VALVE DEVICE FOR A PNEUMATICALLY ACTUATED FRICTION CLUTCH

Description

[0001] The invention relates to a valve device for a pneumatically actuated friction clutch, comprising an inlet valve designed as a 2 / 2-way solenoid seat valve, which can be connected on the inlet side to a pressurized supply line and on the outlet side to a working inlet of an actuating cylinder of the friction clutch, and an outlet valve designed as a 2 / 2-way solenoid seat valve, which can be connected on the inlet side to the working inlet of the actuating cylinder and on the outlet side to a venting outlet.

[0002] In a pneumatically actuated friction clutch, opening the inlet valve pressurizes the associated actuating cylinder, thereby disengaging or engaging the friction clutch depending on the design. Opening the outlet valve vents the actuating cylinder, thereby engaging or disengaging the friction clutch depending on the design. The pressure-maintaining valve, which is a check valve closing towards the inlet valve, has the function of maintaining the working pressure in the actuating cylinder when the inlet valve is open and the actuating cylinder is ventilated, provided the supply pressure in the supply line drops, for example due to a line break or a defect in the compressed air supply system. This prevents unintentional actuation of the friction clutch caused by uncontrolled venting of the actuating cylinder.The drain valve, which is a check valve that closes towards a vent outlet when the air pressure on the inlet side is high and opens when the air pressure on the inlet side is low, has the function of draining compressed air flowing in via the inlet valve due to leakage when the inlet valve is closed and the actuating cylinder is vented, thus preventing unintentional actuation of the friction clutch caused by uncontrolled ventilation of the actuating cylinder.

[0003] Such a valve device for a pneumatically actuated friction clutch is known, for example, from DE 102 10 877 A1. The drain valve is designed as a ball check valve or a piston check valve and is located either in the piston of the actuating cylinder, in the housing of the actuating cylinder, or in the housing of the outlet valve. Due to their design, the drain valve versions used there have a large axial height relative to the opening cross-section, which makes their integration into the housing of another valve, for example, an inlet valve or an outlet valve, difficult. Furthermore, the valve device described there does not have a pressure-maintaining valve.

[0004] DE102007002899A1 discloses a valve arrangement for a motor vehicle comprising an inlet chamber connected to an inlet and an outlet chamber separated from the inlet chamber by a partition wall and connected to an outlet, and a check valve integrated into the partition wall which releases a passage from the inlet chamber to the outlet chamber when a minimum overpressure is reached, and a pressure control valve integrated into the partition wall which blocks a passage from the outlet chamber to the inlet chamber when a minimum underpressure is reached.

[0005] US4729401A discloses a valve assembly. The valve assembly comprises a main body having two passages therein which meet at a large central cavity within the body; a body cap for closing an open side of the central cavity in the main body, the cap having an outlet passage; a central support structure within the central cavity of the main body; two coaxial valve discs mounted within the central body cavity and held in operative relationship by the central support structure; and wherein the main body, the body cap, and the central support structure each have valve disc support means.

[0006] WO2012131503A1 relates to irrigation valves and in particular to irrigation valves that can be controlled by an external signal.

[0007] Until now, the valves in such valve systems have been designed separately and connected mechanically and fluidically via screw connections or plug-in connectors. This inevitably results in larger valve systems and relatively complex assembly work.

[0008] The present invention was therefore based on the object of presenting a valve device for a pneumatically actuated friction clutch of the type mentioned at the outset, which has comparatively compact dimensions and requires little assembly effort.

[0009] This object was achieved with a valve device having the features of claim 1. Advantageous embodiments and further developments of these valve devices are defined in the dependent claims.

[0010] The invention therefore relates to a valve device for a pneumatically actuated friction clutch, comprising an inlet valve designed as a 2 / 2-way solenoid seat valve, which can be connected on the inlet side to a pressurized supply line and on the outlet side to a working inlet of an actuating cylinder of the friction clutch, an outlet valve designed as a 2 / 2-way solenoid seat valve, which can be connected on the inlet side to the working inlet of the actuating cylinder and on the outlet side to a vent outlet, a pressure holding valve designed as a check valve, which can be connected on the inlet side to the outlet of the inlet valve and on the outlet side to the working inlet of the actuating cylinder, and a drain valve designed as a check valve, which can be connected on the inlet side to the working inlet of the actuating cylinder and on the outlet side to a vent outlet.

