CN115805613A - Hand-held electric circular saw - Google Patents

Abstract

The invention discloses a hand-held electric circular saw, comprising: a saw blade; an output shaft; a motor; the motor comprises a shell, a handle and a motor, wherein the shell comprises a motor shell for accommodating a motor and a holding part for being held by a user; a base plate including a base plate plane for contacting a workpiece; the fixed shield is fixedly connected with the shell; the movable shield is rotatably connected with the fixed shield; the handheld electric circular saw can be supported on a working surface through the movable shield and the bottom plate; when the hand-held electric circular saw is supported on the working face through the movable protective cover and the bottom plate, the plane of the bottom plate inclines relative to the working face, and the cutting plane where the saw blade is located is basically vertical to the working face. The scheme can provide a complete machine equilibrium good more than adopting, and the difficult incline more is favorable to the hand-held type electric circular saw that the user gripped, and this hand-held type electric circular saw's guard shield and bottom plate can not the side direction atress, can prolong the life of guard shield and bottom plate effectively.

Description

Hand-held electric circular saw

Technical Field

The invention relates to an electric tool, in particular to a handheld electric circular saw.

Background

In recent years, users who use the handheld electric circular saw are increasing, and the handheld power supply electric circular saw is also increasing in function. At present, the hand-held type electric circular saw of great majority adopts three point inclined support, supports on the working face through motor casing, bottom plate and activity guard shield respectively, and the cutting plane at saw bit place this moment is not the vertically between cutting plane and the working face, and the activity guard shield can bear certain side direction component this moment to make the activity guard shield warp easily, lead to the life-span to shorten. On the other hand, when hand-held type electric circular saw adopted the three point inclined support, the focus of complete machine was partial to one side certainly, and this makes the user can not experience better feeling in the use.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides the handheld electric circular saw which is more stable in placement of the whole machine and better in hand-held hand feeling.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a hand-held electric circular saw comprising: a saw blade; the output shaft is used for mounting the saw blade and driving the saw blade to rotate; the motor is used for driving the output shaft to rotate; the shell comprises a motor shell for accommodating the motor and a holding part for holding by a user; a base plate connected to the housing, the base plate including a base plate plane for contacting a workpiece; the fixed shield is fixedly connected with the shell; the movable shield is rotatably connected with the fixed shield; the hand-held electric circular saw can be supported on a working surface through the movable guard and the bottom plate; when the handheld electric circular saw is supported on a working face through the movable protective cover and the bottom plate, the plane of the bottom plate inclines relative to the working face, and the cutting plane where the saw blade is located is basically perpendicular to the working face.

Further, the motor is located behind the fixed shield in the extending direction of the housing, and a projection of the motor on the cutting plane is not coincident with a projection of the fixed shield on the cutting plane.

Further, the motor at least comprises a motor shaft, and an included angle formed by a straight line formed by the projection of the motor shaft and the output shaft on the cutting plane and the projection of the bottom plate plane on the cutting plane is larger than or equal to 10 degrees and smaller than or equal to 30 degrees.

Further, the housing is formed with a grip portion for a user to grip, the grip portion being symmetrically disposed about the first plane.

Further, the distance from the center of gravity of the hand-held electric circular saw to the first plane is greater than or equal to 0 and less than or equal to 5mm.

Furthermore, the orthographic projections of the handheld electric circular saw on the plane where the bottom plate plane is located are located in the bottom plate plane.

Further, the case is also formed with a coupling portion for connecting a battery pack, the battery pack being detachably coupled to the coupling portion.

Further, the projections of the holding part, the saw blade and the combining part on the plane of the bottom plate are approximately positioned on the same straight line.

Furthermore, the shell is also provided with an air inlet and an air outlet for air flow circulation.

Further, the air outlet at least comprises a first air outlet and a second air outlet, and the first air outlet and the second air outlet are located on two sides of the cutting plane where the saw blade is located.

Drawings

Fig. 1 is a perspective view of a hand-held electric circular saw in a first embodiment;

FIG. 2 is a perspective view of the hand-held electric circular saw of FIG. 1 from another perspective;

FIG. 3 is a cross-sectional view of the hand-held electric circular saw of FIG. 2;

FIG. 4A is a block diagram of the transmission;

FIG. 4B is a block diagram of another perspective of the transmission;

FIG. 5A is a perspective view of the hand-held electric circular saw positioned on a work surface;

FIG. 5B is a perspective view of the hand-held electric circular saw with the battery pack attached and placed on a work surface;

FIG. 6 is a perspective view of the hand-held electric circular saw of FIG. 1 from yet another perspective;

FIG. 7 is a partial exploded view of the hand held electric circular saw;

FIG. 8 is a structural view of a dust outlet pipe and a fixed guard of the hand-held electric circular saw;

FIG. 9 is a cross-sectional view of the dust pipe and the stationary shroud of FIG. 8 from another perspective;

fig. 10 is a structural view of a base plate of the hand-held electric circular saw;

fig. 11 is a perspective view of a hand-held electric circular saw in a second embodiment;

FIG. 12 is a cross-sectional view of the hand-held electric circular saw of FIG. 11;

FIG. 13 is a perspective view of the hand-held electric circular saw of FIG. 11 from another perspective;

FIG. 14 is a cross-sectional view from yet another perspective of the hand-held electric circular saw;

FIG. 15 is a block diagram of the air inlet of the hand-held electric circular saw of FIG. 11;

FIG. 16 is a partial exploded view of the hand-held electric circular saw of FIG. 11;

fig. 17 is a structural view of an airflow guide part of the hand-held electric circular saw of fig. 11.

Detailed Description

The invention is described in detail below with reference to the figures and the embodiments.

