Corrugated steering piece

Abstract

A diverting bellows comprising a sleeve bounded by a peripheral side wall, said sleeve comprising, in order in an axial direction: at least one first annular end, referred to as a large base; a deformable portion that is deformable in a direction in which the bellows is elongated or shortened and is formed by a continuous coaxial bend; and a second annular end, referred to as a small base, said sleeve comprising a transition region between the deformable portion and the large base, and said sleeve having, in the transition region, a radial output provided in the outer peripheral side wall of the sleeve. The radial output is closed by a tubular end piece mounted on the radial output and having a first end connected to the radial output and an opposite closed end, the end piece extending outside the sleeve, the end piece delimiting internally a cavity to receive at least one sensor sensing the fluid tightness of the bellows.

Description

Technical Field

[0001] The utility model relates to a steering corrugated piece.

[0002] The utility model particularly relates to a steering corrugated member, which includes a sleeve limited by an outer peripheral side wall, and the sleeve includes in sequence in the axial direction: at least one first annular end, which is called a large base, and the large base can form an end for fixing the corrugated member to a first steering element such as a steering housing or a steering casing to be protected; a portion that can be deformed along the elongation or shortening direction of the corrugated member and is formed by a continuous coaxial bend (turn); a second annular end, which is called a small base, and the small base can form an end for fixing the corrugated member to a second steering element such as a steering tie rod to be protected, and the sleeve includes a transition area between the deformable portion and the large base, and the sleeve has a radial output portion in the transition area, and the radial output portion is formed in the outer peripheral side wall of the sleeve. Background Art

[0003] In a motor vehicle rack-type steering system, a steering pinion is linked in rotation with the steering column and is steered using the vehicle's steering wheel, the pinion engaging with a rack, which is mounted to slide in the longitudinal direction of the rack in a steering sleeve. The two opposite ends of the rack, located outside the sleeve, are coupled to steering tie rods, which are respectively associated with the right and left steering wheels of the vehicle, the tie rods ensuring the link between the rack and each of the stub axles. Thus, a rotation of the steering wheel in one direction or the other and therefore of the steering pinion is converted into a corresponding translation of the rack, which itself, via the tie rods and the stub axles, causes the orientation of the vehicle's wheels to turn right or left.

[0004] In such a rack-type steering system, the articulated link between each end of the rack and the corresponding tie rod is a spherical joint type link, a so-called "axial" spherical joint, which is produced by: an axial spherical joint housing, which is fixed to the end of the rack; and an axial spherical joint with a spherical head pivot, which is fixed to the tie rod and is mounted to rotate in any direction in the axial spherical joint housing.

[0005] Taking into account the mobility of the rack relative to the steering sleeve and the variable orientation of the ends of the tie rods relative to the rack, protection of the steering device in the region of each axial spherical joint is usually ensured by a bellows which links the adjacent end of the steering sleeve to the corresponding tie rod by surrounding the end of the rack (outside the housing) and the axial spherical joint. An annular end of the bellows is fixed around the end of the steering sleeve by means of a first attachment ring, which is fixed around this end. The other annular end of the bellows is fixed around the tie rod or the axial spherical joint pivot by means of a second attachment ring, which is fixed around the other annular end. By such fixing, the bellows ensures the tightness of the gap between the steering sleeve and the tie rod.

[0006] Between its two ends thus attached, the bellows has a number of bends which allow it to lengthen or shorten, depending on the position of the rack relative to the steering housing, and which also allow it to flex, depending on the variable orientation adopted by the tie rod by means of the articulation of the spherical joint.

[0007] Motor vehicle rack-type steering systems are usually produced in a completely sealed manner in order to avoid any undesired ingress of water or moisture into the steering device.

