Hydraulic fluid heating module, modular valve block, and utility vehicle

Abstract

The invention relates to a hydraulic fluid heating module (24) for a modular valve block (18), comprising a housing block (32) and an adjustable pressure-limiting valve (38) which is arranged at least partially within the housing block (32), the housing block (32) having a first hydraulic fluid connection (36) and a second hydraulic fluid connection (37), the pressure-limiting valve (38) being connected to the first hydraulic fluid connection (36) and to the second hydraulic fluid connection (37), and the pressure-limiting valve (38) being designed to heat hydraulic fluid (F) flowing through the pressure-limiting valve (38) during operation of the hydraulic fluid heating module (24) in that the pressure-limiting valve (38) transfers its hydraulic power loss to the hydraulic fluid (F) in the form of heat (Q).

Description

[0001] RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 1 HYDRAULIC FLUID HEATING MODULE, MODULAR VALVE BLOCK AND COMMERCIAL VEHICLE The present invention relates to a hydraulic fluid heating module for a modular valve block, a modular valve block with at least one such hydraulic fluid heating module and a commercial vehicle, in particular a military commercial vehicle, with at least one such hydraulic fluid heating module and / or at least one such modular valve block. When operating commercial vehicles, it may be necessary, particularly at low ambient temperatures, to preheat a hydraulic fluid circulating in a hydraulic system of the commercial vehicle in order to reduce its viscosity. According to internal company knowledge, such preheating of the hydraulic fluid can be carried out electrically. However, electrical hydraulic fluid preheating requires long warm-up phases and large installation spaces in a tank of the hydraulic system.A commercial vehicle's electrical system is subjected to significant stress, especially at very low temperatures. The battery performance of a commercial vehicle's battery drops significantly at low temperatures, and an average installed generator output is generally insufficient to additionally heat the hydraulic fluid. Alternatively, the hydraulic fluid can be preheated stationary via an external power supply before the hydraulic system is put into operation, but this has a negative impact on the operational capability and flexibility of the commercial vehicle. At low temperatures, the wind and the typically large radiating surface of the hydraulic system's tank can lead to a significant cooling of the hydraulic fluid, which cannot be compensated for by a stationary power supply.The potential surface area of ​​electric heating elements is low due to the sometimes very low flow rates within the tank. Therefore, the use of heating elements within the tank does not offer a satisfactory solution. Furthermore, according to internal company findings, it is possible to use hydraulic fluid-to-water heat exchangers to preheat the hydraulic fluid. However, such hydraulic fluid-to-water heat exchangers require increased piping complexity for both the hydraulic system and the engine coolant circuit of a commercial vehicle engine. The additional heat removal from the coolant circuit extends the engine's warm-up phase. After the engine has reached operating temperature, the coolant temperature is generally higher than the optimal temperature range for the hydraulic fluid.Even during a temporary shutdown of the hydraulic system, the hydraulic fluid would have to be circulated, or the hydraulic fluid-to-water heat exchanger would have to be disconnected from the coolant circuit to prevent overheating of the hydraulic fluid in the hydraulic fluid-to-water heat exchanger. Against this background, one object of the present invention is to provide an improved hydraulic fluid heating module. Accordingly, a hydraulic fluid heating module for a modular valve block is proposed.The hydraulic fluid heating module comprises a housing block and an adjustable pressure relief valve which is arranged at least in sections within the housing block, wherein the housing block has a first hydraulic fluid connection and a second hydraulic fluid connection, wherein the pressure relief valve is connected to the first hydraulic fluid connection and to the second hydraulic fluid connection, and wherein the pressure relief valve is configured to heat a hydraulic fluid flowing through the pressure relief valve during operation of the hydraulic fluid heating module by the pressure relief valve transferring its hydraulic power loss to the hydraulic fluid in the form of heat.Because the hydraulic fluid heating module has the pressure relief valve, which can transfer its power loss as heat to the hydraulic fluid, electrical heating of the hydraulic fluid or heating of the hydraulic fluid with the aid of a hydraulic fluid-water heat exchanger is unnecessary. This results in a simple and trouble-free design. Furthermore, the compact hydraulic fluid heating module allows for significant space savings. Thermal damage to the hydraulic fluid is eliminated. The fact that the valve block is "modular" in this case means, in particular, that the valve block can be constructed from a multitude of different valve block modules. One type of such a valve block module is the aforementioned hydraulic fluid heating module. A "module" in this case is understood to mean, in particular, a compact unit or a compact assembly that can be handled as a whole.The hydraulic fluid heating module can, for example, have a block-shaped or cuboidal structure. This makes it possible to construct the modular valve block from a multitude of different valve block modules that are connected to one another to form the modular valve block. The "adjustable" pressure relief valve is understood here to mean, in particular, that a hydraulic fluid pressure can be set at which the pressure relief valve opens. The higher this set hydraulic fluid pressure, the smaller the flow cross-section of the pressure relief valve for a defined, in particular constant, volume flow of the hydraulic fluid.The smaller the flow cross-section, the greater the hydraulic power loss of the pressure relief valve at the defined volume flow of the hydraulic fluid, and thus more heat is transferred to the hydraulic fluid. The preheating of the hydraulic fluid is thus achieved in particular with the help of the defined volume flow of the hydraulic fluid, which works against the pressure relief valve with its defined hydraulic fluid pressure setting. Hydraulic power generated in the pressure relief valve, in particular its hydraulic power loss, is converted into heat and transferred in particular to the hydraulic fluid and / or to the pressure relief valve. The housing block is preferably cuboidal or cubic. The housing block can be made, for example, from a steel alloy or an aluminum alloy.The housing block can have a bore in which the pressure relief valve is accommodated. The pressure relief valve can protrude from the housing block. The pressure relief valve can be screwed into the housing block as a compact unit. In particular, the pressure relief valve is in fluid communication with the first hydraulic fluid connection and with the second hydraulic fluid connection. The first hydraulic fluid connection and the second hydraulic fluid connection can be couplings or connecting elements attached to the housing block, which enable hydraulic fluid lines to be connected to the first hydraulic fluid connection and to the second hydraulic fluid connection, which lead to and away from the housing block. Within the housing block, in particular, hydraulic fluid lines are provided, which can be introduced into the housing block in the form of bores.With the help of these hydraulic fluid lines, the pressure relief valve is in fluid communication with the first hydraulic fluid connection and with the second hydraulic fluid connection.RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 5 At least part of the power loss is