DE3225132A1 - Hydraulic safety brake valve - Google Patents

Abstract

A hydraulic safety brake valve is arranged in the feed lines of a double-acting, preloaded, hydraulic consuming unit. In the event of a pipe fracture when lowering the preload, uncontrolled lowering is prevented in that in the lifting line a throttle valve is arranged, which is controlled by a flow meter, which is arranged in the lowering line. The flow meter is a differential pressure valve. The throttle valve is hydraulically pilot controlled by the pressure differential on the flow meter. <IMAGE>

Description

225132

Beb 81/1 - 8 -

Hydraulic safety brake valve

When operating hydraulically operated consumers, which under If there is a preload, especially when operating excavators, cranes, and elevators, there is a problem in the event of a pipe burst the hydraulic supply line that applies hydraulic fluid to the consumer against the preload (lifting line), to avoid that the consumer gives in to the preload. This is a safety requirement for excavators, cranes and elevators, since without such a safety brake valve the load would crash in the event of a pipe burst - hydraulic consumers In the context of this application are in particular hydraulic motors and hydraulic cylinder-piston units.

When operating the hydraulic consumer against the preload, i.e. when an excavator, crane or elevator moves upwards In the simplest case, such a safety brake valve can be constructed as a check valve, which is combined with the hydraulic Consumer, e.g. the hydraulic cylinder, is in a break-proof hydraulic connection, e.g. component of the cylinder or is flanged to this cylinder.

^"2o When moving in the direction of the preload of the consumer, however, is pressurized in the direction of the preload, so that the check valve must be opened for the return flow from the consumer or bypassed. If there is now a fraction of the lift line, which in this load case the return oil flow

leads from the consumer to the pump, the non-return valve is inoperative and special hydraulic precautions must be taken be taken to put it back into operation or the bypass line, which bypasses the check valve, as well to close or to keep their opening under control

and a further lowering of the preload at an uncontrolled speed (Crashing of the Vorlasft) to prevent. Safety brake valves are known for this purpose.

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The main disadvantages of known safety brake valves can be summarized in that these safety brake valves also have an adverse effect on the operation of the consumer, bring especially the lowering movement with it. In particular, there are start-up delays and changes in driving behavior and in particular a dependency of the driving behavior of the consumer on the level of the static pressure.

The invention specified in claim 1 solves the problem of providing a hydraulic safety brake valve for hydraulic, under Provide preload consumers, which without additional control effort, in particular without additional Cables on the one hand meet the safety requirements as outlined above, but on the other hand the driving and pressure behavior of the consumer is not impaired in a way that is noticeable for operation.

The principle of the invention is that for the lowering movement of the consumer, the flow rate in the lowering line, which in this state, the pump oil flow leads, measured and the measured value is used to control the opening of a throttle valve which is switched on in the lifting line, which lifting line the return oil flow in the operating state of lowering

leads from the consumer to the tank.
25th

This control of the return oil flow as a function of the pump oil flow makes the lowering movement of the consumer independent of pressure losses in the lifting line in the event of a pipe rupture, which in this operating state prevents the return oil flow leads. It is even preferably provided that the lifting line in the Operating case of lowering is switched essentially without pressure, so that there is no enlargement in the event of a pipe rupture the pressure difference at the throttle valve and thus also does not lead to an increase in the return oil flow.

COPY

Beb 81/1 - 10 -

As a flow meter in the lowering line carrying the pump oil flow In the simplest case, a rigid diaphragm can be used, the pressure difference of which - if necessary after a Reinforcement - used to control the throttle valve in the lift line. However, there is the disadvantage of a rigid aperture

in that there is a quadratic dependence between the flow velocity and the pressure difference exists. There are also flow meters according to different functional principles and with different ones conceivable as hydraulic output signals. 10

The throttle piston of the throttle valve is preferably hydraulic controlled. For this purpose, the throttle piston is in the closing direction with a spring and the discharge pressure of the flow meter and in The inlet pressure of the flow meter is applied to the opening direction. This increases the throttle piston in the lifting line, which leads the return oil flow, introduces an equilibrium position, which depends on the flow rate in the lowering line carrying the pump oil flow. In lifting operation, i.e. when the lifting line conducts the pump oil flow, the throttle piston closes.

