ELECTRIC CIRCULAR SAW

An electric circular saw includes a housing, a motor including a motor shaft enabled to rotate about a first rotation axis, and a transmission assembly including a first transmission member and a second transmission member. The motor shaft has a first end and a second end oppositely arranged in a longitudinal direction and the first transmission member is mounted to the second end of the motor shaft. In a coordinate system having an origin defined by a point on a center line of the second transmission member, a positive direction of an X axis defined by a forward direction of the electric circular, and a positive direction of a Y axis defined by an upper side of the electric circular saw, the second end of the motor shaft is arranged in a first quadrant of the coordinate system.

RELATED APPLICATION INFORMATION

This application claims the benefit under 35 U.S.C. § 119(a) of Chinese Patent Application No. CN 202010398344.8, filed on May 12, 2020, which is incorporated by reference in its entirety herein.

BACKGROUND

An electric circular saw is a tool that, powered by a single-phase series motor, drives a saw blade through a transmission mechanism to perform sawing operations. According to the type of power supply, electric circular saws are basically categorized into DC circular saws and AC circular saws. DC circular saws are popular among users because of safety, reliability, high work efficiency, and easy carrying.

However, for a DC circular saw on the current market, the motor is usually arranged on one side of the saw blade, making the center of gravity of the electric circular saw to be located on one side of the saw blade. Therefore, during operation of the electric circular saw, the user needs to apply a great force to prevent the electric circular saw from overturning, which causes the electric circular saw to be laborious and inconvenient to control.

SUMMARY

In one aspect of the disclosure, an electric circular saw includes: a housing; a motor including a motor shaft enabled to rotate about a first rotation axis, the motor at least partially disposed in the housing; a transmission assembly including a first transmission member connected with the motor for introducing power into the transmission assembly and a second transmission member for outputting power, the second transmission member enabled to rotate about a second rotation axis; wherein the motor shaft has a first end and a second end oppositely arranged in a longitudinal direction, and the first transmission member is mounted to the second end of the motor shaft; in a coordinate system with a point on a center line of the second transmission member as an origin, a forward direction of the electric circular saw as a positive direction of an X axis, and an upper side of the electric circular saw as a positive direction of a Y axis, the second end of the motor shaft is arranged in a first quadrant of the coordinate system.

In an example, the first transmission member is arranged in the first quadrant of the coordinate system.

In an example, the first end of the motor shaft is arranged in a second quadrant of the coordinate system.

In an example, the first end of the motor shaft is arranged on an upper side of the second end.

In an example, the electric circular saw has a cutting plane, and the cutting plane is an extended plane of a saw blade when the saw blade is mounted to the electric circular saw; a projection of a line connecting the first end of the motor shaft and the center of the second transmission member on the cutting plane is a first projection line, and an included angle b formed by an oblique intersection of the first projection line and the Y axis is greater than or equal to 0 degree and less than or equal to 30 degrees.

In an example, a projection of a line connecting the second end of the motor shaft and the center of the second transmission member on the cutting plane is a second projection line, and an included angle c formed by an oblique intersection of the second projection line and the Y axis is greater than or equal to 0 degree and less than or equal to 60 degrees.

In an example, a projection of a line connecting the second end of the motor shaft and the center of the second transmission member on the cutting plane is a second projection line, and an included angle d formed by an intersection of the second projection line and the first projection line is greater than or equal to 0 degree and less than or equal to 90 degrees.

In an example, the housing further includes: a main handle for a user to hold; a switch assembly mounted to the main handle; a motor casing portion enclosing the motor; and a battery mounting portion configured to detachably mount a battery pack; wherein the battery mounting portion is configured to connect the motor casing portion and the main handle.

In an example, the electric circular saw also includes a saw blade for cutting a workpiece; wherein a distance between the first end of the motor shaft and the saw blade is less than a sum of a distance between the second end of the motor shaft and the saw blade and a length of the motor shaft.

In an example, a ratio of the distance between the first end of the motor shaft and the saw blade to the sum of the distance between the second end of the motor shaft and the saw blade and the length of the motor shaft is greater than or equal to 0.8.

In an example, the distance between the first end of the motor shaft and the saw blade is greater than or equal to 105 mm and less than or equal to 160 mm.

In an example, the electric circular saw further includes: a battery pack mounted to the housing for supplying electric energy to the motor; wherein the first transmission member is enabled to rotate synchronously with the motor, the second transmission member is enabled to be driven by the first transmission member to rotate about the second rotation axis, and the second rotation axis substantially extends along a left-right direction; the first rotation axis intersects the left-right direction; in an up-down direction, the second end is located on a lower side of the first end, and the up-down direction is substantially perpendicular to the left-right direction.

In an example, the electric circular saw further includes: a cutting attachment enabled to be driven by the motor to rotate about the second rotation axis; the cutting attachment has a first side surface, and the first side surface is parallel to the cutting plane; the motor has a first end surface, in the left-right direction, the first end surface is located on a side away from the cutting attachment; a distance between the first end surface and the first side surface along a first direction parallel to the first rotation axis is a first length L1; a distance between the first end surface and the first side surface along a second direction parallel to the second rotation axis is a second length L2; wherein a ratio of the first length L1to the second length L2ranges from 1.02 to 1.1.

In an example, the first transmission member is fixedly connected or integrally formed with the motor shaft; the first transmission member engages with the second transmission member.

In an example, a ratio of a rotational speed of the first transmission member driven by the motor to a rotational speed of the second transmission member driven by the first transmission member is a reduction ratio, and the reduction ratio is greater than or equal to 4 and less than or equal to 6.5.

