CN220556788U

CN220556788U - Switch assembly for power tool

Info

Publication number: CN220556788U
Application number: CN202321358318.8U
Authority: CN
Inventors: 孙立峰
Original assignee: Bosch Power Tools China Co Ltd
Current assignee: Bosch Power Tools China Co Ltd
Priority date: 2023-05-30
Filing date: 2023-05-30
Publication date: 2024-03-05
Anticipated expiration: 2033-05-30

Abstract

The present application provides a switch assembly for a power tool, comprising: an electronic control assembly comprising at least one heat-generating region; a heat dissipating assembly comprising a first portion and a second portion, the first portion being made of a first material having a first thermal conductivity and the second portion being made of a second material having a second thermal conductivity; wherein the first thermal conductivity is greater than the second thermal conductivity, a first section of the first portion is adjacent to and establishes a thermal connection with the heat generating region, and the second portion is molded around the first portion such that the first portion is fixed relative to and embedded within the second portion. The switch assembly for the electric tool has the advantages of simple structure, easiness in implementation, convenience in use and the like, and can provide improved heat conduction capability.

Description

Switch assembly for power tool

Technical Field

The application relates to the field of electrical heat dissipation. More specifically, the present application relates to a switch assembly for a power tool that aims to provide an improved heat conduction solution.

Background

The electrical device may include one or more electrical components. Some electrical components may generate significant heat during operation. For example, metal-Oxide-semiconductor field effect transistors (MOSFET for short) may be used to perform electronic operations. During operation, it is desirable to dissipate heat generated by the electrical components as quickly as possible to avoid abnormal increases in temperature caused by localized heat build-up.

Typical heat dissipation means include heat sinks. The heat sink may include an aluminum alloy housing and a thermally conductive silicone pad. The pad may be positioned adjacent to the electrical component so as to conduct heat generated by the electrical component to the housing.

Disclosure of Invention

It is an object of an aspect of the present application to provide a switch assembly for a power tool that provides improved heat conduction properties.

The purpose of the application is realized through the following technical scheme:

a switch assembly for a power tool, comprising:

an electronic control assembly comprising at least one heat-generating region;

a heat dissipating assembly comprising a first portion and a second portion, the first portion being made of a first material having a first thermal conductivity and the second portion being made of a second material having a second thermal conductivity;

wherein the first thermal conductivity is greater than the second thermal conductivity, a first section of the first portion is adjacent to and establishes a thermal connection with the heat generating region, and the second portion is molded around the first portion such that the first portion is fixed relative to and embedded within the second portion.

In the above-described switch assembly for a power tool, optionally, the electronic control assembly includes one or more field effect transistors positioned at the heat generating region.

In the above-described switch assembly for a power tool, optionally, the first portion further includes a second section extending from the first section and spaced apart from the heat generating region.

In the above-described switch assembly for a power tool, optionally, the first section and/or the second section has a profile of one of the following shapes: triangle, rectangle, prism, pentagon, hexagon, circle, ellipse, torus, or combinations thereof.

In the above-described switch assembly for a power tool, optionally, the second portion is shaped to fit the outer contour of the electronic control assembly and includes a wall at an outer edge of the second portion extending toward the electronic control assembly to receive the electronic control assembly within the wall.

In the above-described switch assembly for a power tool, optionally, a heat-conductive paste is further included, the heat-conductive paste being distributed on a surface of the heat-dissipating assembly facing the electronic control assembly and being disposed between the heat-generating region and the first section.

In the above switch assembly for a power tool, optionally, the thermally conductive paste is one of: epoxy resin and silica gel.

In the above-described switch assembly for a power tool, optionally, the first material is one of: copper, copper alloy, silver alloy, and gold.

In the above-described switch assembly for a power tool, optionally, the second material is one of: aluminum alloy, steel, iron.

In the above-described switch assembly for a power tool, optionally, the melting point of the first material is higher than the melting point of the second material.

Drawings

The present application will be described in further detail below with reference to the attached drawings and the preferred embodiments. Those skilled in the art will appreciate that these drawings are drawn for the purpose of illustrating preferred embodiments only and thus should not be taken as limiting the scope of the present application. Moreover, unless specifically indicated otherwise, the drawings are merely intended to conceptually illustrate the compositions or constructions of the described objects, and may contain exaggerated representations. The figures are also not necessarily drawn to scale.

Fig. 1 is an exploded view of one embodiment of a switch assembly for a power tool of the present application.

Fig. 2 is a front view of the embodiment of fig. 1 with the components spread apart.

Fig. 3 is a front view of the embodiment of fig. 1 after assembly in place.

Fig. 4 is a rear view of the embodiment shown in fig. 3.

Detailed Description

Preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive, exemplary, and should not be construed as limiting the scope of the present application.

First, terms of top, bottom, upward, downward, and the like are defined with respect to directions in the drawings. These orientations are relative concepts and will therefore vary depending on the location and state in which they are located. These and other directional terms should not be construed as limiting.

Furthermore, it should also be noted that, for any individual feature described or implied in the embodiments herein or any individual feature shown or implied in the figures, these features (or their equivalents) can be combined further to obtain other embodiments not directly mentioned herein.

