Power conversion device

Abstract

The utility model relates to a power conversion device. The power conversion device includes: a first case; a containing cavity is defined by the second shell and the first shell, and the first shell and / or the second shell comprise / comprises a plurality of ultrasonic protruding strips arranged at intervals in the circumferential direction; and the sealant is arranged around the accommodating cavity and is in a closed loop shape, and the sealant is connected between the first shell and the second shell to seal the accommodating cavity. Therefore, water molecules in the containing cavity penetrate through the sealant in a gas state, and the water molecules further penetrate through the micro gap between the two adjacent welding seams to be discharged out of the containing cavity, so that erosion caused by the water molecules remaining in the containing cavity is avoided, and the service life of the whole power conversion device is prolonged. Welding seams formed by the ultrasonic protruding strips arranged at intervals are evenly formed, and therefore the mechanical strength of the power conversion device is improved. And the sealant and the weld joint jointly form dual connection and dual sealing effects, so that the mechanical strength and the service life of the power conversion device are further improved and prolonged.

Description

Technical Field

[0001] This application relates to the field of new energy technologies, and particularly to a power conversion device. Background Art

[0002] With the rapid development of new energy technologies, solar energy has been widely applied to daily production and life due to its advantages such as pollution - free and sustainable utilization. Generally, the solar light energy can be converted into electrical energy through photovoltaic power generation technology. The direct current generated by the photovoltaic power generation technology is then converted into alternating current through a power conversion device, and this alternating current can become available electrical energy and be input into the power grid through a connector; the power conversion device can also convert alternating current into direct current. However, for traditional power conversion devices, there are usually defects such as poor mechanical strength and low service life. Summary of the Invention

[0003] One technical problem solved by this application is how to improve the mechanical strength of the power conversion device so as to increase its service life.

[0004] A power conversion device includes:

[0005] A first shell;

[0006] A second shell that forms an accommodation cavity with the first shell, and the first shell and / or the second shell includes a plurality of ultrasonic ribs arranged at intervals in the circumferential direction; and

[0007] A sealant that is arranged around the accommodation cavity and is in a closed - loop shape, and the sealant is connected between the first shell and the second shell to seal the accommodation cavity.

[0008] In one embodiment, both the first shell and the second shell have welding surfaces for ultrasonic welding, and the ultrasonic ribs protrude on the welding surfaces of the first shell and / or the second shell.

[0009] In one embodiment, the welding surface includes a first welding area and a second welding area. The ultrasonic ribs on the first welding area and the first welding area extend along a straight line, and the ultrasonic ribs on the second welding area and the second welding area at least partially extend along a curve.

[0010] In one embodiment, the length of the ultrasonic ribs on the second welding area is greater than or equal to the length of the ultrasonic ribs on the first welding area.

[0011] In one embodiment, the second welding area surrounds the transformer, and / or the second welding area is located at the corner of the first shell and the second shell.

[0012] In one embodiment, the welding surface further includes a third welding area located on both sides of the mounting opening, and the ultrasonic rib extends to the third welding area.

[0013] In one embodiment, the protruding height of the ultrasonic rib relative to the welding surface is 0.1 mm to 0.5 mm, and the maximum width of the ultrasonic rib is 0.2 mm to 0.7 mm.

[0014] In one embodiment, the first housing has a profiling structure matching the shape of the electronic components in the accommodating cavity, and the first housing includes the ultrasonic rib.

[0015] In one embodiment, the first housing includes a first outer wall, the ultrasonic rib is protrudingly arranged on the surface of the first outer wall close to the second housing, the second housing includes a second outer wall, and the surface of the second outer wall close to the first housing can contact the ultrasonic rib and be welded to the first outer wall.

[0016] In one embodiment, the first housing includes a first outer wall and a first convex ring, the first convex ring is protrudingly arranged on the surface of the first outer wall close to the second housing, and the part of the surface of the first outer wall outside the coverage of the first convex ring forms a first welding surface surrounded by the first convex ring, and the ultrasonic rib is arranged on the first welding surface;

[0017] The second housing includes a second outer wall and a second convex ring, the second convex ring is protrudingly arranged on the surface of the second outer wall close to the first housing, and the surface of the second convex ring forms a second welding surface contacting the ultrasonic rib.

