CN212556480U - Super-magnetostrictive clearance adjusting device of gear rack steering gear - Google Patents

Abstract

The utility model discloses a super magnetostrictive gap adjusting device of rack and pinion steering gear, including the steering gear casing, rack and pinion subassembly and supporting yoke, the steering gear casing is equipped with the clearance adjustment chamber that corresponds with the rack, supporting yoke movable mounting supports in the clearance adjustment chamber and supports and lean on the rack back, steering mechanism clearance adjustment device still includes magnetostrictive actuator assembly and elasticity preloading subassembly, magnetostrictive actuator assembly includes exciting coil, the magnetostrictive rod, the lower oral area in clearance adjustment chamber is installed and is adjusted the plug screw, the elasticity preloading subassembly is exerted preloading force to the magnetostrictive rod. The utility model discloses according to road surface and automobile body vibration condition, change the electric current that lets in the excitation coil to change magnetic field intensity, utilize the different characteristics of super magnetostrictive material elongation length under the different intensity magnetic fields, realized the real-time adjustment in elastomer preloading force and rack and pinion clearance.

Description

Super-magnetostrictive clearance adjusting device of gear rack steering gear

Technical Field

The utility model belongs to the technical field of automobile parts, especially, relate to steering mechanism.

Background

The steering gear is a speed reduction transmission device in a steering system and generally comprises a 1-2 stage speed reduction transmission pair; according to different structural forms of a transmission pair, the steering gear can be divided into a plurality of types, and the steering gear is widely used in automobiles at present and comprises a rack and pinion type, a circulating ball-rack toothed sector type, a circulating ball-crank finger pin type and the like. Among them, rack and pinion steering is the most common type of steering; a steering gear as a driving sub-driving member of the rack and pinion steering gear is mounted in a housing to be engaged with a steering rack arranged horizontally. The spring presses the rack against the steering gear by means of a pressure piece to ensure a play-free engagement. When the steering rack works, the middle part of the steering rack is connected with the steering pull rod bracket, and the steering left and right tie rods are connected with the steering knuckle arm. When the steering wheel is rotated, the steering gear is transferred to make the steering rack engaged with the steering gear move along the axial direction, so that the left and right tie rods drive the left and right steering knuckles to transfer, the steering wheel is deflected, and the steering of the automobile is realized.

The gap eliminating device adopted by the existing gear rack steering gear is mainly used for eliminating the gap generated after the gear and the rack are abraded, and the basic principle is that the rack is pressed by the preload force of a spring, so that the constant gap between the gear and the rack is ensured. The spring pressing device effectively solves the problem that the gap is increased after the gear and the rack are worn; however, the road surface condition of the vehicle is complex when the vehicle actually runs, the spring preload force generated by the current anti-backlash mechanism cannot be adjusted in real time in the running process of the vehicle, and the larger preload force can accelerate the abrasion of a steering system and cause heavy steering; a lower preload force in turn can lead to problems of abnormal noise when the vehicle is driven over rough road surfaces. With the increasing noise control requirements of vehicles, current steering mechanism clearance adjustment devices have been unable to meet the requirements.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a giant magnetostrictive gap adjusting device of rack and pinion steering gear is just provided, when the effective compensation is because the normal work wearing and tearing of gear and rack and the clearance that causes, can adjust preloading force in real time at the vehicle in-process that traveles.

In order to solve the technical problem, the utility model adopts the following technical scheme: the giant magnetostrictive gap adjusting device of the gear-rack steering gear comprises a steering gear shell, a gear rack component and a support yoke, wherein the gear rack component comprises a gear and a rack meshed with the gear, a gap adjusting cavity corresponding to the rack is arranged on the steering gear shell, the support yoke is movably arranged in the gap adjusting cavity and abuts against the back surface of the rack, the gap adjusting device of the steering gear further comprises a magnetostrictive actuator assembly and an elastic preloading component, the magnetostrictive actuator assembly comprises an actuator shell, an exciting coil positioned in the actuator shell and a magnetostrictive rod nested in the exciting coil, the upper end of the magnetostrictive rod abuts against the support yoke, the lower end of the magnetostrictive rod abuts against the bottom of the actuator shell, an adjusting screw plug is arranged at the lower opening of the gap adjusting cavity, and the upper end of the elastic preloading component abuts against the actuator shell, the lower end of the elastic preloading component is abutted with the adjusting screw plug, and the elastic preloading component applies preloading force to the magnetostrictive rod through the exciter shell.

