JP2002079417A - Cutting mechanism of saber saw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low vibration saber saw capable of orbital cutting regardless of the securing direction of a blade 27. SOLUTION: Orbital cutting motion can be given to the blade 27 regardless of the securing direction of the blade 27 by providing a plurality of orbit faces 31a and 31b for controlling the reciprocating locus of a plunger 20 with the faces 31a and 31b engaged with a part of the plunger 20 properly in a balance weight 31 which reciprocates in the phase reverse to that of the plunger 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the construction of houses and buildings,
The present invention relates to a saver saw cutting mechanism for cutting wood, steel, pipes, and the like in equipment, remodeling, demolition work, and the like.

[0002]

2. Description of the Related Art There is a saver saw as a reciprocating cutting tool driven by an electric motor. As is well known, a saver saw generally reciprocates a reciprocating shaft (hereinafter, referred to as a plunger) equipped with a linear saw blade (hereinafter, referred to as a blade) and cuts the blade with the blade.

[0003] In the saver saw, a plunger is simply reciprocally driven to perform cutting, and a plunger is reciprocated and simultaneously provided with a swinging operation in a vertical direction so that the blade is vigorously bitten into the material to be cut. Some are designed to improve efficiency. Such a mode in which the blade 27 is driven and cut by a combined operation of the reciprocating motion and the swinging motion is referred to as orbital cutting. As a conventional example of a saver saw provided with an orbital cutting mechanism as described above, U.S. Pat.
No. 30983), No. 3461732, etc., which are particularly effective for improving the cutting efficiency in cutting work of a relatively soft material such as wood.

Some saver saws are provided with a balance weight that reciprocates in a phase opposite to the reciprocating motion of the plunger in order to suppress the axial vibration of the plunger generated by the reciprocating plunger and blade. U.S. Pat. No. 5,025,562 (Japanese Patent No. 2860173) is an example of a conventional saver saw having the above-described low vibration mechanism. U.S. Pat. No. 5,555,626 and the like include a saver saw provided with the orbital cutting mechanism and the low vibration mechanism.

[0005]

As shown in FIG. 1, a saver saw is generally used with a blade 27 attached downward, but when a cutting operation is performed in a narrow place such as near a wall or a floor, FIG. In many cases, the blade 27 is used by being mounted upward as shown in FIG. When the blade is used with the blade mounted upward as described above, US Pat.
No. 120, No. 3461732, No. 5,555,626 and the like have a problem that orbital cutting cannot be performed.

A saver saw capable of imparting an orbital cutting operation irrespective of the mounting direction of the blade has been proposed and commercialized in Japanese Patent Application No. 11-67109. Further, International Patent Publication No. WO98 / 7544 proposes a saver saw having a low vibration mechanism and capable of giving an orbital cutting operation irrespective of the mounting direction of a blade, but has not been commercialized.

It is an object of the present invention to provide a saver saw that can be orbitally cut regardless of the direction in which the blade is mounted and that can be commercialized with a low vibration mechanism.

[0008]