[0008] The advantage of such a fully manual steering system is that, if a problem occurs, in particular in the event of a loss of sealing of the bellows, a steering change due to corrosion is easier to detect. However, with the development of autonomous vehicles and cable steering control, there is no longer necessarily any direct mechanical connection between the steering wheel and the rest of the steering system. As a result, it is more difficult to detect rack damage associated with a loss of sealing of the bellows. Now, the loss of sealing of the bellows must be detected very quickly, otherwise the rest of the steering system is at risk of deteriorating very quickly. Bellows with a radial output closed by a closure are known, as shown in Korean document KR1020130128622. Bellows that accommodate at least one sensor are known, as shown in patents JP 2012 22 4274 and JP 2012 240435. However, the sensors are not satisfactory, in particular due to their lack of responsiveness. Utility Model Content

[0009] One object of the invention is to propose a deflecting bellows whose design allows it to be adapted to any type of steering system without affecting the possibility of detecting any malfunction with regard to the tightness of the bellows.

[0010] Another object of the present invention is to provide a deflection bellows, the design of which allows the loss of sealing of the bellows to be detected in a very short time.

[0011] To this end, the subject of the utility model is a turning corrugation, which includes a sleeve bounded by an outer peripheral side wall, and the sleeve includes in the axial direction: at least one first annular end, which is called a large base; a portion that can be deformed along the elongation or shortening direction of the corrugation and is formed by a continuous coaxial bend; a second annular end, which is called a small base, the sleeve includes a transition area located between the deformable portion and the large base, and the sleeve has a radial output portion in the transition area, which is formed in the outer peripheral side wall of the sleeve, characterized in that the radial output portion is closed by a tubular end connector, which is added to the radial output portion and has a first end connected to the radial output portion and an opposite closed end, the end connector extends outside the sleeve, and the end connector internally defines a cavity, which accommodates at least one sensor for sensing the fluid tightness of the corrugation. Incorporating at least one sensor of fluid tightness, i.e. a sensor for determining a parameter representing the tightness of the fluid (i.e. liquid and gas) of the bellows, in a tubular end connector located outside the sleeve allows easy installation and maintenance of the sensor. An end connector located outside the sleeve is understood to be an end connector that does not protrude into the sleeve. The first end of the end connector does not extend from the outlet of the radial output in the sleeve to protrude into the sleeve. Thus, the risk of the end connector forming an obstacle to the flow of the fluid in the radial output inside the sleeve due to its first end is avoided. The first end of the end connector preferably extends flush with the outlet of the radial output in the sleeve. By means of this design of the end connector located outside the sleeve, water that may be present in the sleeve due to a loss of tightness can be easily brought to the sensor without having to pass through any obstacles. An end connector located outside the sleeve is understood to be an end connector that extends to protrude from the sleeve. Regardless of any type of steering system, the presence of such a sensor and its design in combination with the end connection and the radial output allow quick and easy detection of a loss of tightness of the bellows. Such a loss of tightness of the bellows or a leak in the bellows can be the result of a hole or a void simply caused by wear of the bellows.

[0012] According to one embodiment of the utility model, the end connector is provided with a peripheral flange, which is positioned to be pressed onto the periphery of the radial output portion when the end connector is in a state of being coupled with the sleeve. The result of the peripheral flange is that the installation of the end connector is simplified and a sealed installation is easily formed between the end connector and the sleeve.

[0013] According to one embodiment of the utility model, the sensor for sensing the fluid tightness of the bellows is an electrical sensor, which is equipped with at least one wire, and the wire or at least one of the wires passes through the closed end of the end connector and extends from the end connector. This design allows the sensor to be easily connected to the control unit later.

[0014] As a variation, the fluid tightness sensing sensor includes an accumulator, and the fluid tightness sensing sensor communicates with a remote terminal in a wireless manner.

[0015] According to one embodiment of the present invention, the end connector comprises a tubular body which is open at each of its ends and a cover for closing one end of the body to form a closed end of the end connector.

