Valve unit for modulating pressure in an air-brake system

1. A valve unit ( 1 ) 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 ), respective precontrol valves ( 8 , 9 ) which are each configured as a 3/2-way solenoid valve,

an elongate valve housing ( 2 ) that is divided by a division plane ( 10 ) extending horizontally 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 valve base housing ( 11 ), the diaphragm valves ( 6 , 7 ) are arranged behind each other in the 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 an arrangement of diaphragms ( 16 , 17 ) associated with the diaphragm valves 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 wherein the precontrol valves ( 8 , 9 ) are arranged in the housing cover ( 12 ), and

a silencer ( 75 ) at the purge output ( 5 ), the silencer including a cylindrical silencer housing ( 76 ) with an inlet opening ( 77 ), a calming chamber ( 78 ) arranged radially inside the silencer, a large outlet opening ( 79 ) and a silencer insert ( 80 . 1 , 80 . 2 ) arranged upstream of the outlet opening ( 79 ) inside the silencer housing ( 76 ) and made of an air-permeable and sound-deadening material, wherein the silencer ( 75 ) is attached to the base housing ( 11 ) with base walls ( 83 , 84 ) oriented parallel to the division plane ( 10 ) between the brake pressure input ( 3 ) and the brake pressure output ( 4 ).

2. A valve unit ( 1 ) 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 ), respective precontrol valves ( 8 , 9 ) which are each configured as a 3/2-way solenoid valve,

an elongate valve housing ( 2 ) that is divided by a division plane ( 10 ) extending horizontally 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 valve base housing ( 11 ), the diaphragm valves ( 6 , 7 ) are arranged behind each other in the 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 an arrangement of diaphragms ( 16 , 17 ) associated with the diaphragm valves 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 wherein the precontrol valves ( 8 , 9 ) are arranged in the housing cover ( 12 ), and a silencer ( 75 ) at the purge output ( 5 ), the silencer including cylindrical silencer housing ( 76 ) with an inlet opening ( 77 ), a calming chamber ( 78 ) arranged radially inside the silencer, a large outlet opening ( 79 ) and a silencer insert ( 80 . 1 , 80 . 2 ) arranged upstream of the outlet opening ( 79 ) inside the silencer housing ( 76 ) and made of an air-permeable and sound-deadening material, wherein the silencer ( 75 ) is attached to the base housing ( 11 ) with base walls ( 83 , 84 ) oriented parallel to the division plane ( 10 ) between the brake pressure input ( 3 ) and the brake pressure output ( 4 ),

wherein the silencer housing ( 76 ) consists of a pot-shaped cylindrical bottom housing ( 81 ) with a cylinder wall ( 82 ) and a housing floor ( 83 ), and of a flat housing lid ( 84 ), wherein in the installed state, the housing floor ( 83 ) of the bottom housing ( 81 ) faces the division plane ( 10 ), the inlet opening ( 77 ) lying against the purge output ( 5 ).

3. The valve unit as claimed in claim 2 , wherein the outlet opening ( 79 ) of the silencer housing ( 76 ) is arranged in the cylinder wall ( 82 ) of the bottom housing ( 81 ) and extends relative to the brake pressure input ( 3 ), over an angular region of at most 270°.

4. The valve unit as claimed in claim 3 , wherein the outlet opening ( 79 ) contains a plurality of webs ( 86 ) that are evenly distributed over a periphery of the bottom housing ( 81 ) and arranged between the housing floor ( 83 ) and an outer edge ( 85 ) of the bottom housing ( 81 ).

5. The valve unit as claimed in claim 2 , wherein the housing floor ( 83 ) of the bottom housing ( 81 ) comprises at least one elevation ( 88 , 88 ′) directed axially outward, which in the installed state engages in a corresponding recess in the base housing ( 11 ).

6. The valve unit as claimed in claim 1 , wherein the silencer insert ( 80 . 1 ) has a partially cylindrical shell ( 89 ) which in the installed state, lies inside the silencer housing ( 76 ) against the outlet opening ( 79 ) of the silencer housing ( 76 ) and is reinforced by a circular flat floor portion ( 90 ).

7. The valve unit as claimed in claim 1 , wherein the silencer insert ( 80 . 2 ) has two partially cylindrical shells ( 91 , 92 ) which are arranged coaxially to each other and radially spaced apart, and are connected by a circular floor portion ( 93 ) and circumferentially directly connected together, and of which the radially outer shell ( 92 ), in the installed state, lies on the inside against the outlet opening ( 79 ) of the silencer housing ( 76 ).

8. The valve unit as claimed in claim 1 , wherein the silencer insert ( 80 . 1 , 80 . 2 ) is a braid of mineral fibers, metal fibers or plastic fibers.

9. The valve unit as claimed in claim 1 , wherein the silencer insert ( 80 . 1 , 80 . 2 ) is a sintered component of metal or plastic.

10. The valve unit as claimed in claim 1 , wherein the silencer insert ( 80 . 1 , 80 . 2 ) is a porous casting of metal or plastic.

11. The valve unit as claimed in claim 1 , wherein the base housing ( 11 ) of the valve unit ( 1 ) has an underside facing away from the division plane ( 10 ) and has a recess ( 94 ) in which the silencer housing ( 76 ) is at least partially inserted in the installed state.

12. A valve unit ( 1 ) 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 ), respective precontrol valves ( 8 , 9 ) which are each configured as a 3/2-way solenoid valve,

an elongate valve housing ( 2 ) that is divided by a division plane ( 10 ) extending horizontally 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 valve base housing ( 11 ), the diaphragm valves ( 6 , 7 ) are arranged behind each other in the 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 an arrangement of diaphragms ( 16 , 17 ) associated with the diaphragm valves 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 wherein the precontrol valves ( 8 , 9 ) are arranged in the housing cover ( 12 ), and a silencer ( 75 ) at the purge output ( 5 ), the silencer including cylindrical silencer housing ( 76 ) with an inlet opening ( 77 ), a calming chamber ( 78 ) arranged radially inside the silencer, a large outlet opening ( 79 ) and a silencer insert ( 80 . 1 , 80 . 2 ) arranged upstream of the outlet opening ( 79 ) inside the silencer housing ( 76 ) and made of an air-permeable and sound-deadening material, wherein the silencer ( 75 ) is attached to the base housing ( 11 ) with base walls ( 83 , 84 ) oriented parallel to the division plane ( 10 ) between the brake pressure input ( 3 ) and the brake pressure output ( 4 ),

wherein the silencer housing ( 76 ) is fixed to the valve housing ( 2 ) by a screw connection ( 95 , 96 , 97 ) of a housing lid ( 84 ) of the silencer housing ( 76 ) to the base housing ( 11 ).

13. The valve unit as claimed in claim 1 , wherein a connecting channel ( 55 ′) inside the base housing, adjacent to the silencer and open toward the silencer is closed in the installed state by a housing floor ( 83 ) of the silencer housing ( 76 ), and wherein sealing elements ( 100 , 101 ) are arranged between housing walls ( 98 , 99 ) of the base housing ( 11 ) delimiting the connecting channel ( 55 ′) and the housing floor ( 83 ).