JPH09174461A - Control method for operating characteristics of fluid drive shock machine with shock piston, and shock machine for carrying out this method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To destroy a material without changing a fluid cross flow quantity by setting the delay time changeable by the operating pressure released by a shock piston, first applying a return stroke to the shock piston during the delay time, then applying a residual return stroke. SOLUTION: A position adjusting face AV2 connects a delay element 18 to a switching control pipe 13 via a pilot control pipe 20. The delay element 18 forms a flow regulator having an objective value adjustable depending on pressure. A shock piston 3 connects a control pipe 9 to a return pipe 10 via a peripheral groove 3c. A control spider 5a in an operation stroke is moved to the left by the action of a slider face AS1 applied with operating pressure (a). When the slider 5a reaches the return stroke position by this leftward motion, a piston face A1 is immediately connected to the return pipe 10 via the switching control pipe 13, a control valve 5, and a pipe 12 (b). The shock piston 3 starts a return stroke by the pressing force of a piston face A2 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling the operating characteristics of a fluid drive impact device having an impact piston that alternately performs an actuation stroke and a return stroke under the action of a control device. Depending on the distance during the stroke, the impact signal is generated by the impact piston at the beginning and the release signal initiates the switching of the control device to the return stroke position, the control device being in the return stroke position and for all impact cycles. On the other hand, the invention relates to a method for controlling the operating characteristics of an impact device with an impact piston, which is arranged to reach an end point located after the completion of the actuation stroke, with a substantially constant delay time, and to an impact device implementing this method.

A method and a fluid-operated percussion device of the type mentioned at the outset are known from DE-A-3434542. In this case, the impact energy is transferred via the tool to the impact piston by the use of a special holding valve or an alternating switching valve, which is incorporated in the control conduit which cooperates with the control device and which is also optionally connected to the return conduit. Even if reflected, this reflected energy is guaranteed to be hydraulically recovered, which can increase the number of impacts of the impact piston.

Fluid-operated percussion devices, such as hydraulic hammers, are used for crushing materials (crushing rock or concrete). This crushing is achieved in that the kinetic energy of the impact piston is introduced into the material to be processed via the tool and the tool tip by the impact on the tool and converted into a breaking operation at that point. Depending on the hardness of the material to be machined, only part of the kinetic energy is converted into destructive work, the unconverted energy part is reflected through the tool to the impact piston and used to increase the number of impacts with a corresponding device it can. On the contrary, in soft materials the impact energy is completely converted into destructive work.

A work process in which the impact energy generated is greater than the energy required for crushing the material is not desirable because it imposes a high load on the impact device.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to allow impact forces to fracture material without the impact forces significantly changing the fluid throughflow required to accelerate the impact piston. To provide a method and a percussion device suitable for carrying out the method, which in turn changes the impact force of the percussion piston automatically and in dependence on the reflectivity to match the material hardness. It is in.

[0006]

According to the present invention, in the first aspect of the invention, a delay time (Δt2) that is directly or indirectly released by an impact piston and can be changed by operating pressure is set. Depending on the setting, the impact piston first performs a return stroke that depends on the reflectivity of the material to be processed during the delay time (Δt1), and then performs a residual return stroke, and the residual return stroke is the reflectivity that changes the working pressure. Of the second delay time (Δt
The problem is solved by initiating the switching of the control device to the working stroke position regardless of the position of the shock piston at the end of 2). And a control slider moving in the control valve, the impact piston having two piston surfaces (A1, A2) of different sizes, the piston surface (A1,
The piston surface (A2) of A2) acting towards the smaller return stroke is always connected to the pressure conduit to which the working pressure is applied, and the piston surface (A2) acting towards the larger working stroke is controlled. Connected selectively via a valve to a pressure conduit and a pressureless return conduit, the control sliders having different sizes and acting in opposite directions of movement 2
The slider surface (A _S1 ) which has two slider surfaces and which acts on the slider toward the return stroke position of the control slider, which is the smaller of the slider surfaces, is always connected to the pressure conduit, and the large slider surface (A _S2 ) is connected. , A method of controlling the operating characteristics of a percussion device having percussion pistons which are connected only temporarily and alternately to a pressure conduit or a return conduit via circumferential grooves arranged between the piston faces (A1, A2), respectively. In a fluid driven impact device, a large slider (A _S2 ) acting towards the working stroke position of the control device is connected via an additional conduit to the outlet of a pilot valve fitted with a return element,
The pilot valve can be moved from the open position to the shut-off position of the pilot valve by applying a force against the return element, and the adjustment force against the return element can be applied to the large piston surface (A
The operating pressure applied to 1) is generated via the pilot control conduit so as to act on the adjusting surface of the pilot valve, the delay element is arranged in the pilot valve, and the operation of the delay element causes the pilot valve to operate depending on the operating pressure. Adjusted duration (Δt
2) Delayed switching from the closed position to the open position, connecting the pilot valve inlet directly to the pressure conduit, or only temporarily depending on the position of the impact piston in the working cylinder, a small piston The solution is achieved by connecting to the pressure conduit via the front cylinder chamber section, which is also bounded by the surface (A2).

The second delay time can be released directly or indirectly by the impact piston. For example, a circuit for starting the second delay time described above after a lapse of a predetermined time interval (additional timing It is possible to operate (via the element). This second delay time is adjustable to match different working conditions and depends on the reflectivity (and thus on the material hardness) unless the adjustment value is changed.

Thus, if the material to be processed is very soft (ie, the reflectivity is near zero), the impact piston will, at most, have a very slight return stroke after the first delay time has elapsed. Just do it. In response,
The return stroke followed until the switching of the control device to the operating stroke position is generally short, so that the subsequent operating stroke is correspondingly small and the impact energy therefore has a correspondingly small value.

When the impact piston strikes through its tool a very hard (relatively high reflectivity) hard material, the rebounded impact piston already has a relatively long return stroke during the first delay time. This return stroke is followed by a residual return stroke forced by the drive unit until the switching of the control device to the operating stroke position during the second delay time. The impact on the hard material thus causes the impact piston to carry out a relatively large return stroke and a subsequent working step with a correspondingly high impact force during a usable time interval which depends on the magnitude of the reflectivity. . Only during the residual return stroke the impact piston expels the hydraulic liquid into the return conduit of the impactor. Since the volumetric flow balance in the percussion device is zero, a lower residual return stroke height means a greater number of percussions at a given volumetric flow rate.

