JP2019093780A - Double wishbone type suspension device - Google Patents

Abstract

To suppress weight and improve rigidity while securing layout property of an arm part for connecting a knuckle body part (axle fastening part) to an upper arm of a double wishbone type suspension device.SOLUTION: A double wishbone type suspension device has an arm part 24 of an aluminum knuckle 12 that connects an upper arm 16 to a lower arm 14 and has a structure reinforced by reinforcement members 40, 42 made of a CFRP (carbon fiber-reinforced plastic).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a double wishbone type suspension device in which an axle is supported by an upper arm and a lower arm having a rotation axis parallel to the traveling direction of a vehicle, and then coupled to a vehicle body frame by a coil spring and a shock absorber.

  For example, in Patent Document 1, a knuckle for rotatably supporting a wheel, a lower arm for supporting a lower portion of a knuckle main body through which an axle penetrates vertically movable on a vehicle body, and an arm portion extending upward from the knuckle main body A so-called high mount type double wishbone type suspension device is disclosed (FIG. 1 of Patent Document 1).

  Patent Document 2 discloses an example of an adhesive that can be used when manufacturing the double wishbone type suspension device according to the present invention (for example, [0064] of Patent Document 2).

JP, 2010-126139, A International Publication No. 2016 / 084,960

  In the high mount double wishbone type suspension device as disclosed in Patent Document 1, since the arm portion to which the bending moment is applied is constituted by a curved portion like a crane neck, further rigidity is secured. In order to do that, you need to be thick.

  However, it is not preferable to increase the thickness because the weight increases and the layout property is deteriorated.

  The present invention has been made in consideration of such problems, and provides a double wishbone type suspension device capable of suppressing the weight and improving the rigidity while securing the layout property. The purpose is

  In the double wishbone type suspension device according to the present invention, the arm portion of the aluminum knuckle connecting the upper arm and the lower arm is reinforced by a reinforcing member made of carbon fiber reinforced plastic (CFRP). is there.

As described above, the knuckle connecting the upper arm and the lower arm is reinforced by the reinforcement member made of carbon fiber reinforced plastic with the arm portion to which the bending moment in the vertical direction is applied. However, the weight can be suppressed and the rigidity can be improved.
In this case, the reinforcing member is bonded to the arm portion by an adhesive.

  By using an adhesive (for example, the adhesive described in Patent Document 2) which has taken measures to reduce thermal expansion strain, thermal expansion strain generated at the interface between aluminum material of aluminum knuckle and carbon fiber reinforced plastic material is absorbed. can do. As a result, it is possible to realize more reliable specifications in terms of strength and durability, and also to prevent peeling and breakage of a reinforcing member made of carbon fiber reinforced plastic.

  Moreover, in general, aluminum material and carbon fiber reinforced plastic material have a potential difference (different ionization tendency), and there is a possibility that they may be electrolytically etched through moisture and oxygen if they are brought into direct contact. By interposing, electrolytic corrosion can be prevented.

  Preferably, the reinforcing member is formed in a U-shaped groove that is curved according to the shape of the arm so as to cover at least the inner side in the vehicle width direction of the arm.

  As described above, the rigidity of the arm portion can be improved by covering the arm portion with the U-shaped groove-shaped reinforcing member, but when covering, the wheel is fixed by adhesion so as to cover at least the inner side in the vehicle width direction. By rolling up pebbles etc., it is possible to reduce the possibility of the occurrence of cracks in the reinforcing member made of carbon fiber reinforced plastic. Note that pebbles and the like wound up by the wheels are likely to hit the outer side in the vehicle width direction of the arm portion.

  Further, it is preferable that the reinforcing member is formed in a U-shaped groove shape that is curved according to the shape of the arm portion so as to cover at least the vehicle rear side of the arm portion.

  As described above, the rigidity of the arm portion can be improved by covering the arm portion with the U-shaped groove-shaped reinforcing member, but when covering, the wheel is adhered and fixed so as to cover at least the vehicle rear side. A pebble etc. can be rolled up and the possibility that a crack may arise in the reinforcement member which consists of carbon fiber reinforced plastics can be reduced. Note that pebbles and the like wound up by the wheels are likely to hit the vehicle front side of the arm portion.

