CN103962818B - Work head is loaded and unloaded on the operational approach of power tool - Google Patents

Abstract

The present invention provides an operation method for loading and unloading a working head on a power tool, wherein the power tool includes: an output shaft for installing and driving the working head to work, a fastening device for fixing the working head on the output shaft A locking member, a locking member that moves between a locking position and a release position, wherein the locking member is used to lock and release the working head; the operation method includes the following steps: a) installing the working head on the mounting part and the pressure plate, the rod passes through the working head and extends into the receiving hole; b) presses the pressure plate along the axial direction of the output shaft, so that the locking member moves and clamps Hold the fastener. Therefore, the working head can be easily installed on the output shaft without external auxiliary tools, and the operation is very convenient.

Description

How to attach and detach the working head to the power tool

technical field

The invention relates to an operation method for loading and unloading a working head on a power tool.

Background technique

A working head in a power tool, such as a circular saw blade, is typically driven by a rotary output shaft coupled to the power tool's motor. In many cases, circular saw blades have a hole through the center that accommodates the output shaft. One end of the output shaft where the circular saw blade is installed is provided with an internal thread. When installing, place the saw blade on the output shaft, extend the fastening bolt through the hole on the saw blade into the thread of the output shaft, and then tighten the fastening bolt with a wrench to fix the circular saw blade on the output shaft ; Similarly, loosen the fastening bolt by a wrench, and take off the fastening element from the output shaft to take off the circular saw blade. It can be seen that the traditional structure of installing the working head on the output shaft is very cumbersome and time-consuming to operate.

Therefore, it is necessary to provide an improved power tool to solve the above problems.

Contents of the invention

The technical problem to be solved by the present invention is to provide an operation method that can conveniently and quickly load and unload the working head on the power tool.

In order to solve the above problems, the present invention provides an operation method for attaching and detaching the working head to the power tool. The power tool includes: an output shaft for installing and driving the working head to work, including a mounting part matched with the working head and A longitudinally extending receiving hole; a fastener, used to fix the working head on the output shaft, including a pressing plate matched with the working head and a rod extending into the receiving hole; a locking member, used for locking position and a release position for locking or releasing the rod; the operation method includes the following steps: a) installing the working head between the mounting part and the pressure plate, the The rod part passes through the working head and extends into the receiving hole; b) presses the pressing plate along the axial direction of the output shaft, so that the locking member moves and clamps the fastener.

In the operation method disclosed in the present invention, the operator can easily install the working head on the output shaft without external auxiliary tools only by pressing the pressing plate of the fastener, and the operation is very convenient.

Preferably, the power tool further includes a stopper selectively cooperating with the locking member, and an elastic element for urging the locking member to always move towards the locking position. In step b), the locking The firmware pushes the stopper, so that the stopper is disengaged from the locking member, and the locking member moves under the action of the elastic element and clamps the rod.

Preferably, in step b), the stopper is disengaged from the locking member along the axial direction of the output shaft.

Preferably, in step b), the elastic element urges the locking member to move in a direction inclined relative to the axis of the output shaft.

Preferably, the power tool further includes a driving member movably arranged on the output shaft, and the operation method further includes the step of: c) pressing the driving member to drive the locking member to move so as to release the locking member; firmware.

Preferably, in step c), the driving member is pressed along the axial direction of the output shaft.

Preferably, in step c), the driving member drives the locking member to move in a direction inclined relative to the axis of the output shaft.

Preferably, in step c), the stopper is movably engaged with the locking member along the axial direction of the output shaft.

Preferably, a spring is provided between the stopper and the driving member.

Preferably, in step c), the stopper pushes the fastener under the action of the spring.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is a perspective view of the power tool of the present invention.

Fig. 2 is a partial perspective view of the power tool shown in Fig. 1 without the housing.

Fig. 3 is a three-dimensional exploded view of the quick clamping device of the power tool of the present invention.

FIG. 4 is an exploded perspective view from another angle of the quick clamping device of the power tool of the present invention.

Fig. 5 is a partial perspective view of the quick clamping device of the power tool of the present invention, at this time, the locking member is not clamping the fastener.

Fig. 6 is a partial perspective view of the quick clamping device of the power tool of the present invention, at this time, the locking member clamps the fastener.

