JP2008214708A - Thermal spraying apparatus and thermal spraying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit a substance converted into fume out of sprayed particles which have been thermal-sprayed from a thermal spraying gun, from depositing on a portion in a more forward side in a moving direction of the thermal spraying gun than an already thermal-sprayed portion, on a treatment surface of an object to be thermal-sprayed. <P>SOLUTION: When forming a thermal-sprayed coating film on an inner surface of a cylinder bore 3, this thermal spraying method includes: inserting a thermal spraying gun 5 of a thermal spraying apparatus 4 into the inner part of a liner 2; making the thermal spraying gun 5 thermal-spray the spray particles in the state; and simultaneously moving the thermal spraying gun 5 from one side to the other side in a direction along the central line of the cylinder bore 3, while rotating the thermal spraying gun 5 around the central line. The thermal spraying gun 5 thermal-sprays the spray particles toward a portion on the inner surface of the cylinder bore 3, which is closer to one side of the central line direction than the portion on the inner surface, which is closest to the thermal spraying gun 5. Thereby, the substance converted into the fume out of the spray particles which have been thermal-sprayed from the thermal spraying gun 5 is inhibited from flying toward the forward side of the moving direction of the thermal spraying gun 5 (the other side of the central line direction). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal spraying apparatus and a thermal spraying method.

2. Description of the Related Art Conventionally, in an internal combustion engine, in order to improve the slidability of the inner peripheral surface of a cylinder bore of a cylinder block, a thermal spray coating is formed by spraying spray particles such as iron melted on the cylinder bore. . As a thermal spraying apparatus used for forming such a thermal spray coating, for example, the one shown in Patent Document 1 is known. The device has a spray gun inserted into the cylinder bore, and sprays the spray particles melted from the spray gun toward the inner surface of the cylinder bore while rotating the spray gun around the center line of the cylinder bore. Is moved from one side to the other side. By using this thermal spraying apparatus, it becomes possible to form a thermal spray coating by spraying molten thermal spray particles on the entire inner peripheral surface of the cylinder bore.
JP 2006-322049 A (FIG. 1, FIG. 3, paragraph [0032])

  By the way, among the sprayed particles sprayed from the spray gun, those having a small particle diameter are oxidized at a high temperature and become so-called fume (iron oxide). These fumes are scattered or bounced by hitting the inner peripheral surface of the cylinder bore, so that the spray gun has more sprayed particles than the sprayed particles on the inner peripheral surface. There is a possibility of adhering to a portion on the front side in the moving direction. In this way, if fumes adhere to the portion of the inner peripheral surface of the cylinder bore that is sprayed forward of the spraying particles relative to the sprayed portion of the spray gun, the thermal spray gun sprays the thermal spraying particles to overlap the adhered fumes. As a result, a sprayed coating is formed. However, of the thermal spray coating formed on the entire inner peripheral surface of the cylinder bore, the adhesive force on the inner peripheral surface is weak with respect to the portion that overlaps the attached fume, and subsequent honing or the like of the inner peripheral surface of the cylinder bore There is a risk of peeling.

  Such a problem is not limited to the case where the thermal spray coating is formed on the inner peripheral surface of the cylinder bore, but is generally common even when the thermal spray coating is formed on the processing surface of an object other than the inner peripheral surface of the cylinder bore. ing.

  The present invention has been made in view of such a situation, and the purpose thereof is spraying on the processing surface of an object on which a fume of sprayed particles sprayed from a spray gun is sprayed. An object of the present invention is to provide a thermal spraying apparatus and a thermal spraying method capable of suppressing adhesion to a portion on the front side in the moving direction of the thermal spray gun from the portion.

In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, according to the first aspect of the present invention, a spray gun having a moving direction on a straight line parallel to a processing surface of an object to be sprayed is provided, and the sprayed particles melted from the spray gun are treated as described above. In the thermal spraying apparatus that moves the thermal spray gun from one side of the moving direction to the other side while spraying toward the surface, the thermal spray gun moves more than the portion that is the shortest distance from the thermal spray gun on the processing surface. The gist is that the thermal spraying is performed toward a portion located on one side of the direction.

