Power tool

Abstract

The utility model discloses an electric tool, including casing, motor, air guide ring and fan, the casing has first end and second end in its axial direction, is equipped with the air outlet of close first end and the intercommunication inside thereof on the casing, and the air inlet of close second end and the intercommunication inside thereof, the motor is located between the air inlet and the air outlet in the casing, and the air duct is formed between the motor and the casing, the air guide ring is located in the motor close air outlet one side in the casing, and the air guide ring includes the air inlet section and the air outlet section that set in proper order, and the air inlet section is partially overlapped with the motor in the axial direction, and is annularly arranged in the motor periphery in the radial direction, and the air inlet section is communicated with the air duct, and the air outlet section is communicated with the air outlet, the fan is located in the air outlet section, so not only can improve the utilization rate of cold air flow, but also can enhance the heat dissipation efficiency through optimizing the airflow path, improve cooling effect.

Description

Technical Field

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

[0002] Power tools typically consist of a housing, a motor assembly housed within the housing, and a working head driven by the motor assembly. Taking a grooving machine as an example, a cutting disc or other tool head is mounted at the output end of the motor assembly. When the tool head is driven to rotate by the motor assembly, it can perform operations such as grooving and grinding. During operation, the internal power module of the grooving machine generates heat, therefore, a cooling system is usually installed inside the grooving machine. The cooling system includes an air inlet and an air outlet on the housing, and a fan located near the air outlet, which is positioned closer to the working head. An air guide ring is also installed at the air outlet, but because one end of the air guide ring abuts against the motor stator, the air guiding effect is poor, thus affecting the cooling effect. Utility Model Content

[0003] The main purpose of this utility model is to propose a power tool that aims to solve the problem that the poor effect of the air guide ring in existing power tools affects the air cooling effect.

[0004] To achieve the above objectives, this utility model proposes an electric tool, comprising:

[0005] The housing has a first end and a second end in its axial direction, and the housing is provided with an air outlet near the first end and communicating with its interior, and an air inlet near the second end and communicating with its interior.

[0006] The motor is located inside the housing and between the air inlet and the air outlet, and an air duct is formed between the motor and the housing;

[0007] An air guide ring, disposed within the housing and located on the side of the motor near the air outlet, comprises a sequentially arranged inlet section and an outlet section. The inlet section partially overlaps the motor axially and radially surrounds the motor. The inlet section communicates with the air duct, and the outlet section communicates with the air outlet.

[0008] A fan is located in the air outlet section.

[0009] Optionally, the housing includes a first housing segment and a second housing segment that are connected. The first housing segment is disposed near the first end and its inner diameter is larger than that of the second housing segment, so as to form a first stepped surface on the inner wall of the housing.

[0010] The air guide ring is housed in the first housing section, and the end of its air inlet section away from the air outlet section abuts against the first stepped surface;

[0011] The motor is partially housed in the second housing section and partially extends into the first housing section.

[0012] Optionally, the end of the air inlet section away from the air outlet section is adapted to the shape of the first stepped surface and fits tightly.

[0013] Optionally, the inner diameter of the air inlet section is smaller than the inner diameter of the air outlet section;

[0014] At the connection between the air inlet section and the air outlet section, the inner wall of the air guide ring is provided with a radially inwardly extending annular baffle.

[0015] Optionally, the inner diameter of the air inlet section is gradually reduced in the direction toward the air outlet section; and / or,

[0016] The inner diameter of the air outlet section gradually increases in the direction away from the air inlet section.

[0017] Optionally, the housing includes a hollow and connected head shell and a main shell. The head shell is used to install the working head, and the main shell houses the motor. The output shaft of the motor is disposed towards the head shell and is driven by the working head.

[0018] The air outlet includes a main air outlet located on the head shell, and the main air outlet is located near the connection between the head shell and the main shell;

[0019] The air guide ring is housed in the main shell, the air outlet section is close to the connection between the main shell and the head shell and is connected to the main air outlet, and the main air outlet is axially opposite to the air outlet section.

[0020] Optionally, the air outlet further includes a secondary air outlet located on the main housing, the secondary air outlet being located near the connection between the main housing and the head housing;

[0021] A notch is provided at a certain location in the air outlet section, the edge of the notch is attached to the inner wall of the main shell, and the notch is connected to the secondary air outlet.

