JPH10130880A - Composite plating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly enhance wear resistance of a composite plating film by uniformly precipitating ceramic particles into a metallic matrix of this composite plating film. SOLUTION: A cylindrical electrode 4 is arranged in a hollow part 3 by opening a clearance and the peripheral wall of this cylindrical electrode 4 is provided with through-holes 26.... Then, a composite plating liquid 5 is injected from the through-holes 26... to the outer side of the cylindrical electrode 4, by which the injected composite plating liquid 5 may be brought into collision against the inside surface of the hollow part 3. Consequently, the composite plating liquid 5 attains a turbulent state and the SiC particles 32... are uniformly dispersed into the composite plating liquid 5 and, therefore, the SiC particles 32... are uniformly precipitated in the metallic matrix of the composite plating film 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite plating apparatus for forming a composite plating film on the inner surface of a hollow portion of a work.

[0002]

2. Description of the Related Art In a cylinder block for an internal combustion engine, an inner surface of a cylinder serving as a sliding surface of a piston is die-cast integrally with the cylinder block.
Some are provided with a SiC composite plating film. Ni / Si
The C composite plating film is obtained by eutecting silicon carbide (SiC) particles in a Ni matrix, which is a metal phase, and has improved abrasion resistance on the inner surface of the cylinder.

On the other hand, a high-speed plating method is disclosed in Japanese Unexamined Patent Publication No. Hei 7-118891, "Surface treatment apparatus".
According to this high-speed plating method, the composite plating solution can be forcibly flowed along the inner surface of the cylinder, and the composite plating film can be applied to the inner surface of the cylinder at high speed. The following figure shows the Ni / SiC composite plating film treatment by the apparatus of the publication.

FIG. 11 is an explanatory view of a conventional Ni / SiC composite plating process. Opening 10 of cylinder block 100
1 and the cylindrical electrode 102 is arranged with a gap S therebetween, so that the annular passage 10 is formed between the opening 101 and the electrode 102.
4 is formed. The composite plating solution is caused to flow through the annular passage 104 in the direction of the arrow.
02 is turned back inside.

While the flow of the composite plating solution is continued, an electric current is applied to the electrode 102 and the cylinder block 100 so that a plurality of SiC particles 106 are formed in the Ni matrix 105 of the composite plating film 107. The same shall apply hereinafter.).

[0006]

However, the composite plating film 107 shown in FIG. 11 has a problem shown in the following figure.
FIG. 12 is an enlarged view of a part 12 of FIG. Since the composite plating solution flows in the direction of the arrow along the annular passage 104, a large amount of SiC particles 106 are contained in the Ni matrix 105 on the downstream side.
Is eutectoid. Therefore, the composite plating solution moves upward (downstream).
SiC particles 106 in the composite plating solution as they flow
Decrease, and the eutectoid amount of the SiC particles 106 gradually decreases toward the downstream side. For this reason, there is a problem that the wear resistance of the composite plating film decreases on the downstream side.

Accordingly, an object of the present invention is to provide a technique for uniformly eutectifying ceramic particles such as SiC particles into a composite plating film to uniformly increase the wear resistance of the composite plating film.

[0008]

In order to solve the above-mentioned problems, a first aspect of the present invention is to dispose a gap in a hollow portion of a work having a hollow portion, and provide a work having a bottom or a lid and having the hollow portion. A cylindrical electrode having a plurality of through holes in a peripheral wall opposed to the inner surface of the cylindrical electrode, a composite plating solution in which ceramic particles are mixed with a plating solution is supplied to the inside of the cylindrical electrode, and the composite plating solution is jetted through the through holes in the peripheral wall. A composite plating apparatus is constituted by a plating solution circulating mechanism for recovering from the outside of the shaped electrode and an energizing mechanism for energizing the work and the cylindrical electrode.

[0009] The composite plating solution is jetted from the plurality of through holes to the outside of the cylindrical electrode, and the jetted composite plating solution collides with the inner surface of the hollow portion. Therefore, the composite plating solution is in a turbulent state, and the ceramic particles in the composite plating solution are uniformly dispersed. As a result, the ceramic particles are uniformly eutectoid in the metal matrix of the composite plating film.

