Printed circuit board for electric tool and electric tool

Abstract

The utility model relates to a printed circuit board for an electric tool and the electric tool. The printed circuit board comprises a PCB body; the heat dissipation piece is connected with the PCB body; the plurality of switches are electrically connected with the PCB body and connected with the heat dissipation piece, and the switches are used for controlling a motor of the electric tool to be started and stopped; the plastic supporting piece is located between the PCB body and the heat dissipation piece, and the plastic supporting piece is used for supporting the heat dissipation piece and separating the PCB body from the heat dissipation piece in an insulated mode. According to the printed circuit board provided by the utility model, the plastic supporting piece is arranged between the PCB body and the heat dissipation piece, so that an insulation effect is achieved, the PCB body and the switch can be protected, and the PCB body is prevented from being bent or the switch is prevented from falling off.

Description

Technical Field

[0001] This utility model relates to the field of power tool technology, and in particular to a printed circuit board for power tools and a power tool. Background Technology

[0002] Power tools use an electric motor as a power source. The motor consists of a stator and a mover. The stator is electrically connected to a switch (such as a field-effect transistor) on a printed circuit board through stator terminals. The printed circuit board supplies power to the motor through the switch.

[0003] To prevent overheating of printed circuit boards (PCBs) from affecting their lifespan, PCBs are usually equipped with heat sinks, and insulating components are placed between the heat sinks and the PCB body. When the heat sink is squeezed, the squeezing force is transmitted to the PCB body through the insulating components. The PCB body is prone to bending, and switches (such as field-effect transistors) mounted on the PCB body are also prone to stress and detachment. Utility Model Content

[0004] Based on the aforementioned deficiencies in the prior art, the purpose of this utility model is to provide a printed circuit board with a plastic support between the PCB board and the heat sink, which serves as insulation and also protects the PCB board and the switch, preventing the PCB board from bending or the switch from falling off.

[0005] Therefore, the present invention provides the following technical solution.

[0006] This utility model provides a printed circuit board for power tools, the printed circuit board comprising:

[0007] PCB board;

[0008] A heat sink, which is connected to the PCB board;

[0009] Multiple switches are electrically connected to the PCB board and to the heat sink. The switches are used to control the start and stop of the motor of the power tool.

[0010] A plastic support is located between the PCB board and the heat sink, the plastic support being used to support the heat sink and to insulate and separate the PCB board from the heat sink.

[0011] Optionally, the switch is connected to the heat sink via a first fastener.

[0012] Optionally, the heat sink includes a first side arm and a second side arm disposed opposite to each other, with part of the switch connected to the first side arm and part of the switch connected to the second side arm.

[0013] Optionally, the plastic support includes a first support arm, a connecting arm, and a second support arm connected in sequence, and the heat sink is supported on the first support arm and the second support arm.

[0014] Optionally, the heat sink includes a first leg and a second leg, the first leg being supported on the first support arm and the second leg being supported on the second support arm.

[0015] Optionally, the first leg, the first support arm, and the PCB board are connected by a second fastener, and the second leg, the second support arm, and the PCB board are connected by a third fastener.

[0016] Optionally, the heat sink includes:

[0017] The first side arm, part of the switch is connected to the first side arm;

[0018] The second side arm, part of the switch is connected to the second side arm;

[0019] A connecting rib is located between the first side arm and the second side arm, and is connected to the first side arm and the second side arm.

[0020] An extension arm is connected to the connecting rib and extends along the length of the first side arm, and part of the switch is connected to the extension arm.

[0021] Optionally, a plurality of first heat dissipation fins are provided on the inner surface wall of the first side arm, and the first heat dissipation fins extend in a direction toward the second side arm and away from the PCB board.

[0022] And / or, a plurality of second heat dissipation fins are provided on the inner wall surface of the second side arm, and the second heat dissipation fins extend in a direction toward the first side arm and away from the PCB board body;

[0023] And / or, the connecting rib is arranged parallel to the PCB board body, the connecting rib is provided with a plurality of third heat dissipation fins, and the third heat dissipation fins extend in a direction perpendicular to the PCB board body.