In an example, the electric circular saw includes at least two battery packs.

In an example, the housing includes a main handle, a motor casing portion for accommodating the motor, and a battery mounting portion provided between the main handle and the motor casing portion, the battery mounting portion comprises a first mounting portion for guiding a first battery pack to be coupled to the housing in a first linear direction and a second mounting portion for guiding a second battery pack to be coupled to the housing in a second linear direction, and the second mounting portion is provided at a lower side of the first mounting portion.

In an example, the first linear direction is parallel to the second linear direction.

In an example, the first linear direction obliquely intersects the first rotation axis.

In an example, the main handle is basically symmetrically arranged about a plane and the first linear direction obliquely intersects the plane.

In another aspect of the disclosure, an electric circular saw includes a housing; a motor comprising a motor shaft enabled to rotate about a first rotation axis, the motor at least partially disposed in the housing; a transmission assembly comprising a first transmission member connected with the motor for introducing power into the transmission assembly and a second transmission member for outputting power, the second transmission member enabled to rotate about a second rotation axis. The motor shaft has a first end and a second end oppositely arranged in a longitudinal direction, and the first transmission member is mounted to the second end of the motor shaft. In a coordinate system with a point on a center line of the second transmission member as an origin, a forward direction of the electric circular saw as a positive direction of an X axis, and an upper side of the electric circular saw as a positive direction of a Y axis, the first rotation axis obliquely intersects with the positive direction of the positive direction of the Y axis to form an angle a, and the angle a is greater than 0 degrees and less than 90 degrees.

In an example, the second end of the motor shaft is arranged in a first quadrant of the coordinate system.

DETAILED DESCRIPTION

In order to clearly illustrate the technical solution of the present application, up, down, front, rear, left, and right directions are defined as shown inFIG. 1.

FIGS. 1-4shows a circular saw100according to a first example, specifically, a hand-held circular saw, including: a housing10, a motor20, a battery pack30, a transmission assembly40, a cutting attachment50, an output shaft60and a base plate70, wherein the housing10forms an accommodating cavity. The motor20has a motor shaft21enabled to rotate about a first rotation axis101. The motor20is configured to drive the output shaft60to rotate about a second rotation axis102. The motor20is at least partially disposed in the accommodating cavity. The battery pack30is mounted to the electric circular saw100to provide electric energy for the motor20. The transmission assembly40is configured to transmit power output by the motor20to the output shaft60, and the transmission assembly40includes a first transmission member41and a second transmission member42. The first transmission member41is enabled to form a synchronous rotation with the motor shaft21. The first transmission member41is used to introduce power from the motor20, and the second transmission member42is used to output power. Specifically, the second transmission member42can be driven by the first transmission member41to rotate about the second rotation axis102. The cutting attachment50is for cutting a workpiece, specifically, the cutting attachment50may be a saw blade51. The base plate70is formed with a base plate plane71for contact with the workpiece. In the present application, the second rotation axis102extends substantially in the left-right direction.

In this example, the motor shaft21has a first end22and a second end23along its longitudinal direction. The second end23is used to output power to the transmission assembly40, that is, the second end23is the output end of the motor shaft21. The first transmission member41is mounted to the second end23of the motor shaft21, specifically, the first transmission member41is fixedly mounted to the second end23, or the first transmission member and the second end23are integrally formed. In the left-right direction, the first end22is configured to be farther away from the cutting attachment50than the second end23. In the up-down direction, the second end23is located on the lower side of the first end22. Thus, the distance L2between the first end22of the motor shaft21and the saw blade51in the direction along the second rotation axis102is less than the sum of the distance L3between the second end23and the saw blade51in the direction along the first rotation axis101and the length L of the motor shaft, that is L2<L3+L. In this way, the dimension of the circular saw100in the left-right direction is relatively small, and the whole structure is compact, thereby enabling the circular saw100to work in narrow space, which facilitates user's operation, transportation and storage. In this way, the center of gravity G of the circular saw100is closer to the blade51, the distance D between the center of gravity G and the blade51is reduced. If the distance D between the center of gravity G and the blade51is large, in other words, the overturning moment of the electric circular saw100is large, the electric circular saw100may overturn easily when the user is cutting some narrow workpiece and the grip strength is relatively small. In order to avoid the circular saw100from overturning, the user needs to hold the electric circular saw100with greater strength to make the electric circular saw100run stably. With the above arrangement, the center of gravity G is close to the saw blade51, and the overturning moment of the electric circular saw100is reduced, thereby facilitating the user's operation.

In the present example, the ratio of the distance L2between the first end22of the motor shaft21and the saw blade51to the sum of the distance L3between the second end23and the saw blade51and the length L of the motor shaft is greater than or equal to 0.8, that is L2/L3+L≥0.8. in this way, the dimension of the electric circular saw100in the left-right direction is more reasonable, and there is some space between the motor20and the saw blade51for accommodating the transmission assembly40. The transmission assembly40is configured as a gear assembly with a small space occupation to realize power transmission, so that the structural layout of the whole machine is more reasonable. Furthermore, the size of the electric circular saw100in the front-rear direction is not increased when the size of the electric circular saw100in the left-right direction is reduced, that is, the length and width of the electric circular saw100are taken into account at the same time, so that the entire machine is relatively compact. Further, L2is greater than or equal to 105 mm and less than or equal to 160 mm.

