Resin spring insulator

Abstract

To provide a resin spring insulator of a novel structure capable of preventing a forming failure of a soft resin layer while preventing deformation of a hard resin layer during formation of the soft resin layer.SOLUTION: A resin spring insulator 10 staked on the end of a coil spring 12 comprises: a hard resin layer 16 provided with a plate-like seating part 20; and first and second soft resin layers 30 and 32 made of soft resin materials lower in hardness than the hard resin layer 16 and secured to both surfaces of the seating part 20 of the hard resin layer 16. A notch 24 (26) is formed at the end of the hard resin layer 16, and a soft resin connection part 38 (42) for integrally connecting the first and second soft resin layers 30 and 32 through the notch 24 (26) is provided. A resin injection trace 40 is formed in the soft resin connection part 38 (42) through injection molding of the soft resin material in at least one soft resin connection part 38 (42).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a resin spring insulator that is overlapped with an end of a coil spring in, for example, an automobile suspension mechanism. [Background technology]

[0002] Conventionally, in automobile suspension mechanisms and the like, spring insulators are arranged in the portions that receive the ends of coil springs to prevent abnormal noise and damage. As disclosed in, for example, JP 2016-215961 A (Patent Document 1), the spring insulator has a structure in which a soft layer (elastic member) is fixed to the surface of a hard layer (insert member), and is interposed between the coil spring and the vehicle body or the like to prevent direct contact between the coil spring and the vehicle body or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-215961 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional spring insulators are generally formed by adhering a soft rubber layer to the surface of a hard metal layer, but such rubber spring insulators have the problem that they require the application of an adhesive to the hard layer to bond the soft layer and the hard layer, and also require a long time for vulcanization molding of the soft layer.

[0005] Therefore, the present inventor is considering the adoption of a resin spring insulator in which a soft resin layer is fixed to the surface of a hard resin layer. The resin spring insulator can be obtained by molding a hard resin layer made of a hard synthetic resin material, and then molding a soft resin layer with the hard resin layer inserted therein. With such a resin spring insulator, both the hard resin layer and the soft resin layer can be molded in a short time, and it is also expected that the hard resin layer and the soft resin layer can be fused together by the heat generated during molding of the soft resin layer, and thus easily integrated.

[0006] However, the inventors of the present invention have found that when a soft resin layer is injection molded on the surface of a hard resin layer, if the injection pressure of the soft resin material is set high, the thin and relatively weak hard resin layer is deformed by the injection pressure of the soft resin material. On the other hand, if the injection pressure of the soft resin material is reduced to a level at which the hard resin layer is not deformed, there is a problem that molding defects such as sink marks and voids are likely to occur in the soft resin layer covering the surface of the hard resin layer.

[0007] An object of the present invention is to provide a resin spring insulator having a novel structure that can prevent deformation of the hard resin layer and also prevent molding defects in the soft resin layer when the soft resin layer is molded.

[0008] Another object of the present invention is to provide a novel method for manufacturing a resin spring insulator, which can prevent deformation of the hard resin layer and also prevent molding defects in the soft resin layer when molding the soft resin layer. [Means for solving the problem]

[0009] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely illustrative and may be combined with one another as appropriate, and the multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0010] The first aspect is a resin spring insulator that is overlaid on the end of a coil spring, and includes a hard resin layer with a plate-shaped seating portion, and a first soft resin layer and a second soft resin layer that are made of a soft resin material that is lower in hardness than the hard resin layer and are fixed to both sides of the seating portion of the hard resin layer, wherein a notch is formed at the end of the hard resin layer, and a soft resin continuous portion is provided that integrally connects the first soft resin layer and the second soft resin layer through the notch, and at least one of the soft resin continuous portions has a resin injection mark on it due to the soft resin material being injected and molded in the soft resin continuous portion.

[0011] In the resin spring insulator constructed according to this embodiment, a notch is provided at the end of the hard resin layer, so that when the first soft resin layer and the second soft resin layer are molded on the surface of the hard resin layer, the soft resin material flows through the notch and is easily diverted to both sides of the hard resin layer, making it easier to avoid molding defects in the first soft resin layer and the second soft resin layer.

[0012] Moreover, the position of the injection port of the soft resin material is set so that a resin injection mark is formed in the soft resin connecting portion that connects the first soft resin layer and the second soft resin layer to each other through the notch, which makes it easier for the soft resin material to flow to both sides of the hard resin layer through the notch and prevents the injection pressure of the soft resin material from being directly applied to the hard resin layer, thereby preventing deformation of the hard resin layer due to the injection pressure of the soft resin material.

[0013] In a second aspect, in the resin spring insulator described in the first aspect, the hard resin layer has a ring-shaped seating portion and a cylindrical insertion portion protruding from an inner peripheral end portion of the seating portion toward one side in the plate thickness direction of the seating portion, and the notch is formed on at least one of the outer peripheral end portion of the seating portion and the protruding tip end of the cylindrical insertion portion.

