JP2009154340A - Saber saw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a saber saw capable of performing orbital cutting operation irrespective of a mounting direction of a blade. <P>SOLUTION: A swing rail 23 which appropriately controls reciprocating motion trajectory of a plunger 20 by engaging with a part of the plunger 20 is mounted in the same direction as the reciprocating motion orbit of the plunger 20 and a plurality of raceway surfaces 23a, 23b of the swing rail 23 are provided on the top and bottom of the plunger 20. Consequently, the orbital cutting operation can be applied on the blade 27 irrespective of the mounting direction (upward and downward) of the blade 27 thereby. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a saver saw that cuts wood, steel, pipes, etc. in the construction, equipment, renovation, demolition work, etc. of houses and buildings.

  There is a saver saw as a reciprocating type cutting tool driven by an electric motor. As is well known, a saver saw is generally cut by a blade by reciprocating a reciprocating shaft (hereinafter referred to as a plunger) equipped with a linear saw blade (hereinafter referred to as a blade).

  In saver saws, the plunger is simply driven to reciprocate linearly, and the plunger is reciprocally driven, and at the same time the vertical swinging action is applied, and the blade is vigorously bitten into the material to be cut to improve cutting efficiency. There are things that try to plan. Such a form in which the blade 27 is driven and cut by a combined operation of reciprocating motion and rocking motion is called orbital cutting.

  FIG. 1 shows an example of a saver saw in which orbital cutting is performed. An eccentric cylindrical shaft portion 9 a is formed on the second shaft 9 that is rotationally driven by the drive gear 8, and a reciprocating plate 18 that converts rotational motion into reciprocating motion is attached to the second shaft 9. The plunger 20 with the blade 27 attached to the tip is slidably attached to the inside of a guide sleeve 13 attached to the gear cover 6 so as to be swingable about a fulcrum A, and the reciprocating plate is rotated by rotating the second shaft 9. 18 to reciprocate. A connecting plate 35 having a lower end extending downward and contacting the eccentric cylindrical shaft portion 9a is attached to the rear of the guide sleeve 13, and the rear portion of the guide sleeve 13 has a fulcrum A as a result of a cutting reaction force F1 applied to the blade 27 during cutting. The lower end of the connecting plate 35 is pressed against the eccentric cylindrical shaft portion 9a. Accordingly, the eccentric cylindrical shaft portion 9a rotates with the rotation of the second shaft 9, whereby the guide sleeve 13 is pushed up by the connecting plate 35. As a result, the plunger 20 swings up and down through the guide sleeve 13 while reciprocating. Dynamic movement.

  The movement trajectory of the blade 27 by the combined operation of the reciprocating motion and the swinging motion as described above is described in US Pat. An elliptical trajectory can be obtained. As described above, the form in which the blade 27 is driven by an elliptical trajectory and cut is called orbital cutting. As shown in FIG. 2, when the blade 27 is pulled toward the saver saw body, the blade 27 is cut by the workpiece 36. By setting the motion trajectory in the direction of biting, cutting efficiency can be remarkably improved especially in cutting work of relatively soft materials such as wood.

  The saver saw is generally used with the blade 27 mounted downward as shown in FIG. 3, but when cutting in a narrow place such as near a wall or floor, the blade 27 is directed upward as shown in FIG. Often worn and used. In this case, as shown in FIG. 5, the cutting reaction force F2 works in a direction to separate the lower end (upper end in FIG. 5) of the connecting plate 35 from the eccentric cylindrical shaft portion 9a, so that the plunger 20 cannot be swung up and down. There is a problem.

  In the saver saw described in U.S. Pat. No. 3,945,120, the components corresponding to the connecting plate 35 are pivotally integrated with the eccentric cylindrical shaft portion 9a so that the plunger 20 can be moved vertically even when the blade 27 is mounted upward. The blade 27 can be swung, and the blade 27 can draw an elliptical locus. However, since the phase angle of the eccentric cylindrical shaft portion 9a with respect to the plunger 20 is constant, as shown in FIG. 6, when the blade 27 is drawn into the saver saw body side, the blade 27 moves in a direction away from the material to be cut 36. Since orbital cutting is not possible, there is a problem that cutting efficiency cannot be improved. That is, in the conventional saver saw, there was no technical idea that orbital cutting can be performed even when the blade 27 is mounted upward.

