JPS5840586Y2 - Pressure relief device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pressure relief device that protects a tank of equipment from abnormal internal pressure.

Various types of pressure relief devices have been known for oil-filled equipment such as transformers, but the most reliable one releases the restraint of the energy storage device when a certain predetermined pressure is reached. One example is a mechanical type that uses stored force to break the pressure relief plate of the pressure relief pipe that communicates with the equipment tank and release the pressure.

FIG. 1 is an example of the principle structure of a typical conventional mechanical pressure relief device.

A rotary lever 4 that rotates around a hinge 3 is provided in a pressure relief pipe 2 that is sealed by a pressure relief plate 1 and communicates with a tank of an oil-filled device (not shown).

One end of the lever 4 is pulled by a spring 5 so that the other end moves in the direction of the pressure relief plate 1. A pawl 6 is provided on the other end, and the pressure relief plate 1 is provided between the pawl 6 and the hinge 3.
A knife 7 is provided facing the direction.

The pawl 6 is a latch 10 on the pressure receiving plate 9 of the pressure responsive device 8.
is restricted by.

Further, the pressure receiving plate 9 forms a sealed space 14 communicating with the pressure relief pipe 2 through the bellows 11,
The bellows 11 expands and contracts depending on the pressure within the space.

When a certain predetermined pressure is reached, the bellows 11 contracts, the pawl 6 is released from being restrained by the latch 10, the lever 4 rotates counterclockwise in the figure, and the pressure release plate 1 is broken by the knife 7 and the pressure is released.

Further, a detection switch 12 and a terminal box 13 for the switch are provided for warning the outside of the operation of the pressure relief device.

However, this type of conventional pressure relief device has the following drawbacks.

(1) Since it is a link mechanism, the structure is complicated.

(The diagram is simplified to explain the principle.) (2) It takes time to assemble and adjust, resulting in high price.

(3) Since the pressure relief device operation detection switch is housed within the pressure relief pipe, the structure becomes even more complicated.

The present invention was conceived in view of the above points, and an object thereof is to provide a pressure relief device that is simple in structure, reliable in operation, and economical.

For this purpose, a rupture rod is provided which is pressed in the direction of the pressure relief plate by a stored spring, and the rupture rod is locked by a rod that responds to the pressure of the equipment, and when a predetermined pressure is reached, the rupture rod is The lock is released and the pressure relief plate is destroyed by the destruction rod to release the pressure.

FIG. 2 is a structural diagram of an embodiment of the present invention, in which a hollow cylindrical guide 21 is released into a pressure relief pipe 2 whose end is sealed by a pressure relief plate 1 such as a phenol resin plate and connected to a tank of an equipment (not shown). It is fixedly provided to the pressure pipe 2.

One end of the guide in the axial direction faces the pressure relief plate and is provided close to the pressure relief plate so as not to be in contact with it at all times.

The other axial end of the guide 21 is attached to a mounting seat 22 fixed inside the pressure relief pipe 2 by a fastening device 23 such as a bolt.

A breaking rod 24 is installed inside the guide 21 .

The destruction rod 24 consists of a head 25 that is pointed toward the pressure relief plate 1 and a shaft portion 26 that is thinner than the head, each of which is connected to a guide 2.
Hollow large diameter cylinder part 27 and hollow small diameter cylinder part 2 in 1
Can freely slide within 8.

Further, the head 25 of the destruction rod 24 is stored with energy by an energy storage spring 29 that extends and contracts within the large diameter cylinder portion 27 surrounding the shaft portion 26, and the destruction rod 24 is pressed in the direction of the pressure release plate 1. Ru.

Further, a stopper 30 is provided at the rear of the shaft portion 26 to prevent it from falling off.

Furthermore, a locking groove 31 is dug on the outer periphery of the shaft portion 26,
The groove side surface 32 on the side opposite to the head 25 is continuous with a tapered surface 33 extending on the opposite side from the head, leaving a required dimension from the groove bottom surface.

A pressure responsive device such as a bellows 35 is provided in the bottom recess 34 of the pressure relief pipe 2 to separate the inside of the pressure relief pipe 2 from the outside air, and is airtightly attached to the pressure relief pipe 2 by a flange 36.

Further, a rod 38 is installed airtightly passing through the pressure receiving plate 37 at the top of the bellows 35, and the upper end of this rod 38 passes through the wall of the guide 21 and is inserted into the groove 31 provided on the outer periphery of the breaking rod 24. engage.

Further, the lower end of the rod 38 passes through the inside of the bellows 35 and the flange 36 and extends to the outside of the pressure relief pipe 2, so that a detection switch 39 provided outside the pressure relief pipe can be operated.

