JP2010040642A - Pressure discharge device for electrical device storage box, and electrical device - Google Patents

Description

  The present invention is a sealed electrical equipment storage box that stores a circuit breaker, a terminal block, and the like. For example, the pressure in the box rises due to arc gas at the time of a short circuit accident, and the door is damaged due to breakage of the door or removal of the clasp TECHNICAL FIELD The present invention relates to a pressure relief device for an electrical equipment storage box that prevents the occurrence of opening of the electrical equipment, and an electrical equipment provided with the pressure relief device.

  There exists patent document 1 as a closing device of a door. This is because the handle holding body is fixed to the door, the handle holding body penetrates the handle, and a spring for urging the handle forward is provided in the handle holding body, and the inclined surface of the lever provided on the handle on the back side of the door is a box. The door is slid on the front edge of the locking hole of the body and pressed by a spring to close the door. Since the inclined surface of the lever is in sliding contact with the front edge of the locking port and pressed by the spring, the strength is high and safety against accidents in the box can be ensured. Further, the door is closed without rattling by a spring for biasing the handle forward, and can be opened and closed without requiring a large force even if the steel plate thickness of the door increases.

Patent Document 2 describes a door hinge having a pressure releasing function. This uses a U-bolt to fix the box-side hinge pipe to the outside of the base of the U-bolt, insert both legs of the U-bolt from the outside into the insertion holes in the edge plate of the box, and Each nut is screwed and a spring is wound around the U bolt between the nut and the inner surface of the edge plate. A draining packing is attached to the insertion hole of both legs of the U bolt and the gap between the outer circumferences of both legs of the U bolt. A hinge pin is inserted into the door-side and box-side hinge pipes to support the door on the box, and when the internal pressure rises, the spring shrinks due to the force of opening the door, creating a gap between the box and the door and releasing the pressure.
JP 2003-262065 A Japanese Utility Model Publication No. 55-19401

  In patent document 1, since the spring which pushes a handle is provided in the handle holding body, it cannot be applied to a general-purpose handle. Moreover, since a space is required in the handle, it is difficult to manufacture a handle having a waterproof structure. Furthermore, it is necessary to make a handle, a lever and a box firmly so as to withstand the rising pressure in the box due to an accident.

  In Patent Document 2, a box-side hinge pipe is fixed to the outside of the base portion of the U bolt, and the hinge structure is complicated and the number of parts is large and assembly is difficult. A nut is screwed onto both leg end portions of the U-bolt, and a spring is wound around the U-bolt between the nut and the inner surface of the edge plate, so that a protruding portion into the box body is enlarged and a dead space is increased. Since the door is supported by a hinge via a spring, when the door is heavy, the door falls due to its own weight. Moreover, when installing outdoors, the draining packing for waterproofing is required.

  Accordingly, an object of the present invention is to provide a pressure relief device for an electrical equipment storage box and an electrical equipment that can be simple and inexpensive in structure and can be applied to an existing handle.

The pressure relief device for an electric equipment storage box according to the present invention has an opening and a box of an electric equipment storage box having an engaging portion inside an edge of the opening, and the opening of the box is hermetically sealed. A door that opens through the door and opens and closes the door; and a stopper that locks the locking portion by operating the handle so that the door can be closed in a sealed state.
The handle has a fitted portion having an axial direction in a direction approaching and separating from the door on the inner surface side of the door, and the stopper is fitted to the fitted portion in the axial direction and is engaged in the circumferential direction. And a fitting that interlocks with the turning operation of the handle, and that is provided on the handle and presses the fitting portion in the axial direction via an elastic body to prevent the fitting from coming off. And the fitting is pulled by the door to be opened as the pressure in the box increases, and a pressure-releaseable gap is formed between the door and the opening of the box. As described above, the elastic body is compressed against the fitting portion of the stopper.

  In the above configuration, the elastic body is a disc spring.

  In the above configuration, the elastic body has a plurality of disc springs alternately stacked in opposite directions.

  The said structure WHEREIN: The said box has a locking tool with an insertion hole between the said latching | locking part and the said handle | steering-wheel, The said stopper latches to the said latching | locking part through the said penetration hole, and the said door is the said A latching piece that is caught in the insertion hole when being opened by being pushed by the rising pressure in the box is provided.

  The electric device of the present invention includes the pressure relief device for the electric device storage box having the above-described configuration.