The hand-held electric circular saw 100 of the first embodiment shown in fig. 1 may be used to cut wood, fiberboard, plastics, and the like. For convenience of explanation of the technical solution of the present invention, a front side, a rear side, a left side, a right side, an upper side and a lower side as shown in fig. 1 are also defined. As shown in fig. 1 to 3, the hand-held electric circular saw 100 includes: the device comprises a shell 11, an output shaft 121, a saw blade 122, a bottom plate 13, a motor 14 and a power supply device. The housing 11 is configured to accommodate a motor 14 and the like, and the motor 14 is configured to provide a power source and can drive the output shaft 121 to rotate around the first axis 101 to output power. The saw blade 122 is used to cut a workpiece, the base plate 13 is formed with a base plate plane 131 for contact with the workpiece, and the saw blade 122 is disposed to pass through the base plate plane 131. The power supply device is used for connecting a power supply required by the handheld electric circular saw 100 to work. The power supply device is optionally set as an alternating current power supply, and 120V or 220V alternating current commercial power is connected through an alternating current plug. The power supply means may also take the form of a dc power supply, for example a battery pack 151 which may be removably coupled to the housing 11.

As shown in fig. 1 to 2, the housing 11 is formed with a grip portion 111 to be gripped by a user, and the grip portion 111 is further provided with a trigger switch 111a and a safety switch 111b. The trigger switch 111a is movably connected to the holding portion 111, and when a hand of a user is held by the holding portion 111, the hand of the user can trigger the trigger switch 111a to start the handheld electric circular saw 100. The safety switch 111b is provided on the grip portion 111 or in the vicinity of the grip portion 111, and the safety switch 111b is used to lock the trigger switch 111a at a position that is not triggered by a user, thereby preventing accidental activation of the electric circular saw 100 and protecting the user from injury. It is understood that the safety switch 111b may be disposed at the left or right side of the grip portion 111 or both sides thereof. The grip portion 111 has a first end 111c and a second end 111d in the extending direction thereof, respectively. The case 11 is further formed with a coupling portion 112 for coupling the battery pack 151, and the coupling portion 112 is coupled to the first end 111c of the grip portion 111. Specifically, the coupling portion 112 is used to connect the battery pack 151 to supply power to the handheld electric circular saw 100. In this embodiment, the battery pack 151 is detachably connected to the coupling portion 112. The nominal voltage of the battery pack 151 was 18V, and the nominal capacity was 3000mAh. The battery pack 151 comprises a plurality of battery cells, and the width of the battery pack 151 is 84mm.

Referring to fig. 2 and 3, the housing 11 is formed with a first accommodation portion 113 and a second accommodation portion 114. The first receiving portion 113 is connected to the second end 111d of the holding portion 111, and the second receiving portion 114 is disposed below the holding portion 111 and between the combining portion 112 and the second receiving portion 114. The first accommodation portion 113 is formed with a first accommodation cavity 113a, and the circuit board assembly 18 is disposed in the first accommodation cavity 113 a. The housing 11 of the handheld electric circular saw 100 in this embodiment is a two-half housing, the holding portion 111 is symmetrically disposed about the first plane 102, and the first plane 102 is perpendicular to the first axis 101. In the present embodiment, the first accommodating portion 113 is connected to the second end 111d of the holding portion 111, the first accommodating portion 113 is also disposed symmetrically with respect to the first plane 102, and further, the circuit board assembly 18 is disposed in the first accommodating cavity 113a formed by the first accommodating portion 113, it can be understood that the circuit board assembly 18 is also disposed symmetrically with respect to the first plane 102. The circuit board assembly 18 includes: the control circuit of the handheld electric circular saw 100 may be partially disposed on the first circuit board and partially disposed on the second circuit board, so that the sizes of the first circuit board and the second circuit board are relatively small, thereby avoiding the problem that the circuit board is inconvenient to set due to the fact that the circuit board has a relatively large size when all the control circuits are disposed on one circuit board, and further facilitating the disposition of the first circuit board and the second circuit board at appropriate positions in the housing 11. Further, the first circuit board is used for controlling the output power of the motor 14, and the second circuit board can be used for controlling the battery pack 151, but not limited thereto. In the present embodiment, the circuit board assembly 18 further includes a heat sink (not shown) for dissipating heat.

The second receiving portion 114 is formed with a second receiving chamber 114a, and the motor 14 and the transmission 17 are disposed in the second receiving chamber 114 a. The motor 14 may be a brushless motor 14, and the motor 14 includes a motor shaft 141 that can rotate around a second axis 103, where the second axis 103 is parallel to the first axis 101. Preferably, the diameter of the motor 14 is 45mm to 65mm, and the ratio of the rated power of the handheld electric circular saw 100 to the diameter of the motor 14 is 25W/mm or more and 35W/mm or less, and further, the ratio is 30W/mm.

Specifically, the motor 14 and the transmission 17 are sequentially disposed in the second accommodation chamber 114 a. It is understood that the motor 14 is disposed within the second receiving cavity 114a near one end of the coupling portion 112. Referring to fig. 3, the motor 14 is positioned at an upper rear position of the stationary shroud 161. Specifically, a straight line D passes through the motor shaft 141 and the output shaft 121, and an included angle between a projection of the straight line D on the first plane 102 and a projection of the bottom plate plane 131 on the first plane 102 is 10 ° or more and 30 ° or less.

Referring to fig. 4A and 4B, the transmission 17 includes a belt drive assembly 171 and a gear drive assembly 172, although it is understood that in other embodiments, the transmission 17 may include only the belt drive assembly 171 or only the gear drive assembly 172. Specifically, the belt drive assembly 171 specifically includes: a first pulley 171a, a second pulley 171b, a drive belt 171c and an intermediate shaft 171d. The first pulley 171a is fixedly connected to the motor shaft 141, the second pulley 171b is fixedly connected to the intermediate shaft 171d, and the transmission belt 171c is stretched over the first pulley 171a and the second pulley 171b, thereby achieving power transmission. The intermediate shaft 171d extends in a direction of a third axis 104 parallel to the first axis 101, and when the motor shaft 141 rotates, the transmission belt 171c rotates the second pulley 171b, and the second pulley 171b rotates the intermediate shaft 171d together with the third axis 104. The gear assembly 172 includes: the first gear 172a is fixedly connected to the intermediate shaft 171d, and the second gear 172b is connected to the output shaft 121, and the first gear 172a can transmit power output by the intermediate shaft 171d to the output shaft 121, thereby driving the output shaft 121 to rotate about the first axis 101. In the present embodiment, the first gear 172a and the second gear 172b are engaged with each other, and it is understood that in other embodiments, a gear for enabling the user to transmit power between the first gear 172a and the second gear 172b may be further disposed between them.

