JPS6325084Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electric polishing device for brush cutter blades, and the brush cutter is used for mowing undergrowth in forestry, weeding on fallow fields and roadside edges, etc. However, while using such a brush cutter, the blade part of the cutting blade gradually wears out, and when used in places where hard objects such as stones are mixed, the blade part quickly wears out. The present invention relates to a polishing device.

[Prior art and problems]

In the past, when the cutting edge of a mower blade became worn out, the user had to sharpen it themselves or ask a sharpening company to do it, but simply polishing the blade would cause the entire blade to become unbalanced. If the brush cutter is attached to a brush cutter and used, vibrations are generated, causing discomfort to the user, and when the vibrations are large, there is a risk of injury to the user.

[Means for solving problems]

The present invention solves the above problems, and its means are that the slider, which can slide in directions that can move toward and away from the grindstone, has a cutting blade receiver and a lever that have blades formed at equal intervals on the outer periphery. It is rotatably installed on the shaft and has a cutting blade attachment part for fixing the cutting blade at the center of the cutting blade receiver, and the lever and slider are biased in the direction of engagement with the blade part of the cutting blade receiver. In order to move the position of the cutting blade toward and away from the fixed grindstone, a rounding holder is provided on the rounding base and has a curved shape that matches the shape of the cutting blade. The curved shape of the handle is suitable for various types of cutting blades such as 8-blade cutting blades, 4-blade cutting blades, etc. By configuring the blade to fit the shape of the blade, the blade can be held against a fixed grindstone by rotating the lever within a predetermined range, whose movement is regulated by the wheel support. By sliding the removable slider, the surface of the cutting blade comes into contact with the grinding wheel accurately and uniformly, so each blade of the cutting blade can be ground in a well-balanced manner. By making it rotatable around the point, the cutting thickness of the cutting blade can be changed arbitrarily.

In addition, by providing a rounded part on one end of the rounding holder with a radius of (rounding pin radius) + (radius of the rounded part attached to the bottom of the cutting blade), a constant radius can always be attached to the bottom of the blade. It is.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a commercially available baby angle grinder (hereinafter referred to as a grinder), 2 is a grinder fixing bundle, and 3 is a grinder receiver, which are provided on a common base 17. Reference numeral 13 denotes a corner base, which is provided with a corner receiver 12 on its upper part and guides 14 on both sides. The corner base 13 is moved left and right along the guide 14 by rotating the position adjustment screw 15. Reference numeral 9 indicates a slider, and slide rails 10 are provided on both sides, and the slider 9 also has slide rails 1.
You can move left and right along 0. At the top of the slider 9, a cutting blade receiver 4 and a lever 8 are provided on the same axis.
is rotatably provided. The cutting blade receiver 4 is provided with a blade portion 4a whose outer periphery is divided into eight equal parts, and further provided with a cutting blade presser 5 and a cutting blade fixing handle 6 on the upper part for fixing the cutting blade. The lever 8 and the slider 9 have claws 7a and 7b connected to shafts 7c and 7b, respectively.
7d so as to be rotatable, and springs 18a, 18b
Therefore, part of the claws 7a and 7b are always pressed against the outer periphery of the cutting blade receiver 4. Further, the lever 8 is provided with a corner pin 11 that fits into the corner receiver 12. A stopper 16 adjusts the rotation of the lever 8.

Next, we will explain how to easily balance and sharpen an 8-blade cutting blade.

Figure 2 shows an eight-blade cutting blade structure. That is,
The outermost periphery of the cutting blade is located on the circumference centered on point D, but the actual outer periphery of the cutting blade is formed by a circular arc centered on points D′, D″... This kind of circular arc divides the entire circumference of the cutting blade into eight equal parts.

3A, B, and C are explanatory diagrams of the polishing mechanism.
In FIG. 3A, point O indicates the center point of the cutting blade receiver 4.

Here, when starting to grind the cutting blade, the contact point between the cutting blade 20 and the grindstone 21 of the grinder is located at point A, and the cutter receiver 12 is positioned so that -=-=.

