Portable Cutting Machine

Abstract

To increase the maximum tilting angle of a plunge circular saw.SOLUTION: A plunge circular saw 10 includes: a base 20; a body portion 30 disposed on a second side relative to the base 20; and a cover 50 disposed on the second side relative to the base 20. The body portion 30 is displaceable with respect to the base 20 and the cover 50 between a first position in which a cutting tool 35 is entirely housed in the cover and a second position in which the cutting tool 35 protrudes beyond the base 20 toward the first side opposite to the second side and is partially exposed outside the cover. The cover 50 includes a cover body 52 and an auxiliary cover 500 that is disposed to function as a part of a portion of the cover 50 close to the base 20 and is relatively movable with respect to the cover body 52. The body portion 30 and the cover body 52 are tiltable about a first tilting axis AX6 located on a first side with respect to the base 20.SELECTED DRAWING: Figure 21

Description

[Technical Field]

[0001] The present invention relates to a portable plunge cut-off machine. [Background technology]

[0002] Various portable cutting machines (e.g., circular saws, cutters, etc.) known as plunge-type machines have been known for some time. For example, a plunge-type circular saw (hereinafter simply referred to as a circular saw) includes a main body and a generally rectangular base having a contact surface for contacting the workpiece. The main body includes an electric motor and a disk-shaped cutting tool that is driven and rotated by the electric motor. The cutting tool is housed in a cover while being biased upward by a biasing member (the position of the cutting tool at this time is also referred to as the top dead center).

[0003] When using such a circular saw, the user places the saw at the cutting start position for the workpiece so that the contact surface of the base contacts the workpiece. Next, while the cutting tool is rotating, the user moves the cutting tool downward from the top dead center as far as possible (the position of the cutting tool at this time is also called the bottom dead center). At this time, the lower part of the cutting tool protrudes downward from the base, and cutting of the workpiece begins. Next, while maintaining the cutting tool at the bottom dead center, the user moves the circular saw forward to the cutting end position. Then, the user stops the rotation of the cutting tool and returns it to the top dead center. This cutting method is called a plunge cut.

[0004] As such a plunge circular saw, a type in which the main body and the cover can be tilted relative to the base is known (for example, see Patent Document 1 below). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2018-176310 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in this type of plunge saw, the cover extends closer to the base than in a non-plunge saw. Furthermore, the tilting axis of the body and cover is located below the base. Therefore, if the body and cover are tilted too far, the cover will interfere with the workpiece. Therefore, in conventional plunge saws, the maximum tilt angle of the body and cover is typically limited to approximately 48 degrees. This maximum tilt angle of such a plunge saw is smaller than the maximum tilt angle (typically approximately 60 degrees) of a non-plunge saw (i.e., a type in which the lower part of the cutting tool always protrudes below the base). For this reason, there is still room for a larger maximum tilt angle in plunge saws to improve convenience. [Means for solving the problem]

[0007] This specification discloses a portable cutting machine. The portable cutting machine may include a base for contacting a workpiece, a main body having a motor configured to provide rotational driving force to a cutting tool, the main body being disposed on a second side relative to the base, and a cover disposed on the second side relative to the base for at least partially covering the cutting tool. The main body may be configured to be displaceable relative to the base and the cover between a first position in which the cutting tool is completely housed within the cover and a second position in which the cutting tool protrudes beyond the base to a first side opposite the second side and is partially exposed outside the cover. The cover may include a cover main body and an auxiliary cover arranged to function as a part of the portion of the cover adjacent to the base and movable relative to the main body cover. The main body and the cover main body may be configured to be tiltable about a first tilting axis located on the first side relative to the base. The auxiliary cover may be configured to at least partially tilt about a second tilting axis located on a second side of the first side of the base in conjunction with the tilting movement of the cover main body.

[0008] According to the above configuration, the auxiliary cover, which is positioned close to the base, tilts at least partially around the second tilting axis, which is located on the second side of the first side of the base. Therefore, no matter how much the cover is tilted, the auxiliary cover will not interfere with the workpiece located on the first side. This allows for a larger maximum tilt angle than conventional plunge cut-off machines.

[0009] This specification further discloses a portable cutting machine. The portable cutting machine may include a body portion having a motor configured to provide rotational driving force to a cutting tool, the body portion being disposed on a second side relative to the base, and a cover disposed on the second side relative to the base for at least partially covering the cutting tool. The body portion may be configured to be displaceable relative to the base and the cover between a first position in which the cutting tool is completely housed within the cover and a second position in which the cutting tool protrudes beyond the base to the first side opposite the second side and is partially exposed outside the cover. The body portion and the cover may be configured to be tiltable up to 60 degrees relative to the base.

[0010] According to the above configuration, the maximum tilt angle can be increased compared to the conventional plunge-type cutting machine, which has a maximum tilt angle of 48 degrees. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view showing an example of a circular saw according to a first embodiment, with a main body at the top dead center. [Figure 2] FIG. 1 is a perspective view of a circular saw with the body at the bottom dead center. [Figure 3] FIG. 1 is a perspective view of a circular saw with the body at the top dead center. [Figure 4] FIG. 1 is a perspective view of a circular saw with the body at the bottom dead center. [Figure 5] FIG. 1 is a perspective view of a circular saw with the body at the top dead center. [Figure 6] FIG. 1 is a partially enlarged perspective view of the circular saw with a portion of the cover removed and the lock operating member in a blocking position. [Figure 7] FIG. 10 is a partially enlarged perspective view of the circular saw with a portion of the cover removed and the lock operating member in the allowable position. [Figure 8] This is a perspective view of the circular saw with the door open. [Figure 9] FIG. [Figure 10] FIG. 1 is a perspective view of a circular saw with some parts removed. [Figure 11] 10 is a cross-sectional view showing the positional relationship between the lock operating mechanism and the gear housing, with the main body at the top dead center and the lock operating mechanism at the blocking position. FIG. [Figure 12] 10 is a cross-sectional view showing the positional relationship between the lock operation mechanism and the gear housing, with the main body at the top dead center and the lock operation mechanism at the permitted position. FIG. [Figure 13] 10 is a cross-sectional view showing the positional relationship between the lock operating mechanism and the gear housing, with the main body at the bottom dead center and the lock operating mechanism at the blocking position. FIG. [Figure 14] FIG. 1 is a longitudinal cross-sectional view of the circular saw, showing the lock operating mechanism in a blocking position. [Figure 15] FIG. 1 is a longitudinal cross-sectional view of the circular saw, showing the lock operating mechanism in an allowable position. [Figure 16] FIG. 2 is a left side view of the circular saw with the battery not installed. [Figure 17] FIG. 2 is a left side view of the circular saw with the battery attached. [Figure 18] FIG. 2 is a longitudinal cross-sectional view of the circular saw, showing the engaging member in an engaged position. [Figure 19] 1 is a longitudinal cross-sectional view of a circular saw, showing an engaging member in a disengaged position. [Figure 20] FIG. 1 is a vertical cross-sectional view of a circular saw. [Figure 21] FIG. 2 is a vertical cross-sectional view of the circular saw showing a state in which the main body and the cover are not tilted. [Figure 22] FIG. 2 is a vertical cross-sectional view of the circular saw showing a state in which the main body and the cover are inclined to the maximum inclination angle. [Figure 23]FIG. 10 is a perspective view of the auxiliary cover when the main body and the cover are not tilted. [Figure 24] 10 is a perspective view of the auxiliary cover in a state in which the main body and the cover are inclined to the maximum inclination angle. FIG. [Figure 25] FIG. 10 is a perspective view of the auxiliary cover when the main body and the cover are not tilted. [Figure 26] FIG. [Figure 27] FIG. 27 is a cross-sectional view taken along line AA in FIG. 26. [Figure 28] 10A and 10B are schematic diagrams showing the relationship between the inclination of the cover body and the cover member and the amount of movement of the cover member. [Figure 29] FIG. 10 is a perspective view of a gear housing according to a second embodiment. [Figure 30] 10 is a cross-sectional view showing the positional relationship between the lock operating mechanism and the gear housing, with the main body at the top dead center and the lock operating mechanism at the blocking position. FIG. [Figure 31] 10 is a cross-sectional view showing the positional relationship between the lock operation mechanism and the gear housing, with the main body at the top dead center and the lock operation mechanism at the permitted position. FIG. [Figure 32] 10 is a cross-sectional view showing the positional relationship between the lock operating mechanism and the gear housing, with the main body at the bottom dead center and the lock operating mechanism at the blocking position. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Representative, non-limiting embodiments of the present invention will now be described in detail with reference to the accompanying drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Additionally, additional features and inventions disclosed below may be used separately or in conjunction with other features and inventions to provide further improved devices, methods of making and using the same.

