JP2016003365A - Plated composite article and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high corrosion resistance and improve the appearance while keeping floating of bonded parts in a smooth state.SOLUTION: A composite article comprises at least two parts 2 and 3 bonded inseparably in a freely floating state through an engagement structure between them. In the individual parts 2 and 3, there is formed a surface-treated layer 10 with a Zn plating as the outermost layer, in an engagement part where the parts 2 and 3 come in slide contact with each other during floating. In parts other than the engagement part, there is formed a surface-treated layer 11 formed by laminating a metal plating layer on the Zn plating as the ground layer.

Description

  The present invention relates to a plated composite product obtained by plating a composite product such as a nut with a seat, and a method of manufacturing the plated composite product.

  Like the seated nut illustrated in FIG. 3, a composite product in which an accessory part 101 such as a spring washer or a disc spring is freely movable (in the illustrated example, rotatable) and inseparably coupled to a main body part 102 such as a nut. 100 is well-known (for example, refer patent document 1 etc.). As such a composite product 100, in addition to the above-mentioned nuts with seats, etc., nuts incorporating coil springs and locking parts, etc., or spring washers and plain washers are fitted into the necks of bolts in a freely rotatable manner. A bolt with a built-in washer is also known.

  Even in such a composite article 100, in order to improve corrosion resistance or give a metallic luster in many cases, for example, plating with an alloy of nickel and zinc with trivalent chromate (see Patent Document 2, etc.) is performed. I am doing so.

Japanese Patent Laid-Open No. 9-4630 JP 2005-126696 A

  When the composite part 100 is plated, when the accessory part 101 and the main body part 102 are joined and immersed in the plating tank, a gap S (an example of a seated nut) is generated between the attachment part 101 and the main body part 102 at the fitting portion. Then, the circumferential gap between the outer peripheral surface of the stepped convex portion provided on the nut for fitting the disc spring and the inner peripheral portion of the disc spring, the gap that can be formed on the upper and lower sides of the disc spring, etc.) are very small. In some cases, the plating solution hardly penetrated into the gap S. For this reason, there is a problem in that the fitting portion (gap S) has a poor appearance because the plating has not been deposited or the plating thickness has become extremely thin, resulting in a dark appearance. In addition, there is a problem that it is difficult to improve the corrosion resistance in a portion where the plating is not deposited or the plating thickness is thin.

  On the other hand, for the purpose of solving this problem, it is assumed that the accessory part 101 and the main body part 102 are separately plated before joining, and then the manufacturing procedure of the composite product 100 is changed so that they are joined. To do. By doing in this way, both the attachment part 101 and the main-body part 102 can perform uniform plating on the whole surface. However, in many cases, since the surface of the plating is rough and the smoothness is lowered, when the attachment part 101 and the main body part 102 after the entire plating are joined, the mobility between them is lowered. There was also a problem.

In addition, when the attachment part 101 and the main body part 102 are joined together, when caulking or the like is required on one of the parts, the surface of the part is damaged by caulking, and corrosion starts or expands due to this scratch. There was also the problem of doing.
The present invention has been made in view of the above circumstances, and is a plated composite product capable of obtaining high corrosion resistance and improving appearance while maintaining smooth play between joined parts, and its An object is to provide a manufacturing method.

In order to achieve the above object, the present invention has taken the following measures.
That is, the plated composite product according to the present invention is a composite product in which at least two parts are freely movable and separable by a fitting structure between each other. A surface treatment layer having Zn plating as the outermost layer is formed at the fitting part that is in sliding contact with the other part, and other metal other than the fitting part is made of Zn plating as a base layer on the base layer. A surface treatment layer formed by laminating plating layers is formed.

The other metal plating layer is preferably a Ni—Zn alloy plating layer.
It is also possible to further apply a surface treatment layer with trivalent chromate on the other metal plating layer.
On the other hand, the method of manufacturing a plated composite product according to the present invention is a method of manufacturing a plated composite product in which at least two parts are freely and separably joined by a fitting structure between them. Each part is individually surface-treated by Zn plating, and each part is fitted to each other in a freely movable state, and then further separably coupled, and each metal is different from the Zn plating in a state in which each part is coupled. The surface treatment is performed by plating.