The pressure difference that is dependent on the flow rate according to a predetermined law, preferably linearly dependent, becomes according to the invention in a preferred embodiment produced in that the flow meter as a differential pressure valve is formed with a throttle piston. This throttle piston is in the closing direction by a spring and the discharge pressure of the differential pressure valve and controlled in the opening direction by the inlet pressure of the differential pressure valve. Through the Formation of the throttle area can be a predetermined err desired dependency between the pressure difference generated (Inlet pressure minus outlet pressure) and the flow rate. The opening of the throttle piston of the pressure differential valve can be limited by an adjustable stop pin. Furthermore, it is possible and preferred that the springs, which on the throttle piston of the differential pressure valve on the one hand and

Beb 81/1

of the throttle valve act on the other hand, are adjustable in their bias. This allows the pressure behavior and flow behavior of the differential pressure valve and the throttle valve to be coordinated with one another.
5

An overpressure in the lifting line carrying the return oil flow, which can occur in particular due to sudden loads or too sudden control maneuvers, is controlled by a secondary pressure relief valve avoided in the lifting line between consumer and throttle valve.

A suction valve, which the lowering line between consumers and the differential pressure valve connects to the tank, ensures that the oil flow to the tank if the lowering movements are too rapid Lower side of the consumer does not tear off.

It has already been mentioned that according to the invention the lifting line pressure should be switched off between control valve 4 and throttle valve 7. Although various measures are conceivable for this are, it is proposed as preferred that this depressurization takes place with the aid of the safety brake valve. For this if the throttle piston of either the throttle valve or the differential pressure valve has a control edge, which the lifting line depending on the position of the throttle piston connects to the tank.

Another solution, which is characterized in that it can be integrated into existing control valves, has one 3-way switch that is switched on in the lifting line and the connection from the control valve to the throttle valve is only released when there is pressure at the output of the control valve. In its zero position, this 3-way switch connects the throttle valve with the tank.

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The check valve securing the lifting operation is preferably arranged in the throttle piston of the throttle valve. Likewise is A check valve is provided in the lowering line, which is preferably also in the throttle piston of the pressure differential valve can be arranged.

An essential feature of the invention in its further embodiment consists in the substantially identical construction for the differential pressure valve and the throttle valve. Next to Manufacturing advantages also result from the fact that both valves can be switched in their function when the The preload direction of the consumer is reversed. This applies in particular to those consumers who, when moving drive through a dead center position. This is the case, for example, with the booms of excavators that drive through a vertical position. According to the invention, a switchable safety brake valve is characterized in that the throttle pistons of the two Safety brake valve parts (throttle valve, differential pressure valve) are pressurized with the pressure of the control line, which

^ O leads the pump oil flow to the safety brake valve. The spring sides of the throttle pistons, on the other hand, are subjected to the lower of the pressures in the lines, which lines connect the safety brake valve to the consumer. This is preferably done using a shuttle valve on the one hand, and a 3/2-way valve on the other, the two switching positions of which are piloted by the pressure in the two connecting lines between the safety brake valve and the consumer so that the lower pressure is applied to the spring side of the throttle piston.

It is also of particular advantage in the design of the throttle valve that the piston of the throttle valve is due to the flow force closes automatically depending on the flow rate. On the one hand, this means that the spring of the throttle valve can be interpreted relatively weak. On the other hand, it means that in the event of severe leaks, an intensified

Beb 81/1

Returns the restoring force of the throttle piston in the closing direction. The axial force that acts on the throttle piston is namely the same

F = K'-j / dp. Q.

The spring has a preload of 3 to 10 bar.

.

In addition to the previously described hydraulic connection between the throttle piston of the differential pressure valve and the throttle piston of the throttle valve, a mechanical connection is also possible, which ensures that the two throttle pistons move in the same direction Perform movements in the opening and closing directions. Such a mechanical connection can preferably thereby be made that the two throttle pistons are components of the same control piston, which is axially in a cylinder is movable and on its one spring-loaded side with the discharge pressure of the pump oil flow from the safety brake valve and on the other end with the inlet pressure of the pump oil flow is loaded to the safety brake valve. In this case, a throttle area of the control piston is in the lowering line and the other drumming area switched into the lift line. Another control edge can be provided through which the lifting line is connected to the tank when the throttle points are opened.

In the hydraulic connection of the two throttle pistons, "these can be parallel to one another in one joint or in two be arranged in separate housings. But it is also possible to align the two throttle pistons in one behind the other a cylinder to be arranged so that the with the inlet pressure of the pump oil flow acted upon end faces are opposite in the same cylinder space. In this case, the axial movement the throttle piston is limited in the direction of each other by stops.

ORIGINAL INSPECTED ^Cop V

Deb 81/1

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In the following, exemplary embodiments of the invention are described with reference to the drawings.

