JP2019181598A - Hand-held tool - Google Patents

Abstract

To take a measure to prevent a hand-held tool such as a disc grinder from falling by using a suspension instrument such as a tether strap when performing operation with the tool at an elevated place; and to report to an operator such an incident as when a connection part, to which the suspension instrument for fall prevention is connected, is damaged, so as to surely achieve the original suspension function of the suspension instrument.SOLUTION: A cavity part 12 is provided along an inner peripheral hole 10a of an annular connection part 10. The thinned cavity part 12 is made to function as a part with low shock resistance. A crack is caused by shock added to the cavity part 12. A user can recognize the need of maintenance for the connection part 10 by visually checking any crack, and can stop the use so far.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hand-held tool used by a worker, for example, a disc grinder.

  For example, for hand-held tools such as disc grinders used for grinding work, use hand-held tools such as tether straps to prevent accidental dropping, especially when working at high places. Measures are taken to connect to scaffolding and handrails. The following patent documents disclose a technique related to a hook for connecting this type of hanging tool or for hanging the hand-held tool on a work belt, a scaffold or the like when the work is interrupted.

JP 2006-326753 A JP2015-178154A

  For this type of hand-held tool, the coupling part that couples a hanging tool such as a tether strap for preventing fall is damaged by a large impact applied through the hanging tool, resulting in a hanging function. In order to prevent the worker from continuing to use the hanging tool without knowing the fact, or to promote the recovery of the joint by maintenance. There was not enough countermeasures.

  The present invention informs the operator of the fact when the connecting part for connecting the hanging tool for preventing the fall is damaged, so that the original hanging function of the hanging tool is surely performed. The purpose is to.

  The above problems are solved by the following inventions. 1st invention is a hand-held tool which an operator uses in his / her hand, and is provided with a connecting part for connecting a hanging tool, and a notifying means for visually recognizing deformation of the connecting part. It is.

  According to the first invention, the hanging tool such as a tether strap is coupled to the coupling portion, and the handheld tool is prevented from falling. When an impact is applied to the coupling portion via the hanging tool, this fact is notified by the notification means, and the user can recognize the fact visually. By visually informing that the coupling part has been damaged, the operator can recognize that it is necessary to perform maintenance such as recovery of the coupling part. It is possible to ensure that (the function of the coupling portion) is exhibited.

  A second invention is a hand-held tool according to the first invention, wherein the coupling portion is provided with a portion having high impact resistance and a portion having low impact resistance, and the portion having low impact resistance is deformed to be used as a notification means.

  According to the second invention, when an impact is applied to the coupling portion via the hanging tool, stress concentrates on a portion having low impact resistance and the portion is easily damaged and deformed. When the portion having low impact resistance is damaged and deformed, it is notified that the connecting portion has been damaged. By actively providing a portion having low impact resistance and fixing a portion that is damaged by impact, the fact of the fact of damage can be more reliably notified.

  A third invention is the hand-held tool according to the second invention, wherein a hollow portion is provided inside as a portion having low impact resistance.

  According to the third invention, when an impact is applied to the coupling portion through the hanging tool, the fact that the cavity portion as a portion having low impact resistance is deformed and the coupling portion is damaged is notified. The

  A fourth invention is the hand-held tool according to the second invention, wherein the rib is provided around the inner peripheral side of the loop-shaped coupling portion as a portion having low impact resistance.

  According to the fourth aspect of the invention, when an impact is applied to the coupling portion via the hanging tool, the fact that the rib as a portion having low impact resistance is deformed and the coupling portion is damaged is notified. .

  5th invention is the handheld tool which provided the alerting | reporting means inside the coupling | bond part in 1st invention.

  According to the fifth aspect of the present invention, when the joint is damaged by the impact applied through the hanging tool, this fact is notified by the notifying means provided inside the joint. By visually checking the notification means, the user can recognize the fact that the joint has been damaged, and this facilitates the maintenance of the joint and ensures the suspension function of the hanging tool. Can be demonstrated.

  6th invention is the handheld tool which equipped the light source as an alerting | reporting means in 5th invention.

  According to the sixth invention, when the coupling portion is damaged due to the impact applied through the hanging tool, light is leaked from the damaged portion, and the fact that the coupling portion is damaged is notified. .

  7th invention is the handheld tool which filled the coating material as alerting | reporting means in 5th invention.