It should be noted that in different drawings, the same reference numerals denote the same or substantially the same components.

Fig. 1 is an exploded view of one embodiment of a switch assembly for a power tool of the present application, and fig. 2 is a front view of the embodiment of fig. 1 with its components spread flat. Specifically, the switching assembly may include an electronic control assembly 100, a heat dissipation assembly 200, and the like.

The electronic control assembly 100 may have a structure that is conventional electronic control assemblies, including, for example, a PCB, leads, electrical interfaces, and one or more electronic components, etc. In the illustrated embodiment, the electronic control assembly 100 may include one or more Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) 101. The mosfet 101 may be arranged within the heat generating region 110. In fig. 1 and 2, the heat generating region 110 is schematically shown with rectangular broken lines, and six metal oxide semiconductor field effect transistors 101 are arranged in a2×3 matrix pattern within the heat generating region 110. It is readily understood that other arrangements of the mosfet 101 may be employed, or more or less than six mosfets may be disposed on the electronic control assembly 100.

In one embodiment, the electronic control assembly 100 includes control circuitry for a power tool, a switch operator, a transmission mechanism, a trigger mechanism, and the like. The control circuitry may include, for example, one or more Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) 101. The electronic control assembly may include more or fewer components depending on the actual needs.

The heat sink assembly 200 may have a shape profile that is compatible with the electronic control assembly 100. For example, the heat sink assembly 200 in fig. 2 will fit the contours of the electronic control assembly 100 after being flipped 180 degrees. Accordingly, the heat sink assembly 200 is shown in FIG. 2 for clarity only, and the particular manner in which the switch assembly is assembled may be understood in conjunction with other figures (e.g., FIG. 1).

The heat dissipation assembly 200 may include a first portion 210 and a second portion 220. In one embodiment, the first portion 210 may be made of a first material and the second portion 220 may be made of a second material. The first material may have a first thermal conductivity and the second material may have a second thermal conductivity. In one embodiment, the first thermal conductivity may be greater than the second thermal conductivity. For example, the first material may be one of: copper, copper alloy, silver alloy, and gold. The second material may be one of: aluminum alloy, steel, iron. In summary, the thermal conductivity of the first material is only greater than that of the second material. For example, in one embodiment, the first material may be copper and the second material may be an aluminum alloy.

The first portion 210 may include at least a first section 211 and a second section 212. In one embodiment, the first section 211 may correspond in size to the heat generating region 110 and be positioned adjacent to the heat generating region 110 so as to establish a thermal connection between the metal oxide semiconductor field effect transistor 101 and the first section 211 of the first portion 210 of the heat sink assembly 200. The second section 212 may extend from the first section 211 and follow the contour of the first portion 210 of the heat dissipating assembly 200. Thus, the second section 212 may be spaced apart from the heat-generating region 110, or, alternatively, there may be no direct thermal connection between the second section 212 and the heat-generating region 110. In the illustrated embodiment, the second section 212 may be disposed at both sides of the first section 211. The arrangement of the second section 212 allows the heat transferred to the first section 211 to spread out quickly to the surroundings in order to provide better heat capacity, heat dissipation rate and the ability to cope with short time high power heating.

In the illustrated embodiment, the first portion 210 is generally rectangular in configuration, and the first section 211 and the second section 212 also have rectangular profiles. However, the present application is not limited to the illustrated case, and the first section 211 and/or the second section 212 may have different profiles according to actual needs. Such contours include, but are not limited to, triangles, rectangles, prisms, pentagons, hexagons, circles, ovals, circles, or combinations thereof.

The second portion 220 may be disposed around the entire perimeter of the first portion 210. In one embodiment, the second portion 220 is molded around the first portion 210, and the first portion 210 is at least partially embedded within the second portion 220. For example, a recess 222 shown in fig. 1 inside the second portion 220 may be used to accommodate the first portion 210. In other words, the first portion 210 may be disposed in the recess 222. Arrow A2 schematically illustrates the direction of embedding the first portion 210 in the second portion 220. In one embodiment, first portion 210 may be made separately and then first portion 210 is immersed in the second material in a molten state to mold second portion 220 around first portion 210. Thus, the melting point of the first material may be higher than the melting point of the second material in order to complete the molding operation described above. In the embodiment of fig. 1 and 2, the surfaces of the first portion 210 and the second portion 220 facing the electronic control assembly 100 may be substantially flush.

The second portion 220 may have a profile that is adapted to at least a portion of the electronic control assembly 100. Further, the edge of the second portion 220 may include a wall 221 extending toward the electronic control assembly 100. The wall 221 may surround the electronic control assembly 100 during subsequent assembly operations. The glue may then fill the cavity enclosed by the wall 221, thereby protecting the electronic control assembly from the external environment and stresses, and further enhancing the heat dissipation capacity of the electronic control assembly, thereby providing improved protection. In fig. 1, an arrow A1 schematically illustrates an assembly direction of the electronic control assembly 100 and the heat dissipation assembly 200. It is readily understood that the edge of the electronic control assembly 100 may be positioned at the inside of the wall 221.

