Switch

Abstract

To provide a switch which can control size of a gap to be formed by abnormal rise of inner pressure in a case.SOLUTION: A switch comprises: a case which has an opening accommodating an opening / closing mechanism having a fixed electrode and a movable electrode which can contact or separate from the fixed electrode and opening upward; a cover which is provided to block the opening of the case; and a control unit which is arranged upward of the cover; wherein a gap for pressure discharge is formed between the cover and the case by abnormal rise of inner pressure of the case, and the control unit contacts an upper surface of the cover to control size of the gap.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a switch. [Background technology]

[0002] 2. Description of the Related Art A switch is known that includes a case that houses a switching mechanism that opens and closes an electric circuit in an electric power system, and a cover that is provided to close an opening of the case.

[0003] In the above switch, if an abnormal increase in pressure occurs inside the case due to an internal short circuit or the like, a gap is formed between the cover and the case, which allows the internal pressure inside the case to be released. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-152228 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, if an abnormal increase in internal pressure within the case causes the cover to be displaced significantly upward, the gap may become too large, causing components to fly out through the gap.

[0006] An object of the present disclosure is to provide a switch capable of controlling the size of the gap formed due to an abnormal increase in internal pressure within the case. [Means for solving the problem]

[0007] One aspect of the present disclosure is an opening / closing device comprising: a case having an opening that opens upward and houses an opening mechanism having a fixed electrode and a movable electrode that can contact or be separated from the fixed electrode; a cover provided to cover the opening of the case; and a control unit disposed above the cover, wherein an abnormal increase in internal pressure within the case forms a gap between the cover and the case for pressure relief, and the regulating unit contacts an upper surface of the cover to control the size of the gap. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing an example of a switch according to the present embodiment. [Diagram 2] FIG. 2 is a diagram illustrating the main internal configuration of the switch according to the present embodiment. [Diagram 3] FIG. 2 is a cross-sectional view of a connecting member according to the embodiment. [Figure 4] 13 is a diagram showing a state of a switch in an abnormal state when the rigidity of a connecting member is low. FIG. [Diagram 5] 11A and 11B are diagrams showing the state of a switch in an abnormal state when the connecting member according to the present embodiment is used; [Figure 6] 11 is a diagram showing the state of the switch after pressure is released according to the present embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described below through the embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention. In the drawings, in order to explain the embodiments, some parts are enlarged or emphasized, and the scale is appropriately changed to express the embodiment, and the dimensions and shape may differ from those of the actual product.

[0010] In the drawings, the directions in the drawings may be explained using an XYZ coordinate system. In the XYZ coordinate system, a plane parallel to the horizontal plane is the XY plane. One direction in this XY plane is referred to as the X direction, and the direction perpendicular to the X direction is referred to as the Y direction. Additionally, the direction perpendicular to the XZ plane is referred to as the Z direction. The X, Y, and Z directions will be explained assuming that the direction indicated by the arrow in the drawing is the + (plus) direction, and the direction opposite to the direction indicated by the arrow is the - (minus) direction.

[0011] Fig. 1 is a perspective view showing an example of a switch SW according to the present embodiment, Fig. 2 is a diagram illustrating the main internal configuration of the switch SW.

[0012] The switch SW is installed, for example, in a power system. As an example, the switch SW is installed on an electric line extending from a power plant or a substation to the power system, or on a power receiving and distributing facility of a general consumer. The switch SW opens and closes the load current of the power system or of electric power equipment such as a transformer or a disconnecting switch in the system under normal conditions, and in the event of an accident, protects the equipment on the load side by cutting off the accident current and prevents the accident from spreading.

[0013] As shown in FIGS. 1 and 2, the switch SW includes a supply terminal 10A, a demand terminal 10B, a case 20, a cover 30, a fixing member 40, an opening / closing mechanism 50, and a hanging bracket 90.

[0014] The supply side terminal 10A is electrically connected to an electric circuit on the supply side of the power system. The demand side terminal 10B is electrically connected to an electric circuit on the demand side of the power system. In this embodiment, the supply side terminals 10A and the demand side terminals 10B are each arranged for three phases. That is, the switch SW includes supply side terminals 10A for three phases and demand side terminals 10B for three phases.

[0015] The supply side terminal 10A includes, for example, a terminal member 11A and a porcelain tube 12A.