Further, the direction of the first rotation axis101and the direction of the second rotation axis102obliquely intersect. The included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is an acute angle, and the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 10 degrees and less than or equal to 45 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 10 degrees and less than or equal to 35 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 10 degrees and less than or equal to 30 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 10 degrees and less than or equal to 20 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 12 degrees and less than 30 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 12 degrees and less than 25 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 12 degrees and less than or equal to 20 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 12 degrees and less than or equal to 18 degrees. Further, the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102is greater than or equal to 15 degrees and less than or equal to 25 degrees. Therefore, by setting the included angle formed by the intersection of the direction of the first rotation axis101and the direction of the second rotation axis102to be within a certain range, the size of the electric circular saw100in the left-right direction can be reduced, while the size of the electric circular saw100in the front-rear direction is not increased or insignificantly increased.

The electric circular saw100further includes a guard80, and the cutting attachment50can be driven by the motor20to rotate about a second rotation axis. Wherein, the second rotation axis is parallel to or coincides with the second rotation axis102. The guard80partially encloses the cutting attachment50in the circumferential direction of the second rotation axis to protect the user from injury. The guard80is mounted to the electric circular saw100. The guard80includes a fixed guard and a movable guard, the fixed guard is fixed relative to the housing10, and the movable guard can rotate relative to the fixed guard. The base plate70is configured to support the electric circular saw100. The fixed guard is arranged on the upper side of the base plate70and is connected to the housing10. The base plate70is also formed with an opening for the saw blade51to at least partially pass through, so that the saw blade51can extend to the lower side of the floor plane71. The base plate70has an angle plate72disposed on the front side of the base plate70. The user can operate the angle plate72to enable the base plate70to rotate about a first rotating shaft104so as to adjust the cutting angle of the electric circular saw100. The base plate70also has a depth adjusting plate, which is arranged on the rear side of the base plate70. The user can operate the depth adjusting plate to enable the base plate70to rotate about a second rotating shaft105relative to the housing10so as to adjust the cutting depth of the electric circular saw100. When the base plate70rotates about the second rotating shaft105, the base plate70has an initial position with the maximum cutting depth with respect to the housing10. At this time, the size of the part of the saw blade51that extends out of the base plate70is the largest, and the saw blade51is perpendicular to the base plate plane71. In this example, the second rotation axis102coincides with the second rotation axis.

The transmission assembly40is arranged in the gear box, and the gear box is fixedly connected with the guard80. The first transmission member41is enabled to rotate in a direction parallel to or coincident with the direction of the first rotation axis101. The first transmission member41is fixedly connected or integrally formed with the motor shaft21. In an example, it can be understood that the first transmission member41and the motor shaft21may be directly fixed or indirectly fixed, that is, the first transmission member41and the motor shaft21may be directly fixed by interference fit or the like, alternatively, the first transmission member41and the motor shaft21may be indirectly fixed through an intermediate connecting member. In this example, the first transmission member41and the motor shaft21are integrally formed, that is, the first transmission member41is a part of the motor shaft21. In summary, in this application, the specific connection means between the first transmission member41and the motor shaft21is not limited, as long as the first transmission member41and the motor shaft21can be relatively fixed and form a synchronous rotation. The second transmission member42is enabled to be driven by the first transmission member41to rotate about the second rotation axis102to drive the saw blade51to rotate to realize the cutting function. Specifically, the first transmission member41is a helical gear, which forms an interference fit with the motor shaft21. The second transmission member42is a helical gear, which is fixedly connected with the output shaft60. The helical gears are directly engaged, that is, the helical gear of the motor shaft21drives the helical gear of the output shaft60to rotate. The ratio of the rotational speed of the helical gear driven by the motor20to the rotational speed of the helical gear fixedly connected to the output shaft60is a reduction ratio. In this example, the reduction ratio of the transmission assembly40is greater than or equal to 4 and less than or equal to 6.5. Of course, a bevel gear assembly of a smaller volume may also be used for transmission; specifically, both a first transmission member and a second transmission member are bevel gears.

It should be noted that, unless otherwise specified, a fixed connection mentioned in this application can be understood as either direct fixation or indirect fixation, as described above.

For the convenience of description, as shown inFIG. 5,FIG. 6, andFIG. 12, a coordinate system with a point on the center line of the second transmission member as the origin O is established, wherein the front-rear direction is the direction of the X-axis, and the direction pointing to the front side is the positive direction of the X-axis; the up-down direction is the direction of the Y-axis, and the direction pointing to the upper side is the positive direction of the Y-axis. The center line is the second rotation axis102. In the present example, the first rotation axis obliquely intersects with the positive direction of the positive direction of the Y axis to form an angle a, and the angle a is greater than 0 degrees and less than 90 degrees. The second end23of the motor shaft21is disposed in the first quadrant of the coordinate system, such that the first transmission member41is disposed in the first quadrant, in the front-rear direction, the first transmission member41is arranged on the front side of the second rotation axis102, in the up-down direction, the first transmission member41is arranged on the upper side of the second rotation axis102. The second end23of the motor shaft21is disposed on the front side of the second rotation axis102, and the first transmission member41is disposed on the front side of the second rotation axis102, which can make full use of the space on the front side of the second rotation axis102. This not only saves the space in the rear half of the electric circular saw100, but also avoids the length of the electric circular saw100in the front-rear direction to be too long when the first transmission member41is arranged in the second quadrant or the third quadrant. The second end23of the motor shaft21is disposed on the upper side of the second rotation axis102to make use of the space on the upper side the second rotation axis102, and to avoid or reduce the use of space on the lower side of the second rotation axis102, thereby reducing the distance from the second rotation axis102to the base plate70, in other words, reducing the distance from the center of the saw blade51to the base plate70, thus ensuring or increasing the maximum cutting depth of the circular saw100, and avoiding increasing the distance from the center of the saw blade51to the base plate70when the second end23of the motor shaft21is arranged in the third quadrant or the fourth quadrant. In fact, in this example, the second end23of the motor shaft21is arranged on the upper side of the second rotation axis102, so that there is enough space on the lower side of the motor20to allow a motor shell to wrap the motor20and also the housing10to wrap the motor20and the motor shell even when the distance between the second rotation axis102of the first transmission member41and the base plate70remains unchanged. Specifically, the housing10includes a motor casing portion14and a transmission casing portion15. The transmission assembly40is arranged in the gear box, the gear box is fixedly connected with the guard80, and the transmission casing portion15wraps the gear box. The motor20is arranged in the motor shell, and the motor casing portion14then wraps the motor shell. Wherein, the motor shell and the gear box are both made of metal materials, and the motor casing portion14and the transmission casing portion15are both made of plastic materials. Thus, since the second end23of the motor shaft21is arranged in the first quadrant of the coordinate system, the motor casing portion14and the transmission casing portion15only occupy a small space on the lower side of the second rotation axis102, thereby increasing the maximum cutting depth of the electric circular saw100. Of course, from a cost perspective, the motor shell may also be made of plastic.

