JPH0853798A - Masking method for plating cylinder and device therefor - Google Patents

Abstract

PURPOSE:To surely mask a surface having ruggedness to be masked at a cylinder end. CONSTITUTION:A masking body 16 consists of a material having flexibility and is constituted by forming a hollow part 17 and supplying and discharging an expanding medium into and from this hollow part 17 by supplying the medium thereto from an expanding medium supply pipe 20. The hollow part 17 is internally emptied to reduce the masking body 16 and the masking body 16 is passed through a narrow part of a journal part 10 by a cylinder 23 and is lowered down to the prescribed position of the cylinder 1 in a first stage. The expanding medium is then supplied into the hollow part 17 from the expanding medium supply pipe 20 to expand the masking body 16. The mask surface 19 of the masking body 16 is deformed in compliance with the rugged surface of the surface 11 to be masked of the cylinder 1 by expansion of this mask body 16. The mask surface 19 is brought into pressurized contact with the surface 11 to be masked of the cylinder 1 by the internal pressure of the hollow part 17, by which the surface 11 having the ruggedness to be masked is surely masked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for masking the open end of a cylinder when plating the inner peripheral surface of the cylinder.

[0002]

2. Description of the Related Art The inner peripheral surface of an engine cylinder is electroplated to improve its wear resistance. An outline of the typical plating method will be described with reference to FIG.
Mask bodies 4 and 5 are respectively provided on the head side 2 and the crankcase side 3 of the cylinder 1, a cylindrical electrode 6 is inserted inside the cylinder 1, and a voltage is applied between the electrode 6 and the cylinder 1 by a power supply 7. Apply. In this manner, the plating liquid in the tank 8 is supplied into the cylinder 1 by the pump 9 while the voltage is applied between the electrode 6 and the cylinder 1, and the tank 8 is again supplied to the tank 8 through the inside of the cylindrical electrode 6. Return the plating solution.

While the plating solution is being circulated in this way, a predetermined plating layer is formed on the inner peripheral surface of the cylinder 1. At the time of plating the inner peripheral surface of the cylinder 1, the openings on the head side 2 and the crankcase 3 side of the cylinder 1 are provided to prevent the plating solution from splashing outside and adhering to the external equipment. Is fitted with mask bodies 4 and 5. The head side 2 of the cylinder 1 also prevents the plating liquid from adhering to the sealing surface of the head side 2 in order to maintain the sealing property with the head (not shown).

The opening on the head side 2 of the cylinder 1 is a machined flat surface in order to maintain the sealing property with the cylinder head, but the crankcase side 3 is a crankcase (not shown). ), The open end has a complicated shape. The shape of the open end of the crankcase side 3 will be described with reference to FIGS. 20 and 21. That is, the journal portion 10 for receiving the crankshaft is provided on the crankcase 3 side as shown in FIG.
As shown in FIG. 21, which is provided so as to cross a part of the cylinder 1 as shown in FIG. 20 and which is a longitudinal sectional view taken along line AA of FIG. The portion that intersects with is projected from the mask surface 11. Then, as shown in FIG. 20, (a) of the mask surface 11
The width of the part is narrowed.

Further, the mask surface on the crankcase side 3
11 is a casting surface that has not been machined (as-cast surface), and the chip removing portion 12 is recessed from the mask surface 11
And the counterweight relief groove 13 is formed,
The mask surface 11 is not necessarily a flat surface like the head side 2. A masking method for the head side 2 is disclosed, for example, in JP-A-1-136990.
The present invention will be described below for the masking of the crankcase side 3 which is difficult to mask.

FIG. 22 is a view showing the masking device prototyped previously, which uses a cup-shaped mask body 5 made of deformable silicon rubber which is an electrically insulating material. When the is mounted on the mask surface 11 of the cylinder 1, the mask body 5 is deformed and fitted into the mask surface 11 using a specially prepared tool in order to pass the journal portion 10 protruding from the mask surface 11. After that, the mask body 5 is restored to its original shape by using a special tool, and the mask body 5 is pressed to mask the mask surface 11.

[0007]

Since the mask body used is a cup-shaped body formed according to the diameter of the cylinder and the size of the mask surface, there are the following problems.
First of all, the first problem is that the opening of the cylinder on the crankcase side is provided with a chip removing part and a counterweight relief groove, the mask surface at the cylinder opening end is not flat, and it is an as-cast surface. Therefore, there is a problem that the mask surface of the cup-shaped mask body cannot be completely sealed by deforming along the irregularities of the chip removing portion and the counterweight escape groove.

Further, in order to deform the mask surface of the mask body along the uneven surface, it is necessary to increase the force for pressing the mask body. As shown in FIG. The width of surface 11 is extremely narrow,
If the pressing force of the mask body 5 is too large, the mask body 5 will come off the mask surface 11 and fall into the cylinder 1, so that a large pressing force that the mask surface of the mask body is deformed along the uneven surface is masked. The reality is that you cannot put it on your body 5.

As described above, when the inner peripheral surface of the cylinder is plated with the mask at the cylinder opening incomplete,
As shown in 15, a raised portion 15 is formed at the end of the plated layer 14. When the raised portion 15 is formed in this way, the cylinder 1
When assembling the piston in the (plated layer 14), it becomes difficult to assemble the piston into the cylinder, and even if the piston is assembled, this bulge 15 will peel off and the secondary It also causes problems.

In view of the assembling property of the piston and a secondary problem in the prior art, therefore, the raised portion 15 is scraped off to form the ideal surface S, so that an extra machining process called scraping is performed. It becomes necessary and there is a problem in productivity. In addition, at the time of this scraping, the plating layer 14
There is a possibility of peeling off, and once the plating layer 14 peels off, the engine as a whole becomes a defective product. Therefore, there is a problem that the shaving process of the raised portion 15 requires careful and time consuming. Also, if the plating range is set slightly below the masking, this problem will be solved, but in order to obtain the prescribed output as the engine, the height of the cylinder must be increased correspondingly, and as a result, the engine itself. It is not a good idea in terms of automobile performance due to the increase in size and weight.

The present invention provides a cylinder plating masking method and apparatus for reliably masking the mask surface of a cylinder.

[0012]

A method according to the present invention for solving the above-mentioned problems is to form a mold in which a mask surface of a cylinder end portion to be masked is made, and a mask body is formed by using this mold. Aligning the mask surface of this mask body with the mask surface of the cylinder, the mask body is placed on the mask surface of the cylinder,
It is characterized in that the mask body is pressed by the pressing means to press the mask surface of the cylinder and the mask surface of the mask body together.