[0022] Optionally, the end of the air outlet section away from the air inlet section is radially outward to form an annular convex edge, which is sandwiched at the connection between the main shell and the head shell.

[0023] Optionally, the housing includes a first housing segment and a second housing segment that are connected. The first housing segment is disposed near the first end and its outer diameter is larger than that of the second housing segment, so as to form a second stepped surface on the outer wall of the housing. The second stepped surface is inclined toward the first end.

[0024] Optionally, the central axis of the fan is arranged along the axial direction of the casing, and at least the fan blades are located within the air outlet section.

[0025] The technical solution provided by this utility model has at least the following advantages:

[0026] The power tool provided by this utility model includes a housing, a motor housed within the housing, and a guide ring. An air duct is formed between the motor and the housing. The housing has an air outlet and an air inlet located near its first and second ends, respectively. Cold air enters the air duct through the air inlet, cools the motor, and then flows out through the air outlet, thus achieving air cooling of the motor. Simultaneously, the guide ring is positioned close to the air outlet. The air inlet section of the guide ring partially overlaps with the motor axially and is radially arranged around the motor, thus connecting the air inlet section to the air duct. A fan is positioned at the air outlet section of the guide ring, and the air outlet section connects to the air outlet. In this way, when cold air enters the air inlet section of the guide ring from the air duct, the possibility of cold air diffusing outwards is reduced, forcing the cold air to concentrate and flow within the guide ring. This ensures that all the cold air is guided into the guide ring, achieving efficient airflow. This not only improves the utilization rate of the cold air but also enhances heat dissipation efficiency and improves the cooling effect by optimizing the airflow path. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the structure of an embodiment of an electric tool provided by this utility model;

[0029] Figure 2 for Figure 1 A schematic diagram of the structure of the power tool (without the head housing installed);

[0030] Figure 3 for Figure 2 The power tool is shown in a cross-sectional view along AA.

[0031] Figure 4 for Figure 3 The cross-sectional view of the power tool along AA;

[0032] Figure 5 for Figure 2 An exploded view of the structure of the power tool;

[0033] Figure 6 for Figure 2 A schematic diagram of the structure of the power tool with respect to the air guide ring;

[0034] Figure 7 for Figure 1 A schematic diagram of the structure of the power tool (with head housing installed);

[0035] Figure 8 for Figure 7 The power tool is shown in a cross-sectional view along BB.

[0036] Explanation of icon numbers:

[0037] 100 Power tool; 1 Housing; a. Head housing; b. Main housing; c. Rear housing; 11. First end; 12. Second end; 13. Air outlet; 131. Main air outlet; 132. Secondary air outlet; 14. Air inlet; 15. Air duct; 16. First housing section; 17. Second housing section; 18. First stepped surface; 19. Second stepped surface; 2 Motor; 21. Screw; 3. Air guide ring; 31. Air inlet section; 32. Air outlet section; 33. Annular partition; 34. Notch; 35. Annular protruding edge; 36. Clearance groove; 4 Fan; 5 Handle; 51. First grip; 52. Second grip; 53. Third grip; 54. Connecting part; 541. First connecting rod; 542. Second connecting rod; F1 Axial direction.

[0038] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0041] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0042] Power tools are widely used electrical equipment in construction, decoration, manufacturing, and repair. Taking a grooving machine as an example, the output end of the motor assembly of a grooving machine is equipped with a cutting disc or other tool head. When the tool head is driven to rotate by the motor assembly, it can perform operations such as grooving and grinding. During operation, the internal power module of the grooving machine generates heat, so a cooling system is usually installed inside the grooving machine. The cooling system includes an air inlet and an air outlet on the machine casing, as well as a fan located near the air outlet, which is positioned closer to the working head. An air guide ring is also installed at the air outlet, but because one end of the air guide ring abuts against the motor stator, the air guiding effect is poor, thus affecting the cooling effect.

[0043] In order to solve the above problems, this application improves the power tool 100. The power tool 100 will be described in detail below with reference to the accompanying drawings.

