DE7724137U1 - TWO-CIRCUIT CONTROL VALVE - Google Patents

Description

R. " ⁴⁰⁴ °

19. γ. 1977 He / Th

Robert Bosch GmbH, Stuttgart

Dual-circuit control valve Summary

It is proposed a two-circuit control valve that one lying between the two pressure change chambers of the two circles, has the outlet valve seats of the two individual valves supporting weighing pistons.

. The two outlet valve seats are arranged coaxially on the weighing piston, and two sealing rings ensure that the weighing piston is sealed in the housing. There is one between the two sealing rings Outside air connection, which is shared with an outside air connection for the two individual valves is guided to the outside via the axially pierced weighing piston.

The purpose of the weighing piston is uniform and simultaneous pressure change in the two circles. In addition, because of the immediate limitation of the weighing piston Pressure change chamber of the brake circuit I by means of a graduated and feedback piston a compact design that enables installation of the valve is permitted under space-saving conditions, e.g. in the driver's cab. The two-circuit control valve is preferably applicable as a double wide valve for braking systems of vehicles.

State of the art

The invention is based on a two-circuit control valve
the genre of the main claim. Such a control valve is known (GB-PS 10 10

In this known control valve, the first is the plunger;

adjacent first individual valve is switched over and then the 1

Pressure applied to a piston in the first brake circuit in the | _

Control valve, which then switches over the second individual valve. f As a result, the pressure rises are like all pressure changes in general

f never evenly in the two brake circuits, which results in a different ί Liehe braking at the various groups of brake cylinders I to be.

In addition, the known control valve is relatively long

and consequently requires a large installation space. ,

Advantages of the invention

The two-circuit control valve according to the invention with the characterizing features of the main claim has the advantage
that the pressure changes in the two circles can be carried out completely uniformly with simple means. !

In addition, it is advantageous that the two exhaust valve seats |

load-bearing weighing piston as well as the one immediately next to the weighing piston i

arranged graduated and feedback piston a very short and low |

allow compact design of the control valve. As a result, the I control valve can preferably be used for controlling purposes on motor vehicles
of dual-circuit air brakes.

drawing

An exemplary embodiment of the invention is shown in the drawing and explained in more detail in the following description.

to . .1

Description of the invention

A two-circuit control valve is inserted as a two-circuit brake valve and has a housing 1 into which a plunger 2 is inserted from above. The plunger 2 presses on a sleeve 3 with a shoulder ij, under which a displacement spring 5 lies. The other end of the displacement spring 5 engages a two-part, but one-part, graduated and feedback piston 6 which has an upper »annular space 9 located between two equally sized O-rings 7 and 8. The annular space 9 has a supply line connection 9 'for a first supply air inflow.

v. ' At least one point is the annular space 9 over a radial Opening 10 connected to an inner storage chamber 11. In this storage chamber 11 are a valve spring 12 and a Closing body 13, and it is also limited by an inlet valve seat 1 * J, which is arranged on the stepping and feedback piston 6 is. With a shoulder 15 of smaller diameter, the stepping and feedback piston 6 protrudes into a pressure change chamber 16 into it. The pressure change chamber 16 is delimited on its other side by a weighing piston 17, which is in the pressure change chamber 16 lying end coaxially carries an outlet valve seat 18 of a first individual valve 19. The exhaust valve seat l8 is arranged within the intake valve seat IiJ.

The weighing piston 17 is provided with an axial through hole 21. It has two O-rings 24 and 25 on its circumference, between which an outside air chamber 17 'is arranged. This outside air chamber 17 'is via a radial channel 20 with the Bore 21 connected. The weighing piston 17 is also provided with a second exhaust valve seat 22 at its other end provided, which is arranged coaxially to the first exhaust valve seat l8.

The closing body 13 of the first individual valve 19 and a closing body 29 of a second individual valve 28 are pierced axially to relieve them of pressure. About this perforation of the closing \ body 29 and an outdoor air connection 3 ^ is a joint! Connection of the two individual valves 19 and 28 to the outside air established. _.!..; ■ · _{;:: ""} ■ ;: _";" "·"':: ·.

