Spring

This application is a 371 U.S. national phase stage of PCT/JP2019/008923, filed Mar. 6, 2019, which claims priority to Japanese Patent Application No. 2018-40752 and Japanese Patent Application No. 2018-40753 filed with the Japan Patent Office on Mar. 7, 2018, the contents of each of which are incorporated herein by reference in their entireties.

The present disclosure relates to a spring, and in particular to a spring that can be used in a suspension device such as a suspension device for a vehicle.

For example, in a spring device of an invention described in Patent Document 1, a coil spring made of metal and a holding member made of plastic are adhered via an adhesive. In the invention described in Patent Document 1, after the adhesive is applied to the holding member, the coil spring is adhered to the holding member by placing the coil spring on the adhesive-applied position.

Patent Document

Patent Document 1: Japanese Patent Publication No. 2017-15249

Problems to be Solved by the Invention

In the spring device described in Patent Document 1, the coil spring may be damaged early for the following reasons.

In other words, after the adhesive is applied to the holding member, if the coil spring is placed on the adhesive-applied position, part of the applied adhesive is extremely likely to overflow from the adhered surfaces of the coil spring and the holding member.

Cracks may occur between the adhesive overflowing from the adhered surfaces (hereinafter referred to as the overflow part) and the adhesive existing on the adhered surfaces (hereinafter referred to as the adhesion layer), and the overflow part may be broken from the adhesion layer, due to factors such as vehicle vibration and changes over time.

In the case where the overflow part is broken, if load acts on the coil spring to deform the coil spring and the holding member, the overflow part is relatively displaced with respect to the coil spring. If the overflow part is displaced relative to the coil spring, the broken position of the overflow part and the coil spring rub against each other.

If the broken position of the overflow part and the coil spring rub against each other, a coating layer provided on the surface of the coil spring may be damaged, and hence the coil spring may be early damaged starting from the damaged position.

In view of the above points, the present disclosure discloses an example of a spring capable of suppressing early damage of a spring section constituted by a wire made of metal.

Means for Solving the Problems

A spring for a suspension device for a vehicle according to an aspect of the present disclosure comprises: a wire made of metal, constituting a spring section, and provided with a coating layer on its surface; and a seat section made of an elastically deformable material, bearing load acting on the spring section, having a groove section into which the wire is fitted, and adhered to the wire by an adhesive.

In the configuration described above, it is preferable that a minimum thickness dimension of the adhesive overflowing from the groove section is greater than or equal to a thickness dimension of an adhesion layer formed in the groove section.

This can suppress an excessively small thickness dimension of a boundary between the overflow part and the adhesion layer. Therefore, the breakage of the overflow part is suppressed, so that early damage of the spring section can be suppressed.

Even if there is an adhesive accumulation portion at an end portion of the groove section in a width direction, on which the adhesive is accumulated to restrict the flow of the adhesive, and the boundary between the overflow part and the adhesion layer can be suppressed from having an excessively small thickness dimension.

Therefore, even if there is an adhesive accumulation portion, the breakage of the overflow part can be suppressed, so that early damage of the spring section can be suppressed.

FIG. 1 is a diagram showing a spring according to a first embodiment of the invention.

FIG. 2 is a diagram showing a seat section in the first embodiment.

FIG. 3 is a diagram showing an adhesion layer and its vicinity in the first embodiment.

FIG. 4 is a diagram showing a part A of FIG. 3 , which is a characteristic part of the first embodiment.

FIG. 5 is a diagram for illustrating a comparative example.

FIG. 6 is a diagram showing a characteristic part of a second embodiment of the invention, which corresponds to the part A of FIG. 3 .

FIG. 7 is a diagram showing a characteristic part of a third embodiment of the invention, which corresponds to the part A of FIG. 3 .

FIG. 8 is a diagram showing the characteristic part of the third embodiment, which corresponds to the part A of FIG. 3 .

The following “embodiment of the invention” shows an example of an embodiment falling within the technical scope of the present disclosure. In other words, the invention-specifying matters recited in the claims are not limited by specific structures, configurations, or the like shown in the following embodiments.

Arrows or the like indicating directions marked in the drawings are described to provide easy understanding of the relationships between the drawings. The invention described in this specification is not limited by the directions marked in the drawings.

A member or portion described at least with a reference numeral is provided at least one in number unless specified with the term “one” or the like. In other words, two or more such members may be provided when not specified with the term “one” or the like.

This embodiment is an example in which the spring of the present disclosure is applicable as a spring for a suspension device, such as a spring for a suspension device for a vehicle.

First Embodiment

1. Structure of Spring for Suspension Device

A spring 1 for a suspension device shown in FIG. 1 (hereinafter referred to as a spring 1 ) comprises at least a spring section 2 and a seat section 3 . The spring section 2 is a spring constituted by a wire 2 A made of metal.

A coating layer 2 B covering the entire wire 2 A is provided on the surface of the wire 2 A. The spring section 2 of this embodiment is a coil spring formed in a coil shape. The coating layer 2 B is a thin film formed from a resin such as a thermosetting resin by stoving varnish.

The seat section 3 is a seat bearing load acting on the spring section 2 , and is, for example, a rubber seat. The seat section 3 is made of an elastically deformable material. The material of the seat section 3 may exemplarily include at least one of rubber and resin. As shown in FIG. 2 , the seat section 3 is provided with a groove section 3 A into which a part of the wire 2 A is fitted.

