Valve unit

Abstract

Valve unit (1), comprising an electrofluidically piloted main valve (13) which has a main valve spool (28) that can be moved back and forth by mutually opposing fluid application while performing a switching movement (29), and with a pilot valve assembly (14) which is arranged adjacent to the main valve (13) in a valve longitudinal direction (2) perpendicular to a valve vertical direction (3) and by which the fluid supply to the main valve spool (28) can be controlled by means of a pilot fluid via a first pilot working channel (37) and a second pilot working channel (38) of the valve unit (1), wherein the pilot valve assembly (14) has two first and second pilot valves (18, 19) which can be electrically actuated by means of an electromagnetic actuator (52), wherein the first pilot valve (18) has a first pilot valve housing (22) in which a first valve chamber (42) is formed in which a first pilot valve element (46) is located, wherein a fluid flow of the pilot fluid in the first pilot working channel (37) can be controlled by means of the first pilot valve (18) and a fluid flow of the pilot fluid in the second pilot working channel (38) can be controlled by means of the second pilot valve (19), and wherein the first pilot valve (18) is equipped with a manual actuating device (72) comprising a manual actuating element (76) that is at least partially received in an actuating element receiving chamber (74) and is accessible from outside the pilot valve assembly (14) for manually initiating an actuating movement (77), wherein the second pilot working channel (38) penetrates the actuating element receiving chamber (74) in the area of ​​the manual actuating element (76) with a receiving chamber channel section (83), characterized in that that the two pilot valves (18, 19) are arranged in series in the valve longitudinal direction (2), wherein the first pilot valve (18) is arranged between the main valve (13) and the second pilot valve (19), wherein the second pilot working channel (38) passes through the first pilot valve (18) on its way between the second pilot valve (19) and the main valve (13), the first pilot valve housing (22) of which has the actuating element receiving chamber (74), wherein the manual actuating element (76) during its actuating movement (77) actuates the first pilot valve (18) by mechanically acting on the associated first pilot valve element (46) and switching the same independently of the electromagnetic drive device (52).

Description

[0001] The invention relates to a valve unit with an electrofluidically piloted main valve, which has a main valve spool that can be moved back and forth by means of opposing fluid application in a switching movement, and with a pilot valve device which is arranged adjacent to the main valve in a valve longitudinal direction perpendicular to a valve vertical direction and by which the fluid supply to the main valve spool can be controlled by means of a pilot fluid via a first pilot working channel and a second pilot working channel of the valve unit, wherein the pilot valve assembly has two first and second pilot valves which can be electrically actuated by means of an electromagnetic actuator, wherein the first pilot valve has a first pilot valve housing in which a first valve chamber is formed in which a first pilot valve element is located, wherein the first pilot valve can be used to control the flow of the pilot fluid in the first pilot working channel and the second pilot valve can be used to control the flow of the pilot fluid in the second pilot working channel, and wherein the first pilot valve is equipped with a manual actuating device comprising a manual actuating element which is at least partially received in an actuating element receiving space and which is accessible from outside the pilot valve device for manually initiating an actuating movement, wherein the second pilot working channel penetrates the actuator receiving space in the area of ​​the manual actuator with a receiving space channel section.

[0002] A valve assembly of this type, known from EP 1 508 732 A1, has a main valve with a main valve spool, wherein the main valve spool can be switched between different switching positions by selectively applying fluid to its two opposing end faces. For this fluid application, the valve assembly contains two pilot working channels, each assigned to one of two pilot valves of a pilot valve assembly axially mounted to the main valve. A first of the two pilot valves is located between the main valve and a second of the two pilot valves and can control the fluid flow of a pilot fluid in one of the first of the two pilot working channels. For this purpose, the first pilot working channel extends from the first pilot valve to the main stage.The second pilot valve can control the fluid flow of a pilot fluid in a second of the two pilot working channels. This channel originates from the second pilot valve and, on its way to the main valve, passes through a pilot valve body of the first pilot valve, referred to as the first pilot valve body. Both pilot valves are equipped with a manual override device to allow manual actuation as an alternative to electric actuation, if required. In the first pilot valve, the manual override device includes a manually adjustable actuating element, accessible from outside the valve unit for applying a manual actuating force.The manual actuator is located in an actuator receptacle of a nozzle-like extension of a component belonging to a solenoid valve cartridge within the first pilot valve housing. The second pilot working channel passes laterally through this extension on its way to the main valve, within a housing component that encloses the solenoid valve cartridge. The channel sections of the two pilot working channels within the pilot valve assembly open side-by-side, perpendicular to the valve's vertical direction, onto a front end face of the first pilot valve housing, where the pilot valve assembly is mounted to the main valve. Due to the described channel configuration of the two pilot working channels, a certain minimum width of the pilot valve assembly, measured both vertically and perpendicularly to the valve's longitudinal direction, cannot be undercut.

[0003] EP 1 508 732 A1 discloses a valve assembly comprising at least one solenoid valve cartridge forming a single unit with a coil carrier and a valve body connected thereto. The valve body has two valve seats, each associated with a valve element. The valve body has a housing extension projecting axially beyond the second valve seat, in which both the second valve element and, accessible from the outside, a manual actuating element are held.

[0004] EP 1 184 611 A2 discloses a distributor valve consisting of a solenoid valve and a distributor base on which the solenoid valve is mounted. The solenoid valve includes a magnet mounted on a piston and a recess in which a sensor is to be mounted, positioned corresponding to that of the magnet. The distributor base includes a magnetometric sensor protruding in a position corresponding to the recess, and the magnetometric sensor is automatically mounted in the recess when the solenoid valve is mounted on the distributor base.

[0005] The invention is based on the objective of taking measures that enable a reduction in the overall width of the pilot valve assembly while ensuring functional reliability.

[0006] To solve this problem, a valve unit with the aforementioned features is provided in such a way that the two pilot valves are arranged in series in the longitudinal direction of the valve, wherein the first pilot valve is arranged between the main valve and the second pilot valve, wherein the second pilot working channel passes through the first pilot valve on its way between the second pilot valve and the main valve, the first pilot valve housing of which has the actuating element receiving space, wherein the manual actuating element, during its actuating movement, actuates the first pilot valve by mechanically acting on the associated first pilot valve element and switching it independently of the electromagnetic drive device.