[0016] According to one embodiment of the invention, the cover is at least snap-fitted, screwed, glued or welded to the body and the sensor or at least one of the sensors is fixed to the cover. This arrangement allows easy installation of the sensor.

[0017] According to one embodiment of the utility model, the end connector is a one-piece integral component. Likewise, this embodiment allows easy installation of the sensor.

[0018] According to one embodiment of the utility model, the sensor or at least one of the sensors sensing the fluid tightness of the bellows is a gas concentration measurement sensor. This solution has the following advantages: it is insensitive to harmful media of the rack and allows continuous tracking of any leakage of the bellows.

[0019] According to an embodiment of the utility model, the sensor or at least one of the sensors for sensing the fluid tightness of the bellows is a liquid detection sensor. This design allows for a simplified implementation.

[0020] According to an embodiment of the present invention, the sensor or at least one of the sensors for sensing the fluid tightness of the bellows is a pressure sensor or a flow sensor.

[0021] The sensor or at least one of the sensors sensing the fluid tightness of the bellows may thus be selected from sensors comprising: a gas concentration measuring sensor, a liquid detection sensor, a pressure sensor, a flow sensor.

[0022] According to one embodiment of the invention, the end connection is fixed to the radial output portion by overmolding.

[0023] According to one embodiment of the utility model, the outer peripheral side wall of the sleeve is provided with an inner circumferential groove on the inner surface side facing the inside of the sleeve, and the inner circumferential groove is formed in the radial output portion of the sleeve. The existence of the groove can form a guide portion for the fluid to flow toward the radial output portion.

[0024] According to one embodiment of the present invention, the inner circumferential groove extends over a portion of the inner circumference of the sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be better understood by reading the following description of exemplary embodiments with reference to the accompanying drawings, in which:

[0026] [ Figure 1 ] represents a schematic diagram of a steering system;

[0027] [ Figure 2 ] represents a schematic cross section of the bellows when it is in a state of being coupled to an element of a steering system;

[0028] [ Figure 3 ] is a schematic diagram showing a corrugated member according to the utility model;

[0029] [ Figure 4 ]express Figure 3 Detailed view of the end connection of

[0030] [ Figure 5 ] is a schematic diagram showing a corrugated member according to the utility model;

[0031] [ Figure 6 ]express Figure 5 Detailed view of the end connection of

[0032] [ Figure 7 ] represents a partial view of a bellows, the sleeve of which is provided with an inner circumferential groove;

[0033] [ Figure 8 ] represents a partial view of a bellows, the sleeve of which is provided with an inner circumferential groove. DETAILED DESCRIPTION

[0034] As mentioned above, the utility model relates to a turning corrugated member 1, which is combined with Figure 1 In a steering system of the type represented in , the steering system is a rack-type steering system for a motor vehicle.

[0035] In the steering system, a steering wheel 20 is used to steer a steering column 22. The steering column 22 is rotationally fixed to a pinion 21, which engages a rack 23 mounted to slide in a steering sleeve 24 in its longitudinal direction.

[0036] The two ends of the rack 23 outside the sleeve 24 are coupled to a steering tie rod 25 which is respectively associated with a right 26 and a left 26 steering wheel of the vehicle.

[0037] Thus, a rotation of the steering wheel in one direction or in the other and thus a corresponding rotation of the steering pinion is converted into a corresponding translation of the rack, which itself, via the tie rods and the stub axle, causes an orientation of the vehicle's wheels to make a right or left turn.

[0038] In this rack-type steering system, the articulated link between each end of the rack 23 and the corresponding tie rod 25 is a spherical joint type link, namely the so-called axial spherical joint, which is formed by the following two: an axial spherical joint housing, which is fixed to the end of the rack 23; and an axial spherical joint with a spherical head pivot, which is fixed to the tie rod 25 and is installed to rotate in any direction in the axial spherical joint housing.

