JP7094778B2 - Cutting machine - Google Patents

Description

The present invention relates to a cutting machine, and more particularly to a cutting machine having a movable cover covering approximately half of a rotary cutting tool.

Conventionally, in a cutting machine such as a portable circular saw, the height of the output shaft of the rotary saw with respect to the lower end of the circular saw body is lowered (the height of the output shaft with respect to the base) in order to secure a deep cutting depth of the rotary saw blade or the like. The technology (lowered) is already known. As such a technique, in the following Patent Document 1 (first conventional technique), the rotating cylinder 170, which is a movable part of the movable cover 150, is displaced from the bearing 120 on the tip end side of the final shaft 119 to the saw blade 105 side. The portable circular saw 101 is disclosed (see FIG. 17). Further, as such a technique, in the following Patent Document 2 (second conventional technique), the thickness of the lower wall of the bearing box 222 to which the bearing 220 on the tip end side of the final shaft 219 to which the saw blade 205 is fastened is assembled is set to the thickness of the upper wall. A cutting machine 201 thinner than the thickness is disclosed (see FIG. 18). Since the cutting depth of the saw blades 105 and 205 can be secured deeply by these techniques, it is possible to cut even a material to be cut (not shown) such as thick wood.

Japanese Unexamined Patent Publication No. 2008-265124 Japanese Unexamined Patent Publication No. 2010-201599

However, in the technique of Patent Document 1 described above, the bearing 120 on the tip end side of the final shaft 119 and the rotating cylinder 170 which is a movable portion of the movable cover 150 are arranged in the axial direction. Therefore, the axial size of each component is added as it is, and there is a problem that the portable circular saw 101 becomes larger in the axial direction of the saw blade 105. On the other hand, in the technique of Patent Document 2 described above, the center of the shaft processing of the outer diameter portion to which the movable cover 250 is attached is biased in the height direction with respect to the center of the hole processing of the hole 222a into which the bearing 220 of the bearing box 222 is inserted. It was a composition that made me wonder. Therefore, there has been a problem that the workability is poor, such as the lathe cannot be used for machining the bearing box 222. As a result, there has been a problem that the productivity of the cutting machine 201 is poor.

The present invention is intended to solve such a problem, and an object of the present invention is to increase the size of a rotary cutting tool in the axial direction and to improve productivity in a cutting machine having a movable cover that covers approximately half of the rotary cutting tool. It is to secure a deep cutting depth of the rotary cutting tool without making it worse.

According to one feature of the present disclosure, the cutting machine comprises a cutting machine body having a movable cover covering approximately half of a rotary cutting tool that is rotated by the drive of an electric motor. The movable cover is composed of a movable cover main body and a rotating cylinder that is rotatably assembled to the cutting machine main body. The movable cover body is made of a rigid synthetic resin. The rotating cylinder is formed of a metal member thinner than the wall thickness of the movable cover body.

Therefore , even if the rotating cylinder, which is a movable part of the movable cover, is arranged outside the bearing on the tip end side of the final shaft of the rotary cutting tool, the height of the output shaft of the rotary cutting tool with respect to the lower end of the cutting machine main body can be suppressed. .. Therefore, the effect of arranging the rotating cylinder and bearing of the movable cover in the axial direction (since the axial size of each part is not added as it is, the rotary cutting tool becomes larger in the axial direction). It is possible to secure a deep cutting depth for the rotary cutting tool while eliminating the problem. Since the rotary blade does not become large in the axial direction in this way, the rotary blade and the bearing on the tip side of the final shaft do not separate significantly, and as a result, the runout of the rotary blade in the rotating state can be suppressed. can. Further, even if the cutting depth of the rotary cutting tool can be secured deeply in this way, as described in the prior art, it is a movable part of the movable cover with respect to the center of the hole drilling of the hole into which the bearing of the bearing box is inserted. It is not necessary to eccentric the center of the shaft processing of the shaft portion to which the rotating cylinder is attached in the height direction. Therefore, the workability of the bearing box does not deteriorate, such as the fact that a lathe can be used for processing the bearing box. Therefore, the productivity of the cutting machine does not deteriorate.

