Suspension coil spring device

Abstract

This suspension coil spring device comprises: a coil spring including an upper-side end turn portion and a lower-side end turn portion, and having a coating layer fixed to at least a part of at least the lower-side end turn portion; and a spring receiving member that supports the lower-side end turn portion. At least a part of the spring receiving member supports the lower-side end turn portion via the coating layer. The coating layer is provided in a non-adhering state to the spring receiving member. The coil spring is provided with a coating film. The material of the coating film and the material of the coating layer are different from each other.

Description

Suspension coil spring device

[0001] This application claims priority to U.S. patent application Ser. No. 63 / 621,119, filed Jan. 16, 2024, the contents of which are incorporated herein by reference.

[0002] Coil spring suspension devices equipped with coil springs are used in the suspension mechanisms and equipment suspensions of vehicles such as automobiles. If a foreign object such as a flying stone hits the coil spring while the automobile is traveling, the surface of the coil spring will be damaged, causing corrosion and breakage. For this reason, the surface of the coil spring is protected by a coating.

[0003] Patent Documents 1 and 2 propose a coil spring device for suspension in which a spring bearing member is attached to a coil spring. The coil spring and the spring bearing member are joined with an adhesive. By providing adhesive in the gap between the coil spring and the spring bearing member, pebbles, sand, mud, etc. are prevented from entering the gap between the coil spring and the spring bearing member, and damage to the coating of the coil spring is suppressed.

[0004] Japanese Patent Application Publication No. 2017-015249 International Publication No. 2020 / 040292

[0005] In conventional suspension coil spring devices, there is room for improvement in the structure for preventing damage to the coating of the coil spring.

[0006] The present invention aims to provide a suspension coil spring device that can suppress damage to the coating of the coil spring.

[0007] A suspension coil spring device according to a first aspect of the present invention comprises a coil spring having an upper end winding portion and a lower end winding portion, with a coating layer fixed to at least a portion of the lower end winding portion, and a spring bearing member supporting the lower end winding portion, at least a portion of the spring bearing member supporting the lower end winding portion via the coating layer, the coating layer being provided in a non-adhered state on the spring bearing member, and the coil spring being provided with a coating film, the material of the coating film and the material of the coating layer being different from each other.

[0008] A suspension coil spring device according to a second aspect of the present invention comprises a coil spring having an upper end winding portion and a lower end winding portion, with a coating layer fixed to at least a portion of the lower end winding portion, and a spring bearing member supporting the lower end winding portion, wherein the coating layer and the spring bearing member are provided at different positions in the circumferential direction of the coil around the coil axis of the coil spring, and the coil spring is provided with a coating film, the material of which is different from the material of the coating layer.

[0009] According to the suspension coil spring device of the present invention, damage to the coating of the coil spring can be suppressed.

[0010] FIG. 1 is a perspective view showing a suspension coil spring device according to a first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a diagram showing a method of assembling the suspension coil spring device according to the first embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1. FIG. 5 is a cross-sectional view showing a suspension coil spring device according to a modified example of the first embodiment. FIG. 6 is a cross-sectional view of a suspension coil spring device according to a second embodiment. FIG. 7 is a cross-sectional view of a suspension coil spring device according to the second embodiment. FIG. 8 is a view of a suspension coil spring device according to a third embodiment, viewed from below.

[0011] <First Embodiment> A suspension coil spring device according to a first embodiment of the present invention will be described in detail below with reference to the drawings. As shown in Fig. 1, a suspension coil spring device 1 of this embodiment includes a coil spring 10 and a spring bearing member 20. The coil spring 10 is formed in a helical shape and has a pair of upper and lower end winding portions 10a, 10b.

[0012] Of the pair of upper and lower end turn portions 10a, 10b, the lower end turn portion 10a is supported by a spring bearing member 20. As shown in Fig. 2, a coating layer 30 is fixed to at least a portion of the lower end turn portion 10a. At least a portion of the spring bearing member 20 supports the lower end turn portion 10a via the coating layer 30. The coating layer 30 is provided on the spring bearing member 20 in a non-adhered state.