[0011] To further achieve the stated objective, this valve device further provides that the pressure-maintaining valve is arranged within the valve housing of the inlet valve coaxially to its valve seat between a central channel adjacent to the valve seat and an outlet chamber connected to the outlet of the inlet valve, and that the discharge valve is arranged within the valve housing of the inlet valve, or that the discharge valve is arranged within the valve housing of the outlet valve. In one embodiment, the pressure-maintaining valve and the discharge valve of the valve device are designed as diaphragm disc valves.

[0012] Due to this design of the pressure holding valve and the discharge valve, these valves have a comparatively low axial height in relation to their opening cross-section and can therefore be easily integrated into the housing of the inlet valve and / or the outlet valve.By integrating the pressure-maintaining valve and the discharge valve into the inlet valve (first embodiment) or the pressure-maintaining valve into the inlet valve and the discharge valve into the outlet valve (second embodiment), installation space is saved and assembly effort is significantly reduced, since the number of valve units to be assembled is reduced from four to two in both embodiments. With regard to the first embodiment, it is preferably provided that the discharge valve is arranged within the valve housing of the inlet valve coaxially to its valve seat and axially adjacent to the pressure-maintaining valve in an opening in a housing wall of the valve housing adjacent to the outlet chamber. This results in a particularly space-saving design.

[0013] In the second embodiment, however, it is preferably provided that the drain valve is arranged within the valve housing of the outlet valve, coaxial with its valve seat, in an opening in a housing wall of the valve housing adjacent to an inlet chamber connected to the inlet of the outlet valve. This also creates a very compact valve structure.

[0014] According to another development of the valve device, it can be provided that in the pressure-maintaining valve and / or in the discharge valve, a flexurally elastic membrane disc is arranged at least partially within an annular-cylindrical housing axially between a conical support body connected to the housing via at least one diagonal strut and an annular collar of the housing or an axially adjacent component.

[0015] The diaphragm disc of the pressure holding valve and / or the discharge valve can each be mounted exclusively in a floating manner within the respective housing, i.e. can be arranged without any special fastening.

[0016] In order to prevent a displacement of the respective diaphragm disc from a centered target position, it can be provided that the diaphragm disc of the pressure holding valve and / or the drain valve has a continuous central bore by means of which the diaphragm disc is fastened to the support body of the respective housing.

[0017] For this purpose, the respective diaphragm disc of the pressure holding valve and / or the discharge valve can be fastened by slipping the central bore of the diaphragm disc over a mushroom head of the respective housing which is fastened to the tip of the respective support body or is integrally formed on the support body.

[0018] In the said first embodiment of the valve device according to the invention, the housing of the pressure-maintaining valve is preferably inserted precisely into the housing of the discharge valve and is fastened via this to a housing insert of the inlet valve having the valve seat.

[0019] In the said second embodiment of the valve device according to the invention, however, the housing of the pressure-maintaining valve is preferably directly locked to the housing insert of the inlet valve having the valve seat.

[0020] The housing of the discharge valve, however, is locked to a housing insert of the inlet valve or the outlet valve having the valve seat, depending on the design variant of the valve device according to the invention.

[0021] The invention will be further explained below with reference to exemplary embodiments shown in the accompanying drawings. Fig. 1a a first embodiment of an inlet valve of a valve device according to the invention with two integrated valves located in a first switching position in a sectional view, Fig. 1b the inlet valve according to Fig. 1a with the two integrated valves in a second switching position, Fig. 2a a second embodiment of an inlet valve of a valve device according to the invention with an integrated valve located in a first switching position in a sectional view, Fig. 2b the inlet valve according to Fig. 2a with the integrated valve in a second switching position, Fig. 3a an embodiment of an outlet valve of a valve device according to the invention with an integrated valve located in a first switching position in a sectional view, Fig. 3b the exhaust valve according to Fig. 3a with the integrated valve in a second switching position, and Fig. 4 the valve device with the valves according to the Figuren 1a bis 3b in general form in a schematic overview.

