JP4555198B2 - Cutting machine - Google Patents

Description

  The present invention relates to a cutting machine in which a main body provided with a cutting blade that is driven to rotate is provided on an arm standing on a base on which a material to be cut is placed, such as a cutter or a table-top circular saw.

For example, in a tabletop circular saw, a main body equipped with a disk-like saw blade (cutting blade) that is driven to rotate by a motor on an arm projecting from the back of the base can be moved up and down by a support shaft and is dead by an urging means. It is provided in a state of being urged to a point, and the material to be cut set on the base can be cut by lowering the main body. Note that “top dead center” refers to an upper limit position at which a main body that is not lowered is stopped, and “bottom dead center” described later refers to a lower limit position at which a main body that has been lowered is stopped.
Also, the main body is rotatably attached to a blade case that partially covers the saw blade leaving its work opening portion and rotatably mounted on the blade case, and is normally biased to a position that covers the work opening portion of the saw blade. And a safety cover. A link member is installed between the arm and the eccentric position from the rotation center of the safety cover. When the main body is lowered, the link member urges the safety cover to rotate in the saw blade exposure direction, and cuts. The safety cover is retracted to a position that does not interfere with the work (see, for example, Patent Document 1).

  As a connecting structure between the link member and the safety cover, a shaft body (pin or bolt) provided on the safety cover is loosely inserted into a long groove provided on the link member so that a shaft is formed at the top dead center and the bottom dead center of the main body. A structure is often used in which the body is engaged with the end of the long groove so that the link member that pivots upward as the main body moves up and down can apply a rotational force to the safety cover via the shaft. Yes. In such a structure, sliding of the shaft body in the long groove is allowed at the top dead center of the main body, so that only the safety cover can be rotated independently, and the saw blade can be replaced at the top dead center. Etc. are possible.

Japanese Patent No. 3431403

  In the tabletop circular saw machine, if the link member is deformed by an external force, the shaft body cannot slide in the long groove, and there is a possibility that the single rotation of the safety cover may be hindered. Accordingly, it is conceivable that the width of the long groove is created with a dimension having a margin more than the diameter of the shaft body, and even if the link member is deformed, the safety cover can be independently rotated. However, for this reason, rattling occurs between the safety cover and the link member even at the top dead center or bottom dead center of the main body, and noise is generated during use and the link member vibrates, causing discomfort to the operator. And in turn leads to a decline in product value.

  Accordingly, the present invention provides a cutting machine that can maintain a suitable feeling of use and commercial value by eliminating the generation of noise due to rattling, as well as ensuring the independent rotation of the safety cover regardless of the deformation of the link member. It is intended to do.

In order to achieve the above object, the invention according to claim 1 is provided such that the engaging side of the shaft body in the long groove of the link member has a tapered portion whose width gradually narrows toward the end, and a continuous taper portion. In this case, the shaft body is formed with a terminal portion into which the shaft body is fitted.
In addition to the object of claim 1, the invention described in claim 2 is characterized in that in order to enable smooth movement of the shaft body with respect to the end portion of the long groove, the taper portion of the long groove is provided with the safety cover as the top dead center of the main body. In this case, the length is set to approximately one third of the maximum stroke in which the shaft body slides in the long groove when it is independently rotated.

