JPH0532694Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial field of application This invention is based on the invention that uses a manhole cover attached to a pressure tank to open and close a manhole provided in the pressure tank, and a pressure tank. The present invention relates to a safety device for a manhole cover for a pressure tank, which is provided to prevent the manhole cover from suddenly opening due to residual pressure in the pressure tank.

(2) Conventional technology Conventionally, such safety devices have been developed, for example, by
It is known from the publication No. 18204.

(3) Problems to be solved by the invention However, in the above conventional method, as shown in FIG. 5, a locking pin 23' is provided on the manhole cover 3,
The pressure tank 1 supports an engaging piece 24' which is biased by a spring 30 in the direction of engaging the locking pin 23'. Therefore, as shown in FIG. 6, in order to open the manhole cover 3 and throw the loaded material into the pressure tank 1 from the manhole 2, a chute 35 made of canvas material, for example, is stretched outside the manhole 2 and the loaded material is introduced. Then, the chute 35 may get caught on the engaging piece 24' and may be damaged.

In addition, in the above-mentioned conventional device, as shown in FIGS. 5 and 6, an operating lever 32' is provided on the engaging piece 24' for rotating the engaging piece 24' against the biasing force of the spring 30.
When the chute 35 is extended to the outside of the manhole in the tank 1 so as not to interfere with the chute 35, the weight of the operating lever 32' will cause the engagement piece 24' to move against the locking pin 23'.
This generates a moment that causes the spring 30 to rotate in the disengagement direction (counterclockwise in the drawing), which increases the load on the spring 30, and in the event that the spring 30 is damaged, the moment causes the engagement piece 24 to rotate. rotates to the disengaged position with the locking pin 23',
If you try to open the manhole cover without noticing this, there is a risk that the cover will suddenly open due to the residual pressure inside the tank. In addition, the above operation lever 3
The longer the length of 2' is made to improve the operability, the larger the moment becomes, and the problem becomes more pronounced.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a safety device for a manhole cover for a pressure tank that can solve all of the above-mentioned problems of conventional devices.

B. Structure of the invention (1) Means for solving the problems According to the invention, in order to achieve the above object, a locking pin is fixed to the pressure tank and is perpendicular to the opening direction of the manhole cover. teeth,
An engaging piece biased by a spring to rotate in the direction of engagement with the locking pin is rotatably supported around a rotation axis parallel to the locking pin, and the engaging piece is supported by the spring. An operating lever for rotationally operating against a biasing force is integrally extended, and when the manhole cover closes the manhole, the weight of the engaging piece and the operating lever engages the engaging piece. The relative positions of the engagement piece, the operating lever, and the rotation axis are set so as to generate a moment in the direction.

(2) Effect When the manhole cover can be opened, if there is residual pressure in the pressure tank, the manhole cover will be operated in the opening direction, but the engaging piece will engage with the locking pin and the opening operation will be blocked. be done. The manhole cover can be opened by operating the engagement piece with the operation lever so that it does not engage with the locking pin, but at this time, since the engagement piece is supported by the manhole cover, the engagement piece and the An integrated operating lever is not present near the manhole, so interference between the engagement piece or the operating lever and the chute is avoided.

In addition, when the manhole cover closes the manhole, the weight of the engaging piece and the operating lever generates a moment in the engaging piece in the direction of engagement with the locking pin, that is, in the same direction as the spring. Even in the case of damage, the engagement piece can remain in the engagement position with the locking pin, allowing the engagement piece to effectively perform its intended function.

(3) Embodiment An embodiment of the present invention will be explained below with reference to the drawings. First, in FIGS. 1 and 2, a circular manhole 2 is provided at the top of a pressure tank 1. is removably closed by a manhole cover 3. Furthermore, a handle 4 is attached to the manhole cover 3.

A cylindrical rim 5 is fixed to the pressure tank 1 so as to form a manhole 3, and an annular seal member 6 attached to the manhole cover 3 comes into pressure contact with the upper end surface of the rim 5, thereby forming a manhole. A seal between the cover 3 and the rim 5 is achieved.

A pair of brackets 7 are fixed to the outer surface of the pressure tank 1 on the outer side of the rim 5. This bracket 7
One end of a pair of support arms 9 is supported via a horizontal support shaft 8, and the other end of these support arms 9 is fixed to the manhole cover 3. Therefore, the manhole cover 3 is rotatable around the axis of the support shaft 8.