[0016] The terminal member 11A is a conductive member extending in the X direction. The terminal member 11A is, for example, a rod-shaped member formed of a metal material. The terminal base end 13A of the terminal member 11A is accommodated in the case 20, and the terminal tip end 14A protrudes from the case 20 in the +X direction. The terminal tip end 14A is electrically connected to an electric circuit on the supply side of the power system. The porcelain tube 12A covers a middle portion of the terminal member 11A. The porcelain tube 12A is cylindrical and extends along the extension direction of the terminal member 11A, and covers the outer circumferential side of the middle portion of the terminal member 11A.

[0017] The demand side terminal 10B includes, for example, a terminal member 11B and a porcelain tube 12B.

[0018] The terminal member 11B is a conductive member extending in the X-direction. The terminal member 11B is, for example, a rod-shaped member formed of a metal material. The terminal base end 13B of the terminal member 11B is accommodated in the case 20, and the terminal tip end 14B protrudes from the case 20 in the -X-direction. The terminal tip end 14B is electrically connected to an electric circuit on the demand side of the power system. The porcelain tube 12B covers a middle portion of the terminal member 11B. The porcelain tube 12B is cylindrical and extends along the extension direction of the terminal member 11B, and covers the outer circumferential side of the middle portion of the terminal member 11B.

[0019] The case 20 houses the opening / closing mechanism 50. The case 20 has an opening AP at the top. The case 20 integrally includes a bottom plate 21 and a side plate 22. The bottom plate 21 forms the bottom surface of the case 20. The bottom plate 21 is formed in a rectangular shape when viewed from below. The side plate 22 forms an outer peripheral side surface 20s of the case 20. The side plate 22 extends upward from each of the four sides of the bottom plate 21. The shape of the case 20 is arbitrary, and may be any shape as long as it can house the opening / closing mechanism 50. For example, the case 20 may be circular when viewed from below. The material of the case 20 is not particularly limited, but metal material, resin material, etc. are used.

[0020] The upper ends of the four side plates 22 include extending portions 221 extending toward the inside of the case 20, and rising walls 222 rising upward from the extending portions 221. The rising walls 222 rise upward along the outer periphery of the opening AP, and are formed continuously along the outer periphery of the opening AP.

[0021] The cover 30 is disposed on the upper side of the case 20. The cover 30 is provided so as to cover the opening AP of the case 20. The inside of the case 20 to which the cover 30 is attached becomes a sealed space. This sealed space may be filled with air or a predetermined gas, or a predetermined liquid may be injected. The predetermined gas is, for example, a gas having insulating properties. The predetermined liquid is, for example, insulating oil.

[0022] As shown in FIG. 1 and FIG. 2, the cover 30 is integrally provided with a top plate portion 31, an inclined portion 32, and an outer peripheral plate portion 33. The top plate portion 31 is formed in the center of the cover 30. The top plate portion 31 is formed in a rectangular shape when viewed from above. The inclined portion 32 is inclined obliquely downward from each side of the rectangular top plate portion 31 toward the outer peripheral side. The outer peripheral plate portion 33 extends in a horizontal direction from the lower end of the inclined portion 32 toward the outer peripheral side. The outer peripheral plate portion 33 forming the outer peripheral portion of the cover 30 protrudes toward the outer peripheral side beyond the case 20 when viewed from the top-bottom direction. The outer peripheral plate portion 33 abuts against the upper end of the rising wall 222. The cover 30 is fixed by the fixing member 40 in a state in which it is provided so as to close the opening AP of the case 20, that is, in a state in which the upper end of the rising wall 222 abuts against the outer peripheral plate portion 33.

[0023] The fixing members 40 fix the cover 30 to the case 20. A plurality of fixing members 40 are arranged at intervals on the outer periphery of the cover 30. As shown in FIG. 1, in this embodiment, a total of six fixing members 40 are provided, two along each of the long sides and one along each of the short sides of the rectangular cover 30 when viewed from above. The six fixing members 40 are arranged at equal or nearly equal intervals. The number and arrangement of the fixing members 40 used can be set arbitrarily.

[0024] Each fixing member 40 is formed in an L-shape when viewed from the side. One end of the fixing member 40 is fastened to the side surface of the case 20 by a bolt 41. The other end of the fixing member 40 extends horizontally along the upper surface of the outer peripheral plate portion 33 of the cover 30. In a state in which one end of the fixing member 40 is fastened to the side surface of the case 20 by the bolt 41, the other end of the fixing member 40 engages with a part of the upper surface of the outer peripheral plate portion 33 of the cover 30.

