A device with a sealed internal chamber

Abstract

The present invention relates to a sealed device having a seal around an internal chamber, the seal having at least two closed loop portions through which a piercing element extends.

Description

Technical Field

[0001] The present invention relates to a device having a sealed internal chamber with a simple design. A non-limiting use of the present invention relates to the field of electrical disconnecting devices where plasma is generated following the appearance of an electric arc when opening a circuit.

Background Art

[0002] There is known a pyrotechnic disconnecting device comprising a body having an initiating part therein, the initiating part being configured to move, when actuated, in the direction of a conductive bar to be cut by a piston provided with a relief part. The destruction of the conductive bar through which current passes can cause the generation of plasma inside the internal chamber of the device. It is desirable to minimize the risk of exhaust of plasma outside the disconnecting device. It is desirable to have a solution for ensuring in a simple way a good seal of the internal chamber of the device.

Summary of the Invention

[0003] The present invention provides a device, wherein the device comprises an assembly of a first part and a second part forming the body of the device and forming an internal chamber, a through element extending through the internal chamber between the first part and the second part, a seal of the internal chamber surrounding the internal chamber, the seal comprising at least two closed-loop parts surrounding the through element and ensuring a seal along the through element, and at least two connecting parts connecting the at least two closed-loop parts, existing between the first part and the second part and ensuring a seal between the first part and the second part.

[0004] By implementing this seal, it is possible to ensure in a simple way a continuous seal of the internal chamber over its entire circumference, particularly at the level of the through element, using a single piece.

[0005] In an exemplary embodiment, the at least two closed-loop parts are diametrically opposite.

[0006] In one exemplary embodiment, the closed-loop portion has a substantially rectangular shape, and the through-element has a substantially rectangular cross-section at least at the level of the closed-loop portion.

[0007] In one exemplary embodiment, the cross-section of the through element has rounded corners.

[0008] In one exemplary embodiment, the seal is made of a flexible material, and the closed loop portion is oriented laterally with respect to the plane containing the connection portion by rotating it around it.

[0009] In one exemplary embodiment, the device is an electrical interruption device, the through-element is a conductive element, and the device comprises a movable piston in an internal chamber that can destroy the through-element following activation.

[0010] In this application, this seal prevents any risk of plasma exhaust from the interior chamber during the rupture of the penetration element due to impact with the piston during the shutoff.

[0011] In particular, this device can be a pyrotechnic shutoff device that includes a detonator and in which a piston can move following the operation of the detonator.

[0012] In this application, the main body may be equipped with a gas discharge orifice that communicates with the internal chamber and can discharge its contents, and a gas introduction orifice that communicates with the internal chamber and can introduce gas into the internal chamber, and the gas introduction orifice and the gas discharge orifice may be the same or separate.

[0013] In this application, the internal chamber can be filled with a dielectric gas whose dielectric breakdown voltage is greater than that of air at a reference pressure set at 0.1 MPa (1 bar).

[0014] Thus, pyrotechnic circuit breakers offer superior electric arc interruption performance compared to air-filled devices without increasing the mass or size of the device.

[0015] For this application, the dielectric gas composition may comprise at least 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile (CF3)2CFCN.

[0016] In this application, the dielectric gas may further comprise at least one gas from among dry air, nitrogen, and carbon dioxide.

[0017] For this application, the molar content of 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile ((CF3)CFCN) in the dielectric gas can be between 10% and 60%.

[0018] A gas exhaust orifice can, in particular, exhaust air contained within an internal chamber. A gas introduction orifice can, in particular, introduce a dielectric gas into an internal chamber.

[0019] In this application, the dielectric gas can pressurize the internal chamber to a pressure of at least 0.1 MPa (1 bar) at a temperature of -40°C.

[0020] Furthermore, the present invention relates to a safe electrical installation comprising the above-described circuit breaker and an electrical circuit connected to a penetration element.

[0021] The present invention also relates to a vehicle equipped with the aforementioned electrical equipment.