Therefore, when the lever 8 is rotated in the direction of the solid arrow and reaches the stopper 16, the knife pin 11 moves from point M to point N along the knife receiver 12, and the claw 7a provided on the lever 8 moves to the cutting blade receiver 4. The cutting blade 20 is given a rotational movement of ∠MON (45° in the case of 8 blades) about the center point O, and furthermore, the cutting blade 20 is rotated by ∠MON (45° in the case of 8 blades). Due to the relationship between the blade support 12 and the center point O of the cutting blade support 4, the center point O of the cutting blade support 4 moves in the direction of the broken line arrow to the point O'. In other words, since =′, ′=
−=. Therefore, as shown in FIG. 3B, the point of contact between the cutting blade 20 and the grindstone 21 is from point A.
Follow AB to point B.

Next, when the lever 8 is rotated in the direction of the solid line arrow from the state shown in FIG. 3B, the corner pin 11 moves along the corner receiver 12 from point N to point M. On this occasion,
Since the claw 7b is engaged with the blade part 4a of the cutting blade receiver 4, the cutting blade receiver 4 does not rotate. That is, −
Only ON=, point O' moves in the direction away from the grindstone 21 (in the direction of the arrow shown by the broken line in FIG. 3B) and comes to the position of point O. Therefore, the point of contact between the cutting blade 20 and the grindstone 21 moves from point B to point C, resulting in the state shown in FIG. 3C, and point C has come to the position where point A was in FIG. 3A. Therefore, when the above operation is performed again, the points of contact between the cutting blade 20 and the grindstone 21 change to points C, D, and E. That is, by repeating the above operation, a cutting blade in which the entire circumference of the cutting blade 20 is divided into eight equal parts can be provided.

Furthermore, by making the corner support 12 rotatable around an arbitrary point on the corner support 12, -='= can be changed. That is, by moving the cutter receiver 12, it is possible to provide a cutting blade having any desired cutting length dimension desired by the user.

In addition, the curve of the corner receiver 12 is an arc whose radius is the same length as the distance from the cutting blade attachment center to the corner pin 11, and the corner receiver 12 is =
When set to the position, the cutting blade receiver 4 only rotates around point O, thereby making it possible to sharpen a four-blade cutting blade.

Figure 4 shows the general structure of a four-blade cutting blade.
As shown in the figure, the four blades are composed of two circles with radii R ₁ and R ₂ centered on the center point E of the cutting blade, and a straight line with the blade section between the two circles. Therefore,
When polishing the outer periphery of the cutting blade with radius R ₁ and the inner periphery with radius R ₂ , only rotational movement around point E is required.

Next, the method for polishing a four-blade cutting blade is shown in Figure 5A.
This will be explained with reference to B, C, and D. As shown in FIG. 5A, the center of the grinder is shifted by half the width of the blade, and further set so that the point of contact between the cutting blade 20 and the grindstone 21 is at point A. At this time, stopper 1 is placed on lever 8.
Make sure that 6 are touching. Therefore, when the lever 8 is moved in the direction of the solid line arrow along the stopper 16, the contact point between the cutting blade 20 and the grindstone 21 moves from point A to point B, and when the lever 8 is further moved in the direction of the same arrow, the contact point between the cutting blade 20 and the grindstone 21 moves from point A to point B. The grindstone 21 no longer makes contact, resulting in the state shown in FIG. 5B.

Next, the lever 8 is rotated in the direction of the solid line arrow until the pawl 7a touches the blade part 4b from the blade part 4a of the cutting blade receiver 4, and the lever 8 is rotated again in the direction of the broken line arrow.
When it returns to 6, the state shown in Fig. 5C is reached.

Then, when the lever 8 is moved in the direction of the solid arrow until the edge pin 11 hits the edge receiver 12, the cutting blade 20 and the grindstone 21 come into contact at point D. Further, when the lever 8 is moved in the direction of the dashed arrow by the corner pin 11 along the corner receiver 12, the state shown in FIG. 5D is obtained.
When the lever 8 is moved in the direction of the solid arrow along the edge support 12 until the lever 8 hits the stopper 16, the point of contact between the cutting blade 20 and the grindstone 21 moves from point D to point E. This means that point D has come to point A in FIG. 5A.

By repeating the above operations, the sections AB and DE of the cutting blade 20 can be polished as shown in FIG. 5A.
The gaps between the CDs can also be polished by turning the cutting blade 20 over.

Furthermore, for polishing between B and C of the cutting blade 20, set the contact point between the cutting blade 20 and the grindstone 21 at point B as shown in FIG.
It can be polished by rotating it vertically along the .

Next, if you think about the mower blade, you will find that there are 8 blades and 4 blades.
Both blades have a radius on the bottom of the blade. This is because when the cutting blade hits a stone or other type of object while using a brush cutter, if an edge forms on the bottom of the blade, stress will concentrate on the edge and cause cracks, or in severe cases, the blade will fly off. This is to avoid concentration of stress.