Furthermore, a heat-conducting glue may be arranged at least between the heat-generating region 110 and the first section 211. In one embodiment, the side of the first and second portions 210, 220 facing the electronic control assembly 100 may be provided with a thermally conductive glue and ensure that a thermally conductive glue is arranged between the heat generating region 110 and the first section 211. Thus, the path of heat conduction may be: the mosfet 101-the heat generating region 110-the thermally conductive glue-the first section 211-the second section 212-the second portion 220. In one embodiment, the heat conductive gel may be one of the following: epoxy resin and silica gel.

The switch assembly for a power tool of the present application may be installed as an integrated switch in a handle of the power tool. The user can operate the switch while holding the handle. The integration and size of the switch assembly is relatively small due to the size limitation of the handle, and thus places high demands on heat dissipation. Meanwhile, the power tool also has a need for cost control.

Fig. 3 is a front view of the embodiment of fig. 1 after assembly in place, and fig. 4 is a rear view of the embodiment of fig. 3. As shown, the heat sink assembly 200 is attached to the electronic control assembly 100 and the profile of at least a portion of the second portion 220 is adapted to the profile of at least a portion of the electronic control assembly 100 such that at least a portion of the electronic control assembly 100 is surrounded by the wall 221 and, on a contact surface, not shown, the heat generating region 110 is adjacent to the first section 211 and establishes a thermal connection by a thermally conductive glue therebetween, thereby providing heat sink capability for electrical components on the electronic control assembly 100. Furthermore, the second section 212 of the first portion 210 is partially visible in fig. 4, and the second section 212 may thus rapidly conduct heat outside the invisible first section 211 and diffuse into the second portion 220 or air. Such a configuration further improves the heat dissipation efficiency.

Compared with the scheme of using the insulating gasket, the heat-conducting glue can completely wrap the heating area and can further penetrate into gaps of pins of the heating electric element, and therefore heat-conducting efficiency can be remarkably improved. Thus, the heat dissipation solution of the present application may provide better heat transfer rates and better buffering capacity for short-time, explosive heating. The first portion 210 provides the possibility of rapid heat dissipation and the second portion 220 provides a greater heat capacity, thereby reducing temperature fluctuations due to short bursts of heat.

The switch assembly for the electric tool has the advantages of simplicity, reliability, easiness in implementation, convenience in use and the like, and can provide improved heat conduction performance. The present application thus provides a simple and reliable solution with excellent heat transfer performance.

The description makes reference to the accompanying drawings to disclose the present application, and also to enable any person skilled in the art to practice the present application, including making and using any devices or systems, selecting suitable materials and using any incorporated methods. The scope of the present application is defined by the claims and encompasses other examples that occur to those skilled in the art. Such other examples should be considered to be within the scope of protection as determined by the claimed subject matter, so long as such other examples include structural elements that are not literally different from the claimed subject matter, or include equivalent structural elements with insubstantial differences from the literal languages of the claimed subject matter.

Claims

1. A switch assembly for a power tool, comprising:

an electronic control assembly (100) comprising at least one heat generating region (110);

-a heat dissipating assembly (200) comprising a first portion (210) and a second portion (220), the first portion (210) being made of a first material having a first thermal conductivity and the second portion (220) being made of a second material having a second thermal conductivity;

wherein the first thermal conductivity is greater than the second thermal conductivity, a first section (211) in the first portion (210) is adjacent to the heat generating region (110) and establishes a thermal connection, and the second portion (220) is molded around the first portion (210) such that the first portion (210) is fixed relative to the second portion (220) and embedded within the second portion (220).

2. The switch assembly for a power tool of claim 1, wherein the electronic control assembly (100) includes one or more field effect transistors (101), the field effect transistors (101) being positioned at the heat generating region (110).

3. The switch assembly for a power tool of claim 1, wherein the first portion (210) further comprises a second section (212), the second section (212) extending from the first section (211) and being spaced apart from the heat generating region (110).

4. A switch assembly for a power tool according to claim 3, characterized in that the first section (211) and/or the second section (212) has a profile of one of the following shapes: triangle, rectangle, prism, pentagon, hexagon, circle, ellipse, torus, or combinations thereof.

5. The switch assembly for a power tool of claim 1, wherein the second portion (220) is shaped to fit an outer contour of the electronic control assembly (100) and includes a wall (221) at an outer edge of the second portion (220) extending toward the electronic control assembly (100) to accommodate the electronic control assembly (100) within the wall (221).

6. The switch assembly for a power tool of claim 1, further comprising a thermally conductive adhesive distributed on a surface of the heat sink assembly (200) facing the electronic control assembly (100) and disposed between the heat generating region (110) and the first section (211).

7. The switch assembly for a power tool of claim 6, wherein the thermally conductive paste is one of: epoxy resin and silica gel.

8. The switch assembly for a power tool of any one of claims 1-7, wherein the first material is one of: copper, copper alloy, silver alloy, and gold.

9. The switch assembly for a power tool of any one of claims 1-7, wherein the second material is one of: aluminum alloy, steel, iron.

10. The switch assembly for a power tool of any one of claims 1-7, wherein the first material has a melting point that is higher than a melting point of the second material.