JP2008303439A - Method for removing excess sprayed coating, device therefor, and liquid injection nozzle used for the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with a work for removing residue after the removal of excess sprayed coating. <P>SOLUTION: When a sprayed coating 9 is formed at the inner face 3a of a cylinder bore in a cylinder block 1, a thermal spraying material is stuck to the inner face 5a of a crankcase 5, so as to form an excess sprayed coating 15. This excess sprayed coating 15 is removed by water injection from a water injection nozzle 19. At this time, the water injection nozzle 19 is equipped with a first injection port 21 of low pressure injection and a second injection port 23 each provided at the tip side, a water curtain is formed by low pressure injection from the first injection port 21, and the excess sprayed coating 15 is removed by high pressure injection from the second injection port 23. The water curtain of low pressure injection acts so as to block the going of the water of high pressure injection toward the sprayed coating 9, thus the peeling of the sprayed coating 9 is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for removing an excess sprayed coating formed by forming a sprayed coating on a thermal sprayed part that needs to be sprayed on a workpiece, and then removing an excess sprayed coating adhering to a part that does not require a thermal sprayed coating adjacent to the sprayed part, and The present invention relates to an apparatus and a liquid jet nozzle used in the apparatus.

  From the standpoint of improving the output, fuel consumption, exhaust performance of an internal combustion engine, and reducing the size and weight, the design requirements for eliminating the cylinder liner applied to the cylinder bore of the aluminum cylinder block are extremely high. Application of a thermal spraying technique for forming a thermal spray coating made of an iron-based material on the inner surface of an aluminum cylinder bore is being promoted.

  By the way, when forming the above-mentioned sprayed coating, it is required to minimize the adhesion of the surplus sprayed coating to a portion other than the cylinder bore portion where spraying is necessary, such as the inner surface of the crankcase, where spraying is unnecessary. Such an excess sprayed coating is usually located at a position farther from the nozzle that sprays the sprayed material than the cylinder bore part that is pre-sprayed to increase the degree of adhesion. Peeling is likely to occur, and the excess sprayed coating that has been peeled off may be mixed into the lubricating oil in the crankcase.

  For this reason, when forming a thermal spray coating, it is possible to use the protective mask apparatus as described in the following patent document 1, for example. However, this protective mask device prevents the excessive sprayed coating from adhering to the upper end portion of the cylinder block at the start of thermal spraying, and such a protective mask device is mounted on a complicated shape portion such as the inner surface of the crankcase, for example. In addition, it is difficult to attach a protective mask device, so that there is a limit to mass production in consideration of quality and cost.

On the other hand, for example, Patent Document 2 below describes that the above-described excessive sprayed coating is removed in a post-process after the sprayed coating is formed. In this state, in a state where the inner surface of the cylinder bore on which the sprayed coating is formed is covered with a masking cylindrical member, the surplus sprayed coating is removed by performing a blasting process or a shot process on the portion to which the surplus spraying coating has adhered.
JP 2002-339053 A JP 2002-302755 A

  However, the method of removing surplus sprayed coating by blasting or shot processing may leave blasting material or shot material used in that processing in the cylinder block. Occasionally it will trigger a bug. For this reason, it is necessary to perform a cleaning operation for further removing this residue, and an extra man-hour is required, resulting in an increase in cost.

  Then, this invention aims at making the removal operation | work of the residue after removing an excess sprayed coating unnecessary.

  The present invention relates to a method for removing an excess sprayed coating that removes an excess sprayed coating adhering to a site that does not require thermal spraying of the workpiece after forming a sprayed coating on a site that requires thermal spraying of the workpiece. And a spray-free part at the boundary between the spray-free part and a spray-free part, and a liquid spray is applied to the spray-unneeded part side to remove the excess spray coating. This is the main feature.

