Power conversion device and manufacturing method therefor

Abstract

A power conversion device (10), comprising: a first shell (100); a second shell (200), defining an accommodating cavity (101) together with the first shell (100), wherein the first shell (100) and / or the second shell (200) comprise a plurality of spaced ultrasonic protruding strips (150) in the peripheral direction; and a sealant (300), arranged around the accommodating cavity (101) and in a closed ring shape, wherein the sealant (300) is connected between the first shell (100) and the second shell (200) so as to seal the accommodating cavity (101).

Description

Power conversion device and its manufacturing method

[0001] Related applications

[0002] This disclosure claims priority to Chinese patent application No. 2024109413770, filed on July 12, 2024, entitled "Power Conversion Device and Method of Manufacturing Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of new energy technology, and in particular to a power conversion device and its manufacturing method. Background Technology

[0004] With the rapid development of new energy technologies, solar energy is widely used in daily production and life due to its advantages such as being pollution-free and sustainable. Generally, solar energy can be converted into electrical energy through photovoltaic power generation technology. The direct current (DC) generated by photovoltaic power generation is then converted into alternating current (AC) through a power conversion device. This AC power can then be used as electrical energy and input into the power grid through a connector. The power conversion device can also convert AC power back to DC power. However, traditional power conversion devices typically suffer from drawbacks such as poor mechanical strength and short service life.

[0005] Summary of the Invention

[0006] One technical problem addressed by this disclosure is how to improve the mechanical strength of power conversion devices, thereby increasing their service life.

[0007] The first aspect of this disclosure provides a power conversion device, comprising:

[0008] First shell;

[0009] A second shell, together with the first shell, forms a receiving cavity, wherein the first shell and / or the second shell includes a plurality of ultrasonic protrusions spaced circumferentially; and

[0010] A sealant is disposed around the accommodating cavity in a closed loop, and the sealant is connected between the first shell and the second shell to seal the accommodating cavity.

[0011] A second aspect of this disclosure provides a manufacturing method for processing the above-described power conversion device, comprising the following steps:

[0012] The sealant is applied between the first shell and the second shell to seal the accommodating cavity;

[0013] The first shell and the second shell are welded using an ultrasonic welding process.

[0014] Details of one or more embodiments of this disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the invention will become apparent from the specification, drawings, and claims. Attached Figure Description

[0015] To better describe and illustrate embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the currently described embodiments and / or examples, or the best mode of these inventions as currently understood.

[0016] Figure 1 is a three-dimensional structural schematic diagram of a power conversion device provided in an embodiment.

[0017] Figure 2 is an exploded view of the power conversion device shown in Figure 1.

[0018] Figure 3 is a schematic diagram of the planar structure of the first shell in the power conversion device shown in Figure 1.

[0019] Figure 4 is a schematic diagram of the three-dimensional cross-sectional structure of Figure 2.

[0020] Figure 5 is a schematic diagram of the three-dimensional cross-sectional structure of Figure 1.

[0021] Figure 6 is a process flow diagram of a method for manufacturing a power conversion device provided in an embodiment. Detailed Implementation

[0022] To make the above-described objects, features, and advantages of this disclosure more apparent and understandable, specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this disclosure. However, this disclosure can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this disclosure. Therefore, this disclosure is not limited to the specific embodiments disclosed below.

[0023] In the description of this disclosure, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0024] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0026] In this disclosure, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening 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 intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this disclosure are for illustrative purposes only and do not represent the only possible implementation.

[0028] Referring to Figure 1, a power conversion device 10 is provided in one embodiment of this disclosure. The power conversion device 10 is a power conversion equipment used to convert electrical energy from one form to another, realizing energy transmission and control under different power requirements. The power conversion device 10 can be a micro-inverter, energy storage converter, 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, enabling the power conversion device 10 to convert input DC power into AC power output, or vice versa. For example, the power conversion device 10 can be applied in the field of photovoltaic power generation technology. The DC power generated by photovoltaic power generation technology is converted back into AC power by the power conversion device 10, and this AC power becomes usable electrical energy and is input to the power grid through connector 410.