dissipated as heat to the pressure relief valve, in particular to a valve body and to a valve housing of the pressure relief valve. The pressure relief valve, in turn, dissipates the absorbed heat to the hydraulic fluid flowing through the pressure relief valve. Furthermore, the hydraulic fluid dissipates heat to the pressure relief valve and to the housing block. The pressure relief valve dissipates heat to the housing block by heat conduction and vice versa. The housing block, in turn, dissipates heat to the hydraulic fluid flowing through the housing block.During operation of the hydraulic fluid heating module, a continuous heat exchange takes place between the hydraulic fluid, the pressure relief valve, and / or the housing block. This can lead to the hydraulic fluid heating module heating evenly. Heating occurs, in particular, through friction when the hydraulic fluid flows through the pressure relief valve, which functions as a throttle or throttling point. According to one embodiment, the hydraulic fluid heating module has a shut-off valve arranged at least partially within the housing block, which is located between the first hydraulic fluid connection and the pressure relief valve. The shut-off valve is, in particular, a 2 / 2-way valve. The shut-off valve can be arranged partially within the housing block and partially outside the housing block. The hydraulic fluid heating module can be activated and deactivated using the shut-off valve.If the shut-off valve is closed, no hydraulic fluid flows through the hydraulic fluid heating module. If the shut-off valve is opened, the hydraulic fluid heating module is activated so that the hydraulic fluid flows through the hydraulic fluid heating module to absorb heat. In particular, the pressure relief valve is in fluid communication with the first hydraulic fluid connection and with the second hydraulic fluid connection when the shut-off valve is open. According to a further embodiment, the hydraulic fluid heating module has a volume flow orifice arranged at least in sections within the housing block, which is arranged between the first hydraulic fluid connection and the pressure relief valve. In particular, the volume flow orifice is arranged between the first hydraulic fluid connection and the shut-off valve.The shut-off valve is accordingly positioned between the volume flow orifice and the pressure relief valve. A first hydraulic fluid line, arranged within the housing block, leads from the first hydraulic fluid connection to the pressure relief valve. The first hydraulic fluid line can be implemented through bores drilled into the housing block. The shut-off valve is connected to this first hydraulic fluid line. The volume flow orifice is also connected to the first hydraulic fluid line. The volume flow orifice functions, in particular, as a throttle or throttling point. According to a further embodiment, the hydraulic fluid heating module has an adjustable primary pressure relief valve arranged at least partially within the housing block and located between the first hydraulic fluid connection and the second hydraulic fluid connection.In particular, a second hydraulic fluid line runs from the second hydraulic fluid connection through the housing block to the pressure relief valve. The primary pressure relief valve is arranged between the first hydraulic fluid line and the second hydraulic fluid line, with a third hydraulic fluid line leading from the first hydraulic fluid line to the second hydraulic fluid line. The primary pressure relief valve is connected to this third hydraulic fluid line. RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 7. The primary pressure relief valve can prevent pressure-related damage to the hydraulic fluid heating module.According to a further embodiment, the hydraulic fluid heating module has a load detection volume flow orifice arranged at least partially within the housing block, wherein the pressure relief valve and the load detection volume flow orifice are connected in parallel. In particular, a load detection line branches off from the first hydraulic fluid line, into which the load detection volume flow orifice is connected. The load detection volume flow orifice functions in particular as a throttle or throttling point. According to a further embodiment, the hydraulic fluid heating module has a load detection changeover valve arranged at least partially within the housing block and located downstream of the load detection volume flow orifice. A volume flow of the hydraulic fluid reduced by the load detection volume flow orifice flows via the load detection changeover valve to a load detection connection.According to a further embodiment, the hydraulic fluid heating module has a load detection connection attached to the housing block. The load detection connection is operatively connected, in particular, to a load detection controller of a control pump.RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 8 According to a further embodiment, the load detection connection can be connected to a load detection controller of a control pump in order to request from the control pump a hydraulic fluid pressure required for the pressure relief valve of the hydraulic fluid flowing through the pressure relief valve during operation of the hydraulic fluid heating module.The control pump with its load detection controller can be part of a hydraulic system that has the hydraulic fluid heating module. According to a further embodiment, the pressure relief valve has a movable valve body and an actuating element for moving the valve body.The actuating element can be used to adjust the hydraulic fluid pressure at which the pressure relief valve opens. The valve body can be displaced linearly relative to a valve housing of the pressure relief valve to open and close the pressure relief valve. The actuating element is provided for this purpose. Alternatively, the valve body can also perform a rotary movement relative to the valve housing to open and close the pressure relief valve. The actuating element can be, for example, an electric motor, an electromagnet, or a piezo element. The actuating element is particularly preferably an adjusting screw with a lock nut. The valve body is spring-loaded, in particular toward a closed state of the pressure relief valve. For this purpose, the pressure relief valve can have a spring element.The valve body can be moved against a spring preload of the spring element in order to move the pressure relief valve from the closed state to an open state. This spring preload of the spring element can be changed using the actuating element in order to set the desired hydraulic fluid pressure at which the pressure relief valve should open.RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 9 According to a further embodiment, a flow cross-section of the pressure relief valve and thus a heating output of the hydraulic fluid heating module can be adjusted using the valve body. The smaller the flow cross-section, the higher the flow resistance of the pressure relief valve. The pressure relief valve comprises a valve opening that can be covered and uncovered by the valve body. The more the valve body covers the valve opening, the smaller the flow cross-section.In this context, the "flow cross-section" refers to a cross-section through which the hydraulic fluid can flow when the pressure relief valve is open. According to a further embodiment, the hydraulic fluid heating module has a hydraulic fluid circuit arranged within the housing block, wherein the hydraulic fluid circuit has the first hydraulic fluid connection, the second hydraulic fluid connection, and the pressure relief valve. The hydraulic fluid circuit can also have the shut-off valve, the volume flow orifice, the primary pressure relief valve, the load-sensing volume flow orifice, and / or the load-sensing changeover valve.According to a further embodiment, the hydraulic fluid circuit comprises hydraulic lines arranged within the housing block, wherein the first hydraulic