[0024] Optionally, the plastic support member is U-shaped, C-shaped, V-shaped, or W-shaped;

[0025] And / or, the plastic support is of nylon structure;

[0026] And / or, the plastic support member has a cutout on the side facing the PCB board;

[0027] And / or, the PCB board body and the plastic support are engaged by positioning protrusions and positioning holes to achieve positioning pre-assembly;

[0028] And / or, the switch is connected to the PCB board via pins;

[0029] And / or, the printed circuit board further includes a base, the PCB body is mounted in the base, and the PCB body, the switch and the plastic support are all located in the base;

[0030] And / or, the switch is selected from any one of a field-effect transistor, a bipolar junction transistor, an insulated gate bipolar transistor, a gate turn-off thyristor, a MOS-controlled thyristor, an integrated gate commutated thyristor, and an electron-injected enhancement gate transistor.

[0031] This utility model also provides an electric tool, the electric tool comprising:

[0032] chassis;

[0033] The motor is located within the housing;

[0034] As described above, the printed circuit board for power tools controls the start and stop of the motor via the switch.

[0035] This utility model has the following technical effects:

[0036] This utility model provides a printed circuit board. By setting a plastic support between the PCB board and the heat sink, the plastic support serves as insulation to prevent short circuits. Furthermore, the plastic support supports the heat sink. If the heat sink is deformed due to compression, the plastic support is not easily deformed and can absorb stress, thus preventing the PCB board from bending due to the deformation of the heat sink. In addition, the heat sink also provides support for the switch, reducing the stress on the switch and preventing the switch from falling off due to vibration or compression. Attached Figure Description

[0037] Figure 1 This is a three-dimensional structural diagram of the power tool of this utility model;

[0038] Figure 2 This is a three-dimensional structural diagram of the printed circuit board of this utility model;

[0039] Figure 3 This is a top view of the printed circuit board of this utility model;

[0040] Figure 4 This is a cross-sectional view of the printed circuit board of this utility model;

[0041] Figure 5 This is an exploded view of the printed circuit board structure of this utility model;

[0042] Figure 6This is a three-dimensional structural diagram of the plastic support component of this utility model.

[0043] Explanation of reference numerals in the attached figures

[0044] 100. Power tools;

[0045] 1. Printed circuit board;

[0046] 11. PCB board;

[0047] 12. Heat sink; 121. First side arm; 1211. First heat sink fin; 122. Second side arm; 1221. Second heat sink fin; 123. First support leg; 1231. First mounting hole; 124. Second support leg; 1241. Fourth mounting hole; 125. Connecting rib; 1251. Third heat sink fin; 126. Extension arm;

[0048] 13. Switch; 131. Pin;

[0049] 14. Plastic support component; 141. First support arm; 1411. First clearance through hole; 142. Connecting arm; 143. Second support arm; 1431. Second clearance through hole; 144. Hollowed-out part; 145. Positioning protrusion;

[0050] 151. First fastener; 152. Second fastener; 153. Third fastener; 154. Fourth fastener;

[0051] 16. Base;

[0052] 2. Casing. Detailed Implementation

[0053] To make the technical solution and beneficial effects of this utility model more apparent and understandable, a detailed description is provided below by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0054] In the description of this utility model, unless otherwise expressly defined, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this utility model and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. That is, they should not be construed as limitations on this utility model.

[0055] In this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating the relative importance of the indicated features or the number of indicated technical features. Therefore, a feature specified as "first" or "second" can explicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two; "several" means at least one; unless otherwise expressly defined.

[0056] In this utility model, unless otherwise explicitly defined, the terms "installation," "connection," "linking," "fixing," and "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral molding; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0057] In this utility model, unless otherwise explicitly defined, the terms "above," "on top of," "above," "over," "below," "below," "below," or "below" for "first feature above second feature" can refer to direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Furthermore, "above," "above," and "over" for "first feature above second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature below second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0058] The following is based on Figures 1 to 6 This utility model describes the power tool in detail.

[0059] In this embodiment, such as Figure 1 and Figure 2 As shown, the power tool 100 includes a printed circuit board 1, a housing 2, and a motor. The housing 2 forms the outer contour structure of the power tool 100, and the printed circuit board 1 and the motor are both located inside the housing 2.