  According to the pressure relief device for an electrical equipment storage box of the present invention, the fitting portion of the stopper is held by the fitting portion of the handle by the attachment tool via the elastic body, and the fitting state is maintained. The stopper can be locked or released from the locking portion by operation. When the box body pressure suddenly rises due to an accident and the box body expands due to the internal pressure, the elastic body is compressed against the fitting part of the stopper with the force to open the door, and this causes the box body to A gap is formed between the edge of the opening and the door, and pressure can be released from the gap. Therefore, damage to the electrical equipment storage box can be prevented. In addition, since the elastic body is interposed between the stopper and the attachment, the structure is simple and inexpensive, and can be applied to an existing handle. In addition, the operation of locking the locking portion of the handle becomes smooth by the elastic body, the adhesion between the edge of the opening of the box and the door is good, and a highly airtight electrical device storage box or electrical device can be provided.

  By using a disc spring as the elastic body, the height of the elastic body can be reduced, the dead space in the box can be reduced, and the degree of freedom of storage of storage devices and the like can be increased. The spring constant and stroke can be freely set according to the quantity and combination of the disc springs, and a clearance for releasing pressure suitable for the box of the electrical equipment storage box can be set.

  When the elastic body is stacked with a plurality of disc springs alternately in opposite directions, the pressure relief operation is performed smoothly and the secular change is small, and it is possible to easily design the optimum pressure relief by increasing or decreasing the number of disc springs. it can.

  Since the stopper has a latching piece that is locked to the locking part through the insertion hole of the lock tool and that is caught in the insertion hole, an abnormal pressure rise occurs, the elastic body is compressed, the door opens, and a gap is formed between the box and the door. When this happens, the latching piece of the stopper latches on the locking device, so that the stopper does not come off from the locking part of the box and the door does not open greatly, preventing the stopper from coming off. However, it is possible to reliably release the rising pressure in the box.

(Embodiment 1)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view of an electric device. In this electric device, an electric device main body (not shown) such as a circuit breaker and a terminal block is stored in a box 2 of an electric device storage box with a door 3. Reference numeral 4 denotes a hinge, 7 denotes a handle, and 24 denotes an attachment portion to the wall surface of the box body 2.

  FIG. 2 is a partially cutaway bottom view of the electrical equipment storage box, and FIG. 3 is a partially enlarged view thereof. The electrical equipment storage box 1 is composed of a box 2 and a door 3 that closes the opening 2 a of the box 2. The door 3 is hinged to the edge of the opening 2 a of the box 2 with a hinge 4 and attached to the box 2. The opening 2a can be freely opened and closed. Packing 5 that is an airtight member is provided on the inner peripheral surface of the door 3, and the inside of the box 2 is hermetically sealed when the packing 5 is in close contact with the contact piece 6 that forms the edge of the opening 2 a of the box 2 when the door is closed. It is comprised so that.

  On the opening and closing side of the door 3, a handle rotation shaft 8 of the handle 7 is provided to pass through the door 3 so as to be rotatable, and on the inner surface side of the door 3, a stopper 9 as a stopper is attached to the handle rotation shaft 8. It is attached with the attachment screw 10 which is. Specifically, as shown in FIG. 3, a screw hole 8 a is formed at the center of the tip of the handle rotation shaft 8, and the axial direction of the fitted portion 8 b is moved closer to and away from the axial direction of the screw hole 8 a, that is, the door 3. Protrudes in the direction. The shape of the fitted portion 8b viewed in the axial direction is non-circular, for example, a quadrangle. The base end portion of the clasp 9 is formed by forming a fitting portion 9a fitted in the fitted portion 8b in the axial direction with a rectangular hole having a shape similar to the shape of the fitted portion 8b seen in the axial direction. Yes. Therefore, the fitting portion 9a is fitted to the fitted portion 8b in the axial direction, but is engaged with the fitted portion 8b in the circumferential direction, and when the handle 7 is rotated around the handle rotating shaft 8, Accordingly, the clasp 9 rotates. With the fitting portion 9a fitted to the fitted portion 8b, the base end portion of the clasp 9 is pressed by the cylindrical elastic body 12, and the tip 10b of the mounting screw 10 penetrating the elastic body 12 is inserted into the screw hole 8a. The elastic body 12 is supported by the screwed head portion 10a, whereby the base end portion of the clasp 9 is pressed and held via the elastic body 12 by the head portion 10a. The cylindrical elastic body 12 is made of rubber such as urethane rubber. On the other hand, the front end portion of the clasp 9 is released from the locking portion 11 at a position to be locked to the locking portion 11 formed by bending the base side of the contact piece 6 of the box 2 and released from the locking portion 11. It rotates with the operation of the handle 7 between the positions, the door 3 is closed in a sealed state at the former position, and the door 3 is opened at the latter position. In this way, the clasp 9 is attached to the handle rotation shaft 8 with the mounting screw 10 via the elastic body 12, and the clasp 9 is locked or engaged with the locking portion 11 by rotating the handle 7. The lock is released. In addition, flat plates 13 and 14 are provided on the front and rear surfaces of the elastic body 12 so that a load is evenly applied to the stopper 9.

