DE102009060188A1 - Adjustable valve for positive-displacement pump, has pressure chamber whose inlet and outlet are separated from each other with valve body provided in one position and connected with each other with valve body in another position - Google Patents

Abstract

The valve (30) has a valve housing (29) with a pressure chamber (24), which includes an inlet (27) and an outlet (28) for pressure fluid. A valve body (31) is subjected with control force (16), and another valve body (32) is moved in a direction up to one position and moved in another direction up to another position. The inlet and the outlet of the pressure chamber are separated from each other with the latter valve body in the former position and connected with each other with the latter valve body in the latter position. An independent claim is also included for a positive-displacement pump comprising a housing.

Description

The invention relates to an adjustment valve for the adjustment of the delivery volume of a positive displacement pump and a positive displacement pump with the adjustment valve, which is arranged for the adjustment of the delivery volume of a fluid to be delivered by the pump in a fluid circuit of the pump. The invention accordingly also relates to the adjustment valve as such, as far as it is provided for the adjustment of the delivery volume of a positive displacement pump. The positive displacement pump can be used in particular as a lubricating oil pump for the lubricating oil supply of an internal combustion engine, in particular a drive motor of a motor vehicle, or an automatic transmission.

Displacement pumps, such as gear pumps and vane pumps, have a constant specific delivery volume. The delivery volume is therefore proportional to the pump speed, usually the speed of one or more impellers of the respective pump, as long as the degree of filling of the pump delivery cells is 100%. In many applications, this proportionality is disturbing. In a press, for example, a high delivery quantity of pressure oil is necessary for the rapid traverse, but in the final phase of the working stroke of the press only high pressure is required, while the demand for delivery volume goes back to zero. Disturbing is an excess of oil flow, for example, in pumps for supplying an internal combustion engine or an automatic transmission of a motor vehicle with lubricating oil or working oil. Although these units require at low engine speed and correspondingly lower pump speed, especially at idle, a minimum delivery volume and at high engine speed a minimum oil pressure, the oil demand at higher speed is well below the proportional line.

The specific delivery volume of pumps should be adapted to the needs of the consumer, such as an internal combustion engine, an automatic transmission or a press, i. H. be adjustable.

Gear pumps with adjustable delivery volume are for example from the DE 102 22 131 B4 and the DE 102 37 801 A1 known. External gear pumps are described whose specific delivery volume can be adjusted by adjusting the axial engagement length of the conveyor wheels in engagement. The DE 102 22 131 C2 also describes an internal gear pump whose specific delivery volume is adjustable by adjusting the eccentricity of the conveyor wheels engaged. The adjustment takes place for both pump types by means of an adjusting member, which is formed in the external gear pumps by an axially adjustable displacement unit and the internal gear pump by an adjusting ring. By adjusting the respective adjusting the position of one of the feed wheels of the respective pump is adjusted relative to the other feed wheel. In the case of vane pumps and pendulum slide pumps, which represent further preferred pump types, for example, a collar surrounding the conveyor wheel, whose eccentricity is adjustable relative to the feed wheel, form the adjusting member. Moreover, it is also possible to adjust the position of an inlet into a pumping chamber or an outlet from the pumping chamber or both in combination relative to the or in the pump chamber arranged impeller or conveyor wheels, wherein in such embodiments, the inlet or the outlet or both forming adjusting is arranged correspondingly adjustable. The adjusting members are acted upon in each case in a direction of their adjustability with the pumped pressure fluid and the pressurized fluid counteracting in the other direction by the spring force of a spring member, so that adjusts an equilibrium position according to the spring stiffness and the oil pressure. The pressure fluid acts in the direction of a reduction of the specific delivery volume and the spring member biases the adjusting member in the direction of maximum specific delivery volume.

The adjusting members of the known from the two documents pumps are each acted upon via a control valve with the pressurized fluid. The control valves each have a control piston, which is acted upon in a direction counteracting the pressure fluid and the pressure fluid with the spring force of a control spring. To be able to adjust by means of the control valve, the pressure level at which the pump stops, the DE 102 37 801 A1 to form the control piston as a stepped piston or to support the control spring with a magnetic additional force or to use a control spring with adjustable spring tension. The control valve with stepped piston allows the Abregelung from reaching a predetermined lower pressure level and always regulates on reaching a predetermined upper pressure levels. Although the control valve with adjustable spring tension allows stepless adjustment of the spring tension basically a stepless adjustment of the pressure level of Abregulation, by adjusting the spring tension, however, it can easily lead to vibrations and unstable states.

The speed-proportional pumping behavior leads to problems in the cold state, ie with cold and therefore viscous fluid and high hydraulic resistance of an aggregate to be supplied with the fluid. The unit takes less pressure fluid than the pump promotes according to their specific delivery volume, so that in the supply line to the unit a pressure level adjustment that may cause damage to the engine upstream components, such as a radiator or a filter. To solve such a cold start problem, a cold start valve is usually provided in the supply circuit of drive motors of motor vehicles, which dissipates excess lubricating oil in the sump.

The DE 102 37 801 A1 encounters the cold start problem with an additional electronic control component, which via an electrically controlled valve, a solenoid valve or a stepper motor, the adjustment valve can influence such that the oil pressure is reduced in the cold start phase.

It is an object of the invention to adjust the delivery volume of a positive displacement pump to the needs of an aggregate to be supplied by the pump in a simpler manner.

The object is achieved by the adjustment valve according to claim 1 and the displacement pump with adjustable delivery volume according to claim 14.

The invention relates to an adjustment valve for the adjustment of the delivery volume of a positive displacement pump. The adjustment valve has a valve housing with a pressure chamber having an inlet and an outlet. Preferably, the pressure chamber is partially formed directly from the housing or at least partially mitgebildet by the housing. In the housing, a first piston or valve body is present, which is acted upon by a control force and a relative to this first valve body movable second piston or valve body which is movable in a first direction to a first position and in a second direction to a first position second position is movable. The second valve body has a valve body surface, which can be acted upon by the pressure fluid in the second direction. Furthermore, the adjustment valve comprises a return member acting on the second valve body, which counteracts the pressure fluid. The inlet and the outlet of the pressure chamber are separated from each other when the second valve body is in its first position, the inlet and outlet are preferably completely connected to each other when the second valve body is in its second position. Fully connected should mean here that the inlet and outlet ports are completely within the pressure chamber. On the way from the first position to the second position, the outlet may be only partially covered by the second valve body, so that a preferably stepless opening of the outlet to the pressure chamber is possible and a corresponding stepless adjustment of the adjusting valve.

In other words, the adjustment valve according to the invention comprises a housing in which two valve bodies, which form the actuators of the valve, are arranged in series or in series, so that they operate in series or in series. In this case, the first and the second valve body are each acted upon by at least one force, the first valve body with a control force and the second valve body with the force of a pressurized fluid and a counteracting restoring force. By the engaging forces, at least the second valve body may be moved relative to the first valve body, and preferably also relative to the housing, from a first position where the inlet and outlet of the pressure chamber are separated from each other to a second position where inlet and outlet of the first Pressure chamber are interconnected. In this case, the second valve body may be, for example, a piston, a ball or a plate, which rests against the generator of the restoring force, for example a spring, or is firmly connected to the generator of the restoring force. If the valve body is a ball or a plate, these are preferably moved, for example in a type of cage made of wire or rods, which can protrude, for example, from the end of the first valve body facing the second valve body.

