Vehicle air dryer system, air dryer, pneumatic vehicle system and vehicle

Abstract

The invention relates to a vehicle air dryer system, an air dryer, a pneumatic vehicle system and a vehicle. An automotive air dryer system (10) includes: a dryer inlet (1) configured to receive air from a compressor discharge line (11); a dryer outlet (2) configured to supply dry air; a desiccant cartridge (22) configured to receive the air from the dryer inlet (1) via a dryer inlet line (1A) and to provide the dried air via a dryer outlet line (28) for output to the dryer outlet (2); a dryer exhaust device (3); a pneumatic control valve assembly (30, 40) configured to selectively exhaust from the compressor exhaust line (11) and / or from the desiccant cartridge (22) via the dryer exhaust device (3); and a control valve assembly (59) configured to provide a control pressure signal (CP1, CP2, CP3) to at least one of the pneumatic control valve assembly (30, 40) and a compressor (91) connected to the compressor discharge line (11).

Description

Automotive air dryer systems, air dryers, pneumatic vehicle systems and vehicles Technical Field

[0001] This disclosure relates to an automotive air dryer system. Furthermore, this disclosure relates to an air dryer for an automotive air dryer system, to a pneumatic vehicle system having an automotive air dryer system, and to a vehicle including a pneumatic vehicle system, particularly a commercial vehicle. Background Technology

[0002] Many vehicles include one or more pneumatic consumables, such as brake cylinders, height adjustment cylinders, and / or sensor cleaning systems, but are not limited to these. A compressor can be provided to supply compressed air to the pneumatic consumable system. For various types of pneumatic consumables, it is desirable to reduce the humidity of the compressed air before supplying it to the consumable. An automotive air dryer, including a desiccant cartridge, can be installed downstream of the compressor. The automotive air dryer system can be configured to provide desiccant regeneration.

[0003] US 2013 / 0195682 A1 and EP 4 112 399 A1 disclose pneumatic vehicle systems including an air dryer system having at least one pneumatic control valve.

[0004] Typically, an automotive air dryer system may include: an air dryer inlet configured to receive air from a compressor discharge line; a dryer outlet configured to supply dry air; a desiccant cartridge configured to receive air from the dryer inlet via a dryer inlet line and supply dry air for output to the dryer outlet via a dryer outlet line; and a dryer exhaust device. The automotive air dryer system can be configured to operate in a drying mode and a regeneration mode. In drying mode, a stream of humid compressed air supplied by the compressor can be guided through the desiccant cartridge, wherein the desiccant in the cartridge is configured to adsorb moisture from the humid compressed air stream. Since the desiccant reaches saturation after adsorbing a certain level of moisture, the desiccant cartridge can be regenerated in regeneration mode. In regeneration mode, a relatively dry regeneration air stream is guided through the desiccant, which can thus decompose water and draw it into the regeneration air stream. The regeneration air stream can be guided through the desiccant cartridge in the opposite flow direction to the compressed air stream. The regeneration air stream can be discharged via the dryer exhaust device. The desiccant can be, for example, a suitable adsorbent, such as zeolite. Because desiccants can be easily degraded, desiccant boxes can be configured to be replaceable and can be replaced, for example, after a certain number of drying and regeneration cycles.

[0005] For example, when discharging a humid regenerated airflow in regeneration mode, the discharge of the desiccant box via the dryer exhaust system can be associated with simultaneous discharge from the dryer inlet line. Depending on the type of compressor connected to the dryer inlet line via the compressor discharge line, a decrease in pressure in the dryer inlet line may affect the operating efficiency of the connected compressor. Furthermore, when the automotive air dryer system operates in regeneration mode, it may be necessary to set the compressor to an unloaded state, such as compressor idling or shutdown. Conversely, discharge from the compressor discharge line, especially in the drying mode of the automotive air dryer system, may affect the pneumatic consumable system connected to the automotive air dryer system. Summary of the Invention

[0006] In view of the above, an object of the present invention is to provide an automotive air dryer system that is operable in a more versatile, flexible, and efficient manner. In particular, an object is to provide an automotive air dryer system with improved emissions performance. Another object of the present invention is to provide an improved air dryer for an automotive air dryer system, an improved pneumatic vehicle system, and an improved vehicle including the pneumatic vehicle system.

[0007] The present invention provides an automotive air dryer system, an air dryer for an automotive air dryer system, a pneumatic vehicle system, and a vehicle including a pneumatic vehicle system as indicated in the appended claims.

[0008] According to a first aspect of the invention, an automotive air dryer system is provided, comprising: a dryer inlet configured to receive air from a compressor discharge line; a dryer outlet configured to supply dry air; a desiccant cartridge configured to receive the air from the dryer inlet via a dryer inlet line and to supply the dry air for output to the dryer outlet via a dryer outlet line; a dryer exhaust device; a pneumatic control valve assembly configured to selectively exhaust air from the compressor discharge line and / or from the desiccant cartridge via the dryer exhaust device; and a control valve assembly configured to provide a control pressure signal to at least one of the pneumatic control valve assembly and a compressor connected to the compressor discharge line.

[0009] The automotive air dryer system achieves various technical benefits. A pneumatic control valve assembly, configured to selectively vent from either or both the compressor discharge line and the desiccant cartridge via the dryer venting device, allows selective venting from the compressor discharge line without affecting the pneumatic consumable system connected to the dryer outlet; allows venting from the desiccant cartridge without affecting the compressor discharge line and the connected compressor; or allows venting from both the compressor discharge line and the desiccant cartridge. By providing independent venting functionality, the compressor no longer needs to be stopped or set to idle mode when the desiccant cartridge is vented. Therefore, using the proposed automotive air dryer system can achieve improved drying and regeneration modes, as well as increased efficiency and protection for the connected compressor and the connected pneumatic consumable system.

[0010] This document describes an automotive air dryer system, an automotive air dryer, an automotive air dryer assembly, a pneumatic vehicle system, and a vehicle. As used herein, the term "automotive air dryer system" refers to an automotive system that includes components integrated into an automotive air dryer, and it is not required that all components of the automotive air dryer system be structural elements of the automotive air dryer. For illustration, an automotive air dryer system according to some embodiments may include a control valve assembly separate from and fluidly connected to the automotive air dryer. The term "automotive air dryer assembly" refers to an assembly that includes an automotive air dryer, which includes the automotive air dryer system according to embodiments, or an assembly that includes a control valve assembly and an automotive air dryer, wherein the automotive air dryer includes at least a pneumatic control valve assembly controllable by the control valve assembly. An automotive air dryer assembly may include additional components, such as one or more compressors, compressor discharge lines, and / or supply lines. A pneumatic vehicle system may include an automotive air dryer system, a compressor, and at least one pneumatic consumer system. The at least one pneumatic consumer system may include, but is not limited to, a pneumatic braking system and / or a pneumatic leveling system. As used herein, the term "pneumatic vehicle system" encompasses electric pneumatic vehicle systems, such as electric pneumatic brakes and / or electric leveling systems.

[0011] According to this disclosure, a vehicle air drying system is typically a structural unit implemented or adapted to be implemented in a vehicle for receiving and drying compressed air in order to provide dry compressed air to a pneumatic consumable system. The vehicle can be any type of motor vehicle designed to transport people and / or goods. In particular, the vehicle can be a commercial vehicle, i.e., a vehicle used commercially to transport goods or paying passengers. For example, a commercial vehicle can be a truck or a bus. At least some of the components of the vehicle air drying system can be arranged within the housing of the vehicle air drying system. The vehicle air drying system may include additional air handling peripherals, such as protective valve assemblies or air filters. The vehicle air drying system includes a desiccant cartridge containing a desiccant. Depending on the selected desiccant material and its degradation properties, the desiccant cartridge may be provided as a replaceable cartridge. The desiccant can be configured to remove moisture from the airflow passing through it via adsorption treatment. Upon reaching a certain saturation point, regeneration of the desiccant may be required via a suitable desorption treatment. Typically, desiccant regeneration can be performed by guiding a dry regeneration airflow through the desiccant. The dry regeneration airflow removes moisture from the desiccant, and the humid regeneration airflow can be discharged via a dryer exhaust device. Therefore, the automotive air dryer system can operate in a drying mode for drying the received compressed air, and in a regeneration mode for regenerating the desiccant cartridge using the received regeneration air. The regeneration air can be, for example, an airflow of dried compressed air transferred from the dryer outlet or from a supply line connected to the dryer outlet.

[0012] As described above, the automotive air dryer system includes a pneumatic control valve assembly. The pneumatic control valve assembly may include at least one valve, preferably at least two valves, configured to selectively vent from the compressor discharge line and / or from the desiccant box by selectively opening or blocking the fluid connection between the dryer inlet line and the dryer exhaust device, and by selectively opening or blocking the fluid connection between the desiccant box and the dryer exhaust device.

[0013] As described above, the automotive air dryer system may further include a control valve assembly. The control valve assembly may include at least one valve, preferably at least two valves, configured to provide a control pressure signal to at least one of a pneumatic control valve assembly and a compressor connected to a compressor discharge line. The control valve assembly may include at least one of a solenoid control valve and a pneumatic control valve. Preferably, the control valve assembly includes multiple solenoid control valves, thus forming a solenoid valve assembly as the control valve assembly, which is configured to selectively control the pneumatic control valve assembly.

[0014] According to an embodiment of a first aspect of the present invention, a pneumatic control valve assembly may include a purge valve having a first purge valve port connected to a dryer inlet line and a second purge valve port connected to a dryer exhaust device, and a switching valve having a first switching valve port connected to a dryer inlet line, a second switching valve port connected to a desiccant box, and a third switching valve port connected to a dryer exhaust device.

[0015] By providing a purge valve with a first purge valve port and a second purge valve port, and a switching valve including a first switching valve port, a second switching valve port and a third switching valve port, selective venting can be implemented using a simple structure with a low number of valves and low system complexity.

[0016] The purge valve and switching valve can be pneumatically controllable. The control valve assembly may include a first control valve configured to provide a first control pressure signal to control the purge valve. The control valve assembly may include a second control valve configured to provide a second control pressure signal to control the compressor. At least one of the first and second control valves may be an electromagnetic control valve. Providing a first control valve configured to provide a first control pressure signal to control the purge valve, and providing a second control valve separate from the first control valve and configured to provide a second control pressure signal to control the compressor, allows the automotive air dryer system to provide additional functionality, such as enabling the desiccant cartridge to regenerate without setting the compressor to an unloaded state, such as idling or stopping. Providing a pneumatically controllable valve assembly associated with the control valve assembly also allows for compressor discharge via the discharge line without affecting a pneumatic consumable system that may be directly or indirectly connected to the dryer outlet.

[0017] The control valve assembly may include a third control valve, preferably an electromagnetic control valve, configured to provide a regeneration control pressure signal to regenerate the desiccant cartridge. This further enhances the versatility of the automotive air dryer system. Providing a third control valve separate from a first control valve operable to control a purge valve and from a second control valve operable to control a compressor enables the automotive air dryer system to provide functions such as: reducing pressure in the supply line even when the compressor is pumping; reducing or eliminating movement on the compressor discharge line while regenerating the desiccant cartridge; and / or enabling discharge from the compressor discharge line without affecting the pneumatic consumer system pressure.

[0018] The third control valve can be configured to provide both a regeneration control pressure signal and a third control pressure signal to control the switching valve. Thus, an automotive air dryer system with three control valves, particularly for a single-chamber configuration, or with four or five control valves, particularly for a dual-chamber configuration, can be used to perform the following functions: loading operation, where the compressor provides compressed air dried by the desiccant cartridge, wherein the dried air is supplied to at least one pneumatic consumer; unloading operation, where the compressor is set to idle or stopped; reducing pressure in the supply line via the automotive air dryer system without the compressor being unloaded; regenerating the desiccant cartridge, for example by airflow from the dryer outlet through the automotive air dryer system to the dryer exhaust device, without affecting the compressor exhaust line connected to the dryer inlet, and discharging from the compressor exhaust line, for example via the dryer exhaust device, without affecting the pneumatic consumer system pressure.

[0019] The control valve assembly can be configured to independently provide a first control pressure signal, a second control pressure signal, and a regenerative control pressure signal. Thus, various states of the automotive air dryer system can be achieved using the control valve assembly to provide various control pressure signals.

[0020] The control valve assembly can be configured such that the first, second, and third control valves are independently controllable. Thus, the following functions can be implemented by controlling the first, second, and third control valves: loading operation; unloading operation; reducing pressure in the supply line via the automotive air dryer system without the compressor being unloaded; regenerating the desiccant cartridge without affecting the compressor discharge line; and discharging from the compressor discharge line without affecting the pneumatic consumer system pressure.

[0021] Typically, the first, second, and third control valves can be configured as pneumatically controlled valves. Preferably, the first, second, and third control valves can be configured as electrically controllable solenoid valves. An automotive air dryer system or an air dryer assembly including an automotive air dryer system may include an electronic control unit (ECU) configured to provide electrical control signals to the control valves of the control valve assembly to control the control valve assembly. The ECU can be configured to generate electrical control signals to control the control valves of the control valve assembly to perform functions including at least: regeneration without the compressor being unloaded; and discharge through a discharge line that does not affect the pressure in the supply line connected to the dryer outlet. The ECU can be configured to generate electrical control signals for the different control valves of the control valve assembly independently but in a coordinated manner to perform the desired functions. Therefore, the ECU can control the following functions: loading operation; unloading operation; reducing the pressure in the supply line via the vehicle air dryer system without the compressor being unloaded; regenerating the desiccant box without affecting the compressor discharge line; and discharging from the compressor discharge line without affecting the pneumatic consumer system pressure.

[0022] The purge valve can have a first purge valve position and a second purge valve position. The purge valve can be configured such that when in the first purge valve position, it reduces or blocks the air passage between the dryer inlet line and the dryer exhaust device. Thus, the purge valve is operable to block the fluid communication between the dryer inlet line and the dryer exhaust device via the purge valve, thereby achieving functions such as: supplying dry air via the dryer outlet, wherein a fluid communication is established between the dryer inlet line and the desiccant box via a switching valve; blocking the fluid communication between the dryer inlet and the dryer exhaust device via the purge valve; and regeneration, wherein a fluid communication is established between the desiccant box and the exhaust device port via the switching valve without affecting the compressor discharge line connected to the dryer inlet.