[0007] In this way, the second pilot working channel, which can be controlled with respect to the fluid flow of a pilot fluid by means of the second pilot valve, is not routed laterally alongside the actuator receiving chamber inside the first pilot valve housing, but extends directly through the actuator receiving chamber, which at least partially accommodates the manual actuator. The channel section of the second pilot working channel that passes through the actuator receiving chamber is referred to as the receiving chamber channel section. According to the invention, a component of the first pilot valve that is required anyway for the implementation of the manual actuation device, namely the actuator receiving chamber, is used for the channel routing of the second pilot working channel, and it is therefore unnecessary to route the second pilot working channel laterally alongside the manual actuation device of the first pilot valve.This offers the advantageous possibility of reducing the width of the pilot valve assembly, and thus the entire valve unit, as needed. The valve unit can be manufactured cost-effectively in a very compact design.

[0008] Advantageous further developments of the invention are set out in the dependent claims.

[0009] The two pilot valves could, for example, be piezoelectric valves. However, a design as electrically actuated solenoid valves is considered particularly advantageous.

[0010] The main valve, which can be actuated by means of the pilot valve assembly, expediently has a main valve housing in which the main valve spool is located and in which two actuation chambers, designated as first and second actuation chambers, are formed. The first actuation chamber is bounded by a first actuation surface of the main valve spool, and the second actuation chamber by a second actuation surface of the main valve spool that is axially opposite to the first actuation surface. For controlled fluid supply with a pilot fluid, the first actuation chamber is fluidically connected to the first pilot working channel, and the second actuation chamber is fluidically connected to the second pilot working channel.

[0011] The two drive chambers are preferably assigned to opposite end sections of the main valve housing in the longitudinal direction of the valve. Alternatively, it is also possible to assign both drive chambers to one and the same axial end section of the main valve housing and, for example, to equip the main valve spool with a double-acting drive piston.

[0012] To fulfill the desired pilot valve function, the first pilot valve expediently has a first pilot valve element movably arranged in a valve chamber of the first pilot valve housing. The first pilot valve element can expediently be positioned in one of two switching positions, in which it selectively either vents or purges the first pilot working channel. The second pilot valve expediently has a corresponding design. A fluid-tight separation is expediently implemented between the receiving channel section penetrating the actuating element receiving chamber of the first pilot valve and the valve chamber of the first pilot valve to reliably prevent mutual fluidic influences. This fluid-tight separation is expediently achieved by means of a sealing device.

[0013] Preferably, the receiving chamber channel section in the actuator receiving chamber is designed such that it extends at least a short distance peripherally around the manual actuator. The receiving chamber channel section thus runs in a space between the outer circumference of the manual actuator and the inner circumference of the actuator receiving chamber. Such a design is, at least with regard to the manual actuator, more cost-effective than a design that is also possible in principle, in which the receiving chamber channel section passes through the manual actuator.

[0014] A ring-shaped configuration of the receiving chamber channel section is considered particularly advantageous, such that it extends completely around the manual actuator within the actuator receiving chamber. In this context, the ring-shaped receiving chamber channel section is advantageously bounded radially on the inside by the manual actuator and radially on the outside by a housing section of the first pilot valve housing that peripherally defines the actuator receiving chamber. The receiving chamber channel section can, for example, be implemented as an annular gap that is coaxially formed around the manual actuator. The ring shape of the receiving chamber channel section can be implemented particularly easily by ensuring that the manual actuator has a smaller outer diameter in its associated length segment than the inner diameter of the actuator receiving chamber.To realize the ring-shaped receiving chamber channel section, it is also possible, for example, to form an annular groove in the outer circumference of the hand actuator and / or in the inner circumference of the actuator receiving chamber.

[0015] The second pilot valve working channel, in addition to the receiving chamber channel section, expediently has two further channel sections in the first pilot valve housing: a front channel section leading to the main valve and a rear channel section leading to the second pilot valve. These two front and rear channel sections expediently open into the receiving chamber at circumferential areas spaced apart from each other in the circumferential direction of the actuator receiving chamber, each with an inner channel opening, and thus transition into the receiving chamber channel section.

[0016] It is considered advantageous if the inner channel opening of the front channel section and the inner channel opening of the rear channel section are arranged in circumferential areas of the actuator receiving chamber that are diametrically opposed to each other in the longitudinal direction of the valve. The inner channel opening of the front channel section is located on the side of the main valve, and the inner channel opening of the rear channel section is located on the side of the second pilot valve.

[0017] The manual actuation device is preferably designed such that the direction of movement of the actuation element, by which the operating state of the first pilot valve can be changed, runs in the vertical direction of the valve unit, perpendicular to the longitudinal direction of the valve. The manual actuation element expediently has an actuating surface on the upper side of the valve unit, oriented in the vertical direction of the valve, which can be actuated by hand or by means of a hand tool, for example a screwdriver, to initiate the actuation movement.

[0018] To execute the actuating movement, the manual actuator is expediently designed to be purely linearly displaceable within the actuator's receiving space. This makes manual operation particularly simple. Alternatively, a combined rotary-linear movement would also be possible, for example.

[0019] Preferably, the manual actuating element is pre-tensioned in an unactuated home position by a return spring, the spring force of which must be overcome to move it into an actuated position. The manual actuating device can have locking means that allow the manual actuating element to be releasably locked in the actuated position.

[0020] In a particularly cost-effective implementation, the manual actuating element is plunger-shaped and has a round, and in particular a circular, peripheral outer contour. The actuating element receiving chamber has a round inner contour that is complementary to this round outer contour.

[0021] Preferably, the manual actuator has two sealing rings spaced apart from each other in the direction of its actuation movement. These sealing rings slide against an inner circumferential surface of the actuator's receiving chamber and axially seal the receiving chamber channel section of the second pilot working channel that extends through the actuator's receiving chamber. Advantageously, one of the sealing rings seals the actuator's receiving chamber to the surroundings of the valve unit, while the other sealing ring seals the actuator's receiving chamber to a valve chamber formed inside the valve housing, in which a pilot valve element of the first pilot valve is located. In an alternative embodiment, the sealing rings are fixed to the first valve housing, and the manual actuator slides against the sealing rings.

