JPS5813311B2 - hydraulic impulse device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic impulse device, in particular a working piston displaceable in a working cylinder and at least one actuating piston on which pressure from a control channel connected to the working cylinder acts. A liquid impulse device having a control member having a control surface and capable of displacing within a control cylinder, a pressure tank connected to a pressure flow path, and a pump device for supplying pressurized liquid to the pressure flow path. Regarding.

The liquid impulse device is disclosed in German Patent Publication No. 2024501 and Swiss Patent No. 53456.
No. 7, it is known that in these cases the control of the working piston is carried out by a small control piston which is displaceable in a control cylinder.

This displacement of the control piston is effected hydraulically via a control channel extending from the working cylinder.

The impulse device has a liquid-pneumatic pressure tank connected to the pressure channel or the outward flow channel, which pressure tank is filled with working fluid during a predetermined phase of the working cycle of the working piston, and The working fluid is discharged again during other stages where a high degree of pressure energy is required.

In the known device, the reversal of the control piston takes place only by virtue of the state of the working piston.

As a result, the working piston reaches its proper lift position before the required amount of liquid in the pressure vessel is still available.

This is particularly the case when the impulse device is used in combination with a pump device which has a relatively slow discharge rate, ie an inadequate amount of discharge per unit time under the required pressure.

In such cases, the known impulse device does not have a sufficient amount of working fluid available in the pressure vessel to supply sufficient impulse energy to the piston from the pressure vessel, which does the work with little reduction in the number of impulses. Because there is no impact force, the impact force is significantly reduced.

In some cases, users of impulse devices may only have special purpose pressure pumps.

In such cases, it may also occur that the discharge capacity of the pressure pump is insufficient to apply the required strength of impulse force (impact force) to the working piston during an impulse.

The object of the invention is to provide an impulse device which can be operated with a constant impulse force, regardless of the discharge capacity of the pressure pump used.

To solve this problem, the present invention provides a control system that corresponds to an impulse movement of the working piston only when, during or following the lift of the working piston, the pressure and volume in the pressure vessel exceed a discrimination limit value. It is intended to provide a device for returning the member to the above-mentioned impulse device from the beginning.

The basic principle of the invention is to ensure that no impact or downward movement of the working piston takes place until the required pressure has been built up in the pressure vessel by the pump.

The advantage of this mode of operation is that the required impact force for each operation can be obtained independently of the delivery capacity of the pump used, and that if the pump delivery capacity is inadequate, it is necessary to operate with a reduced number of shocks. It is.

Various modes can be employed to slow down the displacement movement of the control piston.

For example, a valve operated by pressure may be provided in the control flow path connected to the control cylinder.

In this case, in the control flow path, a pressure corresponding to the pressure in the pressure flow path and the pressure in the pressure tank is obtained near the end of the return process of the working piston l/n.

If a valve actuated by pressure is provided in the control channel, reverse flow in the control channel will not occur until the discrimination limit of the valve is exceeded, and the downward movement of the working piston will only occur when the control member is reversed or diverted. produce an impulse.

Another method of ensuring an increase in pressure in the pressure vessel is to apply a spring force to the control member that acts in the opposite direction to the pressure in the control channel.

In this case, the control member cannot move until the pressure acting on its control surface becomes greater than the adjustable spring bias.

In such devices, it is convenient for the control member to be subjected to pressure on both its end faces, so that the pressures are substantially balanced.

This pressure compensation means that the spring need only be designed to be strong enough to exert a force corresponding to the pressure discrimination limit and is not required to counteract the hydraulic bias.

The spring can therefore also be hydraulically supported in the device, so that the pressure surface acting from the same direction as the spring is larger than the pressure surface acting in the opposite direction.

A third way in which the reversal or switching of the control piston can be delayed is by adding a constriction in the flow path in which the flow occurs during the lift of the working piston, which slows down the liquid flow and decelerates the working piston when the working piston lift occurs. and the restriction is designed such that the working piston does not reach a lift or impact position that causes a reversal of the control member until the pressure vessel is filled with a predetermined minimum amount of liquid.

The restriction slows down the return stroke of the working piston so that the working piston acts on the control flow path to delay reversal of the control member.

