JP2002001613A - Engine cutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine cutter in which when work strikes on a protective cover for a rotary blade, the protective cover is turned backward, and when no collision is caused, it automatically returns to the initial position. SOLUTION: This engine cutter is provided with the protective cover. The protective cover 28 turned along the outer periphery of the rotary blade to cover outside a part of the rotary blade 2 abutted on the work W is so constructed that the rotating central part is freely rotatably supported by a support member 29, a spring storing member 31 having a cylindrical part for storing a winding part 30a of a torsion coil spring 30 cut in a designated range is mounted on the support member, the winding part of the torsion coil spring is stored in the spring storing member so that both end parts 30b, 30c extended in the tangential direction of the outer periphery of the winding part of the torsion coil spring can slide in the cylindrical partially cut part 31a of the spring storing member, when the torsion coil spring is rolled in by turning of the protective cover, the other end part 30c (or one end part 30b) is locked on one end 31b of the cylindrical partially cut part 31a, and projections 28a and 28b on which one end part 30b (or the other end part 30c) is locked is provided on the side surface 28c of the protective cover.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a so-called engine cutter such as a portable circular saw for cutting concrete or asphalt road pavement.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a perspective view of an engine cutter provided with a protective cover for a rotary blade disclosed in Japanese Unexamined Patent Publication No.
A protection cover 12 that rotates along the outer periphery of the rotary blade 11 so as to cover a portion other than the portion that comes into contact with one workpiece W is provided so that a rotation center portion thereof is rotatably supported by a support member 13. A sliding and holding member 1 of a compression spring having a long groove 14a having an arcuate concave shape at least in a rotation range of the protective cover 12 on a side surface of the protective cover 12 at a desired radius away from the support member 13.
4, and at least a long hole (not shown) in the rotation range of the protective cover 12 formed in the bottom surface of the long groove 14 a is slidably fitted to a fixing pin 16 (see FIG. 10) fixed to the bearing housing 15. Compression springs 17 and 17 'are respectively inserted into the long grooves 14a of the protection cover 12 in one rotation direction side and the other rotation direction side of the compression spring sliding holding member 14 with the fixing pin 16 interposed therebetween. Are stored to form a protective cover for the rotary blade. Reference numeral 25 denotes an engine body, and reference numeral 26 denotes a handle.

As shown in FIG. 10 (a), when the upper portion of the rotary blade 11 is pressed against the lower portion of the workpiece W to cut the rotary blade 11 as shown in FIG. The protection cover 12 rotates counterclockwise as shown by arrow A,
Circular concave long groove 1 of sliding holding member 14 of compression spring
The compression spring 17 housed in one rotation direction side (upper side in the figure) of the protective cover 12 is compressed from the fixed pin 16 fitted to 4a, and the other side of the protection cover 12 is rotated from the fixed pin 16 in the rotation direction. The compression spring 17 ′ housed in the lower side (in the figure, below) is not compressed. Accordingly, when the cutting of the work W is completed and the protective cover 12 is separated from the contact with the work W, the protective cover 12 is rebounded by the compressed spring 17 and the protective cover 1 is moved.
2 is pushed clockwise and returns to its original position.

As shown in FIG. 10B, when the lower part of the rotary blade 11 is pressed against the upper part of the work W to be cut, the lower end 12b of the protective cover 12 is cut.
Strikes the work W, the protective cover 12 rotates clockwise as shown by the arrow B, and the fixing pin 16 fitted in the arc-shaped concave long groove 14a of the sliding and holding member 14 of the compression spring.
The compression spring 17 ′ housed on the other rotation direction side (lower side in the figure) of the protection cover 12 is compressed, and is stored on the one rotation direction side (upper side in the figure) of the protection cover 12 from the fixing pin 16. The compressed compression spring 17 is not compressed. Accordingly, when the work W is cut and the protective cover 12 is released from contact with the work W, the protective cover 12 is pushed counterclockwise by the repulsive force of the compressed compression spring 17 ′. Then, it returns to the original position. The rotary blade 11 is rotating clockwise as indicated by an arrow C.

