Portable circular saw for cutting metal

Abstract

This application discloses a portable circular saw for cutting metal, comprising: a base having a lower surface side that abuts against the material to be cut, and a cutting machine body at least partially supported on the upper surface side of the base; the cutting machine body includes: a circular saw blade, a fixed guard covering the outer circumference of the circular saw blade; a metal chip guide tube disposed within the fixed guard and surrounding a portion of the outer circumference of the circular saw blade, including a chip guide cavity for guiding chips; the ratio of the outer surface area S1 of the metal chip guide tube to the surface area S2 covered by the fixed guard is greater than 1. The above technical solution provides a portable circular saw with an upper guard that is less prone to deformation or melting.

Description

Technical Field

[0001] This application relates to the field of power tools, and more specifically to a portable circular saw for cutting metal. Background Technology

[0002] A circular saw is a toothed tool used to cut metal. During the cutting process, it produces metal shavings. The circular saw is equipped with an upper guard and a dust collection assembly to collect these shavings. The upper guard surrounds the dust collection assembly. As the metal shavings enter the dust collection assembly and are collected, the upper guard may experience thermal deformation or even melt due to the high temperature carried by the shavings.

[0003] This section provides background information related to this application, which is not necessarily prior art. Summary of the Invention

[0004] One object of this application is to solve or at least alleviate some or all of the aforementioned problems. Therefore, one object of this application is to provide a portable circular saw with an upper protective cover that is not easily deformed or melted.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In some embodiments, a portable circular saw for cutting metal includes:

[0007] A base having a lower surface side that abuts against the material being cut, and a cutting machine body having at least a portion supported on the upper surface side of the base;

[0008] The main body of the cutting machine includes:

[0009] The circular saw blade protrudes downwards from a window on the base and cuts into the material.

[0010] A fixed protective cover that covers the outer circumference of the circular saw blade;

[0011] A metal chip guide tube, located inside a fixed cover and surrounding a portion of the outer circumference of a circular saw blade, includes a chip guide cavity for guiding chips.

[0012] The ratio of the outer surface area S1 of the metal chip guide tube to the surface area S2 covered by the fixed protective cover is greater than 1.

[0013] In some embodiments, the ratio of the outer surface area S1 of the metal chip guide tube to the surface area S2 covered by the fixed cover is greater than or equal to 1.2.

[0014] In some embodiments, the metal chip guide tube is fixed to the fixed cover by a support member.

[0015] In some embodiments, the support is integrally formed with the fixed cover or connected to the fixed cover.

[0016] In some embodiments, at least a portion of the support is disposed at both ends of the lower surface of the metal chip guide tube.

[0017] In some embodiments, the thermal conductivity of the fixed shield differs from that of the metal chip guide tube.

[0018] In some embodiments, the metal chip guide tube is integrally formed.

[0019] In some embodiments, the upper, left, and right surfaces of the metal chip guide tube abut against the inner surface of the fixing cover via spaced ribs.

[0020] In some embodiments, the heat transfer coefficient of the metal chip guide tube is 15 W / (m²·K).

[0021] In some embodiments, the portable circular saw also includes a battery pack for powering the portable circular saw.

[0022] In some embodiments, a portable circular saw for cutting metal includes:

[0023] A base having a lower surface side that abuts against the material being cut, and a cutting machine body having at least a portion supported on the upper surface side of the base;

[0024] The main body of the cutting machine includes:

[0025] The circular saw blade protrudes downwards from a window on the base and cuts into the material.

[0026] A fixed protective cover that covers the outer circumference of the circular saw blade;

[0027] A movable guard that rotates relative to a fixed guard and can cover part of the outer circumference of the circular saw blade.

[0028] A metal chip guide tube is installed inside a fixed cover and surrounds a portion of the outer circumference of the circular saw blade, including a chip guide cavity for guiding chips.

[0029] After removing the saw blade or movable guard, the bottom of the metal chip guide tube can be seen from the lower surface of the base along the window of the base to the upper surface.

[0030] In some embodiments, the metal chip guide tube is fixed to the fixed cover by a support member.

[0031] In some embodiments, the support is integrally formed with the fixed cover or connected to the fixed cover.

[0032] In some embodiments, at least a portion of the support is disposed at both ends of the lower surface of the metal chip guide tube.

[0033] In some embodiments, the thermal conductivity of the fixed shield differs from that of the metal chip guide tube.

[0034] In some embodiments, the metal chip guide tube is integrally formed.

[0035] In some embodiments, the upper, left, and right surfaces of the metal chip guide tube abut against the inner surface of the fixing cover via spaced ribs.

[0036] In some embodiments, the ratio of the outer surface area S1 of the metal chip guide tube to the surface area S2 covered by the fixed cover is greater than or equal to 1.2.

[0037] In some embodiments, the heat transfer coefficient of the metal chip guide tube is 15 W / (m²·K).

[0038] In some embodiments, the portable circular saw also includes a battery pack for powering the portable circular saw.

[0039] The advantage of this application is that by setting the ratio of the outer surface S1 of the metal chip guide tube to the surface area S2 covered by the fixed cover to be greater than 1, the fixed cover does not completely cover the metal chip guide tube, thereby making the fixed cover less prone to deformation or melting. Attached Figure Description

[0040] Figure 1 This is a perspective view of a circular saw according to one embodiment;

[0041] Figure 2 yes Figure 1 A three-dimensional view of the medium circular saw from another angle;

[0042] Figure 3 yes Figure 1 Exploded three-dimensional view of the fixed guard and chip collection assembly of a medium circular saw;

[0043] Figure 4 yes Figure 1 Side view of a medium circular saw;

[0044] Figure 5 A top view of a circular saw including a seal, according to one embodiment;

[0045] Figure 6 yes Figure 5 3D view of the central sealing component;

[0046] Figure 7 yes Figure 2 A close-up view of the middle auxiliary handle;

[0047] Figure 8 A perspective view of a circular saw including a first section and a second section, according to one embodiment;

[0048] Figure 9 yes Figure 8Side view of the fixed protective cover;

[0049] Figure 10 yes Figure 8 Side view of the lower middle section;

[0050] Figure 11 Is with Figure 8 Chip movement trajectory diagrams corresponding to the first and second sections;

[0051] Figure 12 This is a perspective view of the lower end and base of a circular saw according to one embodiment;

[0052] Figure 13 yes Figure 12 Top view of the lower middle section and base;

[0053] Figure 14 This is a perspective view of the fixed guard and metal chip guide tube of a circular saw according to one embodiment;

[0054] Figure 15 yes Figure 14 Front view diagram;

[0055] Figure 16 yes Figure 14 Exploded view of the fixed protective shield;

[0056] Figure 17 yes Figure 16 The circular saw in the figure includes a three-dimensional view of the support part;

[0057] Figure 18 yes Figure 1 A schematic diagram of the middle hook assembly rotated 90 degrees;

[0058] Figure 19 yes Figure 1 A schematic diagram of the middle hook assembly rotating 180 degrees. Detailed Implementation

[0059] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0060] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0061] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "and / or" relationship.

[0062] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0063] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​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 associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to 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 specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0064] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0065] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0066] This application provides a circular saw 100, specifically a portable circular saw for cutting metal. For example... Figure 1 and Figure 2 As shown, the circular saw 100 includes a base 110, a handle assembly 120, a drive mechanism 130, a battery pack 140, and a cutting machine body 100a. The cutting machine body 100a is at least partially supported on the upper surface of the base 110, and includes a circular saw blade 200, a fixed guard 300, a movable guard 400, and a chip collection assembly 500. To clearly illustrate the technical solution of this application, the following are also defined: Figure 1 The diagram shows the top, bottom, left, right, front, and rear sides. With the cutting direction of the circular saw 100 as the front, the corresponding direction is the rear, the left side of the cutting direction is the left, and the right side of the cutting direction is the right.