The second aspect is characterized in that the plurality of through holes have a large diameter on the upstream side along the flow inside the cylindrical electrode and have a gradually decreasing diameter toward the downstream side.

Since the composite plating solution is supplied to the bottomed or covered cylindrical electrode, the flow of the composite plating solution is blocked at the bottom or the lid. Accordingly, the composite plating solution pressure on the bottom or the lid side increases, so that the composite plating solution pressure increases on the downstream small-diameter through-hole, and the composite plating solution pressure decreases on the upstream large-diameter through-hole. Therefore, a fixed amount of the composite plating solution can be sprayed from all the through holes. Therefore, since the ceramic particles can be uniformly applied to the hollow portion of the work, the ceramic particles can be co-deposited uniformly with the metal phase.

According to a third aspect of the present invention, the plurality of through holes are arranged in a grid on the peripheral wall of the cylindrical electrode.

[0013] Since the composite plating solution can be sprayed at equal intervals from the peripheral wall, the ceramic particles can be uniformly applied to the hollow portion of the work. Therefore, the ceramic particles can be uniformly eutectoid with the metal phase.

According to a fourth aspect of the present invention, the plurality of through holes are arranged in a zigzag pattern on the peripheral wall of the cylindrical electrode.

[0015] Compared to the case where a plurality of through holes are arranged in a grid, the through holes can be densely arranged in the circumferential direction. Therefore, since the ceramic particles can be applied to the hollow portion of the work in a dense state, the ceramic particles can be eutectoid to the metal phase in a dense state.

According to a fifth aspect of the present invention, the plurality of through holes are tapered holes having a small diameter inside the cylindrical electrode and a large diameter outside.

Since the composite plating solution can be sprayed while diffusing outward from the plurality of through holes, it can be widely applied to the hollow portion of the work. Therefore, the ceramic particles in the composite plating solution sprayed from the plurality of through holes can be efficiently and uniformly dispersed, and the dispersed ceramic particles can be co-deposited with the metal phase.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 shows a composite plating apparatus (first embodiment) according to the present invention.
FIG. Composite plating apparatus 1 has a cylindrical electrode 4 arranged with a gap S ₁ in the hollow portion 3 of the cylinder block 2 for an internal combustion engine as a work, a composite plating solution which will be described later in the inner channel of the cylindrical electrode 4 5, a plating solution circulating mechanism 6, a cylinder block 2, and a cylindrical electrode 4.
And an energizing mechanism 7 for energizing the components. The cylindrical electrode 4
Will be described with reference to FIG.

Reference numeral 8 denotes an annular passage formed by the hollow portion 3 and the cylindrical electrode 4, 9 denotes a water jacket serving as a cooling water passage,
Reference numeral 10 denotes an inner surface of the cylinder, 11 denotes a crank chamber, and 12 denotes a shielding plate. The shielding plate 12, the gap between the hollow portion 3 is small elastic member from the hollow portion 3 formed so as to be S _2.

The plating solution circulating mechanism 6 includes a tank 13 for storing the composite plating solution, a pump 14 communicating the suction port with the tank 13, and a supply pipe 15 connecting the discharge port of the pump 14 to the inlet of the cylindrical electrode 4. 1 on which a cylinder block 2 is placed and a recovery passage 16 communicating with the annular passage 8 is provided.
7 and a return pipe 18 that communicates the collection passage 16 of the base 17 with the tank 13.

Reference numeral 19 denotes a relief circuit, and reference numeral 20 denotes a relief valve. When the internal pressure of the supply pipe 15 exceeds a predetermined value, the relief valve 20 opens to release the pressure to the return pipe 18 so that the internal pressure of the cylindrical electrode 4 is reduced. Is prevented from becoming excessive. The composite plating solution 5 was prepared by adding 400 g of nickel sulfate (NiSO ₄ ), 35 g of boric acid, and 2.5 g of sodium saccharin per liter of water to adjust the hardness to PH = 4. It is a suspension.