[0022] It should be noted that the present invention is not limited to applications to electrical shutoff devices. The penetration element may be an element carrying one or more sensors that enable the measurement of physical or chemical quantities of gas flowing through an internal chamber, where it is desired to prevent any risk of exhaust outside the device. The sensors may be, for example, pressure sensors and / or temperature sensors. [Brief explanation of the drawing]

[0023] [Figure 1] Figure 1 is a schematic diagram of an example of the apparatus according to the present invention. [Figure 2] Figure 2 is an exploded view of the apparatus of Figure 1. [Figure 3] Figure 3 is a detailed view of the apparatus of Figure 1. [Figure 4] Figure 4 corresponds to a cross-sectional view of the apparatus of Figure 1 in a first configuration that allows the passage of current. [Figure 5] Figure 5 corresponds to a cross-sectional view of the apparatus of Figure 1 in a second current interruption configuration. [Figure 6] Figure 6 is a schematic diagram of an example of a seal before the insertion of a through element through a closed loop portion. [Figure 7] Figure 7 is a schematic diagram of a safe electrical installation including the apparatus of Figure 1. [Figure 8] Figure 8 is a detail of a modified example of a closed loop portion that can be used in the present invention.

Mode for Carrying Out the Invention

[0024] The following description is made with respect to an example of an apparatus 100 according to the present invention that constitutes an electrical interruption device. As described above, the present invention is not limited to this application.

[0025] Figures 1, 2, 4, and 5 show a shutoff device 100 according to one embodiment of the present invention, comprising a body 10 in which a detonator 20, a piston 30, and a through element 40 are installed inside. The body 10 has a shape that extends along the main axis Z. The body 10 may have a substantially cylindrical shape, as in the illustrated example. The body 10 is formed by an assembly of a first part 11 and a second part 12. The first part 11 and the second part 12 can be superimposed. The first part 11 and the second part 12 can form the upper part 11 and the lower part 12 of the body 10. The through element 40 is here a conductive element in the form of, for example, a bar or a conductive tab. The through element 40 extends through the device 100 and is located between the first part 11 and the second part 12. The through element 40 passes through the body 10 and is present both inside and outside the body 10. The through element 40 is present at the level of the region of the assembly between the first part 11 and the second part 12. The through-hole element 40 has two terminals 41 and 42 intended to be connected to an electrical circuit (not shown). Terminals 41 and 42 form the terminals of the device 100, here corresponding to the two ends of the through-hole element 40. The piston 30 is mounted to be movable between a first current-passing position (a high position in the illustrated example, see Figure 4) and a second current-blocking position (a low position in the illustrated example, see Figure 5). The first portion 11 forms a retraction cavity 11a where the piston 30 is located when it is in its first position. The second portion 12 forms a receptive cavity 12a communicating with the retraction cavity 11a. The receptive cavity 12a can be aligned with the retraction cavity 11a along the main axis line Z. The receptive cavity 12a is intended to receive the piston 30 when it is in the second position, corresponding to the configuration in Figure 5. The junction between the storage cavity 11a and the receiving cavity 12a forms an internal chamber 13 in which the piston 30 is intended to move. The piston 30 can extend along the main axis Z. In the illustrated example, the piston 30 can have a shape of revolution about the main axis Z. The main axis Z can correspond to the displacement axis of the piston 30. The piston 30 is provided with a circumferential groove that accommodates a seal 31, such as an O-ring.The piston 30 can move between a first position and a second position along the direction of displacement A along the main axis Z inside the body 10. Unless the detonator 20 is activated, the piston 30 is in its first position. The penetrating element 40 passes through the internal chamber 13. In the illustrated example, the penetrating element 40 extends along the diameter of the internal chamber 13.

[0026] Following the activation of the detonator 20, the piston 30 is moved from its first position to its second position. The function of the piston 30 is to destroy the penetration element 40 during its passage from its first position to its second position, and thus to interrupt the flow of current through the penetration element 40. The detonator 20 comprises explosives connected to a connector 21. The explosives, when ignited, for example using current passing through the connector 21, can generate pressurized gas through combustion. The illustrated modification shows a pyrotechnically actuated shutoff device 100, but does not depart from the scope of the invention if the piston is moved in other ways, for example, after the release of a return element or after the release of gas stored under pressure.

[0027] To facilitate the fracture of the penetrating element 40 by the piston 30, the penetrating element 40 may optionally comprise one or more regions of a weak area 43 intended to form a fracture point of the penetrating element 40. The illustrated penetrating element 40 comprises two regions of weak area 43, ensuring fracture at two fracture points and allowing the fractured portion 44 to be separated from the rest of the penetrating element 40. In one variant not shown, the penetrating element has only a single region of weak area and fractures at a single fracture point, the fractured portion of which is bent by the piston in the receiving cavity when the piston is in a second position.