  According to the present invention, since the excess sprayed coating is removed by spraying the liquid on the side where the spraying is not required with the liquid protecting portion as a boundary, the coating removing operation itself can also be cleaned with the liquid, This eliminates the need for a cleaning operation, eliminates the need for a residue removal operation such as in blasting and the like, and reduces the work cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a surplus sprayed coating removing apparatus according to a first embodiment of the present invention, in which a cylinder bore 3 is opened with respect to a cylinder block 1 of an automobile engine as shown in FIG. The excess sprayed coating is removed in an inverted state so that the mounting side is the bottom.

  The cylinder block 1 here has a ladder-like shape called a ladder frame having a bearing portion that rotatably supports a journal portion of a crankshaft (not shown) at the end on the crankcase 5 side opposite to the cylinder head mounting side. The member 7 is attached. Thereby, the rigidity of the cylinder block 1 is increased, and when the sprayed coating 9 is formed on the inner surface 3a of the cylinder bore 3, the deformation of the cylinder block 1 due to the influence of heat during spraying can be prevented.

  As shown in FIG. 3, the thermal spray coating 9 is formed by inserting the thermal spray nozzle 11 into the cylinder bore 3 while rotating the thermal spray nozzle 11 in an upright state in which the opening side of the cylinder bore 3 is the upper side as shown in FIG. At this time, the molten iron-based material spray 13 ejected from the thermal spraying nozzle 11 adheres to the cylinder bore inner surface 3a which is the thermal spraying part to form the thermal spray coating 9.

  In the process of forming the sprayed coating 9 in this way, the sprayed coating 9 is applied to the cylinder bore 3 in the vicinity of the crankcase 5 in a state where the sprayed nozzle 11 is particularly located at the lowermost end as shown by a two-dot chain line in FIG. When spraying, a part of the spray 13 of the sprayed material scatters toward the inner surface 5a of the crankcase 5, and if the scattered or suspended particles are only the inner surface 5a, they adhere to the inner surface 7a of the member 7. As a result, an excessive sprayed coating 15 is formed on the part that does not require spraying.

  Therefore, in the present embodiment, the above-described excessive sprayed coating 15 is removed, but before that, the end of the sprayed coating 9 on the crankcase 5 side in FIG. 3 includes the base portion (cylinder block 1). As shown in FIG. 4 in an enlarged manner, chamfering is performed so that the tapered surface 17 is obtained. This chamfering is performed by inserting a boring bar (not shown) into the cylinder bore 3. Such chamfering is also performed on the upper end portion of the cylinder bore 3 in FIG.

  After the above chamfering process, although not shown in particular, the surface of the sprayed coating 9 is finished by rotating a honing head having a grindstone on the outer peripheral portion while inserting it into the cylinder bore 3. At this time, the thermal spray coating 9 can prevent peeling during the honing process by performing the chamfering process to become the tapered surface 17 described above.

  In this embodiment, after finishing by honing, as shown in FIG. 1, the excess sprayed coating 15 is removed in an inverted state opposite to that shown in FIG. 3 so that the crankcase 5 is on the upper side as shown in FIG. Do.

  The removal of the excessive sprayed coating 15 uses a water spray nozzle 19 as a liquid spraying means for spraying water as a liquid, for example. The water injection nozzle 19 is inserted into the crankcase 5 while rotating from the top in FIG. 1, and a first injection port 21 and a second injection port 23 are provided on the side of the tip (lower end in FIG. 1). And are provided. Among these, the first injection port 21 is provided on the distal end side and injects low-pressure water 24, and the second injection port 23 is adjacent to the first injection port 21 and on the proximal end side (in FIG. 1). It is provided on the upper side) and injects high-pressure water 26.

  The excess sprayed coating 15 is removed by jetting the high-pressure water 26 from the second jet port 23, and the low-pressure water 24 is jetted from the vicinity of the upper end of the tapered surface 17 to the upper side. A water curtain as a protective part made of liquid is formed by the water 24 jetted at this low pressure. The sprayed film 9 is protected from the high-pressure water 26 by this water curtain. That is, in this embodiment, a protective part made of a liquid separating the two parts is provided at the boundary part between the thermal spraying part and the spraying unnecessary part, and the liquid is sprayed to the spraying unnecessary part side with this protective part as a boundary. Remove excess sprayed coating.