As another method, pressure is applied to the hollow portion of the expandable and deformable mask body formed of a flexible material so that the mask surface of the mask body is deformed following the mask surface at the cylinder end. The mask surface of the cylinder end and the mask surface of the mask body are brought into close contact with each other.

As another method, the mask surface of the mask body is made to follow the mask surface of the cylinder end by the deformation of the temperature-dependent member provided on the mask surface portion of the deformable mask body formed of a flexible material. Is deformed to bring the mask surface of the cylinder end into close contact with the mask surface of the mask body.

As an apparatus for carrying out the above method, a mask body in which the mask surface of the mask body made of a flexible material is formed on the mask surface similar to the mask surface of the cylinder, and the mask body on the side opposite to the mask surface of the mask body It is characterized by comprising a wedge having an inclined portion fixed to the surface and a means for pressing the inclined portion of the wedge.

As another device, a mask body made of a flexible material having a hollow portion, which is expandable / contractible and deformable, and forms a mask surface to be brought into close contact with the mask surface of the cylinder in the expanded and deformed state, Means for supplying and discharging an expansion medium to and from the hollow portion of the mask body to expand and contract the deformation of the mask body.

As still another device, a temperature-dependent deformable member is provided on the mask surface portion of a mask body made of a flexible material, and the temperature-dependent deformable member follows the contractive deformation of the mask body and the mask surface of the cylinder. The mask surface of the mask body is stored so that the mask surface can be deformed by at least two kinds of temperature dependence.

The mask body used in each of the above devices is characterized by being formed of a conductive member.

[0019]

Since the present invention is constructed as described above, it has the following effects. That is, a mask body having a mask surface similar to the concave-convex surface of the mask surface of the cylinder is obtained by molding the mask body using a mold obtained by molding the mask surface of the cylinder end portion to be masked. Then, by placing the mask body on the mask surface of the cylinder so that the mask surface of the mask body is aligned with the mask surface of the cylinder end portion, the mask surface of the uneven cylinder end portion and the mask surface of the mask body adhere to each other. To do. Then, the mask body is pressed by the pressing means to press-fit the mask surface of the cylinder end portion and the mask surface of the mask body.

Further, by deforming the mask surface of the mask body along the mask surface of the cylinder end portion by the internal pressure of the hollow portion of the mask body which is formed of a flexible material and is expandable and deformable, the mask surface of the cylinder end portion is deformed. And the mask surface of the mask body. Then, the inner pressure of the hollow portion is adjusted, and the mask surface of the cylinder end portion and the mask surface of the mask body are pressure-bonded to each other using the elastic force of the mask body.

Further, by deforming the temperature-dependent member provided on the mask surface portion of the deformable mask body formed of a flexible material, the mask surface of the mask body is deformed following the mask surface at the cylinder end. The mask surface of the mask body is brought into close contact with the mask surface of the cylinder end portion, and the mask surface of the cylinder end portion and the mask surface of the mask body are pressure bonded using the elastic force of the mask body.

Then, a mask body made of a flexible material in which the mask surface of the mask body is similar to the mask surface of the actual cylinder is placed on the mask surface of the cylinder,
By pressing the inclined portion of the wedge fixed to the surface opposite to the mask surface of the mask body by the pressing means, the pressing force in the direction of the center line of the cylinder and the force in the direction orthogonal thereto are exerted on the mask body. The flexible mask body is masked while being pressed in the orthogonal force direction.

Further, the expansion medium is discharged from the hollow portion of the mask body which is provided with a hollow portion and is expandable / contractible and which forms a mask surface in the expanded state, so as to shrink the mask body, The body is positioned on the mask surface of the cylinder, and then the mask body is expanded by supplying an expansion medium to the hollow portion, and the expansion of the mask body causes the mask surface of the mask body to follow the mask surface of the cylinder end. Transformed,
The mask surface of the mask body is pressure bonded to the mask surface of the cylinder.

As still another device, the temperature-dependent deformable member provided on the mask surface portion of the mask body made of a flexible material is deformed to contract and deform the mask body, and the mask body is used as the mask surface of the cylinder. Then, the temperature-dependent deformable member is deformed to deform the mask surface of the mask body along the mask surface at the cylinder end, and the mask surface of the mask body is brought into close contact with the mask surface at the cylinder end.

By using a conductive member as the material of the mask body used in each of the above-mentioned devices, a local flow between the mask surface of the mask body and the mask surface of the cylinder end, which are pressure-bonded to each other, flows locally. Prevents the flow of large currents and reduces plating swell.

[0026]

EXAMPLE An example of the present invention will be described below. In FIG. 1, the mask body 16 is a hollow body in which a hollow portion 17 is formed, and a side surface seal portion 18 and a mask surface seal portion 19 are formed. And the mask body 16 composed of this hollow body
The thickness of the is not constant, the thickness of the portion that needs to be deformed is thin, and the thickness of other portions is large. For example, from the expansion medium supply pipe 20 to the hollow portion 17 the expansion medium (for example, air,
When the mask body 16 expands by supplying (water, oil, etc.), the mask body 16 is quickly expanded and inserted into the lower space portion 21 of the journal portion 10. The thickness of the bottom portion (b) is increased, and the side portion (e) and the mask surface seal portion (c) are reduced.

Further, the wall thickness of the mask surface seal portion (c) is made thinner than that of the side portion (e) so that it can be deformed along the uneven surface of the mask surface 11 of the cylinder 1. Further, since the side seal portion (d) expands in the diametrical direction due to the entire expansion of the mask body 16, the thickness of the side seal portion (d) is made smaller than that of the shoulder portion (a) and the bottom portion (b), so that the mask body 16 can be quickly expanded. Expansion, and
In order to effectively expand the mask surface sealing portion 19, the thickness is made thicker than the mask surface sealing portion 19. In this way, the mask body 16 can be efficiently expanded quickly and deformed along the uneven surface of the masking surface 11 after the expansion.
I try to change the wall thickness of.

Further, as the material of the mask body 16, a material such as rubber such as silicone rubber or fluororubber or resin such as flexible nylon which is mixed with aluminum or copper powder or carbon fiber is used. Then, adjust the amount of aluminum or copper powder or carbon fiber mixed according to the plating conditions,
The conductivity (electrical resistance value) of the mask body 16 is adjusted.