[0029] 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 form a receiving cavity 101. The first housing 100 and / or the second housing 200 include a plurality of ultrasonic protrusions 150, which are spaced apart circumferentially along the power conversion device 10. The ultrasonic protrusions 150 allow the first housing 100 and the second housing 200 to be welded together using an ultrasonic welding process. The sealant 300 surrounds the receiving cavity 101 and is in a closed-loop shape. The sealant 300 connects the first housing 100 and the second housing 200, thus serving not only to connect the first housing 100 and the second housing 200 but also to seal the receiving cavity 101.

[0030] Sealant 300 has good liquid-blocking and gas-permeable functions, meaning that liquids cannot pass through sealant 300, while gases can pass through sealant 300.

[0031] Referring to Figure 2, during the welding process, the ultrasonic head can be moved on the first shell 100 or the second shell 200. The ultrasonic waves generated by the ultrasonic head will act on the ultrasonic protrusion 150, causing the ultrasonic protrusion 150 to generate high-frequency vibrations of tens of thousands of times per second. Subsequently, the ultrasonic protrusion 150 generates heat and melts under the action of high-frequency vibration. After the molten ultrasonic protrusion 150 is cooled and solidified, it is connected to the weld of the first shell 100 and the second shell 200. After the first shell 100 and the second shell 200 are welded to form the shell 102 by the ultrasonic welding process, a casting liquid can be injected into the shell 102. After the casting liquid solidifies, it can form a cover covering the electronic components located inside the shell 102, so that the cover protects the electronic components and ensures that the power conversion device 10 can be used in various harsh environments such as humidity, heat, acid and alkali, rain, snow and ice. It can also improve the impact resistance of the power conversion device 10.

[0032] In some existing technologies, for example, the first housing 100 and the second housing 200 are connected by bolts. This requires installing multiple bolts between the first housing 100 and the second housing 200, leading to increased material costs and reduced assembly efficiency, thereby increasing the manufacturing cost of the power conversion device 10. Alternatively, the first housing 100 and the second housing 200 are connected by conventional welding processes. This requires a large amount of consumables such as welding rods, which also increases material costs and reduces assembly efficiency, ultimately increasing the manufacturing cost of the power conversion device 10.

[0033] For example, in the case of connecting the first shell 100 and the second shell 200 using ultrasonic welding, the ultrasonic protrusion 150 is a continuous closed loop, resulting in a closed loop weld between the first shell 100 and the second shell 200. This leads to at least three defects:

[0034] Firstly, given the need to inject casting liquid into the housing 102, and the closed-loop welding strip sealing the entire accommodating cavity 101, and the weld seam having good liquid and gas isolation functions, meaning that neither gas nor liquid can pass through the weld seam, the water molecules generated by the casting liquid in the accommodating cavity 101 cannot be discharged through the weld seam formed by the ultrasonic protrusion 150. In other words, the water molecules will not be discharged outside the housing 102 and will remain inside the accommodating cavity 101. This results in excessive humidity inside the accommodating cavity 101, thereby affecting the service life of various electronic components inside the accommodating cavity 101, and ultimately affecting the service life of the entire power conversion device 10.

[0035] Secondly, during the process of forming a closed-loop weld with the closed-loop ultrasonic protrusion 150, given that the length of the closed-loop ultrasonic protrusion 150 is relatively large, the relatively long ultrasonic protrusion 150 will require more ultrasonic energy, thereby increasing the manufacturing cost of the entire power conversion device 10.

[0036] Third, the closed-loop ultrasonic protrusion 150 is prone to uneven melting during the welding process, resulting in uneven weld formation. Consequently, the stress that each part of the weld can withstand is uneven, leading to the weakest point in the entire weld with relatively low stress, which ultimately affects the mechanical strength of the weld and the entire power conversion device 10.