[0013] Of the pair of upper and lower end turn portions 10a, 10b, the upper end turn portion 10b can be housed in a spring holding member (not shown). The suspension coil spring device 1 is used in the suspension mechanism of a vehicle such as an automobile, the suspension of equipment, etc. When used in the suspension mechanism of an automobile, the suspension coil spring device 1 works in cooperation with a damper to buffer or damp the vertical movement of the vehicle.

[0014] The coil spring 10 includes a wire 12 and a coating 14 on the surface of the wire 12. The wire 12 has a circular cross section. Examples of materials for the wire 12 include spring steel, hardened spring steel, and fiber-reinforced plastic. The coating 14 protects the wire 12 from collisions with flying stones and corrosion. Examples of materials for the coating 14 include epoxy resin.

[0015] The spring bearing member 20 has an arc shape extending around the coil axis O1 when viewed from a direction along the coil axis O1 of the coil spring 10. For example, the spring bearing member 20 extends over an angular range of 180° to 360° around the coil axis O1. The material of the spring bearing member 20 may be, for example, metal or rubber.

[0016] The spring bearing member 20 is formed in an area including the lower end of the lower end turn portion 10a. A recess 21 is provided on the upper surface of the spring bearing member 20. The recess 21 extends around the coil axis O1. The lower end turn portion 10a, to which the coating layer 30 is fixed, is inserted into the recess 21. The inner surface of the recess 21 has a concave curved shape that curves along the outer peripheral surface of the coil spring 10 in a cross-sectional view perpendicular to the central axis O2 of the wire 12. In the following description, the direction of winding around the coil axis O1 of the coil spring 10 as viewed from the direction along the coil axis O1 is also referred to as the coil circumferential direction. The direction of winding around the central axis O2 as viewed from the direction along the central axis O2 of the wire 12 is also referred to as the wire circumferential direction.

[0017] The coating layer 30 is fixed to the coating film 14 on the lower end turn portion 10a. The coating layer 30 is, for example, applied to the coating film 14 on the lower end turn portion 10a. The coating layer 30 is provided along the outer peripheral surface of the lower end turn portion 10a. The coating layer 30 is provided so as to cover at least the lower end of the outer peripheral surface of the lower end turn portion 10a. The material of the coating film 14 and the material of the coating layer 30 are different from each other. Note that the phrase "the material of the coating film 14 and the material of the coating layer 30 are different from each other" includes cases where the coating film 14 and the coating layer 30 are based on the same epoxy resin but have different compositions. The material of the coating layer 30 can be either a thermoplastic resin composition or a composition for forming a thermosetting resin. Examples of thermoplastic resins include acrylic resin, polystyrene resin, polyethylene resin, polypropylene resin, polyamide resin, nylon resin, vinyl chloride resin, polyacetal resin, polycarbonate resin, polyphenylene ether resin, polybutylene terephthalate resin, polyphenylene sulfone resin, polysulfone resin, polyarylate resin, polyetherimide resin, etc. Examples of thermosetting resins include urethane resin, epoxy resin, cyanate resin, melamine resin, phenolic resin, etc. Other examples of materials for the coating layer 30 include rubber materials such as natural rubber, butadiene rubber, chloroprene rubber, nitrile butadiene rubber, and styrene butadiene rubber.

[0018] As shown in Figure 3, the coating layer 30 is placed on the spring bearing member 20 while being fixed to the lower end turn portion 10a. The coating layer 30 is placed on the spring bearing member 20 in a non-adhesive state. The coating layer 30 and the spring bearing member 20 are arranged so as to be in contact with each other. Furthermore, the lower end turn portion 10a is inserted into the recess 21, thereby fixing the lower end turn portion 10a and the coating layer 30 to the spring bearing member 20. The hardness of the coating layer 30 is higher than that of the spring bearing member 20. Furthermore, the hardness of the paint film 14 is higher than that of the spring bearing member 20.