That is, as shown in FIG. 18, when the mask body 16 is made of a non-conductive material, the mask body 16 and the mask surface 11
The current concentrates on the contact portion between and, and a bumpy plating layer 22 is formed on the plating layer 14. On the other hand, when the conductive mask body 16 is used, it is possible to prevent the electric current from concentrating on the contact portion between the mask body 16 and the mask surface 11, and as shown in FIG. A thin plating layer 14 'can also be formed on the back surface of the body 16. The thin plating layer 14 'can have an ideal shape by adjusting the amount of current by adjusting the conductivity of the mask body 16.

By utilizing this principle, the conductivity of the mask body 16 is adjusted so that the bumpy plating layer 22 as shown in FIG. 16 is not formed and a plating layer close to the ideal surface S is formed. can do. Further, when the mask body 16 made of a non-conductive material is used, since the hump-shaped plating layer 22 is formed, the plating layer 22 is caught when the piston is inserted and the assembling property of the piston is impaired. The plating layer 22 must be removed, but the mask body 16 is made to have conductivity, and the conductivity (electrical resistance value) is changed to form the ideal surface S, thereby omitting the above machining. Will be able to.

Next, a masking method using the mask body 16 will be described. As shown in FIG. 1, in the initial state of being suspended by the cylinder 23, the hollow portion 17 of the mask body 16 is not filled with the expansion medium. Therefore,
The mask body 16 is in a contracted state, and with the center of the mask body 16 and the center of the cylinder 1 aligned, the rod of the cylinder 23 is extended to prevent the mask body 16 from interfering with the journal portion 10. The mask body 16 can be inserted into the cylinder 1. And the mask body 16 is the cylinder 1
When the predetermined position is reached, the extension of the rod of the cylinder 23 is stopped.

In this state, next, as shown in FIG. 2, the expansion medium is supplied from the expansion medium supply pipe 20 into the hollow portion 17 so that the outer periphery of the mask body 16 is lightly pressed against the inner peripheral surface of the cylinder 1. The pressure in the hollow portion 17 is controlled to expand the mask body 16.
Then, the rod of the cylinder 23 is retracted to move the mask body.
By raising 16 by a height H, the constraint by the inner wall of the cylinder 1 is released and the outer periphery of the mask body 16 is repelled to form a predetermined shape, and as shown in FIG. The outer periphery of the mask body 16 can be fitted into the portion 21.

As described above, the mask body 16 is expanded, and the expanded mask body 16 is expanded into the space of the journal portion 10.
The reason why the mask body 16 can be fitted in is that the wall thickness of the mask body 16 is set and changed so that the mask body 16 expands in a constant shape. In this way, the mask body 16
Is inserted into the cylinder 1 and the outer periphery of the mask body 16 is pressed against the inner peripheral surface of the cylinder 1, and then the mask body 16 is pulled up to fit the outer periphery of the mask body 16 into the space portion 21 of the journal portion 10. Flexible mask body that expands and contracts
Positioning of the 16 cylinders 1 can be easily set, and the control can be simplified.

Next, the outer periphery of the mask body 16 is the journal portion 10.
In the state of being fitted in the space portion (21), the retraction of the rod of the cylinder (23) is stopped and the state is maintained. In this way, the cylinder 23 maintains a state in which the upward escape of the mask body 16 is restricted, the expansion medium is supplied from the expansion medium supply pipe 20 into the hollow portion 17, and the pressure inside the hollow portion 17 is controlled. As a result, the mask surface sealing portion 19 of the mask body 16 having a reduced thickness
However, it can be deformed and adhered closely following the uneven surface of the mask surface 11 of the cylinder 1. In this way, the mask face seal part
Since 19 is deformed by the pressure in the hollow portion 17, there is no directivity with respect to the uneven surface of the mask surface 11 of the cylinder 1, and the mountability of the mask body 16 on the mask surface 11 of the cylinder 1 is simplified. Then, the pressure inside the hollow portion 17 is controlled, and the pressure inside the hollow portion 17 is maintained at a predetermined pressure at which the thin mask surface seal portion 19 is pressed against the uneven surface of the mask surface 11.
The inner peripheral surface of the cylinder 1 is electroplated.

In this electroplating, since the mask body 16 is made of a conductive material, current does not concentrate between the mask body 16 and the mask surface 11 of the cylinder 1, and the ideal surface S as shown in FIG. It is possible to eliminate unnecessary plating layer shaving due to mechanical processing, improve piston assemblability, and eliminate secondary problems caused by peeling of the plating layer. Is improved. Next, the mask body 16 is contracted by discharging the expansion medium in the hollow portion 17 from the expansion medium supply pipe 20 after the completion of plating, whereby the outer periphery of the mask body 16 is pulled out from the space portion 21 of the journal portion 10, By retracting the rod of the cylinder 23 and pulling up the mask body 16, the mask body 16 can be returned to the original position in FIG. 1 without interfering with the journal portion 10.

As described above, since the mask body 16 is simply moved up and down with the mask body 16 suspended from the rod of the cylinder 23, a large number of adjacent cylinders 1 are provided.
The mask bodies 16 can be simultaneously masked without interfering with each other, and a large number of masks can be masked in a short time. The cylinder 23 moves the mask body 16 up and down, and the pressure in the hollow portion 17 is controlled by supplying and discharging the expansion medium from the expansion medium supply pipe 20. Since the mask body 16 can be controlled, the control itself is simple, and since the mask body 16 is masked by the expansion and deformation of the mask body 16, the size and type of the cylinder 1 are slightly changed. Also, the same mask body 16 can be used, and it is possible to mask a plurality of types of cylinders 1 at the same time, improve the plating efficiency of the cylinders, and reduce the cost. Also, the plating process of the cylinder 1 can be automatically controlled. Furthermore, since the mask surface sealing portion 19 of the mask body 16 is pressed against the mask surface 11 of the cylinder 1 by the internal pressure of the hollow portion 17, the cylinder 1
Even if the width of the mask surface 11 is narrow, the mask body 16 does not come off from the mask surface 11.

In the masking step, the mask body
16 is once inserted into the cylinder 1 and the outer periphery of the mask body 16 is pressed against the inner peripheral surface of the cylinder 1, and then the mask body 16 is pulled up to fit the outer periphery of the mask body 16 into the space portion 21 of the journal portion 10. However, without inserting the mask body 16 into the cylinder 1, when the mask body 16 expands, the outer periphery of the mask body 16 descends to a position where it is fitted into the space portion 21 of the journal portion 10, 16 may be inflated.
As a result, the step of raising the mask body 16 (raising the height H in FIG. 2) is omitted, and masking can be performed in a shorter time.