  FIG. 5 is a cross-sectional view showing a part of the tip side of the water jet nozzle 19 described above, and a nozzle end 27 is attached to the tip of the nozzle body 25. The nozzle body 25 has a high-pressure passage 25a as a liquid passage penetrating in the axial direction at the center, and high-pressure water is supplied to the high-pressure passage 25a from an external high-pressure water supply source (not shown) as indicated by an arrow B. The

  A high-pressure discharge port 25 b that communicates radially outward is provided near the tip (lower end in FIG. 5) of the high-pressure passage 25 a, and the high-pressure discharge port 25 b communicates with the second injection port 23. That is, the high-pressure water supplied to the high-pressure passage 25a is jetted to the outside from the second jet port 23 via the high-pressure discharge port 25b.

  The nozzle end 27 attached to the nozzle body 25 so as to cover the outer periphery of the end of the high-pressure passage 25a on the tip side from the high-pressure discharge port 25b is centered on the low-pressure passage 27a having a smaller passage diameter than the high-pressure passage 25a. I have.

  One end of the low-pressure passage 27a communicates with the center of the high-pressure passage 25a, and the other end communicates with a volume expanding portion 27b provided on the tip side. A part of the outer peripheral side of the volume expanding portion 27 b communicates with the first injection port 21. Since the volume of the volume expanding portion 27b is larger than that of the low pressure passage 27a, the pressure of the inflowing water is reduced, and the low pressure water 24 is ejected to the outside through the first injection port 21.

  As shown in FIG. 1, the surplus sprayed coating removing apparatus configured as described above is inserted into the inverted cylinder block 1 while rotating the water spray nozzle 19 from the crankcase 5 side, and the first spray port Water is ejected from 21 and the second ejection port 23.

  At that time, the excessive sprayed coating 15 is removed by the high-pressure water 26 ejected from the second injection port 23. The crankcase inner surface 5a and the inner surface 7a of the member 7 on which the excessive sprayed coating 15 is formed are shown in FIG. As shown, since the suspended particles of the sprayed material to be sprayed are mainly attached to the position far from the cylinder bore inner surface 3a from the spray nozzle 11, the adhesion force is weak, and therefore the high-pressure water 26 Can be easily removed by spraying.

  When the water injection nozzle 19 is positioned at the lowermost end near the upper end of the cylinder bore 3 as shown in FIG. 1, the water curtain formed by the low-pressure water 24 injected from the first injection port 21 is the second The high-pressure water 26 sprayed from the nozzle 23 is prevented from moving toward the cylinder bore 3, and the high-pressure water 26 is bonded to the base 29 at the end portion of the sprayed coating 9, particularly at the end shown in FIG. 6. It is possible to prevent the sprayed coating 9 from being peeled off by being sprayed on the surface.

  At this time, a part of the excess sprayed coating 15 can be removed also by the low-pressure water 24 sprayed from the first injection port 21, and the low-pressure water 24 is applied to the sprayed coating 9 of the cylinder bore 3, for example. However, since this water has a low pressure and the thermal spray coating 9 has a higher degree of adhesion than the surplus thermal spray coating 15, it does not peel off.

  FIG. 7 shows a modification of the water injection nozzle 19 shown in FIG. The water injection nozzle 19A shown in FIG. 7 has the water injection nozzle 19 of FIG. 1 with the injection direction of the low-pressure water 24A from the first injection port 21A forming the water curtain as the direction away from the second injection port 23. Compared with the injection direction of the first injection port 21 in FIG.

  As a result, the water injection nozzle 19A is not inserted to a deeper position in the cylinder block 1 than the water injection nozzle 19 of FIG. It is possible to form a curtain. In this example, even if the vicinity of the tip of the water injection nozzle 19 at the position of FIG. 1 interferes with the inner wall portion of the cylinder block 3, the water injection nozzle 19A is located in FIG. A water curtain can be formed by jetting low-pressure water 24A from an upper position.