Fig. 7 is a cross-sectional view of the quick clamping device of the power tool of the present invention, and the driving member is at the initial position at this moment.

Fig. 8 is a cross-sectional view of the quick clamping device of the power tool of the present invention, and the locking member is at the release position at this moment.

Fig. 9 is a cross-sectional view of the quick clamping device of the power tool of the present invention, and the locking member is in the locked position at this moment.

Fig. 10 is a perspective view of another angle of the power tool of the present invention.

In the picture:

30． Small electric circular saw32. Housing 34. Motor

36. Transmission assembly 38. Circular saw blade 40. Output shaft

42. Housing front 44. Housing rear 46. Housing middle

48. Power cord 49. Switch 50. Fastener

52. Mounting part 54. Receiving hole 56. Center hole

58. Boss 60. Connector 62. Protrusion

64. Press plate 65. Convex button 66. Rod

68. Fixed end 70. Free end 72. Step

74. Abutting surface 76. Locking piece 78. Elastic element

80. Stopper 81. Mounting seat 82. First split seat

84. Second split seat 86. Mounting sleeve 88. First guide surface

90. Second guide surface 92. Limiting groove 94. Main body

96. Through hole 98. Limit hole 100. Locking surface

102. Limiting part 104. Protruding part 106. Limiting surface

108. Adjacent surface 110. Guide part 112. Fitting part

114. Fitting groove 116. Body 118. Support part

120. Groove 122. U-shaped groove 124. Spring

126. Driver 128. Operation part 130. Engagement part

132. Guide part 134. Guide groove 136. First engaging surface

138. Second engaging surface 139. Threaded hole 140. Protective cover

142. hole

detailed description

The invention relates to a power tool, in particular to a structure and a method for installing a working head on the power tool. Among them, the power tools can be electric circular saws, small electric circular saws, swing machines, angle grinders, miter saws, etc.; and the working head can be a straight saw blade, or a circular saw blade, sand disc, scraper, etc. other accessories.

In this embodiment, a small electric circular saw is cited to illustrate the creative concept of the present invention.

1 and 2, a small electric circular saw 30 includes a housing 32, a motor 34 accommodated in the housing 32, a transmission assembly 36 connected to the motor 34 for power transmission, driven by the transmission assembly 36 and used To install the output shaft 40 of the circular saw blade 38 (as shown in FIG. 3 ). In the description of the present invention, unless otherwise indicated, directional terms, such as front, back, left, right, up and down, etc., are relative to the direction of normal use of the small electric circular saw, such as defining the forward direction of the small electric circular saw The direction is forward, and the direction opposite to the forward direction of the small electric circular saw is rear, etc.

The housing 32 includes a housing front 42 , a housing rear 44 and a housing middle 46 connecting the housing front 42 and the housing rear 44 . Here, the middle part 46 of the housing is the handle holding part, of course, the handle holding part can also be provided at other parts of the housing 32 or separately.

In this embodiment, the motor is the motor 34, and the motor 34 transmits power to the output shaft 40 through the transmission assembly 36, thereby driving the circular saw blade 38 to perform cutting work. The motor may also be a pneumatic motor, a hydraulic motor, etc., as is well known to those skilled in the art. The motor 34 is accommodated in the rear part 44 of the casing, and the motor 34 is electrically connected to a power line 48 so as to be connected to an AC power source (not shown). Of course, the motor 34 may also be powered by a DC battery. The small electric circular saw 30 also includes a switch 49 , which is electrically connected to the motor 34 to control the start and stop of the motor 34 .

As shown in FIG. 3 , the output shaft 40 extends longitudinally, having an axis X. As shown in FIG. A circular saw blade 38 is mounted to one end of the output shaft 40 by a fastener 50 . The output shaft 40 includes a mounting portion 52 matched with the circular saw blade 38 and a receiving hole 54 extending longitudinally.

