Steering system with steering housing and fluid detection system, and motor vehicle comprising such a steering system

Abstract

The invention relates to a steering system (18) with a steering housing (22) and a fluid detection system. At least one fluid transport means (36) is provided, by means of which fluid can be transported from a first steering housing region (24) to a second steering housing region (28).

Description

[0001] Description

[0002] Steering system with steering housing and fluid detection system, and motor vehicle with such a steering system

[0003] The invention relates to a steering system comprising a steering housing and a fluid detection system according to the preamble of claim 1, and to a motor vehicle comprising such a steering system.

[0004] From US patent 11,435,253 B2, a steering system with a steering housing is known that includes a fluid sensor located at the lowest point of the steering housing. The sensor is an electrical sensor that uses an electric current to detect whether fluid has entered the steering housing. It employs a swelling material whose volume increases upon contact with fluid, causing a switching element to move from a first position to a second position.

[0005] From US patent 2021 / 0404903 A1, a steering system with a steering housing and a fluid detection system arranged in the steering housing is known. The fluid detection system comprises a fluid-absorbing material equipped with electrical contacts and a processor. The absorbent material is intended to be non-conductive in the dry state and electrically conductive in the wet state, so that fluid can be detected by the current flow using the processor.

[0006] From WO 2016 / 098557 A1 a fluid detection system for a steering system with steering housing is known, which detects fluid in the steering housing and electrically reports it to a receiving unit by means of a wireless transmission system.

[0007] Prior art steering systems with fluid detection systems have the disadvantage that fluid is typically detected where it is expected, by positioning a sensor or other detection element – ​​usually electronic – at the corresponding location. This often leads to considerable effort in the reliable routing and long-term maintenance of a connecting cable through which the signal output by the detection element is to be transmitted to an electronic control unit. The invention is based on the objective of providing a steering system with a steering housing and fluid detection system, a method for operating a steering system, and a motor vehicle with such a steering system, which enable a simple and reliable alternative method of fluid detection.

[0008] The problem is solved according to the invention by the features of the independent claims. Further practical embodiments and advantages of the invention are described in connection with the dependent claims.

[0009] In a steering system according to the invention, comprising a steering housing and a fluid detection system, at least one fluid transport means is provided by means of which fluid can be transported from a first steering housing area to a second steering housing area. Thus, the invention makes it possible to transport any fluid that may have entered a steering system, even within the steering housing, to another (practically any) detection point in the steering housing, thereby minimizing the effort associated with the – in particular electrical – detection of the fluid and the associated electrical wiring and signal lines.

[0010] In a practical embodiment of a steering system according to the invention, at least one hose or at least one rope-like element is provided as a fluid transport means, by means of which fluid detected in the steering housing area can be conveyed from the first steering housing area to the second steering housing area. A hose or rope-like element is understood to be any element whose length is significantly greater than its diameter (if it is an element with a circular cross-section) or the largest of its other dimensions perpendicular to the main direction of extension (i.e., in particular, its width or height if it is an element with a rectangular cross-section). The element must be suitably designed and / or arranged to be able to transport the fluid itself.This can be achieved by an arrangement such that the fluid is conveyed by gravity through a hose or hose-like element. Alternatively or additionally, however, fluid transport systems can be designed independently of gravity, enabling the fluid to be conveyed within the steering housing even against gravity. Various material properties and design options can be used for this purpose, which will be discussed in more detail below.In connection with a hose, particular reference is made to the possibility of encasing a rope-like element with a hose only over part of its length, so that in a first steering housing area, where the rope is at least partially not encased by a hose, a moisture-absorbing area of ​​the rope is formed, followed by a moisture-conducting area enclosed by the hose, which extends, in particular, to a sensor in the second steering housing area. For the connection between the end of the hose and a connection area in the second steering housing area, a mechanical coupling element in the area of ​​the hose end and a complementary receiving element on the sensor can be provided, in particular similar to hose couplings on garden hoses that allow tool-free connection via snap-fit ​​connections.

[0011] Alternatively or in addition to the described mechanical coupling element, a connection between the moisture transport medium and the sensor can be made by gluing or by ultrasonic bonding.