  Furthermore, as for the thickness of the adhesive layer interposed between the arm portion and the reinforcing member, the thickness of the adhesive layer in the vehicle width direction of the arm portion is thicker than the thickness of the adhesive layer in the vehicle longitudinal direction. Is preferred.

  That is, the bending moment (stress) in the vehicle vertical direction applied to the arm portion of the knuckle of the double wishbone type suspension device is larger than the bending moment (stress) in the vehicle longitudinal direction. Therefore, the amount of deflection (vibration amplitude) in the vehicle width direction that vibrates in accordance with the travel of the arm in the vehicle direction becomes larger than that in the longitudinal direction of the vehicle.

  Therefore, the thickness of the adhesive layer interposed between the arm portion and the reinforcing member is made thicker than the thickness of the adhesive layer in the vehicle front-rear direction of the arm portion in the vehicle width direction. Thus, it is possible to equalize the difficulty of peeling off the reinforcing member in the vehicle width direction and the vehicle front-rear direction, and maintain a stable bonding state.

  According to this invention, the knuckle connecting the upper arm and the lower arm is constructed such that the arm portion to which the bending moment in the vertical direction is applied is reinforced by the reinforcing member made of carbon fiber reinforced plastic. While securing, weight can be suppressed and rigidity can be improved.

It is a partially cutaway perspective view of a double wishbone type suspension device concerning an embodiment of this invention. FIG. 2A is a partially cutaway perspective view of the knuckle (before reinforcement) before adhesively fixing the reinforcement member to the arm portion. FIG. 2B is a schematic exploded perspective view showing a knuckle before reinforcement, an adhesive layer, and a reinforcement member to which the adhesive layer is applied. FIG. 3A is a schematic exploded perspective view showing a state in which a reinforcing member provided with an adhesive layer is opposed to a knuckle before reinforcing. FIG. 3B is a perspective view showing a state in which a reinforcing member provided with an adhesive layer is temporarily fixed to a knuckle. It is a table figure which shows the method of raising the resonant frequency etc. of a double wishbone type suspension apparatus. It is a partially omitted perspective view of the double wishbone type suspension device of the modification of an embodiment. It is a partially omitted perspective view of the double wishbone type suspension device of other embodiments. It is a partially omitted perspective view of the double wishbone type suspension device of the modification of other embodiments.

  BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the double wishbone type suspension device according to the present invention will be described below in detail with reference to the attached drawings.

[overall structure]
FIG. 1 is a partially cutaway perspective view of a double wishbone type suspension device 10 according to an embodiment of the present invention.

  For example, a double wishbone type suspension device (hereinafter simply referred to as a suspension device) 10 for suspending a front wheel (wheel) W, which is a steered wheel, basically has the knuckle 12, the lower arm 14, and the upper arm 16 , A hydraulic damper 18, and a suspension spring 20.

  The knuckle 12 includes a knuckle main body 22, an arm 24 extending upward from the knuckle main body 22 in a crane neck shape and reaching the upper side of the wheel W, and a support bracket 30 provided at the lower end of the knuckle main body 22.

  An outer reinforcing member (simply referred to as a reinforcing member) 40 made of CFRP (Carbon Fiber Reinforced Plastics: carbon fiber reinforced plastic) is adhesively fixed to the arm portion 24 from the outer side in the vehicle width direction via the adhesive layer 50. At the same time, an inner reinforcing member (simply referred to as a reinforcing member) 42 made of CFRP is adhesively fixed from the inner side in the vehicle width direction via the adhesive layer 52.

  The adhesive used for the adhesive layers 50 and 52 contains at least an epoxy resin, an acrylic particle, and a curing agent as described in Patent Document 2 above, and the acrylic particle is a butadiene rubber and a polymethacrylate. Or a pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive composition which is a core-shell structure having a polyacrylate, and a measure for reducing thermal expansion strain.

  The outer reinforcing member 40 has a U-shaped groove shape (the cross section in the horizontal direction is U-shaped) in which the bottom side is curved in a convex shape in the vehicle vertical direction following the shape of the outer side of the arm portion 24 in the vehicle width direction. It is done.