FIG. 2 is a sectional view of a cylindrical electrode (first embodiment) according to the present invention. The cylindrical electrode 4 is, for example, a Cu-based alloy electrode or a Ti-coated metal electrode, and has a large-diameter peripheral wall 25 facing the inner surface of the hollow portion 3 shown in FIG. The through-hole 26 and the peripheral wall 2
The cover 27 is provided at the upper end of the peripheral wall 5 and has a small diameter neck 28 extending downward from the lower end of the peripheral wall 25.

FIG. 3 shows a composite plating apparatus (first embodiment) according to the present invention.
FIG. 9 is a first operation explanatory diagram of the embodiment). The cylinder block 2 is placed on the cylindrical electrode 4 from above and set on the base 17, and the collection passage 16 of the base 17 and the annular passage 8 communicate with each other. At this time, since the gap between the shielding plate 12 and the hollow portion 3 has a S _2, the hollow portion 3 is not interfere worry shield 12 during the set.

In this state, the pump 14 shown in FIG. 1 is driven to supply the composite plating solution 5 in the tank 13 to the inside of the cylindrical electrode 4 via the supply pipe 15. Therefore, the composite plating solution 5 flows in the direction of the arrow. Here, since the cylindrical electrode 4 is provided with the lid 27 on the downstream side, the flow of the composite plating solution 5 in the arrow direction is blocked by the lid 27 and flows in the direction of the arrow toward the through holes 26. Next, the composite plating solution 5 is applied to the through holes 2.
6, are injected into the annular passage 8 (that is, in the direction of the arrow) and collide with the inner surface of the hollow portion 3. The composite plating solution 5 that has collided with the hollow portion 3 flows downward (in the direction of the arrow) along the annular passage 8, and flows in the order of the recovery passage 16 → the return pipe 18 shown in FIG. 1 → the tank 13. The shielding plate 12 also functions to prevent the composite plating solution 5 from entering the crank chamber 11.

FIG. 4 shows a composite plating apparatus (first embodiment) according to the present invention.
FIG. 10 is a second operation explanatory diagram of the embodiment). Since the composite plating solution 5 sprayed from the through holes 26 into the annular passage 8 as shown by arrows collides with the inner surface of the hollow portion 3, the composite plating solution 5 flowing through the annular passage 8 is indicated by loop arrows. Turbulence. Accordingly, the SiC particles 32, which are ceramic particles, are uniformly dispersed in the composite plating solution 5 in the annular passage 8.

In this state, the energizing mechanism 7 shown in FIG. 1 is operated to energize the cylindrical electrode 4 and the cylinder block 2. Ni ions in the composite plating solution 5 are precipitated on the inner surface of the hollow portion 3, and SiC particles 32 are co-deposited in the Ni matrix 33. At this time, since the SiC particles 32 are uniformly dispersed in the composite plating solution 5, the SiC particles 32 are uniformly eutectoid in the Ni matrix 33.

FIG. 5 shows a composite plating apparatus (first embodiment) according to the present invention.
7 is a glass in which Example) is compared with a conventional composite plating apparatus. The horizontal axis indicates the plating position between the cylinder head side end P ₁ and the crankcase side end P ₂ of the hollow portion 3, and the vertical axis indicates the SiC particles 32 in the Ni / SiC composite plating film 34.
(See FIG. 4). The bold solid line is a graph of the first embodiment in which the Ni / SiC composite plating film 34 is applied by the composite plating apparatus 1 (shown in FIG. 1) according to the present invention, and the thin solid line is Ni / SiC in the conventional apparatus shown in FIG. It is a graph of the comparative example which provided the SiC composite plating film.

[0028] In the first embodiment, it is understood that the cylinder head side end portion P ₁ of the hollow portion 3 to the crank chamber-side end portion P _2, SiC particles 32 ... of eutectoid amount is kept constant.
On the other hand, in the case of the comparative example, the closer from the cylinder head side end portion P ₁ of the hollow portion 3 in the crank chamber side end portion P _2, SiC
It can be seen that the eutectoid amount of the particles 32 gradually decreases. Therefore, according to the first embodiment, since the SiC particles 32 can be co-deposited uniformly on the Ni / SiC composite plating film 34, the wear resistance of the hollow portion 3 can be uniformly increased.

FIG. 6 is a sectional view showing a cylindrical electrode (second embodiment) according to the present invention. The cylindrical electrode 40 has a through hole 41
Are characterized in that, along the flow inside the cylindrical electrode 40, the upstream side has a large diameter and the downstream side has a gradually decreasing diameter.

