Power Tools

Abstract

The present invention discloses an electric tool, comprising: a housing, a motor and a circuit board contained in the housing, the housing being provided with a plurality of air inlets and a plurality of air outlets, the circuit board being electrically connected to the motor and driving the motor to operate; a first fan and a second fan being respectively installed at both axial ends of the motor, driving the first and second fans to rotate, the first fan introducing airflow from an air inlet, and discharging airflow from an air outlet after passing through the motor, forming a first cooling air duct; the second fan introducing airflow from another air inlet, and discharging airflow from another air outlet after passing through the circuit board, forming a second cooling air duct, the first cooling air duct and the second cooling air duct being independent and isolated from each other. Two fans are used to cool the motor and the circuit board respectively, thereby enhancing the cooling effect.

Description

[Technical field]

[0002] The present invention relates to the field of electric tools, and in particular to a cutting electric tool. [Background technology]

[0004] Traditional power tools have cooling ducts to cool the motor to prevent the motor from overheating. With the progress of society, the application of brushless motors is becoming more and more popular, and brushless motors are usually connected to a circuit board that controls their speed; in addition, the connecting wires between the motor and the switch are usually replaced with circuit boards to achieve miniaturization, and the circuit boards will heat up due to the operation of the power tool, so the circuit boards need to be cooled while cooling the motor.

[0005] Please refer to the Chinese invention patent announcement No. CN104114335B, which discloses a portable electric cutting machine. The portable electric circular saw includes a centrifugal fan fixed to the output shaft of the motor, which is driven to rotate by the motor, and the motor is cooled by the fan airflow generated by the rotation. The circuit board has cooling air holes formed on the housing. Between the back surface of the fan guide and the outer wall of the housing, an air flow path connecting the motor housing and the circuit board housing is set. The rotation of the fan causes negative pressure on the inside of the fan guide, and the cooling air flows from the cooling air holes through the circuit board and then reaches the inside of the fan guide. However, the portable electric cutting machine cools the motor and the circuit board at the same time through a single fan, and the airflow originally used to cool the motor alone is divided into two, resulting in a poor heat dissipation effect for either the motor or the circuit board, which affects the service life of the product.

[0006] Therefore, it is necessary to design a new electric tool to solve the cooling effect of the equipment inside the tool. [Summary of the invention]

[0008] To solve the above problems, the present invention provides an electric tool with improved cooling effect.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions: an electric tool, comprising: a shell and a motor and a circuit board accommodated in the shell, the shell is provided with a plurality of air inlets and a plurality of air outlets, the circuit board is electrically connected to the motor and drives the motor to operate; a first fan and a second fan are respectively installed at both axial ends of the motor, and drive the first and second fans to rotate, the first fan introduces airflow from an air inlet, and discharges it from an air outlet after passing through the motor, forming a first cooling air duct; the second fan introduces airflow from another air inlet, and discharges it from another air outlet after passing through the circuit board, forming a second cooling air duct, the first cooling air duct and the second cooling air duct are independent of each other and separated.

[0010] A further improved solution is: the housing has a first accommodating portion for accommodating the motor and a second accommodating portion for accommodating the circuit board, the first cooling air duct flows through the first accommodating portion, and the second cooling air duct flows through the second accommodating portion.

[0011] A further improvement is as follows: the air inlet includes a first air inlet communicating with the first accommodating portion and a second air inlet communicating with the second accommodating portion, and the air outlet includes a first air outlet communicating with the first accommodating portion and a second air outlet communicating with the second accommodating portion; the airflow of the first cooling air duct flows into the first accommodating portion through the first air inlet, flows through the motor in the first accommodating portion, and is discharged from the first accommodating portion through the first air outlet; the airflow of the second cooling air duct flows into the second accommodating portion through the second air inlet, flows through the circuit board in the second accommodating portion, and is discharged from the second accommodating portion through the second air outlet.

[0012] A further improvement is: the second accommodating portion also includes a wind shield ring located on the right side of the motor and a cover plate abutting the right end of the wind shield ring, the cover plate and the wind shield ring surround an internal cavity, the internal cavity accommodates a second fan, the internal cavity has a notch in the radial direction of the second fan, and the notch constitutes the above-mentioned second air outlet.

[0013] A further improvement is that the second accommodating portion also has a pipe extending along the outer side wall of the first accommodating portion and integrally formed with the first accommodating portion, the pipe and the internal cavity are connected to each other to form the second cooling air duct, and the first air inlet is arranged on the outer circle of the right end of the cover plate.