[0044] Please see Figures 1 to 3 The power tool 100 includes a housing 1, which comprises a head housing a, a main housing b, and a rear housing c connected in sequence. The housing 1 has a first end 11 and a second end 12 opposite to each other along its axial direction F1. The first end 11 is configured as the end of the head housing a facing away from the main housing b, and the second end 12 is configured as the end of the rear housing c facing away from the main housing b. The housing 1 is provided with an air outlet 13 near the first end 11 and communicating with its interior, and an air inlet 14 near the second end 12 and communicating with its interior.

[0045] The head housing a is used to mount the working head. Taking a grooving machine as an example, the working head can be set as a cutting disc or a grinding disc, etc. The working head is rotatably mounted on the head housing a, and the axis of rotation of the working head is arranged radially along the main housing b. The air outlet 13 includes a main air outlet 131 provided on the head housing a.

[0046] The main housing b has two ends along its axial direction F1, one of which is connected to the head housing a. The main housing b is used to house the motor assembly. The main housing b and the head housing a are internally connected. The motor 2 of the motor assembly is configured as a brushed motor or a brushless motor. The axis of the output shaft of the motor 2 is aligned with the axial direction F1 of the main housing b, and the output shaft of the motor 2 extends into the head housing a. Since the axial direction F1 of the output shaft of the motor 2 intersects with the rotation axis of the working head, a transmission assembly is usually provided to drive the output shaft of the motor 2 and the working head. The air outlet 13 includes a secondary air outlet 132 located on the main housing b.

[0047] The main housing b has two ends along its axial direction F1, with the other end connected to the rear housing c, which houses the circuit board assembly. The rear housing c is internally connected to the main housing b, and an air inlet 14 is provided on the side of the rear housing c away from the main housing b and near its end. An air duct 15 is formed inside the rear housing c, the main housing b, and the head housing a. During the operation of the power tool 100, cold air enters the air duct 15 through the air inlet 14, sequentially cooling the circuit board assembly and the motor assembly, and then flows out through the air outlet 13, thereby achieving air cooling of the motor assembly and the circuit board assembly.

[0048] Meanwhile, to improve heat dissipation efficiency, an air guide ring 3 is installed inside the casing 1, positioned close to the air outlet 13. The air guide ring 3 includes an inlet section 31 and an outlet section 32 arranged sequentially. The inlet section 31 of the air guide ring 3 partially overlaps with the motor 2 in the axial direction F1 and is arranged radially around the motor 2, thus connecting the inlet section 31 with the air duct 15. The fan 4 is located in the outlet section 32 of the air guide ring 3, and the outlet section 32 is connected to the air outlet 13. In this way, when the cold airflow enters the inlet section 31 of the air guide ring 3 from the air duct 15, the possibility of the cold airflow diffusing outwards is reduced, forcing the cold airflow to concentrate and flow within the air guide ring 3. This ensures that all the cold airflow is guided into the air guide ring 3, achieving efficient airflow. This not only improves the utilization rate of the cold airflow but also enhances heat dissipation efficiency and improves the cooling effect by optimizing the airflow path.

[0049] Continuing from the previous statement that "the air inlet section 31 partially overlaps with the motor 2 in the axial direction F1 and is arranged radially around the periphery of the motor 2," it means that the radial dimension of the air inlet section 31 of the air guide ring 3 is larger than the radial dimension of the motor 2, and part of the motor 2 extends into the air inlet section 31. For ease of installation of the air guide ring 3 and the motor 2, in one embodiment, please refer to... Figures 3 to 5 The housing 1 includes a first housing section 16 and a second housing section 17 that are connected. The first housing section 16 is located near the first end 11 and its inner diameter is larger than that of the second housing section 17, so as to form a first stepped surface 18 on the inner wall of the housing 1. The air guide ring 3 is housed in the first housing section 16, and the end of its air inlet section 31 away from the air outlet section 32 abuts against the first stepped surface 18. The motor 2 is partially housed in the second housing section 17 and partially extends into the first housing section 16.

[0050] In this embodiment, a second housing section 17 with a smaller inner diameter is used to house the motor 2, while a first housing section 16 with a larger inner diameter is used to house the air guide ring 3, making the assembly of the motor 2 and the air guide ring 3 more reasonable. Simultaneously, a first stepped surface 18 is formed on the inner wall of the housing 1, and the end of the air inlet section 31 of the air guide ring 3, away from the air outlet section 32, abuts against the first stepped surface 18, providing a limiting effect for the installation of the air guide ring 3.