Preferably, the support yoke is provided with an arc-shaped groove corresponding to the arc-shaped part on the back of the rack, and the surface of the arc-shaped groove is provided with an anti-friction cushioning layer.

Preferably, the lower part of the support yoke is provided with a support groove, and the upper end of the magnetostrictive rod extends into the support groove and abuts against the top wall of the support groove.

Preferably, at least one sealing ring matched with the inner wall of the clearance adjusting cavity is arranged on the outer cylindrical surface of the supporting yoke.

Preferably, the elastic preload assembly is a disc spring assembly.

Preferably, the disc spring assembly comprises two groups of disc springs, each group of disc springs is composed of two disc springs which are overlapped and connected in parallel, and the two groups of disc springs are connected in an involutive series connection mode.

Preferably, the magnetostrictive actuator assembly further comprises an actuator top cover for closing the opening of the actuator shell and a coil bobbin movably nested outside the magnetostrictive rod, and the actuator coil is wound around the coil bobbin, assembled inside the actuator shell and pressed by the actuator top cover.

Preferably, the bottom of the exciter shell is provided with a convex column, the adjusting screw plug is provided with a sliding hole, an inner hole of the disc spring assembly is nested in the convex column, and the convex column extends into the sliding hole in a sliding mode.

Preferably, at least one sealing ring is mounted on the outer cylindrical surface of the actuator housing.

The utility model discloses a technical scheme, following beneficial effect has:

the length of the magnetostrictive rod is increased through magnetostriction, the elastic preloading component is extruded by the exciter shell, the deformation of the elastic preloading component is increased, larger preloading force is generated, the preloading force increased by the elastic preloading component is transmitted through the exciter assembly and the support yoke, the rack is further pressed, the gap between the rack and the gear is reduced, and the gap caused by normal working abrasion of the gear and the rack can be effectively compensated.

Because the steering hand feeling of a driver can be changed due to overlarge preload force, and the abnormal sound problem cannot be avoided due to the overlong preload force, the current introduced into the exciting coil is changed according to the vibration conditions of the road surface and the vehicle body, so that the magnetic field intensity is changed, the real-time adjustment of the elastomer preload force and the gap between the gear and the rack is realized by utilizing the characteristic that the giant magnetostrictive material has different extension lengths under magnetic fields with different intensities, and the abnormal sound problem of the steering mechanism on the bumpy road surface is avoided on the basis of ensuring the flexible steering of the vehicle when the vehicle runs on a good pavement road surface.

Because the dish spring group is formed by two sets of dish springs which are overlapped and connected in parallel, the contact surfaces between the dish springs generate relative displacement and rub against each other, and energy is dissipated and vibration is attenuated through friction damping.

Because the first sealing ring and the second sealing ring of the supporting yoke, and the first sealing ring and the second sealing ring of the exciter are installed in a tight fit mode, friction force opposite to the movement direction of the supporting yoke is generated, energy is dissipated through friction damping, and vibration is attenuated.

The specific technical solution and the advantages of the present invention will be described in detail in the following detailed description with reference to the accompanying drawings.

Drawings

The invention will be further described with reference to the accompanying drawings and specific embodiments:

FIG. 1 is a schematic structural view of a super magnetostrictive gap adjustment device of a rack and pinion steering gear;

FIG. 2 is a schematic structural view of the support yoke assembly;

FIG. 3 is a schematic diagram of the actuator assembly.

In the figure: the steering gear comprises a steering gear shell 1, a gear shaft 2, a rack 3, a support yoke assembly 4, a magnetostrictive actuator assembly 5, a connector 6, a fixing nut 7, an adjusting screw plug 8, a disc spring assembly 9, a first support bearing 10, a second support bearing 11, a support yoke 401, an anti-friction shock absorption layer 402, an air vent 403, a support groove 404, a first support yoke seal ring 405, a second support yoke seal ring 406, an actuator top cover 501, an actuator shell 502, a convex column 5021, a positioning groove 5022, an excitation coil 503, a coil framework 504, an outlet wire hole 505, a magnetostrictive rod 506, a first actuator seal ring 507 and a second actuator seal ring 508.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Such terms as "upper", "lower", and the like, indicating an orientation or positional relationship, are based only on the orientation or positional relationship shown in the drawings and are merely for convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device/element referred to must have a particular orientation or be constructed and operated in a particular orientation and therefore should not be construed as limiting the invention.