[0014] In a resin spring insulator constructed according to this embodiment, the cylindrical insertion portion is provided so as to protrude from the inner peripheral end portion of the annular plate-shaped seating portion in the plate thickness direction of the seating portion, thereby improving the deformation rigidity of the hard resin layer. In particular, the reinforcing effect of the cylindrical insertion portion is exerted on the seating portion, making it easier to prevent deformation of the seating portion due to the injection pressure during molding of the soft resin material.

[0015] In a third aspect, in the resin spring insulator described in the second aspect, both the notch formed in the outer peripheral end portion of the seating portion and the notch formed in the protruding tip portion of the cylindrical insertion portion are provided, the first soft resin layer is fixed to one surface of the seating portion in the plate thickness direction and the second soft resin layer is fixed to the other surface of the seating portion in the plate thickness direction, the first soft resin layer extends and is fixed to the outer peripheral surface of the cylindrical insertion portion and the second soft resin layer extends and is fixed to the inner peripheral surface of the cylindrical insertion portion.

[0016] According to the resin spring insulator having the structure according to this embodiment, a notch is provided at both ends of the inner periphery and the outer periphery of the hard resin layer, and the first soft resin layer and the second soft resin layer are each provided to extend to the cylindrical insertion portion. Therefore, the first soft resin layer and the second soft resin layer are formed so as to be continuous on both sides through the notches at both ends of the hard resin layer, so that molding defects of the first soft resin layer and the second soft resin layer are avoided. Also, because the first soft resin layer and the second soft resin layer are continuous on both ends of the hard resin layer, peeling of the first soft resin layer and the second soft resin layer from the hard resin layer is easily prevented.

[0017] A fourth aspect is a resin spring insulator according to the second or third aspect, wherein the resin injection mark is located within the notch formed in the outer peripheral end of the seating portion.

[0018] With a resin spring insulator constructed according to this embodiment, by injecting the soft resin material at a position close to the seating portion, which affects the supporting performance of the coil spring, during injection molding of the first soft resin layer and the second soft resin layer, it is possible to more effectively prevent molding defects in the first soft resin layer and the second soft resin layer which cover the seating portion.

[0019] A fifth aspect is a resin spring insulator according to any one of the first to fourth aspects, wherein the notch is formed in an outer peripheral end of the seating portion, and the seating portion protrudes outward further than the first soft resin layer and the second soft resin layer at a portion circumferentially away from the notch.

[0020] In a resin spring insulator constructed according to this embodiment, for example, when the soft resin layer is injection molded with the hard resin layer set in the molding die, the outer peripheral end of the seating portion is supported by the molding die, making it easier to prevent deformation of the seating portion due to the injection pressure of the soft resin material.

[0021] A sixth aspect is the resin spring insulator according to any one of the first to fifth aspects, wherein the first soft resin layer adhered to the surface of the seating portion facing the coil spring is thicker than the second soft resin layer, and the resin injection mark provided in the soft resin continuous portion is located closer to the surface of the second soft resin layer than to the surface of the first soft resin layer.

[0022] In the resin spring insulator constructed according to this embodiment, the first soft resin layer is made thick, so that the cushioning performance of the first soft resin layer interposed between the coil spring and the seating portion of the hard resin layer can be advantageously obtained, and the second soft resin layer is made thin, so that, for example, the mounting stability of the resin spring insulator to a vehicle body member that receives the end of the coil spring can be improved.

[0023] Since the injection port for the soft resin material is set at a position biased towards the second soft resin layer side, molding defects in the thin second soft resin layer can be more effectively prevented.

[0024] A seventh aspect is the resin spring insulator according to any one of the first to sixth aspects, wherein the notches are provided at a plurality of positions in the circumferential direction of the hard resin layer.

[0025] According to the resin spring insulator constructed according to this embodiment, the hard resin layer has a plurality of notches in the circumferential direction, so that the first soft resin layer and the second soft resin layer are formed to be continuous with each other through the plurality of notches, which makes it easier to prevent molding defects in the first soft resin layer and the second soft resin layer.

[0026] An eighth aspect is a manufacturing method for a resin spring insulator to be overlaid on an end of a coil spring, the method including: (a) a hard resin layer preparation step of preparing a hard resin layer having a plate-shaped seating portion and a notch formed in a component edge portion; and (b) a soft resin layer formation step of injecting a soft resin material into the edge portion of a cavity of a molding die in which the hard resin layer is set, and diverting the soft resin material from the notch to both sides of the hard resin layer, thereby integrally forming a first soft resin layer and a second soft resin layer, each having a hardness lower than that of the hard resin layer, on both sides of the seating portion.

[0027] According to the manufacturing method of the resin spring insulator of this embodiment, when the first soft resin layer and the second soft resin layer are molded, the soft resin material easily flows into both sides of the hard resin layer through the notches in the hard resin layer, thereby preventing molding defects in the first soft resin layer and the second soft resin layer that are fixed to both sides of the seating portion of the hard resin layer.

[0028] Moreover, since the soft resin material is injected into the cavity from the notch-forming portion outside the hard resin layer, the injection pressure of the soft resin material is prevented from being directly applied to the hard resin layer, and deformation of the hard resin layer due to the injection pressure of the soft resin material can be prevented. Also, since the injection position of the soft resin material is set to the notch-forming portion in the hard resin layer, the injected soft resin material easily flows into both sides of the hard resin layer, and molding defects of the first soft resin layer and the second soft resin layer are more effectively prevented.

