DE102016223347A1 - Pressure control valve with a damping device - Google Patents

Abstract

The present invention relates to a pressure control valve for high-pressure hydraulic systems with a supply pressure range, a control pressure range, a housing, a relative to the housing movable control piston (162) and a damping device (140). The control piston is (162) pressurized against a spring force and adapted to shift due to the spring force, a main valve closing element in an open position relative to a main valve seat), so that a pressure of a hydraulic fluid in the control pressure range is regulated. The damper device (140) is configured to damp a movement of the control piston (162) and includes a storage chamber (148), a displacement piston (144), and a throttled damping flow path, the storage chamber (148) loading and unloading hydraulic fluid via the restricted damping flow path is refillable. The displacement piston (144) is movable together with the control cradle (162) and is adapted to cause via its movement a loading and Entfüllung the storage chamber (148) with hydraulic fluid. The invention is characterized in that the damping flow path is at least partially defined via a passage gap (142) between an outer periphery of the displacement piston (144) and an inner periphery of a housing wall (146) adjacent to the displacement piston, and the passage gap (142) is one from a position of the displacement piston (144) relative to the housing (101) dependent variable minimum flow cross-section.

Description

The invention relates to a pressure regulating valve for a high-pressure hydraulic system having a supply pressure range, a control pressure range, a housing, a control piston movable relative to the housing for adjustably regulating the pressure of a pressure medium or a hydraulic fluid in the control pressure range, and a damping device. The control piston is regularly acted upon by a spring force with pressure and is adapted to shift due to the spring force a main valve closing element in an open position relative to a main valve seat, so that a pressure of a hydraulic fluid in the control pressure range is regulated.

Pressure control valves, which are also known as pressure reducing valves, are regularly used to reduce the high pressure applied to the supply pressure range of the hydraulic fluid to a lower control pressure in the control pressure range and to provide this a hydraulic consumer. For example, such pressure control valves are used in hydraulically operated clamping devices of machine tools for adjusting the clamping pressure or the control pressure. Here, the desired control pressure may well be only 10% of the supply pressure.

If the control pressure falls in the control pressure range due to the operation of the hydraulic consumer, the spring force on the control piston is greater than the applied control pressure, so that the control piston is moved due to the spring force and the main valve closing element moves from the main valve seat to the open position. Consequently, the control pressure in the control pressure range rises again to the value set on the pressure control valve. In particular, in the case of continuous operation of the hydraulic consumer, high-frequency lifting and lowering of the main valve closing element from or to the main valve seat occurs. This leads to a disturbing Rattergeräusch. On the other hand increases a mostly fast closing movement of the main valve closing element, which is due to the above-mentioned often high pressure difference between the supply pressure range and the control pressure range, the wear of the main valve closing element and the main valve seat.

For this reason, the use of hydraulic damping devices for damping the movement of the main valve closing element has proven itself. For example, shows the EP 0 829 794 B1 a pressure regulating valve with a damping device. The damping device has a storage chamber which can be filled with and filled with hydraulic fluid via a damping flow path and a displacement piston and is designed to damp a movement of the control piston.

For this purpose, the displacement piston is movable together with the control piston and designed to effect about its movement loading and deflating the storage chamber.

Like in the EP 0 829 794 B1 2, the accumulator chamber is filled and deflated with hydraulic fluid via the throttled damping flow path, this being caused by movement of the displacer piston moving in concert with the control piston. Due to the concomitant throttling during the loading and unloading of the storage chamber, the movement of the control piston is consequently attenuated overall in both directions. Thus, the movement of the main valve closing element is also damped in the closing direction, so that the closing element is brought to the main valve seat at a lower speed than in conventional pressure control valves without such a damping device.

Although with such a damping device, the disturbing Rattergeräusche and the associated wear are effectively reduced, however, there is the problem that this damping due to the reduced speed of movement of the control piston also leads to an increase in the response time of the pressure control valve. As a result, there may be some major and undesirable pressure fluctuations in the control pressure range.

Therefore, it is the object of the present invention to provide a pressure control valve with a damping device in which the response time of the pressure control valve is reduced compared to the known pressure control valves, and at the same time the Rattergeräusche and wear are kept low.

The solution of the problem is achieved with a pressure control valve according to claim 1. Advantageous further developments are described in the dependent claims.

The pressure regulating valve according to the invention is distinguished in particular from the known pressure control valves in that the damping flow path is defined at least partially via a passage gap between the outer periphery of the displacement piston and an adjacent housing wall and the passage gap has a variable minimum flow cross section which is dependent on the position of the displacement piston relative to the housing.

This particular dependent of the stroke of the control piston design allows, in contrast to the known from the prior art position-independent damping of the movement of the control piston, a dependent on the position of the displacement or control piston variable damping of the movement of the control piston. This makes it possible to specifically influence and optimize a course of movement of the control piston via the special design of the damping region for different regions of the movement process. As a result, in particular, the response time of the pressure regulating valve with respect to the known pressure regulating valves can be reduced while suppressing the occurrence of chattering noise and keeping down the pressure regulating valve wear. In particular, it is possible to adjust the speed of movement of the control piston during the movement in one direction due to the changed throttling.

