Strut bearing device and strut suspension for vehicle

Abstract

The present invention improves the effect of reducing the speed of high-speed water such as muddy water entering an axial gap from the outside in the radial direction before reaching an outer diameter-side seal. The lower housing first wall surface (3A) is an outer peripheral surface facing the axial gap (C). The lower housing second wall surface (3B) is an annular surface extending radially outward (RO) from the upper end of the lower housing first wall surface (3A). The lower housing third wall surface (3C) is an outer peripheral surface extending upward from an end (E) on the radially outer side (RO) of the lower housing second wall surface (3B). The upper housing first wall surface (2A) is an inner circumferential surface facing the upper portion of the lower housing first wall surface (3A). The upper housing second wall surface (2B) is an annular surface extending radially inward (RI) from the upper end of the upper housing first wall surface (2A). The upper housing third wall surface (2C) is an inner peripheral surface that extends upward from an end portion (F) of a radial inner side (RI) of the upper housing second wall surface (2B) and faces the lower housing third wall surface (3C).

Description

Technical Field

[0001] The present invention relates to a strut bearing device used in a strut type suspension of a vehicle. Background Art

[0002] As a suspension that supports the wheel to the vehicle body through coil springs and has a shock absorber to absorb vertical vibration, there is a strut suspension in which a telescopic column (pillar) with a built-in shock absorber is fixed to the axle. The strut suspension is widely used mainly for the front wheels of passenger cars.

[0003] As a strut bearing device used in the upper part of a strut-type suspension, there is a strut bearing device, which comprises: an upper shell made of synthetic resin (for example, the upper cover 3 of patent document 1), which holds the upper raceway ring; a lower shell made of synthetic resin (for example, the lower cover 4 of patent document 1), which holds the lower raceway ring; an inner diameter side seal made of an elastic system (for example, the inner seal 6 of patent document 1), which is a seal arranged on the above-mentioned lower shell and located radially inside the rolling element; and an outer diameter side seal made of an elastic system (for example, the outer seal 7 of patent document 1), which is a seal located radially outside the rolling element (for example, refer to patent document 1).

[0004] Patent Document 1: U.S. Patent No. 10,753,389

[0005] As described above, the upper housing and the lower housing are made of synthetic resin, and therefore, in order to eliminate the generation of abnormal noise and increase in torque due to contact between them, an axial gap and a radial gap of a required size are provided between the upper housing and the lower housing.

[0006] In addition, the support bearing device is used in a severe muddy water environment where it directly receives muddy water on the road surface splashed by the wheels. Furthermore, if a high-pressure cleaner is used when washing a car, the support bearing device receives high-pressure water released from the high-pressure cleaner when washing the wheel axle.

[0007] Therefore, for example, in the strut bearing device of patent document 1, when high-speed water such as muddy water penetrates into the axial gap between the upper cover 3 and the lower cover 4 from the outer diameter side, the water rises along the outer peripheral surface of the lower cover 4, and reaches the outer seal 7 without sufficient deceleration, causing the outer seal 7 to be immersed in water, so that the sealing performance may be reduced. Summary of the invention

[0008] An object of the present invention is to provide a strut bearing device that can improve the effect of decelerating high-speed water such as muddy water that penetrates into the axial gap between the upper housing and the lower housing or the axial gap between the upper housing and the upper spring seat from the radial outside before reaching the outer diameter side seal.