The blade51is mounted to the output shaft60and forms a synchronous rotation with the output shaft. The circular saw100has a cutting plane P, wherein the cutting plane P is the extended plane of the saw blade when the saw blade51is mounted to the electric circular saw100. The first end22of the motor shaft21is displaced in the second quadrant, and the projection of a line connecting the first end22of the motor shaft21and the center of the second transmission member42on the cutting plane P is a first projection line211. The included angle b formed by the oblique intersection of the first projection line211and the positive direction of the Y-axis is greater than or equal to 0 degree and less than or equal to 30 degrees. The rotor and the stator of the motor20are arranged closer to the first end22than to the second end23, that is, in the up-down direction, the length of the motor20close to the first end22is the largest. This arrangement can make the first end22of the motor20substantially located on the upper side of the second rotation axis102, that is, the entire motor20can be substantially located on the upper side of the second rotation axis102without taking up the position of the second rotation axis102to ensure the cutting depth of the electric circular saw100. The projection of a line connecting the second end23of the motor shaft21and the center of the second transmission member42on the cutting plane P is a second projection line212. The second end23of the motor shaft21is located in the first quadrant. The included angle c formed by the oblique intersection of the second projection line212and the Y-axis is greater than or equal to 0 degree and less than or equal to 60 degrees. That is, the second end23of the motor shaft21is located on the upper side of the second rotation axis102. By arranging the second end23of the motor shaft21within the above range, the second end23of the motor shaft21is substantially located in the upper space of the second rotation axis102, If the position of the second end23is arranged on the lower side of the second rotation axis102, the transmission casing portion15and the motor casing portion14would take up more space on the lower side of the second rotation axis102, thereby causing the base plate70to be placed too low, which affects the maximum cutting depth of the electric circular saw100. Further, the included angle d formed by the intersection of the first projection line211and the second projection line212is greater than or equal to 0 degree and less than or equal to 90 degrees, and the above arrangement makes the motor20substantially located on the upper side of the second rotation axis102, so that there is enough space on the lower side of the second rotation axis102to arrange the motor shell and motor casing portion14, etc. If the motor shell and motor casing portion14take up too much space on the lower side of the second rotation axis102, the base plate70has to be set lower, which affects the cutting depth of the electric circular saw100.

As shown inFIGS. 4, 7, and 8, the cutting plane P and the second rotation axis102are perpendicular to each other, and the cutting plane P and the first rotation axis101intersect obliquely. The cutting plane P of the electric circular saw100obliquely intersects the first rotation axis101of the motor shaft21, wherein the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 100 degrees and less than or equal to 145 degrees. Further, the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 100 degrees and less than or equal to 125 degrees. Further, the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 100 degrees and less than or equal to 120 degrees. Further, the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 100 degrees and less than or equal to 110 degrees. Further, the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 102 degrees and less than or equal to 120 degrees. Further, the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 102 degrees and less than or equal to 115 degrees. Further, the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 102 degrees and less than or equal to 110 degrees. Further, the angle formed by the oblique intersection of the cutting plane P and the first rotation axis101is greater than or equal to 102 degrees and less than or equal to 108 degrees. In this example, in the direction along the first rotation axis101, the distance between the first end22of the motor shaft21and the saw blade51is L1. In the direction along the second rotation axis102, the distance between the first end22of the motor shaft21and the saw blade51is L2, wherein the ratio of L1to L2is greater than or equal to 1.02 and less than or equal to 1.2. Further, the ratio of L1to L2is greater than or equal to 1.02 and less than or equal to 1.1.

The circular saw100further includes a shaft lock assembly43. The shaft lock assembly43is used to lock the rotation of the second transmission member42. When the second transmission member42is locked, the user can easily remove or install the saw blade51. The shaft lock assembly43is arranged close to the helical gear. In order to facilitate user operation, the shaft lock assembly43is at least partially located outside the housing10for user operation. As shown inFIGS. 3 and 4, the first end22of the motor20is at least partially arranged in the second quadrant of the coordinate system, that is, in the front-rear direction, the first end22of the motor20is arranged behind the second end23, in other words, in the front-rear direction, the distance from the first end22of the motor20to the angle plate72is greater than the distance from the second end23of the motor20to the angle plate72. The shaft lock assembly43is arranged in the first quadrant and is located on the front side of the motor20. With the above arrangement, the motor20is tilted backward to allow for enough space on the front side of the motor20for the user's hand to reach near the shaft lock assembly34to operate the shaft lock assembly43; also, the distance between the angle plate72and the housing10is increased, so that the user can observe the cutting condition of the saw blade51from the right side of the electric circular saw. In the up-down direction, the first end22of the motor shaft21is also arranged on the upper side of the second end23, which further allows the housing10to accommodate the motor20while not reducing the maximum cutting depth of the electric circular saw100.