[0029] In a ninth aspect, in the manufacturing method of a resin spring insulator described in the eighth aspect, the molding die is provided with a support protrusion that protrudes into the cavity, and in the soft resin layer forming process, the support protrusion abuts against the seating portion of the hard resin layer set in the cavity to support the seating portion in the plate thickness direction.

[0030] According to the manufacturing method of the resin spring insulator according to this embodiment, the seating portion is supported in the plate thickness direction by the support protrusion of the molding die when the soft resin material is injected, thereby preventing deformation of the seating portion in the plate thickness direction due to the injection pressure of the soft resin material. Effect of the Invention

[0031] According to the present invention, in a resin spring insulator and in the manufacture of a resin spring insulator, it is possible to prevent deformation of a hard resin layer during molding of a soft resin layer, while also preventing defective molding of the soft resin layer. [Brief description of the drawings]

[0032] [Figure 1]FIG. 1 is a perspective view showing a resin spring insulator according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view showing the resin spring insulator of FIG. 1 at an angle different from that of FIG. 1. [Diagram 3] Plan view of the plastic spring insulator shown in Figure 1 [Figure 4] Bottom view of the plastic spring insulator shown in Figure 1 [Diagram 5] VV cross section of Figure 3 [Figure 6] VI-VI cross section of Figure 3 [Figure 7] FIG. 2 is a perspective view of a hard resin layer constituting the resin spring insulator shown in FIG. 1; [Figure 8] FIG. 8 is a perspective view showing the hard resin layer shown in FIG. 7 from a different angle. [Figure 9] FIG. 2 is a vertical cross-sectional view illustrating the manufacturing process of the resin spring insulator shown in FIG. [Figure 10] FIG. 11 is a vertical cross-sectional view different from that of FIG. 9, illustrating the manufacturing process of the resin spring insulator shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0034] 1 to 6 show a resin spring insulator 10 as a first embodiment of the present invention. The resin spring insulator 10 is, for example, in an automobile suspension mechanism, superimposed on an end of a coil spring 12 as shown in FIG. 5, and serves as a buffer member interposed between the end of the coil spring 12 and a receiving member 14. The resin spring insulator 10 has a structure in which a soft resin layer 18 is fixed to the surface of a hard resin layer 16. In the following description, in principle, the up-down direction refers to the up-down direction in FIG. 1, the front-rear direction refers to the up-down direction in FIG. 2, and the left-right direction refers to the left-right direction in FIG. 2.

[0035] The hard resin layer 16 is a hard member having a higher hardness (deformation rigidity) than the soft resin layer 18, and is formed of a hard resin material such as polypropylene, and more preferably a fiber-reinforced synthetic resin in which a hard resin material is mixed with a reinforcing material such as glass fiber or carbon fiber. As shown in Figs. 7 and 8, the hard resin layer 16 is integrally provided with an annular plate-shaped seating portion 20 and a cylindrical insertion portion 22 protruding upward from the inner peripheral end of the seating portion 20.

[0036] An outer peripheral cutout 24 is formed as a notch at the outer peripheral end of the seating portion 20. The outer peripheral cutout 24 opens to the outer peripheral surface of the seating portion 20 and penetrates the seating portion 20 in the up-down direction, which is the plate thickness direction. As shown in Figures 3 and 4, the outer peripheral cutout 24 has an outer peripheral portion that extends in the radial direction with a substantially constant circumferential width dimension, and an inner peripheral end that is substantially semicircular when viewed in the up-down direction, and the width gradually narrows in the circumferential direction toward the inner circumference.

[0037] The number of outer peripheral cutouts 24 is not particularly limited, but is preferably a plurality, and in this embodiment, the outer peripheral cutouts 24 are provided at six locations in the circumferential direction. When a plurality of outer peripheral cutouts 24 are provided, the arrangement of the outer peripheral cutouts 24 in the circumferential direction is not particularly limited, but is preferably arranged so as to be substantially evenly distributed in the circumferential direction. This arrangement of the outer peripheral cutouts 24 increases the degree of freedom in the circumferential direction orientation of the hard resin layer 16 relative to the molding die 44 when the hard resin layer 16 is set in the molding die 44 described below.

[0038] The circumferential width dimension of the outer circumferential opening of the outer circumferential cutout 24 is preferably within a range of 1 / 20 to 1 / 5 times, and more preferably within a range of 1 / 15 to 1 / 10 times, the circumferential length of the outer circumferential surface of the seating portion 20. The radial length dimension of the outer circumferential cutout 24 is preferably within a range of 1 / 10 to 1 / 2 times, and more preferably within a range of 1 / 5 to 1 / 3 times, the radial length dimension of the seating portion 20.