Advantageously, the minimum interference cross-section of the passage gap in a first position of the displacement piston relative to the housing has a first value and in a second position of the displacement piston relative to the housing has a second value, wherein the first position of the displacement piston from the second position of the displacement piston and the first value for the minimum flow area of the second value for the minimum flow area.

This makes it possible to set different damping values for the movement of the control piston for two specific positions of the displacement piston and of the control piston and thus to adapt it to special requirements for the movement of the control piston. In particular, these two positions of the displacement piston can be assigned to the positions of the control piston, which occur when the control piston is in one of its maximum achievable deflections, and / or when a pressure in the control pressure range just corresponds to the set control pressure.

Advantageously, the inner circumference of the housing wall changes in an area of the housing wall in the axial direction of the displacement piston. In this area, in which for further positions of the displacement piston along a direction of movement of the displacement piston, which lie between the first position and the second position of the displacement piston, minimum flow cross-sections for the passage gap can be reached, these values are variable. The values along the direction of movement of the displacement piston can in particular vary continuously and particularly preferably vary monotonically along only one direction of movement of the displacement piston. This adaptation of the inner circumference of the housing wall to change the minimum flow cross section of the passage gap is structurally simple to implement, since it is not necessary to adapt the displacement or control piston.

In particular, the inner circumference of the housing wall in a region of the housing wall in the axial direction of the displacement piston or of the housing in cross-section may be configured stepwise. This step-shaped design allows a clear and clear differentiation of different damping ranges of the movement of the control piston. Such a clear differentiation is advantageous for example in pressure control valves, in which a movement of the control piston for different pressure ranges must meet different requirements. Also, a step-shaped design manufacturing technology advantageous because it can be easily formed material erosion.

Conveniently, the inner circumference of the housing wall decreases in an area of the housing wall in the axial direction of the displacement piston in the closing direction of the main valve closing element. By means of this embodiment, the damping of the closing movement of the main valve closing element is increased, which leads to a reduction in the contact speed of the main valve closing element on the main valve seat. Thus, wear of the main valve closing member and the main valve seat is reduced, and the intensity of impact noise of the main valve closing member on the main valve seat is lowered.

Advantageously, the outer circumference of the displacement piston changes in the axial direction of the displacement piston. The outer circumference of the displacement piston can consequently have variable values along a direction of movement of the displacement piston in an area of the housing wall into which minimum flow cross sections for the passage gap can be reached for further positions of the displacement piston lying between the first position and the second position of the displacement piston. In this case, the outer circumference of the displacement piston along the direction of movement of the displacement piston in particular continuously and particularly preferably monotonically change along only one direction of movement of the displacement piston. If the outer circumference of the displacement piston changes continuously, it can be avoided that the intended damping leads to sudden changes in the speed of movement of the control piston of the main valve closing element. For the sake of simplicity, it is particularly preferred if the values of the outer circumference of the displacement piston between the two positions along only one Movement direction of the displacement piston, so along the upward movement or along the downward movement of the displacement piston, monotonically change, as this is favorable to implement manufacturing technology.

In particular, the outer circumference of the displacement piston in the axial direction of the displacement piston in cross-section is designed step-shaped. The step-shaped configuration of the outer circumference is thus provided in a region in which for further positions of the displacement piston, which lie between the first position and the second position of the displacement piston, minimum flow cross-sections for the ventilation gap can be achieved. This step-shaped design allows a clear and clear differentiation of different damping ranges of the movement of the control piston. Such a clear differentiation is conceivable, for example in pressure control valves, in which a movement of the control piston for different pressure ranges must meet different requirements. Also, a step-shaped design manufacturing technology is easy to implement.

It is advantageous if the outer circumference of the displacement piston decreases in the axial direction of the displacement piston in the closing direction of the main valve closing element. By means of this embodiment, the damping of the closing movement of the main valve closing element is increased, which advantageously leads to a reduction in the contact speed of the main valve closing element on the main valve seat.

Conveniently, the storage chamber is formed as part of a control chamber in which the control piston is movable. Thus, it is possible to keep the structure of the pressure regulating valve simple, whereby a production and maintenance of the pressure regulating valve is easier and less expensive.

Preferably, a minimum flow area of the damping disturbance path for displacer piston positions in which the main valve closing element is substantially in the open position is greater than for positions of the displacer piston in which the main valve closing element is substantially in a closed position. Thus, it is possible to reduce the moving speed of the main valve closing member during the application to the main valve seat, thereby suppressing the noise and reducing the wear. In this case, allows the lower damping of the movements of the main valve closing element beyond the closed position of the main valve closing element, a fast movement of the main valve closing element and thus a significant reduction in the response time of the pressure control valve.

Advantageously, the pressure regulating valve has a discharge region for discharging hydraulic fluid from the regulating pressure range when a set regulating pressure in the regulating pressure range is exceeded, wherein the discharge range can be hydraulically connected by a movement of the regulating piston to the regulating pressure range. By way of a discharge region designed in this way, an overpressure or secondary pressure in the regulating pressure range, which is caused, for example, by thermal expansion of the hydraulic fluid in the regulating pressure range, can be effectively reduced. This can prevent overpressure caused damage to hydraulic components in the control pressure range or connected to the control pressure range components.