During the state of the slow return process, the pressure tank can be filled again. The slowdown of the return process can be carried out by a mechanism in which a restriction is provided either in the return flow path or in the pressure flow path leading to the working cylinder. .

In the latter case, the constriction is expediently bridged by a non-return valve which is permeable to the liquid exiting the working cylinder, or the constriction element itself can be passed in the return direction.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which embodiments of the invention are shown.

In FIG. 1, the working piston 11 is connected to the working cylinder 10.
It is arranged vertically displaceably within the anvil 12 and periodically impinges on the anvil 12.

This anvil can, for example, be connected to a drilling linkage.

A pressure medium is introduced into the device through the supply channel 13, which medium passes through the pre-tensioned non-return valve 14 into the pressure channel 1.
5.

The check valve 14 consists of a spring-biased sleeve 45 having an annulus 46 at its lower end. The rear portion is connected to a pressureless return flow path 21 .

The spring 47 that drives the sleeve 45 downwards is designed such that the pressure acting on the lower end face 48 normally drives the sleeve 45 upwards. Do not lower the spring 47 until it can no longer be blocked.

The specified pressure in the liquid pressure tank 43 connected to the pressure channel 15 is 50 bar.

Since the pressure channel 15 is permanently connected to the lower chamber 16 of the cylinder 10, hydraulic pressure acts on the small-diameter annular surface 17 of the constantly active piston 11 and tends to propel the annular surface 17 upward.

The upper chamber 18 of the cylinder 10 is connected to a control valve 20 by a flow path 19.
It is connected to the.

Control valve 20 selectively connects flow path 19 to pressure flow path 15 and return flow path 21 .

The upper chamber 18 is bounded by the large diameter annular surface 22 of the working piston.

Therefore, when the total pressure acts on both the small diameter annular surface 17 and the large diameter annular surface 220, the working piston 11 is propelled downward.

On the other hand, the pressure medium acts only on the small diameter annular structure 17,
When the flow path 19 is connected to the no-pressure return flow path 21, the working piston 11 is in a return process, during which it moves in the -L direction.

The hollow control sleeve 55 disposed within the control valve 20 is formed at its rear with a wide groove 29 that allows interconnecting the longitudinally centered offset holes of the flow channels 19 and 21 with each other. ing.

At the other end shown, the connection to the return flow path 21 is blocked by the control sleeve, but the hole to the flow path 19 is open, and the inside of the through-hollow control sleeve and the pressure flow path 15
has been contacted.

The inner diameter of the control sleeve is constant.

The rear end surface 30 is connected to the front end surface 57 along with the active control surface 58.
, but it is smaller than the front end face 57.

Control of the control sleeve 55 takes place via the control channel 24, the pressure from which acts on the control surface 58 of the annulus 56.

The front forming surface 59 of the annular portion 56 is always connected to the return flow path 21. In this embodiment, the control flow path 24 includes three first branch flow paths 65, 66, 67 and four first branch flow paths 65, 66, 67. It branches into second branch passages 25, 26, 27, and 28, and each branch passage communicates with an annular groove formed in the working cylinder 10.

In the region of the annular groove communicating with the branch channel, the working piston 11 has a lower piston element 62 of increased diameter, the diameter of which is adapted to the diameter of the cylinder.

This piston element 62 can sealingly close the branch channel communicating with the annular groove.

The piston element has an annular surface 17 on its underside.
It is also delimited on the upper side by an annular surface 61 .

Adjacent to the annular surface 61 is a wide annular groove 69, on which another piston element of the same radius as the piston element 62 is arranged.

In the area of the annular groove 69 formed in the piston 11, a return flow channel 52 extends from the working cylinder.

The annular groove 69 of this working piston is formed in such a way that it communicates with the return flow path 52 in any position of the working piston.

Thus, if the working piston 11 is lowered to such an extent that the upper annular surface 61 of the piston element (or piston member) 62 is displaced to a position below the first open branch channels 65-67, the associated branch channels 65. 66 and 67 are annular grooves 6
9 to the return flow path 52, and the control flow path 24 becomes pressureless.

