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EP-4741238-A1 - PNEUMATIC SYSTEM

EP4741238A1EP 4741238 A1EP4741238 A1EP 4741238A1EP-4741238-A1

Abstract

A pneumatic system comprises a compressor and an air dryer for supplying a first set of consumers in a main circuit having multi-circuit protection valve system and at least one further consumer is a subsidiary circuit. A selection valve is used to control the coupling of the output of the air dryer to either the main circuit or the subsidiary circuit. The supply is provided to the subsidiary circuit only when a fluid pressure associated in the main circuit exceeds a threshold.

Inventors

  • Albrecht, Tobias
  • Bosl, Markus
  • KLAUS, MICHAEL

Assignees

  • AGCO International GmbH

Dates

Publication Date
20260513
Application Date
20251105

Claims (14)

  1. A pneumatic system, comprising: a compressor (10); an air dryer system (150) having an input (152) coupled to the compressor and an output (154); a first set of consumers (162) in a main circuit (160) comprising a multi-circuit protection valve system (164) upstream of the consumers (162) in the first set; at least one further consumer (172) in a subsidiary circuit (170); and a selection valve (180), wherein the selection valve (180) is configured to control a coupling of the output (154) of the air dryer system (150) to either the main circuit (160) or the subsidiary circuit (170) and wherein the selection valve (180) is configured to couple the output of the air dryer system to the subsidiary circuit (170) only when a fluid pressure in the main circuit (160) exceeds a threshold.
  2. The pneumatic system of claim 1, wherein the selection valve (180) comprises a pneumatically pilot controlled valve, wherein a pilot pressure control line (183) to the selection valve is coupled to an input (165) to the multi-circuit protection valve system (164) in the main circuit (160).
  3. The pneumatic system of any one of claims 1, wherein the selection valve (180) comprises pneumatically pilot controlled valve, wherein a pilot pressure control line (183) to a pilot port of the selection valve (180) is selectively coupled to an input to the multi-circuit protection valve system (164) through an electrically controlled valve (189).
  4. The pneumatic system of claim 1, wherein the selection valve (180) comprises an electrically controlled valve.
  5. The pneumatic system of claim 3 or claim 4, wherein the system comprises a valve controller (190) for controlling operation of the electronically controlled valve (180; 189) and at least one pressure sensor (192, 196) associated with at least one of the consumers in the main circuit (160) for providing a sensed pressure to the valve controller (190).
  6. The pneumatic system of any one of claims 1 to 5, wherein each consumer of the first set (160) of consumers has a lower maximum air flow demand than each consumer of the second set (170) of consumers.
  7. The pneumatic system of any one of claims 1 to 6, wherein the air dryer (150) system comprises a single electrically operated air dryer, the air dryer comprising a dryer unit and a regeneration system.
  8. The pneumatic system of any one of claims 1 to 6, wherein the air dryer system (150) comprises a double chamber air dryer.
  9. The pneumatic system of any one of claims 1 to 6, wherein the air dryer system (150) compromise two electrically operated air dryers (200, 210) each having an output coupled to the air dryer system output (154) and each having a input (201, 211), the air dryer system (150) including an air dryer selection valve (220) for selectively coupling the input (201, 211) of either a first of the electrically operated air dryers (200) or a second of the electrically operated air dryers (210) to the air dryer system input (152).
  10. A vehicle comprising: the pneumatic system of any one of claims 1 to 9; and the one or more consumers that are supplied by the pneumatic system.
  11. The vehicle of claim 10, wherein the first set of consumers comprises one or more selected from the following list: rear service brake; front service brake; park brake; trailer brake.
  12. The vehicle of claim 10 or 11, wherein the second set of consumers comprises one or more selected from the following list: tire pressure control system (184); cab air supply; dust discharge system.
  13. The vehicle of claim 12, wherein the tire pressure control system comprises a supply circuit through which air is provided to at least one tire of the vehicle and a control circuit having a valve manifold for controlling the supply circuit, and wherein a valve manifold supply pressure (185) is provided from the main circuit, through a pressure regulating valve (186).
  14. The vehicle of any one of claims 10 to 13 comprising an agricultural vehicle, or a combination of an agricultural vehicle and an associated implement.