According to the first aspect of the present invention, independent rotation of the safety cover can be ensured regardless of deformation of the link member due to external force, and generation of sound due to rattling at the top dead center or bottom dead center is eliminated. Therefore, a suitable feeling of use is obtained and the commercial value can be maintained.
According to the second aspect of the present invention, in addition to the effect of the first aspect, smooth movement is possible when the shaft body enters and exits the end portion of the long groove.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view of a tabletop circular saw machine, which is an example of a cutting machine, as viewed from the side. The tabletop circular saw machine 1 has a turntable 3 mounted in a substantially center of a base 2 so as to be horizontally rotatable. An arm 4 is erected on the rear side of the turntable 3 (left side in the figure), and a main body 6 is pivotally attached to an intermediate portion of the arm 4 by a support shaft 5 so as to be movable up and down. The main body 6 is biased to the top dead center position in FIG. 1 by a torsion spring 7 provided on the support shaft 5 portion. Reference numeral 8 denotes a guide fence constructed in the left-right direction on the base 2 so as to cross the turntable 3, and 9 denotes an operation lever for rotating the turntable 3.
The main body 6 includes a blade case 10 provided with a motor (not shown), a disk-like saw blade 11 (cutting blade) that is covered by the blade case 10 at a top dead center and substantially half on the diagonally rear side, and is rotated by the motor. A handle 12 for up and down operation and a safety cover 13 that is attached to the blade case 10 and can cover the exposed portion (work release portion) of the saw blade 11 are provided. The safety cover 13 is attached so as to be rotatable about the shaft 14 from the outside of the blade case 10, and is rotated at a position where the exposed portion of the saw blade 11 is covered at the top dead center as shown in FIG. It is energized.

On the other hand, a link plate 15 as a link member is installed between an eccentric position slightly above the shaft 14 at the center of the safety cover 13 and the tip of the arm 4. The link plate 15 is a belt-like plate body that once extends upward from the distal end side of the arm 4 and then bends in two stages forward. The step plate bolt has a pin 16 on the arm 4 side and a shaft body on the safety cover 13 side. 17 are each pivotally attached. In particular, as shown in FIG. 2, the safety cover 13 side is attached to the long groove 18 provided on the end side of the link plate 15 by loosely inserting a stepped bolt 17 having a sleeve 19 on its outer side. It is structured to be screwed to the connecting piece 21. Reference numeral 20 denotes a washer for preventing the link plate 15 from coming off. The long groove 18 has a width W larger than the diameter of the sleeve 19 so that the slide of the stepped bolt 17 can be secured even if the link plate 15 is deformed by an external force. Yes.
However, the end portion on the front end side of the link plate 15 in the long groove 18 has a tapered portion 22 whose width becomes narrower toward the end, an arc-shaped end portion 23 in which the tapered portion 22 is continuous and the sleeve 19 is fitted. It is formed with. The stepped bolt 17 is located at the end portion 23 of the long groove 18 at the top dead center and the bottom dead center of the main body 6.

  In the desktop circular saw 1 configured as described above, when the handle 6 is gripped from the top dead center of FIG. 1 and the main body 6 is pushed down, the main body 6 rotates downward about the support shaft 5. At this time, the link plate 15 is located on the rear side of the support shaft 5, which is the rotation center of the main body 6, and the shaft 14 is positioned on the safety cover 13 side. Therefore, the stepped bolts 17 are pulled backwards while turning downward together with the main body 6. In this way, the safety cover 13 rotates counterclockwise around the shaft 14 against the rotation bias, and the lower part of the saw blade 11 is exposed, so that the workpiece to be cut placed on the turntable 3 is cut by the exposed saw blade 11. It becomes possible. When the main body 6 reaches the bottom dead center, the safety cover 13 exposes the lower half of the saw blade 11 almost completely as shown in FIG. Between the top dead center and the bottom dead center, the stepped bolt 17 of the safety cover 13 is always located at the end portion 23 of the long groove 18 of the link plate 15, but the sleeve 19 and the end portion 23 of the long groove 18. Are in a fitted state, so that no rattling occurs between the stepped bolt 17 and the link plate 15.

When the push-down of the main body 6 is released after the cutting operation is completed, the main body 6 is rotated upward by the urging force of the torsion spring 7 of the support shaft 5, and the link plate 15 is also swung upward at the same time. Return to top dead center on the trajectory. Therefore, the safety cover 13 also rotates clockwise until it returns to the position shown in FIG. 1 by the urging of the torsion spring.
If the saw blade 11 needs to be replaced, as shown in FIG. 4, if only the safety cover 13 is rotated against the rotational bias at the top dead center of the main body 6, the saw blade 11 is moved. Can be exposed arbitrarily. At this time, the stepped bolt 17 rotates counterclockwise around the shaft 14, and moves backward along the long groove 18 while pushing the link plate 15 upward from the end portion 23 of the long groove 18 of the link plate 15. Here, since the width W of the long groove 18 allows more margin than the sleeve 19 of the stepped bolt 17, the stepped bolt 17 does not interfere with the inside of the long groove 18 even if the link plate 15 is slightly deformed by an external force. And the safety cover 13 can be smoothly and independently rotated.