  Moreover, according to this embodiment, since the protection part which consists of liquid is comprised with the water injected from the water injection nozzles 19 and 19A, it can respond also to complicated shapes like a cylinder block inner surface, and versatility. It is expensive.

  Further, the water spray nozzles 19 and 19A that are liquid spray means include first spray ports 21 and 21A that spray water that forms a water curtain that is a protection part, and are excessively sprayed that adhere to a spray-free portion. Since the second spray port 23 for spraying water on the coating 15 side is provided, it is not necessary to provide a dedicated spray nozzle for forming the water curtain, and simplification of the entire equipment can be achieved.

  Furthermore, since the liquid which comprises a protection part is sprayed at a low pressure rather than the liquid sprayed on the spraying unnecessary site | part side to which the excess sprayed coating 15 has adhered, peeling of the sprayed coating 9 formed in the spraying site can be prevented. .

  The water injection nozzles 19, 19 a are provided with a second injection port 23 communicating with a high-pressure passage 25 a to which liquid is supplied from the outside. Since the volume expanding part 27b is provided and the first injection port 21 is provided in communication with the volume expanding part 27b, the pressure of the water flowing out from the one high pressure passage 25a to the volume expanding part 27b is reduced. The low-pressure water 21 can be injected from the first injection port 21.

  FIG. 8 is a cross-sectional view corresponding to FIG. 1, showing an excessive sprayed coating removing apparatus according to the second embodiment of the present invention. In this embodiment, the water injection nozzle 19B has a structure in which an injection port 31 for injecting high-pressure water for removing the excess sprayed coating 15 is provided at the tip of the water injection nozzle 19B. The excess sprayed coating is removed in a state in which the inverted cylinder block 1 is turned upside down so that the entire area of the cylinder bore 3 is submerged in the water 33 that is liquid.

  Specifically, the cylinder block 1 is inserted into the water 33 so that the tapered surface 7 on the crankcase 5 side including the cylinder bore 3 is also submerged. At this time, the liquid surface 33a of the water 33 constitutes a protection unit that replaces the water curtain in the first embodiment.

  In this state, the water injection nozzle 19B is inserted into the cylinder block 1 while being rotated in the same manner as the water injection nozzles 19 and 19A in the first embodiment. At this time, from the injection port 31, the water injection nozzle 19B is in accordance with the first embodiment. By spraying high-pressure water 26 similar to the second injection port 23 of the water injection nozzles 19 and 19A, the excessive sprayed coating 15 on the inner surface 5a of the crankcase 5 and the inner surface 7a of the member 7 is removed.

  At this time, the liquid surface 33a of the water 33 protects the thermal spray coating 9 from the high-pressure water 26 ejected from the ejection port 31, and the high-pressure water 26 is applied to the thermal spray coating 9 particularly at the joint portion 29 shown in FIG. Peeling of the sprayed coating 9 due to spraying can be prevented.

  In the embodiment shown in FIG. 8, the water injection nozzles 19 and 19A used in the first embodiment may be used instead of the water injection nozzle 19B. That is, in this case, the protective part that protects the sprayed coating 9 from the high-pressure water 26 that is ejected from the ejection port 31 is a double of the water surface 33a and the water curtain that is ejected from the first ejection ports 21 and 21A. It becomes a structure and can prevent the peeling of the sprayed coating 9 more reliably.

  FIG. 9 is a perspective view showing a configuration of the entire facility which is a more specific example of the above-described second embodiment. The cleaning tank 35 is open at the top and can be opened and closed by moving the shutter 37 in the vertical direction at the right side opening in FIG.

  In this cleaning tank 35, a jig 39 for fixing and holding the cylinder block 1 as a work and a work reversing mechanism 43 for installing and fixing the jig 39 are installed, and water is filled with the shutter 37 closed. A water injection nozzle 41 is provided. The jig 39 can be rotated 180 degrees together with the cylinder block 1 by the work reversing mechanism 43, and includes a jig receiver 45 for fixing the jig 39 and a pair of rotation support legs 47 for rotating and supporting the jig receiver 45. ing.

  FIG. 10 is a side view of the cylinder block 1 and the work reversing mechanism 43 fixed on the jig 39.