[0009] The support bearing device according to the first aspect of the present invention is a support bearing device including a support bearing and an upper spring seat of a spring support member supporting the upper end of a coil spring. The support bearing includes an upper housing and a lower housing; an upper raceway ring held by the upper housing; a lower raceway ring held by the lower housing; a rolling element rolling between the upper raceway ring and the lower raceway ring; and a seal located radially outside the rolling element. The upper spring seat is in contact with the lower housing. An axial gap exists between the upper housing and the upper spring seat. The upper housing includes an upper housing first wall surface, an upper housing second wall surface, and an upper housing third wall surface. The lower housing includes a lower housing first wall surface, a lower housing second wall surface, and a lower housing third wall surface. The lower housing first wall surface is an outer peripheral surface facing the axial gap. The lower housing second wall surface is an annular surface extending radially outward from the upper end of the lower housing first wall surface. The third wall surface of the lower housing is an outer peripheral surface extending upward from the radially outer end of the second wall surface of the lower housing. The first wall surface of the upper housing is an inner peripheral surface facing the upper portion of the first wall surface of the lower housing. The second wall surface of the upper housing is an annular surface extending radially inward from the upper end of the first wall surface of the upper housing. The third wall surface of the upper housing is an inner peripheral surface extending upward from the radially inner end of the second wall surface of the upper housing and facing the third wall surface of the lower housing.

[0010] The support bearing device according to the second aspect of the present invention comprises: an upper housing and a lower housing; an upper raceway ring held by the upper housing; a lower raceway ring held by the lower housing; a rolling element rolling between the upper raceway ring and the lower raceway ring; and a seal member located radially outside the rolling element. The lower housing is made of a synthetic resin with a core iron built in, has a cylindrical portion and an annular portion extending radially outward from the upper portion of the cylindrical portion, and has a function as a spring support member supporting the upper end of a coil spring. An axial gap exists between the upper housing and the lower housing. The upper housing comprises: an upper housing first wall surface, an upper housing second wall surface, and an upper housing third wall surface. The lower housing comprises: a lower housing first wall surface, a lower housing second wall surface, and a lower housing third wall surface. The lower housing first wall surface is an outer peripheral surface facing the axial gap. The lower housing second wall surface is an annular surface extending radially outward from the upper end of the lower housing first wall surface. The third wall surface of the lower housing is an outer peripheral surface extending upward from the radially outer end of the second wall surface of the lower housing. The first wall surface of the upper housing is an inner peripheral surface facing the upper portion of the first wall surface of the lower housing. The second wall surface of the upper housing is an annular surface extending radially inward from the upper end of the first wall surface of the upper housing. The third wall surface of the upper housing is an inner peripheral surface extending upward from the radially inner end of the second wall surface of the upper housing and facing the third wall surface of the lower housing.

[0011] The support bearing device involved in the third viewpoint of the present invention is constructed as follows: in the support bearing device involved in the first viewpoint or the second viewpoint, the angle formed by the first wall surface of the lower shell and the second wall surface of the lower shell, and / or the angle formed by the first wall surface of the upper shell and the second wall surface of the upper shell are acute angles.

[0012] A strut type suspension for a vehicle according to a fourth aspect of the present invention includes the strut bearing device according to the first aspect or the second aspect.

[0013] According to the above-mentioned strut bearing device involved in the present invention and the strut type suspension of the vehicle, the upper shell has: the first wall surface of the upper shell, the second wall surface of the upper shell and the third wall surface of the upper shell, and the lower shell has: the first wall surface of the lower shell, the second wall surface of the lower shell and the third wall surface of the lower shell.

[0014] When high-speed water such as muddy water penetrates from the above-mentioned axial gap, the high-speed water hits the first wall of the lower shell which is the outer peripheral surface facing the above-mentioned axial gap and rebounds, hits the first wall of the upper shell which is the inner peripheral surface, and the water flow toward the outer diameter side seal which is the seal located radially outside the above-mentioned rolling element hits the second wall of the upper shell which is the annular surface, and then passes through the radial gap between the third wall of the lower shell and the third wall of the upper shell.

[0015] Therefore, the high-speed water hits the first wall surface of the lower housing as the outer peripheral surface facing the axial gap, the first wall surface of the upper housing as the inner peripheral surface, and the second wall surface of the upper housing as the annular surface, and after the water potential is attenuated and the direction of the water flow is dispersed, it passes through the radial gap and approaches the outer diameter side seal. Therefore, the effect of decelerating the high-speed water such as muddy water that penetrates into the axial gap from the radial outside before reaching the outer diameter side seal can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a partial cross-sectional schematic diagram of a strut type suspension of a vehicle including the strut bearing device according to the first embodiment of the present invention.