Show it

Fig. 1 shows an embodiment in which the valve parts of the Safety brake valve are arranged axially parallel to one another and are movable;

Fig. 2 shows an embodiment in which the parts of the

Safety brake valve are arranged in alignment in a cylinder ^ O;

3 like FIG. 2, but with an unpressurized return line;

4 shows a 3-way switch for the embodiment according to Fig. 2;

5 shows an embodiment in which the valve parts ^ 5 of the safety brake valve are mechanically coupled;

6 shows the exemplary embodiment of a circuit for operation with a change in preload;

7 shows the exemplary embodiment of a switchover valve.

The representation of Fig. 1 shows - partially schematically Arrangement of the safety brake valve 1 in a hydraulic control for actuating a double-acting consumer 2. The consumer 2 is designed here as a hydraulic cylinder-piston unit, such as that used for actuating

Dredging, cranes, elevators, etc. is used. The piston this unit is under a preload. The arrow 26 shows the direction of the lowering movement and the direction of action of the Preload on. A hydraulic pump 3 conveys hydraulic fluid into a 4/3-way control valve 4. In its central position, it can the delivery flow of the pump 3 flow off to the tank without pressure. By actuating the 4/3-way valve 4, the consumer 2 can be steered in the desired direction at any speed. For lifting, i.e. moving the piston against the direction of action 26 of the preload becomes consumer 2

Beb 81/1

with its lifting side 27 via the lifting line 5 and the lifting line connection 6 connected to the pump 3. Here, the control valve 4 is switched so that the oil flow from the lowering side 28 of the Consumer 2 can flow to tank 29 without pressure as possible. To lower the preload with the lowering movement 26, the Control valve 4 switched so that the oil flow from the pump 3 via the lowering line 15 and the lowering line connection 14 with the Lower side 28 of the consumer is connected. Here, the oil flows from the lifting side 27 via connection 6 and lifting line 5 into the Tank 29 back.

In the arrangement shown in FIG. 1, it is assumed that the consumer 2, shown as a double-acting cylinder is loaded by the preload in the one illustrated direction 2 6, which the piston rod would push into the cylinder, if the piston could not be supported on the column of liquid on the stroke side 27.

The safety brake valve 1 serves the purpose of lifting and the Keep the lowering movement under control in the event of a pipe rupture. This will be discussed in detail later. Highlighted It should be noted, however, that the subject of the invention is above all the securing of the lowering movement in which the control valve 4 in the right switch position the pump 3 with the lowering side 28 of the consumer via the lowering line 15 and the lowering line connection 14 and the lifting side 27 of the consumer 2 via the connection 6 and the lifting line 5 with the tank 29.

A break in the line 5 between the consumer 2 and the • ^ ⁰ control valve 4 would result in an uncontrolled retraction of the piston rod into the cylinder and thus an uncontrolled movement of the preload if no safety brake valve 1 were attached. It should be emphasized that the safety brake valve 1 is connected to the consumer 2,

COPY

Beb 81/1

"16 ~

that in connection 6 or 14 no break can occur. Can do this the safety brake valve e.g. be flanged to consumer 2 or rigidly connected to it.

The safety brake valve 1 consists of a throttle valve 7 with a throttle valve piston (throttle piston) 30 and the differential pressure valve 48 trained flow meter 50, the execution of which will be discussed later. First of all, here is the training of the throttle valve 7 described.

The throttle valve 7 has a throttle piston 30 which is movable in a cylinder and has a control edge 31 and a conical throttle area 32 on. The throttle valve housing is via the connections 33 and 34 16 with the lifting line 5 and the lifting line connection 6

^ 5 tied. Within the throttle piston 30 is in the bypass 35 to the Control edge 31, which via bores 36, 37 the connections 33, 34 bridged by bypassing the control edge 31, the check valve 8, which opens in the direction of flow from lifting line 5 to connection 6, i.e. when the consumer is lifted.

The passage between the connections 33 and 34 at the control edge 31 is closed both when the consumer 2 is at a standstill and during the lifting movement of the consumer. While the hydraulic fluid from the pump 3

Passed through the lifting line 5 and the bypass 35 with check valve 8 via connection 6 to the consumer on its lifting side 27. A rupture of the line 5 with a subsequent pressure drop in the same leads to an immediate closing of the check valve 8. The throttle piston 30 remains in its closed position in any case due to the compression spring 9. If a leak-free one If flow is desired, the throttle piston 30 can be equipped with a collar 38 and the valve housing 16 with a seat 39.