It will be appreciated by those skilled in the art that features from the examples and embodiments described below may be combined with each other without conflict.

Example one

Referring to fig. 1 to 3, the super magnetostrictive gap adjustment device of a rack and pinion steering gear includes a steering gear housing 1, a pinion shaft 2, a rack 3, a support yoke assembly 4, a magnetostrictive exciter assembly 5, a connector 6, a fixing nut 7, an adjustment screw plug 8, a disc spring assembly 9, a first support bearing 10, and a second support bearing 11.

Wherein, a first supporting bearing 10 is connected to the one end of gear shaft 2, and a second supporting bearing 11 is connected to the other end of gear shaft 2, and gear shaft 2 is assembled in the horizontal cavity of steering gear housing 1 via first supporting bearing 10 and second supporting bearing 11. In the present embodiment, the gear is integrally formed on the gear shaft 2, but it is understood that the gear shaft and the gear may be formed as separate bodies.

One side of the rack 3 with teeth is meshed with the gear on the gear shaft 2, and the other side of the rack 3 is matched with the support yoke assembly 4. The steering gear shell 1 is correspondingly provided with a gap adjusting cavity communicated with the horizontal cavity below the rack 3, the lower opening part of the gap adjusting cavity is communicated with the bottom surface of the steering gear shell, and the support yoke assembly 4, the magnetostrictive exciter assembly 5, the disc spring assembly 9 and the adjusting screw plug 8 are sequentially assembled in the gap adjusting cavity of the steering gear shell 1. An adjusting screw plug 8 is screwed in the lower opening part of the clearance adjusting cavity, the adjusting screw plug 8 compresses the support yoke assembly 4 through a disc spring assembly 9 and a magnetostrictive exciter assembly 5, and a fixing nut 7 is screwed in from the lower end thread part of the adjusting screw plug 10 and compresses the lower end of the steering gear shell 1. The connector 6 passes through and is fixed in the connector mounting hole on the side surface of the steering gear shell 1, and is connected with a power supply through the connector 6.

The support yoke assembly 4 includes a support yoke 401, a friction reducing cushioning layer 402, a support yoke first seal 405, and a support yoke second seal 406. The support yoke 401 is provided with an arc-shaped groove corresponding to the arc-shaped part on the back of the rack, and the antifriction shock absorption layer 402 is coated on the surface of the arc-shaped groove and is abutted against the arc-shaped part on the back of the rack. The first sealing ring 405 and the second sealing ring 406 are sequentially assembled on the outer cylindrical surface of the support yoke 401, and the axis of the support yoke 401 is provided with an air vent 403 and a support groove 404, wherein the air vent 403 penetrates through the support yoke 401 and the friction reducing and cushioning layer 402, and the support groove 404 is located on the side of the support yoke 401 contacting the exciter assembly 5 and is communicated with the air vent 403. The friction reducing and cushioning layer 402 may be made of Polytetrafluoroethylene (PTFE) or other materials known in the art. In order to ensure that the magnetostrictive rod shakes, the matching clearance between the magnetostrictive rod and the supporting yoke groove is designed to be very small, if no air hole is arranged, when the magnetostrictive rod is inserted into the supporting yoke groove, the magnetostrictive rod is difficult to install due to internal pressure, and the problem is avoided by arranging the air hole.

Referring to fig. 1 and 3, the magnetostrictive actuator assembly 5 includes an actuator top cover 501, an actuator housing 502, an actuator coil 503, a bobbin 504, a magnetostrictive rod 506, an actuator first gasket 507, and an actuator second gasket 508. The coil frame 504 wound with the exciting coil 503 is assembled inside the exciter housing 502 and pressed by the exciter top cover 501, the magnetostrictive rod 506 is positioned on the axis of the exciter housing 502 and passes through the coil frame 504 and the exciter top cover 501, the first sealing ring 507 and the second sealing ring 508 of the exciter are assembled on the outer cylindrical surface of the exciter housing 502 in sequence, the lower end of the exciter housing 502 is further provided with an outlet hole 505 for passing through the lead of the exciting coil 503, and the lead led out from the outlet hole 505 is connected with the connector 6.