According to other features of the present disclosure, the movable cover is configured such that the movable cover main body and the rotating cylinder are integrally molded or press-fitted.

Therefore , when producing the movable cover, it is possible to omit the step of joining the rotating cylinder and the movable cover main body (for example, the work of fastening with a screw or the like, the work of adhering with an adhesive or the like). Therefore, the productivity of the movable cover can be increased, and as a result, the productivity of the portable circular saw can also be increased. In addition, since no screws or adhesives are used, there is no cost increase.

According to other features of the present disclosure, the metal member is iron.

Therefore , it has higher strength than other materials and can be rolled thinly, so that the thickness of the rotating cylinder can be easily reduced.

According to other features of the present disclosure, the rotating cylinder is formed by press molding of sheet metal.

Therefore , the rotating cylinder can be mass-produced in a short time as compared with the case of forming by cutting or casting a metal member.

According to another feature of the present disclosure , unevenness is formed at the joint portion of the rotating cylinder with respect to the movable cover main body.

Therefore , the joint between the movable cover main body and the rotating cylinder can be strengthened.

It is a right side view of the portable circular saw which concerns on embodiment. It is a top view of the portable circular saw of FIG. FIG. 3 is a sectional view taken along line III-III of FIG. It is an enlarged view of the main part of FIG. FIG. 2 is a sectional view taken along line VV of FIG. It is an overall perspective view of the movable cover of FIG. It is a vertical sectional view of the movable cover of FIG. It is a left side view of the movable cover of FIG. FIG. 8 is a sectional view taken along line IX-IX of FIG. It is a right side view of the rotating cylinder of FIG. It is a top view of the rotating cylinder of FIG. FIG. 10 is a sectional view taken along line XII-XII of FIG. FIG. 1 is a diagram showing a state in which the movable cover is fully opened. FIG. 3 is a diagram showing a state in which the movable cover is fully opened. It is an enlarged view of the main part of FIG. FIG. 5 is a diagram showing a state in which the movable cover is fully opened. It is a vertical sectional view of the portable circular saw which concerns on the 1st prior art. It is a vertical sectional view of the cutting machine which concerns on the 2nd prior art.

Hereinafter, embodiments for carrying out the present invention will be described with reference to FIGS. 1 to 16. In the following description, "portable circular saw 1" will be described as an example of the "cutting machine". Further, in the following description, the terms "upper, lower, front, rear, left, and right" indicate the directions of up, down, front, rear, left, and right described in the above-mentioned figure. That is, the front direction indicates the cutting direction (traveling direction) of the portable circular saw 1.

First, the overall configuration of the portable circular saw 1 will be described with reference to FIGS. 1 to 12. The portable circular saw 1 is formed on a substantially rectangular plate-shaped base 2 that is pressed against the upper surface of a material to be cut (for example, wood or the like (not shown)) to be cut when performing cutting work, and on the base 2. It is composed of a circular saw main body 3 provided with a disk-shaped saw blade 5 that is rotationally driven by an electric motor (brushless motor) 4 (see FIGS. 1 and 2). The circular saw main body 3 is composed of a motor housing 6 accommodating an electric motor 4, a handle housing 7 fastened to the motor housing 6, and a gear housing 8 fastened to the handle housing 7.

Both ends of the drive shaft 9 of the electric motor 4 housed in the motor housing 6 are in a state of being bearing by bearings 10 and 11 (see FIG. 3). The load-side bearing 10 of the drive shaft 9 is assembled on the outer surface of the gear housing 8 described later. Further, the bearing 11 on the counterload side of the drive shaft 9 is assembled on the inner surface of the motor housing 6. As a result, the drive shaft 9 of the electric motor 4 can be smoothly rotated. Further, a cooling fan 12 is attached to the drive shaft 9 of the electric motor 4. As a result, when the electric motor 4 is driven, the cooling fan 12 also rotates due to the rotation of the drive shaft 9. Therefore, the electric motor 4 can be cooled without requiring external power or the like.