[0023] The purge valve can be configured to provide fluid communication between the dryer inlet and the dryer exhaust system when it is in the second purge valve position. Thus, the purge valve can be operated to selectively establish communication between the dryer inlet line and the dryer exhaust system, for example, to discharge from the compressor exhaust line connected to the dryer inlet, where this discharge is performed via an automotive air dryer system. In addition to the first control valve, a second control valve allows control of the purge valve and the compressor, such that the compressor is in a pumping state and the purge valve establishes fluid communication between the compressor exhaust line and the dryer exhaust system. Even when the compressor is pumping, the pressure in the pneumatic consumable system can be reduced.

[0024] The purge valve can be configured such that it is normally in a first purge valve state and, in response to a first control pressure signal, for example, when the first control pressure signal equals the pressure at the dryer outlet, the purge valve selectively switches to a second purge valve state. Thus, the purge valve can remain in its static configuration for use in the loaded state, or can be selectively activated to reduce pressure in the pneumatic consumer system and / or for discharge from the compressor discharge line. The purge valve can be or may include a 2 / 2-way valve. Therefore, the aforementioned operations can be achieved in an efficient manner.

[0025] The switching valve can have a first switching valve position and a second switching valve position. The switching valve can be configured to provide fluid communication between the dryer inlet and the desiccant box when in the first switching valve position. The switching valve can also be configured to block the fluid communication between the desiccant box and the dryer exhaust device when in the first switching valve position. Thus, the switching valve is operable to establish fluid communication between the dryer inlet and the desiccant box via the switching valve, thereby enabling functions such as supplying dry air via the dryer outlet, wherein the fluid communication between the dryer inlet and the dryer exhaust device is blocked via a purge valve.

[0026] The switching valve can be configured to provide fluid communication between the desiccant cartridge and the dryer exhaust system when the switching valve is in the second switching valve position. The switching valve can also be configured to block the fluid communication between the dryer inlet and the desiccant cartridge when the switching valve is in the second switching valve position. Thus, the switching valve can be operated to selectively establish fluid communication between the desiccant cartridge and the dryer exhaust system while blocking the fluid communication between the dryer inlet and the desiccant cartridge, thereby achieving functions such as reducing pressure in the pneumatic consumable system, for example, by reducing pressure in the supply line connected to the dryer outlet, via the automotive air dryer system; or regeneration.

[0027] The switching valve can be configured such that it is normally in a first switching valve state and, in response to a third control pressure signal, for example, when the third control pressure signal equals the pressure at the dryer outlet, selectively switches to a second switching valve state. Thus, the switching valve can remain in its static configuration for loading, or it can be selectively activated to reduce the pressure in the pneumatic consumer system without affecting the compressor discharge line and / or for regeneration. The switching valve can be or may include a 3 / 2-way valve. Therefore, the above-described operation of the switching valve can be achieved in an efficient manner.

[0028] An automotive air dryer system may include a dryer outlet line, also referred to as a supply port line, which includes an outlet check valve and connects to the desiccant cartridge and the dryer outlet. A regeneration line may include a regeneration check valve and may be in fluid communication with the dryer outlet line at a location between the desiccant cartridge and the outlet check valve. The automotive air dryer system can be operated such that providing a regeneration signal to the regeneration line enables air to flow from the pneumatic consumer system to the desiccant cartridge to perform regeneration. Thus, regeneration can be implemented in an efficient manner.

[0029] The control valve assembly can be configured such that each of the first, second, and third control valves is operable to output a control pressure signal that can switch between two different signal pressure values ​​(also referred to herein as the first pneumatic signal value and the second pneumatic signal value). These two states can also be represented as logic "0," for example, no positive pressure at the control valve output, and logic "1," where the control valve output is equal to the pressure at the dryer outlet. Thus, the control valve assembly can be implemented efficiently, with each control valve having an input that is in fluid communication with the supply line or, in other cases, with the dryer outlet.

[0030] The control valve assembly can be configured such that each of the first, second, and third control valves outputs a first pneumatic signal value, for example, without positive pressure at the control valve output, for a loaded state in which the compressor pumps and the automotive air dryer provides dry air at the dryer outlet. Thus, the control valve assembly can be operated to provide a control pressure signal that sets the automotive air dryer assembly to the loaded state.

[0031] Alternatively or additionally, the control valve assembly can be configured such that each of the first and third control valves outputs a first pneumatic signal value, for example, no positive pressure at the control valve output, while the second control valve outputs a second pneumatic signal value, for example, the pressure at the dryer outlet, for an unloading state in which the compressor is set to unload operation, for example, idling or stopping. Thus, the control valve assembly can be operated to provide a control pressure signal that sets the automotive air dryer assembly to an unloading state.

[0032] Alternatively or additionally, the control valve assembly can be configured such that each of the first and third control valves outputs a second pneumatic signal value, such as the pressure at the dryer outlet, while the second control valve outputs a first pneumatic signal value, such as no positive pressure at the control valve output, to reduce the pressure in the pneumatic consumer system while the compressor continues pumping. Thus, the control valve assembly can operate such that the purge valve is set to a second purge valve state, thereby establishing fluid communication between the dryer inlet and the dryer exhaust device, such that the switching valve is set to a second switching valve state, which blocks the fluid communication between the dryer inlet and the desiccant box and establishes fluid communication between the desiccant box and the exhaust device port, and enables airflow from the dryer outlet to the desiccant box by regenerating the control pressure signal.

[0033] Alternatively or additionally, the control valve assembly can be configured such that each of the second and third control valves outputs a second pneumatic signal value (e.g., pressure at the dryer outlet), while the first control valve outputs a first pneumatic signal value (e.g., no positive pressure at the control valve output) for regeneration. Thus, the control valve assembly can operate such that the compressor is set to unload operation, e.g., idling or stopped, the purge valve is in a first purge valve state, thereby blocking the fluid communication between the dryer inlet and the dryer exhaust device, the switching valve is set to a second switching valve state, which blocks the fluid communication between the dryer inlet and the desiccant box and establishes a fluid communication between the desiccant box and the exhaust device port, and enables airflow from the dryer outlet to the desiccant box via the regeneration control pressure signal. Thus, regeneration is performed in a manner that does not affect the compressor discharge line connected to the dryer inlet.

[0034] Alternatively or additionally, the control valve assembly can be configured such that each of the first and second control valves outputs a second pneumatic signal value (e.g., pressure at the dryer outlet), while the third control valve outputs a first pneumatic signal value (e.g., no positive pressure at the control valve output), for performing discharge from the compressor discharge line. Thus, the control valve assembly can operate such that the compressor is set to unload operation, e.g., idling or stopping, the purge valve is set to a second purge valve state, thereby establishing fluid communication between the dryer inlet and the dryer exhaust device, and the switching valve is in a first switching valve state, which blocks the fluid communication between the desiccant box and the exhaust device port by switching the valve. This allows discharge from the compressor discharge line without affecting the pneumatic consumer system pressure.

[0035] The ECU can be configured to generate a first electrical control signal for controlling a first control valve, a second electrical control signal for controlling a second control valve, and a third electrical control signal for controlling a third control valve, in order to provide the various functions described herein.

[0036] Automotive air dryer systems may include an additional desiccant cartridge. This allows the automotive air dryer system to have a dual-chamber configuration. This provides an additional benefit of extending the lifespan of the cartridge before it needs to be replaced.

[0037] The automotive air dryer system may include an additional pneumatic control valve assembly, which includes an additional purge valve and an additional switching valve. The additional purge valve may be pneumatically controllable. The additional switching valve may also be pneumatically controllable. Thus, pneumatic control is implemented for both chambers of the dual-chamber air dryer system. This allows for the use of, for example, four or five control valves to perform various functions.

[0038] The first control valve can be configured to provide a first control pressure signal to control both the purge valve and another purge valve. Thus, the first control valve can be used to pneumatically control both the purge valve and the other purge valve.

[0039] The automotive air dryer system may include additional inlet ports and additional exhaust ports configured to connect to the compressor discharge line. An additional purge valve may be configured to selectively establish fluid communication between the additional inlet port and the additional exhaust port. An additional switching valve may be configured to establish fluid communication between an additional desiccant cartridge and one of the additional inlet port and the additional exhaust port. Thus, the additional purge valve and the additional switching valve are configured to operate as explained in conjunction with the purge valve and the switching valve.

[0040] The control valve assembly may include at least one fourth control valve configured to generate at least one fourth control pressure signal to control at least one of the switching valves and other switching valves. This allows selection of which of the desiccant cartridges and other desiccant cartridges is used to dry the air received from the compressor discharge line and which of the desiccant cartridges and other desiccant cartridges will be regenerated.

[0041] The control valve assembly can be configured such that the at least one fourth control pressure signal selects one of the desiccant cartridges and another desiccant cartridge to perform desiccant regeneration or air drying. This allows selection of which of the desiccant cartridges and another desiccant cartridges will dry the air received from the compressor discharge line and which of the desiccant cartridges and another desiccant cartridge will be regenerated.

[0042] According to an embodiment of the first aspect of the invention, a pneumatic control valve assembly can be arranged in a valve housing mechanically connected to a cartridge retainer that receives a desiccant cartridge, wherein a purge valve and a switching valve can be arranged in parallel within the valve housing. In this way, a compact arrangement with a robust design can be provided, allowing for short fluid paths and optional shared components as a common exhaust volume or a common muffler, as further described below. In the parallel arrangement, the purge valve and the switching valve can include parallel extending longitudinal valve axes. The purge valve and the switching valve can be positioned directly adjacent to each other, i.e., not separated by additional functional components other than the valve housing. The purge valve and the switching valve can include comparable valve components having similar or identical dimensions. Preferably, the purge valve and the switching valve are independently controllable and can include separate control ports. The purge valve and the switching valve can include substantially the same mechanical structure and components. For example, the purge valve and the switching valve can each include a movable piston having an upper piston element interconnected to a lower piston element via a screw adapter, an insert, a retaining ring, or a coupling, thus providing a robust valve design. When using a screw adapter, the screw connection between the upper and lower piston elements can be secured with a screw lock. Furthermore, both the purge valve and the switching valve may each include a return spring disposed between the upper piston element and the valve body for automatic valve reset. For reliable operation, the purge valve and the switching valve may also include O-rings or combined seals. The purge valve and the switching valve may include similar or identical sealing components and locations.

[0043] According to an embodiment of the first aspect of the invention, the purge valve and the switching valve can extend vertically to the housing retainer. Vertical orientation facilitates gravity-assisted removal of contaminants and residues, such as water or oil droplets. Furthermore, vertical orientation helps to hold the purge valve and the switching valve in the open position. By extending vertically to the housing retainer, the purge valve and the switching valve can extend vertically to the ground under installation conditions, i.e., when the automotive air dryer system is arranged in a conventional installation orientation in a vehicle. For example, the conventional installation orientation of an automotive air dryer system may include a horizontal orientation of the housing retainer.

[0044] According to an embodiment of the first aspect of the invention, the purge valve and the switching valve may include a common bottom element having a first purge valve seat for the purge valve and a first switching valve seat for the switching valve. In this way, a compact arrangement with a reduced number of parts can be provided, and an inexpensive design with reduced mechanical complexity can be achieved. For example, the common bottom element may be arranged below the valve, and the first purge valve seat and the first switching valve seat may be arranged adjacent to each other within the common bottom element. According to a modified embodiment, the first purge valve seat and the first switching valve seat may include similar or identical geometries and dimensions. The common bottom element may form part of the aforementioned valve housing. Typically, the valve housing and / or the common bottom element may be configured to receive more than two valves, thereby allowing for more complex valve configurations.

[0045] According to a modified embodiment, the valve housing may include a second switching seat for switching the valve. Since the purge valve can be configured as a 2 / 2-way valve and the switching valve can be configured as a 3 / 2-way valve, implementing an additional switching seat in the valve housing allows for a simple and compact implementation of different valve configurations.

[0046] According to a modified embodiment, the valve housing may further include a second purge valve seat for the purge valve, wherein the purge valve or the valve housing includes a blocking element for limiting the purge valve stroke of the purge valve to a lower valve stroke compared to the switching valve stroke of the switching valve. Therefore, the valve housing may include the same profile for both the purge valve and the switching valve for ease of manufacture, while different valve configurations can be implemented with different valve strokes.

[0047] According to an embodiment of the first aspect of the invention, the purge valve and the switching valve may share a common vent volume disposed in the bottom region of the valve housing. In this way, a compact arrangement with a shared vent volume can be provided. Positioning the common vent volume in the bottom region of the valve housing can facilitate the efficient removal of water or oil contaminants from the pneumatically controlled valve assembly while preventing the formation of water traps. Optionally, the removal of water or oil contaminants may be supported by an inclined or curved profile of the valve housing. The bottom region of the valve housing may be arranged in a relative position to the housing retainer. In other words, the purge valve and the switching valve may extend between the housing retainer and the bottom region. The bottom region may abut a common bottom element. For example, the common vent volume may extend below the common bottom element of the purge valve and the switching valve, i.e., on the underside of the common bottom element away from the purge valve and the switching valve. Preferably, the common vent volume may be located at the lowest point of the valve housing relative to the ground.

[0048] According to the improved embodiment, the silencer can be arranged in a common exhaust volume. In this way, improved noise reduction can be achieved during exhaust treatment. Exhaust treatment can result in significant noise emissions due to high pressure gradients and flow velocities. Preferably, a single common silencer can be provided for both the purge valve and the switching valve, thereby facilitating the pneumatic control valve assembly structure. Furthermore, due to the extended common exhaust volume, a larger silencer can be used compared to providing a separate silencer for each valve. However, the common exhaust volume can be configured to have silencers of different sizes installed within it, thus providing increased flexibility and scalability. The silencer can be attached to the common exhaust volume by, for example, screws to a common bottom element, thereby enabling easy assembly and installation. Since the selective exhaust option is provided by using a pneumatic control valve assembly configured to selectively exhaust from the compressor discharge line or from the desiccant cartridge via a dryer exhaust device, the volume of air discharged at one time can be lower compared to a non-selective exhaust solution, thus contributing to further reductions in noise emissions.