Conventionally, in order to create a radius, a radius was added to the whetstone itself, and a radius was added to the bottom of the cutting blade, but as the whetstone itself is shaved while the whetstone is in use, the shape of the radius changes, and it is difficult to keep a constant radius on the blade. It was difficult to attach it to the bottom.

FIG. 7 is an enlarged view illustrating the movement of the corner support 12 and the corner pin 11. In FIG. 3B, if we are trying to round the bottom point B of the cutting blade, the relationship between the rounding holder 12 and rounding pin 11 determines the point of contact between the grindstone 21 and the cutting blade 20. , countermeasures are required for the corner receiver 12.

That is, when the edge pin 11 moves along the X-axis in the edge holder 12 from point M to point N, and then moves along the Y-axis, the contact point between the cutting blade 20 and the grindstone 21 moves from point A to point B in FIG. 3B. Then move to point C.
Therefore, in Fig. 7, the intersection point N of the X axis and Y axis
Instead of passing through the center of the center pin 11, it is sufficient to pass along a locus having an arbitrary radius R around point P near point N.

However, the central locus of the corner pin 11 is determined by the corner surface of the corner receiver 12 and the corner pin 1.
Since the outer diameter is 1, the shape of the round surface of the round support 12 is a rounded part whose center is the point P and whose radius is (radius of the round pin 11) + (arbitrary curve radius). Therefore, by providing a rounded portion at one end of the rounding support 12 with a radius equal to the sum of the radius of the rounding pin 11 and the radius of the rounded portion desired to be attached to the bottom of the cutting blade 20, a constant radius can be maintained on the blade of the cutting blade 20. It can be attached to the bottom.

〔effect〕

According to the configuration of the present invention, the curved shape of the knife can be configured to match the shape of the cutting blade to be polished for various types of cutting blades such as 8-blade cutting blades and 4-blade cutting blades. Therefore, by rotating the lever within a predetermined range whose movement is regulated by the corner holder, the mower blade can be adjusted by sliding the movable slider that holds the mower blade against the fixed grindstone. The surface contacts the whetstone accurately and uniformly, so each blade of the mower blade can be ground in a well-balanced manner.
In addition, by making the edge holder rotatable around an arbitrary point on the edge holder, the cutting thickness of the cutting blade can be arbitrarily changed.

In addition, by providing a rounded part on one end of the rounding holder with a radius of (rounding pin radius) + (radius of the rounded part attached to the bottom of the cutting blade), a constant radius can always be attached to the bottom of the blade. It is.

[Brief explanation of drawings]

Fig. 1 is a plan view of an embodiment of the electric polishing device for brush cutter blades of the present invention, Fig. 2 is a plan view of an 8-blade cutting blade, and Figs. 3 A to C are 8-blade cutting blades. Fig. 4 is a plan view of a four-blade cutting blade, Fig. 5A is an explanatory diagram of the polishing method.
-D and FIG. 6 are explanatory diagrams of a method for polishing a four-blade cutting blade, and FIG. 7 is an explanatory diagram of a mechanism for forming a radius on the bottom of the cutting blade. 4...Mowing blade holder, 7a, 7b...Claw, 8...Lever, 11...Nari pin, 12...Nari holder, 20...Mowing blade, 21...Whetstone.

Claims (1)

[Claims for Utility Model Registration] (1) A slider that can slide in directions that can move toward and away from the grindstone has a cutting blade receiver and a lever that have blades formed at equal intervals on the outer periphery that can rotate on the same axis. It is provided with a cutting blade attachment part to fix the cutting blade in the center position of the cutting blade receiver, and the lever and slider have a detachable mechanism that is biased in the direction of engagement with the blade part of the cutting blade receiver. In order to move the cutting blade toward and away from the fixed grindstone, a rounding holder with a curved shape that matches the shape of the cutting blade is provided on the rounding base, and a lever is provided with respect to this rounding holder. An electric polishing device for brush cutter blades, characterized in that a sharpening pin is configured to be freely engageable and detachable. (2) The brush cutter according to claim 1, wherein the brush cutter is provided with a rounded portion having a radius of (radius of the rounded pin) + (radius of the rounded portion attached to the bottom of the cutting blade) at one end of the rounded support. Electric polishing device for mower blades.