[0022] The two pilot working channels each expediently have a longitudinal section extending within the pilot valve assembly, which is referred to as a pilot valve channel section. Each pilot valve channel section expediently transitions into a main valve channel section extending within the main valve of the associated first or second pilot working channel, respectively. The two pilot valve channel sections expediently open at a front end face of the first pilot valve body facing the main valve, each with an outlet opening, wherein the outlet opening of the pilot valve channel section of the first pilot working channel is referred to as the first pilot outlet opening and the outlet opening of the pilot valve channel section of the second pilot working channel is referred to as the second pilot outlet opening.Each of these two pilot valve outlets conveniently connects to one of the aforementioned main valve channel sections. When the pilot valve assembly is mounted to the main valve, the desired channel connections are established accordingly.

[0023] Due to the routing of the second pilot working channel through the actuator receiving chamber, the two pilot outlet openings can be advantageously positioned on the front face of the first pilot valve housing, spaced apart in the valve's vertical direction, such that they lie in a common central plane of the valve unit. This central plane is defined by the valve's longitudinal axis (defining the valve's longitudinal direction) and its vertical axis (also defining the valve's vertical direction). This allows the two pilot outlet openings to be positioned centrally on the front face of the first pilot valve housing, creating favorable conditions for a simple fluid connection to the main valve.

[0024] Advantageously, the pilot valve assembly also includes a section of a pilot supply channel for the pilot fluid and a pilot vent channel used for pilot venting. These channel sections also advantageously terminate at the front end face of the first pilot valve housing, and are likewise advantageously located in the aforementioned central plane of the valve assembly.

[0025] The pilot valve assembly can be designed as a single unit in which the two pilot valves are integrated, with both pilot valves sharing a common first pilot valve housing. However, a design in which the two pilot valves are separate from each other is considered more advantageous, with the second pilot valve having a separate second pilot valve housing relative to the first pilot valve housing of the first pilot valve. The two pilot valve housings are joined in a joint area with their end faces facing each other in the longitudinal direction of the valve. Such a separate design of the two pilot valves simplifies, among other things, the implementation of the required valve channels.

[0026] In connection with the implementation of the pilot valve assembly using separate first and second pilot valve housings for each of the two pilot valve units, it is advantageous if the second pilot working channel has a first working channel section extending through the first pilot valve housing and containing the receiving chamber channel section, and a second working channel section extending within the second pilot valve housing, wherein the first and second working channel sections are in fluid communication with each other in the joining area of ​​the two pilot valve housings. The first and second working channel sections open in the joining area at the opposing end faces of the two pilot valve housings in such a way that they merge into one another – particularly with the interposition of a suitable sealing device.

[0027] In principle, only the first pilot valve can be equipped with a manual override, while the second pilot valve is exclusively electrically actuated. However, it is more advantageous if the second pilot valve is also equipped with a manual override, so that each pilot valve has its own manual override for individual manual actuation as needed, in addition to the possibility of electrical actuation triggered by an electronic control unit.

[0028] The manual actuation device of the second pilot valve preferably has a manual actuation element that is at least partially enclosed in an actuation element receiving chamber and is accessible from outside the pilot valve assembly for manually initiating an actuation movement that actuates the second pilot valve. The two manual actuation devices are arranged, in particular, such that they are accessible from the same side of the valve assembly, especially from the top of the valve assembly oriented in the vertical direction.

[0029] Preferably, the first pilot valve has a first pilot valve element movably arranged within its first pilot valve housing, while the second pilot valve has a movable second pilot valve element. Both pilot valve elements are electrically actuated to change the operating state of the associated pilot valve. Furthermore, the pilot valve element of each pilot valve equipped with a manual actuation device can alternatively also be manually actuated.

[0030] The invention will now be explained in more detail with reference to the accompanying drawing. This drawing shows: Fig. 1 a longitudinal section of a preferred embodiment of the valve unit according to the invention in section plane II Fig. 2, Fig. 3 and Fig. 4, where a main valve slide of the main valve is only indicated by a dash dot, Fig. 2 a section through the valve unit Fig. 1 according to section plane II-II from Fig. 1, Fig. 3 and Fig. 4 in the transition area between the pilot valve assembly and the main valve, Fig. 3 a longitudinal section according to section plane III-III from Fig. 1 and Fig. 2 with only a partial image of the main valve and Fig. 4. a further longitudinal section according to section plane IV-IV Fig. 1 and Fig. 2, where again the main valve is only partially visible.

[0031] The valve unit, designated in its entirety by reference numeral 1, has a longitudinal valve axis 2, a vertical valve axis 3 perpendicular to it, and a transverse valve axis 4 perpendicular to both axes 2 and 3. Directions extending in the respective axial direction are designated, using the same reference numeral, as the longitudinal valve direction 2, the vertical valve direction 3, and the transverse valve direction 2.

[0032] Notwithstanding these axis designations, the valve unit 1 can be operated with any spatial orientation, for example with a vertically or horizontally oriented valve vertical axis 3.

[0033] The valve unit 1 has a design oriented in the valve height direction 3 and in Fig. 1. The valve unit 1 has a top surface 5. In contrast, the valve unit 1 has a bottom surface 6. Furthermore, the valve unit 1 has a surface oriented in the longitudinal direction 2 of the valve and in Fig. 1 left-hand valve front 7 and an axially opposite valve back 8.

[0034] The dimensions of the valve unit 1 in the valve transverse direction 4 define a width of the valve unit 1. An imaginary median plane 12 extends through the valve unit 1 at its midpoint, spanned by the valve longitudinal axis 2 and the valve vertical axis 3.

[0035] The valve unit 1 has a main valve 13 and a pilot valve assembly 14. The latter serves for electrofluidic and, in particular, electropneumatic pilot control of the main valve 13.

[0036] The main valve 13 has a main valve housing 15 with a rear end face 16 facing the rear of the valve 8, wherein the pilot valve assembly 14 is attached to and fastened to the rear end face 16 of the main valve housing 15 with a front end face 17 facing the front of the valve 7. It is evident that the pilot valve assembly 14 is arranged adjacent to the main valve 13 in the longitudinal direction 2 of the valve.