The second delay time is either initiated directly by the release signal generated by the impact piston (ie distance-dependent) or only indirectly by the impact piston, ie independent of distance. To be done.

In an embodiment according to claim 2 for carrying out the method according to the invention in a particularly simple manner, the start of the second delay time coincides with the end of the delay time.

For economic reasons, and in particular for avoiding undesired loads on the impact device, in an embodiment as claimed in claim 3, the second delay time is
The start of the switching of the control device at the end of the affiliation causes the impact piston to perform a structurally determined maximum return stroke at a certain reflectivity of the material to be machined below the maximum reflectivity (and this Do not make it longer or shorter than the stroke).

In an embodiment of the invention as claimed in claim 4, which is advantageous for values of reflectivity greater than a predetermined value, the second delay time is set by the impact piston via the limit stop at a suitable time depending on the distance. , Which ensures that the switching of the control device into the working stroke position is completed at the latest, when the impact piston reaches the structurally provided upper reversal point.

In an embodiment of the invention as claimed in claim 5, a second delay time is provided, in which the impact piston is structurally provided with an inversion at the maximum possible reflectivity of the material to be processed. Choose to reach a point.

The method embodiment of the invention as claimed in claim 6 ensures that the impact piston makes one predetermined minimum return stroke each time by matching the second delay times. In the embodiment as claimed in claim 7, the value of this minimum return stroke is set to 20 of the maximum return stroke which is structurally provided.
Set to a size between ~ 50%.

The object of the present invention is solved by the features described in the characterizing part of claim 8 in the second invention.

The subject of the invention in this solution is to use a pilot valve which is switched with a time delay, which pilot valve (in the usual case) switches from the return stroke position of the control unit to the working stroke position. To do.

In an embodiment as claimed in claim 8, a large slider surface acting towards the operating stroke position of the control device is connected via an additional conduit to the outlet of the pilot valve fitted with a return element, Can be moved from the open position of the pilot valve to the shut-off position by applying a force against the return element, and the operating pressure applied to the large piston surface of the impact piston exerts an adjusting force against the return element via the pilot control conduit. Generated on the adjustment surface of the pilot valve. A delay element is arranged on this pilot valve, and the action of this delay element causes the pilot valve to switch from the closed position to the open position with a delay of an adjustable duration. The inlet of this pilot valve is either directly connected to the pressure conduit or only temporarily depending on the position of the impact piston in the working cylinder, a front cylinder which is also bounded by a small piston face. It is connected to the pressure conduit via a chamber section.

Therefore, when the pressure in the pilot control conduit drops, the pilot valve, due to the action of the delay element, transitions from the shut-off position to the open position only after an adjustable duration and then, for the first time, if necessary, the working cylinder. Introducing a switching of the control slider to the working stroke position depending on the position of the impact piston in the. In doing so, the control device is automatically operated as long as the control slider of the control device requires one time interval conditioned by the system for the movement from the return travel position to the working travel position and vice versa. It is operated with a time delay.

The delay element can be arbitrarily formed in consideration of the requirements imposed on the delay element. In one advantageous embodiment according to claim 9, the delay element is formed by a flow regulator with a pressure-dependent adjustable target value, which is connected directly to the return conduit. Alternatively, it is indirectly connected to the return conduit via a switching control conduit which departs from the control device and applies pressure to the large piston face.
The flow regulator allows the volume flow through it to be adjusted to the adjusted target value, unless pressure changes that change the adjustment occur. As rock hardness changes, the impact piston bounce height changes, which in turn changes the system pressure. The flow regulator is then adjusted to a new target value depending on the system pressure, which determines or changes the residual return stroke of the impact piston. Normally, the flow regulator is such that the flow-through cross section of the flow regulator is completely open if the flow regulator is flowed through in the opposite direction, i.e. the outlet of the flow regulator is subjected to a higher pressure. Is formed. When the pressure in the switching control line drops, the pilot valve is switched from the initially taken shut-off position to the open position by the action of the return element and against the action of the flow regulator, and thus, depending on the case. A working pressure is applied to the large slider surface of the device.

However, in one advantageous embodiment of the impact device according to claim 10, a non-return valve is connected in parallel with the flow regulator towards the pilot valve, the non-return valve having the pilot valve shut off itself. It takes the closed position while switching from the position to the open position.

Not only does the check valve allow for rapid filling of the pilot control conduit, but the pilot valve may, in some cases, move to its shut-off position more quickly than if only by the action of the flow regulator. It also ensures the transition. Correspondingly, with the additional use of the check valve, which can also be designed to be spring-loaded in some cases,
Overall, a longer delay time can be obtained.

The aforementioned return element of the pilot valve (towards the open position) is in the simplest case the small dimension of the pilot valve (opposite the larger adjusting surface connected to the pilot control conduit). It can be realized by always connecting to the pressure conduit via a defined adjusting surface.

In an embodiment as claimed in claim 11, the inlet-side conduit, which is connected to the inlet of the pilot valve, is in communication with the pressure conduit in the front cylinder chamber section when viewed in the longitudinal direction of the impact piston. Between the mouth and the communication opening of the control conduit in the cylinder chamber, the communication opening of the inlet-side conduit is arranged in the cylinder chamber so that it is closed by the impact piston at the time of impact of the impact piston.

The communication of the inlet-side conduit or the control conduit into the cylinder chamber forms a short-stroke hole or a long-stroke hole. The inlet conduit of the pilot valve is first actuated via this short-stroke bore, and then the percussion piston follows a certain distance during the percussion stroke of the percussion piston.

In the twelfth aspect of the invention, the additional conduit is provided with an alternating switching valve, and the alternating switching valve is connected to the return conduit.

German Patent 344, whose structure and operation are described above.
The alternating diverter valve disclosed in 3542 ensures, inter alia, that the movement of the control slider to the return position is not disturbed, independent of the position of the impact piston in the cylinder chamber.

In an embodiment as claimed in claim 13, a flow regulator connected in parallel with the non-return valve to the pilot control conduit is permanently connected to the return conduit, this embodiment comprising:
The delay time produced by the flow regulator has the advantage that it is largely independent of the pressure conditions in the switching control conduit for the larger piston surface. The pressure build-up in this switching control conduit proceeds more or less rapidly depending on the operating conditions, and thus a second delay time is present if the flow regulator is directly connected to the switching control conduit. Control.