Next, another embodiment will be described. FIG.
Unlike the mask body 16 shown in FIG. 1, the mask body 16 shown in FIG. 1 is solid without a hollow portion 17, and the outer peripheral portion of the mask body 16 has a temperature-dependent deformable member having an L-shaped cross section ( Memory alloy) 24 is buried. Thus, the temperature-dependent deformable member 24 has an L-shaped cross section because the mask body 16
The mask 25 is effectively deformed in the direction of the outer circumference 25 and the mask surface 26. Also, the temperature-dependent deformation member
A space hole 27 for circulating a temperature adjusting medium for adjusting the temperature of the temperature-dependent deformable member 24 is provided at a position close to 24, and an expansion medium supply pipe 20 (not shown) is provided in the space hole 27. It is connected.

As shown in FIG. 8, the temperature-dependent deformable member 24 is embedded in the outer peripheral portion of the mask body 16 in a state of being divided into short arcs (four divisions in this embodiment). In addition, the ring-shaped temperature-dependent deformation member is not divided in this way.
24 may be embedded in the outer periphery of the mask body 16. In this embodiment, the temperature-dependent deformable member 24 is embedded in the outer peripheral portion of the mask body 16, but the present invention is not limited to this. In short, the mask surface of the mask body 16 is the mask surface of the cylinder 1. The temperature-dependent deformable member 24 may be exposed from the mask body 16 as long as it directly contacts and deforms the member 11. Similarly, as the material of the mask body 16, a material obtained by mixing powder of aluminum or copper or carbon fiber into rubber such as silicone rubber or fluororubber or resin such as flexible nylon is used.
Then, the conductivity of the mask body 16 is adjusted by adjusting the mixing amount of aluminum or copper powder or carbon fiber according to the plating condition.

The temperature-dependent deformable member 24 embedded in the outer periphery of the mask body 16 is memorized so as to be deformed into a shape as shown in FIG. 8 when the mask body 16 is not mounted on the cylinder 1 (at normal temperature). The amount of deformation is such that the outer diameter D of the mask body 16 is smaller than the width W of the journal portion 10 shown in FIG. 7 as shown in FIG. Then, when the mask body 16 is mounted on the cylinder 1 and reaches a predetermined temperature (for example, a plating temperature of about 60 ° C.), the temperature-dependent deformable member 24 is deformed into a circular shape as shown in FIG. The mask surface 26 side of the body 16 is stored so as to be deformed following the uneven surface of the mask surface 11 of the cylinder 1. Further, as shown in FIG. 7, when the mask body 16 is not attached to the cylinder 1, the temperature-dependent deformable member 24 is deformed as shown in FIG.
The jig 34 keeps a constant temperature so that the state shown in FIG.

Next, a masking method using the mask body 16 will be described. First, the mask body 16 is the cylinder 1
In a normal temperature state (FIG. 7) not attached to the mask body 16, the temperature-dependent deformable member 24 is deformed as shown in FIG. 8, and the outer diameter D of the mask body 16 becomes narrower than the width W of the journal portion 10. ing. As a result, the rod of the cylinder 23 can be extended and the mask body 16 can be lowered to the position of the mask surface 11 of the cylinder 1 without interfering with the journal portion 10. In the case where the temperature-dependent member 24 is a ring-shaped member which is not divided, it is also deformed into an elliptical shape having a shorter diameter than the width W of the journal portion 10 so that it does not interfere with the journal portion 10 as well. Then, the mask body 16 can be lowered.

Next, for example, hot water is passed from the expansion medium supply pipe 20 (not shown) through the space hole 27 to raise the temperature of the temperature-dependent deformable member 24 to a predetermined temperature. As shown in FIG. 3, the mask body 16 is deformed into an arc shape in a short time to deform the outer periphery of the mask body 16 into a predetermined circular shape, and the outer periphery is inserted into the space portion 21 of the journal portion 10. Is deformed following the uneven surface of the mask surface 11 of the cylinder 1. Then, next, by extending the rod of the cylinder 23 and pressing the mask body 16,
The 16 mask surfaces 26 can be pressed against the mask surface 11 of the cylinder 1 for a complete seal. Thereby, the plating can be performed without forming the raised portion 15 as shown in FIG. In addition, the temperature-dependent deformation member 24 is shown in FIG.
As shown in FIG. 4, the temperature for maintaining the arc shape is set to a temperature close to the plating temperature and stored so that even if the plating liquid comes into contact with the mask body 16, the mask body 16 is kept in the plating state during plating. It is possible to reliably maintain the adhesiveness between the mask surface 26 of the cylinder 1 and the mask surface 11 of the cylinder 1.

Next, when the plating is completed, the temperature-dependent member 24 is cooled by flowing cold water, for example, from the expansion medium supply pipe 20 (not shown) to the space hole 27, and as shown in FIG. Can be deformed in a short time. As a result, the outer diameter of the mask body 16 is reduced to D and is removed from the journal portion 10, and the mask body 16 is returned to the original position shown in FIG. 7 by the cylinder 23 so as not to interfere with the journal portion 10.
Can be raised.

Further, the temperature-dependent deformation member 24 is attached to the mask body 16
If it is exposed without being embedded in the
Instead of adjusting the temperature of the temperature-dependent deformable member 24, the temperature-dependent deformable member 24 may be deformed into an arc shape as shown in FIG. 9 using the heat of the circulating plating solution. . When the temperature of the temperature-dependent member 24 is raised by using the heat of the plating solution as described above, only the vertical movement of the mask body 16 by the cylinder 23 is required, so that the control is extremely simple.
In the case of this embodiment as well, similar to the above-mentioned embodiment, the masking of a large number of adjacent cylinders 1 can be performed without interfering with each other, and by forming the mask body 16 with a conductive material, the cylinder 1 The ideal surface S can be formed on the inner peripheral surface.

Next, in the embodiment shown in FIG. 5, the temperature-dependent deformation member 24 is embedded in the outer peripheral portion of the mask body 16 in which the hollow portion 17 is formed. This embodiment is similar to the embodiment shown in FIG.
It has both functions of the embodiment shown in FIG. That is, the expansion medium is supplied from the expansion medium supply pipe 20 into the space 17 so that the mask body 16 is expanded, and the temperature-dependent deformable member 24 is expanded by the heat of the expansion medium supplied to the space 17. The temperature rises and the temperature-dependent deformation member 24
Is deformed according to the irregularities of the mask surface 11 of the cylinder 1.