[0037] The pilot valve assembly 14 has two pilot valves 18 and 19 arranged in series along the valve longitudinal direction 2, each electrically actuated. For clarity, these are referred to as the first pilot valve 18 and the second pilot valve 19. The first pilot valve 18 is positioned between the main valve 13 and the second pilot valve 19 with respect to the valve longitudinal direction 2 and has a valve housing 22, designated as the first pilot valve housing, on which the end face 17 of the pilot valve assembly 14 mentioned above is formed.

[0038] Preferably, the two pilot valves 18, 19 are designed separately from one another according to the illustrated embodiment and are joined together in a joining area 24 in the longitudinal direction 2 of the valve. For this purpose, the second pilot valve 19 has its own valve housing, designated as the second pilot valve housing 23, which has a front end face 23 facing the first pilot valve 18, with which it is joined in the joining area 24 to a rear end face 26 of the first pilot valve housing 22 facing the rear of the valve 8.

[0039] The two pilot valves 18, 19 are firmly connected to each other and to the main valve 13 by means of fastening means not further illustrated, such as fastening clamps and / or fastening screws, in particular in a detachable manner.

[0040] In an embodiment not illustrated, the two pilot valves 18, 19 arranged in series are integral components of the pilot valve assembly 14, which in this case is designed as a pilot valve unit. In this case, only one pilot valve housing is present, with the first pilot valve housing 22 in particular simultaneously functioning as the valve housing for the second pilot valve 19.

[0041] The main valve 13 is a multi-way valve with virtually any functionality. It is primarily a two-position or three-position valve. As an example, the main valve 13 is designed as a 5 / 2 multi-way valve.

[0042] Inside the main valve housing 15, a cavity extending in the longitudinal direction 2 of the valve and serving as a valve receptacle 27 is formed. An elongated main valve valve spool 28, indicated only by dashed lines in the drawing, extends within the valve receptacle 27. This spool can be switched between at least two switching positions by means of a linear switching movement 29 in the longitudinal direction 2 of the valve, indicated by a double arrow. Several main valve channels 32, passing through the main valve housing 15, open laterally into the valve receptacle 27 at intervals. Depending on the current switching position of the main valve spool 28, these channels are connected to and / or separated from each other in different channel configurations.

[0043] By way of example, the five main valve channels 32 define one main feed channel 32a, two main working channels 32b, 32c and two main vent channels 32d, 32e. In the two exemplary switching positions of the main valve spool 28, the main feed channel 32a is connected to either one or the other working feed channel 32b, 32c, while at the same time the other main working channel 32c, 32d is connected to one of the two main vent channels 32d, 32e.

[0044] In the operation of valve unit 1, the main feed channel 32a is connected to a pressure source that provides a fluidic pressure medium, in particular compressed air, to be distributed by the main valve 13. The two main working channels 32b, 32c are connected to a fluidically controlled consumer, for example, a fluid-actuated actuator. The two main vent channels 32d, 32e are connected to a pressure sink, in particular the atmosphere.

[0045] The main valve spool 28 has a first actuation surface 33 facing the rear of the valve 8 and a second actuation surface 34 oriented axially opposite to it. By way of example, these two actuation surfaces 33, 34 are each located at one of the two axial end regions of the main valve spool 28. While the first actuation surface 33, together with the main valve housing 15, defines a first actuation chamber 35, the second actuation surface 34, together with the main valve housing 15, defines a second actuation chamber 36. The first actuation chamber 35 is located in the rear end region of the main valve housing 15 adjacent to the pilot valve assembly 14, while the second actuation chamber 36 is formed in the axially opposite front end region of the main valve housing 15.

[0046] The valve unit 1 is traversed by a first pilot working channel 37 and a second pilot working channel 38. The first pilot working channel 37 establishes a fluid connection between the first pilot valve 18 and the first actuator chamber 35, while the second pilot working channel 38 establishes a fluid connection between the second pilot valve 19 and the second actuator chamber 36.

[0047] Each pilot control working channel 37, 38 has a main valve channel section 37a, 38a extending in the main valve housing 15, which opens at one end into one of the two drive chambers 35, 36 and at the other end opens to the rear end face 16.

[0048] The main valve channel section 37a of the first pilot working channel 37 is followed by a pilot valve channel section 37b of the first pilot working channel 37 running in the first pilot valve housing 22, which opens on the one hand into a first valve chamber 42 formed in the first pilot valve housing 22 and on the other hand has a first pilot outlet opening 44 opening towards the front end face 17, which is aligned with the opposite channel opening of the main valve channel section 37a of the first pilot working channel 37 arranged on the rear end face 16 and is thus fluid-connected.

[0049] The main valve channel section 38a of the second pilot working channel 38 is followed by a pilot valve channel section 38b of the second pilot working channel 38 running in the pilot valve assembly 14, which opens at one end into a valve chamber of the second pilot valve 19 designated as the second valve chamber 43 and at the other end opens on the front end face 17 with a second pilot outlet opening 45, which is positioned so that it is aligned with the channel opening of the main valve channel section 38a of the second pilot working channel 38 arranged opposite on the rear end face 16 and is thus fluidly connected.

[0050] In this way, a constant fluid connection exists both between the first valve chamber 42 and the first drive chamber 35 and between the second valve chamber 43 and the second drive chamber 36.

[0051] Accordingly, the first pilot valve 18 is able to supply the main valve spool 28 with pilot fluid in a first direction via the first pilot working channel 37, while the second pilot valve 19 is able to supply the main valve spool 28 with pilot fluid in a second direction via the second pilot working channel 38. The controlled fluid supply manifests itself either as a supply of pilot fluid, also referred to as venting, or as a discharge of pilot fluid, also referred to as venting.Depending on the set operating state of the pilot valves 18, 19, the main valve spool 28 experiences an actuating force in the first direction or in the opposite second direction, so that it is moved either into a first switching position or into a second switching position, each of which specifies one of two channel configurations of the main valve channels 32.