[0014] A further improvement is as follows: an external cavity is provided around the outer periphery of the wind shield ring and the cover plate; both the wind shield ring and the cover plate are provided with an inner ring wall isolating the internal cavity from the external cavity; and the external cavity and the first accommodating portion form the first cooling air duct.

[0015] A further improved solution is: the second fan is a discrete fan, and the second air outlet is arranged below the above-mentioned internal cavity and is inclined toward the rotation direction of the discrete fan.

[0016] A further improved solution is: the second accommodating portion further comprises a cover plate located at the right end of the first accommodating portion, the cover plate and the right side wall of the first accommodating portion are surrounded by an internal cavity, and the internal cavity accommodates the second fan.

[0017] A further improved solution is: the second accommodation portion further has a pipe extending along the outer side wall of the first accommodation portion and integrally formed with the first accommodation portion, and the pipe is connected to the internal cavity to form the second cooling air duct.

[0018] A further improvement is as follows: the cover plate is provided with an external cavity located at the outer periphery of the cover plate and an inner annular wall isolating the external cavity from the internal cavity; the first air inlet is arranged at the outer periphery of the cover plate and communicates with the external cavity; the second air inlet is located in the middle of the cover plate and communicates with the internal cavity; the external cavity and the first accommodating portion form the first cooling air duct.

[0019] A further improved solution is: the electric tool is an electric circular saw, the electric circular saw includes a base plate, and the shell is connected to the base plate.

[0020] The present invention adopts another scheme: an electric tool, comprising: a housing, a motor and a circuit board, the housing is provided with a first accommodating portion for accommodating the motor and a second accommodating portion for accommodating the circuit board, the first accommodating portion is provided with a first air inlet and a first air outlet, the second accommodating portion has a second air inlet and a second air outlet; the circuit board is electrically connected to the motor and drives the motor to operate; a first fan and a second fan are respectively installed at both axial ends of the motor, the first fan forms an airflow flowing in the first accommodating portion, the second fan forms an airflow flowing in the second accommodating portion, and the first accommodating portion and the second accommodating portion are not connected.

[0021] A further improvement is that the airflow direction in the first accommodation portion and the airflow direction in the second accommodation portion are at least partially parallel to each other.

[0022] Compared with the prior art, the present invention has the following beneficial effects: by respectively installing the first fan and the second fan at the axial ends of the motor, the first fan introduces airflow to cool the motor and form a first cooling air duct, and the second fan introduces airflow to cool the circuit board that drives the motor to operate and form a second cooling air duct. The first cooling air duct and the second cooling air duct are independent and isolated from each other, which is beneficial to increasing the airflow throughput in each air duct, preventing the airflow in the cooling air duct from flowing in series or diverting, improving the cooling effect on the motor and the circuit board, and thereby increasing the service life of the power tool.

Brief Description of the Drawings

[0024] Figure 1 is a three-dimensional view of a first embodiment of the electric tool of the present invention;

[0025] Figure 2 yes Figure 1 A three-dimensional view without the right housing;

[0026] Figure 3 yes Figure 1 A partial exploded view of

[0027] Figure 4 yes Figure 1 A partial cutaway diagram of

[0028] Figure 5It is a partial cutaway schematic diagram of a second embodiment of the electric tool of the present invention. [Specific implementation method]

[0030] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments, wherein the implementation of the power tool is described in detail by taking an electric circular saw as an example.

[0031] Please refer to Figures 1 to 4 As shown, a schematic diagram of a first embodiment of the electric tool 100 of the present invention is shown, and the electric tool comprises: a housing 1, a bottom plate 7 supporting the housing 1, a motor 2 and a transmission assembly contained in the housing 1, a saw blade fixedly connected to the transmission assembly, and a circuit board 3. The housing 1 is connected to the bottom plate 7; the output direction of the electric circular saw is defined as left, and the housing 1 comprises a left housing 19, a right housing 12 covering the left housing 19, and a gear box 11 fixed to the left end of the left housing 19. The left housing 19 accommodates the motor 2, and the gear box 11 accommodates the transmission assembly. When the electric tool 100 is in operation, the motor 2 drives the transmission assembly to rotate, and the transmission assembly drives the saw blade to cut the workpiece, and then the housing 1 is rotated relative to the bottom plate 7 to adjust the cutting depth of the saw blade.