As shown in fig. 2, the handheld electric circular saw 100 further includes a locking member 123 for locking the rotation of the output shaft 121, and the locking member 123 can lock the rotation of the output shaft 121 when cooperating with any one of the rotating components in the transmission 17 to lock the rotation of the component, or the locking member 123 can cooperate directly with the motor shaft 141 or the output shaft 121 to lock the rotation of the output shaft 121. In the present embodiment, as shown in fig. 4B, the second pulley 171B is formed with the locking groove 171e, and the locking groove 171e is recessed inward in a radial direction perpendicular to the third axis 104. The locking member 123 is partially disposed in the second receiving cavity 114a formed in the second receiving portion 114, the locking member 123 is formed with a locking protrusion 123a capable of being inserted into the locking groove 171e, and the locking member 123 can rotate relative to the housing 11. When the user operates the locking member 123 to rotate relative to the housing 11, the locking protrusion 123a is fitted into the locking groove 171e to lock the rotation of the second pulley 171b, and the rotation of the output shaft 121 is locked.

The housing 11 of the hand-held electric circular saw 100 in this embodiment is a two-half housing. The grip 111 is also symmetrically disposed about a first plane 102, the first plane 102 being perpendicular to the first axis 101. The length of the motor 14 used in the handheld electric circular saw 100 of the present embodiment is preferably 56mm, whereas the length of the motor used in the conventional electric circular saw is about 96mm, and therefore, the size of the motor 14 of the handheld electric circular saw 100 of the present embodiment is significantly reduced, so that the external dimension of the whole handheld electric circular saw 100, particularly the dimension in the direction perpendicular to the plane of the saw blade 122 is significantly reduced, as shown in fig. 6, in which the size of the housing 11 of the handheld electric circular saw 100 is smaller than the size of the bottom plate 13. It will be appreciated that in a direction perpendicular to the base plate 13, the projection of the housing 11 falls within the area defined by the boundaries of the base plate 13. The weight of the motor 14 is one of the important components of the overall weight of the hand-held electric circular saw 100 in the present embodiment, and since the size of the motor 14 is reduced, further, the motor 14 is symmetrically disposed about the first plane 102, so that the motor 14 and the center of gravity thereof are located closer to the grip portion 111. In a state that the battery pack 151 is not mounted, the distance from the center of gravity of the handheld electric circular saw 100 to the first plane 102 of the center symmetry of the grip 111 is not more than 5mm. Preferably, when the battery pack 151 is mounted to the handheld electric circular saw 100, it is understood that the center of gravity of the battery pack 151 is also substantially located on the first plane 102. Therefore, the distance from the center of gravity of the hand-held electric circular saw 100 to the first plane 102 of the center symmetry of the grip 111 is constant, i.e., not more than 5mm, regardless of whether the battery pack 151 is mounted. Preferably, the center of gravity of the entire hand-held electric circular saw 100 is located on the first plane 102 having the center symmetry of the grip 111.

The hand-held electric circular saw 100 further includes a guard assembly 16. The shield assembly 16 includes a fixed shield 161 and a movable shield 162. The fixed guard 161 is fixed to the housing 11 on the upper side of the saw blade 122, and covers the upper half of the saw blade 122 in the circumferential direction of the saw blade 122. Specifically, referring to fig. 3, the fixing guard 161 covers an upper half portion of the saw blade 122 in a radial direction of the saw blade 122. It will be appreciated that the housing 11 can be indirectly connected to the base plate 13 by a fixed shroud 161. The housing 11 is also optionally indirectly connected to the fixed shield 161 via the bottom plate 13, and can be designed by those skilled in the art according to actual requirements. In addition, the fixing shield 161 may be made of metal, plastic, a combination of metal and plastic, or other materials. The movable shield 162 is rotatable about the first axis 101 with respect to the housing 11. The movable shield 162 extends at least partially to the underside of the floor plane 131. When the movable shield 162 rotates relative to the housing 11, the movable shield 162 and the fixed shield 161 are displaced to expose the saw blade 122, and the exposed portion of the saw blade 122 gradually increases as the movable shield 162 rotates. After the movable guard 162 is moved above the base plate 13, the hand-held electric circular saw 100 may be used to perform a cutting work.

As shown in fig. 5A and 5B, the hand-held electric circular saw 100 can be supported on the work surface a by the movable guard 162 and the base plate 13. When the handheld electric circular saw 100 is supported on the working surface a by the movable guard 162 and the base plate 13, the base plate plane 131 is inclined with respect to the working surface a, and the plane of the saw blade 122 is substantially perpendicular to the working surface a. Specifically, when the handheld electric circular saw 100 is placed on the working surface a without the battery pack 151 mounted thereon, the saw blade 122 is supported on the working surface a by the movable guard 162 and the bottom plate rear edge 132 in a plane substantially perpendicular to the working surface a. When the hand-held electric circular saw 100 is placed on the working surface a in a state where the battery pack 151 is attached, the saw blade 122 is supported on the working surface a by the movable guard 162 and the battery pack 151 in a plane substantially perpendicular to the working surface a. It should be noted here that the plane of the saw blade 122 is substantially perpendicular to the working plane a, which is understood that the plane of the saw blade 122 is not limited to 90 °, and there may be a deviation of 0 ° or more and 10 ° or less. In some embodiments, when the handheld electric circular saw 100 is supported on the working surface a by the movable guard 162 and the battery pack 151 in a state where the battery pack 151 is mounted, the handheld electric circular saw 100 may be more balanced in a placed state. In other embodiments, the handheld electric circular saw 100 is supported on the work surface a by the movable guard 162, the bottom plate rear edge 132, and the battery pack 151 in a state where the battery pack 151 is mounted. The supporting method of the handheld electric circular saw 100 in this embodiment is different from the placing manner of the conventional circular saw, the movable guard 162 and the bottom plate 13 are not stressed laterally, the service lives of the movable guard 162 and the bottom plate are prolonged, and the handheld electric circular saw 100 is safer when placed on the working surface a.