[0052] The pilot fluid is primarily compressed air. Alternatively, the pilot fluid, as well as the fluid controlled by the main valve 13, can be a hydraulic fluid.

[0053] In the first valve chamber 42 belonging to the first pilot valve 18, there is a first pilot valve element 46. A second pilot valve element 47 is located in the second valve chamber 43 belonging to the second pilot valve 19. Each pilot valve element 46, 47 is designed as a single piece or in multiple pieces and can perform a linear working movement 48, indicated by a double arrow, in opposite directions, the directions of movement being exemplified by the valve's vertical direction 3.

[0054] Each pilot valve 18, 19 expediently includes an electromagnetic actuator 52 by which the working movement 48 of the associated first or second pilot valve element 46, 47 can be induced in order to set one of two possible operating states of the respective pilot valve 18, 19. These two operating states are, on the one hand, a venting operating state and, on the other hand, a purging operating state.

[0055] Each electromagnetic actuator 52 can be connected, or is connected, via electrical conductors 49, implemented for example by means of cables or circuit boards, to an electronic control unit (not shown) capable of providing electrical control signals for the electrical actuation of the actuator 52. In this way, automated operation of the valve unit 1 is possible.

[0056] Each electromagnetic actuator 52 expediently has a current-energized coil assembly 53 and a movable magnetic armature 54. By alternately activating and deactivating the coil assembly 53, the magnetic armature 54 can be moved to cause the working movement 48 of the associated pilot valve element 46, 47. In this context, the magnetic armature 54 cooperates in an actuating manner with the associated first or second pilot valve element 46, 47 or is an integral part of this first or second pilot valve element 46, 47.

[0057] Each pilot valve element 46, 47 can alternately seal with either a vent valve seat 55 or a vent valve seat 56, depending on its position. The vent valve seat 55 surrounds an inlet opening through which a pilot feed channel 57 opens into the associated valve chamber 42, 43. The vent valve seat 56 surrounds an outlet opening through which a pilot vent channel 58 opens into the respective associated valve chamber 42, 43. Preferably, both vent valve seats are associated with a common pilot feed channel 57, just as a common pilot vent channel 58 is advantageously associated with both vent valve seats 56.

[0058] The pilot supply channel 57 extends partly within the two pilot valve housings 22, 23 and partly within the main valve housing 15. By way of example, it opens into the main supply channel 32a in the main valve housing 15 via a tap opening 61, so that the pilot fluid for the pilot valve assembly 14 is drawn from the main supply channel 32a. It is understood, however, that alternatively, the pilot fluid can be fed into the pilot supply channel 57 independently of the main supply channel 32a.

[0059] The pilot vent channel 58 extends partly into the two pilot valve housings 22, 23 and also partly into the main valve housing 15, where, for example, it opens into one of the main vent channels 32e via a vent opening 62. Alternatively, the pilot vent channel 58 can also be connected to the atmosphere independently of the main vent channels 32d, 32e of the main valve 13.

[0060] In the venting state of a pilot valve 18, 19, its pilot valve element 46, 47 seals against the vent valve seat 56 and simultaneously releases the vent valve seat 55, allowing pilot fluid from the pilot feed channel 57 to flow through the associated valve chamber 42, 43 into the connected first or second pilot working channel 37, 38. In the venting state, the pilot valve element 46, 47 seals against the associated vent valve seat 55 and is simultaneously lifted from the vent valve seat 56, allowing the associated pilot working channel 37, 38 to be vented through the valve chamber 42, 43 and the associated pilot vent channel 58.

[0061] Advantageously, each pilot valve element 46, 47 is biased into a home position by an associated spring device 63, which exemplifies the venting operating state. By electrically activating the associated electromagnetic actuators 52, the pilot valve element 46, 47 can be moved out of the home position to change the operating state.

[0062] The pilot valve channel section 37b of the first pilot working channel 37 extends in the pilot valve assembly 14 exclusively within the first pilot valve housing 22. There, it has, by way of example, a straight course in the valve longitudinal direction 2 between the first valve chamber 42 and the front end face 17.

[0063] The pilot valve channel section 38b of the second pilot working channel 38 is divided into two longitudinal sections that merge into each other in the joining area 24, namely into a first working channel section 64 which passes through the first pilot valve housing 22 between the front end face 17 and the rear end face 26 and a second working channel section 65 which opens into the second valve chamber 43 at one end and opens at the other end via a front channel opening 66 to the front end face 25 of the second pilot valve housing 22 in such a way that it is aligned with and fluidically connected to the end of the first working channel section 64 which opens at the rear end face 26 of the first pilot valve housing 22.Thus, the ventilation and venting of the second drive chamber 36 takes place through the first pilot valve housing 22, specifically through the first working channel section 64 of the second pilot working channel 38 which passes through the first pilot valve housing 22.

[0064] A seal 67 placed in the joining area 24 seals the fluid connection between the two working channel sections 64, 65 to the environment.

[0065] The aforementioned seal 67 also serves expediently for sealing the pilot feed channel 57 and the pilot vent channel 58. These two channels 57, 58 each extend in both pilot valve housings 22, 23, merging into one another in the joining area 24, their transition areas into the joining area 24 being sealed to the environment by means of the seal 67.

[0066] The longitudinal sections of the pilot feed channel 57 and the pilot vent channel 58, extending within the pilot valve assembly 14, open at the front end face 17 of the pilot valve assembly 14, specifically with a feed channel outlet opening 68 and a vent channel outlet opening 69. Opposite these outlet openings 68, 69, on the rear end face 16 of the main valve housing 15, are channel openings formed by longitudinal sections of the pilot feed channel 57 and the pilot vent channel 58 extending within the main valve housing 15, thus ensuring a continuous fluid connection within the pilot feed channel 57 and the pilot vent channel 58.

[0067] The first pilot valve 18 is equipped with a manual override 72, which, as an alternative to using the electromagnetic actuator 52, allows manual switching of the operating state of the first pilot valve 18. Thus, manual operation is possible, if required, without the involvement of the preferably connected electronic control unit.

[0068] Preferably, the second pilot valve 19 is also equipped with a corresponding manual actuation device 73. For clarity, the first pilot valve 18 will be referred to as a first manual actuation device 72, and the second pilot valve 19 as a second manual actuation device 73. Since the two manual actuation devices 72 and 73 are preferably identical, a uniform description will be given below, using the same reference numerals for corresponding components.

