Sealed case

Abstract

To provide a sealed case with a sealing structure which achieves high reliability with a simple configuration.SOLUTION: A sealed case 1 includes: a case body 7 formed with an opening 9; a cover part 8 which covers the opening 9; a gasket 10 sandwiched between the case body 7 and the cover part 8; and a fastening member 13 which fixes the cover part 8 to the case body. The gasket 10 is compressed by fastening force of the fastening member 13. At least one of the case body 7 and the cover part 8 is provided with stoppers 14 which define an amount of compression of the gasket 10. When an internal pressure of the sealed case 1 increases, the fastening member 13 elastically deforms to allow the cover part 8 to separate from the case body 7 and release contact of the stoppers 14.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sealed case that can be suitably installed in a location where a high-temperature atmosphere occurs, such as an engine room. [Background technology]

[0002] Conventionally, a sealed case of this type is known that is installed in the engine compartment of an automobile and houses an intake control device inside (see, for example, Patent Document 1 below).

[0003] This device comprises a case body with an opening on one side and a cover part that closes the opening of the case body. The cover part is fastened to the case body with a plurality of screw members while the case body is closed.

[0004] A gasket is provided between the case body and the cover portion, and is compressed and deformed by the fastening force of the screw member when the cover portion is closed, thereby sealing the case body airtightly. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-172428 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the above-described conventional configuration, the case body and the cover portion can be firmly fastened together using screw members, and the space between the case body and the cover portion is reliably sealed via a gasket, thereby ensuring airtightness inside the case body.

[0007] However, due to the need to process the screw holes required for fastening the screw members and the arrangement of the screw members, not only was the number of processing steps large, but it was also difficult to reduce the size.

[0008] In view of the above, an object of the present invention is to provide a sealed case having a highly reliable sealed structure with a simple configuration. [Means for solving the problem]

[0009] In order to achieve this object, a first invention provides a sealed case that is housed near an internal combustion engine of a vehicle or in an engine compartment that houses the internal combustion engine, the sealed case comprising a case body having an opening formed in a portion thereof, a cover portion that closes the opening of the case body, a gasket sandwiched between the case body and the cover portion, and a fastening member that fixes the cover portion to the case body, wherein the gasket is compressed by the fastening force of the fastening member, and at least one of the case body and the cover portion is provided with a stopper that abuts against the other and receives the fastening force in a direction that compresses the gasket, thereby determining the amount of compression of the gasket, and when the internal pressure of the sealed case becomes higher than the external pressure of the sealed case, the fastening member elastically deforms, thereby allowing the cover portion to be displaced so as to move away from the case body, and making it possible to release the abutment of at least a portion of the stopper When a cross section cut in a direction perpendicular to the circumferential direction surrounding the opening and cutting a range including the fastening member is viewed, the fastening member is a clip member including a pair of elastic arms extending so as to move away from a stopper end that abuts on the case body or the cover part of the stopper as it moves away from the opening, and a connecting base that connects the sides of the pair of elastic arms farther from the opening, and both or either of the cover part and the case body are provided with a fastening abutment surface that abuts on the elastic arms, and a falling-off prevention levee that is located at a position farther from the opening and farther from the stopper end than the fastening abutment surface, and the surface of the falling-off prevention levee that faces the elastic arm is curved. It is characterized by:

[0010] According to the first aspect of the present invention, when the internal pressure of the sealed case increases, the fastening member elastically deforms, displacing the cover portion away from the case body. This releases at least a portion of the stopper from contacting the cover portion, and simultaneously loosens the compressed state of the gasket between the cover portion and the case body. This reduces the sealing performance of the gasket, providing a so-called relief function that releases the internal pressure within the case to the outside. When the internal pressure within the case is released to the outside, the restoring elasticity of the fastening member applies a pressure force to the cover portion against the case body, causing the stopper to return to its contact state and the gasket to return to its compressed state, thereby sealing the sealed case.

