JP4224769B2 - Portable electric cutting tool having a blade edge illumination device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a portable electric cutting tool, and more particularly to an electric tool including an illumination device for illuminating the vicinity of a cutting portion.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-170203 [Patent Document 2]
Japanese Utility Model Publication No. 60-98602 [Patent Document 3]
JP 2001-300818 A [Patent Document 4]
US Pat. No. 5,461,790 An electric cutting tool such as an electric circular saw is widely used for cutting a work material along a black line written on the work material. FIG. 9 shows a state in which the work material 20 is cut by the portable dust collecting circular saw 1, and the circular saw body 1 is moved with the notch 12 provided in the base 2 aligned with the black line 21. As a result, the saw blade 4 cuts the workpiece 20 along the black line 21. FIG. 10 is a partially enlarged view showing a situation where a large amount of chips are generated when the saw blade 4 cuts the work material.
[0003]
In Japanese Utility Model Laid-Open No. 60-98602 (Patent Document 2), an illuminator with a transparent window is attached to the protective cover of the rotary blade in order to perform highly accurate work using an electric circular saw, and a light bulb is arranged inside it. Such a structure is disclosed.
[0004]
Japanese Patent Laid-Open No. 11-170203 (Patent Document 1) illuminates the blade edge of the saw blade in a direction perpendicular to the cutting direction of the saw blade in order to improve the visibility and assembly of the blade edge. A portable circular saw provided with a light bulb is disclosed.
[0005]
Furthermore, Japanese Patent Laid-Open No. 2001-300818 (Patent Document 3) discloses that a light bulb is placed at a position shifted in a direction perpendicular to the cutting blade in order to prevent the illumination efficiency from being lowered even if the chips are wound up by cutting. An arranged portable circular saw is disclosed.
[0006]
In addition, US Pat. No. 5,461,790 (Patent Document 4) proposes a structure in which a laser diode is provided on a shield part of a saw blade in order to perform cutting with higher accuracy using a circular saw. Yes.
[0007]
[Problems to be solved by the invention]
As described above, the electric cutting tool provided with the illumination device is roughly classified into two types depending on the portion to be illuminated. First, when cutting a work material with an electric cutting tool, the user moves the cutting tool so that the notch of the base provided on the cutting tool matches the black line written on the work material. Taking this into consideration, it is a type that illuminates the vicinity of the guide portion indicating the blade tip position provided at the tip of the base.
[0008]
Second, although the guide part and the black line are used as a guide for moving the electric cutting tool, the operator cuts while confirming whether the cutting edge of the cutting tool actually cuts a desired part of the work material. In consideration of moving the tool, it is a type that illuminates the vicinity of the portion where the cutting edge of the cutting tool cuts the work material.
[0009]
In the case of an electric cutting tool equipped with the first type of lighting device, a light bulb or laser diode illuminator is attached to a relatively high part of the main body away from the base, and the structure is such that it is irradiated obliquely from above. I must. However, in this case of circular saws and dust collecting circles, the circular saw body has a structure that rotates around a predetermined fulcrum in order to change the depth of cut. The area changes, making it difficult to always illuminate the desired site. In particular, the lighting device often becomes useless in an environment where a large amount of chips are generated, such as an environment where a dust collection circular saw is used.
[0010]
On the other hand, in the case of the electric cutting tool equipped with the second type of lighting device, the portion where the saw blade cuts the work material is directly illuminated, but the light is blocked by the dust to illuminate the most dusty part. In many cases, the lighting desired by the operator cannot be obtained.
[0011]
An object of this invention is to provide the portable electric cutting tool which solved the above problems. That is, an object of the present invention is to provide an electric tool including an illumination device in which a portion where a saw blade cuts a work material can be easily seen even in a work environment where a large amount of dust is present.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises a base and a cutting tool body supported to be tiltable with respect to the base. The cutting tool body includes an electric motor and a saw blade that is rotationally driven by the electric motor. A portable electric cutting tool having a lighting device that illuminates the vicinity of a cutting portion where the saw blade cuts the work material, and the lighting device is attached to be inclined with respect to a side surface of the saw blade. The first light emitting diode mainly irradiates the vicinity of the cut portion when the cut depth is deep, and the second light emitting diode mainly irradiates the vicinity of the cut portion when the cut depth is shallow. it has one of the features that have to be.
