JP2022146868A - work machine - Google Patents

Abstract

To provide a work machine which has high strength against an impact caused by falling etc.SOLUTION: A work machine 1 has a motor 13 and includes a housing 10 including a base part 11 which houses the motor 13. The housing 10 has: a holding part 20 connected to the base part 11; and a battery attachment/detachment part 23 connected to the holding part 20. A cushioning part 20a is provided in an end at the battery attachment/detachment part 23 side of the holding part 20. The cushioning part 20a is a curved part which curves to the inner side of the holding part 20. The cushioning part 20a has a groove shape recessed to the inner side of the holding part 20 and is arranged over an entire periphery of a center axis of the holding part 20.SELECTED DRAWING: Figure 2

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work machine provided with a housing that accommodates a prime mover.

Patent Literature 1 listed below discloses a work machine driven by a battery. The battery is detachable from the working machine.

Japanese Patent Application Laid-Open No. 2020-179479

A working machine is often formed with a gripping portion, and a part of the gripping portion is thin for ease of gripping. Therefore, when dropped, the impact force concentrates on the thin portion, which may cause damage or deformation. In addition, if the mold is split to allow for partial structural changes, it is difficult to provide a reinforcing elastic body or the like in the split part, which reduces the durability of the split part. Resulting in.

SUMMARY OF THE INVENTION The present invention has been made in recognition of such circumstances, and an object thereof is to provide a working machine having a high strength against impact caused by dropping or the like.

One aspect of the present invention is a work machine having a prime mover,
a housing including a base for housing the prime mover;
The housing has a grip portion connected to the base portion, a battery attachment/detachment portion connected to the grip portion, and a buffer portion at an end of the grip portion on the battery attachment/detachment portion side.
According to this aspect, the shock-absorbing function of the shock-absorbing portion can suppress damage or deformation of the housing.

The buffer portion may be a curved portion.

The grip may have a hollow tubular shape.

The buffer portion may be arranged symmetrically with respect to the central axis of the grip portion.

The buffer portion may be arranged all around the central axis.

The buffer portion may form an integral structure with the grip portion.

The cushioning portion may have a groove shape, and an elastic body may be provided therein.

An end portion of the elastic body may be positioned inside the buffer portion.

The buffer portion has an inwardly recessed shape,
The elastic body may be arranged on the outer surface of the cushioning section.

The elastic body provided on the holding portion may be continuous with the elastic body provided on the buffer portion.

The housing may have a split portion between the holding portion and the battery attaching/detaching portion.

Another aspect of the present invention is a working machine having a prime mover, in which a damping portion is provided in a split portion of a housing that accommodates the prime mover.

Yet another aspect of the present invention is a work machine having a prime mover, wherein an elastic body is provided on the outer surface of a housing that accommodates the prime mover, and the outer surface of the housing is curved at the position of the end face of the elastic body. is. According to this aspect, durability can be improved.

Any combination of the above constituent elements, and conversion of expressions of the present invention between methods and systems are also effective as embodiments of the present invention.

Advantageous Effects of Invention According to the present invention, it is possible to provide a working machine having a high strength against impact caused by dropping or the like.

FIG. 2 is a right side view of work implement 1 according to the embodiment of the present invention. Fig. 2 is a right side view of the working machine 1 with the right housing 10R removed; FIG. 3 is a perspective view of a portion of the working machine 1 below the grip portion 20; FIG. 4 is a perspective view similar to FIG. 3 omitting an elastic body 22 covering the surface of the grip portion 20; FIG. 4 is a perspective view similar to FIG. 3 with the right housing 10R removed; (A) is a right cross-sectional view of the lower portion of the grip portion 20 and the battery attaching/detaching portion 23; (B) is a left side view of the same. 6(A) is a diagram in which the elastic body 22 is omitted from FIG. 6(A); (B) is a diagram in which the elastic body 22 is omitted from FIG. 6(B).

Hereinafter, the same or equivalent constituent elements, members, etc. shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. The embodiments are illustrative rather than limiting of the invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

The present embodiment relates to a working machine 1. FIG. The working machine 1 is a knife cutter. The work machine 1 has a housing 10, a base 30 and a dust collection case 40, and is suitable for cutting plate materials such as plywood and gypsum board.