In this case, the discharge region is preferably coupled to the regulating pressure region via a drain valve, the drainage valve having a drain valve closing element movable relative to the housing, a drain valve spring and a drain valve seat. The bleed valve closing member is pressed by the bleed valve spring onto the bleed valve seat to cause the bleed valve to close while the bleed valve closure member is liftable against the pressure of the bleed valve spring from the bleed valve seat to cause the bleed valve to open, thus hydraulically closing the bleed area Control pressure range to connect. This embodiment is similar to the main valve and accordingly easy to implement.

In particular, the drain valve seat is movable together with the control piston and the impact firmly connected to the housing. About this configuration is very simple and direct a coupling of a control of the drain valve with a movement of the control piston obtained. In particular, the drain valve seat may be fixedly connected to the control piston and may even be designed as part of the control piston, which would result in a simple construction.

Conveniently, the discharge area and / or the discharge valve is at least partially arranged in the control piston and / or in the displacement piston. This particular embodiment leads to an increase in the functional density of the control piston or the displacement piston, which can effectively save space.

Advantageously, the storage chamber forms part of a hydraulic flow path from the control pressure range to the discharge region. This way further space can be saved.

Advantageously, the minimum flow cross-section of the passage gap in a third position of the displacement piston relative to A housing in which the drain area is hydraulically connected to the control pressure range has a third value and a fourth value in a fourth position of the displacement piston relative to the housing in which the drain area is hydraulically separated from the control pressure area, the third value being smaller than that fourth value. This leads to an increased or maximum damping of the movement of the control piston when the control pressure in the control pressure range is exceeded. Thus, due to a resulting increased wear suppression on the one hand it is possible to make the discharge valve finer and correspondingly faster, and on the other hand to suppress undesirable vibration effects in the discharge valve. Overall, as well as a stronger damping of the movement of the control piston and thus the Ablassventilschließelements be achieved when exceeding the set control pressure.

In particular, the pressure regulating valve may have a main chamber which is in hydraulic communication with the storage chamber via the damping flow path. The damping flowpath may then include at least one bypass flowpath adjacent the passageway, the bypass flowpath being configured as a direct hydraulic connection between the storage chamber and the main chamber. Due to the bypass flow path, loading and unloading of the storage chamber, which is independent of the flow cross section of the passage gap, is made possible, allowing further adjustments of the damping curve of the movement of the control piston. The bypass flow path can serve, for example, as a backup of a minimum flow cross section of a damping flow path for supplying the storage chamber with hydraulic fluid.

Advantageously, a part of the bypass flow path passes through the displacement piston and / or the control piston. By means of this particular embodiment, an input port and an exit port of the bypass flow path move together with the displacement piston and the control piston, respectively, whereby the bypass flow path can provide communication between the storage chamber and the main chamber for all positions of the displacement piston. In addition, no special adaptation of the housing is required, while the functional density of the displacement and control piston is increased, which ultimately saves space.

Advantageously, at least a portion of the bypass flow path passes through the housing. If the bypass flow path is alternatively provided in the housing, there is the advantage that there is no need for any special adaptation of the displacement or control piston and this can thus be easily formed. It is also conceivable, of course, that the bypass flow path is provided in addition in the housing.

It is advantageous if the bypass flow path has at least one check valve. This makes it possible to make available the provision of the additional flow cross section for the damping flow path effectively in only one direction of movement of the displacement piston or the control piston and accordingly to reduce or change the damping in only one direction of movement of the displacement piston or control piston. It is particularly advantageous to dampen the movement of the control piston in the opening direction of the main valve less than in the closing direction of the main valve, so as to allow a quick opening on the one hand and on the other hand continue to reduce chatter noise and wear of the main valve or main closing element.

• 1 eine Seitenansicht eines Druckregelventils sowie einen entsprechenden Anschluss an ein Hochdruck-Hydrauliksystem;
• 2A eine seitliche Schnittansicht eines Ventilbereichs eines Druckregelventils in einer ersten Stellung des Regelkolbens;
• 2B eine seitliche Schnittansicht eines Ventilbereichs eines Druckregelventils in einer zweiten Stellung des Regelkolbens;
• 2C eine seitliche Schnittansicht eines Ventilbereichs eines Druckregelventils in einer dritten Stellung des Regelkolbens;
• 3 eine vergrößerte seitliche Schnittansicht einer aus dem Stand der Technik bekannten Dämpfungsvorrichtung ;
• 4A eine vergrößerte seitliche Schnittansicht der Dämpfungsvorrichtung des Druckregelventils aus 2A entsprechend einer ersten Ausführungsform;
• 4B eine vergrößerte seitliche Schnittansicht der Dämpfungsvorrichtung des Druckregelventils aus 2B entsprechend der ersten Ausführungsform;
• 4C eine vergrößerte seitliche Schnittansicht der Dämpfungsvorrichtung des Druckregelventils aus 2C entsprechend der ersten Ausführungsform;
• 4D ein vergrößerter Ausschnitt aus 4A;
• 5 eine Schnittansicht durch einen Teil eines erfindungsgemäßen Regelkolbens;
• 6A eine vergrößerte seitliche Schnittansicht einer Dämpfungsvorrichtung gemäß einer zweiten Ausführungsform;
• 6B eine vergrößerte seitliche Schnittansicht einer Dämpfungsvorrichtung gemäß einer dritten Ausführungsform;
• 6C eine vergrößerte seitliche Schnittansicht einer Dämpfungsvorrichtung gemäß einer vierten Ausführungsform; und
• 6D eine vergrößerte seitliche Schnittansicht einer Dämpfungsvorrichtung gemäß einer fünften Ausführungsform.