In other embodiments, the handheld electric circular saw 100 can be supported on the working surface a only by the movable guard 162 and the base plate 13 without the battery pack 151. Further, in the case where the hand-held electric circular saw 100 is not mounted with the battery pack 151, it can be supported on the work surface a only by the movable guard 162 and the bottom plate rear edge 132. Further, in the case where the hand-held electric circular saw 100 is not mounted with the battery pack 151, it can be supported on the work surface a only through the movable guard 162 and at least two points on the bottom plate rear edge 132.

The hand-held electric circular saw 100 generates a large amount of dust generated when cutting a workpiece, and the dust is discharged from the vicinity of the fixed guard 161 by the air flow generated when the motor 14 rotates. When the motor 14 reaches a certain rotation speed, the generation and discharge speed of the dust is significantly increased, so that the dust splashes, which seriously affects the user's sight and environment during the cutting operation. Referring to fig. 7 and 8, in the present embodiment, a fixed shield 161 is fixedly connected to the housing 11, and a dust outlet 161a and a dust outlet channel 161b are formed in the fixed shield 161. Wherein. The dust outlet 161a communicates with the dust outlet passage 161b. The dust outlet channel 161b is connected to a dust outlet pipe 163 for discharging dust quickly and efficiently when the hand-held electric circular saw 100 is operated at a high speed. Specifically, the dust outlet 161a is provided on the front side of the fixed shroud 161. Referring to fig. 8, the teeth of the blade 122 intersect the plane 131 of the base plate at point B, through which there exists a tangent line C to a circle having a diameter equal to the diameter of the blade 122, the tangent line C being rotated 30 ° clockwise in the plane of the blade 122 about the point B to form a first straight line C1, and the tangent line C being rotated 30 ° counterclockwise in the plane of the blade 122 about the point B to form a second straight line C2. It will be appreciated that the fixed guard 161 covers the circumferential direction of the saw blade 122, and the first and second straight lines C1 and C2 necessarily intersect the fixed guard 161. In the present embodiment, the dust outlet 161a is preferably disposed between the first straight line C1 and the second straight line C2. The teeth of the blade 122 intersect the floor plane 131 at point B, which is further understood to be the point B where the blade 122 intersects the surface of the workpiece when it has the greatest depth of cut. Here, when the movable guard 162 is completely located above the bottom plate plane 131, there is no overlapping area between the movable guard 162 and the dust outlet 161a in the radial direction of the saw blade 122, and when the movable guard 162 rotates relative to the housing 11 about the first axis 101 as an axis, the dust outlet effect of the dust outlet 161a is not affected at all times.

The dust outlet pipe 163 communicates with the dust outlet passage 161b of the fixed shield 161 via the connecting member 164. Specifically, the connector 164 is fixedly installed on the dust outlet path 161b. Referring to fig. 9, the dust outlet pipe 163 is a pipe with two open ends, and has a dust outlet pipe inlet 163a and a dust outlet 163b disposed at two ends of the dust outlet pipe 163. Wherein, the dust outlet pipe inlet 163a is connected with the connector 164 so that the dust outlet pipe 163 communicates with the dust outlet 161 a. To improve the dust extraction efficiency, the diameter of the dust extraction pipe outlet 163b is set larger than the diameter of the dust extraction pipe inlet 163 a. Specifically, the diameter of the outlet 163b of the dust outlet pipe ranges from 24mm to 40mm, and the diameter of the inlet 163a of the dust outlet pipe ranges from 19.5mm to 32.5mm. In order to prevent dust from flying up seriously when the user uses the hand-held electric circular saw 100 to cut a workpiece, the dust outlet pipe 163b faces the bottom plate plane 131 after the dust outlet pipe 163 is mounted to the dust outlet passage 161b. It can be understood that when the handheld electric circular saw 100 is in operation, the dust enters the dust outlet channel 161b through the dust outlet 161a on the fixed shield 161, then enters the dust outlet pipe 163, and finally is discharged downwards through the dust outlet pipe 163b, so as to further reduce the obstruction of the user's sight line when the dust is discharged. Preferably, referring to the cross-sectional view of the dust outlet pipe 163 shown in fig. 9, in the plane of the cross-sectional view, the included angle between the line 107 and the line 108 is α, and it can be understood that the outlet 163b of the dust outlet pipe forms an angle α with the plane 131 of the bottom plate. Specifically, the angle α ranges from 0 to 90 °.

In this embodiment, the dust outlet tube 163 is located right in front of the saw blade 122 and the holding portion 111. The dust outlet 161a, the dust outlet channel 161b, the holding portion 111 and the combining portion 112 are arranged on a straight line in the orthographic projection on a reference plane perpendicular to the cutting plane of the saw blade 122. It will be appreciated that the gripping portion 111, the coupling portion 112, and the blade 122 are generally symmetrically disposed about the first plane 102. Further, the dust outlet holes 161a provided at the front side of the fixed shroud 161 are also provided substantially symmetrically with respect to the first plane 102.

