CN217849929U - Control assembly and brushless electric tool - Google Patents

Abstract

The application provides a control assembly of a brushless motor and a brushless electric tool, the control assembly comprises a circuit board, a power element arranged on the circuit board and a packaging box for covering the circuit board and the power element, the circuit board is provided with a first surface and a second surface which are arranged in parallel, the power element is arranged on the first surface, the packaging box comprises a main body part and a heat conduction part formed by sinking the main body part, the main body part and the second surface are arranged at intervals, the heat conduction part is provided with a heat dissipation bottom surface which is abutted against the second surface of the circuit board and a heat conduction side surface which extends from the heat dissipation bottom surface along the direction far away from the circuit board, and the heat dissipation bottom surface and the heat conduction side surface are arranged on one side of the heat conduction part, which is opposite to the circuit board; the power element forms a first orthographic projection on the first surface, the heat conducting part forms a second orthographic projection on the first surface, and the first orthographic projection and the second orthographic projection are at least partially overlapped. The heat conducting part is directly formed from the main body part, so that heat is released, a large enough heat conducting area is ensured, element materials are reduced, and cost reduction is facilitated.

Description

Control assembly and brushless electric tool

Technical Field

The application relates to the field of motor control, in particular to a control assembly and a brushless electric tool.

Background

The brushless motor adopts a semiconductor switching device to realize electronic commutation, namely the electronic switching device replaces the traditional contact commutator and electric brush, and has the advantages of high reliability, no commutation spark, low mechanical noise and the like, thereby being widely applied to electronic products. Accordingly, the complexity of the control assembly of the brushless motor is far superior to that of the brush motor.

General brushless motor subassembly, encapsulation shell adopt aluminum alloy material die-casting to form, and when the wall thickness was less, the great and inefficiency of the technology degree of difficulty of die-casting, in addition, die-casting forming's size precision is low, and the outward appearance is relatively poor. In addition, the power device on the circuit board is not in contact with the heat dissipation structure, so that the heat conduction effect is poor.

Disclosure of Invention

The application provides a control assembly and brushless electric tool, provides good heat dispersion and good manufacturability.

The application provides a control assembly of a brushless motor, which comprises a circuit board, a power element arranged on the circuit board and a packaging box for covering the circuit board and the power element, wherein the circuit board is provided with a first surface and a second surface which are arranged in parallel, the power element is arranged on the first surface, the packaging box comprises a main body part and a heat conduction part formed by sinking the main body part, the main body part and the second surface are arranged at intervals, the heat conduction part is provided with a heat dissipation bottom surface which is abutted against the second surface of the circuit board and a heat conduction side surface which extends from the heat dissipation bottom surface along the direction away from the circuit board, and the heat dissipation bottom surface and the heat conduction side surface are arranged on one side of the heat conduction part back to the circuit board; the power element forms a first orthographic projection on the first surface, the heat conducting part forms a second orthographic projection on the first surface, and the first orthographic projection and the second orthographic projection at least partially coincide.

Further, the first orthographic projection is located within the second orthographic projection.

Furthermore, the packaging box comprises a side wall vertically connected with the main body part, the side wall and the main body part enclose a space, and the circuit board and the power element are positioned in the space; the control assembly further comprises packaging glue, and the circuit board and the power element are packaged together by the packaging box and the packaging glue.

Further, the control assembly comprises a plurality of power elements, and the heat conducting part and an orthographic projection of each power element on the first surface at least partially coincide.

Further, the heat conducting portion includes a plurality of sub heat dissipation areas, each sub heat dissipation area corresponds to one power element, and the sub heat dissipation areas are configured to conduct heat of the corresponding power element.

Furthermore, the heat conducting part comprises a first heat dissipation area and a second heat dissipation area which are separately arranged, the plurality of power elements are arranged in two rows, the projection of the first heat dissipation area and the projection of one row of power elements are at least partially overlapped, and the projection of the second heat dissipation area and the projection of the other row of power elements are at least partially overlapped.

Further, the heat conducting portion comprises a transition area which is connected with the first heat dissipation area and the second heat dissipation area, and the first heat dissipation area, the transition area and the second heat dissipation area are integrally W-shaped.

Further, the heat conducting portion is formed by punching from the main body portion.

Further, the distance between the main body part and the heat dissipation bottom surface in the direction perpendicular to the first surface is 1-4 mm.

In another aspect, the present application also provides a brushless electric tool including a housing, a brushless motor assembled to the housing, an output shaft driven by the brushless motor, and a control assembly as described above configured to control an operating state of the brushless motor.