[0013] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to practicing the invention in its broadest sense, but are described solely to illustrate specific exemplary embodiments of the invention. Furthermore, the various features of the exemplary embodiments described above and below, and those described in the independent and dependent claims, do not necessarily have to be combined in the exact embodiments described herein, or in the exact order listed, to provide additional and useful embodiments of the invention.

[0014] All features described in this specification and / or claims are intended to be disclosed individually and independently of one another as limitations on the original disclosure and claimed particulars, apart from any configuration of the features described in the embodiments and / or claims. Furthermore, all numerical ranges and group or aggregation descriptions are intended to disclose intermediate configurations thereof as limitations on the original disclosure and claimed particulars.

[0015] In one or more embodiments, the auxiliary cover may be configured to move in conjunction with the tilting movement of the cover body so that when the main body is in the second position and not tilted relative to the base, the auxiliary cover and the rotation axis of the cutting tool overlap when viewed in the direction of the rotation axis, and so that when the main body is in the second position and maximally tilted relative to the base, the auxiliary cover and the rotation axis do not overlap when viewed in the direction of the rotation axis. This configuration allows the auxiliary cover to adequately cover the sides of the cutting tool when the main body is not tilted relative to the base. Furthermore, because the auxiliary cover can be tilted to a position where the auxiliary cover and the rotation axis do not overlap when viewed in the direction of the rotation axis, the rotation axis of the cutting tool (in other words, the part located at the center of the cutting tool that holds the cutting tool) can be moved as close as possible to the base. This allows the cutting tool to achieve a large cutting depth into the workpiece.

[0016] In one or more embodiments, the auxiliary cover may include a cover member for covering the side of the cutting tool, and a support member for supporting the cover member so that the cover member can tilt about the second tilt axis, the support member being arranged so that the position of the support member in the direction from the second side to the first side is fixed. With this configuration, the position of the second tilt axis in the direction from the second side to the first side can be reliably fixed regardless of how much the auxiliary cover is tilted. Therefore, it is possible to reliably prevent the cover member from reaching the first side beyond the base and interfering with the workpiece.

[0017] In one or more embodiments, the cover member may include a substantially rectangular first portion for covering the sides of the cutting tool, and second and third portions extending from both longitudinal edges of the first portion toward the interior of the cover so as to face each other. With this configuration, when the cover tilts, the surface of the cover facing the auxiliary cover can be brought into contact with the second and third portions at an early stage of the tilting (or even before the tilting). Therefore, the tilting of the cover main body about the first tilting axis and the tilting of the cover member about the second tilting axis can be smoothly linked.

[0018] In one or more embodiments, the auxiliary cover may be configured such that, when the cover main body tilts about the first tilting axis, the cover member is pressed by the cover main body to tilt about the second tilting axis, and the support member is pressed by the cover main body to move in a direction perpendicular to the second tilting axis, parallel to the base, and toward the interior of the cover. With this configuration, when the cover main body tilts about the first tilting axis, the second tilting axis moves together with the support member in a direction opposite to the tilting direction of the cover member, allowing the cover main body to tilt more smoothly.

[0019] In one or more embodiments, the base may have a through hole that penetrates in a direction in which the support member moves when the cover body tilts about the first tilt axis. The support member may pass through the through hole and be slidably disposed on the base. This configuration allows the support member to be securely held on the base.

[0020] In one or more embodiments, the support member may include a first support portion and a second support portion that respectively support the cover member at both longitudinal ends of the cover member so that the cover member can tilt. With this configuration, when the cover body tilts about the first tilting axis, the cover member can tilt more stably about the second tilting axis.

[0021] Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

[0022] A first embodiment of the present invention will be described below. In this embodiment, a plunge circular saw 10 (hereinafter simply referred to as the circular saw 10) will be illustrated as an example of a portable processing machine. In the following description, for convenience of explanation, the side on which the circular saw 10 moves when a user holds the circular saw 10 and cuts a workpiece (the cutting direction) will be defined as the front side of the circular saw 10, and the opposite side will be defined as the rear side of the circular saw 10. In addition, the side positioned vertically above will be defined as the upper side of the circular saw 10, and the opposite side will be defined as the lower side of the circular saw 10. In addition, the direction perpendicular to the front-to-rear direction and the up-down direction will be defined as the left-to-right direction of the circular saw 10. In the left-to-right direction, the right side when viewed from the rear to the front will be defined as the right side of the circular saw 10, and the opposite side will be defined as the left side of the circular saw 10.

[0023] First, the schematic configuration of the circular saw 10 will be described mainly with reference to FIGS. 1 to 5. As shown in FIGS. 1 to 5, the circular saw 10 includes a base 20 for contacting the upper surface of a workpiece, a main body 30, and a cover 50. The base 20 has a substantially rectangular outer shape. The longitudinal direction of the base 20 is the front-to-rear direction. The base 20 includes a lower surface 21 for contacting the upper surface of the workpiece when cutting the workpiece. However, the base 20 is not necessarily positioned so that the lower surface 21 contacts the upper surface of the workpiece. When a ruler is used together with the circular saw 10 to linearly cut the workpiece, the base 20 may be positioned so that the lower surface 21 contacts the upper surface of the ruler.

[0024] The main body 30 is basically disposed above the base 20. The main body 30 includes a motor housing 31 that houses an electric motor 33 (see FIG. 21) and a grip portion 32 that a user can hold by hand. The electric motor 33 includes a motor shaft 34. The electric motor 33 (the motor shaft 34) provides rotational driving force to a saw blade 35 (see FIGS. 2 and 4) via a reduction gear 43 (see FIG. 21) and an output shaft 42 (see FIG. 21) housed in a gear housing 60 (see FIG. 3). The saw blade 35 is a circular saw blade known as a chip saw. In this embodiment, the gear housing 60 is integrally formed with the motor housing 31.

[0025] The cover 50 is disposed above the base 20 and on the right edge of the base 20. The cover 50 is fixed to the base 20 via the angular contact 26 and angular contact plates 24, 25 (details of which will be described later). The saw blade 35 has a disk shape and is at least partially housed inside the cover 50. Specifically, an arc-shaped through-hole 37 (see FIG. 3) penetrating the left side surface of the cover 50 in the left-right direction is formed in the left side surface of the cover 50. The output shaft 42 extends through the through-hole 37 into the cover 50. Inside the cover 50, the saw blade 35 is attached to the tip of the output shaft 42 by a flange 36 (see FIG. 8). As a result, the saw blade 35 rotates integrally with the output shaft 42 about the rotation axis AX1 (see FIG. 6) when the electric motor 33 is driven by receiving power supply from a battery 45 (see FIGS. 3 and 4) as a power source attached to a battery mounting portion 46 (see FIG. 16). A trigger 38 (see FIG. 4) for starting and stopping the electric motor 33 is provided at the front end of the grip portion 32.

[0026] As shown in Fig. 16, the battery mounting section 46 is disposed at the rear and lower portion of the main body 30. The battery 45 can be slidably mounted in the battery mounting section 46. Specifically, the battery mounting section 46 has a plurality of terminals 47 extending like rails. When the battery 45 is mounted in the battery mounting section 46 by sliding it in the direction in which the plurality of terminals 47 extend, the plurality of terminals 47 are electrically connected to a plurality of terminals (not shown) of the battery 45.