[0011] Although the relief function may be set to not work at the guaranteed temperature, it is not desirable to make the device unusable immediately when the guaranteed temperature is exceeded. Therefore, even in the case of abnormal use such as exceeding the guaranteed temperature, the configuration of the present invention can advantageously ensure minimum functionality and expand the scope of the guarantee.

[0013] Also As the internal pressure of the sealed case increases and the cover displaces away from the case body, the contact point between the elastic arm of the clip member and the fastening abutment surface moves further and further from the opening. At this time, the input point of the fastening force applied to the fastening arm approaches the connecting base. Therefore, if you try to increase the moment based on the connection point between the fastening arm and the connecting base, the rate of increase in the force that must be applied to the connecting arm is greater than the rate of increase in the moment. In other words, the farther the cover is from the case body, the greater the force required to separate the cover from the case body.

[0014] Due to the above-mentioned action, even if the internal pressure of the sealed case increases and the cover portion is displaced away from the case body, the distance between the cover portion and the case body can be maintained within a certain range.

[0015] Furthermore, by employing the clip member having the above-described configuration as the fastening member, it is not necessary to drill screw holes as is the case when a plurality of screw members are used, and miniaturization is also possible.

[0016] In addition, in the second invention, when the cross section is viewed, the gasket is in a substantially linear shape that contacts the case body when the fastening force is removed. The a first side and a second side facing the first side and in contact with the cover portion; The The first and second sides are both provided, and the space between the first and second sides is solid.

[0017] The above item 2According to the invention, the amount of compression displacement in the fastening direction is not required to ensure the surface pressure required for sealing. In other words, if the cover part is displaced only slightly in the direction of releasing the compression, the sealing performance can be immediately lost. In other words, the displacement of the cover part can be kept to a minimum when the above-mentioned relief function is activated.

[0018] Furthermore, the above-mentioned 1 If the configuration of the first invention is adopted, when the cover portion is displaced beyond a certain position, there is a risk that the clip member will deform beyond its elastic deformation range. However, by adding the configuration of the third invention, the internal pressure of the sealed case is released within the elastic deformation range, suppressing displacement and preventing abnormal deformation of the clip member. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is an explanatory perspective view showing a sealed case according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory cross-sectional view of a main part of the sealed case of the embodiment. [Figure 3] 5A and 5B are explanatory diagrams showing the operation of the main parts of the sealed case of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows an intake control device equipped with a sealed case 1 of the present invention. This intake control device is installed near an internal combustion engine mounted on a vehicle, and as shown in Fig. 1, it includes a valve body 2 and a valve drive unit 3. The valve drive unit 3 is housed in the sealed case 1. The valve body 2 is provided in a cylindrical portion 4 connected to the sealed case 1.

[0021] An intake passage 5 is formed inside the cylindrical portion 4. The valve element 2 is located inside the cylindrical portion 4 and adjusts the amount of air flowing through the intake passage 5. The valve element 2 is fixed to a valve shaft 6 that extends across the intake passage 5 and is rotatably supported by the cylindrical portion 4.

[0022] The sealed case 1 comprises a case body 7 and a cover part 8. The case body 7 has an opening 9 that opens one side, and the opening 9 is closed by the cover part 8. At this time, a gasket 10 is interposed between the periphery of the opening 9 of the case body 7 and the periphery of the cover part 8, and when the opening 9 is closed by the cover part 8, the gasket 10 ensures airtightness.

[0023] The case body 7 accommodates an electric motor 11 and a power transmission mechanism 12. The power transmission mechanism 12 is made up of a plurality of gears and transmits the power of the electric motor 11 to the valve shaft 6.

[0024] The cover portion 8 is fastened to the case body 7 by a plurality of clip members 13 provided as fastening members. For ease of explanation, the opening 9 of the case body 7 is shown in an open state in Fig. 1.

[0025] When the cover part 8 closes the opening 9 of the case body 7, a gasket 10 is sandwiched between the cover part 8 and the case body 7, as partially shown in Figure 2. A stopper 14 is formed on the cover part 8.