[0051] Specifically, the end of the air inlet section 31 furthest from the air outlet section 32 is shaped and closely fitted to the first stepped surface 18. In this way, while the end of the air inlet section 31 is confined to the first stepped surface 18, it also seals the end of the air inlet section 31 with the inner wall of the main shell b, thereby preventing the cold air from overflowing from the junction of the air inlet section 31 and the inner wall of the main shell b when the cold air flows from the air duct 15 to the air inlet section 31, thus improving the cooling effect.

[0052] In one embodiment, please refer to Figure 6 The inner diameter of the air inlet section 31 is smaller than that of the air outlet section 32. At the connection between the air inlet section 31 and the air outlet section 32, a radially inwardly extending annular baffle 33 protrudes from the inner wall of the air guide ring 3. It can be understood that the airflow will pass through the annular baffle 33 as it flows from the air inlet section 31 to the air outlet section 32. Since the annular baffle 33 extends radially inward, the airflow will accelerate due to the sudden contraction of the inner diameter of the air guide ring when it passes through the annular baffle 33, forcing the cold airflow to concentrate and flow towards the air outlet section 32, thereby achieving efficient airflow guidance. In this way, not only can the utilization rate of the cold airflow be improved, but the heat dissipation efficiency can also be enhanced by optimizing the airflow path, thus improving the cooling effect.

[0053] Furthermore, following the previous statement that "the air inlet section 31 partially overlaps with the motor 2 in the axial direction F1 and is arranged radially around the motor 2," in order to further improve the air guiding effect, in one embodiment, the inner diameter of the air inlet section 31 is gradually reduced in the direction towards the air outlet section 32. That is, the inner diameter of the air inlet section 31 is largest at the local position where it overlaps with the motor 2, so that all the airflow in the air duct 15 can be guided into the air inlet section 31. At the same time, the inner diameter of the air inlet section 31 gradually reduces in the direction towards the air outlet section 32, thereby increasing the airflow velocity in the air inlet section 31 and forcing the airflow to concentrate and flow towards the air outlet section 32.

[0054] In one embodiment, the inner diameter of the outlet section 32 gradually increases in the direction away from the inlet section 31. As the airflow moves from the inlet section 31 to the outlet section 32, the gradually increasing inner diameter of the outlet section 32 makes the airflow smoother.

[0055] It should be noted that the above two technical features can be selected as one or both. Specifically, in one embodiment, both technical features are provided simultaneously. That is, the inner diameter of the air inlet section 31 gradually decreases in the direction towards the air outlet section 32; and the inner diameter of the air outlet section 32 gradually increases in the direction away from the air inlet section 31. The air guide ring 3 has an hourglass-shaped cross-section in its axial direction. The airflow is pressurized in the air inlet section 31, thus flowing at high speed towards the air outlet section 32; and after entering the air outlet section 32, it can be quickly discharged. In this way, rapid airflow guidance and discharge can be achieved, thereby making the airflow smoother.

[0056] Following the previous statement that "the housing 1 is provided with an air outlet 13 near the first end 11 and connected to its interior," when the cold airflow in the air duct 15 passes through the air inlet section 31 of the air guide ring 3 and all flows into the air outlet section 32, in order to ensure smooth airflow, in one embodiment, please refer to... Figures 7 to 8 The housing 1 includes a hollow and interconnected head shell a and a main shell b. The head shell a is used to install the working head, and the main shell b houses the motor 2. The output shaft of the motor 2 faces the head shell a and drives the working head. The air outlet 13 includes a main air outlet 131 located on the head shell a, near the connection between the head shell a and the main shell b. The air guide ring 3 is housed in the main shell b, and the air outlet section 32 is located near the connection between the main shell b and the head shell a and communicates with the main air outlet 131. The main air outlet 131 is axially opposite to the air outlet section 32. In this way, after the airflow flows out from the air outlet section 32, it can quickly and autonomously exit through the air outlet 131, thereby allowing the airflow to be quickly discharged from the housing 1.

[0057] The air outlet 13 also includes a secondary air outlet 132 located on the main housing b, near the connection between the main housing b and the head housing a. A notch 34 is provided in a localized area of ​​the air outlet section 32, with the edge of the notch 34 abutting against the inner wall of the main housing b, and the notch 34 connecting with the secondary air outlet 132. Thus, when the airflow flows towards the outlet of the air outlet section 32, a portion of the airflow will flow through the notch 34 to the secondary air outlet 132 for preferential discharge, which not only reduces the airflow pressure at the main air outlet 131 but also further accelerates the discharge of airflow from the housing 1.