[0017] Figure 2 It is an enlarged longitudinal sectional view showing the main parts of the strut bearing device and the upper insulator.

[0018] Figure 3 It is an enlarged longitudinal sectional view of the main parts showing the structure around the axial gap.

[0019] Figure 4 It is an enlarged longitudinal sectional view of the main parts showing the first modified example.

[0020] Figure 5 It is an enlarged longitudinal sectional view of the main parts showing the second modified example.

[0021] Figure 6 It is an enlarged longitudinal sectional view of the main parts showing the third modified example.

[0022] Figure 7 It is an enlarged longitudinal sectional view of a main part showing a strut bearing device according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0024] In this specification, the rotation axis O (refer to Figure 1 ) is called the "axial direction" (for example, refer to Figure 1The direction perpendicular to the rotation axis O is called the “radial direction” (for example, refer to Figure 1 The radial direction close to the rotation axis O is referred to as the "radial inner side" (for example, refer to Figure 1 The radial direction away from the rotation axis O is referred to as the “radial outer side” (for example, referring to Figure 1 RO).

[0025] [Implementation Method 1]

[0026] <Strut suspension>

[0027] Figure 1 The strut type suspension S of the vehicle shown is used in a state where a telescopic strut 10 having a built-in shock absorber is fixed to an axle (not shown) and an upper frame 16 is fixed to a vehicle body.

[0028] A strut bearing 1 is provided at the upper portion of the strut type suspension S. The strut bearing 1 swings and rotates while supporting the vehicle body, and the amount of the swing rotation corresponds to the amount of change in direction of the steering wheel in response to the steering operation. The swing angle of the strut bearing 1 is determined according to the allowable steering angle of the wheel, and is set, for example, in the range of 40° to 50°.

[0029] A coil spring 11 as a suspension spring and a dust cover 12 for protecting the oil seal of the shock absorber from foreign matter such as sand are provided on the radially outer side RO of the strut 10. The strut type suspension S includes a spring support member 13 supporting the upper end of the coil spring 11. The spring support member 13 is composed of an upper spring seat 14 and an upper insulator 15.

[0030] <Strut bearing device>

[0031] like Figure 1 and Figure 2 As shown, a strut bearing device A according to the first embodiment of the present invention includes a strut bearing 1 and an upper spring seat 14 of a spring support member 13 that supports an upper end of a coil spring 11 .

[0032] The strut bearing 1 includes an upper housing 2 and a lower housing 3 , upper raceways 4 and 5 , rolling elements 6 , a retainer 7 , inner diameter side seals 8 and outer diameter side seals 9 , and the like.

[0033] The upper housing 2 is fixed to the upper end of the support 10, and the lower housing 3 receives the upper spring seat 14 from above. The upper race 4 is held by the upper housing 2, and the lower race 5 is held by the lower housing 3. The rolling element 6 rolls between the upper race 4 and the lower race 5, and the retainer 7 holds the adjacent rolling elements 6 in a non-contact manner.

[0034] The inner diameter side seal 8 is located on the radially inner side RI of the rolling element 6 , and the outer diameter side seal 9 is located on the radially outer side RO of the rolling element 6 .

[0035] The upper race 4, the lower race 5, and the upper spring seat 14 are made of steel and are formed by pressing a steel plate. The upper housing 2 and the lower housing 3 are made of synthetic resin, and the inner diameter side seal 8 and the outer diameter side seal 9 are made of an elastomer.

[0036] The synthetic resin used in the upper shell 2 and the lower shell 3 is, for example, a polyamide-based resin (PA66, PA46, PA612, PA6, PA9T, PA10T, etc.), and contains, for example, 20 to 60% by weight of glass fiber (GF) as reinforcing fiber.

[0037] As thermoplastic elastomer (TPE), the elastomer used in the inner diameter side seal 8 and the outer diameter side seal 9 is TPS (styrene), TPO (olefin), TPU (polyurethane), TPA (amide), TPEE (ester), etc., and as rubber material, it is nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), acrylic rubber (ACM), ethylene-acrylic rubber (AEM), fluororubber (FKM, FPM), silicone rubber (VQM), etc. The rubber material can be used by mixing one or more rubbers as appropriate.