Another embodiment of the invention is described in claims 14 and 15. In these cases, a return force, which is hydraulically or mechanically generated, is applied to the pilot valve in the opening direction.

In the closing direction, the pilot valve is actuated by a working pressure (system pressure) via an adjusting throttle having a fixedly adjusted cross section, and is also fixedly adjusted by means of a control conduit. The pressure is applied.

The above-mentioned returning force in the opening direction can be generated by a pressure reducing valve, for example. Alternatively, the return force can also be mechanically generated by a return spring.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail based on embodiments with reference to the drawings.

The distance-time diagrams shown in FIGS. 1a and 1b show the material to be machined when the period T of the working cycle of the impact piston of the hydraulic impact device is adjusted so that the impact piston stroke S is constant. Shows that as the hardness increases, it becomes shorter, which is the case when using a control device that is usually configured to operate dependent on piston distance.

In the figure, different lengths of duration T of the operating cycle result from the interval between two adjacent times when the impact piston reaches the top dead center OT (or top reversal point). The impact point AP indicates that the impact piston impacts the tool, which is usually a chisel at the time point described above.

The control of the percussion device is carried out on the one hand for the changeover from the operating stroke position to the return stroke position, and on the other hand for the changeover from the return stroke position to the operating stroke position Δt1 (start time T1 It requires a time interval Δt3 with an end time T2) and a start time T4.

The switching of the control from the actuating stroke position to the return stroke position, as shown in the figure, is usually introduced in time by a release signal generated before the collision point AP.

When machining a soft material (FIG. 1a), the impact piston does not actually make any movement for a short time after impact with the tool, because the impact energy is not reflected, ie the impact piston's The return stroke movement takes place only after the control switches to the return stroke position at time T2. Correspondingly, a relatively long time interval is required for the return stroke of the predetermined distance S.

If the impact piston impinges on the relatively hard material via the associated tool, it depends on the reflectivity of the material to be machined, as can be seen in FIG. 1b, already by a considerable distance by the end time T2. And then the residual return stroke to the upper reversal point OT is performed by the action of the control.

Due to the partial return bounce of the impact piston in the direction of the return stroke, part of the impact energy is recovered by the impact piston pumping hydraulic fluid into the accumulating means over a wider piston face and a residual return stroke. The duration required to do is relatively short. Correspondingly, the number of impacts of the impact piston is greater in the case of machining a hard material than in the case of machining a soft material due to the use of distance-dependent control. FIG. 1c, in relation to FIG. 1d, shows that the number of impacts z increases with increasing magnitude of the reflectivity R when the impact piston distance S is held constant.

Unlike the prior art, within the scope of the present invention,
By varying the duration of the entire return stroke, it is proposed to shorten or lengthen the distance S traversed by the impact piston, depending on the material.

To achieve this, in addition to the delay time Δt1 for switching the control to the return stroke position, a second delay time Δt2, which depends on the reflectivity, is set in operation (FIG. 2a). After elapse of time Δt2 (end time T4)
A switching of the control from the return stroke position to the operating stroke position (time interval Δt3) is introduced. Therefore, the introduction of the switching at the end time T4 depends only on time and, accordingly, is independent of the impact piston distance S traced at the end time T4.

The starting time point T3 of the second delay time Δt2 can be set at an arbitrary time point by an appropriate release signal. In the embodiment shown in FIGS. 2a and 2b, the starting point T3 coincides with the ending point T2 of the first delay time Δt1.

From FIG. 2a, the distance S of the impact piston is about 1/2 when processing soft material compared to FIG. 1a.
You can see that it is nothing more. This means that the impact force is significantly reduced compared to the embodiment of FIG. 1a and only the impact force necessary for breaking the soft material is generated. However, the number of impacts remained at almost the same level as when machining hard materials due to the short duration T of the operating cycle.

As can be clearly seen from FIG. 2b, the second delay time Δt2 (H) is designed to reach a structurally pregiven maximum return stroke when processing hard materials. Top dead center O in the case of FIG. 1b and FIG. 2b
The distance S between T and the collision point AP has the same length. The delay time Δt2 (H) is the delay time of the soft material (Δ in FIG. 2a).
longer than t2 (W)).

Within the scope of the invention, the second delay time Δt2
2 is adjusted appropriately depending on the material hardness or the reflectivity R, the impact piston distance S is, as can be seen from FIG. 2c, the impact piston distance S is increased to a lower limit value R ₀ and then fixed by a limit stop. It can be changed as it is. The associated course of the shock number z depending on the reflectivity R is obtained from FIG. 2d. The method according to the invention is preferably designed such that the impact number starts from R ₀ and increases towards R = 0 (see the solid line in FIG. 2d).

This is because the limit stop is R according to the present invention.
= 100% and R = R _0, which can be realized by operating in the region and then switching the pilot valve. Value R
_Only below ₀ is the switching of the impact piston via the pilot valve (with a second delay time Δt2 adjusted in a pressure-dependent manner).

Therefore, by adjusting the second delay time Δt2, and by controlling the impact piston return stroke length depending on the reflectivity R by the second delay time Δt2, the impact piston is controlled. The operating characteristics of are optimally matched to the material hardness.

The liquid volume returned during the jumping back movement of the impact piston is accommodated by accumulating means in a known manner,
It becomes active again during the subsequent working stroke.

The impact device 1 (see FIG. 3a) has an actuating cylinder 2 outside the conduit and drive and control elements described below, in which the impact piston 3 is reciprocally movable in the longitudinal direction. Held in. The impact piston 3 has two piston collars 3a, 3b located in the inner chamber of the working cylinder.
The b's are separated from each other by a circumferential groove 3c. Piston surface A1 facing outward of the piston collar 3a or 3b
And A2 cooperate with the working cylinders and limit the rear and front cylinder chamber subsections 2a or 2b.

Outside the working cylinder 2, the impact piston 3 moves to the piston tip 3d, and a tool in the form of a chisel 4 is positioned opposite to the piston tip 3d.

The piston surface A2 is dimensioned smaller than the piston surface A1.

FIG. 3 a shows the impact piston immediately after the impact piston 3 has collided with the chisel 4. The associated impact piston position is indicated by a circle in the distance / time diagram of FIG. 7a.