COPY

Beb 81/1

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To ensure the lowering movement, the throttle piston 40 is controlled as a function of the flow rate, which is measured by means of the flow meter 50 between the lowering line 15 and the lowering line connection 14. A wide variety of devices with a wide variety of output signals can be used as the flow meter 50! use. In order to avoid a conversion of the output signal of the flow meter 50, a hydraulic control is provided for the throttle piston 40 in an advantageous manner according to the invention.
10

In the exemplary embodiment shown in FIG. 1, the flow meter 50 is designed as a differential pressure valve 48. The differential pressure valve has the piston 40 designed as a throttle piston, which has a control edge 41 and a conical throttle area 42 and connects the lowering line 15 to the lowering line connection 14 via the connections 43, 44 with the corresponding position of the control edge 41. The piston 40 is pressed into its closed position by the compression spring 17. In this closed position, a flow of oil is from the lowering side 28 via the terminal 14 to ® lowering conduit 15 and into the tank 29 via the lying between the holes 46 and 47, bypass 45 and the opened therein and in this flow direction the check valve. 13

The piston 40 of the differential pressure valve 48 is hydraulically controlled by the input pressure in the lowering line 15 or Connection 43 via line 19 to an end face 49 'and the outlet pressure of the differential pressure valve 48 in connection 44 via control line 23 together with the pretensioning force of the compression spring 17

is given to the other face. 30th

If the piston rod of the cylinder is now to be retracted, i.e. the load is to be lowered in the direction of movement 26, the Control valve 4, the pump 3 is connected to the lowering line 15,. while the line 5 is in communication with the tank 29. Of the Throttle piston 40 of the differential pressure valve 48 is through the

COPY \

^{Beb 81/1} - 18 -

Compression spring 17 held in closed position against stop 18, J when there is no flow from line 15 to sink line connection 14. With a corresponding opening of the control valve 4 results in | the flow, however, a pressure difference between the lowering line 15 j with connection 43 and connection 44 or sink line connection 14, since I only through this pressure difference a flow opening for the Flow at the control edge 41 converged. [

According to the invention, this differential pressure is used to control the throttle valve 7 by applying the pressure in the lowering line 15 via the control line 19 to one end face 51 of the throttle piston 30 and the lower pressure in the connection 44 or the lowering line connection 14 via the control line 23 together with the The pretensioning force of the compression spring 9 acts on the other end face 11 j of the throttle piston 30. As a result, the opening at the control edge 31 of the throttle piston 30 is controlled as a function of the pressure difference in the differential pressure valve 48 and thus as a function of the flow rate in the opening direction. As the flow increases, the flow opening on the cone 21 of the throttle area 42 of the piston 40 of the differential pressure valve 48 increases so that the pressure difference increases proportionally with the flow and the flow opening on the throttle piston 30 of the throttle valve 7 is opened proportionally to this pressure difference.

Through the force of the spring 17 and the cross-sectional profile on the cone 21 in the throttle area 42, the relationship between the differential pressure and the flow rate can be influenced as desired. The static pressure of the system has, as its end faces have no influence on the ^ ⁰ position of the piston 40 of the differential pressure valve 48 on both sides of the same size.

Through the control lines 23 and 19, the differential pressure acts in the opening direction on the throttle piston 30 of the throttle valve 7 and moves this against the force of the spring 9. Because the static overpressure has no effect on this throttle piston 30 either

COPY

Beb 81/1 - 19 -

(same end faces), the opening cross-section on the cone 25 in the throttle area 32 of the throttle piston 30 is only due to the flow from lowering line 15 to lowering line connection 14 controllable. This enables a precise retraction movement of the cylinder's piston rod possible by actuating the control valve 4 in the inlet to the consumer. The maximum opening of the pistons 30 and 40 can be through the stops 52 and 53, which are preferably designed as stop screws, can be adjusted. It can also be in here not shown are provided that the biases of the compression springs 9 and 17 are matched to one another, that the flow cross-section at the control edge 31 of the flow, amount at the control edge 41 is adapted. !