Exemplary embodiments of the invention will be described below with reference to the figures. Here are shown schematically:

• 1 a side view of a pressure control valve and a corresponding connection to a high-pressure hydraulic system;
• 2A a side sectional view of a valve portion of a pressure regulating valve in a first position of the control piston;
• 2 B a side sectional view of a valve portion of a pressure regulating valve in a second position of the control piston;
• 2C a side sectional view of a valve portion of a pressure regulating valve in a third position of the control piston;
• 3 an enlarged sectional side view of a known from the prior art damping device;
• 4A an enlarged sectional side view of the damping device of the pressure control valve 2A according to a first embodiment;
• 4B an enlarged sectional side view of the damping device of the pressure control valve 2 B according to the first embodiment;
• 4C an enlarged sectional side view of the damping device of the pressure control valve 2C according to the first embodiment;
• 4D an enlarged section 4A ;
• 5 a sectional view through a part of a control piston according to the invention;
• 6A an enlarged sectional side view of a damping device according to a second embodiment;
• 6B an enlarged sectional side view of a damping device according to a third embodiment;
• 6C an enlarged sectional side view of a damping device according to a fourth embodiment; and
• 6D an enlarged sectional side view of a damping device according to a fifth embodiment.

In the figures, the same or similar elements are provided with the same or similar reference numerals. On the repetition of a description of functions already eigeführter components of the pressure control valves shown is omitted for clarity.

As in 1 is shown, has an inventive pressure control valve 100 a tax area 120 and a valve area 110 on. The pressure control valve 100 has a housing as shown 101 on. The tax area 102 has one in the housing 101 recorded and not shown here control spring, which by a Regelfedervorspannmechanismus 104 can be biased. For adjusting the preload of the control spring by the Regelfedervorspannmechanismus 104 has the control spring biasing mechanism 104 here a Handschraubvorrichtung 106 on. However, this is not necessarily necessary, what the Regelfedervorspannmechanismus 104 For example, it may also have an electrically operated actuator or a screwing mechanism that can be operated only with the aid of a tool for pretensioning the control spring.

The valve area 110 of the pressure control valve 100 has a supply pressure range 120 , a control pressure range 130 , a damping device 140 and a drain or tank pressure range 150 up and is trained to over a connection 170 to be connected to a hydraulic system. At the same time, the supply pressure range becomes 120 of the valve area 110 with a supply pressure line P of the connection 170 hydraulically connected during the control pressure range 130 of the valve area 110 with a control pressure line A of the connection 170 is brought into hydraulic connection. The drainage area 150 of the valve area 110 is doing with a tank return line T of the connection 170 coupled so that it forms a tank pressure range. It should be noted that the exact spatial distribution of the different areas of the valve area 110 can be varied as desired, as far as they finally a spatial distribution of the lines of the connection 170 correspond. In addition, the valve area can 110 even without the drainage area 150 be educated.

In the following, with reference to Figs. 2A to 2C, the configuration of the valve area 110 explained in more detail.

Once the valve area 110 of the pressure control valve 100 with the connection 170 Connected via the Regelfedervorspannmechanismus 104 preloaded the control spring and thus set a control pressure. The control spring presses in consequence of the operation of the pressure control valve 100 in the high-pressure hydraulic system, a control piston 162 which is in a control chamber 160 is movably arranged, in the direction of the supply pressure range 120 , So in Figs. 2A to 2C down. This is one with the control piston 162 connected plunger 164 on a main valve closing element 126 a main valve 122 pressed. In this embodiment, the main valve closing element 126 as shown a ball. The one by the pestle 164 on the main valve closing element 126 applied pressure acts against the pressure of a main valve spring 124 which the main valve closing element 126 on a main valve seat 128 press, and also on the main closing element 126 acting pressure of the hydraulic fluid in the supply pressure range 120 , This will be the main valve 122 closed. Once the pressure of the plunger 164 on the main valve closing element 126 greater than the total on the main valve closing element 126 acting pressure becomes the main valve closing element 126 from the main valve seat 128 lifted (or pushed down) and hydraulic fluid can from the supply pressure line P through provided filters F and the supply pressure range 120 over the main valve 122 in the control pressure range 130 and thus in the control pressure line A to flow, cf. 2A , The hydraulic fluid passes from the main valve 122 over a main chamber 132 the control pressure range 130 and main exits 134 in the control pressure line A ,

