JPH0741549B2 - Impact tool - Google Patents

Description

The present invention relates to an impact tool for perforating concrete or the like.

"Prior Art" An impact tool for drilling concrete is a tool that impacts a bit in the axial direction and rotates the bit at the same time, and a tool body has an impact mechanism and a rotation mechanism.

The striking mechanism is generally provided with a striker that reciprocates in the cylinder due to fluctuations in air pressure, and is configured to strike the head of the bit directly or via an intermediate element.

In addition, the rotating mechanism is generally configured to rotate the bit separately from the striking mechanism, and is equipped with a clutch to prevent the tool body from rotating when the rotation of the bit is restricted. is there.

Lubricating oil is required for these striking mechanism and rotating mechanism, so that the portion communicating with the outside such as a bit is sealed to confine the lubricating oil inside.

The lubricating oil contained in this way acts as a lubricating oil on a necessary moving part by vigorous motion of the rotating mechanism and the striking mechanism.

"Problems to be solved by the invention" However, the inside of the cylinder of the striking mechanism, which is the most violent motion, becomes inadequate unless it is forcedly circulated in the case of lubricating oil, especially crease, and it forms between the cylinder of the striker. The packing and the like to be worn are easily worn. Also,
Lubricating oil may decrease due to long-term use, or may be unevenly distributed to the bit side due to movement of the striker and may not act on the striker much.

This shortens the life of the impact tool, which often had to be disassembled for repair.

The present invention has been made in view of such circumstances,
The purpose of the invention is to forcibly circulate the lubricating oil, solve the problems, and construct a highly reliable impact tool.

"Means for Solving Problems" The present invention provides a drive gear that covers the striking mechanism, and a coil spring is provided on the outer periphery of the drive gear.
The problem is solved by forming a rotating mechanism through a clutch that utilizes the pressing force of the coil spring and forming a through hole in the drive gear that communicates with the striking mechanism.

"Operation" As the coil spring rotates, the screw pump acts to form a circulation path for the lubricating oil through the through hole, so that the lubricating oil effectively acts on the striker, which tends to lack the lubricating oil.

Then, since the lubricating oil does not stop inside the striking structure, uneven distribution of the lubricating oil is eliminated, and a small amount of lubricating oil effectively acts on the moving part.

[Examples] The present invention as described above will be explained based on an example shown in the drawings. The drawings are longitudinal cross-sectional views of a main part of an impact tool showing an example of the present invention.

An electric motor 2 is provided inside the case 1, and a shaft 3 of the electric motor 2 is transmitted to a striking mechanism 4 and a rotating mechanism 5 to strike and rotate a bit (not shown).

In the striking mechanism 4, the rotation of the shaft 3 of the electric motor 2 rotates the intermediate shaft 6 via a reduction gear (not shown), and the swash plate cam 7 configured on the intermediate shaft 6 causes the piston 8 to reciprocate.
The cylinder 9 and the striker 10 are configured to strike the meson 11.

The rotating mechanism 5 is configured to rotate a drive gear 12 configured to cover the outer circumference of a cylinder 9 that constitutes the striking mechanism 4, via an intermediate shaft 6 via a gear (not shown). , Is connected to the intermediate member 11 via balls 13.

Further, the ball 13 is provided with an inclined plate 14 so that the connection between the drive gear 12 and the intermediate element 11 is released, and the inclined plate 14 is pressed by a coil spring 15 provided on the outer periphery of the drive gear 12. Form a clutch.

Further, the drive gear 12 is formed with a through hole 16 communicating with the striking mechanism 4, and a coil spring 15 arranged on the outer periphery of the drive gear 12 is configured to rotate together.

The coil spring 15 is configured so that when it rotates together with the drive gear 12, a screw pump action is exerted from the intermediate member 11 side to the cylinder 9 side.

With such a configuration, when the impact tool is operated by filling the case 1 with lubricating oil, the lubricating oil acts on the moving parts such as the striking mechanism 4 and the rotating mechanism 5 to ensure smooth operation. .

Then, the coil spring 15 is rotated by the rotation of the drive gear 12, and the lubricating oil is moved from the clutch portion constituted by the inclined plate 14 toward the cylinder 9 by the screw pump action.

Then, by this movement of the lubricating oil, the internal lubricating oil of the striking mechanism 4 enters from the through hole 16 of the drive gear 12, and further moves toward the clutch by the striker 10 to form a circulation path.

Since the through hole 16 causes a pressure fluctuation due to the reciprocating movement of the striker 10 of the striking mechanism 4, even the through hole 16 having a small diameter can effectively operate.

When such a lubricating oil circulation path is formed, the lubricating oil is forcibly circulated in the portion of the striker 10 that performs the most violent motion of the striking mechanism 4, causing a shortage of the lubricating oil or a locally aged lubricating oil. Can be solved.

When the coil spring 15 has a rectangular cross section, the action of the screw pump is increased, and sufficient circulation of the lubricating oil can be obtained even when the drive gear 12 rotates slowly.

Therefore, even high-viscosity lubricating oil such as grease can be used without any problems.
By making the outer diameter side of the casing a casing, the screw pump action by the coil spring 15 becomes extremely strong, and the lubricating oil can be forcibly circulated to each part by any configuration, and epoch-making results can be obtained. To be

[Advantages of the Invention] According to the present invention, the lubricating oil is effectively circulated even in a striking mechanism such as a striker in which the circulation of the lubricating oil is poor, and stable operation can be performed for a long period of time. Since it is not necessary to fill the case with oil and reliable circulation of the lubricating oil can be obtained, a highly reliable impact tool can be obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of an impact tool showing an embodiment of the present invention. 1 ... Case, 4 ... Impact mechanism, 5 ... Rotation mechanism, 6 ...
… Intermediate shaft, 9 …… Cylinder, 10 …… Strike, 11 ……
Meson, sleeping 12 …… Drive gear, 15 …… Coil spring, 16 …… Through hole.

Claims (2)

[Claims] 1. An impact tool comprising a striking mechanism and a rotating mechanism for striking and rotating a bit, wherein a drive gear covering the striking mechanism is provided, and a coil spring is provided on the outer periphery of the drive gear. An impact tool characterized in that a rotation mechanism is configured via a clutch that utilizes a pressing force of a spring, and a through hole communicating with the striking mechanism is formed in the drive gear. 2. The impact tool according to claim 1, wherein the coil spring has a rectangular cross section.