JP3751088B2 - safety valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a safety valve attached to a tank (pressure vessel) for storing various liquids such as a developer.
[0002]
[Prior art]
As disclosed in Japanese Utility Model Publication No. 3-30272, JP-A-6-156505, or JP-A-6-156506, in a storage tank for various liquids such as a developer, the liquid stored therein is used. Nitrogen gas or the like is supplied into the tank for taking out the liquid, and the liquid is taken out using the pressure of the gas.
[0003]
In addition, various liquid storage tanks are provided with a safety valve for releasing the gas in the tank to the outside before the pressure in the tank becomes abnormally high.
The structure of this safety valve is such that the tip of the pin-shaped valve body is pressed against the valve seat surface by a spring at a pressure below a predetermined pressure, and when the gas pressure in the tank increases, the pin resists the spring force of the spring due to the gas pressure. The valve body is lifted to remove gas from the tank.
[0004]
[Problems to be solved by the invention]
After the developer in the storage tank is used up, it is necessary to drain the pressurized gas remaining in the tank when returning to the manufacturing factory or the like for refilling. For this reason, conventionally, the pin-shaped valve main body is lifted by pulling an annular lever attached to the base end of the pin-shaped valve main body.
However, it takes time for the pressurized gas remaining in the tank to completely escape. Meanwhile, the pin-shaped valve body must be lifted manually.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems, the safety valve according to the present invention has a pin-shaped valve body whose tip is pressed against the valve seat surface by the spring force of the spring, and the base end of the pin-shaped valve body protruding from the cap. An annular lever for pulling up the pin-shaped valve body in the opening direction against the spring is attached, and a pair of locking projections are provided on the outer surface of the cap with the pin-shaped valve body interposed therebetween.
[0006]
Insert your finger into the annular lever, lift the pin-shaped valve body in the axial direction, and further turn the annular lever about 90 ° around the shaft. The annular lever engages with a pair of engaging projections, and the valve opens even if you release your hand. State is maintained.
[0007]
The shape of the annular lever is configured such that a portion inserted through the proximal end portion of the pin-shaped valve body is a straight portion, and the length of the straight portion is larger than the diameter of the cap.
In other words, when the lever is annular, if any force acts downward on the annular lever, after the annular lever hits the cap, the pin valve body is pulled up by the lever principle, and the gas escapes. End up . However, the portion that is inserted into the base end of the pin-shaped valve body is a straight portion, and the length of this straight portion is larger than the diameter of the cap, so that even if a downward force acts on the lever, The pin-shaped valve body is not pulled up by the principle of.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is an overall perspective view of a portable storage tank to which the safety valve according to the present invention is applied, FIG. 2 is a sectional view of the safety valve, and FIG. 3 is a plan view of the safety valve.
[0009]
The portable storage tank is provided with a lid 2 that opens when a liquid such as a developer is filled in the center of the upper surface of an airtight tank main body 1 made of stainless steel, and a pedestal 3 for a gas supply pipe, a liquid at the periphery of the upper surface of the tank main body 1 The pedestal 4 for the take-out pipe and the safety valve 5 according to the present invention are provided, and the pedestal 3 and 4 and the safety valve 5 are prevented from being damaged by the protect pipe 6 when the tumbler falls.
[0010]
The structure of the safety valve 5 is such that a cylindrical body 7 is welded onto an opening 1 a formed on the upper surface of the tank body 1, a release hole 7 a is formed on the side surface of the cylindrical body 7, and a cap 8 is attached to the upper surface opening of the cylindrical body 7. The pin-shaped valve body 9 is inserted through the cap 8 by screwing.
[0011]
The pin-shaped valve main body 9 is provided with a flange portion in the middle, and a spring 10 is compressed between the flange portion and the cap 8, and the spring 10 is elastically applied to the tip of the pin-shaped valve main body 9. The fitted O-ring 11 is brought into contact with the valve seat surface formed on the inner side of the cylinder 7 so that the gas from the tank body 1 does not leak when the pressure in the tank body 1 is below a predetermined value. Yes.
[0012]
Further, the base end portion of the pin-shaped valve body 9 projects outward from the cap 8, a ring-shaped lever 12 is attached to the base end portion, and the pin-shaped valve body 9 is attached to the outer surface of the cap 8. A pair of locking projections 13 and 13 are provided on both sides.
[0013]
Thus, in order to remove the gas remaining in the tank 1, if the lever 12 is pulled upward to some extent against the spring 10, the lever 12 is rotated about 90 ° around the axis. Then, the lever 12 rides on the locking projections 13 and 13 and the pin-shaped valve body 9 is lifted upward against the spring force of the spring 10, and the state where the O-ring 11 is separated from the valve seat surface is maintained. The gas remaining in the tank 1 is discharged to the outside through the release hole 7a.
[0014]
4 is a side view of the safety valve 5. When a force is applied to the lever 12 from above for some reason, the pin-shaped valve body 9 is shown by the lever principle with the contact point P between the lever 12 and the cap 8 as a fulcrum. As shown by the imaginary line, the gas is lifted upward and the gas in the tank escapes when not intended.
[0015]
The structure of the safety valve 5 that eliminates this disadvantage is shown in FIGS . In this case, the safety valve 5, the shape of lever 12 without it an annular (ring-shaped) which is cyclic, the portion inserted through the proximal end portion of the pin-shaped valve body 9 and a straight portion 12a, further this line The length of the portion 12 a is made larger than the diameter of the cap 8.
[0016]
By making the shape of the lever 12 as described above, even if a force from above is applied to the lever 12, the outer end portion of the lever 12 only hits the side surface of the cylinder 7 as shown in FIG. The valve body 9 is not lifted upward.
In the case of performing the degassing tank, as described above, a certain degree lift the lever 12 and then turning about 90 °.
[0017]
【The invention's effect】
As described above, according to the safety valve according to the present invention, the portion inserted through the base end portion of the pin-shaped valve body is defined as the straight portion at the base end portion protruding outside the pin-shaped valve body passing through the cap. Since the annular lever is attached and a pair of locking projections are provided on the outer surface of the cap with the pin-shaped valve body in between, a finger is inserted into the annular lever and the pin-shaped valve body is lifted in the axial direction. When the annular lever is rotated about 90 °, the annular lever is locked to the pair of locking projections, and the valve can be kept open even if the hand is released, and gas can be easily vented.
[0018]
The part of the annular lever that is inserted into the base end of the pin-shaped valve body is a straight part, and the length of this straight part is larger than the diameter of the cap, so that downward force acts on the lever. Even so, the pin-shaped valve body is not lifted by the lever principle, so that it is possible to prevent the gas in the tank from being inadvertently removed.
[Brief description of the drawings]
1 is an overall perspective view of a storage tank to which a safety valve according to the present invention is applied. FIG. 2 is a sectional view of the safety valve. FIG. 3 is a plan view of the safety valve. Side view as described [FIG. 5] Plan view of the safety valve according to the present invention in which inconveniences are also eliminated [FIG. 6] Side view of the safety valve according to the present invention in which inconveniences are also eliminated

Claims (1)

In the safety valve in which the tip of the pin-shaped valve body is pressed against the valve seat surface by the spring force of the spring, the pin-shaped valve body penetrates the cap and its base end protrudes to the outside. the annular lever is mounted to pull the pin-shaped valve body against the spring in the opening direction, a pair of locking projections are provided, et al is to sandwich the pin-shaped valve body to the outer surface of the front Symbol cap, said annular lever The safety valve is characterized in that at least a portion inserted through the base end portion of the pin-shaped valve body is a straight portion, and the length of the straight portion is larger than the diameter of the cap .

Images