Capacitor

Abstract

According to the capacitor, a heat dissipation piece is exposed out of resin to be in contact cooling with an external cooling source, the external cooling source can be directly in contact with a heating source of the capacitor, the cooling effect is remarkable, and the capacitor comprises a capacitor shell, the resin, a capacitor core, a first busbar, a second busbar and the heat dissipation piece; the accommodating cavity of the capacitor shell is filled with resin; the capacitor core is arranged in the accommodating cavity and is embedded in the resin; the first parts of the first busbar and the second busbar are arranged in the accommodating cavity, are embedded in the resin and are electrically connected with the upper surface and the lower surface of the capacitor core respectively; the second parts of the two are exposed out of the resin and are led to the side edge of the capacitor shell to serve as connecting terminals; the heat dissipation piece comprises an exposed part exposed out of the resin and a buried part buried in the resin; the exposed part is in direct contact with an external cooling source, and the buried part is fixedly connected with the first part of the first busbar; in a plan view, only part of the exposed part is overlapped with the capacitor core, and the rest part is closer to the connecting terminal of the first busbar.

Description

Technical Field

[0001] The invention belongs to the technical field of capacitors, and in particular relates to a capacitor. Background Art

[0002] With the rapid development of electronic power technology, metallized film capacitors are increasingly used in industrial control, new energy, automotive electronics, rail transit, power grid and other fields. At the same time, the heating problem of capacitors is becoming more and more prominent.

[0003] In the early days, the industry often used capacitor shells for cooling. When using plastic shells for cooling, the heat dissipation effect is poor due to the low thermal conductivity of the plastic shell and the distance between the cooling source and the heat source; when using metal shells for cooling, although the thermal conductivity of the metal shell is high, the cooling source is still far from the heat source, and the use of metal shells will lead to increased material investment, higher costs, and increased product weight. At the same time, the insulation between the electrode plate and the metal shell will also become a difficulty, and the heat dissipation problem cannot be effectively solved and there is no economic advantage.

[0004] In the prior art, such as the "Capacitor" disclosed in CN113811965B, the busbar is in contact with the first electrode of the capacitor and has an exposed portion exposed outside the filling resin. When observed from a direction perpendicular to the bottom surface of the shell, the exposed portion overlaps with the capacitor element inside the shell. Although the heat generated by the capacitor element can be conducted out through the exposed portion, the heat dissipation effect is still not ideal, and the core problem of capacitor heat generation is not solved, and the following defects are also present: ① The exposed portion is not in direct contact with the capacitor element, and the heat dissipation effect is poor; ② The exposed portion has insufficient supporting strength and is difficult to support a cooling unit with a certain weight such as a cooler; ③ The busbar is a metal sheet formed in one piece through bending, stamping and other processes, which has problems such as complex process, low yield rate, and large tolerance during processing. Another example is the "Capacitor" disclosed in CN116783669A, which has a heat-conducting plate arranged on the upper surface of the first electrode at intervals through an insulating sheet. The heat-conducting plate is provided with an exposed surface exposed to the filling resin, and a cooling component is provided on the exposed surface. The insulating sheet affects the heat conduction effect between the capacitor element and the heat-conducting plate. As in the previous patent, the position of the heat-conducting plate also overlaps with the capacitor element, and the heat dissipation effect is still not ideal. At the same time, the heat-conducting plate and the first electrode are separated by an insulating sheet and are not connected and fixed. The heat-conducting plate is positioned only by the filling resin, and the structure is unstable and there is a problem of insufficient mechanical strength. Summary of the invention

[0005] The main purpose of the present invention is to provide a capacitor, which improves the relevant structure of the prior art and proposes a new heat dissipation design. A heat sink is arranged between the heat-generating busbar and the external cooling source, so that the heat sink is exposed outside the resin and is contact-cooled with the external cooling source. The external cooling source can directly contact the heat source of the capacitor, and the cooling effect is significant.