  According to the seventh aspect of the present invention, when the joint is damaged by an impact applied through the hanging tool, the paint flows out from the damaged portion and the joint is damaged. The fact is visually informed. Visibility can be further enhanced by using a fluorescent paint as the paint.

1 is an overall side view of a hand-held tool according to a first embodiment of the present invention. It is a longitudinal cross-sectional view of the coupling part according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line (III)-(III) in FIG. 1, and is a cross-sectional view of the coupling portion according to the first embodiment. It is a side view of the joint part concerning a 2nd embodiment. FIG. 5 is a cross-sectional view taken along line (V)-(V) in FIG. 4, and is a cross-sectional view of a coupling portion according to the second embodiment. It is a longitudinal cross-sectional view of the coupling part according to the third embodiment. It is a longitudinal cross-sectional view of the coupling part according to the fourth embodiment.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 3 show a hand-held tool 1 according to a first embodiment of the present invention. In the first embodiment, a disc grinder is illustrated as the hand-held tool 1. The hand-held tool 1 includes a main body 3 in which an electric motor 2 as a drive source is housed in a cylindrical main body housing 3a. The main body housing 3a is set to a thickness that is easy for a user to hold with one hand and functions as a grip portion.

  A large switch lever 4 is provided on the lower surface of the main body 3 so as to be tiltable up and down. When the switch lever 4 is pulled upward with the fingertip of the hand holding the main body 3, the electric motor 2 is activated. The switch lever 4 is provided with a small lock-off lever 4a. As shown in the figure, when the lock-off lever 4a is raised, the switch lever 4 cannot be pulled upward, so that the electric motor 2 is maintained in a stopped state (lock-off state). The switch lever 4 can be pulled upward by tilting the lock-off lever 4a backward to release the lock-off state.

  A gear head portion 5 is coupled to the front side of the main body portion 3. The gear head portion 5 includes a gear train (not shown in the figure) that decelerates the output of the electric motor 2 and outputs it to the spindle 5a. The spindle 5 a is orthogonal to the motor axis of the electric motor 2. The spindle 5 a protrudes downward from the lower surface of the gear head portion 5. A circular grindstone 6 is attached to the lower part of the spindle 5a. The rear side of the grindstone 6 is covered with a cover 6a.

  The rear side of the main body 3 is covered with a rear case 7 having a left / right halved structure. A main switch that is turned on and off by the operation of the switch lever 4 is housed inside the rear case 7 formed by abutting the left and right half cases together. A large number of air inlets 7 a for introducing outside air are provided on the rear surface and the left and right side portions of the rear case 7. Although not visible in the figure, a cooling fan is attached to the output shaft of the electric motor 2. When the electric motor 2 is activated, the cooling fan rotates, and outside air is introduced into the rear case 7 and the main body housing 3a through the air inlet 7a. The electric motor 2 is mainly cooled by the introduced outside air (motor cooling air). The motor cooling air is exhausted from the vicinity of the joint between the main body 3 and the gear head 5.

  In the present embodiment, an AC power source handheld tool 1 is illustrated. One power cord 8 is drawn from the rear surface of the rear case 7. AC power is supplied through the power cord 8.

  The hand-held tool 1 according to the first embodiment includes a coupling portion 10 for coupling a hanging tool S such as a tether strap for preventing falling during work. The coupling portion 10 of the first embodiment is provided at the rear of the rear case 7 and below the power cord 8. The coupling portion 10 is provided integrally with the rear case 7 made of resin, and has a left / right halved structure like the rear case 7. A hanging tool S such as a tether strap can be coupled to the coupling portion 10 made of resin and halved.

  The coupling part 10 of the first embodiment has an annular shape. The hanging tool S is inserted into the inner peripheral hole 10a of the connecting portion 10 and connected. As shown in FIG. 2, a metal reinforcing plate 11 is housed inside the coupling portion 10. The reinforcing plate 11 also has an annular shape. The reinforcing plate 11 is fixed so as to be immovable by a screwing boss portion 7b of the rear case 7 and two engaging convex portions 7c. The reinforcing plate 11 is disposed along the entire circumference of the coupling portion 10.