[0069] Since the manual actuation devices 72, 73 enable an alternative, substitute manual actuation with respect to the electrical actuation, they can also be referred to as manual auxiliary actuation devices 72, 73.

[0070] Each manual actuating device 72 has an actuating element receiving chamber 74 formed in the associated pilot valve housing 22, 23, which is realized, for example, by means of a housing recess extending from an upper housing outer surface 75 located on the valve top 5 into the pilot valve housing 22, 23 in the valve height direction 3. The actuating element receiving chamber 74 transitions, for example, directly into the adjoining first or second valve chamber 42, 43.

[0071] How to particularly the Fig. As can be seen from 3, the actuating element receiving chamber 74 preferably has a round and in particular a circular inner contour with an inner circumferential surface 79, which is formed on a housing section of the associated first or second pilot valve housing 22, 23 that peripherally limits the actuating element receiving chamber 74.

[0072] In each actuating element receiving chamber 74, which is open towards the upper outer surface 75 of the housing, a manual actuating element 76 is located. The manual actuating element has an outer contour adapted to the peripheral inner contour of the actuating element receiving chamber 74 such that it is linearly displaceable relative to the associated pilot valve housing 22, 23 in the valve vertical direction 3. The movement that can be performed by the manual actuating element 76 is indicated by a double arrow and is referred to as the actuating movement 77.

[0073] In each pilot valve 18, 19, the manual actuating element 76 and the pilot valve element 46, 47 are arranged in particular such that the actuating movement 77 and the working movement 48 have the same orientation or are aligned parallel to each other.

[0074] Each manual actuating element 76 is pre-tensioned to an unactuated basic position by a return spring 78 arranged in the actuating element receiving chamber 74 and / or in the associated first or second valve chamber 42, 43.

[0075] In this unactuated basic position, there is an axial distance between the manual actuating element 76 and the associated pilot valve element 46, 47, so that the latter can be electrically actuated without hindrance.

[0076] Each manual actuating element 76 has an actuating surface 81 pointing away from the associated pilot valve housing 22, 23 and accessible from outside the pilot valve assembly 14. The actuating surface 81 is facing away from the pilot valve element 46, 47 adjacent in the valve height direction 3 in the valve height direction 3.

[0077] By manually applying pressure to the actuating surface 81, the manual actuating element 76 can be caused to perform an actuating movement 77 in the direction of the axially aligned first or second pilot valve element 46, 47, overcoming the restoring force of the return spring 78. This actuating movement 77 causes the manual actuating element 76 to mechanically act on the associated pilot valve element 46, 47, switching it independently of the electromagnetic actuator 52.

[0078] For example, the pilot valve element 46, 47 can be moved from a basic position specified by the spring device 63 by the actuation of the manual actuating element 76 in order to bring about a change in the operating state of the respective pilot valve 18, 29.

[0079] A locking element 82 anchored in the pilot valve 22, 23 prevents the manual actuating element 76 from falling out of the actuating element receiving space 74.

[0080] For example, the manual actuating element 76 is arranged completely inside the actuating element receiving space 74, regardless of its position. In an embodiment not illustrated, it protrudes at least partially from the associated pilot valve housing 22, 23, at least in the unactuated basic position.

[0081] As an example, the manual actuating element 76 is purely linearly displaceable in the actuating element receiving space 74 for executing the actuating movement 77. Alternatively, the manual actuating device 72, 73 can also be designed, for example, such that the linear actuating movement 77 results from a screw movement of the manual actuating element 76, which can be brought about by rotating the manual actuating element 76, so that an overall superimposed rotary-linear movement is present.

[0082] In an embodiment of the valve unit 1 which is also not shown, at least one manual actuating element 76 is designed to perform a purely rotary actuating movement 77, wherein it expediently has an actuating cam that interacts with the associated pilot valve element 46, 47.

[0083] It is advantageous if the manual actuating element 67 is designed in a plunger shape according to the illustrated embodiment and has a round peripheral outer contour.

[0084] The manual actuating element 76 can be made from a solid material, but as an example it has a cavity open towards the adjacent valve chamber 42, 43, so that it is cup-shaped.

[0085] A special feature of the first manual actuating device 72 is that its actuating element receiving chamber 74 contributes to the formation of the second pilot working channel 38. The second pilot working channel 38, with its first working channel section 64, penetrates the actuating element receiving chamber 74 formed in the first pilot valve housing 22 in the area of ​​the manual actuating element 76, so that the actuating element receiving chamber forms a longitudinal section of the second pilot working channel 38 designated as receiving chamber channel section 83.

[0086] The receiving chamber channel section 83 is preferably annular in shape, so that, as in the illustrated embodiment, it extends completely around the hand actuator 76. By way of example, the hand actuator 78 has a longitudinal axis 84 extending in the valve's vertical direction 3, the direction of which coincides with the direction of the actuating movement 77. The receiving chamber channel section 83 extends circumferentially around the hand actuator 76 along the longitudinal axis 84. Radially on the inside, the thus annular receiving chamber channel section 83 is advantageously directly bounded by the hand actuator 76, while radially on the outside it is bounded by the radially inwardly projecting inner circumferential surface 79 of the actuator receiving chamber 74.

[0087] Preferably, a radial annular gap extends coaxially around the hand actuating element 76 in the actuating element receiving space 74, forming the receiving space channel section 83.

[0088] In an embodiment not shown, the receiving chamber channel section 83 does not extend completely, but only a short distance peripherally around the hand actuating element 76, for example along a circumferential angle of 180 degrees.

[0089] In another embodiment not shown, the manual actuating element 76 is penetrated within the actuating element receiving space 74 by a receiving space channel section 83, in particular diametrically.

[0090] By way of example, the receiving chamber channel section 83 is located between a front channel section 85 and a rear channel section 86 of the first working channel section 64, which passes through the first pilot valve housing 22. The front channel section 85 extends between the second pilot valve outlet 45 and a first inner channel opening 85a, through which it opens into the actuator receiving chamber 74 at the inner circumferential surface 79. The rear channel section 86 extends between the rear end face 26 of the first pilot valve housing 22 and a second inner channel opening 86a, the latter also opening into the actuator receiving chamber 74 at the inner circumferential surface 79.