[0037] In the power conversion device 10 described above, the first housing 100 and the second housing 200 are welded using ultrasonic welding. Compared with bolted connections and conventional welding methods, this eliminates the need for consumables such as bolts or welding rods, thereby reducing the manufacturing cost of the power conversion device 10. Multiple ultrasonic protrusions 150 are spaced apart circumferentially along the power conversion device 10, forming multiple spaced weld seams. Simultaneously, sealant 300 connects the first housing 100 and the second housing 200 to seal the accommodating cavity 101. This provides at least three beneficial effects:

[0038] First, the sealant 300 has air permeability. Water molecules generated by the pouring liquid in the accommodating cavity 101 pass through the sealant 300 in a gaseous manner, 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 corrosion of various electronic components by water molecules remaining in the accommodating cavity 101, which can improve the service life of the entire power conversion device 10.

[0039] Secondly, the total length formed by the multiple spaced ultrasonic protrusions 150 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.

[0040] Third, the spaced ultrasonic protrusions 150 ensure more uniform melting during welding, resulting in a more uniform weld formation and preventing the weld from having the weakest point with relatively low stress, thereby improving the mechanical strength of the weld and the entire power conversion device 10. Furthermore, the sealant 300 enhances the connection strength between the first housing 100 and the second housing 200, thus improving the mechanical strength of the housing 102 and the entire power conversion device 10. The sealant 300 also has excellent liquid-sealing properties, preventing liquid from entering the accommodating cavity 101 and corroding electronic components, thereby extending the service life of the power conversion device 10.

[0041] Referring to Figure 5, in some embodiments, both the first shell 100 and the second shell 200 have a welding surface 103 for ultrasonic welding, and an ultrasonic protrusion 150 protrudes from the welding surface 103 of the first shell 100 and / or the second shell 200. That is, the ultrasonic protrusion 150 may protrude only from the welding surface 103 of the first shell 100; or only from the welding surface 103 of the second shell 200; or both the first shell 100 and the second shell 200 may have ultrasonic protrusions on their welding surfaces 103 simultaneously. By protruding the ultrasonic protrusion 150 from the welding surface 103, welding efficiency and the connection strength between the first shell 100 and the second shell 200 can be improved.

[0042] The following explanation uses the example of setting an ultrasonic protrusion 150 on the welding surface 103 of the first shell 100.

[0043] The welding surface 103 may include a first welding region 1031 and a second welding region 1032. The first welding region 1031 extends in a straight line, and the ultrasonic protrusion 150 on the first welding region 1031 also extends in a straight line. The second welding region 1032 extends at least partially along a curve, for example, the entire second welding region 1032 extends in a curve, or a portion of the second welding region 1032 extends in a curve while another portion extends in a straight line. The ultrasonic protrusion 150 on the second welding region 1032 also extends at least partially along a curve, for example, the entire ultrasonic protrusion 150 extends in a curve, or a portion of the ultrasonic protrusion 150 extends in a curve while another portion extends in a straight line. This allows the weld formed by the ultrasonic protrusion 150 to be adapted to the different shapes of the first welding region 1031 and the second welding region 1032, thereby improving the connection strength between the first shell 100 and the second shell 200, and ultimately improving the service life and mechanical strength of the power conversion device 10. It should be noted that, given that the ultrasonic protrusion 150 on the first welding area 1031 extends in a straight line, this facilitates the forming of the ultrasonic protrusion 150, thereby helping to improve the processing efficiency of the power conversion device 10 and reduce manufacturing costs.

[0044] 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 arranged around the transformer 420.

[0045] In some embodiments, a portion of the second welding region 1032 may extend along a straight line and another portion may extend along a curve. The portion of the second welding region 1032 that extends along the curve is referred to as the curved portion, which is disposed around the transformer 420. The portion of the second welding region 1032 that extends along a straight line is referred to as the straight portion, which is closer to the first welding region 1031 than the curved portion.

[0046] In some embodiments, the second welding region 1032 is located at the corner of the housing 102. A portion of the second welding region 1032 may extend along a straight line and another portion may extend along a curve. The portion of the second welding region 1032 extending along the curve is referred to as the curved portion, and the portion of the second welding region 1032 extending along the straight line is referred to as the straight portion. There is one curved portion and two straight portions. The curved portion is connected between the two straight portions, and the straight portion is closer to the first welding region 1031 than the curved portion.