[0018] In one embodiment, the part of the surface of the second outer wall outside the coverage of the second convex ring forms a step surface surrounding the second convex ring, and the step surface abuts against the first convex ring.

[0019] In one embodiment, an annular groove is provided on the second housing, the annular groove is in a closed loop and surrounds the accommodating cavity, the first housing is matched with the annular groove, and the sealant is located in the annular groove and connected to the first housing.

[0020] In one embodiment, the first housing includes a first substrate, a first outer wall, and a first inner wall. The first outer wall and the first inner wall both protrude from the first substrate, and the first outer wall surrounds the first inner wall. The second housing includes a second substrate, a second outer wall, and a second inner wall. The second outer wall and the second inner wall both protrude from the second substrate, and the second outer wall surrounds the second inner wall. The second outer wall is welded to the first outer wall. The first inner wall, the second inner wall, the first substrate, and the second substrate enclose the accommodation cavity. An annular groove is formed between the second outer wall and the second inner wall, and the first inner wall is inserted into the annular groove.

[0021] In one embodiment, the width of the sealant is from 2 mm to 5 mm.

[0022] In one embodiment, the materials of the first housing and the second housing are both plastics.

[0023] A manufacturing method for processing the power conversion device according to any one of the above, the manufacturing method comprising the following steps:

[0024] Connect the sealant between the first housing and the second housing to seal the accommodation cavity;

[0025] Weld the first housing and the second housing by an ultrasonic welding process.

[0026] In one embodiment, the ultrasonic welding process is performed before the sealant solidifies into its final state.

[0027] One technical effect of an embodiment of the present application is that, in view of the fact that a plurality of ultrasonic ridges are arranged at intervals along the circumferential direction of the power conversion device, a plurality of welds arranged at intervals are formed by the plurality of ultrasonic ridges, and at the same time, a sealant is connected between the first shell and the second shell to seal the accommodation cavity. In this way, water molecules in the accommodation cavity permeate through the sealant in a gaseous state, and the water molecules will further permeate through the micro-gaps between adjacent two welds and be discharged outside the accommodation cavity, thereby avoiding the erosion of various electronic components caused by the water molecules remaining in the accommodation cavity and improving the service life of the entire power conversion device. Moreover, the total length formed by the plurality of ultrasonic ridges arranged at intervals is relatively small, thereby reducing the ultrasonic energy consumed during the welding process and ultimately reducing the manufacturing cost of the entire power conversion device. Furthermore, during the welding process of the ultrasonic ridges arranged at intervals, the melting is more uniform, making the welds formed uniformly and avoiding the weakest positions with relatively low stress-bearing capacity in the welds, thereby improving the mechanical strength of the welds and the entire power conversion device. Further, the sealant not only plays a sealing role but also can enhance the connection strength between the first shell and the second shell, thereby further improving the mechanical strength of the power conversion device to increase the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 FIG. 6 is a schematic perspective structure diagram of a power conversion device provided for an embodiment.

[0029] Figure 2 FIG. Figure 1 FIG. 7 is an exploded structure diagram of the power conversion device shown.

[0030] Figure 3 FIG. Figure 1 FIG. 8 is a schematic plan structure diagram of the first shell in the power conversion device shown.

[0031] Figure 4 FIG. Figure 2 FIG. 9 is a schematic perspective sectional structure diagram of FIG.

[0032] Figure 5 FIG. Figure 1 FIG. 10 is a schematic perspective sectional structure diagram of FIG.