[0091] The two inner channel openings 85a, 86a are located on circumferential regions of the actuator receiving space 74, spaced apart from each other in the circumferential direction. The illustrated arrangement is preferred, in which the two inner channel openings 85a, 86a are assigned to circumferential regions of the actuator receiving space 74 that are diametrically opposite each other in the longitudinal direction 2 of the valve. Preferably, the two inner channel openings 85a, 86a lie in the central plane 82 described above, and it is advantageous if the entire front and rear channel sections 85, 86 of the second pilot working channel 38 extend in this central plane 12.

[0092] Since the second pilot valve working channel 38 passes through the actuator receiving chamber 74 inside the first pilot valve housing 22, a lateral passage in the area of ​​the two longitudinal sides of the first pilot valve housing 22 oriented in the valve transverse direction is unnecessary. Thus, the first pilot valve housing 22 can be designed to be extremely narrow in the valve transverse direction 4 and, accordingly, with a very small width. The section of the first pilot valve housing 22 located between the actuator receiving chamber 74 and the two side surfaces 87 of the first pilot valve housing 22 oriented in the valve transverse direction 4 is preferably designed without channels.

[0093] To prevent interaction between the pilot fluid flowing in the second pilot working channel 38 and the pilot fluid located in the first valve chamber 42, the receiving chamber channel section 38 is expediently permanently fluid-tightly separated from the adjacent first valve chamber 42. This is expediently achieved by equipping the manual actuating element 76 with a sealing ring 88 in a region located between the receiving chamber channel section 83 and the first valve chamber 42. For clarity, this sealing ring 88 may be referred to as the inner sealing ring 88. This inner sealing ring 88 is preferably held in an annular groove on the outer circumference of the manual actuating element 76 and is slidably abutted against the inner circumferential surface 79 of the actuating element receiving chamber 74.

[0094] It is advantageous if the receiving chamber channel section 83 is also sealed to the environment. This reliably prevents fluid leakage even in the area of ​​the upper outer housing surface 75. For sealing purposes, a sealing ring 91 is also expediently provided, which, for better differentiation, may be referred to as the outer sealing ring 91 and which is fixed at an axial distance from the inner sealing ring 88 on the radial outer circumference of the manual actuating element 76, expediently also in an annular groove formed there.

[0095] Advantageously, a guide section 92 of the manual actuating element 76 is attached to each of the two sealing rings 88, 91 on the axial side facing away from the other sealing ring 91, 88. This guide section rests against the inner circumferential surface 79 with minimal play, thus providing linear guidance of the manual actuating element 76 for the execution of the actuating movement 77 and preventing tilting. The guide section 92 is preferably cylindrically contoured.

[0096] In the longitudinal section located axially between the two sealing rings 88, 91, the manual actuating element 76 is expediently provided with a reduced outer diameter to form an annular gap through which the pilot fluid can flow, the annular gap forming the receiving chamber channel section 83.

[0097] Due to the ring shape of the receiving chamber channel section 83, the manual actuating element 76 can be surrounded by the pilot fluid with a parallel flow on diametrically opposite circumferential sides, as is the case in Fig. 3 is indicated by dotted flow arrows 93. The fluid flow can split into two flow branches within the actuating element receiving chamber 74, so that a relatively small cross-section of the receiving chamber channel section 83 is sufficient to ensure the required flow rate.

[0098] The Fig. Figure 2 illustrates the advantageous possibility, realized in the illustrated embodiment, of arranging the two pilot control outlet openings 44, 45 at intervals from each other in the valve's vertical direction 3 within the central plane 12 defined above. The feed channel outlet opening 68 and the vent channel outlet opening 69 are also expediently placed in this central plane 12, resulting in a row of four outlet openings 44, 45, 68, 69 spaced successively in the valve's vertical direction 3.

[0099] The row arrangement of the outlet openings 44, 45, 68, 69, concentrated on the middle plane 12, also favors a narrow design of the valve unit 1 in the valve transverse direction 4.

[0100] Between the rear end face 16 of the main valve housing 15 and the front end face 17 of the pilot valve assembly 14, a space made of Fig.2 clearly visible seals 94 are incorporated, which individually surround the individual outlet openings 44, 45, 68, 69 and thus enable the desired channel connections without risk of leakage.