Further, on the outer surface of the pressure tank 1 on the outside of the rim 5, a plurality of pairs, for example, three sets of brackets 10 are fixed at positions equally spaced in the circumferential direction, and each set of brackets 10 has a bracket 10 fixed thereto. The proximal ends of tightening arms 12 each having a presser protrusion 11 on its intermediate lower surface that can come into contact with the upper surface of the peripheral edge of the manhole cover 3 are rotatably supported by horizontal shafts 13. Moreover, on the surface of each tightening arm 12 opposite to the presser projection 11, that is, on the upper surface when the presser projection 11 is in contact with the manhole cover 3, there is a protrusion 14 extending in the longitudinal direction at the center in the width direction. It is installed protrudingly.

A screw shaft 15 is fixed to the center of the manhole cover 3 and protrudes upward from its outer surface.
A pressing member 16 is screwed onto this screw shaft 15 .
Moreover, a stopper 17 is fixed to the tip of the screw shaft 15 to prevent the pressing member 16 from coming off. Further, an arc-shaped connecting member 18 is provided on the upper part of the pressing member 16.
Both ends of the connecting member 18 are fixed to each other, and a base end of a handle 19 extending outward is fixed to the circumferential center of the connecting member 18 . This handle 19 allows the pressing member 16 to be rotated.

A pressing ring 20 is held on the pressing member 16 so as to be able to rotate relative to the pressing member 16 . On the periphery of the pressing ring 20, approximately U-shaped engaging claws 21 that can come into contact with the top surface of the tip of the tightening arm 12 while sandwiching the protrusion 14 from both sides are provided at a plurality of positions, e.g., three positions equally spaced in the circumferential direction. It is installed integrally at certain points.

Therefore, by bringing the engagement claw 21 into contact with the tip of each tightening arm 12 and tightening the pressing member 16, each tightening arm 12 is pressed toward the manhole cover 3 side with the shaft 13 as a fulcrum, and the pressing protrusion 11 presses the manhole cover 3 toward the rim 5 side, and the closed state of the manhole cover 3 is firmly maintained. Further, when the pressing member 16 is loosened, the engaging claw 21 can be disengaged from the engagement with the tightening arm 12, and the manhole cover 3 can be opened in this state.

When the manhole cover 3 is made openable,
If there is residual pressure in the pressure tank 1, the manhole cover 3 will open suddenly, which is dangerous.
A safety device 22 is provided in between.

3 and 4, safety device 22
The locking pin 2 is fixedly disposed on the pressure tank 1 side.
3, and an engagement piece 24 that is engageable with the locking pin 23 and supported on the manhole cover 3.

A pair of brackets 25 are fixed to the outer surface of the pressure tank 1 on the outside of the rim 5 on an imaginary straight line passing through the axis of the rim 5 in a direction perpendicular to the imaginary straight line connecting the axis of the rim 5 and the support shaft 8. be done. Between both brackets 25, there is a
A horizontal locking pin 23 is installed perpendicularly to the upper direction of the figure.

On the other hand, a pair of brackets 26 are fixed to the side edges of the manhole cover 3 at positions corresponding to the locking pins 23, and a shaft 27 parallel to the locking pins 23 is installed between the brackets 26. Furthermore, a rotating cylinder 28 is rotatably supported by this shaft 27 around the center axis l of the shaft 27 as a rotating axis, and is formed into a substantially U-shape in order to be locked to the locking pin 23 from below. An engagement piece 24 having an engagement portion 29 formed therein is provided integrally with the rotating cylinder 28 .

Moreover, one end of a torsion spring 30 surrounding the rotating tube 28 is engaged with the engagement piece 24, and the other end of the torsion spring 30 is connected to a pin 31 implanted between both blankets 26.
is engaged with. The torsion spring 30 moves the engaging piece 24 in a direction C in which the intermediate portion thereof engages the pin 31 when the manhole cover 3 closes the manhole 2.
(Counterclockwise direction in Figure 4)
In this state, the engaging portion 29 is located below the locking pin 23. Therefore, if you try to open the manhole cover 3 upward in this state,
When the cover 3 is slightly lifted, the engaging portion 29 engages with the locking pin 23, thereby restricting further opening of the cover 3.