The control element for switching the movement of the impact piston 3 comprises a control slider 5a which is movable in the control valve 5,
The small slider surface A _S1 of the control slider 5a is connected to the return conduit 6
The operating pressure is always applied via the. This operating pressure is generated by an energy source in the form of a hydraulic pump 7. The smaller piston surface A2 is also constantly actuated by a pressure conduit 8 connected to the return conduit 6. The communication port 8a of the pressure conduit is connected to the working cylinder 8
In each case a is located outside the piston collar 3b, and thus in the front cylinder chamber partial section 2b.

Large slider surface A _S2 of the control slider 5a
Is the peripheral groove 3c when the communication port 9a of the control conduit 9 is in the state shown.
Via the control conduit 9 to the cylinder chamber via the control conduit 9 as it is connected to the return conduit 10 which is held without pressure. Therefore, the communication port 9a of the return conduit and the communication port 1
When viewed in the longitudinal direction of the impact piston 3, 0a is located opposite to each other with a distance shorter than the axial length of the circumferential groove 3c.

The control valve 5 is connected on the one hand to the pressure conduit 8 via the conduit 11 and on the other hand to the return conduit 10 via the conduit 12. On the other hand, the control valve 5 is the switching conduit 1
Connected to the rear cylinder chamber partial section 2a via 3,
A working pressure is applied to the large piston surface A1 via the rear cylinder chamber partial section 2a.

The control valve 5 can take two valve positions, ie one valve position is the illustrated (left-hand) actuation stroke position, in which actuation stroke the large piston surface A
1 is actuated via switching control conduit 13 and conduit 11 and the other valve position is the return stroke position (on the right), in which the rear cylinder chamber partial section 2
a is held pressureless via the switching control conduit 13, conduit 12 and return conduit 10.

The delay time required to switch the control valve 5 from the working stroke position to the return stroke position or from the return stroke position to the working stroke position is represented by the symbol "Δt1" or "Δt".
3 ".

In the present invention, the impact device 1 is additionally provided with a pilot valve 14, which on the one hand is connected to the cylinder chamber via an inlet-side conduit 15 and on the other hand is controlled via an additional conduit 16. It is connected to the conduit 9. The pilot valve 14 is configured such that the pilot valve 14 assumes the shut-off position shown or the open position in which the conduits 15 and 16 are connected to each other.

Communication port 1 of inlet side conduit 15 to the cylinder chamber
5a is arranged such that this communication port 15a is located between the communication ports 8a and 9a when viewed in the longitudinal direction of the impact piston 3 and is closed by the piston collar 3b at the collision position of the impact piston shown. There is.

The position of the pilot valve 14 is controlled via two faces, one face being a small dimensioned return face _AV1 and the other face being a large alignment face _AV2 . The working pressure is constantly applied to the former surface via a return conduit 17 connected to the pressure conduit 8. The pilot valve 14 thus acts to assume the open position.

The position adjusting surface A _V2 has a delay element 18 inserted in the middle thereof (a check valve 19 is optionally connected in parallel to the delay element 18, as shown in FIG.
The pilot control conduit 20 is connected to the switching control conduit 13. Therefore, when an operating pressure is applied to the switching control conduit 13, that is, when the impact piston 3 is driven in the impact direction via the large piston surface A1, the pilot valve 14 is actuated by the position adjusting surface A _V2 to close the shutoff position. And in this cut-off position conduits 15 and 16
Does not work. The delay element 18 can be designed, for example, as a flow regulator with an adjustable target value depending on the pressure.

As can be seen from FIG. 3 a, the impact piston 3 connects the control conduit 9 to the return conduit 10 via a circumferential groove 3 c. Therefore, the control slider 5 still in the operating stroke position
a is moved to the left by the action of the slider surface A _S1 to which the operating pressure is applied.

As soon as the control slider 5a reaches its return stroke position by the movement to the left, the large piston surface A1 is connected to the pressureless return conduit 10 via the switching control conduit 13, the control valve 5 and the conduit 12. (Fig. 3b).
The percussion piston 3 begins its own (in the figure upwards) return stroke by the action of a pressing force applied to the small piston surface A2 via the pressure conduit 8 (in this regard shown in FIG. 7b). Impact piston position).

The control slider 5a has a small slider surface A _S1.
The delay time when switching from the operating stroke position to the return stroke position by the action of is indicated by the symbol "Δt1".

After the switching of the control slider 5a and the consequent pressure drop in the switching control conduit 13, the pilot valve 14 moves towards its open position by the action of the return surface A _V1 to which pressure is applied. Start the migration (see Figure 4 for this). This switching movement is carried out via the delay element 18 (with the check valve 19 closed) after a lapse of the time interval given beforehand by the material hardness (FIG. 5).
Controlled to reach the open position (as shown in FIG. In the meantime, the impact piston 3 continues its return stroke movement (see FIG. 7c for this).

This movement of the actuating cylinder 2 interrupts the connection between the control line 9 and the return line 10 on the one hand. On the other hand, the piston collar 3b opens the communication port 15a of the inlet-side conduit 15, which is therefore connected to the pressure conduit 8 via the front cylinder chamber section 2b.

As soon as the pilot valve 14 reaches the open position in FIG. 5 after the delay time Δt2 has passed, the large slider surface A _S2 is actuated via the additional conduit 16 and the control conduit 9. As a result, the control slider 5a starts moving from the return stroke position to the impact stroke position, and the control slider 5a reaches the impact stroke position after the elapse of the time interval Δt3.

In this connection, from FIG. 7d, during which the impact piston 3 performs most of its return stroke,
It can be seen that a switching of the control valve 5 to the working stroke position is introduced as described above.

The control slider 5a is in the operating stroke position (FIG. 6).
Is immediately applied to the switching control conduit 13 via conduit 12, this operating pressure being the large piston surface A
1, also triggers the next working stroke.

It can be seen from the corresponding FIG. 7e that the impact piston has reached top dead center or top reversal point (OT) and has followed a distance S with respect to the collision point AP (FIG. 6).

Large position adjusting surface A _{V2 of} pilot valve 14
Is applied with operating pressure via the switching control conduit 13, whereby the pilot valve 14 is inserted and connected in the middle of the pilot control conduit 20 and must act like a check valve when the operating pressure is applied. It is switched to the shut-off position via a delay element 18 which must be provided or which must have a check valve connected in parallel, whereby the conduits 15 and 1
6 is switched so that it does not work.

