Valve unit for modulating pressure in an air-brake system

1. A valve unit ( 1 . 1 , 1 . 2 , 1 . 3 ) for modulating pressure in a compressed air braking system, the valve unit comprising

a brake pressure input ( 3 ),

a brake pressure output ( 4 ), and

a purge output ( 5 ),

an inlet valve ( 6 ) configured as a diaphragm valve,

an outlet valve ( 7 ) configured as a diaphragm valve,

for each of the diaphragm valves ( 6 , 7 ), a respective precontrol valve ( 8 , 9 ), each of which is configured as a 3/2-way solenoid valve,

an elongate valve housing ( 2 ), which is divided by a division plane ( 10 ), which extend in a horizontal direction in an installation position, into a base housing ( 11 ) and a housing cover ( 12 ), wherein the brake pressure input ( 3 ) and the brake pressure output ( 4 ) and the purge output ( 5 ) are arranged in the base housing ( 11 ), the diaphragm valves ( 6 , 7 ) are arranged behind each other in a longitudinal direction ( 13 ) in the base housing ( 11 ) between the brake pressure input ( 3 ) and the brake pressure output ( 4 ), with parallel actuation axes ( 14 , 15 ) and with diaphragms ( 16 , 17 ) arranged in a common diaphragm plane parallel to and proximate to the division plane ( 10 ), and clamped between the base housing ( 11 ) and the housing cover ( 12 ), and the precontrol valves ( 8 , 9 ) are arranged in the housing cover ( 12 ),

wherein the precontrol valve ( 8 ) of the inlet valve ( 6 ) and the precontrol valve ( 9 ) of the outlet valve ( 7 ) are arranged in the housing cover ( 12 ) with actuation axes in the longitudinal direction ( 13 ), with an orientation of their actuation axes ( 18 , 19 ) parallel to the division plane ( 10 ), above the diaphragms ( 16 , 17 ) of the inlet valve ( 6 ) and the outlet valve ( 7 ), and

wherein the housing cover ( 12 ) consists of a centrally arranged magnet module ( 20 ) containing magnetic coils ( 21 , 22 ) of the precontrol valves ( 8 , 9 ) and of two air guide modules ( 23 , 24 ) arranged each at an end adjacent to the magnet module ( 20 ) in the longitudinal direction ( 13 ), each of the air guide modules comprising valve bores ( 25 , 26 , 27 , 28 ) and control channels ( 29 , 30 , 31 , 32 , 33 , 34 ) of the precontrol valves ( 8 , 9 ), and each of the air guide modules having a control chamber upper part ( 35 , 36 ) of the inlet valve ( 6 ) or the outlet valve ( 7 ), and being connected via a single connecting element ( 45 ) both to the other one of the two air guide modules and to the base housing ( 11 ).

2. The valve unit as claimed in claim 1 , wherein the connecting element ( 45 ) is a flat fixing plate ( 46 )

which, parallel to the division plane ( 10 ) of the valve housing ( 2 ), engages in corresponding recesses ( 47 , 48 ) of at least one of the air guide modules ( 23 , 24 ) each arranged between the valve bores ( 25 , 26 , 27 , 28 ) and an associated control chamber upper part ( 35 , 36 ), and

which, with unilaterally open transverse slots ( 49 , 50 , 51 , 52 ), surrounds respectively at least one transverse web ( 53 , 54 , 55 , 56 ) of the at least one of the air guide modules ( 23 , 24 ) running at right angles to the division plane ( 10 ) and to the longitudinal direction ( 13 ) of the valve housing ( 2 ), and

which comprises bores ( 57 ) for bolting the housing cover ( 12 ) to the base housing ( 11 ).

3. The valve unit as claimed in claim 2 , wherein the control channels ( 29 , 30 , 31 , 32 , 33 , 34 ) of the precontrol valves ( 8 , 9 ) are arranged in transverse webs ( 53 , 54 , 55 , 56 ) of the air guide module ( 23 , 24 ).

4. The valve unit as claimed in claim 1 , wherein the precontrol valves ( 8 , 9 ) are configured as separate solenoid valves with opposite switching directions, each of the precontrol valves having a valve seat ( 59 , 60 ) facing a respective one of the diaphragms ( 16 , 17 ) of the inlet valve and the outlet valve ( 6 , 7 ), the precontrol valves ( 8 , 9 ) being arranged axially parallel and radially adjacent to each other in the magnet module ( 20 ) and in the air guide modules ( 23 , 24 ).

