JP4532164B2 - Cutting tool - Google Patents

Description

  The present invention relates to a cutting tool such as a reciprocating saw that performs a cutting operation with a reciprocating blade.

A cutting tool such as a reciprocating saw is provided with a slider that reciprocates in accordance with the rotation of a motor in a housing, and a blade can be mounted via a connecting portion provided at the tip of the slider.
As a structure of this connection part, patent document 1 has an indication, for example. Here, a slit for inserting the blade and a blade locking pin are provided at the front end of the plunger (slider), and a blade holder is provided so as to enclose the outer periphery of the blade mounting end, and the blade holder is rotated and retracted. By moving the blade locking pin to the open position, the blade can be inserted into the slit, and the blade holder is rotated forward in the opposite direction, so that the blade locking pin is engaged with the blade and the blade is fixed. It is.

JP 2000-301411 A

In such a cutting tool, a guide shoe for performing cutting guide by penetrating the blade orthogonally in front of the housing is detachably provided. However, in some cases, the cutting work may be performed by removing the guide shoe. In this case, the connecting portion of the slider is likely to collide with the material to be cut, and the connecting portion and the internal mechanism of the housing may be damaged by an impact.
On the other hand, as the slider reciprocates, heat is likely to be generated in the connecting portion, which causes discomfort to the operator who touched the connecting portion when replacing the blade.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cutting tool that can effectively prevent damage due to an impact on a connecting portion and can ensure a good feeling of use.

In order to achieve the above object, the invention described in claim 1 is characterized in that a separate protector made of an elastic material is attached to the connecting portion.
In addition to the object of claim 1, the invention described in claim 2 is such that the thickness of the front portion of the protector is made thicker than the other portions in order to obtain a buffering effect more effectively.

According to the first aspect of the invention, the protector can effectively prevent damage associated with the impact on the connecting portion, and can ensure a good feeling of use. In addition, the dust-proof property of the connecting portion is increased by being covered with the protector, and a secondary effect that good operation of the movable portion can be maintained by dust is obtained.
According to the second aspect of the invention, in addition to the effect of the first aspect, it is possible to effectively protect the front portion that is easily hit, and a more effective buffering effect can be expected.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial side view of a reciprocating saw as an example of the cutting tool of the present invention, FIG. 2 is a central longitudinal sectional view thereof, and the reciprocating saw 1 is located in front of a metal motor housing 2 containing a motor 3 (FIG. 1). And a main body housing 5 in which a cylindrical rod-like slider 6 that can move back and forth and a crank mechanism 7 that converts the rotation of the output shaft 4 of the motor 3 into the reciprocating motion of the slider 6 are connected. The main body housing 5 is a metal lower housing 8 integrally having a flange portion 9 screwed and connected to the motor housing 2 and a cylinder that is assembled above the lower housing 8 and opens forward at the front end. The upper housing 10 is also made of the same metal with the shape portion 11 extended. A rubber insulating cover 12 is attached to the main body housing 5.

  The crank mechanism 7 is rotatably mounted on a shaft 13 erected upward at the bottom of the lower housing 8 via a needle bearing 14, and engages with the output shaft 4, and the bevel gear 15 has an upper surface eccentric position. A projecting eccentric pin 16 and a slide plate 17 having a U-shaped cross section fixed to the lower side of the slider 6 in an orthogonal manner are rotatably supported by the eccentric pin 16. Reference numeral 18 denotes a motor cooling fan fixed to the output shaft 4 in the flange portion 9 of the lower housing 8, which is for cooling from an unillustrated intake port provided behind the motor housing 2 as the output shaft 4 rotates. The motor 3 is cooled by sucking air and exhausting it through the exhaust ports 19, 19... Respectively formed in the upper and lower surfaces of the flange portion 9.

The slider 6 is held by guide sleeves 20, 20 accommodated in front and rear positions in the upper housing 10 so as to be movable back and forth, protrudes forward through the cylindrical portion 11 of the upper housing 10, and is a connecting portion provided at the front end. The blade can be mounted via the blade holder 21.
As shown in FIG. 3, the blade holder 21 is rotatably mounted on the slider 6, and a driving sleeve 22 that is urged to rotate in one direction by a torsion spring 23, and an axis of the slider 6. A push pin 26 accommodated in a slit 24 formed so as to be movable back and forth and biased forward by a coil spring 25, and a locking pin 27 penetrating the push pin 26 in an orthogonal shape and locking to the driving sleeve 22 And a stepped pin 29 which is accommodated in the slider 24 so as to be able to protrude and retract and is urged by the coil spring 28 in the retracting direction from the slit 24.

  The blades 30 are connected as follows. When the rear end of the blade 30 is inserted into the slit 24 from the front, the rear end of the blade 30 moves the push pin 26 against the coil spring 25. Since the locking pin 27 is retracted together with the push pin 26 and is disengaged from the driving sleeve 22, the driving sleeve 22 is rotated by the urging force of the torsion spring 23, and the inclined surface 31 formed on the inner peripheral surface thereof. The stepped pin 29 is pressed in the protruding direction into the slit 24. Therefore, the stepped pin 29 protruding into the slit 24 penetrates the through hole 32 provided at the rear end of the blade 30 and prevents the blade 30 from coming off. When the blade 30 is removed, if the driving sleeve 22 is rotated against the urging force of the torsion spring 23 by using the operation piece 33 extending to the outer periphery thereof, the step by which the pressure by the inclined surface 31 is released. Since the attached pin 29 moves backward to release the retaining of the blade 30, the blade 30 can be pulled out as it is. The driving sleeve 22 is locked again in the initial rotational position by a locking pin 27 that has advanced with the push pin 26.

