JPH0126402Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting tool that transmits power from a motor to a swinging arm via a gear and cuts a wooden board or the like using a blade attached to the swinging arm.

Common tools for cutting materials such as wood are the widely known rotating circular saw blade, reciprocating or linear motion saws, such as band saws, scroll saws, and jigsaws, all of which have a saw at the cutting edge. Cutting with a knife blade is also well known. The scale of mechanical tools that can be used for these varies, but hand tools are extremely limited. That is, they are saw cutting tools such as portable electric circular saws and electric jigsaws, and hand tools such as hand saws and work knives. In all sawing operations using these so-called portable tools, cutting chips are generated during the cutting operation, and in the case of power tools, these cutting chips are scattered considerably, deteriorating the working environment. Additionally, hand tools can be dangerous depending on how they are used, such as accidentally injuring someone when operating them. Furthermore, attempts have been made to improve this type of drawback to some extent, and power oscillating type cutting tools as shown in FIGS. 1 and 2 are also known. Figure 2 is the first
Figure shows a cross section taken along line AA. That is, an eccentric cam 3 disposed at the tip of the power shaft 2 causes the swinging arm 5 to swing from side to side about the output shaft 7 via the bearing 4.
The workpiece is cut with a saw blade 8 attached to the end of the output shaft. In this example, a part of the saw blade cuts the workpiece because it is part of the rotational motion, although it is a swinging motion, but the cutting is similar to that of the circular saw mentioned above, although the degree of cutting varies depending on the swinging angle or swinging speed. waste removal,
There is scattering. Fig. 3 is a schematic diagram of a plate material being cut with a so-called cutter knife, but the knife body 10
It is common to insert and fix the knife blade 11 inside and cut the workpiece with one hand. Therefore, the remaining hand must be used to grip and fix a part of the workpiece 12, so the knife runs along the grain of the workpiece and is forced to make an unintended cut, or in extreme cases, the workpiece cannot be gripped and fixed. There is also the risk of cutting your fingers while doing so.

An object of the present invention is to provide a cutting tool that is safe and free from the discharge and scattering of chips, without the drawbacks of the prior art described above.

The present invention focuses on the fact that when cutting with a knife-like thin blade, there is no or very minimal discharge or scattering of cutting waste, and by applying a certain type of movement using power, it can be used to cut wood, plywood, etc. It was devised to make it possible to cut relatively hard workpieces, which was impossible with thin-edged knives.

The present invention will be explained in detail with reference to FIGS. 4 to 8. FIG. 3 is a perspective view of one embodiment of the swing-type cutting tool of the present invention, and FIGS. 5 to 7 are side, plan, and front views, respectively, with some sections shown. be. A handle 22 is arranged on the upper part of the motor main body 21, and a switch 23 is housed inside the handle, as well as a power source, wiring inside the motor, etc. Gear cases 24 and 24' for housing a reduction unit and an output shaft are disposed in front of the motor, and a guide surface plate 27 is mounted below the motor body 21 and gear case 24. An eccentric cam 25 is formed on the output shaft protruding from the gear case 24 , and the eccentric cam 25 engages with the swing arm 26 via a swing bearing 35 . The swinging arm 26 is rotatable and vertically movable around swinging center supports 30 and 37. A knife-like thin blade 28 having a cutting edge in the direction of rotation is attached to the swinging arm 26 by a blade holder 29. A cutter 28 protrudes from the lower surface of the guide surface plate 27 by penetrating through a cutting edge 27a formed by cutting out a part of the guide surface plate 27. It has a cover 38 that covers these swing mechanisms. The general configuration is as described above, and its operation will be described in detail below. The motor armature within the motor body 21 has a motor shaft 39 at its rotation axis, is supported by bearings at both ends, and has a pinion 32 at its tip for rotation. There is a gear 33 that meshes with the pinion 32 and is fixed to the output shaft 34 to transmit the rotational force of the pinion 32. Bearings are installed near both ends of the output shaft to enable smooth rotation. An eccentric cam 25 is integrally or separately formed near the tip of the output shaft 34, an eccentric bearing 35 is fitted therein, and one end of a swinging arm is fitted into the outer ring portion of the eccentric cam 25. Therefore, when the motor shaft 39 rotates, the output shaft 34 rotates,
Since the eccentric cam 25 that is eccentric from this rotation center by an appropriate amount rotates, the eccentric bearing 35 swings around with an eccentric amount with respect to the axis of the output shaft 34. The swinging arm 26 has a swinging center fulcrum 37 approximately in the middle thereof, and is formed into an oblong hole. This is to enable vertical movement and rotation of the fulcrum 30 with respect to the fulcrum sliding portion 36. One end of the swinging arm 26 is connected to the eccentric cam 2 as described above.
5 and the eccentric bearing 35, it moves vertically and horizontally about the fulcrum 30, that is, it moves up and down while rocking. Therefore, the other end of the swinging arm 26 also moves in the same manner, and by attaching the knife-like thin blades 28, 28' to this, it becomes possible to swing the knife. The knife-like thin-edged blade 28 is attached to the blade holder 29 with its cutting edge lines 41 and 42 facing the swinging direction of the swinging arm 26. Further, the guide surface plate 27 has a cutting edge 27a, and a knife-like thin-edged tool is mounted so as to penetrate through the cutting edge 27a and protrude. The amount of protrusion can be arbitrarily selected. Furthermore, as shown in FIG. 7, the mounting direction can be parallel to the orthogonal line 40 that is orthogonal to the guide surface 27b of the guide surface plate 27, and if necessary, it can be mounted at an arbitrary angle α or The shape of the cutter holder 29 is adjusted so that it can be tilted by β. The direction of the cutting reaction force when cutting the material can be selected by the swing direction and the direction of the cutting edge line.
This is also to enable selection of the direction of the burr during cutting. However, depending on the conditions of the workpiece, etc., it is of course possible to provide a tool according to the present invention by fixing it without having to select it arbitrarily.