[0060] like Figures 2 to 5As shown, the printed circuit board 1 includes a PCB board body 11, a heat sink 12, multiple switches 13, and a plastic support 14. The heat sink 12 is connected to the PCB board body 11 and is used to conduct heat generated by the PCB board body 11 to the outside. The switches 13 are electrically connected to the PCB board body 11 and connected to the heat sink 12, which provides support for the switches 13. When the motor needs to be turned on, the switch 13 couples the stator coil of the motor to the power supply so that the stator coil can generate a magnetic field. When the motor needs to be turned off, the switch 13 disconnects the coupling between the stator coil and the power supply. That is, the switch 13 is used to control the start and stop of the motor. The plastic support 14 is located between the PCB board body 11 and the heat sink 12. The plastic support 14 supports the heat sink 12 and insulates and separates the PCB board body 11 from the heat sink 12.

[0061] In the above technical solution, a plastic support 14 is provided between the PCB board 11 and the heat sink 12. The plastic support 14 serves as insulation to prevent short circuits. Furthermore, the plastic support 14 supports the heat sink 12. If the heat sink 12 is deformed due to compression, the plastic support 14 is not easily deformed and can absorb stress, thus preventing the PCB board 11 from bending due to the deformation of the heat sink 12. In addition, the heat sink 12 also provides support for the switch 13, reducing the stress on the switch 13 and preventing the switch 13 from falling off due to vibration or compression.

[0062] In one implementation, such as Figures 2 to 4 As shown, the switch 13 and the heat sink 12 are connected by a first fastener 151 (such as a screw or rivet), which makes assembly quick and the connection secure.

[0063] Furthermore, such as Figures 2 to 4 As shown, the heat sink 12 includes a first side arm 121 and a second side arm 122 disposed opposite to each other. A portion of the switches 13 are connected to the outer side of the first side arm 121, and a portion of the switches 13 are connected to the outer side of the second side arm 122. The first side arm 121 and the second side arm 122 serve both for heat transfer and for mounting and supporting the switches 13. Furthermore, distributing the multiple switches 13 and mounting them separately on the first side arm 121 and the second side arm 122 facilitates balanced force distribution on the heat sink 12. Additionally, both the first side arm 121 and the second side arm 122 extend in a direction perpendicular to the PCB board 11.

[0064] In one implementation, such as Figures 4 to 6As shown, the plastic support 14 includes a first support arm 141, a connecting arm 142, and a second support arm 143 connected in sequence. The first support arm 141 and the second support arm 143 are spaced apart and connected by the connecting arm 142. The shape of the plastic support 14 includes, but is not limited to, a U-shape, a C-shape, a V-shape, or a W-shape. The heat sink 12 is supported on the first support arm 141 and the second support arm 143, which reduces the obstruction of the PCB board 11 by the heat sink 12 and facilitates the rapid transfer of heat generated by the PCB board 11 through the plastic support 14 to the heat sink 12, thereby improving the heat dissipation efficiency.

[0065] Furthermore, such as Figure 4 and Figure 6 As shown, the heat sink 12 includes a first leg 123 and a second leg 124. The first leg 123 is supported by a first support arm 141, and the surface of the first support arm 141 facing away from the first leg 123 abuts against the PCB board 11. The second leg 124 is supported by a second support arm 143, and the surface of the second support arm 143 facing away from the second leg 124 abuts against the PCB board 11. In this design, the bottom of the heat sink 12 is configured with the first leg 123 and the second leg 124, which helps to improve the heat exchange rate between the PCB board 11 and the heat sink 12, thus accelerating heat dissipation.

[0066] Furthermore, such as Figure 4 As shown, the first leg 123, the first support arm 141, and the PCB board 11 are connected by a second fastener 152 (such as a screw or rivet), and the second leg 124, the second support arm 143, and the PCB board 11 are connected by a third fastener 153 (such as a screw or rivet), so that the heat sink 12, the plastic support 14, and the PCB board 11 are connected sequentially, making assembly quick and stable. Specifically, as... Figures 4 to 6 As shown, the first leg 123 is provided with a first mounting hole 1231, the first support arm 141 is provided with a first clearance through hole 1411, and the PCB board 11 is provided with a second mounting hole (not shown in the figure). The second fastener 152 passes through the second mounting hole, the first clearance through hole 1411 and the first mounting hole 1231 in sequence to achieve fastening. The second leg 124 is provided with a third mounting hole 1241, the second support arm 143 is provided with a second clearance through hole 1431, and the PCB board 11 is provided with a fourth mounting hole (not shown in the figure). The third fastener 153 passes through the fourth mounting hole, the second clearance through hole 1431 and the third mounting hole 1241 in sequence to achieve fastening, thereby assembling the heat sink 12, the plastic support 14 and the PCB board 11 together.