In this case, the temperature is set close to the temperature of the plating solution so that the temperature-dependent deformable member can be used during plating.
The deformation of 24 is maintained in a stable state, and the adhesion between the mask surface 26 of the mask body 16 and the mask surface 11 of the cylinder 1 is maintained. The temperature-dependent deformation member 24 is stored so as to be deformed following the uneven surface of the mask surface 11 of the cylinder 1 when the temperature-dependent deformation member 24 is at a predetermined temperature. Further, as shown in FIG. 9, the temperature-dependent deformable member 24 is divided into arcuate shapes having a radius of curvature when the mask body 16 expands into a predetermined shape.

Similarly, the thickness of the mask body 16 is not constant, and the thickness of the portion that needs to be deformed is thin and the thickness of the other portions is large. However, in the case of this embodiment, unlike the embodiment shown in FIG. 1, the mask surface 26 of the mask body 16 is
Is the mask surface of the cylinder 1 by the temperature-dependent deformation member 24.
The mask surface 26 may be thickened because it is forcibly deformed along the uneven surface of 11.

The material of the mask body 16 is the same as in the embodiment shown in FIGS. 1 and 4, rubber such as silicone rubber and fluororubber, or resin such as flexible nylon such as aluminum or copper powder or carbon. Use a mixture of fibers. Then, the conductivity (electrical resistance value) of the mask body 16 is adjusted by adjusting the mixing amount of aluminum or copper powder or carbon fiber according to the plating condition.

Next, a masking method using the mask body 16 will be described. Since the mask body 16 has a hollow portion 17 and has a predetermined wall thickness, and the temperature-dependent deformable member 24 is further divided, the cylinder 23 is similar to the embodiment shown in FIG. In the first state suspended by, the hollow portion 17 of the mask body 16 is not filled with the expansion medium, and the mask body 16 is in a contracted state, and the center of the mask body 16 and the center of the cylinder 1 are In the aligned state, the rod of the cylinder 23 is extended so that the mask body 16 does not interfere with the journal portion 10, and the mask body 16 is moved to the cylinder 1
It is possible to insert it inside. Then, when the mask body 16 reaches a predetermined position of the cylinder 1, the extension of the rod of the cylinder 23 is stopped.

In this state, next, as shown in FIG. 2, the expansion medium is supplied from the expansion medium supply pipe 20 into the hollow portion 17 so that the outer periphery of the mask body 16 is lightly pressed against the inner peripheral surface of the cylinder 1. The pressure in the hollow portion 17 is controlled to expand the mask body 16.
At this stage, the temperature-dependent deformable member 24 starts to be heated by the expansion medium. Then, the rod of the cylinder 23 is retracted and the mask body 16 is pulled up by a height H, so that the restraint by the inner wall of the cylinder 1 is released and the outer periphery of the mask body 16 is repelled into a predetermined shape. As shown in FIG. 6, the mask body 16 is provided in the space 21 of the journal 10.
It is possible to fit the outer periphery of the. Even during this period, the temperature-dependent deformable member 24 is heated by the expansion medium.

In this way, the mask body 16 is expanded, and the expanded mask body 16 is moved to the space portion of the journal portion 10.
As with the embodiment shown in FIG. 1, the thickness of the mask body 16 can be set to 21 so that the mask body 16 expands in a constant shape. Because it is changing. Further, after the mask body 16 is once inserted into the cylinder 1 and the outer periphery of the mask body 16 is pressed against the inner peripheral surface of the cylinder 1, the mask body 16 is pulled up and the outer periphery of the mask body 16 is provided with the space 21 of the journal portion 10. Figure 1
Similar to the embodiment shown in FIG. 6, the setting of the position of the flexible mask body 16 that expands and contracts with respect to the cylinder 1 is facilitated, and the control thereof can be simplified.

Then, with the outer periphery of the mask body 16 fitted in the space portion 21 of the journal portion 10, the backward movement of the rod of the cylinder 23 is stopped and the state is maintained. Next, maintaining the state in which the upward escape of the mask body 16 is restricted by the cylinder 23, the expansion medium is supplied from the expansion medium supply pipe 20 into the hollow portion 17, and the pressure inside the hollow portion 17 is controlled. Due to
The temperature-dependent deformable member 24 is heated to a predetermined temperature and deformed, and the mask surface 26 of the mask body 16 becomes the mask surface of the cylinder 1.
It can be deformed following the uneven surface of 11. And
By controlling the pressure in the hollow portion 17, the mask surface 26 is changed to the mask surface 11
The hollow part where a predetermined pressure is reached, which makes close contact with the uneven surface of
The pressure inside 17 is maintained, and the inner peripheral surface of the cylinder 1 is electroplated. In this way, the cylinder 1 is driven by the internal pressure of the hollow portion 17.
Since the mask surface 26 of the mask body 16 is pressed against the mask surface 11 of the cylinder body 16, even if the width of the mask surface 11 of the cylinder 1 is narrow, the mask body 16 does not come off from the mask surface 11 of the cylinder 1.

In this electroplating, since the mask body 16 is made of a conductive material, current does not concentrate between the mask body 16 and the mask surface 11 of the cylinder 1, and the ideal surface S as shown in FIG. It is possible to eliminate the unnecessary scraping of the plating layer by machining, improve the assemblability of the piston, and eliminate the secondary problem caused by the peeling of the plating layer. Next, after the plating is completed, the mask medium 16 is reduced by discharging the expansion medium in the hollow portion 17 from the expansion medium supply pipe 20, and even if the deformation of the temperature-dependent deformable member 24 remains as it is, the mask The outer periphery of the body 16 can be pulled out from the space portion 21 of the journal portion 10, and then the rod of the cylinder 23 is retracted to pull up the mask body 16 so that the mask body 16 is shown in FIG. 1 without interfering with the journal portion 10. It can be returned to its original position as shown. In this way, since the mask body 16 can be pulled up while the deformation of the temperature-dependent deformable member 24 is maintained, it is not necessary to wait for the temperature-dependent deformable member 24 to cool down and return to its original shape. The mask body 16 can be pulled up in a short time.