[0047] Because 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 susceptible to external impact. Therefore, the length of the ultrasonic protrusion 150 on the second welding area 1032 can be greater than the length of the ultrasonic protrusion 150 on the first welding area 1031, thereby making the length of the weld on the second welding area 1032 greater than the length of the weld on the first welding area 1031. This ultimately improves the mechanical strength of the position of the power conversion device 10 corresponding to the second welding area 1032 and prevents the power conversion device 10 from being damaged under external impact.

[0048] Of course, under conditions where the probability of being subjected to external impact is relatively low, the length of the ultrasonic protrusion 150 on the second welding area 1032 can be approximately equal to the length of the ultrasonic protrusion 150 on the first welding area 1031. For example, for the second welding area 1032, which extends entirely along the curve and surrounds the transformer 420, the length of the ultrasonic protrusion 150 on the second welding area 1032 can be approximately equal to the length of the ultrasonic protrusion 150 on the first welding area 1031.

[0049] Referring to Figure 3, in some embodiments, a mounting port 104 may be provided on the first housing 100 and / or the second housing 200 for mounting a DC or AC connector 410. The welding surface 103 also includes a third welding region 1033 located on both sides of the mounting port 104. An ultrasonic protrusion 150 extends to the third welding region 1033, allowing it to extend to the edge of the mounting port 104. The location of the mounting port 104 typically affects the connection strength and sealing performance of the power conversion device 10; that is, the area near the mounting port 104 is a relatively weak point. However, because the third welding region 1033 is provided with the ultrasonic protrusion 150, it can effectively compensate for the weakening effect of the mounting port 104 on the connection strength and sealing performance. This ensures that the power conversion device 10 has sufficient connection strength and sealing performance at the location of the mounting port 104, ultimately improving the service life and mechanical strength of the power conversion device 10. Experiments show that by setting ultrasonic protrusions 150 in the third welding area 1033, the location near the mounting port 104 can be guaranteed to have an IP68 protection level against liquids such as water.

[0050] Referring to Figure 4, in some embodiments, the cross-sectional size of the ultrasonic protrusion 150 can gradually decrease along the protrusion direction of the ultrasonic protrusion 150 relative to the welding surface 103. Thus, the cross-section of the ultrasonic protrusion 150 can be triangular or isosceles trapezoidal, etc., and the end of the ultrasonic protrusion 150 away from the welding surface 103 can be rounded. The protrusion height of the ultrasonic protrusion 150 relative to the welding surface 103 is 0.1mm to 0.5mm, and the specific value of the protrusion height can be 0.1mm, 0.2mm, or 0.5mm, etc. The maximum width of the ultrasonic protrusion 150 is 0.2mm to 0.7mm, and the specific value of the maximum width can be 0.2mm, 0.5mm, or 0.7mm, etc. The above-described structure of the ultrasonic protrusion 150 can reasonably improve the connection strength of the weld formed by the ultrasonic protrusion 150 and reduce the ultrasonic energy consumed during the welding process. The width of sealant 300 can be from 2mm to 5mm, for example, the specific value of the width of sealant 300 can be 2mm, 3mm or 5mm, etc. This ensures that sealant 300 has reasonable bonding strength and sealing function.

[0051] In some embodiments, the first shell 100 and the second shell 200 can both be made of plastic, such as PPO (Polyphenylene Oxide) plastic, which gives the first shell 100 and the second shell 200 good ultrasonic welding performance, thereby reducing the ultrasonic energy consumed in the welding process and ultimately reducing the manufacturing cost of the power conversion device 10.

[0052] Referring to Figure 4, in some embodiments, the first shell 100 has a contoured structure that matches the shape of the electronic components in the accommodating cavity 101. This contoured structure can be understood as an uneven structure suitable for electronic components protruding at different heights within the accommodating cavity 101. The ultrasonic protrusion 150 is only provided on the welding surface 103 of the first shell 100; that is, only the first shell 100 includes the ultrasonic protrusion 150, while the welding surface 103 of the second shell 200 does not have the ultrasonic protrusion 150. During the welding process, since the second shell 200 does not have a contoured structure, its outer surface is relatively flat. Therefore, placing the second shell 200 on a support facilitates clamping with a fixture. When the ultrasonic head contacts the first shell 100, this prevents the entire power conversion device 10 from tilting or swaying relative to the support under the pressure of the ultrasonic head, thereby improving welding accuracy and efficiency.

