Cutting tool and hand-held tool

Abstract

The cutting tool comprises a trunk assembly and a head assembly, the head assembly comprises a motor, a second shell containing the motor, an output shaft used for installing a cutting piece and a transmission assembly, and the transmission assembly is connected between a motor shaft and the output shaft and used for transmitting driving force of the motor to the output shaft. The cutting tool further comprises a third shell which at least contains part of the transmission assembly, and in the process that the cutting piece cuts the workpiece, the third shell and the workpiece are provided with a first contact face and a second contact face. Under the condition that the first contact surface and the second contact surface are in contact with the workpiece, the cutting piece has the maximum cutting depth; the included angle between the first contact face and the second contact face is larger than or equal to 50 degrees and smaller than or equal to 85 degrees, and the maximum cutting depth is larger than or equal to 20 mm. Through the arrangement, when a user using the left hand and the right hand or cutting at different cutting angles, the same maximum cutting depth can be achieved, the cutting angle is maintained in a proper range, and the use experience of the user is optimized.

Description

Technical Field

[0001] This application relates to the technical field of power tools, and particularly to a cutting tool and a handheld tool. Background Art

[0002] Power tools are mechanical tools powered by an electric motor or an electromagnet, and drive a working head through a transmission mechanism. They can be held and operated by hand, with a small-power electric motor or an electromagnet as the power source, and drive the working head of the operation through a transmission mechanism. In order to facilitate use even in relatively dim light, existing power tools are generally provided with a lighting device.

[0003] For cutting tools such as angle grinders and cutters, in order to prevent debris, wooden boards or weeds from flying around during grinding or cutting, the working head accessories, such as grinding wheels, saw blades, and cutting discs, from breaking for some reason, and to prevent users from being accidentally injured by the saw blade, a cutting guard is usually provided.

[0004] When a cutting tool cuts a workpiece, the maximum cutting depth it can reach is limited. During the cutting process, when cutting parts such as cutting discs gradually approach the workpiece and cut deeper and deeper, structures such as the outer shell and cutting guard of the cutting tool will eventually fit against the workpiece and cannot continue to cut deeper, so that the cutting parts reach the maximum cutting depth. Therefore, the shape design of the cutting tool affects the maximum cutting depth it can reach. In addition, the shape design of the cutting tool also affects the range of cutting angles. From the user's perspective, it is often desirable for the cutting tool to achieve both a relatively large cutting depth and a relatively large cutting angle.

[0005] During the use of some cutting tools, only when the cutting guard is adjusted to the extreme positions at both ends can the user cut the cutting disc to the maximum cutting depth. When the cutting guard is in other positions, even if the cutting tool penetrates until the outer shell and the like abut against the workpiece, the maximum cutting depth of the cutting tool cannot be reached. Summary of the Utility Model

[0006] An object of this application is to solve or at least mitigate part or all of the above problems. To this end, an object of this application is to provide a cutting tool or a handheld tool.

[0007] With the above concept, the technical solution adopted in this application is as follows:

[0008] A cutting tool, comprising: a torso assembly, at least including a first housing for hand gripping; a head assembly, including: a motor; a second housing configured to accommodate the motor; an output shaft configured to mount a cutting member for cutting a workpiece; a transmission assembly connected between the motor shaft and the output shaft to transmit the driving force of the motor to the output shaft; characterized in that it further includes: a third housing that at least accommodates part of the transmission assembly, and during the process of the cutting member cutting the workpiece, the third housing has a first contact surface and a second contact surface with the workpiece; when the first contact surface and the second contact surface are in contact with the workpiece, the cutting member has a maximum cutting depth; the included angle range between the first contact surface and the second contact surface is greater than or equal to 50 degrees and less than or equal to 85 degrees, and the maximum cutting depth is greater than or equal to 20 mm.

[0009] In one embodiment, the second housing and the third housing are fixed by screws.

[0010] In one embodiment, it further includes a battery pack for powering the cutting tool, and the rated voltage of the battery pack is greater than or equal to 8V.

[0011] In one embodiment, the output power of the motor is greater than or equal to 250W.

[0012] In one embodiment, it further includes a head adjustment assembly disposed on the first housing and / or the second housing; when the head adjustment assembly is operated, the head assembly can rotate relative to the torso assembly.

[0013] In one embodiment, it further includes a main switch disposed on the first housing; when the head adjustment assembly is operated, the main switch is restricted from being operated.

[0014] In one embodiment, it further includes a cutting guard and a guard accessory, the cutting guard covers the cutting member in the radial direction and can rotate around the output shaft; the guard accessory is detachably mounted on the cutting guard; at least one dust suction pipe is detachably mounted on the guard accessory.

[0015] In one embodiment, it further includes a third contact surface, and when the third contact surface is in contact with the workpiece, the cutting member has a maximum cutting depth.

[0016] In one embodiment, when observed in a plane perpendicular to the output shaft, the projection of the third contact surface on the plane is located between the projection of the first contact surface on the plane and the projection of the second contact surface on the plane.

[0017] In one embodiment, it further includes a cutting guard that covers the cutting member in the radial direction and can rotate around the output shaft; the third contact surface is disposed on the cutting guard or the third housing.

[0018] A handheld tool, comprising: a torso assembly including at least a first housing for hand gripping; a head assembly including: a motor; a second housing configured to accommodate the motor; an output shaft configured to mount a cutting member for cutting a workpiece; a transmission assembly accommodated in a third housing and connected between the motor shaft and the output shaft to transmit the driving force of the motor to the output shaft; and further including a cutting guard that covers the cutting member in the radial direction and is rotatable relative to the second housing about the output shaft; the cutting guard is adjustable between a first extreme position and a second extreme position, the first extreme position and the second extreme position being two extreme positions that the cutting guard can reach by rotating in opposite directions about the output shaft; when the cutting guard is in the first extreme position, the third housing has a first contact surface with the workpiece, and when the cutting guard is in the second extreme position, the third housing has a second contact surface with the workpiece; a third contact surface is provided on the third housing, and when the third contact surface contacts the workpiece, the cutting member can reach its maximum cutting depth, and the third contact surface is provided as an arc surface with a fixed radius of curvature, and the radius of curvature is greater than or equal to 13 mm.

[0019] In one embodiment, when observed in a plane perpendicular to the output shaft, the projection of the third contact surface on the plane is located between the projection of the first contact surface on the plane and the projection of the second contact surface on the plane.

