecting portion (3e) and the contact projecting portion (3g), and the manhole cover (2) is further opened from this state. Then, the lock member (3) moves upward, and the engagement protrusion (3e) comes into contact with the lower surface of the inner peripheral end of the manhole opening frame (1), thereby preventing the manhole cover (2) from being further opened. , Characterized in that:

According to a second aspect of the present invention, there is provided a lock structure for a manhole cover, wherein the support rods (3c) of the lock member (3) correspond to the support grooves (1b) on both side walls of the manhole opening frame (1). And a guide groove (1e) for guiding the guide groove is formed.

Further, in the locking structure of the manhole cover according to the third aspect, a projection (2p) is formed on the upper surface of the tip of the engagement projection (2a), and the engagement projection (3e) is formed. A projection (3p) engageable with the projection (2p) of the engagement projection (2a) is formed on the lower surface of the tip.

The symbols in parentheses indicate corresponding elements or matters described in the drawings and the embodiments of the invention described later.

According to the first aspect of the present invention,
When the manhole cover is closed, the engaging projections enter into the assembling opening of the lock member attached to the manhole opening frame in a loosely fitted state, and the manhole cover is closed and locked. . From this locked state, even if the manhole cover is to be opened, the engagement protrusion of the manhole cover is sandwiched between the engagement protrusion and the contact protrusion that form the assembly opening of the lock member, and Since the engagement protrusion contacts the lower surface of the inner peripheral end of the manhole opening frame, it cannot be opened.

The locked state of the manhole cover is obtained by simply closing the manhole cover, and can be obtained without any other special operation, so that the closing operation is extremely easy.

According to the second aspect of the present invention, since the guide groove which is continuous with the support groove is formed in the storage recess of the manhole opening frame, the lock member can be detachably attached to the manhole opening frame. That is, the support rods protruding from both side ends of the lock member can be fitted into the guide grooves of the manhole opening frame, and can pass through the guide grooves to be positioned in the support grooves. Therefore, each of the manhole opening frame, the manhole cover and the lock member is a simple separate molded product, and the overall structure is simple. In addition, its manufacture and assembly are facilitated.

Further, according to the third aspect of the present invention, a projection is formed on the upper surface of the tip of the engagement projection, and the projection of the engagement projection is formed on the lower surface of the tip of the engagement projection. Since the protruding portion engageable with the protruding portion is formed, it is difficult to open the manhole cover illegally.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lock structure for a manhole cover according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial sectional side view showing a lock structure, FIG. 2 is a front view showing a lock member, and FIG. 3 is a side view thereof. FIG. 4 is a plan view showing a manhole opening frame, and FIG. 5 is a partial cross-sectional side view showing a storage recess and a support groove. FIG. 6 is a bottom plan view of the manhole cover. FIGS. 7 to 14 are side sectional views showing the operation of the lock structure in order from the step of closing the manhole cover until the manhole cover is about to be opened.

The locking structure of the manhole cover according to the embodiment of the present invention is a flat circular manhole opening frame 1 made of iron.
A manhole cover 2 for closing the manhole opening frame 1, and an iron lock member 3 which is attached to the manhole opening frame 1 in a loosely fitted state and prevents unauthorized opening of the manhole cover 2. Have been.

An accommodating recess 1a having a substantially triangular support groove 1b formed on both side walls at one location on the inner peripheral surface of the manhole opening frame 1 and a standing protrusion 1d standing upright at the entrance.
Is formed. Further, an assembling plate 1f is laterally provided at the other position on the inner peripheral surface of the manhole opening frame 1 facing the storage recess 1a with reference to the center point of the manhole opening frame 1,
A hole 1c is formed in the assembling plate 1f.