[0005]

Each time the protective cover 12 of the rotary blade rotates in the direction of the arrow A (counterclockwise) or the direction of the arrow B (clockwise), the compression springs 17, 17 '.
Slides in the long groove 14a, and the sliding resistance causes the protection cover 12 by the compression springs 17, 17 '.
, The pressing force is weakened, and the protective cover 12 does not rotate smoothly. Further, since the compression springs 17, 17 'slide in the elongated grooves 14a, the compression springs 17, 17' and the elongated holes 14a are worn,
There was a problem that there was a risk of failure.

According to the present invention, a long groove 14 formed on the side surface of the protective cover as described above is used to rotate the protective cover.
a, one end of the torsion coil spring is engaged with a projection provided on the side surface of the protective cover, and the other end of the torsion coil spring is not engaged with the cylindrical cutout of the spring housing member. The present invention provides an engine cutter configured to return a protective cover rotated against a torsion coil spring to an original rotation position by a repulsive force of the torsion coil spring by being locked at one end. It is the purpose.

Another object of the present invention is to provide an engine cutter in which when an air cleaner of an engine causes dust or dirt to be clogged, the condition can be confirmed from a see-through window provided in a part of the air cleaner cover. It is intended for. Further, the present invention provides an engine cutter which can supply lubricating grease to the bearing of a pulley attached to a shaft via a bearing without removing a pulley cover. It is intended for. It is another object of the present invention to provide an engine cutter which can be mounted on a pulley without removing a pulley cover.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, the rotary blade 27 is rotated along the outer periphery of the rotary blade 27 so as to cover a portion other than the portion contacting the workpiece W. The movable protective cover 28 is rotatably supported by a support member 29 at the center of rotation thereof.
A spring accommodating member 31 in which a cylindrical portion capable of accommodating the 0-turn portion 30a is removed in a predetermined range is attached to the support member 29, and both ends of the torsion coil spring 30 extend in the tangential direction on the outer periphery of the winding portion. The winding portion 30a of the torsion coil spring 30 is housed in the spring housing member 31 so that the portions 30b and 30c can slide in the tube cutout portion 31a of the spring housing member 31. When the coil spring 30 is wound, the other end 30c (or one end 30b) is engaged with the one end 31b (or the other end 31b ') of the tube lacking portion 31a, and the one end 30b (or the other end 30c) is engaged. Projection 28 to be stopped
An engine cutter is provided with a protective cover in which a and 28b are provided on a side surface 28c of the protective cover 28.

The invention according to a second aspect of the present invention is to provide a bellows 36 which expands and contracts due to the pressure difference between the inside and outside gas in a pipe 35 connecting the carburetor side 33 and the atmosphere side 34 of the air cleaner 32. When the air becomes difficult to pass due to dust or clogging of dust, the extended state of the bellows 36 due to the pressure difference between the atmospheric pressure in the pipe 35 and the atmospheric pressure causes the see-through window 37 a provided in a part of the air cleaner cover 37.
The engine cutter is provided with a dust monitor configured to be able to be checked from the engine cutter.

The invention according to a third aspect of the present invention is directed to a shaft 39 of a rear pulley cover 41 for covering a pulley 40 attached to a shaft 39 via a bearing 38, through a flow hole 39a for supplying lubricating grease to the bearing 38. An engine cutter characterized in that a resilient cover 42 having a small hole 42a formed in the center is attached to a position facing the engine cutter.