[0020] In one embodiment, when observed in a plane perpendicular to the output shaft, the first contact surface is tangent to the third contact surface, and the second contact surface is tangent to the third contact surface.

[0021] In one embodiment, the projection of the cutting guard in the direction perpendicular to the output shaft has a first guard edge and a second guard edge; when the cutting guard is in the first extreme position, the first guard edge is substantially parallel to the first contact surface; when the cutting guard is in the second extreme position, the second guard edge is substantially parallel to the second contact surface.

[0022] Advantages of the present application:

[0023] For the cutting tool and the handheld tool proposed in the present application, by providing the third housing and the first contact surface and the second contact surface provided on the third housing, the cutting angle is limited to be greater than or equal to 95 degrees, and at the same time, the cutting depth achieved is greater than or equal to 20 mm. With such a setting, whether the user uses it with the left hand or the right hand, or cuts at different cutting angles, the same maximum cutting depth can be achieved, and the cutting angle is also maintained within a suitable range, optimizing the user experience. Description of the Drawings

[0024] Figure 1 is a schematic diagram of the cutting tool provided by the present application;

[0025] Figure 2 is Figure 1 the internal structure schematic diagram of the cutting tool provided

[0026] Figure 3 is Figure 1 The top view of the cutting power tool provided;

[0027] Figure 4 is Figure 1 The partial exploded view of the head component in;

[0028] Figure 5a is Figure 1 The side view when the cutting guard in is adjusted to the first extreme position;

[0029] Figure 5b is Figure 1 The side view when the cutting guard in is adjusted to the middle position;

[0030] Figure 5c is Figure 1 The side view when the cutting guard in is adjusted to the second extreme position;

[0031] Figure 6 is Figure 1 The bottom view of the partial structure in;

[0032] Figure 7 is Figure 1 The partial enlarged schematic diagram of the head component and the cutting guard of;

[0033] Figure 8 is Figure 1 The schematic diagram of the regulation component of;

[0034] Figure 9 is Figure 1 The schematic diagram of the internal structure of the torso component of;

[0035] Figure 10 is Figure 1 The schematic diagram of the torso component from another perspective of;

[0036] Figure 11 is Figure 1 The schematic diagram of the cutting tool from another perspective of;

[0037] Figure 12 is Figure 11 The cross-sectional view of the installation of the guard attachment and the dust suction pipe of; Detailed implementation manners

[0038] Before explaining in detail any implementation manner of the present application, it should be understood that the present application is not limited to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0039] In this application, the terms "comprise", "include", "have" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element.

[0040] In this application, the term "and / or" describes an associative relationship between associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "and / or" relationship.

[0041] In this application, the terms "connect", "combine", "couple", "mount" may be direct connections, combinations, couplings or mountings, or may be indirect connections, combinations, couplings or mountings. Among them, by way of example, a direct connection means that two parts or components are connected together without the need for an intermediate member, and an indirect connection means that two parts or components are respectively connected to at least one intermediate member, and these two parts or components are connected through the intermediate member. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings and may include electrical connections or couplings.

[0042] In this application, those of ordinary skill in the art will understand that relative terms used in connection with a quantity or condition (e.g., "about", "approximately", "substantially", etc.) are intended to include the stated value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances resulting from manufacturing, assembly, use, etc. associated with a particular value. Such terms should also be considered to disclose a range defined by the absolute values of two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values not using relative terms should also be disclosed as having tolerances. In addition, "substantially" when expressing a relative angular positional relationship (e.g., substantially parallel, substantially perpendicular) may refer to plus or minus a certain number of degrees (e.g., 1 degree, 5 degrees, 10 degrees or more) from the indicated angle.

[0043] In this application, those of ordinary skill in the art will understand that functions performed by a component may be performed by one component, multiple components, one part, or multiple parts. Similarly, functions performed by a part may also be performed by one part, one component, or a combination of multiple parts.

[0044] In this application, the orientation terms such as "upper", "lower", "left", "right", "front", and "rear" are described based on the orientation and positional relationship shown in the drawings, and should not be construed as a limitation on the embodiments of this application. In addition, in the context, it should also be understood that when it is mentioned that one component is connected "above" or "below" another component, it can not only be directly connected "above" or "below" another component, but also be indirectly connected "above" or "below" another component through an intermediate component. It should also be understood that the orientation terms such as the upper side, lower side, left side, right side, front side, and rear side not only represent the positive orientation, but can also be understood as the side orientation. For example, the lower side can include directly below, lower left, lower right, lower front, and lower rear, etc.

[0045] In this application, the terms "controller", "processor", "central processing unit", "CPU", and "MCU" can be used interchangeably. When using the units "controller", "processor", "central processing unit", "CPU", or "MCU" to perform specific functions, unless otherwise specified, these functions can be performed by a single one of the above units or multiple of the above units.

[0046] In this application, the terms "device", "module", or "unit" can be implemented in the form of hardware or software in order to achieve specific functions.

[0047] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or a similar electronic computing device (such as a controller, a processor, etc.).

[0048] This application provides a cutting tool 100 or a hand-held tool, specifically, it can be an angle grinder or an angle cutter, and can be equipped with different grinding wheels and cutting discs, and is suitable for grinding and cutting different materials such as steel, plastic, wood, and ceramic tiles.

[0049] As Figures 1 to 3 shown, the cutting tool 100 includes a torso assembly 10 and a head assembly 20. The torso assembly 10 includes a first housing 111 for holding by hand. That is to say, the first housing 111 forms a holding portion 1111 for the user to hold. The head assembly 20 includes a motor 12, a guard 20, a second housing 112, a third housing 113, an output shaft 163, and a transmission assembly 16. The motor 12 is accommodated in the second housing 112, and the motor 12 includes a motor shaft that rotates around the second axis 102. The first housing 111 and the second housing 112 are arranged in sequence from front to back.

[0050] The cutting tool 100 can be powered by the battery pack 40 or mains power. In this embodiment, the first housing 111 extends along the front-rear direction of the cutting tool 100. One end of the first housing 111 is connected to the second housing 112, and the other end forms or is connected to a battery pack coupling portion 13 for mounting the battery pack 40.

