WO2016111866A1

WO2016111866A1 - Steering system water sensor

Info

Publication number: WO2016111866A1
Application number: PCT/US2015/067654
Authority: WO
Inventors: Ismail Dagli; Carsten Ulrich RAU; Llya ROZENTULER
Original assignee: Robert Bosch Automotive Steering Llc
Priority date: 2015-01-05
Filing date: 2015-12-28
Publication date: 2016-07-14

Abstract

The steering system having a housing that contains components of the steering system. A water sensor is positioned on the housing that surrounds the steering system. The sensor is positioned on the section of the housing where water is most likely to be found.

Description

STEERING SYSTEM WATER SENSOR

Cross Reference To Related Applications This application claims the benefit of U.S. provisional patent application serial no. 62/099,756 filed on January 5, 2015.

BACKGROUND OF THE INVENTION

In most vehicle applications it is desirable to limit the intrusion of water into critical systems that are involved with the safe operation of the vehicle. When water does manage to intrude into a critical system, this can lead to failure of that system or to dependent failures in the system which compromises the safe operation of the vehicle. For some system on a vehicle it is not possible to completely protect the system from the intrusion of water. In particular, the steering system that is used for a vehicle is difficult to entirely protect from the intrusion of water. The steering system is normally located in an exposed position on the lower part of the vehicle where water from wet roadways frequently comes into contact with the steering system. Any leak or damage in the steering system, such as damaged bellows, allows water to enter the steering system. The steering system usually has a steering gear that is utilized to move the steering rack that is connected to the steerable wheels of the vehicle. At least a portion of the steering gear is usually one of the low spots for the steering system. This position for the steering gear frequently allows water that enters the steering system to migrate to this low point in the steering system. The inclusion of water into the steering gear can result in damage to the steering gear through corrosion. In addition, water in the steering gear in cold climates can result in the formation of ice that will impact the use of the steering system. If the water in the steering system is not removed and the system repaired, the water can cause a failure in the steering system through corrosion or the formation of ice and such failures can compromise the safe operation of the vehicle. Accordingly, there is a need in the industry for a detection system that can determine if water is present in the steering system or other critical systems of the vehicle and provide a warning to the user of the vehicle that unsafe conditions may exist.

SUMMARY OF THE INVENTION

The steering system having a housing that contains components of the steering system, operatively connected to the steering rack. A water sensor is positioned on the housing that surrounds the steering gear. The sensor is positioned on the section of the housing where water is most likely to be found.

Other objects and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description of the preferred embodiments and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of the invention.

Fig. 2 is a side elevational view.

Fig. 3 is a schematic side elevational view of a sensor.

Fig. 4 is a perspective view of a sensor.

Fig. 5 is a schematic side elevational view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The invention is directed to a system for detecting the presence of water in safety critical systems for a vehicle. The detection system is particularly useful when implemented on the steering system for the vehicle. It should be appreciated, however, that the system can be utilized in association with other safety critical systems of a vehicle. The features of the invention will be readily understood by referring to the attached drawings in connection with the following description.

Most vehicles have at least one steerable wheel which can be used to change the direction at which the vehicle is moving. For most vehicles there are two steerable wheels and these wheels are usually located on the front of the vehicle. As shown in Figs. 1 -5, the vehicle has a steering rack 10 that is connected to the steerable wheels of the vehicle in a manner that is well known in the art. The invention is being described with respect to a steering system that utilizes a steering rack. It should be appreciated, however, that the invention can also be utilized with other steering systems, such as a hydraulic power assisted system, that does not utilize a steering rack. The vehicle has a steering wheel 15 that is connected to a steering column 17. The steering column extends into housing 25 and is operatively connected to steering gear 21 that is located in the housing. The steering gear is operatively connected to the steering rack 10. Rotation motion of the steering wheel 15 is directed through the steering column 17 to the steering gear 21 . The steering gear 21 then interacts with the steering rack to move the wheels of the vehicle to a desired position. A motor 23 is operatively connected to the steering gear to provide assistance for positioning the wheels of the vehicle in the desired position. The steering gear 21 is located in the housing 25 that is positioned on the steering rack 10. The housing a first side 27 that is adjacent the steering column 17 and a second side 29 that is spaced apart from the steering column. The second side 29 of the housing 25 usually extends below the steering rack 10 and is the lowest point in the steering system. Any water that might find its way into the steering system will usually migrate to the second side 29 of the housing 25 as water will naturally flow to the low spot in a confined system.

A sensor 35 is positioned on the second side 29 of the housing 25. The sensor 35 is designed to detect the presence of water in the housing 25 that contains the steering gear 21 . The sensor 35 is operatively connected to the ECU 31 that controls the motor 23 that provides assistance to the steering gear 21 . The ECU 31 can be utilized to provide power for the sensor 35. The ECU will supply power to the sensor when the ECU is activated. The ECU is activated when the vehicle is started and power is supplied to the power steering system. The sensor 35 is designed to provide a check for the presence of water every time the sensor is activated by the supply of power from the ECU. This means the sensor does a check at least once every drive cycle for the vehicle. The sensor can also check more than once during a drive cycle if desired. If water is present in the housing 25 the sensor 35 will send a signal to the ECU. The sensor sends a signal to the ECU by modulating the current that is sent back to the ECU. Generally, a wire is utilized to send current from the ECU to the sensor and a separate wire is utilized to send current from the sensor back to the ECU.