The invention according to claim 4 is characterized in that a belt 43 is provided near the pulley inside 41a of the rear pulley cover 41.
When the belt 43 hangs on the pulley 40, the belt 43
And a pulley cover formed with a belt guide rib 41b that guides the engine cutter so as to be hooked.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an engine cutter according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing a main part of an engine cutter provided with a protective cover according to a first embodiment of the present invention. The protection cover 28 that rotates by the rotation is supported by a support member 29 so that the rotation center portion thereof can rotate. Further, a spring housing member 31 in which a cylindrical portion capable of housing the winding portion 30a of the torsion coil spring 30 for returning the protective cover 28 to the original rotation position is omitted in a predetermined range, is provided by the support member 29. Mounted on The torsion coil spring 30 is regulated by the tube notch 31a of the spring housing member 31 so that both end portions 30b and 30c extending in the same direction from the tangent line of the outer periphery of the winding portion 30a are parallel to each other. At the time of rotation of the cover 28, the winding part 30a of the torsion coil spring 30 is stored in the cylindrical part of the spring storage member 31 so as to be slidable by the cylinder notch 31a. , 30c
However, the front ends of the spring storage members 31 are bent outward so as to be engaged with projections 28a and 28b provided on the side surface 28c of the protective cover 28, respectively.

With this configuration, as shown in FIG. 1A, when the upper portion of the rotary blade 27 is pressed against the workpiece W to be cut, the upper end portion of the protective cover 28 is cut off. 28d hits the work W and the protective cover 2
8 rotates counterclockwise against the elastic force of the torsion coil spring 30. During this rotation, one end 30b of the torsion coil spring 30 is connected to the side surface 2 of the protective cover 28.
8c, the other end 30c is locked to one end 31b of the tube cutout portion 31a of the spring storage member 31, the torsion coil spring 30 is caught, and the elasticity of the torsion coil spring 30 is increased. Strengthens.

As shown in FIG. 1 (b), when the lower part of the rotary blade 27 is pressed against the work W to be cut, the lower end 28e of the protective cover 28 hits the work W. The protection cover 28 rotates clockwise against the elastic force of the torsion coil spring 30. At the time of this rotation, the other end 3 of the torsion coil spring 30
0c is a projection 28b provided on a side surface 28c of the protective cover 28.
, The one end 30b is locked to the other end 31b 'of the tube cutout portion 31a of the spring storage member 31, and the torsion coil spring 30 is rolled up, so that the elastic force of the torsion coil spring 30 is increased. The ends 30b and 30c of the torsion coil spring 30 tangentially projecting from the outer periphery of the winding portion 30a are made parallel in the same direction, and the tip of the torsion coil spring is locked to the projection, thereby torsion coil spring. When the winding portion 30a is wound, friction between the winding portion 30a and the cylindrical portion of the spring storage member 31 that houses the winding portion 30a can be prevented.

FIG. 2 is a side view of an engine cutter provided with a protective cover 28 constructed as in the first aspect of the present invention. FIG. 3 is a plan view of the engine cutter, and members not described above will be described. Reference numeral 44 denotes an engine cylinder, 45
Is a cylinder cover, 46 is a muffler, 47 is a throttle lever, 48 is a rear handle, and 49 is a front handle.

Reference numeral 50 shown in FIGS. 1 to 4 denotes an arc-shaped slit 50a having a side surface 28c of the protective cover 28.
Is an arc-shaped slide plate fixed at a predetermined interval to the slide plate. Both ends of the slide plate 50 are fixed to the side surfaces 28c of the protective cover 28 by fixing members 50b, 50b, and rotate integrally with the protective cover 28. The slit 50 of the slide plate 50
A screw 52 having a washer 52 a (see FIGS. 3 and 4) penetrating through a is screwed into a screw hole (not shown) of the fixing portion 53. The head of the screw 52 has a lock lever 5
The screw 52 can be rotated by rotating the lock lever 51. With this configuration, when the protection cover 28 is manually rotated to a desired angle and then the lock lever 51 is rotated, the screw 52 is screwed into the screw hole of the fixing portion 53 and the washer is screwed. The slide plate 50 is sandwiched between the portion 52a and the fixing portion 53, and the protective cover 28 is fixed (locked) at its rotational position.