[0051] It should be noted that Figure 2 it is only a schematic diagram of the transmission assembly 16 of the cutting tool 100, Figure 2 and the housing accommodating the motor 12 and the transmission assembly 16 in Figure 2 is also only a schematic diagram. Specifically, the first housing 111, the second housing 112 and the third housing 113 need to refer to the parts indicated by reference numerals in other drawings except

[0052] The output shaft 163 is arranged for mounting a cutting member for cutting a workpiece. The cutting member can be a grinding disc or a saw blade, etc. It can be understood that the cutting member is detachable and can be replaced according to actual needs. The motor 12 can drive the cutting member to rotate around the first axis 101 for operation. In this embodiment, the first axis 101 and the second axis 102 are substantially parallel. The distance between the first axis 101 and the second axis 102 can be greater than or equal to 10.5 mm and less than or equal to 15.8 mm. In this embodiment, the distance between the first axis 101 and the second axis 102 is about 13.21 mm.

[0053] The transmission assembly 16 is connected between the motor shaft and the output shaft 163 and transmits the driving force of the motor 12 to the output shaft 163. In this embodiment, the transmission assembly 16 includes gears, and at least part of the gears are arranged in the third housing 113. The transmission assembly 16 includes a driving gear 161 and a driven gear 162. The driving gear 161 is arranged on the motor shaft, the driven gear 162 is arranged on the output shaft 163, and the driving gear 161 meshes with the driven gear 162. The transmission assembly 16 transmits the speed and torque of the motor 12 to the output shaft 163, and the transmission assembly 16 can reduce the speed of the motor 12 and then transmit it to the output shaft 163.

[0054] The third housing 113 houses at least part of the transmission assembly 16. In this embodiment, compared with the second housing 112, more of the transmission assembly 16 is housed in the third housing 113. That is to say, a part of the transmission assembly 16 is housed in the second housing 112, and the other part is housed in the third housing 113. The second housing 112 and the third housing 113 are combined to form an integral body that houses structures such as the motor 12 and the transmission assembly 16 of the cutting tool 100. When the cutting tool 100 performs a cutting operation, the third housing 113 is in direct contact with the workpiece, forming a contact surface. The integral body formed by the first housing 111, the second housing 112, and the third housing 113 is referred to as the main housing 11. In this application, the "workpiece" always refers to the workpiece being cut by the cutting tool 100.

[0055] The cutting guard 21 is mounted to the third housing 113. When the cutting tool 100 performs a cutting operation, the cutting guard 21 covers at least part of the cutting member, so that the debris generated by the cutting member during the cutting operation can be blocked by the cutting guard 21. The cutting guard 21 covers the cutting member in the radial direction and can rotate around the output shaft 163. The cutting guard 21 can rotate relative to the main housing 11 around the first axis 101, facilitating the adjustment of the position of the cutting guard 21 according to requirements, and can play a good role in blocking debris.

[0056] The cutting tool 100 further includes a main switch 14 and a circuit board. The main switch 14 is used to control the start and stop of the motor 12. In one embodiment, the circuit board is disposed in the first housing 111, the motor 12 is connected to the circuit board through the main switch 14, and the battery pack 40 can supply power to the circuit board.

[0057] As Figure 2 shown, the head assembly 20 includes a transmission assembly 16. The center distance between the driving gear 161 and the driven gear 162 of the transmission assembly is greater than or equal to 11 mm and less than or equal to 15 mm. In one embodiment, the center distance between the driving gear 161 and the driven gear 162 can be 12 mm, 13 mm, or 14 mm. The pitch diameter of the driving gear 161 is approximately 15.16 mm, and the pitch diameter of the driven gear 162 is approximately 10.37 mm. The transmission ratio formed by the driving gear 161 and the driven gear 162 is 19:13. With such a setting, the gear structure of the transmission assembly 16 forms a smaller area in the plane perpendicular to the motor shaft. Thus, the transmission assembly 16 can be housed within the inner diameter range of the second housing 112. The boundary of the third housing 113 and the second housing 112 in the forward direction is basically flush, and the third housing 113 does not protrude from the second housing 112. The overall proportion of the machine is relatively coordinated, and the volume of the head assembly 20 is small. The maximum outer diameter T of the head assembly 20 is less than or equal to 55 mm. In some embodiments, the maximum outer diameter T of the head assembly 20 can be 48 mm, 50 mm, 52 mm, or 54 mm.

[0058] The head assembly 20 further includes an axial locking structure 17, and the axial locking structure 17 includes an axial locking button 171, an axial locking rod 172, and a first elastic member 173. When the axial locking button 171 is pushed upward, the first elastic member 173 is compressed, and the axial locking rod 172 is inserted upward into the slot of the output shaft 163, so that the output shaft 163 cannot rotate. When the axial locking button 171 is pressed again, the first elastic member 173 resumes, and the axial locking rod 172 pops out of the slot of the output shaft 163.

[0059] As Figure 3 shown, the holding portion 1111 of the torso assembly 10 extends from the second housing 112 to the battery pack coupling portion 13. The holding portion 1111 has a plurality of different outer diameters. The holding portion 1111 forms a minimum first outer diameter D1 at the transitional joint with the battery pack coupling portion 13, and the first outer diameter D1 is less than or equal to 40 mm. In some embodiments, the first outer diameter D1 may be 35 mm, 36 mm, 37 mm, 38 mm, or 39 mm. In this embodiment, the area where the first outer diameter D1 is located is the farthest point of the user-holdable area. The holding portion 1111 forms a second outer diameter D2 at the midpoint in the front-rear direction, and the second outer diameter D2 is located at the geometric center of the entire holding area in the front-rear direction. The second outer diameter D2 may be approximately 41 mm, 43 mm, or 45 mm. In this embodiment, the holding area outside the main switch 14 is the part with the largest outer diameter on the holding portion 1111. The outer diameter of the holding area outside the main switch 14 is the third outer diameter D3, and the third outer diameter D3 is less than or equal to 50 mm. In some embodiments, the third outer diameter D3 is approximately 42 mm, 44 mm, 46 mm, or 48 mm.

[0060] The ratio of the maximum outer diameter T of the head assembly 20 to the second outer diameter D2 of the holding portion 1111 is greater than or equal to 1.05 and less than or equal to 1.37. In one embodiment, the ratio of the maximum outer diameter T to the second outer diameter D2 is greater than or equal to 1.1 and less than or equal to 1.3. In some embodiments, the ratio of the maximum outer diameter T to the second outer diameter D2 is approximately 1.19.