fluid connection, the second hydraulic fluid connection, and the pressure relief valve are connected to one another by means of the hydraulic fluid lines. In particular, the first hydraulic fluid connection, the second hydraulic fluid connection, and the pressure relief valve are fluidly connected to one another by means of the hydraulic fluid lines. In particular, the hydraulic fluid circuit comprises the aforementioned first hydraulic fluid line, which leads from the first hydraulic fluid connection to the pressure relief valve, and the second hydraulic fluid line, which leads from the pressure relief valve to the second hydraulic fluid connection.According to a further embodiment, the pressure relief valve is cartridge-shaped, with the pressure relief valve being screwed into the housing block. "Cartridge-shaped" is understood here in particular to mean that the pressure relief valve is designed as a compact assembly that can be handled as a single unit and can be mounted on or in the housing block. In particular, "cartridge-shaped" can also mean that the pressure relief valve is constructed rotationally symmetrically to a central or symmetry axis. Furthermore, a modular valve block with at least one such hydraulic fluid heating module is proposed. The modular valve block can have any number of hydraulic fluid heating modules. In addition to the hydraulic fluid heating module, the modular valve block can have different valve block modules, which together form the modular valve block.The valve block modules can differ from one another in their function and / or structure. The modular valve block can further comprise a connecting plate and a closing plate, wherein the valve block modules are arranged between the connecting plate and the closing plate. The connecting plate and the closing plate can be connected to one another using fastening elements, for example in the form of screws, so that the valve block modules are clamped or tensioned between the connecting plate and the closing plate. The fastening elements are preferably passed through all of the valve block modules. Furthermore, a commercial vehicle, in particular a military commercial vehicle, with at least one such hydraulic fluid heating module and / or at least one such modular valve block is proposed.The commercial vehicle comprises, in particular, a hydraulic system as mentioned above, wherein the hydraulic fluid heating module and / or the modular valve block are part of this hydraulic system. The hydraulic system, in turn, can be part of a chassis of the commercial vehicle. The commercial vehicle is, in particular, an armored commercial vehicle. The commercial vehicle can be a truck. In particular, the commercial vehicle is an off-road truck. The commercial vehicle is multi-axle. The commercial vehicle can be two-axle, three-axle, four-axle, or five-axle. The commercial vehicle preferably includes all-wheel drive. The commercial vehicle can therefore also be referred to as an all-wheel drive commercial vehicle. The term "protected" is understood here to mean, in particular, that the commercial vehicle is protected against shelling, booby traps, improvised explosive devices (IEDs), mines, or the like.The embodiments and features described for the proposed hydraulic fluid heating module apply to the proposed modular valve block and the proposed commercial vehicle, and vice versa. "One" is not necessarily to be understood as limiting the number to exactly one element. Rather, multiple elements, such as two, three, or more, may also be provided. Any other numbering term used here should also not be understood as implying a limitation to the exact number of elements stated. Rather, numerical deviations upwards and downwards are possible, unless otherwise stated.Further possible implementations of the hydraulic fluid heating module, the modular valve block, and / or the commercial vehicle also include combinations of features or embodiments described previously or below with regard to the exemplary embodiments, which are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the hydraulic fluid heating module, the modular valve block, and / or the commercial vehicle. Further advantageous configurations and aspects of the hydraulic fluid heating module, the modular valve block, and / or the commercial vehicle are the subject of the dependent claims and the exemplary embodiments of the hydraulic fluid heating module, the modular valve block, and / or the commercial vehicle described below.The hydraulic fluid heating module, the modular valve block and / or the commercial vehicle are explained in more detail below using preferred embodiments with reference to the attached figures. Fig. 1 shows a schematic side view of an embodiment of a commercial vehicle; Fig. 2 shows a schematic perspective view of an embodiment of a modular valve block for the commercial vehicle according to Fig. 1; Fig. 3 shows a schematic perspective view of an embodiment of a hydraulic fluid heating module for the modular valve block according to Fig. 2; RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 13 Fig. 4 shows a schematic view of an embodiment of a hydraulic system for the commercial vehicle according to Fig. 1; and Fig. 5 shows a schematic sectional view of an embodiment of a pressure relief valve for the hydraulic fluid heating module according to F. ig. 3.In the figures, identical or functionally equivalent elements have been provided with the same reference numerals unless stated otherwise. Fig. 1 shows a schematic side view of an embodiment of a commercial vehicle 1. The commercial vehicle 1 is a land vehicle. The commercial vehicle 1 is in particular a military commercial vehicle. The commercial vehicle 1 can therefore also be referred to as a military commercial vehicle. The commercial vehicle 1 can be a truck. In particular, the commercial vehicle 1 is an off-road truck. The commercial vehicle 1 can be an armored vehicle. The commercial vehicle 1 can therefore also be referred to as an armored commercial vehicle. The commercial vehicle 1 is assigned a coordinate system with a longitudinal direction or x-direction x, a transverse direction or y-direction y and a vertical direction or z-direction z. The directions x, y, z are oriented perpendicular to one another.The z-direction z is oriented parallel to a direction of gravity g. The direction of gravity g is oriented from top to bottom in the orientation of Fig. 1. The commercial vehicle 1 is a wheeled vehicle. The commercial vehicle 1 comprises a chassis 2 with a plurality of axles 3, 4, 5, 6. The axles 3, 4, 5, 6 carry wheels 7, 8, 9, 10. Each of the axles 3, 4, 5, 6 is assigned at least one pair of wheels 7, 8, 9, 10. For example, four axles 3, 4, 5, 6 can be provided. This means that the commercial vehicle 1 is a four-axle vehicle in this case. However, the number of axles 3, 4, 5, 6 is arbitrary. Commercial vehicle 1 can also be a two-axle, a three-axle, or a five-axle vehicle. Commercial vehicle 1 preferably includes all-wheel drive. This means that all axles 3, 4, 5, and 6 are driven. Commercial vehicle 1 can therefore also be referred to as an all-wheel drive commercial vehicle.At least one of the axles 3, 4, 5, 6 is steerable. Preferably, two front axles or front axles 3, 4 are steerable. All axles 3, 4, 5, 6 can also be steerable. The chassis 2 supports a driver's cab 11 of the commercial vehicle 1. The driver's cab 11 is preferably protected against gunfire, booby traps, improvised explosive devices (IEDs), mines, or the like. The driver's cab 11 defines an interior space 12 in which passengers, for example a driver and a passenger, can be located. The driver's cab 11 encloses the interior space 12 and thus separates it from the surroundings 13 of the driver's cab 11. The interior space 12 is accessible from the surroundings 13 by means of openable doors 14. The chassis 2 is suitable for supporting, in addition to the driver's cab 11, an interchangeable body 15 of the commercial vehicle 1.The superstructure 15 can, for example, be