The housing 10 is a resin molding, for example, and includes a base portion 11 , a base support portion 12 , a grip portion 20 , and a battery attachment/detachment portion 23 . The housing 10 is composed of a right housing 10R and a left housing 10L. The right housing 10R and the left housing 10L form the housing 10 by being fixed to each other while facing each other.

The dust collection case 40 is provided at one longitudinal end of the base 11 . The dust collection case 40 has a box-like appearance whose longitudinal direction is perpendicular to the longitudinal direction of the base 11 . In the work machine 1, the longitudinal direction of the base 11 is defined as the front-rear direction, the side where the dust collection case 40 is provided is defined as the front, and the side opposite to the side where the dust collection case 40 is provided is defined as the rear. The longitudinal direction of the dust collection case 40 is the vertical direction, the side on which the base 30 is provided is the upper side, and the side on which the grip portion 20 is provided is the lower side. Furthermore, let the direction orthogonal to the front-back direction and the up-down direction be a left-right direction. The left and right sides are determined based on the case where the working machine 1 is viewed from the front. The longitudinal direction of the base 11 and the longitudinal direction of the base 30 match.

The grip portion 20 is connected to the base portion 11 and positioned below the base portion 11 . The grasping portion 20 has a hollow cylindrical shape. The battery attaching/detaching portion 23 is connected to the lower end of the grip portion 20 . The base 30 is supported by the base support portion 12 and positioned above the housing 10 . The dust collection case 40 is positioned on the front side of the housing 10 . The right housing 10R forms the right half of the housing 10 and the left housing 10L forms the left half of the housing 10. As shown in FIG.

As shown in FIG. 2, a motor 13 as a prime mover is accommodated in the base portion 11 of the housing 10 . In addition to the motor 13, the housing 10 accommodates a reduction mechanism, a conversion mechanism, and the like. The motor 13 is an electric motor powered by a battery (for example, a lithium ion battery) 14 attached to the lower end of the grip portion 20 . The motor 13 is a brushless motor that includes a motor housing that accommodates a rotor and a stator, an output shaft that is fixed to the rotor and rotates integrally with the rotor, and the like. The output shaft is rotatably supported by bearings, and a small-diameter bevel gear 15a is provided at the tip of the output shaft.

The small-diameter bevel gear 15a meshes with the large-diameter bevel gear 15b that rotates about a straight line extending in a direction that intersects the output shaft. The small-diameter bevel gear 15a and the large-diameter bevel gear 15b constitute a reduction mechanism that reduces the rotational speed of the output shaft of the motor 13 and increases the torque. An eccentric cam (not shown) is provided on the support shaft on which the large-diameter bevel gear 15b is provided. Like the large diameter bevel gear 15b, the eccentric cam rotates about a straight line extending in a direction intersecting the output shaft of the motor 13 as a rotation axis. However, the eccentric cam is eccentric with respect to the large diameter bevel gear 15b.

A substantially L-shaped mounting rod (not shown) is provided in the housing 10 when viewed from the side. The mounting rod is supported to move up and down and back and forth. The lower portion of the mounting rod engages an eccentric cam and the upper portion of the mounting rod is connected to the cutting edge 18 . A mounting rod that engages the eccentric cam cycles as the eccentric cam rotates. Specifically, the mounting rod periodically reciprocates vertically and longitudinally as the eccentric cam rotates. A cutting blade 18 connected to the mounting rod operates in response to the periodic motion of the mounting rod 16 to cut an object such as a board. Thus, the eccentric cam and the mounting rod constitute a conversion mechanism that converts the rotary motion of the output shaft of the motor 13 into the reciprocating motion (oscillation) of the cutting blade 18 .

When the switch 21 provided at the upper end of the grip portion 20 is operated, power is supplied to the motor 13 and the output shaft of the motor 13 rotates. As described above, the rotational motion of the output shaft of the motor 13 is reduced by the reduction mechanism (the small diameter bevel gear 15a and the large diameter bevel gear 15b), and converted into the reciprocating motion of the cutting blade 18 by the conversion mechanism (eccentric cam and mounting rod). . The user grips the grip portion 20 with the right or left hand and operates the switch 21 with the index finger of the hand gripping the grip portion 20 . For example, the user grips the grip portion 20 with the right hand and moves the work implement 1 from the rear to the front while operating the switch 21 with the index finger of the right hand. In other words, the work implement 1 is pulled forward.