The handle housing 7 is formed in a substantially loop shape such that the upper side thereof forms a grip portion 7a that can be gripped by one hand of the operator (see FIG. 1). Inside the loop of the grip portion 7a, a trigger 41 that can be pulled in and operated by an operator is assembled in order to operate (ON) the switch 41a housed in the handle housing 7.

A controller (not shown) is housed on the lower side of the handle housing 7. In this controller, the above-mentioned electric motor 4, switch 41a, and power supply unit 30 described later are connected to (battery pack 31) via lead wires (not shown). As a result, when the operator pulls in the trigger 41, the electric motor 4 can be driven.

Further, a power supply unit 30 is provided on the rear side of the motor housing 6, and a battery pack 31 can be attached to and removed from the power supply unit 30 by a slide (see FIG. 2). The mounting direction of this slide is from the left side to the right side, and the removing direction of this slide is from the right side to the left side. As a result, the battery pack 31 can be easily attached and detached.

A fixed cover 8a that covers substantially the upper half of the saw blade 5 is attached to the gear housing 8. Both ends of the intermediate shaft 14 housed in the gear housing 8 are in a state of being bearing by bearings 15 and 16 (see FIG. 3). The bearings 15 and 16 are assembled on the inner surface of the gear housing 8. As a result, the intermediate shaft 14 housed in the gear housing 8 can be smoothly rotated. Further, a second gear 17 that can be meshed with the first gear 13 formed on the outer peripheral surface of the drive shaft 9 is fixed to the outer peripheral surface of the intermediate shaft 14.

Further, both ends of the final shaft (output shaft) 19 housed in the gear housing 8 are in a state of being bearing by the bearings 20 and 21. The bearing 20 on the tip end side of the final shaft 19 is housed in the gear housing 8 via a bearing box 22 having a cylindrical shaft portion 23 (see FIG. 4). Further, the bearing 21 on the base end side of the final shaft 19 is assembled to the inner surface of the gear housing 8 (see FIG. 3). As a result, the final shaft 19 housed in the gear housing 8 can be smoothly rotated.

Further, a fourth gear 24 that can be meshed with the third gear 18 formed on the outer peripheral surface of the intermediate shaft 14 is fixed to the outer peripheral surface of the final shaft 19. The saw blade 5 described above is fastened via a bolt 25 so as to be orthogonal to the tip of the final shaft 19. As a result, when the electric motor 4 is driven, the saw blade 5 can be rotated via the drive shaft 9, the intermediate shaft 14, and the final shaft 19.

Further, the fixed cover 8a of the gear housing 8 described above has its front end pivotally attached to a bracket 32 having a U-shape in a plan view so as to be swingable in the vertical direction by a support shaft 33 (see FIGS. 1 and 2). .. The bracket 32 is erected on the base 2 and can be fixed to an angular plate 35 having an arc-shaped guide groove (not shown) at an arbitrary position along the guide groove by a lever 36. The bracket 32 is angular via a support shaft 35a. It is connected to the plate 35.

On the other hand, the boss 38 is also erected on the base 2 on the rear side of the fixed cover 8a. A depth guide 39 that curves forward in an arc shape on the side of the fixed cover 8a is connected to the boss 38 via a support shaft 35a so that it can be fixed at an arbitrary position along the guide groove 39a by the lever 43. Has been done. Therefore, the circular saw main body 3 swings around the support shaft 33 by changing the coupling position (clamp position) of the fixed cover 8a along the depth guide 39, and the saw blade 5 protrudes downward to the base 2. The amount (cutting depth of the saw blade 5) can be adjusted.

Further, by changing the fixing position of the bracket 32 with respect to the angular plate 35, the circular saw body 3 is tilted to the right from the right angle position where the saw blade 5 is orthogonal to the base 2, and the saw blade 5 is at an angle of 45 ° with the base 2. It can be fixed at any tilt angle up to the maximum tilt position. At the front end of the base 2, notches 40 are formed at right-angled (0 °) positions of the saw blade 5 and at 45 ° positions where the side edges are respectively located on the extension of the saw blade 5, and the upper surface of the material to be cut is formed. By aligning the side edge of the notch 40 with the black line indicated in 1 above, cutting along the black line is easily possible.