Also in this embodiment, the cylinder 23
With the mask body 16 suspended from the rod of
Since it is simply moved up and down, when masking a large number of adjacent cylinders 1, the mask bodies 16 can be simultaneously performed without interfering with each other, and a large number of masking can be performed in a short time. Becomes Also,
Since the mask body 16 is moved up and down by the cylinder 23 and the pressure in the hollow portion 17 is controlled by supplying and discharging the expansion medium from the expansion medium supply pipe 20, each mask body 16 can be controlled and its control can be performed. It can be simplified.

Also in this embodiment, in the masking step, the mask body 16 is once inserted into the cylinder 1 and the outer periphery of the mask body 16 is pressed against the inner peripheral surface of the cylinder 1, and then the mask body 16 is removed. Although the outer periphery of the mask body 16 is fitted into the space portion 21 of the journal portion 10 by pulling up, the mask body 16 is not inserted into the cylinder 1 and the mask body 16 is not inserted.
Is expanded, the outer periphery of the mask body 16 descends to a position where it is fitted into the space portion 21 of the journal portion 10, and the mask body 16
May be inflated. This allows the mask body 16
The step of raising (the height of H in FIG. 2) is omitted, and masking can be performed in a shorter time.

In the embodiment shown in FIG. 5 described above, the temperature-dependent deformable member 24 is stored only in a shape similar to the uneven surface of the mask surface 11 of the cylinder 1. However, as shown in FIG. 8 and FIG. In addition, even if the outer shape of the mask body 16 is deformed and stored together, the masking can be performed by the same method as the above masking method.

Next, as another embodiment, an embodiment will be described in which the temperature-dependent deformation member 24 in FIG. 5 is not divided into an arc shape but is formed into a ring shape. When the temperature-dependent deformable member 24 has a ring shape, the mask body having the hollow portion 17 is formed.
Even if 16 is reduced, the journal section 10 cannot be passed. Therefore, when the ring-shaped temperature-dependent member 24 is used, the outer shape of the mask body 16 becomes an elliptical shape having a shorter diameter than the width W (see FIG. 7) of the journal portion 10 at room temperature. As described above, the temperature-dependent member 24 is stored, and at a predetermined temperature (approximately the temperature of the plating solution), the temperature-dependent member 24 becomes circular and deforms following the irregularities of the mask surface 11 of the cylinder 1. To memorize. The other parts are the same as those of the embodiment shown in FIG. 5, and the description thereof will be omitted.

Next, the ring-shaped temperature-dependent deformable member
A masking method using the mask body 16 using 24 will be described. First, as shown in FIG. 1, when the mask body 16 is suspended above the cylinder 1 by the cylinder 23, the expansion medium of a predetermined temperature (for example, air at room temperature) is filled in the hollow portion 17 of the mask body 16. Are filled, and the temperature-dependent deformable member 24 has an elliptical shape. As described above, the expansion of the temperature-dependent deformable member 24 into the space 17 by deforming the temperature-dependent deformable member 24 into an elliptical shape is different from the division of the temperature-dependent deformable member 24. Then, in a state where the center of the mask body 16 and the center of the cylinder 1 are aligned with each other, the rod of the cylinder 23 is extended to prevent the mask body 16 from interfering with the journal portion 10, and the mask body 16 is placed inside the cylinder 1. When the mask body 16 reaches the predetermined position of the cylinder 1,
The point at which the extension of the rod of 23 is stopped is the temperature-dependent deformation member 24.
Is the same as the one obtained by dividing.

In this state, next, the expansion medium in the hollow portion 17 is replaced with the expansion medium having a predetermined temperature (approximately plating temperature). As a result, as shown in FIG. 6, the temperature-dependent deformable member 24 is heated by the expansion medium to be deformed into a circular shape and a shape similar to the uneven surface of the mask surface 11 of the cylinder 1 and the mask body 16 Is inserted into the space portion 21 of the journal portion 10. When the temperature-dependent deformable member 24 is divided, as shown in FIG. 2, the temperature-dependent deformable member 24 is once inserted into the cylinder 1 and inflated, and then the height H is raised to insert the masking body 16 into the journal portion 10. Can be, but temperature-dependent deformation member
When 24 is ring-shaped, the mask body 16 is deformed into a circular shape with a strong force, and therefore it is different in that it cannot be lifted after being deformed in the cylinder 1. In this way, the mask body 16 is forcibly deformed by the deformation of the temperature-dependent deformable member 24 and inserted into the journal portion 10, so that the mask body 16 can be mounted on the mask surface 11 of the cylinder 1 in a short time. Becomes

As described above, the process after the outer periphery of the mask body 16 is fitted into the space portion 21 of the journal portion 10 is the same as the division of the temperature dependent member 24. That is, stopping the backward movement of the rod of the cylinder 23, restraining the escape of the mask body 16 upward, supply the expansion medium of a predetermined temperature from the expansion medium supply pipe 20 into the hollow portion 17, the pressure in the hollow portion 17 By controlling the temperature of the temperature-dependent deformable member 24, the mask surface 26 of the mask body 16 is pressure-bonded to the uneven surface of the mask surface 11 of the cylinder 1. Then, the pressure inside the hollow portion 17 is controlled so that the mask surface 26 is in close contact with the uneven surface of the mask surface 11.
The pressure inside 17 is maintained, and the inner peripheral surface of the cylinder 1 is electroplated. In this case as well, even if the width of the mask surface 11 of the cylinder 1 is narrow, the mask body 16 does not come off from the mask surface 11.

After the electroplating is completed, the expansion medium inside the hollow portion 17 is replaced with the expansion medium having a predetermined temperature to lower the temperature of the temperature-dependent deformable member 24 and deform it into an elliptical shape. As a result, the mask body 16 is forcibly pulled out from the space portion 21 of the journal portion 10. Next, using the cylinder 23, the mask body 16
Pull up. When the mask body 16 is pulled up, the mask body 16 is deformed into an elliptical shape by the temperature-dependent member 24, so that the mask body 16 can be pulled up without interfering with the journal portion 10.

In this embodiment also, the mask body 16
Since is a conductive material, it is possible to form an ideal surface S as shown in FIG. 16, omit cutting of an excessive plating layer by machining, and improve the assemblability of the piston. Also in this embodiment, since the mask body 16 is simply moved up and down while the mask body 16 is suspended from the rod of the cylinder 23, when masking a large number of adjacent cylinders 1. The mask bodies 16 can be simultaneously performed without interfering with each other, and a large number of masks can be masked in a short time. Further, since the mask body 16 is moved up and down by the cylinder 23, and the pressure in the hollow portion 17 is controlled by supplying and discharging the expansion medium from the expansion medium supply pipe 20, it is possible to control each mask body 16. Its control can be simplified.