[0012] The moisture transport medium itself can also be used as part of the sensor and designed in such a way that its properties are selected and positioned so that water is utilized by means of a corresponding section of the moisture transport medium. In this regard, particular reference is made to the possibility of forming the moisture transport medium, at least partially, from an electrically non-conductive material that becomes electrically conductive upon contact with moisture.

[0013] In conjunction with at least one hose, reference is made to the possibility of using several hoses to pump water from different locations towards a sensor using the respective hose.

[0014] A rigid or flexible hose or a corresponding rope-like element can be used. Rigid hoses or rope-like elements have the advantage that they can be easily and automatically positioned and inserted into the steering system by machine. Flexible hoses or rope-like elements have the advantage that they can be threaded and guided through complex geometries and structures.

[0015] In connection with a rope-like element, particular reference is made to rope-like elements made of hydrophilic materials that exhibit properties utilized in candle wicks or oil-removing braids in other technical fields. These can be textile structures, fiber bundles, or woven fabrics, such as cords.

[0016] In the solution according to the invention, the moisture transport medium itself takes over the transport of the liquid, so that a sensor can be positioned relatively freely by positioning the end of the liquid transport medium.

[0017] The steering system according to the invention has the following advantages:

[0018] - The sensitivity of the sensor is improved because more moisture, especially water, reaches the sensor at an earlier time; for example, water reaches a sensor positioned on a control unit with the help of the moisture transport agent before such water would reach this sensor by other means without the moisture transport agent.

[0019] - The degrees of freedom for positioning the sensor are greater. This allows moisture to be detected in areas of the steering system where no electronics are installed or cannot be installed. This can be advantageous because the measuring point or the area in which the measuring point is located may be critical with regard to electromagnetic compatibility (EMC), voltage protection, or the presence of conductive elements.

[0020] - The detection chamber can be completely sealed - apart from the passage of the moisture transport medium.

[0021] If the steering system includes a drive element with a drive chamber surrounding this drive element, and the steering system includes a control unit to directly or indirectly control or regulate the drive of the drive element, it is advantageous for the fluid transport medium to run from the drive chamber to the control unit. In this case, the fluid itself can be conveyed by the fluid transport medium to the vicinity of, or directly to, the control unit, so that electrical detection, as well as the associated signal acquisition and processing, can then take place at or near the control unit. This results in minimal effort required for the electrical acquisition and transmission of a fluid detection signal.The electrical installation effort within the steering system and the associated safety precautions can be kept correspondingly low, resulting in an overall simply constructed and robust steering system with fluid detection.

[0022] In a first embodiment, the liquid transport means is designed to utilize capillary action, at least in part. In particular, a thin, tube-like element or a hose can be provided as the liquid transport means, the diameter of which is designed such that, after liquid penetrates one end of the hose, the liquid is conveyed towards the other end by means of capillary action.

[0023] In a further embodiment of a steering system according to the invention, which can be implemented alternatively or additionally, the liquid transport means is formed at least partially from at least one hydrophilic material. In this regard, reference is made – albeit only by way of example – to the possibility of using paper or cardboard as a hydrophilic material, i.e., a material that attracts liquids. Such material tends to actively absorb and soak up liquids, so that – particularly in the case of a rope-like or tube-like design of the liquid transport means – a certain conveying effect is created due to the material's suction. As soon as one end of the paper or cardboard rope becomes wet, the moisture spreads briefly over the entire length of the paper or cardboard rope, so that the other end is also wet within a short time and the liquid has been transported from one end to the other.Liquid detection is then also possible at the other end, especially in the area of ​​another end that is located near or directly adjacent to a control unit.

