SU926267A1 - Pneumatic hammer with balanced impact mechanism - Google Patents

Description

The invention relates to impact machines, and more specifically to pneumatic machines with a dynamically balanced impact mechanism intended for use in mining and mining in the form of perforators and demolition hammers, machine building in the form of chipping and riveting hammers, construction in the form of concrete hammers, demolition hammers. etc.

Machines with a dynamically balanced percussion mechanism {1. Such machines have a hollow body, c. The front part of which is equipped with a working tool (a drill, a pick, a chisel, etc.), and in the internal cavity there are successively (one after the other) moving stepped drummer and a balancing piston moving in the longitudinal direction. The system of channels and openings in the casing provides compressed air to the chambers bounded by the casing walls, working tools, a drummer and a balancing piston. Exhaust of exhaust air from these chambers into the environment is made depending on the position of the impactor or piston relative to the casing.

When the compressed air enters the machine, the 1-hriyik and the piston reciprocate inside the housing. In the process of movement, the drummer strikes the working tool. The resultant of all forces applied to the body of such a machine is worthy, i.e. the main source of vibration is missing. For the operation of the machine, the minimum required for the specified values of energy and frequency of impacts, the pressing force.

The disadvantage of such a machine is the longitudinal overall size, as compared with machines without a counterbalanced piston. Increasing the length of the wire is a consequence of the sequential (one after the other) placement of the hammer and the balancing piston.

The closest in technical essence and the achieved result is a pneumatic hammer with balanced impact mechanism 2. It contains a hollow body with a tool fixed in its nose part and a balancing moving stepped hollow piston inside its nose part, inside which the hammer is movable.

front, middle and additional chambers, an intermediate chamber permanently connected to a source of compressed air, an opening in the side wall of the balancing piston to let in compressed air into the middle chamber, and exhaust from it exhaust air, an exhaust window in the wall of the housing.

The disadvantage of this hammer is the relatively long portion of the working tool integrated into the body. This elongation is due to the need to ensure that the piston, even in its extreme rearward position, does not come out of harmony with the working tool (otherwise, it would be impossible for the mother to work). Due to the length of the built-in part of the working tool, the overall length of the machine is increased. A significant drawback of the machine is also the complexity of its design.

The purpose of the invention is to reduce the overall dimensions of the hammer.

This goal is achieved by t & l that a channel is made in the housing for the gentle communication of the additional and anterior chambers, while these X1 measures are isolated from the source of compressed air, and the rear edge of the exhaust window is located between the boundary positions of the rear end of the balance piston.

Fig. 1 shows a pneumatic hammer with a balanced strike mechanism, a slit; 2 - the same, the arrangement of the elements corresponds to the moment of the impact of the striker with the instrument.

A pneumatic hammer with a balanced hammer mechanism contains a hollow body 1, a working tool 2 built into its new part, a balancing movable stepped hollow piston 3 and a hammer 4 placed inside this piston located inside the body.

The piston 3 is installed with the possibility of free movement inside the housing 1 in the longitudinal direction between the extreme boundary (front and rear) positions. The drummer 4, in turn, can move inside the piston 3.

The internal cavity of the housing is divided by a hammer 4 and a piston 3 into a series of chambers. The front chamber 5 is bounded by the walls of the housing 1, the working tool 2, the piston 3 and the front part of the hammer 4 and is isolated from the source of compressed air (not shown in the drawing).

The additional chamber 6 is bounded by the wall of the rear part of the housing 1 and the rear end of the piston 3, is also isolated from the compressed air source and is permanently connected to the front chamber 5, for which a channel is made

; 7. Intermediate Ks1mera 8 is bounded by the walls of the housing 1 and the outer side surface of the piston 3 with burtsm 9 is permanently connected to the source of compressed air through the opening 10 in the housing 1. The middle chamber 11 is bounded by the walls of the rear part of the piston 3 and the body of the hammer 4 and depending on the position of the piston 3 with respect to housing 1, it can be communicated either with an intermediate chamber 8, which is constantly under pressure, or with the environment. For this, one or several through holes 12 are made in the side wall of the porous 3. And in the case 1 there is an internal shoulder 13 separating the intermediate chamber 8 from the environment, and the exhaust window 14. The rear internal window 15 of the exhaust window 14 is located between two boundary holes. positions 16 of the front end 16 of the balancing piston 3 front (Fig. 1) and rear (Fig. 2), and the front inner edge 17 of this window is located between the two extreme positions of the through hole 12, in the walls of the piston 3 - front (Figure 1) and rear (figure 2).