  According to the above configuration, the thermal spraying of the sprayed particles from the moving spray gun to the processing surface of the object is performed toward the portion located on the rear side in the moving direction with respect to the spray gun on the processing surface. For this reason, it becomes difficult for the sprayed spray particles that have become fumes to fly toward the front side in the moving direction of the spray gun. Accordingly, it is possible to suppress the fume from adhering to a portion on the front side in the moving direction of the spray gun from a portion of the processing surface where the spray particles are not sprayed, that is, a portion where the spray particles are sprayed by the spray gun.

  According to a second aspect of the present invention, in the thermal spraying apparatus according to the first aspect, the air from the other side in the moving direction of the thermal spray gun along the process toward the one side in the vicinity of the processing surface of the object. An airflow device that causes the flow of

  According to the above configuration, the spraying direction of the sprayed particles from the spray gun is the direction toward the downstream side of the air flow generated by the airflow device. Of the spray particles sprayed from the spray gun, those that become fumes are flowed to the rear side in the moving direction of the spray gun (one side in the moving direction) by the air flow generated by the airflow device. For this reason, the fumes are more difficult to fly toward the front side in the moving direction of the spray gun (the other side in the moving direction), and the portion of the spray gun in the moving direction forward of the sprayed portion on the processing surface. It becomes possible to more accurately suppress adhesion to the surface.

  According to a third aspect of the present invention, a thermal spray gun is inserted into the cylinder bore, and the thermal spray particles melted from the thermal spray gun are sprayed toward the inner peripheral surface of the cylinder bore while the thermal spray gun is moved in the direction of the center line of the cylinder bore. In the thermal spraying method of moving from one side to the other side, the cylinder bore is formed on an inner peripheral surface of a cylindrical liner attached to a cylinder block, and the thermal spray gun includes the liner in the cylinder block The cylinder bore is inserted into the cylinder bore formed on the inner peripheral surface of the liner in a state of being removed from the cylinder bore and moved from one side to the other side in the center line direction of the cylinder bore while being at the shortest distance from the spray gun in the cylinder bore. The thermal spraying is performed toward a portion located closer to one side in the center line direction than the portion to be formed.

  According to the above method, the spraying of the sprayed particles from the moving spray gun to the inner peripheral surface of the cylinder bore is performed on one side in the center line direction, that is, on the rear side in the moving direction of the spray gun from the same spray gun on the inner peripheral surface. It is done toward the part located at. For this reason, it becomes difficult for the sprayed spray particles that have become fumes to fly toward the front side in the moving direction of the spray gun. Therefore, the fume is prevented from adhering to the portion of the inner peripheral surface of the cylinder bore where the sprayed particles are not sprayed, that is, the portion forward of the spraying gun in the moving direction of the spraying gun from the portion where the spraying of the sprayed particles is completed. it can.

  Further, the spraying of the spray particles onto the inner peripheral surface of the cylinder bore is performed in a state where the liner on which the cylinder bore is formed is removed from the cylinder block. If the sprayed particles are sprayed on the inner peripheral surface of the cylinder bore with the liner having the cylinder bore attached to the cylinder block, the cylinder block is masked to spray the portion other than the inner peripheral surface of the cylinder bore. Particles must be prevented from sticking. However, according to the above method, the labor of performing such masking can be saved.

  Further, when spraying spray particles on the inner peripheral surface of the cylinder bore, when air is caused to flow inside the cylinder bore and the fumes are to flow out of the cylinder bore, a duct or the like for flowing the air is formed in a cylindrical shape. Connect to the other liner. For this reason, it is possible to easily connect the duct and the like to the liner.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the present invention is embodied in a thermal spraying apparatus and a thermal spraying method for forming a thermal spray coating on an inner peripheral surface of a cylinder bore of an engine will be described with reference to FIGS.
In the engine, as shown in FIG. 1, a cylindrical liner 2 is attached to a cylinder block 1, and a cylinder bore 3 is formed on the inner peripheral surface of the liner 2. The thermal spray coating is formed on the inner peripheral surface of the cylinder bore 3 by the thermal spraying device 4 shown in FIG. 2 with the liner 2 removed from the cylinder block 1.

