JPH10235602A - Blade holding device for cutting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the deflection of a blade during a cutting operation by mounting a set ring having an abutment portion adapted to be brought into abutment with the upper surface of the blade and having an inner wall forming a width slightly larger than the width of a blade mounting portion in a notched portion provided at a lower end portion of a plunger to function as a blade locking portion. SOLUTION: A knob bolt 6 is loosened that is provided on a plunger 1 in such a manner as to intersect an axial center of the plunger 1 at right angles, and a blade 5 is inserted into a notched portion 3 having a width slightly larger than the width of a blade mounting portion from a lower end direction of the plunger 1. When the knob bolt 6 is tightened, the blade 5 is held between a presser member 4 and a side wall 3a of the notched portion 3, whereby it is retained within the notched portion 3. When the blade 5 is inserted into the notched portion 3, the upper surface of the blade 5 and a side thereof confronting at right angles a cutting direction of a raised portion of the mounting portion are regulated by an abutment surface and an inner wall, this preventing the blade 5 from rotating about a tip end of the knob bolt 6 during a cutting operation. This makes it possible to mount various types of blades having mounting portions each different in configuration and size, thereby making it possible to surely prevent the deflection of the blade 5 during a cutting operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade holding device for a cutting machine such as a jigsaw and a reciprocating saw. Hereinafter, the cutting machine will be described as a jigsaw.

[0002]

2. Description of the Related Art FIG. 13 shows an example of a jigsaw provided with a blade holding device. The jigsaw reciprocates the plunger 1 up and down by a motor (not shown), and performs a cutting operation by a blade 5 attached to an end of the plunger 1. Many blades 5 are prepared according to the material and thickness to be cut, and it is necessary to replace the blade 5 each time according to the cut material. As shown in FIGS. 6 and 7, since the blades 5 have different shapes and widths of the mounting portions 11, various blades 5 having different shapes and widths can be mounted on the plunger 1. A device has been proposed.

FIGS. 14 and 15 show an example of a conventional blade holding device. At the lower end of the plunger 1, a blade locking portion 10 is provided and a bolt 12 projecting into the blade locking portion 10 and having a tip pressing the blade 5 toward the blade locking portion 10 is provided. A set piece 13 is provided on the tip side of the bolt 12 in the plunger 10.
It is fixed to. The blade 5 is attached by bolts 12
The blade 5 is inserted into the blade engaging portion 10 with the blade loosened, and the upper surface of the blade 5 is brought into contact with the blade engaging portion 1 shown in FIG.
Butt against step 9 in 0, then tighten bolt 12
This is performed by clamping the blade 5 between the tip of the bolt 12 and the set ring 13.

FIGS. 16 and 17 show the blade 5 shown in FIGS.
1 shows a blade holding device to which is attached. Blade locking part 1
Numeral 0 is a hole formed by a plurality of rotary cutting members having different diameters. Side surfaces 9a, 9b, 9c having different inner diameters are formed in the blade locking portion 10, and the side walls 9a, 9b A step 9d is formed therebetween, and a step 9e is formed between the side walls 9b and 9c. Side wall 9
6b has a width slightly larger than the width of the mounting portion 11 of the blade 5 in FIG. 6 in the blade locking portion 10, and the side wall 9c is slightly larger than the width of the projection 11a of the blade 5 in FIG. Form a large width. Also, a step 9d is provided so that the upper surface of the blade 5 in FIGS. 6 and 7 abuts. For this reason, when the blade 5 of FIG. 6 is inserted into the blade locking portion 10 until the upper surface hits the step 9d,
As shown by 6, the surface of the mounting portion 11 of the blade 5 perpendicular to the cutting direction is regulated by the side wall 9b.
The same applies to the blade 5 of FIG. 7, and the surface of the mounting portion 11 perpendicular to the cutting direction of the protruding portion 11a is regulated by the side wall 9c.

[0005] With the conventional blade holding device having the above-described structure, the blade 5 rotates around the pinching point between the bolt 12 and the set piece 13, that is, the blade 5 during cutting operation. Shake was prevented.