[0049] According to an embodiment of the first aspect of the invention, an automotive air dryer system may include a refilling device for selectively refilling the dryer inlet line using compressed air from the dryer outlet line or from a supply line connected to the dryer outlet. This can be advantageous, particularly for certain types of compressors, when an exhaust-related pressure drop occurs in the dryer inlet line, to enable the refilling function to provide a defined positive minimum pressure in the dryer inlet line. For example, some configurations in practice may include a shut-off valve for temporarily closing the compressor discharge line, for example, during regeneration processing. If the compressor discharge line is reconnected to the dryer inlet, the dryer inlet line may be at a low pressure level due to previous exhaust processing. If the compressor is unloaded, the low pressure level in the dryer inlet line may affect the operating efficiency of the connected compressor. Therefore, a refilling device for selectively refilling the dryer inlet line before the compressor restarts can be beneficial for maintaining reliable and efficient compressor operability. For example, refilling can be performed after regeneration processing. In particular, refilling can be performed while the compressor is unloaded. Compressed air can be advantageously obtained from the dryer outlet line to provide a compact and efficient arrangement of system components for the automotive air dryer system. For example, compressed air can be obtained downstream of a system check valve located in the dryer outlet line to generally prevent backflow from the dryer outlet or from a connected pneumatic consumable system. Typically, refilling devices can be implemented using automotive air dryer systems that operate pneumatically or electronically with regenerative signals.

[0050] According to a modified embodiment, the refilling device may include a refill valve disposed in a bypass line connecting the dryer inlet line and the dryer outlet line, thereby allowing efficient control of refilling. The refill valve may be, for example, a 2 / 2-way valve. Furthermore, a check valve may be disposed in the bypass line to prevent bypassing the desiccant cartridge in drying mode. Typically, the refill valve can be optionally implemented upon customer request without complex system modifications. For example, if the refill valve is omitted or removed, the bypass line can be closed with a plug.

[0051] According to the improved embodiment, the refill valve can be pneumatically controlled in coordination with the purge valve. In this way, finely coordinated valve actuation can be achieved. For example, the refill valve can be actuated only when the purge valve is in the purge state, and it can further prevent backflow via the bypass line in the drying mode of the automotive air dryer system. To control the refill valve in coordination with the purge valve, the pressure signal for the purge valve can be split and provided to the control ports of both the purge valve and the refill valve. The refill valve can allow refill airflow through it in the deactivated state and can block refill airflow through it in the activated state. By providing coordinated pressure signals to the purge valve and the refill valve, the refill valve can be activated to block the refill airflow when the compressor discharge line discharges via the dryer exhaust system. This also allows discharge from the compressor discharge line without affecting the system pressure via the bypass line.

[0052] According to a modified embodiment, the refill valve may include a flow restrictor. In this way, fail-safe operation of the automotive air dryer system can be facilitated. The flow restrictor may be an orifice element to limit the flow rate of air through the refill valve. The flow restrictor may include an orifice of a predetermined maximum size that allows the automotive air dryer system to compensate for external leakage of the refill valve by operating the compressor. Simultaneously, the orifice may have a predetermined minimum size to allow for efficient refilling of the dryer inlet line.

[0053] Typically, it is advantageous to configure the automotive air dryer system to maintain a regeneration control signal after the regeneration process is complete until the dryer inlet line is refilled. For this purpose, it is advantageous to use an electrical regeneration control signal instead of a pneumatic regeneration control signal. For example, the regeneration line of the automotive air dryer system can be connected to a separate, additional control input port for selectively supplying regeneration airflow from an external source (e.g., from a supply line connected to the dryer outlet) based on electronic regeneration and refill signals. Compared to a regeneration signal optimized for desiccant cartridge regeneration, an electronic regeneration and refill signal can maintain the regeneration and refill airflow through the regeneration line for a longer period, allowing refilling of the dryer inlet line with regeneration airflow after a switching valve already activated in coordination with the regeneration process has been deactivated. For example, a solenoid control valve can be used to coordinate the combined regeneration and refill processes. The solenoid control valve for controlling the combined regeneration and refill processes can be controlled by the aforementioned ECU.

[0054] According to an embodiment of the first aspect of the invention, the automotive air dryer system may further include a regeneration line that bypasses an outlet check valve in the dryer outlet line, wherein the automotive air dryer system is configured to refill the dryer inlet line with compressed air from the dryer outlet line via the regeneration line. In this way, a simple and compact implementation can be provided for refilling via the regeneration line. Therefore, refilling of the dryer inlet line can be performed without controlling an additional refill valve. The regeneration line may include a regeneration check valve and a restrictor for reducing the pressure of the regeneration gas flow. The regeneration line may be connected to the dryer outlet line at a location between the desiccant cartridge and the outlet check valve. The regeneration process can be initiated by activating a switching valve to discharge the desiccant cartridge volume. Upon completion of the regeneration process, the switching valve can be deactivated, and the dryer inlet line can be refilled with the regeneration gas flow from the dryer outlet line until the compressor restarts.

[0055] A vehicle air dryer system can be implemented within a vehicle air dryer. The vehicle air dryer may include an air dryer housing and a vehicle air dryer system according to any aspect or embodiment disclosed herein. A pneumatic control valve assembly may be arranged within the air dryer housing. A control valve assembly may be arranged within the air dryer housing. This achieves ease of installation, as both the control valve assembly and the pneumatic control valve assembly can be arranged within the air dryer housing. Alternatively, the control valve assembly may be located outside the vehicle air dryer and separate from it. The combination of the vehicle air dryer and the control valve assembly is also referred to herein as a vehicle air dryer assembly. A vehicle air dryer assembly may include an air dryer housing and a vehicle air dryer system according to any aspect or embodiment disclosed herein. The pneumatic control valve assembly may be arranged within the air dryer housing. The control valve assembly may be arranged outside the air dryer housing and can be connected to the pneumatic control valve assembly via a pneumatic connection. This provides greater flexibility in positioning the control valve assembly. Providing a control valve assembly separate from the vehicle air dryer can also be advantageous for use with a dual-chamber air dryer.

[0056] The air dryer housing may have a first control pressure port configured to receive a first control pressure signal, a second control pressure port configured to receive a second control pressure signal, a third control pressure port configured to receive a third control pressure signal, and a regeneration control signal port configured to receive a regeneration control pressure signal. Thus, ports configured to receive various pressure control signals are provided on the air dryer housing.

[0057] According to a second aspect of the invention, an air dryer is provided for use in any aspect or embodiment of an automotive air dryer system disclosed herein, the air dryer comprising: a dryer inlet configured to receive air from a compressor discharge line; a dryer outlet configured to supply dry air; a desiccant cartridge configured to receive the air from the dryer inlet via a dryer inlet line and to supply the dry air for output to the dryer outlet via a dryer outlet line; a dryer exhaust device; and a pneumatic control valve assembly configured to selectively exhaust air from the compressor discharge line and / or from the desiccant cartridge via the dryer exhaust device.

[0058] In this way, a compact air dryer with enhanced emission control can be provided. To provide an automotive air dryer system according to any aspect or embodiment disclosed herein, the air dryer can be combined with an external control valve assembly configured to provide a pressure control signal to the pneumatic control valve assembly of the air dryer.

[0059] According to a third aspect of the present invention, a pneumatic vehicle system is provided, comprising: a compressor connected to a dryer inlet via a compressor discharge line; an automotive air dryer system according to any of the preceding claims; a pneumatic consumer system connected to a dryer outlet via a supply line; and a control unit configured to control the control valve assembly.

[0060] The proposed pneumatic vehicle system provides an enhanced automotive air dryer system, which can, for example, lead to higher operating efficiency and longer lifespan of the pneumatic vehicle system components. Furthermore, due to optimized and fine-tuned drying and regeneration processes, high-quality dry air supplied by the automotive air dryer system can be provided to the pneumatic consumable system.

[0061] The control unit may be an electronic control unit (ECU). The control valve assembly may include an electrically controllable solenoid valve, and the ECU may be configured to selectively provide electrical signals to the solenoid valve.

[0062] Pneumatic consumable systems can be configured as pneumatic braking systems, pneumatic air suspension systems, and / or tire inflation systems. Since these pneumatic systems may require large quantities of dry compressed air, enhanced pneumatic vehicle systems can ensure a reliable and efficient supply of dry compressed air to these systems.

[0063] According to a fourth aspect of the invention, a vehicle, particularly a commercial vehicle, is provided that includes a pneumatic vehicle system as described in the third aspect or any relevant embodiment disclosed herein. The vehicle can be any type of motor vehicle designed to transport people and / or goods. In particular, the vehicle can be a commercial vehicle, i.e., a vehicle used commercially to transport goods or paying passengers. For example, a commercial vehicle can be a truck or a bus. For commercial vehicles, the advantages of an improved pneumatic vehicle system, including an automotive air dryer system that reliably supplies high-quality dry air, can significantly improve the vehicle's operating efficiency, particularly regarding the primary consumption of compressed air, compared to non-commercial vehicles. Furthermore, reduced noise emissions can be achieved, especially for large commercial vehicles, by enhancing the emission capabilities of the automotive air dryer system included in the pneumatic vehicle system. However, the invention can also generally be applied to personal vehicles.

[0064] According to another aspect, a method for controlling a pneumatic vehicle system can be provided. The pneumatic vehicle system may include a compressor and an air dryer, the compressor including a compressor discharge port, and the air dryer connected to the compressor discharge port via a compressor discharge line. The air dryer may include: a dryer inlet configured to receive air from the compressor discharge line; a dryer outlet configured to supply dry air; a desiccant cartridge configured to receive air from the dryer inlet and supply dry air for output via the dryer outlet; and a dryer exhaust device. The air dryer may also include a pneumatic control valve assembly. The pneumatic control valve assembly may include: a purge valve including a first purge valve port connected to the dryer inlet and a second purge valve port connected to the dryer exhaust device, the purge valve being pneumatically controllable; and a switching valve including a first switching valve port connected to the dryer inlet, a second switching valve port connected to the desiccant cartridge, and a third switching valve port connected to the dryer exhaust device, the switching valve being pneumatically controllable. The method may include providing a first control pressure signal from a first control valve to control the purge valve, and providing a second control pressure signal from a second control valve to control the compressor.

[0065] Various technical effects are achieved through the control methods described above. By using a first control valve to provide a first control pressure signal to control the purge valve and a second control valve to provide a second control pressure signal to control the compressor, the air dryer system can provide additional functions. Examples of such functions include enabling the desiccant cartridge to regenerate without setting the compressor to an unloaded state, such as idling or stopping. By using a control valve assembly associated with a pneumatic control valve assembly, the control method can also enable discharge from the compressor discharge line without affecting the pressure in the supply line connected to the dryer outlet.

[0066] This method may include providing a regeneration control pressure signal via a third control valve to regenerate the desiccant in the desiccant cartridge. This further enhances the versatility of the pneumatic vehicle system. A third control valve is provided, separate from a first control valve operable to control a purge valve and from a second control valve operable to control a compressor, enabling the vehicle air dryer system to provide functions such as: reducing pressure in the supply line even when the compressor is pumping; reducing or eliminating movement in the compressor discharge line while regenerating the desiccant cartridge; and / or enabling discharge from the compressor discharge line without affecting the pneumatic consumer system pressure.

[0067] This method may include both a regenerative control pressure signal and a third control pressure signal provided by a third control valve to control the switching valve. Thus, various functions can be implemented without significantly increasing the complexity of the control valve assembly.

[0068] The method may further include providing an electrical control signal from an electronic control unit (ECU) to a control valve of the control valve assembly to control the control valve assembly. The control valve assembly may include an electrically controllable solenoid valve. The method may include the ECU generating an electrical control signal to control the solenoid valve of the control valve assembly to perform functions including at least: regeneration without the compressor being unloaded; and discharge via a discharge line that does not affect the pressure in the supply line connected to the dryer outlet. Thus, the ECU can control various functions of the air dryer assembly.

[0069] The additional features of the control method and the effects thereby achieved correspond to the features disclosed in connection with an automotive air dryer system, automotive air dryer or automotive air dryer assembly, pneumatic vehicle system or commercial vehicle. The method can be performed by or using the automotive air dryer system, automotive air dryer or automotive air dryer assembly, pneumatic vehicle system or commercial vehicle disclosed herein.

[0070] Various effects and advantages are achieved through the automotive air dryer system, automotive air dryer, automotive air dryer components, pneumatic vehicle system, commercial vehicle, and control method disclosed herein. The automotive air dryer system is more versatile and offers additional functionality. Attached Figure Description

[0071] The above and other features will become clear through the following description of illustrative, non-limiting examples, which will be further outlined with reference to the accompanying drawings. The drawings are not necessarily drawn to scale. Some features may be exaggerated or minimized to show detail of particular parts. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but rather serve only as a representative basis for teaching those skilled in the art.

[0072] Figure 1 is a pneumatic circuit representation of an air dryer system according to an embodiment.

[0073] Figure 2 is a pneumatic circuit representation of an air dryer system according to another embodiment.

[0074] Figure 3 is a schematic representation of a pneumatic vehicle system including the air dryer system of Figure 2.

[0075] Figure 4 is a schematic representation of a pneumatic vehicle system including the air dryer system of Figure 1.

[0076] Figure 5 is a pneumatic circuit representation of an air dryer system with a dual-chamber configuration according to an embodiment.

[0077] Figure 6 is a pneumatic circuit representation of an air dryer system with a dual-chamber configuration according to another embodiment.

[0078] Figure 7 is a schematic representation of a vehicle including a pneumatic vehicle system according to an embodiment.

[0079] Figure 8 is a schematic representation of a vehicle including a pneumatic braking system according to an embodiment.

[0080] Figure 9 is a schematic representation of a vehicle including a pneumatic braking system according to an embodiment.

[0081] Figure 10 is a flowchart of the method according to an embodiment.

[0082] Figure 11 is a flowchart of the method according to an embodiment.

[0083] Figure 12 is a schematic representation of a commercial vehicle including an air dryer system according to an embodiment.

[0084] Figure 13 is a schematic cross-sectional view of an air dryer for an air dryer system according to an embodiment.

[0085] Figure 14 provides an enlarged view of the pneumatic control valve assembly of the air dryer depicted in Figure 13 according to an embodiment.

[0086] Figure 15 provides an enlarged view of the switching valve of the pneumatic control valve assembly depicted in Figure 14.

[0087] Figure 16 is a schematic cross-sectional view of the pneumatic control valve assembly of an air dryer according to another embodiment.