In addition to the second valve body, the first valve body may also be movably mounted in the housing so that the acting control force can move the first valve body relative to the second valve body and relative to the housing. That is, both valve bodies are movable and can be moved by the forces acting on them in the same direction or in opposite directions, that is, for example, towards or away from each other.

The movements of the valve bodies may be linear movements along a common line or at a parallel offset straight line, the straight lines being the axes of rotation of the valve body. Instead of a linear movement and a rotational movement is conceivable in which the two valve body can rotate in the same and / or opposite directions. It is also possible that one of the valve body is moved linearly while the other valve body is rotated. However, it is preferred if the valve body or bodies can only move linearly along their axes lying on a common line.

In the preferred linear movement of the valve body, the control force for the first valve body to counteract the restoring force of the return member. That is, the control force of the first valve body and the force of the pressure fluid acting on the second valve body urge the second valve body in a same second direction as that of the second valve body first direction of the restoring force is opposite.

The first valve body of the adjustment valve may have one or more first valve body surface (s) which can be acted on by a second pressure fluid to generate the control force. If more than one first valve surface is present, then the plurality of first valve surfaces are acted upon by a supply line with pressurized fluid. In this case, each of the first valve surfaces can be pressurized individually independently of each other of the first valve surfaces, but it is also possible for a plurality or even all of the first valve surfaces to be supplied with pressurized fluid at the same time. In this case, several or all pressure fluid supply lines can be supplied from a common source of pressurized fluid, but it is also conceivable that one, several or each of the pressure fluid lines is connected or connectable to a separate source of pressurized fluid. When the pressurized fluid is provided from a pressurized fluid source, devices may be provided in one or more or all of the pressurized fluid conduits to manipulate the pressure of the pressurized fluid.

The first valve body surface or the first valve body surfaces of the first valve body are valve body surfaces, which can not face the pressure chamber, but point away from it. The first valve body surfaces are thus the valve body surfaces of the first valve body, which are preferably in the housing but outside the pressure chamber, or form a side outer wall of the housing. In order to be able to act upon these valve body surfaces with a pressurized fluid, the housing wall can have further inlets in this region, through which the pressurized fluid can flow and exert pressure on the first valve body surfaces. An inlet may, especially when a first valve body surface forms a side outer wall of the adjusting valve, have the same diameter as the valve body at this position itself, so that always the pressure prevailing in the supply line pressure acts directly on this first valve body surface. However, this inlet can also have a smaller diameter, through which the pressure fluid then preferably flows into a further pressure chamber formed by the housing and the first valve body surface and thus builds up the control force. If the valve body has a plurality of first valve body surfaces, a pressure chamber is preferably formed in the housing in front of each of the first valve body surfaces, into which the pressure fluid can flow and build up a control force.

If the first valve body, as preferred, can be moved along a translation axis relative to the second valve body, then the second valve body can extend around the first valve body and slide in its linear movement over the first valve body. In the rest position, however, the first valve body can also project into the second valve body and move out of it during its adjustment movement. Finally, both valve body can be moved relative to each other, that is, pushed into each other or pulled apart. Favor lead in all these movements, the valve body axially against each other, that is, the first valve body forms the axial guide for the second valve body, et vice versa. The first and the second valve body may each have an abutment surface at each axial end, the two abutment surfaces lying opposite one another and the two valve bodies abutting one another on the abutment surfaces so that both valve bodies can be displaced linearly together without overlapping ,

The first and the second valve body in this case have a diameter which preferably corresponds to the inner diameter of the pressure chamber. In order to reliably prevent the pressurized fluid from flowing between the valve body peripheral surface and the pressure chamber inner wall, additional sealing measures, for example sealing rings made of a flexible material, may be provided in grooves formed on the valve body peripheral surface or the pressure chamber inner wall. Alternatively, labyrinth seals or any other type of suitable seal can be used. However, it is preferred to keep the manufacturing tolerances between the valve body diameter and the pressure chamber inner wall so low that no additional sealing measures are necessary.

The first valve body may have two facing valve body surface in the pressure chamber, one of which is acted upon in the second direction with the pressurized fluid. The second direction is identical to the direction in which the control force presses the first valve body when it contacts the outside of the first valve body, the first valve body surface. The valve body surface of the first valve body facing this valve body surface in the pressure chamber is simultaneously acted upon by the pressure fluid in the first direction opposite to the second direction, and thus also acts counter to the effective direction of the control force. In this case, at least one of the two valve body surfaces of the first valve body limit the pressure chamber at one of its end faces.

It is preferred if the adjustment valve with the second valve body in its second position connects the inlet into the pressure chamber directly with the outlet from the pressure chamber. This means that the pressure fluid flows through the inlet directly into the pressure chamber and from this, without having to flow through further valves or chambers, directly leaves the pressure chamber again through the outlet. The Pressure chamber is in this sense only part of a connecting line that connects, for example, a pump via the pressure chamber with a customer, without taking any influence on the pressure of the fluid flowing through.

Alternatively, the adjustment valve can also have a first valve body, which has a connection channel and connects the inlet of the pressure chamber with the outlet of the pressure chamber via this connection channel. In the first position of the second valve body, the passageway of the first valve body is closed by the second valve body, upon movement of the second valve body to the second position, the passageway of the first valve body is then opened so that now the pressurized fluid can flow from the inlet to the outlet.

In this case, the restoring force, or the return member of the second valve body can be supported by at least one further return member, wherein the further return member of the adjusting valve is disposed on the same side as the return member, but instead can act directly on the first valve body on the second valve body. This is only possible if the diameter of the second valve body is smaller than that of the first valve body or the second valve body has openings on its side facing away from the pressure chamber, this can act across the second return member directly on the first valve body.

However, the further return member can also be arranged in the interior of the first valve body and be supported on the side of the second valve body facing the first valve body. Finally, the further return member can also be arranged on the first valve body on the side facing away from the second valve body, for example in a pressure chamber adjoining the first valve body in the axial direction for the pressurized fluid. Other arrangements of the return member and the further return member to each other and in relation to the first and (or second valve body are also covered by the invention, as long as they are advantageous for the function of the adjusting valve.

With the first valve body of the alternative adjustment valve, the flow rate of the pressure valve from the inlet to the outlet of the pressure chamber from a first amount to a second amount can be changed. The first valve body has for this purpose a valve body end piston and a Ventilkörperauslassbereich, each of which has a valve body surface, which face in the pressure chamber. The two valve body areas are rigidly connected by a shaft or made together with the shaft in one part, so that they can only be moved together. Shortly before the valve body region, which is closer to the outlet (valve body outlet region), a bore is introduced into the shaft, which is perpendicular to the longitudinal axis of the shaft and can be designed as a through hole, that is completely pierces the shaft. In the region of the bore, the shaft is designed in the direction of the outlet valve body region and in the subsequent Ventilkörperauslassbereich as a hollow shaft which extends to the end of the Ventilkörperauslassbereichs and thus to this end of the first valve body and is open at its end remote from the pressure chamber. The through hole and the hollow shaft are connected to each other so that the pressure fluid can flow through the through hole in the hollow shaft. In the valve body outlet region, another bore is introduced perpendicular to the longitudinal axis of the valve body, which completely pierces the valve body outlet region.

