A charging machine switch tube ground structure and vehicle-mounted charging machine

Abstract

The utility model discloses a kind of charger switch tube grounding structure and vehicle-mounted charger, switch tube is set on substrate, the substrate is vertical substrate, ground device is provided on the substrate, the ground device includes the first connecting end for with the electrical connection of switch tube ground terminal, and the second connecting end for with the electrical connection of connecting charger cabinet, buffer portion is formed between the first connecting end and the second connecting end, the ground device makes the electrical passage between the switch tube and the cabinet. The utility model utilizes specially designed ground device of switch tube ground. Compared with prior art, the utility model's grounding path is shorter, which can effectively reduce the loss of grounding path. The utility model's ground device is sheet metal part, the sheet metal part has circuitous bending portion in middle and forms buffer portion. Buffer portion can buffer stress, avoid mechanical stress to cause damage to substrate and other components.

Description

Technical Field

[0001] This utility model relates to the field of electrical grounding technology, and in particular to a grounding structure for a charger switch tube and an on-board charger. Background Technology

[0002] In vehicle charging modules, the switching transistors are typically integrated on the substrate. Current technology grounds these transistors by connecting them to the grounding terminal of the PBC (Power Circuit Board) via a long busbar, thus creating a grounding path. While this grounding is achieved, the busbar generates heat during operation, resulting in losses. Therefore, the longer the grounding busbar path, the greater the losses. A grounding structure that can both ground the switching transistor and reduce losses due to the busbar path is needed. Utility Model Content

[0003] To address the problem of high power loss caused by long grounding paths of switching transistors, this invention proposes a grounding structure for the switching transistors of a charger, which connects the bottom end of the switching transistor to the casing as close as possible, thereby reducing the grounding path and lowering power loss.

[0004] The technical solution adopted in this utility model is to design a grounding structure for a charger switch tube, including at least one switch tube disposed on a substrate. The substrate is a vertical substrate, and a grounding device is disposed on the substrate. The grounding device includes a first connection terminal for electrically connecting to the grounding terminal of the switch tube and a second connection terminal for electrically connecting to the charger housing. A buffer portion is provided between the first connection terminal and the second connection terminal. The grounding device enables an electrical path to be formed between the switch tube and the housing.

[0005] In some embodiments, the grounding device is a sheet metal part, and the buffer part is a meandering bend located on the sheet metal part.

[0006] In some embodiments, a first busbar is provided on the substrate, and the grounding device is electrically connected to the grounding terminal of the switching transistor through the first busbar or other electrical paths.

[0007] In some embodiments, the second connection end of the grounding device is provided with a screw hole for connecting to the housing.

[0008] In some embodiments, at least two grounding devices are provided on the substrate, and the different grounding devices are electrically connected through a second busbar provided on the substrate.

[0009] In some embodiments, the second busbar includes a plurality of bus segments arranged at intervals.

[0010] In some embodiments, a backup grounding device is also provided on the substrate, and the backup grounding device is electrically connected to the grounding device via a third busbar.

[0011] In some embodiments, the second busbar and the third busbar are fixed along the edge of the substrate.

[0012] An on-board charger includes a housing and a grounding structure for the charger switch tube, wherein a second connection terminal is connected to the housing.

[0013] In some embodiments, a circuit board is also included, and the grounding device includes a connecting pin for connecting to the ground terminal of the charger circuit board, the connecting pin being connected to the circuit board.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention proposes a grounding device. One end of the grounding device is connected to the housing of the on-board charger, and the other end is connected to the grounding terminal of the switching transistor, forming a grounding path of "switching transistor - busbar - grounding device - housing," thereby achieving grounding of the switching transistor. Compared with the grounding path of the prior art, the grounding path of this invention is shorter, which can effectively reduce the grounding path loss. The grounding device of this invention is a sheet metal part with a meandering bend in the middle to form a buffer. The buffer can buffer stress and prevent mechanical stress from damaging the substrate and other components. Attached Figure Description

[0016] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. To illustrate the details and facilitate understanding of its principles, the drawings are not necessarily to scale, and similar reference numerals may describe similar components in different views. The accompanying drawings generally illustrate the embodiments discussed herein by way of example and not limitation. Wherein:

[0017] Figure 1 This is a three-dimensional schematic diagram of the grounding device.

[0018] Figure 2 This is a side view of the grounding device.

[0019] Figure 3 yes Figure 2 A diagram showing the view from the right.

[0020] Figure 4 yes Figure 2 A top-down view.

[0021] Figure 5 This is a schematic diagram of Example 1.

[0022] Figure 6 This is a schematic diagram of Example 2.

[0023] Figure 7 This is a schematic diagram of Example 3.

[0024] Figure 8 This is a schematic diagram of the charger switch grounding structure set on the charger in Embodiment 3.

[0025] Figure 9 yes Figure 8 A schematic diagram of the cross-section at the grounding device.