[0006] In order to achieve the above object, the solution of the present invention is: A capacitor comprises a capacitor housing, a resin, a capacitor core, a first busbar, a second busbar and a heat sink; the capacitor housing is provided with a cavity opening upward, the cavity is filled with the resin; the capacitor core is arranged in the cavity and buried in the resin; the first parts of the first busbar and the second busbar are both arranged in the cavity, buried in the resin and electrically connected to the upper and lower surfaces of the capacitor core respectively; the second parts of both are exposed from the resin and led to the side of the capacitor housing to serve as connection terminals; the heat sink comprises an exposed part exposed from the resin and a buried part buried in the resin; the exposed part is in direct contact with an external cooling source, and the buried part is connected and fixed to the first part of the first busbar.

[0007] When viewed from a direction perpendicular to the bottom wall of the cavity, the exposed portion only partially overlaps the capacitor core, and the remaining portion of the exposed portion is closer to the connection terminal of the first busbar.

[0008] A plurality of capacitor cores are arranged in parallel in the length direction of the capacitor housing; the heat sink is parallel to the length direction of the capacitor housing, and at least one heat sink is arranged in the length direction of the capacitor housing; or, the heat sink is parallel to the width direction of the capacitor housing, and at least a plurality of heat sinks are arranged in parallel along the length direction of the capacitor housing.

[0009] The external cooling source is wind, air, a liquid cooling pipeline or a liquid cooling panel; the material of the heat sink is aluminum or copper.

[0010] The heat sink and the first busbar are connected by soldering, laser welding, rivet-free riveting or self-positioning assembly.

[0011] The surface of the exposed portion is subjected to insulation treatment.

[0012] The second parts of the first busbar and the second busbar are led to the same side of the capacitor housing, and the two are isolated by insulating paper.

[0013] Preferably, the first part of the first busbar is a first connecting portion buried in the resin and attached to the upper surface of the capacitor core, and the second part is a plurality of first connecting terminals exposed in the resin, the first connecting portion is parallel to the first connecting terminal, and the two are integrally connected with a plurality of first connecting portions which are partially buried in the resin and partially exposed in the resin, and the first connecting portion is perpendicular to the first connecting portion.

[0014] Preferably, the first part of the second busbar is a second connecting part buried in the resin and attached to the lower surface of the capacitor core, a second connecting part bent and connected to the second connecting part, and a third connecting part bent and connected to the second connecting part, and the second part is a plurality of second connecting terminals exposed in the resin, and has a fourth connecting part integrally connected between the third connecting part and the second connecting segment, the fourth connecting part is partially buried in the resin and partially exposed in the resin, the first connecting part, the third connecting part, and the second connecting terminal are all parallel, the second connecting part and the fourth connecting part are parallel and perpendicular to the first connecting part; the third connecting part is located on the lower surface of the first connecting part, the fourth connecting part is located on the outer side surface of the first connecting part, and the second connecting terminal is located on the lower surface of the first connecting terminal, and they are all separated by the insulating paper.

[0015] The heat sink is a solid piece. Alternatively, the exposed portion of the heat sink is a plate-like or sheet-like piece that does not contact the resin, and the buried portion is a plurality of connecting pieces that are bent and connected to both sides of the exposed portion, the connecting pieces are buried in the resin and are connected and fixed to the first busbar; a plurality of through holes are provided at the connection between the exposed portion and the buried portion.

