Patent Grant
11987309
The present invention relates to a steering wheel device for a vehicle which is capable of effectively damping low-frequency vibrations generated in the steering wheel and has a simple structure.
Patent document 1 discloses a steering wheel device for a vehicle in which an airbag module is attached by being engaged with a steering wheel via an engaging mechanism arranged around the steering wheel center of steering.
In the “steering wheel” of Patent Document 1, a pin holder (slider) is arranged outside a snap pin (support member) so as to be slidable in the front-to-back direction, and is biased backward by a coil spring (biasing member). The contact holder (cap member) covers the snap pin and the pin holder from the rear while being separated rearward from the rear end of the pin holder. A contact terminal (movable side contact portion) and a damper holder covering a part of the pin holder are mounted in the contact holder. An elastic member is interposed between the pin holder and the damper holder. A transmitting part is provided on the inner peripheral portion of the damper holder, and a transmitted portion (receiving portion) is provided on the outer peripheral portion of the pin holder in front of the transmitting portion to which the forward movement of the damper holder is transmitted through the transmitting portion.
In Patent Document 1, an elastic member that constitutes a dynamic damper is provided. In Patent Document 1, three horn switch mechanisms for attaching the airbag module to the steering wheel are arranged around the center of steering of the steering wheel.
The vibration modes generated in the steering wheel include (1) vertical vibration caused by the engine in the low-frequency band of 30 to 50 Hz and (2) deformation resonance of the steering wheel in the high frequency band of 70 to 90 Hz.
The vibration mode in low-frequency bands can be damped considerably by a dynamic damper as disclosed in Patent Document 1.
However, since the dynamic dampers that are arranged at three locations are composed of at least three parts, being the elastic member, the pin holder, and the damper holder, there is a problem that the structure is complicated and the cost is high.
In light of the conventional issues described above, an object of the present invention is to provide a steering wheel device for a vehicle that is capable of effectively suppressing low-frequency vibrations generated in the steering wheel and that has a simple structure.
The steering wheel device for a vehicle according to the present invention is a steering wheel device for a vehicle, in which an airbag module is attached to an engagement element that is arranged around a steering wheel center of steering and is engaged with said steering wheel, where:
A gap between the second pin and second bushing of the second engagement element is desirable. A gap between the first pin and first bushing of the first engagement element is desirable. The gap is preferably in the range of 0.05 mm or more and 0.3 mm or less.
Instead of including the second pin and the second bushing, the second engagement element is desirably a leaf spring member with a first end joined to the airbag module and a second end provided with the engaging part that engages with the engaged part. It is preferable that the engaging part is provided with an insulator.
The second elastic member is preferably provided between the steering wheel and the airbag module to elastically support the airbag module on the steering wheel. Preferably, the second elastic member is a coil spring.
The first engagement element is preferably arranged on a vertical axis passing through the center of steering with reference to the neutral position of the steering wheel, and the second engagement elements are preferably arranged in a region between the vertical axis passing through the center of steering and a horizontal axis orthogonal to the vertical axis, and at symmetrical positions with respect to the vertical axis.
The steering wheel device for a vehicle according to the present invention has a simple structure, and can effectively damp low-frequency vibrations in the steering wheel.
A suitable Embodiment of the vehicle steering wheel device according to the present invention will be described in detail below with reference to the accompanying drawings.
In these drawings, up, down, left, and right directions are indicated on the steering wheel with respect to the neutral position at a zero steering angle. Otherwise, the side viewed from the driver's side shall be described as the front side and the opposite side as the back side.
The steering wheel 1 is installed in the driver seat of a vehicle. The boss portion 2 of the steering wheel 1 is connected to a steering shaft passing through the interior of a steering column (not shown). The steering shaft transmits the operating force of the driver to the steering gear and the like.
An airbag module 3 that functions as a front airbag in an emergency is mounted in the center of the steering wheel 1.
The airbag module 3 also functions as a horn switch under normal operation that a driver pushes to cause the horn to sound.
As illustrated in
The airbag module 3 includes a metal housing 6 with an airbag cushion 4 and an inflator 7, which will be described in detail later. The airbag cushion 4 is provided in a folded state. The inflator 7 supplies inflator gas to the airbag cushion 4.
When a signal is sent from a vehicle sensor in an emergency, inflation gas is supplied from the inflator 7 to the airbag cushion 4. The airbag cushion 4 to which the inflation gas is supplied cleaves the horn cover 5 and expands and deploys into the vehicle interior space. The expanded and deployed airbag cushion 4 restrains and protects the driver.
In general, the steering wheel 1 includes a central cored bar 8, a circular rim part 9, and spokes 10 connecting the central cored bar 8 and the rim part 9. The boss part 2 is formed in the central cored bar 8. The rim part 9 is grasped by the driver.