[0032] The housing 1 has a first accommodating portion 19a for accommodating the motor 2 and a second accommodating portion 13 for accommodating the circuit board 3. The first accommodating portion 19a and the second accommodating portion 13 are not connected to each other to prevent airflow from flowing through, which will be described in detail later. The left housing 19 and the right housing 12 are covered to form a handle for holding, and a accommodating cavity 13b is formed below the handle. The accommodating cavity 13b is adjacent to the circumferential wall of the first accommodating portion 19a. The second accommodating portion 13 includes the accommodating cavity 13b, and the circuit board 3 is accommodated in the accommodating cavity 13b.

[0033] The circuit board 3 is electrically connected to the motor 2 and drives the motor 2 to operate. The circuit board 3 includes a drive circuit for driving the motor 2 and a control circuit for controlling the drive circuit. The motor 2 is a brushless inner rotor motor. The motor 2 includes a rotor 23 and a stator 24 mounted on the outer periphery of the rotor 23. The left end of the rotor 23 is supported on the gear box 11 through a bearing, and the right end is supported on the left housing 19. The first fan 21 located at the left end and the second fan 22 located at the right end are respectively installed in the axial direction of the rotor 23, and the first and second fans are driven to rotate.

[0034] The first accommodating portion 19a is provided with a first air outlet 6 located on the left side thereof and a first air inlet 17a located on the right side thereof (depending on the selected fan specifications or the different rotation directions of the fan blades, the air inlet in the embodiment of the present invention can be used as an air outlet, and similarly the air outlet can also be used as an air inlet). The second accommodating portion 13 has a second air inlet 13a located on the left side thereof and a second air outlet 15 located on the right end thereof. The second accommodating portion 13 also includes a windshield ring 16 located on the right side of the motor 2 and a cover plate 17 abutting against the right end of the windshield ring 16. The windshield ring 16 and the cover plate 17 are both fixed to the right side of the first accommodating portion 19a. The cover plate 17 and the windshield ring 16 are surrounded by an internal cavity 17c, and the internal cavity 17c accommodates a second fan 22, which is a discrete fan. A through hole is provided in the middle of the wind shield ring 16, which passes through the accommodating cavity 13b and the internal cavity 17c. The rotor 23 has a spindle, which passes through the through hole of the wind shield ring 16 and extends into the internal cavity 17c. The second fan 22 is fixed on the spindle 23a.

[0035] The outer periphery of the wind shield ring 16 and the cover plate 17 is provided with an external cavity 17d, and the wind shield ring 16 and the cover plate 17 are provided with an inner ring wall isolating the internal cavity 17c from the external cavity 17d. The first air inlet 17a is arranged on the outer ring of the right end of the cover plate 17 and communicates with the external cavity 17d. The first fan 21 is adjacent to the right side of the gear box 11, and the first air outlet 6 is arranged on the gear box 11. The external cavity 17d is communicated with the first accommodating portion 19a and forms a first cooling air duct. The first cooling air duct flows through the first accommodating portion 19a, and the first fan 21 introduces airflow from the first air inlet 17a into the first cooling air duct, and after flowing through the motor 2 in the first accommodating portion 19a, it is discharged from the first accommodating portion 19a through the first air outlet 6.

[0036] The second accommodating portion 13 also has a duct 19b extending along the outer side wall of the first accommodating portion 19a and integrally formed with the first accommodating portion 19a. The duct 19b is parallel to the first accommodating portion 19a. Of course, the "parallel" described in this embodiment excludes slight angle differences caused by draft angles or molding errors. The duct 19b, the internal cavity 17c, and the accommodating cavity 13b are connected to each other and form a second cooling air duct. The internal cavity 17c has a notch radially below the second fan 22, and the notch constitutes the above-mentioned second air outlet 15. The second air outlet 15 is arranged to be inclined toward the rotation direction of the second fan 22, which is conducive to discharging the airflow along the airflow direction of the second fan 22 and reducing air resistance. The second cooling air duct flows through the second accommodating portion 13. The right end of the accommodating cavity 13b is provided with a plurality of ventilation holes, which constitute the second air inlet 13a. The second fan 22 introduces airflow into the second cooling air duct from the second air inlet 13a, and the airflow flows through the circuit board and then is discharged from the second accommodating portion 13 through the second air outlet 15. The first cooling air duct and the second cooling air duct are independent and isolated from each other to prevent the interference of airflows flowing in series or diverting each other, thereby enhancing the cooling effect. In addition, the airflow in the duct 19b is parallel to the airflow in the first accommodating portion 19a. The different air ducts are arranged adjacent to each other, which is conducive to reducing the volume of the electric circular saw.