[0061] As Figure 4As shown, the second housing 112 includes an upper housing 1121 and a lower housing 1122, and the upper housing 1121 and the lower housing 1122 are plugged together. The second housing 112 further includes a side housing 1123. After the upper housing 1121 and the lower housing 1122 are combined, the side housing 1123 is installed on the same side of the upper housing 1121 and the lower housing 1122, which is the left side in this embodiment. The first screw 1124 is used to fix the side housing 1123 to the upper housing 1121 and the lower housing 1122. In this embodiment, the number of the first screws 1124 is two. The driving gear 161 is accommodated in the side housing 1123. In some embodiments, the output end of the motor shaft of the motor 12 may also extend into the side housing 1123.

[0062] The third housing 113 is located on the left side of the side housing 1123. In other words, the third housing 113 is located between the cutting guard 21 and the side housing 1123. At least part of the transmission assembly 16 is accommodated in the third housing 113. The third housing 113 and the second housing 112 are fixed by screws. The third housing 113 is sealed by the second screw 1125 passing through the side housing 1123 and extending into the upper housing 1121 and the lower housing 1122. In this embodiment, the number of the second screws 1125 is two. A gasket 22 is provided on the left side of the cutting guard 21, and the third screw 1126 passes through the gasket 22 to rotatably fix the cutting guard 21 to the third housing 113. In this embodiment, the number of the third screws 1126 is three.

[0063] In this embodiment, the third housing 113 and the side housing 1123 are made of the same material, which is aluminum alloy. The upper housing 1121 and the lower housing 1122 are made of the same material, which is plastic. The accommodation space formed by the third housing 113 and the side housing 1123 jointly accommodates the transmission assembly 16, and during the cutting process, the third housing 113 may come into contact with the workpiece. In one embodiment, the material of the side housing 1123 may be the same as that of the upper housing 1121 and the lower housing 1122. There is no restriction on the materials of the respective housings.

[0064] The connection between the side housing 1123 and the upper housing 1121 and the lower housing 1122 and the connection between the third housing 113 and the side housing 1123 use a hidden design, that is, there are no screws on the circumferential outer surface of the housing along the second axis 102. Thus, the second housing 112 and the third housing 113 are complete cylindrical surfaces without externally visible screws, with a better visual effect, a simple structure and a small volume. When the head assembly 20 rotates around the third straight line 103, cutting can still be performed without being restricted by the position of the screws.

[0065] Combined Figure 4 and Figure 1As shown, the cutting assembly 100 further includes a lighting assembly 30, which includes a first lighting member 31 and a second lighting member 32 arranged vertically. The first lighting member 31 is disposed within the upper housing 1121, and the upper housing 1121 includes a first opening 311 through which the light of the first lighting member 31 emerges. The second lighting member 32 is disposed within the lower housing 1122, and the lower housing 1122 includes a second opening 321 through which the light of the second lighting member 32 emerges. The first lighting member 31 and the second lighting member 32 are symmetrically arranged along the parting surface of the upper housing 1121 and the lower housing 1122. With this arrangement, the lighting during the operation of the cutting assembly 100 can be compatible with left- and right-handed cutting, and the operating area can be illuminated regardless of the operating posture used.

[0066] When the main switch 14 is operated to power on the cutting assembly 100, the rotation of the motor 12 powers on the circuit board, and the lighting assembly 30 is lit. When the main switch 14 is operated to power off the cutting assembly 100, the lighting assembly 30 goes out after a delay compared to the stopping of the cutting member.

[0067] Continue as Figure 4 As shown, the third housing 113 has a first contact surface 1131 and a second contact surface 1132. Among them, a transition surface 1133 is further formed between the first contact surface 1131 and the second contact surface 1132, and the transition surface 1133 connects the first contact surface 1131 and the second contact surface 1132. When the user cuts a workpiece, during the process of the cutting member gradually extending into the workpiece, the first contact surface 1131 or the second contact surface 1132 gradually approaches the workpiece until contact. When the first contact surface 1131 or the second contact surface 1132 contacts the surface of the workpiece to be cut, the cutting tool 100 reaches the maximum cutting depth. In this embodiment, due to the size of the transition surface 1133 compared to the first contact surface 1131 and the second contact surface 1132, during the cutting process, the transition surface 1133 does not contact the workpiece.

[0068] In this embodiment, the first contact surface 1131 and the second contact surface 1132 are substantially flat. In other possible embodiments, the first contact surface 1131 can be arranged to be formed by at least one contact point. For example, the top of a convex structure can also form the first contact surface 1131. When the workpiece and the cutting tool 100 are in point contact, at least two contact points together form a contact plane, and this contact plane can be understood as the first contact surface 1131 in this embodiment. Similarly, the second contact surface 1132 can also be defined in this way.

[0069] Figures 5a to 5cThe schematic diagrams show the cutting guard 21 rotated to different positions. In this embodiment, the cutting guard 21 can rotate relative to the main body housing 11. The cutting guard 21 can be adjusted between a first extreme position and a second extreme position, which are the two extreme positions that the cutting guard 21 can reach by rotating around the output shaft 163 in opposite directions. When the cutting guard 21 is in the first extreme position, the third housing 113 has a first contact surface 1131 with the workpiece, and when the cutting guard 21 is in the second extreme position, the third housing 113 has a second contact surface 1132 with the workpiece.

[0070] Figure 5a is a schematic diagram of the cutting guard 21 rotated to the first extreme position. In this position, the cutting assembly 100 can cut the workpiece mainly located on its upper side. Figure 5b and Figure 1 is a schematic diagram of the cutting guard 21 rotated to an intermediate position. In this position, the cutting assembly 100 can cut the workpiece mainly located on its front side. Figure 5c is a schematic diagram of the cutting guard 21 rotated to the second extreme position. In this position, the cutting assembly 100 can cut the workpiece mainly located on its lower side. When the cutting guard 21 is adjusted between the first extreme position and the second extreme position, the user can cut the workpiece in all directions by rotating the angle of the hand relative to the workpiece.