[0067] Furthermore, in order to improve the stability of the assembly of the heat sink 12, the plastic support 14 and the PCB board 11, the first leg 123, the first support arm 141 and the PCB board 11 are connected by three second fasteners 152, and the second leg 124, the second support arm 143 and the PCB board 11 are connected by three third fasteners 153.

[0068] Furthermore, such as Figure 6 As shown, the cross-sectional dimensions of the first clearance through-hole 1411 and the second clearance through-hole 1431 can be as large as possible. In this way, some of the heat generated by the PCB board 11 can be transferred to the heat sink 12 through the first clearance through-hole 1411 and the second clearance through-hole 143, which is beneficial to accelerate the heat dissipation of the PCB board 11.

[0069] In one implementation, such as Figure 2 , Figure 4 and Figure 5 As shown, the heat sink 12 also includes a connecting rib 125 and an extension arm 126. The connecting rib 125 is located between the first side arm 121 and the second side arm 122, and its two ends are respectively connected to the first side arm 121 and the second side arm 122. The extension arm 126 is connected to the connecting rib 125 and extends along the length direction of the first side arm 121. A portion of the switches 13 can also be connected to the extension arm 126. The extension arm 126 increases the heat exchange area of ​​the heat sink 12 and increases the number of switches 13 that can be installed on the heat sink 12. In one specific embodiment, as... Figure 2 As shown, there are seven switches 13, three of which are connected to the first side arm 121, three of which are connected to the second side arm 122, and one switch 13 is connected to the extension arm 126.

[0070] Furthermore, such as Figure 2 and Figure 4 As shown, the inner surface of the first side arm 121 is provided with multiple first heat dissipation fins 1211, which extend toward the second side arm 122 and away from the PCB board 11. The inner surface of the second side arm 122 is provided with multiple second heat dissipation fins 1221, which extend toward the first side arm 121 and away from the PCB board 11. The connecting rib 125 is arranged parallel to the PCB board 11 and is provided with multiple third heat dissipation fins 1251, which extend in a direction perpendicular to the PCB board 11. This solution improves the heat dissipation performance of the heat sink 12 by optimizing the extension direction of each heat dissipation fin.

[0071] In one embodiment, the plastic support 14 is made of nylon. Nylon has high mechanical strength, good electrical insulation, and is not prone to stress deformation, which can better protect the PCB board 11 and the switch 13.

[0072] In one implementation, such as Figure 6 As shown, the plastic support 14 has a cutout 144 on the side facing the PCB board 11. The heat dissipation channel formed between the cutout 144 and the PCB board 11 is conducive to accelerating the heat dissipation of the PCB board 11.

[0073] In one embodiment, the PCB board 11 and the plastic support 14 are engaged by positioning protrusions and positioning holes to achieve pre-positioning. Specifically, as shown... Figure 6 As shown, the bottom wall of the plastic support 14 has multiple positioning protrusions 145, and the PCB board 11 has multiple positioning holes (not shown in the figure). The positioning protrusions 145 and the positioning holes are arranged one-to-one. When assembling the PCB board 11 and the plastic support 14, the positioning protrusions 145 are aligned with the positioning holes and inserted, and then the PCB board 11 and the plastic support 14 are connected by the second fastener 152 and the third fastener 153. Of course, the positioning pre-assembly structure of the PCB board 11 and the plastic support 14 is not limited to this. Positioning protrusions can also be provided on the PCB board 11, and positioning holes can be provided on the plastic support 14. Preferably, since the PCB board 11 is easier to drill, positioning protrusions 145 are provided on the bottom wall of the plastic support 14, and positioning holes are provided on the PCB board 11 to achieve positioning pre-assembly of the two.

[0074] In one implementation, such as Figure 4 As shown, switch 13 is connected to PCB board 11 via pin 131, making assembly convenient.

[0075] In one implementation, such as Figures 2 to 5 As shown, the printed circuit board 1 also includes a base 16. The PCB board 11 is mounted in the base 16 by a fourth fastener 154. The PCB board 11, the switch 13 and the plastic support 14 are all located in the base 16. The base 16 can play a protective role to prevent damage to electronic components during transportation or storage.

