JPH0588883U - Impact tool dustproof device - Google Patents

Abstract

(57) [Summary] [Configuration] A scraper 10 is provided on the packing 8 in contact with the brim 7 of the chisel 3 and the end of the wear bush 4, and the sliding surface of the chisel near the packing. [Effect] The foreign matter is prevented from entering the sliding surface of the chisel by the packing, and after passing through the packing, the foreign matter is discharged by the scraper to improve the dustproof effect.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dustproof device for an impact tool, and more particularly, to a dustbreaker for a hydraulic breaker that can be used in an atmosphere such as a tunnel where dust, earth and sand are often present.

[0002]

[Prior Art]

 By switching the hydraulic passage of the control valve, the striking piston reciprocates up and down, and the striking piston strikes the head of the chisel inserted in the casing to give an impact motion, and a hydraulic breaker that crushes rock etc. at the tip of the chisel is created. Known as an impact tool.

When the hydraulic breaker is used in an atmosphere such as a tunnel where a lot of dust and earth and sand are present, dust and the like enter the sliding surface between the casing and the chisel, and further enter the impact chamber and the sliding surface of the chisel. There is a problem that the sliding surface of the impact piston is damaged, and further, the hydraulic equipment of the mounting truck such as the power shovel that operates the hydraulic breaker is damaged.

To solve this problem, it has been proposed, for example, in Japanese Utility Model Application Laid-Open No. 63-113578 to attach a collar to the chisel and provide packing between the casing end and the collar of the chisel. However, such a conventional device has a drawback that the dustproof effect is still insufficient.

[0005]

[Problems to be solved by the device]

 An object of the present invention is to solve the above conventional problems and provide a dustproof device for an impact tool that protects a chisel, a striking piston, and the like from damage due to dust.

[0006]

[Means for Solving the Problems]

 The present invention solves the above-mentioned problems between a casing and a chisel of an impact tool having a striking piston that is reciprocated by switching hydraulic passages and a chisel with a collar that is fitted into the casing and is striking by the striking piston. In a dustproof device for preventing foreign matter from entering, there is a packing installed between the casing end surface and the brim of the chisel, and a scraper provided on the sliding surface of the casing and the chisel at a position close to the packing. It was solved by a dustproof device for impact tools featuring a two-stage sealing device.

[0007]

[Action]

 According to the present invention, external dust is prevented from entering the sliding surface of the chisel through the gap formed between the casing and the chisel by the elastic packing installed between the flange of the chisel and the end of the casing. To be done. Even if there is dust or other foreign matter that enters through the packing, a scraper is provided near the packing to prevent further entry of foreign matter along the sliding surface between the chisel and the casing. , Is affected by the scraper. Therefore, the dustproof effect is improved.

[0008]

【Example】

 The details of the present invention will be described based on an embodiment shown in the drawings.

In FIG. 1, an impact tool, such as a hydraulic breaker, has a casing 1, a striking piston 2 that slides in the casing 1, and a chisel 3.

The chisel 3 is formed with a collar 7 projecting outward at an intermediate portion thereof, that is, near an upper end portion of a portion which is not inserted into the wear bush 4. A ring-shaped packing 8 is attached to the side of the chisel 3 that is inserted into the wear bush 4, and the packing 8 is located between the brim 7 of the chisel 3 and the end surface of the wear bush 4, and the brim with the chisel 3 pressed down. The close contact between the wear bush 4 and the wear bush 4 prevents foreign matter such as sand and dust from entering the sliding surface between the wear bush 4 forming a part of the casing and the chisel 3. It The packing 8 is made of an elastic material and is configured to maintain a close contact with the flange 7 and the end surface of the wear bush 4 even when the chisel 3 reciprocates. Near the end of the wear bush 4 facing the brim 7, that is, near the packing 8, the scraper 10 is mounted in the ring groove 9 formed in the wear bush 4, and the tip of the scraper 10 has an outer peripheral surface of the chisel 3. The scraper 10 has an edge portion that slides in pressure contact with the foreign matter, which enters through the packing 8 by the scraper 10. The sealing device for preventing intrusion of shopping is formed as a two-stage sealing device by the packing 8 and the scraper 10. The scraper 10 has a function of scraping foreign substances that enter the casing 1, and the dust that has passed through the packing 8 for some reason is reliably removed and discharged by the scraper 10.

The scraper 10 has its tip edge abutted on the outer peripheral surface of the chisel 3, and the scraper 10 is formed so as to discharge the intruding dust downward in the drawing.

[0012]

[Effect of the device]

 According to the present invention, dust entering the sliding surface of the chisel can be reliably discharged by the packing and scraper forming the double seal device, the dustproof effect is improved, and the sliding surface of the chisel and the striking piston are improved. Wear was prevented, and damage to the hydraulic system that operated the striking piston due to dust was also prevented.

[Submission date] April 22, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The chisel 3 is formed with a collar 7 projecting outward at an intermediate portion thereof, that is, near an upper end portion of a portion which is not inserted into the wear bush 4. A ring-shaped packing 8 is attached to the side of the chisel 3 to be inserted into the wear bush 4, and the packing 8 is located between the brim 7 of the chisel 3 and the end surface of the wear bush 4, and the chisel 3 is pressed. The close contact between the brim 7 and the wear bush 4 prevents foreign matter such as sand and dust from entering the sliding surface between the wear bush 4 forming a part of the casing and the chisel 3. To be done. The packing 8 is made of an elastic material and is configured to maintain a close contact with the flange 7 and the end surface of the wear bush 4 even when the chisel 3 reciprocates. A scraper 10 is mounted in a ring groove 9 formed in the wear bush 4 near the end of the wear bush 4 facing the brim 7 and near the packing 8, and the tip of the scraper 10 is attached to the chisel 3. The outer peripheral surface has an edge portion that slides under pressure, and foreign matter that enters through the packing 8 is discharged by the scraper 10. Sealing device for preventing intrusion of foreign matter is formed as a two-stage sealing device by the packing 8 and the scraper 10. The scraper 10 has a function of scraping foreign substances that enter the casing 1, and the dust that has passed through the packing 8 for some reason is reliably removed and discharged by the scraper 10.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a hydraulic breaker according to the present invention.

[Explanation of symbols]

 1 case 2 striking piston 3 chisel 4 wear bush 7 collar 8 packing 10 scraper

Claims (1)

[Scope of utility model registration request] 1. A foreign matter invasion between a casing and a chisel of an impact tool having a striking piston reciprocated by switching a hydraulic passage and a chisel with a collar fitted into the casing and hit by the striking piston. In a dustproof device for preventing, a two-stage sealing device having a packing mounted between an end surface of a casing and a brim portion of a chisel and a scraper provided on a sliding surface of the casing and the chisel at a position close to the packing, A dustproof device for impact tools.