[0027] The main body 30 is configured to be swingable relative to the base 20 and the cover 50 about a support shaft 22 (see FIG. 3 ) supported by a trunnion 27 formed integrally with the angular contact 26 supported by the base 20. The support shaft 22 (in other words, the swing axis AX2 of the main body 30) is parallel to the rotation axis AX1. Specifically, as shown in FIGS. 1 and 3 , the main body 30 is displaceable between a position (also referred to as top dead center) in which the entire saw blade 35 is located above the lower surface 21 of the base 20 and is entirely housed within the cover 50, and a position (also referred to as bottom dead center when the saw blade 35 protrudes most from the lower surface 21) in which the saw blade 35 protrudes downward beyond the lower surface 21 of the base 20 and is partially exposed outside the cover 50, as shown in FIGS. 2 and 4 . Note that the saw blade 35 being "entirely" housed within the cover 50 means that the entire saw blade 35 is not located outside the outer contour of the cover 50 when viewed in the direction in which the rotation axis AX1 extends.

[0028] A torsion spring 23 is disposed around the support shaft 22. The torsion spring 23 constantly biases the main body 30 from the bottom dead center toward the top dead center. Therefore, the top dead center is the initial position of the main body 30.

[0029] The top dead center position is determined by a lock pin 39 (see FIG. 3 ) extending from the gear housing 60 toward the cover 50 and a recess 51 (see FIG. 4 ) formed on the left side surface of the cover 50 (more specifically, a cover main body 52, which will be described later). Specifically, the lock pin 39 is constantly biased toward the right (i.e., toward the cover 50) by a biasing member (not shown). When the lock pin 39 is in a position facing the recess 51, the tip of the lock pin 39 fits into the recess 51. This locks the cover 50 at the top dead center. When the user operates the release button 40 (see FIG. 4 ), the lock pin 39 retracts to the left against the biasing force of the biasing member. This releases the engagement between the lock pin 39 and the recess 51. When the user presses the main body 30 downward in this state, the main body 30 is displaced toward the bottom dead center against the biasing force of the torsion spring 23.

[0030] The position of the lower end of the main body 30 (the lower limit of movement) is determined by the stopper 41 (see FIGS. 3 and 4). The user can push the main body 30 down until the gear housing 60 abuts against the stopper 41. The stopper 41 is configured to be vertically positionable. This allows the user to change the position of the stopper 41 (i.e., the position of the lower end of the main body) according to the desired cutting depth. The bottom dead center described above is the position of the main body 30 when the main body 30 is lowered to the lower end of the main body with the stopper 41 positioned at its lowest point. Note that in the following description, the "lower end of the main body" is also referred to as the "bottom dead center" assuming that the stopper 41 is positioned at its lowest point. When the user releases the force pushing the main body 30 downward while the main body 30 is at the lower end of the main body, the main body 30 returns to the top dead center due to the biasing force of the torsion spring 23.

[0031] Furthermore, the main body 30 and the cover 50 are configured to be tiltable relative to the base 20. Specifically, angular plates 24, 25 are attached to the base 20. The angular plates 24, 25 each have an approximately quarter-circular arc shape centered on a first tilting axis AX6 (see FIG. 22). The angular plate 24 is fixed to the front edge of the base 20, and the angular plate 25 is fixed to the rear edge of the base 20. The front and rear portions of the angular plate 26 have approximately the same arc shape as the angular plates 24, 25 and are arranged to overlap the angular plates 24, 25, respectively. The portion between the front and rear portions of the angular plate 26 has an approximately flat plate shape extending in the front-to-rear and left-to-right directions with the front-to-rear direction being the longitudinal direction (see FIG. 3). As is well known, loosening the thumbscrews 28, 29 attached to the angular plates 24, 25 releases the fixed relationship between the angular 26 fixed to the cover 50 and the angular plates 24, 25, allowing the main body 30 and cover 50 to be tilted relative to the base 20. Then, tightening the thumbscrews 28, 29 at a desired tilt position establishes the fixed relationship between the angular 26 fixed to the cover 50 and the angular plates 24, 25, thereby fixing the tilt position of the main body 30 and cover 50 relative to the base 20. An angle switching knob 58 is provided on the front surface of the angular plate 24. By rotating the angle switching knob 58, the limit angle to which the main body 30 and cover 50 can be tilted can be selected to 22.5 degrees, 45 degrees, or 60 degrees. Even when the main body 30 and the cover 50 are tilted relative to the base 20, the main body 30 can be displaced between the top dead center and the bottom dead center in the same manner as described above.

[0032] Next, a configuration for replacing the saw blade 35 of the circular saw 10 will be described. As shown in FIGS. 1 and 8, the cover 50 includes a cover body 52 and an openable / closable door 53. The door 53 functions as part of the right side of the cover 50. The door 53 is large enough to cover the entire upper portion and approximately half of the lower portion of the saw blade 35 when the body 30 is at the top dead center. Therefore, as shown in FIG. 8, when the door 53 is opened, the flange 36 that secures the saw blade 35 to the output shaft 42 by sandwiching the saw blade 35 laterally is completely exposed. Therefore, the saw blade 35 can be easily replaced by loosening the flange 36 using a box wrench or the like.

[0033] As shown in FIG. 8 , the door 53 can be opened and closed by a hinge mechanism 54 formed by a part of the cover body 52 and a part of the door 53. In this embodiment, the hinge mechanism 54 is disposed forward of the rotation axis AX1 of the saw blade 35. The hinge mechanism 54 is oriented such that the pivot axis of the door 53 intersects the horizontal direction (the direction perpendicular to the vertical direction) and the vertical direction. Therefore, the rotational motion of the door 53 includes a horizontal component. The horizontal component in the rotational motion of the door 53 can prevent the door 53 from opening wide and forcefully against the user's intention due to its own weight. Furthermore, the hinge mechanism 54 is oriented such that the rotational motion of the door 53 includes a vertical component and the opening motion of the door 53 includes an upward component. Therefore, the user's operation to open the door 53 involves a rotation of the door 53 against its own weight. Therefore, the door 53 can be further prevented from opening wide and forcefully against the user's intention. This effect can be similarly obtained even if the hinge mechanism 54 is disposed rearward of the rotation axis AX1.

[0034] The circular saw 10 further includes an opening / closing mechanism 70 for opening and closing the door 53, and a lock operation mechanism 80 that can lock the opening / closing mechanism 70 in a closed state (i.e., a state in which the door 53 is closed). The opening / closing mechanism 70 and the lock operation mechanism 80 will be described below. As shown in FIGS. 6 and 7, the opening / closing mechanism 70 includes an engaging portion 71 that holds the door 53 in a closed state. The engaging portion 71 is pivotally supported on the left side portion of the cover body 52. ​​The engaging portion 71 is displaceable between a closed position (see FIG. 6) in which the engaging portion 71 engages with the door 53 to hold it in a closed state, and an open position (see FIG. 7) in which the engaging portion 71 does not engage with the door 53 and allows the door 53 to be opened.

[0035] The engaging portion 71 has a first engaging piece 72 and a second engaging piece 73 that protrude radially outward relative to the pivot axis AX3. As shown in FIGS. 14 and 15, the door 53 has an engaging portion 55 that protrudes in an L-shape from its inner surface (left surface) to the left (saw blade 35 side) of the door 53. When the engaging portion 71 is in the closed position (see FIG. 6), as shown in FIG. 14, the first engaging piece 72 of the engaging portion 71 and the tip (portion extending in the up-down direction) of the engaging portion 55 of the door 53 engage in the left-right direction. Therefore, the door 53 cannot move in the opening direction (rightward) and is maintained in the closed state. On the other hand, when the engaging portion 71 is in the open position (see FIG. 7), as shown in FIG. 15, the first engaging piece 72 of the engaging portion 71 and the engaging portion 55 of the door 53 do not engage in the left-right direction. Therefore, the door 53 can be opened.

[0036] The engagement portion 71 is configured to interlock with a lock operation mechanism 80. As shown in FIG. 9 , the lock operation mechanism 80 includes an operation portion 81, a base portion 82, a connecting portion 83, an arm portion 84, and an abutment portion 85. The base portion 82 has a generally cylindrical shape. The operation portion 81 is a portion manually operated by a user and is in the form of a generally L-shaped lever. The operation portion 81 extends radially outward from the base portion 82, then bends and extends toward the left. The connecting portion 83 is a portion for connecting with the engagement portion 71 and extends cylindrically from the base portion 82 toward the right. As shown in FIGS. 14 and 15 , the connecting portion 83 is connected to the engagement portion 71 by a screw 74. The connecting portion 83 is disposed to pass through a through-hole in the cover main body 52, and therefore the engagement portion 71 and the lock operation mechanism 80 are integrally supported by the cover main body 52 so as to be pivotable about a pivot axis AX3. The arm portion 84 extends radially outward from the base portion 82 at a circumferential position different from that of the operating portion 81. A cylindrical contact portion 85 is formed at the tip of the arm portion 84 and protrudes toward the left side (toward the gear housing 60 of the main body portion 30).