[0013]
Another feature of the present invention is that the first and second light emitting diodes are arranged in a space between the saw blade and the handle portion and in a position close to the saw blade .
[0014]
Another feature of the present invention resides in that the first and second light emitting diodes are arranged such that the central axis of the irradiated light has different angles with respect to the side surface of the saw blade.
[0015]
Another feature of the present invention is that a third light emitting diode that mainly irradiates the vicinity of the tip of the base when the cutting depth is deep and a fourth light emitting diode that mainly irradiates the vicinity of the tip of the base when the cutting depth is shallow. The light emitting diode is provided.
[0016]
Another feature of the present invention is that the third light emitting diode is disposed at an upper position of the circular saw body, and the fourth light emitting diode is disposed at a lower position of the circular saw body, and emitted from each light emitting diode. This is because the vicinity of the tip of the base is irradiated after the light has crossed .
[0017]
Another feature of the present invention resides in that the third and fourth light emitting diodes are located on the handle side when viewed from the saw blade and in a position close to the saw blade .
[0018]
Other features and advantages of the present invention will be more clearly understood from the following description of embodiments.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Although the present invention can be applied to various electric cutting tools, particularly when applied to a portable dust collecting circular saw, a particularly great effect can be obtained, so this embodiment of the portable dust collecting circle will be described below.
[0020]
FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a plan view seen from the upper surface, and FIG. 3 is a rear view. The portable dust collecting circular saw includes a circular saw main body 1 and a base 2 placed on the upper surface of a work material to be cut. The circular saw body 1 and the base 2 rotate relative to each other, and the protrusion 3 of the saw blade 4 from the lower surface of the base 2, that is, the depth of cut, can be adjusted by the support portion 3 serving as a rotation fulcrum. The saw body 1 and the base 2 are connected. A circular saw blade 4 is rotatably held by the circular saw body, and is driven to rotate by using an electric motor (not shown) as power. An upper side and a side of the saw blade 4 are covered with a saw cover 5.
[0021]
A safety cover 7 is rotatably attached to the rotary shaft 6 of the saw blade 4 so as to cover the lower half of the range of the lower side of the saw blade 4. When the circular saw body 1 is moved in the cutting progress direction, the circular saw body 1 is rotated so that the lower half of the saw blade 4 is gradually exposed.
[0022]
A gear case 8 is provided on the side surface of the saw blade 4. A gear (not shown) for decelerating the rotation of the electric motor provided in the electric motor cover 9 is built in the gear case 8. The rotation of the electric motor is transmitted to the rotary shaft 6 of the saw blade 4 via the gear in the gear case 8 so that the saw blade 4 rotates. Dust generated by cutting the work material by the rotation of the saw blade 4 is discharged to the outside through a tubular dust discharge port 11.
[0023]
In the present embodiment, four light emitting diodes for illumination are mounted. The two light emitting diodes L <b> 1 and L <b> 2 are located below the circular saw body 1 between the saw blade 4 and the handle portion 10, and are disposed in proximity to the saw blade 4. The light emitting diodes L1 and L2 can be used to check whether or not the saw blade 4 is cutting along the black line drawn on the upper surface of the work material. Irradiate the area (FIG. 1).
[0024]
On the other hand, the other two light emitting diodes L3 and L4 are positioned on the upper part of the circular saw body between the saw blade 4 and the handle portion 10 (FIG. 4), and irradiate the front of the base 2. That is, the light emitting diodes L3 and L4 are circular saws so that it can be confirmed whether or not the guide portion 12 (FIG. 6) provided on the base 2 is moved along the black line drawn on the upper surface of the workpiece. It is provided to irradiate a region in the traveling direction of the main body 1 and close to the base 2.
[0025]
In the present invention, there is one feature particularly in the arrangement of the light emitting diodes L1 and L2. First, two light emitting diodes L1 and L2 are attached in the lateral direction as seen from the side surface of the saw blade 4 as shown in FIG. In the state of FIG. 1 in which the saw blade 4 is at the maximum cutting depth, the light emitting diode L1 mainly plays a role of irradiating the vicinity of the cutting portion.