[0025] The fixing member 40 is not limited to being L-shaped when viewed from the side, and may be U-shaped or V-shaped when viewed from the side. The fixing member 40 may be arbitrarily shaped as long as it is capable of locking the cover 30. When the cover 30 is fixed to the case 20 by the fixing member 40, a packing 42 is sandwiched between the case 20 and the cover 30 in a state of being compressed in the vertical direction. The packing 42 is made of an elastic material such as a resin or a rubber-based material. This allows the airtightness inside the case 20 to be better maintained.

[0026] The fixing member 40 is deformable. Specifically, in normal times, the fixing member 40 reliably fixes the cover 30 to the case 20. On the other hand, in abnormal times, the fixing member 40 deforms. In an abnormal time, the pressure inside the case 20 is abnormal due to an internal short circuit or the like. In an abnormal time, the pressure inside the case 20 is abnormal, for example, when an abnormal increase in the internal pressure occurs and the pressure inside the case 20 becomes an abnormal value. A gap SK for pressure relief is formed between the cover 30 and the case 20 due to the deformation of the fixing member 40 in an abnormal time. For example, when an abnormal increase in the internal pressure occurs, the cover 30 fixed to the case 20 is subjected to an upward force by the pressure inside the case 20. As a result, for example, the cover 30 is deformed so as to open outward with the bolt 41 as a fulcrum, and the tip portion 43 of the fixing member 40 is slightly bent in the opening direction. The rigidity of the fixing member 40 is set according to the pressure inside the case 20. As an example, the fixing member 40 is configured to deform when the pressure inside the case 20 reaches a certain threshold value (limit of airtight performance). The threshold value here varies depending on the type, shape, and thickness of the member / steel material used and the size of the switch SW, but may be set to, for example, about 20 to 50 kPa.

[0027] When an internal short circuit or the like occurs, a gap SK opens between the cover 30 and the case 20, which releases the abnormal pressure. When the pressure inside the case 20 subsequently returns to normal, the cover 30 returns to its original position or close to its original position. This causes the gap SK to disappear, or the gap SK to narrow, although not completely. As a result, the inflow of outside air can be suppressed.

[0028] The opening and closing mechanism 50 is housed in the case 20. The opening and closing mechanism 50 includes a fixed electrode 51, a movable electrode 52, and a drive mechanism 53. The opening and closing mechanism 50 switches between a contact-on state in which the fixed electrode 51 and the movable electrode 52 are in contact with each other, and a contact-off state in which the fixed electrode 51 and the movable electrode 52 are not in contact with each other, by moving the movable electrode 52 with the drive mechanism 53. In the contact-on state, electricity is conducted between the fixed electrode 51 and the movable electrode 52.

[0029] The fixed electrode 51 is electrically connected to the terminal base end 13B of the demand side terminal 10B. The fixed electrode 51 is electrically connected to, for example, the demand side terminal 10B. The fixed electrode 51 includes a pair of fixed contacts. The pair of fixed contacts are provided on both sides of the terminal base end 13B and are electrically connected to the terminal base end 13B. The pair of fixed contacts are formed of, for example, a metal material.

[0030] The movable electrode 52 is electrically connected to, for example, the supply-side terminal 10A. The movable electrode 52 is movable relative to the fixed electrode 51. In other words, the movable electrode 52 is capable of coming into contact with or being separated from the fixed electrode 51.

[0031] The movable electrode 52 integrally includes a pivotal support portion 80, an arm portion 81, and a movable contact 82. The pivotal support portion 80 is rotatably supported by, for example, a conductor bracket BR attached to the terminal base end portion 13A of the supply-side terminal 10A. That is, the movable electrode 52 is rotatable about the pivotal support portion 80. The arm portion 81 is a member extending from the pivotal support portion 80. The movable contact 82 extends in a bent manner from the tip of the arm portion 81.

[0032] The movable electrode 52 rotates around the pivot support 80 (counterclockwise in FIG. 2), and the movable contactor 82 is inserted between the pair of fixed contactors, resulting in a contact-on state in which the movable contactor 82 is in contact with the fixed electrode 51. When the movable contactor 82 comes into contact with the fixed electrode 51, the fixed electrode 51 and the movable contactor 82 are electrically connected. In addition, the movable electrode 52 rotates around the pivot support 80 (clockwise in FIG. 2), and the movable contactor 82 retreats upward from between the pair of fixed contactors, resulting in a contact-off state in which the movable electrode 52 is separated from the fixed electrode 51.