[0026] Stopper 14 is formed near gasket 10, and when cover part 8 closes opening 9 of case body 7, end 14a (stopper end) abuts against the periphery of opening 9 of case body 7. At this time, stopper 14 regulates the approach distance between cover part 8 and case body 7, and determines the amount of compression of gasket 10.

[0027] The clip member 13 is made of an elastic material and includes a pair of elastic arms 15 and a connecting base 16. The elastic arms 15 extend so as to move away from the stopper end 14a as they move away from the opening 9 of the case body 7. The connecting base 16 connects the base ends of the elastic arms 15 (the ends farther from the opening 9) together.

[0028] The clip member 13 is formed so that the tips of the pair of elastic arms 15 are biased in a direction to approach each other, and this biasing force acts as a fastening force.

[0029] The outer peripheral surface of the cover portion 8 is provided with a fastening abutment surface 17 against which the elastic arm portion 15 of the clip member 13 abuts, and a drop-off prevention levee 18 that protrudes along the outer edge of the fastening abutment surface 17. The drop-off prevention levee 18 is positioned farther from the opening 9 than the fastening abutment surface 17, and farther from the stopper end portion 14a than the fastening abutment surface 17.

[0030] As shown in Fig. 2, the gasket 10 is a solid rectangle in cross section, and has a first side 19 that contacts the case body 7 and a second side 20 that contacts the cover part 8. The gasket 10 is formed so that the first side 19 and the second side 20 are substantially linear when no fastening force is applied by the clip member 13. Note that the gasket 10 has the first side 19 and the second side 20 in cross section, and both the first side 19 and the second side 20 form annular surfaces.

[0031] The sealed case 1 configured as described above can provide a so-called relief function to the sealing state of the case body 7 by the cover part 8. That is, when the internal pressure of the sealed case 1 rises to a level that counteracts the fastening force of the clip member 13, the stopper end 14a of the cover part 8 separates from the case body 7, and the compressed state of the gasket 10 is relaxed. This allows the excess internal pressure of the sealed case 1 to be released to the outside, preventing an extreme rise in the internal pressure of the sealed case 1.

[0032] Furthermore, when a guaranteed temperature is set for the sealed case 1, even if the device is used in an environment where the guaranteed temperature is exceeded, the above-mentioned action of mitigating an extreme increase in the internal pressure of the sealed case 1 can be achieved. As a result, even if the device is used abnormally, such as when the guaranteed temperature is exceeded, the above-mentioned configuration can ensure minimum functionality and also make it possible to expand the scope of the guarantee.

[0033] Furthermore, with the sealed case 1 configured as described above, when the internal pressure increases and the cover portion 8 is displaced away from the case body 7, the distance between the cover portion 8 and the case body 7 can be maintained within a certain range.

[0034] To explain the action at this time in detail, even if the internal pressure of the sealed case 1 increases, as long as the abutment between the stopper 14 of the cover portion 8 and the case body 7 is maintained, the abutment between the first abutment point P1 of the elastic arm portion 15 of the clip member 13 and the fastening abutment surface 17 is maintained, as shown in Figure 3A.

[0035] When the internal pressure of the sealed case 1 continues to rise and exceeds the fastening force of the clip member 13, the cover part 8 separates from the case body 7. As a result, the elastic arm part 15 of the clip member 13 is deformed and moves away from the opening 9.

[0036] 3B, the second abutment point P2 of the elastic arm portion 15 of the clip member 13 on the connecting base 16 side abuts against the side surface of the fall-off prevention bank 18. At this time, the fastening force of the clip member 13 at the second abutment point P2, which is located closer to the connecting base 16 side than the first abutment point P1, is greater than the fastening force at the first abutment point P1.

[0037] Furthermore, as the internal pressure of the sealed case 1 continues to rise and becomes even higher, the elastic arm portion 15 of the clip member 13 moves further away from the opening 9, and as shown in Figure 3C, the elastic arm portion 15 of the clip member 13 abuts against approximately the top of the anti-detachment embankment 18 at the third abutment point P3.

