JP3988370B2 - Saver saw - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
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.
[0002]
[Prior art]
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).
[0003]
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. US Pat. Nos. 3,945,120 (Japanese Patent Laid-Open No. 51-130983), US Pat. No. 3,461,732, etc., are conventional examples of saver saws equipped with the orbital cutting mechanism as described above. Particularly, cutting work of relatively soft materials such as wood. This is effective for improving the cutting efficiency.
[0004]
Some saver saws are provided with a balance weight that reciprocates in the opposite phase to the reciprocating motion of the plunger in order to suppress vibration in the plunger axis direction generated by the reciprocating plunger and blade. US Pat. No. 5,025,562 (Japanese Patent No. 2,860,173) or the like is a conventional example of a saver saw equipped with the low vibration mechanism as described above. US Pat. No. 5,555,626 discloses a saver saw equipped with the orbital cutting mechanism and the low vibration mechanism.
[0005]
[Problems to be solved by the invention]
The saver saw is generally used with the blade 27 mounted downward as shown in FIG. 1, but when cutting in a narrow place such as near a wall or floor, the blade 27 is mounted upward as shown in FIG. Often used. When the blade is mounted with the blades facing upward as described above, the conventional examples such as US Pat. Nos. 3,945,120, 3,461,732 and 5,555,626 have a problem that orbital cutting cannot be performed.
[0006]
Japanese Patent Application No. 11-67109 proposed and commercialized a saver saw that can be given an orbital cutting action regardless of the blade mounting direction. Further, International Patent Publication No. WO 98/7544 proposes a saver saw that has a low vibration mechanism and that can be given an orbital cutting operation regardless of the blade mounting direction, but has not been commercialized.
[0007]
An object of the present invention is to provide a saver saw that can be orbital cut regardless of the mounting direction of the blade and that can be commercialized with a low vibration mechanism.
[0008]
[Means for solving the problems]
The above-described object is achieved by providing a balance weight that reciprocates in a phase opposite to that of the plunger with a raceway surface that controls a movement trajectory in a direction perpendicular to the reciprocating direction of the plunger.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to FIGS. 3 to 18 showing an embodiment.
(Motor part)
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 a 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. The second shaft 9 has first inclined shafts each having a predetermined angle in an opposite phase with respect to the axis of the driven gear 10 so that the plunger 20 and the balance weight 31 can be reversed (moving in phase by 180 °). A portion 9a and a second inclined shaft portion 9b are 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 holder)
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 be swingable about the axis of the shaft bolt 12 (FIG. 4). 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. 5). 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. 5 shows a state where the swing of the guide sleeve 13 is allowed.
(Plunger rotation-reciprocation converter)
A first reciprocating plate 18 having a swinging shaft portion 18 a is attached to the first inclined shaft portion 9 a 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 swing shaft portion 18a of the first reciprocating plate 18 passes through 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. Is converted into a reciprocating motion of the plunger 20.
(Balance weight holder)
The balance weight 31 is supported by two guide shafts 33 so as to reciprocate in the same direction as the plunger 20. Both ends of the guide shaft 33 are fixed to the inner cover 5 and the gear cover 6, respectively. The balance weight 31 includes the guide sleeve 13 and is formed in a cross-sectional shape such that the center of gravity of the balance weight 31 substantially coincides with the center of gravity of the plunger 20 (FIGS. 5 and 6).
(Rotation of balance weight-reciprocating motion converter)
A second reciprocating plate 32 having a rocking shaft portion 32 a is attached to the inclined shaft portion 9 b of the second shaft 9 via a bearing 17. A spherical portion 32b is formed at the tip of the swing shaft portion 32a (FIG. 3). The first reciprocating plate 18 and the second reciprocating plate 32 are attached to the second shaft 9 at an offset angle α ° so that the spherical portions 18b and 32b 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 to an offset angle α ° so that the plunger 20 and the balance weight 31 can be reversed (movements whose phases are different by 180 °). It is decided in consideration. That is, each inclination angle with respect to the axis of the driven gear 10 is set to be maximum at the offset angle α °. The balance weight 31 is provided with a hole portion 31c, and the spherical portion 32b of the second reciprocating plate 32 is engaged with the inside of the hole portion 31c so as to be able to roll with a slight gap. Is converted into a reciprocating motion of the balance weight 31 (FIG. 7).
[0010]
In order to substantially eliminate the vibration of the plunger 20 in the axial direction, the product of the mass of the balance weight 31 and the amount of reciprocating motion (hereinafter referred to as balance weight stroke amount) is the product of the mass of the plunger 20 and the amount of reciprocating motion (hereinafter referred to as plunger stroke amount). Achieved by making it equal to the product.