A plug 68 inserted into the branch passages 65-67 is inserted in the branch passages 65-67 in such a way that the pressure acting on the control surface 58 of the control sleeve dissipates during movement of the piston.
4 has the role of determining the position of the piston that is initially made pressureless.

The second branch channels 25 to 28 are arranged below the first branch channel, and the pressure channel 15 is introduced into the control channel 24, which is constantly carried out in the lower chamber 16 of the working cylinder during the reciprocating movement of the piston. Determine the pressure.

A valve 34 is inserted in the control channel 24, which is actuated by pressure and only opens the control sleeve 5 when the pressure exceeds a preset minimum value (which can be set to any value).
Allowing liquid flow in the direction towards 5.

In the reverse direction, ie from the control sleeve to the working cylinder, the control flow path 24 is completely permeable, which is shown in the figure by a non-return valve 38 connected non-parallel to the valve 34.

When the pressure in the control passage 24 exceeds the minimum value set in the valve 34, that pressure acts on the control surface 58 of the control sleeve.

To explain how the impulse device operates, we begin with the components shown.

In the figure, control sleeve 55 connects flow path 19 to pressure flow path 1.
5, and the connection to the return flow path 21 is cut off.

The working piston 11 is propelled downwards because the total pressure acts on both the upper large annular surface 22 and the lower smaller annular surface 11 of the working piston.

When this happens, the piston element 62 first successively closes the branch channels 28 , 27 , 26 , 25 and then closes the first branch channel 65 , 66 , 67 unless it is sealed with a plug 68 . Open the flow path.

When the first branch flow path 25 is sealed, the control flow path 24 is disconnected from the high pressure, and when the uppermost branch flow path 65 is opened, the branch flow path is connected to the pressureless return flow path 52.

In this condition, therefore, liquid flows back through the valve 38 which allows liquid to pass, reducing the force acting on the control surface of the control sleeve.

Control piston 5 under pressure acting on large end face 57
5 is displaced upward.

During the downward movement of the working piston, the pressure vessel 43 is extremely large, since the upper end surface 22 is relatively large, and a large amount of liquid must be propelled into the working cylinder in a short period of time so as to generate a high degree of impact energy upon impact. liquid is drained.

During the subsequent return stroke of the working piston, the pressurized liquid acts only on the relatively small surface area 17.

At the same time as the working piston is raised, the pressure tank 43 is refilled.

Therefore, the pressure within the pressure channel 15 increases.

This pressure is transmitted via the control channel 24 to a pressure-actuated valve 34, which is initially closed until the pressure reaches a minimum set point.

A pressure pump (not shown) connected to the device pumps the pressure vessel 4 to such an extent that a pressure discrimination limit is achieved in the control channel 24.
3, the valve 34 switches and the pressure fluid entering the control cylinder 23 forces the control sleeve 55 back into the position shown in FIG.

Until the required pressure is established in the pressure channel 15, i.e. until the pressure reservoir 43 is filled to the required extent, the control sleeve 55 responds to the downward movement of the working piston by virtue of the pressure-actuated valve 34. It cannot be pushed down into position.

At the same time, a constant impact energy is provided for each stroke of the working piston, regardless of the displacement capacity of the pressure pump connected to the supply channel 13.

FIG. 2 shows an alternative embodiment in which the control sleeve is biased to one side by means of a spring, the other parts being the same as the device of FIG.

In the embodiment of FIG. 2, a sleeve 551 is provided which has two end faces of substantially the same size and is spring biased, ie, biased to one side by spring 35.

The annular surface 58 of the annular portion 561 receives pressure from the control flow path 24 here as well, but the control flow path 24 is not provided with any valves, and the annular chamber connected to the pressureless return flow path 21 is A front annular surface 59 is arranged at.

This annular surface 59 is recessed from the end surface 57.

In order to pretension the control sleeve 551, a helical spring 35 is arranged inside it, which abuts the sleeve at one end and the fixing screw 36 at the other end.

Spring 35 biases control sleeve 551 toward top dead center corresponding to the lift of the working piston.

The spring force acts in a direction opposite to the pressure acting on the annular surface 58 of the control channel 24.

