Relay Valve Control Arrangement to Provide Variable Response Timing on Full Applications

Abstract

A brake system and related components including a metering device are configured to regulate a control signal received from a brake control device such that a control valve delays the supply of a level of requested braking pressure for a prescribed amount of time. The metering device can be an inversion valve and orificed check valve in a control circuit adapted to allow relatively unrestricted flow until a threshold pressure is reached, after which pressure the inversion valve closes and the flow is metered through an orifice. This has the effect of allowing rapid brake actuation to a first level, and then slowing further application of the brake until full requested braking is achieved. An electronic control unit can also be configured to regulate a control signal to delay development of the requested brake pressure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application is a continuation of application Ser. No. 13 / 315,640 filed Dec. 9, 2011. The entire disclosure of the aforementioned application is herein expressly incorporated by reference.BACKGROUND[0002]The present exemplary embodiment relates to controlling pressure systems. It finds particular application in conjunction with control arrangements for controlling pressure in pneumatically operated vehicle system, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications.[0003]Air brake systems installed on large vehicles typically utilize pressurized air to operate the brakes of the vehicle. Prior art air brake systems usually include a combination of three different braking systems, namely: the service brakes, the parking brakes, and the emergency brakes. The service brake system applies and releases the brakes wh...

AI Technical Summary

Benefits of technology

This patent describes an electronic control unit for controlling a control valve that supplies pressure to a brakes system. The control unit receives a signal indicating the desired pressure level and regulates it to gradually increase the pressure over a period of time. This helps to prevent the brakes from being overwhelmed with pressure too quickly, which can cause damage. The control unit can also allow for a delay in the supply of pressure for a specific purpose such as allowing for additional cooling of the brakes system.

Problems solved by technology

The availability of full braking power as soon as possible if and when requested by an operator has been found to increase braking distances in some circumstances and, in particular, when such application of full braking power would result in wheel lockup and / or ABS activation.

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