[0033] As shown in FIG. 2, the driving mechanism 53 operates the movable electrode 52. For example, the driving mechanism 53 can perform a closing operation in which the movable electrode 52 is rotated in a first rotation direction (counterclockwise in FIG. 2) toward the fixed electrode 51 to bring the movable electrode 52 into contact with the fixed electrode 51. The opening / closing mechanism 50 transitions from a contact cut-off state to a contact make-on state by performing the closing operation. In addition, the driving mechanism 53 can perform a cut-off operation in which the movable electrode 52 is rotated in a second rotation direction (clockwise in FIG. 2) that is opposite to the first rotation direction from a state in which the movable electrode 52 is in contact with the fixed electrode 51, i.e., from a contact make-on state. The opening / closing mechanism 50 can transition to a contact cut-off state by separating the movable electrode 52 from the fixed electrode 51 by performing the cut-off operation. As an example, the driving mechanism 53 includes a link mechanism 70 and a rotation mechanism 71 as shown in FIG. 2.

[0034] One end of the link mechanism 70 is connected to the middle part of the arm part 81, and the other end is connected to the rotation axis AR. The rotation mechanism 71 operates the link mechanism 70. For example, the rotation mechanism 71 operates the link mechanism 70 by rotating the rotation axis AR. For example, the rotation mechanism 71 rotates the rotation axis AR in a first rotation direction to rotate the movable electrode 52 in the first rotation direction via the link mechanism 70. For example, the rotation mechanism 71 rotates the rotation axis AR in a second rotation direction to rotate the movable electrode 52 in the second rotation direction via the link mechanism 70.

[0035] The operation of the rotation mechanism 71 may be started by a manual operation by a user. For example, a manual operation unit (not shown) is rotatably provided on a side surface of the case 20. The user drives the rotation mechanism 71 by rotating the manual operation unit.

[0036] The hanging bracket 90 hangs the switch SW from the utility pole. The hanging bracket 90 includes a pair of support plates 91, a connecting member 92, and a locking portion 93. The connecting member 92 is an example of a "control portion" of the present invention. Note that one of the pair of support plates 91 may be referred to as a first support plate 91A, and the other may be referred to as a second support plate 91B.

[0037] The first support plate 91A is fixed to a first side surface of the case 20. The second support plate 91B is fixed to a second side surface of the case 20. The second side surface is the side surface opposite to the first side surface. In one example of this embodiment, the pair of support plates 91 are disposed on both sides of the case 20 in the long side direction.

[0038] As an example, the lower end of the first support plate 91A is fixed to a first side surface of the outer circumferential side surface 20s at four locations by fixing bolts 98. The second support plate 91B is fixed to a second side surface of the outer circumferential side surface 20s at four locations by fixing bolts 98. In this manner, each of the first support plate 91A and the second support plate 91B is fixed to the outer circumferential side surface 20s at four locations, but this is not limited thereto, and each may be fixed at one location or at multiple locations other than four locations.

[0039] The first support plate 91A and the second support plate 91B extend above the top plate portion 31 of the cover 30. An upper end portion of the first support plate 91A is fixed to one end of a connecting member 92. An upper end portion of the second support plate 91B is fixed to the other end of the connecting member 92.

[0040] The first support plate 91A and the second support plate 91B have an edge portion 910 extending in the up-down direction. The edge portion 910 is bent in an L-shape. In the example shown in FIG. 1, the edge portion 910 is bent in the opposite direction (outward) to the direction (inward) in which the case 20 is arranged. This can improve the rigidity of the hanging bracket 90. Note that the method of improving the rigidity of the hanging bracket 90 is not limited to bending the edges of the first support plate 91A and the second support plate 91B into an L-shape, and the plate thickness may be increased, or a steel plate with high hardness may be used.

[0041] The first support plate 91A is fixed to the first side surface and the second support plate 91B is fixed to the second side surface with high strength and rigidity. Therefore, even if the fixing member 40 is deformed due to an increase in the internal pressure of the case 20, the state in which the first support plate 91A and the second support plate 91B are fixed to the case 20 is maintained.