  The inner reinforcement member 42 is shaped to conform to the inner shape of the arm portion 24 in the vehicle width direction, and has a U-shaped groove (the cross section in the horizontal direction is U-shaped) whose bottom side is curved concavely in the vehicle vertical direction. ing.

  An arm support 34 is provided at the upper end of the arm 24. The arm support 34 pivotally supports the tip of the upper arm 16 via the ball joint 36.

  A ball bearing support hole 26 to which a ball bearing (not shown) is fitted is formed at the center of the knuckle body 22, and the knuckle body 22 is formed of an axle (not shown) of the wheel W as the ball bearing (not shown). It supports rotatably via).

  The hydraulic damper 18 to which the suspension spring 20 is engaged is connected to the lower arm 14 via a bifurcated portion.

  A knuckle fastening portion 48 provided with a ball joint 44 having a shaft portion 46 is fastened by a screw member 49 at an end of the lower arm 14 on the outer side in the vehicle width direction.

  The ball joint 44 is fixed to the support bracket 30 of the knuckle 12 via the shaft 46.

  Thus, the knuckle 12 is pivotally supported by the ball joint 44 relative to the lower arm 14.

[Method of Manufacturing Reinforcement Structure of Arm 24 of Knuckle 12]
FIG. 2A is a partially cutaway perspective view of the knuckle 112 alone (before reinforcement) before adhesively fixing the outer reinforcement member 40 and the inner reinforcement member 42 to the arm portion 24. As shown in FIG. The knuckle 112 before reinforcement is manufactured, for example, by casting or forging using an aluminum material.

  FIG. 2B shows the knuckle 112 before reinforcement, the outer reinforcement member 40, the inner reinforcement member 42, and the adhesive layers 50, 52 provided on the reinforcement members 40, 42 by application or the like for the convenience of understanding the layer structure. For this purpose, it is an exploded perspective view schematically drawn apart from the reinforcing members 40 and 42.

  The adhesive layer 50 provided (applied) to the outer reinforcement member 40 by application or the like shares one side with the bottom wall adhesive layer 50b that abuts the bottom wall 40b of the outer reinforcement member 40 and the bottom wall adhesive layer 50b. Side wall adhesive layer 50s (both sides) abutting on the inner side wall 40s (both sides) of the outer reinforcement member 40.

  The adhesive layer 52 provided (applied) to the inner reinforcement member 42 by application or the like is a bottom wall adhesive layer 52b that abuts on the bottom wall 42b of the inner reinforcement member 42 and the bottom wall adhesive layer 52b. And the side wall adhesive layers 52s (both sides) that abut the inner side walls 42s (both sides) of the inner reinforcement member 42.

  In this case, as shown in FIG. 1, since the amount of deflection in the vehicle width direction due to the vertical movement of the wheel W while the vehicle is traveling is larger than the amount of deflection in the vehicle longitudinal direction as shown in FIG. Bonding of the bottom walls 40b and 42b of 40 and 42 is more likely to be peeled off than the side walls 40s and 42s. Therefore, in order to make the peeling resistance equal, in the adhesive layer 50, it is preferable to make the thickness of the bottom wall adhesive layers 50b and 52b thicker than the thickness of the side wall adhesive layers 50s and 52s.

  The thickness of the adhesive layer 50 can be changed, for example, by making the diameter of the glass beads mixed to make the film thickness of the adhesive layer 50 uniform. That is, the diameter of the glass beads mixed with the bottom wall adhesive layers 50b and 52b may be larger than the diameter of the glass beads mixed with the sidewall adhesive layers 50s and 52s.

  FIG. 3A shows a state in which reinforcing members 40 and 42 having adhesive layers 50 and 52 applied to the knuckle 112 before reinforcement are opposed.

  FIG. 3B shows the knuckle 12 in a state in which the reinforcing members 40 and 42 having the adhesive layers 50 and 52 are attached to the arm 24 of the knuckle 112 before reinforcement and temporarily fixed.

  In the temporarily fixed state, the temporary fixing portion is pressurized and heated to cure the adhesive layers 50, 52, whereby the knuckle 12 in which the reinforcing members 40, 42 are adhesively fixed to the arm portion 24 is manufactured.