As a result of the inflow of hydraulic fluid from the supply pressure line P in the control pressure line A A hydraulic pressure builds up in the control pressure line A as well as in the main chamber 132 the control pressure range 130 on. The pressure in the main chamber 132 acts on the control piston 162 in the opposite direction to the pressure by the control spring 108 (upward in Figs. 2A to 2C). With increasing pressure in the main chamber 132 becomes the control piston 162 in the direction of the drainage area 150 or tank pressure range (ie upwards). This is also the plunger 164 in Direction of the drainage area 150 (thus moving upwards) and finally makes it possible, as soon as a pressure in the main chamber 132 via the control spring biasing mechanism 104 adjusted control pressure corresponds to that of the main closing element 126 on the main valve seat 128 applies and thus the main valve 122 is closed, cf. 2 B , As soon as a hydraulic pressure in the control pressure line A and therefore in the main chamber 132 corresponds to a set control pressure, is the main valve 122 closed and there can be no hydraulic fluid from the supply pressure line P in the control pressure line A flow. Thus, in the control pressure line A provided the set control pressure.

As soon as the hydraulic pressure in the control pressure line A falls below the set control pressure, the main valve closing element 126 through the control piston 162 over the pestle 164 again against the pressure of the skin valve spring 124 from the skin valve seat 128 raised (ie lowered down) and pressurized hydraulic fluid can again from the supply pressure range 120 in the control pressure line A flow to the pressure in the control pressure line A to raise back to the set control pressure, cf. 2A ,

Should a hydraulic pressure in the control pressure line A exceed the set control pressure, which, for example, by thermal expansion of the hydraulic fluid in the control pressure line A can happen is the control piston 162 against the pressure of the control spring 108 even further in the direction of the drainage area 150 or Tankdruckbereichs (ie up) moves. The drainage area 150 is as shown via a drain valve 152 with the control pressure range 130 coupled. The drain valve 152 has a drain valve closing element 156 on which via a drain valve spring 154 on a drain valve seat 158 is pressed. The drain valve seat 158 is here as part of the control piston 162 trained, which is not necessarily necessary. Comes over the pressure of the drain valve spring 154 on the drain valve seat 158 pressed and thus together with the control piston 162 moving drain valve closing element 156 an impulse 166 , which here exemplarily as the conclusion of the storage chamber 160 is formed in the form of a pressed-in pin, the drain valve closing element 156 from the drain valve seat 158 lifted.

By lifting the drain valve closing element 156 from the drain valve seat 158 becomes the drain valve 152 opened and hydraulic fluid can from the control pressure range 130 over the drainage area 150 through discharge exits 151 in the tank return line T drain, leaving the drainage area 150 forms a tank pressure range, cf. 1 and 2 B , This is an overpressure in the control pressure line A until the set control pressure has been reached. The control piston 162 is then again in a position in which the drain valve closing element 156 by the pressure of the drain valve spring 154 and the movement of the control piston 162 back to the drain valve seat 158 comes to the concern.

This makes it possible over the shown configuration of the valve area 110 a negative pressure as well as an overpressure in the control pressure line A to avoid or reduce as quickly as possible.

As already mentioned above, the valve area has 110 a damping device 140 on. The damping device 140 dampens the movement of the control piston 162 to suppress or reduce unpleasant chatter and wear on the valve components. Hereinafter, the damper device 140 a pressure control valve according to the invention 100 described in more detail, first with reference to 3 a known from the prior art damping device 40 is described.

In 3 is a damping device 40 of the prior art. As shown, the damping device 40 a storage chamber 48 and a displacement piston 44 on. The storage chamber 48 is about as a passage gap 42 formed damping flow path, which between the outer periphery of the displacement piston 44 and the inner periphery of the displacement piston 44 nearest housing wall 46 provided with the main chamber 132 connected. The passage gap 42 indicates its course along a direction of movement of the displacement piston 44 (from top to bottom) a constant flow area and the displacement piston 44 is integral with the control piston 162 educated.

Moves the control piston 162 about one in the main chamber 132 prevailing pressure, the storage chamber becomes 48 through the passage gap 42 with hydraulic fluid from the main chamber 132 filled or filled. Because the passage gap 42 has a limited flow area, the loading or deflating the storage chamber 48 throttled, bringing a pressure difference between the hydraulic fluid in the storage chamber 48 and the hydraulic fluid in the main chamber 132 arises. This pressure difference leads to a pressure on the displacement piston 44 and thus the control piston 162 , which a current direction of movement of the displacement piston 44 or the control piston 162 is opposite. This effectively becomes a pressure which is the control piston 162 to the movement drives diminished and thus reduced acceleration of the control piston, which effectively to a damping of the movement of the control piston 162 leads.

As described above, the movements of the valve closing elements are dependent 126 respectively. 156 the valves provided 122 respectively. 152 directly from the movements of the control piston 162 so that their movement is also dampened. This eventually leads to the suppression of the disturbing Rattergeräusche and to reduce wear on the valves 122 and 152 , Here, the here of the position of the displacement piston ensures 44 independent constant flow cross-section of the passage gap 42 for a constant position or stroke-independent damping of the corresponding movements, which not only the placement of the valve closing elements 126 respectively. 156 on the valve seats 128 respectively. 158 but the entire movement of the control piston 162 is largely homogeneously damped. This leads to a greater response time of the pressure control valve 100 and thus to undesirable pressure fluctuations in the control pressure range 130 ,

In the following, with reference to Figs. 4A to 4D, a first embodiment of the invention described, wherein the figures on positions of the control piston 162 according to Figs. 2A to 2C relate.