The circular saw100also includes a main handle11and the auxiliary handle12. The main handle11and the auxiliary handle12are both used for the user to grip. The main handle11is fixedly connected or integrally formed with the housing10. In the present example, the housing10is formed with the main handle11, that is, the main handle11and the housing10are integrally formed, wherein the main handle11is provided with a switch assembly for prohibiting and allowing the battery pack30to provide energy to the motor20. The housing10is connected to or formed with a battery mounting portion13for mounting the battery pack30. In this example, the battery mounting portion13is formed by the housing10itself, that is, the battery mounting portion13and the housing10are integrally formed. In the front-rear direction, the battery mounting portion13is arranged between the rear end of the main handle11and the motor20. In this way, in the front-rear direction, the battery pack30is arranged closer to the motor20, so that the center of gravity G of the whole machine is closer to the motor shaft21in the front-rear direction. In this example, in the front-rear direction, when the battery pack30is installed, the distance between the center of gravity G of the electric circular saw100and the center of the saw blade51is reduced, thereby, the torque arm of the electric circular saw100to be overturned during the working process can be reduced, and the torque of the electric circular saw100to be overturned can be reduced, the working stability of the electric circular saw100can be improved, and the user's work efficiency can be improved. The battery mounting portion13is formed with an enclosing receiving groove131with an opening that opens to the right, and the opening allows the battery pack30to be inserted into the receiving groove131from the right to the left. The receiving groove131embraces the battery pack30from the left side, upper side, lower side, front side, and rear side of the battery pack30. On the one hand, the battery pack can be prevented from accidental detachment; on the other hand, the battery mounting portion13can also enhance the strength of the front and rear connection of the housing. In this way, the battery mounting portion13has a top surface and a bottom surface, the top surface connects the upper side of the casing portion of the motor20and the front end of the main handle11, and the bottom surface is connected to the rear end of the main handle11. Therefore, the battery mounting portion13can also enhance the strength of the housing while mounting the battery pack30. In the present example, the battery mounting portion13is provided such that the main handle11is directly connected to the motor casing portion14though the battery mounting portion13, thus, in the front-rear direction, there is also a certain gap between the main handle11and the battery mounting portion13and the rear side of the guard80, so as to facilitate the heat dissipation of the motor20, the gear box and other electronic components inside the housing10, and the heat dissipation of the battery pack30.

The battery pack30and the battery mounting portion13form a detachable sliding connection. Specifically, the battery mounting portion13is provided with a guide rail for the battery pack30to slide, and the battery pack30is provided with a sliding groove that engages with the guide rail. In another example, a sliding groove for sliding the battery pack30may be provided on the battery mounting portion13, and a guide rail that engages with the sliding groove is provided on the battery pack30. In summary, the main handle11, the housing10and the battery mounting portion13are fixedly connected or integrally formed. Preferably, the main handle11, the housing10and the battery mounting portion13are integrally formed. It can be understood that the guard80and the housing10are two parts. The helical gears are at least partially arranged in the gear box casing, the gear box and the guard80are fixedly connected or integrally formed, and the housing10is fixedly connected with the gear box casing. When the saw blade51rotates at a high speed to cut a workpiece, lots of heat will be generated. The guard80is made of metal to facilitate the heat dissipation of the saw blade51. The housing10can be made of plastic.

The battery pack30is mounted to the battery mounting portion13along a first straight line103, and the first straight line103is substantially parallel to the base plate plane71. In the left-right direction, the projection of the battery pack30on the base plate plane71protrudes from the projection of the motor20on the base plate plane71. In other words, when the battery pack30is installed on the electric circular saw100, the maximum distance from the battery pack30to the first side surface52in the direction along the second rotation axis102is greater than the maximum distance from the motor20to the first side surface52in the direction along the second rotation axis102. That is, the motor20in this application has a smaller size in the left-right direction compared to the battery pack30, which shortens the projection length of the motor20, and reduces the width of the whole machine, and makes the center of gravity of the whole machine closer to the saw blade51, thereby reducing the torque. During cutting operation, the user does not need to apply a great force to prevent the electric circular saw100from overturning, which improves the user experience. When the battery pack30is mounted to the battery mounting portion13along the first straight line103, the maximum distance L4of the electric circular saw100in the direction along the second rotation axis102is greater than or equal to 162 mm. When the battery pack30is not mounted to the battery mounting portion13, the maximum distance L5of the electric circular saw100in the direction along the second rotation axis102is greater than or equal to 159 mm.

In this application, the electric circular saw100includes a plurality of battery packs30, and the plurality of battery packs30are connected in series with each other. Specifically, the electric circular saw100may be provided with at least two battery packs30of the same capacity, which not only enhances the cutting speed of the electric circular saw100, but also enhances the overload capacity of the circular saw100. In the left-right direction, the battery pack30is provided on the right side of the cutting plane P, in particular, the circular saw100includes at least two battery pack30, for the convenience of description, the battery pack30near the main handle11is defined as a first battery component, and the battery pack30near the motor20is defined as a second battery component. The projection of the main handle11in the up-down direction and the projection of the first battery component in the up-down direction at least partially overlap, and the first battery component is mounted to the battery mounting portion13along the first straight line103, the second battery component is mounted to the battery mounting portion13along a second sliding direction, wherein the second sliding direction is parallel to the first straight line103, the first straight line103intersects the first rotation axis101, and the first straight line103has the same direction of the second sliding direction. The first battery component and the second battery component are both arranged on the right side of the cutting plane P, the first battery component and the second battery component are both arranged on the upper side of the base plate70, namely the first battery component and the second battery component are arranged on the same side as motor20.