Description

FIELD Embodiments of the present disclosure relate generally to pneumatic systems, in particular pneumatic supply systems, especially for industrial or utility vehicles, such as tractors, other agricultural vehicles, construction vehicles and others. BACKGROUND Pneumatic air supply systems for vehicles typically comprise a compressor that provides a compressed air supply to a range of different pneumatic consumers (i.e., system hardware such as pneumatic actuators, pneumatic cylinders and pneumatic motors together with associated actuating valves and reservoirs/accumulators for storing a pressurized air supply for such equipment) on the vehicle and/or on an associated implement attached to or towed by the vehicle. Some consumers may be regarded as primary consumers whose operation is prioritized over other consumers that are regarded as secondary. Primary consumers may be safety critical, such as pneumatic brake systems, for example. Examples of secondary consumers include a pneumatic cab suspension system, pneumatic driver seat suspension system, pneumatic engine brake system and a tire pressure control system (TPCS). It is known for a TPCS to have two circuits: a supply circuit which supplies air to the tires when being inflated, and a control circuit which is used to actuate valves to control the supply circuit. A TPCS may be used to deflate the tires (e.g. on a tractor) when a vehicle is used in a field as this improves grip and reduces soil compaction and to reinflate the tires to a higher pressure when the vehicle is driven on the road. With this arrangement, it is necessary to re-inflate the tires when transitioning from field use to road use. This needs to be done as quickly as possible, hence there is a need for a high flow rate but low-pressure air supply in the TPCS supply circuit whereas the control circuit requires a higher pressure but low flow rate supply. Different consumers on a vehicle will often have different requirements in terms of flow rate and air pressure. Most consumers, including safety-critical pneumatic brake circuits, require a relatively low flow rate but high-pressure air supply. However, some consumers require a relatively high flow rate but a lower pressure. This is the case for example with the supply circuit of a TPCS through which air is introduced into the tires. In certain circumstances, meeting the demand of a high flow rate consumer can potentially impact on the ability of the pneumatic system to meet the demands of the primary consumers. BRIEF SUMMARY The scope of this disclosure is defined by the claims. According to examples in accordance with this disclosure, there is provided a pneumatic system according to claim 1. Further optional features are set out in the claims dependent on claim 1. BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of this disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. 1 shows a tractor, as one example of a vehicle that can make use of the pneumatic system of this disclosure;FIG. 2 shows a circuit diagram of part of a pneumatic supply system suitable for use in the vehicle of FIG. 1, the pneumatic system having a single Electrically Operated Air Dryer (EOD);FIG. 3 shows the EOD of FIG. 2 operating in a loading mode;FIG. 4 shows the EOD of FIG. 2 operating in a non-loading (idle) mode;FIG. 5 shows the EOD of FIG. 2 in an overpressure protection mode;FIG. 6 shows the EOD of FIG. 2 operating in a regeneration mode;FIG. 7 shows a first example of a pneumatic system of this disclosure;FIG. 8 shows a second example of a pneumatic system of this disclosure;FIG. 9 shows a third example of a pneumatic system of this disclosure; andFIG. 10 shows a fourth example of a pneumatic system of this disclosure. DETAILED DESCRIPTION The subject matter of this disclosure will be described with reference to the Figures. It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. These and other features, aspects, and advantages of the apparatus, systems and methods of the present disclosure will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts. This disclosure provides a pneumatic system comprising a compressor and an air dryer system having an input coupled to the compressor and an output. A first set of consumers is provided in a main circuit comprising a multi-circuit protection valve system upstream of the consumers in the first set. At least one further consumer is provided in a subsidiary circuit. A consumer ci