Because the support yoke first seal ring 405 and the support yoke second seal ring 406, and the exciter first seal ring 507 and the exciter second seal ring 508 are tightly fitted, a frictional force opposite to the movement direction of the support yoke 4 is generated, and energy is dissipated through frictional damping, so that vibration is damped.

The disc spring assembly 9 comprises two groups of disc springs, each group of disc springs is composed of two disc springs which are overlapped and connected in parallel, and the two groups of disc springs are connected in a closing and series connection mode. Because the dish spring subassembly 9 is formed by two sets of dish springs of coincide parallelly connected combination, the contact surface between the dish spring produces relative displacement and mutual friction, dissipates the energy through friction damping, damps the vibration.

Of course, it will be understood by those skilled in the art that other springs or similar resilient members may be substituted for the resilient preload assembly as a variation of the disc spring assembly described above. In order to ensure the output characteristics of the giant magnetostrictive material, the spring should have a variable stiffness characteristic, and a section in the force-displacement curve of the spring is relatively gentle, so that a disc spring is preferably used, and the disc spring can save space.

In the above structure, the bottom of the actuator casing is provided with a downwardly protruding boss 5021, the upper surface of the bottom of the actuator casing is provided with a positioning groove 5022, the upper end of the magnetostrictive rod extends into the supporting groove 404 and abuts against the top wall of the supporting groove, and the lower end abuts against the positioning groove 5022. The adjusting screw plug 8 is provided with a sliding hole, an inner hole of the disc spring assembly is nested in the convex column 5021, and the convex column 5021 extends into the sliding hole in a sliding mode.

Example two

The active adjusting method for the steering mechanism clearance based on giant magnetostriction comprises the following steps:

1) when a vehicle runs into a bumpy road surface such as a non-paved road surface, the vibration conducted to a steering mechanism is increased, so that in order to avoid abnormal sound of a steering system, the rack 3 needs larger preload force to be pressed on a gear of the gear shaft 2, and current is firstly introduced into the exciting coil 503;

2) the current passed through the exciting coil 503 generates a magnetic field at the axial position of the magnetostrictive actuator assembly 5;

3) the magnetostrictive rod 506 positioned on the axis of the magnetostrictive actuator assembly 5 is magnetostrictive under the action of a magnetic field, and due to the characteristics of the giant magnetostrictive material, the length of the magnetostrictive rod 506 can be increased no matter the direction of the magnetic field positioned on the axis of the magnetostrictive actuator assembly 5 is positive or negative, so that the direction of the magnetic field in the step 1) does not need to be defined;

4) the elongated magnetostrictive rod 503 presses the disc spring assembly 9 through the exciter housing 502, the disc spring assembly 9 deforms and increases, and a greater preload force is generated;

5) the preloading force increased by the disc spring assembly 9 is transmitted through the magnetostrictive actuator assembly 5 and the support yoke assembly 4, so that the rack 3 is further compressed, the gap between the rack 3 and the gear of the gear shaft 2 is reduced, and abnormal sound caused by collision of a steering system on a bumpy road surface due to the gap is avoided;

6) because the steering hand feeling of a driver can be changed due to overlarge preload force, and the abnormal sound problem cannot be avoided due to the overlarge preload force, the current introduced into the exciting coil 503 is changed according to the vibration conditions of the road surface and the vehicle body, so that the real-time adjustment of the preload force of the disc spring assembly 9 and the gap between the gear and the rack 3 on the gear shaft 2 is realized;

7) due to the characteristics of the giant magnetostrictive material, after an external magnetic field is removed, residual magnetism inside the giant magnetostrictive rod 506 can cause the magnetostrictive rod 506 to be incapable of retracting to the original length, so that after a vehicle drives off a bumpy road surface, current opposite to the direction of the step 1) is introduced into the exciting coil 503 for a short time, the residual magnetism inside the magnetostrictive rod 506 is eliminated, and the magnetostrictive rod 506 is enabled to recover to the original length.