According to the first embodiment of the pressure control valve according to the invention 100 has the damping device 140 also a storage chamber 148 and a displacement piston 144 on, with the storage chamber 148 about as a passage gap 142 formed damping flow path in hydraulic communication with the main chamber 132 of the pressure control valve 100 stands. Here is the passage gap 142 between the outer periphery of the displacement piston 144 and the inner periphery of the displacement piston 144 nearest housing wall 146 educated. The displacement piston 144 is integral with the control piston 162 designed to be a movement of the displacement piston 144 with a movement of the control piston 162 to pair. However, this common design is not necessarily necessary if the displacement piston 144 in his movement to a movement of the piston 162 is coupled.

In this embodiment, the outer periphery of the displacement piston 144 a cross-section in the axial direction of the displacement piston 144 seen stepped course with a displacement piston stage 144 ' on, cf. also 4D and the sectional view through the corresponding part of the control piston 144 as in 5 shown. In addition, the inner circumference of the housing wall is also 146 in cross-section in the axial direction of the displacement piston 144 seen step-shaped and has the housing wall stage 146 ' on. About the stepped configuration of the displacement piston 144 and the housing wall 146 is a minimum flow area of the passage gap 142 , which at a position of the minimum flow cross section 142 ' from the position of the displacement piston 144 and thus of the position of the control piston 162 dependent and changing with this.

The outer circumference of the displacement piston 144 So it is in the axial direction of the displacement piston 144 and in the closing direction of the main valve closing element 126 seen smaller, cf. also 4D and 5 , Likewise, the inner circumference of the housing wall 146 in the axial direction of the displacement piston 144 and in the closing direction of the main valve closing element 126 seen also smaller.

4A shows the damping device 140 of the valve area 110 in the first position of the control piston accordingly 2A , In this position lies the step 146 ' in the inner circumference of the housing wall 146 in the direction of movement of the control piston 162 which is vertical here, well above the step 144 ' in the outer periphery of the displacement piston 144 ,

In the first position of the control piston shown here 162 So if the main valve 122 is opened substantially, is a minimum flow cross-section for the passage gap 142 in one area 142 ' which reaches substantially between the region of the increased outer circumference of the displacement piston 144 and the area of the raised inner circumference of the housing wall 146 lies.

The minimum flow cross-section obtained in the first position corresponds to the, over all positions of the control piston 162 and thus the displacement piston 144 largest flow cross-section for the passage gap 142 , whereby the movement of the control piston and thus of the main closing element 126 of the main valve 122 only minimally damped while the main valve 122 is substantially in the open position, cf. 2A ,

In 4B is the damping device 140 in a second position of the control piston 162 corresponding 2 B shown. Accordingly, the level lies 144 ' on the outer circumference of the displacement piston 144 approximately at the height of the step 146 ' the inner circumference of the housing wall 146 as soon as the main valve 122 is essentially closed or just before the main valve 122 closed is. In this case, a position of the minimum flow cross section 142 ' just between the edges of the two steps 144 ' and 146 ' achieved, wherein the minimum flow cross-section obtained here is smaller as the minimum flow area obtained in the region of the first position. As a result, the loading and unloading of the storage chamber 148 in this area of movement of the control piston 162 further damped, resulting in an overall increased damping of the movement of the control piston 162 and thus the movement of the main closing element 126 of the main valve 122 leads. This has the consequence that the main closing element 126 at a lower speed on the main valve seat 128 comes to concern and thus chattering noise and wear on the main valve 122 prevented or reduced.

In 4C is the damping device 140 in a third position of the control piston 162 corresponding 2C shown. In this third position is the drain valve 152 opened because the drain valve closing element 156 at the kick-off 166 is present, cf. also 2C , The stage has 144 ' in the outer periphery of the displacement piston 144 the position of the stage 146 ' the housing wall 146 happens in the vertical direction. Accordingly, now a minimum flow cross-section of the passage gap 142 between the region of the displacement piston 144 with maximum outer circumference and the area of the housing wall 146 provided with minimal inner circumference. As a result, the minimum flow area of the passage gap 142 between the displacement piston 144 and the housing wall 146 Here an absolute minimum, resulting in maximum damping of the movement of the control piston 162 leads. As well as out 2C shows, so that the opening and closing movements of the drain valve 152 maximum steamed. This is particularly advantageous because the drain valve 152 due to the limited space and the here lower prevailing pressures is generally smaller and thus more susceptible to wear. In addition, unwanted vibration effects in the drain valve can thus be suppressed.

An enlarged section of the stepped construction of the outer periphery of the displacement piston 144 with the displacement piston stage 144 ' on as well as the likewise stepped construction of the inner circumference of the housing wall 146 with the housing wall step 146 ' is in 4D shown. The position of the displacement piston 144 relative to the housing here corresponds to in 4A shown position.