FIG. 5 is a view showing a main part of an engine cutter according to a second embodiment of the present invention.
A bellows (bellows) 3 that expands and contracts due to the pressure difference between the inside and outside gas in the middle of a pipe 35 connecting the carburetor side 33 and the atmosphere side 34
When the air cleaner 32 becomes difficult to pass air due to dust or dirt clogging, the bellows 36 gradually expands from the contracted state due to the pressure difference between the atmospheric pressure in the pipe 35 and the atmospheric pressure. And a dust monitor configured to be visible from a see-through window 37a provided in a part of the air cleaner cover 37.
More specifically, the bellows 3 whose tip is sealed
6 is slidably housed in a transparent cylinder 37b with its open rear end communicating with the atmosphere side 34, and the tip of a bellows 36 communicating with the pipe 35 is inserted into the transparent cylinder 37b. The coil spring 37c is pushed to the rear end side.

With this configuration, as shown in FIG. 5A, when there is no dust or clogging in the air cleaner 32, the tip end of the bellows 36 is pushed by the coil spring 37c. The bellows 36 moves to the rear end side, and the bellows 36 cannot be confirmed from the see-through window 37a. In addition, as shown in FIG. 5B, when dust or dirt is clogged in the air cleaner 32, the pressure in the pipe 35 becomes lower than the atmospheric pressure, so that the bellows communicating with the atmospheric pressure is used. Since the pressure on the rear end side of the 36 becomes stronger than the pressure on the front end side, the bellows 36 is pushed out against the coil spring 37c, and the bellows 36 can be confirmed through the see-through window 37a. If the bellows 36 is colored, for example, red, it is easy to confirm that the bellows 36 is extended.

FIGS. 6 to 8 are views showing a main part of the engine cutter according to a third aspect of the present invention. FIG. 8 is an enlarged view of the pulley 4 attached to a shaft 39 via a bearing 38.
An elastic cover 42 having a small hole 42a at the center thereof is attached to the shaft 39 of the rear pulley cover 41 covering the shaft 0 at a position facing the flow hole 39a for supplying lubricating grease to the bearing 38. It is a thing. With this configuration, when lubricating grease is supplied to the bearing 38, the open end of the grease gun D is inserted into the small hole 42a of the elastic cover 42,
By supplying the lubricating grease by pressing it against the lubricating grease flow hole 39a on the end surface of the shaft 39, the lubricating grease can be supplied without removing the rear pulley cover 41.

The invention according to claim 4 is characterized in that a belt 43 is provided near the pulley inside 41a of the rear pulley cover 41.
When the belt 43 hangs on the pulley 40, the belt 43
And a pulley cover on which a belt guide rib 41b for guiding the belt is provided. With this configuration, the belt 4 is attached to the pulley 40 attached to the shaft 39.
3, the belt 43 is guided by the belt guide ribs 41b and is hung on the pulley 40. Therefore, when the belt 43 is hung on the pulley 40, the rear pulley cover 41 is not removed. Can also be done.

Reference numeral 54 shown in FIGS. 6 to 8 denotes a clutch member which is fixed to the shaft 39 which is rotated by the engine, and when the rotation speed of the shaft 39 exceeds a predetermined speed, one clutch member which spreads outward due to centrifugal force. The other clutch member 55 that rotates integrally with the pulley 40 is provided on the outer periphery of the clutch member 55. The rotary shaft 56 to which the rotary blade 27 is attached is supported by the support member 2.
The belt 43 is hung between the pulley 40 and the pulley 58 attached to the rotating shaft 56 via bearings 57 and 57. The support member 29 of the rotating shaft 56 is provided at the distal end of a bearing case 59 movable in the longitudinal direction of the belt 43. The base end of the bearing case 59 is connected to the bearing case 60 of the shaft 39 rotated by the engine. Is attached to the front end of the belt so as to be movable in the longitudinal direction of the belt and fixed by fixing bolts 61, 61. When tightening the belt 43 hung between the pulley 40 and the pulley 58, the fixing bolt 6
After loosening the fixing bolts 61, the fixing bolts 61, 61 are tightened after the bearing case 59 is advanced by turning the belt tightening adjustment bolt 62 screwed to the bearing case 60 to advance the bearing case 59.

