SU754054A1 - Pneumatic jack hammer - Google Patents

Description

(54) PNEUMATIC HAMMER

one

The invention relates to mining and construction percussion machines and can be used in the creation of manual pneumatic hammers, as well as heavy pneumatic impact machines for the destruction of rocks and frozen soils.

According to the main author. St. No. 658268 is known for a pneumatic hammer with a stepped drummer, having a housing with air inlet, exhaust pipes and a central stepped channel in which a stepped impactor with axial and radial channels is installed with the possibility of reciprocating motion. The drummer forms with the hull a controlled working stroke chamber, an annular network pressure chamber, which is an idling chamber and constantly communicating with a source of compressed air, an accumulation chamber and an atmospheric pressure chamber.

The accumulator chamber is communicated by the choke with the mains pressure chamber. The hammer also contains a handle with a starting device, an exhaust ring that forms an exhaust chamber and a working tool with the outer surface of the housing.

The accumulation chamber fed from the network pressure chamber through the throttle channel in the annular body hull increased the average air pressure in the working stroke chamber 5 as the striker moved in the direction of the tool and reduced the peak pressure in the said chamber during idling when they communicated.

As a result, the energy of a single blow has increased significantly. The vibration and power characteristics of the pneumatic hammer also improved.

However, the presence of a constant back pressure from the side of the idling chamber, at a certain calculated area of the ring of the firing stage, over the entire duration of the working stroke, is fading. This causes losses from 10 to 20% of the magnitude of the energy of a single impact, while reducing from 5 to 10% of the frequency of impacts, as with constant braking, 20 times the working stroke increases.

The purpose of the invention is to increase the energy of a single blow by obtaining an additional impulse to idle. The goal is achieved due to the fact that the hammer has a pneumatic buffer chamber located in front of the atmospheric pressure chamber relative to the working tool and periodically communicated with it, these chambers are separated by an annular sealing isthmus, which is made on the inner surface of the housing. The drawing shows a pneumatic hammer with a partial longitudinal incision. The hammer includes a housing 1 with a central stepped channel in which a stepped drummer 2 with an axial 3 and 4 radial channels, a handle 5 with a starting device and a working tool 6 with a spring device 7 for holding it are installed with reciprocating motion. The housing 1 has air inlet channels 8, throttle channels 9 and exhaust channels 10 closed by an exhaust ring 11. The impactor 2 forms with the walls of the housing 1 a controllable working stroke chamber 12, an idling annular chamber 13, an accumulator annular chamber 14, an annular chamber 15 of atmospheric pressure and a chamber 16 of a pneumatic buffer with a volume larger than the volume displaced by a hammer in it, separated from the chamber 15 of atmospheric pressure by an annular sealing neck 17, periodically interacting The chambers of idling 13 and accumulator 14 are communicated by means of drossel 9, made permanently in collar 18. Periodically, depending on the position of the striker 2, the accumulation chambers 14 and the working stroke 12, as well as the idle speed chamber 13 and the working stroke 12 are communicated via channels 4 and 3. Also the atmospheric pressure chamber 15 is periodically communicated through channels 3 and 4 of the striker 2 divided by a sealing shoulder 19 with an accumulation chamber 14, with a working stroke chamber 12, from which, as a result, exhaust occurs. The chamber 15 is permanently connected to the atmosphere by the exhaust ports 10, and the chamber 13, with the handle starting device turned on, is permanently connected to the compressed air network. The pneumatic buffer chamber 16, whose volume is larger than the volume displaced in it by the hammer 2, periodically communicates with the atmospheric chamber 15. Pneumatic hammer works as follows. After starting the handle 5, the compressed air enters through channels 8 into the idle chamber 13, from which through the throttle channel (or channels) 9 it enters the accumulator chamber 14. The pressure of the compressed air on the annular end of the striker 2 from the chamber 13 causes the movement of the firing pin from tool 6. The idle begins. After blocking the radial channel 4 of the striker with the flange 19, the air pressure cut off by the B chamber of the working stroke 12 will begin to increase. However, communication via channels 3 and 4 of chambers 12 and 14 causes a smooth subsequent pressure build-up in accumulation chamber 14, eliminating the appearance of "pressure peaks in the working stroke chamber 12. Due to the significant flow area of channels 3 and 4 of the impactor 2, pressure in chambers 12 and 14 equalizes during the entire period of their communication. At some point, chambers 12 and 14 are separated. As the back pressure increases in the working stroke chamber 12, the movement of the striker 2 slows down, and since its thin part leaves the chamber of the pneumatic buffer 16, when communicating with the atmospheric pressure chamber 15, the difference in pulses from the said chambers predetermines even more deceleration of the striker 2 At some point in time at the end of idling, channels 3 and 4 are opened by flange 18 and chambers 12 and 13 communicate with each other, which causes an increase in pressure in chamber 12 and a complete stop of the striker 2, after which it will begin The effect of the difference of the pulses from the chambers is the accelerated movement to the tool 6. The working stroke begins. The radial channel 4 of the shock first closes with the flange 18 of the housing 1 - the process of intensive air expansion in the chamber 12 begins. The impactor 2 crosses the sealing ring isthmus 17 with its thin end, and the channels 3 and 4 are opened from the side of the accumulation chamber 14 and the accumulated air enters on them into the chamber of working stroke 12, providing an increased average pressure along the path of the impactor, and, as a result, an increase in the energy of a single blow. The effect of increasing the average pressure on the side of the chamber 12 is enhanced due to the smaller area of the annular stage of the drummer 2 on the side of the idling chamber 13, and a smaller backpressure impulse inhibiting the movement of the drummer 2 to the tool 6 is provided. In the chamber 16 of the pneumatic buffer, the cut-off in it is atmospheric air. The magnitude of the back pressure pulse is much smaller than was the case with a larger area of the ring of the striker 2 and the absence of the chamber 16, the functions of which are to provide the necessary and sufficient additional pulse providing the idling parameters. In addition, the braking impulse from the side of the chamber 16 acts on the drummer

Claims (1)

Claim Pneumatic hammer St. No. 658268, characterized in that, in order to increase the energy of a single blow by obtaining an additional impulse for idling, it has a pneumatic buffer chamber located in front of the atmospheric pressure chamber relative to the working tool and periodically communicated with it, while these chambers are divided among themselves annular sealing neck, which is made on the inner surface of the housing. TsNIIIPI of the USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Branch of the PPP Patent, Uzhgorod, ul. Project, 4