  The jig receiver 45 includes a bottom plate 49 on which the jig 39 is placed, and a pair of side plates 51 that rise from both side edges of the bottom plate 49, and a rotation support shaft portion 53 that protrudes to the outside of the side plate 51 has a rotation support leg. 47 is rotatable. The rotation center P of the rotation support shaft portion 53 coincides with the center of a crankshaft support hole 55 that rotates and supports a crankshaft (not shown) in the cylinder block 1.

  In FIG. 10, a rotation driving mechanism (not shown) for rotating the rotation support shaft 53 is provided outside the rotation support shaft 53 of the right rotation support leg 47 on the right side.

  Further, the bottom plate 49 and the jig 39 of the jig receiver 45 are provided with openings 49a and 39a for inserting the water spray nozzle 19B described above into the cylinder block 1, respectively. The water injection nozzle 19B here can be rotated and moved in the vertical direction Z as described above by NC control, and at the same time, the longitudinal direction X of the cylinder block 1 and the Y direction orthogonal to the X direction. It is possible to move in three axis directions.

  In the workpiece cleaning equipment having such a configuration, the cylinder block 1 is fixed on the jig 39 in an upright state with the cylinder bore 3 at the top and the crankcase 5 at the bottom with the shutter 37 opened and removed. Is fixed on the bottom plate 49 of the jig receiver 45.

  9 and 10, the rotary drive mechanism (not shown) is operated to rotate the jig receiver 45 together with the cylinder block 1 180 degrees, and the cylinder block 1 has the cylinder bore 3 at the bottom and the crankcase 5 at the top. The inverted state shown in FIG.

  Then, water is supplied from the water injection nozzle 41 into the washing tank 35 with the shutter 37 closed, and the liquid level 33a is detected and controlled by, for example, a water level sensor (not shown) so as to be at the position shown in FIG. After that, as described above, the water spray nozzle 19B is inserted into the cylinder block 1 while being rotated, thereby removing the excess sprayed coating 15. At this time, the water spray nozzle 19B is appropriately moved by NC control to sequentially insert the four cylinder bores 3 to remove the excess sprayed coating 15.

  After the excess sprayed coating 15 is removed while the cylinder block 1 is in an inverted state as described above, the cylinder block 1 is returned to the upright state shown in FIG. 9, and the water injection nozzle is applied to the inner surfaces 5a and 7a of the crankcase 5 and the member 7. Water is sprayed again from 19B to perform cleaning.

  The cylinder block 1 in the upright state in FIG. 9 is not in contact with the water 33 because the rotation surface is the crankshaft support hole 55 if the water surface 33a in FIG. 8 remains unchanged. The water injection nozzle 19B is inserted to a position where the injection port 31 faces the inner surfaces 5a, 7a of the crankcase 5 and the member 7, and the corners and the like that cannot be removed in an inverted state are cleaned (excess coating removal). .

  In each of the above-described embodiments, the excess sprayed coating 15 is removed after the honing process on the sprayed coating 9, but may be performed before the honing process. In that case, the inside of the cylinder block 1 is separately cleaned after honing.

It is sectional drawing which shows the state which has removed the excessive sprayed coating by the excessive sprayed coating removal apparatus concerning the 1st Embodiment of this invention. It is a perspective view of the cylinder block of the engine for motor vehicles which removes an excessive thermal spray coating by the excessive thermal spray coating removal apparatus of FIG. It is sectional drawing which shows the state which forms a sprayed coating with respect to the cylinder bore inner surface of a cylinder block. It is sectional drawing which expands and shows the chamfering process part with respect to the edge part of the thermal spray coating after thermal spray coating formation of FIG. It is sectional drawing which shows a part of the front end side of the water-injection nozzle which performs excess thermal spray coating removal. It is sectional drawing which expands and shows the chamfering site | part of FIG. It is sectional drawing of the principal part which shows the modification of the water injection nozzle of FIG. It is sectional drawing corresponding to FIG. 1 which shows the excessive thermal spray coating removal apparatus concerning the 2nd Embodiment of this invention. It is a perspective view which shows the structure of the whole installation which actualized 2nd Embodiment more. FIG. 10 is a side view of the cylinder block and workpiece reversing mechanism of FIG. 9.