  The knuckle 12 in which the reinforcing members 40 and 42 are adhered and fixed to the arm portion 24 is engaged with the upper arm 16 and the lower arm 14 as shown in FIG. Is manufactured.

[Summary and modification]
In the double wishbone type suspension device 10 according to this embodiment, as shown in FIG. 1, the arm portions 24 of the aluminum knuckle 12 connecting the upper arm 16 and the lower arm 14 are CFRP outer and inner reinforcing members 40. , 42 has a reinforced structure.

  As described above, the arm portion 24 to which a bending moment in the vertical direction of the vehicle is applied between the vehicle body frame and the wheel W (not shown) via the upper arm 16 and the lower arm 14 is reinforced by the outer and inner reinforcing members 40 and 42 made of CFRP. Since the structure is adopted, rigidity can be secured or improved without thickening the arm portion 24 of the knuckle 12. Since the arm portion 24 of the knuckle 12 does not become thick, the layout property related to the arrangement of the wheel W and the like is not impaired.

  As can be seen from the chart 100 showing the relationship between the rigidity and the suspension resonance frequency shown in FIG. 4, when the rigidity (arm rigidity) of the arm 24 is moved up and down, the rigidity (knuckle rigidity) of the knuckle 12 moves up and down, The suspension resonance frequency goes up and down. That is, in order to increase the rigidity of the arm portion 24 in the past, it was necessary to increase the shaft diameter of the arm portion 24 to increase the cross section, but the layout property is deteriorated and the weight is also increased. On the other hand, according to this embodiment, the knuckle stiffness can be increased without increasing the shaft diameter of the arm portion 24.

  Furthermore, the reinforcing members 40 and 42 are bonded to the arm 24 by adhesive layers 50 and 52.

  Thus, the thermal expansion distortion which generate | occur | produces in the boundary surface of the aluminum material of aluminum knuckle 12, and CFRP material can be absorbed by using the adhesive agent which took the measures of relaxation of thermal expansion distortion. As a result, a more reliable specification can be realized in terms of strength and durability, and peeling and breakage of the outer and inner reinforcing members 40 and 42 made of CFRP can be prevented.

  Moreover, in general, there is a potential difference between the aluminum material and the CFRP material (the ionization tendency is different) and there is a possibility that electrolytic corrosion may occur through moisture and oxygen if they are brought into direct contact. Can prevent electrolytic corrosion.

[Modification 1]
FIG. 5 shows the configuration of a double wishbone type suspension device (also referred to simply as a suspension device) 10A of the first modification provided with a knuckle 12A.

  In the suspension device 10A, illustration of components other than the knuckle 12A is omitted for the convenience of understanding.

  The suspension device 10A includes, as a reinforcing member, a knuckle 12A in which only the reinforcing member 42 on the inner side in the vehicle width direction is adhesively fixed to the arm portion 24A via the adhesive layer 52.

  As described above, by bonding and fixing the reinforcing member 42 so as to cover at least the inner side in the vehicle width direction, the possibility that the wheel W rolls up pebbles and the like and cracks occur in the reinforcing member 42 made of CFRP can be reduced. Although it is highly possible that pebbles and the like wound up by the wheel W hit the outer side in the vehicle width direction of the arm portion 24A, in the suspension device 10A of the first modification, no reinforcing member is provided in that portion.

[Modification 2]
FIG. 6 shows the configuration of a double wishbone type suspension device (also referred to simply as a suspension device) 10B of Modification 2 (another embodiment) provided with a knuckle 12B.

  Also in the suspension device 10B, illustration of components other than the knuckle 12B is omitted for the convenience of understanding.

  The suspension device 10B includes, as a reinforcing member, a knuckle 12B having the arm portion 24B in which the reinforcing member 140 on the vehicle rear side and the reinforcing member 142 on the vehicle front side are bonded to the arm 24B by adhesive layers 150 and 152, respectively. .

  Also in this case, as in the case of the suspension device 10 shown in FIG. 1, substantially the entire outer peripheral surface of the arm portion 24B of the knuckle 12B is reinforced by the reinforcing members 140 and 142. While, rigidity can be improved.