[0022] One in Fig. 4 The valve device 2, 2' of a pneumatically actuated friction clutch, depicted in schematic form, comprises an inlet valve 4, 4', an outlet valve 6, 6', a pressure-maintaining valve 8, 8', and a drain valve 10, 10'. The inlet valve 4, 4' is designed as a 2 / 2-way solenoid seat valve and has an inlet 12 and an outlet 14. A pressurized supply line 18, which is connected to a compressed air source 16, is connected to the inlet 12 of the inlet valve 4, 4'. A working inlet 24 of an actuating cylinder 20 of the friction clutch is connected to the outlet 14 of the inlet valve 4, 4'. The actuating cylinder 20 is designed as a piston-cylinder arrangement. In the de-energized state shown, the inlet valve 4, 4' is closed, thus blocking the inlet 12 from the outlet 14. This vents the pressure chamber 22 of the actuating cylinder 20 and engages or disengages the friction clutch, depending on its design.When energized, the inlet valve 4, 4' is open, i.e. the outlet 14 is connected to the inlet 12, whereby the pressure chamber 22 of the actuating cylinder 20 is ventilated and the friction clutch is disengaged or engaged depending on the design.

[0023] The outlet valve 6, 6' is also designed as a 2 / 2-way solenoid seat valve and has an inlet 26 and an outlet 28. The working inlet 24 of the actuating cylinder 20 is connected to the inlet 26 of the outlet valve 6, 6'. A vent outlet 30 leading to the atmosphere is connected to the outlet 28 of the outlet valve 6, 6'. In the de-energized state shown, the outlet valve 6, 6' is closed, i.e., the inlet 26 is blocked off from the outlet 28. As a result, the pressure chamber 22 of the actuating cylinder 20, if vented, is not vented via the outlet valve 6, 6', and the friction clutch remains disengaged or engaged, depending on the design. In the energized state, the outlet valve 6, 6' is open, i.e. its inlet 26 is connected to its outlet 28, whereby the pressure chamber 22 of the actuating cylinder 20, if it is ventilated, is vented via the outlet valve 6, 6' and the friction clutch is engaged or disengaged depending on the design.

[0024] The pressure-maintaining valve 8, 8' is arranged between the outlet 14 of the inlet valve 4, 4' and the working inlet 24 of the actuating cylinder 20 and is designed as a check valve closing in the direction of the inlet valve 4, 4'. When the inlet valve 4, 4' is open and the actuating cylinder 20 is vented, the pressure-maintaining valve 8, 8' functions to maintain the working pressure in the pressure chamber 22 of the actuating cylinder 20, provided the supply pressure in the supply line 18 drops, for example, due to a line break or a defect in the compressed air source 16 (compressed air supply device). This prevents unintentional actuation of the friction clutch caused by uncontrolled venting of the actuating cylinder 20.

[0025] The drain valve 10, 10' is located between the working inlet 24 of the actuating cylinder 20 and the inlet 26 of the outlet valve 6, 6'. It is designed as a check valve that closes toward a vent outlet 32 ​​leading to the atmosphere when the inlet air pressure is high and opens when the inlet air pressure is low. When the inlet valve 4, 4' is closed and the actuating cylinder 20 is vented, the drain valve 10, 10' functions to vent compressed air flowing in through the inlet valve 4, 4' due to leakage, thus preventing unintentional actuation of the friction clutch caused by uncontrolled venting of the actuating cylinder 20.

[0026] The following is based on the Figuren 1a and 1ba first embodiment of the inlet valve 4 of a first embodiment variant of the valve device 2 according to the invention is described, in which the pressure holding valve 8 and the discharge valve 10 are arranged within the valve housing 34 of the inlet valve 4 and are thus integrated into the inlet valve 4.

[0027] The inlet valve 4 is designed as a 2 / 2-way solenoid seat valve. The valve housing 34 of the inlet valve 4 has a cylindrical interior 40, which is connected to the inlet 12 of the inlet valve 4 and, via an annular cylindrical outlet chamber 42, to the outlet 14 of the inlet valve 4. A stepped cylindrical housing insert 44 provided with diagonal openings 46 is inserted into the interior 40. The housing insert has a valve seat 48 and a cylindrical central channel 50 radially adjacent to the valve seat and leading toward the outlet chamber 42. The inlet 12 and the interior 40 of the valve housing 34 are sealed by two sealing rings 56, 58 arranged between the inner wall of the interior 40 and the housing insert 44.The valve seat 48 can be closed by means of a cylindrical disk-shaped sealing element 60, which is held on the valve seat 48 by a valve spring in a manner not shown and can be lifted off the valve seat 48 by energizing an electromagnet.