[0067] The base 110 serves as a support platform for the entire circular saw 100. When the circular saw 100 cuts metal materials, the lower surface of the base 110 can abut against the cutting material to position the circular saw 100 relative to the material and provide a certain degree of support for the circular saw 100. By placing the base 110 against the cutting material and pushing the circular saw 100 forward, the circular saw 100 can cut and process the metal material.

[0068] The handle assembly 120 is located on the upper side of the base 110, allowing the user to easily operate the circular saw 100 by gripping the handle assembly 120. The handle assembly 120 includes a main handle 121 and a secondary handle 122. The main handle 121 is angled to facilitate pushing the circular saw 100 from back to front for cutting operations. The secondary handle 122 is positioned such that... Figure 1 The front end is shown. The secondary handle 122 is used to assist in holding the circular saw 100 during cutting. When using the circular saw 100 for cutting operations, the user holds the main handle 121 with one hand and the secondary handle 122 with the other hand, making the operation more stable. Figure 2As shown, a switch 1211 is provided on the main handle 121. The switch 1211 is a push-button switch, which controls the working state of the circular saw 100, that is, turning the circular saw 100 on or off.

[0069] The drive mechanism 130 is located on the upper side of the base 110, next to the main handle 121. The drive mechanism 130 drives the circular saw blade 200 to rotate around the first axis A for cutting operations. The drive mechanism 130 can be a motor. The connection between the motor and the circular saw blade 200 can be a direct connection or a connection through other transmission structures, such as gear transmission or belt transmission, etc., without limitation. It is understood that the drive mechanism 130 is electrically connected to the switch 1211, which can control the start and stop of the drive mechanism 130, thereby controlling the rotation or stop of the circular saw blade 200, realizing the control of the working state of the circular saw 100. Of course, the circular saw 100 may also include a control mechanism, such as a control circuit board assembly. The switch 1211 and the drive mechanism 130 are respectively electrically connected to the control mechanism to realize the control of the whole machine.

[0070] The battery pack 140 cooperates with the battery pack interface 123 located on the rear side of the handle assembly 120. The battery pack 140 is detachably connected to the circular saw 100 based on the battery pack interface 123. The battery pack 140, together with the corresponding power circuit, supplies power to the circular saw 100 to drive the drive mechanism 130. Those skilled in the art should understand that the DC power supply is not limited to the scenario of using the battery pack 140; it can be a built-in rechargeable battery pack or a standard battery pack. It is understood that the circular saw 100 can also supply power to corresponding components within the machine via mains power or AC power, along with corresponding rectification, filtering, and voltage regulation circuits. This application uses the battery pack 140 for specific power supply description, but this should not be construed as a limitation of this application. Optionally, the nominal voltage of the battery pack 140 can be 24V. Optionally, the nominal voltage of the battery pack 140 can also be other values, which are not limited in this application.

[0071] like Figure 3 As shown, the base 110 includes a window portion 111, specifically a hollow portion on the base 110. A circular saw blade 200 can be disposed within the window portion 111 of the base 110 and protrude downwards from the window portion 111, such that a portion of the circular saw blade 200 is located above the base 110, and another portion is located below the base 110. The circular saw blade 200 along... Figure 1 The circular saw blade 200 is positioned in a forward and backward direction, with the portion protruding from the window portion 111 cutting into the material for cutting processing. The circular saw blade 200 is located on the main handle 121 on the opposite side from the drive mechanism 130.

[0072] A fixed guard 300 covers part of the outer circumference of the circular saw blade 200. The fixed guard 300 serves two purposes: firstly, it protects the circular saw blade 200, and secondly, it blocks the chips generated during cutting, preventing chip splatter. For example... Figure 4 As shown, the fixed guard 300 includes a main guard 310 and a lower end 320. The main guard 310 and the lower end 320 are fixedly connected. The main guard 310 includes a portion located on the upper side of the circular saw 200 and at the rear in the cutting direction, while the lower end 320 is located at the front in the cutting direction. Figure 4 As shown, line P is the dividing line between the main body shield 310 and the lower end portion 320 on the fixed shield 300. The lower end portion 320 is located at the front of the circular saw blade 200 in both the front-rear direction and the rear portion of the circular saw blade 200 in the front-rear direction, and the upper portion of the circular saw blade 200 in the vertical direction. This application does not limit the method of fixing the main body shield 310 to the lower end portion 320; any method that can securely connect the main body shield 310 and the lower end portion 320 is acceptable.

[0073] The movable guard 400 rotates relative to the fixed guard 300 and covers a portion of the outer circumference of the circular saw blade 200. When the circular saw 100 is not in use, the movable guard 400 is located under the base 110 and covers at least a portion of the circular saw blade 200 protruding below the window 111, preventing the circular saw blade 200 from being exposed and causing injury to the operator. When the circular saw 100 needs to cut, the movable guard 400 is pushed open and rotated as the circular saw blade 200 moves during cutting, and the angle at which the movable guard 400 is pushed open and rotated varies depending on the cutting depth of the circular saw blade 200 and the material being cut. After the circular saw 100 stops cutting and is removed from the material, the movable guard 400 automatically returns to the initial protective state shown in the figure. The movable guard 400 is made of plastic.

[0074] The chip collection assembly 500 is used to guide and collect the chips generated when the circular saw 100 cuts metal, such as... Figure 3As shown, the chip collection assembly 500 includes a chip guide pipe 510 and a dust collection box 520. The chip guide pipe 510 is connected to the dust collection box 520 and is used to guide the chips. The chips pass through the chip guide pipe 510 and accumulate in the dust collection box 520. The chip guide pipe 510 is located inside the fixed cover 300, specifically inside the main cover 310. The chip guide pipe 510 is a metal chip guide pipe, which is made of a different material than the fixed cover 300. The term "metal chip guide pipe 510" will be used to refer to the chip guide pipe 510 in the following text. The chips generated during metal cutting have a certain temperature. By using a metal chip guide tube 510, on the one hand, high-temperature chips can be prevented from entering the metal chip guide tube 510 and causing damage, thus ensuring the service life of the metal chip guide tube 510; on the other hand, metal has good heat dissipation performance. During the chip guiding process, the chips can dissipate heat and cool down by collision. Therefore, the chips entering the metal chip guide tube 510 can be dissipated, causing the chip temperature to drop and become low-temperature chips, which are less likely to adhere to the metal chip guide tube 510.

[0075] In some embodiments, such as Figure 5 As shown, a gearbox 210 is disposed between the drive mechanism 130 and the circular saw blade 200. The drive mechanism 130 drives the circular saw blade 200 to rotate based on the gearbox 210. The circular saw 100 includes a housing assembly 101, the drive mechanism 130 is disposed inside the housing assembly 101, the gearbox 210 includes a portion exposed outside the housing assembly 101, the housing assembly 101 includes portions surrounding three sides of the gearbox 210, and a certain gap exists between the housing assembly 101 and the gearbox 210. Figure 5 As shown, a seal 211 is provided between the gearbox 210 and the housing assembly 101, specifically between the gearbox 210 and the housing assembly 101 where the drive mechanism 130 is located. Optionally, the seal 211 can be made of silicone. Optionally, the seal 211 can also be made of any material capable of sealing and filling gaps; this application does not impose any limitations.

[0076] The seal 211 includes a first sealing portion 2111 and a second sealing portion 2112, which are integrally formed. The first sealing portion 2111 is substantially along the front-rear direction and is used to seal the housing assembly 101 around a first side of the gearbox 210; the second sealing portion 2112 is located on both sides of the first sealing portion 2111 and is used to seal the corresponding sides of the housing assembly 101 around the gearbox 210. The specific shapes of the first sealing portion 2111 and the second sealing portion 2112 are not limited in this application; the first sealing portion 2111 and the second sealing portion 2112 are configured based on the specific shape of the gap between the housing assembly 101 and the gearbox 210 to fully fill the gap.

