SU1535711A1 - Air-operated hammer - Google Patents

Abstract

The invention is intended for use in construction and mining. The goal is to increase reliability by reducing frostbite. A pneumatic hammer contains a barrel 1, on top of which a glass 6 is fixed to an air distribution device 8. The barrel 1, the glass and device 8 form an end cavity 15 between them, communicated with an additional longitudinal channel 17. The cavity 15 and channel 17 form a reservoir for lubricant. During operation, the lubricant is intensively mixed and transfers heat from the heated sections of the barrel 1 to its cooling section. 1 hp f-ly, 1 ill.

Description

The invention relates to pneumatic percussion machines, namely, jackhammers, concrete breakers, perforators, etc., which are used in the construction, mining and other industries.

The purpose of the invention is to increase reliability by reducing frostbite.

The drawing shows a pneumatic hammer, longitudinal section.

A pneumatic hammer consists of a barrel 1, in the central channel 2 of which a drummer 3 is placed, dividing the barrel 2 of a working chamber 4 and a blank 5 stroke.

A cup 6 is screwed on the upper end of the barrel 1, the threaded joint of which is sealed with a rubber ring 7. Between the ends of the barrel 1 and the cup 6 an air distribution device 8 is installed, consisting of a box 9, in the upper part of which a valve 11 is laterally moved. The groove 10 with its end communicates with the channel 12 in the glass 6, the channel 13 in the box 9 and the longitudinal channel 14 in the barrel 1 - with the idling chamber 5 and with the working stroke chamber 4. The barrel 1, the barrel 6 and the air-distributing device 8 form between each other an end cavity 15, which through an opening 16 in the box 9 communicates with an additional longitudinal channel 17 in the barrel 1 which is made to the full length of the latter.

The end cavity 15 and the additional longitudinal channel 17 form a reservoir for the lubricant 18.

In places adjacent to each other, the barrel 1 and the box 9 formed a gap

19, and boxes 9 and glasses 7 - a gap

20. The gap 20 communicates with the axial channel 12 in the glass 6 for supplying compressed air to the air distribution device 8 and with the end cavity 15. The gap 19 communicates the end cavity

15 with central channel 2, the totality of these elements forms a system

five

about

five

Q 5

-Q

five

five

Subject for the supply of lubricant 18.

Pneumatic hammer works as follows.

Compressed air supplied to the axial channel 12 alternately, depending on the position of the valve 11, through the groove 10, channel 13, and the longitudinal channel is fed into the idle chamber 5 or the working 4 stroke of the central channel 2 and causes the hammer 3 to reciprocate. As a result, the latter strikes the working tool 21. The exhaust air from the feces 2 is exhausted through the opening 22.

During operation, the air in the chambers of worker 4 and idling 5 is heated by compressing and cooling it in the area of the orifice 22 due to a sharp expansion during exhaust. As a result, the upper and lower parts of the barrel 1 are heated, and a part of it in the zone of the hole 22 is cooled. The lower part of the barrel 1 is also heated by collisions with the working tool. The lubricant is in continuous motion due to a change in the position of the hammer in the space during its operation and due to vibration. In this case, there is an intensive transfer of heat from the heating parts of the barrel 1 to its cooling partly. This is facilitated by the higher thermal conductivity of the lubricant 18 as compared with the material of the barrel 1 (as a rule, steel). Thus, the temperature of the barrel 1 in the zone of the exhaust port 22 rises, which contributes to the reduction of frost "

Lubrication of the hammer is as follows. The barrel 1, the box 9 and the cup 6 are under the influence of shock pulses due to the collisions of the barrel 1 with the working tool 21. At the same time, these parts experience alternate compression and stretching, and the gaps 19 and 20 change in different dimensions. Compressed air and channel 12 through the gap 20 periodically enters the end cavity 15 and creates an overpressure in it, under the influence of which lubricant 18 also periodically through the gap 19 enters the central channel 2 for lubrication. The dimensions of the gaps 19 and 20, and consequently, the consumption of the lubricant 18, are controlled by the pulling force of the cup 6 on the barrel 1.

Claims (2)

1. A pneumatic hammer containing a barrel with a central and longitudinal channels, a hammer located in the central channel, dividing the barrel cavity into the worker’s chambers and 0 five 0 idling covering the barrel with the formation of the end cavity of the cup with an axial bore for supplying compressed air, installed between the ends of the barrel and the cup air distribution device, tank and lubricant supply system, characterized in that, in order to increase reliability by reducing freezing, the tank for The lubricant is an additional longitudinal channel communicated with the end cavity. 2. A hammer according to Claim 1, characterized in that the system for supplying a lubricant is formed by gaps between the surfaces of the barrel, the air-distributing device and the barrel.