[0016] After adopting the above technical solution, the present invention has the following technical effects: The present invention provides a heat sink having a buried portion directly in contact with the heat source inside the resin, namely, the first busbar, and an exposed portion exposed from the resin. The heat generated by the busbar can be directly conducted out, and the heat can be dissipated through the exposed portion directly in contact with the external cooling source, thereby reducing the temperature inside the capacitor and achieving good thermal conductivity. At the same time, the heat sink is closer to the connection terminal of the busbar in the arrangement direction, that is, closer to the main heat source when the capacitor is running, namely, the position where the current enters the capacitor. Therefore, the heat sink can be close to the heat source and the cooling source at the same time, thereby further improving the heat dissipation effect on the capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of a first embodiment of the present invention; Figure 2 An exploded view of a first embodiment of the present invention; Figure 3is a cross-sectional view of a first embodiment of the present invention; Figure 4 A top view of the first embodiment of the present invention (resin hidden) Figure 5 is a perspective view of a second embodiment of the present invention; Figure 6 An exploded view of a second embodiment of the present invention; Figure 7 is a cross-sectional view of a second embodiment of the present invention; Figure 8 A top view of the second embodiment of the present invention (resin hidden) Description of Figure Numbers: 1-capacitor housing; 11-capacitor cavity; 2-resin; 3- Capacitor core; 4-first busbar; 41-first connecting portion; 42-first connecting terminal; 43-first connecting portion; 5-second busbar; 51-first connection portion; 52-second connection portion; 53-third connection portion; 54-second connection terminal; 55-fourth connection portion; 6-heat sink; 61-exposed portion; 62-buried portion; 63-perforated portion; 7- Insulation paper. DETAILED DESCRIPTION

[0018] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0019] refer to Figure 1-8 As shown, the present invention discloses a capacitor, comprising a capacitor housing 1, a resin 2, a capacitor core 3, a first busbar 4, a second busbar 5 and a heat sink 6; The capacitor housing 1 is provided with a cavity 11 opening upward, and the cavity 11 is filled with resin 2; The capacitor core 3 is disposed in the cavity 11 and buried in the resin 2; The first parts of the first busbar 4 and the second busbar 5 are both arranged in the cavity 11, buried in the resin 2 and electrically connected to the upper and lower surfaces of the capacitor core 3 respectively; the second parts of both are exposed from the resin 2 and led to the side of the capacitor housing 1 to serve as connection terminals; The heat sink 6 includes an exposed portion 61 exposed to the resin 2 and a buried portion 62 buried in the resin 2; the exposed portion 61 is in direct contact with the external cooling source, and the buried portion 62 is connected and fixed to the first portion of the first busbar 4; When viewed from a direction perpendicular to the bottom wall of the cavity 11 (ie, a top view), the exposed portion 61 only partially overlaps the capacitor core 3 , and the rest of the exposed portion 61 is closer to the connection terminal of the first busbar 4 .

[0020] Through the above scheme, the present invention sets a heat sink 6, and the heat sink 6 has a buried portion 62 directly in contact with the heat source inside the resin 2, namely, the first busbar 4, and an exposed portion 61 exposed to the resin 2. The heat generated by the busbar can be directly conducted out, and the heat is dissipated through the exposed portion 61 directly in contact with the external cooling source, thereby reducing the temperature inside the capacitor and achieving good thermal conductivity. At the same time, the heat sink 6 is closer to the connection terminal of the busbar in the arrangement direction, that is, closer to the main heat source when the capacitor is running, namely, the position where the current enters the capacitor. Therefore, the heat sink 6 can be close to the heat source and the cooling source at the same time, so that the heat dissipation effect of the capacitor is further improved.

[0021] In some embodiments of the present invention, a plurality of the capacitor cores 3 are arranged in parallel in the length direction of the capacitor housing 1; the heat sink 6 is parallel to the length direction of the capacitor housing 1, and at least one is arranged in the length direction of the capacitor housing 1: when only one heat sink 6 is provided, its length is preferably able to cover all the capacitor cores 3, that is, the heat sink 6 partially overlaps with each capacitor core 3 in a top-down perspective; when multiple heat sinks 6 are provided, it is best to ensure that each capacitor core 3 has at least one heat sink 6 that partially overlaps with it in a top-down perspective.

[0022] In some embodiments of the present invention, a plurality of capacitor cores 3 are arranged in parallel in the length direction of the capacitor housing 1; the heat sink 6 is parallel to the width direction of the capacitor housing 1, and at least a plurality of heat sinks 6 are arranged in parallel along the length direction of the capacitor housing 1. In a top view, it is best to ensure that each capacitor core 3 has at least one heat sink 6 partially overlapping with it.