[0053] Referring to Figure 5, for example, the first shell 100 includes a first bottom wall 110 and a first outer side wall 120, the first outer side wall 120 surrounding the first bottom wall 110 and protruding relative to the first bottom wall 110. The second shell 200 includes a second bottom wall 210 and a second outer side wall 220, the second outer side wall 220 surrounding the second bottom wall 210 and protruding 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 adjacent to the second outer side wall 220 is the welding surface 103 of the first shell 100, and the surface of the second outer side wall 220 adjacent to the first outer side wall 120 is the welding surface 103 of the second shell 200. An ultrasonic protrusion 150 protrudes from the welding surface 103 of the first shell 100. After the ultrasonic protrusion 150 forms a weld, the weld will connect the welding surfaces 103 of the first shell 100 and the second shell 200, thereby realizing the welded connection between the first shell 100 and the second shell 200 formed by the ultrasonic welding process.

[0054] Referring to Figure 4, for example, the first shell 100 may also include a first protruding ring 130. The first protruding ring 130 protrudes from the surface of the first outer side wall 120 near the second outer side wall 220. The portion of the surface of the first outer side wall 120 outside the coverage area of ​​the first protruding ring 130 forms a welding surface 103, which may be referred to as the first welding surface 103a. The first protruding ring 130 is arranged around the first welding surface 103a, and the ultrasonic protrusion 150 is disposed on the first welding surface 103a.

[0055] Furthermore, the second shell 200 may also include a second protruding ring 230, which protrudes from the surface of the second outer side wall 220 near the first outer side wall 120. The second protruding ring 230 contacts the ultrasonic protrusion 150, and the surface of the second protruding ring 230 in contact with the ultrasonic protrusion 150 is the welding surface 103 of the second shell 200, which is denoted as the second welding surface 103b. The portion of the surface of the second outer side wall 220 outside the coverage area of ​​the second protruding ring 230 forms a stepped surface 221, which surrounds the second protruding ring 230 and abuts against the first protruding ring 130. By providing the first protruding ring 130 and the second protruding ring 230, the first shell 100 and the second shell 200 can form an interlocking relationship, thereby further improving the connection strength between the first shell 100 and the second shell 200, and ultimately further improving the mechanical strength of the power conversion device 10.

[0056] Referring to Figure 5, in some embodiments, the second shell 200 is provided with an annular groove 250. The annular groove 250 is closed-loop and surrounds the receiving cavity 101. The first shell 100 mates with the annular groove 250, and the sealant 300 is located in the annular groove 250 and connected to the first shell 100. By providing the annular groove 250, on the one hand, it is convenient for the annular groove 250 to contain liquid adhesive and prevent adhesive overflow; on the other hand, the annular groove 250 will limit the sealant 300 formed by the curing of liquid adhesive, thereby improving the installation accuracy of the sealant 300. In Figure 5, the sealant 300 only exemplary fills 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 completely fill the annular groove 250. Referring to Figure 5, the first shell 100 may also include a first inner sidewall 140. After the first inner sidewall 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.

[0057] In one possible implementation, the first inner sidewall 140 also protrudes from the first bottom wall 110, and the first outer sidewall 120 surrounds the first inner sidewall 140. The second shell 200 may further include a second inner sidewall 240, which also protrudes from the second bottom wall 210, and the second outer sidewall 220 surrounds the second inner sidewall 240. The first inner sidewall 140, the second inner sidewall 240, the first substrate, and the second substrate form a receiving cavity 101, and an annular groove 250 is formed between the second outer sidewall 220 and the second inner sidewall 240, with the first inner sidewall 140 inserted into the annular groove 250. This improves the sealing effect of the sealant 300 on the receiving cavity 101 and also enhances the connection strength of the sealant 300 to the first shell 100 and the second shell 200.

[0058] Referring to Figure 6, this disclosure also provides a method for manufacturing a power conversion device 10, which mainly includes the following steps:

[0059] Sealant 300 is applied between the first shell 100 and the second shell 200 to seal the receiving cavity 101.

[0060] The first shell 100 and the second shell 200 are welded using ultrasonic welding.