The heat conducting part is directly formed from the main body part, so that heat of the power element is released, a large enough heat conducting area is ensured, element materials are reduced, and cost reduction is facilitated.

Drawings

FIG. 1 is a schematic front view of a control assembly according to one embodiment of the present application.

Fig. 2 is a rear view of the control assembly shown in fig. 1.

Fig. 3 isbase:Sub>A schematic cross-sectional view taken along linebase:Sub>A-base:Sub>A of fig. 2.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which the invention belongs. As used in this application, the terms "first," "second," and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. "plurality" or "a number" means two or more. Unless otherwise indicated, "front," "back," "lower," and/or "upper," and the like are for convenience of description, and are not limited to one position or one spatial orientation. The word "comprising" or "comprises", and the like, means that the element or item listed after "comprises" or "comprising" is inclusive of the element or item listed after "comprising" or "comprises", and the equivalent thereof, and does not exclude additional elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

Referring to fig. 1 to 3, the present embodiment provides a control assembly of a brushless motor, where the control assembly includes a circuit board 1, a power element 2 disposed on the circuit board 1, and a packaging box 3 covering the circuit board 1 and the power element 2, and the packaging box 3 and a packaging adhesive jointly encapsulate the circuit board 1 and the power element 2.

The circuit board 1 has a first surface 101 and a second surface 102, and the power component 2 is located on the first surface 101, where the power component may be a switching element, such as a MOS transistor. The packaging box 3 comprises a main body 31, a heat conduction part 32 formed by sinking the main body 31 and a side wall 33 vertically connected with the main body 31, wherein the heat conduction part 32 is abutted against the second surface 102 of the circuit board 1, and the main body 31 and the second surface 102 are arranged at intervals. The side wall 33 and the main body 31 enclose a space 300, and the circuit board 1 and the power element 2 are at least partially accommodated in the space 300.

Preferably, the heat dissipation area 32 is formed by stamping from the main body 31, and compared with die-casting, the material does not need to be melted into a liquid state, so that energy is saved and waste water is not generated. For the packaging box with smaller thickness, the die-casting process is difficult to form, the stamping process is easier to form, and the stamping efficiency is far higher than that of the die-casting process. From the outward appearance of product, the die-casting shaping outward appearance is poor, and size precision is low, and the stamping forming outward appearance is good, and size precision is high, does benefit to reliable location installation. From the mould perspective, the stamping die manufacturing cost is lower than the die-casting mould and the mould has long service life, the average service life of the die-casting mould is about 10 ten thousand times, and the service life of the stamping die can reach 800 ten thousand times.

The heat conducting portion 32 is provided with a heat dissipating bottom 321 and a heat dissipating side 322 extending from the heat dissipating bottom in a direction away from the circuit board, and the heat dissipating bottom 321 and the heat dissipating side 322 are disposed on a side of the heat conducting portion 32 facing away from the circuit board 1. The power element 2 forms a first orthographic projection on the first surface 101, the heat conducting part 32 forms a second orthographic projection on the first surface 101, and the first orthographic projection and the second orthographic projection are at least partially overlapped, so that heat generated by the power element is conducted to the heat conducting part through the circuit board and finally dissipated to the air. Preferably, the first orthographic projection is located in the second orthographic projection, so that the whole surface of the power element 2 contacting the circuit board can be subjected to heat dissipation, and the heat dissipation effect is further improved.

The distance between the heat dissipation bottom 321 and the first surface 101 (the sum of the thickness of the heat conducting portion and the thickness of the main body portion) is 3 to 5mm, and the distance between the first surface 101 and the second surface 101 (i.e., the thickness of the circuit board 2) is 1 to 2mm. The distance between the main body 31 and the bottom 321 in the direction perpendicular to the first surface 101 is 1-4 mm, that is, the height of the side surface is 1-4 mm, so that the heat conducting portion provides a sufficiently large heat dissipating surface, which is beneficial to ensure a good heat dissipating effect.

Optionally, the control assembly includes a plurality of power elements 2, and the heat conduction portion 32 and an orthographic projection of each power element 2 on the first surface at least partially coincide, so that the heat conduction portion 32 can simultaneously realize heat conduction of the plurality of power elements.

In this embodiment, the heat conducting portion 32 includes a first heat dissipation area 32A, a second heat dissipation area 32B, and a transition area 36 connecting the first heat dissipation area 32A and the second heat dissipation area 32B, the plurality of power components 2 are arranged in two rows, projections of the first heat dissipation area 32A and the row of power components 2A at least partially overlap, and projections of the second heat dissipation area 32B and the other row of power components 2B at least partially overlap. The first heat dissipation area 32A and the second heat dissipation area 32B are separately disposed to respectively conduct heat, so as to avoid over-high heat of a part of power components, and to avoid heat from flowing back to an adjacent power component. The first heat dissipation area, the transition area and the second heat dissipation area are integrally W-shaped, so that a large enough heat dissipation surface is provided, and the heat dissipation effect is improved.