a flatbed, a container, a box, a tank, or the like. Figure 1 shows a superstructure 15 in the form of a container. The commercial vehicle 1 can move in a direction of travel 16 on a surface 17 with the aid of the wheels 7, 8, 9, 10. The direction of travel 16 is oriented opposite to the x-direction x. However, this does not preclude the commercial vehicle 1 from moving opposite to the direction of travel 16 on the surface 17—for example, in reverse gear. The ground 17 can be a road or any terrain.RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 15 Fig. 2 shows a schematic perspective view of an embodiment of a modular valve block 18 for the commercial vehicle 1. The valve block 18 is part of a hydraulic system, not shown, of the commercial vehicle 1. The hydraulic system can in turn be part of the chassis 2.For example, the hydraulic system is part of an all-wheel drive system of the commercial vehicle 1, as mentioned above. The hydraulic system can be part of any hydraulic assemblies of the commercial vehicle 1. The valve block 18 comprises a plurality of valve block modules 19, 20, 21, 22, 23, 24, which can be combined with one another, connected to one another, and separated from one another as desired. Each valve block module 19, 20, 21, 22, 23, 24 forms a compact unit or assembly that can be handled independently. The valve block modules 19, 20, 21, 22, 23, 24 are preferably block-shaped or cuboid-shaped. This makes it possible to arrange the valve block modules 19, 20, 21, 22, 23, 24 next to one another to form the valve block 18.The term "modular" for the valve block 18 is understood to mean that the valve block modules 19, 20, 21, 22, 23, 24 can be combined and connected to one another as desired to form the valve block 18. To equip the valve block 18 with specific properties, the valve block modules 19, 20, 21, 22, 23, 24 can be selected, for example, from a modular system containing a wide variety of valve block modules 19, 20, 21, 22, 23, 24 and combined with one another. The valve block modules 19, 20, 21, 22, 23, 24 are arranged between a connecting plate 25 and an end plate 26. The connecting plate 25 and the end plate 26 are connected to one another by means of three fastening elements 27, 28, 29, for example in the form of so-called stud nuts. The fastening elements 27, 28, 29 extend through all valve block modules 19, 20, 21, 22, 23, 24.For example, the fastening elements 27, 28, 29 are passed through holes provided in the end plate 26 and screwed into threaded holes provided in the connecting plate 25. The valve block modules 19, 20, 21, 22, 23, 24 are clamped together by means of the fastening elements 27, 28, 29. Seals, for example in the form of O-rings, can be provided between the valve block modules 19, 20, 21, 22, 23, 24. Furthermore, two screw plugs 30, 31 are shown in Fig. 2. For example, the valve block module 19 is a first directional valve module and is also referred to as such below. The valve block module 20 can be a second directional valve module and is also referred to as such below. The valve block module 21 is a priority module and is also referred to as such below. The valve block module 22 is a third directional valve module and is also referred to as such below.The valve block module 23 is a fourth directional control valve module and will also be referred to as such below. The valve block module 24 is a hydraulic fluid heating module and will also be referred to as such below. In the orientation of Fig. 2, the connection plate 25, the first directional control valve module 19, the second directional control valve module 20, the priority module 21, the third directional control valve module 22, the fourth directional control valve module 23, the hydraulic fluid heating module 24, and the end plate 26 are arranged side by side from left to right. Fig. 3 shows a schematic perspective view of an embodiment of a hydraulic fluid heating module 24 as mentioned above. During operation of the commercial vehicle 1, in particular at low ambient temperatures, it may be necessary to preheat a hydraulic fluid circulating in the hydraulic system of the commercial vehicle 1 in order to reduce its viscosity.According to internal company knowledge, such preheating of the hydraulic fluid can be carried out electrically. However, electrical hydraulic fluid preheating requires long warm-up phases and large installation spaces in a tank of the hydraulic system. Especially at very low temperatures, the electrical system of commercial vehicle 1 is subjected to considerable stress. The battery performance of a commercial vehicle 1 battery decreases significantly at low temperatures, and an average installed generator output is generally insufficient to additionally heat the hydraulic fluid. Alternatively, the hydraulic fluid can be preheated stationary via an external power supply before commissioning the hydraulic system, but this has a negative impact on the operational capability and flexibility of commercial vehicle 1.At low temperatures, the wind and the typically large radiating surface of the hydraulic system's tank can lead to a significant cooling of the hydraulic fluid, which can no longer be compensated for by a stationary power supply. The potential surface area of ​​electric heating elements is low due to the sometimes very low flows within the tank. Therefore, the use of heating elements within the tank does not offer a satisfactory solution. Furthermore, according to internal company knowledge, it is possible to use hydraulic fluid-to-water heat exchangers to preheat the hydraulic fluid. However, such hydraulic fluid-to-water heat exchangers require increased piping complexity for both the hydraulic system and the engine coolant circuit of an engine of commercial vehicle 1. The additional heat removal from the coolant circuit extends the engine's warm-up phase.After the engine has reached operating temperature, the coolant temperature is typically higher than the optimal temperature range for the hydraulic fluid. Even if the hydraulic system is temporarily shut down, the hydraulic fluid would have to be recirculated, or the hydraulic fluid-water heat exchanger would have to be separated from the coolant circuit to prevent overheating of the hydraulic fluid in the hydraulic fluid-water heat exchanger. These aforementioned problems are solved with the help of the compact hydraulic fluid heating module 24, as explained below.With the help of the hydraulic fluid heating module 24, it is possible to provide an easy-to-integrate, compact, and powerful hydraulic fluid preheater for hydraulic systems in mobile applications, particularly in or on the commercial vehicle 1, where there is no stationary electrical supply and long warm-up phases before commissioning are completely or partially impossible. The use of a hydraulic fluid-water heat exchanger can be dispensed with. To ensure fast and reliable operation of the hydraulic system, the hydraulic fluid must be within an appropriate temperature range, starting at approximately 15°C. The hydraulic fluid heating module 24 enables this. Furthermore, it is possible to selectively quickly switch the hydraulic fluid heating module 24 on and off depending on the performance requirements of the mobile application, particularly of the commercial vehicle 1. The hydraulic fluid heating module 24 is part of the valve block 18.The valve block 18 can have any number of such hydraulic fluid heating modules 24. The hydraulic fluid heating module 24 comprises a cuboid-shaped or block-shaped housing block 32. The housing block 32 can be made, for example, from a steel alloy or an aluminum alloy. The housing block 32 comprises three openings 33, 34, 35 through which the aforementioned fastening elements 27, 28, 29 are passed. The openings 33, 34, 35 can be bores. The housing block 32 further comprises hydraulic fluid connections 36, 37, which are closed by means of the locking screws 30, 31 in the end plate 26. A first hydraulic fluid connection 36 and a second hydraulic fluid