[0039] The steering corrugation 1 comprises a sleeve 2 which is delimited by a peripheral side wall 3. The sleeve 2 preferably has a tapered cylindrical form. This sleeve 2, which is usually produced in a synthetic material by injection molding or blow molding, comprises in succession in the axial direction: at least one first annular end, referred to as a large base 4, which is able to form the end that fixes the corrugation 1 to a first steering element, such as a steering housing or a steering sleeve 24 to be protected; a portion 5, which is deformable in the direction of elongation or shortening of the corrugation 1 and is formed by a continuous coaxial bend; a second annular end, referred to as a small base 6, which is able to form the end that fixes the corrugation 1 to a second steering element, such as a steering tie rod 25 to be protected. The sleeve 2 also comprises a transition zone 7 between the deformable portion 5 and the large base 4.

[0040] Taking into account the movability of the rack 23 relative to the steering sleeve 24 and the variable orientation of the ends of the tie rods 25 relative to the rack 23, protection of the steering system is ensured in the region of each axial spherical joint by means of a bellows 1 which links the adjacent end of the steering sleeve 24 to the corresponding tie rod 25 by surrounding the end of the rack (located outside the housing) and the axial spherical joint.

[0041] The large base 4 of the bellows 1 is fixed around the end of the steering sleeve 24 by means of a first attachment ring fixed around this end. The small end 6 of the bellows 1 is pivotally fixed around the tie rod 25 or the axial ball joint by means of a second attachment ring fixed around the small base 6.

[0042] The deformable portion 5 of the deflecting bellows 1 allows the bellows to be extended or shortened depending on the position of the rack 23 relative to the deflecting sleeve 24 .

[0043] The sleeve 2 has a radial output 8 in the transition region 7, which is formed in the peripheral side wall 3 of the sleeve 2. This radial output 8 is closed by a tubular end connection 9, which is added to said radial output 8.

[0044] The tubular end connector 9 has a first end 10 connected to the radial output 8 and an opposite closed end 11. When the bellows is in a state of being installed in the steering system, the closed end of the tubular end connector 9 preferably constitutes the low point of the bellows. The end connector 9 extends to the outside of the sleeve 2 without protruding into the sleeve. The end connector 9 does not extend into the sleeve and extends beyond the outlet of the radial output 8 inside the sleeve. Therefore, the end connector 9 cannot form an obstacle to the flow of fluid inside the radial output 8. The end connector 9 can be straight (as shown in the example) or curved or have any other type of form without departing from the utility model. The end connector 9 internally delimits a cavity 12, which accommodates at least one sensor 13, which is used to determine a parameter representing the fluid tightness of the bellows 1.

[0045] One or more leak-sensing sensors 13 make it possible to detect leaks of the bellows.In fact, motor vehicle rack-type steering systems are usually produced in a completely sealed manner to avoid any undesired entry of water or moisture into the interior of the steering system.

[0046] As mentioned above, the end connector 9 may take a variety of forms.

[0047] Independently of this embodiment, the end connection piece 9 is provided with a peripheral flange 14 which, when the end connection piece 9 is in the coupled state with the sleeve 2 , is positioned to be press-fitted onto the periphery of the radial output portion 8 of the sleeve.

[0048] This press fit is maintained by overmolding when manufacturing the sleeve 2, when the end connector 9 is an insert positioned in the bellows manufacturing mould. Obviously, other embodiments of coupling the end connector 9 to the sleeve 2 can be formed. Thus, snap-fitting, gluing or welding etc. can be envisaged.

[0049] exist Figure 3 and Figure 4In the example shown in , the end connector 9 is a one-piece integral component. The sensor 13 sensing the tightness of the bellows 1 for fluids, ie gases and liquids, is therefore pre-positioned in the cavity 10 of the end connector 9 and the end connector 9 is then fixed to the sleeve 2.

[0050] exist Figure 5 and Figure 6 In the example shown, the end connector 9 includes a tubular body 16 that is open at each of its ends and a cover 17 for closing one end of the body 16 to form a closed end of the end connector 9 .