FIG. 4 shows the operation of the door when an abnormal pressure rise occurs in the electrical equipment storage box 1 due to arc gas or the like in FIG. A force that pushes and opens the door 3 due to the sudden internal pressure P acts on the inner surface of the electrical equipment storage box 1, but at this time, the mounting screw 10 is pulled by the door 3 in the opening direction of the door 3 through the handle 7. The elastic body 12 is compressed between the head 10a and the clasp 9 locked to the locking portion 11. As a result, a gap 23 is generated between the packing 5 and the abutment piece 6 while maintaining the fitted state of the fitting portion 9a and the fitted portion 8b. Damage to the box 1 can be prevented.
(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. That is, a plurality of disc springs are used instead of rubber as the elastic body 12 of the first embodiment. FIG. 5 corresponds to FIG. 3, and the stopper 9 is attached to the handle rotating shaft 8 with an attachment screw 10 via an elastic body 12 using a disc spring. A flat plate 13 is provided on the front surface of the disc spring so that the load is evenly applied to the stopper plate 9.

  FIG. 6 corresponds to FIG. 4, and in the event of a short circuit accident or the like, a force that pushes and opens the door 3 due to a sudden pressure rise P acts on the inner surface of the electrical equipment storage box 1, but at this time, the elasticity of the disc spring When the body 12 is compressed, a gap 23 is generated between the packing 5 and the contact piece 6. The clearance 23 can safely release the pressure and prevent the electrical equipment storage box 1 from being damaged.

  The disc spring is compact and can obtain a large load as compared with the coil spring and other elastic bodies. There are various sizes of disc springs, and the feature is that the load and stroke can be set freely by combining multiple disc springs. By taking advantage of this feature and attaching the clasp 9 via a suitable disc spring, the height H2 (FIG. 5) of the disc spring is lower than the height H1 (FIG. 3) of the elastic body 12 of the first embodiment. can do. Therefore, the protruding part to the inside of the box body 2 can be reduced, and the dead space as in the prior art is reduced, so that the inside of the box body 2 can be used effectively.

  A disc spring is essentially a spring used for a press die or the like, and is therefore known to have high durability and reliability. By using this as one part of the electrical equipment storage box, it is possible to provide a highly reliable electrical equipment storage box with an inexpensive and simple structure.

As another embodiment, it is possible to alternately stack a plurality of disc springs in opposite directions. In this case, the pressure relief operation is performed smoothly and the secular change is small, and the optimum pressure relief design can be easily achieved by increasing or decreasing the number of disc springs.
(Embodiment 3)
A third embodiment of the present invention will be described with reference to FIGS. The difference from the second embodiment is that a latch piece 17 and a lock fitting 18 as a lock tool are added to the second embodiment. FIG. 7A is a front view of the clasp 9 and FIG. 7B is a left side view thereof. The clasp 9 has a latching piece 17 projecting from a side portion of the tip portion that is latched to the latching portion 11 of the box body 2 and is inclined at an inclination angle θ in the plate thickness direction as will be described later. As described above, the fitting portion 9a is a hole that is fitted into the fitting portion 8b protruding from the handle rotation shaft 8 and attaches the stopper 9 and is, for example, the fitting portion 8b of the handle rotation shaft 8. It is formed in a quadrangular shape to match the quadrangular shape and forms a stop.