[0028] The impact of the piston 30 causes the penetration element 40 to break, which can lead to the generation of a gaseous plasma in the internal chamber 13, where leakage through the main body 10 is desired. To this end, the device is provided with a seal 50.

[0029] The seal 50 surrounds the internal chamber 13 around its entire circumference and thus surrounds the region where the plasma is generated. The seal 50 is located in the region of the assembly between the first part 11 and the second part 12. The first part 11 and the second part 12 may each have a slot intended to receive the seal 50. The slot has a shape complementary to the seal 50. The seal 50 here forms a closed, substantially circular shape, but it is understood that other shapes such as polygons or ellipses are also possible, depending on the shape of the body 10. The internal chamber 13 is located inside the closed shape formed by the seal 50. The penetrating element 40, in particular the region of its vulnerable part 43, is located inside the closed shape formed by the seal 50. In the illustrated example, the seal 50 comprises two closed-loop portions 53 and two connecting portions 51 that connect these closed-loop portions 53. Each connecting portion 51 is located between these closed-loop portions 53. The connecting portion 51 may be formed from a single stranded wire, and the closed-loop portion 53 may be formed from two stranded wires. The two ends of the connecting portion 51 are connected to the closed-loop portion 53. As shown in the figure, the stranded wire forming the connecting portion 51 can be divided at these ends of the connecting portion 51 to form the closed-loop portion 53. The connecting portion 51 may be a single stranded wire, and the closed-loop portion 53 may be a double stranded wire. The stranded wires forming the connecting portion 51 and / or the closed-loop portion 53 may have a circular, elliptical, or polygonal cross-section, such as a square, or a non-square cross-section. The stranded wires forming the connecting portion 51 and the closed-loop portion 53 may have the same shape and / or a larger, identical transverse dimension, such as the same diameter. Such features contribute to further improvement in sealing performance. The through-element 40 is introduced inside the closed-loop portion 53 and extends between the connecting portions 51. The through-element 40 is housed inside the closed-loop portion 53. The through element 40 and the connecting portion 51 can be located in the same plane. The closed loop portion 53 can be oriented laterally to the plane containing the connecting portion 51, or, for example, perpendicular to this plane. The closed loop portion 53 surrounds the through element 40. The closed loop portion 53 can traverse the through element 40, for example, perpendicular to the longitudinal axis X.The closed-loop portion 53 locally surrounds the through-element 40 over its entire circumference centered on its longitudinal axis X. The closed-loop portion 53 is in contact with the through-element 40. The shape of the closed-loop portion 53 can be identical to the cross-sectional shape of the through-element 40 at that level. Unless otherwise specified, the cross-section of the through-element is taken transversely, for example, perpendicular to its longitudinal axis X. The closed-loop portion 53 is located between the first portion 11 and the second portion 12. The closed-loop portion 53 ensures a seal at the level of the portion of the through-element 40 located over the region of the assembly of the first portion 11 and the second portion 12. The closed-loop portion 53 ensures a seal along the longitudinal axis X of the through-element 40. In the illustrated example, the closed-loop portion 53 has a substantially rectangular shape with rounded inner corners C1. The through-element 40 does not have sharp protrusions at the level of the region surrounded by the closed-loop portion 53. The raised portion, or corner C2, of the through-element 40 can be rounded at the level of these areas, for example, by machining. The presence of rounded corners C1 and C2 can improve sealing performance. Note that other shapes are possible for the closed-loop portion, depending on the cross-sectional shape of the through-element, such as a roughly square, circular, or elliptical shape.

[0030] The closed-loop sections 53 can form openings on the same surface. This allows for simpler manufacturing of the seal 50. Similarly, the cross-sections of the through-elements 40 at the level of each closed-loop section 53 can be identical. The connecting sections 51 ensure, for those sections, a seal over the area of ​​the assembly between the first section 11 and the second section 12 in the transverse direction with respect to the longitudinal axis X of the through-element 40. The seal 50 consists of identical elements, which allows for the assurance of a continuous seal around the internal chamber 13.