The circular saw blade 38 is provided with a central hole 56 , and the output shaft 40 is provided with a boss 58 matching the central hole 56 . In this embodiment, the size of the central hole 56 is larger than the size of the boss 58 . Therefore, the small electric circular saw 30 is also provided with a connecting piece 60 . The connecting piece 60 is provided with four cylindrical protrusions 62 for matching with the four arc corners of the central hole 56 . During installation, the four cylindrical protrusions 62 of the connector 60 pass through the mounting part 52 and cooperate with the four arc corners 6 of the central hole 5, so that the circular saw blade 38 is firmly installed on the output shaft 40 At the same time, the power is transmitted better. Of course, those skilled in the art can easily understand that the boss 58 can match or not match the central hole 56 in shape, size or both. The cross-section of the central hole 56 can be in many shapes, such as circular, elliptical, triangular or special-shaped or the like. Similarly, the cross section of the boss 58 can also have many shapes, such as ellipse, triangle, polygon and so on.

The fastener 50 is used to install the circular saw blade 38 on the output shaft 40 , the fastener 50 passes through the central hole 56 of the circular saw blade 38 , and then connects the circular saw blade 38 to the mounting portion 52 of the output shaft 40 .

In order to quickly install or remove the circular saw blade 38 , the small electric circular saw 30 is provided with a quick clamping device that can quickly install or remove the fastener 50 .

In this embodiment, the fastener 50 includes a pressing plate 64 matched with the circular saw blade 38 and a rod portion 66 extending into the receiving hole 54 . The bottom surface of the pressing plate 64 may be substantially conical. A convex button 65 is arranged on the bottom surface of the pressing plate, which is convenient for the operator to press. The stem portion 66 is generally cylindrical. Of course, the cross section of the rod portion 66 can be in many shapes, such as rectangle, ellipse and so on.

The rod portion 66 includes a fixed end 68 connected to the pressing plate 64 and a free end 70 oppositely disposed. The end of the free end 70 is a tapered end.

The rod portion 66 is provided with a step 72 near the free end 70 , and the step 72 forms an abutting surface 74 substantially perpendicular to the axis X of the output shaft 40 . In this embodiment, the outer contour of the abutting surface 74 is circular. Of course, those skilled in the art can easily understand that the outer contour of the abutting surface 74 can be in many other shapes, such as multiple shapes, ovals, triangles, etc. Wait. The specific functions of the tapered end 70 and the abutting surface 74 will be described in detail later.

Referring to Fig. 3, the quick clamping device includes a locking member 76 that can move between a locking position and a release position, an elastic element 78 for urging the locking member 76 to always face the locking position, and can optionally cooperate with the locking member 76 The stopper 80.

A mount 81 is connected to the output shaft 40 . In this embodiment, the mounting base 81 includes first and second split bases 82 and 84 , wherein the second split base 84 is fixedly connected to the output shaft 40 . In this embodiment, the second split seat 84 is provided with a threaded hole, and the output shaft 40 is provided with an external thread at the other end far away from the mounting part 52, so that the output shaft 40 is connected to the second split seat 84 by screw fit. Together. Of course, the output shaft 40 and the second split seat 84 can also be fixed together by screws, rivets, welding and other installation methods known to those skilled in the art.

The outer side of the mounting seat 81 is covered with a mounting sleeve 86 with internal threads, and the second split seat 84 is provided with external threads (not shown). The internal thread of the mounting sleeve 86 cooperates with the external thread of the second split base 84 , so that the first and second split bases 82 and 84 are fixedly connected together. Of course, the external thread can also be provided on the first split seat 82 . It can be understood that the mounting base 81 can also be a single body; or form a single body with the output shaft 40; or be fixed with the output shaft 40 by bolts, screws, rivets and other installation methods known to those skilled in the art. .

A guiding groove (not numbered) cooperating with the locking member 76 is provided in the installation seat 81 . The locking member 76 moves in the guide groove to realize switching between the locking position and the releasing position.

The first split seat 82 is provided with a first guide surface 88 that cooperates with the locking member 76 . Here, the first guide surface 88 is arranged obliquely with respect to the axis X of the output shaft 40 .

As shown in FIG. 4 , the second split seat 84 is provided with a second guide surface 90 that cooperates with the locking member 76 . Similarly, the second guide surface 90 is inclined relative to the axis X of the output shaft.

However, when the first and second split seats 82 and 84 are fixedly connected together, a guiding groove that cooperates with the locking member 76 is formed between the first guiding surface 88 and the second guiding surface 90 . Thus, the guide groove is arranged obliquely with respect to the axis X of the output shaft.

