Variable steering wheel damper using electromagnets

Abstract

The present invention relates to a variable steering wheel damper using an electromagnet, the damper comprising: a plate fastened to a hub of a steering wheel; at least one support made of rubber, wherein a first side of each of the at least one support is fixed to a surface of the plate and a second side extends perpendicular to the surface of the plate; a mass body which is spaced apart from the plate, mounted on a second side of the at least one support, supported by the at least one support and configured as a magnet; and an electromagnet formed by winding a coil on an iron core fixed to the surface of the plate.

Description

Technical Field

[0001] The present invention relates to a steering wheel damper, and more particularly to a damper comprising: a plate fastened to a steering wheel hub; one or more pillars, one side of each pillar being fixed to the surface of the plate and the other side extending perpendicularly to the surface of the plate; a mass body, which is spaced apart from the plate, mounted on the other side of the pillar, supported by the pillar, and whose upper and lower parts are configured as magnets with different polarities; and an electromagnet formed by winding a coil on an iron core fixed to the surface of the plate. Background Art

[0002] Generally, a steering wheel for steering a vehicle is installed in a driver's seat of the vehicle.

[0003] The steering shaft and the steering column are connected to the steering wheel to transmit the operating force of the steering wheel. The steering gear is installed to convert the rotational force of the steering wheel transmitted through the steering shaft to change the direction of the wheel, so that when the driver rotates the steering wheel, the rotational force is transmitted to the steering gear and the direction of the wheel is changed.

[0004] The steering wheel includes: a circular rim configured to be gripped by a driver; a hub mounted at a central portion of the steering wheel; and spokes configured to connect the hub and the rim, and an airbag and a horn for the driver are embedded in the hub.

[0005] In this case, a vibration absorber for reducing vibration is installed in the hub of the steering wheel to prevent the steering wheel from vibrating when the vehicle is running.

[0006] Generally, a steering wheel damper includes: a base plate fastened to a wheel hub; a support column made of rubber and mounted on the base plate; and a mass body spaced apart from the base plate and supported by the support column.

[0007] However, the steering wheel damper has a natural frequency to minimize the vibration of the steering wheel, and the natural frequency can be adjusted by adjusting variable values ​​of design elements such as stiffness, hardness, and mass of pillars and mass bodies as constituent elements of the damper.

[0008] The adjustment of the natural frequency of the shock absorber is determined based on the vibration characteristics of the steering wheel, and the natural frequency of the shock absorber is fixed according to the variable value of the design element of the strut or the mass body. Generally, the natural frequency is fixed according to the vibration characteristics of the steering wheel in three positions of the steering wheel, namely the retracted position, the telescopic intermediate position and the extended position, at the engine idle state.

[0009] However, there are still limitations in reducing the various driving vibrations transmitted to the steering wheel. For example, overall vibrations transmitted from driving vibrations, such as vibrations generated when the vehicle creeps (in an automatic transmission vehicle, when the gear is set to the driving gear, the vehicle moves forward slowly even when the accelerator pedal is not depressed), vibrations generated when the vehicle accelerates, and vibrations generated when the clutch is locked while the vehicle is driving, are still transmitted to the steering wheel.

[0010] Meanwhile, as related arts related to a steering wheel damper of a vehicle, arts of Korean Patent Application Publication Nos. 10-2009-0029400, 10-2014-0042162, and 10-2017-0069743 are known.

[0011] The information disclosed in this Background of the Invention section is only for enhancement of understanding of the overall background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0012] Various aspects of the present invention are directed to a steering wheel damper in which the length of a strut made of a rubber material is changed by using an electromagnet and the rigidity of the strut of the steering wheel damper is changed, thereby reducing vibrations transmitted from various driving vibrations.

[0013] Various aspects of the present invention are directed to a variable steering wheel damper using an electromagnet, the variable steering wheel damper comprising: a plate fastened to a hub of a steering wheel; one or more pillars, each of which has one side fixed to a surface of the plate and the other side extending perpendicularly to the surface of the plate; a mass body, which is spaced apart from the plate, mounted on the other side of the pillar, supported by the pillar, and having an upper portion and a lower portion, the upper portion and the lower portion being configured to be arranged adjacent to each other and respectively having magnets of different polarities; and an electromagnet formed by winding a coil on an iron core fixed to the surface of the plate.