[0006]

The restriction of the upper surface of the blade 5 and the surface perpendicular to the cutting direction of the mounting portion 11 in the blade locking portion 10 is the same as that of the blade locking portion 10.
The inner shape must be high precision, and if the precision is low, problems such as blurring of the blade 5 during the cutting operation or inability to attach the blade 5 occur. In the above-mentioned conventional blade holding device, a hole is formed by a plurality of rotary cutting members having different diameters, and this is used as the blade locking portion 10. However, it is not possible to form the high-precision blade locking portion 10 by cutting. It is difficult and the productivity is very poor. Further, there is a limit in providing a side wall having a different inner diameter in the blade locking portion 10, and the shape and dimensions of the mounting portion 11 of the blade 5 do not correspond to the steps or side walls provided in the blade locking portion 10. In this case, there is a disadvantage that the blade 5 cannot be attached unless the plunger 1 itself is replaced. SUMMARY OF THE INVENTION An object of the present invention is to provide a blade holding device which can solve the above-mentioned drawbacks, can mount various blades having different shapes and sizes of mounting portions, and can reliably prevent the blade from being shaken during a cutting operation. .

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide a notch at the lower end of a plunger, which serves as a blade locking portion, and has an inner wall formed in the notch so as to have a width slightly larger than the lateral width of the blade mounting portion. This is achieved by attaching a set ring provided with an abutting portion having an abutting surface against which the blade upper surface abuts. Further, the present invention is achieved by forming at least one or more inner walls and abutting surfaces in the notch portions having a width corresponding to the shapes and dimensions of the mounting portions of the plurality of blades at the butting portions of the set ring. Further, this is achieved by manufacturing the set ring with a metal injection mold.

[0008]

1 and 2 show an embodiment of the blade holding device according to the present invention. FIG. 2 is a sectional view taken along line AA of FIG. As shown in the figure, a notch 3 serving as a blade locking portion is provided at the lower end of the plunger 1, and a pressing member 4 that can protrude into the notch 3 is attached. A set ring 2 having a shape covering the outer periphery of the lower end of the plunger 1 and having an abutting portion 8 protruding into the notch 3 is attached by a pin 2a. When the knob bolt 6 provided on the plunger 1 is loosened so as to be perpendicular to the axis of the plunger 1, the blade 5 is inserted into the notch 3 from the lower end of the plunger 1, and the knob bolt 6 is tightened. I do. When the knob bolt 6 is tightened, the blade 5 is pressed against the pressing member 4 and the side wall 3 of the notch 3.
a and is held in the notch 3. When removing the blade 5, it is only necessary to loosen the knob bolt 6.
When the knob bolt 6 is loosened, the pressing member 4 moves in the outer peripheral direction of the plunger 1 by the spring force of the coil spring 7.

The set ring 2 is shown in FIGS. As shown in FIG. 11, the butting portion 8 of the set ring 2 includes
Inner walls 9a, 9b, 9c are formed and inner wall 9a
A striking surface 9d is formed between the inner wall 9b and the inner wall 9b, and a striking surface 9e is formed between the inner wall 9b and the inner wall 9c. The inner wall 9b has a width slightly larger than the width of the mounting portion 11 of the blade 5 in FIG.
In FIG. 6, a width slightly larger than the width of the protruding portion 11a of the blade 5 in FIG. 6 is formed. When the blade 5 shown in FIGS. 6 and 7 is inserted into the cutout portion 3, an abutting surface 9d is formed at a position where the upper surface of the blade 5 abuts.
The reason why the width formed by the inner walls 9b and 9c in the notch 3 is slightly larger than the width of the mounting portion 11 of the blade 5 is as follows.
If the width is smaller than the width of the mounting portion 11, the blade 5 cannot be inserted into the cutout portion 3, and if the width is larger, the surface of the mounting portion 11 at right angles to the cutting direction cannot be regulated. If there is, the blade 5 cannot be easily attached and detached, and the width formed by the inner wall 9b and the inner wall 9c in the notch 3 is
It is sufficient that the blade 5 can be easily attached to and detached from the inside, and the movement of the attachment portion 11 can be restricted.

FIGS. 3 to 5 show a state in which the blade 5 shown in FIGS. 6 and 7 is attached to the blade holding device having the set ring 2 having the above-described structure. FIG. 4 shows a blade holding device holding the blade 5 of FIG. With the knob bolt 6 loosened, the blade 5 is inserted from below the plunger 1 into the notch 3 until the upper surface of the blade 5 abuts against the abutment surface 9d.
The installation of is completed. When the blade 5 is inserted into the notch 3, the upper surface and the surface perpendicular to the cutting direction of the mounting portion 11 are regulated by the abutting surface 9d and the inner wall 9b. As shown in FIG. 5, even when the blade 5 of FIG. 7 is held, when the blade 5 is similarly inserted into the notch 3, the cutting direction of the upper surface of the blade 5 and the convex portion 11 a of the mounting portion 11 is changed. The surface to the right angle is the abutment surface 9d and the inner wall 9
e. For this reason, the blade 5 does not rotate around the tip of the knob bolt 6 during the cutting operation, and the blur of the blade 5 can be prevented.

