SU1726655A1 - Hydraulic mechanism with impact action - Google Patents

Abstract

Use: compaction and loosening of the soil, the destruction of coatings. SUMMARY OF THE INVENTION: When turning on a pump, a step valve with a grooved sleeve periodically connects the control and drainage chambers. Overflow holes connect the working and drainage chambers. The control and working chambers are connected by a channel formed by a groove. The reciprocating movement of the piston provides a blow to the tool at a working stroke and, at idle, a movement of the valve. The hole in the housing provides for switching the mechanism on and off when the pump is running. 1 hp ff. 2 Il.

Description

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The invention relates to construction and road machines, in particular to hydraulic percussion machines, such as hammers, concrete breakers, rammers.

A hydraulic percussion mechanism is known, including a housing with platoon and working chambers, a differential piston-block and a distribution organ (valve). For the implementation of the reciprocating movement of the striker, two-stage control schemes with hydromechanical couplings of the striker and valve are used.

The disadvantage of this mechanism is the relatively large mass, complexity of manufacture and the presence of unproductive leaks during the period of switching of the striker and valve to the working stroke.

Closest to the proposed is a hydraulic percussion mechanism comprising a housing with channels, a working tool and a control spring-loaded handle installed in the housing with the possibility of axial movement, a stepped valve and a differential firing piston, having on the outer surface larger and smaller diameters forming with the housing of the control chamber, discharge, pressure, cocking and working stroke, the pressure chamber being constantly connected to the pressure line by means of the channels of the housing and the chamber It has a periodic connection with the working stroke chamber, and the firing piston is made with an annular groove on a degree of smaller diameter.

The disadvantages of this mechanism are low reliability and high

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dimensions and weight, due to the large number of mating surfaces of the piston with the housing and striker.

The purpose of the invention is to increase reliability and ease of operation by reducing the number of mating surfaces of the piston with the housing and optimizing the hydraulic circuit of the mechanism.

FIG. 1 shows a hydraulic percussion mechanism, a longitudinal section; Fig. 2 shows the same embodiment.

The hydraulic percussion mechanism contains a composite body 1 (Figures 1 and 2) with a handle 2, a working tool 3, a piston-striker 4, a stepped valve 5 with a sleeve 6. The differential piston-striker 4 has a stepped shape with parts of a larger 7 and smaller 8 and 9 diameters. In section 9, an annular groove 10 is formed. Differential valve 5 is made with a stepped surface having portions larger than 11 and smaller than 12 and 13 diameters. The larger diameter section 11 mates with the seat 14, and the inner surface of the valve sections 12 and 13 is connected with the step 15 of the mechanism housing 1, the lateral surface of the valve 5 (section 12) is made with radial holes 16 located between the slots 17. The smaller section 13 the diameter mates with the sleeve 6, on the outer surface of which grooves 18 are made.

The housing 1, the piston head 4, the valve 5 and the sleeve 6 form chambers: platoon 19, stroke 20, head 21, drain 22 and control 23.

The mechanism and the casing comprise a pressure hydroline 24, channels 25 and 26, a throttle bore 27, a drain hydroline 28, a control bore 29. To provide vibration protection, a spring 30 is installed between the casing and the handle.

The hydraulic percussion mechanism works as follows.

When the pump (not shown) is turned on, the fluid through the pressure line 24 goes into the channel 25 and the pressure chamber 21, ensuring that the valve 5 is kept in the initial position, as well as into the charging chamber 19, which causes the piston 4 to move to the right ( the drawing) relative to the fixed body 1, the valve 5 and the tool 3 (idle stroke of the piston-strike 4). The movement of the piston-block 4 leads to the disappearance of the gap along the annular groove 10 between the piston-striker 4 and the degree 15 of the housing 1, and therefore, the separation of the control and control chambers 23 20. The fluid from the working chamber 20

the stroke is forced into the drainage hydroline 28 through the openings 16 of the valve 5, the discharge chamber 22, the throttle opening 27, whose cross-sectional area is determined on the basis of ensuring the best pump loading.

