Bus duct

Abstract

The invention relates to the technical field of cable or wire installation, and discloses a bus duct, which comprises a shell, a heat dissipation plate and a conductor, and is characterized in that the shell comprises a top cover part, a partition plate part and a base part, the partition plate part is provided with a heat dissipation cavity penetrating through the upper side and the lower side of the partition plate part, the top cover part is provided with a first through hole, and the base part is provided with a second through hole; rainwater can pass through the first through hole and the second through hole; the heat dissipation plates are arranged on the two sides of the partition plate part, and two containing cavities are formed between the heat dissipation plates and the shell. The number of the conductors is four, the four conductors are divided into two groups and penetrate through the two containing cavities in a one-to-one correspondence mode, the two conductors in each group are the first conductor and the second conductor respectively, one side of the first conductor is attached to the heat dissipation plate, and one side of the second conductor is attached to the outer wall of the partition plate part; the shell further comprises grounding parts which are arranged at the two ends of the partition plate part and located between the two sets of conductors. The heat dissipation function of the bus duct can be improved, the use effect of the bus duct is ensured, and the bus duct is prevented from being damaged by rainwater.

Description

Technical Field

[0001] The present invention relates to the technical field of cable or wire installation, in particular to a bus duct. Background Art

[0002] In power supply systems, especially those in high-rise buildings, it is very important that the main power supply lines can operate stably. For high-rise buildings, if traditional insulated wires are installed in the main lines, they can no longer meet the power load requirements, and bus ducts are usually required to be installed. However, the existing bus ducts still have the problem of poor heat dissipation during use. When the temperature of the bus duct is too high, it will accelerate the aging of parts and even cause damage to the bus duct. The replacement of the bus duct takes a lot of time, which brings great inconvenience and economic losses to customers. In addition, due to frequent water leakage problems in buildings, the bus duct is easily wetted during use, and the accumulation of water will cause damage to the bus duct. If the bus duct is poorly grounded, there will be certain safety risks. For this reason, the market is in urgent need of a bus duct product with good heat dissipation effect, safety and reliability. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a bus duct, which improves the heat dissipation function of the bus duct, ensures the use effect of the bus duct, and prevents rainwater from damaging the bus duct.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A bus duct, comprising:

[0006] The housing comprises a top cover, a partition, and a base, wherein the partition is provided with a heat dissipation cavity extending through the top and bottom sides thereof, the top cover is provided with a first through hole communicating with the heat dissipation cavity, and the base is provided with a second through hole communicating with the heat dissipation cavity, wherein the first through hole and the second through hole are configured to allow rainwater to pass through;

[0007] A heat dissipation plate, which is arranged on both sides of the partition portion and forms two accommodating cavities with the shell;

[0008] Four conductors, divided into two groups and correspondingly arranged in the two accommodating cavities, the two conductors in each group being a first conductor and a second conductor, the side of the first conductor away from the second conductor being in contact with the heat sink, and the side of the second conductor away from the first conductor being in contact with the outer wall of the partition portion;

[0009] The housing further includes a grounding portion, which is provided at both ends of the partition portion and located between the two groups of conductors;

[0010] If the thickness of the conductor is t and the width of the heat dissipation cavity is W, then W≥5t.

[0011] Preferably, the outer sides of the conductors are covered with an insulating layer, and the parts of each group of conductors located inside the heat dissipation cavity are in contact with each other.

[0012] Preferably, a plurality of first heat dissipation teeth are provided on a side of the middle portion of the heat dissipation plate away from the accommodating cavity, and a plurality of second heat dissipation teeth are provided on the inner wall of the heat dissipation cavity.

[0013] Preferably, it includes a protective plate, which is provided at both ends of the housing and located on both sides of the conductor;

[0014] The protective plate includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the shell, and the distance between the two second connecting portions is L. If the thickness of the grounding portion is T, then L≥3(Wt)+4t+T.

[0015] Preferably, the shell also includes a first sealing member fastened to the front and rear ends of the top cover by screws, and a second sealing member fastened to the front and rear ends of the base by screws, and the protective plate is connected to the first and second sealing members by screws.