[0033] Reference numerals: Power conversion device 10, Welding surface 103, First welding area 1031, Second welding area 1032, Third welding area 1033, Mounting opening 104, Housing 102, Accommodation cavity 101, First shell 100, First bottom wall 110, First outer side wall 120, First convex ring 130, First inner side wall 140, First welding surface 103a, Ultrasonic ridge 150, Second shell 200, Second bottom wall 210, Second outer side wall 220, Step surface 221, Second convex ring 230, Second inner side wall 240, Second welding surface 103b, Annular groove 250, Sealant 300, Connector 410, Transformer 420. Detailed implementation manners

[0034] To make the above objects, features, and advantages of the present application more apparent and understandable, the following provides a detailed description of the specific implementation manners of the present application with reference to the accompanying drawings. A lot of specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0035] In the description of the present application, it should be understood that if terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0036] In addition, if terms such as "first" and "second" appear, these terms are only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0037] In the present application, unless otherwise clearly specified and limited, if terms such as "mounted", "connected", "connected to", "fixed", etc. appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0038] In this application, unless otherwise clearly defined and limited, if there is a description such as the first feature being "on" or "under" the second feature, its meaning can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0039] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0040] Referring to Figure 1 , a power conversion device 10 provided in an embodiment of the present application. The power conversion device 10 is a power conversion device used to convert electrical energy from one form to another to achieve energy transmission and control under different power requirements. The power conversion device 10 can be a micro-inverter, an energy storage converter, an optimizer, etc. Exemplarily, the DC terminal of the power conversion device 10 can be connected to a DC source, and the AC terminal of the power conversion device 10 can be connected to an AC source, so that the power conversion device 10 can convert the input direct current into alternating current for output, or convert the input alternating current into direct current for output. For example, the power conversion device 10 can be applied to the field of photovoltaic power generation technology. The direct current generated by the photovoltaic power generation technology is converted into alternating current through the power conversion device 10, and the alternating current will become available electrical energy and be input into the power grid through the connector 410.

[0041] The power conversion device 10 includes a first housing 100, a second housing 200, and a sealant 300. The first housing 100 and the second housing 200 enclose a receiving cavity 101. The first housing 100 and / or the second housing 200 includes a plurality of ultrasonic ribs 150. The plurality of ultrasonic ribs 150 are arranged at intervals along the circumferential direction of the power conversion device 10. Through the ultrasonic ribs 150, the first housing 100 and the second housing 200 can be welded and connected by an ultrasonic welding process. The sealant 300 is arranged around the receiving cavity 101, and the sealant 300 is in a closed-loop shape. The sealant 300 is connected between the first housing 100 and the second housing 200, so that the sealant 300 can not only connect the first housing 100 and the second housing 200, but also seal the receiving cavity 101.

[0042] The sealant 300 can have a good liquid-blocking and air-permeable function, that is, liquid cannot pass through the sealant 300, while gas can pass through the sealant 300.

[0043] Refer to Figure 2 , during the welding process, the ultrasonic head can be moved on the first housing 100 or the second housing 200. The ultrasonic waves formed by the ultrasonic head will act on the ultrasonic ribs 150, causing the ultrasonic ribs 150 to generate high-frequency vibrations tens of thousands of times per second. Subsequently, the ultrasonic ribs 150 generate heat and melt under the action of the high-frequency vibrations. After the melted ultrasonic ribs 150 are cooled and solidified, they are connected to the weld seams of the first housing 100 and the second housing 200. After the first housing 100 and the second housing 200 are welded by the ultrasonic welding process to form a housing 102, a casting liquid can be injected into the housing 102. After the casting liquid solidifies, it can form a covering body covering the electronic components located inside the housing 102, so that the covering body plays a protective role for the electronic components, ensuring that the power conversion device 10 can be applied to various harsh environments such as humid heat, acid-base, rain, snow, ice and freezing, and can also improve the anti-impact performance of the power conversion device 10.

[0044] In some existing technologies, for example, the first housing 100 and the second housing 200 are connected by bolts. In this way, a plurality of bolts will be installed between the first housing 100 and the second housing 200, resulting in an increase in material costs and a decrease in assembly efficiency, thereby increasing the manufacturing cost of the power conversion device 10. Another example is that the first housing 100 and the second housing 200 are welded and connected by a conventional welding process. In this way, a large amount of consumables such as welding rods will be used, which will also lead to an increase in material costs and a decrease in assembly efficiency, ultimately increasing the manufacturing cost of the power conversion device 10.

