JP2001347502A - Reciprocating saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reciprocating saw wherein the number of parts of a power transmission mechanism is decreased, its structure is simplified, its assembly and deassembling are made easy, its miniaturization and making light weighted are effectively achieved, and vibration can be suppressed from being generated. SOLUTION: A reciprocating saw is equipped with a plunger P which is linearly reciprocatively arranged and has a saw blade S freely detachably attached, a motor M for driving that, and a power transmission mechanism TM for transmitting power of the motor M to the plunger P by connecting its output shaft Ma to the plunger P to convert rotary motion of the output shaft Ma of the motor M to linearly reciprocative motion. The power transmission mechanism TM is fitted to a gear G which is driven by an output shaft Ma of the motor M and has an oval guide groove 9 and the plunger P, and contains a plunger guide member 10 which is fitted to the plunger P and movably inserted into the guide groove 9 along the groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating saw such as a jigsaw.

[0002]

2. Description of the Related Art Generally, a reciprocating saw such as a jigsaw is disposed so as to be capable of linearly reciprocating movement, a plunger to which a saw blade is detachably attached, a motor for driving the plunger, an output shaft of the motor and the plunger. And a power transmission mechanism that converts the rotational motion of the output shaft of the motor into a linear reciprocating motion and transmits the power of the motor to the plunger.

Japanese Utility Model Laid-Open Publication No. Sho 62-182701 discloses a reciprocating saw of this type. The power transmission mechanism is driven by an output shaft of a motor and has a gear having an eccentric portion, and a gear integrated with the gear. , A pin attached to the weight holder at a position eccentric from the center of rotation, a connector provided on a plunger arranged to be able to reciprocate linearly, and a metal attached to the connector and receiving the pin. And a bush.

[0004]

However, in the above-mentioned conventional reciprocating saw, the power transmission mechanism has a large number of parts and its structure is complicated, so that it is not easy to assemble and disassemble, and the size is reduced. It has been difficult to effectively reduce the weight. Also, since the gear has an eccentric part,
A balanced smooth rotation is not possible, which results in inappropriate vibrations.

An object of the present invention is to reduce the number of parts of a power transmission mechanism, simplify its structure, facilitate assembly and disassembly, and effectively reduce its size and weight. An object of the present invention is to provide a reciprocating saw capable of suppressing generation of vibration.

[0006]

In order to solve the above-mentioned problems, the present invention according to claim 1 comprises a plunger (P) which is arranged so as to be able to reciprocate linearly and to which a saw blade (S) is detachably attached. , A motor (M) for driving the plunger (P), an output shaft (Ma) of the motor (M) and the plunger (P) are connected to each other, and the output shaft (Ma) of the motor (M) is connected. ) Is converted into a linear reciprocating motion, and a power transmission mechanism (TM) for transmitting the power of the motor (M) to the plunger (P). ) Is driven by the output shaft (Ma) of the motor (M) and is mounted on the gear (G) having an oval guide groove (9) and the plunger (P), and the guide groove (9) Is movably inserted along this The plunger guide member (10)
And characterized in that:

According to a second aspect of the present invention, in the reciprocating saw of the first aspect, the balance weight is arranged so as to extend in a moving direction of the plunger (P) and to be capable of reciprocating along a straight line passing through the center of gravity. (W), the balance weight (W) is movably inserted into the guide groove (9) of the gear (G) along the guide groove (9), and the balance weight (W) is connected to the plunger. It has a balance weight guide member (11) for moving in the direction opposite to the movement direction of (P).

According to a third aspect of the present invention, in the reciprocating saw of the second aspect, the weight of the balance weight (W) is substantially equal to the total weight of the plunger (P) and the saw blade (S). It is the same.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A reciprocating saw according to an embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

The reciprocating saw of the present invention comprises a casing C, a plunger P, a motor M, a power transmission mechanism TM, and a balance weight 15.

The casing C comprises a casing body Cb,
And a handle portion Ch. The casing C is divided at an appropriate position. That is, the casing C
Consists of two halves which are screwed together in combination. A platen (not shown) is detachably attached to the lower end of the casing C.

The casing main body Cb has a plurality of ribs therein, and the motor housing 1 and the power transmission mechanism housing 2 are formed in the casing main body Cb by these ribs. In the power transmission mechanism housing part 2, a holder housing part 3 is provided at a part on the handle part Ch side, while, at a part away from the handle part Ch,
A pair of upper and lower bush storage portions 4 and 5 are formed at an interval from each other. These bush storage sections 4 and 5 are provided along a single vertical straight line as shown in FIG. In the lower bush storage section 4,
The metal bush 12 for the plunger is incorporated, while
A metal bush 13 for balance weight is incorporated in the upper bush storage section 5.

As shown in FIG. 1, the plunger P penetrates the plunger metal bush 12 and is supported by the casing C so as to be movable in the vertical direction. The plunger P projects coaxially upward from its upper end,
It has a guide shaft 14 having an outer diameter smaller than its upper end. A saw blade S is detachably attached to a lower end of the plunger P via a fixing device (not shown).