In the open end of the Ventilkörperauslassbereichs sits the second valve body which is linearly movable in the bore as in the first variant, wherein the bore serves the second valve body as a linear guide. The second valve body also has a through bore transverse to its longitudinal axis and is connected thereto in the direction away from the pressure chamber formed as a valve hollow body, wherein the two bores are interconnected. In its first position, the second valve body closes the hollow shaft in the area between the through-hole of the shaft and the through-hole through the valve body outlet portion so that pressurized fluid can not flow through the hollow shaft to the outlet while simultaneously communicating the through-hole of the valve body outlet portion of the first valve body and the second valve body overlap, so that fluid from the outlet through the through hole of the Ventilkörperauslassbereichs and the through hole of the second valve body can penetrate into the valve hollow body of the second valve body and is discharged through the valve hollow body, for example, to the environment. In order to ensure that the two through bores always come to rest exactly one above the other, the first valve body can have guide grooves, in which the second valve body can be moved against rotation in the first valve body with guide rails formed on its outside. However, a second valve body having a circumferential groove in the region of the through-bore is preferred and simpler to produce since, in this case, the elaborate axial guidance can be dispensed with.

When the pressure of the fluid flowing in through the inlet rises to a value which is greater than the restoring force of the first return element, the second valve body becomes in its second position which clears the path for the fluid from the inlet to the outlet.

Consequently, fluid flowing into the pressure chamber can now flow from the inlet to the outlet via the through-bore in the shaft of the first valve body, the hollow shaft and the through-bore through the valve body outlet region.

If the first valve body is now additionally acted upon at its inlet-side valve body outlet surface (first valve body surface) of the valve body end piston, that is to say the valve body surface facing away from the pressure chamber of the valve body region of the first valve body farther from the outlet, a control force which acts counter to the direction of the restoring member or r, Thus, the first valve body with a correspondingly large control force can be displaced as a whole linearly in the direction of the outlet, so that the pressure chamber, which is formed in this case by the space between the Ventilkörperendkolben and the Ventilkörperauslassbereich the first valve body, now connects the inlet directly to the outlet , While the second valve body again assumes the position relative to the second valve body as in the rest position, wherein the through holes of the Ventilkörperauslassbereichs and the second valve body but no fluid connection z to have more outlet.

The invention further relates to a displacement pump with a previously described adjustment valve with a constant or adjustable delivery volume. In a fixed displacement pump, that is, a constant displacement pump, the inlet of the adjusting valve is connected to the outlet of the positive displacement pump, while the outlet of the adjusting valve, for example, has a direct connection into a reservoir for the pressurized fluid or the suction area. If, in the constant-displacement pump, the pressure fluid joins the inlet of the adjusting valve to the outlet due to the pressure forces that occur, a portion of the pressure fluid is directed directly into, for example, the reservoir or the suction area of the pump, thereby reducing the volume flow in the direction of the unit or consumer and thus the flow rate Pressure is reduced. If the pressure falls below the predetermined opening pressure of the adjusting valve due to the fluid volume withdrawn from the fluid flow, the valve closes and the return flow into the reservoir or the suction region of the pump is interrupted. The displacement pump with an adjustable displacement comprises a housing, a delivery chamber formed in the housing with an inlet for a pressurized fluid on a low pressure side and an outlet for the pressurized fluid on the high pressure side of the pump and at least one delivery member movably mounted in the delivery chamber for delivery of the pressurized fluid. Furthermore, the displacement pump has an arranged on an end side of the conveyor member or the conveyor member surrounding actuator which is movable for the adjustment of the delivery volume in the housing back and forth, a return line for pressurized fluid to produce a in the direction of the mobility of the actuator acting on this actuator and a return member for acting on the actuator with a restoring force counteracting the restoring force. Further, the positive displacement pump has an adjustment valve as described above and a valve lead connecting the outlet of the delivery chamber to the inlet of the adjustment valve, the return conduit returning the pressure fluid from the outlet of the adjustment valve to the pump.

In this case, at least one hydraulic resistance and an aggregate to be supplied with the pressure fluid can be arranged in a supply line downstream of the delivery chamber, the valve supply line connecting the outlet of the delivery chamber to the inlet of the adjustment valve preferably branching off from the supply line before the resistance, and from the resistor or in a region after the resistor branches off a second valve lead.

The control force for the adjustment valve is preferably applied by a pressurized fluid that branches off at a consumer, preferably at an aggregate to be supplied with the pressurized fluid, and is supplied via one or more supply lines to the first valve body surface (s) of the first valve body of the adjustment valve. In this case, the control force can be influenced by various factors, such as a speed or temperature generated in the unit. It is preferred in this case if the unit itself is supplied with pressure fluid of the pressure side of the displacement pump and the control force consequently changes with changing pressure of the pressure fluid. If the adjusting valve has more than one first valve body surface and more than one supply line for the pressurized fluid, the control force can also be changed by opening or closing only one, several or all supply lines depending on the operating state.

The resistor is preferably a filter for the pressurized fluid, the positive displacement pump is a lubricating oil pump for an internal combustion engine of a motor vehicle, which is driven at a speed dependent on the rotational speed of the internal combustion engine.

The adjustment valve described has an integrated cold start function. As described, in the starting position the inlet into the pressure chamber is opened, whereas the outlet is separated from the pressure chamber, for example closed or preferably connected to the environment. Now, when the positive displacement pump is started, there is an inflow of the pressurized fluid into the pressure chamber and a pressure build-up in the pressure chamber before a control force is built up from the consumer. As a result of the pressure in the pressure chamber, as soon as the pressure force exceeds a restoring force, the second valve body can be moved from its first position to its second position, whereby the inlet of the pressure chamber is connected to the outlet of the pressure chamber and pressurized fluid is returned to the pump through the return line. The recirculated pressure causes via the actuator an adjustment of the movably arranged conveying member relative to the stationary conveying member. Due to the changed geometry of the pump, the pressure in the pressure chamber is reduced until the restoring force is greater than the force of the pressure fluid. The restoring force now pushes the second valve body back into its first position, that is, the outlet of the pressure chamber is closed again, the return line for the pressurized fluid is reconnected to the environment. If, for example, increasing the speed of the motor results in an increase in the displacement of the positive displacement pump, pressure may again build up in the pressure chamber, which in turn forces the second valve body to its second position and establishes fluid communication between the pressure chamber and the actuator becomes.

When the control force exceeds the value of the restoring force, the first valve body may be moved from its first position to a second position such that, although the second valve body now occupies its first position relative to the first valve body, the inlet of the pressure chamber is directly connected to the outlet of the pressure chamber is.

Advantageous embodiments of the invention will be described with reference to the following figures. It is all that is not described but shown in the figures belonging to the invention with the scope of the invention. In the figures, embodiments are shown and described, which do not limit the scope of the invention, but serve to explain the objects according to the invention.

The figures show in detail:

1 : Adjusting valve of a first embodiment with the first valve body and the second valve body in the first position

2 : Adjusting valve of a first embodiment with the first valve body in the first position and the second valve body in the second position

3 : Adjustment valve of a first embodiment with the first valve body and the second valve body in the second position

4 : Circuit diagram of a positive displacement pump with an adjusting valve of a second embodiment with the first valve body and the second valve body in the first position

5 : Circuit diagram of a displacement pump with adjusting valve of a second embodiment during cold start

6 : Circuit diagram of a positive displacement pump with adjusting valve of a second embodiment in continuous operation

7 a third embodiment of the adjusting valve with ball as the second valve body in the normal position

8th : Adjustment valve the 7 at cold start

9 : Adjustment valve the 7 with controlled operation

10 A fourth embodiment of the adjusting valve with ball as a valve body in the normal position

11 : Adjustment valve after 10 at cold start

12 : Adjustment valve after 10 with controlled operation

13 : Circuit diagram of a displacement pump with controlled delivery volume with adjustment valve in continuous operation

14 : multi-stage adjustment valve

15 : Adjustment valve the 15 in the initial, cold start and regulation position

16 : Adjustment valves with two reset elements each

1 shows an inventive adjusting valve of a first embodiment. The adjustment valve 30 has a housing 29 up, with an inlet 27 that with a supply line 11a connected, and an outlet 28 that with a return line 12 connected is. The feed line 11a For example, it may be powered by a reservoir or pump (not shown). Preferably, the supply line is fed by a positive displacement or compressor pump, more preferably by a positive displacement pump of an internal combustion engine, for example an oil pump. It is about the feed 11 supplied medium, a fluid, preferably a pressurized fluid or pressurized fluid. The unmarked arrows in all figures represent the effective direction of the pressure force of the pressure fluid and the flow path of the pressure fluid.