[0045] Another example is that the first housing 100 and the second housing 200 are welded and connected by an ultrasonic welding process, but the ultrasonic ribs 150 are in a continuous closed-loop shape, resulting in the weld seam between the first housing 100 and the second housing 200 being in a closed-loop shape. This will cause at least the following three defects:

[0046] First, considering that it is necessary to inject casting liquid into the housing 102, and the closed-loop welding strip seals the entire accommodating cavity 101, and the weld has good liquid and gas isolation functions, that is, neither gas nor liquid can penetrate through the weld, so that the water molecules generated by the casting liquid in the accommodating cavity 101 cannot be discharged through the weld formed by the ultrasonic ribs 150, that is, the water molecules cannot be discharged outside the housing 102 and still remain in the accommodating cavity 101. In this way, the humidity in the accommodating cavity 101 is too high, which affects the service life of various electronic components in the accommodating cavity 101 and ultimately affects the service life of the entire power conversion device 10.

[0047] Second, in the process of forming a closed-loop weld by the closed-loop ultrasonic ribs 150, considering that the length of the closed-loop ultrasonic ribs 150 is relatively large, the ultrasonic ribs 150 with a relatively large length will consume more ultrasonic energy, thus increasing the manufacturing cost of the entire power conversion device 10.

[0048] Third, the closed-loop ultrasonic ribs 150 are prone to uneven melting during the welding process, resulting in uneven weld formation. Subsequently, the stresses that each part of the weld can withstand are uneven, leading to the weakest position with relatively low stress-bearing capacity in the entire weld, ultimately affecting the mechanical strength of the weld and the entire power conversion device 10.

[0049] For the power conversion device 10 in the above embodiment, the first housing 100 and the second housing 200 are welded and formed by ultrasonic welding process. Compared with bolt connection and conventional welding modes, the use of consumables such as bolts or welding rods can be saved, thereby reducing the manufacturing cost of the power conversion device 10. A plurality of ultrasonic ribs 150 are arranged at intervals along the circumference of the power conversion device 10, so that a plurality of ultrasonic ribs 150 form a plurality of welds arranged at intervals. At the same time, the sealant 300 is connected between the first housing 100 and the second housing 200 to seal the accommodating cavity 101. In this way, there are at least the following three beneficial effects:

[0050] First, the sealant 300 has air permeability, and the water molecules generated by the casting liquid in the accommodating cavity 101 pass through the sealant 300 in a gaseous state, and the water molecules will further pass through the micro-gap between two adjacent welds and be discharged outside the housing 102, thereby avoiding the erosion of various electronic components caused by the water molecules remaining in the accommodating cavity 101. Thus, the service life of the entire power conversion device 10 can be improved.

[0051] Second, the total length formed by a plurality of ultrasonic ribs 150 arranged at intervals is relatively small, thereby reducing the ultrasonic energy consumed during the welding process and ultimately reducing the manufacturing cost of the entire power conversion device 10.

[0052] Thirdly, during the welding process of the spaced ultrasonic ribs 150, the melting is more uniform, making the weld formation uniform and avoiding the weakest position with relatively low stress-bearing capacity in the weld, thereby improving the mechanical strength of the weld and the entire power conversion device 10. Further, the sealant 300 will improve the connection strength between the first housing 100 and the second housing 200, thereby improving the mechanical strength of the housing 102 and the entire power conversion device 10. Moreover, the sealant 300 has good sealing performance against liquids, preventing liquids from entering the accommodation cavity 101 to erode the electronic components, thereby increasing the service life of the power conversion device 10.