[0023] In some embodiments of the present invention, the external cooling source includes but is not limited to wind, air, liquid cooling pipelines, liquid cooling panels, etc.

[0024] In some embodiments of the present invention, the material of the heat sink 6 includes but is not limited to high thermal conductivity materials such as aluminum and copper.

[0025] In some embodiments of the present invention, the connection method between the heat sink 6 and the first busbar 4 includes but is not limited to soldering, laser welding, rivet-free riveting, self-positioning assembly, etc.

[0026] In some embodiments of the present invention, if necessary, the surface of the exposed portion 61 may be subjected to insulation treatment, such as adding an insulating member, the material of which may be insulating paper, plastic, or the like.

[0027] In some embodiments of the present invention, the second parts of the first busbar 4 and the second busbar 5 are led to the same side of the capacitor housing 1, and the two are isolated by insulating paper 7 to meet the insulation requirements between the positive and negative electrodes of the capacitor.

[0028] Furthermore, the first part of the first busbar 4 is a first connecting portion 41 buried in the resin 2 and attached to the upper surface of the capacitor core 3, and the second part is a plurality of first connecting terminals 42 exposed in the resin 2. The first connecting portion 41 is parallel to the first connecting terminal 42, and a plurality of first connecting portions 43 partially buried in the resin 2 and partially exposed in the resin 2 are integrally connected therebetween. The first connecting portion 43 is perpendicular to the first connecting portion 41, and the first connecting portion 43, the first connecting portion 41 and the first connecting terminal 2 can be formed by bending.

[0029] Secondly, the first part of the second busbar 5 is a second connection part 51 buried in the resin 2 and attached to the lower surface of the capacitor core 3, a second connection part 52 bent and connected to the second connection part 51, and a third connection part 53 bent and connected to the second connection part 52. The second part is a plurality of second connection terminals 54 exposed in the resin 2, and has a fourth connection part 55 integrally connected between the third connection part 53 and the second connection segment 54. The fourth connection part 55 is partially buried in the resin 2 and partially exposed in the resin 2. The first connection part 51, the third connection part 53, and the second connection terminal 54 are all parallel, and the second connection part 52 and the fourth connection part 55 are parallel and perpendicular to the first connection part 51; the third connection part 53 is located on the lower surface of the first connection part 41, the fourth connection part 55 is located on the outer side of the first connection part 43, and the second connection terminal 54 is located on the lower surface of the first connection terminal 42, and they are all separated by insulating paper 7.

[0030] See also Figure 1-4 , showing the first embodiment of the present invention.

[0031] In the first embodiment, the heat sink 6 is a solid piece with a certain thickness. Since the heat sink 6 is connected and fixed to the first busbar 4 during assembly, it has a certain position stability. The solid structure itself can also ensure sufficient support strength. In actual products, when a cooling component with a certain weight such as a liquid cooling panel is installed on the upper surface of the heat sink 6, it will not collapse. In addition, the first busbar 4 is in close contact with the capacitor core 3, with a large contact area, and the solid heat sink 6 is used for heat dissipation, so the heat dissipation effect is better.

[0032] See also Figure 5-8 , showing a second embodiment of the present invention.

[0033] In the second embodiment, the exposed portion 61 of the heat sink 6 is a plate or sheet that does not contact the resin 2, and the buried portion 62 is a plurality of connecting pieces bent and connected to both sides of the exposed portion 61, and the connecting pieces are buried in the resin 2 and fixedly connected to the first busbar 4. In addition, the first busbar 4 is in close contact with the capacitor core 3, with a large contact area, and the heat sink 6 is used for heat dissipation, so the heat dissipation effect is better.