[0037] The lock operation mechanism 80 is configured to be manually displaceable between a blocking position (see FIGS. 5 and 6) that blocks the opening of the door 53 by the opening / closing mechanism 70, and an allowable position (see FIG. 7) that allows the opening of the door 53 by the opening / closing mechanism 70. Specifically, as described above, the lock operation mechanism 80 is configured to pivot integrally with the engaging portion 71, and when the lock operation mechanism 80 is in the blocking position, the engaging portion 71 is in the closed position, and when the lock operation mechanism 80 is in the allowable position, the engaging portion 71 is in the open position. Therefore, the user can open the door 53 only when the lock operation mechanism 80 is displaced from the blocking position, which is the initial position, to the allowable position.

[0038] As shown in FIG. 6 , when the main body 30 is at the top dead center and the lock operation mechanism 80 is at the blocking position, the lock operation mechanism 80 (more specifically, the operation unit 81) is located below the slide path for sliding the battery 45 into the battery mounting portion 46. Therefore, the battery 45 can be attached to the battery mounting portion 46 without interfering with the slide path. On the other hand, as shown in FIG. 7 , when the main body 30 is at the top dead center and the lock operation mechanism 80 is at the allowable position, the lock operation mechanism 80 (more specifically, the operation unit 81) interferes with the slide path of the battery 45. Therefore, the battery 45 cannot be attached to the battery mounting portion 46. In other words, when the lock operation mechanism 80 is at the allowable position, which allows the door 53 to be opened, power is not supplied to the electric motor 33. Therefore, the user does not need to be careful to prevent the saw blade 35 from rotating unintentionally when the door 53 is open.

[0039] As shown in FIG. 5 , when the lock operation mechanism 80 is in the blocked position, the tip of the operating portion 81 of the lock operation mechanism 80 is located below the battery 45 with the battery 45 attached to the battery attachment portion 46. Therefore, even if a user attempts to move the lock operation mechanism 80 from the blocked position (see FIG. 5 ) to the permitted position (see FIG. 7 ), the operating portion 81 interferes with the battery 45. Therefore, with the battery 45 attached to the battery attachment portion 46, the user cannot move the lock operation mechanism 80 from the blocked position to the permitted position. On the other hand, as is clear from FIGS. 6 and 7 , with the battery 45 removed, the lock operation mechanism 80 can be moved from the blocked position to the permitted position without interfering with other components. In other words, the user cannot operate the lock operation mechanism 80 to open the door 53 unless power is supplied to the electric motor 33 and the circular saw 10 is unusable. Therefore, the user does not need to open or close the door 53 while paying attention to preventing the saw blade 35 from rotating unintentionally.

[0040] Furthermore, the lock operation mechanism 80 is configured so that displacement of the lock operation mechanism 80 from the blocking position to the allowing position is permitted only when the main body 30 is at top dead center, and displacement of the lock operation mechanism 80 from the blocking position to the allowing position is prohibited when the main body 30 is at any position other than top dead center. Such a configuration will be described below with reference to Figures 10 to 13. As shown in Figure 10, a first abutted portion 61, a recess 62, a recess 63, and a second abutted portion 64 are formed on the right surface of the gear housing 60.

[0041] The relief portion 62 and the recessed portion 63 are in the form of a groove recessed toward the left side. The relief portion 62 and the recessed portion 63 are continuous with each other and have a generally V-shape (more precisely, a V-shape formed by arcs) as a whole. The first abutted portion 61 is an arc-shaped portion adjacent to the recessed portion 63 and forms a side wall of the recessed portion 63 (the side wall closer to the relief portion 62) along the recessed portion 63. The second abutted portion 64 is an arc-shaped portion adjacent to the relief portion 62 and forms a side wall of the relief portion 62 (the side wall closer to the recessed portion 63) along the relief portion 62. The relief portion 62 and the recessed portion 63 are located further leftward than the first abutted portion 61 and the second abutted portion 64.

[0042] An abutment portion 85 of the lock operation mechanism 80 (which protrudes in the recessed direction of the recess 62 and the recess 63) is housed within the recess 62 and the recess 63. In other words, the abutment portion 85 is always located opposite either the recess 62 or the recess 63 in the left-right direction. The position within the recess 62 or the recess 63 at which the abutment portion 85 is located changes depending on the swing position of the main body 30 and the pivot position of the lock operation mechanism 80.

[0043] 11, when the main body 30 is at the top dead center and the lock operation mechanism 80 is in the blocking position (in other words, the opening / closing mechanism 70 is in the closed position), the abutment portion 85 is in a position facing the base end of the recess 62 (the connection point with the recess 63). In this state, the lock operation mechanism 80 (in other words, the abutment portion 85) is allowed to move from the blocking position to the allowing position. Specifically, when the user moves the lock operation mechanism 80 from the blocking position shown in FIG. 11 to the allowing position shown in FIG. 12, the abutment portion 85 moves from a position facing the base end of the recess 62 to a position facing the tip of the recess 62 (the end opposite the connection point with the recess 63), as shown in FIG. Although the recess 62 is adjacent to the first abutted portion 61, it is located in a position retreated from the first abutted portion 61, so the movement of this abutting portion 85 is not hindered by abutment with the first abutted portion 61.

[0044] 12, i.e., when the main body 30 is at the top dead center and the lock operation mechanism 80 is in the permitted position, displacement of the main body 30 from the top dead center toward the bottom dead center is prohibited. Specifically, even if the user attempts to displace the main body 30 toward the bottom dead center in the state shown in Fig. 12, the second abutted portion 64 abuts against the abutting portion 85 in a direction that prohibits the displacement. Therefore, the user cannot displace the main body 30 toward the bottom dead center.

[0045] 11, i.e., when the main body 30 is at the top dead center and the lock operation mechanism 80 is in the blocking position, displacement of the main body 30 from the top dead center toward the bottom dead center is permitted. Specifically, when the user displaces the main body 30 to the bottom dead center in the state shown in Fig. 11, the abutment portion 85 moves relatively within the recess 63 to a position facing the tip of the recess 63 (the end opposite to the connection point with the relief portion 62), as shown in Fig. 13.

[0046] 13, i.e., when the main body 30 is in a position other than the top dead center and the lock operation mechanism 80 is in the blocking position, the lock operation mechanism 80 (in other words, the abutting portion 85) is prohibited from moving from the blocking position to the allowing position. Specifically, even if the user attempts to move the lock operation mechanism 80 from the blocking position to the allowing position in the state shown in FIG. 13, the abutting portion 85 abuts against the first abutted portion 61 in a direction that prohibits the movement. Therefore, the user cannot move the lock operation mechanism 80 toward the allowing position.

[0047] As is clear from the above description, with the circular saw 10, the lock operating mechanism 80 can be displaced from the initial blocking position to the permitting position to open the door 53 only when the main body 30 is at the top dead center. Therefore, if the main body 30 is moved from a position other than the top dead center to the top dead center with the lock operating mechanism 80 displaced to the permitting position, a situation in which the gear housing 60 and the lock operating mechanism 80 collide strongly and cause damage will not occur. Therefore, when opening the door 53, the user does not need to operate the circular saw 10 carefully to avoid damaging it due to incorrect operation. This improves user convenience.

[0048] Furthermore, with the circular saw 10, the main body 30 can be displaced from the top dead center toward the bottom dead center to perform cutting with the circular saw 10 only when the lock operating mechanism 80 is in the blocking position (in other words, only when there is no possibility that the door 53 will open). This allows the user to use the circular saw 10 without having to check whether the door 53 is open (or whether the door 53 is in a state where it can be opened). This improves user convenience.