[0053] Referring to Figure 5 , in some embodiments, both the first housing 100 and the second housing 200 have welding surfaces 103 for ultrasonic welding, and the ultrasonic ribs 150 are protrudingly arranged on the welding surfaces 103 of the first housing 100 and / or the second housing 200. That is, the ultrasonic ribs 150 can be protrudingly arranged only on the welding surface 103 of the first housing 100; or the ultrasonic ribs 150 can be protrudingly arranged only on the welding surface 103 of the second housing 200; or the ultrasonic ribs 150 can be protrudingly arranged on the welding surfaces 103 of both the first housing 100 and the second housing 200 at the same time. By protrudingly arranging the ultrasonic ribs 150 on the welding surface 103, the welding efficiency and the connection strength between the first housing 100 and the second housing 200 can be improved.

[0054] Taking the setting of the ultrasonic ribs 150 on the welding surface 103 of the first housing 100 as an example, the following is an illustration.

[0055] The welding surface 103 can include a first welding area 1031 and a second welding area 1032. The first welding area 1031 extends linearly, and the ultrasonic ribs 150 on the first welding area 1031 also extend linearly; the second welding area 1032 extends at least partially along a curve. For example, the second welding area 1032 extends entirely along a curve, or a part of the second welding area 1032 extends along a curve while the other part extends linearly. The ultrasonic ribs 150 on the second welding area 1032 also extend at least partially along a curve. For example, the ultrasonic ribs 150 extend entirely along a curve, or a part of the ultrasonic ribs 150 extends along a curve while the other part extends linearly. In this way, the weld formed by the ultrasonic ribs 150 can respectively adapt to the different shapes of the first welding area 1031 and the second welding area 1032, thereby improving the connection strength between the first housing 100 and the second housing 200, and ultimately increasing the service life and mechanical strength of the power conversion device 10. It should be noted that in view of the fact that the ultrasonic ribs 150 on the first welding area 1031 extend linearly, it is convenient for the formation of the ultrasonic ribs 150, which helps to improve the processing efficiency of the power conversion device 10 and reduce the manufacturing cost.

[0056] In some embodiments, given that the transformer 420 in the power conversion device 10 is generally cylindrical, the second welding area 1032 can extend entirely along a curve such that the second welding area 1032 can be arc-shaped, and the arc-shaped second welding area 1032 is disposed around the transformer 420.

[0057] In some embodiments, a part of the second welding area 1032 can extend along a straight line and another part can extend along a curve. The part of the second welding area 1032 that extends along the curve is denoted as the bent portion, and the bent portion is disposed around the transformer 420. The part of the second welding area 1032 that extends along the straight line is denoted as the straight portion, and the straight portion is closer to the first welding area 1031 than the bent portion.

[0058] In some embodiments, the second welding area 1032 is located at a corner of the housing 102. A part of the second welding area 1032 can extend along a straight line and another part can extend along a curve. The part of the second welding area 1032 that extends along the curve is denoted as the bent portion, and the part of the second welding area 1032 that extends along the straight line is denoted as the straight portion. The number of bent portions is one, and the number of straight portions can be two. The bent portion is connected between the two straight portions, and the straight portions are closer to the first welding area 1031 than the bent portion.

[0059] Since the position of the power conversion device 10 corresponding to the second welding area 1032 protrudes relative to the position corresponding to the first welding area 1031, the position of the power conversion device 10 corresponding to the second welding area 1032 is more vulnerable to external force impacts. Therefore, the length of the ultrasonic ribs 150 on the second welding area 1032 can be made greater than the length of the ultrasonic ribs 150 on the first welding area 1031, so that the length of the weld seam on the second welding area 1032 is greater than the length of the weld seam on the first welding area 1031, ultimately improving the mechanical strength at the position of the power conversion device 10 corresponding to the second welding area 1032 and preventing the power conversion device 10 from being damaged under the action of external force impacts.

[0060] Of course, under working conditions where the probability of being impacted by external forces is relatively small, the length of the ultrasonic ribs 150 on the second welding area 1032 can be made approximately equal to the length of the ultrasonic ribs 150 on the first welding area 1031. For example, for the second welding area 1032 that extends entirely along a curve and is disposed around the transformer 420, the length of the ultrasonic ribs 150 on the second welding area 1032 can be approximately equal to the length of the ultrasonic ribs 150 on the first welding area 1031.