[0019] 2 , in the present embodiment, in a cross-sectional view perpendicular to the central axis O2 of the wire 12, the coating layer 30 extends outward beyond the end of the recess 21. That is, the coating layer 30 has a first protruding portion 31 (protruding portion) that extends outward beyond the spring bearing member 20 in the circumferential direction of the wire around the central axis O2 of the wire 12.

[0020] At the contact portion between the spring bearing member 20 and the coating layer 30, in a cross-sectional view perpendicular to the central axis O2 of the wire 12, the radius of curvature of the inner surface of the spring bearing member 20 (more specifically, the inner surface of the recess 21) is smaller than the radius of curvature of the outer surface of the coating layer 30. With this configuration, the surface pressure generated between the spring bearing member 20 and the coating layer 30 at the end portions P1 and P2 in the circumferential direction of the wire is higher than that at the central portion P3 in the circumferential direction of the wire.

[0021] As shown in FIG. 4, the coating layer 30 has a second protruding portion 32 (protruding portion) that extends outward in the circumferential direction of the coil about the coil axis O1 beyond the spring bearing member 20.

[0022] In the illustrated example, the coating layer 30 is provided so as to contact the entire spring bearing member 20 in the coil circumferential direction. However, as shown in Fig. 5, it is sufficient that the coating layer 30 is provided at least in a position of the spring bearing member 20 that contacts the end portion 20a in the coil circumferential direction.

[0023] As described above, the suspension coil spring device 1 of this embodiment includes a coil spring 10 having an upper end turn portion 10b and a lower end turn portion 10a, with a coating layer 30 fixed to at least a portion of the lower end turn portion 10a, and a spring bearing member 20 supporting the lower end turn portion 10a. At least a portion of the spring bearing member 20 supports the lower end turn portion 10a via the coating layer 30. The coating layer 30 is provided on the spring bearing member 20 in a non-adhered state. The coil spring 10 is provided with a coating film 14, and the material of the coating film 14 is different from the material of the coating layer 30. This configuration prevents foreign matter such as pebbles, sand, and mud from entering between the lower end turn portion 10a and the spring bearing member 20. Furthermore, even if foreign matter enters between the lower end turn portion 10a and the spring bearing member 20, the coating layer 30 prevents damage to the coating film 14.

[0024] Furthermore, the spring bearing member 20 is provided with a recess 21 into which the lower end turn portion 10a is inserted. According to the above configuration, the recess 21 allows the lower end turn portion 10a to be fixed to the spring bearing member 20. Therefore, the stability of the coil spring 10 is improved.

[0025] Furthermore, the coating layer 30 has protruding portions 31, 32 that extend outward beyond the spring bearing member 20. Specifically, the coating layer 30 has a first protruding portion 31 that extends outward in the wire circumferential direction beyond the spring bearing member 20. The coating layer 30 has a second protruding portion 32 that extends outward in the coil circumferential direction beyond the spring bearing member 20. According to the above configuration, the provision of the protruding portions 31, 32 makes it possible to fill the gap between the lower end turn portion 10a and the spring bearing member 20, and more effectively prevents foreign matter from entering between the lower end turn portion 10a and the spring bearing member 20.

[0026] Furthermore, at the contact portion between the spring bearing member 20 and the coating layer 30, the radius of curvature of the inner surface of the spring bearing member 20 is smaller than the radius of curvature of the outer surface of the coating layer 30 in a cross-sectional view perpendicular to the central axis O2 of the wire 12 of the coil spring 10. At the contact portion between the spring bearing member 20 and the coating layer 30, the surface pressure generated between the spring bearing member 20 and the coating layer 30 is higher at the ends in the circumferential direction of the wire than at the center in the circumferential direction of the wire. With the above configuration, the surface pressure at the ends in the circumferential direction of the wire can be increased, which more effectively prevents foreign matter from entering between the lower end turn portion 10a and the spring bearing member 20.

[0027] Furthermore, the hardness of the coating layer 30 is greater than the hardness of the spring bearing member 20. According to the above configuration, even if a foreign object gets between the coating layer 30 and the spring bearing member 20, the foreign object is received on the spring bearing member 20 side, and damage to the coating layer 30 and the paint film 14 can be prevented.

