JP2002254342A - Power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive power tool by reducing waste of elastomer and suppressing economic loss. SOLUTION: An extension portion 15' formed out of elastomer 15 is provided in a shaft direction of a motor 2 from a carbon brush insertion hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric or hydraulic power tool such as an impact driver or an impact wrench, and more particularly to an elastomer provided on a surface of a split housing.

[0002]

2. Description of the Related Art A conventional power tool will be described with reference to FIGS. FIG. 7 is a side view showing a split housing 1 (hereinafter referred to as a housing) of the power tool, and FIG.
It is a schematic side view which shows the working state which provides the elastomer 15, 15a on the surface of.

In FIG. 7 and FIG. 8, an impact driver or an impact wrench having an outer frame such as a housing 1 and a hammer case has a substantially T-shape, and a main body 1b formed by the housing 1 has A handle portion 1c which accommodates a motor as a drive source and a deceleration mechanism portion, and which is suspended from a body portion 1b, has a contact electrically connected to a trigger switch for supplying power to the motor and a connection terminal of a storage battery. Etc. are accommodated. Also,
A hammer case arranged in contact with the housing 1 accommodates a striking mechanism for converting the rotational power of the motor into a striking force, a tip tool holder such as a bit and a wrench (not shown), and the like.

In such a configuration, the rotational power of the motor is transmitted from the pinion, which is the output shaft of the motor, to the speed reduction mechanism, and the rotational force and the impact force are transmitted from the speed reduction mechanism to the tip tool via the impact mechanism. Have been.

The impact mechanism includes a spindle, a hammer rotatable through a steel ball (steel ball) inserted into a cam groove formed in the spindle and movable in the axial direction of the rotary shaft, and a plurality of hammers provided on the hammer. And a spring that constantly urges the hammer to the anvil side.

The reduction mechanism has a fixed gear support jig, a fixed gear, a planetary gear, and a spindle, which are supported in the housing 1 with a rotation stopper, and a rotating shaft of a planetary gear supported by the spindle. And a needle pin.

A pulsed impact (impact) applied to a screw or a nut tightened by a tip tool is supplied to the motor by operating a trigger switch, and the motor is driven to rotate. Is transmitted to the spindle via a planetary gear unit (planetary planetary gear, fixed gear) via a pinion connected to the spindle, and the steel ball disposed between the cam groove of the spindle and the cam groove of the hammer is used to transmit the power to the spindle. The rotating force is transmitted to the hammer, and the hammer claw of the hammer and the anvil claw of the anvil, which are urged forward (toward the tool bit) by a spring disposed between the hammer and the planetary gear of the spindle, engage with the anvil claw of the anvil. As a result, the anvil rotates, so that a rotational force is applied to the tip tool. When the tightening torque of the screw or the like by the tip tool exceeds a predetermined value, the engagement between the two claws is temporarily released because the hammer claw gets over the anvil claw. That is, when the tightening torque exceeds the predetermined value, the hammer resists the spring. To move (retreat) to the motor side. Thereafter, the hammer is pushed back in the anvil direction by the compression force of the spring, and the hammer claw collides with the anvil claw to generate a striking force. By repeating the rotation and the axial movement of the hammer in this manner, a continuous impact torque is given to the tip tool.

As described above, the surfaces of the main body 1b and the handle 1c formed by the housing 1 are provided with elastomers 15, 15a as shown in FIG. As shown in FIG. 8, the elastomers 15 and 15a are formed by injecting a molten elastomer from the inside of the two runners 16 '. In addition, elastomer 1
The purpose of providing 5, 15a is to prevent slippage for securely gripping the power tool, or to improve gripping comfort and operability and workability, and further, to absorb an impact when dropped on the ground. This is to prevent the power tool from being damaged or to prevent the power tool from sliding down along the slope when the power tool is placed on an inclined surface.

Therefore, the above-mentioned elastomers 15, 15a
Are mainly provided on the main body 1b and the handle grip 1c of the split housing 1. In addition, elastomer 1
5 and the elastomer 15a are provided at positions separated from each other, so that the power tool is held at two or more positions with respect to the grounding surface.

[0010]

As described above, when an elastomer is molded on the surface of a split housing,
As shown in FIG. 8, the molten elastomer was caused to flow into the two runners. By this method, the elastomer can be easily formed on the surface of the split housing. However, since the melted elastomer flows in the runner as described above, the elastomer not used for molding remains. The remaining elastomer disturbs the next injection step, and is cooled and solidified in the runner by a cooling device or the like. Thereafter, the solidified elastomer is taken out of the runner and discarded, so that the melted elastomer can be flown into the runner again. It should be noted that if the elastomer in the solidified runner is heated and melted and then reused, it takes time until the elastomer is melted, and a problem occurs that the newly flowing elastomer is deteriorated. In this method, the solidified elastomer is removed from the runner and discarded.