[0014] According to the variable steering wheel damper using an electromagnet according to an exemplary embodiment of the present invention constructed as described above, the rigidity of the strut of the steering wheel damper is changed by changing the length of the rubber strut using the electromagnet, thereby changing the natural frequency of the damper. Therefore, the performance of the noise, vibration and harshness (NVH) (noise, vibration, and noise and vibration caused by external impact) of the vehicle can be improved by reducing the overall vibration transmitted from various running vibrations of the vehicle, thereby improving the riding comfort and enhancing the marketability.

[0015] The steering wheel damper according to an exemplary embodiment of the present invention has a relatively simple structure, so that cost and weight can be reduced and fuel economy can be improved.

[0016] The method and apparatus of the present invention also have other features and advantages, which will be apparent from or described in more detail in the accompanying drawings and the following specific embodiments in conjunction with this document, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view exemplarily showing a steering wheel and a steering wheel damper according to an exemplary embodiment of the present invention installed in the steering wheel;

[0018] Figure 2 is an exploded perspective view exemplarily showing a steering wheel damper according to an exemplary embodiment of the present invention;

[0019] Figure 3 is a flow chart for controlling a steering wheel damper according to an exemplary embodiment of the present invention;

[0020] Figure 4 is a view exemplarily showing an operating state of a steering wheel damper according to an exemplary embodiment of the present invention, Figure 4 (a) is a view exemplarily showing an initial working state; (b) is a view exemplarily showing a working state when a first current is applied; and (c) is a view exemplarily showing a working state when a second current is applied.

[0021] It should be understood that the accompanying drawings are not necessarily drawn to scale, but rather present somewhat simplified representations of various features illustrating the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, directions, positions, and shapes, will be determined in part by the specific intended application and use environment.

[0022] In the drawings, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. Specific embodiments

[0023] Reference will now be made in detail to various embodiments of the present invention, examples of which are shown in the accompanying drawings and described below. Although the present invention will be described in conjunction with exemplary embodiments of the present invention, it should be understood that this description is not intended to limit the present invention to these exemplary embodiments. On the contrary, the present invention is intended to cover not only these exemplary embodiments of the present invention, but also various alternative forms, modifications, equivalents and other embodiments that may be included in the thought and scope of the present invention as defined by the appended claims.

[0024] Hereinafter, the construction and operation of a variable steering wheel damper using an electromagnet according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

[0025] However, the included drawings are provided as examples to fully convey the spirit of the present invention to those skilled in the art. Therefore, the present invention is not limited to the drawings included below, and may be embodied in other aspects.

[0026] Unless otherwise defined, the terms used in the description of the present invention have the meanings that are commonly understood by a person of ordinary skill in the art to which the exemplary embodiments of the present invention relate, and in the following description and drawings, detailed descriptions of well-known functions and configurations will be omitted to avoid unnecessarily confusing the subject matter of the present invention.

[0027] Figure 1 is a perspective view exemplarily showing a steering wheel damper according to an exemplary embodiment of the present invention, Figure 2 is an exploded perspective view exemplarily illustrating a steering wheel damper according to an exemplary embodiment of the present invention.

[0028] Referring to the corresponding drawings, a steering wheel damper 1 (hereinafter referred to as "damper") according to an exemplary embodiment of the present invention includes: a flat plate 10, which is fastened to a hub 110 of a steering wheel 100; one or more pillars 20, one side of each pillar being fixed to a surface of the plate 10 and the other side extending perpendicular to the surface of the plate 10; a mass body 30, which is configured to be spaced apart from the plate 10 and supported by the pillar 20 by being mounted to the other side of the pillar 20, and whose upper and lower parts are configured as magnets with different polarities; and an electromagnet 40, which is formed by winding a coil 42 on an iron core 41 fixed to the surface of the plate 10.

[0029] The material of the support 20 is rubber. As shown in the figure, in the exemplary embodiment of the present invention, there are a total of four support posts 20 installed on the board 10, and one support post 20 is installed at each corner of the board 10.

[0030] The coil 42 is wound several times around the outer peripheral surface of the core, and includes an electric conductor so that a current can be applied to the coil 42 .