[0037] The electric tool 100 of the first embodiment of the present invention is provided with a first fan 21 and a second fan 22 respectively installed at both ends of the axial direction of the motor 2. The first fan 21 introduces airflow to cool the motor and form a first cooling air duct, and the second fan 22 introduces airflow to cool the circuit board 3 and form a second cooling air duct. The first cooling air duct and the second cooling air duct are independent and isolated from each other, which is conducive to increasing the airflow through each air duct and preventing the airflow in the cooling air duct from flowing in series or splitting, thereby enhancing the cooling effect on the motor 2 and the circuit board 3, and further enhancing the service life of the electric tool 100. In addition, the airflow introduced by the first fan 21 and the second fan 22 in this embodiment is in opposite directions, and the first fan 21 and the second fan 22 are adjacent to their respective air outlets, thereby increasing the airflow through rate of their respective cooling air ducts and further enhancing the cooling effect.

[0038] Please refer to Figure 5 As shown, a second embodiment of the present invention is shown. Compared with the first embodiment, only the second accommodating portion 13' and the second cooling air duct are changed. In the second embodiment, the wind shield ring 16 in the first embodiment is cancelled, the second air inlet 13a in the first embodiment is changed into a second air outlet 13a', and a second air inlet 17b' is arranged in the middle of the cover plate 17'.

[0039] The second accommodation portion 13 ′ and the second cooling air duct in the second embodiment are further described below. The second accommodation portion 13 ′ has a second air inlet 17 b ′ at the right end and a second air outlet 13 a ′ at the left end.

[0040] The second accommodating portion 13' includes a cover plate 17' located at the right end of the first accommodating portion 19a, and the cover plate 17' and the right side wall of the first accommodating portion 19a are surrounded by an internal cavity 17c', and the internal cavity 17c' accommodates the second fan 22. The right end periphery of the cover plate 17' is provided with a first air inlet 17a', and the second air inlet 17b' is located in the middle of the right end of the cover plate 17'. The cover plate 17' is provided with an external cavity 17d' located at its periphery and an inner ring wall isolating the external cavity 17d' from the internal cavity 17c', the first air inlet 17a' is in communication with the external cavity 17d', and the second air inlet 17b' is in communication with the internal cavity 17c'. The second accommodating portion 13' also has a pipe 19b' extending along the outer wall of the first accommodating portion 19a and integrally formed with the first accommodating portion 19a. The pipe 19b' is parallel to the first accommodating portion 19a. The pipe 19b', the internal cavity 17c', and the accommodating cavity 13b' are connected to form the second cooling air duct. The second fan 22 introduces air flow into the second cooling air duct from the second air inlet 17b', and the air flows through the circuit board 3 and then is discharged from the second accommodating portion 13' through the second air outlet 13a'.

[0041] The electric tool 100 of the second embodiment of the present invention is configured by respectively installing a first fan 21 and a second fan 22 at the axial ends of the motor 2. The first fan 21 introduces airflow to cool the motor and form a first cooling air duct. The second fan 22 introduces airflow to cool the circuit board 3 and form a second cooling air duct. The first cooling air duct and the second cooling air duct are independent and isolated from each other, which is beneficial to increasing the airflow rate in each air duct and preventing the airflow in the cooling air duct from flowing in series or being diverted, thereby enhancing the cooling effect on the motor 2 and the circuit board 3, and thereby improving the service life of the electric tool 100.

[0042] The present invention is not limited to the above-mentioned specific implementation modes, and the protection scope of the present invention shall be subject to the contents of the claims.

Claims

1. An electric tool, comprising: A housing and a motor and a circuit board contained in the housing, wherein the housing is provided with a plurality of air inlets and a plurality of air outlets, and the circuit board is electrically connected to the motor and drives the motor to operate; characterized in that: a first fan and a second fan are respectively installed at both axial ends of the motor, and the first and second fans are driven to rotate, the first fan introduces airflow from an air inlet, and discharges airflow from an air outlet after passing through the motor to form a first cooling air duct; the second fan introduces airflow from another air inlet, and discharges airflow from another air outlet after passing through the circuit board to form a second cooling air duct, and the first cooling air duct and the second cooling air duct are independent and isolated from each other; The housing has a first accommodating portion for accommodating the motor and a second accommodating portion for accommodating the circuit board, the first cooling air duct flows through the first accommodating portion, and the second cooling air duct flows through the second accommodating portion; The second accommodating portion further includes a wind shield ring located on the right side of the motor and a cover plate abutting against the right end of the wind shield ring. The cover plate and the wind shield ring surround an internal cavity, and the internal cavity accommodates the second fan.