The mounting base 81 is provided with a limiting slot 92 for receiving the stopper 80 . Preferably, the extending direction of the limiting groove 92 is set parallel to the axis X of the output shaft. Of course, those skilled in the art can easily understand that the extending direction of the limiting groove 92 can also be set obliquely with respect to the axis X of the output shaft 40 .

The locking member 76 is made of rigid material, and it is installed in the installation seat 81 and located in the space formed by the first and second split seats 82 and 84 . The locking member 76 includes a substantially U-shaped main body 94 , and the main body 94 is provided with a through hole 96 through which the abutting surface 74 can pass and a limiting hole 98 through which the abutting surface 74 cannot pass. The through hole 96 and the limiting hole 98 are respectively located at two ends of the main body 94 and communicate with each other. The through hole 96 may or may not match the outer contour of the abutting surface 74 , and only needs to be slightly larger than the outer contour of the abutting surface 74 . However, in this embodiment, the through hole 96 is approximately square. The limiting hole 98 communicating with the through hole 96 is rectangular, and its width is slightly smaller than the side length of the through hole 96 .

A locking surface 100 abutting against the abutting surface 74 is formed on the surface of the main body 94 . The through hole 96 is opened on the locking surface 100 .

Referring to FIG. 5 , when the locking member 76 is at the release position, the through hole 96 is aligned with the receiving hole 54 (not shown) on the output shaft 40 , allowing the abutment surface 74 on the fastener 50 to pass through the through hole 96 at the same time. and the receiving hole 54; referring to Fig. 6, when the locking member 76 is in the locking position, the through hole 96 and the receiving hole 54 on the output shaft 40 are staggered due to the radially outward movement of the locking member 76, and the limiting hole 98 and the receiving hole 54 The accommodating holes 54 are at least partly aligned, and the abutting surface 74 on the fastener 50 cannot pass through due to the narrow limit hole 98, and under the action of the elastic element 78, the locking surface 100 on the locking member 76 and the The abutment surface 74 cooperates so that the locking member 76 locks the fastener 50 on the output shaft 40 . The rod portion 66 includes a limiting portion 102 connected to the step 72 , and the limiting portion 102 can pass through the limiting hole 98 .

Two symmetrical protrusions 104 extend radially outward from an end portion of the main body 94 where the through hole 96 is disposed. The protruding portion 104 includes a limiting surface 106 perpendicular to the abutting surface 74 . The limiting surface 106 and the adjacent surface 108 on the mounting base 81 form a space for receiving the elastic element 78 . That is to say, one end of the elastic element 78 abuts against the limiting surface 106 , and the other end abuts against the abutting surface 108 .

Referring to FIG. 4 again, the locking member 76 is provided with a guiding portion 110 matching the guiding groove. Certainly, the guide groove can also be provided on the locking member 76 , and the guide part 110 can be provided on the mounting base 81 .

The guiding portion 110 is disposed on both sides of the through hole 98 , and the extending direction of the guiding portion 100 is inclined relative to the locking surface 100 . Thus, when the locking member 76 moves, the upper and lower surfaces of the guide part 100 are in contact with the first and second guide surfaces 88 and 90 respectively, so that the guide part 100 can move in the guide groove along the relative The axis X of the output shaft moves obliquely. Of course, those skilled in the art understand that, here, the moving direction of the locking member 76 may also be perpendicular to the axis X of the output shaft 40 .

The stopper 80 is made of rigid material, and it is movably received in the limiting groove 92, so that the stopper 80 is movably installed on the output shaft 40, and can move along the axial direction of the output shaft 40 . Of course, as understood by those skilled in the art, the moving direction of the stopper 80 can be set obliquely or vertically relative to the axis X of the output shaft 40 .

The stopper 80 is optionally engaged with the locking member 76 . One of the stopper 80 and the locking member 76 is provided with a matching groove, and the other of the stopper 80 and the locking member 76 is provided with a matching portion matched with the matching portion.

In this embodiment, the fitting portion 112 is disposed on the stopper 80 , and the fitting groove 114 is disposed on the locking member 76 . The fitting groove 114 extends in the axial direction of the output shaft 40 .

