JP3820414B2 - Functional film sequential coating method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of coating a functional film along an inner surface of a cylindrical hole of an object having a cylindrical hole such as an engine cylinder.
[0002]
BACKGROUND OF THE INVENTION
Conventionally, automobile engines are made of cast iron, and the inner surface of the cylinder has been given a specific function mainly by heat treatment.
On the other hand, in recent years, aluminum engines have come to be used due to demands for reducing the weight of automobiles. In this case, specific functions such as imparting high-temperature strength are imparted to the inner surface of an aluminum cylinder, that is, the inner surface of the cylindrical hole. As a method, sleeve casting and press fitting such as cast iron liner and hard aluminum liner are mainly adopted.
In addition, plating on the inner surface of the cylinder, thermal spraying and overlaying as a surface melting alloy, and nitriding and diffusion penetration as surface treatments have been put into practical use.
[0003]
However, in the sleeve casting and press-fitting methods, there is a limit to the thinning of the sleeve itself as a functional film, and there is a problem that a minute gap is formed between the inner surface of the cylinder and adversely affects the cylinder performance.
Also, the functional film on the inner surface of the cylinder should have a thickness of 1 mm when the cylinder is completed. However, it is difficult to form a thin sleeve with this sleeve casting and press-fitting method. It is the actual situation.
[0004]
On the other hand, although treatment methods such as plating and diffusion penetration can be made into a very thin film, it is affected by the properties of the inner surface of the cylinder as a base, and even with pinholes of about 0.3 mm, it has good adhesion. Deteriorate.
In addition, in the case of this processing method, it is difficult to increase the film thickness to about 1 mm, and the film has to be a thin film.
[0005]
On the other hand, thermal spraying or overlaying is effective as a method for forming a functional film having a thickness of about 1 mm, but the thermal spraying deteriorates adhesion when there is a defect in the cylinder base as in plating. Since the thermal spray is not fused with the substrate, the peel strength is low.
Further, when the thickness is increased, the thermal effect is increased, and there is a strong tendency to cause defects such as residual strain.
[0006]
Under such circumstances, the following Patent Document 1 discloses a novel functional film coating method.
FIG. 6 shows a specific example, in which 200 is a cylindrical hole, 202 is a pressure rod, and 204 is a membrane material for coating the functional membrane 210.
In this coating method, the membrane material 204 is set on the bottom 208 of the object 206 having the cylindrical hole 200, and the pressure rod 202 is inserted into the cylindrical hole 200 while rotating, and is advanced downward in the figure. The membrane material 204 is pressurized by the movement, and the frictional heat generated by the rotation of the pressure rod 202 causes the membrane material 204 to be heated and softened to be plastically flowed, and this is transferred between the pressure rod 202 and the inner surface of the cylindrical hole 200. The functional film 210 is coated on the inner surface of the cylindrical hole 200 by pushing upward from the side of the bottom 208 along the gap.
[0007]
However, in this research, in the case of this coating method, the functional film 210 and the inner surface of the cylindrical hole 200 can be joined, but the heat-softened and plastic fluidized film material 204 is plasticized upward along the inner surface of the cylindrical hole 200. In the process of flowing, resistance due to friction or the like with the outer surface of the pressure rod 202 or the inner surface of the cylindrical hole 200 acts, and the plastic flow smoothly and upwards along a minute gap between the pressure rod 202 and the inner surface of the cylindrical hole 200. In addition, the temperature also decreases in the meantime, and the resistance is increased. Therefore, it may be difficult to form the functional film 210 over a sufficient height (length in the axial direction). The film thickness of the functional film 210 is likely to be uneven, such as the film thickness of 210 is thin and the film thickness is thin at the upper part. If despite Linda like its thickness less thick small about 10 mm, it was found that a problem of causing cracks by the pressure of the radial direction.
However, when the thickness of the object 206 is 10 mm or more, the functional film 210 can be sufficiently formed by this method.
[0008]
FIG. 7A illustrates a photograph of the result when the functional film 210 is formed and tested by this coating method. The functional film 210 is thick at the bottom and thin at the top. The film thickness of the film 210 is not uniform in the axial direction.
[0009]
FIG. 7B illustrates the result of the cylinder deformation evaluation test performed in the same manner. In FIG. 7B, reference numeral 212 denotes an inner surface of the cylinder, that is, the inner surface of the cylindrical hole 200 in order to evaluate the deformation of the cylinder. And a through hole having a diameter of 5 mm provided in the vertical direction.
The lower part of the through hole 212 is crushed due to deformation of the cylinder after the coating method is performed.
[0010]
[Patent Document 1]
JP 2000-312981 A
[Means for Solving the Problems]
The functional film sequential coating method of the present invention has been devised in order to solve such problems.