[0038] <Structure for decelerating high-speed water entering from the axial gap>

[0039] like Figure 2 and Figure 3 As shown, there is an axial gap C between the upper housing 2 and the upper spring seat 14. The upper housing 2 has: an upper housing first wall surface 2A, an upper housing second wall surface 2B, and an upper housing third wall surface 2C. The lower housing 3 has: a lower housing first wall surface 3A, a lower housing second wall surface 3B, and a lower housing third wall surface 3C.

[0040] The lower case first wall surface 3A is an outer peripheral surface facing the axial gap C. The lower case second wall surface 3B is an annular surface extending from the upper end portion of the lower case first wall surface 3A toward the radially outer side RO. The lower case third wall surface 3C is an outer peripheral surface extending upward from the end portion E of the lower case second wall surface 3B at the radially outer side RO.

[0041] The upper housing first wall surface 2A is an inner circumferential surface facing the upper portion of the lower housing first wall surface 3A. The upper housing second wall surface 2B is an annular surface extending from the upper end portion of the upper housing first wall surface 2A to the radial inner side RI. The upper housing third wall surface 2C is an inner circumferential surface extending upward from the end portion F of the radial inner side RI of the upper housing second wall surface 2B and facing the lower housing third wall surface 3C.

[0042] exist Figure 2 and Figure 3 In the example, the upper housing first wall 2A faces the upper portion of the lower housing first wall 3A, and faces the end E of the radially outer side RO of the lower housing second wall 3B, and the lower portion of the lower housing third wall 3C. In addition, the lower housing third wall 3C faces the lower portion of the upper housing third wall 2C, and faces the end F of the radially inner side RI of the upper housing second wall 2B, and the upper portion of the upper housing first wall 2A. Therefore, the water flowing to the outer diameter side seal 9 passes from the first radial gap G1 between the lower housing third wall 3C and the upper housing first wall 2A, and passes through the second radial gap G2 between the lower housing third wall 3C and the upper housing third wall 2C, which has a diameter smaller than the first radial gap G1.

[0043] Figure 3 The axial lengths J1, J2, J3, and J4 shown are J1<J2<J3<J4, but J2=J3. In other words, J1<J2≤J3<J4 is sufficient. When J2=J3, the end E of the radially outer side RO of the second wall surface 3B of the lower case and the end F of the radially inner side RI of the second wall surface 2B of the upper case are opposite in the radial direction R.

[0044] in addition, Figure 3 The radii R1, R2, R3, and R4 shown are R1<R2<R3<R4. In a preferred embodiment, the length of the second radial gap G2 in the radial direction R, that is, R3-R2, is 2.0 mm or less.

[0045] <Effects>

[0046] When high-speed water such as muddy water penetrates from the axial gap C, the high-speed water hits the first wall surface 3A of the lower shell which is the outer peripheral surface facing the axial gap C and rebounds, hits the first wall surface 2A of the upper shell which is the inner peripheral surface, and the water flow toward the outer diameter side seal 9 hits the second wall surface 2B of the upper shell which is the annular surface, and then passes through the second radial gap G2 between the third wall surface 3C of the lower shell and the third wall surface 2C of the upper shell.

[0047] Therefore, the high-speed water hits the lower housing first wall surface 3A as the outer peripheral surface facing the axial gap C, the upper housing first wall surface 2A as the inner peripheral surface, and the upper housing second wall surface 2B as the annular surface, and after the water potential is attenuated and the direction of the water flow is dispersed, it passes through the second radial gap G2 and approaches the outer diameter side seal 9. Therefore, the effect of decelerating the high-speed water such as muddy water that penetrates into the axial gap C from the radial outer side RO before reaching the outer diameter side seal 9 can be improved. As a result, the water flow rate reaching the lip periphery of the outer diameter side seal 9 can be reduced.