[0016] Preferably, the top cover portion, the partition portion and the base portion are integrally cast, and both the top cover portion and the base portion are in the shape of a Chinese character "凵".

[0017] Preferably, the top cover portion includes a top cover body and first clamping plates provided on both sides of the top cover body, a first clamping protrusion is provided inside the first clamping plate, and first clamping grooves are provided at both ends of the first blocking member, and the first clamping grooves correspond to the first clamping protrusions one-to-one and are clamped to each other;

[0018] The base portion includes a base body and second clamping plates arranged on both sides of the base body, a second clamping protrusion is provided inside the second clamping plate, and second clamping grooves are provided at both ends of the second sealing member. The second clamping grooves correspond one-to-one to the second clamping protrusions and are clamped to each other.

[0019] Preferably, the top end and the bottom end of the conductor are respectively in contact with the top cover and the base through insulating support members.

[0020] Preferably, the first through hole and the second through hole are aligned in the vertical direction;

[0021] The second through hole is provided in the middle of the base portion and extends along the length direction of the base portion. The thickness of the base portion gradually decreases from the edge of the base portion toward the second through hole.

[0022] Preferably, the grounding portion is a conductive wire or a conductive plate, which is welded to the housing.

[0023] A bus duct in an embodiment of the present invention has the following beneficial effects compared with the prior art: a heat dissipation cavity is opened on the partition portion, passing through the upper and lower sides thereof, a first through hole connected to the heat dissipation cavity is opened on the top cover portion, and a second through hole connected to the heat dissipation cavity is opened on the base portion. At the same time, two accommodating cavities are formed between heat dissipation plates and the shell body on both sides of the partition portion, and four conductors are divided into two groups, and the side of the first conductor of each group away from the second conductor is in contact with the heat dissipation plate, and the side of the second conductor away from the first conductor is in contact with the outer wall of the partition portion, so that each corresponding conductor is directly in contact with a heat dissipation body (heat dissipation plate or partition portion), so that the heat dissipation effect of each conductor is equivalent, and the heat of each conductor is directly discharged, and the heat does not need to be conducted between the conductors and then discharged, which not only improves the heat dissipation efficiency, but also ensures the balanced heat dissipation of each conductor, thereby improving the overall heat dissipation function.

[0024] In addition, when it rains, the rainwater can flow out directly through the first through hole, the heat dissipation cavity and the second through hole, thereby preventing the rainwater from damaging the bus duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an axonometric view of the bus duct of the present invention.

[0026] Figure 2 for Figure 1 A partial enlarged view of middle A.

[0027] Figure 3 It is a side view of the bus duct of the present invention.

[0028] Figure 4 It is a cross-sectional view of the bus duct of the present invention.

[0029] Among them: 1-shell; 11-top cover; 111-first through hole; 112-top cover body; 113-first snap-in plate; 114-first snap-in protrusion; 12-partition part; 121-heat dissipation cavity; 122-second heat dissipation tooth; 13-base; 131-second through hole; 132-base body; 133-second snap-in plate; 134-second snap-in protrusion; 14-first blocking member; 141-first slot; 15-second blocking member; 151-second slot; 16-grounding part; 2-heat dissipation plate; 21-first heat dissipation tooth; 3-conductor; 31-first conductor, 32-second conductor, 33-insulating layer; 4-protective plate; 41-first connecting part; 42-second connecting part; 5-insulating support member. DETAILED DESCRIPTION

[0030] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0031] like Figure 1-4 As shown, a bus duct according to a preferred embodiment of the present invention includes a shell, a heat dissipation plate and a conductor;

[0032] The housing includes a top cover 11, a partition 12, and a base 13. The partition 12 defines a heat dissipation cavity 121 extending from top to bottom. The top cover 11 defines a first through-hole 111 communicating with the heat dissipation cavity 121, and the base 13 defines a second through-hole 131 communicating with the heat dissipation cavity 121. The first and second through-holes 111, 131 are designed to allow rainwater to pass through. To prevent rainwater from damaging the bus duct, other electrical equipment cannot be installed within the heat dissipation cavity 121 to prevent short circuits.