[0077] Therefore, during the operation of the circular saw 100, thanks to the seal 211, the cutting chips generated will not pass through the gap between the gearbox 210 and the housing assembly 101, nor will they reach the drive mechanism 130 inside the housing assembly 101. This avoids the drawback of chip friction against the drive mechanism 130, which could potentially damage the drive mechanism 130 and affect the service life of the circular saw 100 and the user experience. In addition, the seal 211 can be easily inserted into the gap between the gearbox 210 and the housing assembly 101, making assembly convenient.

[0078] In some embodiments, such as Figure 2 and Figure 5 As shown, in the front-to-back direction, the auxiliary handle 122 is located on the front side of the drive mechanism 130 and connected to the housing assembly 101 where the drive mechanism 130 is located; that is, the auxiliary handle 122 is generally located on the front side of the main handle 121. In the left-to-right direction, the auxiliary handle 122 is located on one side of the main handle 121. Therefore, when the user holds the main handle 121 with one hand and the auxiliary handle 122 with the other hand for cutting operations, the hand holding the auxiliary handle 122 will not obstruct the user's view. This ensures that the user's perspective on the specific cutting situation of the circular saw blade 200 is not obstructed, guaranteeing cutting accuracy and improving the user experience.

[0079] In some embodiments, such as Figure 7 As shown, the auxiliary handle 122 can be connected to the housing assembly 101 via a hexagonal nut 1221, thus facilitating the disassembly and installation of the auxiliary handle 122. The auxiliary handle 122 also includes a groove 1222 for holding a hexagonal wrench that matches the hexagonal nut 1221. This allows the user to directly retrieve the hexagonal wrench from the circular saw 100 when disassembling or installing the auxiliary handle 122, eliminating the need for additional preparation and improving the ease of disassembly and installation. Figure 7 As shown, a retaining groove 1011 matching the hex wrench is also provided on the housing assembly 101 near the secondary handle 122. When the hex wrench is placed on the secondary handle 122, the hex wrench is placed in the groove 1222, and its end is inserted into the retaining groove 1011, so that the hex wrench is stably installed on the secondary handle 122. When the circular saw 100 is used for cutting, the hex wrench will not fall off the circular saw 100, thus ensuring the safety of the circular saw 100 during use to a certain extent. Furthermore, to facilitate easy access for the user, the hex wrench includes a portion protruding from the groove 1222 at the front of the secondary handle 122 when installed in the groove 1222. The user can easily remove the hex wrench by pulling outwards on the protruding front portion. In addition, Figure 7The location of the upper fixing groove 1011 is only an example. The fixing groove 1011 can be located at any position that is convenient for fixing with a hex wrench, and this application does not limit it. In addition, the secondary handle 122 can also be connected to the housing assembly 101 by other types of components, and the disassembly or installation tools provided on the secondary handle 122 can also be changed accordingly, and this application does not limit it.

[0080] In some embodiments, the specific arrangement of the fixed cover 300 has a certain impact on the dust collection efficiency of the circular saw 100. The fixed cover 300 is described in detail below.

[0081] like Figure 4 and Figure 8 As shown, the main body cover 310 of the fixed cover 300 is fixedly connected to the lower end 320. The fixed cover 300 is made of plastic, the main body cover 310 is opaque, and the lower end 320 is transparent. This allows the user to clearly see the cutting process when the circular saw blade 200 is cutting within the fixed cover 300, and also ensures the correctness of the cutting position based on the transparent lower end 320.

[0082] In some embodiments, since the main body cover 310 is opaque and the lower end portion 320 is transparent, the main body cover 310 and the lower end portion 320 are formed separately and then fixedly connected together. For example... Figure 8 As shown, both the main body cover 310 and the lower end 320 include outwardly extending portions with holes, so that the outer extensions of the main body cover 310 and the lower end 320 can be fixedly connected based on screws 311.

[0083] A limiting mechanism 330 is also provided at the connection between the main body cover 310 and the lower end 320. The limiting mechanism 300 includes two limiting mechanisms: a first limiting mechanism 331 and a second limiting mechanism 332. The first limiting mechanism 331 is parallel to the connection between the main body cover 310 and the lower end 320, and the second limiting mechanism 332 intersects with the connection between the main body cover 310 and the lower end 320. The first limiting mechanism 331 is longer and narrower, while the second limiting mechanism 332 is shorter and wider. Optionally, the first limiting mechanism 331 and the second limiting mechanism 332 are in contact. Optionally, the first limiting mechanism 331 and the second limiting mechanism 332 can be... Figure 9 The non-contact shown is not a limitation of this application.

[0084] During the cutting process of the circular saw 100, the rotating wind generated by the rotation of the circular saw blade 200 blows metal chips upwards, causing them to continuously fall onto the lower end 320. The outer side of the lower end 320 is fixedly connected to the outer side of the main body shield 310 by screws 311. However, the connection between the lower end 320 and the main body shield 310 may flip outwards due to repeated impacts from the metal chips, causing deformation of the lower end 320 and making it difficult for the circular saw 100 to continue working. By setting the aforementioned first limiting mechanism 331 and second limiting mechanism 332, the lower end 320 can be prevented from flipping outwards, ensuring a tight connection between the lower end 320 and the main body shield 310, thereby improving the stability of the circular saw 100 during operation.

[0085] In some embodiments, such as Figure 9 and Figure 12 As shown, the bottom end 323 of the lower end 320 of the fixed cover 300 includes an upward-facing notch, so that the bottom end 323 maintains a certain distance from the base 110. Figure 13 As shown, the window portion 111 on the base 110 extends to the edge of the fixed cover 300, specifically to the edge of the bottom end 323, resulting in a larger area for the window portion 111. Therefore, when the circular saw 100 is cutting, the probability of chips falling from the window portion 111 out of the base 110 is higher, and the chips can splash outwards from the notch at the bottom end 323 between the base 110 and the lower end 320. This reduces the probability of chips accumulating between the base 110 and the lower end 320, and also reduces the probability of the lower end 320 melting due to accumulated chips, further improving the reliability of the lower end 320, ensuring the effective working life of the circular saw 100, and enhancing the user experience. Furthermore, reducing the probability of chips accumulating between the base 110 and the lower end 320 also reduces the probability of the movable cover 400 located under the base 110 melting or deforming due to high temperatures, extending the service life of the movable cover 400.

[0086] like Figure 8 As shown, the lower end 320 of the fixed guard 300 includes at least a first section 321 and a second section 322. Both the first section 321 and the second section 322 are disposed in the radial direction of the circular saw blade 200. Specifically, the radial direction of the circular saw blade 200 is the extension direction of the plane containing the circular saw blade 200. The slopes of the first section 321 and the second section 322 are different. The first section 321 and the second section 322 are specifically... Figure 8 The section corresponding to the centerline of the lower end portion 320 shown is specifically defined as the centerline of the lower end portion 320 in the left-right direction. This application will be specifically described using the example that the centerline of the lower end portion 320 and its left and right sides lie on the same plane. Figure 9 and Figure 10The segments in the side view of the lower end portion 320 can represent the first segment 321 and the second segment 322 corresponding to the center line. Furthermore, in some embodiments, the center line may not lie on the same plane as the planes on its left and right sides; this will not be specifically described here. Additionally, the lower end portion 320 may include three segments, four segments, or any other number of segments greater than two; this application does not limit this, and multiple segments have the same specific structure as the first segment 321 and the second segment 322 of this application, but the slopes of the multiple segments are different; this application will not elaborate further.