Claims

[1] Valve unit (1), comprising an electrofluidically piloted main valve (13) which has a main valve spool (28) that can be moved back and forth by mutually opposing fluid application while performing a switching movement (29), and with a pilot valve assembly (14) which is arranged adjacent to the main valve (13) in a valve longitudinal direction (2) perpendicular to a valve vertical direction (3) and by which the fluid supply to the main valve spool (28) can be controlled by means of a pilot fluid via a first pilot working channel (37) and a second pilot working channel (38) of the valve unit (1), wherein the pilot valve assembly (14) has two first and second pilot valves (18, 19) which can be electrically actuated by means of an electromagnetic actuator (52), wherein the first pilot valve (18) has a first pilot valve housing (22) in which a first valve chamber (42) is formed in which a first pilot valve element (46) is located, wherein a fluid flow of the pilot fluid in the first pilot working channel (37) can be controlled by means of the first pilot valve (18) and a fluid flow of the pilot fluid in the second pilot working channel (38) can be controlled by means of the second pilot valve (19), and wherein the first pilot valve (18) is equipped with a manual actuating device (72) which has a manual actuating element (76) which is at least partially received in an actuating element receiving space (74) and which is accessible from outside the pilot valve device (14) for manually initiating an actuating movement (77), wherein the second pilot working channel (38) penetrates the actuating element receiving space (74) in the area of ​​the manual actuating element (76) with a receiving space channel section (83). characterized by , that the two pilot valves (18, 19) are arranged in series in the valve longitudinal direction (2), wherein the first pilot valve (18) is arranged between the main valve (13) and the second pilot valve (19), wherein the second pilot working channel (38) passes through the first pilot valve (18) on its way between the second pilot valve (19) and the main valve (13), the first pilot valve housing (22) of which has the actuating element receiving chamber (74), wherein the manual actuating element (76) during its actuating movement (77) actuates the first pilot valve (18) by mechanically acting on the associated first pilot valve element (46) and switching the same independently of the electromagnetic drive device (52). [2] Valve unit (1) according to claim 1, characterized by , that the two pilot valves (18, 19) are electrically actuated solenoid valves. [3] Valve unit (1) according to claim 1 or 2, characterized by, that the main valve (13) has a main valve housing (15) accommodating the main valve spool (28), in which two first and second drive chambers (35, 36) are formed, bounded by first and second drive surfaces (33, 34) of the main valve spool (28) oriented oppositely to each other in the longitudinal direction (2) of the valve, wherein the first pilot working channel (37) is fluidically connected to the first drive chamber (35) and the second pilot working channel (38) is fluidically connected to the second drive chamber (36). [4] Valve unit (1) according to any one of claims 1 to 3, characterized by , that the first pilot valve (18) has a first pilot valve element (46) movably arranged in a first valve chamber (42) of the first pilot valve housing (22), wherein the receiving chamber channel section (83) is fluid-tightly separated from the first valve chamber (42). [5] Valve unit (1) according to any one of claims 1 to 4, characterized by, that the receiving chamber channel section (83) of the second pilot working channel (38) extends peripherally around the manual actuator (76) in the actuator receiving chamber (74). [6] Valve unit (1) according to claim 5, characterized by , that the receiving chamber channel section (83) of the second pilot working channel (38) is ring-shaped and extends peripherally completely around the manual actuating element (76) in the actuating element receiving chamber (74). [7] Valve unit (1) according to claim 6, characterized by , that the annular receiving chamber channel section (83) is bounded radially inside by the manual actuating element (76) and radially outside by a housing section of the first pilot valve housing (22) peripherally bounding the actuating element receiving chamber (74). [8] Valve unit (1) according to any one of claims 1 to 7, characterized by, that the second pilot working channel (38) in the first pilot valve housing (22) has a front channel section (85) leading to the main valve (13) and a rear channel section (86) leading to the second pilot valve (19), wherein these two channel sections (85, 86) open into the actuator receiving space (74) at circumferential areas of the actuator receiving space (74) spaced apart from each other in the circumferential direction of the manual actuator (76) with each an inner channel opening (85a, 86a). [9] Valve unit (1) according to claim 8, characterized by , that the inner channel opening (85a) of the front channel section (85) and the inner channel opening (86a) of the rear channel section (86) are arranged in circumferential areas of the actuating element receiving space (74) that are diametrically opposite each other in the valve longitudinal direction (2). [10] Valve unit (1) according to any one of claims 1 to 9, characterized by, that the manual actuating device (72) is designed such that the direction of movement of the actuating movement (77) of the manual actuating element (76) runs in the valve vertical direction (3) of the valve unit (1) perpendicular to the valve longitudinal direction (2). [11] Valve unit (1) according to claim 10, characterized by , that the manual actuating element (76) is arranged to be linearly displaceable in the actuating element receiving space (74) of the first pilot valve housing (22) for the execution of its actuating movement (77). [12] Valve unit (1) according to any one of claims 1 to 11, characterized by , that the hand actuating element (76) is plunger-shaped with a round peripheral outer contour, wherein the actuating element receiving space (74) has a complementary round inner contour at least in the area of ​​the hand actuating element (76). [13] Valve unit (1) according to any one of claims 1 to 12, characterized by, that the manual actuating element (76) has two sealing rings (88, 91) spaced apart from each other in the direction of its actuating movement, which are slidably in contact with an inner circumferential surface (79) of the actuating element receiving space (74) and which axially seal the receiving space channel section (83) of the second pilot working channel (38) extending through the actuating element receiving space (74) on both sides. [14] Valve unit (1) according to any one of claims 1 to 13, characterized by, that on a front end face (17) of the first pilot valve housing (22) facing the main valve (13) a pilot valve channel section (37b) of the first pilot working channel (37) extending in the pilot valve assembly (14) opens with a first pilot outlet opening (44) and a pilot valve channel section (38b) of the second pilot working channel (38) also extending in the pilot valve assembly (14) opens with a second pilot outlet opening (45). [15] Valve unit (1) according to claim 14, characterized by , that the two pilot-operated outlet openings (44, 45) are spaced apart from each other in the valve vertical direction (3) in a common central plane (12) of the valve unit (1), which is spanned by a valve longitudinal axis defining the valve longitudinal direction (2) and a valve vertical axis defining the valve vertical direction (3) of the valve unit (1). [16] Valve unit (1) according to any one of claims 1 to 15, characterized by , that the two pilot valves (18, 19) are designed separately from each other and the second pilot valve (19) has a second pilot valve housing (23) separate from the first pilot valve housing (22), wherein the two pilot valve housings (22, 23) are joined together in a joining area (24) with end faces (25, 26) facing each other in the longitudinal direction (2) of the valve. [17] Valve unit (1) according to claim 16, characterized by, that the second pilot working channel (38) has a first working channel section (64) extending through the first pilot valve housing (22) of the first pilot valve (18) and containing the receiving chamber channel section (83), and a second working channel section (65) extending in the second pilot valve housing (23) of the second pilot valve (19), wherein the first working channel section (64) and second working channel section (65) are in fluid communication with each other in the joining area (24) of the two pilot valve housings (22, 23). [18] Valve unit (1) according to any one of claims 1 to 17, characterized by, that the second pilot valve (19) is also equipped with a manual actuating device (73) which has a manual actuating element (76) that is at least partially received in an actuating element receiving space (74) and is accessible from outside the pilot valve device (14) for manually triggering an actuating movement (77) that actuates the second pilot valve (19). [19] Valve unit (1) according to any one of claims 1 to 18, characterized by , that the second pilot valve (19) has a second pilot valve element (47), wherein each pilot valve element (46, 47) is electrically actuated to change the operating state of the associated pilot valve (18, 19) and wherein the pilot valve element (46, 47) of each pilot valve (18, 19) equipped with a manual actuating device (72, 73) is alternatively also manually actuated.

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