JPH0333428Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lubrication and cooling structure for the striking part of an air impact wrench.

[Conventional technology and its problems]

Currently, air-driven impact wrenches are small, lightweight, and safe, so they are widely used for various types of screw tightening work in all industries, including automobiles, light electrical appliances, and construction.

Impact wrenches generally tighten screws that are engaged with the tip of an anvil using rotational and striking motions, but conventional impact wrenches use a system that allows the exhaust gas from the air motor, which contains lubricating oil, to be discharged directly into the atmosphere. It's getting old. As a result, due to the intense rotation and striking motion of several thousand times per minute, the striking part cannot always be kept in a lubricated state, and the parts of the striking part are subject to significant wear and damage due to friction.
The surface temperature of the parts rises (in the absence of lubrication, the temperature at the engagement points between the hammer and anvil and the hammer and driver shown in Figures 2 and 3 rises to 200 to 300 degrees Celsius, and in local areas at the time of impact). (up to nearly 1000℃), which is the biggest cause of impact wrench performance degradation, unstable hitting, and stopping of impact wrenches.

For this reason, in the past, methods such as applying a large amount of grease to the striking part or filling the striking part with oil were used to keep the striking part in an appropriate lubricated state as a means of reducing wear and heat generated by friction. There is.

However, in the former method, the centrifugal force caused by rotation and the impact movement cause the grease to scatter immediately, making it ineffective. An impact clutch has been devised that uses plate blades to scrape up the waste and push it into the clutch frame, but this has problems such as wear of the plate blades and increased sliding resistance, and has no cooling effect. In addition, in the latter method, fine metal powder, etc. generated by impact or rotational movement is continuously used while still being contained in the oil, which may accelerate wear or cause the phenomenon of gating. or

[Means for solving problems]

The impact wrench of the present invention has a conduit that communicates the exhaust chamber of the air motor section and the striking section in order to maintain the striking section in a lubricated state and to forcibly cool the striking section to solve the above problems. , one opening is provided so as to face the hammer of the striking mechanism section, and an exhaust hole is provided to the atmosphere from the front of the striking section (the left side in Figure 1, the tip side), thereby reducing the low temperature after the air motor is driven. Blow oil-impregnated air onto the striking mechanism,
After the striking mechanism is forcibly lubricated and cooled, the air is exhausted from the front exhaust hole.

[Effect]

The operation of the above structure will be described, and the rotation/impact mechanism is the same as that of a conventional impact wrench.

By operating the lever on the handle part, air flows in through the air supply valve 5, flows into the air motor part while sucking lubricating oil in the oil tank 6, rotates the motor, and then is exhausted into the exhaust chamber 8. . The low-temperature oil-containing air in the exhaust chamber is blown onto the striking mechanism section through a pipe 16 communicating with the striking chamber 10, lubricates and cools the striking section, and then is discharged to the atmosphere from an exhaust hole 17 provided in the front. .

During the operation of the impact wrench, the above actions are performed continuously, so the striking part is always kept at a low temperature and lubricated state, which has the great advantage of reducing performance loss, malfunction, and wear and tear of parts. It will be done.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal cross-sectional view of an impact wrench showing a first embodiment, and FIGS. 2 and 3 are cross-sectional views at - and - of FIG. 1, respectively. FIG. 4 shows a second embodiment.

The impact wrench 1 consists of a striking part 2, an air motor part 3, and a handle part 4, and the handle part has an air supply valve 5 that is opened and closed by a lever, and an oil tank 6 (this oil tank is connected to the air supply line to the impact wrench). ) etc. may be provided.

The air motor section is provided with an air motor 7, which is rotated by oil-containing air sucking an appropriate amount of lubricating oil from an oil tank 6 after flowing in through an air supply valve, so that its tip protrudes toward the striking section side. 8 is an exhaust chamber for air from the air motor. In the striking section connected to the front of the air motor section (the left side in the figure), a striking mechanism section is incorporated in a striking chamber 10 within the case 9.
This striking mechanism includes a driver 11 that is spline-coupled to the tip of the air motor and rotates integrally with the air motor, a hammer 12 that has a protrusion 12b that engages with a recess 11a of the driver, and a hammer 12 that is rotatably pivoted in a hammer frame 13. The anvil 15 has a convex portion 15b that engages with a concave portion 12a of the hammer. In the case 9 of the air motor section and the striking section, there is a conduit 16 that communicates the exhaust chamber 8 and the striking chamber 10.
is provided so that one opening is in a position facing the hammer 12 of the striking mechanism section, and a plurality of exhaust holes 17 are provided in the front wall of the striking chamber.

In the above configuration, the oil-impregnated air that has sucked the lubricating oil from the oil tank 6 rotates the air motor and is discharged into the exhaust chamber 8 as low-temperature oil-impregnated air. During the operation of the impact wrench, this low-temperature, oil-containing air is constantly blown through the pipe 16 directly to the collision area between the hammer and anvil in the striking chamber, forcibly lubricating and cooling the striking mechanism, and then passing through the exhaust hole 17. Since it is discharged from the machine, it rotates. Even after the initially applied grease is scattered due to impact, the low-temperature, oil-containing air circulates within the impact chamber and is then discharged from the front exhaust hole, so the impact mechanism remains lubricated and operates smoothly. There is no sudden temperature rise at the impact point.

FIG. 4 shows an embodiment in which a second oil tank 18 is further provided in the striking part of the impact wrench shown in FIG. 19 is a small hole connecting the oil tank to the pipe line 16.

In this embodiment, the oil-laden air passing through the line 8 transfers the lubricating oil in the second oil tank 18 to the small hole 19.
The air containing more oil is blown onto the striking mechanism while being sucked in through the air.

〔effect〕

The present invention has the above configuration and has the following effects.

(1) Since the striking mechanism is always kept lubricated and cooled by low-temperature exhaust gas, rapid temperature rises are suppressed, and the durability of striking parts is dramatically improved, making tool maintenance easier.・Management costs will be significantly reduced.

Example of experimental results: The oil film breakage life with the conventional grease application method is approximately 60 hours, while with the method of this invention it is approximately 300 hours or more (2) The striking part operates stably over a long period of time, improving the tightening accuracy of bolts, etc. .

(3) Fewer failures and better productivity.

(4) The above effects can be obtained by simply modifying a conventional impact wrench.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an impact wrench showing an embodiment of the present invention, FIGS. 2 and 3 are cross-sectional views - and - of FIG. 1, and FIG. 4 shows another embodiment. 2...Breaking part, 6...Oil tank, 7...Air motor, 8...Exhaust chamber, 9...Case, 10...Breaking chamber, 11...Driver, 12...Hammer, 15
...anvil, 16...pipeline, 17...exhaust hole,
18...Oil tank, 19...Small hole.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In an impact wrench 1 consisting of a striking part 2, an air motor part 3, and a handle part 4, a conduit 16 that communicates an exhaust chamber 8 of the air motor part with a striking chamber 10 of the striking part is provided. This conduit 1 is drilled in the case 9.
An impact wrench characterized in that one end of the impact wrench is opened at a position facing a hammer 12 of a striking mechanism part, and an exhaust hole 17 is provided at a front position of a case 9. (2) The impact wrench according to claim 1 of the utility model registration, characterized in that the case 9 is provided with an oil tank 18 that is connected to the pipe line 16 through a small hole 19.