[0087] In some embodiments, the first segment 321 is a first arc, and the second segment 322 is a second arc, that is, the lower end 320 is composed of at least two arcs. In this case, the slope of the tangent plane containing the two endpoints of the first arc is the slope of the first segment 321, and the slope of the tangent plane containing the two endpoints of the second arc is the slope of the second segment 322. Figure 10 In the first section 321 and the second section 322, both are circular arcs. In this case, the slope of the first circular arc is... Figure 10 As shown in the diagram, k1 has a slope of 0.5° for the second arc. Figure 10 k2 is shown in the diagram. The radii of the first and second arcs can be the same or different, and the centers of the first and second arcs can be the same or different; this application does not impose any limitations on this. Therefore, the first and second arcs can be classified into four cases: the first and second arcs have the same radii and the same center position; the first and second arcs have the same radii and different center positions; the first and second arcs have different radii and the same center position; and the first and second arcs have different radii and different center positions.

[0088] In some embodiments, the first segment 321 or the second segment 322 is a straight line segment, that is, one segment of the first segment 321 and the second segment 322 is a straight line segment, and the other segment is an arc segment, with the lower end 320 having at least one arc segment in the radial direction of the circular saw blade 200. In this case, the slope of the straight line segment in the first segment 321 or the second segment 322 is the slope of the corresponding straight line, and the slope of the arc segment is the slope of the tangent plane where the two endpoints are located.

[0089] This application will be further explained below using the example of both the first segment 321 and the second segment 322 being circular arc segments. In this case, the first segment 321 is the first circular arc segment 321, and the second segment 322 is the second circular arc segment 322. The radii of the first circular arc segment 321 and the second circular arc segment 322 may be the same or different, and the center positions of the first circular arc segment 321 and the second circular arc segment 322 may be the same or different.

[0090] In some embodiments, at least one center of the first arc corresponding to the first segment 321 and the second arc corresponding to the second segment 322 is located above the center of the circular saw blade 200, that is, at least one center of the first arc segment 321 and the second arc segment 322 is located above the center of the circular saw blade 200. Specifically, when the center of the first arc segment 321 is located above the center of the circular saw blade 200, the center of the second arc segment 322 can be located at any position to the left of the center of the circular saw blade 200. Similarly, when the center of the second arc segment 322 is located above the center of the circular saw blade 200, the center of the first arc segment 321 can be located at any position to the left of the center of the circular saw blade 200.

[0091] In some embodiments, when the center of the first arc segment 321 is located above the center of the circular saw blade 200, and the center of the second arc segment 322 is located at any position to the left of the center of the circular saw blade 200, the line connecting the center of the first arc segment 321 to any point on the first arc segment 321 is located above the center of the circular saw blade 200, and the line connecting the center of the second arc segment 322 to any point on the second arc segment 322 includes the portion located above the center of the circular saw blade 200. Similarly, when the center of the second arc segment 322 is located above the center of the circular saw blade 200, and the center of the first arc segment 321 is located at any position to the left of the center of the circular saw blade 200, the situation is the same as described above, and will not be repeated here. When the circular saw 100 cuts, the chips will splash onto the first arc segment 321 or the second arc segment 322. The positions of the two arc centers and the lines connecting the two arcs to their respective centers relative to the center of the circular saw blade 200 are designed to maximize the angle of incidence and reflection of the chips splashing onto the first arc segment 321 or the second arc segment 322. This ensures that the chips enter the metal chip guide tube 510 as much as possible for collection. The angle of incidence and the angle of reflection are the same.

[0092] This application uses the example that the centers of both arc segments are located above the center of the circular saw blade 200, and that the lines connecting the centers of the two arc segments to any point on them are also located above the center of the circular saw blade 200, for specific illustration. Figure 11 As shown, the center of the circular saw blade 200 is the saw blade center 201, the center of the first arc segment 321 is the first center 3211, and the center of the second arc segment 322 is the second center 3221. The first center 3211 and the second center 3221 are both located above the saw blade center 201, and the line connecting the first center 3211 to any point on the first arc segment 321, as well as the line connecting the second center 3221 to any point on the second arc segment 322, are both located above the saw blade center 201. Figure 11 In the middle, the circular saw blade 200 cuts at the corresponding cutting point C, and Figure 11An example is given of the splash trajectory of the chip at cutting point C onto either the first arc segment 321 or the second arc segment 322. When the chip splashes onto the first arc segment 321, from... Figure 11 The splash trajectory shows that the incident angle of the chip is angle E, and the reflection angle is angle E'. Angles E and E' are equal and both are relatively large, allowing the chip to enter the metal chip guide tube 510 based on these large incident and reflection angles. When the chip splashes onto the second arc segment 322, from... Figure 11 As can be seen from the splash trajectory, the incident angle of the chip is angle D, and the reflection angle is angle D'. The angles of angles D and D' are equal and both are relatively large, so the chip can enter the metal chip guide tube 510 based on the large incident angle and reflection angle.

[0093] Therefore, this application sets the lower end 320 of the fixed cover 300 to include at least one arc structure, such that the center of at least one arc on the lower end 320 is located above the center of the circular saw blade 200, the line connecting the center of at least one arc to any point on the arc is located above the center of the circular saw blade 200, and the centers of other arcs are located to the left of the center of the circular saw blade 200. As a result, the incident angle and reflection angle of the chips when they fall onto the lower end 320 are larger, and they can enter the metal chip guide tube 510 as much as possible, thereby improving the dust collection efficiency of the circular saw 100.

[0094] In some embodiments, such as Figure 11 As shown, the minimum distance between the top tooth of the circular saw blade 200 and its lower end 320 is greater than or equal to 11 mm and less than or equal to 16 mm. Optionally, the minimum distance between the top tooth of the circular saw blade 200 and its lower end 320 can be 12.3 mm. Optionally, the minimum distance between the top tooth of the circular saw blade 200 and its lower end 320 can be 13 mm. Optionally, the minimum distance between the top tooth of the circular saw blade 200 and its lower end 320 can be 14.5 mm. Optionally, the minimum distance between the top tooth of the circular saw blade 200 and its lower end 320 can be 15 mm. The top tooth of the circular saw blade 200 is the edge of the saw blade, and the distance from the edge of the saw blade to the lower end 320 is specifically the distance along the radial direction of the saw blade.

[0095] By setting the minimum distance between the top tooth of the circular saw blade 200 and the lower end 320 within a reasonable range, the space between the circular saw blade 200 and the lower end 320 is appropriate. This avoids the disadvantages of the lower end 320 being too far from the front of the circular saw blade 200, which would hinder the effective blowing of the rotating airflow from the circular saw blade 200 onto the chips and prevent the chips from being efficiently blown into the dust collection box 520, thus improving the dust collection efficiency of the circular saw 100. At the same time, setting the minimum distance between the top tooth of the circular saw blade 200 and the lower end 320 within a reasonable range avoids the disadvantages of the lower end 320 being too close to the front of the circular saw blade 200, which would cause the chips to collide with each other in the lower end 320 and deviate from their original track, ensuring that the chips can be blown into the metal chip guide tube 510 along the preset track.

[0096] In some embodiments, the specific configuration of the chip collection assembly 500 also has a certain impact on the dust collection efficiency of the circular saw 100. The chip collection assembly 500 is described in detail below.

[0097] The chip collection assembly 500 includes a metal chip guide tube 510 and a dust collection box 520. The metal chip guide tube 510 surrounds a portion of the outer circumference of the circular saw blade 200. The metal chip guide tube 510 includes a chip guide cavity 513 for guiding chips, and an inlet 511 and an outlet 512 communicating with the chip guide cavity 513. The inlet 511 is used to receive chips reflected from the lower end 320, thereby the chips enter the chip guide cavity 513 and are guided to the outlet 512 based on the chip guide cavity 513. The inlet 511 is located near the connection between the main body cover 310 and the lower end 320 to facilitate the reception of chips reflected from the lower end 320. The dust collection box 520 communicates with the chip guide cavity 513 and collects the chips discharged from the outlet 512 of the metal chip guide tube 510. When the chips accumulate to a certain level, the dust collection box 520 can be opened to empty the chips.