[0071] Viewed from the left side of the cutting tool 100, the cutting guard 21 can rotate clockwise by a first angle γ1 from the intermediate position to the first extreme position, or can rotate counterclockwise by a second angle γ2 from the intermediate position to the second extreme position. In this embodiment, the first angle γ1 is 75 degrees, and the second angle γ2 is also 75 degrees. The first angle γ1 and the second angle γ2 can be the same or different. In one embodiment, both the first angle γ1 and the second angle γ2 are 60 degrees. In one embodiment, both the first angle γ1 and the second angle γ2 are 70 degrees. The larger first angle γ1 and second angle γ2 allow the user to cut when the cutting guard 21 rotates within a larger range, facilitating user operation. As Figure 5a shown, the cutting guard 21 rotates to the first extreme position and cuts. When the first contact surface 1131 contacts the workpiece, the cutting tool 100 reaches the maximum cutting depth. As Figure 5b shown, the cutting guard 21 rotates to the second cutting position and cuts. When the end face 211 of the guard and the end face 221 of the gasket gradually approach the workpiece until they contact each other, the cutting piece cuts to the deepest position. In this embodiment, since the end face 211 of the guard and the end face 221 of the gasket are part of a circle, the workpiece can contact any part of the end face 211 of the guard and the end face 221 of the gasket. As Figure 5cAs shown, the cutting shield 21 rotates to the second extreme position for cutting. When the second contact surface 1132 contacts the workpiece, the cutting tool 100 reaches the maximum cutting depth.

[0072] As Figure 5a and Figure 5c shown, the projection of the cutting shield 21 in the direction perpendicular to the output shaft 163 has a first shield edge 212 and a second shield edge 213. When the cutting shield 21 is in the first extreme position, the first edge 212 is substantially parallel to the first contact surface 1131; when the cutting shield is in the second extreme position, the second edge 213 is substantially parallel to the second contact surface 1132.

[0073] That is to say, during the process of the cutting member cutting the workpiece, the third housing 113 and the workpiece have a first contact surface 1131 and a second contact surface 1132; when the first contact surface 1131 and the second contact surface 1132 contact the workpiece, the cutting member reaches the maximum cutting depth.

[0074] Now refer to Figures 4 to 7 , the cutting shield 21 has a shield end face 211, and the shield end face 211 is set as Figure 1 the foremost side of the cutting shield 21 shown in

[0075] As Figure 7 shown, in this embodiment, the gasket 22 is also circular, and the radius of the gasket 22 is the same as the distance from the rotation center of the cutting shield 21 to the shield end face 211. When the gasket 22 is installed on the cutting shield 21, the part of the gasket 22 located at Figure 1 the foremost side shown in

[0076] is the gasket end face 221. When observed in the left-right direction of the cutting tool 100, at least part of the outer contour of the gasket 22 substantially coincides with the outer contour of the cutting shield 21. In this embodiment, the gasket end face 221 substantially coincides with the shield end face 211. In this embodiment, when the cutting member cuts to the maximum depth, the shield end face 211 and the gasket end face 221 jointly contact the workpiece. Figure 1 Figure 5b Figure 5b shown for cutting, the housing end face 1134 is the surface of the third housing 113 that is closest to the workpiece.

[0077] The cutting tool 100 has a spacer end face 221, a shield end face 211, and a housing end face 1134 in sequence from left to right along the direction of the first axis 101. A third contact surface 1135 is defined as at least one of the spacer end face 221, the shield end face 211, and the housing end face 1134. When the third contact surface 1135 contacts the workpiece, the cutting tool 100 can reach the maximum cutting depth. The third contact surface 1135 is located between the first contact surface 1131 and the second contact surface 1132. Here, "between" means that when observed in a plane perpendicular to the output shaft, the projection of the third contact surface 1135 on the plane is located between the projection of the first contact surface 1131 on the plane and the projection of the second contact surface 1132 on the plane.

[0078] The third contact surface 1135 is set as an arc surface with a fixed radius of curvature, and the radius of curvature of this arc surface is greater than or equal to 13 mm. In some embodiments, the radius of curvature of the third contact surface 1135 can be 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. Taking a saw blade with an installation diameter of 76 mm as an example, when the radius of curvature of the third contact surface 1135 is 16 mm, the maximum cutting depth is 22 mm. When observed in a plane perpendicular to the output shaft, the first contact surface 1131 is tangent to the third contact surface 1135, and the second contact surface 1132 is tangent to the third contact surface 1135 (see Figure 5b and Figure 6 ). With such a setting, when the cutting shield 21 of the cutting tool 100 rotates to any angle and the user pushes the cutting tool 100 to the deepest part of the workpiece, the maximum cutting depth obtained is the same. That is to say, when the user uses the cutting tool 100, there is no need to adjust the cutting tool 100 to a certain angle to cut the cutting blade to the deepest part, and this beneficial effect greatly improves the user experience.

[0079] In one embodiment, when the cutting shield 21 is in the middle position as shown in Figure 5b , the housing end face 1134 can contact the workpiece to cut the cutting piece to the maximum depth. That is to say, the third contact surface 1135 includes the housing end face 1134, and the shield end face 211, the spacer end face 221, and the housing end face 1134 can all touch the workpiece at the same time, and at this time the cutting tool 100 reaches the cutting depth.

[0080] In one embodiment, the third contact surface 1135 only includes the shield end face 211 and the spacer end face 221, and the housing end face 1134 cannot contact the workpiece. In this embodiment, due to the errors caused by manufacturing and installation, the housing end face 1134 is slightly lower than the shield end face 211 and the spacer end face 221.

[0081] It should be noted that in the case where the cutting shield 21 is in two extreme positions, there may be other contact surfaces in addition to the first contact surface 1131 and the second contact surface 1132. However, only when the first contact surface 1131 and the second contact surface 1132 are in contact with the workpiece, the cutting device 100 forms the maximum cutting depth.

[0082] As Figure 6 shown, a first included angle α is formed between the first contact surface 1131 and the second contact surface 1132, and the first included angle α is greater than or equal to 50 degrees and less than or equal to 85 degrees. In one embodiment, the first included angle α is greater than or equal to 60 degrees and less than or equal to 85 degrees. In some embodiments, the first included angle α can be 73 degrees, 75 degrees, 78 degrees, 80 degrees, 82 degrees, etc. The cutting angle β of the cutting tool 100 is complementary to the first included angle α. Therefore, the cutting angle β is greater than or equal to 90 degrees and less than or equal to 120 degrees. In some embodiments, the cutting angle β can be 98 degrees, 100 degrees, 102 degrees, 105 degrees, 107 degrees, etc. When the cutting angle β is within the above range, the maximum cutting depth of the cutting tool 100 reaches 22 mm. In some embodiments, the maximum cutting depth of the cutting tool 100 can be 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, etc.