connection 37 are provided. Hydraulic fluid lines in the form of bores extend through the housing block 32, although these are not shown in Fig. 3.The housing block 32 is preferably a one-piece component, in particular a single-piece component. "One-piece" or "single-piece" means in particular that the housing block 32 is not composed of multiple subcomponents that must be connected to one another to form the housing block 32. "Single-piece material" in this case means in particular that the housing block 32 is made entirely of the same material. For example, the housing block 32 can be machined from a block-shaped semi-finished product using a machining process. Alternatively, the housing block 32 can also be made of several parts. An adjustable pressure relief valve 38 is accommodated in the housing block 32. The pressure relief valve 38 can be arranged partially inside and partially outside the housing block 32. The pressure relief valve 38 is particularly preferably cartridge-shaped.This means, in particular, that the pressure relief valve 38 is an easy-to-handle unit or assembly, which is, for example, screwed into a bore 39 provided on the housing block 32. "Cartridge-shaped" can also include the pressure relief valve 38 being constructed rotationally symmetrically to a central or symmetry axis. Furthermore, the hydraulic fluid heating module 24 includes a primary pressure relief valve 40. The primary pressure relief valve 40 can be arranged partially inside and partially outside the housing block 32. The primary pressure relief valve 40 is also cartridge-shaped and can be screwed into a bore 41 machined into the housing block 32. The pressure relief valve 38 and the primary pressure relief valve 40 can be constructed identically. However, this is not mandatory.The hydraulic fluid heating module 24 further includes a shut-off valve 42. The shut-off valve 42 is, in particular, a 2 / 2-way valve. The shut-off valve 42 can be screwed into a bore 43 of the housing block 32. With the aid of the shut-off valve 42, the hydraulic fluid heating module 24 can be selectively switched on or off. If the shut-off valve 42 is closed, no hydraulic fluid flows through the hydraulic fluid heating module 24 to be heated. If the shut-off valve 42 is open, hydraulic fluid flows through the hydraulic fluid heating module 24 to be heated. The hydraulic fluid is preheated using a defined volume flow of hydraulic fluid, which works against the pressure relief valve 38 with a defined hydraulic fluid pressure setting.Hydraulic power generated in the pressure relief valve 38, in particular its hydraulic power loss, is converted into heat and transferred to the hydraulic fluid and to the pressure relief valve 38. Figure 4 shows a schematic view of an embodiment of a hydraulic system 44 for the commercial vehicle 1. The valve block 18 is part of the hydraulic system 44. However, Figure 4 only shows the hydraulic fluid heating module 24 of the valve block 18. The hydraulic fluid heating module 24 comprises a hydraulic fluid circuit 45 arranged within the housing block 32. The hydraulic fluid circuit 45 is implemented by bores machined into the housing block 32. A hydraulic fluid F to be heated, in particular a hydraulic oil, can circulate in the hydraulic fluid circuit 45. Accordingly, a "fluid" is understood in this case to mean a liquid RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 21 ity.The terms "hydraulic fluid," "hydraulic oil," and "hydraulic fluid" can therefore be interchanged as desired. The hydraulic fluid circuit 45 is incorporated into the housing block 32 in such a way that the flow direction of the hydraulic fluid F, as it flows through the hydraulic fluid circuit 45, changes within the housing block 32 at least once, but preferably several times. In other words, the hydraulic fluid F can be redirected or deflected multiple times within the housing block 32. The flow direction of the hydraulic fluid F within the housing block 32 can also be reversed or reversed. The hydraulic fluid circuit 45 comprises a first hydraulic fluid line 46, which leads from the first hydraulic fluid connection 36 into the housing block 32.The first hydraulic fluid connection 36 can be a screw connection or other detachable coupling with the aid of which the hydraulic fluid heating module 24 can be connected to the hydraulic system 44. The first hydraulic fluid line 46 can be formed by a plurality of intersecting bores that are machined into the housing block 32 to form the first hydraulic fluid line 46. The first hydraulic fluid line 46 leads from the first hydraulic fluid connection 36 to the pressure relief valve 38. A volume flow orifice 47 is connected into the first hydraulic fluid line 46. The volume flow orifice 47 limits a volume flow of the hydraulic fluid F that can flow through the first hydraulic fluid line 46. Furthermore, the shut-off valve 42 is connected into the first hydraulic fluid line 46. The volume flow orifice 47 is arranged between the first hydraulic fluid connection 36 and the shut-off valve 42.The order of flow orifice 47 and shut-off valve 42 can also be reversed without affecting function. The shut-off valve 42 is arranged between the flow orifice 47 and the pressure relief valve 38. The shut-off valve 42 can be used to selectively open or close the first hydraulic fluid line 46. Upstream of the pressure relief valve 38, a load detection line 48 branches off from the first hydraulic fluid line 46, which has a load detection flow orifice 49. The pressure relief valve 38 and the load detection flow orifice 49 are connected in parallel. This means that the pressure relief valve 38 and the load-sensing volume flow orifice 49 can be flowed through by the hydraulic fluid F simultaneously and not one after the other. A load-sensing changeover valve 50 is arranged downstream of the load-sensing volume flow orifice 49.A load sensing connection 51 is assigned to the load sensing changeover valve 50. A second hydraulic fluid line 52 leads from the pressure relief valve 38 to the second hydraulic fluid connection 37, which is attached to the housing block 32. The second hydraulic fluid connection 37 can be a screw connection or other detachable coupling, with the aid of which the hydraulic fluid heating module 24 can be connected to the hydraulic system 44. The second hydraulic fluid line 52 can be formed by several intersecting bores that are machined into the housing block 32 to form the second hydraulic fluid line 52. A third hydraulic fluid line 53 runs between the two hydraulic fluid lines 46, 52 and fluidically connects the two hydraulic fluid lines 46, 52. Thus, the two hydraulic fluid connections 36, 37 are also in fluid communication with each other via the third hydraulic fluid line 53.The third hydraulic fluid line 53 can be a bore machined into the housing block 32. The primary pressure relief valve 40 is connected into the third hydraulic fluid line 53. The primary pressure relief valve 40 is thus arranged between the first hydraulic fluid port 36 and the second hydraulic fluid port 37. The hydraulic system 44 includes a tank 54 in which a portion of the hydraulic fluid F is accommodated. The tank 54 acts as a reservoir for the hydraulic fluid F. A suction line 55 leads from the tank 54 to a control pump 56 of the hydraulic system 44. A pressure line 57 leads from the control pump 56 to the first hydraulic fluid connection 36, so that the first hydraulic fluid connection 36 is in fluid communication with the tank 54 via the suction line 55, the control pump 56 and the pressure line 57.The control pump 56 is assigned a load sensing controller 58, which is operatively connected to the load sensing connection 51. A discharge line 59 is connected to the second hydraulic fluid connection 37, which leads from the second hydraulic fluid connection 37 to the tank 54. The heated hydraulic fluid F can be supplied to the tank 54 without pressure via the discharge line 59. Figure 5 shows a schematic sectional view of an embodiment of a pressure