  An object of the present invention is to eliminate the drawbacks of the above-described saver saw cutting mechanism according to the prior art and to improve the cutting work efficiency by enabling orbital cutting regardless of the blade mounting direction.

  The above object is achieved by providing a guide member having a raceway surface for controlling a motion trajectory in a direction perpendicular to the reciprocating motion direction accompanying the reciprocating motion of the plunger, and changing the reciprocating motion trajectory of the plunger.

  As described above, according to the present invention, since the plunger, that is, the blade is reciprocated along the raceway surface of the guide member, the blade can be swung according to the shape of the inclined surface, and the efficiency is further improved. Orbital cutting can be performed, and orbital cutting can be performed regardless of the mounting direction of the blade, so that the cutting work efficiency can be improved.

The present invention will be described below with reference to FIGS. 7 to 16 showing an embodiment.
(Motor) The electric motor 1 is built in a resin motor housing 2, 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.
(Decelerator) An aluminum inner cover 5 and a gear cover 6 incorporating power transmission means described below are connected to the front of the motor housing 2. A drive gear 8 is formed at the tip 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 connected to the second shaft by the pair of reduction gears 8, 10. 9 is driven to rotate. An inclined shaft portion 9a having an angle of about 14 ° with respect to the axis of the driven gear 10 is formed in front of the second shaft 9, and a subshaft 11 concentric with the axis of the driven gear 10 is attached to the tip. ing. 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 in front of the gear cover 6, and a guide sleeve 13 is attached to the tip of the shaft bolt 12 so as to be swingable around the shaft core of the shaft bolt 12. (FIG. 8). A square through hole 14 is formed at the rear end of the guide sleeve 13 on the electric motor 1 side, and a change shaft 15 that is rotatably attached through the inner cover 5 is formed in the square through hole 14 of the guide sleeve 13. (FIG. 9). A symmetric flat surface portion 15a is formed in the central portion of the change shaft 15 in a range larger than the diameter of the guide sleeve 13, and the change shaft 16 is rotated by the change lever 16 to selectively allow the guide sleeve 13 to swing. Or it can be suppressed (FIG. 9).
(Rotation-reciprocation conversion portion) A reciprocating plate 18 having a swinging shaft portion 18 a is attached to the inclined shaft portion 9 b of the second shaft 9 via two bearings 17. 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, and a plunger 20 is attached so as to reciprocate through the bearing metal 19. A large-diameter portion 20a that slides with a slight gap is provided on the inner periphery of the guide sleeve 13 behind the plunger 20, and a hole portion 20b is provided in the large-diameter portion 20a at a right angle to the axial direction. The swinging shaft portion 18a of the reciprocating plate 18 penetrates the plunger 20, and the spherical portion 18b at the tip is engaged with the inside of the hole portion 20b so as to be able to roll with a slight gap. Convert to 20 reciprocating motions.
(Blade holding portion) A blade mounting end 20c in front of the plunger 20 is provided with a slit 20d for inserting the blade 27 and a stepped blade locking pin 30, and the blade is attached so as to contain the outer periphery of the blade mounting end 20c. Holders 28 and 29 are provided. The blade 27 can be mounted by rotating the blade holder 28 backward to move the stepped blade locking pin 30 to the open position so that the blade 27 can be inserted into the slit 20d, and the blade holder 28 is rotated forward in the opposite direction. Thus, the stepped blade locking pin 30 engages with the blade 27 and the blade 27 is fixed. The blade 27 can be mounted upside down. The configuration of such a blade holding portion is described in the applicant's application (Japanese Patent Application No. 10-301923) and is not directly related to the present invention, and therefore detailed description thereof is omitted.
(Main body front holding portion) A resin-made front cover 24 is provided outside the inner cover 5, the gear cover 6, and a part of the housing 1. A base 25 that stabilizes the saver saw body against the material to be cut 36 during a cutting operation is attached to the front end portion of the gear cover 6 by a fixing lever 26 so as to be able to advance and retract.
(Oscillating cutting mechanism portion) In FIGS. 10 to 11, swing rollers 22 are rotatably attached to both ends of a roller shaft 21 penetrating a long hole portion 13a extending in the axial direction of the guide sleeve 13 and the plunger 20. The roller shaft 21 and the swing roller 22 are provided so as to be able to reciprocate integrally with the plunger 20 using the elongated hole portion 13a as a guide. The height of the elongated hole portion 13a is slightly larger than the shaft diameter of the roller shaft 21, and the circumferential rotation of the plunger 20 is suppressed by the guide sleeve 13 through the roller shaft 21, thereby preventing the blade 27 from falling. Like to do.