[0058] In summary, in this embodiment, the air outlet 13 includes a main air outlet 131 and a secondary air outlet 132. The main air outlet 131 is located on the head shell a and near the connection between the head shell a and the main shell b. The outlet of the air outlet section 32 of the air guide ring 3 is opposite to and connected to the main air outlet 131. Meanwhile, the secondary air outlet 132 is located on the main shell b and near the connection between the head shell a and the main shell b. A notch 34 is provided in a local position of the air outlet section 32, and the notch 34 is connected to the secondary air outlet 132.

[0059] When the airflow enters the air outlet section 32, part of the airflow flows out through the gap 34 from the secondary air outlet 132, and part of the airflow flows out from the main air outlet 131 on the head shell a. In this way, the airflow can be discharged smoothly, thereby ensuring that the power tool 100 is cooled smoothly.

[0060] Furthermore, in one embodiment, the central axis of the fan 4 is arranged along the axial direction F1 of the housing 1, and at least the fan blades of the fan 4 are located within the air outlet section 32. The airflow generated by the rotation of the fan blades is rectified by the air outlet section 32. When the fan 4 is running, it guides the external cold airflow from the air inlet 14 into the air duct 15 and cools the motor 2. After flowing through the air duct 15, the hot airflow, after heat exchange, is rectified by the air outlet section 32 and flows out through the main air outlet 131 and the secondary air outlet 132, thus achieving better air cooling of the power tool 100.

[0061] Based on the above air outlet positions, it is easy to see that both the main air outlet 131 and the secondary air outlet 132 are located near the connection between the head shell a and the main shell b. In other words, the end of the air outlet section 32 furthest from the air inlet section 31 is located near the connection between the head shell a and the main shell b. For ease of assembly of the air guide ring 3, in one embodiment, please refer to... Figure 8 The end of the air outlet section 32, which is far from the air inlet section 31, is radially outward to form an annular protrusion 35, which is sandwiched at the connection between the main shell b and the head shell a.

[0062] In this embodiment, the end of the air outlet section 32 away from the air inlet section 31 is provided at the connection between the head shell a and the main shell b, and the end is turned outward to form an annular protrusion 35. When the main shell b and the head shell a are connected, the annular protrusion 35 is clamped at the connection between the main shell b and the head shell a. In this way, the air guide ring 3 is assembled without the need to design other installation structures. The structure is simple and the assembly is convenient.

[0063] During the assembly of the air guide ring 3, the air inlet section 31 overlaps with the motor 2. In order to ensure that the air guide ring 3 is properly assembled, the air inlet section 31 is provided with a clearance groove 36 at the end away from the air outlet section 32 to avoid the mounting screws 21 on the motor 2.

[0064] In some applications, when using power tool 100 as an angle grinder, please refer to [the relevant documentation / reference]. Figure 7 and Figure 8 The housing 1 includes a first housing segment 16 and a second housing segment 17 that are connected. The first housing segment 16 is disposed near the first end 11 and its outer diameter is larger than that of the second housing segment 17, so as to form a second stepped surface 19 on the outer wall of the housing 1. The second stepped surface 19 is inclined toward the first end 11.

[0065] In other words, the housing 1 includes a first housing segment 16 with a larger outer diameter and a second housing segment 17 with a smaller outer diameter, and a second stepped surface 19 is formed at the connection between the first housing segment 16 and the second housing segment 17. At this time, the user can hold the second housing segment 17 and the web of the hand can press against the second stepped surface 19, which makes it convenient for the user to hold and operate.

[0066] In other application scenarios, when the power tool 100 is used as a grooving machine, please refer to [the relevant documentation] for ease of user operation. Figure 1 Typically, a handle 5 is also provided on the housing 1. The handle 5 has a first grip portion 51 for the user to hold, and a grip gap is formed between the first grip portion 51 and the housing 1 to accommodate the hand. One end of the first grip portion 51 is connected to the rear shell c, and the other end is bent along the axis F1 of the housing 1 and extends toward the head shell a.