FIG. 7 is a view showing a state in which the rotary blade 27 is replaced. To change the attachment, loosen the belt tightening adjustment bolt 62, remove the fixing bolts 61, 61, remove the front pulley cover 63, remove the belt 43 from the pulley 58, and remove the bearing case 59 from the tip of the bearing case 60. And the bearing case 59 is attached to the tip of the bearing case 60. At the time of this replacement, the belt 43 is attached to one of the pulleys 4.
Although the state is loosened from zero, the state where it is again hung on the other pulley 58 in the bearing case 60 is maintained. Then, as shown in FIG. 7, when the belt 43 hung on the other pulley 58 is tightened after the replacement of the bearing case 59, the belt 43 is guided by the belt guide rib 41b, and the one pulley 40 , The belt 43 can be hung on the pulley 40 without removing the rear pulley cover 41.

[0023]

According to the first aspect of the present invention, the protective cover that rotates along the outer periphery of the rotary blade so as to cover a portion other than the portion of the rotary blade that comes into contact with the workpiece is rotatable around the center of rotation. A spring housing member, which is supported by a support member and has a cylindrical portion capable of housing the winding portion of the torsion coil spring, is removed in a predetermined range, is attached to the support member, and a tangent to the outer periphery of the winding portion of the torsion coil spring The winding portion of the torsion coil spring is housed in the spring housing member so that both end portions extending in the direction can slide in the cylinder notch portion of the spring housing member, and the winding of the torsion coil spring is caused by the rotation of the protective cover. Sometimes, the other end is locked to one end of the tube notch and the engine cutter is provided with a protection cover configured by providing a protrusion on one end to the side surface of the protection cover. When the torsion coil spring slides on the protective cover when the bar rotates, the resilience of the torsion coil spring does not weaken due to the sliding resistance, and the torsion coil spring wears. Nor.

According to a second aspect of the present invention, a bellows is provided in the middle of a pipe connecting the carburetor side and the atmosphere side of the air cleaner so that the bellows expands and contracts due to the pressure difference between the internal and external gases. When the air becomes difficult to pass, a dust monitor configured so that the extended state of the bellows can be confirmed from a see-through window provided in a part of the air cleaner cover by a pressure difference between the atmospheric pressure in the pipe and the atmospheric pressure. Since the engine cutter is provided with such an engine cutter, dust and dust clogging of the air cleaner which is particularly likely to occur in this type of engine cutter can be promptly confirmed and repaired.

According to a third aspect of the present invention, the center of the pulley cover for covering the pulley attached to the shaft via a bearing is located at a position opposite to a flow hole for supplying lubricating grease to the bearing. Since the engine cutter is provided with a resilient cover in which a small hole is formed in the portion, lubrication grease can be supplied to the bearing without removing the rear pulley cover.

According to a fourth aspect of the present invention, there is provided a pulley cover having a belt guide rib formed in the vicinity of the pulley inside the pulley cover so as to guide the belt to be engaged with the pulley when the belt is engaged with the pulley. Since the engine cutter is provided with a belt, it is possible to attach the belt to the pulley without removing the pulley cover.

[Brief description of the drawings]

FIG. 1 is a view showing a main part of an engine cutter provided with a protective cover according to the first embodiment of the present invention; FIG. 1 (a) shows a case where the protective cover is rotated counterclockwise; FIG. It shows a case in which it turns in the direction.

FIG. 2 is a side view of the engine cutter provided with the protective cover according to the first aspect of the present invention.

FIG. 3 is a plan view of an engine cutter provided with the protective cover according to the first embodiment of the present invention;

FIG. 4 is a view showing a fixing mechanism of the protective cover, and FIG.
The figure is a side view, and the figure (b) is a plan view.

FIG. 5 is a diagram showing a main part of the invention according to claim 2,
(A) shows the case where the air cleaner has no dust or dirt clogging, and (b) shows the case where the air cleaner has dust or dirt clogging.