  FIG. 8 is a partial side view of the lock fitting 18 viewed from the handle 7 side toward the locking portion 11 of the box body 2, and FIG. 9 is a partial vertical cross-sectional view of a state in which the clasp 9 is locked to the locking portion 11. FIG. 10 is also a partial cross-sectional view. The box body 2 is provided with a lock fitting 18 having an insertion hole 19 between the locking portion 11 and the handle 7. The lock fitting 18 is fixed to the contact piece 6 of the box 2. The clasp 9 is rotated by the operation of the handle 7 so that the latching piece 17 is locked or released from the locking portion 11 through the insertion hole 19 without being caught by the end of the insertion hole 19. When the door 3 is pushed by the internal pressure in the box 2 while the stopper 9 is locked to the stopper 11, the stopper 9 does not rotate, so that the latching piece 17 is attached to the lock fitting 18. It can be hooked to the end 20 of the insertion hole 19. The insertion hole 19 has a groove shape, and is provided with a recess 21 that is formed wide so that the stopper 9 can be easily inserted and the handle 7 can be easily unlocked even if it is deformed. The latch piece 17 is easily inserted into the insertion hole 19 by the inclination angle θ. The lock fitting 18 and the latch piece 17 are not in contact with each other, and a gap 22 is provided so as not to prevent the compression of the elastic body 12 and the formation of the gap 23 between the packing 5 and the contact piece 6.

  FIG. 11 is a partial cross-sectional view when the internal pressure increases. Similarly to what has been described with reference to FIG. 6, when the elastic body 12 is compressed by the abnormal pressure increase P in the box body 2, the door 3 is released. In this case, the latching piece 17 is securely latched to the end 20 of the insertion hole 19 of the lock fitting 18 so that the latch 9 does not slide out from the latching portion 11 of the box 2 and the door 3 is opened. The opening of the door 3 is prevented.

  In the present invention, the elastic body 12 may be a coil spring, a leaf spring, or the like. The latch piece 17 and the lock fitting 18 of the third embodiment can also be applied to the first embodiment.

It is a front view of the electric equipment of a 1st embodiment of the present invention. It is a partially cutaway bottom view with the door closed. FIG. 3 is a partially enlarged sectional view of FIG. 2. It is a fragmentary sectional view showing the pressure release state where the elastic body was compressed by the rising pressure in the box and a gap was generated between the box and the door. It is a fragmentary sectional view of the state where the clasp of the electric equipment storage box of a 2nd embodiment was locked to the locking part of a box. It is a fragmentary sectional view showing the pressure release state where the disc spring was compressed by the rising pressure in the box and a gap was generated between the box and the door. (A) is the front view of the clasp which protruded the latching piece of 3rd Embodiment, (b) is the left view. It is a partial side view of the state where the lock metal fitting was fixed to the box of a 3rd embodiment. It is a fragmentary longitudinal cross-sectional view of the state which the latching piece of the clasp latched on the lock metal fitting. It is a partial cross-sectional view of a state in which a latch piece of a clasp is hooked on a lock fitting. It is a fragmentary cross-sectional view which shows the operation | movement accompanying the raise pressure in a box.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrical equipment storage box 2 Box body 2a Opening 3 Door 4 Hinge 5 Packing 6 Contact piece 7 Handle 8 Handle rotating shaft 8a Screw hole 8b Fit part 9 Stopper 9a Fitting part 10 Mounting screw 10a Head 10b Tip DESCRIPTION OF SYMBOLS 11 Locking part 12 Elastic body 17 Latching piece 18 Lock metal fitting 19 Insertion hole 20 End part 21 Recessed part 23 Gap 24 Attachment part

Claims (5)

A box of an electrical equipment storage box having an opening and a locking portion inside an edge of the opening; a door for sealing the opening of the box so as to be opened and closed; and a door penetrating through the door. A handle that opens and closes, and a stopper that locks to the locking portion by operation of the handle and enables the door to be closed in a sealed state,
The handle has a fitted portion having an axial direction in a direction approaching and separating from the door on the inner surface side of the door, and the stopper is fitted to the fitted portion in the axial direction and is engaged in the circumferential direction. And a fitting that interlocks with the turning operation of the handle, and that is provided on the handle and presses the fitting portion in the axial direction via an elastic body to prevent the fitting from coming off. And the fitting is pulled by the door to be opened as the pressure in the box increases, and a pressure-releaseable gap is formed between the door and the opening of the box. Thus, the pressure relief device of the electrical equipment storage box that compresses the elastic body against the fitting portion of the stopper.   The pressure relief device for an electric equipment storage box according to claim 1, wherein the elastic body is a disc spring.   The pressure relief device for an electrical equipment storage box according to claim 1, wherein the elastic body has a plurality of disc springs alternately stacked in opposite directions.   The box has a locking tool having an insertion hole between the locking part and the handle, and the stopper is locked to the locking part through the insertion hole and the door is raised in the box. 4. The pressure relief device for an electric equipment storage box according to claim 1, further comprising a latching piece that is caught by the insertion hole when being opened by being pressed by pressure.   An electric device comprising the pressure relief device for an electric device storage box according to claim 1, claim 2, claim 3 or claim 4.

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