In order that the user can determine the flying direction of the dusts without spraying the dusts onto the body, the connection member 164 is preferably provided with a rotary cavity 164a, and the dust outlet pipe 163 is mounted to the connection member 164 to be rotatable in the rotary cavity 164 a. Further, the dust outlet pipe 163 rotates left or right within the rotary cavity 164a of the connecting member 164 by an angle greater than or equal to 0 ° and less than or equal to 150 ° with the first plane 102 as a central plane. It will be appreciated that the stop for the maximum angle of rotation of the dirt discharge tube 163 in the rotary cavity 164a on the connector 164 is the housing 11. That is, when the dust outlet pipe 163 rotates to the left or right to the maximum angle of 150 °, the dust outlet pipe 163 contacts the housing 11, and the dust outlet pipe 163 cannot rotate any more by a larger angle due to the presence of the housing 11. The user can rotate out dirt pipe 163 to suitable position according to actual use operating mode or individual custom, because certain reaction force can be produced when the dirt passes through the dirt pipe and discharges for play dirt pipe 163 probably appears the removal in left and right sides direction, in this embodiment, in order to prevent that rotatable play dirt pipe 163 can't fix the required position of user, still be provided with a damping piece 165 between dirt pipe 163 and the connecting piece 164 in order to increase the frictional force between the two.

The bottom plate 13 of the hand-held electric circular saw 100 needs to support the housing 11 when performing a workpiece cutting operation, and therefore the bottom plate 13 is generally made of a metal material to ensure that the bottom plate 13 has a certain strength. When the user uses the hand-held electric circular saw 100, the user may carelessly drop the hand-held electric circular saw to the ground, thereby causing an impossible deformation, such as a curling, of the edge of the base plate 13. Since the bottom plate 13 needs to be in contact with the workpiece surface during the cutting operation of the handheld electric circular saw 100, if the edge of the bottom plate 13 is deformed, the contact between the bottom plate plane 131 and the workpiece surface is affected, thereby affecting the cutting effect. In this embodiment, the rear edge 132 of the bottom plate 13, the left edge (not shown) of the bottom plate, and the right edge (not shown) of the bottom plate are all configured to be turned up, so that the bottom plate 13 designed according to this is not easy to deform when it is faded.

Referring to fig. 9, the base plate 13 further includes a reinforcing member 134 for reinforcing the strength of the base plate 13. The reinforcing member 134 is fixedly coupled to the upper surface of the base plate 13. The stiffener 134 is disposed at the floor front edge 134 of the floor 13 and extends in a direction parallel to the first axis 101. Specifically, the length of the reinforcement 134 in the extending direction is equal to or less than the length of the bottom plate front edge 135, that is, the reinforcement 134 can be stacked and mounted to the upper surface of the bottom plate 13. The distance between the foremost end of the reinforcement 134 and the floor front edge 135 is 0mm or more and 10mm or less. It is preferable to set the distance between the forwardmost end of the stiffener 134 and the front edge 135 of the sole plate to be substantially 0. It should be noted here that the reinforcement 134 is not integrally formed with the bottom plate 13. The upper surface of the stiffener 134 is also provided with graduation marks 1342 for the user to refer to when performing a cutting operation. The front end of the stiffener 134 is also provided with a notch 1343. Further, the notch 1343 and an orthographic projection of the blade 122 on the plane of the base plate 131 are substantially aligned.

In this embodiment, the stiffener 134 forms or is connected with a bracket 1341, and the stiffener 134 is fixedly connected to the base plate 13 and is also rotatably connected to the fixed shield 161 through the bracket 1341. Wherein the bracket 1341 is preferably provided as a hinge, the bracket 1341 is rotatably connected with the fixed shield 161. It is understood that when the user adjusts the cutting depth of the handheld electric circular saw 100, the bottom plate 13 rotates relative to the housing 11 about the fourth axis 106, the support 1341 is fixedly connected to the bottom plate 13, and the support 1341 rotates relative to the fixed guard 161 about an axis parallel to the first axis 101. The front floor edge 35 is also of greater strength without convenient handling because the reinforcement 134 is disposed near the front floor edge 135. In this embodiment, the reinforcing member 134 is fixedly connected to the bottom plate 13 by means of screw fastening, but it should be understood that other means may be used to fixedly connect the reinforcing member 134 to the upper surface of the bottom plate 13. The upper surface of the reinforcing member 134 is also provided with an indication scale for indicating the position of the saw blade 122 to facilitate the cutting operation by the user.

Referring to fig. 1 to 4A, the housing 11 is provided with a vent for circulating air. Specifically, in the present embodiment, the housing 11 is provided with an air inlet 115, a first air outlet 116 and a second air outlet 117. Wherein the air inlet 115 is preferably disposed on the housing 11 near the output shaft 141 of the motor 14, the first air outlet 116 is preferably disposed on the housing 11 near the second pulley 171b of the transmission 17, and the second air outlet 117 is preferably disposed on the housing 11 near the fan 142. Among them, the fan 142 in the present embodiment is preferably provided as a centrifugal fan. When the motor 14 is started, the fan 142 starts to operate, and the airflow enters the housing 11 from the air inlet 115, flows through the motor 14, then a part of the airflow flows through the transmission 17 and finally flows out from the first air outlet 116, and another part of the airflow passes through the fan 14 and finally flows out of the housing 11 from the second air outlet 117. It should be noted that the first air outlet 116 is preferably disposed on the housing 11 near the second pulley 171b of the transmission 17, and the second pulley 171b drives the intermediate shaft 171d to rotate around the third axis 104. Referring to fig. 4B, the intermediate shaft 171d connects the shaft lock ring 171f. The shaft locking ring 171f is a fan-like structure that provides additional heat dissipation to the belt drive assembly 171. The whole machine in the embodiment has a good radiating effect, and can radiate the heat of an internal heat source in a shunt way.