The stopper 80 includes a body 116 , and two matching portions 112 and two supporting portions 118 respectively extend from the upper and lower surfaces of the body 116 . The main body 116 is generally in the shape of a sheet, and is provided with a groove 120 matched with the fastener 50, wherein the groove 120 can be in the shape of a semicircle or an arc. During installation, the semicircular or arc-shaped groove 120 faces the through hole 96 on the locking member 76 . In this way, when the tapered end 70 cooperates with the groove 120 , the fastener 50 pushes the stopper 80 to move more stably.

The two matching portions 112 extend axially downward from the lower surface of the body 116 and are arranged symmetrically about the center. When the matching portion 112 is accommodated in the matching groove 114, the stopper 80 prevents the locking member 76 from moving, and the locking member 76 is in the release position; when the matching portion 112 is disengaged from the fitting groove 114, the stopper 80 cannot prevent locking The member 76 moves, and the locking member 76 moves to the locked position under the action of the elastic member 78 . Here, the elastic element 78 may be a compression spring, a torsion spring or the like.

The two support portions 118 extend axially upward from the upper surface of the body 116 and are also arranged symmetrically about the center. A U-shaped groove 122 is disposed on the support portion 118 for partially receiving the spring 124 . The spring 124 is used to urge the stopper 80 to cooperate with the locking member 76 .

In summary, in the release position, the stopper 80 cooperates with the locking member 76, and the fastener 50 can be removed from the output shaft 40, so that the circular saw blade 38 can be quickly disassembled; in the process from the release position to the lock position , the fastener 50 pushes the stopper 80, causing the stopper 80 to disengage from the locking member 76, and the locking member 76 moves to the locking position under the action of the elastic element 78; in the locking position, the rod 66 is clamped on the output shaft 40, and the circular saw blade 38 is clamped between the mounting portion 52 and the pressing plate 64, so that the circular saw blade 38 can be quickly installed. The circular saw blade 38 can thus be replaced quickly without external aids.

Referring again to FIG. 3 , in order to more conveniently switch the locking member 76 from the locking position to the releasing position, the small electric circular saw further includes a driving member 126 for moving the locking member 76 . By operating the driving member 126 , the locking member 76 can be moved from the locking position to the releasing position, and then the fastening member 50 can be moved out of the output shaft 40 .

The driving member 126 is movably disposed on the mounting seat 81 and can drive the locking member 76 to move in a direction inclined relative to the axis X of the output shaft 40 .

The driving member 126 includes an operating portion 128 that can be operated by an operator, an engagement portion 130 connected to the operating portion 128 , and a guide portion 132 . The guiding portion 132 cooperates with the guiding groove 134 on the mounting base 81 to make the driving member 126 move between the driving position and the initial position, wherein the extending direction of the guiding groove 134 is parallel to the axial direction of the output shaft 40 . In this way, the driving member 126 is operable to move along the axial direction of the output shaft 40 . Certainly, the driving member 126 may also move in a direction inclined relative to the axis X of the output shaft 40 or be disposed on the mounting seat 81 by means of rotation or the like.

The engaging portion 130 includes a first engaging surface 136 inclined along the axial direction. When the driving member 126 is active, the locking member 76 is driven to move through the first engaging surface 136 .

The locking member 76 is provided with a second engaging surface 138 (as shown in FIG. 4 ) matching the first engaging surface 136 , and the second engaging surface 138 is inclined relative to the axis X of the output shaft 40 .

Press the driving portion 126 so that the first engaging surface 136 engages with the second engaging surface 138 , thereby driving the locking member 76 to move from the locking position to the releasing position.

Referring to FIG. 7 , in this embodiment, the spring 124 is disposed between the stopper 80 and the driving member 126 . Therefore, the spring force of the spring 124 urges the driving member 126 to always be at the initial position; at the same time, urges the stopper 80 to always move toward the position engaged with the locking member 76 . Certainly, the small electric circular saw 30 can also be provided with two springs, and these two springs respectively urge the driving member 126 to be in the initial position and urge the stopper 80 to always face the position where it engages with the locking member 80 .