[0088] Figure 17 provides a perspective front view of the air dryer depicted in Figure 13.

[0089] Figure 18 provides a perspective front view of the air dryer depicted in Figure 13, in conjunction with an exploded view of the pneumatic control valve assembly of the air dryer according to Figure 14.

[0090] Figure 19 provides a cross-sectional representation of the bottom region of the pneumatic control valve assembly depicted in Figure 13 in the discharge state, including the purge valve in the second purge valve state and the switching valve in the second switching valve state.

[0091] Figure 20 provides a cross-sectional view of the switching valve in the first switching valve state of the pneumatic control valve assembly depicted in Figure 13.

[0092] Figure 21 provides a cross-sectional view of the switching valve in the second switching valve state of the pneumatic control valve assembly depicted in Figure 13.

[0093] Figure 22 provides a cross-sectional view of the purge valve of the pneumatic control valve assembly depicted in Figure 13 in the first purge valve state.

[0094] Figure 23 is a pneumatic circuit representation of an air dryer with a refilling device according to an embodiment.

[0095] Figure 24 provides a cross-sectional representation of the purge valve of the air dryer according to Figure 23.

[0096] Figure 25 provides a cross-sectional representation of the refill valve of the air dryer according to Figure 23.

[0097] Figure 26 is a pneumatic circuit representation of an air dryer with a refilling device according to another embodiment.

[0098] Figure 27 is a pneumatic circuit representation of an air dryer with a refilling device according to another embodiment.

[0099] Embodiments of the invention will be described with reference to the accompanying drawings. In the drawings, similar or identical reference numerals indicate elements having similar or identical configurations and / or functions. To avoid repetition in the drawings and the description of various aspects and illustrative embodiments, it should be understood that many features are common to several aspects and embodiments. The omission of an aspect from the description or figures does not mean that the aspect is missing from embodiments that include it. Rather, the aspect may be omitted for clarity. Identical reference numerals in two or more figures denote the same or similar elements. Detailed Implementation

[0100] Figure 1 illustrates a pneumatic circuit representation of an automotive air dryer system 10, hereinafter referred to as air dryer system 10. According to the illustrated embodiment, air dryer system 10 includes a desiccant cartridge 22 and a pneumatically controllable valve assembly comprising a purge valve 30 and a switching valve 40. Furthermore, air dryer system 10 includes a control valve assembly, which, according to the illustrated embodiment, is configured as a solenoid valve assembly 59, comprising solenoid valves 60, 70, and 80 as control valves. Although not shown in the figure, the control valve assembly may alternatively be configured as a pneumatic valve assembly including pneumatic valves as control valves, or as a hybrid valve assembly including both solenoid valves and pneumatic valves as control valves.

[0101] The air dryer system 10 may include an air dryer 20 having an air dryer housing 21. At least a purge valve 30 and a switching valve 40 may be disposed in the air dryer housing 21. The desiccant box 22 may be configured to reversibly engage and disengage from the air dryer housing 21 in a non-destructive manner.

[0102] Air dryer system 10 has a dryer inlet 1, a dryer outlet 2, and a dryer exhaust device 3. Air dryer system 10 is configured to receive air from compressor discharge line 11 at dryer inlet 1. The air may be pressurized air having a pressure exceeding ambient pressure. Air dryer system 10 is configured to supply dry air to supply line 12, thereby supplying dry air to pneumatic consumer system. Air dryer system 10 is configured to exhaust air through dryer exhaust device 3, for example, during one, several, or all of the following periods: regeneration of desiccant cartridge 22, discharge from compressor discharge line 11, and pressure reduction in pneumatic consumer system.

[0103] The desiccant cartridge 22 has a desiccant cartridge port 23 and another desiccant cartridge port 24. Desiccant cartridge port 23 is connected to the dryer inlet 1 via dryer inlet line 1A. The other desiccant cartridge port 24 is connected to the dryer outlet 2 via dryer outlet line 28. The dryer outlet line 28 has an outlet check valve 25. The air dryer 20 includes a regeneration line 27. The regeneration line 27 is connected to the dryer outlet line 28 at a location between the other desiccant cartridge port 24 and the outlet check valve 25. The regeneration line 27 includes a regeneration check valve 26. This configuration allows regeneration of the desiccant cartridge 22 to be performed in response to providing a regeneration control pressure signal CPR to the regeneration line 27. The air dryer 20 includes several control input ports, including a first control input port 4P, a second control input port 4R, and a third control input port 4S. The second control input port 4R is configured to receive the regeneration control pressure signal CPR.

[0104] The purge valve 30 has a first purge valve port 31 and a second purge valve port 32. The first purge valve port 31 is in fluid communication with the dryer inlet 1 via a first purge valve connection line 51. The second purge valve port 32 is in fluid communication with the dryer exhaust device 3 via a second purge valve connection line 52. The purge valve 30 is pneumatically controllable. The air dryer system 20 is configured such that the purge valve control input 33 is in fluid communication with the first control input port 4P via the purge valve control signal line 53. The purge valve 30 can be selectively set to a second purge valve state via a first control pressure signal CP1, wherein the purge valve 30 provides an airflow path from the first purge valve port 31 to the second purge valve port 32 and thus to the dryer exhaust device 3. The purge valve 30 has a first purge valve state, which can be a stationary state in which the purge valve 30 blocks or significantly reduces the airflow from the first purge valve port 31 through the purge valve 30 to the dryer exhaust device 3. The purge valve 30 can be implemented as a 2 / 2-way valve.

[0105] The switching valve 40 has a first switching valve port 41, a second switching valve port 42, and a third switching valve port 43. The first switching valve port 41 is in fluid communication with the dryer inlet 1 via a first switching valve connection line 54. The second switching valve port 42 is in fluid communication with the desiccant box port 23 via a second switching valve connection line 55. The third switching valve port 43 is in fluid communication with the dryer exhaust device 3 via a third switching valve connection line 56. The switching valve 40 is pneumatically controllable. The air dryer system 20 is configured such that the switching valve control input 44 is in fluid communication with the third control input port 4P via a switching valve control signal line 57. The switching valve 40 has a first switching valve state, wherein the switching valve 40 provides fluid communication between the first switching valve port 41 and the second switching valve port 42 while blocking fluid communication between the second switching valve port 42 and the third switching valve port 43. The switching valve 40 has a second switching valve state, wherein the switching valve 40 blocks the fluid communication between the first switching valve port 41 and the second switching valve port 42, while providing fluid communication between the second switching valve port 42 and the third switching valve port 43. The switching valve 40 can be selectively set to the second switching valve state via a third control pressure signal CP3, wherein the switching valve 40 provides an airflow path from the second switching valve port 44 to the third switching valve port 43 and thus to the dryer exhaust device 3. The switching valve 40 can be implemented as a 3 / 2-way valve.

[0106] Air dryer system 10 includes a solenoid valve assembly 59. The solenoid valve assembly 59 is configured to provide a first control pressure signal CP1, a second control pressure signal CP2 for unloading the compressor, for example by putting the compressor into idle mode or stopping, a third control pressure signal CP3, and a regeneration control pressure signal CPR. The solenoid valve assembly 59 includes a first solenoid valve 60 configured to provide the first control pressure signal CP1. The solenoid valve assembly 59 includes a second solenoid valve 70 configured to provide the second control pressure signal CP2. The solenoid valve assembly 59 includes a third solenoid valve 80 configured to provide the regeneration control pressure signal CPR and the third control pressure signal CP3. The first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80 may be independently controllable. The first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80 may be configured to output a first control pressure value, such as ambient pressure, in their normal solenoid valve state, i.e., in the solenoid valve stationary state when the solenoid valves are not energized. The first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80 can be configured to output a second control pressure value when they are energized, which can be equal to the pressure in the supply line 12. In other words, the first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80 can be configured to selectively provide the supply line pressure as a control pressure signal.

[0107] The first solenoid valve 60 may include a first solenoid valve input port 61 and a first solenoid valve output port 62. The first solenoid valve input port 61 is in fluid communication with the supply line 12 via a first solenoid valve input line 64. The first solenoid valve output port 62 is in fluid communication with the first control input port 4P via a first control signal line 63. The first solenoid valve 60 is configured to establish fluid communication between the first solenoid valve input port 61 and the first solenoid valve output port 62 in response to a first electrical control signal S1.

[0108] The second solenoid valve 70 may include a second solenoid valve input port 71 and a second solenoid valve output port 72. The second solenoid valve input port 71 is in fluid communication with the supply line 12 via a second solenoid valve input line 74. The second solenoid valve output port 72 is configured to provide a second control pressure signal CP2 to the compressor via the compressor unloading control line 13. The second solenoid valve 70 is configured to establish fluid communication between the second solenoid valve input port 71 and the second solenoid valve output port 72 in response to a second electrical control signal S2.

[0109] The third solenoid valve 80 may include a third solenoid valve input port 81 and a third solenoid valve output port 82. The third solenoid valve input port 81 is in fluid communication with the supply line 12 via the third solenoid valve input line 84. The third solenoid valve output port 82 is in fluid communication with the second control input port 4R via the regeneration control signal line 83. The third solenoid valve output port 82 is in fluid communication with the third control input port 4S via the third control signal line 83. The third solenoid valve 80 is configured to establish fluid communication between the third solenoid valve input port 81 and the third solenoid valve output port 82 in response to a third electrical control signal S3. The first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80 may each be implemented as a 3 / 2-way valve, wherein the third solenoid valve port is in communication with the ambient atmosphere, or implemented as a 2 / 2-way valve.

[0110] The solenoid valve assembly 59 can be configured such that each of the first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80 outputs a first pneumatic signal value for a loaded state (e.g., no positive pressure at solenoid valve output ports 62, 72, and 82), in which the compressor pumps and the air dryer 20 provides dry air at the dryer outlet 2. Thus, the solenoid valve assembly 59 is operable to provide a control pressure signal that sets the air dryer assembly 10 to a loaded state.

[0111] The solenoid valve assembly 59 can be configured such that both the first solenoid valve 60 and the third solenoid valve 80 output a first pneumatic signal value (e.g., no positive pressure at solenoid valve output ports 62, 82), while the second solenoid valve 70 outputs a second pneumatic signal value (e.g., pressure at dryer outlet 2), to unload the compressor, for example, to set the compressor to idle mode or stop the compressor. Thus, the solenoid valve assembly 59 can be operated to provide a control pressure signal to set the air dryer assembly 10 to an unloaded state.

[0112] Solenoid valve assembly 59 can be configured such that both the first solenoid valve 60 and the third solenoid valve 80 output a second pneumatic signal value (e.g., pressure at dryer outlet 2), while the second solenoid valve 70 outputs a first pneumatic signal value (e.g., no positive pressure at solenoid valve output port 72), to reduce the pressure in the pneumatic consumer system while the compressor continues pumping. Thus, solenoid valve assembly 59 can operate such that purge valve 30 is set to a second purge valve state, thereby establishing fluid communication between dryer inlet 1 and dryer exhaust device 3, and that switching valve 40 is set to a second switching valve state, which blocks fluid communication between dryer inlet 1 and desiccant box 22 and establishes fluid communication between desiccant box 22 and exhaust device port 3, and enables airflow from dryer outlet 2 to desiccant box 22 via regeneration control pressure signal CPR.

[0113] The solenoid valve assembly 59 can be configured such that both the second solenoid valve 70 and the third solenoid valve 80 output a second pneumatic signal value (e.g., pressure at dryer outlet 2), while the first solenoid valve 60 outputs a first pneumatic signal value (e.g., no positive pressure at solenoid valve output port 72) for regeneration. Thus, the operable solenoid valve assembly 59 sets the compressor to unload operation, e.g., idling or stopping, and the purge valve 30 is in the first purge valve state, thereby blocking the fluid communication between the dryer inlet 1 and the dryer exhaust device 3. This sets the switching valve 40 to the second switching valve state, which blocks the fluid communication between the dryer inlet 1 and the desiccant box 22 and establishes a fluid communication between the desiccant box 22 and the exhaust device port 3, and enables airflow from the dryer outlet 2 to the desiccant box 22 via the regeneration control pressure signal CPR. Thus, regeneration is performed in a manner that does not affect the compressor discharge line 11 connected to the dryer inlet 1.

[0114] The solenoid valve assembly 59 can be configured such that both the first solenoid valve 60 and the second solenoid valve 70 output a second pneumatic signal value (e.g., pressure at dryer outlet 2), while the third solenoid valve 80 outputs a first pneumatic signal value (e.g., no positive pressure at the third solenoid valve output port 82), to perform discharge from the compressor discharge line 11. Thus, the solenoid valve assembly 59 can operate such that the compressor is set to unload operation, e.g., idling or stopping, the purge valve 30 is set to a second purge valve state, thereby establishing fluid communication between the dryer inlet 1 and the dryer exhaust device 3, and the switching valve 40 is in a first switching valve state, which blocks the fluid communication between the desiccant box 22 and the exhaust device port 1. This allows discharge from the compressor discharge line without affecting the pneumatic consumer system pressure, e.g., without affecting the pressure in the supply line 12.

[0115] Therefore, the solenoid valve assembly 59 associated with the pneumatic control valve assembly, including the purge valve 30 and the switching valve 40, is configured to provide more general air dryer system functionality. Because the pneumatic control valve assembly is configured to selectively discharge from the compressor discharge line 11 and / or from the desiccant cartridge 22, the air dryer system 10 is configured to allow regeneration to be performed without affecting the compressor discharge line 11 and / or to perform discharge from the compressor discharge line 11 without affecting the pressure in the pneumatic consumer system (e.g., without affecting the pressure in the supply line 12). The air dryer system 10 also allows for a reduction in the pressure of the pneumatic consumer system while the compressor is pumping.

[0116] The air dryer system 10 of Figure 1 includes a solenoid valve assembly 59, which is separate from the air dryer 20 and in fluid communication with the control input ports 4P, 4S, 4R of the air dryer 20. This configuration provides greater flexibility in positioning the solenoid valve assembly 59. As will be explained in more detail with reference to Figures 5 and 6, such a configuration is also suitable for use in conjunction with a dual-chamber air dryer.