Thus, according to the first aspect of the present invention, there is provided a method of coating a functional film along the inner surface of a cylindrical hole of an object having a cylindrical hole, wherein the pressure applied in the cylindrical hole is smaller in outer diameter than the cylindrical hole. A rod and a backup rod having a diameter larger than that of the pressure rod and having substantially the same outer diameter as that of the cylindrical hole are inserted in the axially opposed state, and the membrane material set in the cylindrical hole is added thereto. The pressure rod and the backup rod are sandwiched in the axial direction and pressed, and the contact portion of the membrane material with the backup rod is not substantially plastically flowed under the pressure, and the pressure rod rotates to rotate the pressure rod. While the contact portion of the membrane material with the axial end surface of the pressure rod is heated and softened by frictional heat generation, it is plastically flowed outward in the radial direction and then into the gap between the pressure rod and the inner surface of the cylindrical hole. Apply pressure rod to the membrane material, back-up By which relatively move forward in the axial direction with respect to the circular column hole inner surface with rods, characterized in that the membrane material into the circular column hole inner surface goes coated sequentially in the same direction as the forward direction.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, the backup rod is kept in a rotation stopped state relative to the membrane material.
[0013]
According to a third aspect of the present invention, in any one of the first and second aspects, at least an end portion of the backup rod on the contact side with the membrane material is cooled, and the plasticity of the membrane material at the contact portion with the backup rod It is characterized by suppressing flow.
[0014]
[Operation and effect of the invention]
As described above, in the present invention, the membrane material is pressed between the pressure rod and the backup rod inside the cylindrical hole in the axial direction, and contact with the pressure rod of the membrane material is performed by rotation of the pressure rod under the pressure. The part is heated and softened by frictional heat generation, and this is plastically flowed outward in the radial direction and then into the gap between the pressure rod and the inner surface of the cylindrical hole, while the pressure rod is joined to the inner surface of the cylindrical hole together with the membrane material and the backup rod. In this case, the membrane material is sequentially coated on the inner surface of the cylindrical hole in the same direction as the forward movement direction of the pressure rod.
In this coating method, the contact portion of the membrane material with the backup rod is kept in a state that does not substantially plastically flow.
[0015]
As a method therefor, the backup rod can be kept in a rotation stopped state relative to the membrane material (claim 2).
[0016]
Alternatively, when the backup rod is rotated with respect to the membrane material, at least the end of the backup rod in contact with the membrane material is cooled, and the contact portion of the membrane material with the backup rod does not plastically flow due to frictional heat generation. (Claim 3).
[0017]
In the coating method of the present invention, the film material that has been softened by heat softening is pushed up (climbed up) all along the entire axial length of the inner surface of the cylindrical hole, and more specifically over the entire axial length to be coated. Rather than filling the plastic fluidized membrane material little by little between the pressure rod and the inner surface of the cylindrical hole, advance the pressure rod while sequentially plasticizing and filling the gap with new membrane material. It will be moved.
That is, in this coating method, the plastically flowing membrane material enters the gap between the cylindrical hole inner surface and the pressure rod only in the vicinity of the tip of the pressure rod, and the pressure rod moves forward together with the membrane material and the backup rod. Accordingly, the filling of the gap between the film materials and the application to the inner surface of the cylindrical hole are continuously performed, and finally a functional film is formed on the inner surface of the cylindrical hole over a predetermined target range.
[0018]
Such a coating method of the present invention causes the membrane material to be plastically fluidized little by little and attached to the inner surface of the cylindrical hole, and as the pressure rod advances, the plastic fluidization of the next membrane material and the inner surface of the cylindrical hole are performed. Therefore, the functional film can be satisfactorily formed on the inner surface of the cylindrical hole.
[0019]
According to the present invention, it is possible to form a functional film over a sufficient axial length on the inner surface of the cylindrical hole, and it is possible to form a functional film with a uniform thickness over the axial direction. Become.
Further, it is possible to solve a problem that an object such as a cylinder is damaged by applying an excessive pressure in the radial direction to break the object.
[0020]
One feature of the present invention is that the contact portion of the membrane material with the backup rod is not substantially plastically fluidized.
When the membrane material is heated and softened at the contact portion with the backup rod and plastically fluidized, it is plasticized and fluidized at the contact portion between the membrane material and the backup rod that is softened and heated at the contact portion with the pressure rod. The membrane material causes a flow collision on the inner surface of the cylindrical hole and creates a weld line there, or the membrane material that is heated and softened at the contact with the backup rod and plastically fluidized outward in the radial direction is pressurized. This causes problems such as obstructing the progress of the rod.
[0021]
Therefore, the present invention does not plastically fluidize the membrane material at the contact portion with the backup rod, but substantially plastically fluidizes only at the contact portion with the pressure rod. By doing so, the functional membrane can be smoothly smoothed. Can be formed on the inner surface of the cylindrical hole.