[0028] Furthermore, the coating layer 30 is provided at a position that contacts at least the end 20 a in the coil circumferential direction of the spring bearing member 20. This configuration reduces wear of the spring bearing member 20 and the coating film 14 caused by repeated contact and separation between the spring bearing member 20 and the coating film 14 when the coil spring 10 expands and contracts.

[0029] Second Embodiment Next, a suspension coil spring device 2 according to a second embodiment of the present invention will be described with reference to Figures 6 and 7. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being described.

[0030] As shown in Fig. 6 , in the suspension coil spring device 2 according to this embodiment, the coating layer 30 is disposed more inward than the end of the recess 21 in a cross-sectional view perpendicular to the central axis O2 of the wire 12. That is, the end of the coating layer 30 in the wire circumferential direction is disposed more inward than the spring bearing member 20 in the wire circumferential direction. Also, as shown in Fig. 7 , the end of the coating layer 30 in the coil circumferential direction is disposed more inward than the spring bearing member 20 in the coil circumferential direction.

[0031] Even with the above configuration, it is possible to prevent foreign matter such as pebbles, sand, and mud from getting between the lower end turn portion 10a and the spring bearing member 20. Moreover, even if foreign matter gets between the lower end turn portion 10a and the spring bearing member 20, the coating layer 30 can prevent damage to the paint film 14. Furthermore, since the amount of coating layer 30 can be reduced compared to when the coating layer 30 has protruding portions 31, 32, the weight of the suspension coil spring device 2 can be reduced, and the manufacturing cost can also be reduced.

[0032] Although the end of the coating layer 30 in the circumferential direction of the wire is disposed more inward than the spring bearing member 20 in the circumferential direction of the wire, the end of the coating layer 30 in the circumferential direction of the coil may extend more outward than the spring bearing member 20 in the circumferential direction of the coil (i.e., may have a second protruding portion 32). Furthermore, although the end of the coating layer 30 in the circumferential direction of the coil is disposed more inward than the spring bearing member 20 in the circumferential direction of the coil, the end of the coating layer 30 in the circumferential direction of the wire may extend more outward than the spring bearing member 20 in the circumferential direction of the wire (i.e., may have a first protruding portion 31).

[0033] Third Embodiment Next, a suspension coil spring device 3 according to a third embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a view of the suspension coil spring device 3 as seen from below. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being described.

[0034] In this embodiment, the suspension coil spring device 3 includes a spring bearing member 40 instead of the spring bearing member 20. The spring bearing member 40 has a first portion 41, a second portion 42, and a third portion 43 that are spaced apart in the coil circumferential direction. The first portion 41, the second portion 42, and the third portion 43 are arranged so as not to overlap with the circumferential center of the lower end turn portion 10a in the coil circumferential direction. The coating layer 30 is respectively arranged between the first portion 41 and the second portion 42 and between the second portion 42 and the third portion 43 in the coil circumferential direction. The coating layer 30 and the spring bearing member 40 (the first portion 41, the second portion 42, and the third portion 43) are arranged at different positions in the coil circumferential direction. Therefore, in this embodiment, the coating layer 30 does not contact the spring bearing member 40.

[0035] Here, in the lower end turn portion 10a, stress generated when a load is applied to the coil spring 10 is greatest on the inner diameter side of the coil spring 10. The location of high stress in the lower end turn portion 10a is referred to as the high-stress location. In this embodiment, the area where the spring bearing member 40 (first portion 41, second portion 42, and third portion 43) overlaps with the high-stress location is smaller than when the spring bearing member is continuously provided in the circumferential direction of the coil. By reducing the contact area between the spring bearing member 40 and the coil spring 10, damage to the coating film 14 caused by foreign matter being trapped can be suppressed. The spring bearing member 40 (first portion 41, second portion 42, and third portion 43) directly supports the lower end turn portion 10a without the intermediary of the coating layer 30. The spring bearing member 40 provides three-point support for the lower end turn portion 10a, ensuring stable support of the lower end turn portion 10a.