[0028] The pressure-retaining valve 8 is designed as a diaphragm disc valve. The pressure-retaining valve 8 is arranged coaxially with the valve seat 48 between the central channel 50 of the housing insert 44 and the outlet chamber 42. In a preferred embodiment, the pressure-retaining valve 8 has a flexible diaphragm disc 72, which is guided axially at least partially around the central channel 50 of the housing insert 44 within an annular-cylindrical housing 62 between a conical support body 66 connected to the housing 62 via at least one diagonal strut 64 and an annular collar 52.

[0029] The drain valve 10 is designed as a diaphragm disc valve. The drain valve 10 is arranged coaxially with the valve seat 48 and axially adjacent to the pressure-maintaining valve 8 in an opening 38 in a housing wall 36 of the valve housing 34, said housing wall being axially adjacent to the outlet chamber 42. In a preferred embodiment, the drain valve 10 has a flexurally elastic diaphragm disc 92, which is guided in a floating manner within an annular-cylindrical housing 76, axially between an annular valve seat 78 of the housing 76 and a conical support body 82 connected to the housing 76 via at least one diagonal strut 80, as well as the aforementioned diagonal strut 64 and the support body 66 of the pressure-maintaining valve 8.

[0030] The outlet chamber 42 of the valve housing 34 is sealed by a sealing ring 96 arranged between the inner wall of the opening 38 in the housing wall 36 and the housing 76 of the drain valve 10. The housing 76 of the drain valve 10, which is preferably made of a plastic and manufactured as an injection-molded component, is locked to the housing insert 44 by means of locking lugs 90, which are arranged on an axial extension 86 of the housing 76 provided with radial openings 88, by engaging in an associated internal groove 54 in the housing insert 44. The housing 62 of the pressure-maintaining valve 8, which is also preferably made of a plastic and manufactured as an injection-molded component, is inserted with a precise fit radially inward into the housing 76 of the drain valve 10 and is fastened to the housing insert 44 via this.

[0031] In the illustration of the Fig. 1a the sealing element 60 rests against the valve seat 48, so that the inlet valve 4 is closed. The outlet chamber 42 is depressurized, so that the diaphragm disk 72 of the pressure-maintaining valve 8 rests against the annular collar 52 of the housing insert 44 due to its inherent stress, thus the pressure-maintaining valve 8 is closed. Due to the lack of pressure load, the diaphragm disk 92 of the drain valve 10 is lifted from the valve seat 78 and has assumed a flat shape, so that the drain valve 10 is open. If compressed air now flows into the outlet chamber 42 via the closed inlet valve 4 due to leakage, it flows directly into the environment via the open drain valve 10 according to the flow arrow 98 shown, thereby preventing uncontrolled ventilation of the actuating cylinder 20 and the resulting unintentional actuation of the relevant friction clutch.

[0032] In the illustration of the Fig. 1b the sealing element 60 of the inlet valve 4 is lifted from the valve seat 48, so that the inlet valve 4 is open. Due to the exposure to the compressed air flowing into the central channel 50 via the valve seat 48, the diaphragm disc 72 of the pressure-maintaining valve 8 is lifted from the annular collar 52 of the housing insert 44 and turned inside out until its radially outer edge rests against the diagonal strut 64, so that the pressure-maintaining valve 8 is now open. Due to the exposure to the incoming compressed air, the diaphragm disc 92 of the discharge valve 10 rests on the valve seat 78, so that the discharge valve 10 is closed.Thus, according to the flow arrows 100, 102 shown, compressed air flows from the supply line 18 connected to the inlet 12 of the inlet valve 4 via the open inlet valve 4 and the open pressure-maintaining valve 8 into the pressure chamber 22 of the actuating cylinder 20 connected to the outlet 14 of the inlet valve 4, whereby the respective friction clutch is actuated in the intended manner, i.e., disengaged or engaged depending on the design. If a pressure drop now occurs in the supply line 18 connected to the inlet 12 of the inlet valve 4, the diaphragm disc 72 of the pressure-maintaining valve 8 is pressed against the annular collar 52 of the housing insert 4 due to the effective pressure difference, so that the pressure-maintaining valve 8 is then closed. This prevents a sudden loss of pressure in the actuating cylinder 20 connected to the outlet 14 of the inlet valve 4 and the resulting unintentional actuation of the relevant friction clutch.