[0022]
Embodiment
Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, 10 is a cylinder as an object and has a cylindrical hole 12.
14 is a pressure rod, and 16 is a backup rod. Here, the pressure rod 14 has an outer diameter smaller than that of the cylindrical hole 12, and forms a minute gap with the inner surface of the cylindrical hole 12 when inserted into the cylindrical hole 12.
On the other hand, the backup rod 16 has an outer diameter substantially equal to that of the cylindrical hole 12.
Reference numeral 18 denotes a film material for forming the functional film 20 on the inner surface of the cylindrical hole 12.
[0023]
As shown in FIG. 1A, in this embodiment, the backup rod 16 is inserted into the cylindrical hole 12 upward from the bottom in the figure, and the membrane material 18 is placed on the upper surface of the backup rod 16 in the cylindrical hole 12. Set it.
Then, as shown in FIG. 2 (a), the pressure rod 14 is inserted into the cylindrical hole 12 downward in the figure while rotating at a high speed (for example, 100 to 2000 rpm), and the membrane material 18 together with the backup rod 16 is axially moved. It is sandwiched and pressurized (applying pressure is about 10 to 300 MPa).
[0024]
At this time, the membrane material 18 is heated and softened by the frictional heat generated by the high-speed rotation of the pressure rod 14 at the upper surface portion contacting the shaft end surface (lower surface in the drawing) of the pressure rod 14, and then first outward in the radial direction. Thus, it plastically flows in the gap between the backup rod 16 and the inner surface of the cylindrical hole 12 (see FIG. 2B).
At this time, the backup rod 16 is kept in a stopped state so as not to cause plastic flow due to heat softening at the lower surface portion of the film material 18, that is, the contact portion with the upper surface of the backup rod 16.
[0025]
In this embodiment, subsequently, as shown in FIG. 1B, the pressure rod 14 is moved forward together with the backup rod 16 and the membrane material 18 downward in the figure, and the upper surface portion of the membrane material 18 is continuously moved. The gap between the pressure rod 14 and the cylindrical hole 12 is filled by heating and softening and plastic flow.
As shown in FIG. 1C, the predetermined functional film 20 is formed on the inner surface of the cylindrical hole 12 by the amount that the backup rod 16, the membrane material 18, and the pressure rod 14 are moved in the axial direction with respect to the inner surface of the cylindrical hole 12. Is formed as a coating.
[0026]
Here, the movement speed of the backup rod 16 is set so that the pressure applied when the membrane material 18 is axially pressurized together with the pressure rod 14 even when the membrane material 18 is decreased, and the cylinder of the membrane material 18 is maintained. Control is performed so that the pressure contact force in the radial direction against deformation is appropriate.
The film material 18 may be coated on the inner surface of the cylindrical hole 12 in a semi-molten state or a partially molten state in an alloy system having a large solid-liquid coexistence region. It is sufficient to coat 12 inner surfaces.
[0027]
According to the sequential coating method of the functional film 20 of the present example, the film material 18 is plastically fluidized little by little and is attached to the inner surface of the cylindrical hole 12, and then the pressure rod 14 is moved forward. Since this is a sequential coating method in which the film material 18 is plastically fluidized and attached to the inner surface of the cylindrical hole 12, the functional film 20 can be satisfactorily formed on the inner surface of the cylindrical hole 12.
[0028]
According to this example, the functional film 20 can be formed on the inner surface of the cylindrical hole 12 over a sufficient axial length, and the functional film 20 is formed with a uniform thickness over the axial direction. be able to.
Further, it is possible to solve the problem of damaging the cylinder 10 by applying an excessive pressure in the radial direction to break it.
[0029]
Incidentally, FIG. 3 illustrates a photograph of the result of the coating test of the functional film 20 on the inner surface of the cylindrical hole 12 by the method of this embodiment.
As shown in the figure, according to this method, the functional film 20 can be formed with a substantially uniform film thickness over a sufficient axial length.
[0030]
FIG. 2C shows the method of the comparative example, and here is an example in the case where the backup rod 16 is rotated.
In such a case, the contact portion of the membrane material 18 with the backup rod 16 is heated and softened by frictional heat generation, whereby the lower portion of the membrane material 18 protrudes radially outward, and the pressure rod 14 and the membrane This hinders the progress of the material 18.
[0031]
However, the present invention does not exclude all cases where the backup rod 16 is rotated, and it is also possible to rotate the backup rod 16.
However, in that case, as shown in FIG. 4, the shaft end portion of the backup rod 16 has a water cooling structure having a water passage 30, and cooling water is passed therethrough to cool the shaft end portion, whereby the membrane material 18 Coating is performed while preventing softening and plastic flow at the bottom of the substrate.
[0032]
The pressure rod 14 and the membrane material 18 can have various shapes other than the above examples.
FIG. 5 shows an example.