Only when this pressure overcomes the force of the spring will the control sleeve 551 be displaced downwards, opening the path from the pressure channel 15 through the control sleeve to the channel 19;
This initiates an impulse movement of the working piston in a downward direction.

Since the spring bias can be adjusted by rotating the fixing screw 36, the required impact energy can be easily set by changing the spring bias.

In the embodiment of FIG. 3, a control piston 552 biased with a spring 37 is provided.

The spring 37 is substantially disposed in a blind hole formed in the control piston 552.

The lower end surface 572 constitutes an engagement surface that receives the pressure of the pressure channel 15 together with the bottom surface of the blind hole, and the upper end surface 582 constitutes an engagement surface that receives the pressure of the pressure channel 15.
This is the control surface on which pressure No. 4 is applied.

Control surface 582 is larger than the two lower pressure surfaces.

Furthermore, an annular groove 292 is formed in the control piston, which connects the flow path 19 with the return flow path 21 when the working piston is in one dead center position, and which connects the flow path 19 with the return flow path 21 when the working piston is in the other dead center position. When in position, the flow path 19 is connected to the pressure flow path 1
It is connected to a flow path 152 extending to 5.

After a stroke of the working piston, the spring 37 urges the control surface 582 of the control piston to the upper end position.

The pressure in pressure channel 15 and control channel 24 has decreased to a small value.

During the next lift of the working piston, this pressure increases gradually.

Only when the pressure is such that the difference between the forces acting on the control piston from above and below exceeds the force of the spring 37 will the control piston be propelled downwards, after which the control piston will follow the pressure channel 19. It is connected to a flow path 152 connected to 15.

Therefore, only after that does the next impact or blow occur.

In this embodiment, the control surface 582 is slightly larger than the two lower pressure surfaces of the control piston, so that the spring 37 can also be designed to be relatively weak even at high pressure discrimination limits where reversal or reversal occurs.

In the embodiment shown in FIG. 4, the control sleeve 553
It is exactly the same as the embodiment shown in the figure.

In the case of the embodiment of FIG. 1, the working piston is unimpeded in its movement during its return stroke and the reversal of the control sleeve is delayed under the influence of the magnitude of the control pressure, whereas in the case of the device of FIG. Since the throttle member 40 is inserted into the return flow path 21, the return process of the working piston is delayed.

When the working piston performs its return stroke, the liquid enters chamber 1.
8 to the flow path 19.

Since the outflow of the liquid is slowed down by the constriction section 40 provided in the return flow path 21, the upward movement of the working piston is also slowed down.

The working piston thus connects to the pressure channel 15 in a manner that delays the channel 24 .

This delay allows pressure vessel 43 an opportunity to fill.

The upward movement of the working piston is therefore deliberately slowed down in order to allow the pressure reservoir 43 to fill during its movement.

In the embodiment of FIG. 5, the upward movement of the working piston is also slowed down by the throttle.

In this case, the throttle 41 is provided in the part of the pressure channel 150 arranged between the control sleeve 553 and the working cylinder 10 .

A check valve 42 is connected in parallel with the throttle part 41,
During the downward movement of the working piston, it is open to backflow returning from the working cylinder and closed to the opposite direction.

During an impulse movement of the working piston, liquid flows from the working cylinder into the pressure channel 15.

At the same time, the non-return valve 42 allows liquid to flow through so that the impact or blow is not impeded.

During the next return process, the check valve 42 is closed.

Therefore, the liquid is prevented from flowing through the constriction portion 41.

For this reason, the lifting of the working piston takes place slowly so that the pressure tank 43 is refilled.

The difference from that in FIG. 4 is that, in the case of the device in FIG. 5, a constriction 41 is provided upstream of the working cylinder in the flow direction.

The embodiment of FIG. 6 uses the same control sleeve 553 used in the embodiment of FIG.

The pressure channel 15 has a right-angled bend just before the inlet to the working cylinder, at the rear of which a diaphragm 39 is inserted into the channel.

The diaphragm 39 has a narrow central hole and constitutes a diaphragm member.

A hole 70 extending from the inside into the diaphragm 39 is sealed with a screw plug 71.