[0067] Meanwhile, the handle 5 also has a second grip portion 52 and a connecting portion 54 provided on the head shell a. The second grip portion 52 extends radially along the housing 1. The connecting portion 54 includes a first connecting rod 541 and a second connecting rod 542. The first connecting rod 541 extends axially along the housing 1 for F1 and connects the second grip portion 52 and the other end of the first grip portion 51. The second connecting rod 542 extends radially along the housing 1 and connects the first connecting rod 541 and the rear shell c respectively.

[0068] Furthermore, the handle 5 also has a third grip portion 53 located on the rear shell c. The third grip portion 53 is located at the end of the rear shell c away from the main shell b, and one end of the first grip portion 51 is connected to the rear shell c through the third grip portion 53.

[0069] The extension axis of the first gripping part 51, the extension axis of the second gripping part 52, and the output axis of the motor 2 assembly are arranged in a coplanar manner, which makes it easy for the operator to apply a pushing force along the axis direction. The direction of the applied force is consistent with the direction of the tool movement, the operating force is directly transmitted, the offset error is reduced, and the straightness of the grooving is ensured.

[0070] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the concept of the present utility model and using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A power tool, characterized in that, include: The housing has a first end and a second end in its axial direction, and the housing is provided with an air outlet near the first end and communicating with its interior, and an air inlet near the second end and communicating with its interior. The motor is located inside the housing and between the air inlet and the air outlet, and an air duct is formed between the motor and the housing; An air guide ring, disposed within the housing and located on the side of the motor near the air outlet, comprises a sequentially arranged inlet section and an outlet section. The inlet section partially overlaps the motor axially and radially surrounds the motor. The inlet section communicates with the air duct, and the outlet section communicates with the air outlet. A fan is located in the air outlet section.

2. The power tool according to claim 1, characterized in that, The housing includes a first housing segment and a second housing segment that are connected. The first housing segment is disposed near the first end and its inner diameter is larger than that of the second housing segment, so as to form a first stepped surface on the inner wall of the housing. The air guide ring is housed in the first housing section, and the end of its air inlet section away from the air outlet section abuts against the first stepped surface; The motor is partially housed in the second housing section and partially extends into the first housing section.

3. The power tool according to claim 2, characterized in that, The end of the air inlet section away from the air outlet section is adapted to the shape of the first stepped surface and fits tightly.

4. The power tool according to claim 1, characterized in that, The inner diameter of the air inlet section is smaller than the inner diameter of the air outlet section; At the connection between the air inlet section and the air outlet section, the inner wall of the air guide ring is provided with a radially inwardly extending annular baffle.

5. The power tool according to claim 1, characterized in that, The inner diameter of the air inlet section gradually decreases in the direction toward the air outlet section; and / or, The inner diameter of the air outlet section gradually increases in the direction away from the air inlet section.

6. The power tool according to claim 1, characterized in that, The housing includes a hollow and connected head shell and a main shell. The head shell is used to install the working head, and the main shell houses the motor. The output shaft of the motor is oriented toward the head shell and is connected to the working head for driving. The air outlet includes a main air outlet located on the head shell, and the main air outlet is located near the connection between the head shell and the main shell; The air guide ring is housed in the main shell, the air outlet section is close to the connection between the main shell and the head shell and is connected to the main air outlet, and the main air outlet is axially opposite to the air outlet section.

7. The power tool according to claim 6, characterized in that, The air outlet also includes a secondary air outlet located on the main shell, which is located near the connection between the main shell and the head shell. A notch is provided at a certain location in the air outlet section, the edge of the notch is attached to the inner wall of the main shell, and the notch is connected to the secondary air outlet.

8. The power tool according to claim 6, characterized in that, The end of the air outlet section away from the air inlet section is radially outward to form an annular convex edge, which is sandwiched at the connection between the main shell and the head shell.

9. The power tool according to claim 1, characterized in that, The housing includes a first housing segment and a second housing segment that are connected. The first housing segment is disposed near the first end and its outer diameter is larger than that of the second housing segment, so as to form a second stepped surface on the outer wall of the housing. The second stepped surface is inclined toward the first end.

10. The power tool according to claim 1, characterized in that, The central axis of the fan is arranged along the axial direction of the casing, and at least the fan blades are located within the air outlet section.

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