[0049] Furthermore, the lock operating mechanism 80 can achieve two functions: a closed state lock function that prevents the door 53 from opening when the main body 30 is in a position other than the top dead center, and a main body position lock function that prohibits the main body 30 from moving from the top dead center toward the bottom dead center when the lock operating mechanism 80 is in the allowable position. This allows the circular saw 10 to be made smaller than when these two functions are achieved by separate mechanisms.

[0050] Furthermore, since both the engagement portion 71 of the opening / closing mechanism 70 and the lock operation mechanism 80 are supported by the cover body 52, the engagement portion 71 and the lock operation mechanism 80 can be linked efficiently with a small number of parts.

[0051] Furthermore, as shown in FIG. 6 , the engaging portion 71 and the lock operating mechanism 80 are disposed rearward of the rotation axis AX1 of the saw blade 35, i.e., closer to where the user stands when using the circular saw 10. This makes it easier for the user to operate the lock operating mechanism 80. Moreover, since the distance between the engaging portion 71 and the lock operating mechanism 80 is reduced, the engaging portion 71 and the lock operating mechanism 80 can be interlocked in a compact configuration. Furthermore, the hinge mechanism 54 for opening and closing the door 53 is disposed forward of the rotation axis AX1 of the saw blade 35 (i.e., farther from the engaging portion 71 and the lock operating mechanism 80). This increases the distance between the engaging portion 71 and the hinge mechanism 54, enabling the door 53 to be opened and closed more reliably.

[0052] 11, the contact portion 85 and the first contacted portion 61 are disposed closer to the swing axis AX2 of the main body 30 than to the rotation axis AX1 of the saw blade 35. In other words, the distance between the swing axis AX2 and the contact portion 85 and the first contacted portion 61 is shorter than the distance between the rotation axis AX1 and the contact portion 85 and the first contacted portion 61. This reduces the distance between the swing axis AX2 and the contact portion 85 and the first contacted portion 61. This reduces the circumferential range around the swing axis AX2 in which the first contacted portion 61 should be disposed so that the first contacted portion 61 functions properly throughout the entire swing angle range of the main body 30. In other words, the first contacted portion 61 can be made smaller.

[0053] The circular saw 10 further includes an additional structure for preventing the circular saw 10 from being used with the door 53 open. This structure will be described below. As shown in FIGS. 14 and 15, the opening / closing mechanism 70 includes a compression spring 75 and a locking member 76. As shown in FIGS. 6 and 7, the locking member 76 is located below and adjacent to the engaging portion 71. Note that while FIG. 6 shows a state in which a portion of the cover main body 52 (the right portion located at the rear edge) has been removed, in reality, as shown in FIG. 8, this portion is still attached, and only the locking member 76 is accessible from the right side of the cover main body 52 via the through-hole 56, while the engaging portion 71 is not.

[0054] 14 and 15, locking member 76 has an engaging portion 77 that protrudes upward and a pressed portion 78 that protrudes cylindrically toward the right. A step 79 is formed at the base end of pressed portion 78. Locking member 76 is constantly biased to the right (in other words, in the opening direction of door 53) by a compression spring 75 that is disposed in a compressed state between the left side portion of cover main body 52 and locking member 76.

[0055] As shown in Figure 14, when door 53 is closed with protrusion 57 provided on door 53 inserted into cover 50 through through-hole 56 (when door 53 is held in the closed state by engagement between engagement portion 71 and engagement portion 55), protrusion 57 presses pressed portion 78 toward the left against the biasing force of compression spring 75. In this state, as shown in Figures 6 and 14, engagement portion 77 is retracted to the left of engagement portion 71 and does not interfere with the operation of engagement portion 71. This allows engagement portion 71 to be displaced from the closed position (see Figure 6) to the open position (see Figure 7) in conjunction with lock operation mechanism 80.

[0056] On the other hand, when the engaging portion 71 is displaced from the closed position (see FIG. 6) to the open position (see FIG. 7), the door 53 is released from the closed state (in other words, the pressing force of the protrusion 57). At this time, the locking member 76 is pressed to the right by the biasing force of the compression spring 75 and displaces to the right until the step 79 abuts against the right inner surface of the cover body 52. ​​At this time, the locking member 76 (more specifically, the pressed portion 78) presses the door 53 to the right, so that the door 53 opens by the displacement of the locking member 76, as shown in FIG. 15. Also, as shown in FIGS. 7 and 15, the engaging portion 77 takes the same left-right position as the engaging portion 71 as the locking member 76 displaces. At this time, as is clear from FIG. 7, the engaging portion 77 interferes with the displacement of the engaging portion 71 from the open position (see FIG. 7) to the closed position (see FIG. 6). In other words, when the door 53 is open even slightly, the engaging portion 71 cannot be displaced from the open position (see FIG. 7) to the closed position (see FIG. 6).

[0057] With this configuration, basically, when the door 53 is open, the user cannot displace the lock operating mechanism 80, which is linked to the engaging portion 71, from the permitting position to the blocking position. If the lock operating mechanism 80 is not in the blocking position, the main body 30 cannot be displaced from the top dead center toward the bottom dead center. Therefore, the user does not need to be careful about the saw blade 35 being unintentionally exposed from the cover 50 when the door 53 is open, improving user convenience.

[0058] However, if the user inserts his or her finger into the through-hole 56 and presses the pressed portion 78 to the left with the finger, the locking member 76 will be displaced to the position shown in Fig. 14, and it is possible to displace the main body 30 from the top dead center toward the bottom dead center while maintaining that state. With this configuration, with the battery 45 removed, the saw blade 35 can be displaced toward the bottom dead center, making it easy to clean off cutting debris and the like that exists between the left side of the cover body 52 and the saw blade 35.

[0059] Furthermore, with the above configuration, when the engaging portion 71 is displaced by operating the lock operating mechanism 80, the door 53 is automatically opened slightly by the biasing force of the compression spring 75. As a result, as shown in FIG. 15 , a small gap is created between the door 53 and the outer surface of the right side of the cover main body 52. ​​A user can insert their finger into this gap to easily open the door 53.

[0060] The circular saw 10 further includes a structure for easily replacing the saw blade 35. Such a structure will be described below with reference to FIGS. 16 to 20. The circular saw 10 includes an operating member 90 and an engaging member 94. As shown in FIG. 20, the operating member 90 includes a knob 91, a shaft 92, and a pressing portion 93. The knob 91 is positioned so as to be exposed to the outside of the battery mounting portion 46. The pressing portion 93 is positioned inside the gear housing 60. The shaft 92 rotatably passes through the motor housing 31 and connects the knob 91 and the pressing portion 93.

[0061] 16 and 17, the knob 91 has an arc shape. When the battery 45 is not attached to the battery attachment portion 46, the operating member 90 is in the initial position shown in Fig. 16, and when the battery 45 is attached to the battery attachment portion 46, the operating member 90 is pressed by the battery 45 and pivots to the pressed position shown in Fig. 17. At this time, the shaft 92 and pressing portion 93 integrated with the knob 91 also pivot together with the knob 91.

[0062] The engaging member 94 is disposed inside the gear housing 60. As shown in FIGS. 18 and 19 , the engaging member 94 has an annular portion 95 at one longitudinal end and a pressed portion 97 at the other longitudinal end. The annular portion 95 is disposed so that the motor shaft 34 passes through a through hole formed inside the annular portion 95. The pressed portion 97 is a portion that protrudes to the left. An engaging portion 96 having a through hole whose width is significantly narrower than the through hole of the annular portion 95 is formed at the other end of the annular portion 95. The engaging member 94 is held by a pin 99 so as to be displaceable in the longitudinal direction between an engaged position shown in FIG. 18 and a disengaged position shown in FIG. 19 . The engaging member 94 is constantly biased in a direction in which the pressed portion 97 approaches the motor shaft 34 (i.e., toward the engaged position) by a compression spring 98 disposed in a compressed state between the gear housing 60 and the pressed portion 97.

[0063] When the battery 45 is not attached to the battery attachment portion 46, the engagement member 94 is in the engagement position shown in Figure 18. At this time, the motor shaft 34 fits inside the engagement portion 96, and the motor shaft 34 and the engagement portion 96 are in an engaged state. Therefore, rotation of the motor shaft 34 is prevented, at least when the electric motor 33 is not driven. At this time, the shaft 92 abuts against the pressed portion 97, but does not press against the pressed portion 97.