[0026]
On the other hand, when the circular saw body 1 is rotated around the shaft 3 from this state as shown in FIG. 4 and the cutting depth is reduced, the light emitting diode L2 mainly plays the role of irradiating the vicinity of the cut portion. Thus, by arranging the two light emitting diodes in the lateral direction, the irradiation range can be widened, and it is possible to always irradiate the vicinity of the cut portion even if the cutting depth is changed.
[0027]
In FIG. 1, if the two light emitting diodes L1 and L2 are arranged at the same angle with respect to the base 2, the irradiation range when the depth of cut changes is further increased by arranging them at different angles. Can do.
[0028]
In the embodiment of the present invention, the light emitting diodes L1 and L2 are arranged so as to always irradiate both the saw blade in the vicinity of the cutting portion and the upper surface of the work material in the front portion in the cutting direction regardless of the depth of the cut. ing. Thus, when both are irradiated, the visibility is improved and the working efficiency is improved as compared with the case where only one is irradiated.
[0029]
Further, as shown in FIG. 2, the light emitting diodes L1 and L2 are arranged in a space between the saw blade 4 and the handle portion 10 and in a position close to the saw blade 4, and both the light emitting diodes L1 and L2 are irradiated with the light emitting diodes L1 and L2. The central axis of the light is disposed at an angle inclined with respect to the side surface of the saw blade 4. In this way, the range in which the saw blade 4 is irradiated can be widened. Although not clearly shown in FIG. 2, the two light emitting diodes L <b> 1 and L <b> 2 are housed in one case, and the housing case has two sides facing the base 2 and facing the saw blade 4. Is opened, and the other surface is covered with a light shielding member. In this way, by arranging the light emitting diodes L1 and L2 so as to be as close as possible to the cutting portion and illuminate with the light concentrated in that direction, it is possible to visually check the cutting state by the blade edge even in a large amount of dust. Become.
[0030]
Further, the tip of the saw blade 4 is often not visible unless the operator normally looks into it, but the light is emitted in the space between the saw blade 4 and the handle portion 10 as in the above embodiment. When diodes L1 and L2 are provided, the cutting edge can be seen from the side opposite to the saw blade 4 while holding the handle portion 10 with the right hand, that is, from the side where there is no obstacle such as a motor. The situation can be easily checked. Further, since other light emitting diodes L3 and L4 described later are arranged on the same side with respect to the saw blade 4 when viewed from the upper surface, the light emitting diodes L1 to L4 and their drive circuits are compactly stored in a small space. can do.
[0031]
On the other hand, in the embodiment of the present invention, the light emitting diodes L3 and L4 are attached at an angle slightly inclined with respect to the surface of the saw blade 4 as shown in FIG. It is attached in the vertical direction (vertical direction). When the depth of cut is the deepest as shown in FIG. 3, the region near the tip of the base 2 is illuminated by the light emitting diode L3 located above, and the region ahead of the base 2 is illuminated by the light emitting diode L4 located below. Are arranged to be.
[0032]
As shown in FIG. 5, when the cutting depth of the saw blade 4 is shallow, a region near the tip of the base 2 is illuminated by the light emitting diode L4 located at the bottom. At this time, the irradiation light of the light emitting diode L3 located at the upper part illuminates the rear region in the traveling direction from the tip of the base 2.
[0033]
That is, in the above-described embodiment, the two light emitting diodes L3 and L4 are arranged in the vertical direction, and the light emitted from each of the light emitting diodes L3 and L4 is arranged so as to irradiate the vicinity of the tip of the base 2 once crossing once in the middle. Therefore, when the cut depth is deep, the light emitting diode L3 mainly contributes to the illumination of the base tip portion, and when the cut depth is shallow, the light emitting diode L4 contributes to the illumination of the base tip portion. As a result, the tip of the base is always illuminated regardless of the cutting depth of the saw blade 4, and the black line can be easily confirmed.
[0034]
FIG. 6 is a top view seen from a different angle from FIG. In the planar positional relationship, the light emitting diodes L3 and L4 are located on the handle portion 10 side as viewed from the saw blade 4 and are provided as close to the saw blade 4 as possible. Since the operator is in a posture to look at the tip of the base from the opposite side of the saw blade 4 while holding the handle portion 10, it is desirable that the light emitting diodes L3 and L4 are in the above positions. In addition, when the light emitting diodes L3 and L4 are attached, an electric circuit for light emission is inevitably required, but it is easy to secure a space for storing them in the space between the saw blade 4 and the handle portion 10 and is compact. A lighting device can be attached to the.