[0083] The rated voltage of the battery pack 40 is greater than or equal to 8V and less than or equal to 36V. In some embodiments, the rated voltage of the battery pack 40 can be 12V, 16V, 20V, 24V, etc. The maximum output power of the battery pack 40 is greater than or equal to 250W and less than or equal to 600W. In some embodiments, the maximum output power of the battery pack 40 can be 300W, 320W, 340W, 380W, 400W, 450W, etc.

[0084] The overall weight of the cutting tool 100 refers to the total weight when the battery pack 40 is installed on the cutting tool 100, and the overall weight of the cutting tool 100 is greater than or equal to 1000g. In some embodiments, the overall weight of the cutting tool 100 can be 1100g, 1200g, or 1300g. The bare machine weight of the cutting tool 100 refers to the weight excluding only the battery pack 40, and the bare machine weight of the cutting tool 100 is greater than or equal to 700g. In some embodiments, the bare machine weight of the cutting tool 100 can be 750g, 800g, or 850g.

[0085] Define the power-to-mass ratio of the cutting tool 100 as the ratio of the output power of the battery pack 40 to the overall machine mass. The power-to-mass ratio is greater than or equal to 0.22 and less than or equal to 0.35. In some embodiments, the power-to-mass ratio is approximately 0.24, 0.26, 0.28, 0.3. The output power of the motor 12 is greater than or equal to 200W. In one embodiment, the output power of the motor 12 is greater than or equal to 250W. In some embodiments, the output power of the motor 12 can be 280W, 300W, or 330W.

[0086] Combined with Figure 3 and Figure 8 As shown, a regulation component 15 is provided at the top housing of the battery pack joint 13. The regulation component 15 is a communication channel between the user and the cutting tool 100. The user regulates parts such as the motor 12 and the cutting piece that can be regulated by the user through the regulation component 15. The regulation component 15 includes a control part 151 and a display part 152. The control part 151 includes a first control key 1511 and a second control key 1512. The first control key 1511 is used to adjust the rotation speed of the motor 12, and the second control key 1512 is used to switch the forward and reverse rotation of the output shaft 163. The display part 152 is set to display the rotation speed gear and the forward and reverse rotation information of the cutting tool 100.

[0087] Four LED lamp beads are arranged in the first row of the display part 152, respectively paired with the numbers "1", "2", "3", and "4", and two LED lamp beads are arranged in the second row, respectively paired with the letters "F" and "R". The numbers in the first row represent the rotation speed gear of the cutting tool 100, and the letters in the second row represent that the cutting tool 100 is in the forward rotation or reverse rotation mode. The first control key 1511 is provided with an arrow shape, and the rotation speed of the motor 12 is increased or decreased by pressing the first control key 1511. For example, press the first control key 1511 for the first time, the rotation speed gear is in the first gear. After releasing the first control key 1511, press the first control key 1511 again, and the rotation speed gear rises to the second gear. Starting from the rotation speed gear in the first gear, each time the first control key 1511 is pressed, the rotation speed gear rises by one gear until it rises to the fourth gear. When the rotation speed gear rises to the fourth gear, each time the first control key 1511 is pressed, the rotation speed gear drops by one gear until it drops to the fourth gear. Each time a gear is switched, the corresponding LED lamp lights up.

[0088] The second control key 1512 is arranged on the other side of the first control key 1511 relative to the display part 152, and the letter "F / R" is marked on the second control key 1512. When the second control key 1512 is pressed for the first time, the cutting tool 100 rotates forward, and the LED lamp closest to the letter "F" in the second row of the display part 152 lights up. When the second control key 1512 is pressed again, the cutting tool 100 is adjusted to rotate in the reverse direction, and the LED lamp closest to the letter "R" in the second row of the display part 152 lights up. Pressing the second control key 1512 makes the cutting tool 100 switch cyclically and is displayed by the lighting of the LED lamp. It should be noted that the indicator light of the display part 152 is not necessarily an LED lamp, and other forms of prompting methods can also be used, which are not limited here. The forward rotation and reverse rotation can also be represented by other letters or icons different from "F" and "R", which are not limited here.

[0089] With such a setting, the control component 15 of the cutting tool 100 is arranged at the outrigger, and the speed regulation and commutation functions are integrated on the same interface, which is beneficial to reducing the overall size of the operation panel and reducing its space occupation on the body, facilitating user control.

[0090] In one embodiment, after the rotation direction is set by operating the second control key 1512, the circuit board will memorize the current rotation direction. When the cutting tool 100 is powered off or the battery pack 40 is re-plugged and then the cutting tool 100 is powered on again, the rotation direction used before the previous power-off can be maintained.

[0091] In one embodiment, after the rotation direction is set by operating the second control key 1512, the cutting tool 100 rotates in the first rotation direction. When the cutting tool 100 stops, the time from the stop time to the next startup is the waiting time. When the waiting time is less than the preset stop time period, it is set that when the cutting tool 100 stops and then starts up again, it still works in the first rotation direction. When the waiting time is greater than the preset stop time period, it is set that when the cutting tool 100 stops and then starts up again, it works in the forward rotation mode. The preset stop time period can be less than or equal to 30 minutes. In some embodiments, the preset stop time period can be 5 minutes, 10 minutes, 15 minutes, 20 minutes or 25 minutes. For example, the user operates the second control key 1512 to set the first rotation direction to reverse rotation, and the preset stop time period is 10 minutes. When the cutting tool 100 has worked for a period of time, the user leaves briefly and the machine stops for 5 minutes. When the user comes back and continues to start the machine for cutting, since the actual stop time period is less than the preset stop time period, after starting up again, the cutting tool 100 is still in the reverse rotation state.

[0092] In another embodiment, the second control key 1512 has a long - press function and a short - press function. The long - press function can switch the cutting tool 100 to the memory mode or the reset mode, and the short - press function can normally switch the rotation direction of the second control key 1512. The memory mode means that the cutting tool 100 will consistently maintain the current rotation direction after power - off or battery pack 40 replacement. The reset mode means that the cutting tool 100 will automatically reset to the forward rotation after power - off or battery pack 40 replacement. When the cutting tool 100 is used for the first time, it is in the reset mode. Long - pressing the second control key 1512 will switch the cutting tool 100 to the memory mode. Once again, long - pressing the second control key 1512 will switch the cutting tool 100 back to the reset mode, and so on. Among them, the long - press function can be to continuously press the second control key 1512 for 3 seconds to 5 seconds, or to operate the second control key 1512 for a time period significantly longer than the operation of the short - press function.