  On the inner peripheral side (inner peripheral hole 10a side) of the coupling portion 10 and on the inner peripheral side of the reinforcing plate 11, a hollow portion 12 where the reinforcing plate 11 does not exist is provided. The cavity portion 12 is provided over a substantially half-circumferential range along the lower portion on the inner peripheral hole 10a side. As shown in FIG. 3, the cavity 12 has a flat plate shape that is wide in accordance with the left-right width of the coupling portion 10. In FIG. 2, the range in which the cavity 12 is provided is indicated by the symbol E. Due to the hollow portion 12, the inner peripheral side of the coupling portion 10 is thinned, and the strength against impact (impact resistance) is lower than other portions. In the upper part of the coupling part 10 on the inner peripheral hole 10a side, the cavity part 12 is not provided, and there is only a gap formed by abutment of the left and right halved structures, which is more resistant than the lower part. The impact is high.

  The hanging tool S is coupled to the coupling tool 10 while being wound around both the reinforcing plate 11 and the cavity 12. For this reason, when the hand-held tool 1 falls or the like and an impact is applied to the coupling portion 10 via the hanging tool S, it is added to the cavity portion 12 having the lowest impact resistance. As a result, the cavity 12 is damaged such as cracks by impact. The user is informed that the joint 10 has been damaged by visually checking the inner circumference of the joint 10 for damage such as cracks. The hollow portion 12 functions as a notification means for visually notifying that the coupling portion 10 has been damaged.

  According to the coupling portion 10 of the first embodiment configured as described above, when an impact is applied to the coupling portion 10 through the hanging tool S, the inner peripheral hole 10a whose impact resistance is reduced by the cavity portion 12 is achieved. Damage (deformation) such as cracks on the side. The user is informed that the joint 10 has been damaged to such an extent that it cannot be used as it is by visually checking for damage such as cracks. By visually informing that the coupling portion 10 has been damaged, the operator can recognize that it is necessary to perform maintenance such as recovery of the coupling portion. The lowering function (function of the coupling portion) can be surely exhibited.

  FIGS. 4 and 5 show the coupling portion 20 according to the second embodiment. Similar to the first embodiment, the coupling portion 20 according to the second embodiment is provided at the rear of the rear case 7 and below the power cord 8. The joint portion 20 has an annular shape, and is integrally formed with the resin rear case 7 to have a half structure. In addition, about the site | part and structure which do not require a change, the description is abbreviate | omitted using a same sign.

  A hanging tool S is inserted into and coupled to the inner peripheral hole 20a of the coupling portion 20 of the second embodiment. In the case of the second embodiment, the rib 21 is provided over the inner peripheral hole 20a of the coupling portion 20 as a portion having low impact resistance. The rib 21 extends obliquely rearward from the upper part of the inner peripheral hole 20a and reaches the lower rear side of the inner peripheral hole 20a. The rib 21 has a flat plate shape with a constant width. Both end portions of the rib 21 are firmly coupled to the inner peripheral surface of the coupling portion 20. The rib 21 is provided with a bent portion 21a having a reduced thickness. The bent portion 21 a is provided at one place in the center of the rib 21 in the longitudinal direction.

  When an impact in the thickness direction is applied to the rib 21, the rib 21 is bent at the bent portion 21 a. For this reason, in 2nd Embodiment, the rib 21 functions as a site | part with low durability with respect to the impact added via the suspending tool S. FIG. The bent portion 21a may be omitted, and the entire rib 21 may be thinned and set as a portion having low impact resistance.

  Also by the coupling part 20 of the second embodiment exemplified above, the rib 21 is provided as a portion having low impact resistance, so that the user visually confirms the deformation of the rib 21 and the coupling part 20 is Recognize the fact of damage.

  FIG. 6 shows the coupling portion 30 of the third embodiment, and FIG. 7 shows the coupling portion 40 of the fourth embodiment. The coupling portions 30 and 40 of the third and fourth embodiments are also provided at the rear of the rear case 7 and below the power cord 8. The coupling portions 30 and 40 of the third and fourth embodiments also have an annular shape, and are formed integrally with the resin rear case 7 to have a halved structure. The suspending tool S is coupled to the coupling portions 30 and 40 by being inserted into the inner peripheral holes 30 a and 40 a of the coupling portions 30 and 40.

  An arcuate space 30b is provided inside the coupling part 30 of the third embodiment. A light emitting unit 31 using a light emitting diode (LED) as a light source is provided at an end of the space 30b. The light from the light emitting unit 31 is applied to the entire space 30b. The light emitting unit 31 is turned on when the handheld tool 1 is activated.