[0038] In this way, as the internal pressure of the sealed case 1 increases, the contact position of the elastic arm portion 15 of the clip member 13 moves from the first contact point P1 to the third contact point P3 in the direction in which the fastening force increases. Therefore, the distance between the cover portion 8 and the case body 7 can be maintained within a certain range. As a result, for example, if an aperture sensor (not shown) is provided on the cover portion 8, the change in the distance between the rotor fixed to the valve stem 6 and the aperture sensor can be minimized, thereby maintaining high sensor accuracy.

[0039] Furthermore, as shown in FIG. 2, the gasket 10 has a first edge 19 that contacts the case body 7 and a second edge 20 that contacts the cover part 8, so that a large amount of compressive displacement in the fastening direction is not required to ensure the surface pressure required for sealing.

[0040] Therefore, the sealed state provided by the gasket 10 is easily released by slightly displacing the cover part 8 in the direction in which the compression of the gasket 10 is released. This minimizes the amount of displacement of the cover part 8, allowing the excess internal pressure of the sealed case 1 to be quickly released.

[0041] Moreover, the internal pressure of the sealed case 1 is released within the elastic deformation region of the clip member 13, suppressing displacement of the cover portion 8, so that abnormal deformation of the clip member 13 can be prevented.

[0042] In this embodiment, the stopper 14 is provided on the cover portion 8, but this is not limiting. That is, the stopper in the present invention may be provided on both the cover portion 8 and the case body 7, or may be provided only on the case body 7.

[0043] In addition, in this embodiment, the anti-fall-off embankment 18 is provided only on the cover portion 8, but the anti-fall-off embankment 18 may be provided on both the cover portion 8 and the case body 7, or may be provided only on the case body 7.

[0044] Furthermore, in this embodiment, the sealed case 1 of the intake control device is described as being located near the internal combustion engine mounted on a vehicle, but the sealed case of the present invention is not limited to this and can be suitably used in cases that are located near the internal combustion engine of a vehicle or stored in an engine room in which the internal combustion engine is housed. [Explanation of symbols]

[0045] 1...sealed case, 7...case body, 8...cover portion, 9...opening, 10...gasket, 13...crib member (fastening member), 14...stopper, 14a...stopper end portion, 15...elastic arm portion, 16...connecting base portion, 17...fastening abutment surface, 18...anti-fall-off embankment, 19...first edge, 20...second edge.

Claims

1. A sealed case that is housed near an internal combustion engine of a vehicle or in an engine compartment that houses the internal combustion engine, a case body having an opening formed in a portion thereof; a cover portion that closes the opening of the case body; a gasket that is sandwiched between the case body and the cover portion; and a fastening member that fixes the cover portion to the case body; the gasket is compressed by the fastening force of the fastening member, a stopper is provided on at least one of the case body and the cover portion, the stopper contacting the other and receiving the fastening force in a direction compressing the gasket to determine the compression amount of the gasket; When the internal pressure of the sealed case becomes higher than the external pressure of the sealed case, the fastening member elastically deforms to allow the cover portion to be displaced away from the case body, thereby enabling the abutment of at least a portion of the stopper to be released, When viewed from a cross section cut in a direction perpendicular to the circumferential direction surrounding the opening and cutting a range including the fastening member, the fastening member is a clip member including a pair of elastic arms extending so as to move away from a stopper end portion of the stopper that abuts against the case body or the cover portion as the arm portion moves away from the opening, and a connecting base portion connecting the sides of the pair of elastic arms farther from the opening, a fastening abutment surface that abuts against the elastic arm portion, and a fall-off prevention levee that is disposed at a position farther from the opening than the fastening abutment surface and farther from the stopper end than the fastening abutment surface, on both or either of the cover portion and the case body; A sealed case characterized in that the surface of the fall-off prevention dam facing the elastic arm portion is curved.

2. The sealed case according to claim 1, When looking at the cut surface, the gasket has a first side that is substantially linear and that contacts the case body when the fastening force is removed, and a second side that is substantially linear and that faces the first side and that contacts the cover portion, A sealed case characterized in that the portion between the first side and the second side is solid.

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