[0039] The cylindrical insertion portion 22 is generally cylindrical in shape and protrudes upward from the inner peripheral end of the seating portion 20. The base end portion of the cylindrical insertion portion 22 is curved in a circular arc-shaped cross section rising upward from the seating portion 20 toward the inner peripheral side. The middle portion of the cylindrical insertion portion 22 is tapered cylindrical in shape with a smaller diameter toward the top. The upper end portion of the cylindrical insertion portion 22 is cylindrical in shape and extends straight in the vertical direction with a generally constant diameter.

[0040] An upper end cutout 26 is formed as a notch at the upper end of the cylindrical insertion portion 22. The upper end cutout 26 opens at the upper end surface, which is the protruding tip surface of the cylindrical insertion portion 22, and is formed so as to radially penetrate the cylindrical insertion portion 22. The upper end portion of the upper end cutout 26 extends in the axial direction (up and down direction) with a substantially constant circumferential width dimension, and the lower end portion has both end portions in the circumferential direction formed into an R shape, and the width gradually narrows in the circumferential direction downward when viewed in the radial direction.

[0041] The number of upper end cutouts 26 is not particularly limited, but is preferably a plurality, and in this embodiment, the upper end cutouts 26 are provided at six locations in the circumferential direction. When a plurality of upper end cutouts 26 are provided, the arrangement of the upper end cutouts 26 in the circumferential direction is not particularly limited, but is preferably arranged so as to be substantially evenly distributed in the circumferential direction. This arrangement of the upper end cutouts 26 increases the degree of freedom of the circumferential direction orientation of the hard resin layer 16 relative to the molding die 44 when the hard resin layer 16 is set in the molding die 44, which will be described later. In this embodiment, the upper end cutouts 26 are formed in the same number as the outer circumferential cutouts 24, and are arranged at the same circumferential positions as the outer circumferential cutouts 24.

[0042] The circumferential width dimension at the upper end opening of the upper end cutout 26 is preferably within a range of 1 / 20 to 1 / 8, and more preferably within a range of 1 / 15 to 1 / 10, of the circumferential length of the cylindrical insertion portion 22. The circumferential width dimension of the upper end cutout 26 is preferably larger than the circumferential width dimension of the outer circumferential cutout 24, and is preferably within a range of 2 to 8 times the circumferential width dimension of the outer circumferential cutout 24. In this embodiment, the cutouts 24, 26 are arranged such that the circumferential centers of the outer circumferential cutouts 24 and the circumferential centers of the upper end cutouts 26 are mutually at the same position in the circumferential direction.

[0043] Moreover, the axial length of the upper end cutout 26 is desirably within a range of 1 / 10 to 1 / 2, and more preferably within a range of 1 / 5 to 1 / 3, of the axial length of the cylindrical insertion portion 22. The axial length of the upper end cutout 26 is approximately the same as or slightly larger than the radial length of the outer circumferential cutout 24.

[0044] Between the upper end notches 26, 26 adjacent to each other in the circumferential direction of the cylindrical insertion portion 22, an inner peripheral rib-like portion 28 protruding toward the inner circumference is integrally formed. The inner peripheral rib-like portion 28 extends linearly in the vertical direction with a substantially constant rectangular cross section, and the radial thickness dimension of the cylindrical insertion portion 22 is partially increased at the portion where the inner peripheral rib-like portion 28 is formed. The inner peripheral rib-like portion 28 is provided so as to continuously extend downward from the upper end of the cylindrical insertion portion 22, and preferably, the lower end position is set lower than the lower end of the upper end notch 26. The inner peripheral rib-like portion 28 of this embodiment is disposed in the circumferential center between the upper end notches 26, 26 adjacent to each other in the circumferential direction of the cylindrical insertion portion 22, and one is provided between each of the upper end notches 26, 26 adjacent to each other in the circumferential direction. However, a plurality of inner peripheral rib-like portions 28 may be provided between each pair of upper end cutout portions 26, 26 adjacent to each other in the circumferential direction, and their arrangement in the circumferential direction is not particularly limited.

[0045] 5 and 6, a first soft resin layer 30 is fixed to the upper surface of the seating portion 20 and the outer peripheral surface of the cylindrical insertion portion 22 in the hard resin layer 16. The first soft resin layer 30 has a lower hardness and deformation rigidity than the hard resin layer 16, and is made of a soft resin material such as ethylene propylene rubber (EPDM, EPM). The first soft resin layer 30 has a thicker portion at the fixed portion to the seating portion 20 than the fixed portion to the cylindrical insertion portion 22.