[0098] The dust collection box 520 includes a metal heat dissipation section 521 and a non-metallic anti-scalding section 522. The metal heat dissipation section 521 is located inside the non-metallic anti-scalding section 522, serving as the inner wall of the dust collection box 520. The metal heat dissipation section 521 can be located at the bottom and sides of the dust collection box 520, or it can be located on the entire inner wall of the dust collection box 520. The metal heat dissipation section 521 encloses and forms a dust collection chamber to accommodate chips guided by the metal chip guide tube 510. The metal heat dissipation section 521 is made of metal, providing good heat dissipation performance and preventing the high-temperature chips from melting the dust collection box 520, while also facilitating chip cooling. The non-metallic anti-scalding section 522 is located outside the dust collection box 520, forming the outer wall of the dust collection box 520, thus providing heat insulation and preventing the dust collection box 520 from becoming too hot to handle.

[0099] like Figure 3As shown, the non-metallic heat-resistant part 522 can be integrally formed with the main body cover 310 of the fixed cover 300 through injection molding and other processes, reducing the number of parts and improving the overall assembly speed of the circular saw 100. Of course, in this embodiment, the metal heat dissipation part 521 and the metal chip guide tube 510 of the dust collection box 520 can be integrally formed, that is, as a single metal part, integrally formed through sheet metal bending, stamping and other processes; or the metal heat dissipation part 521 and the metal chip guide tube 510 can be formed separately and then assembled, without limitation.

[0100] like Figure 3 As shown, the dust collection box 520 also includes a cover 523, which is pivotally connected to the dust collection box 520 so that the cover 523 can be opened to empty the chips inside the dust collection box 520. Figure 3 As shown, the metal heat dissipation part 521 covers the inner wall of the dust collection box 520. For example, the metal heat dissipation part 521 also includes a metal sheet 5231 disposed on the inner side of the cover 523. The cover 523 is made of non-metallic material, specifically the same material as the non-metallic anti-scalding part 522 and the main protective cover 310. The metal sheet 5231 can block the chips inside the dust collection box 520 from contacting the cover 523, preventing the chips from contacting the non-metallic cover 523 and protecting the cover 523 from damage. Of course, as an alternative implementation, the dust collection box 520 can also be a separate component. After its processing, the dust collection box 520 can be assembled and connected to the fixed protective cover 300 by screws or other locking devices, as long as its interior is in communication with the chip guiding cavity 513.

[0101] In this application, as Figure 1 As shown, the cover 523 is located on the right side of the dust collection box 520, which is the side of the dust collection box 520 furthest from the handle assembly 120. Combined with... Figure 1 and Figure 3 A dust outlet 524 is provided on the right side of the dust collection box 520. The box cover 523 closes onto the dust outlet 524 to seal or open it. Since the box cover 523 is located on the right side of the dust collection box 520 and a metal sheet 5231 is provided on the inner side of the box cover 523, the metal heat dissipation part 521 of the dust collection box 520 covers the left, right, front, rear, and bottom walls of the dust collection box, forming a cylindrical structure that can accommodate metal chips. The top of the cylindrical structure is open, and the front wall of the metal heat dissipation part 521 extends to the metal chip guide tube 510 of the fixed cover 300, allowing chips in the metal chip guide tube 510 to enter the cylindrical structure from the open portion.

[0102] like Figure 3The cover 523 shown is pivotally connected to the dust collection box 520. The cover 523 rotates around an axis that is vertically oriented. When the cover 523 is pivotally connected to the dust collection box 520, a locking structure, such as a snap-fit ​​connection, can be used to lock the cover 523 onto the dust collection box 520 when closed. Alternatively, the cover 523 can also be connected to the dust collection box 520 via a snap-fit ​​connection; this application does not limit the connection.

[0103] In some embodiments, such as Figure 8 As shown, a viewing section 525 is also provided on the upper side of the dust collection box 520. Specifically, the viewing section 525 is located above the non-metallic anti-scalding section 522 in the dust collection box 520. The viewing section 525 is a transparent component, and the metal heat dissipation section 521 of the dust collection box 520 is a cylindrical structure with an open top. This allows the user to directly see the dust collection status inside the dust collection box 520 based on the viewing section 525, enabling timely cleaning of the dust collection box 520.

[0104] As the chips enter the dust collection box 520 from the metal chip guide tube 510, they will not fall to the upper part of the dust collection box 520, thus preventing the chips from contacting the viewing part 525 and avoiding scratching it. This ensures the user's ability to observe the dust collection box 520. Furthermore, during normal use of the circular saw 100, the user can observe the interior of the dust collection box 520 at any time thanks to the viewing part 525 located on the upper side. Additionally, during use, light will penetrate the upper viewing part 525 to reach the bottom of the dust collection box 520, further facilitating the user's observation of its interior.

[0105] Optionally, the visible part 525 can be heat-resistant glass, transparent plastic, or other transparent heat-resistant materials, so that a certain amount of chips are collected in the dust collection box 520, thus ensuring the service life of the visible part 525 when the temperature is high. Of course, the non-metallic anti-scalding part 522 can also be made entirely of transparent material, which is not limited in this application.

[0106] In some embodiments, the ratio of the area of ​​the inlet 511 of the metal chip guide 510 to the cross-sectional area of ​​the metal chip guide 510 located above the circular saw blade 200 is greater than or equal to 2. Specifically, the cross-sectional area of ​​the metal chip guide 510 located above the circular saw blade 200 refers to the left-right cross-sectional area of ​​the metal chip guide 510 corresponding to the area directly above the rotation center of the circular saw blade 200, that is, the left-right cross-sectional area of ​​the chip guide cavity 513 located directly above the rotation center of the circular saw blade 200 (i.e., the center of the circular saw blade 200), specifically as follows: Figure 4The cross-sectional area of ​​the metal chip guide tube 510 in the left-right direction corresponds to the straight line M extending vertically and passing through the rotation center of the circular saw blade 200. Optionally, the ratio of the area of ​​the inlet 511 to the cross-sectional area of ​​the metal chip guide tube 510 located above the circular saw blade 200 can be 2.25. Optionally, the ratio of the area of ​​the inlet 511 to the cross-sectional area of ​​the metal chip guide tube 510 located above the circular saw blade 200 can be 2.5. The ratio of the area of ​​the inlet 511 to the cross-sectional area of ​​the metal chip guide tube 510 located above the circular saw blade 200 can be 2.8. The ratio of the area of ​​the inlet 511 to the cross-sectional area of ​​the metal chip guide tube 510 located above the circular saw blade 200 can be 3. Furthermore, as... Figure 4 As shown, the area of ​​the inlet 511 is larger than the cross-sectional area of ​​any point on the chip guide cavity 513.

[0107] In some embodiments, the area of ​​the inlet 511 of the metal chip guide 510 is greater than or equal to 600 mm². 2 Optionally, the area of ​​entrance 511 is 604 mm². 2 Optionally, the area of ​​entrance 511 is 610 mm². 2 Optionally, the area of ​​entrance 511 is 623 mm². 2 Optionally, the area of ​​entrance 511 is 645 mm². 2 Optionally, the area of ​​entrance 511 is 650 mm². 2 .

[0108] Based on the area range of the inlet 511 of the metal chip guide tube 510 and the ratio range of the area of ​​the inlet 511 to the cross-sectional area of ​​the chip guide cavity 513 of the metal chip guide tube 510 located above the circular saw blade 200, it can be seen that the area of ​​the inlet 511 of the metal chip guide tube 510 in this application is relatively large, larger than the cross-sectional area of ​​any point on the chip guide cavity 13, and much larger than the cross-sectional area of ​​the chip guide cavity 513 located directly above the rotation center of the circular saw blade 200. By setting a larger inlet 511, the chips can enter the metal chip guide tube 510 more easily, and even when there are many chips, they can also easily enter the metal chip guide tube 510, thereby improving the dust collection efficiency of the circular saw 100.