In this application, in an example, the distance of the first battery component in the left-right direction is greater than the distance of the first battery component in the front-rear direction, and the arrangement of the second battery component is the same as the first battery component, that is, the first rotation axis has the same direction of the second sliding direction, and the first rotation axis is substantially perpendicular to the cutting plane. This arrangement reduces the size of the whole machine in the up-down direction, saves space and facilitates machining. In another example, the first rotation axis intersects the cutting plane, in other words, the battery pack is slidably mounted to the battery mounting portion in an obliquely downward manner. This arrangement facilitates the user to install and remove the battery pack. In some other examples, the first rotation axis is substantially parallel to the cutting plane, that is, the battery pack is slidably mounted to the battery mounting portion in a vertically downward manner, so that the center of gravity of the whole machine is close to the saw blade and the torque is reduced.

In other examples, the number of battery packs may also be one.

In other examples, the battery packs may also be arranged in the position shown inFIG. 10. In this example, the projections of the main handle311and the first battery component330aon the plane of the base plate370at least partially overlap, that is, the first battery component330ais disposed on the lower side of the main handle311and the rear side of the base plate370. The projections of the motor320and the second battery component330bon the plane of the second rotation axis at least partially overlap. The second battery component330bis arranged between the main handle311and the motor320, and on the upper side of the base plate370. The first battery component330aand the second battery component330bare arranged separately. Specifically, the first battery component330ais slidably connected to the battery mounting portion from the rear side to the front side, and the second battery component330bis slidably connected to the battery mounting portion from the upper side to the lower side. With the above arrangement, two battery packs can avoid interference with the operation of the electric circular saw. Of course, the first battery component may also be slidably connected to the battery mounting portion from the right to the front.

In other examples, the battery packs may also be arranged in the position shown inFIG. 11. In this example, two battery packs430are arranged adjacently, and the two battery packs430can be pushed along a direction perpendicular to the saw blade450. When the two battery packs430are mounted to the position shown inFIG. 11, in the front-rear direction, the two battery packs430are arranged between the main handle411and the motor420. When the two battery packs430are installed on the electric circular saw, the central line of the two battery packs430is basically parallel to the grip4111of the main handle411. And the length of the two battery packs430in the left-right direction is within the length of the housing in the left-right direction. Therefore, the two battery packs430can avoid interference with the operation of the electric circular saw.

Referring to the second example shown inFIG. 9, the saw blade, the base plate270, the electric circular saw housing and the battery pack in the second example are basically the same as those in the first example. The difference lies in the way the motor220is arranged. The parts of the first example that are compatible with this example can all be applied to this example, and only the differences between this example and the first example will be described below. The second end223of the motor220is arranged in the first quadrant of the coordinate system, and the first end222of the motor220is arranged in the first quadrant of the coordinate system. The first rotation axis201obliquely intersects the first shaft, i.e., in the front-rear direction, the distance from the second end223of the motor220to the angle plate272is greater than the distance from the first end222of the motor220to the angle plate272. In this example, the first rotation axis201obliquely intersects the cutting plane A, that is, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 45 degrees and less than or equal to 80 degrees. Further, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 55 degrees and less than or equal to 80 degrees. Further, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 60 degrees and less than or equal to 80 degrees. Further, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 65 degrees and less than or equal to 80 degrees. Further, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 45 degrees and less than 78 degrees. Further, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 55 degrees and less than 78 degrees. Further, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 60 degrees and less than or equal to 78 degrees. Further, the angle between the direction of the first rotation axis201and the cutting plane A is greater than or equal to 65 degrees and less than or equal to 78 degrees. Through the above settings, not only the projection length of the motor220on the base plate plane is shortened, the width of the whole machine is reduced, and the distance between the center of gravity of the whole machine and the cutting plane A is shortened, but also the torque is reduced so that the user does not need to apply a great force to prevent the electric circular saw from overturning when operating the electric circular saw. At least more than half of the motor220is arranged in the first quadrant, so that there is more space left on the rear side of the electric circular saw for the battery pack and the circuit board, which facilitates the structural arrangement of the whole machine.

FIG. 13shows a structural diagram of the electric circular saw with the battery pack mounted according to a fifth example. In this example, the saw blade, the motor, the base plate, etc. are basically the same as those in the first example, and the only difference lies in the way in which the battery pack is installed. The parts of the first example that are compatible with this example can all be applied to this example, and only the differences between this example and the first example will be described below. For ease of description, the up, down, front, rear, left, and right directions defined in the first example will continue to be used.

Referring toFIGS. 13-16, the electric circular saw500includes a body500aand a battery pack assembly530. The battery pack assembly530is installed on the battery mounting portion540so that the battery pack assembly530can provide energy to the motor. Specifically, the battery pack assembly530includes a first battery pack531connected to the housing along a first linear direction502and a second battery pack532connected to the housing510along a second linear direction503. The first linear direction502is parallel to the second linear direction503, and the first linear direction502obliquely intersects the second rotation axis501of rotation of the saw blade560. The first battery pack531and the second battery pack532are both detachably connected to the housing510, that is, when the battery pack is exhausted, the user can remove the battery pack and replace with another fully charged battery pack to make the electric circular saw500continue to work. In this example, the first battery pack531and the second battery pack532are basically the same, and the first battery pack531is disposed on the upper side of the second battery pack532in the up-down direction. It should be noted that the number of battery packs in the battery pack assembly530may also be two or more.