[0026] In the figure, 1a is the first busbar; 1b is the second busbar; 1c is the third busbar; 2 is the connecting pin; 3 is the grounding device; 3a is the first connecting end; 3b is the second connecting end; 3c is the buffer part; 3d is the screw hole; 6 is the first spare grounding device; 4 is the housing; 5 is the base plate. Detailed Implementation

[0027] The following are specific embodiments of this utility model, and the technical solution of this utility model will be further described with reference to the accompanying drawings. However, this utility model is not limited to these embodiments, and the following embodiments do not limit the utility model involved in the claims. In addition, all combinations of features described in the embodiments are not necessarily necessary for the solution of the utility model.

[0028] The principle and structure of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0029] Example 1

[0030] The switching transistor in an on-board charger is a key component in power electronic systems, typically used for power conversion and regulation. In an on-board charger, the main function of the switching transistor is to control the flow of current, thereby achieving efficient DC-AC conversion. Grounding of the switching transistor plays a crucial role in power electronic circuits, especially in high-frequency switching circuits. A proper grounding design can improve system stability, reduce noise, and minimize electromagnetic interference. However, because busbars generate heat during actual use, resulting in losses, the longer the grounding bus path, the greater the losses. Therefore, there is a need for a grounding structure that can both ground the switching transistor and reduce losses caused by the bus path.

[0031] like Figure 5 As shown, a grounding structure for a charger switch transistor Q is provided. The switch transistor Q is mounted on a substrate 5, which can be an aluminum substrate, a ceramic substrate, or other substrates, primarily used for heat dissipation of the switch transistor. In this embodiment, the substrate is a vertical aluminum substrate. A grounding device 3 is provided on the substrate, such as... Figure 1 , 2As shown in Figures 3 and 4, the substrate is a vertical substrate, perpendicular to or at a certain angle to the bottom of the charger housing. The grounding device 3 includes a first connection terminal 3a for electrical connection to the grounding terminal of the switch transistor Q, and a second connection terminal 3b for electrical connection to the charger housing. A buffer portion 3c is provided between the first connection terminal 3a and the second connection terminal 3b. The grounding device 3 enables an electrical path to be formed between the switch transistor Q and the housing 4, thereby forming a grounding path and grounding the switch transistor Q. Compared with the grounding path of the prior art, the grounding path of this utility model is shorter, which can effectively reduce the loss of the grounding path.

[0032] Tolerances are unavoidable during installation, so stress will be generated when connecting the second connecting end 3b to the housing 4. The buffer part 3c can buffer the stress and prevent mechanical stress from damaging the base plate 5 and other components. The grounding device 3 is a sheet metal part, and the buffer part 3c is a meandering bend on the sheet metal part. The second connecting end 3b is provided with a screw hole 3d for connecting to the housing 4, so as to facilitate connection by screws. The first connecting end of the grounding device 3 is welded to the base plate 5.

[0033] A first busbar 1a is provided on the substrate, and the grounding device is electrically connected to the ground terminal of the switching transistor through the first busbar 1a. The grounding device can also be electrically connected to the ground terminal of the switching transistor through other electrical paths, such as conductive wires or conductive coatings.

[0034] In this embodiment, eight switching transistors, Q1, Q2, Q3, Q4, Q5, Q6, Q7, and Q8, are mounted on the aluminum substrate. These eight transistors are located on both sides of the first busbar 1a, meaning four transistors are arranged vertically on each side of the first busbar 1a. The first backup grounding device 6 and the first busbar 1a are both fixed to a substrate 5. The housing is, for example, the housing 4 of a charger.

[0035] The first connection terminal 3a of the grounding device 3 is connected to one end of the first busbar 1a; the second connection terminal 3b of the grounding device 3 is connected to the housing 4. The grounding terminal of the switching transistor is connected to the first busbar 1a; the switching transistor Q, the busbar 1a, and the first connection terminal 3a of the grounding device 3 are all soldered onto the substrate 5. This achieves an electrical connection of "switching transistor - first busbar 1a - grounding device 3 - housing 4," thereby forming a grounding path.

[0036] The installation method is as follows: Step 1: Weld the first connection end 3a to the substrate 5. The welding position is at one end of the first busbar 1a to realize the connection between the grounding device 3 and the first busbar 1a.

[0037] Step 2: Place the base plate 5 with the grounding device 3 welded on it in the corresponding position on the housing 4, so that the screw hole on the second connection end 3b corresponds to the screw hole on the housing 4.

[0038] Step 3: Screw the second connection end 3b to the housing 4 to connect the grounding device 3 to the housing 4.

[0039] Tolerances are unavoidable during installation, so stress will be generated when connecting the second connection end 3b to the housing 4. The buffer part 3c can buffer the stress and prevent mechanical stress from damaging the substrate 5 and other components.