  Above and below the swing roller 22, a swing rail 23 constituting the guide member of the present invention having inclined surfaces 23 a and 23 b having a length equal to or longer than the reciprocating motion amount (hereinafter referred to as stroke amount) of the plunger 20 in the axial direction of the plunger 20 It is fixed and attached by being sandwiched between the cover 5 and the gear cover 6. Further, the front end portion of the swing rail 23 is vertically connected and integrated. By reciprocating the swing roller 22 along the upper or lower inclined surfaces 23a, 23b, the plunger 20 is 1.44 up and down around the axis of the shaft bolt 12 shown in FIG. Oscillates at an angle of °. Since the swing roller 22 is integrated vertically as described above and is sandwiched between the inner cover 5 and the gear cover 6, the assemblability is improved and the configuration is simplified. In addition, since the plunger 20 and the like reciprocate via the swing roller 22, the life can be improved.

  11 and 12, the flat portion 15a of the change shaft 15 coincides with the axial direction of the plunger 20 as shown, the guide sleeve 13 is in an open state in which swinging motion is possible, and the swing roller 22 is swinging. The rail 23 can reciprocate while rolling along the inclined surface 23a or the inclined surface 23b.

FIG. 13 shows the movement of the blade 27 at this time. That is, when the swing roller 22 is rolled along the inclined surface 23 a as shown in FIG. 11, the blade 27 moves as indicated by an arrow E. When the swing roller 22 is rolled along the inclined surface 23b as shown in FIG. 12, the blade 27 moves as indicated by an arrow F. Therefore, as shown in FIG. 13, regardless of the mounting direction of the blade 27, the blade 27 can be moved in a direction that vigorously bites into the material to be cut 36 when the blade 27 is pulled into the saver saw body side. That is, orbital cutting is possible regardless of the mounting direction of the blade 27. 11 and 12, two roller shafts 21 and swing rollers 22 are shown, but this shows a state in which these shafts 21 and rollers 22 are positioned at both ends of the reciprocating direction, and actually there is only one. It is.
(Description of Oscillating Cutting Operation) FIGS. 14 to 16 illustrate the relationship between the movement of each part and the force in actual cutting. FIG. 14 shows that the change shaft 15 suppresses the oscillating motion of the guide sleeve 13. Indicates the state. Therefore, the blade 27 performs a simple linear reciprocating motion as indicated by arrows in the figure. The cutting form by such simple linear reciprocating motion is suitable for cutting a hard material having a large cutting reaction force such as a steel material.

  FIG. 15 shows a state where the blade 27 is mounted downward and orbital cutting is performed. At the time of cutting, a pressing force F3 is applied by the operator. At this time, the blade 27 receives a cutting reaction force F4 from the material to be cut, and the plunger 20 pushes down the rear end portion of the guide sleeve 13 around the shaft core of the shaft bolt 12. As a result, the swing roller 22 is pressed against the inclined surface 23a of the swing rail 23 and reciprocates while rolling, so that orbital cutting is performed.

  FIG. 16 shows a state where the blade 27 is mounted upward and orbital cutting is performed. In this state, when a pressing force F5 is applied by the operator during cutting, the blade 27 receives a cutting reaction force F6, contrary to the case of FIG. Accordingly, the swing roller 22 is pressed against the inclined surface 23b of the swing rail 23, contrary to the case of FIG. 15, and reciprocates while rolling, so that orbital cutting is performed.

  According to the above-described embodiment, the plunger 20, that is, the blade 27 is reciprocated along the raceway surface, that is, the inclined surfaces 23 a and 23 b of the swing rail 23, so that the blade 27 is swung according to the shape of the inclined surface. Thus, more efficient orbital cutting is possible, and orbital cutting is performed regardless of the mounting direction of the blade 27, so that the cutting efficiency can be improved.