[0064] On the other hand, when the battery 45 is attached to the battery attachment portion 46, the operating member 90 pivots as described above. As a result, as shown in FIG. 19 , the pressing portion 93 presses the pressed portion 97 against the biasing force of the compression spring 98. As a result, the engaging member 94 is displaced from the engaged position shown in FIG. 18 to the disengaged position shown in FIG. 19 . This disengages the motor shaft 34 from the engaging portion 96, allowing rotation of the motor shaft 34. Therefore, with the battery 45 attached, the engaging member 94 does not affect the rotation of the motor shaft 34. When the battery 45 is removed, the biasing force of the compression spring 98 returns the pressing portion 93 (operating member 90) and the engaging member 94 to the positions shown in FIG. 18 .

[0065] According to the above configuration, the rotation of the motor shaft 34 is prevented by simply removing the battery 45. Therefore, when loosening and tightening the flange 36 using a box wrench or the like to replace the saw blade 35, the motor shaft 34 is prevented from rotating. This makes it easy to replace the saw blade 35, improving user convenience.

[0066] Furthermore, the circular saw 10 is configured to allow the saw blade 35 to tilt at a larger angle than conventional plunge saws. Such a configuration will be described below, mainly with reference to FIGS. 21 to 24. As shown in FIGS. 1 and 2, the cover 50 includes an auxiliary cover 500 that functions as part of the right side of the cover 50. The auxiliary cover 500 is positioned to function as part of the portion of the cover 50 that is close to the base 20 (in other words, as part of the lower edge of the right side of the cover 50). As will be described in more detail below, the auxiliary cover 500 is configured to be movable relative to the cover main body 52.

[0067] As described above, the main body 30 and the cover main body 52 can be tilted relative to the base 20 by loosening the thumbscrews 28, 29 provided on the angular plates 24, 25. This tilting movement is centered around the first tilting axis AX6 (see FIG. 22). As shown in FIG. 22, the first tilting axis AX6 is located below the base 20. A plurality of arc-shaped concave and convex portions are formed on the rear surface of the angular plate 24 and the front surface of the front arc portion of the angular 26, and these concave and convex portions mesh with each other to guide the tilting movement. The centers of the arc-shaped concave and convex portions coincide with the first tilting axis AX6. The same is true for the front surface of the angular plate 25 and the rear surface of the rear arc portion of the angular 26.

[0068] As shown in Fig. 23, the auxiliary cover 500 includes a cover member 510 for covering the side of the saw blade 35 and a support member 520 for supporting the cover member 510. The cover member 510 includes a first portion 511, a second portion 512, a third portion 513, and contact portions 514 and 515. The first portion 511 has a substantially rectangular shape and covers the side of the saw blade 35 as shown in Fig. 1. As shown in Fig. 8, the width of the first portion 511 in the front-rear direction is set so that the first portion 511 extends outward beyond the saw blade 35 in the front-rear direction.

[0069] The second portion 512 and the third portion 513 extend from both longitudinal (front-rear) edges of the first portion 511 toward the interior of the cover 50 (the side where the saw blade 35 is located) so as to face each other. The abutment portions 514 and 515 extend from the left ends of the second portion 512 and the third portion 513, respectively, in a direction away from the first portion 511 and parallel to the first portion 511.

[0070] 24, the cover member 510 is reinforced by a plurality of ribs 516 extending in the longitudinal direction thereof. In order to avoid interference with the flange 36 when the main body 30 and the cover 50 are tilted, no ribs 516 are formed in the central portion of the cover member 510 in the longitudinal direction.

[0071] As shown in FIG. 25, the support member 520 is composed of a first support portion 520a, a second support portion 520b, and a bridge portion 520c. The first support portion 520a and the second support portion 520b are simple, elongated plate-like shapes. The bridge portion 520c is plate-shaped with its longitudinal direction in the front-to-rear direction and has a hinge portion at its right end. The bridge portion 520c is integrated with the first support portion 520a and the second support portion 520b on the left side of the front and rear portions by welding. The first support portion 520a and the second support portion 520b are disposed near the front end and the rear end of the cover member 510, respectively, via the bridge portion 520c. Hinge mechanisms 530a and 530b are formed by a portion of the bridge portion 520c and a portion of the cover member 510. The hinge mechanisms 530a, 530b are located at both longitudinal edges and at the lower lateral edge of the cover member 510. With this configuration, the support member 520 supports the cover member 510 so that it can tilt about the second tilting axis AX7, as shown in Figures 23 to 25. The first support portion 520a and the second support portion 520b, which are spaced apart in the front-rear direction, support the cover member 510 via the bridge portion 520c, allowing the cover member 510 to tilt more stably.

[0072] The first support portion 520a and the second support portion 520b are arranged such that the positions of the first support portion 520a and the second support portion 520b in the up-down direction are fixed. In this embodiment, the first support portion 520a and the second support portion 520b are arranged on the base 20 so as to be movable in the left-right direction. By arranging the first support portion 520a and the second support portion 520b on the base 20, the second tilting axis AX7 of the cover member 510 is positioned above the lower surface 21 of the base 20.

[0073] More specifically, as shown in FIG. 27 , the base 20 has two through-holes 220a and 220b penetrating in the left-right direction, which are disposed at two positions corresponding to the first support portion 520a and the second support portion 520b. The first support portion 520a and the second support portion 520b are disposed on the base 20 so as to be slidable therethrough while passing through the through-holes 220a and 220b, respectively. This configuration allows the first support portion 520a and the second support portion 520b to be securely held on the base 20. Furthermore, the base 20 has two guide grooves 210a and 210b extending in the left-right direction. The first support portion 520a and the second support portion 520b are housed in the guide grooves 210a and 210b, respectively. This configuration prevents the first support portion 520a and the second support portion 520b from being angled with respect to the left-right direction. This stabilizes the sliding properties in the left-right direction.

[0074] The auxiliary cover 500 is configured to tilt about the swing axis AX2 in conjunction with the tilting movement of the cover main body 52 about the first tilt axis AX6. Such a linking movement will be described below. As shown in FIG. 1, the auxiliary cover 500 is disposed so that the upper edge of the cover member 510 is positioned inside the cover main body 52 (so that the upper edge of the cover member 510 is positioned higher than the lower edge of the cover main body 52). As shown in FIG. 6, the auxiliary cover 500 is disposed so that the abutting portions 514 and 515 abut against the left inner surface of the cover main body 52 (more specifically, the protruding portion 52b protruding toward the right) (only the abutment between the abutting portion 514 and the left inner surface of the cover main body 52 can be seen in FIG. 6). Although not shown, the abutting portions 514 and 515 are also disposed so as to abut against the right inner surface of the cover main body 52 (more specifically, the protruding portion protruding toward the left). That is, the contact portions 514 and 515 are sandwiched between the protrusion 52b on the left inner surface of the cover main body 52 and the protrusion on the right inner surface of the cover main body 52.

[0075] 21, when the main body 30 and the cover main body 52 are not inclined relative to the base 20 and the main body 30 is at the bottom dead center, the auxiliary cover 500 (more specifically, the first portion 511 of the cover member 510) and the rotation axis AX1 overlap when viewed in the direction in which the rotation axis AX1 of the saw blade 35 extends (the left-right direction). At this time, as shown in FIG. 2, when the base 20 is placed on the workpiece, the cover member 510 extends downward to a position where there is almost no gap between the workpiece and the cover member 510, and the sides of the saw blade 35 can be sufficiently covered.