[0033] During operation, air enters the heat dissipation cavity 121 through the first through-holes 111 and leaves the bus duct through the second through-holes 131, thereby removing heat from the housing 1 during the flow process and achieving efficient heat dissipation. Furthermore, in the event of a water leak or rain, this structure can also allow water to enter the heat dissipation cavity 121 through the first through-holes 111 and leave the bus duct through the second through-holes 131 under the action of gravity, achieving rapid drainage while absorbing heat through the water.

[0034] The housing 1 is made of aluminum. The top cover 11, the partition 12, and the base 13 can be separate, fixedly connected structures or integrally cast. The housing 1 can extend in a straight line to form a linear product, or it can extend along a folded line or curve to form a curved or bent product, depending on actual needs. The top cover 11 and base 13 are spaced apart from each other, with the partition 12 positioned between them, forming an "I" shape.

[0035] Preferably, the top cover 11, the partition 12, and the base 13 are integrally cast. Furthermore, the top cover 11 and the base 13 are in the shape of a "凵" character, which not only facilitates mounting and fixing to a ceiling or other area via a bracket, but also increases the cross-sectional area of ​​the top cover 11 and the base 13. Furthermore, the integral casting of the top cover 11, the partition 12, and the base 13 not only increases the overall grounding capacity of the bus duct, thereby rapidly directing current into the ground, shortening the current dissipation time, and improving safety, but also enhances the overall impact and deformation resistance of the bus duct housing 1, thereby increasing overall strength and thus improving earthquake resistance.

[0036] The heat dissipation plates 2 are two pieces, symmetrically arranged on both sides of the partition portion 12, and form left and right accommodating cavities between the heat dissipation plates 2 and the housing 1;

[0037] There are four conductors 3 (copper bars), which are divided into two groups and are arranged in the two accommodating cavities one by one. The two conductors 3 in each group are respectively a first conductor 31 and a second conductor 32. The side of the first conductor 31 away from the second conductor 32 is in contact with the heat dissipation plate 2, and the side of the second conductor 32 away from the first conductor 31 is in contact with the outer wall of the partition portion 12.

[0038] Existing bus ducts usually have four copper bars stacked in the middle. In this case, the inner copper bar needs to transfer heat to the outer copper bar, and then dissipate the heat through the heat sink. This not only extends the heat dissipation path, easily leads to heat accumulation and slow heat dissipation rate, but also causes uneven heat dissipation between the copper bars. When the bus duct described in the present invention is in use, each conductor 3 is directly attached to a heat sink (one conductor 3 in each group is attached to the heat sink 2, and the other conductor is attached to the partition part 12), so that the heat dissipation effect of each conductor 3 is equivalent, and the heat of each conductor 3 is directly discharged. The heat does not need to be conducted between the conductors 3 and then discharged. This not only reduces the heat dissipation path and improves the heat dissipation efficiency, but also ensures balanced heat dissipation of each conductor 3, thereby improving the overall heat dissipation function.

[0039] Therefore, the present application improves the heat dissipation effect mainly by fitting the side of the first conductor 31 of each group away from the second conductor 32 to the heat dissipation plate 2, and fitting the side of the second conductor 32 away from the first conductor 31 to the outer wall of the partition portion 12, so that each conductor 3 is directly fitted with a heat sink, ensuring that each of the conductors 3 can correspond to an independent heat dissipation path, so that the heat dissipation effect of each conductor 3 is equivalent, ensuring that the heat dissipation of each conductor 3 is balanced, thereby improving the overall heat dissipation function.

[0040] In addition, to further ensure heat dissipation, a plurality of first heat dissipation teeth 21 are provided on the central portion of the heat dissipation plate 2, away from the accommodating cavity. A plurality of second heat dissipation teeth 122 are provided on the inner wall of the heat dissipation cavity 121. These teeth increase the heat dissipation area and enhance the heat dissipation effect. As can be seen from the above, this application requires ensuring balanced heat dissipation of each conductor 3. Therefore, the total surface area of ​​the first heat dissipation teeth 21 and the second heat dissipation teeth 122 must be comparable.