[0117] Figure 2 shows an air dryer 20 including an air dryer system 10. A solenoid valve assembly 59, a purge valve 30, and a switching valve 40 are incorporated within the air dryer 20. The solenoid valve assembly 59, purge valve 30, and switching valve 40 can be arranged within the air dryer housing 21 of the air dryer 20. A desiccant cartridge 22 can be reversibly engaged and disengaged from the air dryer housing 21 in a non-destructive manner.

[0118] The air dryer 20 includes a solenoid valve assembly 59. Therefore, the air dryer housing 21 does not need to have control input ports 4P, 4R, 4S. The air dryer housing 21 has a compressor control output port 4 to provide a second control signal CP2 for unloading the compressor.

[0119] The first solenoid valve input port 61, the second solenoid valve input port 71, and the third solenoid valve input port 81 are in fluid communication with the dryer outlet 2. For illustration, the first solenoid valve input port 61, the second solenoid valve input port 71, and the third solenoid valve input port 81 may be in fluid communication with the portion of the dryer outlet pipeline 28 between the outlet check valve 25 and the dryer outlet 2.

[0120] The first solenoid valve outlet 62 is connected to the purge valve control signal line 53, which is also connected to the purge valve control signal input 33. The second solenoid valve outlet port 72 is connected to the compressor control outlet port 4 to provide a second control signal CP2 to the compressor via the compressor unloading line 13. The third solenoid valve output port 83 is connected to the switching valve control port 44 via the switching valve control signal line 57. The third solenoid valve output port 83 is also connected to the regeneration line 27.

[0121] The solenoid valve assembly 59, purge valve 30, and switching valve 40 are configured to operate as explained in conjunction with Figure 1. Therefore, the air dryer 20 of Figure 2 is configured to specifically perform regeneration of the desiccant cartridge 22 without affecting the compressor discharge line 11, and / or to perform discharge from the compressor discharge line 11 without affecting the pneumatic consumer system pressure. The housing 22 includes an electrical interface to receive a first electrical control signal S1, a second electrical control signal S2, and a third electrical control signal S3 from the electronic control unit.

[0122] Figure 3 shows a schematic representation of a pneumatic vehicle system 90 according to an embodiment. The pneumatic vehicle system 90 includes an air dryer 20, which includes a solenoid valve assembly 59, a purge valve 30, a switching valve 40, and a desiccant box 22. The air dryer 20 can be configured and operated as explained with reference to Figure 2. The pneumatic vehicle system 90 includes a compressor 91. The compressor 91 is connected to a compressor intake line 93 having an intake opening for air intake. The compressor 91 is coupled to the air dryer 20 via a compressor discharge line 11 and a compressor unloading control line 13. The compressor 91 is operable to enter an unloading state, such as idling or stopping, in response to a second control pressure signal CP2 received via the compressor unloading control line 13.

[0123] The pneumatic vehicle system 90 includes an electronic control unit 97. The electronic control unit 97 is configured to generate a first electrical control signal S1, a second electrical control signal S2, and a third electrical control signal S3 to control the solenoid valve assembly 59. The electronic control unit 97 interfaces with the solenoid valve assembly 59 via one or more electrical control signal links 98.

[0124] The pneumatic vehicle system 90 may include components of a pneumatic consumer system and / or components that interface the air dryer 20 with the pneumatic consumer system, such as a supply tank 94 connected to the dryer outlet 2 via a supply line 12. The pneumatic consumer system may include a pneumatic consumer system reservoir 95 and other pneumatic components, such as a check valve 96.

[0125] Figure 4 shows a schematic representation of a pneumatic vehicle system 90 according to an embodiment. The pneumatic vehicle system 90 includes an air dryer 20 and a solenoid valve assembly 59 separate from the air dryer 20. The air dryer 20 includes a purge valve 30, a switching valve 40, and a desiccant box 22. The air dryer 20 and the solenoid valve assembly 59 can be configured and operated as explained with reference to Figure 1.

[0126] For an air dryer system 10 having a desiccant cartridge 22 (as shown in Figures 1, 2, 3, and 4), the air dryer system 10 is operable to provide the various functions discussed herein by using a solenoid valve assembly 59 comprising a first solenoid valve 60, a second solenoid valve 70, and a third solenoid valve 80 to generate control pressure signals. In this configuration, the air dryer system 10 can be configured such that control pressure signals are provided by the first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80, which are received for loading operations, unloading operations, reducing pneumatic consumable system pressure using the operating compressor 91, regeneration without affecting the discharge from compressor discharge line 11 and compressor discharge line 12. The air dryer system 10 can be configured such that the received control pressure signals are provided by no more than three different solenoid valves 60, 70, and 80 for loading operations, unloading operations, reducing pneumatic consumable system pressure while the compressor 91 is operating, regeneration without affecting the discharge from compressor discharge line 11 and compressor discharge line 12. The solenoid valve assembly 59 may include, for example, more than three solenoid valves when used in a dual-chamber air dryer.

[0127] Figure 5 shows a pneumatic circuit diagram of a pneumatic vehicle system 90 including a compressor 91 and an air dryer system 10 providing a dual-chamber air dryer configuration. The air dryer system 10 includes an air dryer 20, a secondary air dryer 120, and a solenoid valve assembly including a first solenoid valve 60, a second solenoid valve 70, a third solenoid valve 80, and a fourth solenoid valve 150. The air dryer 20 includes a desiccant box 22, a purge valve 30, a switching valve 40, a dryer outlet line 28 including an outlet check valve 25, and a regeneration line 27 including a regeneration check valve 26. The air dryer 20 includes a dryer inlet 1, a dryer outlet 2, and a dryer exhaust device 3. The air dryer 20 includes a first control input port 4S, a second control input port 4P, and a third control input port 4R. These components of the air dryer 20 have been discussed herein and can be configured and operated as previously discussed in conjunction with, for example, Figure 1.

[0128] Air dryer 20 includes a selection control output port 2C, which can be used to select one of air dryer 20 and another air dryer 120 for loading operation or for regeneration. The selection control output port 2C is connected to the dryer outlet line 28 at a location between the desiccant box 22 and the outlet check valve 25.

[0129] The additional air dryer 120 may have the same construction as air dryer 20. This facilitates manufacturing and maintenance. The additional air dryer 120 includes an additional desiccant box 122, an additional purge valve 130 and an additional switching valve 140, an additional dryer outlet line 128 including an additional outlet check valve 125, and an additional regeneration line 127 including an additional regeneration check valve 126. The additional air dryer 120 includes an additional dryer inlet 101, an additional dryer outlet 102, and an additional dryer exhaust device 103. The additional air dryer 120 includes an additional first control input port 104S, an additional second control input port 104P, and an additional third control input port 104R. These components of the additional air dryer 120 can be configured and operated as previously discussed, for example, in conjunction with FIG. 1. The additional air dryer 120 may include an additional selectable control output port 102C, which may become inoperable (e.g., shut off) in the additional air dryer 120.

[0130] Air dryer inlet 1 and another air dryer inlet 101 are connected to compressor discharge line 11. Air dryer outlet 2 and another air dryer outlet 102 are connected to supply line 12 to supply dry air to the pneumatic consumer system.

[0131] The first solenoid valve 60 has a first solenoid valve output port that is in fluid communication with both the first control input port 4P of the air dryer 4P and the other first control input port 104P of the other air dryer 104P. The first solenoid valve 60 is configured to set the purge valve 30 and the other purge valve 130 to a second purge valve state. This establishes fluid communication between the purge valve 30 and the dryer exhaust device 3, and establishes fluid communication between the other dryer inlet 1 and the other dryer exhaust device 103. This is useful for reducing the pressure of the pneumatic consumer system while the compressor 91 continues pumping and / or for discharging from the compressor discharge line 11.

[0132] A second solenoid valve 70 is operable to provide a second control pressure signal to the compressor 91 via the compressor unloading control line 13 to selectively unload the compressor 91. The second solenoid valve 70 has a second solenoid valve output port connected to the compressor unloading control line 13.

[0133] The third solenoid valve 80 has a third solenoid valve control output port that is in fluid communication with both the second control input port 4R and the additional second control input port 104R. Therefore, the third solenoid valve 80 is configured to provide regeneration control pressure signals to both the second control input port 4R and the additional second control input port 104R. It should be noted that at any given time, only one of the air dryer 20 and the additional air dryer 120 is selected for regeneration via the fourth solenoid valve 150.

[0134] The fourth solenoid valve 150 includes a fourth solenoid valve input port 151 in fluid communication with the supply line 12. The fourth solenoid valve 150 also includes a fourth solenoid valve input port 152, which is in fluid communication with the third control input port 4S of the air dryer 20 via a fourth control signal line 153 to provide a fourth control pressure signal CP4. Therefore, the air dryer system 10 is configured to provide different solenoid valves 150, 80 to control the switching valve 40 via the fourth solenoid valve 150, and to provide a regeneration control pressure signal via the third solenoid valve 80. The fourth solenoid control valve 50 can be controlled by a fourth electrical control signal S4, which can be generated by the electrical control unit 97.

[0135] The fourth solenoid valve 150 is configured to control the switching valve 40 to implement a selection function between air dryer 20 and another air dryer 120 for loading operation, wherein air is dried by the selected air dryer 20 and the other air dryer 120, and for regeneration, wherein regeneration is performed for the air dryer 20 and the other air dryer 120 used for loading operation, depending on the output of the fourth solenoid valve. Therefore, the fourth solenoid valve 150 switches between desiccant cartridge 22 and the other desiccant cartridge 122 for loading operation and regeneration, respectively. To implement this change, the selection control output port 2C is in fluid communication with another third control input port 104S of the other air dryer 120 via the selection interconnect line 105.

[0136] The solenoid valve assembly 59 can be configured such that each of the first solenoid valve 60, the second solenoid valve 70, the third solenoid valve 80, and the fourth solenoid valve 150 outputs a first pneumatic signal value for a loaded state (e.g., no positive pressure at the solenoid valve output port), wherein the compressor pumps and the air dryer 20 provides dry air at the dryer outlet 2. Thus, the solenoid valve assembly 59 is operable to provide a control pressure signal that sets the air dryer assembly 10 into a loaded state, wherein the housing 22 of the air dryer 20 provides dry air.

[0137] Solenoid valve assembly 59 can be configured such that each of the first solenoid valve 60, the second solenoid valve 70, and the third solenoid valve 80 outputs a first pneumatic signal value (e.g., no positive pressure at the solenoid valve output port), while the fourth solenoid valve 150 outputs a second pneumatic signal value (e.g., pressure at the supply line 12), for a loaded state in which the compressor pumps and the additional air dryer 120 provides dry air at the additional dryer outlet 102. Thus, solenoid valve assembly 59 is operable to provide a control pressure signal that sets air dryer assembly 10 into a loaded state in which the additional air dryer 20's additional compartment 122 provides dry air. Selection or switching between compartments is achieved via a control pressure signal provided by the fourth solenoid valve 150 to the third control input port 4S of air dryer 20 and then via the selection control output port 2C and the selection interconnection line 105 to the additional third control input port 104S of additional air dryer 120.

[0138] The solenoid valve assembly 59 can be configured such that each of the first solenoid valve 60, the third solenoid valve 80, and the fourth solenoid valve 150 outputs a first pneumatic signal value (e.g., no positive pressure at the solenoid valve output port), while the second solenoid valve 70 outputs a second pneumatic signal value (e.g., pressure at the supply line 12), to unload the compressor, for example, to set the compressor to idle mode or to stop the compressor. Thus, the solenoid valve assembly 59 can be operated to provide a control pressure signal that sets the air dryer system 10 to an unloaded state.

[0139] The solenoid valve assembly 59 can be configured such that both the first solenoid valve 60 and the third solenoid valve 80 output a second pneumatic signal value (e.g., pressure at the supply line 12), while both the second solenoid valve 70 and the fourth solenoid valve 150 output a first pneumatic signal value (e.g., no positive pressure at the solenoid valve output port 72), to reduce the pressure in the pneumatic consumer system connected to the supply line 12 while the compressor 91 continues pumping.

[0140] The solenoid valve assembly 59 can be configured such that each of the second solenoid valve 70, the third solenoid valve 80, and the fourth solenoid valve outputs a second pneumatic signal value (e.g., pressure at the supply line 12), while the first solenoid valve 60 outputs a first pneumatic signal value (e.g., no positive pressure at the solenoid valve output port 72), for performing regeneration of the housing 22 of the air dryer 20.

[0141] The solenoid valve assembly 59 can be configured such that both the second solenoid valve 70 and the third solenoid valve 80 output a second pneumatic signal value (e.g., pressure at the supply line 12), and both the first solenoid valve 60 and the fourth solenoid valve 150 output a first pneumatic signal value (e.g., no positive pressure at the solenoid valve output port 72), for performing regeneration of the additional box 122 of the additional air dryer 120.

[0142] The solenoid valve assembly 59 can be configured such that both the first solenoid valve 60 and the second solenoid valve 70 output a second pneumatic signal value (e.g., pressure at dryer outlet 2), and the third solenoid valve 80 outputs a first pneumatic signal value (e.g., no positive pressure at the output port of the third solenoid valve), to perform discharge from the compressor discharge line 11. In this case, the output of the fourth solenoid valve 150 can be either the first or the second pneumatic signal value. This allows discharge from the compressor discharge line without affecting the pneumatic consumer system pressure, such as the pressure in the supply line 12.

[0143] Therefore, the solenoid valve assembly 59 associated with the pneumatically controllable valve assembly, including purge valve 30, switching valve 40, additional purge valve 130, and additional switching valve 140, is configured to provide more general air dryer system functionality. Specifically, the air dryer system 10 is configured to allow regeneration to be performed separately for cartridge 22 and additional cartridge 122 without affecting the compressor discharge line 11. The air dryer system 10 is configured to perform discharge from the compressor discharge line 11 without affecting the pressure in the pneumatic consumer system, for example, without affecting the pressure in the supply line 12.

[0144] For an air dryer system 10 having a dual-chamber configuration and including a desiccant cartridge 22 and an additional desiccant cartridge 122, the air dryer system 10 is operable to provide the various functions discussed herein by generating a control pressure signal using a solenoid valve assembly 59 including a first solenoid valve 60, a second solenoid valve 70, a third solenoid valve 80, and a fourth solenoid valve 150. In this case, the air dryer system 10 can be configured such that a control pressure signal is provided by the first solenoid valve 60, the second solenoid valve 70, the third solenoid valve 80, and the fourth solenoid valve 150, which is received for: loading operation using the desiccant cartridge 22 for drying; loading operation using the additional desiccant cartridge 122 for drying; unloading operation; reducing the pneumatic consumer system pressure while the compressor 91 is running; regeneration of the desiccant cartridge 22 without affecting the compressor discharge line 11; regeneration of the additional desiccant cartridge 122 without affecting the compressor discharge line 11; and discharge from the compressor discharge line 12. An operable electronic control unit 97 provides a fourth electrical control signal S4 to control the fourth solenoid valve 150.