The above description with respect to FIGS. 3 to 7 assumes that the material to be processed has an intermediate hardness and therefore the impact piston 3 follows an intermediate length distance S. This distance S is longer the higher the reflectivity of the material to be machined, and the overall control depends on the reflectivity R of the working cylinder due to the time-delayed operation of the control valve 5 and the pilot valve 14. Guarantee time T. Duration T is delay time Δ
It consists of t1, Δt2 and Δt3 and the time interval required for the working stroke of the impact piston. The time interval required for the working stroke changes only slightly with a change in the impact piston stroke and thus has a small influence on the duration T. The delay time Δt2 required for switching the pilot valve 14 is determined by a pressure-dependent adjustment of the delay element 18, whereby the duration T of the operating cycle depends on the material hardness (ie the magnitude of the reflectivity R). (Depending on) changes as desired.

8 to 10 show that after the pilot valve 14 has already reached the open position in FIG. 8, then a connection is made between the conduits 15 and 8 via the front cylinder chamber section 2b. Shows an extreme case. The position of the impact piston 3 corresponding to FIG. 8 is shown in FIG. 11a.

This case occurs if the impact device is switched on and the later operating pressure has not yet been set in the first operating cycle or the delay time Δt2 through the delay element 18 is too short.

Due to the premature switching of the pilot valve 14, the control valve 5 is moved into the working stroke position only depending on the position of the impact piston, which transition is shown in FIGS. 9 and 11b. Impact piston 3 is at distance S1
It follows immediately after. This allows the inlet side conduit 15
Is connected to the pressure conduit 8 via the front section 2b of the cylinder chamber and, accordingly, adjusts the operating position of the control slider 5a via the large slider surface A _S2 under pressure. Is started.

When viewed in the longitudinal direction of the impact piston 3, a distance is provided between the communication ports 8a and 15a of the conduits 8 and 15, and the control valve 5 is switched with a time delay, so that the impact piston 5 is moved to the minimum stroke. It is ensured that the actuation stroke is started after following S _min and then after switching the control slider 5 to the actuation stroke position (FIGS. 10 and 11c).

If the impact piston 3 collides with an extremely hard material via the tool 4 and the delay time Δt2 of the delay element 18 is very long, the impact piston 3 will be urged before switching to the open position of the pilot valve 14. The top dead center or top reversal point, which is structurally _{pregiven and} which defines the maximum impact piston distance S _max , may be reached.

In such an exceptional case, the impact piston 3
Return stroke movement overtakes the switching of the pilot valve 14, which is connected via the front cylinder chamber subsection 14 to the control conduit 9 and to the control slider 9 to the pressure conduit 8. It is realized by the control slider 5a initiating the switching to the operating stroke position (with a delay time Δt3).

The communication port 9a of the control conduit 9 is connected to the working cylinder 2
With proper positioning, the impact piston 3 is prevented from hitting the inner wall of the associated housing and overloading the impact device.

From FIGS. 12 and 13, the pilot valve 14
It can be seen that it is possible to interrupt the return stroke movement of the percussion piston independently of the action of ## EQU3 ## depending on the distance after the percussion piston has followed a predetermined maximum distance S _max .

In the embodiment of FIG. 14, the pilot valve 14
The control valve 5 is additionally provided with an alternating switching valve 21, and the structure and operation of the alternating switching valve 21 are described in German Patent 34435.
It is known from specification 42.

The alternating switching valve 21 is connected to the pilot valve 14 via the additional conduit 16, the conduit 16a connected to the additional conduit 16 via the pilot valve 14 is connected to the control conduit 9 and the other conduit 16b. Is connected to the large slider surface of the control valve 5 via. 2 of alternation switching valve 21
By the action of the _two adjusting surfaces W ₁ and W ₂ , the alternating switching valve 21 is
In the blocking or open position shown, in the open position the conduit 16b is routed via conduits 16a, 22 and 12 to the return conduit 1
Connected to 0.

The alternating switching valve 21 has a throttle valve 21a as another important component, and the throttle valve 21a includes the conduits 9 and 16b.
And is incorporated in the middle of the conduit 16a. Throttle valve 2
Due to the action of 1a, a pressure is formed on the control surface W ₁ or W ₂ as the case may be, which pressure causes the alternating switching valve 21 to switch to the blocking or opening position as required.

By the alternating switching valve 21, the control slider 5a
It is ensured that the switching from the working stroke position to the return stroke position is not disturbed regardless of the position of the impact piston 3. This means that the conduit 16b has conduits 16a, 22, 12 and 1
0, the alternating switching valve 21 is held without pressure when it is in the open position.

When the pilot valve 14 reaches the open position, the control valve 5 is pressured via the conduits 16, 16a and 16b, and thus the switching of the pilot valve 14 to the shock stroke position is introduced. The switching valve 21 ensures that the connection between the conduits 16, 16a, 9 and 16b and the conduits 22, 12 and 10 is interrupted.

The inlet conduit 15 is directly connected to the pressure conduit 8 and does not have short stroke holes in the embodiment of FIG.

FIG. 15 illustrates one embodiment of the present invention with a limit stop and no minimum stroke.

The communication port 9a of the control conduit 9 is the impact piston 3
Of the control piston 3 is positioned such that a connection is formed between the conduits 9 and 10 via the circumferential groove 3c before the impact of the control piston 3 on the associated tool 4. As a result, (Fig.
It becomes possible to initiate the switching of the control valve 5 to the return stroke position.

Switching of the control valve 54 when the impact piston 3 can be rapidly bounced back by the pilot valve 14 and switched to the open position of the impact piston 3 by the action of the strongly reflecting material (see FIG. 14 in this regard). Is depending on the distance depending on the case. This is because the piston collar 3b opens the communication port 9a during the course of the return stroke movement,
As a result, the communication port 9a is located in the front cylinder chamber partial section 2b.
And an operating pressure is applied via the pressure conduit 8. The control conduit 9 to which pressure is applied by this
Starts the switching of the control valve 5 to the operating stroke position (see FIG. 14 for this) at a delay time Δt3.