Through the inlet 27 the pressurized fluid enters a pressure chamber 24 directed. The pressure chamber 24 gets from parts of the case 29 and a first valve body 31 educated. In the exemplary embodiment, the pressure chamber 24 a substantially cylindrical space. The in the circumferential direction through the housing 29 is limited and its lateral limits by the first valve body 31 are determined.

The first valve body 31 consists essentially of a valve body end piston 37 a valve body outlet area 38 and one of the two valve body areas 37 . 38 rigidly connecting shaft 39 , The valve body outlet area 38 has four distinguishable areas, namely a first part 38a that has a larger diameter than the shaft 39 but a smaller diameter than the pressure chamber 24 has a second and fourth part 38b . 38d the diameter of which is substantially equal to the diameter of the pressure chamber 24 is, and a third part 38c which has a smaller diameter than the second part 38b and the fourth part 38d ,

In the first part 38a the Ventilkörperauslassbereichs 38 is a through hole 40 introduced perpendicular to the longitudinal axis L of the first valve body 31 stands. Another through hole 41 breaks through the third part 38c and is also perpendicular to the longitudinal axis L. A third hole 42 acting as a blind bore in the longitudinal direction of the first valve body 31 is executed, begins at the first valve body surface 31a relative to the longitudinal axis L opposite end of the first valve body 31 breaks through the hole 41 in the third part 38c and ends in or shortly after the hole 40 In the first part 38a of the valve body end piston 38 ,

In the open end of the hole 42 is a second valve body 32 introduced, which also at its point away from the pressure chamber end a blind hole 43 has in the longitudinal direction of the valve body and a perpendicular to this through hole 44 in the blind hole 43 ends. The second valve body 32 has two sections of different diameters, a first section whose outer diameter is the inner diameter of the bore 42 corresponds and a second section whose diameter is larger than the diameter of the bore 42 and the pressure chamber side end of the second valve body 32 forms.

The second valve body 32 is in the hole 42 the first valve body mounted linearly movable, that is, the second valve body 32 can be relative to the first valve body 31 and relative to the housing 29 move along the common longitudinal axis L. Preferably, the second valve body 32 in the first valve body 31 guided so that only a movement along the longitudinal axis is possible.

The first valve body 31 and the second valve body 32 are in the 1 in their respective first position. In this position, both valve body 31 . 32 together by the one through the inlet 27 inflowing pressure fluid to be subjected to a compressive force. On the one hand, the pressurized fluid acts on the first valve body, namely on the valve body end piston 37 formed valve body surface 31b , the first valve body surface 31a minus the area of the diameter of the shaft 39 corresponds and with respect to the pressure chamber opposite valve body surfaces 31c and 31d that add up to provide the same attack surface for the pressurized fluid. The forces of the pressure fluid on the valve body surfaces 31b and 31c plus 31d are therefore in balance.

Through the hole 40 In the first part 38a the Ventilkörperauslassbereichs 38 can the pressurized fluid from the pressure chamber into the hole 42 flow. This hole is in the in 1 shown operating state of the adjusting valve 30 through the second valve 32 closed, leaving the second valve 32 is acted upon at its pressure chamber side end with the pressure force of the pressure fluid.

The second valve 32 is from a reset element 35 , which may be, for example, a preloaded spring, held in its first position, as long as the force of the return element 35 greater than the pressure force of the pressure fluid. In this position is the outlet 28 over the hole 41 in the third part 38c of the valve body end piston 38 and the holes 44 and 43 of the second valve body connected to, for example, the environment, that is, via this opening, the return line 12 and the unit or element supplied by it is vented.

In addition to the pressure of the pressurized fluid, a control force acts 16 on the first valve body 31 in a first direction, that of the direction of the pressing force of the pressurized fluid on the second valve body 32 equivalent. The control force can be generated by a servomotor, by hydraulic or pneumatic control pistons or other suitable devices. But it can also, as in the 4 to 6 shown to be generated by a second pressurized fluid, which is supplied by the displacement pump with pressurized fluid. To one To prevent movement of the first valve body with only slight control forces, can be another second return element 36 directly to the pressure chamber side end of the Ventilkörperauslassbereichs 38 Act. Should, unlike in the 1 shown, the pressure chamber side end of the second valve body 32 have a diameter which is almost or exactly the diameter of the first valve body 31 corresponds, it could be provided in Druckkammerabseitigen end of the second valve body bores, openings or openings, so that the second return element, the pressure chamber side end of the second valve body 32 can act directly on the first valve body.

The reset element 35 . 36 may be a spring, for example a spiral or compression spring, or another elastic element, for example, filled with a compressible fluid or gas or consists of an elastic material, such as rubber or the like, and that the movement of the first valve body 21 or the second valve body 32 from a first position to a second position against the direction of the return element 35 . 36 when exceeding the restoring force permits, the corresponding valve body 31 . 32 but moved back to its first position when the pressure by the pressure fluid and / or the control force 16 smaller than the respective restoring force.

In 2 the situation is shown in the pressurized fluid in the pressure chamber 24 flows in, on the first valve body 31 but no tax power 16 is applied. This can be the case with an internal combustion engine, for example during a cold start. When cold starting known to occur very high pressures in internal combustion engines, since the oil has no operating temperature, the parts to be moved may stick to each other due to the thickened oil and so on. This means that when cold starting suddenly very high pressure forces occur, which can lead to the destruction of parts of the drive system in the worst case.

In this case, by the pressure forces, by means of the pressure fluid through the holes 40 and 42 at the pressure chamber side end of the second valve body 32 abut, the second valve body 32 against the direction of the restoring force of the restoring element acting on it 35 or pressed a specially provided for the cold start restoring force of a cold spring not shown. This will initially be the outlet 28 from the environment he talks about the holes 44 and 43 in the second valve body 32 was connected, disconnected. In a further movement of the second valve body 32 opposite to the direction of the restoring force is the inlet 27 for the pressurized fluid through the holes 40 . 41 and 42 in the first valve body 31 with the outlet 28 connected, so now through the return line 12 For example, pressurized fluid may flow to a control unit that lowers the pressure of the pressurized fluid.