  The metal plating different from Zn plating is preferably Ni—Zn alloy plating.

  In the plated composite product according to the present invention, high corrosion resistance can be obtained while maintaining the smooth movement between the joined parts, and the appearance can be improved.

It is the sectional side view which showed typically 1st Embodiment of the plated composite goods which concern on this invention. It is the sectional side view which showed typically an example (middle stage) of the manufacturing method about the plated composite goods which concern on this invention. It is the sectional side view which showed the conventional composite goods.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side sectional view schematically showing a first embodiment of a plated composite product 1 according to the present invention, and FIG. 2 schematically shows a stage in the middle of manufacturing the plated composite product 1. FIG. This 1st Embodiment has illustrated the case where a composite article is a nut with a seat. Therefore, this composite product has two parts, an accessory part 2 such as a spring washer and a disc spring, and a main body part 3 such as a nut.

  The main body part 3 is provided with a stepped convex portion 5 (see FIG. 2) protruding in a circular boss shape so as to extend one opening end side of the female screw hole 4 provided through the center. Yes. On the other hand, the accessory part 2 is formed with a central opening 7 that fits into the stepped convex portion 5 of the main body part 3. Therefore, the central opening 7 of the accessory part 2 is fitted into the stepped convex portion 5 of the main body part 3, and thereafter, crimping is performed so that the edge of the stepped convex portion 5 spreads radially outward. Accordingly, the accessory part 2 is held so as to be freely movable (rotatable) and not separable around the stepped convex portion 5 of the body part 3.

That is, the stepped convex portion 5 of the main body part 3 is deformed by caulking to form a circumferential groove for sliding contact with the central opening 7 of the accessory part 2, and the groove inner surface of the circumferential groove is That is, the fitting part is directed to the attached part 2.
On the other hand, in the accessory part 2, the inner peripheral surface of the central opening 7 and the upper and lower surfaces of the peripheral part of the opening are in sliding contact with the fitting part of the main body part 3 (the groove inner surface of the peripheral groove). The part is a fitting part directed to the main body part 3.

  In the plated composite product 1 according to the present invention, Zn plating is applied to the outermost layer of these fitting portions (the groove inner surface of the circumferential groove formed in the main body part 3 and the region fitted in the circumferential groove in the accessory part 2). A surface treatment layer 10 (hereinafter referred to as “first treatment layer” for convenience of description) 10 is formed, and Zn plating is used as an underlayer for other portions except these fitting portions. A surface treatment layer 11 (hereinafter referred to as “second treatment layer” for convenience of explanation) is formed by laminating another metal plating layer on the base layer.

In other words, in the plated composite product 1, only the first treatment layer 10 is formed only in a portion where the accessory part 2 and the main body part 3 are fitted to each other (an area that becomes a small gap when viewed from the outside). The other region (mainly the surface exposed to the outside) is covered with the second treatment layer 11.
In addition, since the outermost layer of the 1st process layer 10 should just be Zn plating, it is arbitrary to provide another plating layer etc. under Zn plating. In addition, if the second treatment layer 11 is also formed by depositing Zn plating as a base layer on the Zn treatment,
It is possible to arbitrarily provide another plating layer under the other metal plating layer.

In the second treatment layer 11, the metal plating layer laminated on the first treatment layer 10 is preferably a Ni—Zn alloy plating layer. In order to further enhance the metallic luster and enhance the corrosion resistance, a chemical surface treatment layer (not shown) of trivalent chromate or the like may be further laminated on the second treatment layer 11.
Next, a method for manufacturing the plated composite article 1 having such a configuration will be described.

First, before fitting the accessory part 2 to the stepped convex portion 5 of the main body part 3, each of the accessory part 2 and the main body part 3 is entirely surface-treated by Zn plating, and the first treatment layer 10 (See FIG. 2).
Next, the central opening 7 of the accessory part 2 is fitted to the stepped convex portion 5 of the main body part 3 and caulking is performed so that the edge of the stepped convex portion 5 extends radially outward. By this caulking, the attachment part 2 and the main body part 3 are coupled to each other so as to be freely movable and inseparable.