2. The electric tool according to claim 1, characterized in that: The air inlet includes a first air inlet communicating with the first accommodating portion and a second air inlet communicating with the second accommodating portion, and the air outlet includes a first air outlet communicating with the first accommodating portion and a second air outlet communicating with the second accommodating portion; the airflow of the first cooling air duct flows into the first accommodating portion through the first air inlet, flows through the motor in the first accommodating portion, and is discharged from the first accommodating portion through the first air outlet; the airflow of the second cooling air duct flows into the second accommodating portion through the second air inlet, flows through the circuit board in the second accommodating portion, and is discharged from the second accommodating portion through the second air outlet.

3. The electric tool according to claim 2, characterized in that: The inner cavity has a notch in the radial direction of the second fan, and the notch constitutes the second air outlet.

4. The electric tool according to claim 3, characterized in that: The second accommodating portion also has a pipe extending along the outer side wall of the first accommodating portion and integrally formed with the first accommodating portion, the pipe and the internal cavity are connected to each other to form the second cooling air duct, and the first air inlet is arranged on the outer circle of the right end of the cover plate.

5. The electric tool according to claim 4, characterized in that: An external cavity is arranged around the outer periphery of the wind shield ring and the cover plate. Both the wind shield ring and the cover plate are provided with an inner ring wall isolating the internal cavity from the external cavity. The external cavity and the first accommodating portion form the first cooling air duct.

6. The electric tool according to claim 5, characterized in that: The second fan is a discrete fan, and the second air outlet is arranged below the internal cavity and is inclined toward the rotation direction of the discrete fan.

7. An electric tool comprising: A housing and a motor and a circuit board contained in the housing, wherein the housing is provided with a plurality of air inlets and a plurality of air outlets, and the circuit board is electrically connected to the motor and drives the motor to operate; characterized in that: a first fan and a second fan are respectively installed at both axial ends of the motor, and the first and second fans are driven to rotate, the first fan introduces airflow from an air inlet, and discharges airflow from an air outlet after passing through the motor to form a first cooling air duct; the second fan introduces airflow from another air inlet, and discharges airflow from another air outlet after passing through the circuit board to form a second cooling air duct, and the first cooling air duct and the second cooling air duct are independent and isolated from each other; The housing has a first accommodating portion for accommodating the motor and a second accommodating portion for accommodating the circuit board, the first cooling air duct flows through the first accommodating portion, and the second cooling air duct flows through the second accommodating portion; The second accommodating portion further includes a cover plate located at the right end of the first accommodating portion, and the cover plate and the right side wall of the first accommodating portion are surrounded by an internal cavity, and the internal cavity accommodates the second fan.

8. The electric tool according to claim 7, characterized in that: The air inlet includes a first air inlet communicating with the first accommodating portion and a second air inlet communicating with the second accommodating portion, and the air outlet includes a first air outlet communicating with the first accommodating portion and a second air outlet communicating with the second accommodating portion; the airflow of the first cooling air duct flows into the first accommodating portion through the first air inlet, flows through the motor in the first accommodating portion, and is discharged from the first accommodating portion through the first air outlet; the airflow of the second cooling air duct flows into the second accommodating portion through the second air inlet, flows through the circuit board in the second accommodating portion, and is discharged from the second accommodating portion through the second air outlet.

9. The electric tool according to claim 8, characterized in that: The second accommodation portion further has a pipe extending along the outer side wall of the first accommodation portion and integrally formed with the first accommodation portion, and the pipe is connected with the internal cavity to form the second cooling air duct.

10. The electric tool according to claim 9, characterized in that: The cover plate is provided with an external cavity located at the outer periphery of the cover plate and an inner annular wall isolating the external cavity from the internal cavity; the first air inlet is arranged at the outer periphery of the cover plate and communicates with the external cavity; the second air inlet is located in the middle of the cover plate and communicates with the internal cavity; the external cavity and the first accommodating portion form the first cooling air duct.

11. The electric tool according to claim 7, characterized in that: The electric tool is an electric circular saw, which comprises a bottom plate, and the housing is connected to the bottom plate.

12. The electric tool according to claim 8, characterized in that: The airflow direction in the first accommodation portion and the airflow direction in the second accommodation portion are at least partially parallel to each other.

Images