[0041] At the same time, for ease of manufacturing, the outer sides of the conductors 3 are coated with an insulating layer 33. The portions of each group of conductors 3 located within the heat dissipation cavity 121 are in close contact with each other, ensuring mutual insulation between the two conductors 3. Furthermore, because the insulating layer 33 is very thin and the copper bars are in close contact with each other, the two conductors 3 in each group can conduct heat to each other, allowing the conductor 3 with a higher temperature to transfer heat to its adjacent conductor 3. This further ensures balanced heat dissipation between the two conductors 3 in each group, avoiding situations where one conductor 3 dissipates heat excessively while the other dissipates heat slowly, further ensuring effective heat dissipation.

[0042] The housing 1 also includes a grounding portion 16, which is provided at both ends of the partition portion 12 and is located between the two sets of conductors 3. The grounding portion 16 can be a conductive wire welded to both ends of the partition portion 12. When in use, it achieves grounding electrical connection between bus ducts through a jumper circuit. Alternatively, it can be a conductive plate (preferred embodiment). The structure of the conductive plate is similar to that of the conductors 3. When the bus duct is connected to the connector, the conductive plate is also electrically connected to the conductive plate of the other bus duct through the conductive structure in the connector. In other words, the electrical connection method of the conductive plate is the same as the electrical connection method of the conductors 3. Therefore, grounding is achieved during installation, simplifying the operation steps.

[0043] Furthermore, since the heat from the second conductors 32 is dissipated through the heat dissipation cavity 121, it is necessary to ensure that the heat dissipation cavity 121 can dissipate the heat promptly. Therefore, the width of the heat dissipation cavity 121 is crucial. Furthermore, since the conductors 3 of adjacent bus ducts are electrically connected via connectors, ensuring circuit connectivity, it is necessary to ensure sufficient spacing between adjacent conductors 3 to allow for connection to the connectors. In this embodiment, the heat dissipation cavity 121 is located between two second conductors 32, so the width of the heat dissipation cavity 121 can be determined by the thickness of the conductors 3. Furthermore, since the grounding portion 16 is provided and located in the center of the heat dissipation cavity 121, it can be determined that if the thickness of the conductors 3 is t and the width of the heat dissipation cavity 121 is W, then W ≥ 5t, such as W = 5t, 6t, 7t, 8t, etc. Only by ensuring W ≥ 5t can the conductors 3 be properly connected via the connectors and the heat dissipation cavity 121 be properly dissipated.

[0044] The bus duct based on the above technical features is provided with a heat dissipation cavity 121 running through the upper and lower sides of the partition portion 12, a first through hole 111 communicating with the heat dissipation cavity 121 is provided on the top cover portion 11, and a second through hole 131 communicating with the heat dissipation cavity 121 is provided on the base portion 13. At the same time, two accommodating cavities are formed between the heat dissipation plate 2 and the shell 1 on both sides of the partition portion 12, and the four conductors 3 are divided into two groups. The side of the first conductor 31 of each group away from the second conductor 32 is in contact with the heat dissipation plate 2, and the side of the second conductor 32 away from the first conductor 31 is in contact with the outer wall of the partition portion 12, so that each corresponding conductor 3 is directly in contact with a heat sink (heat dissipation plate or partition portion), so that the heat dissipation effect of each conductor 3 is equivalent, and the heat of each conductor 3 is directly discharged, and the heat does not need to be conducted between the conductors 3 and then discharged, which not only improves the heat dissipation efficiency, but also ensures the balanced heat dissipation of each conductor 3, thereby improving the overall heat dissipation function.

[0045] In addition, when it rains, the rainwater can flow out directly through the first through hole 111, the heat dissipation cavity 121 and the second through hole 131, thereby preventing the rainwater from damaging the bus duct.