Further, the lock member 3 is constituted by a hook portion 3b that rotates forward and reverse integrally with a support rod portion 3c that is mounted so that both ends thereof are loosely fitted into support grooves 1b formed on both side walls. ing. The number of hooks 3b may be one, and two hooks 3b may be provided at each of the left and right ends of the connecting rod 3a as shown in FIG. And hook part 3b,
A heavy-weight base 3d protruding outside the support rod 3c, that is, below the outer peripheral wall of the manhole opening frame 1,
An engaging projection 3e projecting substantially above the base 3d, a projecting projection 3f projecting inward from the support bar 3c, that is, a lower portion near the center of the manhole opening frame 1, and projecting above the projecting projection 3f. With the contact protruding portion 3g, the side surface shape is substantially H-shaped with the support rod portion 3c substantially at the center.

Further, an engagement projection 2a with which the engagement projection 3e of the lock member 3 engages is formed at one position on the lower surface of the outer peripheral end of the manhole cover 2, and is opposed to the engagement projection 2a. The hole 1 of the manhole opening frame 1 is provided at the other position on the lower surface of the outer peripheral end.
c is provided with a hinge member 2b which is fitted and fitted so that it cannot be pulled out. The hinge member 2b has its upper end pivotally attached to the manhole cover 2 by a pin 2c.
The hinge member 2b has a curved shape, and has a wide portion 2d formed at a lower end thereof. Thereby, the manhole opening frame 1 is prevented from coming out of the hole 1c.

In the lock structure of the manhole cover having such a configuration, the relationship among the manhole opening frame 1, the lock member 3, and the manhole cover 2 is set as follows.

(A) When the manhole cover 2 is open, the lock member 3 rotates forward (clockwise) by the weight of the base 3d until the base 3d comes into contact with the stop projection 1d, and the lock member 3 is engaged. An assembling opening 3h formed between the protrusion 3e and the contact protrusion 3g is opened upward to be in a posture for receiving the engagement protrusion 2a of the manhole cover 2 (see FIG. 7).

(B) When the manhole cover 2 is started to be closed,
The engaging projection 2a of the manhole cover 2 presses the contact protruding portion 3g of the lock member 3, whereby the lock member 3 rotates reversely (counterclockwise) with the support rod 3c as a fulcrum, and the manhole cover The tip of the engagement projection 3e of the lock member 3 abuts on the tip of the second engagement projection 2a (see FIG. 8).

(C) When the manhole cover 2 is further closed, the contact protrusion 3g of the lock member 3 is pushed down by the engagement protrusion 2a of the manhole cover 2, and the lock member 3 is engaged with the engagement protrusion 3e. Rotate in reverse with the tip of the as a fulcrum (see FIG. 9).

(D) When the manhole cover 2 is further closed, the engaging projection 2a of the manhole cover 2
The contact protruding portion 3g is further pushed down to
10a enters the entrance of the assembling opening 3h (FIG. 10).
reference).

(E) When the manhole cover 2 is completely closed, the abutting projection 3f of the locking member 3 abuts against the stop projection 1d of the manhole opening frame 1, and the locking member 3 comes to the tip of the abutting projection 3f. Rotates around the fulcrum (FIG. 11).
reference).

(F) Thereafter, the lock member 3 is moved to the base 3d.
, The manhole cover 2 is closed and locked (see FIG. 12).

(G) When the manhole cover 2 is to be opened from the locked state, the lock member 3 rotates forward with the support bar 3c as a fulcrum due to the weight of the base 3d, and the engagement protrusion of the lock member 3 protrudes. The engaging protrusion 2a of the manhole cover 2 is sandwiched between the portion 3e and the contact protrusion 3g (see FIG. 13).

(H) When the manhole cover 2 is further opened from this state, the lock member 3 moves upward, and the engaging projection 3e abuts on the lower surface of the inner peripheral end of the manhole opening frame 1, and the manhole cover Further opening of the lid 2 is prevented (see FIG. 14).

By setting the manhole opening frame 1, the manhole cover 2, and the lock member 3 in such a relationship, unauthorized opening of the manhole cover 2 is reliably prevented.