In the present embodiment, the inner walls 9b, 9 corresponding to the blades 5 shown in FIGS.
c and the abutment surface 9d are formed. However, when a blade 5 other than the blade 5 having the shape and dimensions of the mounting portion 11 shown in FIGS. 6 and 7 is used, the mounting portion 11 of the blade 5 is used.
A set ring 2 having an abutting portion 8 having an inner wall and an abutting surface corresponding to the shape and dimensions of the plunger 1 may be attached to the plunger 1. Thus, if the set ring 2 is replaced without replacing the plunger 1, various blades 5 having different shapes and dimensions of the mounting portion 11 can be mounted on the plunger 1.

The set ring 2 has a complicated shape in which the butting portion 8 is difficult to manufacture by ordinary cutting.
By manufacturing with a metal injection mold, it is possible to provide an inexpensive blade holding device with high precision, high productivity and high productivity.

Further, in the conventional blade holding device, the diameter of the plunger 1 has to be larger than the lateral width of the mounting portion 11 of the blade 5, but in the blade holding device of the present invention, the diameter of the plunger 1 is smaller than that of the blade. Even if the width of the mounting portion 11 is smaller than the width of the mounting portion 11,
It is only necessary to attach the set ring 2 having an inner wall having a width slightly larger than the width of the plunger 1 to the lower end of the plunger 1.

[0014]

According to the present invention, a notch portion serving as a blade locking portion is provided at the lower end of the plunger, and an inner wall having a width slightly larger than the width of the mounting portion of the blade is formed in the notch portion. Since the set ring with the abutting part with the abutting surface is attached, it can be attached to various blades with different shapes and dimensions of the attaching part, and reliably prevent the blade from shaking during cutting work In addition, it is possible to provide an inexpensive blade holding device with good productivity.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the blade holding device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

3 shows the blade holding device of FIG. 1 in a state where the blade of FIG. 6 is attached.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

5 shows the blade holding device of FIG. 1 in a state where the blade of FIG. 7 is attached.

FIG. 6 is a front view showing an example of a blade.

FIG. 7 is a front view showing another example of the blade.

FIG. 8 is a front view showing an embodiment of a set ring constituting the present invention.

FIG. 9 is a right side view of the set ring of FIG. 8;

FIG. 10 is a bottom view of the set ring of FIG. 8;

FIG. 11 is a sectional view taken along line CC of FIG. 8;

FIG. 12 is a sectional view taken along line EE of FIG. 9;

FIG. 13 is an overall view showing a jigsaw provided with an example of a blade holding device.

FIG. 14 is a sectional view showing an example of a conventional blade holding device.

FIG. 15 is a sectional view taken along line FF of FIG. 14;

FIG. 1 shows a state in which the blade of FIG. 6 is attached.
Blade holding device.

FIG. 17 shows a state in which the blade of FIG. 7 is attached.
Blade holding device.

[Explanation of symbols]

1 is a plunger, 2 is a set ring, 3 is a notch, 4 is a pressing member, 5 is a blade, 8 is an abutment, 9a, 9
b and 9c are the inner walls of the abutting portion, and 9d and 9e are the abutting surfaces of the abutting portion.

Claims (3)

[Claims] 1. A plunger reciprocated in an axial direction by a motor, a blade locking portion provided at a lower end portion of the plunger, and a blade having a mounting portion inserted into the blade locking portion above the blade, In a cutting machine that performs a cutting operation by a blade, a notch portion serving as a blade locking portion is provided at a lower end portion of the plunger, and an inner wall having a width slightly larger than a lateral width of a mounting portion of the blade is formed in the notch portion. A blade holding device for a cutting machine, wherein a set ring provided with an abutting portion having an abutting surface is mounted. 2. An abutting portion of the set ring, wherein at least one or more inner walls and an abutting surface are formed in the notch having a width corresponding to the shape and size of the mounting portion of the plurality of blades. The blade holding device for a cutting machine according to claim 1. 3. The blade holding device for a cutting machine according to claim 1, wherein the set ring is manufactured by metal injection molding.