The above object is achieved by providing a raceway surface for controlling the movement trajectory of the plunger in a direction perpendicular to the direction of reciprocation of the plunger on a balance weight that reciprocates in the opposite phase to the plunger.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. (Motor part) The electric motor 1 is built in a motor housing 2 made of resin, and a handle 3 is connected to the rear of the motor housing 2. The handle 3 has a built-in switch 4 for controlling power supply to the electric motor 1. (Deceleration unit) An aluminum inner cover 5 and a gear cover 6 containing a power transmission unit described below are connected to the front of the motor housing 2. A drive gear 8 is formed at the end of the motor shaft 7, and a driven gear 10 is attached to a second shaft 9 provided in parallel with the motor shaft 7, and the electric motor 1 is driven by the pair of reduction gears 8 and 10. 9 is driven to rotate. The second shaft 9 has a plunger 20 and a balance weight 31.
The first inclined shaft portion 9a and the second inclined shaft portion 9 each having a predetermined angle in opposite phases with respect to the axis of the driven gear 10 so as to be able to reversely move (movement having a phase different by 180 °).
b is formed, and a sub shaft 11 concentric with the axis of the driven gear 10 is attached to the tip. The motor housing 2, the inner cover 5, and the gear cover 6 constitute the housing of the present invention. (Reciprocating shaft holding portion) Two shaft bolts 12 are attached to the front of the gear cover 6, and a guide sleeve 13 is attached to the tip of the shaft bolt 12 so as to swing about the axis of the shaft bolt 12. (FIG. 4). Guide sleeve 13
A rectangular through hole 14 is formed at the rear end of the electric motor 1 side, and a change shaft 15 that is rotatably mounted through the inner cover 5 passes through the rectangular through hole 14 of the guide sleeve 13. (FIG. 5). At the center of the change shaft 15, a symmetrical flat portion 15a is formed in a range larger than the diameter of the guide sleeve 13. By rotating the change shaft 15 by the change lever 16, the swing of the guide sleeve 13 is selectively allowed. Or they can be deterred. FIG. 5 shows a state in which the swing of the guide sleeve 13 is allowed. (Rotation-reciprocation conversion part of plunger) A first reciprocating plate 18 having a swing shaft 18a via two bearings 17 is provided on a first inclined shaft 9a of the second shaft 9.
Is installed. A spherical portion 18b is formed at the tip of the swing shaft portion 18a. A bearing metal 19 is press-fitted into the front inside of the guide sleeve 13.
A plunger 20 is mounted so as to reciprocate therethrough. The guide sleeve 13 is located behind the plunger 20.
A large-diameter portion 20a that slides with a small gap is provided on the inner periphery of the large-diameter portion, and a hole 20b is provided in the large-diameter portion 20a at right angles to the axial direction. Swing shaft 18 of first reciprocating plate 18
a penetrates the plunger 20 and the spherical portion 18b at the tip is rotatably engaged with the inside of the hole 20b with a small gap, and converts the rotational movement of the second shaft 9 into a reciprocating movement of the plunger 20. (Balance weight holding unit) The balance weight 31
The two guide shafts 33 are supported so as to reciprocate in the same direction as the plunger 20. Guide shaft 33
Both ends are fixed to the inner cover 5 and the gear cover 6, respectively. The balance weight 31 is the guide sleeve 13
Are formed in a cross-sectional shape such that the center of gravity substantially coincides with the center of gravity of the plunger 20 (FIGS. 5 and 6). (Rotation-reciprocation conversion part of balance weight) A second reciprocating plate 32 having a swing shaft part 32a is attached to the inclined shaft part 9b of the second shaft 9 via a bearing 17. A spherical portion 32 is provided at the tip of the swing shaft portion 32a.
b is formed (FIG. 3). First reciprocating plate 1
8 and the second reciprocating plate 32 are each
b and 32b are attached to the second shaft 9 at an offset angle α ° so that they do not interfere with each other. The inclination angle of the first inclined shaft portion 9a and the second inclined shaft portion 9b of the second shaft 9 is set at an offset angle α ° so that the plunger 20 and the balance weight 31 can be reversed (movement having a phase difference of 180 °). It is determined by taking into account. That is, the inclination angles of the driven gear 10 with respect to the axis are set to be maximum at the position of the offset angle α °. The balance weight 31 is provided with a hole 31c, and the spherical portion 32b of the second reciprocating plate 32 is rotatably engaged with the inside of the hole 31c with a small gap. Is converted into a reciprocating motion of the balance weight 31 (FIG. 7).

In order to substantially eliminate the axial vibration of the plunger 20, the product of the mass of the balance weight 31 and the reciprocating motion (hereinafter referred to as the balance weight stroke) is calculated by multiplying the mass of the plunger 20 by the reciprocating motion (hereinafter the plunger stroke). ). (Blade holding portion) A slit 20 for inserting a blade 27 is provided at a blade mounting end portion 20c in front of the plunger 20.
d and a stepped blade locking pin 30 are provided, and blade holders 28 and 29 are provided so as to include the outer periphery of the blade mounting end 20c. The blade 27 is mounted by rotating and retracting the blade holder 28, thereby moving the stepped blade locking pin 30 to the open position, inserting the blade 27 into the slit 20d, and rotating and moving the blade holder 28 in the opposite direction. Thereby, the stepped blade locking pin 30 engages with the blade 27 and the blade 27 is fixed. Also, the blade 27
Has a structure that can be mounted upside down.
The configuration of such a blade holding portion is described in an application filed by the present applicant (Japanese Patent Application No. 11-242508), and is not directly related to the present invention, so that detailed description is omitted. (Main Body Front Holder) A resin front cover 24 is provided outside the inner cover 5, the gear cover 6, and a part of the housing 1. A base 25 for stabilizing the saver saw body with respect to the material 36 to be cut during the cutting operation is attached to the front end of the gear cover 6 so as to be able to move forward and backward by a fixed lever 26. (Swinging Cutting Mechanism) A swing roller 22 is rotatably attached to both ends of a roller shaft 21 penetrating the slot 13a extending in the axial direction of the guide sleeve 13 and the plunger 20, and the roller shaft 21 and the swing roller Reference numeral 22 is provided so as to be able to reciprocate integrally with the plunger 20 using the slot 13a as a guide. The height of the long hole portion 13 a is formed slightly larger than the shaft diameter of the roller shaft 21, and the rotation of the plunger 20 in the circumferential direction is suppressed by the guide sleeve 13 via the roller shaft 21, and the blade 27 falls down. I try to prevent it.