In the steering wheel device for a vehicle according to the present Embodiment, the airbag module 3 is attached to the steering wheel 1 by the first engagement element 11 and the second engagement element 31 that are engaged with the steering wheel 1. The first engagement element 11 and second engagement element 31 are arranged around the center of steering C of the steering wheel 1.
Of the steering wheel 1 and airbag module 3, these engagement elements 11 and 31 are provided on the airbag module 3 side. The engagement elements 11 and 31 have engaging parts 12a and 32a that detachably engage with the engaged parts 25 formed on the steering wheel 1 side. Specifically, the engaged part 25 is the structural portion provided in the central cored bar 8 of the steering wheel 1, with the set spring 24 in the insertion hole 8a (see
As illustrated in
The engagement elements 11 and 31 are provided on the airbag module 3 side and are engaged with the steering wheel 1. Of these engagement elements 11 and 31, at least one of the first engagement elements 11 functions as a vibration damping part to dampen the vibration of the steering wheel 1. The airbag module 3 serves as a damper mass for vibration damping.
In other words, the first engagement element 11 is arranged between the steering wheel 1 and the airbag module 3 to dampen vibration transmitted from the steering shaft to the steering wheel 1.
The structures of the first and second engagement elements 11 and 31 will be described in detail with reference to
The airbag module 3 serves as a damper mass of the first engagement element 11, which is a vibration damping part, on the steering wheel 1 side. The first and second engagement elements 11 and 31 are provided between the central cored bar 8 of the steering wheel 1 and the airbag module 3.
The first and second engagement elements 11 and 31 are arranged around the boss part 2 of the steering wheel 1. In the illustrated example, one first engagement element 11 and two second engagement elements 31 are provided. These engagement elements are spaced appropriately apart from each other.
More specifically, as illustrated in
The second engagement elements 31 are arranged on both sides of the boss part 2 in the left-right direction (on the left and right spokes 10 sides).
The housing 6 is provided with an inflator 7 facing the central cored bar 8 of the steering wheel 1 on which the first and second engagement elements 11 and 31 are arranged.
First, the first engagement element 11 will be described. The first engagement element 11, as illustrated in
A holder plate 13, elastic member 14, and cylindrical insulator 15 are set inside the first bushing 18.
The inner periphery of the first bushing 18 is slidably brought into contact with the first pin 12 with a small gap D2 relative to the first pin 12 (see
A metal coil spring 17 that is the second elastic member, is provided between the spring sheet 15a and the central cored bar 8. The coil spring 17 encircles the first pin 12 and elastically supports the airbag module 3 relative to the steering wheel 1.
The elastic member 14 damps the vibration of the steering wheel 1 using the airbag module 3 as a damper mass.
The constituent parts of the first engagement element 11, except for the elastic member 14, are formed of synthetic resin molded parts.
The first pin 12 is provided on the hollow cylindrical first bushing 18 by inserting the engaging part 12a into the first bushing 18 and locking the base plate part 12b to the first bushing 18. The tip 12c of the engaging part 12a is cone-shaped.
The holder plate 13 is provided in the axial direction of the first pin 12 so as to be in close contact with the elastic member 14.
The holder plate 13 is superimposed between the base plate part 12b and the elastic member 14. The holder plate 13 allows the elastic member 14 to exhibit the set damping performance regardless of the mounting accuracy of the first bushing 18 and the first pin 12.
The first pin 12 of the first engagement element 11 is engaged with the central cored bar 8 of the steering wheel 1. The engaging part 12a of the first pin 12 is inserted through an insertion hole 8a that is formed through the central cored bar 8.
The engaging part 12a of the first pin 12 is formed with a narrow part 12d so as to reduce the diameter. The outer diameter of the narrow part 12d is smaller than the hole diameter of the insertion hole 8a.
A locking groove 23 is formed in the back surface of the central cored bar 8 on the side opposite the airbag module 3 side.
A rod-shaped set spring 24 is locked in the locking groove 23. The rod-shaped set spring 24 is supported by the central cored bar 8. In the illustration, an omega spring with a bent part that contacts the back side of the central cored bar 8 is used as the rod-shaped set spring 24. The omega spring prevents the spring from falling out of the locking groove 23.
The set spring 24 is elastically deformed and engaged with regards to the narrow part 12d of the engaging part 12a of the first pin 12, which is positioned across the insertion hole 8a and inserted into the insertion hole 8a. The engaging part 12a, or in other words the first engagement element 11, is thus attached to the central cored bar 8, or in other words to the steering wheel 1.
The actual assembly is performed by fitting the engaging part 12a of the first engagement element 11 attached to the airbag module 3 into the insertion hole 8a of the central cored bar 8.