[0031] The mass body 30 according to the exemplary embodiment of the present invention has a flat plate shape, and the lower portion is an N-pole body 31 as a magnet having an N-pole, and the upper portion is an S-pole body 32 as a magnet having an S-pole.

[0032] Therefore, in the shock absorber 1 according to the exemplary embodiment of the present invention constructed as described above, when current is applied to the coil 42 of the electromagnet 40, a magnetic field is generated by the electromagnet 40 on the upper side of the iron core 41 in the direction of the applied current. Repulsive force or attractive force acts on the mass body 30 through the generated magnetic field, and the mass body 30 is pushed by the repulsive force or pulled by the attractive force, so that the natural frequency of the shock absorber is adjusted as the rubber stiffness of the support 20 for supporting the mass body 30 changes.

[0033] Here, the natural frequency of the vibration absorber can be obtained based on the well-known expression 1 for determining the frequency characteristics of an object:

[0034] (Expression 1)

[0035]

[0036] f: frequency

[0037] k: Rubber stiffness of the shock absorber

[0038] m: mass of the shock absorber

[0039] In other words, the natural frequency of the shock absorber is proportional to the rubber stiffness k of the shock absorber and inversely proportional to the mass m. When the mass m of the shock absorber remains unchanged, the natural frequency of the shock absorber increases as the rubber stiffness k increases, and when the mass m of the shock absorber remains unchanged, the natural frequency of the shock absorber decreases as the rubber stiffness k decreases.

[0040] Therefore, in the case of the vibration absorber according to the exemplary embodiment of the present invention, when current is applied to the coil 42 of the electromagnet 40, a repulsive force or an attractive force acts on the mass body 30 (the upper and lower parts of the mass body 30 are configured as magnets with different polarities) through the magnetic field generated on the upper side of the electromagnet 40 as described above, so that the mass body 30 is pushed in a direction away from the electromagnet 40 or pulled in a direction toward the electromagnet 40. Therefore, the rubber stiffness k of the support column 20 made of rubber and installed on the plate 10 to support the mass body 30 is changed, and the natural frequency of the vibration absorber 1 based on Expression 1 is changed according to the amount of change of the changed rubber stiffness.

[0041] In the present case, in the case of the shock absorber according to the exemplary embodiment of the present invention, the speed (RPM) value of the engine under various conditions is stored in a controller, such as an electronic control unit (ECU) of a vehicle on which the shock absorber is installed. Examples of the RPM value of the engine under various conditions may include: the RPM value of the engine when the vehicle is creeping, the RPM value of the engine when the air conditioner in the vehicle is running, the RPM value of the engine when the vehicle is accelerating, and the RPM value of the engine when the clutch is locked during the vehicle driving. In addition, when the RPM value of the engine corresponds to the RPM value of the engine under various operating conditions, the ECU may apply a current of an amount predetermined by the ECU to the electromagnet 40.

[0042] Meanwhile, the size of the magnetic field generated on the upper side of the electromagnet 40 is changed according to the material, length and area of ​​the core 41, the thickness of the coil 42 and the number of turns of the coil 42, and the size of the magnetic field varies in proportion to the amount of current applied to the coil 42. Therefore, by changing the variables of the design elements of the electromagnet 40, the natural frequency of the vibration absorber according to the exemplary embodiment of the present invention can be adjusted.

[0043] Next, the operation of the steering wheel damper according to the exemplary embodiment of the present invention constructed as described above will be described.

[0044] Figure 3 is a flowchart for controlling a steering wheel damper according to an exemplary embodiment of the present invention, Figure 4 is a view exemplarily showing the working state of the steering wheel damper according to an exemplary embodiment of the present invention, wherein Figure 4 (a) is a view exemplarily showing an initial working state, (b) is a view exemplarily showing a working state when a first current is applied, and (c) is a view exemplarily showing a working state when a second current is applied.

[0045] First, refer to Figure 3 , a steering wheel damper according to an exemplary embodiment of the present invention includes an ECU that stores an RPM value of an engine under a specific operating condition of the engine and applies a predetermined amount of current corresponding to the stored RPM value under the specific operating condition of the engine to the electromagnet 40.