The base 30 has a substantially rectangular shape with long sides extending in the front-rear direction. The base 30 is fixed to the housing 10 by screwing or the like. The upper surface of the base 30 serves as a contact surface that is applied to the surface of the object when the object is cut. The base 30 straddles the housing 10 and the dust collection case 40 . Specifically, the rear portion of the base 30 overlaps the upper portion of the housing 10 (base support portion 12 ), and the front portion of the base 30 overlaps the upper portion of the dust collection case 40 .

The cutting blade 18 penetrates through the opening of the base 30 , and a portion of the cutting blade 18 protrudes upward from the upper surface of the base 30 . When the cutting blade 18 reciprocates (swings) with the upper surface of the base 30 applied to the surface of the object, the projecting portion of the cutting blade 18 protruding from the upper surface of the base 30 cuts the object.

When the cutting blade 18 cuts the object to which the upper surface of the base 30 is applied, dust is generated. Dust generated during cutting is collected in the dust collection case 40 through the opening of the base 30 . In other words, the dust collection case 40 collects dust generated by cutting the object through the opening provided in the base 30 and prevents or reduces scattering to the surroundings.

The dust collection case 40 is made of transparent or translucent resin (for example, polycarbonate). Therefore, the presence and amount of dust in the dust collection case 40 can be visually confirmed. The dust collection case 40 is attachable to and detachable from the housing 10, and the dust collection case 40 can be separated from the housing 10 as needed to dispose of the dust accumulated in the dust collection case 40. - 特許庁

The work machine 1 is characterized in that the housing 10 has a buffer portion 20a at the lower end portion of the grip portion 20 (the end portion on the battery attaching/detaching portion 23 side). This point will be described below.

The grip portion 20 is configured thin for ease of gripping. On the other hand, the battery attaching/detaching portion 23 has a large diameter so that the battery (battery pack) 14 can be connected. Therefore, the housing 10 has a shape that expands downward from the lower end of the grip portion 20 . Therefore, the lower end portion of the grip portion 20 tends to concentrate stress due to impact such as dropping, and is likely to be damaged or deformed.

Furthermore, when the mold for molding the housing 10 is split, the boundary between the grip portion 20 and the battery attachment/detachment portion 23 is configured to be the split portion (the mold for molding the battery attachment/detachment portion 23 and others). It is possible to change the structure of the battery attaching/detaching part 23 (change the size of the battery 14 to be attached/detached) at a low cost. However, when a plurality of molds are used to integrally construct the housing, it is difficult to integrally mold the elastic body on the outer surface of the housing at the positions of the mating surfaces of the plurality of molds. As a result, the lower end of the grip portion 20 is likely to be damaged or deformed. In addition, when the elastic body is provided up to the mold splitting position by integral molding, if the end face of the elastic body is exposed (the end of the elastic body rises from the outer surface of the housing to create a step), the elastic body is peeled off. Therefore, it is necessary to connect the outer surface of the hard resin portion and the outer surface of the elastic body so as not to generate a stepped portion. However, for this reason, a step is formed between the hard resin portion covered with the elastic body and the resin portion not covered, and the end portion of the outer surface of the housing (sinking portion) where the elastic body is provided has a corner. More specifically, in the housing, the receiving portion covered with the elastic body sinks inward with respect to the outer surface portion not covered with the elastic body, and the connecting portion and the receiving portion connecting the outer surface portion and the receiving portion A recessed corner (an internal corner in terms of architecture) is generated. For this reason, stress is concentrated on the stepped portion (corner) at the time of impact, and damage and deformation are likely to occur.