  When an impact is applied to the coupling portion 30 via the suspending tool S, and a crack C is generated in the coupling portion 30 as a result, light from the light emitting portion 31 leaks from the crack C. The user can recognize that the coupling portion 30 has been damaged by visually observing the light leaked from the crack C.

  An arcuate space 40b is provided inside the coupling part 40 of the fourth embodiment. Unlike the space portion 30b according to the third embodiment, the space portion 40b is a space portion that is hermetically sealed from the outside when the left and right half structures are abutted against each other. In the case of the fourth embodiment, the space 40b is filled with a fluorescent paint 41. The fluorescent paint is filled when the hand-held tool 1 is assembled.

  When an impact is applied to the coupling portion 40 through the hanging tool S and as a result, a crack C is generated in the coupling portion 40, the fluorescent paint 41 leaks from the crack C. The user can recognize that the coupling portion 40 has been damaged by visually observing the fluorescent paint leaking from the crack C.

  In the third and fourth embodiments, when the joints 30 and 40 are damaged, light and fluorescent paint leak from the cracks C and are visually informed, so that the user can detect the joints 30 and 40. The need for maintenance or the like can be recognized, and use of the handheld tool 1 can be avoided until the maintenance is completed. Maintenance of the coupling parts 30 and 40 according to the third and fourth embodiments can be performed by exchanging the rear case 7, for example.

  The embodiment described above can be further modified. For example, in the first embodiment, the configuration in which the cavity portion 12 is provided in the range indicated by “E” along the periphery of the inner peripheral hole 10a is illustrated, but the configuration in which the cavity portion provided over the entire circumference is provided or narrower It is good also as a structure which provided the cavity part in the range.

  Further, in the second embodiment, the configuration in which one rib 21 is provided is illustrated, but a configuration in which a plurality of ribs are provided over the inner peripheral hole 20a and a fold portion is provided in each of the ribs may be employed.

  Furthermore, although the coupling portions 10 to 40 formed integrally with the rear case 7 are illustrated, a coupling portion manufactured as a separate part in advance may be provided by screwing the rear case. By making the joints 10-40 separate from the rear case 7, it is possible to continue to use the hand-held tool if only the joints damaged during maintenance are replaced. It becomes possible to plan.

  Further, not only the rear part of the rear case 7 but also a connecting part for connecting the hanging tool S to other parts such as an upper part or a side part of the rear case 7 or an upper part or a side part of the main body part 3 is provided. It is good also as a structure which provides each alerting | reporting means illustrated to the coupling | bond part.

S ... Hanging tool 1 ... Hand tool (disc grinder)
DESCRIPTION OF SYMBOLS 2 ... Electric motor 3 ... Main body part, 3a ... Main body housing 4 ... Switch lever, 4a ... Lock-off lever 5 ... Gear head part, 5a ... Spindle 6 ... Grinding wheel, 6a ... Cover 7 ... Rear case, 7a ... Intake port, 7b ... Screw fixing boss portion, 7c ... engagement convex portion 8 ... power cord 10 ... coupling portion (first embodiment), 10a ... inner peripheral hole 11 ... reinforcing plate 12 ... cavity portion 20 ... coupling portion (second embodiment), 20a ... inner peripheral hole 21 ... rib, 21a ... bent portion 30 ... coupling portion (third embodiment), 30a ... inner circumferential hole, 30b ... space portion 31 ... light emitting portion 40 ... coupling portion (fourth embodiment), 40a ... inner peripheral hole, 40b ... space 41 ... fluorescent paint C ... crack

Claims (7)

A hand-held tool used by a worker to hold in his / her hand, comprising a coupling part for coupling a hanging tool, and a notification means for recognizing deformation of the coupling part by visual observation. The hand-held tool according to claim 1, wherein the joint portion is provided with a portion having high impact resistance and a portion having low impact resistance, and the portion having low impact resistance is deformed to serve as the notification means. . The hand-held tool according to claim 2, wherein the hand-held tool is provided with a hollow portion as a portion having low impact resistance. The hand-held tool according to claim 2, wherein a rib is provided around an inner peripheral side of the loop-shaped coupling portion as the portion having low impact resistance. The hand-held tool according to claim 1, wherein the notification means is provided inside the coupling portion. The hand-held tool according to claim 5, wherein a light source is provided as the notification means. 6. The hand-held tool according to claim 5, wherein the notifying means is filled with a paint.

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