The first battery pack531has a first end533and a second end534that are oppositely arranged in the first linear direction502. Similarly, the second battery pack532has a third end535and a fourth end536that are oppositely arranged in the second linear direction503. In the left-right direction, the second end534is away from the saw blade560relative to the first end533, and the fourth end536is away from the saw blade560relative to the third end535. In the forward direction of the electric circular saw500, the first distance a1from the second end534of the first battery pack531to the second rotation axis501of the saw blade560is smaller than the sum of the second distance a2from the first end533of the first battery pack531to the second rotation axis501in the first linear direction502and the length c1of the first battery pack531. Similarly, the third distance a3from the fourth end536of the second battery pack532to the second rotation axis501is smaller than the sum of the third distance a3from the third end535of the second battery pack532to the second rotation axis501in the second linear direction503and the length c2of the second battery pack532, that is, a1<a2+c1and a3<a4+c2. That is, the first linear direction502and the second linear direction503both obliquely intersect with the forward direction of the electric circular saw500, therefore, the first battery pack531and the second battery pack532are both slidably connected to the battery mounting portion540at an oblique angle. In this example, the output power of the electric circular saw500is greater than or equal to 1.4 kW. In order to ensure the normal operation of the electric circular saw500and its running time, the battery pack assembly530is required to have a higher voltage, thus, the weight of the corresponding battery pack assembly530is relatively large. Therefore, when the battery pack assembly530is installed on the body500a, the center of gravity of the battery pack assembly530will affect the center of gravity G of the body500a, shifting the center of gravity Q of the electric circular saw500to the right, which not only causes the torque to increase, but also makes the electric circular saw500easy to roll over when left standing. Through the above arrangement, the influence of the weight of the battery pack assembly530on the center of gravity Q of the electric circular saw500can be reduced. In other words, the center of gravity Q of the electric circular saw500is configured to be as close as possible to the center of gravity G of the body500a, therefore, when the user installs the battery pack assembly530, the distance between the center of gravity Q of the electric circular saw500and the saw blade560is not increased, and the user does not need to apply a large force to control the electric circular saw500. In the above settings, the user can control the electric circular saw500with a relatively small force, which improves the user's experience and at the same time ensures the stable operation of the electric circular saw500.

The first linear direction502and the second linear direction503are substantially parallel, that is, the first battery pack531and the second battery pack532are installed to the housing510substantially in the same direction. Wherein, in the forward direction of the electric circular saw500, the ratio of the first distance a1from the second end534of the first battery pack531to the second rotation axis501to the sum of the second distance a2from the first end533of the first battery pack531to the second rotation axis501along the first linear direction502and the length c1of the first battery pack531is greater than or equal to 0.7, that is, a1/(a2+c1)≥0.7. The installation directions of the second battery pack532and the first battery pack531are basically the same. Thus, the ratio of the third distance a3from the fourth end536of the second battery pack532to the second rotation axis501to the sum of the fourth distance a4from the third end535to the second rotation axis501along the second linear direction503and the length c2of the second battery pack532is also greater than or equal to 0.7, that is, a3/(a4+c2)≥0.7. This setting can ensure the stable operation of the electric circular saw500, make the size of the electric circular saw500in the left-right direction more reasonable, and avoid increasing the size of the electric circular saw500in the left-right direction. In this application, the forward direction of the electric circular saw500is defined to be substantially the same as the front-rear direction. Of course, the first linear direction and the second linear direction may not be parallel, that is, the first linear direction and the second linear direction intersect obliquely. In this example, preferably, the first linear direction is substantially parallel to the second linear direction.

Referring toFIG. 17, the housing510includes a first housing portion511, a second housing portion512and a third housing portion513. The first housing portion511and the second housing portion512form a motor casing portion59provided with an accommodating cavity for accommodating the motor. In the left-right direction, the first housing portion511is arranged on the left side, and the second housing portion512and the third housing portion513are arranged on the right side. The third housing portion513is fixedly connected to the second housing portion512, and the third housing portion513can be separated from the second housing portion512. The second housing portion512and the third housing portion513form a battery mounting portion540, the battery mounting portion540is disposed between a main handle520and the motor casing portion59, the battery mounting portion540comprises a first mounting portion540afor guiding the first battery pack531to be coupled to the housing510in the first linear direction502and a second mounting portion540bfor guiding the second battery pack532to be coupled to the housing510in the second linear direction503, the second mounting portion540bis provided at a lower side of the first mounting portion540a, and the battery mounting portion540is configured to detachably mount at least one battery pack to provide energy to the motor. Specifically, in the front-rear direction, the battery mounting portion540is arranged between the motor and the main handle520, and in the left-right direction, the main handle520is basically symmetrically arranged about a plane P1, and the battery mounting portion540is arranged on the right side of the plane P1. The first linear direction502obliquely intersects the plane P1. It can also be understood that the battery mounting portion540is provided on the right side of the main handle520. Arranging the battery mounting portion540between the motor and the main handle520can make full use of the space between the motor and the main handle520, and the battery mounting portion540in the present application is basically open, so the user can use battery packs of different capacities according to needs.