[0033] By integrating the pressure holding valve 8 and the discharge valve 10 into the inlet valve 4, the number of valve units to be assembled in the valve device 2 is reduced from four to two valve units, thus reducing the assembly effort accordingly and also saving installation space.

[0034] Below, based on the Figuren 2a and 2b a second embodiment of the inlet valve 4' and based on the Figuren 3a and 3b an embodiment of the outlet valve 6' of a second embodiment of the valve device 2' according to the invention is described. In this second embodiment of a valve device 2' according to the invention, the pressure-maintaining valve 8' is arranged within the housing 34' of the inlet valve 4' and thus integrated into the inlet valve 4' ( Fig. 2a , Fig. 2b ) and the drain valve 10' are arranged within the housing 104 of the outlet valve 6' and thus integrated into the outlet valve 6' ( Fig. 3a , Fig. 3b ).

[0035] The inlet valve 4' according to the Figuren 2a and 2b is largely identical to the inlet valve 4 according to the Figuren 1a and 1bconstructed and differs from this only in that now only the pressure-maintaining valve 8' is arranged within the valve housing 34' of the inlet valve 4', and that the diaphragm disk 72' of the pressure-maintaining valve 8' is now additionally fastened to the support body 66' of the housing 62'. For this purpose, the support body 66' is provided at its tip with an integrally molded mushroom head 68, onto which the diaphragm disk 72' is slipped by means of its central bore 74. The diaphragm disk 72' is thus secured against displacement from the centered desired position. The housing 62' of the pressure-maintaining valve 8', which is preferably made of a plastic and manufactured as an injection-molded component, is locked to the housing 62' by means of locking lugs 70 arranged on the housing 62' by engaging in the aforementioned inner groove 54 of the housing insert 44.

[0036] In the illustration of Fig. 2a The sealing element 60 of the inlet valve 4' rests sealingly against the valve seat 48, so that the inlet valve 4' is closed. The outlet chamber 42 is depressurized, so that the diaphragm disc 72' of the pressure-maintaining valve 8' rests against the annular collar 52 of the housing insert 44 due to its inherent stress, which is why the pressure-maintaining valve 8' is closed.

[0037] In the Fig. 2b the sealing element 60 is lifted from the valve seat 48 of the inlet valve 4', so that the inlet valve 4' is open. Due to the compressed air flowing into the central channel 50 via the valve seat 48, the diaphragm disc 72' of the pressure-maintaining valve 8' is lifted from the annular collar 52 of the housing insert 44 and is turned inside out until its radially outer end rests against the diagonal strut 64', so that the pressure-maintaining valve 8' is opened. Thus, according to the flow arrows 100, 102 shown, compressed air flows from the supply line 18 connected to the inlet 12 of the inlet valve 4' via the open inlet valve 4' and the open pressure holding valve 8' into the pressure chamber 22 of the actuating cylinder 20 connected to the outlet 14 of the inlet valve 4. As a result, the friction clutch is actuated in the intended manner, i.e., depending on the design, it is disengaged or engaged.If a pressure drop occurs in the supply line 18 connected to the inlet 12 of the inlet valve 4, the diaphragm disc 72' of the pressure-maintaining valve 8' is pressed against the annular collar 52 of the housing insert 4 due to the effective pressure difference, so that the pressure-maintaining valve 8' is then closed. This prevents a sudden pressure loss in the actuating cylinder 20 connected to the outlet 14 of the inlet valve 4 and the resulting unintentional actuation of the corresponding friction clutch.

[0038] The outlet valve 6' is designed as a 2 / 2-way solenoid seat valve and is constructed similarly to the inlet valve 4'. The valve housing 104 of the outlet valve 6' has a cylindrical interior 110, which is connected to the outlet 28 and, via an annular-cylindrical inlet chamber 112, to the inlet 26. A stepped cylindrical housing insert 114, provided with diagonal openings 116, is inserted into the interior 110. The housing insert has a valve seat 118 and a cylindrical central channel 120 adjacent thereto, leading toward the inlet chamber 112. The outlet 28 and the interior 110 of the valve housing 104 are sealed by two sealing rings 56', 58' arranged between the inner wall of the interior 110 and the housing insert 114.The valve seat 118 can be closed by means of a cylindrical disk-shaped sealing element 60', which is held on the valve seat 118 by a valve spring in a manner not shown and can be lifted off the valve seat 118 by energizing an electromagnet.