The locking and releasing process of the circular saw blade 38 in this embodiment will be described below with reference to FIG. 8 and FIG. 9 . The driving member 126 can drive the locking member 76 to convert from the locking position to the releasing position. In the locking position, the fastener 50 is clamped by the locking member 76, thereby stably fixing the circular saw blade 38 on the output shaft 40 ; In the release position, the locking member 50 loosens the fastener 50, so that the fastener 50 can be removed from the output shaft 40, so that the circular saw blade 38 can be removed. Therefore, the small electric circular saw can quickly replace the circular saw blade 38 without external auxiliary tools.

As shown in FIG. 8 , the locking member 76 is at the release position at this time. In this position, the stop 80 cooperates with the locking member 76 under the action of the spring 124 . That is, under the action of the spring 124 , the fitting portion 112 on the stopper 80 is engaged in the fitting groove 114 on the locking member 76 . At this time, the through hole 96 on the locking member 76 is roughly aligned with the receiving hole 54 on the output shaft 40 . The locking surface 100 on the locking member 76 disengages the fastener 50 . At this moment, the locking part 76 is in the position of releasing the fastening part 50, and then the fastening part 50 can be removed from the locking part 76, so that the circular saw blade 38 can be taken off.

It should be pointed out that the aforementioned release position is driven by an external force to move the driving member 126 to prompt the locking member 76 to move to the release position. At the release position, despite the removal of the external force, due to the action of the spring 124, the driving member 126 returns to the initial position; the matching portion 112 on the stopper 80 is snapped into the matching groove 114 on the locking member 76, so that The locking member 76 remains in the released position.

Before installing the fastener 50 into the output shaft 40 , the circular saw blade 38 is installed between the mounting portion 52 of the output shaft 40 and the pressure plate 64 . The circular saw blade 38 can be installed on the mounting portion 52 of the output shaft 40 at first, then the fastener 50 can pass through the central hole 56 of the circular saw blade 38, and then extend into the receiving hole 54 of the output shaft 40; The fastener 50 passes through the central hole 56 of the circular saw blade 38 , and then extends into the receiving hole 54 of the output shaft 40 .

When locking is required, the user presses the knob 65 (see FIG. 3 ) on the fastener 50, and the free end 70 of the fastener 50 cooperates with the groove 120 of the stopper 80, prompting the stopper 80 to overcome The elastic force of the spring 124 moves upward for a certain distance until the matching portion 112 on the stopper 80 disengages from the matching groove 114 on the locking member 76 . During the movement of the stopper 80 , the stopper 80 moves in the axial direction of the output shaft 40 .

As shown in FIG. 9 , when the matching portion 112 on the stopper 80 disengages from the matching groove 114 on the locking member 76 , the locking member 76 moves under the action of the elastic element 78 and clamps the rod portion 66 .

It should be pointed out that during the locking process, the locking member 76 moves obliquely relative to the axis X of the output shaft 40 under the action of the elastic element 78; The receiving holes 54 on the output shaft 40 are staggered, so that the limiting portion 102 on the fastener 50 is located in the limiting hole 98 . Under the further action of the elastic element 78, the locking surface 100 on the locking member 76 engages with the abutting surface 74 of the fastener 50, and the fastener 50 is clamped by the locking member 76, thereby fixing the circular saw blade 38 on the Between the mounting part 52 and the pressure plate 64 .

It should be pointed out that, in the aforementioned locking position, the locking surface 100 is substantially perpendicular to the axis X of the output shaft 40 .

It should be pointed out that in the aforementioned locked position, the stopper 80 compresses the spring 124 . The stopper 80 is held in a disengaged position with the locking member 76 by the step surface opposite the abutment surface 74 .

It should be pointed out that in this embodiment, the moving direction of the locking member 76 is set obliquely relative to the extension direction of the axis X of the output shaft 40 , and is not vertically set. This is because the small electric circular saw 30 can be equipped with circular saw blades of different brands and models, and the thickness of such circular saw blades is bound to be inconsistent. Therefore, the inclined setting can eliminate the axial gap caused by the uneven thickness of the circular saw blade. Therefore, those skilled in the art can understand that the axial gap caused by the non-uniform thickness of the circular saw blade can also be eliminated by setting the inclined surface to cooperate with the abutting surface of the fastener. Certainly, if the moving direction of the locking member 76 is perpendicular to the extension direction of the axis X of the output shaft 40 , the locking member 76 can also fix a circular saw blade with a certain thickness.