[0024] In another practical embodiment of a steering system according to the invention, the fluid transport means has a color indicator by means of which it is possible to identify, based on a discolored element of the fluid transport means and / or on a discolored fluid, from which first steering housing area the fluid was conveyed to the second steering housing area. For example, by positioning a color indicator in the area of ​​a first end where detectable fluid is expected, it can be additionally verified and ensured in the area of ​​the second end that the fluid conveyed to a second end by means of the fluid transport means was actually conveyed from the first end to the second end. If the fluid is not discolored, this means that the fluid may have originated from a different area of ​​the steering housing or that the color indicator has not functioned.By using at least one or more color indicators, multiple fluid transport systems can be guided, at least partially, to the second steering housing section. For example, a green color indicator can be located in the first steering housing section and a red color indicator in a third. Based on the color of the fluid arriving in the second steering housing section, it is then possible to determine the fluid's origin, i.e., whether it came from the first or third steering housing section. This reduces the design and material costs associated with multiple fluid transport systems.

[0025] In another practical embodiment, the fluid transport medium of a steering system is functionally coupled to an active fluid drive medium. This includes, in particular, mechanical drive mediums, such as pressure-based drive mediums (pneumatic) or motion-based drive mediums (pumps equipped with moving elements).

[0026] In another practical embodiment of a steering system according to the invention, the active fluid drive element comprises a pressure-actuated hose and / or an electrically actuated switching element consisting of switchable hydrophilic and hydrophobic elements. In both cases, the fluid flow can be actively initiated by actuation, so that, depending on the desired flow rate, the flow rate can also be influenced by appropriate design. Accordingly, in this case, there is the option of increasing the flow rate to enhance safety as needed.

[0027] Switchable elements are those whose material properties change depending on the applied voltage. Electroactive polymers or dielectric elastomers are particularly relevant in this context. Suitable control systems can be implemented using microcontrollers, analog circuits, resonant circuits, and / or timers. The transport of the moisture-carrying medium then occurs, as described in detail below using an exemplary embodiment, by switching between the hydrophilic and hydrophobic properties of individual elements. With appropriate circuitry and control, active fluid transport can be achieved, particularly by switching time-varying patterns.The invention also relates to a method for operating a steering system as described above, in which an overpressure and / or a vacuum is applied to the pressure-actuated hose as an active fluid driving medium and / or in which an alternating switching of hydrophilic and hydrophobic elements of a changeable element takes place in such a way that the changeable element functions as an active fluid driving medium.

[0028] In the first case, i.e., with a fluid propulsion system comprising a pressure-operated hose, the positive and / or negative pressure can be permanently applied, particularly during the use of a steering system when operating and / or using a motor vehicle, so that no specific control is required. In this case, as soon as the fluid enters one end of the hose, it is forced by pressure to the other end of the hose.

[0029] In the second case, the pumping can also be continuous or on demand, at least while a motor vehicle with a steering system is being operated and / or used. In this case, too, no additional control of the fluid transport element is required. Alternatively, to save energy, the fluid pumping can be operated in phases at predetermined times or on demand, for example, when certain predefined conditions are met.

[0030] The invention also relates to a motor vehicle with a steering system as described above. Reference is hereby made again to the advantages already described in connection with the steering system, which also apply to the motor vehicle.

[0031] Further practical embodiments of the invention are described below in connection with the drawings. They show:

[0032] Fig. 1 shows a motor vehicle in a side view,

[0033] Fig. 2 shows a schematic representation of a steering system according to the invention with a fluid transport means,

[0034] Fig. 3 shows an exemplary section of the fluid transport medium of a steering system according to the invention with switchable hydrophilic and hydrophobic elements. Fig. 4 shows six different states of an exemplary section of the fluid transport medium from Figure 3, which are repeatedly and sequentially controlled to convey fluid.

[0035] Figure 1 shows a motor vehicle 10 with a front section 12 and an area 14 marked by a dashed line, in which steerable front wheels 16 are arranged. In the side view shown, only the left front wheel 16 is visible. On the right side (not shown) is another front wheel 16, and between the front wheels 16, in the area 14 marked by the dashed line, a steering system 18 is arranged, which is shown schematically in Figure 2.

[0036] The steering system 18 essentially comprises a steering rod 20, indicated by a dashed line in Figure 2, which is enclosed by a steering housing 22 for at least a certain length, particularly to prevent direct exposure to moisture, dirt, and other particles and substances. Typically, bellows are used to seal the lateral ends from which the steering rod 20 protrudes from the steering housing 22, in order to prevent the ingress of liquids, particles, and other substances into the interior through the open ends of the steering housing 22.