It is also possible to have a wireless communication system for the sensor 35. In this arrangement the sensor 35 is supplied with a power source such as a battery 39 which provides the electrical energy to operate the sensor. The sensor is designed so that it will periodically become active and tries to establish communication with the ECU. If the ECU is in an operational condition the sensor will conduct a self check and a check for the presence of water in the housing 25. The sensor will then send a signal to the ECU with status and if water is present in the housing. The communication system between the ECU 31 and the sensor 35 by wireless communication protocols utilized in the industry.

As shown in Fig. 3 the sensor 35 can operate on a photo-electric principle. The sensor housing 41 is positioned on the housing 25 for the steering gear 21 . A prism 43 extends from the sensor housing 41 into the housing 25. A source of light 45, such as an LED light, is positioned in the housing adjacent the prism. The source of light 45 is disposed to direct light into the prism 43 in a manner that the light will be reflected by the prism and back to a photoelectric element 49. The photoelectric element 49 is operatively connected to an output transmission device 51 and the output transmission device is operatively connected to the ECU 31 . If there is no water present in the housing 25 the light from the LED is reflected by the prism to the photoelectric element 49 which sends a signal to the output transmission device 51 . The output transmission device is designed to send a signal to the ECU that indicates that no water is present in the prism 43. If water is present in the prism the light from the light source 45 will be scattered by the presence of water and the light will not be reflected by the prism to the photoelectric element 49. If the photoelectric element 49 does not receive reflected light from the source of light 45 a signal will be sent to the output transmission device 51. The output transmission device will then send a signal to the ECU that water is present in the housing 25.

The sensor 35, as shown in Fig. 4, can have an alternative configuration where a conductive sensor is utilized. The sensor has a base 57 with a threaded collar 59 that extends from the base. A first electrode 61 and a second electrode 63 extend from the threaded collar in a direction away from the base 57. A first wire 65 extends through the base and threaded collar and is operatively connected to first electrode 61 . A second wire 67 that extends through the base 57 is connected to the second electrode 63. The threaded collar 59 is designed to be threadingly received in an opening in the housing 25 for the steering gear 21 . If an electrical voltage is sent to the first electrodes 61 there will be no electrical connection with the second electrode 63 if there is no water present in the housing 25. If water is present in the housing 25 the water will establish electrical connection between the first and second electrodes and an electrical current will travel to the second electrode and to the second wire that is connected to the second electrode. In this manner, if water is present in the housing 25 a signal will be sent from the sensor 35. As shown in Fig. 5 there is a schematic for the operation of this two wire conductive sensor. A regulated voltage is provided to the first electrode 61 in the threaded collar 59 through a first wire 65. If water is present in the housing 25 the current will pass through the water to the second electrode 63 and along the second wire 67. An electronic control module (ECM) is connected to the second wire 67 to detect the presence of voltage along the second wire 67. If voltage is present a signal is sent to the ECM 71 that water is present in the housing 25. If the electronic control module does not receive voltage from the sensor 35 a signal is from the electronic control module that no water is present in the housing 25.

The above detailed description of the present invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.

Claims

CLAIMS We claim:

1. A steering system comprising:

a housing containing components of the steering system;

a water sensor positioned on the housing for the steering system, to detect the presence of water in the steering system.

2. The system of claim 1 wherein a motor is operatively connected to the steering system for providing assistance to steer the vehicle.

3. The system of claim 2 wherein a control module is operatively connected to the motor to control the assistance provided by the motor.

4. The system of claim 3 wherein the water sensor is operatively connected to the control module, the control module providing power to the sensor and the sensor sends information on the presence of water in the steering system to the module.

5. The system of claim 4 wherein the sensor does a check for the presence of water at least once per drive cycle.

6. The system of claim 5 wherein the sensor is a photoelectric sensor wherein the presence of water disrupts a light beam.

7. The system of claim 6 wherein the sensor sends a signal to indicate the presence of water in the steering system.

8. The system of claim 5 wherein the sensor is a conductive element with two spaced apart electrodes.

9. The system of claim 8 wherein the presence of water completes the circuit between the two electrodes.

10. The system of claim 9 wherein the sensor sends a signal when water is present and completes the circuit.

1 1. The system of claim 3 wherein a power source is operatively connected to the sensor, the power source providing power for the sensor.

12. The system of claim 1 1 wherein the sensor does a check for the presence of water every time the control module is energized.

13. The system of claim 12 wherein the sensor is a photoelectric sensor wherein the presence of water disrupts a light beam.

14. The system of claim 13 wherein the sensor sends a signal to indicate the presence of water in the steering system.

15. The system of claim 12 wherein the sensor is a conductive element with two spaced apart electrodes.

16. The system of claim 15 wherein the presence of water completes the circuit between the two electrodes.

17. The system of claim 16 wherein the sensor sends a signal when water is present and completes the circuit.

18. The system of claim 14 wherein the signal from the sensor is sent wirelessly.

19. The system of claim 17 wherein the signal from the sensor is sent wirelessly.