[0145] Figure 6 shows an air dryer system 10 with a dual-chamber configuration. The air dryer system 10 includes an air dryer 20 and an additional air dryer 120. Both air dryer 20 and the additional air dryer 120 can have the same construction and operation as air dryer 20 in Figure 1. Compared to Figure 5, air dryer 20 and the additional air dryer 120 do not have a switching control output port 2C.

[0146] The selection of one of the air dryers 20 and 120 for loading operation is performed by a fourth solenoid valve 150 and a fourth solenoid valve 160. The fourth solenoid valve 160 has a fourth solenoid valve input port 161 and a fourth solenoid valve output port 162, which is connected via a fourth control signal line 163 to a third control input port 104S to provide a fourth control pressure signal CP4'. The fourth solenoid valve 160 can be controlled by a fourth electrical control signal S4', which can be generated by the electrical control unit 97.

[0147] Solenoid valve assembly 59 can be operated such that, when either loading or regeneration is performed, one of the fourth solenoid valves 150 and 160 outputs a first pneumatic signal value (e.g., no positive pressure at the output port), while the other outputs a second pneumatic signal value, such as the pressure at supply line 12. This selects whether to use desiccant cartridge 22 or another desiccant cartridge 122 to dry the air or to perform regeneration. Other aspects of the operation of solenoid valve assembly 59 correspond to those described in conjunction with Figure 5.

[0148] For an air dryer system 10 having a dual-chamber configuration and including a desiccant cartridge 22 and an additional desiccant cartridge 122, the air dryer system 10 of FIG. 6 is operable to provide the various functions discussed herein by means of a solenoid valve assembly 59, including a first solenoid valve 60, a second solenoid valve 70, a third solenoid valve 80, a fourth solenoid valve 150, and an additional fourth solenoid valve 160, to generate a control pressure signal. In this case, the air dryer system 10 can be configured such that the control pressure signal provided by the first solenoid valve 60, the second solenoid valve 70, the third solenoid valve 80, the fourth solenoid valve 150, and the additional fourth solenoid valve 160 is received for: loading operation using the desiccant cartridge 22 for drying; loading operation using the additional desiccant cartridge 122 for drying; unloading operation; reducing the pneumatic consumer system pressure while the compressor 91 is running; regeneration of the desiccant cartridge 22 without affecting the compressor discharge line 11; regeneration of the additional desiccant cartridge 122 without affecting the compressor discharge line 11; and discharge from the compressor discharge line 11. Although the air dryer system 10 in Figure 6 requires five solenoid valves, the air dryer system 10 provides enhanced switching consistency and signal independence.

[0149] Figure 7 is a schematic diagram of a vehicle 170 including a pneumatic vehicle system 90. The pneumatic vehicle system 170 includes an air dryer system 10 according to one aspect or embodiment, which may be disposed within an air dryer 20. The pneumatic vehicle system 170 includes a compressor 91, a driver 171 configured to drive the compressor 91, and an intake line 93 having an intake opening for ambient air intake. The pneumatic vehicle system 170 includes a compressor discharge line 11 connected to the discharge port of the compressor 91 and the dryer inlet 1 of the air dryer 20. The pneumatic vehicle system 170 includes a compressor unloading control line 13 connected to the unloading control port of the compressor 91 and configured to provide a second control pressure signal CP2 to the compressor 91.

[0150] The pneumatic vehicle system 170 includes a pneumatic consumer system 173. The pneumatic consumer system 173 includes at least one pneumatic consumer 174. The pneumatic consumer system 173 is in fluid communication with and can be directly connected to the supply line 12. The pneumatic consumer system 173 may include at least one pneumatic consumer system valve 175 interconnected between the supply line 12 and the at least one pneumatic consumer 174. The pneumatic consumer system 173 may also include a pneumatic consumer system connection 176 configured to supply dry air to the at least one pneumatic consumer 174. As previously described, the pneumatic vehicle system 170 may include a tank and / or at least one controllable valve coupled to the supply line 12, as shown in Figures 3 and 4. The vehicle 170 may be, in particular, a commercial vehicle.

[0151] Figure 8 shows a schematic representation of a vehicle 170 including a pneumatic vehicle system, which includes a pneumatic braking system 180, such as an electro-pneumatic braking system. The vehicle 170 may be a commercial vehicle. The vehicle 170 has multiple wheels 179 and multiple axles 178, 178'.

[0152] The pneumatic braking system 180 includes a pneumatic consumable comprising a plurality of brake cylinders 181. The plurality of brake cylinders 181 are in fluid communication with the output ports of at least one modulator 183, 184. In the illustrated embodiment, the pneumatic braking system 180 includes a front axle modulator 183 having an electrical control interface 186 connected to an electronic control unit 97 via at least one electrical modulator control line 187. The pneumatic braking system 180 includes a rear axle modulator 184 having an electrical control interface 186 connected to the electronic control unit 97 via the at least one electrical modulator control line 187. The modulators 183, 184 may also interface with a sensor 182 (e.g., a wheel speed sensor).

[0153] An air supply system including compressor 91 and air dryer system 10 provides dry pressurized air, which can be supplied to brake cylinder 181 under the control of modulators 183 and 184.

[0154] Figure 9 shows a schematic representation of a vehicle 170 including a pneumatic vehicle system, which includes a pneumatic leveling system 190, such as an electro-pneumatic leveling system. The vehicle 170 may be a commercial vehicle. The vehicle 170 has multiple wheels 179 and multiple axles 178, 178'.

[0155] The pneumatic leveling system 190 includes a pneumatic consumer comprising a plurality of leveling valves 191. The plurality of leveling valves 191 are in fluid communication with the output ports of at least one modulator 193, 194. In the illustrated embodiment, the pneumatic leveling system 190 includes a front axle modulator 193 having an electrical control interface 186 connected to an electronic control unit 97 via at least one electrical modulator control line 197. The pneumatic leveling system 190 includes a rear axle modulator 194 having an electrical control interface 186 connected to the electronic control unit 97 via the at least one electrical modulator control line 197. The modulators 193, 194 may also interface with a sensor 192 (e.g., a distance sensor).

[0156] An air supply system including compressor 91 and air dryer system 10 provides dry pressurized air, which can be supplied to leveling valve 191 under the control of modulators 193 and 194.

[0157] Figure 10 is a flowchart of a method 200 for controlling a pneumatic vehicle system. Method 200 can be executed automatically by or using an air dryer system 10. Method 200 includes generating a first control pressure signal CP1 by a first solenoid valve 60 to control a purge valve 30 of the air dryer system 10. The purge valve 30 can be controlled to selectively establish fluid communication between the dryer inlet 1 and the dryer exhaust device 3 via the purge valve 30. Generating the first control pressure signal CP1 may include controlling the first solenoid valve 60 by an ECU 79.

[0158] Method 200 includes generating a second control pressure signal CP2 by a second solenoid valve 70 for supplying to a compressor 91 via a compressor unloading control line 13. The compressor 91 can be controlled to selectively unload the compressor, for example, at an idle point or to stop. Generating the second control pressure signal CP2 may include controlling the second solenoid valve 70 by an ECU 79.

[0159] Method 200 includes generating a third control pressure signal CP3 by a third solenoid valve 70 to control a switching valve 40, and a regeneration control pressure signal CPR to be provided to the regeneration line 27. The switching valve 40 can be controlled to selectively block fluid communication between the dryer inlet 1 and the desiccant box 22, and selectively establish fluid communication between the desiccant box and the dryer exhaust device 3. Generating the third control pressure signal CP3 and the regeneration control pressure signal CPR may include controlling the third solenoid valve 80 by an ECU 79.

[0160] In method 200, various control pressure signals are generated to selectively achieve the following functions: loading operation; unloading operation; reducing the pressure in the supply line via the air dryer system without unloading the compressor; regenerating the desiccant box without affecting the compressor discharge line; and discharging from the compressor discharge line without affecting the pneumatic consumer system pressure.

[0161] Figure 11 is a flowchart of a method 210 for controlling a pneumatic vehicle system. Method 210 can be executed automatically by or using an air dryer system 10 with a dual-chamber configuration (such as the air dryer system 10 of Figure 5 or the air dryer system 10 of Figure 6). Method 210 includes generating a first control pressure signal CP1 by a first solenoid valve 60 to control a purge valve 30 and a further purge valve 130 of the air dryer system 10. The purge valve 30 can be controlled to selectively establish fluid communication between the dryer inlet 1 and the dryer exhaust device 3 via the purge valve 30. The further purge valve 130 can be controlled to selectively establish fluid communication between a further dryer inlet 101 and a further dryer exhaust device 103 via the further purge valve 130. Generating the first control pressure signal CP1 may include controlling the first solenoid valve 60 by an ECU 79.

[0162] Method 210 includes generating a second control pressure signal CP2 by a second solenoid valve 70 for supplying to the compressor 91 via the compressor unloading control line 13. The compressor 91 can be controlled to selectively unload the compressor, for example, at an idle point or to stop. Generating the second control pressure signal CP2 may include controlling the second solenoid valve 70 by an ECU 79.

[0163] Method 210 includes generating a regeneration control pressure signal CPR 213 by a third solenoid valve 70 for supplying to regeneration line 27 and additional regeneration line 127. Generating the third control pressure signal CP3 and the regeneration control pressure signal CPR may include controlling the third solenoid valve 80 by an ECU 79.

[0164] Method 210 includes generating 214, via a fourth solenoid valve 150 (FIG. 5) or via a fourth solenoid valve 150 and a further fourth solenoid valve 160 (FIG. 6), at least one third control pressure signal for controlling switching valve 40 and the further switching valve 140. Switching valve 40 can be controlled to selectively block fluid communication between dryer inlet 1 and desiccant box 22, and selectively establish fluid communication between desiccant box and dryer exhaust device 3. The further switching valve 140 can be controlled to selectively block fluid communication between another dryer inlet 101 and another desiccant box 122, and selectively establish fluid communication between another desiccant box 122 and another dryer exhaust device 103. Generating the at least one third control pressure signal may include controlling switching valve 40 and the further switching valve 140 by ECU 79.

[0165] In method 220, various control pressure signals are generated to selectively achieve the following functions: loading operation using desiccant cartridge 22 for drying; loading operation using additional desiccant cartridge 122 for drying; unloading operation; reducing pressure in the supply line via the air dryer system without unloading the compressor; regeneration of desiccant cartridge 22 without affecting the compressor discharge line; regeneration of additional desiccant cartridge 122 without affecting the compressor discharge line; and discharge from the compressor discharge line without affecting the pneumatic consumer system pressure. The techniques disclosed herein are particularly applicable to, but not limited to, commercial vehicles.

[0166] Figure 12 is a schematic representation of a commercial vehicle 220. The commercial vehicle 220 includes at least one pneumatic vehicle system 221. According to an embodiment, the at least one pneumatic vehicle system 220 includes an air dryer system 10.

[0167] Figure 13 schematically illustrates an air dryer 20 for an air dryer system 10 according to an embodiment. The air dryer 20 includes an air dryer housing 21. Within the air dryer housing 21, a box retainer 21a receiving a desiccant box 22 is arranged in a substantially horizontal orientation according to the conventional installation orientation of the air dryer 20. Furthermore, the air dryer 20 includes a valve housing 45 mechanically connected to the box retainer 21a. Within the valve housing 45, a purge valve 30 and a switching valve 40 forming pneumatic control valve assemblies 30, 40 are arranged in parallel. The purge valve 30 and the switching valve 40 are configured to selectively exhaust from a compressor discharge line 11 connected to the air dryer inlet 1 of the air dryer 20 and / or from the desiccant box 22 via a dryer exhaust device 3 of the air dryer 20. The purge valve 30 and the switching valve 40 may be configured according to any of the foregoing aspects and embodiments. By arranging the purge valve 30 and the switching valve 40 in parallel within the valve housing 45, a compact arrangement with a robust design can be achieved, allowing for short fluid paths and shared components as a common exhaust volume 46c, as further described below. The purge valve 30 and the switching valve 40 may comprise substantially the same mechanical structure and components. Preferably, the purge valve 30 and the switching valve 40 can be individually controlled by separately provided pressure control signals.

[0168] As is evident from Figure 13, purge valve 30 and switching valve 40 are connected to air dryer inlet 1 via dryer inlet line 1A. Furthermore, purge valve 30 and switching valve 40 can selectively open or close the fluid communication to the ambient atmosphere via dryer exhaust device 3. Additionally, switching valve 40 can selectively open or close the fluid communication to desiccant box port 23 to selectively enable the use of desiccant box 22 to dry the compressed air received at air dryer inlet 1, or selectively enable the desiccant box 22 to be discharged for system pressure reduction, or to regenerate the desiccant box 22. Furthermore, desiccant box 22 can be connected to air dryer outlet 2 via a separate desiccant box port 24 via dryer outlet line 28 (not further shown in Figure 13).

[0169] As shown in Figure 13, the purge valve 30 and the switching valve 40 extend vertically to the housing retainer 21a, thereby facilitating the removal of water, contaminants, and residues. Furthermore, this vertical orientation helps to keep the purge valve 30 and the switching valve 40 in their deactivated valve state, for example, by gravity-assisted pressing the lower piston element 304 against the first purge valve seat 47a or the first switching valve seat 48a, as explained further below.

[0170] As further apparent from Figure 13, the purge valve 30 and the switching valve 40 include a common bottom element 46a, which can be considered as part of the valve housing 45. The common bottom element 46a may extend substantially parallel to the cartridge retainer 21a. The common bottom element 46a may be positioned in the bottom region 46b of the valve housing 45. By providing a common bottom element 46a for both the purge valve 30 and the switching valve 40, a compact and robust arrangement with a reduced number of parts and low mechanical complexity is provided.