Above, the clamping process of the small electric circular saw 30 in this embodiment has been described in detail, and the releasing process is opposite to the clamping process. When the circular saw blade 38 needs to be disassembled from the output shaft 40 , it is only necessary to manually press the driving part 128 of the driving part 126 to compress the spring 124 to make the driving part 126 move along the axial direction parallel to the output shaft 40 . During the moving process of the driving member 126 , the first engaging surface 136 thereof engages with the second engaging surface 138 on the locking member 76 , thereby driving the locking member 76 to move. When the locking member 76 moves relative to the mounting base 81 , the locking surface 100 disengages from the abutting surface 74 , and the through hole 96 moves to a position roughly aligned with the receiving hole 54 , thereby releasing the fastener 50 . The stopper 80 moves downward axially under the elastic force of the spring 124. Since the groove 120 of the stopper 80 cooperates with the free end 70, it will drive the fastener 50, and finally the fastener 50 will be released from the output shaft. Push out a certain distance inside, so that the fastener 50 can be easily taken out from the output shaft; at the same time, the stopper 80 moves downward axially until the matching part 112 matches the matching groove 114, and then the stopper 80 stops the locking member 76 moves, and the locking member 76 is in the release position.

It should be noted here that, as shown in FIG. 9 , in this embodiment, the receiving hole 54 is provided with a threaded hole 139 at an end close to the circular saw blade 38 . If the fastener is replaced with a threaded fastening bolt or screw. When installing the circular saw blade 38 , it is only necessary to pass the fastener through the central hole 56 on the circular saw blade 38 and screw it into the threaded hole 139 , and the circular saw blade 38 can also be fixed on the output shaft 40 .

Referring to FIG. 10 , a protective cover 140 is provided on the front portion 42 of the housing. The protective cover 140 includes a generally circular aperture 142 . The hole 142 may be closed or semi-closed for receiving the driver 126 . Therefore, it is avoided that the user mishandles the driving member 126; or the driving member 126 is actuated due to placing the small electric circular saw 30 on the workbench.

The present invention is not limited to the aforementioned embodiments, and those skilled in the art may make other changes under the inspiration of the technical essence of the present invention, but as long as the functions realized are the same or similar to those of the present invention, they should all be covered within the protection scope of the present invention .

Claims (10)

1. An operation method for loading and unloading a working head on a power tool, characterized in that, The power tools include: The output shaft is used to install and drive the working head to work, including a mounting part matched with the working head and a longitudinally extending receiving hole; The fastener is used to fix the working head on the output shaft, including a pressing plate matched with the working head and a rod extending into the receiving hole; a locking member movable between a locked position and a released position for locking or releasing the rod; The method of operation comprises the following steps: a) Installing the working head between the mounting part and the pressing plate, the rod passes through the working head and extends into the receiving hole; b) Pressing the pressing plate along the axial direction of the output shaft, so that the locking member moves and clamps the fastener. 2. The operation method according to claim 1, characterized in that: the power tool further comprises a stopper selectively cooperating with the locking member for urging the locking member to always move toward the locked position The elastic element, in step b), the fastener pushes the stopper, urging the stopper to disengage from the locking member, and the locking member is on the elastic member Moves and clamps the rod under action. 3. The operation method according to claim 2, characterized in that in step b), the stopper is disengaged from the locking member along the axial direction of the output shaft. 4. The operation method according to claim 2, wherein in step b), the elastic element urges the locking member to move in a direction inclined relative to the axis of the output shaft. 5. The operating method according to claim 2, characterized in that: the power tool further comprises a driving member movably arranged on the output shaft, and the operating method further comprises the step of: c) pressing the driving member , driving the locking member to move so as to release the fastener. 6. The operation method according to claim 5, characterized in that in step c), the driving member is pressed along the axial direction of the output shaft. 7. The operation method according to claim 5, wherein in step c), the driving member drives the locking member to move in a direction inclined relative to the axis of the output shaft. 8. The operation method according to claim 5, characterized in that in step c), the stopper is movably engaged with the locking member along the axial direction of the output shaft. 9. The operation method according to claim 5, characterized in that a spring is provided between the stopper and the driving member. 10. The operation method according to claim 9, characterized in that in step c), the stopper pushes the fastener under the action of the spring.