[0048] <Modification>

[0049] like Figure 4 As shown, relative to Figure 3 The preferred embodiment is to make the lower shell second wall surface 3B, which is an annular surface, tilt downward as it approaches the radial outer side RO, so that the angle P formed with the lower shell first wall surface 3A is an acute angle (P < 90°). Figure 5 As shown, relative to Figure 3 The preferred embodiment is to make the second wall surface 2B of the upper shell, which is an annular surface, tilt downward as it approaches the radial inner side RI, so that the angle Q formed with the first wall surface 2A of the upper shell is an acute angle (Q < 90°).

[0050] By making the angle P and / or the angle Q acute, the effect of decelerating high-speed water such as muddy water that enters the axial gap C from the radially outer side RO before reaching the radially outer side seal 9 is further improved.

[0051] For example, in Figure 2 In the structure, it is also possible to set a Figure 6 As shown in the figure, an annular inner protrusion H protrudes toward the radial inner side RI. By providing the inner protrusion H, the upper housing 2 and the lower housing 3 can be prevented from being separated.

[0052] <Analysis of the comparison of the flow rate of the intruding muddy water, etc.>

[0053] (Analytical Model)

[0054] Made a parody Figure 6 The analytical model of the present invention of the shape of the support bearing device A and the analytical model of the present invention simulating the shape of the support bearing device A of the patent document 1 Figure 1 The analytical model of the existing shape of the strut bearing device. Figure 3 In the axial length shown, in the analytical model of the present invention, J3 < J4, and in the analytical model of the conventional shape, J3 > J4. The flow velocity of water entering from the axial gap C around the lip of the outer diameter side seal 9 was compared for the analytical model of the present invention and the analytical model of the conventional shape.

[0055] (Analysis conditions)

[0056] For ease of analysis, an underwater environment was used, and a jet port (2 mm in diameter) for jetting water was arranged from the radial outer side RO toward the radial inner side RI of the axial gap C. Analysis was performed under the condition that high-speed water with a flow rate of 8 m / s was jetted from the jet port.

[0057] (Analysis results)

[0058] The flow velocity around the lip of the outer diameter side seal 9 is 1.0 in the above conventional analytical model and 0.80 in the above present analytical model. It is found that the present invention can improve the effect of decelerating the high-speed water entering the axial gap C before reaching the outer diameter side seal 9.

[0059] [Implementation Method 2]

[0060] <Strut bearing device>

[0061] exist Figure 7 In the strut bearing device B according to the second embodiment of the present invention shown in FIG. Figure 1 to Figure 3 The same reference numerals indicate the same or corresponding components, parts or locations.

[0062] The lower housing 3 of the strut bearing 1 as the strut bearing device B is made of synthetic resin with a core iron M built in. The core iron M is made of steel and is formed from a steel plate by press working, and is quenched and hardened after processing as needed. The lower housing 3 is molded by injection molding with the core iron M as an embedded workpiece.

[0063] The lower housing 3 includes a cylindrical portion 3D and an annular portion 3E extending radially outward RO from the upper portion of the cylindrical portion 3D, and has a core iron M therein to support the coil spring 11 (see Figure 1 ) functions as an upper spring seat of the spring support component 13 at the upper end.

[0064] An axial gap D exists between the upper housing 2 and the lower housing 3. The upper housing first wall surface 2A, the upper housing second wall surface 2B, and the upper housing third wall surface 2C of the upper housing 2, and the lower housing first wall surface 3A, the lower housing second wall surface 3B, and the lower housing third wall surface 3C of the lower housing 3 are the same as those of Embodiment 1. Therefore, the support bearing device B of Embodiment 2 has the same function and effect as the support bearing device A of Embodiment 1.

[0065] The above description of the embodiment is for illustrative purposes only and is not intended to be limiting. Various improvements and modifications may be made without departing from the scope of the present invention.