[0046] A second soft resin layer 32 is fixed to the lower surface of the seating portion 20 and the inner peripheral surface of the cylindrical insertion portion 22 in the hard resin layer 16. The second soft resin layer 32 has a lower hardness and deformation rigidity than the hard resin layer 16, and is made of a soft resin material such as ethylene propylene rubber (EPDM, EPM). The first soft resin layer 30 and the second soft resin layer 32 are integrally formed with each other. The second soft resin layer 32 is formed with a substantially constant thickness in a portion fixed to the seating portion 20 and a portion fixed to the base end portion of the cylindrical insertion portion 22. The second soft resin layer 32 is fixed continuously over the entire circumference to the inner peripheral surface of the base end portion and the middle portion of the cylindrical insertion portion 22, and the second soft resin layer 32 is fixed partially in the circumferential direction to the inner peripheral surface of the upper end portion of the cylindrical insertion portion 22. More specifically, the second soft resin layer 32 is fixed to the inner circumferential surface of the cylindrical insertion portion 22 at a portion corresponding to the upper end notch 26 in the circumferential direction, and the hard resin layer 16 is exposed to the inner periphery without the second soft resin layer 32 being fixed to the inner periphery at a portion circumferentially outside the upper end notch 26, and the inner periphery rib-shaped portion 28 protrudes to the inner periphery at the exposed portion. The portion of the second soft resin layer 32 fixed to the upper end portion of the cylindrical insertion portion 22 is thicker than the portions fixed to the base end portion and the middle portion, forming a thick-walled mounting portion 34 that protrudes to the inner periphery. The thick-walled mounting portion 34 of the second soft resin layer 32 protrudes to the inner periphery further than the inner periphery rib-shaped portion 28 of the hard resin layer 16.

[0047] The thickness dimension t2 of the second soft resin layer 32 fixed to the seating portion 20 is smaller than the thickness dimension t1 of the first soft resin layer 30 fixed to the seating portion 20. In addition, as shown in FIG. 5, the support mark 36 is formed in the fixed portion of the second soft resin layer 32 fixed to the seating portion 20. The support mark 36 is a hole that penetrates the second soft resin layer 32 in the vertical direction, and the hard resin layer 16 is exposed at the support mark 36. The cross-sectional shape (hole cross-sectional shape) of the support mark 36 is not particularly limited, but in this embodiment, it is a substantially elliptical shape that is elongated in the radial direction of the seating portion 20. In this embodiment, as shown in FIG. 2 and FIG. 4, a plurality of support marks 36 are provided, and the plurality of support marks 36 are disposed approximately evenly distributed in the circumferential direction. In this embodiment, the support marks 36 are provided at 12 locations in the circumferential direction. Each support mark 36 is disposed circumferentially away from the outer peripheral cutout portion 24 provided in the seating portion 20. In addition, the circumferential center of the support mark 36 and the circumferential end of the upper end cutout 26 provided in the cylindrical insertion portion 22 are positioned relative to each other in the circumferential direction. The support mark 36 in this embodiment has a circumferential width dimension smaller than that of the outer circumferential cutout 24.

[0048] As shown in FIG. 6, the first soft resin layer 30 and the second soft resin layer 32 are integrally connected to each other on the outer periphery side of the seating portion 20 by the outer periphery continuous portion 38 as a soft resin continuous portion. The outer periphery continuous portion 38 is integrally formed on the outer periphery side of the first soft resin layer 30 and the second soft resin layer 32, and connects the outer periphery end of the first soft resin layer 30 and the outer periphery end of the second soft resin layer 32 to each other through the outer periphery cutout portion 24 of the seating portion 20. The radial length of the outer periphery continuous portion 38 is smaller than the radial length of the outer periphery cutout portion 24. Therefore, as shown in FIG. 6, the outer periphery surface of the portion where the outer periphery cutout portion 24 is formed is covered by the outer periphery continuous portion 38 and is not exposed to the outer periphery, and as shown in FIG. 5, the portion outside the outer periphery cutout portion 24 in the circumferential direction is exposed and protrudes toward the outer periphery side beyond the outer periphery continuous portion 38.

[0049] A resin injection mark 40 is present in one of the outer circumferential continuing portions 38. The resin injection mark 40 is a mark left by cutting a runner 56 of the soft resin layer 18 described below, and indicates that the soft resin material from which the soft resin layer 18 is formed has been injected and molded in the outer circumferential continuing portion 38 having the resin injection mark 40. The resin injection mark 40 can be seen, for example, as irregularities formed on the surface of the outer circumferential continuing portion 38, or as a difference in texture in part of the surface of the outer circumferential continuing portion 38. In this embodiment, the resin injection mark 40 is provided in only one outer circumferential continuing portion 38.

[0050] The resin injection mark 40 is provided at a position biased downward with respect to the vertical center of the soft resin layer 18 (described later) including the first soft resin layer 30 and the second soft resin layer 32. In this embodiment, the resin injection mark 40 is positioned with respect to the seating portion 20 in the vertical direction and disposed within the outer peripheral cutout portion 24, and the second soft resin layer 32 adhered to the lower surface of the seating portion 20 is thinner than the first soft resin layer 30 adhered to the upper surface of the seating portion 20, so that the resin injection mark 40 is biased downward from the vertical center of the soft resin layer 18.

[0051] As shown in FIG. 6, the first soft resin layer 30 and the second soft resin layer 32 are integrally connected to each other on the upper side of the cylindrical insertion portion 22 by the upper end continuous portion 42 as a soft resin continuous portion. The upper end continuous portion 42 is integrally formed on the upper side of the first soft resin layer 30 and the second soft resin layer 32, and connects the upper end of the first soft resin layer 30 and the upper end of the second soft resin layer 32 to each other through the upper end notch 26 of the cylindrical insertion portion 22. The axial length of the upper end continuous portion 42 is approximately the same as the axial length of the upper end notch 26. Therefore, as shown in FIG. 6, the portion of the cylindrical insertion portion 22 where the upper end notch 26 is formed is covered by the upper end continuous portion 42 and is not exposed upward, and as shown in FIG. 5, the portion outside the upper end notch 26 in the circumferential direction is exposed upward.