When using a special cold start spring, for example, the cold-start spring can be triggered automatically when turning off the engine, so that they for the next startup on the second valve body 32 is applied. For this purpose, the cold start spring may have a diameter which is smaller or larger than the diameter of the spring 35 , so that the cold start spring in addition to the spring 35 can act on the second valve body. If the cold start spring is then compressed during the cold start due to the compressive forces occurring, or the second valve body 32 shifted in the second direction, this leads to a latching of the cold start spring in a rest position in which they no longer on the second valve body 32 can work. But the cold start spring can also be, for example, by a behind the second valve body 32 be formed in its first position from the housing wall inwardly projecting type of locking, the second valve body 32 when a defined cold start pressure applied to the outside against a restoring force in the housing wall pressed away and locked there. This locking mechanism may, for example, be connected to a temperature sensor which measures the oil temperature and, after stopping the engine and falling below a predetermined oil temperature, releases the lock, so that the lock can be pushed back into its locking position by the restoring force. The two mentioned examples of a cold start spring are only two examples of the claimed principle and the cold start spring is therefore not limited to the two examples.

While the second valve body 32 due to the compressive force of the pressurized fluid from its first position, which he has in the 1 has moved to its second position, has the first valve body, on the, as described above in the pressure chamber 24 In both directions equal forces act and is therefore in equilibrium, not moved from its first position.

A movement of the first valve body 31 from the first position to its second position occurs only when on the first valve body surface 31a a control force is applied which is greater than the restoring force 36 on the first valve body 31 acts. This situation is in the 3 shown. The first valve body 31 from his first position he was in the 1 and 2 held, moved to its second position, this became the third part 38c the Ventilkörperauslassbereichs 38 over the second valve body 32 pushed so that the connection of the inlet 27 the pressure chamber 24 with the outlet 28 over the holes 40 . 41 . 42 in the first valve body again by the penetration of the second valve body 32 into the material bore 43 has been closed. At the same time that was through the first valve body 31 formed pressure chamber 24 but so far shifted that now both the inlet 27 as well as the outlet 28 communicate directly with the pressure chamber. A decrease in taxation 16 below the level of restoring force 36 leads to a movement of the first valve body 31 back to its first position, thereby clearing the path for the pressurized fluid through the holes 40 . 41 . 42 is opened again, or when the pressure force of the pressurized fluid is simultaneously smaller than the first restoring force of the spring 35 , to a return of the system to the position, as in the 1 shown.

The 4 shows a positive displacement pump 6 with adjustable delivery volume with an adjustment valve according to the invention 20 in a second embodiment, wherein instead of this embodiment, the above-described adjustment valve 30 could be used.

With the positive displacement pump 6 it is preferably a rotary piston pump, such as a gear pump, vane pump or pendulum slide pump. Preferably, it is a lubricating oil pump for supplying an internal combustion engine with lubricating oil. However, it may also be a supply pump for a different unit of a motor vehicle or the pump to supply an aggregate, for example a press.

The positive displacement pump 6 has a housing 10 , a pump inlet 7 on a low pressure side and a pump outlet 8th on a high pressure side. In the case 10 a delivery chamber is formed, in which a first delivery member 1 with a second conveyor member 2 cooperates to increase the pressure in a fluid on the way from the low pressure side to the high pressure side. The first conveyor link 1 is connected to a drive that rotates it. The first conveyor link 1 is generally not axially or almost not movable. The first conveyor link 1 , which may be an externally toothed gear, for example, may be a second conveyor member 2 , For example, also an externally toothed gear, drive by a meshing engagement.

The second promoter 2 on the contrary to the first funding member 1 be designed axially adjustable. For this purpose, the conveying member 2 of the 4 an actuator 3a . 3b on, on both sides of the conveyor link 2 followed. In this case, the actuator 3a . 3b with the conveyor link 2 be firmly connected, so that the actuator 3a . 3b and the conveyor member can only be moved together and replaced, for example. The actuator 3a . 3b but can also consist of two parts which are rigidly connected by an axis, wherein the conveying member 2 is rotatably mounted on this axis.

The actuator 3b is in operative connection with a source for a restoring force, here a coil spring 5 that the conveyor member 2 in a first direction in which it is in a maximum overlap with the first conveyor member 1 stands. The actuator 3a can on his the hauler 2 side facing away with a force which is the restoring force of the spring 5 is opposite. This force is preferably generated by the pump itself, as will be explained below.

With the outlet 27 the positive displacement pump 6 connected, attached to this or built into this is an adjustment valve in the embodiment 20 , The adjustment valve 20 is essentially constructed as the above-described adjustment 30 of the 1 to 3 , which is why with both adjusting valves 20 . 30 like parts are denoted by the same reference numerals and are interchangeable.

The adjustment valve 20 has a housing 29 on with an inlet 27 and an outlet 28 , In the case 29 are a first valve body 21 and a second valve body 22 stored, each of the valve body 21 . 22 in an axial direction of the housing is linearly translationally movable in a first position and in a second position which is different from the first position. In this case, each of the valve body 21 . 22 relative to the housing 29 and the valve bodies 21 . 22 be moved relative to each other. The valve body 21 . 22 can be moved towards and away from each other.

In the case 29 is through the valve body 21 . 22 a pressure chamber formed, for example, has a cylindrical shape, whose outer peripheral side through the housing 29 is formed, and the axial end sides of the valve body 21 and 22 be formed. In the 4 the situation is shown where both valve bodies 21 . 22 in their respective first position.

The first valve body 21 has four distinctive sections. The first section has an outer diameter that corresponds to the inner diameter of the pressure chamber 24 corresponds and seals the pressure chamber 24 at one of its axial ends. The second section adjoining the first section is a shaft whose diameter is smaller than the diameter of the first section. The third section is a conical region in which the shaft continuously widens in the exemplary embodiment shown, from the diameter of the shaft to a diameter which is greater than the diameter of the shaft but smaller than the diameter of the first section. The angle with which the Shaft continuously expanding, can be given constructive, reducing the size of this area on the first valve body 21 acting forces can be influenced. Instead of a continuous extension of the shaft can also be a stepped or a combination of continuous and step-like expansion in the production of the first valve body 21 be specified. Finally, the third section can be dispensed with altogether, that is to say directly to the shaft, a cylindrical body follows, which corresponds to the fourth section now described. The fourth section is formed by a cylindrical body adjoining the third section and having the same outer diameter as the third section. All sections directly adjoin one another and have a common axis of rotation.

The second valve body 22 practically forms a cap for the fourth portion of the first valve body 21 , It is a cylindrical hollow body with a closed side and an open side with a blind bore introduced there, which points in the direction of the first valve body. The outer diameter of the second valve body 22 corresponds to the inner diameter of the pressure chamber 24 and the outer diameter of the first portion of the first valve body 21 , The diameter of the blind bore corresponds to the outer diameter of the fourth portion of the first valve body 21 , the depth of the blind bore of the axial length of the fourth section. The sidewall thickness of the second valve body 22 thus corresponds to the difference between the inner diameter of the pressure chamber 24 and the outer diameter of the fourth portion of the first valve body 21 , This sidewall thickness can be achieved by appropriate design of the fourth portion of the first valve body 21 be determined. The minimum thickness of the side wall is determined by the material used, since the second valve body 22 also in a position in which he like in the 5 shown no longer completely on the first valve body 21 sitting, not allowed to be deformed by the attacking forces. On the closed side of the second valve body 22 acts a restoring force, which is applied in the embodiment of a spring and the second valve body 22 pushes in the first direction, so that he is at rest completely on the first valve body 21 , or its fourth section is postponed.