  The thermal spraying device 4 is inserted into the cylinder bore 3 and is movable in the direction of the center line of the cylinder bore 3, and the spray gun 5 is rotated around the center line of the cylinder bore 3 while rotating in the direction of the center line. And a driving device 6 that moves from the side to the other side (from the lower side to the upper side in the drawing). The spray gun 5 that can move in the direction of the center line of the cylinder bore 3 has a movement direction on a straight line parallel to the inner peripheral surface of the cylinder bore 3. Further, the spray gun 5 is arranged such that molten spray particles such as iron are on one side in the center line direction (lower side in the figure) of the inner peripheral surface of the cylinder bore 3 with respect to the shortest distance from the spray gun 5. It sprays toward the part located in the area. That is, the nozzle hole of the spray gun 5 is inclined with respect to the center line so that the spray particles are sprayed in this way.

  Further, the thermal spraying device 4 has a flow of air from the other side in the center line direction toward one side (from the upper side to the lower side in the drawing) in the vicinity of the inner peripheral surface of the cylinder bore 3, that is, thermal spraying in the thermal spray gun 5. An airflow device 7 is provided that causes air to flow in a direction opposite to the direction of movement at the time. The airflow device 7 is provided with a duct 8 connected to an opening portion of the liner 2 in which the cylinder bore 3 is formed. When the airflow device 7 is driven in a state where the duct 8 is connected to the opening portion of the liner 2, the air in the liner 2 is sucked through the duct 8 and from the other side in the centerline direction into the liner 2. An air flow toward one side is caused.

Next, a method for forming a sprayed coating on the inner peripheral surface of the cylinder bore 3 using the spraying device 4 will be described.
In forming a thermal spray coating on the inner peripheral surface of the cylinder bore 3, first, the liner 2 with the cylinder bore 3 is removed from the cylinder block 1, and then the thermal spray gun 5 is opened from the opening located on the other side of the liner 2. Inserted into the liner 2, the tip of the spray gun 5 is positioned in the vicinity of the opening on the one side in the center line direction of the cylinder bore 3 inside the liner 2. Further, the duct 8 of the airflow device 7 is connected to the opening portion on the other side of the liner 2. Then, spraying of the sprayed particles from the spray gun 5 is performed, and the spray gun 5 is moved from one side to the other side in the center line direction while rotating around the center line of the cylinder bore 3 through driving of the driving device 6. . As a result, the spray particles are sprayed from the spray gun 5 over the entire circumferential direction extending from one side to the other side in the center line direction on the inner peripheral surface of the cylinder bore 3, and the spray coating is applied to the entire inner peripheral surface of the cylinder bore 3. It is formed. Further, when spraying of the sprayed particles from the spray gun 5 is performed, an air flow is caused in the liner 2 from the other side to the one side in the center line direction through driving of the airflow device 7.

FIG. 3 is an enlarged cross-sectional view showing a portion of the inner peripheral surface of the cylinder bore 3 where the thermal spray particles 5 are sprayed.
Of the sprayed particles sprayed from the spray gun 5, those having a small particle diameter are oxidized at a high temperature and become so-called fume (iron oxide) 9.

  If the spraying direction of the spray gun 5 is perpendicular to the inner peripheral surface of the cylinder bore 3, such fumes 9 may scatter or bounce off the inner peripheral surface of the cylinder bore 3 to cause the spray particles on the inner peripheral surface to flow. There is a possibility that the thermal spray gun 5 may adhere to a portion on the front side (upper side in the figure) in the moving direction of the sprayed part 5 rather than the part that has not been sprayed, that is, the part that has been sprayed. Note that, on the inner peripheral surface of the cylinder bore 3 in FIG. 3, the sprayed portion is indicated by “A”, and the portion on the front side in the moving direction of the spray gun 5 from that portion is indicated by “B”. . Then, a fume 9 adheres to the portion indicated by “B” on the inner peripheral surface of the cylinder bore 3 as indicated by a two-dot chain line, and a thermal spray coating 10 (two-dot chain line) is formed so as to overlap the adhering fume 9. Then, the adhesive force of the sprayed coating 10 at that portion becomes weak, and there is a risk of peeling.