If the line 5 breaks during the lowering movement controlled in this way the piston rod in the direction of arrow 26, the controlled Einfahrgeschwindxgkeit remains constant and the load can be kept under control by the operator. However, this assumes that the throttle cross-section on the cone in the control area 32 of the throttle piston 30 is much smaller

² ^ as the throttle cross-section on the control valve 4 between the line 5 and the tank 29, so that if the line 5 breaks, there is no great pressure change in it and the pressure gradient from the connection 6 to the lifting line 5 only increases insignificantly. This means that the retraction speed of the piston rod is controlled essentially by the cone 25 in the throttle area 32 and not by the return cross section at the control valve 4, which can be achieved by appropriate design of the control edges. If these instructions are not or only partially observed, this does not mean that the

^ O safety brake valve result. Rather, in this case, when the lifting line 5 breaks, an increased pressure gradient occurs at the control edge 31 of the throttle piston 30 and thus a stronger flow. This results in an increase in the lowering speed in the direction of movement 26. However, this increased lowering speed does not get out of control, but

3ZZ5132

Beb 81/1

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remains controllable, the invention having the particular advantage that with increased flow velocity at the control edge 31, increased axial forces also act on the throttle piston in the closing direction and throttle the flow as a result of the resulting self-regulating effect. For this reason, the spring 9 can be designed to be relatively weak, which results in only low energy losses. The spring 9 may exert a pressure of 3 to 10 bar, for example. In addition, the throttle piston 30 remains controlled by the flow meter 50 even if a larger pressure drop occurs.

It should be noted at this point / that in an advantageous embodiment, which is shown in Fig. 3, it can be provided in a particularly functional manner that the hub line 5 is depressurized during the lowering movement. This will be discussed later.

Another device by which the lifting line 5 can be switched to a pressure- free state during the lowering movement is shown in FIG. It is a 3-way switch 90 which is connected in the lifting line 5 between the output of the control valve 4 and the connection 33 of the throttle valve 7. This 3-way switch 90 is switched on the one hand by a constant force P and the pressure at the connection 33 in its first position / that the connection 33 is connected to the tank 29 and on the other hand by the pressure at the outlet of the control valve 4 in its The second position is switched so that the output of the control valve 4 is connected to the connection 33.

It should be mentioned that such a 3-way switch 90 can take the place of the secondary pressure relief valve usually provided in a control valve 4.

COPY J

Beb 81/1

- 21st

In the embodiment according to FIG. 2, the consumer is again controlled by a control valve 4 via a safety valve 1 controlled. This safety brake valve 1 consists of the throttle valve 7 and the flow meter 50, which in turn as Differential pressure valve 48 is executed. The special feature of this design is that the throttle piston 30 of the throttle valve 7 and the throttle piston 40 of the differential pressure valve are arranged and guided coaxially in a cylinder in such a way that that their respectively acted upon by the inlet pressure of the lowering line 15

^ ⁰ struck end faces 49, 51 lie opposite one another, these end faces resting against the stops 10 and 18. For the description of this exemplary embodiment, reference can also be made to FIG. 1, whereby it should be mentioned that the 3-way switch 90 according to FIG. 4 or the additional measures

^ according to Fig. 3 are applicable here.

On the one hand, the secondary pressure relief valve 54 should also be mentioned v / elches - as also shown in Fig. 1 - at the lift line connection 6 between the stroke side 27 of the consumer 2 and the connection 34 of the throttle valve 7 of the safety brake valve is located and when a pressure predetermined by safety aspects is exceeded, a bypass to the tank 29 is released. Furthermore is in Fig. 2 with the reference numeral 55 denotes a suction valve. This is a check valve with flow from

Tank 29 is formed on the sink side 28 of the consumer. This The anti-cavitation valve 55 is used to release an additional oil supply if the lowering speed is too great the throttle cross-sections in the control valve 4 and flow meter 50 do not allow sufficient flow.

To the throttle areas 32 and 42 of the differential pressure valve 48 and the throttle valve 7 it should be noted that these in the embodiments are shown as cones 21 and 25, respectively. However, it can also be slots, grooves or any other design the drassel areas act that an extension

copy '

Deb 81/1

of the throttle cross-section during an axial movement of the throttle piston 30, 40 according to a specific, predetermined law. Preferably, there should be proportionality between the axial movement of the pistons 30, 40 and the change in the opening cross section exist.

FIG. 3 again shows an exemplary embodiment which is essentially identical to that shown in FIG. It reference is therefore made to the description there. Thieves-

'"üorulcrlu · i L dleütiü Aur.f Uhrurujnbe lapJ oIm consists in the fact that wL (! bore i LiJ announced in the description of Fly To switch pressure off connection 33 of the throttle valve 7. For this purpose, the lifting line 5 has a discharge line 56 to the tank 29, which is controlled by a control edge 57 of the throttle piston 30. The overlap on the control edge 57 and the overlap on the control edge 31 of the control piston 30 are like this selected that the throttle piston 30 at the control edge 31 first opens a certain predetermined amount before the discharge line 56 to the tank 29 at the control edge 57 is opened.