[0040] Example 2

[0041] like Figure 6 As shown, at least two grounding devices are provided on the substrate. In this embodiment, there are two grounding devices. Different grounding devices are electrically connected through a second busbar 1b provided on the substrate 5. The two grounding devices are connected to the housing 4 at two different locations, thereby preventing the switching transistor from failing to ground due to the failure of one grounding device 3. For ease of explanation, the grounding device farther away from the first busbar 1a is defined as the first backup grounding device 6. In this embodiment, a grounding device 3 and a first backup grounding device 6 are provided on the substrate 5, and a second busbar 1b welded to the substrate is used. The second busbar 1b includes multiple spaced-apart bus segments, such as... Figure 6 As shown in the diagram, the busbars 1b1, 1b2, 1b3 and 1b4 form the first backup grounding path. Of course, the second busbar 1b can also be an integral strip structure.

[0042] The structure of the first backup grounding device 6 and the way it is welded to the housing 4 and the base plate 5 are the same as the connection method of the grounding device. Preferably, the conductivity of the first backup grounding device 6 is weaker than that of the grounding device 3.

[0043] The first backup grounding device 6 is welded to one end of the second busbar 1b to realize the electrical connection of "switch tube - first busbar 1a - second busbar 1b - first backup grounding device 6 - chassis", thereby forming the first backup grounding path.

[0044] Because the first backup grounding path is longer than the first grounding path, its conductivity is weaker. Therefore, when the grounding device 3 is functioning normally, the first backup grounding path hardly performs any grounding function. It only performs grounding function when the grounding device 3 malfunctions.

[0045] Example 3

[0046] like Figure 7 ,8 As shown in Figure 9, a second backup grounding device is also included, which is electrically connected to the first backup grounding device 6 via a third busbar 1c. The second backup grounding device, the grounding device 3, the first backup grounding device 6, the first busbar 1a, the second busbar 1b, and the third busbar 1c are all fixed on the same substrate 5. The second backup grounding device includes a connecting pin 2 for connecting to the grounding terminal of the charger circuit board.

[0047] A third busbar 1c and a connecting pin 2 are soldered onto the substrate 5. One end of the third busbar 1c is soldered to one end of the second busbar 1b (specifically, bus segment 1b4), and the other end of the third busbar 1c is connected to the connecting pin 2. The connecting pin 2 is also used to connect to the PCB circuit board. This achieves the electrical connection of "switch transistor - first busbar 1a - second busbar 1b - third busbar 1c - connecting pin - circuit board", thereby forming a second backup grounding path.

[0048] Because the second backup grounding path is longer than both the first and second backup grounding paths, its conductivity is weaker. Therefore, when grounding device 3 or the first backup grounding device 6 is functioning normally, the second backup grounding path hardly performs any grounding function. It only performs grounding function when both grounding device 3 and the backup grounding device 6 malfunction.

[0049] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A grounding structure for a charger switch transistor, comprising at least one switch transistor disposed on a substrate (5), characterized in that, The substrate (5) is a vertical substrate, and a grounding device (3) is provided on the substrate (5). The grounding device (3) includes a first connection terminal (3a) for electrically connecting to the ground terminal of the switch tube, and a second connection terminal (3b) for electrically connecting to the casing (4) of the charger. A buffer portion (3c) is provided between the first connection terminal (3a) and the second connection terminal (3b). The grounding device (3) enables an electrical path to be formed between the switch tube and the casing (4).

2. The charger switch grounding structure according to claim 1, characterized in that, The grounding device (3) is a sheet metal part, and the buffer part (3c) is a meandering bend located on the sheet metal part.

3. The charger switch grounding structure according to claim 1, characterized in that, The grounding device (3) is electrically connected to the grounding terminal of the switch tube through the first busbar (1a) or other electrical path.

4. The charger switch grounding structure according to claim 1, characterized in that, The second connection end (3b) of the grounding device (3) is provided with a screw hole (3d) for connecting the housing (4).

5. The charger switch grounding structure according to claim 1, characterized in that, At least two grounding devices (3) are provided on the substrate (5), and the different grounding devices (3) are electrically connected through a second busbar (1b) provided on the substrate (5).

6. The charger switch grounding structure according to claim 5, characterized in that, The second busbar (1b) comprises multiple busbar segments arranged at intervals.

7. The charger switch grounding structure according to claim 6, characterized in that, The substrate (5) is also provided with a backup grounding device (3), and the backup grounding device (3) is electrically connected to the grounding device (3) through a third busbar (1c).

8. The charger switch grounding structure according to claim 7, characterized in that, The second busbar (1b) and the third busbar (1c) are fixed along the side of the substrate (5).

9. An on-board charger, characterized in that, Includes a housing (4) and a charger switch grounding structure as described in any one of claims 1 to 8, wherein the second connection terminal (3b) is connected to the housing (4).

10. The on-board charger according to claim 9, characterized in that, It also includes a circuit board, and the grounding device (3) includes a connecting pin (2) for connecting to the grounding terminal of the charger circuit board, and the connecting pin (2) is connected to the circuit board.

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