A track surface 3 having a length longer than the sum of the plunger stroke and the balance weight stroke in the axial direction of the plunger 20 is provided above and below the swing roller 22.
1a and 31b are formed inside the balance weight 31 as a part of a pair of long groove shapes (FIGS. 7 and 8).
Although the raceway surfaces 31a and 31b are provided with a slight inclination angle as shown in FIG. 8, this is for adjusting the swinging momentum of the plunger 20, and is not an essential requirement of the present invention.

FIG. 8 shows a state in which the change shaft 15 allows the guide sleeve 13 to swing and the plunger 20 can swing. In this state, the guide sleeve 13 can swing in a range where the swing roller 22 contacts the raceway surface 31a or 31b. That is, the balance weight 31 is
And a role of supporting the swinging motion of the guide sleeve 13 including the plunger 20. The guide sleeve 13 is set so as to swing up and down in a range of about 1.54 ° as shown in FIG. 9, but indirectly engages with the balance weight 31 via the swing roller 22. And does not directly interfere. FIG. 9 shows a state in which the rear portion of the guide sleeve 13 swings upward (solid line) or downward (dashed line). In any state, the guide sleeve 13 may contact the balance weight 31 or interfere with it. It is not shown. (Explanation of Cutting Operation by Linear Reciprocation) FIGS. 10 to 12
Shows a state in which the change shaft 15 is suppressing the swinging motion of the guide sleeve 13. At the time of the cutting operation, the pressing force F1 is applied by the operator, but the swinging motion of the guide sleeve 13 is suppressed.
There is no contact with the first raceway surface 31a or 31b.
Therefore, the blade 27 performs a simple linear reciprocating motion as indicated by the arrow in the figure. Such a cutting mode by a simple linear reciprocating motion is suitable for cutting a hard material having a large cutting reaction force such as a steel material. (Explanation of orbital cutting operation when the blade is mounted downward)
FIGS. 13 to 15 show a state in which the change shaft 15 has released the swinging motion of the guide sleeve 13 and the blade 27 is mounted downward to perform orbital cutting. During the cutting operation, a pressing force F1 is applied to the blade 27 by the operator. Then, the plunger 20 pushes down the rear end of the guide sleeve 13 about the axis of the shaft bolt 12 via the blade 27. As a result, the swing roller 22 moves on the raceway surface 31 of the balance weight 31.
It is pressed against a and reciprocates while rolling,
The guide sleeve 13 has a diameter of 0.44 ° to 1.
The blade 27 reciprocates while oscillating at an angle of 54 °, and as a result, the blade 27 draws an arc-shaped trajectory as shown by the arrow in the drawing, and orbital cutting is performed. During this time, the balance weight 31 reciprocates in a phase opposite to that of the plunger 20, and substantially eliminates the axial vibration of the plunger 20. (Explanation of orbital cutting operation when the blade is mounted upward)
16 to 18 show that the change shaft 15 has released the swinging motion of the guide sleeve 13, and the orbital cutting was performed by mounting the blade 27 upward and inverting the saver saw body as shown in FIG. The state is shown. During the cutting operation, a pressing force F2 is applied by the operator. Then, the plunger 20 pushes up the rear end of the guide sleeve 13 about the axis of the shaft bolt 12 via the blade 27 in the direction opposite to the direction shown in FIGS. As a result, the swing roller 22 is pressed against the raceway surface 31b of the balance weight 31 and reciprocates while rolling, so that the guide sleeve 13 swings at an angle of 0.44 ° to 1.54 ° as shown in the drawing. The blade 27 reciprocates while moving, and as a result, the blade 27 draws an arc-shaped trajectory as shown by the arrow in the figure, and orbital cutting is performed. During this time, the balance weight 31 reciprocates in the opposite phase to the plunger 20, and the plunger 20
The vibration in the axial direction of is almost eliminated.

[0013]

As described above, according to the present invention, the plunger, that is, the blade is reciprocated along the raceway surface provided on the balance weight, so that orbital cutting can be performed regardless of the mounting direction of the blade. In addition, the vibration becomes low and a saver saw that can be commercialized can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory side view showing a cutting mode of a saver saw.

FIG. 2 is an explanatory side view showing a cutting mode of a saver saw.

FIG. 3 is a partially sectional side view showing an embodiment of a saver saw employing the cutting mechanism of the present invention.