It should be mentioned that this pressureless control of the lifting line 5 in the same form by the throttle piston 40 of the differential " pressure valve 48 can take place, since according to the invention both to each other perform proportional movements.

In the embodiment according to FIG. 5 there is the special feature that the throttle pistons 30 and 40 of the throttle valve 7 and ^ O of the differential pressure valve 48 are mechanically coupled to one another and are accordingly designed as control pistons 58. This control piston 58 is pressed into the closed position by the common spring 59 with the control edges 31, 57 and 41. The control piston 58 is acted upon at its end face 60 with the input pressure of the lowering line 15. When opening the flow cross-section

BAD ORIGINAL COPY

Beb 81/1 - 23 -

by means of the control edge 41, the spring side 61 of the control piston 58 is connected to the output pressure of the differential pressure valve via the line 62 48 applied in connection 44, wherein the throttle area 42 is again designed so that the differential pressure after a predetermined regularity, preferably proportional to the opening movement of the piston 40 increases.

The oil drain of the consumer 2 on the stroke side 27 via connection 34 and port 33 of the throttle valve 7 and through the lift line 5 is accordingly depending on the differential pressure at the Differential pressure valve 48 controlled, the overlap on the control edge 31 and the formation of the throttle area 32 can serve as further influencing factors.

It should be noted that here, too, a control edge 57 is provided on the piston 58, which serves the purpose of the lifting line 5 between the outlet of the control valve 4 and the connection 33 of the throttle valve 7 during the downward movement 26 of the consumer

2 to be controlled without pressure.
20th

For the sake of completeness, it should be noted that the check valve 13 of the differential pressure valve 48 - unlike in those previously shown Embodiments - is not in the piston 40. Rather, it is parallel to the cylinder of the throttle piston 40

"Line provided which connects port 44 of the differential pressure valve 48 connects to the terminal 43. A special feature of the safety brake valve 1 according to the invention is that its parts, namely the flow meter 50 and the throttle valve 7 can be made identical. This now allows in advantageous

also use as a safety brake valve 1 for Consumer 2 with changing preload direction 63. Such a change in the preload direction occurs in practice, for example, with such Consumers 2 that exceed a certain dead center position during operation. This is e.g. the case with the arms of Excavators or cranes are the case, which can pass through their vertical dead center position during operation.

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In Fig. 6, a circuit is shown in an embodiment, which reflects the way in which the invention Safety brake valve 1 switched to such consumers 2 have to be.

The consumer 2 is controlled with a changing preload 63 by the control valve 4. In the control lines 64 and 65 are the two parts 66 and 67 of the lowering brake valve 1 installed. These Parts 66 and 67 are identical and are designed, for example, according to Figs. 1/2 and 3, respectively. It should be noted that the embodiment according to Fig. 5 with certain changes in the circuit for this load case can be used.

The parts 66 and 67 of the safety brake valve 1 are connected to the two sides of the consumer via connecting lines 68 and 69 2 connected.

It should be remembered that, according to the illustrated embodiments of this invention, a higher pressure prevails in the control line which leads the oil flow to the consumer 2. ^ O This higher pressure is applied through the shuttle valve 70 onto the end faces 49 and 51 of the throttle pistons 30 and 40 of the two parts 66 and 67 of the safety brake valve 1, via line 71 with the branches 72 and 73rd The shuttle valve 70 causes the higher pressure to take effect.

The spring sides (springs 9, 17) of the throttle piston 30, 4O are connected by the 3/2-way valve 74 to that of the connection lines 68 or 69 which carries the lower pressure. the end For this reason, the 3/2-way valve 74 is brought into the specified position by the higher pressure in each case. For safety reasons can - as already described above - the secondary pressure relief valves 54 for both connection lines 68 and 69 be provided.

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The embodiment of such a 3/2-way valve 74 is shown in FIG 7 shown. The connection of the lines 75, 76 leading to the connecting lines 68, 69 to the line 78 with branches 79 and 80 is controlled by the slide 77. The slide 77 in turn is controlled by the control line 81 and 82 from the connections 75 or 76 controlled hydraulically.