[0046] To ensure that rainwater can pass smoothly through the first through-hole 111, the heat dissipation cavity 121, and the second through-hole 131, and to prevent rainwater from accumulating in the heat dissipation cavity 121 and ultimately corroding the housing 1, the first through-hole 111 and the second through-hole 131 are vertically aligned. Furthermore, the second through-hole 131 is located in the middle of the base portion 13 and extends along the length of the base portion 13. The thickness of the base portion 13 gradually decreases from the edge of the base portion 13 toward the second through-hole 131. That is, the surface of the base portion 13 is inclined toward the edge of the base portion 13 toward the second through-hole 131, thereby allowing rainwater that enters the surface of the base portion 13 to quickly drain out of the second through-hole 131. Both the first through-hole 111 and the second through-hole 131 are single and rectangular, with their lengths extending along the length of the housing 1. This ensures that the first through-hole 111 and the second through-hole 131 have the largest areas, facilitating heat dissipation and drainage.

[0047] In this embodiment, the bus duct further includes a protective plate 4, which is disposed at both ends of the housing 1 and on both sides of the conductor 3 to protect the portion of the copper busbar exposed from the accommodating cavity. Since the spacing between the conductors 3 is the same, the exposed portion of the first conductor 31 needs to be bent to ensure that the spacing between the first conductor 31 and the second conductor 32, and the spacing between the second conductor 32 and the conductive plate are the same. Therefore, for ease of installation, the protective plate 4 includes a first connecting portion 41 and a second connecting portion 42, which are arranged at an angle to each other. The first connecting portion 41 connects to the housing 1, and the spacing between the two second connecting portions 42 is L. If the thickness of the grounding portion 16 is T, then L ≥ 3(Wt) + 4t + T. Generally, T and t have the same value. A first connecting portion 41 and a second connecting portion 42 are provided at the same time. The first connecting portion 41 can be connected to a position close to the middle of the shell 1 as much as possible to ensure the connection strength with the shell 1. At the same time, the spacing between the two second connecting portions 42 satisfies: L≥3(Wt)+4t+T, which can ensure that the conductor 3 is normally connected through the connector and the heat dissipation effect of the heat dissipation cavity 121 is also guaranteed.

[0048] As can be seen from the above, in this application, the spacing L between the second connecting portions 42, the width W of the heat dissipation cavity 121, the thickness t of the conductor 3, and the thickness T of the grounding portion 16 are interrelated and mutually influential, jointly ensuring the heat dissipation effect of the bus duct and the smooth connection between bus ducts via connectors. Therefore, during specific production, the values ​​of the parameters W, L, t, and T must be comprehensively considered.

[0049] In this embodiment, the top and bottom ends of the conductor 3 are respectively in contact with the top cover 11 and the base 13 via the insulating support 5 , thereby achieving fixation and position limitation of the conductor 3 .

[0050] In this embodiment, the housing 1 further includes a first blocking member 14 fastened to the front and rear ends of the top cover 11 by screws, and a second blocking member 15 fastened to the front and rear ends of the base 13 by screws. The first blocking member 14 and the second blocking member 15 are made of conductive material and are tightly fitted to the top cover 11 and the base 13, respectively, so that the housing 1 is electrically connected to the protective plate 4. The upper and lower ends of the protective plate 4 are connected to the first blocking member 14 and the second blocking member 15 by screws, respectively. When the bus duct is connected to the connector, the protective plate 4 is electrically connected to the housing 1 through the screws and the blocking member, and is also electrically connected to the protective plate 4 of another bus duct through the connector, forming a grounding circuit, which is ultimately electrically connected to the grounding device.

[0051] In addition, to ensure the connection stability of the blocking member, the top cover portion 11 includes a top cover body 112 and first clamping plates 113 provided on both sides of the top cover body 112. The first clamping plates 113 are provided with first clamping protrusions 114 inside. Both ends of the first blocking member 14 are provided with first clamping grooves 141. The first clamping grooves 141 correspond to the first clamping protrusions 114 one by one and are clamped to each other, thereby ensuring the connection stability of the first blocking member 14 and the top cover portion 11.