As the 4 shows are the positive displacement pump 6 and the adjustment valve 20 fluidly interconnected. The positive displacement pump 6 gives at her outlet 8th a pressurized fluid to a pipe 11 from. About this line 11 is the pressurized fluid through a resistor 13 For example, a filter to a consumer 14 issued. Before the pressure fluid the resistance 13 reached branches of the line 11 a line 11a from the pressure fluid or parts of the pressurized fluid through the inlet 27 in the pressure chamber 24 passes. He is now in the pressure chamber 24 Anabolic pressure acts in the first direction on the valve body surface 21b of the first valve body 21 and in the second direction, which is opposite to the first direction, on the inclined plane of the third portion of the first valve body 21 and on the visible area of the second valve body 22 between the pressure chamber inner wall and the outer peripheral surface of the fourth portion of the first valve body.

From the consumer 14 is over a line 15 a second pressurized fluid to that of the pressure chamber 24 groundbreaking valve body surface 21a of the first valve body 21 directed. The second pressure fluid may have a lower pressure than the pressure fluid directly downstream of the pump outlet 8th because it's before it's from the consumer 14 to the adjustment valve 20 passes through the resistance 13 is passed, which usually leads to a reduction of the pressure in the pressure fluid. The second pressurized fluid exerts on the first valve body 21 or its valve body surface 21a a tax force 16 out. The 4 shows the control valve in a state where the pressure force of the pressurized fluid on the pressure force of the exposed edge of the second valve body 22 in the pressure chamber 24 acts smaller than the restoring force of the spring 25 , and where the pressure force of the pressure fluid on the valve body wall 21b is greater than the control force 16 plus those on the third part of the first valve body 21 acting pressure force of the pressure fluid.

In this constellation of forces are the first valve body 21 and the second valve body 22 in their respective first position, the pressure chamber 24 only has a connection to the inlet 27 for the pressurized fluid, while the outlet 28 through the second valve body 22 from the pressure chamber 24 is disconnected.

In the 5 is like in the 2 shown the situation in which the pressurized fluid is under high pressure and at the same time still no control force 16 is built in the system, for example, the cold start situation described earlier. This will be in the pressure chamber 24 generates a compressive force that is greater than the restoring force of the spring 25 on the second valve body. As the pressure force only in the area on the second valve body 22 can act in which he directly the pressure chamber 24 protrudes, so alone on the annular end face, the fourth portion of the first valve body 21 Once again, it becomes clear that the size of the part of the second valve body which is exposed to the pressure fluid 22 decides on the pressure force. It is true that the applied compressive force is determined by the area exposed to the pressure multiplied by the applied pressure, that is, the larger the area, the more lower may be the pressure to apply a force greater than the restoring force of the spring 25 ,

Is the compressive force coming from the pressure chamber 24 on the second hoop 22 acts, greater than the restoring force of the spring 25 , the second valve body is moved from its first position to its second position. In this case, the second valve body 22 as far as linear in the second direction, the direction of the restoring force of the spring 25 Opposite, he pressed the connection between the pressure chamber 24 and the outlet 28 free. This allows the pressurized fluid through the return line 12 back to the positive displacement pump 6 and there in a pressure chamber 4 to flow directly to the adjuster 3a at the conveyor member 2 connected away side. The build-up in the chamber pressure leads to an axial displacement of the second conveyor member 2 in the second direction, the direction of the return spring 5 is opposite. As a result, the effective delivery space between the conveyor links 1 and 2 reduced, which leads to a decrease in the throughput and a reduction in the pressure in the pressurized fluid.

As already described, this situation is typical of the start-up phase of a system. It does not have to be an internal combustion engine of a motor vehicle, but it can be any system in the beginning due to the inertia of the system, adhesion and viscous equipment in the cold state, such as oils, the risk of the occurrence of dangerously high pressures in the system , This danger also exists if, at standstill, the pressurized fluid from the system, for example, due to occurring leaks in the system runs back into, for example, a reservoir, so that the system is partially or completely emptied at start. Such systems may be, for example, presses, punches or lifting devices for heavy loads.

In the 5 the system is in a starting state in which the first valve body 21 by the pressure force on its valve body surface 21b acts and the greater or equal to the opposing pressure force on the conical surface of the third part of the first valve body 21 is still in its first position while the second valve body 22 through the in the pressure chamber 24 acting compressive force was pushed from its first position to its second position.

In the 6 the state of the system is shown in equilibrium, for example in continuous operation. Meanwhile, the pressurized fluid has over the line 11 the resistance 13 reached and overcome and is with the consumer 14 arrived. In the consumer 14 a part of the pressure fluid used there is branched off and over the line 15 to the valve body surface 21a of the first valve body 21 directed. The taxpower 16 plus that due to the pressurized fluid on the tapered valve body surface of the third portion of the first valve body 21 acting pressure force in the state shown are greater than the restoring force of the spring 25 plus the on the valve body surface 21b acting force of the pressure fluid. This will both the first valve body 21 as well as the second valve body 22 pressed from their respective first position to their respective second position, so that now the fourth portion of the first valve body 21 completely in the blind bore of the second valve body 22 retracted. At the same time but was the first valve body 21 moved linearly to its second position, at the same time the inlet 27 and the outlet 28 connected to the pressure chamber, despite the fact that the first valve body 21 with its fourth section fully into the blind bore of the second valve body 22 retracted. In the in the 6 shown situation may pressure fluid from the adjustment valve 20 in the pressure chamber 4 the positive displacement pump 6 flow, creating the second conveyor link 2 against the restoring force of the spring 5 can be shifted, whereby the pressure in the pressure fluid decreases. In normal operation, that is, when the piston 1 relative to the piston 2 not moved, the pressure forces on the surfaces lift 22a and 21c and the pressure force counteracting this pressure force 21b on. The only force that still acts on the adjustment valve is the control force 16 ,

If in this control frequency the outlet 28 through the valve body completely from the inlet 27 and the pressure chamber 24 is separated, provides a vent not shown, for example, at the return spring 25 facing side of the second valve body 22 can be formed that in the return line 12 and the pressure chamber 4 For example, existing pressurized fluid can flow back into the sump.

A third embodiment of the control valve according to the invention shows the 7 , here in connection with a constant positive displacement pump. The first valve body 51 and the second valve body 52 form at their mutually facing axial ends each have a contact surface on which the two valve body 51 . 52 collide. The contact surfaces prevent overlapping of the two valve bodies 51 . 52 if one of the two valve body 51 . 52 or both valve bodies 51 . 52 be moved together. In the illustrated third embodiment, the second valve body 52 formed or co-formed by a ball and a guide for the ball. The 7 shows the control valve 50 in its basic position, that is, in the state where in the pressure chamber 24 the same pressure prevails as in the rest of the pipe system or the pipe system is emptied. That is the control valve 50 is located in one, for example Equilibrium state in which the pressure force of the pressure fluid and the restoring force of the return element 55 cancel and the pressure force of the pressure fluid plus the restoring force of the control force 16 correspond. In this state, no pressure fluid flows through the adjustment valve 50 because the inlet 27 in the pressure chamber 24 while open, the outlet 28 from the pressure chamber 24 but through the second valve body 52 , here the ball, is closed.

In this case, the first valve body 51 at its the second valve body 52 facing the end of a blind bore with lateral openings 45 on. Through the side openings 45 can pressure fluid in the hollow area 45 inflow and there directly to the formed as a ball second valve body 52 issue. The ball itself may be loose on the return element 55 , shown here as a spring, rest, can with the return element 55 connected, for example, be soldered or glued or on the return element 55 a receptacle can be formed in which the ball is held in a form-fitting manner. Preferably, the ball is guided in its movement, wherein, for example, three on the ball reaching and distributed over the circumference of the ball rods may suffice. These rods or other guide elements (eg, a mesh tube, a wire cage, a portion of the control valve body having an inner diameter corresponding to the diameter of the ball) for the ball may be either at the end of the first valve body 51 the ball facing is formed or fixed, or be formed by this. But the guide for the ball can also be part of the second valve body 52 or the return element 55 be.