In this embodiment, a guide groove 1e is formed on the side wall of the storage recess 1a of the manhole opening frame 1 so as to be continuous with the support groove 1b. Thus, the assembling of the lock member 3 with respect to the manhole opening frame 1 is performed by fitting both the support rods 3c of the lock member 3 into the corresponding guide grooves 1e of the manhole opening frame 1 and entering the support groove 1b through the guide grooves 1e. Can be achieved. Therefore, each of the manhole opening frame 1, the manhole cover 2, and the lock member 3 can be formed as a separate molded product having a simple structure, and the overall structure is simplified, and its manufacture and assembly are facilitated. .

Further, in the present embodiment, the projection 2p is formed on the upper surface of the tip of the engagement projection 2a, and the projection 2p of the engagement projection 2a is formed on the lower surface of the tip of the engagement projection 3e. Is formed, so that it is more difficult to illegally open the manhole cover.

[0032]

As described above, according to the lock structure of the manhole cover according to the first aspect of the present invention, when the manhole cover is closed, the lock member functions and the manhole cover is closed. Together with the lock state. Even when the manhole cover is to be opened from this locked state, the lock member functions and cannot be opened. Therefore, unauthorized opening of the manhole cover can be prevented.

According to the second aspect of the present invention, the lock member can be detachably attached to the manhole opening frame. Thereby, each of the manhole opening frame, the manhole cover, and the lock member can be formed as a separate molded product having a simple structure, and the overall structure is simplified.
Therefore, their manufacture and assembly are simplified.

Further, according to the third aspect of the present invention, a projection is formed on the upper surface of the tip of the engagement projection, and the lower surface of the tip of the engagement projection is provided with the projection of the engagement projection. Since the protruding portion engageable with the protruding portion is formed, it is difficult to open the manhole cover illegally.

[Brief description of the drawings]

FIG. 1 is a partial sectional side view showing a lock structure of a manhole cover according to an embodiment of the present invention.

FIG. 2 is a front view showing a lock member of the lock structure of the manhole cover shown in FIG. 1;

FIG. 3 is a side view showing a lock member of the lock structure of the manhole cover shown in FIG. 1;

FIG. 4 is a plan view of the manhole opening frame shown in FIG. 1;

FIG. 5 is a partial cross-sectional side view showing a storage recess and a support groove formed in the manhole opening frame shown in FIG. 1;

FIG. 6 is a bottom plan view of the manhole cover shown in FIG. 1;

FIG. 7 is a side sectional view showing an operation of the lock structure of the manhole cover according to the embodiment of the present invention, and shows a state where the manhole cover is open.

FIG. 8 is a side sectional view showing an operation of the lock structure of the manhole cover according to the embodiment of the present invention, and shows a state where the manhole cover has begun to be closed.

FIG. 9 is a side cross-sectional view showing the operation of the lock structure of the manhole cover according to the embodiment of the present invention, and shows a state in which the manhole cover is further closed from the state of FIG.

FIG. 10 is a side sectional view showing an operation of the lock structure of the manhole cover according to the embodiment of the present invention, and shows a state in which the manhole cover is further closed from the state of FIG. 9;

FIG. 11 is a side sectional view showing an operation of the lock structure of the manhole cover according to the embodiment of the present invention, and shows a state in which the manhole cover is completely closed.

FIG. 12 is a side sectional view showing the operation of the lock structure for a manhole cover according to the embodiment of the present invention, and shows a state where a short time has passed since the manhole cover was completely closed.

FIG. 13 is a side cross-sectional view showing an operation of the lock structure of the manhole cover according to the embodiment of the present invention, showing a state where the manhole cover is about to be opened.

FIG. 14 is a side cross-sectional view showing the operation of the lock structure of the manhole cover according to the embodiment of the present invention, showing a state where the manhole cover is about to be opened further from the state of FIG.