  17 and 18 show another embodiment of the present invention, in which the inclined surface of the swing rail 23 is made different in the vertical direction. The inclined surfaces 23c and 23d are each formed in a saw-like shape and a waveform. As a result, the blade 27 draws a movement locus as shown in FIG. 18 with respect to each inclined surface. In any movement trajectory, a shocking cutting force can be applied to the blade 27, which is suitable for cutting a hard and brittle ceramic plate or the like. In this manner, the inclined surface of the swing rail 23 can be arbitrarily changed to a shape suitable for the material to be cut 36, and can be inclined surfaces having different shapes in the upper and lower sides.

  19 and 20 show another embodiment of the swing cutting mechanism. A protrusion 33 is provided at the rear end portion of the plunger 20, and the protrusion 33 protrudes vertically from a long hole portion 32 that extends in the axial direction at the rear portion of the guide sleeve 31. A swing rail 34 that extends in the axial direction on a raceway surface, that is, an inclined surface, with which the projection 33 contacts, is sandwiched and attached to the inner cover 5 and the gear cover 6. According to this embodiment, orbital cutting can be performed with a simple configuration as in the above embodiment, and a small and lightweight saver saw can be provided at low cost.

The principal part cross-sectional side view which shows an example of the conventional saver saw. The side view for description which shows the orbital cutting locus of the saver saw of FIG. The side view which shows the cutting | disconnection form of a saver saw. The side view which shows the cutting | disconnection form of a saver saw. The principal part cross-sectional side view which shows the example of a cutting | disconnection of the saver saw of FIG. The side view for description which shows the orbital cutting locus at the time of the cutting | disconnection of FIG. The partial cross section side view which shows one Embodiment of the saver saw which employ | adopted this invention cutting mechanism. BB sectional drawing of FIG. The DD sectional view taken on the line of FIG. CC sectional view taken on the line of FIG. The side view which shows the principal part of this invention cutting mechanism. The side view which shows the principal part of this invention cutting mechanism. The side view for description which shows the orbital cutting locus of this invention cutting mechanism. The side view which shows the example of a cutting | disconnection by this invention cutting mechanism. The side view which shows the example of a cutting | disconnection by this invention cutting mechanism. The side view which shows the example of a cutting | disconnection by this invention cutting mechanism. The side view which shows other embodiment of the guide member which comprises this invention cutting mechanism. The side view for description which shows the orbital cutting locus by the guide member of FIG. Sectional drawing equivalent to FIG. 10 which shows other embodiment of this invention cutting mechanism. The partial cross section side view of FIG.

Explanation of symbols

1 is an electric motor, 2 is a housing, 5 is an inner cover, 6 is a gear cover, 9 is a second shaft, 9a is an eccentric cylindrical shaft portion, 12 is a shaft bolt, 13 is a guide sleeve, 15 is a change shaft, 18 is a reciprocating plate, 20 is a plunger, 21 is a roller shaft, 22 is a swing roller, 23 is a swing rail, 27 is a blade, and 36 is a material to be cut.

Claims (7)

A housing containing a motor;
Rotatably mounted to the housing, and a second shaft which is rotated by the motor,
Reciprocable as mounted to the housing, a plunger blade is attached to the tip,
The plunger is reciprocally retained, a guide sleeve attached to the housing to be movable in the direction of motion perpendicular to the direction of the plunger,
In saber saw and a motion conversion means provided between said second shaft and said plunger for converting rotary motion of the second shaft into a reciprocating motion of the plunger,
Has a raceway surface extending along a reciprocating direction of the plunger, a guide member attached to said housing,
A roller shaft extending through the elongated hole of the guide sleeve extending along a reciprocating direction of the plunger and the plunger in the direction of reciprocating motion perpendicular to the direction of the plunger at the rear of the plunger,
Attached to both ends of the roller shaft, a swing roller to move along the raceway surface of the guide member,
A saver saw comprising: means for selectively allowing or inhibiting movement of the guide sleeve .   The saver saw according to claim 1, wherein a plurality of the guide members are provided vertically.   The saver saw according to claim 2, wherein one end of the guide member in the longitudinal direction is joined to form a vertically integrated guide member. Said guide member, saber saw according to claim 3, characterized in that to attach to sandwich the inner cover and the gear cover constituting the housing.   The saver saw according to claim 1, wherein the height of the elongated hole of the guide sleeve is formed to be slightly larger than the diameter of the roller shaft.   The saver saw according to claim 1, wherein a raceway surface of the guide member has a sawtooth shape or a corrugated shape.   3. The saver saw according to claim 2, wherein the upper and lower raceway surfaces of the guide member have different shapes.

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