[Modification 3]
FIG. 7 shows a configuration of a double wishbone type suspension device (simply referred to as a suspension device) 10C of Modification 3 (a modification of the other embodiment) provided with the knuckle 12C.

  In the suspension device 10C, for convenience of understanding, illustration of components other than the knuckle 12C is omitted.

  The suspension device 10C includes, as a reinforcing member, a knuckle 12C in which only the reinforcing member 140 on the vehicle rear side is adhesively fixed to the arm portion 24C via the adhesive layer 150.

  By adhesively fixing the reinforcing member 140 so as to cover at least the rear side of the vehicle in this manner, it is possible to reduce the possibility that the wheel W rolls up a pebble or the like to cause a crack in the reinforcing member 140 made of CFRP. Although it is highly possible that pebbles and the like wound up by the wheel W hit the vehicle front side of the arm portion 24C, in the suspension device 10C of the third modification, no reinforcing member is provided in that portion.

[Modification 4]
As described above, the suspension devices 10, 10A, 10B, 10C are the wheels W in the arm portions 24, 24A, 24B, 24C of the knuckles 12, 12A, 12B, 12C that constitute the suspension devices 10, 10A, 10B, 10C. Is suspended, so that the bending moment (stress) in the vehicle vertical direction is larger than the bending moment (stress) in the vehicle longitudinal direction. Therefore, the amount of deflection (vibration amplitude) in the vehicle width direction, which vibrates in accordance with the travel of the arms 24, 24A, 24B, 24C, becomes larger as compared to the longitudinal direction of the vehicle.

  Thus, for example, the side of the bottom walls 40b and 42b of the reinforcing members 40 and 42 adhered so as to cover the arm portions 24 and 24A from the inner and outer sides in the vehicle width direction peels off adhesion easily compared to the inner side walls 40s and 42s . In the adhesive layers 50 and 52, the bottom wall adhesive layers 50b and 52b are made thicker than the side wall adhesive layers 50s and 52s in order to make the peeling resistance equal.

  Similarly, in the suspension devices 10B and 10C shown in FIGS. 6 and 7, the inner side walls 150s and 152s of the reinforcing members 140 and 142 bonded to the arm portions 24B and 24C so as to cover from the vehicle longitudinal direction are bottom walls Adhesion is more likely to peel off compared to the 150b and 152b sides. In order to make peeling difficult, the thickness of the side wall adhesive layer 150s, 152s in the U-shaped adhesive layer {150b, 150s (both sides)} and {(152b, 152s (both sides)}} It is preferable to make it thicker than the thickness of the agent layer 150b and 152b.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various configurations can be adopted based on the contents described in this specification.

10, 10A, 10B, 10C ... double wishbone type suspension device 12, 12A, 12B, 12C ... knuckle 14 ... lower arm 16 ... upper arm 24, 24A, 24B, 24C ... arm section 40, 42 ... reinforcement member 50, 52 ... Adhesive layer

Claims (5)

A double wishbone suspension system,
A double wishbone type suspension device characterized in that an aluminum knuckle arm portion connecting an upper arm and a lower arm is reinforced by a reinforcing member made of carbon fiber reinforced plastic. In the double wishbone type suspension device according to claim 1,
The double wishbone type suspension device, wherein the reinforcing member is adhered to the arm portion by an adhesive. The double wishbone type suspension device according to claim 2
The double wishbone type suspension device characterized in that the reinforcing member is formed in a U-shaped groove shape which is curved according to the shape of the arm portion so as to cover at least the inner side in the vehicle width direction of the arm portion. The double wishbone type suspension device according to claim 2
The double wishbone type suspension device characterized in that the reinforcing member is formed in a U-shaped groove shape which is curved according to the shape of the arm portion so as to cover at least the vehicle rear side of the arm portion. The double wishbone type suspension device according to claim 3 or 4
As for the thickness of the adhesive layer interposed between the arm portion and the reinforcing member, the thickness of the adhesive layer in the vehicle width direction of the arm portion is thicker than the thickness of the adhesive layer in the vehicle longitudinal direction Double wishbone type suspension device characterized by

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