SU1744198A1 - Hydraulic hammer - Google Patents

Abstract

Use: for soil compaction, destruction of asphalt and concrete pavements, for pile driving. The hydraulic hammer includes a cylinder with two cavities, one of which is in communication with the atmosphere, a piston, a rod connected by a flexible connection with the impact mass, an intermediate element, a tool, a pressure and a drain line. The pressure cavity of the cylinder communicates with the pressure line and through the overflow spool valve with a drain line. The magnitude of the flexible coupling connecting the rod with the shock mass satisfies the condition hc hT + hn, where hc is the length of the flexible coupling of the rod with the shock mass; hr is the braking stroke of the piston with the rod; hn is the maximum stroke of an intermediate link. 1 il.

Description

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The invention relates to construction equipment and is intended for compacting soils in cramped conditions, destroying asphalt concrete and concrete pavements, driving piles when constructing pile foundations.

Known hammer, which includes a working cylinder, a piston, a shock part suspended on an adjustable cable.

A disadvantage of the known hammer is the absence of limits for adjusting the length of the suspension, which is a prerequisite for ensuring the reliability of the hammer.

The closest to the proposed technical essence is a hydraulic hammer, comprising a housing, a working cylinder connected to it with a piston, a shock mass connected to the last flexible coupling, movably mounted in the housing of

the working tool attached to it, pressure head and drain lines.

The disadvantage of this hammer is the unreliability of its operation, due to the considerable hydraulic resistance during acceleration of the hammer, and the lack of a definition of the length of the flexible coupling.

The purpose of the invention is to increase the reliability of work.

The goal is achieved by the fact that in a hydraulic hammer, comprising a housing, a working cylinder connected to it with a piston, a shock mass connected to the last flexible coupling, movably mounted in the housing of the jigs with a working tool attached to it, the distributor, pressure head and drainage manifold the cavity of the cylinder is communicated through a spool valve with a drain line, and the magnitude of the flexible connection connecting the rod with the shock mass satisfies the condition

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hc hT + hn,

where hT is the braking stroke of the piston with the rod;

hn is the maximum stroke of an intermediate link.

The drawing shows a hydraulic hammer circuit.

The hydraulic hammer includes a working cylinder 1. having a piston cavity 2 connected to the atmosphere, and a pressure chamber 3, a piston 4 with a tip 5, a rod 6 connected by a flexible coupling 7 to an impact weight 8 that is rigidly connected to the pusher 9, the housing 10, is intermediate link 11, working tool - ramming plate (or peak) 12, overflow spool valve 13, adjustable throttle 14, pressure 15 and drain 16 line.

The discharge cavity 3 is connected to the drain line 11 by means of an overflow spool valve 13 connected in series with the adjustable choke 14.

In the pressure (combined with the drain) cavity of the hydraulic hammer, there is a damping device including a sleeve 17 with a radial 18 and 19 axial holes with an overflow valve 20 arranged between them.

The flexible link 7 is used to prevent the transfer of dynamic loads from the impact mass 8 to the rod 6. In this case, the value of the flexible link must satisfy the condition

hc hT + hn,

where hT is the braking stroke of the piston with the rod;

hn is the maximum stroke of an intermediate link.

In order to ensure minimum time for the platoon and acceleration of the impact mass 8, and consequently, for a high frequency of impacts, the volume of the pressure (drain) cavity 3, depending on the area of the piston 4 on the side of the pressure cavity and the stroke of the piston, is chosen to be minimal but reliable impact weight 8. The impact energy of a hydraulic hammer depends on the weight of the impact weight 8 and the accepted magnitude of the working stroke 6 in the cylinder 1. The magnitude of the working stroke of the rod 6 is taken from design considerations, and the weight of the impact weight is assumed to be the maximum possible.

Hydraulic hammer works as follows.

The working fluid from the pump through the pressure line 15 enters the pressure cavity 3 and moves the piston 4 upwards. The cocking process continues until the pusher 9 connected to the impact weight 8 switches the spool valve 13 to another position where the pressure chamber 3 is connected to the discharge line 16.

The reliability of switching the spool valve 13 provides for the inertial movement of the piston 4 with the rod 6 upwards, which becomes possible due to the absence of a working fluid in the piston cavity 2 connected to the atmosphere. After switching the spool distributor 13, the working fluid in the pressure cavity 3, under the influence of the piston 4 connected to the impact mass 8, is pushed into the drain line 16 through an adjustable throttle 14, which serves to control the hammer's impact energy.

The impact weight 8, moving in the housing 10, strikes the intermediate link 11. The latter, together with the tamping plate 12, is inserted into the ground. When stopping the tamping plate 12 spool valve 13 under the action of the spring closes the drain hole. During acceleration and introduction, the spool valve 13 is kept in the open position due to the hydrodynamic pressure of the working fluid from the pump and from the pressure cavity 3 to the drain line 16. If there is no bottom under the plate 12 or there is little resistance, the movement of the plate 12 may exceed the value of the rod stroke 6, which will lead to the failure of cylinder 1. To avoid this, a damping device is triggered. When this tip 5 of the piston 4 moves the volume of fluid bounded by the tip 5 and the inner surface of the sleeve 17, from under the tip 5 through the relief valve 20 and the radial 18 and axial 19 holes into the drain line 16. The working fluid due to throttling through the holes 18 and 19 brakes the piston 4 with the rod 6.

Further, as a result of supplying the working fluid to the pressure cavity 3, the cycle continues.

The application of the invention allows to simplify the manufacture of hydraulic hammer and increase its reliability in operation.

Claims (1)

Claims of the invention Hydraulic breaker, comprising a housing, a working cylinder connected to it with a piston, a shock mass connected to the last flexible coupling, a movable weight mounted in the housing of the chests with a working tool attached to it a drain line, characterized in that in order to increase operational reliability, the pressure chamber of the cylinder is communicated by means of an overflow spool valve to the drain line, and the length of the flexible connection connecting the rod to the impact mass satisfies the condition hc hr + hn, where Fri is the value of the braking stroke of the piston with the rod, hn is the maximum stroke of the intermediate link.