In other embodiments, the heat conducting portion includes a plurality of sub heat dissipation areas, each sub heat dissipation area corresponds to one power element, that is, each sub heat dissipation area is used for conducting out heat of a corresponding power element.

The packaging box further comprises a mounting part 34 and an auxiliary heat dissipation part 35 which are formed by stamping from the main body part, the mounting part is used for mounting the control assembly to a machine shell of the brushless electric tool, and the lower limit structure ensures that the nut does not protrude out of the main body part, so that the space is saved; the auxiliary heat dissipation portions 35 are used to provide a larger heat dissipation area for conducting heat away from other electronic components of the circuit board, and optionally, a plurality of auxiliary heat dissipation portions are arranged substantially in parallel.

On the other hand, the application also provides a brushless electric tool, which comprises a shell, a brushless motor assembled on the shell, an output shaft driven by the brushless motor and the control component, wherein the brushless motor shell directly drives the output shaft, and also can indirectly drive the output shaft (a speed reducing mechanism is arranged between the output shaft and the output shaft), the output shaft can be used for installing accessories such as a drill bit, a blade, a saw blade and the like, and the control component is configured to control the working state of the brushless motor. The brushless electric tool may be a conventional electric tool such as an electric drill, an angle grinder, a sander, a cutter, or a garden electric tool such as a chain saw, a pruner, or a mower.

Through directly forming heat conduction portion from the main part, release power component's heat, when guaranteeing enough big heat conduction area, reduced the component material, be favorable to reduce cost.

Although the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present invention.

Claims (10)

1. A control component of a brushless motor comprises a circuit board, a power element arranged on the circuit board and a packaging box for covering the circuit board and the power element, wherein the circuit board is provided with a first surface and a second surface which are arranged in parallel, the power element is arranged on the first surface,

the packaging box comprises a main body part and a heat conduction part formed by sinking the main body part, the main body part and the second surface are arranged at intervals, the heat conduction part is provided with a heat dissipation bottom surface abutted against the second surface of the circuit board and a heat conduction side surface extending from the heat dissipation bottom surface along the direction far away from the circuit board, and the heat dissipation bottom surface and the heat conduction side surface are arranged on one side of the heat conduction part back to the circuit board;

the power element forms a first orthographic projection on the first surface, the heat conducting part forms a second orthographic projection on the first surface, and the first orthographic projection and the second orthographic projection at least partially coincide.

2. The control assembly of claim 1, wherein: the first orthographic projection is located within the second orthographic projection.

3. The control assembly of claim 1, wherein: the packaging box comprises a side wall vertically connected with the main body part, the side wall and the main body part form a space in an enclosing mode, and the circuit board and the power element are located in the space;

the control assembly further comprises packaging glue, and the circuit board and the power element are packaged together by the packaging box and the packaging glue.

4. The control assembly of claim 1, wherein: the control assembly includes a plurality of power elements, and the orthographic projection of the heat conducting portion and each power element on the first surface at least partially coincides.

5. The control assembly of claim 4, wherein: the heat conducting part comprises a plurality of sub heat dissipation areas, each sub heat dissipation area corresponds to one power element and is configured to conduct heat of the corresponding power element.

6. The control assembly of claim 4, wherein: the heat conducting part comprises a first heat radiating area and a second heat radiating area which are arranged separately, a plurality of power elements are arranged in two rows, the projection of the first heat radiating area and the projection of one row of power elements are at least partially overlapped, and the projection of the second heat radiating area and the projection of the other row of power elements are at least partially overlapped.

7. The control assembly of claim 6, wherein: the heat conducting part comprises a transition area which is connected with the first heat dissipation area and the second heat dissipation area, and the first heat dissipation area, the transition area and the second heat dissipation area are integrally W-shaped.

8. The control assembly of claim 1, wherein: the heat conducting portion is stamped and formed from the main body portion.

9. The control assembly of claim 8, wherein: and the distance between the main body part and the heat dissipation bottom surface in the direction vertical to the first surface is 1-4 mm.

10. A brushless power tool, characterized by: the brushless power tool comprises a housing, a brushless motor assembled to the housing, an output shaft driven by the brushless motor, and the control assembly of any one of claims 1 to 9 configured to control an operating state of the brushless motor.

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