[0031] An example has been described in which there are exactly two closed-loop portions 53 and two connecting portions 51. If more than two closed-loop portions are used, it does not deviate from the scope of the invention, and for example, it may be possible to have four or six closed-loop portions for a device having two or three through elements, each. In the illustrated example, the closed-loop portions 53 are opposite in the diametrical direction, which allows the use of exactly the same device as if there were no seal 50, in particular the geometric shape of element 40, and thus makes it easier to obtain the device 100, but if this is not the case, it does not deviate from the scope of the invention.

[0032] Figure 6 shows the seal 50 in a stationary state, i.e., before the through-element 40 is positioned through the closed-loop portion 53. In the illustrated example, the seal 50 has a planar shape when stationary. Therefore, the connecting portion 51 and the closed-loop portion 53 are located in the same plane. The strands 52 forming the closed-loop portion 53 are located in the same plane as the strands forming the connecting portion 51 when the seal 50 is stationary. During the assembly of the apparatus 100, the closed-loop portion 53 is straightened to allow the through-element 40 to be positioned within the closed-loop portion 53, thanks to the flexibility of the seal 50. The seal is made of a flexible material that allows the closed-loop portion 53 to be straightened. This seal can be made of one of the following materials in particular: silicone resin, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), ethylene-propylene-diene monomer (EPDM), or fluoroelastomer (FKM). Variations of the flexible seal are particularly easy to manufacture. However, if the seal is obtained directly in a closed loop portion transverse to the connection portion, this does not deviate from the scope of the present invention.

[0033] According to a particular embodiment of the present invention, after the assembly of the shut-off device 100, the air inside the internal chamber 13 can be discharged through a gas discharge orifice. A dielectric gas can then be introduced into the internal chamber 13 of the shut-off device 100 through a gas introduction orifice. The gas discharge orifice and the gas introduction orifice can be the same or separate.

[0034] Dielectric gases have a greater breakdown voltage than air at a reference pressure set at 0.1 MPa (1 bar). Therefore, the circuit breaker 100 has a greater breaking capacity than a device with an internal chamber filled with air, and the electric arc generated inside the internal chamber 13 is extinguished more quickly and over a shorter distance. As a result, better breaking capacity can be obtained without modifying the size or mass of the circuit breaker.

[0035] The dielectric gas is introduced into the shutoff device 100 at room temperature, for example, 20°C. The dielectric gas can pressurize the internal chamber 13 to a pressure of at least 0.1 MPa (1 bar) at a temperature of -40°C. The pressure of the dielectric gas in the internal chamber 13 can be greater than 0.1 MPa (1 bar) even at low temperatures ranging from 0°C to -40°C. The use of the seal 50 described above is particularly advantageous in retaining the dielectric gas in the internal chamber 13 and preventing it from leaking to the outside of the main body 10.

[0036] The dielectric gas may be a mixture of gas (CF3)2CFCN (2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile), which is sold under the name 3M® Novec® 4710, and at least one other gas from among dry gas, nitrogen (N2), and carbon dioxide (CO2). The molar content of Novec® 4710 in the dielectric gas may be 10% to 60%. Preferably, the molar content of Novec® 4710 in the dielectric gas is 15% to 25%.

[0037] Furthermore, to prevent hydrolysis of dielectric gases, a humidity-absorbing product can be placed inside the internal chamber 13, for example, in the form of a metal sulfate or a molecular sieve with a pore size of 5 Å or less.

[0038] An example of a shutoff device 100 that provides a seal against gaseous plasma by implementing seal 50 is the one described above. The shutoff device 100 is intended to be incorporated into safety electrical equipment 300, an example of which will be described next in relation to Figure 7.

[0039] The safe electrical equipment 300 comprises a safe power supply system 310 comprising a circuit breaker 100 (shown very schematically) and a power supply circuit 311, wherein the power supply circuit 311 comprises a generator G connected to the second terminal 42 of the through-hole element 40 of the circuit breaker 100. The generator G may be, for example, a battery or an AC generator. The safe power supply system 310 further comprises a monitoring element C configured to activate the detonator 20 when an abnormality is detected.