The buffer portion 20a suppresses damage or deformation of the lower end portion of the grip portion 20 and increases the strength of the housing 10 against impact caused by dropping or the like. The buffer portion 20a is a curved portion that curves inward (toward the central axis) of the grip portion 20 . More specifically, the cushioning portion 20a has an inwardly recessed outer peripheral side and an inwardly protruding inner peripheral side, thereby forming a curved shape. Between the outer peripheral side and the inner peripheral side of the buffer portion 20a, the outer peripheral side has a larger curvature. Moreover, the thickness of the buffer portion 20a is substantially constant. The buffer portion 20a has a groove shape that is recessed inwardly of the grip portion 20, and is arranged all around the center axis of the grip portion 20 (closes after making a full circle). The cushioning portion 20 a forms an integral structure with the gripping portion 20 as a part of the gripping portion 20 . When an impact is applied to the housing 10, the cushioning portion 20a relatively moves (for example, bends and deforms) with respect to other parts to soften (absorb) the impact. The buffer portion 20a connects one portion of the housing 10 (the motor housing 11, the base 30, the portion accommodating the switch 21, etc.) and the other portion of the housing 10 (the battery attaching/detaching portion 23), and the one portion is connected to the other portion. It functions so as to be elastically movable relative to When an impact or pressure is applied to one part (or the other part), the one part relatively moves so as to rotate with respect to the other part with the central position of the curved shape (hollow part) of the cushioning part 20a as a fulcrum. At this time, a portion of the buffer portion 20a (curving portion) bends (bends) so as to contract, and bends so as to expand at the opposite position (180 degrees reverse) of the portion. Since the housing 10 is made of resin, it has elasticity, and the flexed buffer portion 20a tries to return to its original state. In this manner, the buffer portion 20a functions like a coil spring and suppresses damage due to impact and transmission of vibration.

An elastic body (elastomer) 22 is integrally formed (provided integrally) with the grip portion 20 . The elastic body 22 functions as a non-slip and protects the housing 10 from impact. The end portion 22a of the elastic body 22 is arranged on the outer surface of the buffer portion 20a (the surface facing the outside of the grip portion 20) and positioned inside the groove shape of the buffer portion 20a. The end portion 22a of the elastic body 22 has a back surface that curves along the outer surface of the buffer portion 20a, but a surface that is substantially flat when viewed from the radial direction of the grip portion 20. As shown in FIG. The surface of the end portion 22 a of the elastic body 22 is formed so as to be continuous with the surface of the battery mounting/dismounting portion 23 .

According to this embodiment, the following effects can be obtained.

(1) Since the buffer portion 20a is provided at the lower end portion of the grip portion 20, damage or deformation of the lower end portion of the grip portion 20 can be suppressed. As a result, the lower end portion of the grip portion 20, which is a place where stress due to impact such as dropping tends to concentrate and is likely to be damaged or deformed, is structurally strengthened, and the strength of the housing 10 against impact due to dropping or the like is increased.

(2) Since the cushioning portion 20a has a curved shape, stress can be received in a distributed manner throughout the cushioning portion 20a, resulting in high durability. In addition, since the cushioning portion 20a having a curved shape is provided at the end surface of the elastic body 22, the resin portion of the housing 10 positioned inside the end surface of the elastic body 22 does not form a step, and the outer surface portion and the elastic body 22 do not form a stepped portion. is loosely connected to the receiving portion on which is provided. In other words, the outer surface of the housing 10 located on the inner peripheral side of the end surface of the elastic body 22 does not have an inwardly recessed corner (the above-described internal corner). As a result, the conventional problem that stress concentrates on the stepped portion (corner) can be solved, and the durability can be improved. In particular, as described above, in the split structure, the part at the split position tends to be stepped, so it is very effective to apply the curved structure of the present invention to the end face position of the elastic body in the split structure.

(3) Since the cushioning portion 20a is arranged all around the central axis of the grip portion 20, it is possible to suitably soften impacts applied to the lower end portion of the grip portion 20 in various directions.

(4) Since the cushioning portion 20a is recessed inward, it is possible to suppress the gripping portion 20 from protruding due to the cushioning structure, thereby suppressing deterioration of workability.

(5) Vibration due to work is absorbed by the buffer portion 20a, and a vibration isolation effect for the battery 14 is obtained.

(6) Since the end portion 22a of the elastic body 22 is provided on the outer peripheral portion (inside the groove) of the buffer portion 20a, a shock absorbing effect by the end portion 22a of the elastic body 22 is also obtained. In addition, since the end portion 22a of the elastic body 22 is positioned in the recessed groove-shaped cushioning portion 20a (curved portion), the end portion 22a projects inward, and the convex shape of the end portion 22a engages with the housing 10. The elastic body 22 can be prevented from being peeled off by forming a state in which the elastic body 22 is fitted.

(7) Since the elastic body 22 provided in the grip part 20 continues (extends) inside the buffer part 20a, there is no need to dispose a separate elastic body in the buffer part 20a, which is preferable in terms of manufacturing.