[0037] In the embodiment shown, the steering housing 22 encloses all the elements shown and, in addition to the section surrounding the steering rod 20, includes a first steering housing area 24 in which a toothed belt 26 is arranged and a second steering housing area 28 in which an electronic control unit 30, also called ECU, is arranged.

[0038] The toothed belt 26 is driven via a shaft 32, which is part of an electric motor 34 serving as a drive element.

[0039] In Figure 2, y denotes the vehicle's transverse direction (y-direction), and z denotes the vehicle's upward direction (z-direction). Gravity acts downward in the direction of arrow g in the vehicle's upward direction (z-direction).

[0040] If dirt penetrates, particularly through a defective bellows (not shown) at a lateral end of the upper section of the steering housing 22 enclosing the steering rod 20, it enters the first steering housing section 24 due to gravity and / or contact with the toothed belt 26. A first end 40 of a fluid transport means 36 is arranged in this steering housing section 24, extending into the second steering housing section 28, where the second end 42 is functionally connected to a sensor 38. In the illustrated embodiment, the sensor 38 is arranged directly on the control unit 30.

[0041] If fluid enters the first steering housing area 24 and comes into suitable contact with the fluid transport medium 36, the fluid is conveyed by the fluid transport medium 36 towards the second end 42 of the fluid transport medium 36 and thus towards the sensor 38. There, the fluid is detected, and the information about the fluid entering the steering housing 22 is transmitted as a signal to the control unit 30. The control unit 30 can then take appropriate measures. In particular, the driver of a motor vehicle 10 can be instructed to visit a workshop as soon as possible, or the vehicle can be taken out of service immediately until the steering system 18 has been inspected and, if necessary, repaired by a specialist workshop by eliminating the cause of the fluid ingress (e.g., replacing the bellows, which are not shown).

[0042] The liquid transport means 36 can be a hose, in which case it is necessary for the liquid to be detected to come into contact with an open end of the hose (not shown) in the first steering housing area 24. It is somewhat more flexible and therefore preferred if the liquid transport means 36 is a rope-like element, which makes it possible to pick up and transport liquid at any point in the first steering housing area 24, because it is sufficient for the liquid to come into contact with the liquid transport means 36 at any point in the first steering housing area 24. This is particularly the case with absorbent materials such as paper, cardboard, or similarly absorbent materials.

[0043] In conjunction with Figures 3 and 4, a special liquid transport medium 36 is now described, which has switchable hydrophilic and hydrophobic elements. The basic structure is first described with reference to Figure 3, and the circuit and the method according to the invention that can be carried out with the liquid transport medium 36 are then described with reference to Figure 4. The liquid transport medium 36 according to Figure 3 has elements A, B, and C arranged sequentially one behind the other, each of which can be switched between a hydrophilic and a hydrophobic material property. Optionally, the elements A, B, and C are at least partially surrounded by a type of tube D, which can also be an element switchable between hydrophobic and hydrophilic.Alternatively, hose D is made of a hydrophobic material, so that liquid inside hose D remains there even if it enters through one of the hose's ends. The liquid can then only escape through one of the ends.

[0044] The switching capability and the method for conveying liquid with the liquid transport medium 36 from Figure 3 are now described with reference to Figure 4. Lines 1 to 6 show different states of elements A, B, C, and D. Elements A, B, C, and D marked with diamonds exhibit hydrophobic material properties in their respective shown states, while elements A, B, and C marked with dots exhibit hydrophilic material properties.

[0045] Line 1 shows the initial state of a liquid transport medium 36, whose first elements A and B each exhibit hydrophilic material properties in the region of the first end 40. This allows liquid, visualized as a droplet 44, to penetrate the first end 40. The first element C exhibits hydrophobic material properties, so the droplet 44 is located in the region of elements A and B.

[0046] The first switching operation now takes place to achieve the state shown in line 2. For this, elements A are switched from hydrophilic to hydrophobic. Accordingly, droplet 44 is forced towards element B.