[0093] As Figure 2 , Figure 9 and Figure 10 shown, the head assembly 20 of the cutting tool 100 can rotate around the torso assembly 10. As Figure 2 shown, the torso assembly 10 extends along the third straight line 103, and the head assembly 20 can rotate around the third straight line 103. In this embodiment, the rotation direction of the head assembly 20 is clockwise rotation, referring to the first direction R in Figure 2 .

[0094] Figure 9 and Figure 10 further reveals the working principle of the rotation of the head assembly 20 relative to the torso assembly 10. The cutting tool 100 is provided with a head adjustment assembly 18. The head adjustment assembly 18 is arranged on the first housing 111 and / or the second housing 112. When the head adjustment assembly 111 is operated, the head assembly 20 can rotate relative to the torso assembly 10.

[0095] The head adjustment assembly 18 includes an adjustment switch 181, a locking pin 182, and a second elastic member 183. When the user wants to rotate the head assembly 20, the adjustment switch 181 needs to be operated. The locking pin 182 is driven by the adjustment switch 181 to move, and then is withdrawn from the inside of the housing of the head assembly 20 to unlock the head assembly 20. When the head assembly 20 rotates to the required angle, the adjustment switch 181 is adjusted again to make the locking pin 182 extend into the inside of the housing of the head assembly 20 to lock the head assembly 20. In this embodiment, taking the position revealed in Figure 1 as the position where the head assembly 20 is not rotated or rotated to 0 degrees, the head assembly 20 can also rotate 90 degrees or 180 degrees. In other embodiments, different rotation angles can be set for the head assembly 20.

[0096] The adjustment switch 181 is provided with a driving part 1811, and the driving part 1811 can drive the locking pin 182 to move along its extending direction. The locking pin 182 is provided with a positioning part 1821, and the positioning part 1821 is in contact and cooperation with the driving part 1811. In one embodiment, the driving part 1811 can push the positioning part 1821 along a direction substantially parallel to the driving part 1811, thereby driving the locking pin 182 to move. In another embodiment, the positioning part 1821 can pass through the driving part 1811 along a direction not parallel to the moving direction of the driving part 1811, thereby driving the locking pin 182 to move.

[0097] The head assembly 20 further includes a rotating track 184, and the head assembly 20 and the torso assembly 10 can perform relative rotation on the rotating track 184. Or rather, the relative rotational movement between the first housing 111 and the second housing 112 occurs on the rotating track 184. The rotating track 184 can be provided at the foremost end of the first housing 111, can also be provided at the lowermost end of the second housing 112, or can also be a separate component to connect the first housing 111 and the second housing 112. The rotating track 184 at least includes a recessed track, and the rotating track 184 is distributed in a circular shape. In this embodiment, the rotating track 184 is formed by the second housing 112. Correspondingly, a sliding track that can cooperate with the rotating track 184 is also formed on the first housing 111 to realize the relative movement between the first housing 111 and the second housing 112.

[0098] A plurality of locking holes 1841 are formed on the housing of the rotating track 184, and each locking hole 1841 can be inserted by the locking pin 182. A second elastic member 183 is provided at the rear side of the positioning part 1821. When the locking pin 182 is in the locked state, the second elastic member 183 is compressed to ensure that the locking pin 182 is pushed into the locking hole 1841 and does not fall out; when unlocking the locking pin 182, the second elastic member 183 is further compressed. The force provided by the user's hand compresses the second elastic member 183 to prevent the adjustment switch 181 from being accidentally touched.

[0099] Figure 9 and Figure 10The provided view also reveals the internal structure of the main switch 14. The main switch 14 is arranged on the first shell 111, and when the head adjustment assembly 18 is operated, the main switch 14 is restricted from operation. The lower end of the main switch 14 is connected to the switch pull rod 141, and the front end of the switch pull rod 141 forms a boss 1411, and a groove 142 for inserting the boss 1411 is formed on the rotating track 184. When the head assembly 20 and the torso assembly 10 are at a lockable angle, the main switch 14 is pushed forward, and the switch pull rod 141 can be inserted into the groove 142. It should be noted that after the locking pin 182 is locked in the correct position, the boss 1411 at the switch pull rod 141 can be inserted into the groove 142, and the main switch 142 can be started normally. If the locking pin 182 is in an abnormal position, the boss 1411 will press against the rib surface, so that the main switch 142 cannot be pushed and the machine cannot be started.

[0100] like Figure 11 and Figure 12 As shown, the cutting tool 100 also includes a shield attachment 23, which is detachably mounted on the cutting shield 21. In this embodiment, the shield attachment 23 is sleeved on the cutting shield 21, and at least one dust suction pipe 24 is detachably mounted on the shield attachment 23. In this embodiment, both ends of the shield attachment 23 can be connected to the dust suction pipe 24. The cutting direction of the cutting tool 100 can rotate around the first direction R, that is, the shield 21 and the shield attachment 23 matched with the shield 21 can be located on the left or right side of the grip 1111. Therefore, the installation position of the dust suction pipe 24 can be selected according to the cutting direction and the rotation direction of the saw blade to meet the needs of different working conditions.

[0101] The shield attachment 23 is provided with a first operating member 231 and a second operating member 232 which are arranged opposite to each other, and the first operating member 231 and the second operating member 232 can be used to lock and unlock the dust suction tube 24. The shield attachment 23 also includes a shield attachment housing 233, and the first operating member 231 and the second operating member 232 are both installed or connected to the shield attachment housing 233.

[0102] The first operating member 231 includes a trigger portion 2311, a limit portion 2312 and a connection portion 2313. The trigger portion 2311 is arranged at the end of the first operating member 231 for user operation. The connection portion 2313 is arranged at the other end opposite to the trigger portion, and the first operating member 231 is connected to the shield accessory shell 233 through the connection portion 2313. In this embodiment, the first operating member 231 and the shield accessory shell 233 are integrally formed. In other embodiments, the first operating member 231 can also be separately formed from the shield accessory shell 233 and then connected together. The limit portion 2312 is basically arranged in the middle part of the first operating member 231, and the first operating member 231 basically forms a "√" shape.