[0040] The monitoring element C is connected to the detonator 20 via the connector 21. An abnormality in the response that allows the monitoring element C to start the detonator 20 can be an electrical abnormality such as exceeding a current threshold in the circuit, or a non-electrical abnormality such as the detection of a shock, such as a sudden deceleration of the monitoring element or a change in temperature or pressure. If an abnormality is detected, the monitoring element C can send current to the detonator 20 to start the detonator 20 in order to interrupt the current, as described above.

[0041] The safe electrical equipment 300 finally includes an electrical device D connected to the first terminal 41 of the through-element 40 of the circuit breaker 100, so that it is powered by the safe power supply system 310. To illustrate with an example, an automobile may be equipped with safe electrical equipment 300.

[0042] In the embodiment shown in Figure 6, the strands of the closed-loop portion 53 are of the same length. As a result, the center of the closed-loop 53 lies on the extension of the strands of the connecting portion 51. As shown in Figure 8, the strands of the closed-loop portion 153 may have different lengths, such that one strand is longer than the other. In the modified example shown in Figure 8, the center C of the closed-loop portion 153 is offset from the extension of the strands of the connecting portion 151.

Claims

1. In the apparatus (100), The aforementioned device (100) An assembly of a first part (11) and a second part (12) that forms the main body (10) of the device and the internal chamber (13), A penetrating element (40) extending through the internal chamber between the first and second parts, Apparatus (100) comprising: an internal chamber seal (50) surrounding the internal chamber, the seal (50) configured to create a seal to plasma or gas present in the internal chamber, the seal comprising at least two closed-loop portions (53; 153) surrounding the through-element and ensuring a seal along the through-element, and at least two connecting portions (51; 151) connecting the at least two closed-loop portions and located between the first portion and the second portion, ensuring a seal between the first portion and the second portion; and the internal chamber seal (50).

2. The apparatus (100) according to claim 1, wherein the at least two closed-loop portions (53; 153) are opposite in the diametrical direction.

3. The apparatus (100) according to claim 1 or 2, wherein the at least two closed-loop portions (53; 153) have a substantially rectangular shape, and the through-element (40) has a substantially rectangular cross-section at least at the level of the at least two closed-loop portions.

4. The apparatus (100) according to any one of claims 1 to 3, wherein the cross section of the through element (40) has a rounded corner (C2).

5. The apparatus (100) according to any one of claims 1 to 4, wherein the seal (50) is made of a flexible material, and the at least two closed loop portions (53) are oriented laterally with respect to a plane including the connecting portion (51) by rotating them.

6. The apparatus (100) according to any one of claims 1 to 5, wherein the apparatus is an electrical interruption device, the penetrating element (40) is a conductive element, and the apparatus comprises a movable piston (30) that can destroy the penetrating element after operation within the internal chamber (13).

7. The apparatus (100) according to claim 6, wherein the apparatus is a pyrotechnic shutoff device equipped with a detonator (20), and the piston (30) is capable of moving following the operation of the detonator.

8. The main body (10) is A gas discharge orifice that communicates with the aforementioned internal chamber (13) and can discharge its contents, It comprises a gas introduction orifice that communicates with the internal chamber (13) and allows gas to be introduced into the internal chamber (13), The apparatus (100) according to claim 6 or 7, wherein the gas introduction orifice and the gas discharge orifice are the same or separate.

9. The apparatus (100) according to any one of claims 6 to 8, wherein the internal chamber (13) is filled with a dielectric gas whose dielectric breakdown voltage is greater than that of air at a reference pressure set at 0.1 MPa (1 bar).

10. The dielectric gas is at least 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile (CF ３ ) ２ The apparatus (100) according to claim 9, comprising CFCN.

11. The apparatus (100) according to claim 10, wherein the dielectric gas further comprises at least one gas selected from dry air, nitrogen, and carbon dioxide.

12. 2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile (CF) in the dielectric gas ３ ) ２ The apparatus (100) according to any one of claims 10 or 11, wherein the molar content of CFCN is between 10% and 60%.

13. The apparatus (100) according to any one of claims 9 to 12, wherein the dielectric gas can pressurize the internal chamber (13) to a pressure of at least 0.1 MPa (1 bar) at a temperature of -40°C.

14. A safe electrical installation (300) comprising a circuit breaker (100) according to any one of claims 6 to 13 and an electrical circuit connected to the through-element.

15. A vehicle equipped with the safe electrical equipment (300) described in claim 14.

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