[0036] As described above, the suspension coil spring device 3 of this embodiment includes a coil spring 10 having an upper end turn portion 10b and a lower end turn portion 10a, with a coating layer 30 fixed to at least a portion of the lower end turn portion 10a, and a spring bearing member 40 supporting the lower end turn portion 10a. The coating layer 30 and the spring bearing member 40 are provided at different positions in the coil circumferential direction. The coil spring 10 is provided with a coating film 14, and the coating film 14 and the coating layer 30 are made of different materials. With this configuration, the overlap area between the spring bearing member 40 (first portion 41, second portion 42, and third portion 43) and the high stress position is smaller than when the spring bearing member is provided continuously in the coil circumferential direction. Therefore, the possibility of foreign matter being mixed in at least at the high stress position can be reduced, and damage to the coating film 14 can be prevented. The number and support range of the spring receiving members 40 and the number and support range of the coating layers 30 are not limited to the contents of this embodiment, and various forms can be adopted.

[0037] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

[0038] According to the present invention, it is possible to provide a suspension coil spring device that can suppress damage to the coating of the coil spring.

[0039] REFERENCE SIGNS LIST 1, 2, 3 Suspension coil spring device 10 Coil spring 10a Lower end turn portion 10b Upper end turn portion 12 Wire 14 Coating film 20, 40 Spring receiving member 21 Recess 30 Coating layer 31 First protruding portion (protruding portion) 32 Second protruding portion (protruding portion) O1 Coil axis O2 Central axis of wire

Claims

1. A suspension coil spring device comprising an upper seat winding portion and a lower seat winding portion, and a coating layer is fixed to at least a part of at least the lower seat winding portion; a spring receiving member that supports the lower seat winding portion; at least a part of the spring receiving member supports the lower seat winding portion via the coating layer; the coating layer is provided in a non-adhesive state on the spring receiving member; a coating film is provided on the coil spring, and the material of the coating film is different from the material of the coating layer.

2. The suspension coil spring device according to claim 1, wherein the spring receiving member is provided with a recess into which the lower seat winding portion is inserted.

3. The suspension coil spring device according to claim 1, wherein the coating layer has an overhanging portion that extends outward from the spring receiving member.

4. The suspension coil spring device according to claim 3, wherein the overhanging portion has a first overhanging portion that extends outward in the wire circumferential direction around the central axis of the wire of the coil spring rather than the spring receiving member.

5. The suspension coil spring device according to claim 3, wherein the overhanging portion has a second overhanging portion that extends outward in the coil circumferential direction around the coil axis of the coil spring rather than the spring receiving member.

6. The suspension coil spring device according to claim 1, wherein at the contact portion between the spring receiving member and the coating layer, in a cross-sectional view perpendicular to the central axis of the wire of the coil spring, the radius of curvature of the inner surface of the spring receiving member is smaller than the radius of curvature of the outer surface of the coating layer.

7. The suspension coil spring device according to claim 1, wherein at the contact portion between the spring receiving member and the coating layer, the surface pressure generated between the spring receiving member and the coating layer is such that the end portion in the wire circumferential direction around the central axis of the wire of the coil spring is higher than the central portion in the wire circumferential direction.

8. The suspension coil spring device according to claim 1, wherein the hardness of the coating layer is higher than the hardness of the spring receiving member.

9. The suspension coil spring device according to claim 1, wherein the coating layer is provided at least at a position in contact with the end portion in the coil circumferential direction around the coil axis of the coil spring of the spring receiving member.

10. A suspension coil spring device comprising an upper seat winding portion and a lower seat winding portion, with a coating layer fixed to at least a part of at least the lower seat winding portion, a spring receiving member for supporting the lower seat winding portion, wherein the coating layer and the spring receiving member are provided at different positions from each other in the coil circumferential direction around the coil axis of the coil spring, and a coating film is provided on the coil spring, and the material of the coating film is different from the material of the coating layer.

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