[0109] In some embodiments, such as Figure 3 and Figure 4 As shown, a vertical surface 5111 is included at the bottom of the inlet 511 of the metal chip guide tube 510. The vertical surface 5111 extends in the vertical direction, so that during the process of reflecting chips from the lower end 320 to the inlet 511, the chips may reflect and hit the vertical surface 5111, and then be reflected back into the metal chip guide tube 510. By setting the vertical surface 5111, the probability of chips failing to enter the metal chip guide tube 510 when the chip reflection angle from the lower end 320 is inappropriate is avoided, further improving the dust collection efficiency of the circular saw 100.

[0110] Therefore, based on the larger area of ​​the inlet 511 and the specific structure including the vertical surface 5111 as defined in this application, combined with the specific structure of the lower end 320 including at least one arc, the center of the arc on the lower end 320 being located above the center of the circular saw blade 200, the line connecting the center of the arc to any point on the arc being located above the center of the circular saw blade 200, and the minimum distance between the lower end 320 and the circular saw blade 200, the dust collection efficiency of the circular saw 100 is comprehensively improved, making the dust collection efficiency of the circular saw 100 greater than or equal to 70%. Optionally, the dust collection efficiency of the circular saw 100 is 73%. Optionally, the dust collection efficiency of the circular saw 100 is 75%.

[0111] In some embodiments, in the radial direction of the circular saw blade 200, the distance between the bottom of the inlet 511 of the metal chip guide 510 and the center of the circular saw blade 200 is greater than the radius of the circular saw blade 200. For example... Figure 3 As shown, the metal chip guide tube 510 has outwardly extending extensions 5112 on both sides of the inlet 511. The distance between the extensions 5112 and the center of the circular saw blade 200 is greater than the radius of the circular saw blade 200. Optionally, the radius of the circular saw blade 200 is greater than or equal to 68 mm and less than or equal to 75 mm. Optionally, the radius of the circular saw blade 200 is 70 mm. Optionally, the radius of the circular saw blade 200 is 73 mm. Optionally, the distance between the extensions 5112 and the center of the circular saw blade 200 is greater than 75 mm and less than or equal to 79 mm. Optionally, the distance between the extensions 5112 and the center of the circular saw blade 200 is 76 mm. Optionally, the distance between the extensions 5112 and the center of the circular saw blade 200 is 76.8 mm. Optionally, the distance between the extensions 5112 and the center of the circular saw blade 200 is 78 mm. Optionally, the distance between the extension 5112 and the center of the circular saw blade 200 is 78.5 mm. In addition, the radius of the circular saw blade 200 can be other values, and the distance between the extension 5112 and the center of the circular saw blade 200 can be other distances greater than the radius of the circular saw blade 200. This application does not limit these values.

[0112] In some embodiments, the outer surface area of ​​the metal chip guide tube 510 is S1, and the surface area of ​​the fixed cover 300 surrounding the metal chip guide tube 510 is S2, with the ratio of S1 to S2 being greater than 1. That is, the outer surface area S1 of the metal chip guide tube 510 is larger than the surface area S2 of the fixed cover 300 surrounding it, and the fixed cover 300 does not completely surround the metal chip guide tube 510. Specifically, the outer surface area S1 of the metal chip guide tube 510 refers to the area around the metal chip guide tube 510, and the portion of the fixed cover 300 surrounding the metal chip guide tube 510 is specifically the main cover 310. Optionally, the ratio of S1 to S2 is greater than or equal to 1.2. Optionally, the ratio of S1 to S2 is greater than or equal to 1.35. Optionally, the ratio of S1 to S2 is greater than or equal to 1.4. Optionally, the ratio of S1 to S2 is greater than or equal to 1.5.

[0113] In some embodiments, such as Figure 14 As shown, the fixed cover 300 does not completely enclose the metal chip guide tube 510 at its lower side. After removing the circular saw blade 200 or the movable cover 400, the bottom of the metal chip guide tube 510 can be seen from the lower surface of the base 110 along the window 111 of the base 110 towards the upper surface of the base 110. That is, the lower side of the metal chip guide tube 510 includes a portion exposed to the air. After the chips are reflected into the metal chip guide tube 510 via the lower end 320, most of the chip's trajectory includes falling to the lower side of the metal chip guide tube 510. The portion of the lower side of the metal chip guide tube 510 exposed to the air corresponds to the normal chip falling position. Therefore, after the chips fall, because this part is exposed to the air, the heat of the chips can be directly transferred to the air based on the metal chip guide tube 510, helping the chips to dissipate heat and cool down more effectively.

[0114] In some embodiments, the metal chip guide tube 510 is fixed to the fixed cover 300 by a support member 301. At least a portion of the support member 301 is disposed at both ends of the lower surface of the metal chip guide tube 510, specifically at the left and right ends of the lower surface of the metal chip guide tube 510, so that the support member 301 can support the metal chip guide tube 510 and fix the metal chip guide tube 510 inside the fixed cover 300. The support members 301 at both ends have hollow portions, so that the lower side of the metal chip guide tube 510 includes a portion exposed to the air. Optionally, the support member 301 and the fixed cover 300 are integrally formed, and the support member 301 is part of the fixed cover 300. The support member 301 and the fixed cover 300 are made of the same material, plastic. Optionally, the support member 301 and the fixed cover 300 are formed separately. The support member 301 is fixedly connected to the fixed cover 300. The support member 301 can be made of the same plastic material as the fixed cover 300, or it can be made of a different metal material. Furthermore, the support member 301 can also be made of other materials; this application does not limit its use. When the support member 301 is made of plastic, the hollow design avoids the drawback of the metal chip guide tube 510 overheating, which could potentially cause the support member 301 to melt.

[0115] In some embodiments, multiple ribs 312 are disposed between the metal chip guide tube 510 and the fixed cover 300, so that there is a certain gap between the metal chip guide tube 510 and the fixed cover 300, and the metal chip guide tube 510 and the fixed cover 300 do not directly contact each other. Figure 15 and Figure 16As shown, the upper, left, and right surfaces of the metal chip guide tube 510 are all abutted against the inner surface of the fixed cover 300 by spaced ribs 312, so that after the chips enter the metal chip guide tube 510, the metal chip guide tube 510 can dissipate heat based on the gaps of multiple ribs 312, effectively ensuring the heat dissipation performance of the metal chip guide tube 510.

[0116] Optionally, the metal chip guide tube 510 is integrally formed, thereby ensuring good sealing performance and effectively preventing chips from leaking out of the metal chip guide tube 510 and falling onto the fixed cover 300, which could potentially cause the fixed cover 300 to melt and deform. Optionally, the metal chip guide tube 510 can also be welded from two halves and then assembled into the fixed cover 300 as a whole. The welded metal chip guide tube 510 also has good sealing performance and can achieve the same technical effect as the integrally formed metal chip guide tube 510.

[0117] In some embodiments, the thermal conductivity of the fixed shield 300 differs from that of the metal chip guide 510. Compared to the plastic fixed shield 300, the metal chip guide 510 has a higher thermal conductivity, resulting in better heat dissipation efficiency and enabling timely heat dissipation of chips after they enter the metal chip guide 510. Optionally, the metal chip guide 510 may be made of SUS304 material, and its heat transfer coefficient is 15 W / (m²·K).

[0118] This application improves the heat dissipation effect of the metal chip guide tube 510 by setting the fixed cover 300 to not completely cover the metal chip guide tube 510, and by setting multiple ribs 312 between the fixed cover 300 and the metal chip guide tube 510, while reducing the risk of the fixed cover 300 melting and deforming, extending the life of the fixed cover 300, and thus extending the overall service life of the circular saw 100.