The structure shown in FIG. 16 differs from the embodiment of FIG. 14 in that the communication ports 8a and 15a of the conduits 8 and 15 are different.
Or, 9a is arranged in the same manner as in the case of FIG. 3a, for example.

The inlet-side conduit 15 is first opened in a distance-dependent manner, ie no operating pressure is applied at all times. That is, the connection with the pressure conduit 8 via the front cylinder chamber partial section 2b is formed when the impact piston 3 advances its minimum stroke (depending on the axial distance between the communication openings 8a and 15a).

The communication port 9a of the control conduit 9 is the communication port 15a.
Different from forming a long stroke hole. The long stroke hole allows the control conduit 9 to be actuated independently of the position of the pilot valve 14 and thus the switching of the control valve 5 (of FIG. 14) to the actuation stroke position. This is done by the piston collar 3b passing through the location of the communication opening 9a, which is likewise connected to the pressure conduit 8 via the entire cylinder chamber section 2b.

The embodiment of the percussion device 1 of FIG. 17a corresponds, for example, to the embodiment of FIG. 3a, the valves 5 and 14 being the same.
Is assigned an alternating switching valve 21 (corresponding to FIG. 14). Furthermore, a check valve 19 is additionally connected in parallel with the delay element 18.

The check valve 19 ensures a rapid return stroke of the pilot valve 14.

In FIG. 17b, the delay element 18 is also actuated towards the tank and is accordingly independent of the return pressure which may possibly occur in the impactor. that time,
The return stroke of the pilot valve 14 is controlled via the check valve 19.

The delay element 18 described above is formed as a flow regulator 23 in the embodiment of FIG.
As a result, a constant volume flow rate always flows through regardless of the inlet pressure. Accordingly, the second delay time Δt2 required for the predetermined adjustment of the flow regulator 23 can be kept constant regardless of the operating pressure (system pressure).
The adjustability of the magnitude of the flow regulator setpoint is indicated by arrow 23a.

Within the scope of the solution of the invention, the flow regulator 23
Is dependent on the pressure and is adjustable, that is to say the desired value of the volumetric flow depends on the operating pressure p ₀ and the flow regulator 2
It can be varied by adjusting the flow-through cross section in 3 (Fig. 18b).

To achieve this, the cross-section adjusting device (indicated by arrow 23a) has an actuating element, which has an adjusting piston with a piston rod 24a and a return spring. The movement of the piston rod 24a with respect to the flow regulator 23 changes the size of the throughflow cross section.

In this embodiment, the actuating element and the flow regulator are arranged such that when the working pressure p ₀ decreases (in response to the upward movement of the piston rod 24a), the flow regulator 23 sets the target for adjusting the volume flow rate. It is formed so that the value is controlled to take a larger value. This adjustment of the volumetric flow rate to a larger target value reduces the second delay time Δt2.

When a higher operating pressure p ₀ is applied to the upper piston surface A _SK via the control conduit 26 starting from the pilot conduit 20, the piston rod 24a causes the return spring 2 to move.
5 against the action of 5, causing the flow regulator 23 to have a smaller flow-through cross section.

As described above, the operating pressure rises as the reflectance R increases, so the second delay time Δt2 is equal to the flow regulator 2
It changes as described above depending on the adjustment of 3.

The flow regulator 23 cooperates with the associated actuating element so that, depending on the operating pressure or the system pressure, the second delay time Δt2 and thus the residual return stroke of the percussion piston can be matched depending on the material. Guarantee that. The lower the reflectance R, and accordingly the lower the operating or system pressure, the shorter the residual return stroke, and the higher the reflectance R, the longer the residual return stroke.

The operation of the flow regulator 23 can be advantageously varied by parallelly connecting the return force of the return spring 25 with an adjustable constant additional force, which is also directed towards the return spring 25. It acts against the movement of the adjusting piston 24. This additional force is simply generated by the return spring 25 having a bias tension force, and the bias tension force causes the return spring 25 to be held in contact with a stopper surface (not shown).

As the bias tension increases, the volumetric flow rate target value determined via the flow regulator 23 increases with the operating pressure or system pressure p ₀ remaining constant. This reduces the delay time Δt2 and reduces the magnitude of the residual return stroke at the same working pressure or system pressure and at the same reflectivity R. In response to this, the point R ₀ located on the characteristic curve moves to the right. Therefore, the limit value R ₀ of the reflectivity R can be set or changed depending on the magnitude of the bias tension force, that is, when the limit value R ₀ is exceeded, the target value of the flow regulator 23 and thus the second delay time Δt2. The magnitude is the dimension that determines the magnitude of the residual return stroke as shown in Figures 2c and 2d.

For example, when the delay time Δt2 is shortened as the reflectance R becomes lower, the residual return stroke of the impact piston (and eventually the piston stroke) becomes shorter. The number of shocks z increases accordingly, because the time interval T of the operating cycle has a smaller value.

Within the scope of the invention, the embodiments of FIGS. 19 and 20 likewise increase the working pressure or system pressure as the reflectivity R increases, and accordingly the second delay time Δt2.
Is taken into consideration.

Unlike the embodiment of FIG. 14, the pilot control conduit 20 (with the delay element 18 removed) adjusts the throttle 2
7 is inserted and connected in the middle, and the check valve 28 is connected in parallel to the adjusting throttle 27 and is transferred to the switching control conduit 13.
Furthermore, the control conduit 29 departs from the pressure conduit 8 and the control conduit 2
The pressure is applied to the surface A _V3 of the pilot valve 14 via 9.

The difference between these two embodiments is that the return conduit 17 connected to the pressure conduit 8 in the embodiment of FIG. 19 is provided with a pressure reducing valve 30, and the embodiment of FIG. It has a return spring 31 acting on the valve 14.

The pressure reducing valve 30 (see FIG. 19) is connected to the return conduit 17
The operating pressure or system pressure in the
This predetermined value is applied to surface A _V1 and, by extension, pilot valve 1
4 produces a constant force in the opening direction. The pressing force acting on the surfaces A _V2 and A _{V3 opposes} this force in the opening direction.

The regulated pressure in pilot control conduit 20 is regulated to create a force balance in pilot valve 14. Accordingly, the regulated pressure in pilot control conduit 20 decreases as the operating pressure increases and vice versa.

The volume flow through the regulating throttle 27, which results from the pressure difference between the conduits 20 and 13, determines the regulating speed of the pilot valve 14 and accordingly the magnitude of the second delay time Δt2. Determine.