[0042] The connecting member 92 is disposed above the cover 30 and connects the first support plate 91A and the second support plate 91B. In other words, the connecting member 92 is supported by the first support plate 91A and the second support plate 91B. The connecting member 92 is a member extending along the upper surface of the cover 30. As an example, the connecting member 92 extends in the horizontal direction and connects the first support plate 91A and the second support plate 91B. The connecting member 92 is, for example, a steel material.

[0043] The connecting members 92 are disposed at an interval in the X direction relative to the top panel portion 31 of the cover 30. In the example shown in Fig. 1, two connecting members 92 are disposed at an interval in the X direction relative to the top panel portion 31 of the cover 30. However, this is not limited thereto, and the number of connecting members 92 is arbitrary and may be one, or may be three or more.

[0044] The connecting member 92 controls the size of the pressure relief gap SK formed between the case 20 and the cover 30. As illustrated in FIG. 3, the cross section of the connecting member 92 is, for example, a U-shape or C-shape that opens downward. The connecting member 92 is disposed so that both ends of the U-shape or C-shape face downward, and in the event of an abnormality, the both ends come into contact with the upper surface of the cover 30, thereby controlling the size of the gap SK. Here, the connecting member 92 may or may not come into contact with the upper surface of the cover 30 (the upper surface of the top plate portion 31) in the normal state. FIG. 2 illustrates a case in which the connecting member 92 does not come into contact with the upper surface of the cover 30 (the upper surface of the top plate portion 31).

[0045] In the event of an abnormality, a gap SK for pressure relief is formed between the cover 30 and the case 20 due to deformation of the fixing member 40. In this embodiment, a connecting member 92 that controls the size of the gap SK is provided on the upper surface of the cover 30. This allows the connecting member 92 to regulate the gap SK so that it does not become too large. Here, the connecting member 92 has a rigidity that does not deform even when a gap SK for pressure relief is formed between the cover 30 and the case 20. This allows the connecting member 92 to further regulate the size of the gap SK.

[0046] As an example of ensuring the rigidity so that the connection member 92 does not deform even when the gap SK is formed, the cross section of the connection member 92 is configured to be U-shaped or C-shaped rather than L-shaped. However, the connection member 92 only needs to be able to ensure the rigidity so that the connection member 92 does not deform even when the gap SK is formed, and may be a flat plate, H-shaped steel, I-shaped steel, T-shaped steel, square steel, round bar, etc.

[0047] The locking portion 93 extends upward from the connecting member 92. A hanging fitting for suspending the switch SW from a utility pole is locked to the locking portion 93. For example, a through hole 931 is formed in the locking portion 93. A hook portion formed on one end of the hanging fitting is inserted into this through hole 931, so that the hanging fitting is locked to the locking portion 93. The other end of the hanging fitting is attached to an arm AM attached to the utility pole, for example. The form of the hanging bracket 90 is not limited to the above-mentioned configuration. Any hanging manner is possible as long as the case 20 can be suspended.

[0048] Fig. 4(A) is a diagram showing the state of the switch 200 in an abnormal state when a connecting member 100 with low rigidity is used. Fig. 4(B) is a diagram showing a cross-sectional view (cross-sectional view along AA) of the connecting member 100. Fig. 5(A) is a diagram showing the state of the switch SW in an abnormal state according to this embodiment. Fig. 5(B) is a diagram showing an example of a cross-sectional view (cross-sectional view along BB) of the connecting member 92.

[0049] In the event of an abnormality, i.e., when an abnormal increase in the internal pressure of the switch 200 occurs, the increase in pressure causes the fixing member 40 to deform outward, and the cover 30 to lift up. Here, the cross section of the connecting member 100 is L-shaped as shown in FIG. 4(B). Therefore, the rigidity of the connecting member 100 tends to be low. Therefore, the connecting member 100 may become unable to withstand the force from the cover 30 and may be significantly deformed. As a result, as shown in FIG. 4(A), the cover 30 is significantly lifted, and the gap 300 for pressure relief between the case 20 and the cover 30 becomes large. The gap 300 is large enough to cause components inside the case 20 to fly off, and is, for example, 50 mm or more.