[0119] In some embodiments, a guide portion 340 is provided on the fixed cover 300 near the inlet 511 of the metal chip guide tube 510. The guide portion 340 is used to guide the chips blown up by the circular saw blade 200 during cutting to the inlet 511. The guide portion 340 is the extension portion 5112 described above in this application, and will be referred to as the guide portion 340 in the following detailed description. Figure 16 As shown, the guide portion 340 includes an extension portion 341 that extends from the bottom of the inlet 511 toward the first opening end 410 near the movable shield 400 during circular saw cutting. The extension portion 341 extends to the lower end of the inlet 511 of the metal chip guide tube 510, including a portion protruding from the lower end of the inlet 511. The first opening end 410 of the movable shield 400 is the end of the movable shield 400 that abuts against the cutting material during circular saw cutting.

[0120] In some embodiments, a support portion 342 is connected to or formed on the guide portion 340. The support portion 342 is disposed on the lower side of the metal chip guide tube 510 and connected to the fixing cover 300, thereby fixing the metal chip guide tube 510 and the fixing cover 300 to support the metal chip guide tube 510. In some embodiments, the fixing cover 300 and the support portion 342 are integrally formed, with the support portion 342 extending directly inward on the fixing cover 300. The support portion 342 is made of the same plastic material as the fixing cover 300, allowing the metal chip guide tube 510 to be directly disposed inside the fixing cover 300 and supported by it. In some embodiments, the support member 301 includes a portion disposed near the inlet 511. Optionally, the support portion 342 and the support member 301 can be in contact. Optionally, the support portion 342 and the support member 301 can be two components spaced apart.

[0121] In some embodiments, the guide portion 340 is integrally formed with the metal chip guide tube 510. The guide portion 340 is directly formed on the inner side of the inlet 511 of the metal chip guide tube 510 and connected thereto, thus being fixedly connected to the interior of the protective cover 300. In this case, the guide portion 340 is made of the same metal material as the metal chip guide tube 510. This prevents the guide portion 340 from melting or deforming when chips collide with it during cutting by the circular saw blade 200. In some embodiments, the guide portion 340 may also not be integrally formed with the metal chip guide tube 510; the guide portion 340 is formed separately and fixedly connected to the metal chip guide tube 510.

[0122] like Figure 8 As shown, the movable guard 400 includes a first side portion 420, a second side portion 430, and a bottom portion 440 connecting the first side portion 420 and the second side portion 430. The distance between the first side portion 420 and the second side portion 430 is appropriate, ensuring that when the circular saw blade 200 is assembled into the circular saw 100, the circular saw blade 200 will not contact the first side portion 420 or the second side portion 430. Simultaneously, the suitable distance between the first side portion 420 and the second side portion 430 prevents the circular saw 100 from having a large lateral dimension.

[0123] When the circular saw 100 is cutting, the movable guard 400 rotates clockwise based on the cutting depth of the circular saw blade 200. The rotation angle of the movable guard 400 is at its maximum when the cutting depth of the circular saw blade 200 is at its deepest. At this time, the guide portion 340 comes into contact with the first side portion 420 and the second side portion 430 of the movable guard 400, specifically as follows: Figure 8 The first end 421 of the first side portion 420 and the second end 431 of the second side portion 430 abut against the extension 341 of the movable cover 400.

[0124] like Figure 16 As shown, the guide portion 340 is generally flat, specifically the extension portion 341 included in the guide portion 340 is also basically flat. The guide portion 340 includes a slit 343 formed from its lower end to allow the circular saw blade 200 to enter the slit 343. The slit 343 is formed by the extension portions 341 on both sides, and the width of the slit 343 is greater than the thickness of the circular saw blade 200, ensuring that the circular saw blade 200 does not contact the side walls of the slit 343 during rotation. Simultaneously, the distance between the upper wall of the slit 343 and the center of the circular saw blade 200 in the radial direction is greater than the radius of the circular saw blade 200, ensuring that the circular saw blade 200 does not contact the two upper walls of the slit 343 during rotation. Therefore, the structure of the slit 343 ensures the safety of the circular saw blade 200 during rotation.

[0125] In some embodiments, the slit 343 can be as follows: Figure 16 The rectangular slit shown is shown. In some embodiments, the slit 343 can be a triangular slit. In some embodiments, the slit 343 can be an irregularly shaped slit. Furthermore, the slit 343 can also be any other shape that ensures that the upper wall and side walls do not come into contact with the circular saw blade 200, and this application does not limit the shape.

[0126] By providing guide portions 340 protruding from the lower end of the inlet 511 on both sides of the metal chip guide tube 510, the chips are guided to enter the metal chip guide tube 510 better, and to a certain extent, the chips can be prevented from falling onto the movable shield 400, thus reducing the probability of the movable shield 400 melting or deforming.

[0127] In some embodiments, such as Figure 16 and Figure 17 As shown, a support slit 3421 is formed on the support portion 342. The width of the support slit 3421 is greater than the thickness of the circular saw blade 200, ensuring that the circular saw blade 200 does not contact the two side walls of the support slit 3421 during rotation. Simultaneously, the distance between the upper wall of the support slit 3421 and the center of the circular saw blade 200 in the radial direction is greater than the radius of the circular saw blade 200, ensuring that the circular saw blade 200 does not contact the two upper walls of the support slit 3421 during rotation. Therefore, the structure of the support slit 3421 ensures the safety of the circular saw blade 200 during rotation. This application does not limit the shape of the support slit 3421; the support slit 3421 can be any shape that satisfies the above conditions.

[0128] Furthermore, the upper and side walls of the support slit 3421 are at a certain distance from the circular saw blade 200, but the distance is not large. This ensures that most of the chips from the circular saw blade 200 are blocked by the support 342 and guided into the metal chip guide tube 310 by the guide 340 during rotation. Only a small number of chips pass through the support slit 3421 and fall to the lower side of the base 110, reducing the probability of chips falling into the movable cover 400 and the probability of the movable cover 400 being melted or deformed by the high temperature of the chips, thus extending the service life of the movable cover 400. In some embodiments, the distance between the upper wall of the support slit 3421 and the center of the circular saw blade 200 is greater than 75 mm and less than or equal to 80 mm. Optionally, the distance between the upper wall of the support slit 3421 and the center of the circular saw blade 200 can be 76 mm. Optionally, the distance between the upper wall of the support slit 3421 and the center of the circular saw blade 200 can be 77.3 mm. Optionally, the distance between the upper wall of the support slit 3421 and the center of the circular saw blade 200 can be 78.5 mm.

[0129] In some embodiments, the distance between the bottom of the guide portion 340 and the center of the circular saw blade 200 is greater than 75 mm and less than or equal to 79 mm. Specifically, the distance between the bottom of the extension portion 341 in the guide portion 340 and the center of the circular saw blade 200 is greater than 75 mm and less than or equal to 79 mm. In some embodiments, taking a radius of 75 mm for specific illustration, the distance between the bottom of the support portion 342 and the center of the circular saw blade 200 is greater than or equal to 68 mm and less than or equal to 74 mm. Specifically, the distance between the bottom 3422 of the support portion 342 and the center of the circular saw blade 200 is greater than or equal to 68 mm and less than or equal to 74 mm. Optionally, the distance between the bottom 3422 and the center of the circular saw blade 200 is 69.5 mm. Optionally, the distance between the bottom 3422 and the center of the circular saw blade 200 is 70 mm. Optionally, the distance between the bottom 3422 and the center of the circular saw blade 200 is 71.1 mm. Optionally, the distance between the bottom 3422 and the center of the circular saw blade 200 is 73.5 mm. Since the radius of the circular saw blade 200 is 75 mm, the distance from the bottom 3422 of the support portion 342 to the center of the circular saw blade 200 is less than the radius of the circular saw blade 200. The support portion 342 includes portions extending to the left and right sides of the circular saw blade 200. Thus, when the circular saw 100 is cutting, most of the chips can be blocked by the support portion 342 and guided into the metal chip guide tube 310 via the extension portion 341. Furthermore, in some embodiments, the distance from the bottom of the extension portion 341 to the center of the circular saw blade 200 may also be less than or equal to the radius of the circular saw blade 200, which is not limited in this application.