In the step 1), two methods for detecting that the vehicle drives into bumpy road surfaces such as non-paved road surfaces and the like are adopted:

1) directly detecting the vibration of the whole vehicle: for a vehicle model equipped with an acceleration sensor, a VCU (vehicle control unit) is required to be transmitted to an ECU (electronic control unit) of a steering controller through a CAN (controller area network) signal; if the whole vehicle does not transmit the acceleration signal, an acceleration sensor can be directly integrated on the steering controller. The basic principle of vibration monitoring is to detect acceleration and, when the root mean square/energy of the acceleration increases to a certain threshold, it is considered to enter a bumpy road surface.

2) Detecting the reverse action of the steering system: when the vehicle runs to a bumpy road condition, the steering system inevitably generates reverse action (transmitted to a driver to be represented as a tie-up), and the reverse action can be captured by a torque and rotation angle sensor of the steering system; similarly, when the above-described steering reaction by the road surface reaches a certain threshold value, it is considered that the vehicle enters a bumpy road surface.

The threshold values related to the two methods are predetermined, and the obtaining is a continuously optimized calibration process which needs to be determined according to a specific vehicle model test.

In step 6), before the maximum current limit is reached, the stronger the vibration, the higher the current passed in the exciting coil 503, and the tighter the rack pressure.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and those skilled in the art should understand that the present invention includes but is not limited to the contents described in the above specific embodiments. Any modification which does not depart from the functional and structural principles of the present invention is intended to be included within the scope of the claims.

Claims (9)

1. The super-magnetostrictive clearance adjusting device of the rack and pinion steering gear comprises a steering gear shell, a rack and a rack assembly and a supporting yoke, wherein the rack and the rack assembly are meshed with each other through a gear, a clearance adjusting cavity corresponding to the rack is arranged on the steering gear shell, and the supporting yoke is movably arranged in the clearance adjusting cavity and abuts against the back surface of the rack, and is characterized in that: the clearance adjustment device still includes magnetostrictive actuator assembly and elasticity preloading subassembly, magnetostrictive actuator assembly includes the actuator casing, is located the exciting coil of actuator casing, nests the magnetostrictive rod in the exciting coil, the upper end and the support yoke butt of magnetostrictive rod, lower extreme and actuator casing bottom butt, the regulation plug screw is installed to the lower oral area in clearance adjustment chamber, the upper end and the actuator casing butt of elasticity preloading subassembly, the lower extreme with adjust the plug screw butt, the elasticity preloading subassembly exerts preloading force to the magnetostrictive rod through the actuator casing.

2. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to claim 1, characterized in that: the support yoke is provided with an arc-shaped groove corresponding to the arc-shaped part on the back of the rack, and the surface of the arc-shaped groove is provided with an anti-friction cushioning layer.

3. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to claim 2, characterized in that: and the lower part of the support yoke is provided with a support groove, and the upper end of the magnetostrictive rod extends into the support groove and is abutted against the top wall of the support groove.

4. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to claim 1, characterized in that: and at least one sealing ring matched with the inner wall of the clearance adjusting cavity is arranged on the outer cylindrical surface of the supporting yoke.

5. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to any one of claims 1 to 4, characterized in that: the elastic preloading component is a disc spring component.

6. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to claim 5, characterized in that: the disc spring assembly comprises two groups of disc springs, each group of disc springs is composed of two disc springs which are overlapped and connected in parallel, and the two groups of disc springs are connected in a closing and series connection mode.

7. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to claim 6, characterized in that: the magnetostrictive actuator assembly further comprises an actuator top cover for sealing an opening of the actuator shell and a coil framework movably nested outside the magnetostrictive rod, and the actuator coil is wound on the coil framework, assembled inside the actuator shell and pressed by the actuator top cover.

8. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to claim 7, characterized in that: the bottom of the exciter shell is provided with a convex column, the adjusting screw plug is provided with a sliding hole, an inner hole of the disc spring assembly is nested in the convex column, and the convex column stretches into the sliding hole in a sliding mode.

9. The super magnetostrictive gap adjustment device of a rack and pinion steering gear according to claim 7, characterized in that: at least one sealing ring is arranged on the outer cylindrical surface of the exciter shell.

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