Further, a movable cover 50 is attached to the lower side of the fixed cover 8a described above (see FIGS. 1 and 5). Here, the movable cover 50 will be described in detail. The movable cover 50 is composed of a movable cover main body 60 and a rotating cylinder 70 (see FIGS. 6 to 7). The movable cover main body 60 is composed of a substantially fan-shaped cover member having a groove 61 covering the outer edge of the saw blade 5 described above and a through hole 62 communicating with the insertion hole 71 of the rotary cylinder 70 described later. There is. A hook hole 63 to which a tension spring 51, which will be described later, can be hooked is formed on the edge of the through hole 62 of the movable cover main body 60.

Further, a predetermined region A at the edge of the through hole 62 on the back surface of the movable cover main body 60 (the surface opposite to the saw blade 5) is along the circumferential direction of the outer peripheral surface 73 of the rotary cylinder 70 described later. A rib 64 that looks like a figure is formed (see FIG. 8). The predetermined region A is a region that does not affect the shallow cutting depth of the saw blade 5 from the closed state to the fully open state of the movable cover 50. As is clear from FIG. 8, the height (overhang length in the radial direction) of the rib 64 is gradually (smoothly) increased starting from the hook hole 63 side. The movable cover main body 60 configured in this way is made of a rigid synthetic resin (for example, a PC or the like).

On the other hand, the rotating cylinder 70 is composed of a substantially ring-shaped metal member (for example, a sheet metal such as iron) having an insertion hole 71 that can be inserted into the shaft portion 23 of the bearing box 22 of the gear housing 8. (See FIGS. 10 to 12). The rotating cylinder 70 is formed thinner than the wall thickness of the movable cover main body 60. A curved portion 74 that is inclined inward is formed on one edge of the rotating cylinder 70. A plurality of through holes 75 are formed in the curved portion 74 so as to form uniform intervals along the circumferential direction.

The rotating cylinder 70 is formed by press molding of sheet metal. The rotating cylinder 70 is insert-molded so that its curved portion 74 is joined to the edge of the through hole 62 of the movable cover main body 60 (see FIG. 9). Since the insert is molded in this way, the synthetic resin of the movable cover main body 60 wraps around the through hole 75 of the rotating cylinder 70. This description corresponds to "the unevenness is formed in the joint portion of the rotating cylinder with respect to the movable cover main body" described in the claims. The movable cover 50 is configured in this way.

The movable cover 50 configured in this way is assembled to the bearing box 22 so that the insertion hole 71 is inserted into the shaft portion 23 of the bearing box 22 of the gear housing 8. As a result, the inner peripheral surface 72 of the insertion hole 71 of the movable cover 50 slides with respect to the outer peripheral surface 23a of the shaft portion 23 of the bearing box 22, so that the movable cover with respect to the bearing box 22 (gear housing 8). 50 can be rotated. Further, a tension spring 51 is hooked between the hook hole 8b of the fixed cover 8a of the gear housing 8 and the hook hole 63 of the movable cover 50 (see FIG. 5).

The tension spring 51 is set to be in a steady state when the movable cover 50 is closed. Therefore, when the movable cover 50 is rotated from the closed state to the fully open state, the tension spring 51 is in an extended state while being wound around the rib 64 of the rotated movable cover 50. As described above, the height of the rib 64 is gradually increased starting from the hook hole 63 side. Therefore, the wound tension spring 51 does not get caught in the rib 64. That is, the tension spring 51 can be smoothly wound around the rib 64. The portable circular saw 1 is configured in this way.

Next, the operation of the portable circular saw 1 will be described. When the trigger 41 is pulled in while the base 2 is pressed against the upper surface of the material to be cut, the switch 41a operates (ON) and power is supplied from the battery pack 31 to the electric motor 4. As a result, the electric motor 4 is driven, so that the saw blade 5 rotates via the drive shaft 9, the intermediate shaft 14, and the final shaft 19. Therefore, the material to be cut can be cut.