Explanation of symbols

1 Cylinder block (work)
3a Cylinder bore inner surface (sprayed area)
5a Crankcase inner surface (spray-free part)
7a Inside surface of the member (spray-free part)
9 Thermal spray coating 19, 19A, 19B Water spray nozzle (liquid spray means)
21, 21 </ b> A The first injection port 23 of the water injection nozzle 23 The second injection port 24 of the water injection nozzle 24 Low-pressure water (protective part made of liquid)
25a High-pressure passage (liquid passage)
27a Volume expansion part 33a Water surface (protection part made of liquid)

Claims (9)

  In the method for removing an excessive sprayed coating, which is formed by forming a sprayed coating on a part that requires thermal spraying of the workpiece, and then removing the excess sprayed coating adhering to the part that does not require thermal spraying of the workpiece. A protective part made of a liquid is provided at a spray unnecessary part at a boundary part with an unnecessary spray unnecessary part, and the excess sprayed coating is removed by spraying the liquid toward the spray unnecessary part with the protective part as a boundary. To remove excess thermal spray coating.   The excess sprayed coating removing method according to claim 1, wherein the protective part made of liquid is composed of liquid ejected from a liquid ejecting means.   The said liquid injection means sprays the liquid which comprises the said protection part from the 1st injection port, and sprays a liquid on the said spraying unnecessary site | part side from the 2nd injection port, The feature of Claim 2 characterized by the above-mentioned. Excess thermal spray coating removal method.   The excess sprayed coating removal method according to claim 2 or 3, wherein the liquid constituting the protection part is sprayed at a lower pressure than the liquid sprayed to the spraying unnecessary part side.   2. The surplus according to claim 1, wherein the protection part made of the liquid is configured by a liquid surface of the liquid in a state where the sprayed part side is immersed in the liquid with the protection part as a boundary. Thermal spray coating removal method.   In the surplus spray coating removing device that forms a thermal spray coating on a part that requires thermal spraying of the workpiece and removes the excessive thermal spray coating adhered to the part that does not require thermal spraying of the workpiece, the thermal spraying part that requires thermal spraying and the thermal spraying are unnecessary. A protective portion made of a liquid is provided at a portion that does not require spraying at a boundary portion with a portion that does not require spraying, and a liquid ejecting means that sprays liquid on the side of the spraying unnecessary portion with this protective portion as a boundary is provided. A surplus sprayed coating removal apparatus characterized by the above.   The liquid ejecting means includes a first ejection port that ejects the liquid that constitutes the protection unit, and a second ejection port that sprays the liquid toward the spray unnecessary portion side with the protection unit as a boundary. The excessive sprayed-film removal apparatus of Claim 6 characterized by these.   The liquid ejecting means is provided with the second ejection port in communication with a liquid channel to which a liquid is supplied from the outside, and has a volume expansion that communicates with the liquid channel at a tip side from the second ejection port. The excess sprayed coating removing apparatus according to claim 7, further comprising: a first portion, wherein the first injection port communicates with the volume expanding portion.   This is a liquid spray nozzle used in a surplus spray coating removal device that forms a spray coating on a part that requires thermal spraying of the workpiece and removes the surplus thermal spray coating that adheres to a part that does not require thermal spraying of the workpiece, and the spraying is necessary. A protection part made of a liquid is provided at a spray unnecessary part at a boundary part between a thermal spraying part and a spray unnecessary part that does not require spraying, a first injection port for jetting the liquid constituting the protection part, and the protection part And a second spray port for removing the surplus coating by spraying the liquid on the spray-unnecessary site side, and the second spray port is provided in communication with a liquid channel to which liquid is supplied from the outside. A volume expansion portion communicating with the liquid flow path is provided on the tip side of the second injection port, and the first injection port is provided in communication with the volume expansion portion. Liquid jet nozzle.

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