[0046] When the electromagnet 40 is in a non-operating state, the ECU detects the RPM value of the engine (S1), and the ECU determines whether the detected RPM value of the engine corresponds to the RPM value under the stored specific operating condition (S2). When the detected RPM value of the engine corresponds to the RPM value under the stored specific operating condition, the ECU applies a current of an amount predetermined by the ECU to the electromagnet 40 (S3).

[0047] Therefore, a magnetic field is generated on the upper side of the electromagnet 40 by the current applied to the electromagnet 40, so that repulsive force or attractive force acts on the mass body 30 (S4). The rubber stiffness k of the support 20 is changed according to the applied repulsive force or attractive force, and the natural frequency of the steering wheel damper is adjusted according to the change amount of the changed rubber stiffness (S5).

[0048] Reference Figure 4 , (a) is a view exemplarily showing an initial working state of the vibration absorber (case A). The vibration absorber according to an exemplary embodiment of the present invention is configured to have a predetermined natural frequency f 0 When the length of the support 20 is constant, the shock absorber has an initial rubber stiffness k 0 .

[0049] In the present case, the natural frequency f 0 It can be, for example, a natural frequency for attenuating the vibration transmitted to the steering wheel in three positions of the steering wheel, namely, in the retracted position, the telescopic intermediate position and the extended position, when the engine is idling. Optionally, the natural frequency f 0 It may be a natural frequency for attenuating vibration transmitted to the steering wheel when the air conditioner of the vehicle is running in the idling state of the engine.

[0050] Figure 4 FIG. (b) in FIG. 1 is a view exemplarily showing the working state of the vibration absorber when a predetermined amount of first current is applied to the coil 42 of the electromagnet 40 (case B). In the working state of the vibration absorber, the vibration absorber has a first tuned natural frequency f 1 , the first tuned natural frequency f 1 is tuned to attenuate the predetermined natural frequency f which is set by the vibration absorber in the initial state. 0 In addition to the attenuated vibrations, various types of driving vibrations are transmitted to the steering wheel of the vehicle, for example, vibrations occurring when the vehicle is creeping (in an automatic transmission vehicle, when the gear is set to the driving gear, the vehicle moves forward slowly even if the accelerator pedal is not depressed), vibrations occurring when the vehicle is accelerating, and vibrations occurring when the clutch is locked while the vehicle is driving, etc., which are transmitted from the driving vibrations.

[0051] For example, assuming that the RPM value of the engine under creeping conditions is stored in the vehicle's ECU to reduce the vibration generated when the vehicle creeps, when the vehicle creeps, the vehicle's ECU applies a first current A1 having a predetermined amount (e.g., 10A) to the coil 42 of the electromagnet 40 of the steering wheel damper according to an exemplary embodiment of the present invention.

[0052] In the present case, when the first current A1 is applied to the electromagnet 40 in the direction toward the upper side of the iron core 41, a magnetic field with the N pole of the electromagnet is formed on the upper side of the electromagnet 40, and a magnetic field with the S pole is formed on the lower side of the electromagnet. In this case, since the N pole body 31 is formed on the lower side of the mass body 30, a repulsive force is generated between the electromagnet 40 and the mass body 30, so that the force acts on the mass body 30 in the direction away from the electromagnet 40. Thus, the length of the support 20 increases, and the first rubber stiffness k of the support 20 is increased. 1 The value is less than Figure 4 (a) The rubber stiffness k in the initial state 0 The value of .

[0053] Therefore, according to the above expression 1, when the length of the support 20 increases, the rubber stiffness k decreases so that the first tuning natural frequency f 1The value is smaller than the natural frequency f when the length of the support 20 is constant. 0 The value of .

[0054] Figure 4 FIG. (c) in FIG. 1 is a view exemplarily showing the working state of the vibration absorber when a second current A2 having a current value greater than the first current A1 is applied to the coil 42 of the electromagnet 40 (case C). The second current A2 is to be applied to the electromagnet 40 so that the vibration absorber has a first tuning natural frequency f 1 Different second tuning natural frequencies f 2 of current.