  Next, the entire surface is subjected to surface treatment by Ni—Zn alloy plating while the attached part 2 and the main body part 3 are joined. At this time, the fitting part of the accessory part 2 and the fitting part of the main body part 3 have a very small gap between them, so that the plating solution hardly penetrates, and thus the Ni—Zn alloy plating layer. Is not formed, or even if it is formed, the plating thickness becomes extremely thin, and the characteristic action as the Ni—Zn alloy plating layer hardly occurs.

That is, in the present invention, the fitting part between the accessory part 2 and the main body part 3 is focused on making the gap between each other minute, and this fitting is utilized by utilizing that the plating solution does not enter the gap. It can be said that the Ni—Zn alloy plating layer is not intentionally formed at the joint portion.
In short, even if the surface treatment by Ni-Zn alloy plating is performed, the entire portion excluding the fitting part of the accessory part 2 and the fitting part of the main body part 3 is only covered and formed by the second treatment layer 11, In this fitting part, the 1st processing layer 10 (layer by Zn plating) remains as a substantial outermost layer.

  In the plated composite product 1 manufactured in this way, the fitting part of the accessory part 2 and the fitting part of the main body part 3 are respectively covered with the first treatment layer 10 made of soft Zn plating. Is ensured as a state of excellent smoothness. Needless to say, the fitting part of the accessory part 2 and the fitting part of the main body part 3 are provided with corrosion resistance by the first treatment layer 10 (Zn plating).

  In addition, since the attached part 2 and the main body part 3 are covered with the second treatment layer 11 formed by laminating a hard Ni—Zn alloy plating except for the fitting part, the corrosion resistance and the wear resistance are excellent. Appearance that emphasizes metallic luster. Even if the attachment part 2 and the main body part 3 are joined to each other, even if a small scratch may be caused by caulking, Ni-Zn alloy plating is applied to the second treatment layer 11 after the caulking. Since it is formed, corrosion does not occur due to scratches.

By the way, this invention is not limited to the said embodiment, It can change suitably according to embodiment.
For example, with regard to making the accessory part 2 and the main body part 3 freely movable, it is not limited to being rotatable, but may be a case where the axis is movable or a case where the face part is slidable. To do.

In the first embodiment, the case of the accessory part 2 and the main body part 3 has been described as an example. However, it is not necessarily limited that the master-slave relationship of “attachment” and “main body” occurs between the parts. Absent. Further, regarding the number of parts, the present invention can be applied even when three or more parts are slidably coupled to each other.
In the second treatment layer 11, the metal plating layer laminated on the first treatment layer 10 may be other than the Ni—Zn alloy plating layer. In the first place, the alloy plating layer is not limited. The chemical surface treatment layer provided on the second treatment layer 11 may also be other than trivalent chromate.

DESCRIPTION OF SYMBOLS 1 Plated composite product 2 Attached parts 3 Body parts 4 Female screw hole 5 Convex part 7 Step opening 10 Surface treatment layer (1st treatment layer)
11 Surface treatment layer (second treatment layer)

Claims (5)

A composite product in which at least two parts are freely and separably connected by a fitting structure between them,
In each part, a surface treatment layer having Zn plating as the outermost layer is formed at a fitting portion that is in sliding contact with each other during sliding,
A plated composite product characterized in that a surface treatment layer is formed by laminating another metal plating layer on the base layer using Zn plating as a base layer in other portions except the fitting portion.   The plated composite article according to claim 1, wherein the other metal plating layer is a Ni-Zn alloy plating layer.   3. The plated composite product according to claim 1, wherein a surface treatment layer made of trivalent chromate is further formed on the other metal plating layer. A method of manufacturing a plated composite article in which at least two parts are loosely and non-separably joined by a mating structure between them,
Individual parts are individually surface treated by Zn plating,
After each part is fitted in a freely movable state, it is further connected inseparablely,
A method for producing a plated composite product, characterized in that surface treatment is performed with metal plating different from the Zn plating while the parts are joined.   The method for producing a plated composite product according to claim 4, wherein the metal plating different from Zn plating is Ni-Zn alloy plating.

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