The motor M is fixed to the motor housing 1. The output shaft Ma of the motor M has a pinion Max at the tip.
The pinion Max penetrates through the rib of the casing body Cb and is located in the power transmission mechanism housing 2.

A holder 7 is attached to the holder storage section 3 of the casing body Cb. A bearing 6 is mounted on the holder 7 and rotatably supports an output shaft Ma of the motor M.

A spindle 8 is mounted on the holder 7 at a position above the bearing 6. The spindle 8 protrudes in parallel with the output shaft Ma of the motor M.

The power transmission mechanism TM includes a gear G and a plunger guide member 10. The gear G is rotatably supported by the spindle 8 so as to mesh with a pinion Max of the output shaft Ma of the motor M. FIG.
As is clear from FIG. 5, the gear G has an oval guide groove 9 on one end face thereof, that is, the end face on the plunger P side. The center of the elliptical guide groove 9 coincides with the center axis of the spindle 8, and the guide groove 9 is not only symmetrical with respect to the straight line corresponding to its major axis, but also the straight line corresponding to its minor axis. Is also line symmetric.

The plunger guide member 10 includes a plunger P
And a pin protruding toward the gear G side at the upper end of the gear. The pin 10 is movably inserted along the guide groove 9 of the gear G.

As shown in FIG. 1, the balance weight W penetrates through the metal bush 13 for balance weight and is supported by the casing C so as to be movable in the vertical direction. A guide hole 15 is formed in the balance weight W so as to penetrate the balance weight W in the axial direction, and an upper portion of the guide shaft 14 of the plunger P is slidably inserted into the guide hole 15.

Accordingly, the plunger P is slidably supported by the casing C via the plunger metal bush 12, while the balance weight W is slidably supported by the casing C via the balance weight metal bush 13. Moreover, since the guide shaft 14 of the plunger P is slidably inserted into the guide hole 15 of the balance weight W, smooth and stable vertical linear movement of the plunger P and the balance weight W is ensured. .

The balance weight W has a balance weight guide member 11. The balance weight guide member 11 includes a pin provided at the lower end of the balance weight W so as to protrude toward the gear G. The pin 11 is movably inserted along the guide groove 9 of the gear G.

As described above, the smooth and stable vertical linear movement of the plunger P and the balance weight W is ensured. As a result, the pin 10 as the plunger guide member inserted into the guide groove 9 of the gear G and the balance The pin 11 as a weight guide member moves linearly along a vertical reference line L passing through the center axis of the spindle 8.

In the embodiment described above, the weight of the balance weight W is substantially the same as the total weight of the plunger P and the saw blade S, and the center of gravity of the balance weight W, and the plunger P and the saw blade S The center of gravity of the assembly is located on the reference line L.

Next, the operation of the above-mentioned reciprocating saw of the present invention will be described below.

First, when the motor M is driven by operating a switch (not shown) of the reciprocating saw, the power of the motor M is reduced to a gear G via a pinion Max formed on its output shaft Ma. Transmitted to the gear G
Rotates at an appropriate speed. This gear G is not provided with an eccentric portion as in a conventional reciprocating saw, but is merely provided with a guide groove 9. That is, a stable balance of the gear G is ensured, a balanced and smooth rotation is enabled, and no improper vibration is caused.

With the rotation of the gear G, the plunger P and the balance weight W linearly reciprocate along the reference line L. This linear reciprocation will be described in detail below with reference to FIGS.

FIG. 3B shows a state where the major axis of the guide groove 9 in the gear G coincides with the reference line L.
(A) shows the respective positions of the plunger P and the balance weight W in this state. When the guide groove 9 is placed in the state shown in FIG. 3B, the plunger guide member 10 is placed at the lowest point in the linear reciprocating stroke, and as a result, the plunger P is located at the bottom dead center.
On the other hand, the balance weight guide member 11 is placed at the highest point in the linear reciprocating movement stroke, and as a result, the balance weight W is located at the top dead center.

From the state described above, the gear G is shifted clockwise by 90 degrees.
When rotated by degrees, the major axis of the guide groove 9 in the gear G is orthogonal to the reference line L, as shown in FIG. At this time, the plunger guide member 10 is located at the highest point in the linear reciprocating stroke, and as a result, the plunger P is located at the top dead center. On the other hand, the balance weight guide member 11 is located at the lowest point in the linear reciprocating stroke, and as a result, the balance weight W is located at the bottom dead center.

That is, when the gear G rotates clockwise from the state shown in FIG. 3B to the state shown in FIG.
As shown in FIG. 3A, the plunger P rises in the direction of arrow U from the bottom dead center to the top dead center, while the balance weight W moves in the direction of arrow D from the top dead center to the bottom dead center. Descends.

Similarly, when the gear G is further rotated clockwise by 90 degrees from the state shown in FIG. 4B to the state shown in FIG. 3B, as shown in FIG. , The plunger P descends in the direction of arrow D from the top dead center to the bottom dead center, while the balance weight W rises in the direction of arrow U from the bottom dead center to the top dead center.