[0051] The cover 17 may be snap-fitted, screwed, glued or welded to the body 16 .

[0052] The sensor 13 or at least one of the sensors 13 is preferably fixed to the cover 17. In the case of a snap-fit, it is particularly easy to replace the sensor 13 in the event of a malfunction of the sensor.

[0053] In this embodiment, the body 16 of the end connector 9 and the sleeve 2 may be preassembled by welding during manufacture of the sleeve, and then the fluid tightness sensing sensor 13 fixed to the cover 17 is installed by simply fixing the cover 17 to the body 16 .

[0054] In the example shown, the sensor 13 for the fluid tightness of the bellows is an electrical sensor equipped with at least one wire 15 and this or at least one of the wires 15 projects from the end connection 9 through its closed end 11 .

[0055] This line or these lines make it possible to connect one or more sensors to a control unit not shown.

[0056] The control unit takes the form of an electronic and computing system comprising, for example, a microprocessor and a working memory. According to a particular aspect, the control unit may take the form of a programmable logic controller.

[0057] In other words, the functions and steps described can be implemented in the form of a computer program or via hardware components (e.g. a programmable gate array). In particular, the functions and steps applied by the drive unit or the modules of the drive unit can be generated by an instruction set or a calculation module implemented in a processor or a controller, or by a dedicated electronic component or a component of the programmable logic circuit type (or FPGA, FPGA is the abbreviation of field programmable gate array) or application-specific integrated circuit (or ASIC) type. It is also possible to combine the calculation part and the electronic part.

[0058] When it is specified that the unit or the device or module of the unit is configured to perform a given operation, it means that the unit includes computing instructions and corresponding execution devices so that the operation can be performed, and / or the unit includes corresponding electronic components.

[0059] The sensor or sensors 13 sensing the tightness of the bellows to fluid, ie liquid or gas, may also take various forms.

[0060] Thus, the sensor 13 or at least one of the sensors 13 for sensing the fluid tightness of the bellows 1 can be a sensor for detecting fluids, in particular water. In this case, when the bellows is positioned on the steering system, the end connector 9 forms the low point of the bellows. Figure 2 The low point of the bellows is formed by the end connection 9 together with the sensor 13, so that when the bellows is no longer sealed, water may enter the bellows and be located in the end connection by gravity. This water may also be the result of condensation of moisture inside the bellows.

[0061] The presence of this water is detected by the sensor 13. This information is transmitted to the control unit which can then emit a control signal for an alarm device, such as a device for emitting a sound or light signal.

[0062] As a variant or in addition, the sensor 13 or at least one of the sensors 13 sensing the fluid tightness of the bellows 1 may be a gas concentration measuring sensor. In this embodiment, gas may be introduced into the bellows when it is mounted on the rest of the steering system.

[0063] The sensor 13 can measure the presence of this gas in real time and continuously. In the event of a bellows leak, the drop in gas concentration is observed by comparison with a predetermined value. Likewise, in the event of a problem, the control unit addressed by the signal from the sensor 13 can emit a control signal for an alarm device.

[0064] The gas density sensor 13 may be a sensor for measuring carbon monoxide (CO) in the air. The sensor for measuring CO in the air may be an infrared sensor or combined with a chemical reagent in a manner known per se.

[0065] Obviously, the density of other gases, such as oxygen or nitrogen, can also be measured without departing from the framework of the present invention.

[0066] As a variant or in addition, the sensor 13 or at least one of the sensors 13 sensing the fluid tightness of the bellows 1 can be a pressure sensor. The bellows is connected to a pressure source. The leakage measurement is measured by the pressure loss. This solution is not preferred because it requires a corresponding test phase.

[0067] As a variant or in addition, the sealing sensing sensor 13 or at least one of the sealing sensing sensors 13 can be a flow sensor. In this embodiment, a certain flow of air is injected into the bellows and the flow loss is measured at the radial output. Again, this solution is not preferred because it requires a corresponding test phase.