However, in the above-mentioned molding method, the amount of the remaining / discarded elastomer is larger than the amount of the elastomer used for molding, and the elastomer is expensive. There was a problem that the loss was large.

An object of the present invention is to provide an inexpensive power tool which solves the above-mentioned problems and reduces economical loss by reducing wasteful use of elastomer.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor as a drive source, a speed reduction mechanism for transmitting the rotational power of the motor, a split housing for accommodating the speed reduction mechanism and the motor and forming a handle. And an elastomer provided by two-layer molding from the vicinity of the carbon brush insertion hole formed in the split housing to the surface of the handle portion, the elastomer being formed from the carbon brush insertion hole in the axial direction of the motor by the elastomer. This is achieved by providing an extension.

[0014]

FIG. 1 shows a power tool according to this embodiment.
And FIG. FIG. 1 is a front view showing a power tool according to the embodiment, FIG. 2 is a rear view showing the power tool according to the embodiment, FIG. 3 is a right side view showing the power tool according to the embodiment, and FIG. FIG. 5 is a partially longitudinal plan view showing the power tool according to the present embodiment. FIG.
It is a schematic side view which shows the working state which provides.

In FIGS. 1 to 5, an impact driver or impact wrench having an outer frame such as a housing 1 and a hammer case 2 has a substantially T-shape, and is attached to a main body 1b formed by the housing 1. A motor 3 and a speed reduction mechanism 4 serving as a driving source, and a handle 2c hanging down from the body 1b.
And a contact 7 electrically connected to a connection terminal 6a of the storage battery 6 and the like. A hammer case 2 arranged in contact with the housing 1 houses a striking mechanism 8 for converting the rotational power of the motor 2 into striking force, and a tip tool holder 9 such as a bit or a wrench (not shown). Have been.

In such a configuration, the rotational power of the motor 2 is transmitted from the pinion 2a, which is the output shaft of the motor 2, to the speed reduction mechanism 4, and is rotated from the speed reduction mechanism 4 via the impact mechanism 8 to the tip tool. Force and impact force are transmitted.

The impact mechanism 8 includes a spindle 10 and
The hammer 12 is rotatable via a steel ball 11 (steel ball) inserted into a cam groove 10a formed in the spindle 10, and is movable by a plurality of hammer claws 12a provided on the hammer 12 in a rotational axis direction. It comprises an anvil 13 having a rotating anvil claw 13a, and a spring 14 for constantly biasing the hammer 12 toward the anvil 13.

The reduction mechanism 4 has a fixed gear supporting jig 4a, a fixed gear 4b, a planetary gear 4c, and a spindle 10 which are supported and provided with a rotation stopper in the housing 1, and are supported by the spindle 10. And a needle pin 4d serving as a rotating shaft of the planetary gear 4b.

A pulse-like impact (impact) given to a screw, a nut, or the like tightened by the tip tool is supplied to the motor 2 by operating the trigger switch 5, and the motor 2 is driven to rotate. The rotational power is transmitted to the planetary gear 4b via a pinion 2a connected to the tip of the motor 2, and the rotational power of the pinion 2a is transmitted to the needle pin 4 by meshing with the planetary gear 4c and the fixed gear 4b.
d to the spindle 10 via a steel ball 11 disposed between the cam groove 10b of the spindle 10 and the cam groove 12b of the hammer 12 to transmit the rotational force of the spindle 10 to the hammer 12; Spindle 10
Hammer 12 urged forward (toward the tool bit) by a spring 14 disposed between the hammer 12 and the planetary gear 4c.
When the hammer claw 12a of the anvil 13 and the anvil claw 13a of the anvil 13 are engaged with each other, the anvil 13 is rotated. When the tightening torque of the screw or the like by the tip tool becomes a predetermined value or more, the hammer claw 13a
Gets over the anvil claws 12a, so that both claws 12a, 13
When the engagement by a is temporarily released, that is, when the tightening torque becomes a predetermined value or more, the hammer 12 moves toward the motor 2 (retreats) against the spring 14. Thereafter, the hammer 13 is pushed back in the direction of the anvil 12 by the compression force of the spring 14, and the hammer claw 13a collides with the anvil claw 12a to generate a striking force. By repeating the rotation and the axial movement of the hammer in this manner, a continuous impact torque is given to the tip tool. The power tool is provided with a rotatable hook 17 for hanging the power tool on a waist belt or the like of an operator.