[0052] The base portion 13 includes a base body 132 and second clamping plates 133 arranged on both sides of the base body 132. A second clamping protrusion 134 is provided inside the second clamping plate 133. Second clamping grooves 151 are provided at both ends of the second sealing member 15. The second clamping grooves 151 correspond one-to-one with the second clamping protrusions 134 and are clamped to each other, thereby ensuring the connection stability between the second sealing member 15 and the base portion.

[0053] In the description of this application, it should be understood that if the terms "upper", "lower", "front", "back", "left", "right", "vertical", "top", "bottom", "inside", "outside", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0054] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0055] It should be noted that if an element is referred to as being “fixed to” or “disposed on” another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be “connected to” another element, it may be directly connected to the other element or there may be an intermediate element.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A bus duct, characterized in that: Comprising: A housing, including a top cover portion, a partition portion, and a base portion. A heat dissipation cavity penetrating through the upper and lower sides thereof is provided on the partition portion. A first through hole communicating with the heat dissipation cavity is provided on the top cover portion. A second through hole communicating with the heat dissipation cavity is provided on the base portion, and the first through hole and the second through hole allow rainwater to pass through; A heat dissipation plate, which is arranged on both sides of the partition portion and forms two accommodating cavities between it and the housing; Four conductors, which are divided into two groups and are respectively and correspondingly disposed in the two accommodating cavities. The two conductors in each group are a first conductor and a second conductor respectively. One side of the first conductor away from the second conductor is in contact with the heat dissipation plate, and one side of the second conductor away from the first conductor is in contact with the outer wall of the partition portion; The housing further includes a grounding portion, which is arranged at both ends of the partition portion and is located between the two groups of conductors; If the thickness of the conductor is t and the width of the heat dissipation cavity is W, then W≥5t.

2. The bus duct according to claim 1, wherein: An insulating layer is coated on the outer side of the conductor, and the parts of each group of conductors located inside the heat dissipation cavity are in contact with each other.

3. The bus duct according to claim 1, wherein: A plurality of first heat dissipation teeth are provided on one side of the middle of the heat dissipation plate away from the accommodating cavity, and a plurality of second heat dissipation teeth are provided on the inner wall of the heat dissipation cavity.

4. The bus duct according to claim 1, wherein: Including a protective plate, which is arranged at both ends of the housing and on both sides of the conductor; The protective plate includes a first connecting portion and a second connecting portion. The first connecting portion connects the housing. The distance between the two second connecting portions is L. If the thickness of the grounding portion is T, then L≥3(W - t)+4t+T.

5. The bus duct according to claim 4, characterized in that: The housing further includes a first plugging member fastened to the head and tail ends of the top cover portion by screws, and a second plugging member fastened to the head and tail ends of the base portion by screws. The protective plate is connected to the first plugging member and the second plugging member by screws.

6. The bus duct according to claim 5, characterized in that: The top cover portion, the partition portion, and the base portion are integrally cast, and both the top cover portion and the base portion are in a "U" shape.

7. The bus duct according to claim 6, characterized in that: The top cover portion includes a top cover main body and first clamping plates arranged on both sides of the top cover main body. First clamping protrusions are provided inside the first clamping plates. First clamping grooves are provided at both ends of the first plugging member. The first clamping grooves correspond to the first clamping protrusions one by one and are clamped with each other; The base portion includes a base main body and second clamping plates arranged on both sides of the base main body. Second clamping protrusions are provided inside the second clamping plates. Second clamping grooves are provided at both ends of the second plugging member. The second clamping grooves correspond to the second clamping protrusions one by one and are clamped with each other.

8. The bus duct according to any one of claims 1 to 7, characterized in that: The top end and the bottom end of the conductor are respectively abutted against the top cover portion and the base portion through insulating support members.

9. The bus duct according to any one of claims 1 to 7, characterized in that: The first through hole and the second through hole are aligned in the vertical direction; The second through hole is provided in the middle of the base portion and extends along the length direction of the base portion. From the edge of the base portion to the direction of the second through hole, the thickness of the base portion gradually decreases.

10. The bus duct according to any one of claims 1 to 7, characterized in that: The grounding portion is a conductive wire or a conductive plate, which is welded to the housing.

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