The groove section 3 A is a groove into which a part of the wire 2 A constituting an end turn section is fitted. In other words, the seat section 3 is arranged at an end of the spring section 2 configured in a coil shape in the coil axial direction, and is in contact with the part of the wire 2 A constituting the end turn section (see FIG. 1 ). The wire 2 A described below is the part of the wire 2 A constituting the end turn section.

The wire 2 A is adhered to the inner wall surface of the seat section 3 , i.e., the groove section 3 A, by an adhesive. Therefore, as shown in FIG. 3 , an adhesion layer AD of the adhesive is formed between the wire 2 A and the inner wall surface of the groove section 3 A.

2. Configuration of an Adhesion Part

As shown in FIG. 4 , in the adhesion part A, the minimum thickness dimension Tb of the adhesive overflowing from the groove section 3 A (hereinafter referred to as the overflow part Bo) is greater than or equal to the thickness dimension Td of the adhesion layer AD formed in the groove section 3 A.

Specifically, an adhesive accumulation portion 4 on which the adhesive is accumulated to restrict the flow of the adhesive is provided at an end portion of the groove section 3 A in the width direction. The adhesive accumulation portion 4 of this embodiment is constituted by a planar section 4 A provided at an end portion of the groove section 3 A in the width direction and configured in a substantially planar shape. As shown in FIG. 4 , the planar section 4 A constituting the adhesive accumulation portion 4 of this embodiment spreads from the upper end of the end portion of the groove section 3 A in the width direction in a substantially horizontal direction.

The minimum thickness dimension Tb of the overflow part Bo is, for example, a dimension substantially equal to the distance between positions of the planar section 4 A and the wire 2 A that are closest to each other in the structure shown in FIG. 4 . The thickness dimension Td of the adhesion layer AD refers to, for example, a minimum thickness dimension of the adhesion layer AD, or a thickness dimension of the adhesion layer AD at a position close to the minimum thickness dimension Tb.

In this embodiment, the size of the adhesive accumulation portion 4 , i.e., the width dimension Wo of the planar section 4 A is determined in such a manner that the minimum thickness dimension Tb of the overflow part Bo is greater than the thickness dimension Td of the adhesion layer AD.

3. Characteristics of the Spring of this Embodiment

As shown in the comparative example of FIG. 5 , in the case where the adhesive accumulation portion 4 are not provided at the end portion of the groove section 3 A in the width direction, the adhesive overflowing to end of the groove section 3 A in the width direction flows along the upper surface 3 B of the seat section 3 , therefore there is an extremely high possibility that the minimum thickness dimension Tb of the overflow part Bo becomes too small.

In contrast, in this embodiment, since the adhesive overflowing to end of the groove section 3 A in the width direction is accumulated on the adhesive accumulation portion 4 , the minimum thickness dimension Tb of the overflow part Bo can be suppressed from becoming too small. Therefore, the breakage of the overflow part Bo is suppressed, so that early damage of the spring section 2 can be suppressed.

Second Embodiment

As shown in FIG. 6 , the adhesive accumulation portion 4 of this embodiment is constituted by a weir 4 B provided at an end portion of the groove section 3 A in the width direction. The weir 4 B is constituted by a protruding strip extending along the groove section 3 A in a state where it protrudes upward from the end portion of the groove section 3 A in the width direction.

Thus, the adhesive overflowing to end of the groove section 3 A in the width direction is blocked by the weir 4 B, and hence the adhesive overflowing to the end of the groove section 3 A in the width direction is accumulated in the adhesive accumulation portion 4 . Therefore, the minimum thickness dimension Tb of the overflow part Bo can be suppressed from becoming too small.

The same constituent elements and the like as those in the above embodiment are marked with the same reference numerals as in the above embodiment. Therefore, a repeated description is omitted in this embodiment.

Third Embodiment

The adhesive accumulation portion 4 of the first embodiment is constituted by a planar section 4 A spreading from the upper end of an end portion of the groove section 3 A in the width direction in a substantially horizontal direction (see FIG. 4 ). In contrast, in this embodiment, as shown in FIGS. 7 and 8 , the planar section 4 A or the upper surface 3 B is connected to the inner wall surface of the groove section 3 A by a curved surface 4 C or a flat surface 4 D.

Thus, the adhesion layer AD has a thickness increasing as it approaches the end portion of the groove section 3 A in the width direction, and hence the minimum thickness dimension Tb of the overflow part Bo can be suppressed from becoming too small.

The same constituent elements and the like as those in the above embodiments are marked with the same reference numerals as in the above embodiments. Therefore, a repeated description is omitted in this embodiment.

Other Embodiments

In the above embodiments, the adhesive accumulation portion 4 is used so that the minimum thickness dimension Tb of the overflow part Bo is greater than or equal to the thickness dimension Td of the adhesion layer AD. However, the invention disclosed in the specification of the present disclosure is not limited thereto. In other words, structures other than the adhesive accumulation portion 4 may be used, provided that the minimum thickness dimension Tb is greater than or equal to the thickness dimension Td of the adhesion layer AD.

The weir 4 B of the second embodiment is a protruding strip extending continuously along the groove section 3 A. However, the structure of the weir 4 B is not limited to a protruding strip extending continuously along the groove section 3 A. In other words, for example, it may be constituted by a plurality of protrusions or the like dispersed along the groove section 3 A, or may be constituted by one protrusion or protruding strip.

Furthermore, the present disclosure is not limited to the above embodiments, without departing from the gist of the invention recited in the claims. Therefore, at least two of the above multiple embodiments may be combined.