[0076] When the main body 30 and the cover main body 52 are tilted about the first tilting axis AX6 relative to the base 20 from the state shown in FIG. 21 to the maximum tilt angle (60 degrees) shown in FIG. 22 , the left side of the cover main body 52 presses the contact portions 514 and 515 of the cover member 510 in the tilting direction of the cover main body 52. ​​This causes the cover member 510 to tilt about the second tilting axis AX7. At this time, the first support portion 520a and the second support portion 520b slide toward the right (in other words, in a direction perpendicular to the second tilting axis AX7, parallel to the base 20, and toward the outside of the base 20) to compensate for the misalignment between the first tilting axis AX6 and the second tilting axis AX7. In other words, the cover member 510 tilts while moving the second tilting axis AX7 toward the right. According to this operation, the cover main body 52 and the cover member 510 move relative to each other in the vertical direction (the direction in which the cover main body 52 and the cover member 510 extend parallel to each other) so that the cover member 510 moves upward relative to the cover main body 52. ​​Here, if the vertical distance between the first tilting axis AX6 and the second tilting axis AX7 is R, the amount of relative movement of the cover member 510 is P, and the tilt angle is θ, then the following equation holds (for convenience, the left-right deviation between the first tilting axis AX6 and the second tilting axis AX7 is ignored) (see FIG. 28). When the two tilting axes AX6 and AX7 extend vertically by a distance R, a movement amount P expressed as (R / cos θ)-R is always generated. The series of operations of the auxiliary cover 500 utilizes movements that can be expressed using trigonometric functions in this way.

[0077] At this time, since the second tilting axis AX7 is located above the underside 21 of the base 20, no matter how much the cover member 510 is tilted, the cover member 510 will not interfere with the workpiece located directly below the base 20. Therefore, the maximum tilt angle can be made larger than in conventional plunge cutters. This maximum tilt angle depends on the tilting mechanism of the main body 30 and the cover main body 52.

[0078] 22, when the main body 30 and the cover 50 are tilted to the maximum tilt angle, the auxiliary cover 500 (more specifically, the first portion 511 of the cover member 510) and the rotation axis AX1 do not overlap when viewed in the direction in which the rotation axis AX1 of the saw blade 35 extends (the left-right direction). This allows the flange 36 that holds the saw blade 35 to be as close as possible to the underside 21 of the base 20. This ensures a large cutting depth of the saw blade 35 into the workpiece.

[0079] 21 from the tilted state shown in Fig. 22, the right inner surface of the cover main body 52 presses the abutment portions 514, 515 of the cover member 510. As a result, the first support portion 520a and the second support portion 520b slide toward the left, and the cover member 510 tilts in the opposite direction about the second tilting axis AX7, and the entire auxiliary cover 500 returns to the position shown in Fig. 21.

[0080] According to the above configuration, the abutment portions 514, 515 are always in contact with the left and right inner surfaces of the cover main body 52, respectively. This allows the tilting of the cover main body 52 about the first tilting axis AX6 and the tilting of the cover member 510 about the second tilting axis AX7 to be smoothly linked together. Furthermore, the abutment portions 514, 515 provide a large contact area, further enhancing the smoothness of the linked movement. However, the abutment portions 514, 515 may be omitted. In this case, the second portion 512 and the third portion 513 may be in contact with the left inner surface of the cover main body 52 during the linked movement when transitioning from the non-tilted state to the inclined state, and the upper edge of the first portion 511 may be in contact with the right inner surface of the cover main body 52 during the linked movement when transitioning from the inclined state to the non-tilted state. Furthermore, when the main body 30 and the cover 50 are in a non-tilted state, the abutting portions 514, 515 (or the second portion 512 and the third portion 513) do not have to abut on the left inner surface (protrusion 52b) of the cover main body 52. ​​Even with such a configuration, the second portion 512 and the third portion 513 allow the cover member 510 and the cover main body 52 to abut on each other at an early stage of the tilting operation, thereby achieving a certain degree of effect. Similarly, the abutting portions 514, 515 do not have to abut on the protrusion on the right inner surface of the cover main body 52 when in a non-tilted state.

[0081] In addition to the above-mentioned functions, the second portion 512 and the third portion 513 also function to fill the gap between the cover 50 and the base 20. Specifically, the cover main body 52 has two inclined portions 52a (see FIG. 1) on its right side. The inclined portions 52a are inclined so that the closer they are to the base 20, the closer they are to the left side of the cover main body 52. ​​The two inclined portions 52a are located on both sides of the cover member 510 in the longitudinal direction. The inclined portions 52a are formed to avoid interference between the cover main body 52 and the workpiece when the cover 50 is tilted to the position shown in FIG. 22. The second portion 512 and the third portion 513 are located adjacent to these two inclined portions 52a, so that the gap between the cover 50 and the base 20 that may be formed due to the inclined portions 52a can be filled (FIG. 1 shows only the second portion 512 filling the gap).

[0082] Furthermore, with the above configuration, the first support portion 520a and the second support portion 520b slide relative to each other during tilting, thereby compensating for misalignment between the first tilting axis AX6 and the second tilting axis AX7, thereby achieving smoother interlocking movement between the cover main body 52 and the cover member 510.

[0083] A circular saw 110 according to the second embodiment will be described below with reference to Figures 29 to 32. The circular saw 110 according to the second embodiment differs from the circular saw 10 according to the first embodiment in that it includes a lock operating mechanism 180 instead of the lock operating mechanism 80 and a gear housing 160 instead of the gear housing 60. In other respects, the circular saw 110 has the same configuration as the circular saw 10. Below, only the differences between the circular saw 110 according to the first embodiment will be described.

[0084] As shown in FIG. 29 , a first abutted portion 161, a recess 162, a recess 163, and a second abutted portion 164 are formed on the right surface of the gear housing 160. The recess 162 and the recess 163 are recessed toward the left. The recess 162 and the recess 163 are continuous with each other and have a generally L-shape (more precisely, an L-shape formed by an arc). The first abutted portion 161 is an arc-shaped portion adjacent to the recess 163 and forms a side wall of the recess 163 along with the recess 163. The second abutted portion 164 is an arc-shaped portion adjacent to the recess 162 and forms a side wall of the recess 162 along with the recess 162.

[0085] Although the first abutment portion 161, the clearance portion 162, the recess 163 and the second abutment portion 164 have different shapes from the first abutment portion 61, the clearance portion 62, the recess 63 and the second abutment portion 64 of the first embodiment, respectively, their functions are the same.

[0086] As shown in Figure 30, the lock operation mechanism 180 includes an operation lever 181 and a lock lever 183. One end of the operation lever 181 is supported by the cover main body 52 so as to be pivotable about a first pivot axis AX4. The other end of the operation lever 181 is a free end extending rearward. A cam 182 is formed around the base end (the one end) of the operation lever 181. One end of the lock lever 183 is supported by the cover main body 52 so as to be pivotable about a second pivot axis AX5. An abutment portion 184 that protrudes toward the left side (toward the gear housing 160) is formed at the other end of the operation lever 181.

[0087] As shown in FIG. 30 , when the main body 30 is at the top dead center and the lock operation mechanism 80 is in the blocking position, the abutment portion 184 is in a position facing the base end of the recess 162 (the connection point with the recess 163). In this state, the lock operation mechanism 180 (in other words, the abutment portion 184) is allowed to move from the blocking position to the allowing position. Specifically, when the user moves the operating lever 181 from the blocking position shown in FIG. 30 to the allowing position shown in FIG. 31 , the lock lever 183 is pressed by the cam 182, as shown in FIG. 31 . As a result, the lock lever 183 pivots in the direction opposite to the pivoting direction of the operating lever 181. At this time, the abutment portion 184 moves from a position facing the base end of the recess 162 to a position facing the tip of the recess 162 (the end opposite the connection point with the recess 163), as shown in FIG. 31 . When the user returns the operating lever 181 from the allowable position to the blocking position, the pressing force of the cam 182 is released, and the lock lever 183 returns to its original position due to its own weight.

[0088] 31, that is, when the main body 30 is at the top dead center and the lock operation mechanism 180 is in the permitted position, even if the user attempts to displace the main body 30 toward the bottom dead center, the second abutted portion 164 abuts against the abutting portion 184 in a direction that prevents the displacement. Therefore, the user cannot displace the main body 30 toward the bottom dead center.

[0089] 30, that is, when the main body 30 is at the top dead center and the lock operation mechanism 180 is in the blocking position, when the user displaces the main body 30 to the bottom dead center, the abutment portion 184 moves within the recess 163 to a position facing the tip of the recess 163 (the end opposite to the connection point with the relief portion 162), as shown in Fig. 32. Therefore, displacement of the main body 30 from the top dead center toward the bottom dead center is permitted.