[0039] The drain valve 10' is designed as a diaphragm disc valve as before and is arranged coaxially with the valve seat 118 in an opening 108 in a housing wall 106 of the valve housing 104 adjacent to the inlet chamber 112. The drain valve 10' has a flexible diaphragm disc 92', which is guided axially within an annular cylindrical housing 76' between an annular valve seat 78' and a conical support body 82' connected to the housing 76' via at least one diagonal strut 80', as well as an annular collar 124 formed integrally on the housing 76'. In contrast to the first embodiment of the drain valve 10 according to the Figuren 1a and 1bThe diaphragm disc 92' of the drain valve 10' is now additionally attached to the support body 82' of the housing 76'. For this purpose, the support body 82' is provided at its tip with a one-piece molded mushroom head 84, over which the diaphragm disc 92' is slipped by means of its central bore 94. Thus, the diaphragm disc 92' is secured against displacement from the centered target position.

[0040] The inlet chamber 112 of the valve housing 104 is sealed by a sealing ring 96' arranged between the inner wall of the opening 108 in the housing wall 106 and the housing 76' of the drain valve 10'. The housing 76' of the drain valve 10', which is preferably made of a plastic and manufactured as an injection-molded component, is locked to the housing insert 114 by means of locking lugs 90' arranged on an axial extension 86' of the housing 76' provided with radial openings 88', by engaging in an associated inner groove 122 of the housing insert 114.

[0041] In the Fig. 3a the sealing element 60' rests sealingly against the valve seat 118, so that the outlet valve 6' is closed. The inlet chamber 112 is depressurized, so that the diaphragm disc 92' of the drain valve 10' has lifted off the valve seat 78' due to the lack of pressure load and has assumed a flat shape. The drain valve 10' is thus opened, whereby compressed air flowing through the closed inlet valve 4' to the working inlet 24 of the actuating cylinder 20 and into the inlet chamber 112 flows directly into the environment via the open drain valve 10' according to the flow arrow 98 shown. This prevents uncontrolled ventilation of the actuating cylinder 20 and the resulting unintentional actuation of the relevant friction clutch.

[0042] In Fig. 3bThe sealing element 60' of the outlet valve 6' continues to bear sealingly against the valve seat 118, so that the outlet valve 6' is now closed. However, the inlet chamber 112 is now pressurized due to an open inlet valve 4', whereby the diaphragm disc 92' of the discharge valve 10 rests sealingly against the valve seat 78', so that the discharge valve 10' is closed.

[0043] By integrating the pressure holding valve 8' into the inlet valve 4' and the drain valve 10' into the outlet valve 6', the number of valve units to be assembled in the valve device 2 is reduced from four to two valve units, thus reducing the assembly effort accordingly and also saving installation space. List of reference symbols (part of the description)

[0044] 2Valve device (first embodiment) 2'Valve device (second embodiment) 4, 4'Inlet valve 6, 6'Outlet valve 8, 8'Pressure-maintaining valve 10, 10'Drain valve 12Inlet of the inlet valve 14Outlet of the inlet valve 16Compressed air source 18Supply line 20Actuating cylinder 22Pressure chamber of the actuating cylinder 24Working inlet of the actuating cylinder 26Inlet of the outlet valve 28Outlet of the outlet valve 30Vent outlet of the outlet valve 32Vent outlet of the drain valve 34, 34'Valve housing 36Housing wall 38Opening 40Interior 42Outlet chamber 44Housing insert 46Opening 48Valve seat 50Central channel 52Annular collar 54Inner groove 56, 56'Sealing rings 58, 58'Sealing rings 60, 60'Sealing element 62, 62'Housing 64, 64'Diagonal strut 66, 66'Support body 68Mushroom head 70Locking lug 72, 72'Diaphragm disc 74Central bore 76, 76'Housing 78, 78'Valve seat 80, 80'Diagonal strut 82, 82'Support body 84Mushroom head 86, 86'Extension 88, 88'Opening 90, 90'Locking lug 92, 92'Diaphragm disc 94Central bore 96,96'Sealing rings 98Flow arrow 100Flow arrow 102Flow arrow 104Valve housing 106Housing wall 108Opening 110Interior 112Inlet chamber 114Housing insert 116Opening 118Valve seat 120Central channel 122Inner groove 124Annular collar,