FIG. 7 is an explanatory view of the operation of the cylindrical electrode (second embodiment) according to the present invention. The inner composite plating solution 5 supplied to the cylindrical electrode 40 flows downstream (in the direction of the arrow) and hits the lid 42 of the cylindrical electrode 40, and the flow is interrupted.
The hydraulic pressure on the second side becomes high. Therefore, the through-holes 41 on the side of the lid portion 42 (the side where the hydraulic pressure is high) are made smaller in diameter, and gradually increased in diameter toward the upstream side (the side where the hydraulic pressure is lower), so that all the through-holes 41 are constant. The amount of the composite plating solution 5 can be sprayed.

FIG. 8 is a sectional view showing a cylindrical electrode (third embodiment) according to the present invention. The cylindrical electrode 45 is characterized in that the through-holes 47 are arranged in the peripheral wall 46 in a staggered manner at the same pitch P as the grid arrangement. Through hole 4 compared to grid layout
7 and since the distance S ₃ between the through-hole 47 is reduced, it is possible to densely arranged through holes 47 ... and the circumferential direction. Therefore, the SiC particles 32.
The SiC particles 32
.. Can be eutectoid in the Ni matrix 33 in a dense state.

FIG. 9 is a sectional view showing a cylindrical electrode (fourth embodiment) according to the present invention. The cylindrical electrode 50 is characterized in that the through holes 52 of the peripheral wall 51 are tapered holes having a small diameter inside the cylindrical electrode 50 and a large diameter outside.

FIG. 10 is a diagram for explaining the operation of the cylindrical electrode (fourth embodiment) according to the present invention. The through-holes 52...
The composite plating solution 5 is sprayed into the annular passage 4 while diffusing in the direction of the arrow from the through holes 52. Therefore, the composite plating solution 5 sprayed from the through-holes 52 can be widely applied to the hollow portion 3 of the cylinder block 2, and thus the ceramic particles in the composite plating solution are efficiently and uniformly dispersed on the Ni matrix 33. It can be eutectoid.

In the first embodiment, the case where the shielding plate 12 having a diameter smaller than the inner diameter of the hollow portion 3 is attached to the upper end portion of the cylindrical electrode 4 has been described. Is also good. By increasing the diameter of the shielding plate 12, the upper end of the annular passage 8 can be completely closed by the shielding plate 12. Further, the shielding plate 12 need not be disposed at the upper end of the cylindrical electrode 4.

In the first to fourth embodiments, the case where the composite plating film 34 is applied to the cylinder block 2 for an internal combustion engine as a work has been described. The same effect can be obtained by applying to a work having a hollow part. In the first to fourth embodiments, the Ni / SiC composite plating 5 including the SiC particles 32 is used as the ceramic particles. However, the composite including ceramic particles other than the SiC particles 32 is used. A plating solution may be used. In the first to fourth embodiments, the case where the cylindrical electrode is closed with the lid is described, but the bottom of the cylindrical electrode may be closed as a bottomed cylindrical electrode. At this time, the composite plating solution is supplied from the side opposite to the bottom.

[0036]

According to the present invention, the following effects are exhibited by the above configuration. According to a first aspect of the present invention, a cylindrical electrode is arranged in the hollow portion of the work with a gap therebetween, and a plurality of through holes are provided in a peripheral wall of the cylindrical electrode. Therefore, the composite plating solution can be injected from the plurality of through holes to the outside of the cylindrical electrode, and the injected composite plating solution can collide with the inner surface of the hollow portion. As a result, the composite plating solution is in a turbulent state, and the ceramic particles in the composite plating solution are uniformly dispersed, so that the ceramic particles are uniformly eutectoid in the metal matrix of the composite plating film. Therefore, the wear resistance of the composite plating film can be uniformly increased.