The second engagement element 31 is described next. As illustrated in
The inner periphery of the second bushing 33 is slidably brought into contact with the second pin 32 with a small gap D1 relative to the second pin 32 (see
The second bushing 33 is formed of a material with a larger Young's modulus (less elastic material) than the elastic member 14 of the first engagement element 11, which functions as a vibration damping part. The second bushing 33 is formed, for example, of a general-purpose resin such as PP or POM.
A metal coil spring 17, which is the second elastic member, is provided between the spring sheet 33a formed in the second bushing 33 and the central cored bar 8. The coil spring 17 encircles the second pin 32 and elastically supports the airbag module 3 against the steering wheel 1.
The second pin 32 is installed in the second bushing 33 by inserting the engaging part 32a into the hollow cylindrical second bushing 33 and engaging the base plate part 32b to the second bushing 33.
For the second pin 32 as well, the tip 32c of the engaging part 32a is formed into a cone shape, and formed with a narrow part 32d.
The engaging part 32a of the second engagement element 31 is engaged with the central cored bar 8 of the steering wheel 1 in the same manner as the engaging part 12a of the first engagement element 11.
Next, assembly of the engagement elements 11 and 31, which are engaged with the engaged part 25 of the steering wheel 1 as described above, to the airbag module 3 will be described with reference to
The airbag module 3 includes:
Three through-holes 6b are formed in the housing 6 around the inflator insertion hole 6a, opposite the insertion hole 8a.
The first and second bushings 18 and 33 are attached to each through-hole 6b and are thereby retained in the housing 6 at said through-holes 6b.
The first and second pins 12 and 32 are slidable in the first and second bushings 18 and 33. The inflator 7 is provided with an outer flange 7a abutting the housing 6.
The attachment plate 16 is installed from the horn cover 5 side toward the housing 6 side, facing the first and second pins 12 and 32.
The attachment plate 16 clamps the base plate parts 12b and 32b of the first and second pins 12 and 32 between the housing 6 and the attachment plate 16.
The retainer ring 19 is fastened by a nut 20 and the bolt 19a that passes through attachment plate 16, housing 6, and outer flange 7a of the inflator 7.
This secures the inflator 7, and the like to the housing 6 with the first and second engagement elements 11 and 31 retained in the through-hole 6b of the housing 6.
The horn cover 5 is locked to the attachment plate 16 by a plurality of locking hooks 5a on the periphery of the opening.
The coil spring 17 is provided between the housing 6 on the airbag module 3 side and the central cored bar 8 on the steering wheel 1 side, and surrounds the first and second pins 12 and 32 that protrude from the through-hole 6b of the housing 6 toward the central core bar 8.
For the first and second engagement elements 11 and 31, the first and second bushings 18 and 33 are elastically attached by coil springs 17 from the central cored bar 8 relative to the first and second pins 12 and 32 with the base plate parts 12b and 32b kept between the attachment plate 16 and the housing 6. The first and second engagement elements 11 and 31 are then assembled to the airbag module 3.
The first and second engagement elements 11 and 31 attached to the airbag module 3 have the engaging parts 12a and 32a protruding from the airbag module 3 side toward the steering wheel 1 side.
The first and second pins 12 and 32 of the first and second engagement elements 11 and 31 are engaged by the elasticity of the coil spring 17, with the narrow parts 12d and 32d sliding freely relative to the set spring 24 in the insertion hole 8a.
When the horn cover 5 of the airbag module 3 is operated by pressing, the coil spring 17 contracts. This causes the airbag module 3 to approach the central cored bar 8, which conducts at the horn contacts (not shown) and causes the horn to sound.
When the pressure on the horn cover 5 is released, the coil spring 17 is extended and restored. This breaks the continuity of the horn contact and the horn stops sounding.
As illustrated in
According to the analysis and study of the present invention, the gap D1 is preferably set within the range of 0.05 mm or more and 0.3 mm or less between the inner peripheral surface of the second bushing 32 and the outer peripheral surface of the second pin 32 over the entire inner peripheral surface of the second bushing 32.
Due to the gap D1 of the second engagement element 31, as illustrated in
In addition, the movement along the second pin 32 that occurs between the steering wheel 1 side and the airbag module 3 side can be smoothly guided.
As illustrated in
The gap D2 is preferably set within the range of 0.05 mm or more and 0.3 mm or less between the inner peripheral surface of the first bushing 18 and the outer peripheral surface of the first pin 12 over the entire inner peripheral surface of the first bushing 18. This ensures smooth movement along the first pin 12 that occurs between the steering wheel 1 side and the airbag module 3 side.
In the steering wheel device of the vehicle of the present Embodiment, the airbag module 3 can be attached to the steering wheel 1 by engaging the engaging parts 12a and 32a of the first and second engagement elements 11 and 31 with the engaged part 25 provided in the central cored bar 8.
Vibrations of the steering wheel 1 can be damped by the first engagement element 11 prepared with the elastic member 14.