relief valve 38 as mentioned above. The pressure relief valve 38 is shown only very schematically in Figure 5. The pressure relief valve 38 comprises a valve housing 60. The valve housing 60 can be part of the housing block 32. However, this is not absolutely necessary. In the event that the pressure relief valve 38 is cartridge-shaped and is screwed into the housing block 32, the valve housing 60 is a separate component from the housing block 32.The valve housing 60 comprises a valve opening 61 through which the hydraulic fluid F can flow during operation of the hydraulic fluid heating module 24.RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 24 The valve opening 61 acts as a throttle in the hydraulic fluid circuit 45. The valve opening 61 can have any geometry. For example, the valve opening 61 is a bore made in the valve housing 60. The valve opening 61 has a flow cross-section 62, which is indicated in Fig. 5 by means of hatching. However, the flow cross-section 62 is not constant, but can be changed. This means, in particular, that the flow cross-section 62 is not constant, but can be changed. In order to change the flow cross-section 62 of the valve opening 61, the pressure relief valve 38 comprises a valve body 63.The valve body 63 can close or cover the valve opening 61 completely, partially, or completely. The valve body 63 can be rod-shaped, cylindrical, or conical. In principle, the valve body 63 can have any desired geometry. The valve body 63 can be received within a receiving area 64 provided in the valve housing 60. The receiving area 64 can be a bore. The valve body 63 can be linearly displaced within the receiving area 64, as indicated in Fig. 5 by a double arrow 65. Through this linear displacement of the valve body 63 in the receiving area 64, the flow cross-section 62 can be increased or decreased. Alternatively, the valve body 63 can also be rotated in the receiving area 64 to change the flow cross-section 62. In order to displace the valve body 63 linearly, the pressure relief valve 38 comprises an actuating element 66.The actuating element 66 can, for example, be an electric motor, an electromagnet, a piezo element, or the like. The actuating element 66 can also be an adjusting screw with a lock nut. A control unit 67 is assigned to the actuating element 66. With the help of the control unit 67, the actuating element 66 can, for example, be energized in order to move the valve body 63. The actuating element 66 can also be referred to as an actuator. Furthermore, the pressure relief valve 38 comprises a spring element 68 for spring-biasing the valve body 63. The spring preload of the spring element 68 can be varied with the help of the actuating element 66.The pressure relief valve 38 opens at a preset hydraulic fluid pressure of the hydraulic fluid F, in that the valve body 63 is lifted from a valve seat with the aid of the hydraulic fluid F in order to at least partially open the valve opening 61. With the aid of the adjusting element 66, the hydraulic fluid pressure can thus be adjusted at which the valve body 63 opens against a spring force of the spring element 68 in order to at least partially open the valve opening 61. Furthermore, the adjusting element 66 can be used to adjust the size of the flow cross-section 62 at the predetermined hydraulic fluid pressure. In other words, with the aid of the adjusting element 66, it can be adjusted, for example, whether the valve body 63 opens the valve opening 61 completely or only partially when the predetermined hydraulic fluid pressure is reached.To heat the hydraulic fluid F, a defined volume flow of the hydraulic fluid F, specified by the control pump 56, works against the pressure relief valve 38. The smaller the flow cross-section 62 is set, the greater the heating power provided by the pressure relief valve 38 to heat the hydraulic fluid F. The functionality of the hydraulic system 44 is explained below. As previously mentioned, the hydraulic fluid heating module 24 can be switched on. This means, in particular, that the hydraulic fluid heating module 24 can be used as needed to heat the hydraulic fluid F, for example, at low ambient temperatures. To activate the hydraulic fluid heating module 24, the shut-off valve 42 is opened so that the control pump 56 can supply the hydraulic fluid circuit 45 with hydraulic fluid F via the suction line 55 and the pressure line 57.The hydraulic fluid heating module 24 preferably has a presettable heating output of 2 to 15 kW. Depending on the desired heating output, the pressure relief valve 38 is adjusted accordingly using the actuating element 66. The hydraulic fluid F flows in the first hydraulic fluid line 46, initially through the volume flow orifice 47 and the shut-off valve 42 to the pressure relief valve 38. With the aid of the load detection volume flow orifice 49 and the load detection changeover valve 50, a load detection signal can be generated at the load detection connection 51. The hydraulic fluid F flows from the first hydraulic fluid connection 36 to the pressure relief valve 38 and to the load detection volume flow orifice 49 with a volume flow of the hydraulic fluid F reduced by the fixed, preset volume flow orifice 47.A volume flow of hydraulic fluid F reduced by the load sensing volume flow orifice 49 flows via the load sensing shuttle valve 50 to the load sensing port 51. The load sensing port 51 is operatively connected to the load sensing controller 58 of the control pump 56 and requests the hydraulic fluid pressure of the hydraulic fluid F required by the pressure relief valve 38 from the control pump 56. Once the hydraulic fluid pressure preset at the pressure relief valve 38 is reached, the pressure relief valve 38 opens and the hydraulic fluid F can be pumped back into the tank 54 without pressure via the second hydraulic fluid line 52 and the second hydraulic fluid port 37 as well as the discharge line 59.The pressure relief valve 38 converts its hydraulic power loss into heat transferred to the hydraulic fluid F or transfers the hydraulic power loss as heat Q to the hydraulic fluid F. The heating output of the hydraulic fluid heating module 24 depends in particular on the volume flow of the hydraulic fluid F limited by the volume flow orifice 47 and the hydraulic fluid pressure set at the pressure relief valve 38 and can be preset depending on the application. This preset should preferably be made such that a maximum permissible operating temperature of the hydraulic fluid F used is not exceeded.By using hydraulic preheating of the hydraulic fluid F, increased self-sufficiency and operational readiness of the mobile application, in particular of the commercial vehicle 1, can be achieved, as there is no dependence on an external power supply and, even at low temperatures, the required operating temperature of the hydraulic fluid F is quickly reached without additional load on other systems, thus enabling the mobile application, in particular of the commercial vehicle 1, to be ready for use. Depending on the liter capacity available in the hydraulic system 44 and a maximum hydraulic fluid pressure, the hydraulic preheating of the hydraulic fluid F offers a very high heating output while simultaneously requiring minimal installation space. In addition, only a temperature switch or sensor, if not already present, and another relay to control the pressure relief valve 38 are required in an electrical system.Due to the high circulation of the hydraulic fluid F in the housing block 32, a very high heating output can be achieved in a very small installation space, since the surface area is less critical. Retrofitting is possible with little effort for different hydraulic systems (not shown). The hydraulic fluid heating module 24 can be used both in mobile applications, for example in the commercial vehicle 1, and in immobile applications, for example in non-mobile machines. Although the present invention has been described using exemplary embodiments, it is susceptible to numerous modifications.