According to the second aspect of the present invention, since the composite plating solution is supplied to the bottomed or covered cylindrical electrode, the flow of the composite plating solution is blocked at the bottom or the lid. Accordingly, the composite plating solution pressure on the bottom or the lid side increases, so that the composite plating solution pressure increases on the downstream small-diameter through-hole, and the composite plating solution pressure decreases on the upstream large-diameter through-hole. Therefore, a fixed amount of the composite plating solution can be sprayed from all the through holes. Therefore, since the ceramic particles can be uniformly applied to the hollow portion of the work, the ceramic particles can be co-deposited uniformly with the metal phase.

According to the third aspect, since the composite plating solution can be jetted from the peripheral wall at equal intervals, the ceramic particles can be uniformly applied to the hollow portion of the work. Therefore, the ceramic particles can be uniformly eutectoid with the metal phase.

According to the fourth aspect, the through holes can be densely arranged in the circumferential direction as compared with the case where a plurality of through holes are arranged in a grid. Therefore, since the ceramic particles can be applied to the hollow portion of the work in a dense state, the ceramic particles can be eutectoid to the metal phase in a dense state.

According to the fifth aspect, since the composite plating solution can be sprayed outward while diffusing from the plurality of through holes, the composite plating solution can be widely applied to the hollow portion of the work. Therefore, the ceramic particles in the composite plating solution sprayed from the plurality of through holes can be efficiently and uniformly dispersed, and the dispersed ceramic particles can be co-deposited with the metal phase.

[Brief description of the drawings]

FIG. 1 is an overall view showing a composite plating apparatus (first embodiment) according to the present invention.

FIG. 2 is a sectional view of a cylindrical electrode (first embodiment) according to the present invention.

FIG. 3 is a diagram illustrating a first operation of the composite plating apparatus (first embodiment) according to the present invention.

FIG. 4 is a diagram illustrating a first operation of the composite plating apparatus (first embodiment) according to the present invention.

FIG. 5 is a glass showing data of a composite plating apparatus according to the present invention (first embodiment) and data of a comparative example.

FIG. 6 is a cross-sectional view showing a cylindrical electrode (second embodiment) according to the present invention.

FIG. 7 is a diagram illustrating the operation of a cylindrical electrode (second embodiment) according to the present invention.

FIG. 8 is a sectional view showing a cylindrical electrode (third embodiment) according to the present invention.

FIG. 9 is a sectional view showing a cylindrical electrode (fourth embodiment) according to the present invention.

FIG. 10 is a diagram illustrating the operation of a cylindrical electrode according to the present invention (fourth embodiment).

FIG. 11 is an explanatory view of a conventional Ni / SiC composite plating process.

FIG. 12 is an enlarged view of part 12 of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Composite plating apparatus, 2 ... Work (cylinder block), 3 ... Hollow part, 4, 40, 45, 50 ... Cylindrical electrode,
5: Composite plating solution, 6: Plating solution circulation mechanism, 7: Electric conduction mechanism, 8: Annular passage, 10: Cylinder inner surface, 25, 46,
51 ... peripheral wall, 26, 41, 47, 52 ... through-hole, 27,
42: lid, 32: ceramic particles (SiC particles),
S ₁ ... gap.

Claims (5)

[Claims] A cylindrical electrode having a bottom or a lid and having a plurality of through-holes in a peripheral wall opposed to an inner surface of the hollow portion, the cylindrical electrode being arranged with a gap in the hollow portion of a work having the hollow portion;
A plating solution circulation mechanism for supplying a composite plating solution in which ceramic particles are mixed with a plating solution to the inside of the cylindrical electrode, injecting the composite plating solution through through holes in the peripheral wall, and collecting the plating solution from the outside of the cylindrical electrode; A composite plating apparatus consisting of a current supply mechanism for supplying power to the electrodes. 2. The composite plating apparatus according to claim 1, wherein the plurality of through holes have a larger diameter on the upstream side and a smaller diameter on the downstream side along the flow inside the cylindrical electrode. . 3. The composite plating apparatus according to claim 1, wherein the plurality of through holes are arranged in a grid on a peripheral wall of the cylindrical electrode. 4. The composite plating apparatus according to claim 1, wherein the plurality of through holes are arranged in a zigzag pattern on a peripheral wall of the cylindrical electrode. 5. The composite plating apparatus according to claim 1, wherein the plurality of through holes are tapered holes having a small diameter inside the cylindrical electrode and a large diameter outside the cylindrical electrode.