Further, a pressure adjusting spring 4o is provided in the bellows 35, which surrounds the rod 38 and presses the pressure receiving plate 37 upward.
The pressing force of the pressure receiving plate 37 can be adjusted by being provided in contact with a pressure adjusting screw 41 screwed into the pressure receiving plate 37 .

Further, a friction reducing mechanism 42 such as a ball bushing is provided at a portion where the rod 38 passes through the wall portion of the guide 21 to guide the rod 38.

When the pressure inside the pressure relief pipe 2 increases due to an internal abnormality in the device, the bellows 35 contracts downward in the figure against the adjustment spring 4o.

When the pressure rises to a predetermined value, the groove 31 on the outer periphery of the breaking rod 24 disengages from the rod 38, and the breaking rod 24 momentarily moves to the left in the figure as shown by the dotted line due to the force of the energy storage spring 29. Then, the pressure relief plate 1 is destroyed and the internal pressure is released.

At the same time, the lower end of the rod 38 operates the detection switch 39 to issue an alarm and, if necessary, interrupt the circuit of the device.

At that time, the upper end of the rod 38 and the groove 31 on the outer periphery of the breaking rod
After the rod 38 is disengaged from the side surface 32, the rod 38 is further pushed down along the tapered surface 33, so that the stroke of the rod 38 can be set large.

Therefore, it is easy to adjust the detection switch. This is because without the tapered surface 33, the detection switch 39 would have to operate at the moment the engagement between the rod 38 and the groove 31 of the breaking rod 24 is released, making adjustment difficult.

In addition, in order to prevent variations in the operating force due to changes in the frictional force between the rod 38 and the guide 21, a friction reducing mechanism 42 is provided between the wall of the guide 21 and the rod 38, so that a stable operating pressure can be maintained. can get.

The guide 21 also functions as a stopper to prevent the pressure relief plate 1 from bending inward and breaking during evacuation during oil filling work of the equipment or the like.

After the pressure release device is activated, use the destruction rod 24 to return to the original state.
The operation is very simple as it is only necessary to push the breaking rod head 25 with a suitable holding piece until the upper end of the rod 38 engages with the groove 31 of the breaking rod.

Further, the guide 21 and the seat 22 may be attached integrally by welding or the like, but it is easier to process the guide 21 and the seat 22 by attaching them with bolts or the like as described above.

As is clear from the above explanation, a pressure relief pipe communicating with a tank of equipment is sealed with a pressure relief plate, a guide is fixedly provided inside the pressure relief plate, and the pressure relief plate is installed inside the guide. a break rod which is slidably pressed by a spring in the direction of the guide and has a locking groove on its outer periphery; a rod that is guided through and operates, and one end of which engages in a locking groove on the outer periphery of the destruction rod; and a detection switch that operates by coming into contact with the other end of the rod when the pressure relief device is operated. In the pressure relief device, the side surface of the locking groove provided on the outer periphery of the destruction rod opposite the head of the destruction rod is on the side opposite to the pressure relief plate, leaving a dimension necessary for locking the destruction rod. (Opposite side to the head of the destruction rod)
By providing a friction reducing mechanism in the portion where the rod extends through the wall of the guide and is continuous with the tapered surface, an economical and reliable pressure relief device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a structural diagram of an example of a conventional mechanical pressure relief device, and the second side is a structural diagram of an embodiment of the present invention. 1: Pressure relief plate, 2: Pressure relief pipe, 21 guide, 23: Fastening device, 24: Breaking rod, 29: Accumulating spring, 30: Stopper, 31: Groove, 33...Taper, 38:
Rod, 39: Detection switch, 42: Friction reduction mechanism.

Claims (2)

[Scope of utility model registration request] (1) A pressure relief pipe that communicates with a tank of equipment is sealed by a pressure relief plate, and a guide is provided inside the pressure relief plate and fixed to the pressure relief pipe, and a spring is pressed into the guide in the direction of the pressure relief plate. a destruction rod that is slidably slidable and has a locking groove on its outer periphery; the destruction rod is guided through the wall of the guide in conjunction with a pressure response mechanism that responds to the pressure in the pressure relief pipe; and a pressure relief device comprising a rod whose one end engages with the locking groove on the outer periphery of the destruction rod, and a detection switch which is operated by being brought into contact with the other end of the rod when the pressure relief device is operated. A pressure relief device characterized in that a side surface of the locking groove opposite to the pressure relief plate is connected to a tapered surface extending on the side opposite to the pressure relief plate, leaving a dimension necessary for locking the destruction rod. (2) Utility Model Registration Scope of Claim 1 In the pressure relief device according to claim 1, the rod passing through the wall of the guide is guided via a friction reducing mechanism provided on the guide wall. Pressure device.