FIG. 6 is a diagram showing a portion provided with the invention according to claims 3 and 4;

FIG. 7 is a view showing a portion provided with the invention according to claims 3 and 4;

FIG. 8 is an enlarged view of a portion provided with the invention according to claims 3 and 4;

FIG. 9 is a perspective view of a conventional engine cutter provided with a rotary blade protection cover.

FIG. 10 is an operation explanatory view of a conventional rotary blade protective cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Rotating blade 12 Protective cover 12a Upper tip part 12b Lower tip part 13 Support member 14 Sliding holding member of compression spring 14a Arc-shaped long groove 16 Fixing pin 17, 17 'Compression spring 25 Engine body 26 Handle 27 Rotating blade 28 Protective cover 28a, 28b protrusion 28c Side surface 28d Tip 28e Tip 29 Support member 30 Torsion coil spring 30a Winding portion 30b, 30c both end portions 31 Spring storage member 31a Tube cutout portion 31b One end 31b 'Other end 32 Air cleaner 33 Carburetor Side 34 Atmospheric side 35 Pipe line 36 Bellows 37 Air cleaner cover 37a Transparent window 37b Transparent cylinder 37c Coil spring 38 Bearing 39 Shaft 39a Lubrication grease circulation hole 40 Pulley 41 Rear pulley cover 41a 41b Belt guide rib 42 Elastic cover 42a Small hole 43 Belt 44 Engine cylinder 45 Cylinder cover 46 Muffler 47 Throttle lever 48 Rear handle 49 Front handle 50 Slide plate 50a Arc-shaped slit 50b Fixing member 51 Lock lever 52 Screw 52a Washer part 53 Fixing part 54 One clutch member 55 The other clutch member 56 Rotating shaft 57 Bearing 58 Pulley 59 Bearing case 60 Bearing case 61 Fixing bolt 62 Belt tightening adjusting bolt 63 Front pulley cover

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Nakagana, 35, Shinjijin, Chiyoda-cho, Yamagata-gun, Hiroshima Prefecture Inside the Central Research Laboratory of Shindaiwa Industries Co., Ltd. (72) Inventor Kazuhiro Umetani Chiyoda-cho, Yamagata-gun, Hiroshima 35 Ujigami Shin-Daiwa Industrial Co., Ltd. Central Research Laboratory F-term (reference) 3C040 AA01 GG16 GG42 GG44 LL05

Claims (4)

[Claims] 1. A protective cover that rotates along the outer periphery of a rotary blade so as to cover a portion other than a portion of the rotary blade that comes into contact with a work,
The rotation center portion is rotatably supported by a support member, and a spring storage member in which a cylindrical portion capable of storing a winding portion of the torsion coil spring is omitted in a predetermined range is attached to the support member, and the torsion coil is mounted. The winding portion of the torsion coil spring is housed in the spring housing member so that both ends of the spring winding portion extending in the tangential direction on the outer periphery can slide in the tube-free portion of the spring housing member. When the torsion coil spring is wound by the rotation, the other end is locked to one end of the tube notch, and a projection to which one end is locked is provided on a side surface of the protection cover. An engine cutter characterized in that: 2. A bellows which expands and contracts due to a pressure difference between an internal gas and an external gas in the middle of a pipe connecting the carburetor side and the atmosphere side of the air cleaner. An engine provided with a dust monitor configured so that the extended state of the bellows can be confirmed from a transparent window provided in a part of an air cleaner cover by a pressure difference between an atmospheric pressure in a pipe and an atmospheric pressure. cutter. 3. A small hole is formed in the center of the end surface of the shaft of the pulley cover that covers the pulley attached to the shaft via the bearing, at a position facing a flow hole for supplying lubricating grease to the bearing. An engine cutter having an elastic cover attached thereto. 4. The engine according to claim 1, further comprising a pulley cover formed near the pulley inside the pulley cover and formed with a belt guide rib for guiding the belt to be engaged with the pulley when the belt is engaged with the pulley. cutter.