BATH ORIGINAL

Hob Hl / 1 - 26 -

REFERENCE MARK REPLACEMENT

1 safety brake valve / lowering brake valve

2 consumers

3 pump, hydraulic pump

4 control valve (4/3-way valve)

5 line, lifting line

6 connection, lifting line connection

7 throttle valve

8 check valve

9 compression spring

10 stop

11 face

12 face

13 check valve

14 Connection, submerged line connection

15 pipe, lowering pipe

16 throttle valve body

17 compression spring

18 stop

19 Control hole, control line

21 cone

22 spring space

23 Control hole, control line

24 control line 2 5 cone

26 Lowering movement, arrow for direction of action of the preload

27 Lift side

28 sink side

N · * «PC« 4 ·

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29 tank 30th Throttle piston, throttle valve piston 31 Control edge 32 Throttle range 33 Connection 34 Connection 35 bypass 36 drilling 37 drilling 38 Federation 39 Seat 40 Piston, throttle piston 41 Control edge 42 Throttle range 43 Connection 44 Connection 45 bypass 46 drilling 47 drilling 48 Differential pressure valve 49 Face 50 Flow meter 51 Face 52 Stop screw, stop 53 Stop screw, stop 54 Secondary pressure relief valve 55 According to s augventi1 56 Discharge to the tank 57 Control edge 58 Control piston 59 feather 60 Face 61 Spring side

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6 2 Performance 63 Preload 64 Control line 65 Control line 66 Part of the counterbalance valve 67 Part of the counterbalance valve 68 Connecting cable 69 Connecting cable 70 Shuttle valve 71 management 72 From 7th flat share 73 Junction 74 3/2-way valve 75 management 76 management 77 Slider 78 management 79 Junction 80 Junction 81 Control line 82 Control line

90 3-way switch

Claims (1)