[0052] The first soft resin layer 30 and the second soft resin layer 32 are continuous to each other by the outer periphery continuous portion 38 and the upper end continuous portion 42. In short, the first soft resin layer 30, the second soft resin layer 32, the outer periphery continuous portion 38 and the upper end continuous portion 42 are integrally formed, and as a whole constitute the soft resin layer 18 that is fixed to the surface of the hard resin layer 16. The hard resin layer 16 and the soft resin layer 18 constitute the resin spring insulator 10 of this embodiment.

[0053] The seating portion 20 of the hard resin layer 16 protrudes outward further than the soft resin layer 18 (outer peripheral continuous portion 38) in a portion circumferentially deviating from the outer peripheral cutout 24 covered by the outer peripheral continuous portion 38. Also, the cylindrical insertion portion 22 of the hard resin layer 16 is exposed to the outside without being covered by the soft resin layer 18 in a portion circumferentially deviating from the upper end cutout 26 covered by the upper end continuous portion 42.

[0054] The resin spring insulator 10 is manufactured, for example, by the following manufacturing method.

[0055] That is, first, a mold for molding the hard resin layer 16 (not shown) is prepared, and a hard resin layer preparation step is performed in which the mold is used to mold the hard resin layer 16. The hard resin layer 16 can be obtained, for example, by injection molding a forming material in which a hard resin material such as polypropylene is mixed with a reinforcing material such as glass fiber, but the specific forming method is not limited.

[0056] Next, as shown in Figures 9 and 10, the prepared hard resin layer 16 is set in a molding die 44 for the soft resin layer 18 to form the soft resin layer 18, thereby carrying out a molding step for the soft resin layer. The molding die 44 has a structure in which an upper die 46 for mainly forming the upper surface and outer peripheral surface of the soft resin layer 18 and a lower die 48 for mainly forming the lower surface and inner peripheral surface of the soft resin layer 18 are stacked and combined in the vertical direction. Then, a cavity 50 for molding is formed between the overlapping surfaces of the upper die 46 and the lower die 48 in a shape corresponding to the resin spring insulator 10, and the hard resin layer 16 is set in the cavity 50.

[0057] As shown in FIG. 9, the lower die 48 is provided with a support protrusion 52 protruding into the cavity 50. The support protrusion 52 has a substantially elliptical cross-sectional shape that is elongated in the radial direction and protrudes upward, and is provided at a plurality of locations in the circumferential direction. The hard resin layer 16 is set in the molding die 44 by the outer peripheral end of the seating portion 20 being sandwiched between the upper and lower dies 46, 48 at a portion that is circumferentially out of the outer peripheral cutout portion 24, and the lower surface of the inner peripheral portion of the seating portion 20 being overlapped with the protruding tip surface of the support protrusion 52 and being supported from below by the support protrusion 52. The support protrusion 52 in this embodiment is an oval columnar shape that is elongated in the radial direction of the seating portion 20, and the positioning and holding of the seating portion 20 by the abutment of the support protrusion 52 is realized over a wide range in the radial direction of the seating portion 20. In addition, the inner rib-like portion 28 of the cylindrical insertion portion 22 in the hard resin layer 16 is sandwiched between the upper mold 46 and the lower mold 48 in the vertical direction, and the inner end face is overlapped on the lower mold 48, and the upper end portion of the cylindrical insertion portion 22 is held by the molding mold 44.

[0058] As shown in Fig. 10, a resin injection port 54 is connected to the cavity 50. The resin injection port 54 is provided between the overlapping surfaces of the upper mold 46 and the lower mold 48, and opens toward the outer peripheral cutout 24 of the hard resin layer 16 set in the molding mold 44. A soft resin material that has been fluidized by heating and melting is injected from the outside into the cavity 50 through the resin injection port 54, thereby filling the cavity 50 with the soft resin material to form the soft resin layer 18. The soft resin layer 18 is formed as an insert molded product in which a previously molded hard resin layer 16 is inserted.

[0059] Since the resin injection port 54 opens toward the outer peripheral cutout 24 of the hard resin layer 16, it is possible to prevent the injection pressure of the soft resin material into the cavity 50 from acting directly in the thickness direction on the seating portion 20 of the hard resin layer 16. Therefore, bending deformation in the thickness direction of the seating portion 20 is prevented, and the soft resin layer 18 can be formed on the surface of the hard resin layer 16 while maintaining the shape of the hard resin layer 16.

[0060] In this embodiment, the resin injection port 54 is provided so as to extend radially on the outer circumferential side of the outer circumferential cutout portion 24, and the soft resin material is injected radially from the outer circumferential side toward the seating portion 20 of the hard resin layer 16. Therefore, the injection pressure of the soft resin material is unlikely to act directly on the seating portion 20 in the plate thickness direction, and deformation of the seating portion 20 is more effectively prevented.