[0035]
FIG. 7 shows an embodiment of a circuit for driving the light emitting diodes L1 to L4. The voltage from the power supply is applied to the pair of terminals of the diode bridge circuit BD via the switch SW and resistors R1, R2, R3, and R4. The voltage rectified by the bridge circuit BD is taken out from the other pair of terminals of the bridge BD, is made constant voltage by the Zener diode Z1, and then applied to the light emitting diodes L1 to L4. This electric circuit is accommodated in a part of the space between the saw blade 4 and the handle portion 10 of the circular saw body 1.
[0036]
In the embodiment of the present invention, the values of the resistors R1 to R4 are selected to be predetermined values, the currents flowing through the light emitting diodes L1, L2, L3, and L4 are adjusted, or the number of the light emitting diodes is appropriately selected and the saw is The illuminance of the blade tip and base tip region is set to a desired value.
[0037]
According to the measurement by the present inventor, when the cutting depth of the saw blade 4 is shallow as shown in FIG. 5 as compared with the case where the cutting depth is deep as shown in FIG. 3, the illuminance near the tip of the base 2 is about 30% higher. It was found. In addition, although the cutting depth of FIG. 5 was 9 mm, this is a value in consideration of the minimum thickness for one general work material in which a dust collection circular saw is used.
[0038]
It was confirmed that it is desirable to ensure that the illuminance at the tip of the base is about 100 lux as measured at the bottom of the base in order to prevent the black line from being obstructed even if a very large amount of dust is generated. Therefore, in order to obtain about 100 lux in the state of FIG. 5, about 130 to 140 lux is required in the state of the maximum cutting depth as shown in FIG.
[0039]
On the other hand, the light emitting diodes L1 and L2 that illuminate the cutting edge of the saw blade 4 illuminate a place where there is more dust than the tip of the base, so even if the depth of cut is 9mm (FIG. 4), about 140 lux on the bottom of the base It was confirmed that it was desirable. In the state of FIG. 4, when the illuminance is 140 lux, the illuminance on the bottom of the base when the cutting depth is maximized as shown in FIG. It was confirmed that there was no hindrance to visual inspection.
[0040]
In the embodiment of the present invention, monochromatic light emitting diodes having an emission wavelength in the range of 550 nm to 620 nm are used as the light emitting diodes L to L4. FIG. 8 shows the wavelength characteristics of a light emitting diode that emits yellow (or orange) light that is already on the market. This light emission color is the most visible when viewing the black line in a large amount of dust. Was confirmed. In addition, although about 90 people were confirmed about the good visibility, almost all evaluated that the light emitting diode of the present invention was easier to see than the white light emitting diode, that is, the visibility was excellent.
[0041]
There are various reasons for this, but the relative visual sensitivity is quite high in the region of 550 nm to 620 nm, it is monochromatic light, so there is little reflection from wood, etc., and there is no irregular reflection in a large amount of dust. This is considered to be the cause. In addition, the fog light of the automobile used when irregular reflection such as fog is likely to occur also adopts yellow or orange, and it is considered that yellow is effective as a color that makes black stand out.
[0042]
In the above-described embodiment, an example in which the light emission wavelengths of the light emitting diodes L1 to L4 are in the range of 550 nm to 620 nm is given, but even if all the light emission wavelengths are not in the range of 550 nm to 620 nm, the maximum light emission intensity is obtained. A monochromatic light emitting diode having a light wavelength in the range of 550 nm to 620 nm can also exhibit the same effects as those of the above embodiment.
[0043]
The number of light emitting diodes used for irradiating each region may be larger than two, but the reason for using at least two is as follows. That is, the light emitting diode has an effect that it has a longer life than a light bulb, but has a drawback that the irradiation angle is small. For example, the irradiation angle of the light emitting diode employed in the present invention is 24 degrees. For this reason, in particular, in a portable circular saw provided with a cutting depth adjusting mechanism, it becomes difficult to irradiate a region where irradiation is required by adjusting the cutting depth. By adopting such a configuration, it is possible to provide a portable circular saw that can irradiate a desired region even if the depth of cut is changed and includes a long-life lighting device. .