Beringer-Hydraulik GmbH Werk-fyr- Industrie ⁶ - .. üuö. Aufzughydraulik CH-6345 Neuheim-Zug / Switzerland Beb 81/1 - 1 - Claims (1. ,) Hydraulic safety brake valve in the lines (5, 15) of a double-acting, preloaded hydraulic consumer (2) with lifting line (5) which connects the pump (3) with the lifting side (27) of the consumer to operate the consumer (2) against the preload (26) and with the lowering line (15) which connects the pump (3) with the lowering side (28) of the 10 consumer connects to the operation of the consumer with the preload, which safety brake valve when the consumer (2) is operating in the direction of the preload (26) the lifting line (5) controls, characterized in that the safety brake valve consists of a throttle valve (7) in the lifting line (5) and a flow meter (50) in the lowering line (15),
wherein the throttle valve is controlled by the flow meter with increasing flow rate in the opening direction and with decreasing flow rate in the closing direction. '2. Safety brake valve according to claim 1, characterized in that the flow meter (50) is a differential pressure valve (48) with a hydraulically piloted throttle piston (40), for pilot control on one side (face 49) with the static inlet pressure of the differential pressure valve (48) in the opening direction and on the other side (face 12) with a spring (17) and the outlet pressure (Output 44) of the differential pressure valve is acted upon in the closing direction. COPY ' Beb 81/1 - 2 - 3. Safety brake valve according to claim 1 or 2, characterized in that the throttle piston (40) of the differential pressure valve (48) has a throttle area (42) which is dependent on from the axial movement of the piston (40) / preferably proportional to the axial movement of the piston (40) releases an increasing flow cross-section. 4. Safety brake valve according to claim 3, characterized in that the throttle piston (40) of the differential pressure valve has a conical throttle area (42). 5. Safety brake valve according to one of claims 2 to 4, characterized in that an adjustable stop pin (52) is provided to limit the opening of the differential pressure valve (48) is. 6. Safety brake valve according to one of the preceding Expectations, characterized in that a secondary pressure relief valve (54) in the lifting line (5) between consumer (2) and throttle valve (7) is switched on. 7. Safety brake valve according to one of claims 2 to 6, characterized in that a suction valve (55) in the lowering line (15) between consumer (2) and differential pressure valve (48) with flow direction from the tank (29) into the lowering line (14) is switched on. COPY Beb 81/1 - 3 - 8. Safety brake valve according to one of claims 2 to 7, characterized in that for the hydraulic pilot control of the throttle valve (7) its throttle piston (30) on one side (end face 51) in the opening direction with the inlet pressure (port 43) of the differential valve (48) and on the other Side (face 11) with a preferably adjustable Spring (9) and the output pressure (port 44) of the differential pressure valve (48) are applied in the closing direction will. 9. Safety brake valve according to claim 8, characterized in that the throttle pistons (30 and 40) of the throttle valve (7) and the differential pressure valve (48) in one single cylinders are arranged with opposite end faces (49 and 51), which with the inlet pressure of the differential pressure valve are acted upon. 10. Safety brake valve according to claim 8, characterized by separate housing for throttle valve (7) and differential pressure valve (48). 11. Safety brake valve according to claim 8, characterized in that the throttle valve (7) and differential pressure valve (48) are housed in a common housing with axially parallel cylinders. 12. Safety brake valve according to one of claims 1 to 7, characterized in that the throttle piston (30) of the throttle valve (7) with the mechanically guided flow meter (50) mechanically are coupled in such a way that the mechanical stop COPY of the flow meter (throttle piston 40) opens the opening of the throttle valve cause * -. · • · Beb 81/1 - 4 - 13. Safety brake valve according to one of the claims 2 to 12, characterized in that the throttle pistons (30 and 40) of the throttle valve (7) and the differential pressure valve (48) are guided in alignment in a cylinder and are mechanically coupled, e.g. components (30, 40) of a control piston (58). 14. Safety brake valve according to one of claims 1 to 12, characterized in that for leak-free sealing of the throttle valve (7) in the closed state, the throttle valve and its throttle piston (30) with seat (38, 39) and sealed against the spring chamber (spring 9) are. 15. Safety brake valve according to one of the preceding claims, characterized in that the lifting line (5) between the throttle valve (7) and a control valve (4) is essentially depressurized when the consumer (2) is in lowering mode (arrow 26). 16. Safety brake valve according to claim 15, characterized in that the throttle piston (30 or 40) of the throttle valve and / or the differential pressure valve is connected to a slide valve with a control edge (57) through which the lifting line (5) when the throttle valve (7) is opened between the throttle valve (7) and control valve (4) with the flow direction to the tank (29) is opened. Beb 81/1 - 5 - 17. Safety brake valve according to claim 15, characterized by a 3-way switch, which in its starting position the lifting line (5) between the throttle valve (7) and Control valve (4) (connection 33) with the tank (29) and in its switching position, which is determined by the pressure in the Stroke outlet (H) of the control valve (4) is specified, the stroke outlet (H) of the control valve (4) with that of the Lift line (5) and the connection (33) of the throttle valve (7) connects. 18. Safety brake valve according to one of claims 2 to 17, characterized in that in the supply lines (64, 65) of the consumer valves (66, 67) are switched on, which can optionally be hydraulic pilot-operated throttle valve or as a differential pressure valve can be operated, including the Throttle piston (30 or 40) of one valve (66 or 67) on one side (face 49 or 51) Via a shuttle valve (70) with the higher of the pressures in the control lines (64 or 65) between the control valve (4) and the valves (66 and 67) and on the other, i.e. the spring side (end face 11 or 12) with the lower of the pressures in the connection lines (68 or 69) between the valves (66 and 67) and consumer (2) are pilot operated. 19. Safety brake valve according to one of claims 2 to 18, characterized in that the throttle valve and the differential pressure valve are identical. Beb 81/1 - 6 - 20. Safety brake valve according to claim 18, characterized by a 3/2-way valve (74), both of its feed lines (75, 76) each with one of the line strands (68, 69) between consumer (2) and valves (66, 67) and its one outlet (78) with the spring sides (end faces 11, 12) of the throttle piston (30, 40) of the valves (66 and 67) is connected and which directional valve in each case by the outlet pressure of the consumer (2) is pilot operated on both sides in such a way that the lower of the two in the lines (68, 69) prevailing pressures on the spring sides of the throttle piston of the valves is given. 21. Safety brake valve according to one of the claims 1 to 7, characterized in that the check valves (8, 13) in the lifting line (5) and / or lowering line (15) with flow direction to Lifting the consumer (2) against the preload parallel to the throttle valve (7) or flow meter (50) are arranged. 22. Safety brake valve according to claim 21, characterized in that the check valves (8, 13) in an axial bore (bypass 35, 45) of the throttle piston (30, 40) of the Throttle valve (7) or differential pressure valve (48) are arranged, which bypass the throttle area (32, 42) of the throttle piston short-circuits. Beb 81/1 - - 7 - 23. Safety brake valve according to one of claims 2 to 22, characterized , that the throttle piston (30) with a pilot piston (84) is firmly connected, the end face (51) of which is subjected to the pump pressure. 24. Safety brake valve according to claim 23, characterized in that the throttle piston of both the throttle valve (7) and the differential pressure valve (48) is connected to a pilot piston (83, 84), the The pump pressure is applied to the end faces (49, 51). 'BAD ORIGINAL