[0061] Furthermore, the soft resin material injected radially from the outer periphery toward the outer periphery cutout 24 is divided to both the upper and lower sides of the seating portion 20 and flows appropriately into the molding portions of the first soft resin layer 30 and the molding portions of the second soft resin layer 32 in the cavities 50 provided on both the upper and lower sides of the seating portion 20. Therefore, molding defects of the first soft resin layer 30 and the second soft resin layer 32 are prevented.

[0062] The soft resin material injected into the outer peripheral cutout 24 not only flows separately to the upper and lower sides of the seating portion 20 on the radially inner side, but also flows separately to the upper and lower sides of the seating portion 20 on both sides in the circumferential direction. In short, the circumferential length of the hard resin layer 16 at the injection position of the soft resin material is set long by the formation of the outer peripheral cutout 24, so that the soft resin material flows into both sides of the seating portion 20 over a wider range. Therefore, the soft resin material flows more easily into the molding portion of the first soft resin layer 30 and the molding portion of the second soft resin layer 32 in the cavity 50, and molding defects of the soft resin layer 18 are more effectively prevented.

[0063] In this embodiment, the resin injection port 54 is provided at a position biased downward with respect to the vertical center of the outer circumferential continuous portion 38 of the soft resin layer 18, so that the molding cavity of the second soft resin layer 32, which is thinner than the first soft resin layer 30, is also sufficiently filled with soft resin material. Therefore, it is possible to stably mold the second soft resin layer 32, which is prone to molding defects due to its thin wall.

[0064] Furthermore, since the upper end notch 26 is formed at the upper end of the cylindrical insertion portion 22 in the hard resin layer 16, even if there is a difference in the flow resistance of the soft resin material between the molding portion of the first soft resin layer 30 and the molding portion of the second soft resin layer 32 in the cavity 50, the soft resin material flows through the upper end notch 26, and both the first soft resin layer 30 and the second soft resin layer 32 can be stably molded.

[0065] When molding a plurality of resin spring insulators 10 simultaneously, for example, a molding die having a plurality of cavities 50 arranged in the circumferential direction may be used, and a resin injection port 54 may be provided extending radially from the center of the molding die to each of the cavities 50, thereby allowing the soft resin material to be supplied and injected from one central location into the plurality of cavities 50. By providing a resin injection port 54 extending radially from the outer periphery toward the seating portion 20 in this manner, it becomes easier to mold the soft resin layers 18 of a plurality of resin spring insulators 10 simultaneously.

[0066] Next, the integrally molded product of the soft resin layer 18 with the hard resin layer 16 inserted therein is demolded from the molding die 44. Then, in the demolded molded product, the molded runner 56 is cut by the resin injection port 54 to obtain the resin spring insulator 10, and the manufacture of the resin spring insulator 10 is completed. The trace of cutting the runner 56 forms a resin injection mark 40 on the outer peripheral surface of the soft resin layer 18. Therefore, in the resin spring insulator 10 in which the resin injection mark 40 is formed on the outer peripheral continuous portion 38 of the soft resin layer 18, the soft resin material is injected toward the outer peripheral cutout portion 24 of the hard resin layer 16, and the deformation of the hard resin layer 16 due to the injection pressure is prevented as described above. In addition, the second soft resin layer 32 has a support mark 36 formed as a mark of the seating portion 20 being supported by the support protrusion 52.

[0067] Although the embodiment of the present invention has been described above in detail, the present invention is not limited by the specific description. For example, in the above embodiment, an example in which six outer peripheral cutouts 24 are provided is shown, but the number of outer peripheral cutouts 24 is not particularly limited, and may be one or a number other than six. The number of upper end cutouts 26 is also not particularly limited. The number of outer peripheral cutouts 24 and the number of upper end cutouts 26 may be different from each other.

[0068] In the above embodiment, the peripheral notch 24 and the upper end notch 26 are exemplified as the notches, but since the notch only needs to be formed in at least one edge portion of the hard resin layer 16, it is also possible to provide only one of the peripheral notch 24 and the upper end notch 26.

[0069] The shape of the outer peripheral cutout 24 in top view is not limited to the example of the embodiment, and other shapes may be adopted. Specifically, for example, the outer peripheral cutout 24 may be semicircular in top view. Similarly, the shape of the upper end cutout 26 in radial view is not particularly limited, and may be changed as appropriate.

[0070] In the above embodiment, resin injection marks 40 were present in the outer peripheral continuous portion 38 within the outer peripheral cutout 24, but for example, resin injection marks may be present in the upper end continuous portion 42 within the upper end cutout 26, or resin injection marks may be present in both the outer peripheral continuous portion 38 and the upper end continuous portion 42.

[0071] Resin injection marks may be provided in multiple outer circumferential continuous portions 38, and by injecting (injecting) the soft resin material from multiple locations, it is possible to improve the formability of the soft resin layer 18. Similarly, when resin injection marks are provided in the upper end continuous portion 42, resin injection marks may be present in each of the multiple upper end continuous portions 42.