[0002] RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 29 LIST OF REFERENCE SYMBOLS 1 Nutzfahrzeug 2 chassis 3 Achse 4 Achse 5 Achse 7 Rad 8 Rad 9 Rad 10 Rad 11 Driver's cab12 Interior13 Surroundings 14 Tür15 Aufbau 16 Direction of travel 17 Subsurface 18 Valve block 19 Valve block module / directional valve module 20 Valve block module / directional valve module 21 Valve block module / priority module 22 Valve block module / directional valve module 23 Valve block module / directional valve module 24 Valve block module / hydraulic fluid heating module 25 Connection plate 26 End plate 27 Fastening element 28 Fastening element 29 Fastening element RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 30 30 Plug screw 31 Plug screw 32 Housing block 33 Breakthrough 34 Breakthrough 35 Breakthrough 36 Hydraulic fluid connection 37 Hydraulic fluid connection 38 Pressure relief valve 39 Bore 40 Primary pressure relief valve 41 Bore 42 Shut-off valve 43 Bore 44 Hydraulic system 45 Hydraulic fluid circuit 46 Hydraulic fluid line 47 Flow rate orifice 48 Load sensing line 49 Load sensing flow rate orifice 50 Load sensing changeover valve 51 Load detection connection 52 Hydraulic fluid line 53 Hydraulic fluid line 54 Tank55 Suction line 56 Control pump 57 Pressure line 58 Load sensing controller 59 Discharge line RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 3160 Valve housing 61 Valve opening 62 Flow cross-section 63 Valve body 64 Receiving area 65 Double arrow 66 Actuating element 67 Control unit 68 Spring element F Hydraulic fluid g Direction of gravity Q Wärme x x-directiony y-directionz z-direction