The 8th shows the adjustment valve 50 of the 7 at a cold start. During a cold start, a high pressure suddenly occurs in the pressure fluid. In order not to let this pressure rise too much, it allows the adjustment valve 50 for example, via a return of the high pressure to a pressure chamber of the pump 6 to adjust an actuator and thus by the pump 6 regulate delivered fluid volumes per revolution (see description of the 4 to 6 ). The pressurized fluid at the high pressure penetrates into the pressure chamber 24 the adjusting valve 50 one. By already to 7 described cavity 45 in first valve body 51 the pressure can act on the ball. Exceeds the force acting on the ball pressure force the restoring force, the ball is moved against the direction of the restoring force and thereby the outlet 28 from the pressure chamber 24 of the control valve 50 gradually released. Through the released outlet 28 can pressurized fluid in the suction area of the pump 6 flow back, whereby the flow in the direction of the consumer is reduced, resulting in a pressure drop in the pressure fluid. The greater the pressure force of the pressure fluid, the further the ball is displaced against the restoring force and the farther the outlet opening opens 28 , The farther the outlet is opened, the more pressure fluid will flow through the adjustment valve 50 back to the suction side 7 the pump 6 directed. In this case, the limit pressure from which it comes to a displacement of the ball by the size of the attack surface on the ball for the pressurized fluid and the choice of the restoring force can be determined constructively very accurate.

Instead of the described adjustment of the actuator directly by the pressure of the pressure fluid may also be provided a control unit, which upon detection of a flow of the pressurized fluid through the outlet 28 the pressure chamber 24 measures the outflowing volume per unit time or pressure and, based on the measured value, regulates the flow into the control valve 50 inflowing pressure fluid causes.

8th shows a situation where only a small area of the outlet 28 is released, that is, the pressure of the pressurized fluid on the ball is only slightly larger than the restoring force of the spring 35 ,

In the 9 becomes a position of the valve body 50 shown in controlled operation. In the case shown acts a control force 16 on the first valve body 51 which is greater than the restoring force. This will be the first valve body 51 pressed in the second direction and in turn pushes the second valve body 52 in the same direction. In this movement, the through the valve body 51 . 52 formed pressure chamber 24 linearly shifted so that the pressure chamber 24 now the inlet 27 and the outlet 28 of the control valve 50 connects directly with each other. This allows the pressurized fluid directly into the suction areas of the pump 6 reach. Leaves the tax force 16 After, the restoring force presses the first and second valve body 51 . 52 back in the first direction and the outlet 28 will be closed again. By the opposing linear movements of the two valve body 51 . 52 depending on the first valve body 51 acting control force 16 An effective, fast-reacting control for the delivery volume and thus the system pressure can be achieved in a simple manner.

The 10 to 12 describe a fifth embodiment of the control valve according to the invention, in which the second valve body 62 is formed by a disk or mitgebildet. For these figures, the control valve 60 in the basic position ( 10 ), at cold start ( 11 ) and in regulated operation ( 12 ), it is the same as the one to the 7 to 9 Said. The reference numerals of the first valve body 61 and the spring 65 have been consequently adapted for the embodiment.

The 13 essentially corresponds to the 6 , with the difference that the 13 , as the 7 to 12 , a positive displacement pump 6 with variable displacement, in conjunction with the adjustment valve 20 of the second embodiment shows. That already to the 7 to 12 The above also applies to the 13 , The difference between the 13 and 6 is that in the 13 the outlet 28 from the pressure chamber 24 with a line 12 is connected, through which the pressurized fluid at the connection of the inlet shown 27 with the outlet 28 directly from the pressure chamber 24 back to the suction area 7 the pump 6 is directed. By branching off part of the pump 6 coming volume flow through the adjustment valve 20 into the reservoir, becomes the consumer 14 flowing volume flow decreases and corresponding to that on the or in the filter 13 reducing pressure. If the fluid pressure falls below a predetermined value, the spring can 25 Press the second valve body against the pressure force of the pressure fluid back into a closed position in which the outlet 28 the adjusting valve 20 again from the inlet 27 is disconnected, so no more pressurized fluid through the pipe 12 flows.

The 14 shows a multi-stage adjustment valve, in the example shown, a two-stage adjustment valve. This adjustment valve 20 ' indicates at its first valve body 21 ' two independent valve body surfaces 21a ' and 21a '' on. To each of the two valve body surfaces leads a separate supply line 15 ' . 15 '' about the one from the consumer 14 Coming pressurized fluid to the respective valve body surface 21a ' . 21a '' can be supplied. In this case, both valve body surfaces 21a ' 21a '' simultaneously pressurized fluid are supplied, whereby the then acting control force 16 the sum of the sub-control forces 16 ' and 16 '' is. But it can only be the line 15 ' . 15 '' to one of the valve body surfaces 21a ' or 21a '' be open, so in this case the control force 16 the corresponding partial control force 16 ' . 16 '' equivalent. In the example shown, the pressurized fluid through the line 15 ' directly to the valve body surface 21a ' flow. In contrast, the pressure fluid flows that of the valve body surface 21a '' is supplied via a device which allows, for example, a flow of the pressurized fluid through the device only at a predetermined pressure. The sub-control forces 16 ' and 16 '' can be the same size or different values, depending on the size of the surface on which the pressure fluid can attack. The example described here with the example of a two-stage adjustment valve, of course, also applies to three-stage or n-stage adjustment valves.

The 15 shows the adjustment valve 20 ' of the 14 in the starting position a), in which no tax force 16 on the valve body surfaces 21a ' and 21a '' acts, in the cold start position b), in which the valve body 21 ' is still in its initial position while the valve body 22 ' through the feed line 11a 'supplied pressurized fluid against the restoring force of the spring 36 ' was pushed into an open position. That in the pressure room 24 inflowing pressure medium can now through a hole in the valve body 22 ' that is also the spring 36 ' partially absorbs and leads, through the return line 12 ' either escape to a pressure chamber of the pump or the suction area of the pump. In the control position c), the pressurized fluid acts via the supply lines 15 ' and 15 '' with the taxpower 16 ' on the valve body surfaces 21a ' . 21a '' , and is now together with the restoring force of the spring 36 ' the only force to control the control valve. The illustrated control position c) can be adjusted by either only pressurized fluid via the line 15 ' the valve body surface 21a ' , only pressurized fluid over the line 15 '' the valve body surface 21a '' or both valve body surfaces 21a ' 21a '' simultaneously pressurized fluid via the respective line 15 ' . 15 '' is supplied.

The 16 shows adjusting valves of the type described above, each with two springs 35 ' . 36 ' , This is a non-exhaustive selection of examples that show how the springs work 35 . 36 of the 1 to 3 can be used advantageously in the described adjustment valves. Other arrangements, not shown here, of two or more springs in a control valve are also covered by this application. For example, the valve according to 1 a third spring 35 ' exhibit.