[0103] An engaging portion 241 is formed on the outer wall of the dust suction pipe 24. The engaging portion 241 is a groove that does not penetrate the outer wall. When the user presses the triggering portion 2311, the limiting portion 2312 disengages from the engaging portion 241 of the dust suction pipe 24, thereby allowing the dust suction pipe 24 to slide up and down to disengage from the guard attachment 23. In the natural state, due to the elasticity of the material of the first operating member 231 itself, the limiting portion 2312 is snapped into the engaging portion 241 of the dust suction pipe 24. When the user presses the triggering portion 2311, the first operating member 231 undergoes elastic deformation, and the limiting portion 2312 will only disengage from the engaging portion 241. In this embodiment, the guard attachment 23 is made of a plastic material.

[0104] Generally, angle grinders can be divided into conventional angle grinders and mini angle grinders. The grinding wheel diameter of conventional angle grinders is larger than that of mini angle grinders, and they can achieve a greater cutting depth and a wider cutting angle. The grinding wheel diameter of conventional angle grinders is greater than or equal to 100 mm, while the grinding wheel diameter of mini angle grinders is less than 100 mm. Due to their larger volume, conventional angle grinders have enough space to set a larger cutting depth and cutting angle. However, the technical solution involved in this application enables a larger cutting depth and cutting angle to be obtained in the category of mini angle grinders, and when the cutting guard 21 is turned to any adjustable position, the user can cut to the maximum cutting depth. In this embodiment, the cutting tool 100 is a mini angle grinder and is used in combination with a grinding disc or cutting slice with a diameter of 76 mm.

[0105] In one embodiment, the diameter of the cutting member of the cutting tool 100 is greater than 60 mm and less than 100 mm. In one embodiment, the diameter of the cutting member of the cutting tool 100 is greater than 60 mm and less than 90 mm. In one embodiment, the diameter of the cutting member of the cutting tool 100 is greater than 60 mm and less than 85 mm. In this embodiment, the cutting tool 100 is installed with a grinding disc or cutting slice with a diameter of 76 mm as the cutting member.

[0106] It should be noted that the technical solution disclosed in this specification is applicable not only to the cutting tool 100, but also to handheld tools, angle grinders or angle cutters.

[0107] The above embodiments only illustrate the basic principles and characteristics of this application. This application is not limited by the above embodiments. Without departing from the spirit and scope of this application, there are various changes and modifications to this application, and these changes and modifications all fall within the scope of this application claimed. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A cutting tool comprising: A torso assembly, comprising at least a first shell for hand gripping; Head assembly, including: Motor; A second housing, configured to accommodate the motor; An output shaft, configured to mount a cutting member for cutting a workpiece; A transmission assembly, connected between the motor shaft and the output shaft, transmitting the driving force of the motor to the output shaft; It is characterized by further comprising: The third shell at least accommodates part of the transmission assembly. When the cutting member cuts the workpiece, the third shell has a first contact surface and a second contact surface with the workpiece. When the first contact surface and the second contact surface are in contact with the workpiece, the cutting member has a maximum cutting depth. The angle between the first contact surface and the second contact surface is greater than or equal to 50 degrees and less than or equal to 85 degrees, and the maximum cutting depth is greater than or equal to 20 mm.

2. The cutting tool according to claim 1, characterized in that The second shell and the third shell are fixed by screws.

3. The cutting tool according to claim 1, characterized in that It also includes a battery pack for powering the cutting tool, wherein the rated voltage of the battery pack is greater than or equal to 8V.

4. The cutting tool according to claim 1, characterized in that The output power of the motor is greater than or equal to 250W.

5. The cutting tool according to claim 1, characterized in that It also includes a head adjustment component, which is arranged on the first shell and / or the second shell; when the head adjustment component is operated, the head component can rotate relative to the torso component.

6. The cutting tool according to claim 5, characterized in that It also includes a main switch, which is arranged on the first housing; when the head adjustment assembly is operated, the main switch is restricted from operation.

7. The cutting tool according to claim 1, characterized in that It also includes a cutting shield and a shield attachment. The cutting shield covers the cutting piece in the radial direction and can rotate around the output shaft. The shield attachment is detachably mounted on the cutting shield. At least one dust suction pipe is detachably mounted on the shield attachment.

8. The cutting tool according to claim 1, characterized in that The cutting member further comprises a third contact surface, and when the third contact surface is in contact with the workpiece, the cutting member has a maximum cutting depth.

9. The cutting tool according to claim 8, characterized in that When viewed in a plane perpendicular to the output shaft, a projection of the third contact surface on the plane is located between a projection of the first contact surface on the plane and a projection of the second contact surface on the plane.

10. The cutting tool according to claim 9, characterized in that It also includes a cutting shield, which covers the cutting element in the radial direction and can rotate around the output shaft; the third contact surface is arranged on the cutting shield or the third shell.

11. A handheld tool comprising: A torso assembly, comprising at least a first shell for hand gripping; Head assembly, including: Motor; A second housing, configured to accommodate the motor; An output shaft, configured to mount a cutting member for cutting a workpiece; A transmission assembly, contained in the third housing, connected between the motor shaft and the output shaft, and transmitting the driving force of the motor to the output shaft; It is characterized by further comprising: a cutting shield, which covers the cutting piece in a radial direction and can rotate around the output shaft relative to the second housing; the cutting shield can be adjusted between a first limit position and a second limit position, the first limit position and the second limit position being two limit positions that can be reached by the cutting shield rotating around the output shaft in opposite directions; when the cutting shield is at the first limit position, the third housing has a first contact surface with the workpiece, and when the cutting shield is at the second limit position, the third housing has a second contact surface with the workpiece; The third contact surface is arranged on the third shell. When the third contact surface contacts the workpiece, the cutting member can reach its maximum cutting depth. The third contact surface is arranged as an arc surface with a fixed curvature radius, and the curvature radius is greater than or equal to 13 mm.

12. The handheld tool according to claim 11, characterized in that: When viewed in a plane perpendicular to the output shaft, a projection of the third contact surface on the plane is located between a projection of the first contact surface on the plane and a projection of the second contact surface on the plane.

13. The handheld tool according to claim 11, characterized in that: When viewed in a plane perpendicular to the output shaft, the first contact surface is tangent to the third contact surface, and the second contact surface is tangent to the third contact surface.

14. The handheld tool according to claim 11, characterized in that: The projection of the cutting shield in a direction perpendicular to the output shaft has a first shield edge and a second shield edge; when the cutting shield is in the first extreme position, the first shield edge is basically parallel to the first contact surface; when the cutting shield is in the second extreme position, the second shield edge is basically parallel to the second contact surface.

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