[0050] In this embodiment, when an abnormal increase in internal pressure occurs, a force corresponding to the internal pressure is applied to the cover 30 fixed to the case 20. As a result, the fixing member 40 is deformed outward. Here, the connecting member 92 has a U-shaped or C-shaped cross section as shown in FIG. 5(B) and has high rigidity. Therefore, the connecting member 92 does not deform even if an abnormal increase in internal pressure occurs. Here, the connecting member 92 and the cover 30 are arranged in a state where there is a small space (for example, several millimeters) between them under normal conditions. Therefore, when an abnormal increase in internal pressure occurs in the cover 30, the cover 30 rises by that space, and a gap SK for pressure relief is formed between the case 20 and the cover 30. However, since the cover 30 comes into contact with the connecting member 92 after rising by that space, it does not rise significantly thereafter. Therefore, as shown in FIG. 5(A), the gap SK does not become larger than the gap 300 shown in FIG. 4(A). The gap SK is a size that makes it unlikely that parts inside the case 20 will fly off, for example, 5 mm or more. Furthermore, the cover 30 is not deformed when the gap SK is formed. As shown in Fig. 5(A), a uniform gap SK of about 5 mm is formed between the case 20 and the cover 30. After pressure is released, the cover 30 descends and returns to its normal position. Therefore, as shown in Fig. 6, the gap SK is almost eliminated after pressure is released. As a result, the inflow of outside air can be suppressed.

[0051] Thus, in this embodiment, the connecting member 92 contacts the upper surface of the cover and controls the size of the gap between the cover 30 and the case 20 to release the internal pressure of the case 20. With this configuration, it is possible to regulate the size of the gap between the cover 30 and the case 20, and it is possible to release the internal pressure of the case 20 and to prevent components inside the case 20 from scattering to the outside. Furthermore, the connecting member 92 may have a rigidity that does not deform even when the gap SK is formed. With this configuration, it is possible to further regulate the size of the gap SK.

[0052] In the above embodiment, the fixing member 40 may be configured to deform when the internal pressure in the case 20 reaches a threshold value. In the abnormal event that the pressure in the case 20 reaches a certain threshold value, the fixing member 40 is deformed to form a gap SK between the cover 30 and the case 20 for releasing pressure.

[0053] Although the embodiments have been described above, the technical scope of the present invention is not limited to the scope described in the above-mentioned embodiments. It is clear to those skilled in the art that various modifications or improvements can be made to the above-mentioned embodiments. It is clear from the claims that such modifications or improvements are also included in the technical scope of the present invention. In addition, one or more of the requirements described in the above-mentioned embodiments may be omitted. In addition, the requirements described in the above-mentioned embodiments may be combined as appropriate. In addition, the execution order of each procedure shown in the embodiment can be realized in any order as long as the result of the previous procedure is not used in the subsequent procedure. In addition, even if the operations in the above-mentioned embodiments are described using "first," "next," "followed," etc. for convenience, it is not essential to carry them out in this order. [Explanation of symbols]

[0054] Switch 20 cases 30 Cover 40 Fixing member 50 Opening and closing mechanism 90 Hanging bracket 91A 1st support plate 91B 2nd support plate 92 Connecting member (control part)

Claims

1. a case that houses an opening / closing mechanism having a fixed electrode and a movable electrode that can come into contact with or be separated from the fixed electrode, and has an opening that opens upward; a cover provided to close the opening of the case; A control unit disposed above the cover; Equipped with An abnormal increase in internal pressure in the case causes a pressure relief gap to form between the cover and the case, The control unit contacts an upper surface of the cover to control the size of the gap.

2. The control unit has a rigidity such that it does not deform even when the gap is formed. The switch according to claim 1 .

3. the control unit is a member extending along an upper surface of the cover, The cross section of the control unit is U-shaped or C-shaped and opens downward, The size of the gap is controlled by contacting both ends of the U-shape or the C-shape with the upper surface of the cover. The switch according to claim 1 .

4. A fixing member for fixing the cover to the case is further provided. The fixing member is deformed by an abnormal increase in internal pressure in the case, The gap is formed by deformation of the fixing member. The switch according to claim 1 .

5. A first support plate that supports one end of the control unit; A second support plate that supports the other end of the control unit; Equipped with The first support plate is fixed to a first side surface of the case at four points, The second support plate is fixed at four locations to a second side surface of the case opposite to the first side surface. The switch according to claim 2 .

6. A first support plate that supports one end of the control unit; A second support plate that supports the other end of the control unit; Equipped with the first support plate is fixed to a first side surface of the case, the second support plate is fixed to a second side surface of the case opposite to the first side surface, The first support plate and the second support plate have edges extending along a vertical direction, The edge is bent into an L-shape. The switch according to claim 2 .

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