(8) The back surface of the end portion 22a of the elastic body 22 is curved along the outer surface of the buffer portion 20a, but the front surface thereof is substantially flat when viewed from the radial direction of the grip portion 20. change in grip feeling can be suppressed. In addition, since the surface of the end portion 22a of the elastic body 22 forms a continuous surface with the surface of the battery attachment/detachment portion 23, there is no unnecessary unevenness and it is easy to grip.

(9) By making the holding part 20 hollow, it becomes easier to position the structure such as wiring inside, but the durability is lowered due to the reduction in thickness, but according to the present invention, such a hollow part It can also improve the durability of Therefore, it is particularly effective to apply the present invention to a handle portion that needs to be hollow for arranging wires and switches. In addition, by making it hollow, the flexibility of the curved shape of the cushioning portion 20a can be improved. For example, by changing the thickness and shape, it is possible to easily adjust the impact resistance.

Although the present invention has been described above with reference to the embodiments, it will be understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiments within the scope of the claims. By the way. Modifications will be discussed below.

The cushioning portion 20a is not limited to the configuration in which it is closed by making one turn around the central axis of the grip portion 20, but may be spirally wound around the central axis of the grip portion 20, and the number of turns may exceed one turn.

The cushioning portion 20a may be provided in a limited portion around the central axis of the grip portion 20 . In this case, the cushioning portion 20a is preferably arranged symmetrically with respect to the central axis of the grip portion 20. As shown in FIG. For example, the buffer portions 20a may be provided at the front and rear portions of the lower end portion of the grip portion 20 . In this case, the durability against stress that tends to bend the grip portion 20 in the front-rear direction is enhanced.

The cushioning portion 20a may have an outwardly convex shape.

Instead of or in addition to the lower end of the gripping portion 20, the buffering portion 20a may be provided at another location. For example, when the split portion of the housing 10 exists in a portion other than the boundary between the grip portion 20 and the battery attachment/detachment portion 23, providing a cushioning portion in the split portion reduces the structural weakness caused by the split. make up for it.

Motor 13 may be a brushed motor. The prime mover may be something other than a motor. The working machine of the present invention is not limited to the knife cutter exemplified in the embodiment, and may be of another type such as an impact driver.

DESCRIPTION OF SYMBOLS 1... Working machine (knife cutter), 10... Housing, 10R... Right housing, 10L... Left housing, 11... Base part, 12... Base support part, 13... Motor (prime mover), 14... Battery (battery pack), 15a... Small-diameter bevel gear 15b Large-diameter bevel gear 18 Cutting blade 20 Grip portion 20a Buffer portion 21 Switch 22 Elastic body (elastomer) 22a End 23 Battery attachment/detachment portion 30 Base , 40... Dust collection case.

Claims (13)

A working machine having a prime mover,
a housing including a base for housing the prime mover;
The housing has a grip portion connected to the base portion, a battery attachment/detachment portion connected to the grip portion, and a buffer portion at an end of the grip portion on the battery attachment/detachment portion side. . The work machine according to claim 1, wherein the buffer portion is a curved portion. The work machine according to claim 1 or 2, wherein the grip portion has a hollow tubular shape. The work machine according to any one of claims 1 to 3, wherein the buffer portion is arranged symmetrically with respect to the central axis of the grip portion. The work machine according to any one of claims 1 to 4, wherein the buffer portion is arranged all around the central axis. The work machine according to any one of claims 1 to 5, wherein the cushioning portion is integrally constructed with the grip portion. 7. The working machine according to claim 6, wherein said cushioning portion has a groove shape and is provided with an elastic body therein. The working machine according to claim 7, wherein an end portion of said elastic body is positioned inside said cushioning portion. The buffer portion has an inwardly recessed shape,
The working machine according to claim 7 or 8, wherein the elastic body is arranged on an outer surface of the buffer portion. The working machine according to any one of claims 7 to 9, wherein an elastic body provided in said gripping portion is continuous with an elastic body provided in said buffer portion. The working machine according to any one of claims 1 to 10, wherein the housing has a split portion between the grip portion and the battery attaching/detaching portion. What is claimed is: 1. A work machine having a prime mover, wherein a shock absorbing portion is provided in a split portion of a housing that accommodates the prime mover. A working machine having a prime mover, wherein an elastic body is provided on the outer surface of a housing that accommodates the prime mover, and the outer surface of the housing is curved at the position of the end surface of the elastic body.

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