[0090] 32, that is, when the main body 30 is at a position other than the top dead center and the lock operation mechanism 80 is at the blocking position, even if the user attempts to displace the lock operation mechanism 180 from the blocking position toward the permissible position, the abutting portion 184 abuts against the first abutted portion 161 in a direction that blocks the displacement. Therefore, the user cannot displace the lock operation mechanism 180 toward the permissible position.

[0091] In this way, the lock operation mechanism 180 and the gear housing 160 can also provide functions equivalent to those of the lock operation mechanism 80 and the gear housing 60 according to the first embodiment. Furthermore, by configuring the lock operation mechanism 180 to have two pivot axes, the design freedom of the lock operation mechanism is increased, and operability can be improved.

[0092] Although the embodiments of the present invention have been described above, the above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention includes equivalents thereof. Furthermore, any combination or omission of the elements described in the claims and specification is possible within the scope of solving at least part of the above-described problems or achieving at least part of the effects.

[0093] For example, the lock operating mechanisms 80, 180 may be supported by the gear housings 60, 160 instead of the cover body 52. ​​In this case, the cover body 52 may be provided with components corresponding to the first abutment portions 61, 161, the recesses 62, 162, the recesses 63, 163, and the second abutment portions 64, 164.

[0094] Alternatively, instead of the configuration in which the main body 30 swings about the swing axis AX2, a configuration in which the main body 30 moves horizontally in the vertical direction may be employed. In this case, the shapes of the first abutment portions 61, 161, the relief portions 62, 162, the recesses 63, 163, and the second abutment portions 64, 164 can be set appropriately depending on the displacement direction of the main body 30.

[0095] Alternatively, instead of the above-described configuration in which the engagement member 94 engages with the motor shaft 34 to prevent rotation of the motor shaft 34 when the battery 45 is removed from the battery mounting portion 46, a configuration may be employed in which the engagement member 94 engages with the output shaft 42 to prevent rotation of the output shaft 42 when the battery 45 is removed from the battery mounting portion 46. In this case, any mechanical mechanism that transmits the displacement of the operating member 90 to the engagement member 94 may be employed.

[0096] Alternatively, among the various configurations described above, the configurations not related to the battery 45 can also be applied to a circular saw of a type in which the electric motor 33 is powered by a commercial power source.

[0097] Alternatively, the various interlocking operations between the multiple members described above are not limited to the above-described configurations, and may be achieved by any mechanical configuration that can achieve the same functions.

[0098] Furthermore, the various embodiments described above are not limited to circular saws, but can be applied to any plunge-type portable cutting machine (for example, a cutter, etc.).

[0099] The correspondence between each component of the above embodiment and each component of the present invention is shown below. However, each component of the embodiment is merely an example and does not limit each component of the present invention. The circular saw 10 is an example of a "portable processing machine." The base 20 is an example of a "base." The saw blade 35 is an example of a "cutting tool." The cover 50 is an example of a "cover." The cover main body 52 is an example of a "cover main body." The auxiliary cover 500 is an example of an "auxiliary cover." The top dead center is an example of a "first position." The bottom dead center is an example of a "second position." The first tilt axis AX6 is an example of a "first tilt axis." The second tilt axis AX7 is an example of a "second tilt axis." The cover member 510 is an example of a "cover member." Support member 520 is an example of a "support member," and first support portion 520a and second support portion 520b are examples of a "first support portion" and a "second support portion," respectively. First portion 511 is an example of a "first portion." Second portion 512 is an example of a "second portion." Third portion 513 is an example of a "third portion." [Explanation of symbols]

[0100] 10,110...Circular saw 20...Base 21...bottom surface 22...Spindle 23...torsion spring 24,25...Angular plate 26...Angular 27... Trunnion 28,29...Thumb screws 30...Main body 31...Motor housing 32...Grip section 33...Electric motor 34...Motor shaft 35...Saw blade 36...Flange 37...Through hole 38...Trigger 39...Lock pin 40...Cancel button 41...Stopper 42...Output shaft 43...Reduction gear 45...Battery 46...Battery compartment 47...Terminal 50...Cover 51...recess 52...Cover body 52a...Slope part 53...door 54...hinge mechanism 55...Engagement part 56...Through hole 57...protrusion 58...Angle switch knob 60,160...Gear housing 61,161...First contact part 62,162...Relief area 63,163...recess 64,164...Second contact part 70...Opening and closing mechanism 71...Engagement part 72...First engagement piece 73...Second engagement piece 74...Screw 75...Compression spring 76...Lock member 77...Engagement part 78...Pressure receiving part 79...Step 80,180...Lock operation mechanism 81...Operation unit 82...Base 83...Connection part 84...Arm section 85...Abutment part 90...Operating member 91...Knob 92...shaft 93...Pressing part 94...Engagement member 95...Annular section 96...Engagement part 97...Pressure receiving part 98...Compression spring 99...pin 181...Operating lever 182...Cam 183...Lock lever 184...Abutment part 500...Auxiliary cover 510...Cover member 511...First part 512...Second part 513...Third part 514,515...Abutment part 516...Rib 520...Support member 520a...first support 520b...second support part 530a, 530b...hinge mechanism AX1...rotation axis AX2...oscillating axis AX3...Pivotal axis AX4...First pivot axis AX5...second pivot axis AX6...First tilt axis AX7...second tilt axis

Claims

1. A portable cutting machine, a base for contacting the workpiece; a body having a motor configured to provide rotational drive to the cutting tool, the body being disposed on a second side relative to the base; a cover disposed on the second side of the base for at least partially covering the cutting tool; Equipped with The main body is configured to be displaceable relative to the base and the cover between a first position in which the cutting tool is entirely housed within the cover and a second position in which the cutting tool protrudes beyond the base to a first side opposite the second side and is partially exposed outside the cover, The cover is The cover body, an auxiliary cover that is arranged to function as a part of the cover that is close to the base and is movable relative to the cover main body; Equipped with the main body and the cover main body are configured to be tiltable about a first tilt axis located on the first side with respect to the base, the auxiliary cover is configured to tilt at least partially about a second tilting axis located on the second side of the first side surface of the base in conjunction with the tilting movement of the cover main body, The auxiliary cover is a cover member for covering a side of the cutting tool; a support member that extends from the cover member toward the side where the motor is located in the direction in which the rotation axis of the cutting tool extends, the second tilting axis being movable parallel to the base, and that supports the cover member so that it can tilt about the second tilting axis; Equipped with Portable cutting machine.

2. 2. The portable cutting machine of claim 1, The auxiliary cover is When the main body is in the second position and is not inclined with respect to the base, the auxiliary cover and the rotation axis of the cutting tool overlap each other as viewed in a direction in which the rotation axis extends, When the main body is in the second position and is inclined to the maximum extent relative to the base, the auxiliary cover and the rotation axis do not overlap each other when viewed in the direction in which the rotation axis extends. The cover body is configured to move in conjunction with the tilting movement of the cover body. Portable cutting machine.

3. The portable cutting machine according to claim 1 or 2, The support member is arranged so that the position of the support member in the direction from the second side to the first side is fixed. Portable cutting machine.

4. 4. The portable cutting machine according to claim 3, The cover member includes a substantially rectangular first portion for covering the side of the cutting tool, and a second portion and a third portion extending from both longitudinal edges of the first portion toward the interior of the cover so as to face each other. Portable cutting machine.

5. The portable cutting machine according to any one of claims 1 to 4, When the cover main body tilts about the first tilting axis, the auxiliary cover the cover member is pressed by the cover body and tilts about the second tilt axis; When the cover member is pressed against the cover body, the support member moves in a direction perpendicular to the second tilting axis, parallel to the base, and toward the outside of the base. It was configured as Portable cutting machine.

6. 6. The portable cutting machine according to claim 5, the base has a through hole that penetrates in a direction in which the support member moves when the cover body tilts about the first tilting axis, The support member passes through the through hole and is slidably disposed on the base. Portable cutting machine.

7. A portable cutting machine according to any one of claims 1 to 6, The support member includes a first support portion and a second support portion that respectively support the cover member at both longitudinal ends of the cover member so that the cover member can tilt. Portable cutting machine.

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