As mentioned above, the cutting tool of the present invention has a knife-like thin blade attached to the swinging arm, which is a tool support that generates vertical motion at the same time as swinging motion, and has a guiding surface plate, so that the cutting tool can be guided and fixed. Since it protrudes from the plate, the cutting edge continuously bites into the workpiece by moving the guide surface plate into contact with the upper surface of the workpiece and moving it forward or backward. The workpiece is cut as if a hand-held craft knife were biting into the workpiece with the force of the hand. From the perspective of improving cutting efficiency, if you move the blade up and down, rather than just biting, the cutting speed will double compared to a simple swing motion. be.

In addition, the cutlery in the embodiment of the present invention is
Although only a knife-like thin-edged blade 28 has been described, the scope is not limited to whether it is a general work knife or a specially made blade; however, the conventional example shown in FIG. It is preferable to use a blade such as the so-called cutter knife described in .
This is because the cost is low due to mass production, it is extremely easy to obtain, and it is possible to easily create a new cutting edge by breaking off the worn portion.

In addition to the above-mentioned embodiments, a knife-like thin-edged tool 28
If it is a double-edged type with a cutting edge line at the front and back of one cutting object, it is possible to use the front and rear cutting edges, thereby doubling the cutting capacity and doubling the economic efficiency. .

In addition, when installing the cutter shown in FIG.
However, the blades are not necessarily attached to one piece; one side has an angle of α, the other side has an angle of β, and each blade is attached with the edge line on the opposite side. It is also effective and within the scope of the present invention to perform the cutting operation by. This is because, after cutting is progressed with one blade, the other blade can be used to cut on the return trip. Furthermore, in this case, the cutting groove cut by the front blade can be used as a guide to support lateral vibration or lateral force applied to the blade, so the cutting line can be made straighter.

According to the present invention, motor power is transmitted to the output shaft via a gear, an eccentric cam is disposed on the output shaft, one end of the swing arm is engaged with the eccentric cam, a swing center fulcrum is provided, and the swing arm is engaged with the eccentric cam. dynamic motion or adding vertical motion to this,
A knife-like thin blade is attached to the other end, and it protrudes from the cutting edge of the guide surface plate, and the cutting edge line of the knife is arranged in the swinging direction, and the cutting edge line is in the front and back direction with respect to the orthogonal line that is perpendicular to the guiding surface plate surface. Because it can be attached to any angle, the knife-like thin blade can be used to cut wood boards, plywood, gypsum boards, fiberboards, and other materials that conventionally generate and scatter cutting chips. Therefore, it is possible to provide a cutting tool that is efficient, minimizes the generation of debris during cutting, and makes it possible to significantly improve the processing environment. In addition,
Because it is possible to use hand tools such as katsuta knife blades, which are extremely readily available compared to conventional processing methods,
This makes it possible to perform cutting work at low cost and without the risk of cuts.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing a conventional example of an oscillating cutting tool, and FIG. 2 is a sectional view taken along the line AA in FIG. FIG. 3 is a perspective view showing cutting with a hand tool, a knife cutter. FIG. 4 is a perspective view showing one embodiment of the cutting tool according to the present invention, and FIGS. 5 to 7 are a left side view, a top view, and a front view, respectively, including similar partial sections. FIG. 8 is a partially enlarged view of section A in FIG. 7. In the figure, 21 is a motor main body, 27 is a guide surface plate, 27a is a cutting edge, 28 is a knife-like thin blade,
25 is an eccentric cam, 26 is a swinging arm, 30 is a fulcrum, 3
3 is a gear, 34 is an output shaft, 37 is a swing center fulcrum,
39 is a motor shaft.

Claims (1)

[Scope of utility model registration request] An eccentric cam is disposed on the output shaft that transmits power by decelerating the motor shaft and a gear, and a knife-like thin blade is held on a swinging arm that engages with the eccentric cam. A swinging tool protruding downward from a guide plate installed on the lower surface, the knife-like thin-edged cutting tool having a cutting edge facing in the direction of swinging movement of the swinging arm.