[0047] The next switching operation follows to achieve the state shown in line 3. For this, elements C are switched to hydrophilic mode. This allows droplet 44 to move further towards element C.

[0048] The next switching operation follows to achieve the state shown in line 4. For this, elements B are switched to hydrophobic. This forces droplet 44 to move completely into the area of ​​element C. The next switching operation follows to achieve the state shown in line 5. For this, elements A are switched to hydrophilic. This allows droplet 44 to move from element C further towards the next element A.

[0049] The next switching operation follows to achieve the state shown in line 6. For this, elements C are switched to hydrophobic. This forces droplet 44 to move completely from element C into the area of ​​element A.

[0050] The next switching operation follows to return to the state shown in line 1, whereby the drop 44 has moved further by a sequence of elements A, B, and C. By repeating the switching operations described above, the drop 44 can thus be successively conveyed towards the second end 42.

[0051] The recurring repetitions are visualized by arrow 46.

[0052] The features of the invention disclosed in the present description, the drawings, and the claims can be essential for realizing the invention in its various embodiments, both individually and in any combination. The invention can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art.

[0053] 10 motor vehicle

[0054] 12 Front section

[0055] 14 Area marked with a dashed line 16 Front wheel

[0056] 18 Steering system

[0057] 20 handlebar

[0058] 22 Steering housing

[0059] 24 first steering housing area

[0060] 26 timing belts

[0061] 28 second steering housing area

[0062] 30 control unit

[0063] 32 wave

[0064] 34 Electric motor

[0065] 36 Liquid transport vehicles

[0066] 38 Sensor

[0067] 40 first end

[0068] 42 second end

[0069] 44 drops

[0070] 46 Arrow

[0071] 1 line

[0072] 2nd line

[0073] 3rd line

[0074] 4th line

[0075] 5th line

[0076] 6th line

[0077] A Element

[0078] B Element

[0079] C Element

[0080] The hose

[0081] g arrow

Claims

Patent claims 1. Steering system (18) with steering housing (22) and fluid detection system, characterized in that at least one fluid transport means (36) is provided, by means of which fluid can be transported from a first steering housing area (24) to a second steering housing area (28).

2. Steering system (18) according to the preceding claim, characterized in that at least one hose (D) or at least one rope-like element is provided as a fluid transport means (36), by means of which fluid detected in the steering housing area (24, 28) can be conveyed from the first steering housing area (24) to the second steering housing area (28).

3. Steering system (18) according to the preceding claim, characterized in that the steering system (18) has a drive element with a drive chamber surrounding this drive element, wherein the steering system (18) has a control unit to control or regulate the drive of the drive element directly or indirectly, and wherein the fluid transport means (36) leads from the drive chamber to the control unit.

4. Steering system (18) according to one of the preceding claims, characterized in that the fluid transport means (36) is designed to utilize capillary action at least partially.

5. Steering system (18) according to one of the preceding claims, characterized in that the fluid transport means (36) is formed at least partially from at least one hydrophilic material (in particular paper etc.).

6. Steering system (18) according to one of the preceding claims, characterized in that the fluid transport means (36) has a color indicator by means of which it is recognizable, on the basis of a discolored element of the fluid transport means (36) and / or on the basis of a discolored fluid, from which first steering housing area (24) the fluid was conveyed to the second steering housing area (28).

7. Steering system (18) according to one of the preceding claims, characterized in that the fluid transport means (36) is functionally coupled with an active fluid propulsion means.

8. Steering system (18) according to the preceding claim, characterized in that the active fluid drive means comprises a pressure-actuated hose (D) and / or an electrically actuated switching element made of switchable hydrophilic and hydrophobic elements.

9. Method for operating a steering system (18) according to claim 8, characterized in that an overpressure and / or a negative pressure is applied to the pressure-actuated hose (D) as an active fluid driving medium (in particular permanently) and / or that an alternating switching of hydrophilic and hydrophobic elements of a switching element takes place such that the switching element functions as an active fluid driving medium.

10. Motor vehicle (10) with a steering system (18) according to one of claims 1 to 9.

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