[0130] In some embodiments, such as Figure 1 and Figure 18 , Figure 19As shown, the circular saw 100 also includes a hook assembly 150. The circular saw 100 is a handheld power tool. When operating the circular saw 100, especially when working at heights, users often need to suspend the circular saw 100 via the hook assembly 150 after a period of operation so that it can be used again later. The hook assembly 150 specifically includes a connector 151 and a hook 152, wherein the connector 151 is used to connect the hook assembly 150 to the circular saw 100, and the hook 152 is used to suspend the circular saw 100.

[0131] like Figure 18 As shown, the hook assembly 150 is disposed on the upper part of the front end of the handle assembly 120 of the circular saw 100, located between the main handle 121 and the auxiliary handle 122. Therefore, when the hook assembly 150 is used, hanging the circular saw 100 is more convenient, and no other parts on the circular saw 100 will obstruct its hanging. Figure 19 As shown, a fixing member 124 is provided at the front end of the handle assembly 120. The fixing member 124 cooperates with the connecting member 151 to fix the connecting member 151 to the circular saw 100. Optionally, the fixing member 124 and the connecting member 151 are integrally formed. Optionally, the fixing member 124 and the connecting member 151 are formed separately, but fixedly connected. The fixing member 124 can be fixedly connected to the handle assembly 120 based on components such as screws. Furthermore, the fixing member 124 can also be integrally formed with the handle assembly 120; this application does not limit this.

[0132] The hook 152 can rotate relative to the connector 151, and the hook 152 and the connector 151 are rotatably connected. Specifically, as follows... Figure 19 As shown, the hook 152 rotates about the axis N where the connector 151 is located. The axis N is perpendicular to the rotation center of the circular saw blade 200. Optionally, the hook 152 can rotate 90 degrees. Optionally, the hook 152 can rotate 180 degrees. Furthermore, the hook 152 can rotate to other angles as needed, which are not limited in this application.

[0133] like Figure 18 As shown, a recess 125 is also formed at the front end of the handle assembly 120 to mate with the hook 152 and to accommodate the hook 152. Figure 1 As shown, when the hook 152 is not in use, the hook 152 is located in the recess 125 and is in the first position of being stored. At this time, when the user holds the main handle 121 and the secondary handle 122 with both hands respectively, the hook 152 will not interfere with the user's hands, thus facilitating the user's operation.

[0134] like Figure 18 As shown, when hook 152 needs to be used, hook 152 can be drawn from... Figure 1 Rotate 90 degrees to the first position shown. Figure 18 The second position is shown. When the hook 152 is in the second position, the circular saw 100 can be suspended. During the suspension process, the front end of the auxiliary handle 122 and the fixed cover 300 can abut against the suspended object, serving as two auxiliary suspension fulcrums. That is, the front side of the circular saw 100 abuts against the suspended object, thereby making the suspension of the circular saw 100 more stable.

[0135] like Figure 19 As shown, when hook 152 needs to be used, hook 152 can be drawn from... Figure 18 The second position shown is rotated 90 degrees again to Figure 19 The third position shown is from Figure 1 Rotate 180 degrees to the first position shown. Figure 19 The third position is shown. At this position, the circular saw 100 can be suspended, and during the suspension process, the side ends of the auxiliary handle 122 and the drive mechanism 130 can abut against the suspended object, serving as two auxiliary suspension fulcrums, that is, the left side of the circular saw 100 abuts against the suspended object, thereby making the suspension of the circular saw 100 more stable.

[0136] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that the above embodiments do not limit this application in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this application.

Claims

1. A portable circular saw for cutting metal, comprising: A cutting machine body having a base whose lower surface abuts against the material being cut, and a cutting machine body at least partially supported on the upper surface of the base; The main body of the cutting machine includes: A circular saw blade protrudes downward from a window provided on the base and cuts into the material being cut; A fixed protective cover is provided to cover the outer circumference of the circular saw blade. A metal chip guide tube is disposed inside the fixed cover and surrounds a portion of the outer circumference of the circular saw blade, including a chip guide cavity for guiding chips; Its features are, The ratio of the outer surface area S1 of the metal chip guide tube to the surface area S2 covered by the fixed protective cover is greater than 1.

2. The portable circular saw as described in claim 1, characterized in that, The ratio of the outer surface area S1 of the metal chip guide tube to the surface area S2 covered by the fixed protective cover is greater than or equal to 1.

2.

3. The portable circular saw as described in claim 1, characterized in that, The metal chip guide tube is fixed to the fixed cover by a support member.

4. The portable circular saw as described in claim 3, characterized in that, The support member is integrally formed with the fixed cover or connected to the fixed cover.

5. The portable circular saw as described in claim 3, characterized in that, At least a portion of the support member is disposed at both ends of the lower surface of the metal chip guide tube.

6. The portable circular saw as described in claim 1, characterized in that, The thermal conductivity of the fixed shield is different from that of the metal chip guide tube.

7. The portable circular saw as described in claim 1, characterized in that, The metal chip guide tube is integrally formed.

8. The portable circular saw as described in claim 1, characterized in that, The upper, left, and right surfaces of the metal chip guide tube abut against the inner surface of the fixed cover through spaced ribs.

9. The portable circular saw as described in claim 1, characterized in that, The heat transfer coefficient of the metal chip guide tube is 15 W / (㎡·K).

10. The portable circular saw as claimed in claim 1, characterized in that, The portable circular saw also includes a battery pack for powering the portable circular saw.

11. A portable circular saw for cutting metal, comprising: A cutting machine body having a base whose lower surface abuts against the material being cut, and a cutting machine body at least partially supported on the upper surface of the base; The main body of the cutting machine includes: A circular saw blade protrudes downward from a window provided on the base and cuts into the material being cut; A fixed protective cover is provided to cover the outer circumference of the circular saw blade. A movable guard, which rotates relative to the fixed guard and can cover a portion of the outer circumference of the circular saw blade; a metal chip guide tube, installed inside the fixed guard and surrounding a portion of the outer circumference of the circular saw blade, including a chip guide cavity for guiding chips; Its features are, After the circular saw blade or movable guard is removed, the bottom of the metal chip guide tube can be seen from the lower surface side of the base along the window portion of the base to the upper surface side.

12. The portable circular saw as described in claim 11, characterized in that, The metal chip guide tube is fixed to the fixed cover by a support member.

13. The portable circular saw as described in claim 12, characterized in that, The support member is integrally formed with the fixed cover or connected to the fixed cover.

14. The portable circular saw as described in claim 12, characterized in that, At least a portion of the support member is disposed at both ends of the lower surface of the metal chip guide tube.

15. The portable circular saw as claimed in claim 11, characterized in that, The thermal conductivity of the fixed shield is different from that of the metal chip guide tube.

16. The portable circular saw as claimed in claim 11, characterized in that, The metal chip guide tube is integrally formed.

17. The portable circular saw as claimed in claim 11, characterized in that, The upper, left, and right surfaces of the metal chip guide tube abut against the inner surface of the fixed cover through spaced ribs.

18. The portable circular saw as claimed in claim 11, characterized in that, The ratio of the outer surface area S1 of the metal chip guide tube to the surface area S2 covered by the fixed protective cover is greater than or equal to 1.

2.

19. The portable circular saw as claimed in claim 11, characterized in that, The heat transfer coefficient of the metal chip guide tube is 15 W / (㎡·K).

20. The portable circular saw as claimed in claim 11, characterized in that, The portable circular saw also includes a battery pack for powering the portable circular saw.

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