Claims

RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 32 PATENT CLAIMS1. Hydraulic fluid heating module (24) for a modular valve block (18), comprising a housing block (32) and an adjustable pressure relief valve (38) which is arranged at least in section within the housing block (32), wherein the housing block (32) has a first hydraulic fluid connection (36) and a second hydraulic fluid connection (37), wherein the pressure relief valve (38) is connected to the first hydraulic fluid connection (36) and to the second hydraulic fluid connection (37), and wherein the pressure relief valve (38) is configured, during operation of the hydraulic fluid heating module (24), to heat a hydraulic fluid (F) flowing through the pressure relief valve (38) by the pressure relief valve (38) transferring its hydraulic power loss in the form of heat (Q) to the hydraulic fluid (F).2.Hydraulic fluid heating module according to claim 1, characterized by a shut-off valve (42) arranged at least partially within the housing block (32) and arranged between the first hydraulic fluid connection (36) and the pressure relief valve (38).

3. Hydraulic fluid heating module according to claim 1 or 2, characterized by a volume flow orifice (47) arranged at least partially within the housing block (32) and arranged between the first hydraulic fluid connection (36) and the pressure relief valve (38).

4. Hydraulic fluid heating module according to one of claims 1 - 3, RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 33 characterized by an adjustable primary pressure relief valve (40) arranged at least in sections within the housing block (32), which is arranged between the first hydraulic fluid connection (36) and the second hydraulic fluid connection (37).5.Hydraulic fluid heating module according to one of claims 1-4, characterized by a load detection volume flow orifice (49) arranged at least in sections within the housing block (32), wherein the pressure relief valve (38) and the load detection volume flow orifice (49) are connected in parallel to one another.

6. Hydraulic fluid heating module according to claim 5, characterized by a load detection changeover valve (50) arranged at least in sections within the housing block (32) and arranged downstream of the load detection volume flow orifice (49).

7. Hydraulic fluid heating module according to one of claims 1-6, characterized by a load detection connection (51) attached to the housing block (32).8.Hydraulic fluid heating module according to claim 7, characterized in that the load detection connection (51) is connectable to a load detection controller (58) of a control pump (56) in order to request from the control pump (56) a hydraulic fluid pressure required for the pressure relief valve (38) of the hydraulic fluid (F) flowing through the pressure relief valve (38) during operation of the hydraulic fluid heating module (24).RMM24004PWO DPT24002 WORheinmetall MAN Military Vehicles Österreich GesmbH 349. Hydraulic fluid heating module according to one of claims 1 - 8, characterized in that the pressure relief valve (38) has a movable valve body (63) and an actuating element (66) for moving the valve body (63).

10. Hydraulic fluid heating module according to claim 9, characterized in that with the aid of the valve body (63) a flow cross-section (62) of the pressure relief valve (38) and thus a heating output of the hydraulic fluid heating module (24) can be adjusted.11.Hydraulic fluid heating module according to one of claims 1-10, characterized by a hydraulic fluid circuit (45) arranged within the housing block (32), wherein the hydraulic fluid circuit (45) has the first hydraulic fluid connection (36), the second hydraulic fluid connection (37), and the pressure relief valve (38).

12. Hydraulic fluid heating module according to claim 11, characterized in that the hydraulic fluid circuit (45) has hydraulic fluid lines (46, 52) arranged within the housing block (32), wherein the first hydraulic fluid connection (36), the second hydraulic fluid connection (37), and the pressure relief valve (38) are connected to one another by means of the hydraulic fluid lines (46, 52).Hydraulic fluid heating module according to one of claims 1-12, characterized in that the pressure relief valve (38) is cartridge-shaped, wherein the pressure relief valve (38) is screwed into the housing block (32).

14. Modular valve block with (18) at least one hydraulic fluid heating module (24) according to one of claims 1-13.

15. Commercial vehicle (1), in particular a military commercial vehicle, with at least one hydraulic fluid heating module (24) according to one of claims 1-13 and / or at least one modular valve block (18) according to claim 14.

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