[0034] Furthermore, a plurality of through holes 63 are provided at the connection between the exposed portion 61 and the buried portion 62. Since the heat sink 6 is connected and fixed to the first busbar 4, the heat sink 6 has been assembled on the first busbar 4 and placed above the capacitor core 3 before the resin 2 is filled. By providing the through holes 63, the air below the exposed portion 61 can be easily discharged when the resin 2 is filled, so that the resin 2 can be more fully filled below the heat sink 6, especially below the exposed portion 61, ensuring good sealing performance of the resin 2; at the same time, since the resin 2 can be filled into a part of the through holes 63, the structural stability of the heat sink 6 can be further improved.

[0035] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A capacitor, characterized in that: It includes a capacitor housing, a resin, a capacitor core, a first busbar, a second busbar and a heat sink; The capacitor housing is provided with a cavity opening upward, and the cavity is filled with the resin; The capacitor core is arranged in the cavity and buried in the resin; The first parts of the first busbar and the second busbar are both arranged in the cavity, buried in the resin and electrically connected to the upper and lower surfaces of the capacitor core respectively; the second parts of both are exposed from the resin and led to the side of the capacitor housing to serve as connection terminals; The heat sink includes an exposed portion exposed to the resin and a buried portion buried in the resin; the exposed portion is in direct contact with an external cooling source, and the buried portion is connected and fixed to the first part of the first busbar.

2. The capacitor according to claim 1, wherein: When viewed from a direction perpendicular to the bottom wall of the cavity, the exposed portion only partially overlaps the capacitor core, and the remaining portion of the exposed portion is closer to the connection terminal of the first busbar.

3. The capacitor according to claim 1, wherein: The capacitor cores are arranged in parallel in a plurality in the length direction of the capacitor housing; The heat sink is parallel to the length direction of the capacitor housing, and at least one heat sink is provided in the length direction of the capacitor housing; Alternatively, the heat sink is parallel to the width direction of the capacitor housing, and at least a plurality of heat sinks are arranged in parallel along the length direction of the capacitor housing.

4. The capacitor according to claim 1, wherein: The external cooling source is wind, air, a liquid cooling pipeline or a liquid cooling panel; the material of the heat sink is aluminum or copper.

5. The capacitor according to claim 1, wherein: The heat sink and the first busbar are connected by soldering, laser welding, rivet-free riveting or self-positioning assembly.

6. The capacitor according to claim 1, wherein: The surface of the exposed portion is subjected to insulation treatment.

7. The capacitor according to claim 1, wherein: The second parts of the first busbar and the second busbar are led to the same side of the capacitor housing, and the two are isolated by insulating paper.

8. The capacitor according to claim 7, wherein: The first part of the first busbar is a first connecting portion buried in the resin and attached to the upper surface of the capacitor core, and the second part is a plurality of first connecting terminals exposed in the resin. The first connecting portion is parallel to the first connecting terminal, and a plurality of first connecting portions partially buried in the resin and partially exposed in the resin are integrally connected therebetween, and the first connecting portion is perpendicular to the first connecting portion.

9. The capacitor according to claim 8, wherein: The first part of the second busbar is a second connection part buried in the resin and attached to the lower surface of the capacitor core, a second connection part bent and connected to the second connection part, and a third connection part bent and connected to the second connection part. The second part is a plurality of second connection terminals exposed in the resin, and has a fourth connection part integrally connected between the third connection part and the second connection segment, the fourth connection part is partially buried in the resin and partially exposed in the resin, the first connection part, the third connection part, and the second connection terminal are all parallel, the second connection part and the fourth connection part are parallel and perpendicular to the first connection part; the third connection part is located on the lower surface of the first connection part, the fourth connection part is located on the outer side of the first connection part, and the second connection terminal is located on the lower surface of the first connection terminal, and they are all separated by the insulating paper.

10. The capacitor according to any one of claims 1 to 9, characterized in that: The heat sink is a solid piece; or the exposed portion of the heat sink is a plate-like or sheet-like piece that does not contact the resin, and the buried portion is a plurality of connecting pieces that are bent and connected to both sides of the exposed portion, the connecting pieces are buried in the resin and are connected and fixed to the first busbar; a plurality of through holes are provided at the connection between the exposed portion and the buried portion.

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