A second pressure change chamber also belongs to the second individual valve 28 23, that is between the weighing piston 17 and a stationary housing wall 26. Di.e solid housing wall 26 carries an inlet valve seat. 27 .jcfes. second single valve. 28, the Closing body 29 is urged against the seat by a valve spring 30. Closing body 29 and spring 30 are located in a storage pressure chamber 31, which has a supply air connection 31 ″ for a second supply air inflow. The second outlet valve seat 22 is arranged within the inlet valve seat 28.

In the pressure change chamber 23 there is a spring 32 which controls the weighing • x piston 17 with respect to a spring 33 arranged in the pressure change chamber 16 holds in an initial position which • on the other hand acts on the stepping and feedback piston 6. Each pressure change chamber 16 or 23 is connected via a connection 36 or 37 connected to a brake circuit I or II, and at the end of each brake circuit I and II there is at least one brake cylinder.

Mode of action

When the brake is released, the closing bodies 13 and 29 are lifted from the two outlet valve seats 13 and 22, and the E ^ em circuits I and II are vented via the common outside air connection 34.

If the brakes are applied, the tappet 2 runs into the brake valve and actuates the graduation and by pressing the displacement spring 5 through Reaction piston 6. With the piston 6, the inlet valve seat IM of the first individual valve 19 moves downwards until the Outlet valve 13/18 is closed. It should be noted that the weighing piston 17 is already out of balance and also moves downwards until the outlet valve 22/29 of the second individual valve 28 is closed.

As the graduation and feedback piston 6 continues to move, the inlet valve 13/14 is now pushed open by the outlet valve seat 18. Pressure increase in the pressure change chamber 16. b_ewJLrkt ₃ da.3 the weighing piston 17 goes down against the force of the spring 32. The outlet valve 22/29 closes. With a further increase in pressure in the pressure change chamber 16, the inlet valve 27/29 is now opened by the outlet valve seat 22. With its two identical piston surfaces, the weighing piston weighs out the pressures introduced into the two pressure change chambers 16 and 23. The valve springs 12 and 30 are now also involved in the weighing activity of the weighing piston 17. Supply pressure from the supply chambers 11 and 31 continues to reach the two pressure change chambers 16, J and 23, and the pressure in the two brake circuits I and II rises uniformly and evenly. Changes in pressure cause the weighing piston 17 to constantly weigh out. Even when the brake is released, the pressure decrease in the two brake circuits is completely the same.

If the pressure in brake circuit II fails, pressure is only generated in brake circuit I. If, on the other hand, the brake circuit I has a defect, it applies calibration of the graduated and feedback piston 6 due to the lack of pressure " build on the weighing piston 17 in the pressure change chamber 16, and the second individual valve 28 is controlled mechanically.

/ - ·} The weighing piston carrying the two outlet valve seats 18 and 22 17 as well as the immediate limitation of the pressure change channels l6 of the brake circuit I adjoining the weighing piston 17 by the Staging and feedback pistons 6 allow a very short, compact design of the control valve.

The two-circuit control valve described can also be used in high-pressure, normal-pressure systems that are supplied with high supply pressure. if the graduated and feedback piston directly delimiting the pressure change-over chamber l6 is designed as a stepped piston.

Claims (2)

R. I ΰ 4 O 19- 7 · 1977 He / Do Robert Bosch GmbH3 Stuttgart Claims 1. Intermediate circuit control valve for a brake system of motor vehicles, with two individual valves arranged one behind the other in a valve housing, furthermore with an actuating rod which dips into the valve housing and there mechanically cooperates via a displacement spring and a piston with a closing element for the first individual valve and with a Device for actuating the second single valve, characterized in that the pressure change chamber (16) of the brake circuit (I) directly on the one hand by the stepping and feedback piston (6) and on the other hand by one of the outlet valve seats (18, 22) of the two individual valves (19> 28) bearing weighing piston (17) is limited. 2. Two-circuit control valve according to claim 1, characterized in that that in the pressure change chamber (16) of the first individual valve (19) a spring (33) is provided, the bias of which interacts with one in the pressure change chamber (23) of the second on-valve (28) arranged spring (32) is decisive for the starting position of the weighing piston (17). i * »lit