A spring 72 protrudes from the inner end surface of the screw plug, which applies a low pretension to the diaphragm 39 against the seat of the diaphragm.

Diaphragm 39 is displaceable against the action of spring 720.

At the other end of the diaphragm, which is compressed by the pressure liquid flowing from the working cylinder, the liquid flows through longitudinal grooves 73 formed on the outside of the diaphragm and extending over part of the length of the diaphragm.

In the position of the diaphragm 39 shown in FIG. 6, the groove 73 is closed, so that only the cross-section through the central hole of the diaphragm 39 is utilized for the return process of the working piston.

In the event of an impact, the guiaphram is pushed back so that a longitudinal groove with a larger flow cross section is utilized for the evacuation of the pressure fluid from the working cylinder.

After removing the screw plug 71, various types of diaphragms can be inserted through the hole 70.

The selection of the diaphragm size depends in each case on the discharge capacity of the pump used and on the required impact force.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of an impulse device according to the present invention having a valve operated by the action of pressure in a control line, and FIGS. 2 to 5 show other embodiments of the impulse device according to the present invention. FIG. 6 is a vertical sectional view showing an embodiment of the mechanism shown in FIG. 5. 10-working cylinder, 11-working piston, 12-anvil, 13-supply flow path, 14-return prevention valve, 15-pressure flow path, 20-valve, 21-return flow path, 24-control flow path, 2
5, 26, 27, 28 - second branch flow path, 65, 66, 6
7-first branch channel, 29-annular groove, 55-control sleeve, 40.41-diaphragm, 39-diaphragm, 71-screw plug, 551,553-control sleeve, 55
2 ~ Control piston.

Claims (1)

[Scope of Claims] 1. A control member displaceable in a control cylinder, having a working piston displaceable in the working cylinder and at least one control surface on which pressure from a control channel connected to the working cylinder acts. , comprising a pressure tank connected to the pressure channel and a pump device for discharging pressurized liquid to the pressure channel,
In order to produce a shock or blow whose impact force is constant irrespective of the discharge capacity of the pumping device, only when or following the lift of the working piston 11 the pressure and volume in the pressure vessel 43 exceed the discrimination limit value. Hydraulic impulse device, characterized in that it is provided with a device for reversing or reversing the control member 55 to a state corresponding to the impact movement of the working piston. 2. The impulse device according to claim 1, characterized in that a valve 34 operated by the action of pressure is disposed in a control flow path extending to the control cylinder. 3. The impulse device according to claim 1, wherein a spring force directed in a direction opposite to the pressure of the control flow path acts on the control members 551 and 552. 4. The impulse according to claim 3, wherein the control members 552, 553 are subjected to pressure from both end surfaces thereof, so that the pressures are substantially balanced regardless of the pressure supporting the spring. Device. 5 Flow path 21 where flow occurs during the lift of the working piston 10
, 15 are provided with aperture parts 40 and 41, and the aperture parts provide
The piston causes the reversal of the control member 553 to decelerate the fluid flow and decelerate the working piston during the upward movement of the working piston until the pressure reservoir 34 is filled with a predetermined minimum amount of liquid. 2. The impulse device according to claim 1, wherein the constriction portion is formed so as not to reach the lifting height position at which the lifting height is generated. 6. The impulse device according to claim 5, characterized in that the throttle section 40 is provided in the return flow path 21. 7. The impulse according to claim 5, characterized in that the constriction part 41 is provided in the pressure channel 15 extending into the working cylinder and is bridged by a non-return valve that allows the liquid flowing out of the working cylinder 10 to pass therethrough. Device. 8. The pressure passage 15 reaching the working cylinder 10 is provided with a restrictor member 39 which is displaceable by pressure between two end positions and has a bypass passage that is open only on one side of the end position. An impulse device according to claim 5. 9 The throttle member is a diaphragm 39 disposed at the bending part of the pressure flow path 15, and the longitudinal groove 73 is formed over the entire length of the diaphragm 39.
9. An impulse device according to claim 8, characterized in that it is formed with a hole 70 which reaches the bending part and can be replaced by a hole 70 and can be sealed by a plug 71.