[0068] In order to optimize the bellows, the outer peripheral side wall 3 of the sleeve 2 can be provided with an inner circumferential groove 18 on the inner surface side facing the inside of the sleeve 2, and the inner circumferential groove 18 is formed in the radial output portion (8) of the sleeve 2. This groove 18 makes it possible to guide the fluid, the presence of which is caused by the loss of sealing, to the radial output portion 8 so that the fluid contacts the sensor. Likewise, this arrangement structure makes it possible to increase the response speed of the sensor. In the example shown, the inner circumferential groove 18 extends over a portion of the inner periphery of the sleeve 2. Obviously, the inner circumferential groove 18 can extend over the entire inner circumference of the sleeve without departing from the framework of the utility model.

Claims

1. A turning corrugated member (1), comprising a sleeve (2), the sleeve (2) being bounded by an outer peripheral side wall (3), the sleeve (2) comprising in sequence in the axial direction: at least one first annular end, referred to as a large base (4); a deformable portion (5), the deformable portion (5) being deformable in the direction of elongation or shortening of the turning corrugated member (1), and the deformable portion (5) being formed by continuous coaxial bends; and a second annular end, which is called a small base (6), the sleeve (2) comprising a transition zone (7) between the deformable portion (5) and the large base (4), and the sleeve (2) having a radial output portion (8) in the transition zone (7), the radial output portion (8) being formed in the peripheral side wall (3) of the sleeve (2), characterized in that the radial output portion (8) is closed by a tubular end connector (9), which is added to the radial output portion (8) and has a first end (10) and an opposite closed end (11), the first end (10) being connected to the radial output portion (8), the end connector (9) extending outside the sleeve (2), the end connector (9) internally delimiting a cavity (12), the cavity (12) accommodating at least one sensor (13) for sensing the fluid tightness of the steering bellows.

2. The deflecting corrugated element (1) according to claim 1, characterized in that: The end connector (9) is provided with a peripheral flange (14), which is positioned to be press-fitted onto the periphery of the radial output portion (8) when the end connector (9) is in a state of being coupled to the sleeve (2).

3. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The sensor (13) for sensing the fluid tightness of the turning bellows is an electrical sensor equipped with at least one wire (15), and the wire (15) or at least one of the wires (15) extends from the end connector (9) through the closed end (11) of the end connector (9).

4. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The end connector (9) comprises a cover (17) and a tubular body (16), wherein the body (16) is open at each of its ends, and the cover (17) is used to close one end of the body (16) to form the closed end (11) of the end connector (9).

5. The deflecting corrugated element (1) according to claim 4, characterized in that: The cover (17) is at least snap-fitted, screwed, glued or welded to the body (16), and the sensor (13) or at least one of the sensors (13) is fixed to the cover (17).

6. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The end connector (9) is a one-piece integral component.

7. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The sensor (13) or at least one of the sensors (13) for sensing the fluid tightness of the turning bellows (1) is a gas concentration measurement sensor.

8. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The sensor (13) or at least one of the sensors (13) for sensing the fluid tightness of the steering bellows (1) is a liquid detection sensor.

9. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The sensor (13) or at least one of the sensors (13) for sensing the fluid tightness of the steering bellows (1) is a pressure sensor or a flow sensor.

10. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The end connection (9) is fixed to the radial output portion (8) by overmolding.

11. The deflecting corrugated element (1) according to claim 1 or 2, characterized in that: The outer peripheral side wall (3) of the sleeve (2) is provided with an inner peripheral groove (18) on the inner surface side facing the inside of the sleeve (2), and the inner peripheral groove (18) is formed in the radial output portion (8) of the sleeve (2).

12. The deflecting corrugated element (1) according to claim 11, characterized in that The inner circumferential groove (18) extends over a portion of the inner circumference of the sleeve (2).

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