Of the engagement elements 11 and 31 that attach the airbag module 3 to the steering wheel 1 by engagement, the second engagement element 31 is not provided with an elastic member 14 and has a low cost configuration with fewer parts, thus simplifying the structure and reducing costs. On the other hand, low-frequency vibration mode vibrations that occur in the steering wheel 1 can be sufficiently and effectively damped by the first engagement element 11. According to the present Embodiment, both ensuring vibration damping and cost reduction can be achieved compared to using materials for everything equivalent to the first engagement element 11.
By providing a gap D1 between the second pin 32 of the second engagement element 1 and the second bushing 33, it is possible to create a vibration mode that can be damped by the first engagement element 11, and vibration of the steering wheel 1 can be effectively suppressed.
The second engagement element 31 can be composed of a metal second pin 32 and a second bushing 33, which has a simpler structure than the first engagement element 11, and the second bushing 33 can be molded from general-purpose resin, thus achieving cost reductions.
A telescopic coil spring 17, which is the second elastic member provided between the steering wheel 1 and the airbag module 3, can ensure horn operation.
When the airbag module 3 is attached to the steering wheel 1, the airbag module 3 is lowered by its own weight, as indicated by the arrows in
In other words, when the airbag module 3 attached to the steering wheel 1 is changed from a horizontal state to a mounting angle for mounting, attachment of the airbag module 3 changes such that the gap K with respect to the garnish 45 around the steering wheel 1 increases.
The amount of change in this gap K is called step change amount (SAG) as illustrated in
In this configuration with two second engagement elements 31, the second engagement element 31 is simply the second pin 12 assembled to the second bushing 33. Unlike the first engagement element 11, there is no bending of the elastic member 14 in the second engagement element 31, thus allowing the step change amount to be kept small at 0.25 mm. As a result, the change in the size of the gap K with respect to the garnish 45 is reduced, and the design around the steering wheel 1 can be improved.
The leaf spring member 40 has an engaging part 42 with a first end in the length direction joined to the housing 6 of the airbag module 3 by a rivet or the like and a second end in the length direction thereof engaged to the engaged part 41. A synthetic resin insulator 43 is provided at the engaging part 42.
The leaf spring member 40 is provided so that the plate width direction is oriented in the vertical direction and the plate thickness direction is oriented in the horizontal direction.
The engaged part 41 of the central cored bar 8 is configured by a claw-shaped hook part instead of the configuration described above including the insertion hole 8a and the like.
The engaging part 42 of the leaf spring member 40 constitutes a hole into which the engaged part 41 is releasably inserted and engaged.
As illustrated in
As illustrated in
In this Modified Example, compared to the size of the second engagement element 31 with the hollow cylindrical second bushing 33 of the embodiment described above, the thickness in left and right direction can be roughly as thin as the thickness of the leaf spring member 40. Therefore, the dimension in the left-right direction required for the airbag module 3 can be reduced, and can be applied favorably to narrow-width designs.
In this Modified Example, the coil spring 17 is provided between the steering wheel 1 and the airbag module 3 in parallel with the leaf spring member 40.
The vehicle steering wheel device described above is a preferred example of the present invention, while other Embodiments can also be implemented or carried out by various methods. In particular, unless otherwise described in the specification of the application, the invention is not restricted to the shapes, sizes, configurational dispositions, and the like of the parts illustrated in detail in the accompanying drawings. In addition, the expressions and terms used in the specification of the application are used for providing a description, without limiting the invention thereto, unless specifically described otherwise.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-144815 | Aug 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/027859 | 7/28/2021 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2022/044668 | 3/3/2022 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 8459686 | Suzuki | Jun 2013 | B2 |
| 9550525 | Ishii | Jan 2017 | B2 |
| 10913420 | Ishii | Feb 2021 | B2 |
| 11351915 | Matsuo | Jun 2022 | B2 |
| 11529921 | Hirota | Dec 2022 | B2 |
| 20140131982 | Ishii | May 2014 | A1 |
| 20150042079 | Ishii | Feb 2015 | A1 |
| 20180029556 | Ishii | Feb 2018 | A1 |
| 20230174152 | Ishida | Jun 2023 | A1 |
| Number | Date | Country |
|---|---|---|
| 114750720 | Jul 2022 | CN |
| 102016106280 | Oct 2017 | DE |
| 102018127636 | May 2020 | DE |
| 2010-069934 | Apr 2010 | JP |
| 2015-096375 | May 2015 | JP |
| 2017-052433 | Mar 2017 | JP |
| 2017-197185 | Nov 2017 | JP |
| 2018-024410 | Feb 2018 | JP |
| 2019142655 | Jul 2019 | WO |
| WO-2019142654 | Jul 2019 | WO |
| 2020003777 | Jan 2020 | WO |
| 2020162315 | Aug 2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20230331297 A1 | Oct 2023 | US |