[0171] As further depicted in Figure 13, the purge valve 30 and the switching valve 40 share a common exhaust volume 46c in the bottom region 46b of the valve housing 45. In this way, a compact arrangement can be further improved, and due to the low position of the common exhaust volume 46c in the bottom region 46b, water or oil contaminants can be advantageously removed. The common exhaust volume 46c can lead to or form part of the air dryer exhaust system 3.

[0172] Figure 14 provides an enlarged view of the pneumatic control valve assemblies 30 and 40 of the air dryer 20 depicted in Figure 13. As is evident from Figure 14, the purge valve 30 includes a first purge valve port 31 connected to the dryer inlet line 1A and a second purge valve port 32 connected to the dryer exhaust device 3. The purge valve 30 is pneumatically controllable via a purge valve control input 33. Furthermore, the switching valve 40 includes a first switching valve port 41 connected to the dryer inlet line 1A, a second switching valve port 42 connected to the desiccant box 22, and a third switching valve port 43 connected to the dryer exhaust device 3. The switching valve 40 is pneumatically controllable via a switching valve control input 44.

[0173] As is evident from Figure 14, the common bottom element 46a receiving the purge valve 30 and the switching valve 40 includes a first purge valve seat 47a for the purge valve 30 and a first switching valve seat 48a for the switching valve 40. As shown, the first purge valve seat 47a and the first switching valve seat 48a may include similar or identical geometries and dimensions. Furthermore, the valve housing 45 includes a second switching valve seat 48b for the switching valve 40. By providing only the first purge valve seat 47a for the purge valve 30, and providing both the first switching valve seat 48a and the second switching valve seat 48b for the switching valve 40, a compact and efficient implementation of the switching valve 40 as a 3 / 2-way valve and the purge valve 30 as a 2 / 2-way valve is achieved.

[0174] Figure 15 provides an enlarged view of the switching valve 40 of the pneumatic control valve assemblies 30, 40 depicted in Figure 14, further illustrating the first switching valve port 41, the second switching valve port 42, and the third switching valve port 43. According to the depicted embodiment, the switching valve 40 includes an upper piston element 301 and a lower piston element 304 fixed to each other. The lower piston element 304 is configured to contact a first switching valve seat 48a when the switching valve 40 is in a first switching valve state, in which the switching valve 40 opens fluid communication between the dryer inlet line 1A and the desiccant box 22 via the first switching valve port 41 and the second switching valve port 42, and in which the switching valve 40 blocks fluid communication between the desiccant box 22 and the dryer exhaust device 3 via the second switching valve port 42 and the third switching valve port 43. The lower piston element 304 is also configured to contact the second switching valve seat 48b when the switching valve 40 is in a second switching valve state. In this second switching valve state, the switching valve 40 blocks the fluid communication between the dryer inlet line 1A and the desiccant box 22 via the first switching valve port 41 and the second switching valve port 42. In the same second switching valve state, the switching valve 40 opens the fluid communication between the desiccant box 22 and the dryer exhaust device 3 via the second switching valve port 42 and the third switching valve port 43. The first switching valve state can correspond to the deactivated state of the switching valve 40, while the second switching valve state can correspond to the activated state of the switching valve 40. The switching valve 40 can be activated by the switching valve control input 44 and can be automatically reset by the return spring 300 in the absence of an input signal at the switching valve control input 44.

[0175] Figure 16 depicts a pneumatic control valve assembly 30, 40 of an air dryer 20 according to another embodiment. Compared to the pneumatic control valve assemblies 30, 40 described with reference to Figures 13-15, the pneumatic control valve assemblies 30, 40 of Figure 16 may include substantially similar structures and operating principles. In contrast to the pneumatic control valve assemblies 30, 40 depicted in Figures 13-15, the pneumatic control valve assemblies 30, 40 illustrated in Figure 16 include a valve housing 45 and a blocking element 47c. The valve housing 45 provides a second pneumatic valve seat 47b for a pneumatic valve 30, and the blocking element 47c is used to limit the pneumatic valve stroke 47d of the pneumatic valve 30 to a lower valve stroke compared to the switching valve stroke 48d of the switching valve 40. In this way, the valve housing 45 can include the same profile of the purge valve 30 and the switching valve 40, thereby allowing for easier manufacturing of air dryer components while ensuring efficient implementation of the switching valve 40 as a 3 / 2-way valve and the purge valve 30 as a 2 / 2-way valve.

[0176] As is further apparent from Figure 16, the muffler 46d is arranged in the common exhaust volume 46c of the switching valve 40 and the purge valve 30, thereby improving noise reduction during exhaust treatment. As shown, it can be advantageous to provide a single muffler 46d for both the purge valve 30 and the switching valve 40, in order to reduce mechanical complexity and selectively use a larger muffler compared to the option of separate mufflers for each valve.

[0177] Figure 17 provides a perspective front view of the air dryer 20 depicted in Figure 13, thus illustrating a possible configuration of the air dryer 20 according to an embodiment. In addition to the air dryer inlet 1, air dryer outlet 2, air dryer housing 21, and valve housing 45 already described above with reference to Figure 13, the air dryer 20 shown includes a first control input port 4P communicating with the purge valve control input 33 of the purge valve 30, and an additional control input port 4S communicating with the switching valve control input 44 of the switching valve 40. In this way, the purge valve 30 and the switching valve 40 can be individually controlled by the associated control input ports 4P and 4S. Control valve assemblies (e.g., the solenoid valve assembly 59 described above) can be connected to the control input ports 4P and 4S to provide a control pressure signal to the purge valve control input 33 of the purge valve 30 via the first control input port 4P, and to provide a control pressure signal to the switching valve control input 44 via the additional control input port 4S.

[0178] Figure 18 provides a perspective front view of the air dryer 20 depicted in Figure 13, combined with an exploded view of the pneumatic control valve assemblies 30, 40 of the air dryer 20 according to Figure 14. As is apparent from the exploded view, the pneumatic control valve assemblies 30, 40 can be substantially configured to include similar or identical valve components to form the purge valve 30 and the switching valve 40, thereby providing a simple, cost-effective, and easy-to-assemble valve arrangement. In detail, each of the purge valve 30 and the switching valve 40 may include at least one of the following: a return spring 300 for automatic valve reset in the absence of a pneumatic control signal at the purge valve control input 33 or the switching valve control input 44; an upper piston element 301; a lower piston element 304 configured to be mechanically fixed to the upper piston element 301 by an insert 303; one or more O-rings 302; and a gasket 305. In this way, a robust and reliably operable valve design can be provided. Pneumatic control valve assemblies 30 and 40 can be supported by a common bottom element 46, which further provides a common exhaust volume 46c for both purge valve 30 and switching valve 40. As further described, a common muffler 46d for both purge valve 30 and switching valve 40 can be attached to the common bottom element 46, for example, by screwing it to the common bottom element 46 via assembly screws 306.

[0179] Figure 19 provides a cross-sectional view of the bottom region 46b of the pneumatic control valve assemblies 30, 40 depicted in Figure 13 in a discharge state, in which air is discharged both from the compressor discharge line 11 connected to the air dryer inlet 1 and from the desiccant box 22 via the dryer exhaust device 3. For this purpose, as described above, the purge valve 30 can be activated to enter a second purge valve state, and the switching valve 40 can be activated to enter a second switching valve state. As indicated by the arrow representing the airflow AF, the discharge airflow can be allowed to flow from the second switching valve port 42 connected to the air dryer box 22 and from the first purge valve port 31 connected to the dryer inlet line 1A via the common exhaust volume 46c to the dryer exhaust device 3.

[0180] Figure 20 provides a cross-sectional view of the switching valve 40 of the pneumatic control valve assemblies 30 and 40 depicted in Figure 13 in the first switching valve state. In the first switching valve state, the switching valve 40 provides fluid communication between the first switching valve port 41 and the second switching valve port 42, while blocking fluid communication between the second switching valve port 42 and the third switching valve port 43. In the first switching valve state, the pneumatic input signal at the switching valve control input 44 may be absent, thereby maintaining the switching valve 40 in a deactivated state, in which the lower piston element 304 contacts the first switching valve seat 48a. As indicated by the arrow representing the airflow AF, compressed air supplied by the compressor 91 connected to the dryer inlet 1 can be guided via the dryer inlet line 1A to the first switching valve port 41, flow through the switching valve 40, pass through the second switching valve seat 48b, exit the switching valve 40 at the second switching valve port 42, and flow via the desiccant box port 23 to the desiccant box 22 for drying.

[0181] Figure 21 provides a cross-sectional view of the switching valve 40 of the pneumatic control valve assemblies 30 and 40 depicted in Figure 13 in the second switching valve state. In the second switching valve state, the switching valve 40 provides fluid communication between the second switching valve port 42 and the third switching valve port 43, while blocking fluid communication between the first switching valve port 41 and the second switching valve port 42. In the second switching valve state, a pneumatic input signal may be present at the switching valve control input 44, thereby maintaining the switching valve 40 in an active state, in which the lower piston element contacts the second switching valve seat 48b. As indicated by the arrow representing the airflow AF (which may correspond to the regeneration airflow), the airflow AF may exit the desiccant box 22 via the desiccant box port 23, enter the switching valve 40 at the second switching valve port 42, pass through the first switching valve seat 48a, and exit the switching valve 40 at the third switching valve port 43 for discharge via the dryer exhaust device 3.

[0182] Figure 22 provides a cross-sectional view of the purge valve 30 of the pneumatic control valve assemblies 30, 40 depicted in Figure 13 in the first purge valve state. In the first purge valve state, the purge valve 30 blocks the fluid communication between the first purge valve port 31 and the second purge valve port 32, thereby preventing the airflow AF entering the purge valve 30 via the first purge valve port 31 from passing through the first purge valve seat 47a and exiting in the direction towards the dryer exhaust device 3 via the second purge valve port 32. In the first purge valve state, the pneumatic input signal at the purge valve control input 33 may be absent, thereby keeping the purge valve 30 in a deactivated state.

[0183] Figure 23 is a pneumatic circuit representation of an air dryer 20 with a refill device 14 according to an embodiment. The air dryer 20 includes: a dryer inlet 1 configured to receive air from a compressor discharge line 11 (not shown in Figure 23); a dryer outlet 2 configured to supply dry air; a desiccant cartridge 22 configured to receive air from the dryer inlet 1 via a dryer inlet line 1A and supply dry air to the dryer outlet 2 via a dryer outlet line 28; and a dryer exhaust device 3. Furthermore, the air dryer 20 includes pneumatic control valve assemblies 30 and 40 configured to selectively exhaust air from the compressor discharge line 11 and / or from the desiccant cartridge 22 via the dryer exhaust device 3. These components of the air dryer 20 have been discussed herein and can be configured and operated as previously discussed in conjunction with, for example, Figure 1. Furthermore, the air dryer 20 includes a regeneration line 27 having a restrictor 27a for pressurizing the regeneration gas flow and a regeneration check valve 26. The regeneration line 27 can be connected to a second control input port 4R. The second control input port 4R can also form a third control input port 4S, which is configured to provide a pressure control signal to the switching valve control input 44 of the switching valve 40. In other words, a portion of the regeneration gas flow can be used to pneumatically control the switching valve 40 in coordination with the regeneration mode of the air dryer 20.

[0184] As described above, the air dryer 20 includes a refilling device 14. The refilling device 14 can be configured to selectively refill the dryer inlet line 1A with compressed air from the dryer outlet line 28. Alternatively or additionally, the refilling device 14 can be configured to selectively refill the dryer inlet line 1A with compressed air from the supply line 12 connected to the dryer outlet 2. The refilling device 14 can significantly help maintain or improve the operating efficiency of the compressor connected to the dryer inlet 1. For example, the refilling device 14 can help provide a defined minimum pressure in the dryer inlet line 1A, so that the reactivation of the compressor set to an unloaded state can be unaffected by the low pressure level in the dryer inlet line 1A. For example, refilling can be performed after a regeneration process, which can be associated with a reduction in system pressure via the dryer exhaust device 3. Using compressed air from the dryer outlet line 28 is an efficient and compact implementation option when using the system components of the air dryer 20.

[0185] As depicted in Figure 23, the refill device 14 may include a refill valve 16 disposed in a bypass line 15 connecting the dryer inlet line 1A to the dryer outlet line 28. As shown, the refill valve 16 may be a 2 / 2-way valve. Furthermore, the bypass line 15 is configured to bypass the outlet check valve 25. As further apparent from Figure 23, a bypass check valve 19 may be positioned in the bypass line 15, between the dryer inlet line 1A and the refill valve 16, thereby preventing bypass of the desiccant cartridge 22 during the drying mode of the air dryer 20. Optionally, as depicted in Figure 23, the refill valve 16 may include a flow restrictor 17, such as an orifice plate, which can help ensure fail-safe operation of the air dryer 20 by limiting potential leaks of airflow via the refill valve 16 while allowing efficient refilling of the dryer inlet line 1A.

[0186] As shown in Figure 23, the refill valve 16 can be pneumatically controlled in coordination with the purge valve 30, thereby achieving finely coordinated valve actuation. For example, the purge valve 30 may include a purge valve control input 33 connected to the first control input port 4P via a purge valve control signal line 53, and the refill valve 16 may include a refill valve control input 16a, which is also connected to the first control input port 4P, for example, via a refill valve control signal line 18. In this way, the refill valve 16 can be actuated only when the purge valve 30 is active, and it can further prevent backflow via the bypass line 15 during the drying mode of the air dryer 20.

[0187] Figures 24 and 25 provide cross-sectional representations of the air dryer 20 according to an embodiment in different planes, illustrating the purge valve 30 and refill valve 16 of the air dryer 20, in order to illustrate possible implementations of the refill device 14 described above. As depicted in Figure 24, the dryer inlet line 1A may include a fluid connection to the bypass line 15. As depicted in Figure 25, the refill valve 16 may be arranged near the outlet check valve 25. The refill valve 16 is preferably pneumatically controllable via a first control input port 4P, which is fluidly connected to the refill valve 16 via a refill valve control signal line 18. As is apparent from Figure 25, the first control input port 4P may also be connected to the purge valve control input 33 via a purge valve control signal line 53, thereby allowing coordinated control of the purge valve 30 and the refill valve 16.