[0076] In one embodiment, the switch 13 is selected from any one of a field-effect transistor, a bipolar junction transistor, an insulated gate bipolar transistor, a gate turn-off thyristor, a MOS-controlled thyristor, an integrated gate commutation thyristor, and an electron injection enhancement gate transistor.

[0077] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of this utility model that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of this utility model and do not limit the scope of protection of this utility model patent.

Claims

1. A printed circuit board for power tools, characterized in that, The printed circuit board (1) includes: PCB board (11); Heat sink (12) is connected to the PCB board (11); Multiple switches (13) are electrically connected to the PCB board (11) and to the heat sink (12). The switches (13) are used to control the start and stop of the motor of the power tool. A plastic support (14) is located between the PCB board (11) and the heat sink (12). The plastic support (14) is used to support the heat sink (12) and to insulate the PCB board (11) from the heat sink (12).

2. The printed circuit board for power tools according to claim 1, characterized in that, The switch (13) is connected to the heat sink (12) via a first fastener (151).

3. The printed circuit board for power tools according to claim 2, characterized in that, The heat sink (12) includes a first side arm (121) and a second side arm (122) disposed opposite to each other. Part of the switch (13) is connected to the first side arm (121), and part of the switch (13) is connected to the second side arm (122).

4. The printed circuit board for power tools according to any one of claims 1-3, characterized in that, The plastic support (14) includes a first support arm (141), a connecting arm (142), and a second support arm (143) connected in sequence, and the heat sink (12) is supported on the first support arm (141) and the second support arm (143).

5. The printed circuit board for power tools according to claim 4, characterized in that, The heat sink (12) includes a first leg (123) and a second leg (124), the first leg (123) being supported on the first support arm (141) and the second leg (124) being supported on the second support arm (143).

6. The printed circuit board for power tools according to claim 5, characterized in that, The first leg (123), the first support arm (141) and the PCB board (11) are connected by a second fastener (152), and the second leg (124), the second support arm (143) and the PCB board (11) are connected by a third fastener (153).

7. The printed circuit board for power tools according to claim 4, characterized in that, The heat sink (12) includes: The first side arm (121) is partially connected to the switch (13); The second side arm (122) is partially connected to the switch (13); A connecting rib (125) is located between the first side arm (121) and the second side arm (122), and is connected to the first side arm (121) and the second side arm (122); An extension arm (126) is connected to the connecting rib (125) and extends along the length of the first side arm (121), and part of the switch (13) is connected to the extension arm (126).

8. The printed circuit board for power tools according to claim 7, characterized in that, The inner surface of the first side arm (121) is provided with a plurality of first heat dissipation fins (1211), and the first heat dissipation fins (1211) extend in a direction toward the second side arm (122) and away from the PCB board (11); And / or, a plurality of second heat dissipation fins (1221) are provided on the inner wall surface of the second side arm (122), and the second heat dissipation fins (1221) extend in a direction toward the first side arm (121) and away from the PCB board (11); And / or, the connecting rib (125) is arranged parallel to the PCB board (11), the connecting rib (125) is provided with a plurality of third heat dissipation fins (1251), and the third heat dissipation fins (1251) extend in a direction perpendicular to the PCB board (11).

9. The printed circuit board for power tools according to any one of claims 1-3, characterized in that, The plastic support (14) is U-shaped, C-shaped, V-shaped, or W-shaped; And / or, the plastic support (14) is of nylon structure; And / or, the plastic support (14) has a cutout (144) on the side facing the PCB board (11); And / or, the PCB board (11) and the plastic support (14) cooperate through positioning protrusions and positioning holes to achieve positioning pre-assembly; And / or, the switch (13) is plugged into the PCB board (11) via pin (131); And / or, the printed circuit board (1) further includes a base (16), the PCB board body (11) is mounted in the base (16), and the PCB board body (11), the switch (13) and the plastic support (14) are all located in the base (16); And / or, the switch (13) is selected from any one of a field-effect transistor, a bipolar junction transistor, an insulated gate bipolar transistor, a gate turn-off thyristor, a MOS-controlled thyristor, an integrated gate commutation thyristor, and an electron injection enhancement gate transistor.

10. A power tool, characterized in that, The power tool includes: Casing (2); The motor is located in the housing (2); The printed circuit board for power tools as described in any one of claims 1-9, wherein the printed circuit board (1) controls the start and stop of the motor via the switch (13).

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