An elastomer 15 is formed on the surface of the housing 1 of the power tool having the above-described speed reduction mechanism 4 by two-layer molding. The purpose of providing the elastomer 15 is to prevent slippage for securely gripping the power tool, or to improve gripping comfort and operability and workability, and to further absorb an impact when dropped on the ground. This is to prevent the power tool from being damaged and to prevent the power tool from sliding down along the slope when the power tool is placed on the inclined surface. Therefore, the elastomer 15 is mainly provided on the handle grip 1c of the split housing 1.
And on the rear surface of the main body 1b.

As shown in FIG. 6, in order to mold the elastomer 15 on the surface of the split housing 1, a melted elastomer is caused to flow into one runner 16. Conventionally, when molding the elastomers 15 and 15a at two places on the surface of a split housing, two runners 1
In this embodiment, the elastomer 15 can be formed by two layers from the vicinity of the carbon brush insertion hole to the surface of the handle portion with one runner 16 as described above. This is because the elastomers 15 and 15a can be molded at a stretch by providing the extending portions 15 '(connecting portions) for connecting the elastomers 15 and 15a shown in FIG. Therefore, since the number of runners 16 can be reduced from two to one, the runners 16
Because the amount of elastomer remaining in the interior can be reduced, the amount of waste of the elastomer can be reduced as compared with the conventional case, so that the waste of expensive elastomer can be reduced, and the cost can be reduced by suppressing the economic loss. Power tool can be provided.

Further, by providing the extending portion 15 'as in this embodiment, the bonding area of the elastomer 15 formed on the surface of the split housing 1 is increased, so that the elastomer 15 can be split more firmly. It can be provided on the surface of the housing 1, and furthermore, since the area of the elastomer 15 on the surface of the split housing 1 increases, the power tool may be damaged when dropped on the ground or inclined when the power tool is placed on an inclined surface. It is possible to further prevent the power tool from sliding down.

[0023]

According to the present invention, by providing an extending portion formed of an elastomer in the axial direction of the motor from the carbon brush insertion hole, waste of the elastomer is reduced and economic loss is suppressed. An inexpensive power tool can be provided.

[Brief description of the drawings]

FIG. 1 is a front view showing a power tool according to the present invention.

FIG. 2 is a rear view showing the power tool according to the present invention.

FIG. 3 is a right side view showing the power tool according to the present invention.

FIG. 4 is a vertical sectional front view showing the electric tool according to the present invention.

FIG. 5 is a partially longitudinal plan view showing an electric tool according to the present invention.

FIG. 6 is a schematic side view showing an operation state of providing an elastomer on a surface of a housing according to the present invention.

FIG. 7 is a side view showing a split housing of a conventional power tool.

FIG. 8 is a schematic side view showing an operation state of providing an elastomer on a surface of a conventional housing.

[Explanation of symbols]

1 is a split housing, 1a is a mating portion, 1b is a main body portion, 1c is a handle portion, 1d is a storage battery housing portion, 2 is a motor, 2a is a pinion, 3 is a hammer case, 4 is a reduction mechanism portion, and 4a is Fixed gear support jig, 4b is a fixed gear, 4c is a planetary gear, 4d is a needle pin, 5 is a trigger switch,
6 is a storage battery, 6a is a connection terminal, 7 is a contact, 8 is a striking mechanism, 9 is a tip tool holder, 10 is a spindle, 10a is a cam groove, 11 is a steel ball, 12 is a hammer, 12a
Is a hammer claw, 12b is a cam groove, 13 is an anvil, 13a
Is an anvil claw, 14 is a spring, 15 and 15a are elastomers, 15 'is an extended portion (connection portion), 16 and 16' are runners, and 17 is a hook.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinji Miura 1784 Oji Urushiyama, Yamagata City, Yamagata Prefecture Hitachi Koki Yamagatanai Co., Ltd.

Claims (1)

[Claims] 1. A motor as a drive source, a speed reduction mechanism for transmitting rotational power of the motor, a split housing for accommodating the speed reduction mechanism and the motor and forming a handle portion, An electric tool comprising an elastomer provided by two-layer molding from the vicinity of the carbon brush insertion hole formed in the split housing to the surface of the handle portion,
An electric tool, wherein an extension portion formed by the elastomer is provided in the axial direction of the motor from the vicinity of the carbon brush insertion hole.