[0044]
【The invention's effect】
According to the present invention, the circular saw body, which is a space between the saw blade and the handle portion and is close to the saw blade and close to the base, is arranged side by side as viewed from the side of the saw blade and emits at least two lights. Since the diode is disposed and attached to the side surface of the saw blade at an angle, the cutting portion can be always illuminated regardless of the amount of the cutting depth.
[0045]
In addition, at least two light emitting diodes are arranged in a vertical direction when viewed from the side surface of the round part at a position overlooking the tip of the base, and the light emitted from the light emitting diodes is halfway. Since it is configured to irradiate near the tip of the base after crossing in step 3, the cutting tool main body rotates, and a desired portion can always be irradiated even if the cutting depth changes. Therefore, even in a dusty work environment, the operator can not only accurately move the cutting tool along the black line indicating the cutting position, but can also work while visually observing the actual cutting location. There is an effect that work can be performed efficiently and accurately.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a power tool according to the present invention.
FIG. 2 is a cross-sectional side view of an essential part showing an embodiment of a power tool according to the present invention.
FIG. 3 is a rear view showing one embodiment of the electric power tool according to the present invention.
4 is a front view showing a state in which the cutting depth is changed in the electric power tool shown in FIG. 3; FIG.
FIG. 5 is a rear view showing an embodiment of the electric power tool according to the present invention.
FIG. 6 is a plan view showing an embodiment of an electric power tool according to the present invention.
FIG. 7 is a drive circuit diagram of a light emitting diode used in the electric tool of the present invention.
FIG. 8 is a wavelength characteristic diagram of a light-emitting diode used in the electric tool according to the present invention.
FIG. 9 is an explanatory view showing a state in which a work material is being cut with a portable dust collecting circular saw.
FIG. 10 is a partially enlarged view showing a state where a work material is being cut with a portable dust collecting circular saw.
[Explanation of symbols]
1: Circular saw body 2: Base 3: Support shaft 4: Saw blade 5: Saw cover 6: Rotating shaft 7: Safety cover 8: Gear case 9: Electric motor cover 10: Handle portion 11: Dust outlet 12: Base cover cut Part L1-L4: Light-emitting diode

Claims (6)

A portable electric cutting tool comprising a base and a cutting tool body supported to be tiltable with respect to the base, the cutting tool body having an electric motor and a saw blade that is rotationally driven by the electric motor;
The above-mentioned saw blade is equipped with an illumination device that illuminates the vicinity of the cutting part for cutting the work material,
The lighting device has first and second light emitting diodes mounted at an angle to the side of the saw blade,
The first light emitting diode mainly illuminates the vicinity of the cut portion when the cutting depth is deep,
The portable light cutting tool characterized in that the second light emitting diode mainly irradiates the vicinity of the cutting portion when the cutting depth is shallow.   2. The portable electric cutting tool according to claim 1, wherein the first and second light emitting diodes are arranged such that central axes of the irradiated light are different from each other with respect to a side surface of the saw blade. . The portable electric cutting tool according to claim 1, wherein the first and second light emitting diodes are arranged in a space between the saw blade and the handle portion and in a position close to the saw blade. 2. The third and fourth light emitting diodes according to claim 1, wherein the guide part provided on the base includes a third light emitting diode and a fourth light emitting diode for confirming whether the guide part is moving along the black line on the workpiece. A portable electric cutting tool characterized in that mainly the vicinity of the tip of the base is irradiated when the depth is deep, and the fourth light emitting diode mainly irradiates the vicinity of the tip of the base when the cutting depth is shallow. 5. The light emitting diode according to claim 4, wherein the third light emitting diode is disposed at an upper position of the circular saw body, and the fourth light emitting diode is disposed at a lower position of the circular saw body. A portable electric cutting tool characterized by irradiating the vicinity of the tip of the base after the operation. 5. The portable electric cutting tool according to claim 4, wherein the third and fourth light emitting diodes are disposed on the handle side when viewed from the saw blade and in a position close to the saw blade.

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