[0066] Description of Reference Numerals

[0067] 1…pillar bearing; 2…upper housing; 2A…upper housing first wall; 2B…upper housing second wall; 2C…upper housing third wall; 3…lower housing; 3A…lower housing first wall; 3B…lower housing second wall; 3C…lower housing third wall; 3D…cylindrical portion; 3E…annular portion; 4…upper raceway; 5…lower raceway; 6…rolling element; 7…retainer; 8…inner diameter side seal; 9…outer diameter side seal; 10…pillar; 11…coil spring; 12…dust cover; 13…spring support member; 14…upper Spring seat; 15…upper insulator; 16…upper frame; A, B…pillar bearing device; C, D…axial gap; E…the radially outer end of the second wall of the lower shell; F…the radially inner end of the second wall of the upper shell; G1…the first radial gap; G2…the second radial gap; H…inner tab; J…axial; J1, J2, J3, J4…axial length; M…core iron; O…rotation axis; P, Q…angle; R…radial; R1, R2, R3, R4…radius; RI…radially inner; RO…radially outer; S…pillar suspension.

Claims

1. A support bearing device, comprising: and an upper spring seat of a spring support member supporting the upper end of the coil spring, wherein, The support bearing comprises: an upper housing and a lower housing; an upper raceway ring held in the upper housing; a lower raceway ring held in the lower housing; a rolling element rolling between the upper raceway ring and the lower raceway ring; and a seal located radially outside the rolling element. The upper spring seat is in contact with the lower housing, There is an axial gap between the upper housing and the upper spring seat, The upper shell has: an upper shell first wall surface, an upper shell second wall surface and an upper shell third wall surface. The lower shell has: a lower shell first wall surface, a lower shell second wall surface and a lower shell third wall surface, The first wall surface of the lower housing is an outer peripheral surface facing the axial gap, The second wall surface of the lower shell is an annular surface extending radially outward from the upper end of the first wall surface of the lower shell. The third wall surface of the lower shell is an outer peripheral surface extending upward from the radially outer end of the second wall surface of the lower shell. The first wall surface of the upper shell is an inner peripheral surface facing the upper portion of the first wall surface of the lower shell, The second wall surface of the upper shell is an annular surface extending radially inward from the upper end of the first wall surface of the upper shell. The upper case third wall surface is an inner peripheral surface extending upward from a radially inner end portion of the upper case second wall surface and facing the lower case third wall surface.

2. A support bearing device, comprising: An upper housing and a lower housing; an upper raceway ring held in the upper housing; a lower raceway ring held in the lower housing; a rolling body rolling between the upper raceway ring and the lower raceway ring; and a seal located radially outside the rolling body, wherein: The lower housing is made of synthetic resin with a core iron built in, has a cylindrical portion and an annular portion extending radially outward from the upper portion of the cylindrical portion, and has a function as a spring support member supporting the upper end of the coil spring. There is an axial gap between the upper shell and the lower shell, The upper shell has: an upper shell first wall surface, an upper shell second wall surface and an upper shell third wall surface. The lower shell has: a lower shell first wall surface, a lower shell second wall surface and a lower shell third wall surface, The first wall surface of the lower housing is an outer peripheral surface facing the axial gap, The second wall surface of the lower shell is an annular surface extending radially outward from the upper end of the first wall surface of the lower shell. The third wall surface of the lower shell is an outer peripheral surface extending upward from the radially outer end of the second wall surface of the lower shell. The first wall surface of the upper shell is an inner peripheral surface facing the upper portion of the first wall surface of the lower shell, The second wall surface of the upper shell is an annular surface extending radially inward from the upper end of the first wall surface of the upper shell. The upper case third wall surface is an inner peripheral surface extending upward from a radially inner end portion of the upper case second wall surface and facing the lower case third wall surface.

3. The strut bearing device according to claim 1 or 2, wherein: An angle formed by the first wall surface of the lower case and the second wall surface of the lower case, and / or an angle formed by the first wall surface of the upper case and the second wall surface of the upper case are acute angles.

4. A strut suspension for a vehicle, wherein: The strut type suspension of the vehicle includes the strut bearing device according to claim 1 or 2.

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