[0055] For example, assuming that the RPM value of the engine under high-speed driving conditions is stored in the ECU of the vehicle to reduce the vibration that occurs when the vehicle is driving at high speed, when the vehicle is driving at high speed, the ECU applies a second current A2 having a predetermined amount (e.g., 15A) to the coil 42 of the electromagnet 40 according to an exemplary embodiment of the present invention.

[0056] In the present case, when the second current A2 is applied to the electromagnet 40 in the direction toward the upper side of the iron core 41, a magnetic field with the magnetic pole of the electromagnet being the N pole is formed on the upper side of the electromagnet 40, and a magnetic field with the S pole is formed on the lower side of the electromagnet. Because the amount of the second current applied to the electromagnet 40 is greater than the first current, a larger magnetic field than the magnetic field formed when the first current is applied is formed on the upper side of the electromagnet 40, and a larger repulsive force is generated. Therefore, compared with when the first current A1 is applied, the length of the support 20 is increased to a larger length, so that the second rubber stiffness value k of the rubber stiffness k of the support 20 is 2 The value is less than the first rubber stiffness value k 1 .

[0057] Therefore, based on the above expression 1, the second tuning natural frequency f 2 With a frequency less than the natural frequency f 0 and the first tuning natural frequency f 1 The value of .

[0058] Therefore, by changing the amount of current applied to the electromagnet 40 according to the RPM under various vibration conditions of the vehicle and thereby changing the length of the strut 20, the natural frequency of the shock absorber can be tuned. Therefore, the performance of noise, vibration and harshness (NVH) (noise, vibration, and noise and vibration caused by external impact) of the vehicle can be improved, and the marketability can be improved by improving the comfort of the vehicle.

[0059] For ease of description and accurate definition in the appended claims, the terms "upper", "lower", "inner", "outer", "up", "lower", "upward", "downward", "front", "back", "rear", "inner", "outer", "inner", "outer", "inner", "outer", "forward", and "rearward" etc. are used to describe the features of the exemplary embodiments with reference to their positions as shown in the drawings. It will also be understood that the term "connect" or its derivatives refer to both direct and indirect connections.

[0060] For the purpose of illustration and description, the foregoing description of specific exemplary embodiments of the present invention has been given. This description is not intended to be exhaustive or to limit the present invention to the exact form disclosed, and in view of the above teachings, it is apparent that multiple modifications and variations are possible. The exemplary embodiments are selected and described in order to explain the specific principles of the present invention and its practical application, so that other technical personnel in the field can implement and utilize various exemplary embodiments of the present invention and various alternative forms and variations thereof. It is intended that the scope of the present invention be limited by the appended claims and their equivalents.

Claims

1. A shock absorber mounted on a steering wheel of a vehicle, the shock absorber comprising: a plate fastened to a hub of the steering wheel; at least one strut made of rubber, wherein a first side of each of the at least one strut is fixed to a surface of the plate and a second side extends perpendicular to the surface of the plate; a mass body spaced apart from the plate, attached to the second side of the at least one support post, supported by the at least one support post, and configured as a magnet; and an electromagnet formed by winding a coil on an iron core fixed to a surface of the plate and disposed between the plate and the mass body, wherein, when current is applied to the coil of the electromagnet, repulsive force or attractive force acts on the mass body, the mass body is pushed by the repulsive force or pulled by the attractive force, so that the rubber stiffness of the at least one support changes, and the natural frequency of the shock absorber based on Expression 1 is adjusted according to the amount of change in the rubber stiffness, Expression 1: Where f is the frequency, k is the rubber stiffness of the shock absorber, and m is the mass of the shock absorber.

2. The shock absorber according to claim 1, wherein: The mass body is composed of an upper portion and a lower portion, which are configured as magnets arranged adjacent to each other and respectively having different polarities.

3. The vibration absorber according to claim 1, further comprising: A controller is configured to store a rotation speed value of the engine under the engine operating condition and apply a predetermined amount of current corresponding to the stored rotation speed value under the engine operating condition to the electromagnet.

4. The vibration absorber according to claim 3, wherein: The controller is configured to detect a speed value of the engine, and upon determining that the detected speed value of the engine corresponds to a speed value under the stored operating conditions, the controller applies an amount of current predetermined by the controller to the electromagnet to change the rubber stiffness of the at least one strut.

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