(Blade holder)
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. Blade holders 28 and 29 are included so as to contain the outer periphery of the blade mounting end 20c. Is 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. 11-242508) and is not directly related to the present invention, and thus detailed description thereof is omitted.
(Main body holding part)
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 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 advance and retract.
(Oscillating cutting mechanism)
Swing rollers 22 are pivotally attached to both ends of a roller shaft 21 penetrating the plunger 20 and a long hole portion 13a extending in the axial direction of the guide sleeve 13, and the roller shaft 21 and the swing roller 22 have a long hole portion 13a. A guide is provided so as to reciprocate integrally with the plunger 20. 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 via the roller shaft 21, and the blade 27 is prevented from falling. I try to prevent it.
[0011]
On the top and bottom of the swing roller 22, raceway surfaces 31 a and 31 b having a length longer than the sum of the plunger stroke amount and the balance weight stroke amount in the axial direction of the plunger 20 are part of a pair of long groove shapes inside the balance weight 31. (FIGS. 7 and 8). The raceway surfaces 31a and 31b are provided with a slight inclination angle as shown in FIG. 8, but this is for adjusting the swinging momentum of the plunger 20, and is not an essential requirement of the present invention.
[0012]
FIG. 8 shows a state where 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 has a role of eliminating the vibration in the axial direction of the plunger 20 and a role of supporting the swinging motion of the guide sleeve 13 including the plunger 20. As shown in FIG. 9, the guide sleeve 13 is set to swing up and down within a range of about 1.54 °, but is indirectly engaged with the balance weight 31 via the swing roller 22. And will not interfere directly. FIG. 9 shows a state in which the rear portion of the guide sleeve 13 swings upward (solid line) or downward (broken line), and the guide sleeve 13 contacts the balance weight 31 in any state, that is, interferes. It shows no.
(Explanation of cutting operation by linear reciprocating motion)
10 to 12 show a state in which the change shaft 15 suppresses the swinging motion of the guide sleeve 13. Although the pressing force F1 is applied by the operator during the cutting operation, the swinging motion of the guide sleeve 13 is suppressed, so that the swing roller 22 contacts the track surface 31a or 31b of the balance weight 31 as is apparent from the figure. There is nothing. Therefore, the blade 27 performs a simple linear reciprocating motion as indicated by arrows in the figure. Such a cutting form by a simple linear reciprocating motion is suitable for cutting a hard material having a large cutting reaction force such as a steel material.
(Description of orbital cutting operation when the blade is mounted downward)
13 to 15 show a state in which the change shaft 15 releases the swinging motion of the guide sleeve 13 and the blade 27 is mounted downward to perform orbital cutting. A pressing force F1 is applied to the blade 27 by the operator during the cutting operation. Then, the plunger 20 pushes down the rear end portion of the guide sleeve 13 about the shaft center of the shaft bolt 12 via the blade 27. As a result, the swing roller 22 is pressed against the raceway surface 31a 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 figure. The reciprocating motion is performed while moving, and as a result, the blade 27 draws an arc-shaped locus as indicated by an arrow in the figure and orbital cutting is performed. During this time, the balance weight 31 is reciprocating in a phase opposite to that of the plunger 20, and substantially eliminates vibration in the axial direction of the plunger 20.
(Description of orbital cutting operation when the blade is mounted upward)
16 to 18, the change shaft 15 releases the swinging motion of the guide sleeve 13, and the blade 27 is mounted upward and the saver saw body is inverted as shown in FIG. 2 to perform orbital cutting. Indicates the state. The pressing force F2 is applied by the operator during the cutting operation. Then, the plunger 20 pushes up the rear end portion of the guide sleeve 13 through the blade 27 about the axis of the shaft bolt 12 in the direction opposite to that 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 figure. The reciprocating motion is performed while moving, and as a result, the blade 27 draws an arc-shaped locus as indicated by an arrow in the figure and orbital cutting is performed. Also during this time, the balance weight 31 reciprocates in the opposite phase to the plunger 20 and substantially eliminates the vibration of the plunger 20 in the axial direction.
[0013]
【The invention's effect】
As described above, according to the present invention, since the plunger, that is, the blade is reciprocated along the raceway surface provided on the balance weight, it is possible to perform orbital cutting regardless of the mounting direction of the blade and low vibration. It becomes possible to provide a saver that can be commercialized.
[Brief description of the drawings]
FIG. 1 is an explanatory side view showing a cutting form of a saver saw.
FIG. 2 is an explanatory side view showing a cutting form of a saver saw.
FIG. 3 is a partial sectional side view showing an embodiment of a saver saw employing the cutting mechanism of the present invention.