The hand-held electric circular saw 200 of the second embodiment shown in fig. 11 may be used to cut wood, fiberboard, plastics, and the like. The hand-held electric circular saw 200 includes: the casing 21, the saw blade 222, the bottom plate 23, the motor 24 and the power supply device. Wherein the bed plate 23 is formed with a bed plate plane 231 for contacting the workpiece, and the saw blade 222 is disposed to pass through the bed plate plane 231. The power supply device is used for connecting a power supply required by the operation of the handheld electric circular saw 200. Specifically, the power supply device is optionally set as an alternating current power supply, and 120V or 220V alternating current commercial power is accessed through an alternating current plug. The power supply means may also take the form of dc power, such as a battery pack 251 which is removably connectable to the housing 21.

Referring to fig. 11 to 14, the handheld electric circular saw 200 further includes a guard assembly 26, and the guard assembly 26 includes a fixed guard 261 and a movable guard 262. Wherein the fixed guard 261 is fixedly disposed at an upper side of the saw blade 222 with respect to the housing 21, and specifically, the fixed guard 261 covers an upper half portion of the saw blade 222 in a circumferential direction of the saw blade 222. In this embodiment, it is preferable to provide that the housing 21 is connected to the fixed shield 261, and the fixed shield 261 is connected to the bottom plate 23, that is, the housing 21 is indirectly connected to the bottom plate 23 through the fixed shield 261. Of course, it is also possible to provide that the housing 21 is connected to the base plate 23 and the base plate 23 is connected to the fixed guard 261, i.e. the housing 21 is indirectly connected to the fixed guard 261 via the base plate 23. The connection relationship is not limited, and those skilled in the art can design the connection relationship according to actual requirements. In addition, the material of the fixed shield 261 may be metal, plastic, a combination of metal and plastic, or other materials. The movable shield 262 extends at least partially to the underside of the floor plane 231. When the movable shield 262 rotates relative to the housing 21, the movable shield 262 and the fixed shield 261 are displaced to expose the saw blade 222, and the exposed portion of the saw blade 222 is gradually increased along with the rotation of the movable shield 262. When the movable guard 262 is completely moved above the base plate 23, the hand-held electric circular saw 200 can be used to perform a cutting work.

The housing 21 is formed with a grip 211 to be gripped by a user, and the grip 211 is further provided with a trigger switch 211a and a safety switch 211b. The trigger switch 211a is movably connected to the grip 211, and when a hand of a user is held by the grip 211, the hand of the user can trigger the trigger switch 211a to start the handheld electric circular saw 200. The safety switch 211b is provided on the grip 211 or near the grip 211, and the safety switch 211b is used to lock the trigger switch 211a at a position that is not triggered by a user, thereby preventing accidental activation of the electric circular saw 200 and protecting the user from injury. It is understood that the safety switch 211b may be disposed at the left or right side of the grip 211 or at both sides thereof. The grip portion 211 has a first end 211c and a second end 211d in the extending direction thereof, respectively. Specifically, the first end 211c of the grip 211 is the rear end of the grip 211, and the second end 211d is the front end of the grip 111. The case 21 is further formed with a coupling portion 212 for coupling the battery pack 151, and the coupling portion 212 is coupled to the first end 211c of the grip portion 211. Specifically, the coupling portion 212 is used to connect a battery pack 251 to supply power to the handheld electric circular saw 200. In this embodiment, the battery pack 251 is detachably connected to the coupling part 212. The nominal voltage of the battery pack 251 is 18V, and the nominal capacity is 3000mAh. The battery pack 251 comprises a plurality of battery cells, and the width of the battery pack 251 is 84mm. The second end 211d of the grip 211 is fixedly attached above the fixed guard 261.

The housing 21 further forms a motor housing 213 for accommodating the motor 24, and the motor housing 213 forms a motor accommodating chamber (not shown) in which the motor 24 is disposed. The motor housing 213 is fixedly connected to the fixed guard 261 and extends in a direction perpendicular to the cutting plane in which the saw blade 222 is located. The housing 21 is also formed with a receiving portion 214 for receiving the circuit board assembly 28. Specifically, the accommodating portion 214 is located below the holding portion 211 and extends in the front-rear direction to connect the coupling portion 212 with the motor housing 213 and the fixed guard 261. The circuit board assembly 28 includes: the handheld electric circular saw 200 comprises a first circuit board (not shown) and a second circuit board (not shown), wherein a control circuit of the handheld electric circular saw 200 can be partially arranged on the first circuit board and partially arranged on the second circuit board, so that the sizes of the first circuit board and the second circuit board are smaller, the problem that the circuit boards are inconvenient to arrange due to the fact that the circuit boards are large in size when all the control circuits are arranged on one circuit board is solved, and the first circuit board and the second circuit board can be conveniently arranged at proper positions in the shell 21. Further, the first circuit board is used for controlling the output power of the motor 24, and the second circuit board can be used for controlling the battery pack 251, but not limited thereto. In the present embodiment, the circuit board assembly 28 further includes a heat sink (not shown) for dissipating heat.

Referring to fig. 13, the housing 21 of the hand-held electric circular saw 200 is a two-half housing, and the holding parts 211 are symmetrically disposed about a first plane 202, and the first plane 202 is perpendicular to the motor shaft 241. In this embodiment, the distance between the first plane 202 and the cutting plane of the saw blade 222 is greater than or equal to 0mm and less than or equal to 10 mm. According to the design, the center line of the holding part 211 positioned in the second plane 202 and the cutting line formed by the saw blade 222 are approximately positioned on the same straight line, so that the user can not generate axial component force after applying pushing force during cutting, and the hand feeling is better. The distance between the center line of the holding portion 211 and the cutting plane formed by the saw blade 222 is greater than or equal to 0mm and less than or equal to 10 mm. Further, a distance between the midline of the grip 211 and a cutting plane formed by the saw blade 222 is greater than or equal to 0 and less than or equal to 5. In addition, the diameter of the motor 24 used in the present embodiment is preferably set to be 45mm to 65mm, whereas the diameter of the motor used in the conventional electric circular saw is larger, so that the size of the motor 24 of the hand-held electric circular saw 200 in the present embodiment is significantly reduced, so that the overall size of the hand-held electric circular saw 200, particularly the size in the direction perpendicular to the plane of the saw blade 222 is significantly reduced. In the present embodiment, the ratio of the rated power of the handheld electric circular saw 200 to the diameter of the motor 24 is greater than or equal to 25W/mm and less than or equal to 35W/mm, and more specifically, the ratio is 30W/mm.