It should be noted that the outer circumference of the displacement piston 144 and / or the inner circumference of the housing wall 146 may also be otherwise configured to one of the position of the displacement piston 144 minimum flow cross-section for the passage gap 142 to obtain. In this case, many different embodiments conceivable, which may include, for example, projections, Schrägebenen or curved configurations in cross section of the respective areas.

In Figs. FIGS. 6A to 6D are further embodiments of the pressure regulating valve according to the invention 100 shown which developments of the damping device 140 according to the in 4A to 4C represent embodiment shown. These embodiments have bypass paths 380 . 480 . 580 on, which at least prepared minimum flow cross-section for the supply of the storage chamber 348 . 448 . 548 ensure with hydraulic fluid.

According to the in 6A embodiment shown, the damping device 240 between the storage chamber 248 and the main chamber 232 a restricted bypass flow path 280 on which by the displacement piston 244 runs and the storage chamber 248 parallel to the passage gap directly with the main chamber 232 combines. Through the course of the bypass flow path 280 through the displacement piston 244 becomes the functional density of the displacement piston 244 or the control piston increases, which ultimately saves space.

6B a further embodiment is shown, wherein the damping device 340 similar to 6A a bypass flow path 389 which passes through the displacement piston 344 runs and a storage chamber 348 with a main chamber 332 connects directly. In this particular embodiment, a check valve 382 in the bypass flow path 380 provided to allow only in a flow direction a flow of hydraulic fluid. In the case shown, only a flow of hydraulic fluid is from the main chamber 332 in this storage chamber 348 via the bypass flow path 380 allows and thus advantageously the damping of a downward movement of the control piston 162 lowered, that is opposite to the closing direction of the main valve closing element 126 , Thus, the opening movement of the main closing element 126 less dampened giving a fast response of the main valve 122 allows, during a closing movement of the main valve closing element 126 is attenuated more to keep the noise and wear low.

In 6C is a damping device 440 according to another embodiment of a pressure regulating valve, in which a storage chamber 448 via a throttled bypass flow path 480 passing through the housing wall 446 leads, with one of the main outputs 434 is hydraulically connected.

According to a further embodiment, which in 6D is shown, the damping device 540 a bypass flow path 580 on which the storage chamber 548 through the outer wall of the housing 546 hydraulically coupled to a main output 534. Here is the bypass flow path 580 analogous to 6B with a check valve 582 provided only one direction of flow through the bypass flow path 580 to allow and thus the damping by the damping device 540 in only one direction of movement of the control piston 162 decrease.

LIST OF REFERENCE NUMBERS

40:

damping device

42:

Passage gap

44:

displacement piston

46:

housing wall

48:

storage chamber

100:

Pressure control valve

101:

casing

102:

control area

104:

Control spring biasing mechanism

106:

Handschraubvorrichtung

110:

valve area

120:

Supply pressure range

122:

main valve

124:

Main valve spring

126:

Main valve closure member

128:

Main valve seat

130:

Set pressure range

132:

main chamber

134:

main exit

140:

damping device

142:

Passage gap

142 ':

Range of the minimum flow cross section

144:

displacement piston

144 ':

Stage on the outer circumference of the displacement piston

146:

housing wall

146 ':

Stage on the inner circumference of the housing wall

148:

storage chamber

150:

Discharge range / tank pressure range

151:

drain output

152:

drain valve

154:

Drain valve spring

156:

Drain valve closure member

158:

Discharge valve seat

160:

control chamber

162:

control piston

164:

tappet

166:

kicking off

170:

Connection to hydraulic system

232:

main chamber

240:

damping device

244:

displacement piston

248:

storage chamber

280:

bypass flow

332:

main chamber

340:

damping device

344:

displacement piston

348:

storage chamber

380:

bypass flow

382:

check valve

440:

damping device

446:

housing wall

448:

storage chamber

480:

bypass flow

540:

damping device

546:

housing wall

548:

storage chamber

580:

bypass flow

582:

check valve

A:

Regulating pressure line

F:

filter

P:

Supply pressure line

T:

Tank return line

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0829794 B1 [0004, 0006]

Claims (20)