Due to this arrangement of the inner edges 15 and 17 of the exhaust port 14, an additional 6 may, depending on the position of the piston 3 relative to the housing 1, be either communicated with the environment or isolated from the environment, and the average chamber 11 msms be communicated with either the intermediate chamber 8 and consequently with a source of compressed air, or with an environment

The areas of the collar 18 in the housing 1 and the bottom 19 of the housing 1 are advisable to be the same in order to balance the S5IL, due to the air pressure in the front 5 and an additional 6 KciMepax.

The hammer works as follows. When the compressed air enters the intermediate chamber 8 (Fig. 1), the middle chamber 11 is also under pressure, since the opening 12 is in the zone of the intermediate chamber B. Due to the area of the piston 3 that receives pressure from the middle chamber 11 is larger than the surface area of the collar 9, the piston 3 moves backward. Drummer 4 at this time moves forward (toward tool 2), forcing air from front chamber 5 into additional chamber b, which communicates with the environment.

As it moves backward, the piston 3, even with its rear end 1bc with the edge 15 of the window 14, cuts off the additional chamber 6 from the environment and compresses the air enclosed in this KciMepe. 4 also squeezes when moving to tool 2

the air in the front chamber 5 communicated with the additional chamber 6. Thus, energy is accumulated in the front and additional K 1members 5 and 6 due to the compression of the air enclosed in them. With further movement

piston 3, the hole 12 in the piston 3 initially overlaps with the collar 13, and then, having hit the exhaust window 14, opens the middle killer 11, from which the exhaust air comes into the surrounding environment.

The drummer 4 moves in front of it. It strikes the working tool 2. After the impact, the drummer, 4 and the piston 3, due to the energy of air compressed in the front and additional chambers 5 and 6, move towards each other. As the piston 3 moves towards, with the drummer 4 an additional Kshler through the exhaust port 14 is in contact with the surrounding medium, and the hole 12 in the piston 3 enters the zone of the intermediate chamber 8, and compressed air is introduced into the middle chamber 11. By pressure in the middle chamber 11, the movement of the striker 4 and the piston 3 towards each other stops , by le which is described cycle is repeated.

As can be seen from Figs. 1 and 2, when the hammer is operated, its body 1 is acted upon by a constant force due to the pressure of the rolled air that constantly enters the intermediate chamber 8, the collet 13. To silicon, the body 1 is perceived by the force of the air periodically compressed in the front and additional chambers 5 and 6. These forces are the same at any time due to the equality of the pps of the collet 18 and the bottom 19 and the equal pressure in the front and rear axles pax 5 and 6. and are directed in opposite directions. The result of these forces, therefore, is zero.

Thus, the body is under the action of only one constant force and the hammer is balanced. The main source of vibration is absent, and for normal operation of the hammer, the minimum energy for sufficient values of the energy and frequency of pressure strokes is sufficient.

Due to the fact that the need for constant mating of the piston with the working tool has become redundant, the length of the tail part of the tool is reduced, and therefore the total length of the hammer is reduced.

Claims (2)

1. USSR author's certificate  212918, cl. E 21 C 3/24, 14.11.66. 2. US patent 3456744, cl.173137, published. 07.22.69 W /: / Aff / jf X jryx x iry v-j-T rV v y vvvv:   xx. xv:, y f Л4Г (. 1 r f f f f 7 V l 7 y - - D j ,,,,. ,,. . // te 1 s ts / JT / Tf u W // A y / UL .: J kchuchch: L 1 l.Ug / EE