FIG. 5A shows an example in which the pressure rod 14-1 is configured as a stepped shape having a large-diameter portion 22 at the tip, and is used in combination with a solid membrane material 18-1. Here, the large-diameter portion 22 is about 2 mm in diameter with respect to the main body portion of the pressure rod 14-1. The outer diameter of the large diameter portion 22 is φ37 mm, the outer diameter of the membrane material 18-1 is φ37 mm, and the height is 30 mm.
[0033]
On the other hand, the pressure rod 14-2 in FIG. 5 (b) has a large diameter portion 22, a pin 24, and a taper portion 26 having the same outer diameter as in FIG. In this example, the pressure rod 14-2 and the cylindrical membrane material 18-2 are used in combination.
Here, the outer diameter of the large diameter portion 22 is φ37 mm, the outer diameter of the pin 24 is φ19 mm, the height is 10 mm, the taper angle of the taper portion 26 is 15 °, the outer diameter of the membrane material 18-2 is φ37 mm, and the inner diameter is φ20 mm. ， Height is 40mm.
[0034]
Next, FIG. 5 (c) shows an example in which the pressure rod 14-3 has a shape having a large-diameter portion 22 and a pin 28 at the tip, and this is used in combination with a cylindrical membrane material 18-3. is there.
Here, the outer diameter of the large diameter portion 22 is φ37 mm, the outer diameter of the pin 28 is φ26 mm, the height is 20 mm, and the outer diameter of the membrane material 18-3 is φ37 mm, the inner diameter is φ27 mm, and the height is 45 mm.
[0035]
On the other hand, the pressure rod 14-2 in FIG. 5 (d) has a tip portion having a shape having a large-diameter portion 22, a pin 24, and a tapered portion 26, and this is formed into a cylindrical membrane material 18-4. It is an example used in combination.
The pressure rod 14-2 in FIG. 5 (d) has the same shape as the pressure rod 14-2 in FIG. 5 (b).
On the other hand, the membrane material 18-4 has an outer diameter of 30 mm, an inner diameter of 20 mm, and a height of 50 mm.
[0036]
Among these, the best results were obtained with the combination shown in FIG.
When the pressure rod 14 has a stepped shape as described above, the film material 18 or the coating layer (functional film 20) that plastically flows in the gap between the inner surface of the cylindrical hole 12 and the pressure rod 14 is added. The contact area with the pressure rod 14 can be reduced, the resistance during rotation can be reduced, and the rod life can be extended.
[0037]
Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention can be implemented in variously modified forms without departing from the spirit of the present invention.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a sequential coating method of a functional film according to an embodiment of the present invention.
FIG. 2 is a diagram showing a method of the embodiment and a method of a comparative example.
FIG. 3 is a diagram showing a photograph of the result of coating test of a functional film on the inner surface of a cylindrical hole by the method of the embodiment.
FIG. 4 is a diagram showing another embodiment of the present invention.
FIG. 5 is a diagram showing still another embodiment of the present invention.
FIG. 6 is a view showing a conventionally known method for coating a functional film on the inner surface of a cylindrical hole.
FIG. 7 is a diagram showing a photograph of a result of coating test of a functional film on the inner surface of a cylindrical hole by the method shown in FIG.
[Explanation of symbols]
10 Cylinder (object with cylindrical hole inner surface)
12 Cylindrical hole 14, 14-1, 14-2, 14-3, 14-4 Pressure rod 16 Backup rod 18, 18-1, 18-2, 18-3, 18-4 Membrane material 20 Functional membrane

Claims (3)

A method of coating a functional film along the inner surface of a cylindrical hole of an object having a cylindrical hole, the pressure rod having a smaller outer diameter than the cylindrical hole, and a larger diameter than the pressure rod in the cylindrical hole And a cylindrical rod and a backup rod having substantially the same outer diameter are inserted so as to face each other in the axial direction, and the membrane material set in the cylindrical hole is sandwiched between the pressure rod and the backup rod in the axial direction. And pressurizing with the shaft end surface of the pressure rod of the membrane material by rotation of the pressure rod while keeping the contact portion of the membrane material with the backup rod under substantially no plastic flow The contact portion is heated and softened by frictional heat generation and plastically flows radially outward and then into the gap between the pressure rod and the inner surface of the cylindrical hole. Inside the cylindrical hole Axially by which relatively move forward, a sequential method of coating a functional layer, characterized in that the membrane material into the circular column hole inner surface goes coated sequentially in the same direction as the forward direction with respect. 2. The functional film sequential coating method according to claim 1, wherein the backup rod is kept in a rotation stopped state relative to the film material. 3. The method according to claim 1, wherein at least an end portion of the backup rod in contact with the membrane material is cooled to suppress plastic flow of the membrane material at the contact portion with the backup rod. A sequential coating method for functional films.

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