When the material is cut in this way, the material to be cut presses the movable cover 50, and the pressed movable cover 50 rotates against the urging force of the tension spring 51 (see FIGS. 13 to 16). ). Note that FIGS. 13 to 16 show a state in which the movable cover 50 is fully opened. Eventually, when the cutting of the material to be cut is completed and the pressing of the material to be cut against the movable cover 50 is released, the movable cover 50 is returned to the closed state by the restoring force of the tension spring 51 (FIGS. 1 and 3). See ~ 5).

The portable circular saw 1 according to the embodiment of the present invention is configured as described above. According to this configuration, the rotating cylinder 70 of the movable cover 50 is made of a metal member thinner than the wall thickness of the movable cover main body 60. Therefore, even if the rotating cylinder 70, which is a movable part of the movable cover 50, is arranged outside the bearing 20 on the tip end side of the final shaft 19, the height of the output shaft of the rotary cutting tool with respect to the lower end of the cutting machine main body can be suppressed. It is possible to suppress (lower) the protruding height of the final shaft 19 with respect to the base 2. Therefore, the effect of arranging the rotating cylinder 70 of the movable cover 50 and the bearing 20 in the axial direction (since the axial sizes of the respective parts 20 and 50 are not added as they are, the saw blade 5 is the shaft. It is possible to secure a deep cutting depth of the saw blade 5 while eliminating the problem of increasing the size in the direction). Since the saw blade 5 does not become large in the axial direction in this way, the saw blade 5 and the bearing 20 on the tip end side of the final shaft 19 do not greatly separate from each other, and as a result, the saw blade 5 in the rotating state Runout can also be suppressed. Further, even if the depth of cut of the saw blade 5 can be secured deeply in this way, as described in the prior art, the movable cover 50 has a movable cover 50 with respect to the center of the hole for which the bearing 20 of the bearing box 22 is inserted. It is not necessary to eccentric the center of the shaft processing of the shaft portion 23 to which the rotating cylinder 70, which is a movable portion, is attached in the height direction. Therefore, the workability of the bearing box 22 does not deteriorate, such as the fact that a lathe can be used for machining the bearing box 22. Therefore, the productivity of the portable circular saw 1 does not deteriorate.

Further, according to this configuration, the rotating cylinder 70 is insert-molded so that the curved portion 74 thereof is joined to the edge of the through hole 62 of the movable cover main body 60. Therefore, when the movable cover 50 is produced, the step of joining the rotating cylinder 70 and the movable cover main body 60 (for example, the work of fastening with a screw or the like, the work of adhering with an adhesive or the like, etc.) can be omitted. Therefore, the productivity of the movable cover 50 can be increased, and as a result, the productivity of the portable circular saw 1 can also be increased. In addition, since no screws or adhesives are used, there is no cost increase.

Further, according to this configuration, the metal member is composed of iron. Therefore, it has higher strength than other materials and can be rolled thinly, so that the thickness of the rotating cylinder can be easily reduced.

Further, according to this configuration, the rotating cylinder 70 is formed by press molding of sheet metal. Therefore, the rotating cylinder 70 can be mass-produced in a short time as compared with the case where the metal member is machined or cast.

Further, according to this configuration, the synthetic resin of the movable cover main body 60 wraps around the through hole 75 of the rotating cylinder 70. Therefore, the joint between the movable cover main body 60 and the rotating cylinder 70 can be strengthened.

The above-mentioned contents are merely related to one embodiment of the present invention, and do not mean that the present invention is limited to the above-mentioned contents.

In the embodiment, a portable circular saw 1 has been described as an example of a cutting machine. However, the present invention is not limited to this, and a desktop circular saw may be used (the same feature is that the cutting depth can be increased by suppressing the height of the output shaft of the rotary cutting tool with respect to the lower end of the cutting machine body). .. Of course, any cutting machine may be used as long as it has a movable cover that covers approximately half of the rotary cutting tool. Further, in the embodiment, a mode in which power is supplied from the battery pack 31 as a power source for the portable circular saw 1 has been described. However, the present invention is not limited to this, and power may be supplied from a power cable connected to various power sources (for example, AC100V).