[0072] The direction in which the soft resin material is injected into the cavity 50 of the molding die 44 is not particularly limited. Specifically, for example, the soft resin material may be injected in the vertical direction toward the outer periphery cutout portion 24. In this case, resin injection marks are present on at least one of the upper and lower faces of the outer periphery continuous portion 38.

[0073] In the above embodiment, the cylindrical insertion portion 22 of the hard resin layer 16 is partially exposed from the soft resin layer 18, but the exposed portion may be covered with a thin film integrally formed with the soft resin layer 18. Similarly, the portion exposed in the support mark 36 of the seating portion 20 and the outer peripheral end portion of the seating portion 20 protruding outward from the soft resin layer 18 may also be covered with a thin film integrally formed with the soft resin layer 18.

[0074] The first soft resin layer 30 and the second soft resin layer 32 may be provided on both sides of the seating portion 20 of the hard resin layer 16 , and are not necessarily required to be provided on the inner and outer circumferential surfaces of the cylindrical insertion portion 22 .

[0075] In the above embodiment, the resin spring insulator 10 is generally circular, but the resin spring insulator according to the present invention is not limited to a circular shape and may be, for example, a partially circular arc shape in the circumferential direction. [Explanation of symbols]

[0076] 10 Resin spring insulator (first embodiment) 12 Coil spring 14 Receiving member 16 Hard resin layer 18 Soft resin layer 20 Seating area 22 Cylindrical insertion part 24 Outer periphery cutout (cutout) 26 Upper end notch (notch) 28 Inner rib 30 First soft resin layer 32 Second soft resin layer 34 Thick mounting part 36 Support trace 38 Outer periphery continuous part (soft resin continuous part) 40 Resin injection trace 42 Upper end continuous section (soft resin continuous section) 44 Molding mold 46 Upper mold 48 Lower mold 50 Cavity 52 Support protrusion 54 Resin injection port 56 Runner

Claims

1. A resin spring insulator that is overlapped on an end of a coil spring, The seating portion includes a hard resin layer having a plate-shaped seating portion, and a first soft resin layer and a second soft resin layer formed of a soft resin material having a lower hardness than the hard resin layer and fixed to both sides of the seating portion of the hard resin layer, A notch is formed at an end of the hard resin layer, A soft resin continuous portion is provided which integrally connects the first soft resin layer and the second soft resin layer through the notch, and at least one of the soft resin continuous portions has a resin injection mark present in the soft resin continuous portion due to the soft resin material being injected into the soft resin continuous portion.

2. the hard resin layer includes an annular seating portion and a cylindrical insertion portion protruding from an inner peripheral end portion of the seating portion toward one side in a plate thickness direction of the seating portion, 2. The resin spring insulator according to claim 1, wherein the notch is formed on at least one of an outer circumferential end of the seating portion and a protruding tip end of the cylindrical insertion portion.

3. The notch is formed on the outer peripheral end of the seating portion, and the notch is formed on the protruding tip of the cylindrical insertion portion, the first soft resin layer is fixed to one surface of the seating portion in a plate thickness direction, and the second soft resin layer is fixed to the other surface of the seating portion in the plate thickness direction, 3. The resin spring insulator according to claim 2, wherein the first soft resin layer extends and is fixed to the outer peripheral surface of the cylindrical insertion portion, and the second soft resin layer extends and is fixed to the inner peripheral surface of the cylindrical insertion portion.

4. 4. The resin spring insulator according to claim 2, wherein the resin injection mark is located within the notch formed in the outer circumferential end of the seating portion.

5. The notch is formed on an outer peripheral end of the seating portion, 4. The resin spring insulator according to claim 2, wherein the seating portion protrudes outwardly beyond the first soft resin layer and the second soft resin layer at a portion circumferentially away from the notch.

6. The first soft resin layer adhered to a surface of the seating portion facing the coil spring is thicker than the second soft resin layer, 3. The resin spring insulator according to claim 1, wherein the resin injection mark provided in the soft resin continuous portion is located closer to the surface of the second soft resin layer than to the surface of the first soft resin layer.

7. 3. The resin spring insulator according to claim 1, wherein the notches are provided at a plurality of positions in the circumferential direction of the hard resin layer.

8. A method for manufacturing a resin spring insulator to be fitted onto an end of a coil spring, comprising the steps of: a hard resin layer preparation step of preparing a hard resin layer having a plate-shaped seat portion and a notch formed in an edge portion of a member; a soft resin layer forming step of injecting a soft resin material into the edge portion of the cavity of the molding die in which the hard resin layer is set, and diverting the soft resin material from the notch to both sides of the hard resin layer, thereby integrally forming a first soft resin layer and a second soft resin layer having a hardness lower than that of the hard resin layer on both sides of the seating portion; A method for manufacturing a resin spring insulator comprising the steps of:

9. The molding die is provided with a support protrusion protruding into the cavity, 9. The method for manufacturing a resin spring insulator according to claim 8, wherein in the soft resin layer forming step, the supporting protrusion abuts against the seating portion of the hard resin layer set in the cavity to support the seating portion in a plate thickness direction.

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