  As described above, according to the desktop circular saw machine 1 of the above-described form, the taper portion 22 whose width gradually decreases toward the end on the engagement side of the stepped bolt 17 in the long groove 18 of the link plate 15, and the taper portion thereof. 22 and the terminal portion 23 into which the stepped bolt 17 is fitted, so that the safety cover 13 can be independently rotated regardless of the deformation of the link plate 15 due to external force, and the top dead center or bottom dead center can be secured. At points, the generation of sound due to rattling is eliminated. Therefore, a suitable feeling of use is obtained and the commercial value can be maintained.

The tapered portion provided in the long groove is preferably provided with a length of about one third of the maximum stroke in which the shaft body (stepped bolt) slides when the safety cover rotates alone. With this setting, smooth movement is possible when the shaft enters and exits the end of the long groove.
Moreover, in the said form, although the both-sides edge of a long groove is a taper part which inclines together, the taper part which a width | variety becomes narrow gradually by inclining only the side edge of any one side may be sufficient. Also in this case, even if the width of the long groove is widened, the same effect as the above-described embodiment in which rattling at the top dead center and the bottom dead center is prevented can be obtained.
Furthermore, the shaft body is not limited to the structure in which the sleeve is externally mounted as in the above embodiment, and the shaft body such as a stepped bolt or rod may be slid in a state of directly contacting the long groove.

On the other hand, the link member is not limited to the plate shape as described above, but may be a shaft attachment structure in which the connection with the safety cover is a long groove and a shaft body, even if the link member has another shape such as a long rod shape. For example, the tapered portion and the terminal portion can be formed in the same manner as in the above embodiment.
In addition, the present invention is not limited to a tabletop circular saw, but can be applied to other cutting machines such as cutters and flip over saws.

It is explanatory drawing which looked at the desk circular saw machine from the side (a main part is a top dead center). (A) is the enlarged view of the front-end | tip part of a link plate, (B) is the cross-sectional explanatory drawing. It is explanatory drawing which looked at the desk circular saw machine from the side (the body is a bottom dead center). It is explanatory drawing which looked at the desk circular saw machine from the side (the main body is a top dead center, and only a safety cover is opened).

Explanation of symbols

1 .... Tabletop circular saw machine, 2 .... Base, 3 .... Turntable, 4 .... Arm, 5 .... Support shaft, 6 .... Main body, 10 .... Blade case, 11 .... Saw blade, ... Safety cover, 15 ... Link plate, 17 ... Stepped bolt, 18 ... Long groove, 19 ... Sleeve, 22 ... Taper, 23 ... End.

Claims (2)

A main body with a cutting blade that is driven to rotate is provided on an arm that stands on the base on which the material to be cut is placed, and can be moved up and down and biased to the top dead center. A blade case that partially covers leaving an open portion, and a safety cover that is rotatably attached to the blade case and covers a work opening portion of the cutting blade is provided between the arm and the safety cover, A link member that applies a rotational force to the safety cover in a direction that exposes the work opening portion of the cutting blade by a pivoting movement interlocking with the lowering of the main body is constructed, and the link member and the safety cover are attached to the safety cover. The shaft body provided is connected to the end of the link member with a long groove formed with a width larger than the diameter of the shaft body and into which the shaft body is loosely inserted, and the shaft body is connected to the end of the long groove. Rotating from the link member A grant possible and the cutting machine power,
The engagement side of the shaft body in the long groove of the link member is formed with a tapered portion whose width gradually narrows toward the end, and a terminal portion that is continuous with the tapered portion and into which the shaft body is fitted. Cutting machine characterized by. The taper portion of the long groove is set to a length that is approximately one-third of the maximum stroke that the shaft body slides in the long groove when the safety cover is independently rotated at the top dead center of the main body. Cutting machine.

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