[0061] Refer to Figure 3, in some embodiments, an installation opening 104 may be formed on the first housing 100 and / or the second housing 200. The installation opening 104 is used to install a DC or AC connector 410. The welding surface 103 further includes a third welding area 1033. The third welding area 1033 is located on both sides of the installation opening 104. The ultrasonic rib 150 extends to the third welding area 1033, so that the ultrasonic rib 150 can extend to the edge of the installation opening 104. The setting of the installation opening 104 usually affects the connection strength and sealing performance of the power conversion device 10, that is, the position near the installation opening 104 is a relatively weak position. However, since the ultrasonic rib 150 is provided in the third welding area 1033, the weakening function of the installation opening 104 on the connection strength and sealing performance can be effectively compensated, so as to ensure that the position of the power conversion device 10 at the installation opening 104 has sufficient connection strength and sealing performance, and finally improve the service life and mechanical strength of the power conversion device 10. Experiments show that by providing the ultrasonic rib 150 in the third welding area 1033, the position near the installation opening 104 can be ensured to have an IP68 protection level against liquids such as water.

[0062] Refer to Figure 4 , in some embodiments, along the protruding direction of the ultrasonic rib 150 relative to the welding surface 103, the cross-sectional dimension of the ultrasonic rib 150 may gradually decrease. Thus, the cross-section of the ultrasonic rib 150 may be triangular or isosceles trapezoidal, etc. A rounded corner may be provided at one end of the ultrasonic rib 150 away from the welding surface 103. The protruding height of the ultrasonic rib 150 relative to the welding surface 103 is 0.1 mm to 0.5 mm. The specific value of the protruding height of the ultrasonic rib 150 relative to the welding surface 103 may be 0.1 mm, 0.2 mm or 0.5 mm, etc. The maximum width of the ultrasonic rib 150 is 0.2 mm to 0.7 mm. The specific value of the maximum width of the ultrasonic rib 150 may be 0.2 mm, 0.5 mm or 0.7 mm, etc. Through the above structural setting of the ultrasonic rib 150, the connection strength of the weld formed by the ultrasonic rib 150 can be reasonably improved, and the ultrasonic energy consumed during the welding process can also be reduced. The width of the sealant 300 may be 2 mm to 5 mm. For example, the specific value of the width of the sealant 300 may be 2 mm, 3 mm or 5 mm, etc. Thus, the sealant 300 can be ensured to have reasonable connection strength and sealing function.

[0063] In some embodiments, the materials of the first housing 100 and the second housing 200 may both be plastics, such as PPO (Polyphenylene Oxide) plastics. Thus, the first housing 100 and the second housing 200 have good ultrasonic welding performance, thereby reducing the ultrasonic energy consumed during the welding process and finally reducing the manufacturing cost of the power conversion device 10.

[0064] Refer to Figure 4, in some embodiments, the first housing 100 has a profiling structure that matches the shape of the electronic components in the accommodation cavity 101. The profiling structure can be understood as an uneven structure that is suitable for accommodating electronic components with different heights protruding in the accommodation cavity 101. The ultrasonic ribs 150 are only provided on the welding surface 103 of the first housing 100, that is, only the first housing 100 includes the ultrasonic ribs 150, while the ultrasonic ribs 150 are not provided on the welding surface 103 of the second housing 200. During the welding process, in view of the fact that the second housing 200 does not have a profiling structure and the outer surface of the second housing 200 is relatively flat, the second housing 200 is placed on the support body, which is convenient for clamping with a fixture. When the ultrasonic head contacts the first housing 100, it can prevent the entire power conversion device 10 from tilting or swinging relative to the support body under the pressure of the ultrasonic head, thereby improving the welding accuracy and welding efficiency.