FIG. 15 is a partial cross-sectional side view showing a lock structure of a manhole cover according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Manhole opening frame 1a Storage recess 1b Support groove 1c Hole 1d Stop projection 1e Guide groove 1f Assembling plate 2 Manhole cover 2a Engagement projection 2b Hinge member 2c Pin 2d Wide part 2P Projection 3 Lock member 3a Connecting rod 3b Hook 3c Support rod 3d Base 3e Engagement projection 3f Butt projection 3g Contact projection 3h Assembly opening 3P Projection 4 Manhole opening 4a Hole 4b Projection 5 Manhole cover 5a Hinge 5b Key member 5c spring

Claims (3)

(57) [Claims] 1. A lock for a manhole cover comprising a manhole opening frame, a manhole cover for closing the manhole opening frame, and a lock member attached to the manhole opening frame for preventing unauthorized opening of the manhole cover. A supporting recess is formed at one side of the inner peripheral surface of the manhole opening frame, and a storage recess is formed at the entrance portion with an erect stop protruding piece, and the storage recess is opposed to the storage recess. A hole is formed in the other portion of the inner peripheral surface, and the lock member is integrally formed with a support rod portion which is attached so that both ends are loosely fitted into support grooves formed in the both side walls. The hook portion is configured to rotate in the reverse direction, and the hook portion has a heavy base protruding outward and downward from the support bar portion, an engagement protrusion portion protruding substantially upward from the base portion, and an inner side of the support bar portion. A projecting part that projects downward The contact protruding portion protruding above the abutting protruding portion has a side surface shape that is substantially H-shaped with the support rod portion being substantially at the center. An engagement protrusion is formed to engage with the engagement protrusion of the lock member, and is fitted into the hole of the manhole opening frame at the other position on the lower surface of the outer peripheral end facing the engagement protrusion so as not to be able to be pulled out. When the manhole cover is open, the lock member is
With the weight of the base, rotate forward until the base touches the stop projection,
The assembling opening formed between the engaging protrusion and the contacting protrusion is opened upward to receive the engaging protruding piece of the manhole cover. The engagement protrusion of the lid presses the contact protrusion of the lock member, whereby the lock member rotates in reverse with the support rod portion as a fulcrum, and the engagement protrusion of the lock member contacts the tip of the engagement protrusion of the manhole cover. When the tip of the portion abuts and the manhole cover is further closed, the contact protrusion of the lock member is pushed down by the engagement protrusion of the manhole cover, and the lock member is supported by the tip of the engagement protrusion as a fulcrum. When the manhole cover is further rotated in the reverse direction and the manhole cover is further closed, the engaging projection of the manhole cover pushes down the contact protruding portion of the lock member further downward, and the leading end of the engaging projection engages the entrance of the assembly opening. And completely cover the manhole cover When the lock member is closed, the projecting portion of the lock member abuts against the stop projecting piece of the manhole opening frame, and the lock member rotates in reverse with the tip of the projecting projecting portion as a fulcrum, and then rotates forward with the weight of the base portion, thereby forming When the lid is closed and locked, and when the manhole cover is to be opened from this locked state, the lock member rotates forward with the support rod portion as a fulcrum due to the weight of the base portion, and the lock member engages with the engaging protrusion. When the engaging protruding piece of the manhole cover is sandwiched between the contacting protruding portion and the manhole cover is further opened from this state, the lock member moves upward, and the engaging protruding portion moves to the inner periphery of the manhole opening frame. A lock structure for a manhole cover, which is in contact with an end lower surface to prevent further opening of the manhole cover. 2. The manhole cover according to claim 1, wherein guide grooves are formed on both side walls of the manhole opening frame to guide both support rods of the lock member into corresponding support grooves. Lock structure. 3. A projection is formed on an upper surface of a distal end of the engaging projection, and a projection engageable with the projection of the engaging projection is formed on a lower surface of the distal end of the engaging projection. The lock structure for a manhole cover according to claim 1, wherein the lock structure is provided.