  However, the thermal spraying of the thermal spray particles from the thermal spray gun 5 is a portion located on one side (the lower side in the drawing) in the center line direction with respect to the inner peripheral surface of the cylinder bore 3 with respect to the thermal spray gun 5 and the shortest distance. To be done. As a result, the sprayed particles from the spray gun 5 that become the fumes 9 are less likely to fly toward the front side in the movement direction of the spray gun 5, that is, toward the other side in the center line direction (upper side in the drawing). Become. Therefore, the fume 9 can be prevented from adhering to the portion (“B” in the figure) where the sprayed particles on the inner peripheral surface of the cylinder bore 3 are not sprayed, and as a result, the above-described peeling can be suppressed. In addition, regarding the spraying direction of the sprayed particles from the spray gun 5, the inclination angle of the spraying direction with respect to the center line direction with respect to the normal of the inner peripheral surface of the cylinder bore 3 accurately determines the spraying of the sprayed particles on the inner peripheral surface. It is preferable to set the angle so that the fume 9 is prevented from adhering to the portion indicated by “B”.

  Further, in the vicinity of the inner peripheral surface of the cylinder bore 3, an air flow from the other side in the center line direction toward one side (from the upper side to the lower side in the drawing) is caused by driving the airflow device 7. For this reason, the spraying direction of the sprayed particles from the spray gun 5 is the direction toward the downstream side of the air flow generated by the airflow device 7. Of the sprayed particles sprayed from the spray gun 5, the particles that have become the fumes 9 are caused to flow backward in the moving direction of the spray gun 5, that is, to one side in the center line direction due to the air flow. It will flow in the direction opposite to the direction toward the portion indicated by “B” on the inner peripheral surface. Therefore, the fume 9 is more difficult to fly toward the front side in the moving direction of the spray gun 5, and the adhesion of the fume 9 to the portion indicated by “B” on the inner peripheral surface of the cylinder bore 3 can be more accurately suppressed. become.

According to the embodiment described in detail above, the following effects can be obtained.
(1) Thermal spraying of thermal spray particles from the thermal spray gun 5 is performed on one side in the center line direction (lower side in FIG. 3) of the inner peripheral surface of the cylinder bore 3 with respect to the thermal spray gun 5 at the shortest distance, that is, thermal spraying. It is performed toward the part located on the opposite side to the moving direction of the gun 5. As a result, the sprayed particles from the spray gun 5 that become the fumes 9 are less likely to fly forward in the moving direction of the spray gun 5. Accordingly, it is possible to suppress the fume 9 from adhering to a portion (“B” in the drawing) located on the front side in the moving direction of the spray gun 5 with respect to the portion of the inner peripheral surface of the cylinder bore 3 that has been sprayed.

  (2) The spraying direction of the sprayed particles from the spray gun 5 is the direction toward the downstream side of the air flow generated by the airflow device 7. Of the sprayed particles sprayed from the spray gun 5, those which have become the fumes 9 are in the direction opposite to the moving direction of the spray gun 5 due to the air flow, in other words, FIG. 3 on the inner peripheral surface of the cylinder bore 3. In the direction opposite to the direction indicated by “B”. For this reason, the fume 9 becomes more difficult to fly toward the front side in the moving direction of the spray gun 5, and the sprayed particles on the inner peripheral surface of the cylinder bore 3 of the fume 9 are not sprayed ("B" in the figure). Adhesion to can be suppressed more accurately.

In addition, the said embodiment can also be changed as follows, for example.
As shown in FIG. 4, a thermal spray coating may be formed on the inner peripheral surface of the cylinder bore 3 of the liner 2 with the liner 2 attached to the cylinder block 1. In this case, the masking material 11 is affixed to the inner surface of the portion on the crankcase 1a side of the cylinder block 1 so that the spray particles do not adhere to the inner surface of the portion during spraying of the spray particles from the spray gun 5. Further, a duct 8 of the airflow device 7 is connected to a portion of the cylinder block 1 on the crankcase 1a side, and the airflow device 7 is driven to enter the liner 2 from the other side in the center line direction to the one side (from the upper side in the drawing). An air flow toward the lower side is caused. As described above, when the sprayed coating is formed on the inner peripheral surface of the cylinder bore 3, the same effects as the above (1) and (2) can be obtained.