In this example, the first battery pack531and the second battery pack532are arranged in parallel and side by side on the upper side of the base plate550, that is, the first battery pack531and the second battery pack532are both slidably connected to the battery mounting portion540along the first linear direction502, wherein the included angle between the first linear direction502and the forward direction of the electric circular saw500in a projection plane perpendicular to the up-down direction is a, and the range of the included angle α is greater than 0 degree and less than or equal to 30 degrees. By slidably connecting the battery pack assembly530to the battery mounting portion540in a forwardly inclined manner, the included angle α is configured to be within a reasonable range. The user can insert and remove the battery pack assembly530without being interfered by other parts, thus facilitating the user to insert and remove the battery pack assembly530. Preferably, if the range of the included angle α is greater than 10 degrees and less than or equal to 25 degrees, the result is better. The included angle between the first linear direction502and the forward direction of the electric circular saw500in a projection plane perpendicular to the front-rear direction is β, and the range of the included angle β is greater than or equal to 0 degree and less than or equal to 10 degrees. That is, the battery pack assembly530is slidably connected to the battery mounting portion540in a downwardly inclined manner, that is, the end of the battery pack is slightly tilted to facilitate the user to insert and remove the battery pack assembly530.

Further, the ratio of the first distance a1from the second end534of the first battery pack531to the second rotation axis501in the forward direction of the electric circular saw500to the sum of the second distance a2from first end533of the first battery pack531to the second rotation axis501along the first linear direction502and the length C of the first battery pack531is greater than or equal to 0.8 and less than or equal to 1.2. That is, the first battery pack531will be slidably mounted on the housing510in an inclined manner. This arrangement can prevent the first battery pack531from being too long in the front-to-rear direction or the left-to-right direction, thereby avoiding electric circular saw500to be too long in the front-to-rear direction or the left-to-right direction. At the same time, the space between the motor and the main handle520can be reasonably used, so that the overall machine structure arrangement is more reasonable. Preferably, if the ratio of the first distance a1to the sum of the second distance a2and the length C of the battery pack is greater than or equal to 0.9 and less than or equal to 1.1, the result is better.

The battery mounting portion540includes a guiding portion541, a positioning portion542and a connecting portion543. The guiding portion541is used to guide the battery pack assembly530to slide along the first linear direction502, the connecting portion543is used to connect with the battery pack assembly530to supply electric energy, and the positioning portion542battery mounting portion540are used to locate and fix the connecting portion543. In this example, the connecting portion543is a connecting base, and the battery pack assembly530is connected with the connecting base to realize the energy transmission from the battery pack assembly530to the motor. The connecting portion543is fixedly connected to the guiding portion541through the positioning portion542to achieve positioning. Specifically, the positioning portion542is provided with a positioning groove5421, and the connecting base slides into the positioning groove5421in a direction substantially parallel to the first linear direction502. After the connecting base is slid in place, the guiding portion541is fixedly installed so that the guiding portion541, the positioning portion542and the connecting portion543remain in a relatively fixed state. The positioning portion542is formed by the second housing portion512, and the guiding portion541is formed by the third housing portion513. The third housing portion513is fixedly connected to the second housing portion512by means of screws. This arrangement enables the battery pack assembly530to be slidably connected to the connecting portion543through the guiding portion541. Moreover, the battery mounting portion540is made of a separate housing, which is easy to process and easy to realize.

The electric circular saw500further includes a switch assembly521installed on the main handle520, and the switch assembly521is operated by the user to control the operation of the electric circular saw500. In this example, the ratio of the distance H1from the second end534of the first battery pack531to the second rotation axis501in the forward direction of the electric circular saw500to the distance H2from the switch assembly521to the second rotation axis501in the forward direction of the electric circular saw500is greater than or equal to 0.8 and less than or equal to 1.1. That is, the switch assembly521is arranged on the rear side of the first battery pack531, and there is enough space for the user to operate the switch assembly521between the switch assembly521and the first battery pack531. With this configuration, when the electric circular saw500is working, the first battery pack531is prevented from affecting the user operating the switch assembly521.

In the direction along the second rotation axis501, the distance E from the second end534of the first battery pack531to the plane P1is greater than 45 mm. Thus, there is enough space from the second end of the battery pack assembly530to the main handle520in the left-right direction for the user to operate the switch assembly521.

Referring toFIGS. 18-19, the electric circular saw500further includes a guard580and a discharge assembly570. The guard580is used to partially enclose the saw blade560in the circumferential direction about the first rotation axis to protect the safety of the user. The discharge assembly570is used to discharge airflow A with sawdust when the electric circular saw is cutting. Specifically, the discharge assembly570includes an auxiliary handle571to be held by a user, an exhaust member572for discharging the airflow A with sawdust, and a guide portion575for guiding the flow of the airflow A. The auxiliary handle571is arranged on the upper side of the motor, one end of the auxiliary handle571is fixed on the guard580, and the other end is fixedly connected to the housing510. In the direction extending along the auxiliary handle571, a central channel573for airflow A is formed in the center of the auxiliary handle571. One end of the central channel573is connected with the accommodating cavity of the housing510, and the other end of the central channel573is connected with the exhaust member572, and finally the airflow A with sawdust is exhausted from a vent574on the exhaust member572. The exhaust member572is rotatably connected to the auxiliary handle571. This arrangement facilitates the user to adjust the direction of the vent574, so that the airflow A discharged by the exhaust member572is away from the user. The guide portion575is formed by the guard580and the auxiliary handle571to guide the airflow A to the central channel573in the flow direction as shown inFIG. 17. Specifically, the auxiliary handle571on the side close to the guard580and the left side of the guard580cooperate to form a guide portion575for guiding the airflow A, and the guide portion575is connected with the accommodating cavity. The basic principles, main features and advantages of the subject disclosure have been shown and described above.

Those skilled in the industry should understand that the foregoing examples do not limit the claimed invention in any form, and all technical solutions obtained by equivalent substitutions or equivalent transformations fall within the protection scope of the claimed invention.