The motor 24 in this embodiment is an external rotor motor, which includes: a stator assembly 242, a rotor assembly 243, and a motor shaft 241. The stator assembly 242 is fixedly disposed within the motor receiving cavity and the rotor assembly 243 surrounds the stator assembly 242 and is configured to rotate in synchronization with the motor shaft 241. Wherein the stator assembly 242 is disposed to one side of a cutting plane in which the blade 222 is positioned. It will be appreciated that the stator assembly 242 is disposed to the left or right of the cutting plane in which the blade 222 is located. Further, a motor housing 213 for accommodating the motor 14 is provided at the left or right side of the cutting plane where the saw blade 222 is located. In this embodiment, the stator assembly 242 is disposed to the right of the stationary shield 261, i.e., the motor 14 is located to the right of the cutting plane in which the saw blade 222 is located. Of course, may alternatively be located to the left of the cutting plane in which the fixed guard 261 or saw blade 222 is located. The distance between one side of the motor housing 213 far from the fixed shield 261 and the end surface of the fixed shield 261 close to the motor housing 213 is greater than or equal to 50mm and smaller than 70mm.

The bottom plate 23 of the handheld electric circular saw 200 needs to support the housing 21 when performing a workpiece cutting operation, and therefore the bottom plate 23 is generally made of a metal material to ensure that the bottom plate 23 has a certain strength. The base plate 23 in this embodiment is identical in design to the base plate 13 in the first embodiment described above, including the provision of a reinforcement member 234 on the front side of the base plate 23. In addition, in this embodiment, the fixed guard 261 is also provided with a dust discharging device, which includes a dust discharging connection pipe 261b, a dust discharging pipe 263, and the like, and is used for discharging dust generated during the operation of the handheld electric circular saw 200 into the air. One of the differences between the hand-held electric circular saw 200 of the present embodiment and the first embodiment is that the hand-held electric circular saw 200 of the present embodiment is supported by the movable guard 262, the base plate 23, and the motor case 213 when placed on the work surface. The hand-held electric circular saw 200 configured as above is more stably placed when the movable guard 262 is not opened, that is, not in operation.

When the hand-held electric circular saw 200 has the maximum cutting depth, the dimension h of the hand-held electric circular saw 200 in the up-down direction perpendicular to the bottom plate plane 231 is greater than the diameter of the saw blade 222 and is 200 mm or less. Further, the diameter of the saw blade 222 is 110mm or more and 150mm or less. The ratio of the weight of the hand-held electric circular saw 200 when the battery pack 251 is not mounted to the diameter of the saw blade 222 is 9 or more and 16 or less. Further, the ratio of the weight of the hand-held electric circular saw 200 when the battery pack 251 is not mounted to the diameter of the saw blade 222 is 11 or more and 13 or less. Further, the weight of the hand-held electric circular saw 200 when the battery pack 251 is not mounted is 1400g or more and 1800g or less.

Referring to fig. 15 to 17, the handheld electric circular saw 200 further includes a fan 291 for providing a heat dissipating air flow for the motor 24, the circuit board assembly 28, and the like, the fan 291 is disposed in the motor housing 213 on a side of the motor 24 away from the fixed guard 261, and the fan 291 is preferably a centrifugal fan and rotates in synchronization with the motor shaft 241. The motor 24 further comprises motor bearings (not shown) which overlap with an orthographic projection of the fan 291 on a plane perpendicular to the cutting plane. The motor housing 213 is provided with a housing outlet 217 corresponding to the position of the fan 291. Specifically, the case outlet 217 is disposed in a radial direction of the fan 291. The housing 21 is further formed with an air inlet 216 for ventilation of the air flow in the housing 21, and the air inlet 216 is preferably disposed between the combining portion 212 and the first receiving portion 214 for placing the circuit board assembly 28. When the motor 24 is started, the fan 291 starts to operate, and the airflow enters the housing 21 from the air inlet 216, flows through the circuit board assembly 28 disposed in the first accommodating portion 214, then passes through the motor 24, and flows out of the housing 21 from the housing air outlet 217, so as to take away heat generated by the circuit board assembly 28, the motor 24, and the like when the handheld electric circular saw 200 is in operation, thereby achieving efficient heat dissipation.

In this embodiment, referring to fig. 16, the housing 21 further includes an airflow guide 292 disposed outside the motor housing 213, and the airflow guide 292 is fixedly connected to the motor housing 213 and the fixed cover 261. Specifically, airflow guide portion 292 is formed with an airflow guide passage 292a communicating with case outlet 217 for guiding the airflow flowing through case outlet 217 to the front end of bottom plate 23. The air flow guide 292 is formed with an air outlet 292b communicating with the air flow guide passage 292 a. Specifically, the air outlet 292b is located on the front side of the fixed cover 261 and above the bottom plate 23. When the motor 24 is started, the fan 291 starts to operate, and the airflow enters the housing 21 from the air inlet 216, flows through the circuit board assembly 28 disposed in the first accommodating portion 214, then passes through the motor 24, flows out from the housing air outlet 217 to the airflow guiding channel 292a, and finally flows out from the air outlet 292b, so as to take away heat generated by the circuit board assembly 28, the motor 24 and the like when the handheld electric circular saw 200 is in operation, and achieve efficient heat dissipation. When realizing the heat dissipation, can blow to the front side of bottom plate 23 from some of the air current that air outlet 292b flows out, can understand that the air current can blow to the surface of reinforcement 234 to take away hand-held type electric circular saw 200 at the dust on the surface in front of bottom plate 23, guarantee that the user can observe the scale on the reinforcement 234 upper surface in the cutting process, improve cutting efficiency. In this embodiment, the airflow guiding portion 292 extends along the outer surfaces of the motor housing 213 and the fixed shield 262 to form an airflow guiding channel 292a for airflow circulation and guiding, and is fixedly connected to the motor housing 213 and the fixed shield 262 by fastening screws, so that the air flowing out of the housing air outlet 217 can be blown out from the air outlet 292b to the front end of the bottom plate 23 through the airflow guiding channel 292a to the maximum extent, and the dust blowing efficiency is improved while the heat dissipation effect is high. In this embodiment, the airflow guide 292 is made of plastic, but may be made of other materials, such as metal and silicone. It is to be understood that the air flow guide 292 of the present embodiment is formed with the outer surfaces of the motor housing 213 and the fixed shield 261 to form an air flow guide channel 292a for air flow circulation and guide after being mounted to the housing 23, but it is also possible to provide the air flow guide 292 itself to form a separate air flow guide channel 292a, which is not limited herein.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.