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

FIG. 5 is a sectional view taken along line BB of FIG. 3;

FIG. 6 is a side view showing a main part of the cutting mechanism of the present invention.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a sectional view taken along line DD of FIG. 7;

FIG. 9 is a sectional view taken along line EE of FIG. 7;

FIG. 10 is an explanatory side view showing a straight cutting locus of the cutting mechanism of the present invention, and showing a state where a blade projects most forward.

FIG. 11 is an explanatory side view showing a state in which the blade is retracted from FIG. 10;

FIG. 12 is an explanatory side view showing a state where the blade is further retracted from FIG. 11;

FIG. 13 is an explanatory side view showing an orbital cutting trajectory of the cutting mechanism of the present invention and showing a state where a blade projects most forward.

FIG. 14 is an explanatory side view showing a state where the blade is retracted from FIG. 13;

FIG. 15 is an explanatory side view showing a state where the blade is further retracted from FIG. 14;

FIG. 16 is an explanatory side view showing an orbital cutting trajectory of the cutting mechanism of the present invention, and showing a state where a blade projects most forward.

FIG. 17 is an explanatory side view showing a state where the blade is retracted from FIG. 16;

FIG. 18 is an explanatory side view showing a state where the blade is further retracted from FIG. 17;

[Explanation of symbols]

1 is an electric motor, 2 is a housing, 3 is a handle, 4 is a switch, 5 is an inner cover, 6 is a gear cover, 7 is a motor shaft, 8 is a driving gear, 9 is a second shaft, 9a
Is a first inclined shaft portion, 9b is a second inclined shaft portion, 10 is a driven gear, 11 is a sub shaft, 12 is a shaft bolt, 13 is a guide sleeve, 13a is a long hole portion, 14 is a square through hole, 15
Is a change shaft, 15a is a plane portion, 17 is a bearing, 18 is a first reciprocating plate, 18a is a swing shaft portion,
18b is a spherical portion, 19 is a bearing metal, 20 is a plunger, 21 is a roller shaft, 22 is a swing roller, 2
4 is a front cover, 25 is a base, 26 is a fixed lever, 27 is a blade, 28 is a blade holder, 29 is a blade holder, 30 is a blade locking pin, 31 is a balance weight, 31a and 31b are track surfaces, and 32 is a 2 reciprocating plate, 32a is a swing shaft portion, 32b is a spherical portion, 3
3 is a guide shaft, and 36 is a material to be cut.

Claims (5)

[Claims] 1. A housing having a motor built therein, a second shaft rotatably mounted on the housing and rotationally driven by the motor, a plunger mounted reciprocally on the housing and having a blade mounted on a tip thereof. First movement conversion means provided between the second shaft and the plunger for converting the rotational movement of the second shaft into reciprocating movement of the plunger, a balance weight attached to the housing so as to be able to reciprocate, the second shaft and the balance weight And a second motion converting means for converting the rotational motion of the second shaft into a reciprocating motion of the balance weight. The saver saw extends along the reciprocating motion direction of the plunger and is substantially parallel to the reciprocating motion direction. Forming a perfect raceway surface as a balance weight,
A saver saw cutting mechanism characterized by reciprocating a plunger along a raceway surface of a balance weight. 2. At the rear of the plunger, swing rollers are attached to both ends of a roller shaft penetrating the plunger in a direction perpendicular to the reciprocating direction of the plunger, and the swing roller is moved along the raceway surface of the balance weight. The saver saw cutting mechanism according to claim 1, wherein 3. A housing containing a motor, a second shaft rotatably mounted on the housing and rotatably driven by the motor, a plunger mounted reciprocally on the housing and having a blade mounted on a tip thereof. The plunger is held so as to be able to reciprocate, and is provided between the guide shaft mounted on the housing so as to be movable in a direction perpendicular to the direction of movement of the plunger and the second shaft and the plunger. First motion conversion means for converting into motion;
A saver saw provided with a balance weight attached to the housing so as to be able to reciprocate, and a second motion conversion means provided between the second shaft and the balance weight, for converting a rotational motion of the second shaft into a reciprocal motion of the balance weight; Forming a track surface extending in the reciprocating direction of the plunger and substantially parallel to the reciprocating direction in a balance weight;
A roller shaft extending through a slot in the guide sleeve extending in the direction perpendicular to the reciprocating motion of the plunger at the rear of the plunger and along the reciprocating direction of the plunger; A saver saw cutting mechanism, comprising: a swing roller that moves along a surface. 4. The saver saw cutting mechanism according to claim 1, wherein a plurality of raceway surfaces of the balance weight are provided above and below the plunger shaft. 5. The cutting of a saver saw according to claim 2, wherein the swing roller is pressed against a raceway surface of a balance weight by a reaction force when the blade is pressed against a workpiece. mechanism.