[0065] Refer to Figure 5 , for example, the first housing 100 includes a first bottom wall 110 and a first outer side wall 120. The first outer side wall 120 surrounds the first bottom wall 110 and protrudes relative to the first bottom wall 110. The second housing 200 includes a second bottom wall 210 and a second outer side wall 220. The second outer side wall 220 surrounds the second bottom wall 210 and protrudes relative to the second bottom wall 210. The first bottom wall 110 and the second bottom wall 210 are spaced apart along the thickness direction of the power conversion device 10. The surface of the first outer side wall 120 close to the second outer side wall 220 is the welding surface 103 of the first housing 100, and the surface of the second outer side wall 220 close to the first outer side wall 120 is the welding surface 103 of the second housing 200. The ultrasonic ribs 150 protrude on the welding surface 103 of the first housing 100. After the ultrasonic ribs 150 form a weld seam, the weld seam will connect between the welding surfaces 103 of the first housing 100 and the second housing 200, thereby realizing the welded connection relationship formed between the first housing 100 and the second housing 200 through the ultrasonic welding process.

[0066] Refer to Figure 4 , or, for another example, the first housing 100 may further include a first convex ring 130. The first convex ring 130 protrudes on the surface of the first outer side wall 120 close to the second outer side wall 220. The part of the surface of the first outer side wall 120 outside the coverage of the first convex ring 130 forms the welding surface 103, which can be denoted as the first welding surface 103a. The first convex ring 130 will surround the first welding surface 103a, and the ultrasonic ribs 150 are provided on the first welding surface 103a.

[0067] Furthermore, the second housing 200 may further include a second convex ring 230. The second convex ring 230 protrudes from the surface of the second outer wall 220 close to the first outer wall 120. The second convex ring 230 contacts the ultrasonic rib 150. The surface of the second convex ring 230 in contact with the ultrasonic rib 150 is the welding surface 103 of the second housing 200, and this welding surface 103 is denoted as the second welding surface 103b. The portion of the surface of the second outer wall 220 outside the coverage of the second convex ring 230 forms a stepped surface 221. The stepped surface 221 is arranged around the second convex ring 230 and abuts against the first convex ring 130. By providing the first convex ring 130 and the second convex ring 230, the first housing 100 and the second housing 200 can form an "interlocking" engagement relationship, thereby further improving the connection strength between the first housing 100 and the second housing 200, and ultimately further improving the mechanical strength of the power conversion device 10.

[0068] Referring to Figure 5 , in some embodiments, an annular groove 250 is provided on the second housing 200. The annular groove 250 is in a closed-loop shape and is arranged around the accommodation cavity 101. The first housing 100 cooperates with the annular groove 250, and the sealant 300 is located in the annular groove 250 and connected to the first housing 100. By providing the annular groove 250, on the one hand, it is convenient for the annular groove 250 to accommodate the liquid glue and prevent the glue from overflowing; on the other hand, the annular groove 250 will play a role in limiting the sealant 300 formed by curing the liquid glue, improving the installation accuracy of the sealant 300. Figure 5 The sealant 300 in only exemplarily fills a part of the annular groove 250, that is, the sealant 300 does not fill the entire annular groove 250. Of course, the sealant 300 can fill the entire annular groove 250. Figure 5 The sealant 300 in only exemplarily fills a part of the annular groove 250, that is, the sealant 300 does not fill the entire annular groove 250. Of course, the sealant 300 can fill the entire annular groove 250. Referring to Figure 5 , the first housing 100 may further include a first inner wall 140. After the first inner wall 140 is inserted into the annular groove 250, the sealant overflows upward to fill the entire annular groove 250 until the upper edge of the annular groove 250.

[0069] In a possible implementation, the first inner wall 140 also protrudes from the first bottom wall 110, and the first outer wall 120 is disposed around the first inner wall 140; the second housing 200 may further include a second inner wall 240, which also protrudes from the second bottom wall 210, and the second outer wall 220 is disposed around the second inner wall 240; the first inner wall 140, the second inner wall 240, the first substrate and the second substrate enclose a receiving cavity 101, and an annular groove 250 is formed between the second outer wall 220 and the second inner wall 240, and the first inner wall 140 is inserted into the annular groove 250. In this way, the sealing effect of the sealant 300 on the receiving cavity 101 can be improved, and it is also beneficial to enhance the connection strength of the sealant 300 between the first housing 100 and the second housing 200.