Claims (20)

1. A hand-held electric circular saw comprising:

a saw blade extending in a cutting plane;

the output shaft is used for mounting the saw blade and driving the saw blade to rotate;

the motor is used for driving the output shaft to rotate;

the shell comprises a motor shell for accommodating the motor and a holding part for holding by a user;

a base plate including at least a base plate plane for contacting a workpiece;

the protective cover assembly comprises a fixed protective cover and a movable protective cover, and the movable protective cover is rotatably connected with the fixed protective cover;

wherein the content of the first and second substances,

the handheld electric circular saw can be supported on a working surface through the movable shield and the bottom plate; when the hand-held electric circular saw is supported on a work surface by the movable guard and the base plate, the base plate plane is inclined with respect to the work surface, and the cutting plane is substantially perpendicular to the work surface.

2. The hand-held electric circular saw of claim 1,

the motor is located behind the fixed shield in the extending direction of the shell, and the projection of the motor on the cutting plane is not coincident with the projection of the fixed shield on the cutting plane.

3. The hand-held electric circular saw of claim 2,

the motor at least comprises a motor shaft, and an included angle between a straight line formed by the projection of the motor shaft and the output shaft on the cutting plane and the projection of the bottom plate plane on the cutting plane is more than or equal to 10 degrees and less than or equal to 30 degrees.

4. The hand-held electric circular saw of claim 1,

the housing is formed with a grip portion for a user to grip, the grip portion being symmetrically disposed about a first plane.

5. The hand-held electric circular saw of claim 4,

the distance from the gravity center of the handheld electric circular saw to the first plane is more than or equal to 0 and less than or equal to 5mm.

6. The hand-held electric circular saw of claim 1,

the orthographic projection of the handheld electric circular saw on the plane where the bottom plate plane is located in the bottom plate plane.

7. The hand-held electric circular saw of claim 4,

the case is further formed with a coupling part for coupling a battery pack, which is detachably coupled to the coupling part.

8. The hand-held electric circular saw of claim 7,

the projections of the holding part, the saw blade and the combining part on the plane of the bottom plate are approximately positioned on the same straight line.

9. The hand-held electric circular saw of claim 1,

the shell is also provided with an air inlet and an air outlet for air flow circulation.

10. The hand-held electric circular saw of claim 9,

the air outlet at least comprises a first air outlet and a second air outlet, and the first air outlet and the second air outlet are positioned on two sides of a cutting plane where the saw blade is positioned.

11. A hand-held electric circular saw comprising:

a saw blade extending in a cutting plane;

the output shaft is used for mounting the saw blade and driving the saw blade to rotate;

the motor is used for driving the output shaft to rotate;

the shell comprises a motor shell for accommodating the motor and a holding part for holding by a user;

a base plate including at least a base plate plane for contacting a workpiece;

the protective cover assembly comprises a fixed protective cover and a movable protective cover, and the movable protective cover is rotatably connected with the fixed protective cover;

wherein, the first and the second end of the pipe are connected with each other,

the hand-held electric circular saw can be supported on a working surface through the movable guard and the bottom plate; when the hand-held electric circular saw is supported on a working surface through the movable shield and the bottom plate, the plane of the bottom plate is inclined relative to the working surface, and at least two points of the rear edge of the bottom plate are in contact with the working surface.

12. The hand-held electric circular saw of claim 1,

the motor is located behind the fixed shield in the extending direction of the shell, and the projection of the motor on the cutting plane is not coincident with the projection of the fixed shield on the cutting plane.

13. The hand-held electric circular saw of claim 12,

the motor at least comprises a motor shaft, and an included angle between a straight line formed by the projection of the motor shaft and the output shaft on the cutting plane and the projection of the bottom plate plane on the cutting plane is more than or equal to 10 degrees and less than or equal to 30 degrees.

14. The hand-held electric circular saw of claim 11,

the housing is formed with a grip portion for a user to grip, the grip portion being symmetrically disposed about a first plane.

15. The hand-held electric circular saw of claim 14,

the distance from the gravity center of the handheld electric circular saw to the first plane is more than or equal to 0 and less than or equal to 5mm.

16. The hand-held electric circular saw of claim 11,

the orthographic projection of the handheld electric circular saw on the plane where the bottom plate plane is located in the bottom plate plane.

17. The hand-held electric circular saw of claim 14,

the case is further formed with a coupling portion for coupling a battery pack, the battery pack being detachably coupled to the coupling portion.

18. The hand-held electric circular saw of claim 17,

the projections of the holding part, the saw blade and the combining part on the plane of the bottom plate are approximately positioned on the same straight line.

19. The hand-held electric circular saw of claim 11,

the shell is also provided with an air inlet and an air outlet for air flow circulation.

20. The hand-held electric circular saw of claim 19,

the air outlet at least comprises a first air outlet and a second air outlet, and the first air outlet and the second air outlet are positioned on two sides of a cutting plane where the saw blade is positioned.

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