When the working pressure rises as the magnitude of the reflectance R increases, the adjustment pressure in the pilot control conduit 20 and the pressure difference in the adjustment throttle 27 are small due to the force balance in the pilot valve 14. Become. This allows
The volumetric flow through the regulating throttle 27 is reduced, the speed of the pilot valve 14 is reduced and the second delay time Δt2 is increased (as desired).

In the embodiment shown in FIG. 20, the pilot valve 1
The return force acting in the opening direction of 4 is the return spring 31 described above.
Generated by As in the case of the embodiment of FIG. 19, the working pressure increases as the magnitude of the reflectance R increases. Due to the force balance present in the pilot valve 14, the volume flow through the regulating throttle 27 decreases, as the pilot pressure increases as the working pressure increases.
This is because the adjusted pressure in 0 drops. In response to this, the adjustment speed of the pilot valve 14 decreases, which causes the second valve
The delay time Δt2 of is greater than (as desired).

The advantages obtained by the present invention are, inter alia, the use of additional elements which are simple and less prone to failure, which make it possible to automatically match the impact force generated by the impact device with the hardness of the material to be processed. It is in. This improves the economics of the impact device and reduces its load.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a known impact device, in which a soft material whose impact piston distance is controlled depending on the impact piston distance is controlled, and a distance / time diagram of the distance of the impact piston when machining a hard material and the impact piston depending on the distance. It is a distance / impact number diagram which depends on reflectance in control.

FIG. 2 is a distance-time diagram of the impact piston distance in the case of processing soft and hard materials formed according to the present invention, and the impact piston control depends on the distance and time. It is a distance / impact number diagram.

FIG. 3 is a schematic diagram of a percussion device formed according to the present invention at some point during one operating cycle in which a delay element for a second delay time is also shown.

FIG. 4 is a circuit diagram of a percussion device formed according to the invention at some point during one operating cycle in which a delay element for a second delay time is also shown.

FIG. 5 is a circuit diagram of an impact device formed according to the present invention at some point during one operating cycle where the delay element for the second delay time is also shown.

FIG. 6 is a schematic diagram of an impact device formed according to the present invention at some point during one operating cycle where a delay element for a second delay time is also shown.

FIG. 7 is a distance / time diagram corresponding to FIGS. 3 to 6;

FIG. 8 is a schematic diagram of an impact device formed in accordance with the present invention during a stroke when processing soft materials.

FIG. 9 is a circuit diagram of an impact device formed according to the present invention in a process for processing a soft material.

FIG. 10 is a circuit diagram of an impact device formed according to the present invention in a process in which a soft material is processed.

FIG. 11 is a distance / time diagram corresponding to FIGS. 8 to 10;

FIG. 12 is a circuit diagram of an impact device formed according to the present invention when processing a hard material.

FIG. 13 is a distance / time diagram corresponding to FIG.

FIG. 14 is a circuit diagram of an impact device having an alternating switching valve outside a pilot valve that is operated with a time delay.

FIG. 15 is a circuit diagram showing a part of the circuit diagram of FIG. 14 with another configuration of the impact piston and the conduit communicating with the associated cylinder chamber.

16 is a circuit diagram showing a part of the circuit diagram of FIG. 14 having another configuration formed as a minimum stroke circuit.

17 is a schematic diagram of the percussion device of FIG. 16 in which a check valve is additionally arranged in the delay element for the pilot valve and its schematic diagram in which the delay element is directly connected to the pressureless return conduit. 3 is a circuit diagram showing a part of FIG.

FIG. 18 is a circuit diagram of a flow regulator used as a delay element and a flow regulator with a target value adjusted in dependence of pressure.

FIG. 19 is a circuit diagram of an apparatus for adjusting the second delay time Δt2.

FIG. 20 is a circuit diagram of an apparatus similar to FIG. 19 but different in configuration.

[Explanation of symbols]

1 Impact Device 2 Operation Cycle 2a, 2b Cylinder Chamber Partial Section 3 Impact Piston 3a Piston Collar 3b Piston Collar 3c Circumferential Groove 3d Piston Tip 4 Shaft 5 Control Valve 5a Control Slider 6 Control Slider 7 Hydraulic Pump 8 Pressure Pipe 8a Communication Port 9 control conduit 9a communication port 10 return conduit 10a communication port 11 conduit 12 conduit 13 switching conduit 14 pilot valve 15 inlet side conduit 15a communication port 16 additional conduit 16a conduit 16b conduit 17 return conduit 18 delay element 19 check valve 20 pilot valve 21 Alternate switching valve 21a Throttle valve 22 Conduit 23 Flow regulator 23a Flow regulator Arrow indicating the possibility of adjusting target value 24 Adjustment piston 24a Piston rod 25 Return spring 26 Control conduit 27 Adjustment throttle 28 Check valve 29 Control Conduit 30 Valve 31 return spring A1, A2 piston face AP collision point A _S1 small slider surface A _S2 large slider surface A _V1 back surface A _V2 adjusting surfaces A _V3 surface OT TDC or upper reversal point p ₀ operating pressure R reflectance R ₀ limit S percussion piston stroke S _max maximum shock piston distance S _min minimum stroke T duration T1 beginning T2 end T3 start time T4 start time W _1, W ₂ control plane z impact several Δt1~Δt3 time interval

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Marx Geimer, Federal Republic of Germany Essen Graaf-Spee-Strasse 3 (72) Inventor, Martin Schalina, Federal Republic of Germany Gelsenkirchen Friedhofstraße 1

Claims (15)