5. The valve unit as claimed in claim 4 , wherein each of the two valve seats ( 59 , 60 ) is integrally connected to a respective assigned one of the air guide modules ( 23 , 24 ).

6. The valve unit as claimed in claim 4 , wherein mechanical components ( 39 , 40 , 41 , 42 , 43 , 44 , 59 , 59 ′, 60 , 60 ′) of the solenoid valves ( 8 , 9 ) are combined in a respective valve cartridge ( 68 , 69 ).

7. The valve unit as claimed in claim 1 , wherein the precontrol valves ( 8 ′, 9 ′) are combined in a double-rotor solenoid valve ( 83 ) with a common magnetic coil ( 84 ), in which the precontrol valves ( 8 ′, 9 ′) have opposite switching directions, each of the precontrol valves having a valve seat ( 85 , 86 ) facing a respective one of the diaphragms ( 16 , 17 ) of the inlet valve ( 6 ) and the outlet valve ( 7 ), the precontrol valves ( 8 , 9 ) being arranged coaxially and axially adjacent to each other in the magnet module ( 20 ′) and in the air guide modules ( 23 ′, 24 ′).

8. The valve unit as claimed in claim 7 , wherein the magnetic coil ( 84 ) of the double-rotor solenoid valve ( 83 ) is configured to be powered with a low current and a high current, and wherein the precontrol valves ( 8 ′, 9 ′) are configured such that the precontrol valve ( 8 ′) assigned to the inlet valve ( 6 ) is switched by powering the magnetic coil ( 84 ) with the low current, whereas the solenoid valve ( 9 ′) assigned to the outlet valve ( 7 ) is only switched by powering the magnetic coil ( 84 ) with the high current.

9. The valve unit as claimed in claim 7 , wherein the magnetic coil ( 84 ) of the double-rotor solenoid valve ( 83 ) has a central take-off for partial powering, and wherein the precontrol valves ( 8 ′, 9 ′) are configured such that the solenoid valve ( 8 ′) assigned to the inlet valve ( 6 ) is switched by a partial powering of the magnetic coil ( 84 ), whereas the solenoid valve ( 9 ′) assigned to the outlet valve ( 7 ) is only switched by a full powering of the magnetic coil ( 84 ).

10. The valve unit as claimed in claim 7 , wherein mechanical components ( 90 , 91 , 92 , 93 , 94 , 95 , 96 ) of the double-rotor solenoid valve ( 83 ) are combined in a valve cartridge ( 97 ), wherein the mechanical components ( 90 , 91 , 92 , 93 , 94 , 95 , 96 ) of at least one of the precontrol valves ( 8 ′, 9 ′) have an outer diameter which does not increase in the direction toward the valve seat ( 85 , 86 ).

11. The valve unit as claimed in claim 1 , wherein the magnet module ( 20 ″) and one of the air guide modules ( 24 ″) are configured integrally, wherein at least one of the precontrol valves ( 9 ″) has a valve seat ( 60 ″) arranged in one of the valve bores ( 27 ″) of a respective one of the air guide modules ( 24 ″) and includes mechanical components ( 42 ″, 43 ″, 44 ″) having an outer diameter that does not increase toward the valve seat ( 60 ″).

12. The valve unit as claimed in claim 11 , wherein the at least one of the precontrol valves ( 9 ″) has an internal valve spring ( 44 ″) which is arranged between a respective valve rotor ( 43 ″) and an assigned valve core ( 42 ″).

13. The valve unit as claimed in claim 1 , wherein connecting cables ( 108 ) of the magnetic coils ( 21 , 22 ) are routed within the magnet module ( 20 ) and terminate in contacts ( 109 ) of a connecting bush ( 110 ) formed on the magnet module ( 20 ).

14. The valve unit as claimed in claim 1 , wherein connecting cables ( 111 ) of the magnetic coils ( 21 , 22 ) are routed within the magnet module ( 20 ) and are connected via plug connections ( 112 ) to connecting cables ( 113 ) which are arranged in at least one of the air guide modules ( 23 ) and which terminate in contacts ( 114 ) of a connecting bush ( 115 ) formed on the magnet module ( 20 ).

15. The valve unit as claimed in claim 1 , wherein connecting cables ( 116 ) of the magnetic coils ( 21 , 22 ) are routed within the magnet module ( 20 ) and terminate in contacts ( 117 ) which protrude at an end face from the magnet module ( 20 ) and which extend through openings ( 118 ) into a connecting bush ( 119 ) formed on at least one of the air guide modules ( 23 ).