Claims

1. Valve device (2, 2') for a pneumatically actuated friction clutch, comprising an inlet valve (4, 4') designed as a 2 / 2-way solenoid seat valve, which can be connected on the input side to a pressure-carrying supply line (18) and on the output side to a working inlet (24) of an actuating cylinder (20) of the friction clutch, an outlet valve (6, 6') designed as a 2 / 2-way solenoid seat valve, which can be connected on the input side to the working inlet (24) of the actuating cylinder (20) and on the output side to a vent outlet (30), characterized by: a pressure-maintaining valve (8, 8') designed as a non-return valve, which can be connected on the input side to the outlet (14) of the inlet valve (4, 4') and on the output side to the working inlet (24) of the actuating cylinder (20), and a drain valve (10, 10') designed as a non-return valve, which can be connected on the input side to the working inlet (24) of the actuating cylinder (20) and on the output side to a vent outlet (32), and further characterized in that the pressure-maintaining valve (8, 8') is arranged within the valve housing (34, 34') of the inlet valve (4, 4') coaxially to its valve seat (48) between a central channel (50) adjacent to the valve seat (48) and an outlet chamber (42) connected to the outlet (14) of the inlet valve (4, 4'), and in that the drain valve (10) is arranged within the valve housing (34) of the inlet valve (4), or in that the drain valve (10') is arranged within the valve housing (104) of the outlet valve (6'), and the pressure-maintaining valve (8, 8') and the drain valve (10, 10') being designed as diaphragm disk valves.

2. Valve device according to claim 1, characterized in that the drain valve (10) is arranged within the valve housing (34) of the inlet valve (4) coaxially to its valve seat (48) axially adjacent to the pressure-maintaining valve (8) in an opening (38) in a housing wall (36) of the valve housing (34) adjacent to the outlet chamber (42).

3. Valve device according to claim 1, characterized in that the drain valve (10') is arranged within the valve housing (104) of the outlet valve (6') coaxially to its valve seat (118) in an opening (108) in a housing wall (106) of the valve housing (104) adjacent to an inlet chamber (112) connected to the inlet (26) of the outlet valve (6').

4. Valve device according to claim 1, characterized in that in the pressure-maintaining valve (8, 8') and / or in the drain valve (10, 10') in each case a flexible diaphragm disk (72, 72'; 92, 92') is arranged at least partially within an annular-cylindrical housing (62, 62'; 76, 76') axially between a conical support body (66, 66'; 82, 82') connected to the housing (62, 62'; 76, 76') via at least one diagonal strut (64, 64'; 80, 80') and an annular collar (124) of the housing (76') or an axially adjacent component (44, 52; 62, 64, 66).

5. Valve device according to claim 4, characterized in that the diaphragm disk (72, 92) of the pressure-maintaining valve (8) and / or the drain valve (10) is in each case guided so as to be mounted in a floating manner within the relevant housing (62, 76).

6. Valve device according to claim 4, characterized in that the diaphragm disk (72', 92') of the pressure-maintaining valve (8') and / or the drain valve (10') has a continuous central bore (74, 94) by means of which the diaphragm disk (72', 92') is fastened to the support body (66', 82') of the relevant housing (62', 76').

7. Valve device according to claim 6, characterized in that the relevant diaphragm disk (72', 92') of the pressure-maintaining valve (8') and / or the drain valve (10') is fastened by slipping the central bore (74, 94) of the diaphragm disk (72', 92') over a mushroom head (68, 84) fastened to or formed integrally with the tip of the relevant support body (66', 82').

8. Valve device according to any of claims 1 to 7, characterized in that the housing (62) of the pressure-maintaining valve (8) is precisely inserted into the housing (76) of the drain valve (10) and is fastened via this to a housing insert (44) of the inlet valve (4) having the valve seat (48).

9. Valve device according to any of claims 1 to 7, characterized in that the housing (62') of the pressure-maintaining valve (8') is directly locked to a housing insert (44) of the inlet valve (8') having the valve seat (48).

10. Valve device according to any of claims 1 to 9, characterized in that the housing (76, 76') of the drain valve (10, 10') is locked to a housing insert (44, 114) of the inlet valve (8) or the outlet valve (10') having the valve seat (48, 118).