  Note that a portion on the crankcase side in the cylinder block 1 has a complicated shape such as an uneven shape, and it is difficult to connect the duct 8 to such a portion. However, if the cylindrical liner 2 is removed from the cylinder block 1 and the duct 8 is connected to the liner 2 as in the above embodiment, it is possible to easily perform the connecting operation without performing the difficult connecting operation described above. become. Further, if the duct 8 is connected to the liner 2 removed from the cylinder block 1 as in the above embodiment, the air flow caused by the air flow device 7 may cause stagnation due to the uneven shape of the wall surface. Since it does not occur, the flow of exhaust gas in the liner 2 can be accurately determined in one direction from the other side to the one side. Further, it is not necessary to apply the masking material 11 to the crankcase side portion of the cylinder block 1.

  When the sprayed coating is formed as described above, the present invention can be applied to an engine in which the liner 2 is omitted and the cylinder bore 3 is formed directly on the cylinder block 1. However, in this case, when a manufacturing defect such as a dent occurs on the inner peripheral surface of the cylinder bore 3, the entire cylinder block 1 must be replaced. In this regard, when the liner 2 is used as in the above-described embodiment, it is only necessary to replace the liner 2 when a manufacturing defect such as a depression occurs on the inner peripheral surface of the cylinder bore 3, and this is a wasteful result due to the replacement. Cost generation can be reduced.

The airflow device 7 is not necessarily provided.
In the above embodiment, the present invention is applied to the thermal spraying device 4 that forms the thermal spray coating on the inner peripheral surface of the cylinder bore 3, but the thermal spraying device that forms the thermal spray coating on the treatment surface of the object other than the inner peripheral surface of the cylinder bore 3. The present invention can also be applied to.

Sectional drawing which shows the structure of the cylinder block in an engine. Schematic which shows the structure of the thermal spraying apparatus of this embodiment. The enlarged view which shows the thermal spray coating formation part in the internal peripheral surface of a cylinder bore. Sectional drawing which shows another method of forming a sprayed coating in the internal peripheral surface of a cylinder bore.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cylinder block, 1a ... Crank case, 2 ... Liner, 3 ... Cylinder bore, 4 ... Spraying device, 5 ... Spraying gun, 6 ... Driving device, 7 ... Airflow device, 8 ... Duct, 9 ... Fume, 10 ... Spray coating 11 ... Masking material.

Claims (3)

A spray gun having a moving direction on a straight line parallel to the processing surface of the object to be sprayed is provided, and the spray gun is moved in the moving direction while spraying the spray particles melted from the spray gun toward the processing surface. In a thermal spraying device that moves from one side to the other,
The said thermal spray gun performs the said thermal spray toward the part located in the one side of the said moving direction rather than the part which becomes the shortest distance with the same thermal spray gun in the said processing surface. The thermal spraying device according to claim 1,
A thermal spraying apparatus, further comprising an airflow device for causing an air flow from the other side in the moving direction of the thermal spray gun along the process in the vicinity of the processing surface of the object to the one side. A spray gun is inserted into the cylinder bore, and the spray gun is moved from one side to the other side in the center line direction of the cylinder bore while spraying particles sprayed from the spray gun toward the inner peripheral surface of the cylinder bore. In the spraying method to let
The cylinder bore is formed on the inner peripheral surface of a cylindrical liner attached to the cylinder block,
The thermal spray gun is inserted into the cylinder bore formed on the inner peripheral surface of the liner with the liner removed from the cylinder block, and moves from one side to the other side in the center line direction of the cylinder bore. The thermal spraying method is characterized in that the thermal spraying is performed toward a portion located closer to one side in the center line direction than a portion having the shortest distance from the thermal spray gun in the cylinder bore.

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