Further, in the embodiment, the embodiment in which the rotating cylinder 70 is made of a sheet metal such as iron has been described. However, the present invention is not limited to this, and the rotating cylinder 70 may be formed by carving out a metal member.

Further, in the embodiment, insert molding has been described as an example of integral molding of the movable cover main body 60 and the rotating cylinder 70. However, the present invention is not limited to this, and the movable cover main body 60 and the rotating cylinder 70 may be configured to be integrated by a press-fitting structure. In that case, it is necessary to form convex portions, concave portions, and the like for establishing the press-fitting structure in the movable cover main body 60 and the rotating cylinder 70.

1 Portable circular saw (cutting machine)
2 Base 3 Circular saw body 4 Electric motor 5 Saw blade (rotary blade)
6 Motor housing 7 Handle housing 7a Grip part 8 Gear housing 8a Fixed cover 8b Hook hole 9 Drive shaft 10 Bearing 11 Bearing 12 Cooling fan 13 1st gear 14 Intermediate shaft 15 Bearing 16 Bearing 17 2nd gear 18 3rd gear 19 Final shaft 20 Bearing 21 Bearing 22 Bearing box 23 Shaft 23a Outer peripheral surface 24 4th gear 25 Bolt 30 Power supply 31 Battery pack 32 Bracket 33 Support shaft 34 Guide groove 35 Angular plate 35a Support shaft 36 Lever 38 Boss 39 Depth guide 39a Guide groove 40 Notch 41 Trigger 41a Switch 43 Lever 50 Movable cover 51 Tension spring 60 Movable cover body 61 Groove 62 Through hole 63 Hook hole 64 Rib 70 Rotating cylinder 71 Insertion hole 72 Inner peripheral surface 73 Outer peripheral surface 74 Curved part 75 Through hole

Claims (5)

A cutting machine equipped with a cutting machine body having a movable cover that covers approximately half of a rotary cutting tool that is rotated by the drive of an electric motor.
The movable cover is composed of a movable cover main body and a rotary cylinder body that is rotatably assembled to the cutting machine main body.
The movable cover body is made of a rigid synthetic resin.
The rotating cylinder is formed of a metal member thinner than the wall thickness of the movable cover body .
The rotating cylinder is made of sheet metal and has a rotating cylinder.
An elastic member that urges the movable cover in the closing direction is provided.
A rib along the circumferential direction of the rotating cylinder is formed on the edge of the through hole formed in the movable cover main body.
The rib is formed so that the wall thickness of the region below the final shaft to which the rotary cutting tool is fastened gradually becomes thinner as the movable cover is rotated from the closed state to the open state.
The elastic member is a cutting machine that winds around the peripheral surface of the rib in the circumferential direction when the movable cover is rotated from the closed state to the open state . The cutting machine according to claim 1.
The movable cover is a cutting machine in which the movable cover main body and the rotating cylinder are integrally molded or integrally formed by a press-fitting structure. A cutting machine equipped with a cutting machine body having a movable cover that covers approximately half of a rotary cutting tool that is rotated by the drive of an electric motor.
The movable cover is composed of a movable cover main body and a rotary cylinder body that is rotatably assembled to the cutting machine main body.
The movable cover body is made of a rigid synthetic resin.
The rotating cylinder is formed of a metal member thinner than the wall thickness of the movable cover body.
The rotating cylinder is made of sheet metal and has a rotating cylinder.
The movable cover is a cutting machine in which the movable cover main body and the rotating cylinder are integrally formed by insert molding . The cutting machine according to any one of claims 1 to 3.
The metal member is an iron cutting machine. The cutting machine according to any one of claims 1 to 4 .
A cutting machine in which irregularities are formed at a joint portion of the rotating cylinder with respect to the movable cover main body .

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