[0070] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0071] The above-described embodiments only represent several implementation manners of the present application, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A power conversion device, characterized in that, Comprising: A first shell; A second shell, enclosing an accommodation cavity with the first shell, wherein the first shell and / or the second shell include a plurality of ultrasonic ridges arranged at intervals in the circumferential direction; and A sealant, arranged around the accommodation cavity and in a closed-loop shape, the sealant being connected between the first shell and the second shell to seal the accommodation cavity.

2. The power conversion device according to claim 1, wherein Both the first shell and the second shell have welding surfaces for ultrasonic welding, and the ultrasonic ridges protrude on the welding surfaces of the first shell and / or the second shell.

3. The power conversion device according to claim 2, wherein The welding surface includes a first welding area and a second welding area. The ultrasonic ridges on the first welding area and the first welding area extend linearly, and at least part of the ultrasonic ridges on the second welding area and the second welding area extend along a curve.

4. The power conversion device according to claim 3, characterized in that, The length of the ultrasonic ridges on the second welding area is greater than or equal to the length of the ultrasonic ridges on the first welding area.

5. The power conversion device according to claim 3, characterized in that, The second welding area surrounds the transformer, and / or, the second welding area is located at the corner of the first shell and the second shell.

6. The power conversion device according to claim 3, wherein The welding surface further includes a third welding area, which is located on both sides of the mounting opening, and the ultrasonic ridges extend to the third welding area.

7. The power conversion device according to claim 2, characterized in that, The protruding height of the ultrasonic ridges relative to the welding surface is 0.1 mm to 0.5 mm, and the maximum width of the ultrasonic ridges is 0.2 mm to 0.7 mm.

8. The power conversion device according to claim 1, wherein, The first shell has a profiling structure matching the shape of the electronic components in the accommodation cavity, and the first shell includes the ultrasonic ridges.

9. The power conversion device according to claim 8, characterized in that, The first shell includes a first outer wall, and the ultrasonic ridges protrude on the surface of the first outer wall close to the second shell. The second shell includes a second outer wall, and the surface of the second outer wall close to the first shell can contact the ultrasonic ridges and be welded to the first outer wall.

10. The power conversion device according to claim 8, characterized in that, The first shell includes a first outer wall and a first convex ring. The first convex ring protrudes on the surface of the first outer wall close to the second shell. The part of the surface of the first outer wall outside the coverage of the first convex ring forms a first welding surface surrounded by the first convex ring, and the ultrasonic ridges are arranged on the first welding surface; The second shell includes a second outer wall and a second convex ring. The second convex ring protrudes on the surface of the second outer wall close to the first shell, and the surface of the second convex ring forms a second welding surface in contact with the ultrasonic ridges.

11. The power conversion device according to claim 10, characterized in that, The part of the surface of the second outer wall outside the coverage of the second convex ring forms a stepped surface surrounding the second convex ring, and the stepped surface abuts against the first convex ring.

12. The power conversion device according to claim 8, characterized in that, An annular groove is provided on the second shell. The annular groove is in a closed-loop shape and surrounds the accommodation cavity. The first shell cooperates with the annular groove, and the sealant is located in the annular groove and connected to the first shell.

13. The power conversion device according to claim 12, characterized in that, The first shell includes a first substrate, a first outer wall, and a first inner wall. The first outer wall and the first inner wall both protrude from the first substrate, and the first outer wall surrounds the first inner wall. The second shell includes a second substrate, a second outer wall, and a second inner wall. The second outer wall and the second inner wall both protrude from the second substrate, and the second outer wall surrounds the second inner wall. The second outer wall is welded to the first outer wall. The first inner wall, the second inner wall, the first substrate, and the second substrate enclose the accommodation cavity. An annular groove is formed between the second outer wall and the second inner wall, and the first inner wall is inserted into the annular groove.

14. The power conversion device according to claim 1, wherein The width of the sealant is from 2 mm to 5 mm.

15. The power conversion device according to any one of claims 1 to 14, characterized in that, The materials of the first shell and the second shell are both plastics.

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