An operating lever 32 is integrally provided on the engaging piece 24, and by rotating the operating lever 32 against the spring force of the torsion spring 30, the engaging portion 2
9 and the locking pin 23 can be released. As is clear from FIG. 4, the respective centers of gravity of the operating lever 32 and the engagement piece 24 are located on the outside of the rotation axis l of the engagement piece 24 when the manhole cover 3 closes the manhole 2. Therefore, the respective weights of the operating lever 32 and the engagement piece 24 generate a moment that rotates the engagement piece 24 in the direction C of engagement with the locking pin 23 (counterclockwise in FIG. 4). Therefore, the load on the torsion spring 30 is reduced accordingly, and even if the spring 30 were to break, the engagement piece 24 would remain in the engagement position with the pin 23 due to the above moment, and the intended function would be maintained. is effectively demonstrated.

Next, to explain the operation of this embodiment, it is assumed that there is residual pressure in the pressure tank 1 when the manhole cover 3 can be opened by screwing back the pressing member 16. At this time, a force is applied to the manhole cover 3 in the direction of upward rotation, but the engaging portion 29 of the engaging piece 24 is attached to the locking pin 23.
By engaging with , sudden opening operation can be avoided. Moreover, the engaging portion 29 is the locking pin 23
A slight gap is created between the manhole cover 3 and the rim 5 when the manhole cover 3 and the rim 5 are engaged with each other, and residual pressure is released from this gap.

After the residual pressure is released, the manhole cover 3 can be opened safely by rotating the tightening arm 12 and further rotating the engagement piece 24 using the operating lever 32. Furthermore, in this state, the engaging piece 24 is not present near the manhole 2, and even if a canvas chute or the like is stretched outside the manhole 2 and a loaded object is thrown in, the engaging piece 24 does not have a chute. will not get caught and damage to the chute will be prevented.

C. Effects of the invention As described above, according to the invention, a locking pin is fixedly installed on the pressure tank and is perpendicular to the opening direction of the manhole cover, and a spring is attached to the manhole cover in the direction of engagement with the locking pin. A rotationally biased engagement piece is rotatably supported around a rotation axis parallel to the locking pin, and the engagement piece is configured to rotate against the biasing force of the spring. The operating lever is integrally extended, and the weight of the engaging piece and the operating lever generates a moment on the engaging piece in the engaging direction when the manhole cover closes the manhole. Since the relative positions of the engaging piece, the operating lever, and the rotation axis are set, it is possible to avoid the engaging piece and the operating lever from being in the vicinity of the manhole when the manhole cover is opened. It is possible to prevent damage to the chute due to interference with the joint piece or the operating lever. Furthermore, since the weight of the engagement piece and the operating lever can be used to generate a moment on the engagement piece in the engagement direction, that is, in the same direction as the spring, the load burden on the spring is reduced accordingly.
Moreover, even if the spring should be damaged, the engagement piece can remain in the engagement position with the locking pin, and the engagement piece can effectively perform its intended function. Even if an attempt is made to open the manhole cover without noticing the damage, sudden opening can be avoided.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a vertical side view, and FIG.
2 is a plan view of FIG. 1, FIG. 3 is an enlarged view of FIG.
5 is a longitudinal sectional view corresponding to FIG. 4 of the prior art, and FIG. 6 is a longitudinal sectional side view when the manhole cover is opened to show the problems of the conventional technique. 1...pressure tank, 2...manhole, 3...
Manhole cover, 22...Safety device, 23...
Locking pin, 24... engaging piece, 32... operating lever.

Claims (1)

[Scope of utility model registration request] A structure is provided between the pressure tank 1 and a manhole cover 3 attached to the pressure tank 1 to open and close the manhole 2 provided in the pressure tank 1, to prevent sudden opening of the manhole cover 3 due to residual pressure in the pressure tank 1. In a safety device for a manhole cover for a pressure tank, a locking pin 23 is fixed to the pressure tank 1 and is perpendicular to the opening direction of the manhole cover 3. An engaging piece 24 is rotatably biased in the direction C of engagement with the locking pin 23 and is rotatably supported around a rotation axis l parallel to the locking pin 23. An operating lever 32 for rotating operation against the biasing force of a spring 30 is integrally extended, and when the manhole cover 3 closes the manhole 2, the weight of the engaging piece 24 and the operating lever 32 is The engagement direction C is applied to the engagement piece 24.
the engaging piece 2 so as to generate a moment to
4. A safety device for a manhole cover for a pressure tank, characterized in that the relative positions of the operating lever 32 and the rotation axis l are set.