LIST OF REFERENCE NUMBERS

1

first conveyor link

2

second conveyor link

3a

actuator

3b

actuator

4

pressure chamber

5

feather

6

displacement

7

Pump inlet, suction area

10

casing

11

management

11a

feed

11a '

feed

12

Return line

12 '

Return line

13

resistance

14

consumer

16

control force

16 '

control force

16 ''

control force

20

adjusting valve

20 '

adjusting valve

21

first valve body

21 '

first valve body

21a

Valve body surface

21a '

Valve body surface

21a ''

Valve body surface

21b

Valve body surface

22

second valve body

22 '

second valve body

24

pressure chamber

25

feather

27

inlet

28

outlet

29

casing

30

adjusting valve

31

first valve body

31a

first cobening

31b

Valve body surface

31c

Valve body surface

31d

Valve body surface

32

second valve body

35

Reset element, spring

35 '

Reset element, spring

36

Reset element, spring

36 '

Reset element, spring

37

Ventilkörperendkolben

38

Ventilkörperauslassbereich

38a

first part

38b

second part

38c

third part

38d

fourth part

39

wave

40

Through Hole

41

drilling

42

drilling

43

blind hole

44

drilling

45

perforation

50

adjusting valve

51

first valve body

52

second valve body

55

feather

60

adjusting valve

61

first valve body

62

second valve body

65

feather

L

longitudinal axis

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

• DE 10222131 B4 [0004]
• DE 10237801 A1 [0004, 0005, 0007]
• DE 10222131 C2 [0004]

Claims (19)

Displacement valve for a positive displacement pump, the adjusting valve comprising a) a valve housing ( 29 ) with a pressure chamber ( 24 ), which has an inlet ( 27 ) and an outlet ( 28 ) for the pressurized fluid, b) a first valve body ( 21 ; 31 ), which with at least one control force ( 16 ) is acted upon c) a relative to the first valve body ( 21 ; 31 ) movable second valve body ( 22 ; 32 ), which is movable in a first direction to a first position and in a second direction to a second position, and a valve body surface ( 22a ; 32a ), which is acted upon by the pressure fluid in the second direction, d) and at least one on the second valve body ( 22 ; 32 ) acting return member ( 25 ; 35 ), which counteracts the pressurized fluid, e) the inlet ( 27 ) and the outlet ( 28 ) of the pressure chamber ( 24 ) in the first position located second valve body ( 22 ; 32 ) are separated from each other and in the second position befindlichem second valve body ( 22 ; 32 ) are interconnected. An adjustment valve according to claim 1, wherein said one or more control force / control forces ( 16 . 16 ' . 16 '' ) the force of the at least one return member ( 25 ; 35 . 36 ' counteracts. Adjustment valve according to one of the preceding claims, wherein the first valve body ( 21 ; 21 '; 31 ) at least a first valve body surface ( 21a ; 21a ' 21a ''; 31a ) for generating the at least one control force ( 16 ; 16 ' . 16 '' ) can be acted upon with a second pressurized fluid. Adjustment valve according to the preceding claim, wherein the valve housing ( 29 ) for the admission of the first valve body surface (s) ( 21a ; 21a ' . 21a ''; 31a ) has at least one further inlet for the second pressure fluid. Adjustment valve according to one of the preceding claims, wherein the first valve body ( 21 ; 21 ' ) is movable along a translation axis and the second valve body ( 22 ; 22 ' ) around the first valve body ( 21 ; 21 ' ). Adjustment valve according to one of claims 1 to 4, wherein the first valve body ( 31 ) is movable along a translation axis and the second valve body ( 32 ) in the first valve body ( 31 protrudes. Adjustment valve according to one of the two preceding claims, wherein the valve bodies ( 21 . 22 ; 21 ' . 22 '; 31 . 32 ) are guided axially to each other. Adjustment valve according to one of claims 1 to 4, wherein the first valve body ( 21 ; 21 ' ) and the second valve body ( 22 ; 22 ' ) each have a contact surface at one axial end, the two contact surfaces lying opposite each other and the two valve bodies ( 21 . 22 ; 21 ' . 22 ) abut each other in a joint movement on the contact surfaces. Adjustment valve according to one of the preceding claims, wherein the first valve body ( 21 ; 31 ) facing valve body surfaces ( 21b . 21c ; 31b . 31c ), of which at least one is the pressure chamber ( 24 ) bounded on one end face. An adjusting valve according to the preceding claim, wherein in the second position of the second valve body ( 22 ) the inlet ( 27 ) via the pressure chamber ( 24 ) directly to the outlet ( 28 ) connected is. Adjustment valve according to one of claims 1 to 8, wherein the first valve body ( 31 ) a connection channel ( 33 ) having the inlet ( 27 ) with the outlet ( 28 ) connects when the second valve body ( 32 ) occupies the second position, and of the second valve body ( 32 ) is closed when the second valve body ( 32 ) occupies the first position. Adjustment valve according to one of the preceding claims with at least one additional restoring member ( 36 ), which the restoring member ( 35 ) and / or the tax force ( 16 ; 16 ' . 16 '' ) supported. Adjustment valve according to one of the preceding claims, wherein the second valve body is formed or formed by a piston, a ball or a plate. Positive displacement pump, comprising a) a housing ( 10 ), b) one in the housing ( 10 ) formed with an inlet ( 7 ) for a pressurized fluid on a low pressure side and an outlet ( 8th ) for the pressurized fluid on a high pressure side of the pump ( 6 ), c) at least one in the delivery chamber movably arranged conveyor member ( 2 ) for the delivery of the pressurized fluid, d) an adjustment valve ( 20 ; 30 ) according to one of the preceding claims, e) a valve lead ( 11a ), which is the outlet ( 8th ) of the delivery chamber with the inlet ( 27 ) of the adjusting valve ( 20 ; 30 ) and f) a return line ( 12 ), the pressure fluid from the outlet ( 28 ) of the adjusting valve ( 20 ; 30 ) leads away. Positive displacement pump according to the preceding claim, wherein a) in a supply line ( 11 . 11b ) in the flow direction after the delivery chamber at least one hydraulic resistance ( 13 . 14 ), preferably a filter ( 13 ), and an aggregate to be supplied with the pressurized fluid ( 14 ), b) the valve lead ( 11a ) before the resistance ( 13 . 14 ), and c) from the resistor ( 14 ) or after the resistance ( 13 . 14 ) at least one further valve lead ( 15 ; 15 ' . 15 '' ) branches off. Positive displacement pump according to one of the preceding claims, wherein on a consumer, preferably on an apparatus to be supplied with pressurized fluid ( 14 ), the pressure fluid can be branched off and as a further pressure fluid for acting on the one or more first valve body surface (s) ( 21a ; 21a ' . 21a ''; 31a ) of the first valve body ( 21 ; 21 '; 31 ) of the adjusting valve ( 20 ; 20 '; 30 ) serves as a tax force ( 16 ; 16 ' . 16 '' ) for the adjustment valve ( 20 ; 30 ) acts. Positive displacement pump according to one of the preceding claims, wherein the pump ( 6 ) to an end face of the conveyor member ( 2 ) or the conveyor member ( 2 ) surrounding actuator ( 3a . 3b ), which is for the adjustment of the delivery volume in the housing ( 10 ) is movable back and forth, and wherein the return line ( 12 ) the pressure fluid of the pump ( 6 ) for generating a force which in the direction of mobility of the actuator ( 3a . 3b ) acts on this. Displacement pump according to the preceding claim, wherein the pump ( 6 ) a reset member ( 5 ) for acting on the actuator ( 3a . 3b Having a restoring force counteracting the restoring force. Positive displacement pump according to one of the preceding claims, wherein the pump ( 6 ) is a lubricating oil pump for an internal combustion engine of a motor vehicle and is driven at a speed dependent on the speed of the internal combustion engine speed.

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