By repeating the above-mentioned movement, the plunger P reciprocates linearly, while the balance weight W reciprocates linearly in the direction opposite to the moving direction of the plunger P. As a result, the saw blade S also moves reciprocally in a straight line, thereby enabling cutting of a workpiece (not shown).

As described above, the weight of the balance weight W is substantially the same as the total weight of the plunger P and the saw blade S, and the center of gravity of the balance weight W and
The center of gravity of the assembly of the plunger P and the saw blade S is located on the reference line L. Therefore, the kinetic energy of the plunger P and the saw blade S is offset by the kinetic energy of the balance weight W, and inappropriate vibration caused by the linear reciprocation of the plunger P and the saw blade S is effectively suppressed. Further, as described above, the gear G is not provided with an eccentric portion as in the conventional reciprocating saw, and is merely provided with the guide groove 9, so that a stable balance of the gear G is secured. As a result, balanced and smooth rotation is possible, and no improper vibration is caused. The power transmission mechanism T
The structure of M can be simplified, the reciprocating saw can be easily assembled and disassembled, and the size and weight can be effectively reduced.

In the above embodiment, the saw blade S
Is set to 11.5 mm, but this stroke is determined by the ratio of the major axis to the minor axis in the guide groove 9 of the gear G. Therefore, the stroke of the saw blade S can be changed by changing the ratio. In this case, a plurality of gears G having guide grooves 9 having different ratios of the major axis and the minor axis may be prepared, and the gears G may be selectively used according to the desired stroke of the saw blade S.

In the above-described embodiment, the guide groove 9 of the gear G has been described as having an oval shape. However, any shape that is point-symmetric with respect to the rotation center of the gear G can be adopted. is there.

In the above embodiment, the plunger P has the guide shaft 14 and the balance weight W is slidably mounted on the guide shaft 14. However, the guide shaft 14 is not necessarily provided with the guide shaft 14. It is not necessary, especially when the linear reciprocating stroke of the plunger P and the balance weight W is relatively short, the plunger P and the balance weight W can be moved without providing the guide shaft 14.
The metal bush 12 for plunger and the metal bush 13 for balance weight may be slidably supported respectively.

[0036]

According to the reciprocating saw of the first aspect of the present invention,
A power transmission mechanism includes a gear driven by an output shaft of the motor and having an oval guide groove, and a plunger guide member mounted on the plunger and movably inserted into and along the guide groove. Therefore, there is no need to provide an eccentric portion as in the conventional reciprocating saw, and a stable balance of the gears is ensured, a balanced and smooth rotation is possible, and no inappropriate vibration occurs. Further, the structure of the power transmission mechanism can be simplified, the reciprocating saw can be easily assembled and disassembled, and the size and weight can be effectively reduced.

In the reciprocating saw according to the present invention, a balance weight extending in the moving direction of the plunger and reciprocally movable along a straight line passing through the center of gravity of the plunger is further provided. If the balance weight is provided with a balance weight guide member which is movably inserted along the guide groove of the gear and moves the balance weight in a direction opposite to the movement direction of the plunger, the plunger and the saw blade Inappropriate vibration caused by the linear reciprocating movement of can be effectively suppressed.

In the reciprocating saw according to the present invention, if the weight of the balance weight is made substantially the same as the total weight of the plunger and the saw blade, the above-described effect of suppressing vibration can be reduced. Can be even higher.

[Brief description of the drawings]

FIG. 1 is a partial schematic cross-sectional view of a reciprocating saw of the present invention.

FIG. 2 is a right side view of a gear in the reciprocating saw of the present invention.

FIG. 3 is a diagram showing a state in which the plunger is located at the bottom dead center and the balance weight is located at the top dead center in the reciprocating saw of the present invention.

FIG. 4 is a diagram showing a state in which the plunger is located at the top dead center and the balance weight is located at the bottom dead center in the reciprocating saw of the present invention.

[Explanation of symbols]

 P Plunger S Saw blade M Motor Ma Output shaft TM Power transmission mechanism G Gear 9 Guide groove 10 Plunger guide member W Balance weight 11 Balance weight guide member

Claims (3)

[Claims] 1. A plunger, which is disposed so as to be capable of linear reciprocating movement, and to which a saw blade is detachably attached, a motor for driving the plunger, and an output shaft of the motor and the plunger are connected to each other. A reciprocating saw having a power transmission mechanism for converting the rotational motion of the output shaft into a linear reciprocating motion and transmitting the power of the motor to the plunger, wherein the power transmission mechanism is driven by the output shaft of the motor. A reciprocating saw comprising: a driven gear having an elliptical guide groove; and a plunger guide member mounted on the plunger and movably inserted into and along the guide groove. And a balance weight extending in a movement direction of the plunger and reciprocally movable along a straight line passing through the center of gravity of the plunger, wherein the balance weight is provided in the guide groove of the gear. The balance weight guide member according to claim 1, further comprising a balance weight guide member movably inserted along the direction to move the balance weight in a direction opposite to a movement direction of the plunger. Reciprocating saw. 3. The reciprocating saw according to claim 2, wherein the weight of the balance weight is substantially the same as the total weight of the plunger and the saw blade.