[Claims] 1. A method of controlling the operating characteristics of a fluid driven impact device having an impact piston that alternately performs an actuation stroke and a return stroke under the action of a control device, the method comprising: Dependently, the impact piston generates a release signal at the starting point (T1), which initiates the switching of the control device to the return stroke position, the control device being in the return stroke position for all impact cycles. On the other hand, in a method for controlling an operating characteristic of an impact device having an impact piston, which is configured to reach an end time point (T2) located after completion of an operation stroke with a substantially constant delay time (Δt1), a direct or The delay time (Δt2) that is indirectly released by the impact piston and can be changed by the operating pressure is set, and the impact piston causes the delay time (Δt2) to be changed by this setting.
During t1), first, a return stroke depending on the reflectivity of the material to be processed is performed, and then a residual return stroke is performed, the residual return stroke increasing as the magnitude of the reflectivity that changes the working pressure increases. And, at the end time (T4) of the second delay time (Δt2), the switching of the control device to the operating stroke position of the control device is started independently of the position of the shock piston. How to control characteristics. 2. Impact with an impact piston according to claim 1, characterized in that the starting point (T3) of the second delay time (Δt2) coincides with the ending point (T2) of the delay time (Δt1). A method for controlling the operating characteristics of a device. 3. A second delay time (Δt2) is set at a certain reflectivity of the material to be machined below the maximum reflectivity by the start of the switching of the control device at the end point (T4).
3. A selection according to claim 1 or 2, characterized in that the impact piston has a structurally determined maximum return stroke.
A method for controlling the operating characteristics of an impact device having an impact piston according to claim 1. 4. The upper reversal point, which is structurally provided, even if the switching of the second delay time (Δt2) via the limit stop by the impact piston depending on the distance to the operating stroke position of the control device is delayed. 2. The impact piston is interrupted so as to be terminated when it reaches the impact piston.
3. A method for controlling an operating characteristic of an impact device having the impact piston according to claim 2. 5. A second delay time (Δt2) is selected such that at the highest possible reflectivity of the material to be processed the impact piston reaches the structurally provided upper reversal point. A method of controlling the operating characteristics of an impact device having an impact piston according to claim 4. 6. The control is switched to the operation stroke after the elapse of the second delay time (Δt2) by the second delay time (Δt2).
And the impact piston follows a distance shorter than a predetermined minimum return stroke at the end time (T4), the impact piston having the impact piston according to any one of claims 1 to 5. A method for controlling the operating characteristics of a device. 7. The impact device with an impact piston according to claim 6, characterized in that the minimum return stroke is sized between 20 and 50% of the structurally provided maximum return stroke. Control method of operating characteristics. 8. A percussion piston (3) for colliding with a moving tool (4) in a working cylinder (2) and a control valve (5).
The impact piston (3) has two piston faces (A1, A2) of different sizes, the piston face (A1, A1)
The piston face (A2) of A2) acting towards the small return stroke is always connected to the pressure conduit (8) to which the working pressure is applied, and the piston face (A2) acting towards the large working stroke (A2). A2) is selectively connected to the pressure conduit (8) and the pressureless return conduit (10) via a control valve (5), the control sliders (5a) having different sizes and opposite each other. Of the slider (5) toward the return stroke position of the control slider (5a), which is the smaller of the slider surfaces.
The slider surface (A _S1 ) acting on a) is always connected to the pressure conduit (8) and the large slider surface (A _S2 ) is arranged between the piston surfaces (A1, A2). Control of the operating characteristics of a percussion device with a percussion piston according to any one of claims 1 to 7, which is connected to the pressure conduit or the return conduit (8 or 10) respectively only temporarily and alternately via (3c). In a fluid-driven percussion device (1) carrying out the method, a large slider (A _S2 ) acting towards the working stroke position of the control device is fitted with a return element (17 or 23) via an additional conduit (16). Connecting to the outlet of the pilot valve (14) and moving the pilot valve (14) from the open position to the closed position of the pilot valve (14) by applying a force against the return element (17 or 23). But The adjustment force against the return element (17 or 23)
The operating pressure applied to the large piston surface (A1) is transmitted through the pilot control conduit (20) to the pilot valve (1).
4) is generated so as to act on the adjustment surface (A _V2 ), a delay element (18) is arranged in the pilot valve (14), and the pilot valve (14) is operated by the operation of the delay element (18). Switching from the closed position to the open position with a delay of a duration (Δt2) adjusted depending on the operating pressure, connecting the inlet of the pilot valve (14) directly to the pressure conduit (8), or Depending on the position of the impact piston (3) in the working cylinder (2), only temporarily, the front cylinder chamber subsection (2b) is bounded by the small piston surface (A2). And a fluid-driven percussion device, characterized in that it is connected to said pressure conduit (8) via 9. The delay element is formed by a flow regulator (23) having a pressure-dependent adjustable target value, which flow regulator (23) is directly connected to the return conduit (10). Or connected to said return conduit (10) indirectly via a switching control conduit (13) starting from a control device (control valve 5) and applying pressure to a large piston surface (A1) A fluid driven impact device according to claim 8. 10. A non-return valve (19) connected in parallel to a flow regulator (23) towards a pilot valve (14), the non-return valve (19) comprising a shut-off position of the pilot valve (14) itself. 10. The fluid driven impact device according to claim 9, wherein the fluid driven impact device is in the closed position while being switched from the open position to the open position. 11. Pressure in the front cylinder chamber section (2b) of the inlet conduit (15) connected to the inlet of the pilot valve (14) in the longitudinal direction of the impact piston (3). Between the communication port (8a) of the conduit (8) and the communication port (9a) of the control conduit (9) in the cylinder chamber, the communication port (15a) of the inlet side conduit (15) is in the cylinder chamber. At the time of collision of the impact piston (3), the impact piston (3)
11. A fluid driven impact device according to any one of claims 8 to 10, characterized in that it is arranged to be closed by a. 12. An alternating switching valve (2) in the additional conduit (16).
1) is provided, and the alternating switching valve (21) is connected to the return conduit (1
0) The fluid-driven impact device according to any one of claims 8 to 11, characterized in that it is connected to 0). 13. A switching control conduit (13) is connected to a pilot control conduit (20) via a check valve (19) and is connected in parallel to the check valve (19) with respect to said pilot control conduit (20). 10. A continuous flow regulator (23) is permanently connected to the return conduit (10).
Or the fluid-driven impact device of item 10. 14. A delay element is formed by an adjusting diaphragm (27) having a fixedly set cross section, said pilot element (14) forming a first face (A) in the closing direction on the one hand by the pilot valve (14). _V2 ) applies the operating pressure (system pressure), the second surface (A _V3 ) applies the pressure in the control conduit (29), on the other hand, in the opening direction, the pressure reducing valve (30). A fluid-driven impact device according to any one of claims 8 or 10 to 13, characterized in that a pressure that is fixedly adjusted is applied via the. 15. The pilot valve (14) in the opening direction,
The fluid-driven impact device according to claim 14, wherein a mechanically generated restoring force (return spring 31) is applied.