JP2004114251A - Hammering tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent insufficiency of lubricant, to reduce the weight of a piston, vibration, and cost, and to lengthen a service life in an aluminum cylindrical piston, in an electric hammer drill having: a reciprocating bearing to convert rotation of a motor into a reciprocating motion; and the piston connected to the reciprocating bearing to reciprocatively move. <P>SOLUTION: By adopting a cylindrical piston made of resin, more particularly, resin having self-lubricity and making the piston itself play the role of the lubricant, even if the lubricant becomes insufficient, the service life is improved as compared with the aluminum cylindrical piston. Since the piston is made of resin, the weight, vibration, and cost are reduced. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a striking tool such as an electric hammer drill having a rotation + stroke mode and a rotation-only mode, which employs a resin-made cylindrical piston to reduce weight, reduce vibration, reduce cost, and prolong life. Things.
[0002]
[Prior art]
In the conventional hammer shown in FIG. 2, the electric hammer uses a resin piston, so that it is lightweight, low-vibration, and low-cost. Weight, high vibration and high cost.
[0003]
The conventional electric hammer drill shown in FIG. 3 uses an aluminum cylindrical piston, and has a configuration in which a seal member is provided on a striker that reciprocates inside the cylindrical piston. Therefore, there is a problem that the lubricant is insufficient in the rotation + impact mode, the seal member is melted by frictional heat, and the life is shortened. Furthermore, the use of an aluminum piston resulted in high weight, high vibration and high cost.
[0004]
[Problems to be solved by the invention]
As described above, in the conventional electric hammer drill as shown in FIG. 3, since the aluminum cylindrical piston is used, the life is short, the weight is high, the vibration is high, and the cost is high. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems of the prior art and achieve a reduction in the weight of the piston, a reduction in vibration, a reduction in cost, and a longer life.
[0005]
[Means for Solving the Problems]
The above object is achieved by employing a resin-made cylindrical piston.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of an electric hammer drill according to the present invention. The rotational force of the motor 1 is transmitted to the second shaft 11 via the first gear 2, constantly transmits the rotation to the second gear 6 meshing with the second pinion 11 a on the second shaft 11, and is rotated to the tip tool via the cylinder 5. Had been given. On the other hand, the clutch 12 which is always in spline engagement with the second shaft 11 and the reciprocating bearing 3 rotatably fitted on the second shaft 11 are engaged by claws, and the motor 1 transmitted to the second shaft 11 Is converted into reciprocating motion of the cylindrical piston 4 by the reciprocating bearing 3. The cylindrical piston 4 has a striker 8 inside, and the air chamber 7 fluctuates in air pressure due to the reciprocation of the cylindrical piston 4, and the striker 8 reciprocates due to the air pressure fluctuation, and passes through the meson 10. The striking force is transmitted to a tip tool not shown.
[0007]
Therefore, in the present invention having the above-described structure, since a cylindrical piston made of a resin, particularly a resin having self-lubricating properties, is used, even if the lubricant is insufficient in the rotation + stroke mode, the piston itself is not lubricated. By fulfilling the role, the life can be greatly improved as compared with the cylindrical piston made of aluminum, and since it is made of resin, the weight, vibration and cost can be reduced.
[0008]
【The invention's effect】
According to the present invention, since a cylindrical piston made of resin, particularly resin having self-lubricating properties, is employed, the piston itself plays a role of a lubricant even when the lubricant is insufficient in the rotation + stroke mode. Thereby, the life can be greatly improved as compared with the cylindrical piston made of aluminum, and the weight can be reduced, the vibration can be reduced and the cost can be reduced due to the resin.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a hammer drill according to the present invention.
FIG. 2 is a longitudinal sectional view of a conventional hammer drill using an aluminum piston.
FIG. 3 is a longitudinal sectional view of a conventional hammer drill using a cylindrical piston made of aluminum.
[Explanation of symbols]
1 is a motor, 2 is a first gear, 3 is a reciprocating bearing, 4 is a cylindrical piston (made of resin), 5 is a cylinder, 6 is a second gear, 7 is an air chamber (air spring), 8 is a striker, 9 Is a seal member (O-ring), 10 is a meson, 11 is a second shaft, 12 is a clutch, 11a is a second pinion, 4a is a piston (made of aluminum), and 4b is a cylindrical piston (made of aluminum).

Claims (1)

A motor serving as a driving source, a reciprocating bearing for converting the rotational force of the motor into reciprocating motion, and a reciprocating cylindrical piston connected to the reciprocating bearing. The electric hammer drill, which has a striking mechanism for transmitting the striking force to the tip tool and a rotation transmitting mechanism for transmitting the turning force to the tip tool, employs a resin-made cylindrical piston. And hammering tools.

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