[0188] Figure 26 is a pneumatic circuit representation of an air dryer 20 with a refill device 14 according to another embodiment. The refill device 14 depicted in Figure 26 is configured to use a regeneration line 27 as the refill line, instead of the additional bypass line 15 as explained with reference to Figures 23 to 25. As shown in Figure 26, the regeneration line 27 is adapted to bypass the outlet check valve 25 to fluidly connect the dryer outlet line 28 to the dryer inlet line 1A via the desiccant box 22. In this way, the air dryer 20 is configured to refill the dryer inlet line 1A with compressed air from the dryer outlet line 28 via the regeneration line 27, depending on a pneumatic regeneration control signal.

[0189] Figure 27 is a pneumatic circuit representation of an air dryer 20 with a refill device 14 according to another embodiment. The air dryer 20 according to Figure 27 may include substantially similar structures and operating principles compared to the air dryer 20 according to Figure 26. In contrast to the air dryer 20 according to Figure 26, the air dryer 20 according to Figure 27 includes an electronically controlled refill device 14 using a regeneration line 14 based on the regeneration and refilling process. As depicted, the regeneration line 27 may be connected to a separate, additional control input port 4R for selectively supplying a regeneration airflow from an external source (e.g., from a supply line 12 connected to the dryer outlet 2) based on an electronic regeneration and refill signal. Compared to a regeneration signal optimized for desiccant cartridge regeneration, the electronic regeneration and refill signal can maintain the regeneration and refill airflow through the regeneration line 27 for a longer period, allowing refilling of the dryer inlet line 1A with the regeneration airflow after the switching valve 40, which has been activated in coordination with the regeneration process, has been deactivated.

[0190] Embodiments of the present invention achieve various effects and advantages. For illustration, the embodiments provide an air dryer system capable of operating in a more general manner and a control method for use with such an air dryer system. The air dryer system and control method allow regeneration to be performed without setting the compressor to an unloaded state (e.g., idling or stopped), and / or allow the compressor to discharge from the discharge line without affecting the pneumatic consumer system. The air dryer system and control method provide this functionality with a low number of additional solenoid valves. The air dryer system and control method are easily applied to dual-chamber air dryer configurations.

[0191] Various modifications can be made in the additional embodiments. For illustration, while a pneumatic vehicle system may include a pneumatic braking system and / or a pneumatic leveling system, it may also include alternative or additional pneumatic consumable systems, such as sensor cleaning systems, which may be part of a driver assistance system. To further illustrate, while an air dryer system with a dual-chamber configuration may include two air dryers with identical construction, it may also include two air dryers with different constructions.

[0192] This disclosure also separately covers all additional features shown in the accompanying drawings, although they may not have been described in the preceding or following description. Furthermore, individual alternatives to the embodiments described in the drawings, and individual alternatives to their descriptions and features, may deviate from the subject matter of the invention or the disclosed subject matter. This disclosure includes the subject matter consisting of the features defined in the claims or exemplary embodiments, as well as the subject matter including said features.

[0193] Furthermore, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. A single unit or step can perform the function of several features recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used advantageously. The terms "substantially," "about," "approximately," "basically," etc., in conjunction with an attribute or value, specifically and precisely define that attribute or value. Any reference numerals in the claims should not be construed as limiting the scope.

[0194] List of reference numerals (part of this application):

[0195] 1. Dryer Inlet

[0196] 1A Dryer Inlet Pipeline

[0197] 2 Dryer outlet

[0198] 2C Select Control Output Port

[0199] 3. Dryer exhaust device

[0200] 4 Compressor control output ports

[0201] 4P First Control Input Port

[0202] 4R Second Control Input Port

[0203] 4S Third Control Input Port

[0204] 10 Air Dryer System

[0205] 11 Compressor discharge line

[0206] 12 supply pipelines

[0207] 13 Compressor unloading control line

[0208] 14 Refilling device

[0209] 15 Bypass pipelines

[0210] 16 Refill Valve

[0211] 16a Refill Valve Control Input

[0212] 17 Current Limiter

[0213] 18 Refill Valve Control Signal Line

[0214] 19 Bypass Check Valve

[0215] 20 air dryers

[0216] 21 Air dryer housing

[0217] 21a box retainer

[0218] 22 Desiccant Box

[0219] 23 Desiccant Box Port

[0220] 24 Additional desiccant box ports

[0221] 25 Outlet Check Valve

[0222] 26 Regeneration Check Valve

[0223] 27 Regeneration Pipeline

[0224] 27a limiter

[0225] 28 Dryer outlet pipeline

[0226] 29. Select control pipeline

[0227] 30 purge valve

[0228] 31 First purge valve port

[0229] 32 Second purge valve port

[0230] 33 Purge Valve Control Input

[0231] 40 switching valve

[0232] 41 First switching valve port

[0233] 42 Second switching valve port

[0234] 43 Third switching valve port

[0235] 44 Switching Valve Control Input

[0236] 45 valve housing

[0237] 46a common bottom element

[0238] 46b bottom area

[0239] 46c common exhaust volume

[0240] 46D silencer

[0241] 47a First purge valve seat

[0242] 47b Second purge valve seat

[0243] 47c blocking element

[0244] 47d purge valve stroke

[0245] 48a First Switching Valve Seat

[0246] 48b Second Switching Valve Seat

[0247] 48d switching valve stroke

[0248] 51 First purge valve connection line

[0249] 52 Second purge valve connection line

[0250] 53 Purge Valve Control Signal Line

[0251] 54 First switching valve connection pipeline

[0252] 55 Second switching valve connection pipeline

[0253] 56 Third switching valve connection pipeline

[0254] 57 Switching valve control signal line

[0255] 59 Control valve assembly, solenoid valve assembly

[0256] 60 First Solenoid Valve

[0257] 61 First Solenoid Valve Input Port

[0258] 62 First solenoid valve output port

[0259] 63 First control signal pipeline

[0260] 64 First Solenoid Valve Input Line

[0261] 70 Second Solenoid Valve

[0262] 71 Second Solenoid Valve Input Port

[0263] 72 Second Solenoid Valve Output Port

[0264] 73 Second control signal pipeline

[0265] 74 Second Solenoid Valve Input Line

[0266] 80 Third Solenoid Valve

[0267] 81 Third Solenoid Valve Input Port

[0268] 82 Third Solenoid Valve Output Port

[0269] 83 Regeneration Control Signal Line

[0270] 84 Third Control Signal Line

[0271] 85 Third Solenoid Valve Input Line

[0272] 90 Pneumatic Vehicle System

[0273] 91 compressor

[0274] 92 Compressor Discharge Port

[0275] 93 compressor intake pipe

[0276] 94 supply tank

[0277] 95 Pneumatic Consumer System Storage

[0278] 96 check valve

[0279] 97 Electronic Control Unit

[0280] 98 electrical control signal link

[0281] 99 control pressure signal line

[0282] 101 Other dryer inlets

[0283] 102 Other dryer outlets

[0284] 102C also offers alternative control output ports.

[0285] 103. Additional dryer exhaust system

[0286] 104P's other first control input port

[0287] 104R's additional second control input port

[0288] 104S's additional third control input port

[0289] 105 Select Interconnect Pipeline

[0290] 120 additional air dryers

[0291] 121. Additional casing

[0292] 122 Additional desiccant box

[0293] 125 Additional outlet check valve

[0294] 126. Additional regeneration check valve

[0295] 128. Additional dryer outlet pipeline

[0296] 130 additional purge valve

[0297] 140 additional switching valves

[0298] 150 Fourth Solenoid Valve

[0299] 151 Fourth Solenoid Valve Input Port

[0300] 152 Fourth Solenoid Valve Output Port

[0301] 153 Fourth Control Signal Line

[0302] 160 Another fourth solenoid valve

[0303] 161. An additional fourth solenoid valve input port

[0304] 162. Another fourth solenoid valve output port

[0305] 163. An additional fourth control signal pipeline

[0306] 170 vehicles

[0307] 171 Compressor Driver

[0308] 173 Pneumatic Consumer System

[0309] 174 Pneumatic Consumer

[0310] 175 Pneumatic Consumer System Valve

[0311] 176 Pneumatic Consumer System Connection

[0312] 178' axle

[0313] 179 wheels

[0314] 180 braking system

[0315] 181 brake cylinder

[0316] 182 sensors

[0317] 183, 184 modulators

[0318] 186 electrical control interface

[0319] 187 Electrical Modulator Control Line

[0320] 190 air spring system

[0321] 191 air spring

[0322] 192 sensors

[0323] 193, 194 modulators

[0324] 196 modulator output

[0325] 197 Electrical modulator control line

[0326] 200 methods

[0327] 201 Method Steps

[0328] 202 Method Steps

[0329] 203 Method Steps

[0330] Method 210

[0331] 211 Method and Steps

[0332] 212 Method and Steps

[0333] 213 Method and Steps

[0334] 214 Method Steps

[0335] 220 commercial vehicles

[0336] 221 Pneumatic Vehicle System

[0337] 300 return spring

[0338] 301 upper piston element

[0339] 302 O-ring

[0340] 303 insert

[0341] 304 lower piston element

[0342] 305 gasket

[0343] 306 assembly screws

[0344] AF airflow

[0345] CP1 first control pressure signal

[0346] CP2 Second Control Pressure Signal

[0347] CP3 Third Control Pressure Signal

[0348] CPR regeneration control pressure signal

[0349] S1 First Electrical Control Signal

[0350] S2 Second Electrical Control Signal

[0351] S3 Third Electrical Control Signal

[0352] S4 Fourth Electrical Control Signal

[0353] S4' is another fourth electrical control signal.

Claims

1. A vehicle air dryer system (10), comprising: Dryer inlet (1), configured to receive air from compressor discharge line (11); dryer outlet (2), configured to supply dry air; desiccant box (22), configured to receive the air from dryer inlet (1) via dryer inlet line (1A) and supply the dry air via dryer outlet line (28) for output to dryer outlet (2); dryer exhaust device (3); pneumatic control. The pneumatic control valve assemblies (30, 40) are configured to selectively vent from the compressor discharge line (11) and / or from the desiccant box (22) via the dryer venting device (3), and the control valve assembly (59) is configured to provide control pressure signals (CP1, CP2, CP3) to at least one of the pneumatic control valve assemblies (30, 40) and the compressor (91) connected to the compressor discharge line (11).

2. The vehicle air dryer system (10) according to claim 1, wherein, The pneumatic control valve assembly (30, 40) includes: a purge valve (30) having a first purge valve port (31) connected to the dryer inlet line (1A) and a second purge valve port (32) connected to the dryer exhaust device (3); and a switching valve (40) having a first switching valve port (41) connected to the dryer inlet line (1A), a second switching valve port (42) connected to the desiccant box (22), and a third switching valve port (43) connected to the dryer exhaust device (3).

3. The vehicle air dryer system (10) according to claim 2, wherein, The pneumatic control valve assembly (30, 40) is arranged in a valve housing (45) which is mechanically connected to a box retainer (21a) that receives the desiccant box (22), and wherein the purge valve (30) and the switching valve (40) are arranged in parallel in the valve housing (45).

4. The vehicle air dryer system (10) according to claim 3, wherein, The purge valve (30) and the switching valve (40) extend vertically to the box retainer (21a).

5. The vehicle air dryer system (10) according to any one of claims 2-4, wherein, The purge valve (30) and the switching valve (40) include a common bottom element (46a) having a first purge valve seat (47a) for the purge valve (30) and a first switching valve seat (48a) for the switching valve (40).

6. The vehicle air dryer system (10) according to claim 5, wherein, The valve housing (45) includes a second switching valve seat (48b) for the switching valve (40).

7. The vehicle air dryer system (10) according to claim 6, wherein, The valve housing (45) further includes a second purge valve seat (47b) for the purge valve (30), and wherein the purge valve (30) or the valve housing (45) includes a blocking element (47c) for limiting the purge valve stroke (47d) of the purge valve (30) to a lower valve stroke compared to the switching valve stroke (48d) of the switching valve (40).

8. The vehicle air dryer system (10) according to any one of claims 2-7, wherein, The purge valve (30) and the switching valve (40) share a common exhaust volume (46c) arranged in the bottom region (46b) of the valve housing (45).

9. The vehicle air dryer system (10) according to claim 8, wherein, The muffler (46d) is arranged in the common exhaust volume (46c).

10. The vehicle air dryer system (10) according to any of the preceding claims, wherein, The vehicle air dryer system (10) includes a refilling device (14) for selectively refilling the dryer inlet line (1A) using compressed air from the dryer outlet line (28) or from a supply line (12) connected to the dryer outlet (2).

11. The vehicle air dryer system (10) according to claim 10, wherein, The refilling device (14) includes a refill valve (16) arranged in a bypass line (15) that connects the dryer inlet line (1A) to the dryer outlet line (28).

12. The vehicle air dryer system (10) according to claim 11, wherein, The refill valve (16) can be pneumatically controlled in coordination with the purge valve (30).

13. The vehicle air dryer system (10) according to claim 11 or 12, wherein, The refill valve (16) includes a flow restrictor (17).

14. The vehicle air dryer system (10) according to claim 10 further includes a regeneration line (27) that bypasses the outlet check valve (25) in the dryer outlet line (28), wherein, The vehicle air dryer system (10) is configured to refill the dryer inlet line (1A) via the regeneration line (27) using compressed air from the dryer outlet line (28).

15. An air dryer (20) for use in an automotive air dryer system (10) according to any one of the preceding claims, the air dryer (20) comprising: The dryer inlet (1) is configured to receive air from the compressor discharge line (11), the dryer outlet (2) is configured to supply dry air, the desiccant box (22) is configured to receive the air from the dryer inlet (1) via the dryer inlet line (1A) and supply the dry air via the dryer outlet line (28) for output to the dryer outlet (2), the dryer exhaust device (3), and the pneumatic control valve assembly (30, 40) is configured to selectively exhaust air from the compressor discharge line (11) and / or from the desiccant box (22) via the dryer exhaust device (3).

16. A pneumatic vehicle system (90), comprising: The system includes a compressor (91) connected to the dryer inlet (1) via a compressor discharge line (11), an automotive air dryer system (10) according to any one of claims 1-14, a pneumatic consumer system (173) connected to the dryer outlet (2) via a supply line (12), and an electronic control unit (97) configured to control the control valve assembly (59).

17. A vehicle (170), particularly a commercial vehicle (220), comprising a pneumatic vehicle system (90) according to claim 16.

Images