[0061] Casting liquid is injected into the cavity 101 formed by the first shell 100 and the second shell 200.

[0062] In some embodiments, the ultrasonic welding process is performed before the sealant 300 solidifies to its final state; in other words, the ultrasonic welding process is performed before the sealant 300 is completely solidified. This reduces the internal stress in the sealant 300 and the weld, thereby enhancing the connection strength between the first shell 100 and the second shell 200, and ultimately improving the mechanical strength of the power conversion device 10.

[0063] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the scope of protection of this disclosure. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A power conversion device, wherein, include: First shell; The second shell, together with the first shell, forms an accommodating cavity, and the first shell and / or the second shell includes a plurality of ultrasonic protrusions spaced apart circumferentially; and A sealant is disposed around the accommodating cavity in a closed loop, and the sealant is connected between the first shell and the second shell to seal the accommodating cavity.

2. The power conversion device according to claim 1, wherein, Both the first shell and the second shell have a welding surface for ultrasonic welding, and the ultrasonic protrusion is provided on the welding surface 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 first welding area and the ultrasonic protrusions on the first welding area both extend in a straight line, while the second welding area and the ultrasonic protrusions on the second welding area at least partially extend in a curve.

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

5. The power conversion device according to claim 3, wherein, The second welding area is arranged around the transformer, and / or the second welding area is located at the corner of the first housing and the second housing.

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

7. The power conversion device according to claim 2, wherein, The protrusion height of the ultrasonic protrusion relative to the welding surface is 0.1 mm to 0.5 mm, and the maximum width of the ultrasonic protrusion is 0.2 mm to 0.7 mm.

8. The power conversion device according to claim 1, wherein, The first housing has a contoured structure that matches the shape of the electronic components in the accommodating cavity, and the first housing includes the ultrasonic protrusion.

9. The power conversion device according to claim 8, wherein, The first shell includes a first outer side wall, and the ultrasonic protrusion is provided on the surface of the first outer side wall near the second shell. The second shell includes a second outer side wall, and the surface of the second outer side wall near the first shell can contact the ultrasonic protrusion and be welded to the first outer side wall.

10. The power conversion device according to claim 8, wherein, The first shell includes a first outer side wall and a first protruding ring. The first protruding ring protrudes from the surface of the first outer side wall near the second shell. The portion of the surface of the first outer side wall outside the coverage area of ​​the first protruding ring forms a first welding surface surrounded by the first protruding ring. The ultrasonic protrusion is disposed on the first welding surface. The second shell includes a second outer side wall and a second protruding ring. The second protruding ring protrudes from the surface of the second outer side wall near the first shell, and the surface of the second protruding ring forms a second welding surface that contacts the ultrasonic protrusion.

11. The power conversion device according to claim 10, wherein, The portion of the surface of the second outer sidewall outside the coverage area 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, wherein, The second shell is provided with an annular groove, which is closed and surrounds the accommodating cavity. The first shell mates 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, wherein, The first shell includes a first substrate, a first outer sidewall, and a first inner sidewall. The first outer sidewall and the first inner sidewall both protrude from the first substrate, and the first outer sidewall surrounds the first inner sidewall. The second shell includes a second substrate, a second outer sidewall, and a second inner sidewall. The second outer sidewall and the second inner sidewall both protrude from the second substrate, and the second outer sidewall surrounds the second inner sidewall. The second outer sidewall is welded to the first outer sidewall. The first inner sidewall, the second inner sidewall, the first substrate, and the second substrate form the receiving cavity. The second outer sidewall and the second inner sidewall form the annular groove, and the first inner sidewall is inserted into the annular groove.

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

15. The power conversion device according to any one of claims 1 to 14, wherein, Both the first shell and the second shell are made of plastic.

16. A method for manufacturing the power conversion device according to any one of claims 1 to 15, wherein, The manufacturing method includes the following steps: The sealant is applied between the first shell and the second shell to seal the accommodating cavity; The first shell and the second shell are welded using an ultrasonic welding process.

17. The manufacturing method according to claim 16, wherein, The ultrasonic welding process is performed before the sealant has solidified to its final state.

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