Pressure control valve (100) for high-pressure hydraulic systems with a supply pressure range (120), a control pressure range (130), a housing (101), a relative to the housing (101) movable control piston (162) and a damping device (140); wherein the control piston (162) is pressurized against a spring force and is adapted to shift due to the spring force, a main valve closing element (126) in an open position relative to a main valve seat (128), so that a pressure of a hydraulic fluid in the control pressure range (130) controllable is; wherein the damping device (140) is adapted to damp a movement of the control piston (162) and has a storage chamber (148), a displacement piston (144) and a throttled damping flow path; wherein the storage chamber (148) is fillable and deflatable via the restricted damping flow path with hydraulic fluid; and wherein the displacement piston (144) is movable together with the control piston (162) and is adapted to cause via its movement a loading and unloading of the storage chamber (148) with hydraulic fluid; characterized in that the damping flow path is defined at least in part via a passage gap (142) between an outer circumference of the displacement piston (144) and an inner circumference of a housing wall (146) adjacent to the displacement piston, and the passage gap (142) is displaced from a position of the displacement piston (144) ) relative to the housing (101) dependent variable minimum flow cross-section. Pressure control valve (100) after Claim 1 characterized in that the minimum flow area of the passageway (142) in a first position of the displacement piston (144) relative to the housing (101) has a first value and in a second position of the displacement piston (144) relative to the housing (101) is different from the first position of the displacement piston (144) has a second value which is different from the first value. Pressure control valve (100) after Claim 1 or 2 , characterized in that the inner circumference of the housing wall (146) in a region of the housing wall in the axial direction of the displacement piston (144) changes. Pressure control valve (100) according to any one of the preceding claims, characterized in that the inner circumference of the housing wall (146) in a region of the housing wall in the axial direction of the displacement piston (144) is designed stepwise in cross section. Pressure control valve (100) according to one of the preceding claims, characterized in that the inner circumference of the housing wall (146) in an area of the housing wall in the axial direction of the displacement piston (144) decreases in the closing direction of the main valve closing element (126). Pressure control valve (100) according to any one of the preceding claims, characterized in that the outer periphery of the displacement piston (144) in the axial direction of the displacement piston (144) changes. Pressure control valve (100) according to any one of the preceding claims, characterized in that the outer periphery of the displacement piston (144) in the axial direction of the displacement piston (144) is designed in steps in cross-section. Pressure control valve (100) according to any one of the preceding claims, characterized in that the outer circumference of the displacement piston (144) in the axial direction of the displacement piston (144) decreases in the closing direction of the main valve closing element (126). Pressure control valve (100) according to any one of the preceding claims, characterized in that the storage chamber (148) is a part of a control chamber (160) in which the control piston (162) is movable. Pressure control valve (100) according to any one of the preceding claims, characterized in that a minimum flow cross-section of the damping flow path for positions of the displacement piston (144) in which the main valve closing element (126) is substantially greater in the open position than for positions of the displacement piston (144) which the main valve closure member (126) is substantially in a closed position. Pressure regulating valve (100) according to one of the preceding claims, characterized in that the pressure regulating valve (100) has a discharge region (150) for discharging hydraulic fluid from the regulating pressure region (130) when a set regulating pressure in the regulating pressure region (130) is exceeded, wherein the discharge region ( 150) is hydraulically connectable by a movement of the control piston (162) with the control pressure range (130). Pressure control valve (100) after Claim 11 characterized in that the drain region (150) is connected to the drainage valve (152) via a drain valve (152) Control pressure range (162) is coupled, wherein the drain valve (152) has a relative to the housing (101) movable Ablassventilschließelement (156), a Ablaßventilfeder (154) and a Ablassventilsitz (158), wherein the Ablassventilfeder (154) the Ablassventilschließelement (156) pressure is applied to the drain valve seat (158), and wherein the drain valve closing member (156) is liftable from the drain valve seat (128) by abutment (166) against the pressure of the drain valve spring (154) to hydraulically connect the drain region (150) to the control pressure region (130 ) connect to. Pressure control valve (100) after Claim 12 characterized in that the bleed valve seat (154) is movable together with the control piston (162) and the abutment (166) is fixedly connected to the housing (101), the bleed valve seat (154) in particular being fixedly connected to the control piston (162) is and is particularly preferably formed as part of the control piston (162). Pressure control valve (100) according to one of Claims 11 to 13 , characterized in that the drain region (150) and / or a drain valve (152) is at least partially disposed in the control piston (162) and / or in the displacement piston (144). Pressure control valve (100) according to one of Claims 11 to 14 , characterized in that the storage chamber (148) forms part of a hydraulic flow path from the control pressure region (130) to the discharge region (150). Pressure control valve (100) according to one of Claims 11 to 15 characterized in that the minimum flow area of the passageway (142) has a third value in a third position of the displacement piston (144) relative to the housing (101) in which the drainage area (150) is hydraulically connected to the control pressure area (130) and in a fourth position of the displacer piston (144) relative to the housing (101), in which the bleed area (150) is hydraulically isolated from the control pressure area (130) has a fourth value, the third value being less than the fourth value. Pressure control valve (100) according to one of the preceding claims, characterized in that the pressure regulating valve (100) has a main chamber (232, 332, 432, 532), wherein the main chamber (232, 332, 432, 532) via the damping flow in hydraulic communication with the storage chamber (248, 348, 448, 548) stands; wherein the damping flowpath adjacent the passageway has at least one bypass flowpath (280, 380, 480, 580); and wherein the bypass flow path (280, 380, 480, 580) is formed as a direct hydraulic connection between the storage chamber (248, 348, 448, 548) and the main chamber (232, 332, 432, 532). Pressure control valve (100) after Claim 17 , characterized in that at least a part of the bypass flow path (280, 380) passes through the displacement piston (244, 344) and / or the control piston (162). Pressure control valve (100) after Claim 17 or 18 characterized in that at least a portion of the bypass flow path (480, 580) extends through the housing wall (446, 546). Pressure control valve (100) according to one of Claims 17 to 19 characterized in that the bypass flow path (380, 580) comprises at least one check valve (382, 582).

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