  A protector 34 is attached to the blade holder 21. As shown in FIG. 4, the protector 34 is a rubber sleeve body that covers the blade holder 21 almost completely including the operation piece 33 of the driving sleeve 22, and the front portion is aligned with the slit 24 of the blade holder 21. A notch 35 that allows the blade 30 to enter is formed, and a bulging portion 36 that is thicker than the side surface portion is formed. The protector 34 can be attached from the front of the blade holder 21 without attaching the blade 30 to the blade holder 21, and can be arbitrarily removed from the blade holder 21 without attaching the blade 30.

  On the other hand, a guide shoe 37 is mounted on the lower side of the cylindrical portion 11 in the upper housing 10 (the front side of the lower housing 8). The guide shoe 37 is a U-shaped slide bar 38 that is slidably mounted in the front-rear direction, and a shoe 39 that is fixed to the front end of the slide bar 38 at right angles and through which the blade 30 mounted on the slider 6 passes. It consists of. The slide bar 38 has left and right side walls bent upward and symmetrically provided with continuous corrugated engaging portions 40, 40..., Either of the engaging portions 40, 40. In addition, the slide of the slide bar 38 can be regulated by engaging the cylindrical lock pin 41 slidably mounted in the upper housing 10 so as to be slidable to the left and right. The lock pin 41 has a relief groove (not shown) through which the side wall of the slide bar 38 can pass at a predetermined position in the axial direction, and is normally urged to a lock position in which the relief groove is shifted in the left-right direction from the side wall. ing. Therefore, when the lock pin 41 is slid to the release position where the escape groove coincides with the side wall, the lock pin 41 and the engagement portion 40 are disengaged, and the slide bar 38 can be slid.

In the reciprocating saw 1 configured as described above, when the motor 3 is driven by turning on a switch (not shown) and the bevel gear 15 is rotated by the rotation of the output shaft 4, the slide plate 17 is moved along with the rotational movement of the eccentric pin 16. The slider 6 reciprocates because the diameter of the movement locus of the eccentric pin 16 is a stroke, and the blade 30 connected to the slider 6 via the blade holder 21 can be cut.
Here, since the blade holder 21 is protected by the rubber protector 34, for example, when the cutting work is performed with the guide shoe 37 removed, the blade holder 21 comes into contact with the material to be cut when the blade holder 21 moves forward. Even in such a case, the impact is effectively reduced by the protector 34. Further, even if the blade holder 21 generates heat due to the cutting operation, it does not touch the hand directly, so that the operator is not uncomfortable.

As described above, according to the reciprocating saw 1 of the above embodiment, by attaching the rubber protector 34 to the blade holder 21, the internal mechanism such as the blade holder 21 or the crank mechanism 7 accompanying the impact on the blade holder 21 can be obtained. Can be effectively prevented, and a good feeling of use can be secured. In addition, the dust-proof property of the blade holder 21 is enhanced by being covered by the protector 34, and a secondary effect is also obtained in which a favorable operation of the movable portion such as the driving sleeve 22 and the push pin 26 can be maintained by the dust.
Moreover, since the bulging part 36 in which the thickness of the front part of the protector 34 is made thicker than other parts is formed, the front part that is easily hit can be effectively protected, and a more effective buffering effect can be expected.

The elastic material forming the protector is not limited to rubber, but may be synthetic resin, and the shape can be appropriately changed according to the shape of the connecting portion such as the blade holder. Further, the protector does not necessarily have to be formed of a single member, and for example, a portion covering the side surface portion and the front surface portion of the connecting portion may be formed separately so as to be detachable from the connecting portion. In this case, a different elastic material can be selected for each separate part. Of course, the structure of the connecting portion itself is not limited to the structure of the blade holder, and the protector of the present invention can be used as long as it is a mechanism capable of mounting the blade, such as the structure shown in Patent Document 1 above.

It is a side view of the reciprocating saw (with the insulating cover removed). It is a center longitudinal cross-sectional view of a reciprocating saw. It is explanatory drawing (a protector is removed, an upper part is a longitudinal cross section, and the lower part is an AA line cross section) of a blade holder. It is a perspective view of a protector.

Explanation of symbols

  1. Reciprocating saw, 3. Motor, 5. Body housing, 6. Slider, 7. Crank mechanism, 8. Lower housing, 10. Upper housing, 21. Blade holder, 22. Driving sleeve, 26. Push pin, 29. Step Attached pin, 30 ... blade, 34 ... protector, 36 ... bulge, 37 ... guide shoe.

Claims (2)

A cutting tool provided with a slider that reciprocates in accordance with the rotation of the motor in the housing, and a blade can be attached to a connecting portion provided at the tip of the slider,
A cutting tool characterized in that a separate protector made of an elastic material is attached to the connecting portion.   The cutting tool according to claim 1, wherein the thickness of the front portion of the protector is made thicker than other portions.

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