At the end of the idle stroke, the piston head 4, section 7, comes into contact with section 11 of valve 5, causing it to move to the right (according to the drawing). At the same time, the openings 16 first overlap with the step 15 of the housing 1, which leads to the separation of the working stroke chamber 20 from the discharge chamber 22, and consequently, from the throttle opening 27 and the drain line 28 and connecting to the latter through the slots 18 and 17 of the control chamber 23. Then the valve portion 11 comes out of the mating with the seat 14, providing connection of the working stroke chamber 20 with the pressure chamber 21, platoon chamber 19, and pressure hydraulic line 24. When the chambers 19, 21 and 20 are connected, the fluid pressure in them is equalized, and the pressure in the chamber 20 rises to the pressure in the chamber 19 and 21. The difference in the areas of the piston-bout 4 from the side of the chambers 19 and 20 causes braking and stopping of the piston-bounce 4 (the end of the idle stroke of the piston-bout 4). The valve 5, the movement of which after exiting the saddle 14 of section 11 was carried out due to the high-speed flow of fluid from the chamber 21 into the chamber 20, also stops due to the stop of the section 11 in the stage of the housing 1,

The difference of the forces acting on the piston-block 4 from the side of the chambers 19 and 20, due to the difference in the areas of sections 8 and 9, leads to the beginning of the working stroke of the piston - striker 4 (left according to the drawing).

When the piston-block 4 is moved throughout the entire period of the working stroke, the chamber 20 is disconnected from the drain line 28, which helps to maintain high pressure in the chamber 20 (and, consequently, the speed of the piston-block 4), as it receives fluid from the pump from chamber 19, as well as the liquid stored in pressure line 24 at the platoon stage.

At the end of the stroke, the piston-striker 4 strikes the shank of the tool 8. In this case, the annular groove 10 of the piston-striker 4 leaves the mating with the stage 15 of the housing 1, connecting the control chamber 23 to the working stroke chamber 20 through the holes 29.

Under the action of fluid pressure on the sleeve 6 and the section 13 of the valve 5, the latter begins to move to the left until the stop of the section 11 of the valve 5 into the seat 14. The guaranteed movement of the valve 5 to the closing is ensured by the fact that the working area

valve 5 and bushings 6 on the side of the control chamber 23 are larger than the working area of the valve 5 on the side of the travel chamber 20. After the valve portion 11 enters the seat 14, the radial holes 16 open and the working stroke chamber 20 is connected to the drain hydroline 28, which leads to a drop in pressure in the chamber 20. The pump continues to supply fluid to the chamber 21, ensuring that the valve 5 in the leftmost position (according to the drawing), and the chamber 19, causes the beginning of the piston-arrest cocking-block 4. Then the cycle repeats, the mechanism is turned off by turning off the pump.

The variant of the hydraulic percussion mechanism, the scheme of which is shown in Fig. 2, differs from that described by the implementation of an additional aperture 31 (Fig. 2) in the housing 1, which connects the working stroke chamber 20 via the channel 26 to the platoon chamber 19.

To activate this mechanism while the pump is running, a force is pressed on the handle 2. Under the action of this force, the spring 31 is compressed, which causes the body 1 to move to the left (according to the drawing) relative to the stationary tools 3 and the piston-4. The head 4 in section 7 closes the opening 30, from the connecting hydraulic line 24, the platoon chamber 19 and the pressure 21 from the working stroke chamber 20. The valve 5 is in the leftmost position, in which section 11 is in the saddle 14 of the housing 1, and the openings 16 do not overlap with step 15. In this case, the working travel chamber 20 through the openings 16, the discharge chamber 22, the throttle opening 27 is connected to the drain hydraulic line 28 And through the annular groove 10, the piston-fender 4 and the apertures 29 of the housing 1 are connected to the control chamber 23.

Further, the mechanism works as described.

To turn off the mechanism at the working pump, it is enough to relieve the pressing force from the handle 2. This reduces the external force acting on the body 1 of its spring side 30 and due to the force caused by the final fluid pressure in the working chamber 20, the body 1 will move to the right with respect to the fixed pistons -blow 4 and tool 3. The opening 31 opens and connects the pressure hydraulic line 24 through kg and 25 and 26 with the working stroke chamber 20 and further through the holes 16, the discharge chamber 22 and the throttle opening 27 , - by 28. 28. The liquid from the pump along the indicated path / the path of least resistance will flow to the drain.

Claims (2)

1. Hydraulic percussion mechanism, comprising a housing with channels, a working tool mounted in the housing from one end, on the other end of the housing with the possibility of axial displacements of a control handle spring-loaded relative to the latter, a stepped valve located in the housing and a differential piston-striker forming with the housing of the control chamber, the discharge, the turret, the platoon and the working stroke, —that is, so that, in order to increase reliability and ease of operation, it is equipped with a smaller diameter of the stepped valve with a bushing with a groove on the outer surface, and on the outer surface of the valve there are grooves for periodic connection through the grooves of the bushing of the control and drainage chambers; in the side surface of the valve there are overflow openings for connecting the working stroke and drainage chambers; for communication of control cameras and working motion. 2. The mechanism according to claim 1, in which there is an opening in the housing at the piston stroke section for periodically connecting the working stroke and platoon chambers.