Next, still another embodiment will be described with reference to FIG. The mask surface of the mask body 16 in this embodiment
26 is formed into a cup shape by a mold having the same shape as the uneven surface of the mask surface 11 of the cylinder 1 to be actually masked. The material of the mask body 16 is the same as the material of the mask body 16 shown in FIG. That is, rubber, such as silicone rubber or fluororubber, or resin such as flexible nylon, which is mixed with aluminum or copper powder or carbon fiber is used. Similarly, the conductivity of the mask body 16 is adjusted by adjusting the mixing amount of aluminum or copper powder or carbon fiber according to the plating conditions.

An inclined surface 30 is formed at the center of the upper surface of the mask body 11.
The wedge 29 forming the is fixed with an adhesive or the like.
Then, the inclined surface 31 that abuts the inclined surface 30 of the wedge 29.
The push rod 32 forming the is fixed to the driving body 33 that moves up and down.

Next, a masking method using the mask body 16 will be described. Cylinder 1 as shown in FIG.
Since the journal part 10 is provided so as to cross a part of the above, in the case of this engine, the mask surface 11 of the part (a) is
Is the narrowest position.

Therefore, first, a mask body 16 suitable for the engine type is selected, and the mask body 16 is passed through the journal portion 10 while deforming a part of the mask body 16 to move the mask body 16 into the cylinder 1.
Placed on the mask surface 11 of. And then the mask body 16
Since the mask surface 26 of 1 is formed in the same shape as the mask surface 11 of the cylinder 1 and has directionality, the mask body 16 is positioned so that the mask surfaces 26 and 11 are aligned. At the time of this positioning, as shown in FIG. 11, the direction of the force F2 generated on the wedge 29 by the force F1 that pushes down the driving body 33 is adjusted so that the width W0 of the mask surface 11 of the cylinder 1 faces the narrowest direction.
By fixing the wedge 29 to the upper surface of the mask body 16, for example, the marking provided on the wedge 29 and the cylinder 1
The mask body 16 can be positioned by placing the mask body 16 on the mask surface 11 of the cylinder 1 in conformity with the marking provided on the side.

Then, with the inclined surface 31 of the push rod 32 abutting against the inclined surface 30 of the wedge 29, the push rod 32 is pushed down to generate a force in the F2 direction on the wedge 29.
This force F2 presses the mask body 16 in the horizontal direction, and presses the outer periphery of the mask body 16 against the side wall of the space 21 in the journal 10. Then, in a portion where the width W0 of the mask surface 11 is the narrowest, a combined force of the vertical force F1 and the horizontal force F2 works, and the mask surface 26 of the mask body 16 does not come off from the mask surface 11, The mask surface 26 can be brought into close contact with the mask surface 11.

As described above, since the mask surface 26 and the mask surface 11 of the cylinder 1 are plated in close contact with each other, there is no raised portion 15 as shown in FIG. 15 scraping machining can be omitted. Further, since the mask body 16 is a conductive material,
An electric current is not concentrated between the mask body 16 and the mask surface 11 of the cylinder 1, an ideal surface S as shown in FIG. 16 is formed, and unnecessary scraping of the plated layer by machining is omitted, and It is possible to improve the assemblability and solve the secondary problem caused by the peeling of the plating layer. Then, after the plating is completed, the push rod 32 is raised and retracted, the mask body 16 is deformed, and the journal portion 10 is passed through to remove it from the cylinder 1.

Next, in the embodiment shown in FIG. 12, the guide member 28 is fixed to the upper surface of the mask body 16 and the wedge 29 is attached to the guide member 28.
It is provided on the inner surface of. Figure for other parts
Since it is the same as the embodiment shown in FIG. 10, the same parts are designated by the same reference numerals and the description thereof is omitted. In this mask body 16, the pressing force F1 applied to the push rod 32 as shown in FIG.
Will be received on the circumferential surface of the guide portion 28. Therefore, while the force F1 is applied to the central portion of the mask body 16 as in the embodiment shown in FIG. 10, in the embodiment shown in FIG.
The outer peripheral side of 16 is received by the guide member 28 in a dispersed state, and the force of F1 can be increased. Therefore, the pressing force between the mask surface 26 and the mask surface 11 of the cylinder 1 can be increased.

Further, the mask surface sealing portion 19 of the mask body 16 having the hollow portion 17 shown in FIG. 1 is molded from the mask surface 11 at the end of the cylinder as in the embodiment shown in FIGS. 10 and 12. By making the mask surface similar to the mask surface 11 at the cylinder end, the internal pressure of the expansion medium of the hollow portion 17 is low without increasing the pressure until the mask surface seal portion 19 of the mask body 16 is expanded and deformed. The mask surface seal portion 19 of the mask body 16 can be brought into close contact with the mask surface 11 at the cylinder end portion by the internal pressure. As a result, even if the width of the mask surface 11 is narrow, the mask surface sealing portion 19 is prevented from expanding in the cylinder 1 and the mask surface sealing portion 19 can be brought into close contact with the mask surface 11 at the cylinder end.

[0071]

As described above in detail, according to the present invention, the mask surface of the cylinder is masked by using the mask body having the mask surface obtained by patterning the mask surface of the cylinder end portion to be masked. Therefore, even if the mask surface of the cylinder is uneven, the mask surface of the cylinder can be reliably masked. Furthermore, when masking, there is no mutual interference between adjacent masking, and the efficiency of the plating process can be improved.

Further, by utilizing the internal pressure of the hollow portion of the mask body formed of a flexible material, the mask surface of the mask body is deformed following the mask surface at the cylinder end, and the mask surface at the cylinder end and the mask surface are deformed. By pressing the mask surface of the body against the mask surface using the elastic force of the mask body, the masking surface of the cylinder can be surely masked even if the width of the masking surface of the cylinder is narrow in addition to the above effect.

Further, by utilizing the deformation of the temperature-dependent deformable member provided on the mask surface portion of the mask body formed of a flexible material, the mask surface of the mask body is deformed following the mask surface of the cylinder end portion. By pressing the mask surface of the cylinder end and the mask surface of the mask body using the elastic force of the mask body, even if the width of the masking surface of the cylinder is narrow, the masking surface of the cylinder can be secured. Can be masked to

Then, a mask body made of a flexible material whose mask surface is similar to the mask surface of an actual cylinder is pressed against the cylinder center line direction through the inclined portion of the wedge. And by applying a force in a direction orthogonal to this to the mask body and masking while pressing the flexible mask body in the force direction in the orthogonal direction, even if the width of the masking surface at the cylinder end is narrow, The masking surface at the cylinder end can be reliably masked.