4 is a cross-sectional view taken along line AA in FIG.
5 is a cross-sectional view taken along line BB in FIG.
FIG. 6 is a side view showing the main part of the cutting mechanism of the present invention.
7 is a cross-sectional view taken along the line CC of FIG.
8 is a cross-sectional view taken along the line DD in FIG.
9 is a sectional view taken along line EE in FIG.
FIG. 10 is an explanatory side view showing a straight cutting trajectory of the cutting mechanism of the present invention and showing a state in which the blade protrudes most forward.
FIG. 11 is an explanatory side view showing a state where the blade is retracted from FIG. 10;
12 is an explanatory side view showing a state where the blade is further retracted from FIG. 11. FIG.
FIG. 13 is an explanatory side view showing an orbital cutting locus of the cutting mechanism of the present invention and showing a state in which the blade protrudes 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 locus of the cutting mechanism of the present invention and showing a state in which the blade protrudes most forward.
17 is an explanatory side view showing a state in which the blade is retracted from FIG. 16. FIG.
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 drive 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 rectangular through hole, 15 is a change shaft, 15a is a flat portion, 17 Is a bearing, 18 is a first reciprocating plate, 18a is a rocking 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, 24 is a front cover, 25 is a base, 26 is a fixing 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, 3 b is the track surface, 32 second reciprocating plate, 32a is the pivot shaft portion, 32b is spherical portion, 33 the guide shaft, 36 is a workpiece.

Claims (7)

A housing containing a motor, a second shaft rotatably attached to the housing and driven to rotate by the motor, a plunger attached to the housing so as to be able to reciprocate and having a blade attached to the tip, a second shaft and a plunger; Between the second shaft and the balance weight, the first motion converting means for converting the rotational motion of the second shaft into the reciprocating motion of the plunger, the balance weight attached to the housing so as to be able to reciprocate, And a second motion converting means for converting the rotational motion of the second shaft into the reciprocating motion of the balance weight, and a saver saw configured to reversely move the balance weight and the plunger .
The balance weight is supported on the housing so as to be reciprocally movable, and provided with a raceway surface that extends in a reciprocating direction on the balance weight and can be contacted by swinging the plunger in a vertical direction during the reciprocating operation. A saver saw characterized in that a vertical reciprocating motion is imparted during reciprocation of the plunger by reciprocating the plunger along the track surface.   A swing roller is attached to both ends of a roller shaft that penetrates the plunger in a direction orthogonal to the reciprocating direction of the plunger behind the plunger, and the swing roller is moved along the track surface of the balance weight. The saver saw according to 1.   The saver saw according to claim 1 or 2, wherein a raceway surface of the balance weight is provided above and below the plunger shaft. A housing with a built-in motor, a second shaft that is rotatably attached to the housing and is driven to rotate by the motor, a plunger that is attached to the housing so as to be able to reciprocate and a blade is attached to the tip, and a plunger that can reciprocate The first motion conversion means, which is provided between the second sleeve and the plunger, which is held between the guide sleeve and attached to the housing so as to be swingable, and converts the rotational motion of the second shaft into the reciprocating motion of the plunger, and the housing comprising a balance weight mounted as possible reciprocating, provided between the second shaft and the balance weight, and a second motion converting means for converting the rotational motion of the second shaft into reciprocating motion of the balance weight in the balance A structure in which the weight and the plunger are reversed. In the saber saw,
The balance weight is supported by the housing so as to be reciprocally movable, and a raceway surface extending in the reciprocating direction is provided on the balance weight,
Furthermore, a roller shaft extending in a direction orthogonal to the reciprocating direction of the plunger behind the plunger and penetrating through a long hole of the guide sleeve extending along the reciprocating direction of the plunger and the plunger is attached to both ends of the roller shaft. A swing roller capable of contacting the raceway surface of the balance weight by swinging the guide sleeve and the plunger in a vertical direction during a reciprocating operation ;
A saver saw, wherein the swing roller is reciprocated along the raceway surface so that the plunger swings in a vertical direction during the reciprocating operation .   The saver saw according to claim 4, wherein a plurality of track surfaces of the balance weight are provided above and below the plunger shaft.   The saver saw cutting mechanism according to claim 2 or 3, wherein the swing roller is brought into contact with a raceway surface of a balance weight by a reaction force when the blade is pressed against a material to be cut.   There is provided a switching member that allows / suppresses the swinging of the guide sleeve, and when the swinging of the guide sleeve is allowed, the swing roller can contact the raceway surface of the balance weight, and the swinging of the guide sleeve is possible. The saver saw according to any one of claims 4 to 6, wherein when the movement is suppressed, the swing roller does not contact the raceway surface of the balance weight.

Images