Further, by using a mask body made of a flexible material having a hollow portion and capable of expanding and contracting and forming a mask surface in the expanded and deformed state, the upper end of the cylinder is like a journal portion. Even if there is such an offset portion, the mask body can be mounted on the mask surface of the cylinder, and due to the expansion of the mask body, the mask surface of the mask body is deformed following the mask surface of the cylinder end, Even if the mask surface of the cylinder is an uneven surface, it can be surely masked by crimping the surface to the mask surface at the end of the cylinder. Further, since the mask surface of the mask body is pressed against the mask surface of the cylinder end portion by utilizing the pressure inside the hollow portion, even if the mask surface of the cylinder is narrow, the mask surface can be surely masked.

Further, by using a mask body in which a temperature-dependent deformable member is provided on the mask surface portion of the mask body made of a flexible material, even if there is an offset portion such as a journal portion at the upper end of the cylinder, the mask body is masked. The body can be attached to the mask surface of the cylinder, and the mask surface of the mask body is deformed following the mask surface of the cylinder end by the temperature-dependent deformation member, and the mask surface of the mask body is masked at the cylinder end. Even if the mask surface of the cylinder is an uneven surface, it can be surely masked by pressure-bonding to the surface. Further, since the mask surface of the mask body is pressed against the mask surface of the cylinder end portion by utilizing the deformation of the temperature-dependent deformable member, even if the mask surface of the cylinder is narrow, masking can be surely performed.

By using a conductive member as the material of the mask body used in each of the above-mentioned devices, a local flow between the mask surface of the mask body and the mask surface of the cylinder end which are pressure-bonded to each other is generated. In combination with preventing the flow of a large current and ensuring the masking of the cylinder masking surface, it is possible to reliably prevent the formation of a raised portion of the plating layer, eliminating the need to cut the raised portion of the plating layer. The productivity can be improved, the assemblability of the piston to the cylinder can be maintained, and secondary problems caused by peeling of the plating layer can be eliminated.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a mounting process of the mask body in FIG.

FIG. 3 is a longitudinal sectional view showing a state where the mask body in FIG. 1 is completely attached.

FIG. 4 is a longitudinal sectional view of another embodiment of the present invention.

5 is a vertical cross-sectional view showing a state in which the mask body in FIG. 4 is attached to a cylinder.

FIG. 6 is a vertical sectional view showing another embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing a process of mounting the mask body in FIG.

FIG. 8 is a plan view showing a form at a certain temperature of the temperature-dependent deformable member used in the mask body of FIGS. 5 and 6;

9 is a plan view showing the form of the temperature-dependent deformable member in FIG. 8 at a certain temperature.

FIG. 10 is a vertical sectional view showing another embodiment of the present invention.

11 is a vertical cross-sectional view showing a usage state of the mask body in FIG.

FIG. 12 is a longitudinal sectional view showing another embodiment of the present invention.

13 is a vertical cross-sectional view showing a usage state of the mask body of FIG.

FIG. 14 is a vertical cross-sectional view showing a state where a conventional mask body is used.

FIG. 15 is an explanatory diagram showing a longitudinal section of a plating layer.

FIG. 16 is an explanatory diagram showing a longitudinal section of a plating layer.

FIG. 17 is a vertical cross-sectional view of a plating layer when the mask body is made of an electrically conductive material.

FIG. 18 is a vertical cross-sectional view of a plating layer when the mask body is made of a non-electrically conductive material.

FIG. 19 is an explanatory view showing a longitudinal section of a cylinder plating device.

FIG. 20 is a plan view of the cylinder block on the crankcase side.

21 is a vertical sectional view taken along the line AA of FIG.

FIG. 22 is a vertical cross-sectional view showing a state in which the previously manufactured mask body is used.

[Description of sign]

 1 cylinder 10 journal part 11 mask surface 16 mask body 17 hollow part 19 mask surface seal part 20 expansion medium supply pipe 21 space part 24 temperature dependent deformation member 26 mask surface 28 guide member 29 wedge 30 inclined surface 31 inclined surface 32 pushing rod

Front Page Continuation (72) Inventor Koji Mizuno 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd.

Claims (7)

[Claims] 1. A mold in which a mask surface of a cylinder end portion to be masked is molded is formed, a mask body is molded using this mold, and the mask surface of the mask body is aligned with the mask surface of the cylinder to form the mask body. A cylinder plating masking method, which is characterized in that the mask is placed on a mask surface of a cylinder, and the mask body is pressed by a pressing means to press-bond the mask surface of the cylinder and the mask surface of the mask body. 2. The mask surface of the mask body is deformed following the mask surface of the cylinder end by applying pressure inside the hollow portion of the mask body which is formed of a flexible material and is expandable and deformable. A method for plating and masking a cylinder, characterized in that the mask surface and the mask surface of the mask body are brought into close contact with each other. 3. The mask surface of the mask body is deformed along the mask surface at the cylinder end by the deformation of the temperature-dependent deformable member provided on the mask surface portion of the deformable mask body formed of a flexible material, A method for masking plating of a cylinder, which comprises closely contacting a mask surface of a cylinder end with a mask surface of a mask body. 4. A mask body in which a mask surface of a mask body made of a flexible material is formed on a mask surface similar to the mask surface of a cylinder, and an inclined portion fixed to a surface of the mask body opposite to the mask surface. A plating masking device for a cylinder, comprising a wedge having: and means for pressing an inclined portion of the wedge. 5. A mask body made of a flexible material that has a hollow portion and is expandable / contractible and deformable, and forms a mask surface to be brought into close contact with the mask surface of a cylinder in the expanded and deformed state, and a hollow portion of the mask body. A plating masking device for a cylinder having a means for supplying and discharging an expansion medium to expand and contract the mask body. 6. A mask surface portion of a mask body made of a flexible material is provided with a temperature-dependent deformation member, and the temperature-dependent deformation member follows the contraction deformation of the mask body and the mask surface of the cylinder, and the mask surface of the mask body. A plating masking device for a cylinder, characterized in that at least two kinds of temperature-dependent deformations that cause deformation are stored. 7. The masking device according to claim 4, wherein the mask body is formed of a conductive member.