JP2009136783A - Method for measuring tight adhesive force of sprayed coating and drill used for tight adhesive force measurement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely measure the tight adhesive force of a sprayed coating to the work surface. <P>SOLUTION: A tip adhesive face 11e of a guide part 11 is stuck to and fixed on a sprayed coating 15 formed on the surface of a work W by using an adhesive and a pin 13 is inserted in to a pin insertion hole formed in the center part of the guide part 11 to push the work W and separate the sprayed coating 15 to measure the tight adhesive force. At that time, prior to the measurement of tight adhesive force, a part of the adhesive inserted into the pin insertion hole while rising up in an aperture in the end part of the pin insertion hole in the sprayed coating side is removed by the drill whose tip end is cut to be flat. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal spray coating adhesion measuring method for measuring the adhesion strength of a thermal spray coating formed on the surface of a workpiece and a drill used in the adhesion strength measuring method.

As a cylinder block of an internal combustion engine, there is known a linerless cylinder block in which a thermal spray coating is formed on an inner peripheral surface of a cylinder bore instead of casting a liner (see Patent Document 1 below).
JP 2005-194938 A

  By the way, in the linerless cylinder block as described above, since this thermal spray coating substantially functions as a liner, it is important to secure adhesion with the inner peripheral surface of the cylinder bore, and the adhesion force can be measured as tensile adhesion strength. Although described in Patent Document 1 described above, the measurement needs to be performed with high accuracy.

  Therefore, an object of the present invention is to accurately measure the adhesion of the thermal spray coating to the work surface.

  The present invention is a through-hole in which an adhesive force measuring tool is bonded and fixed with an adhesive on a sprayed coating formed on the surface of a workpiece, and the adhesive is exposed from one end opening provided in the adhesive force measuring tool. The exposed adhesive is removed from the other end opening of the through hole, and the surface of the workpiece is penetrated through the thermal spray coating exposed by removing the adhesive while holding the adhesion measuring instrument. The most important feature is that the thermal spray coating is peeled off from the workpiece surface by pressing with a pressing tool inserted from the other end opening of the hole, and the adhesion of the thermal spray coating to the workpiece surface is measured.

  According to the present invention, the adhesion coating tool is adhered and fixed to the surface of the thermal spray coating via an adhesive, and the thermal spray coating exposed by this removal is removed in a state where the adhesive exposed from the through hole of the adhesion measurement tool is removed. When the workpiece is pressed through, forces in a direction away from each other act between the workpiece surface and the thermal spray coating, and the adhesion force can be measured with high accuracy.

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

  FIG. 1 is a front view showing the configuration of the entire apparatus for measuring the adhesion of a thermal spray coating, showing an embodiment of the present invention. A gate-shaped jig 3 is installed on the base plate 1, and the jig 3 includes a pair of leg portions 5 on both the left and right sides, and a horizontal instrument mounting portion 7 that connects the upper ends of the leg portions 5 to each other. It has.

  A substantially U-shaped recess 7a is formed in the center of the instrument mounting portion 7 in a plan view in FIG. 1, and the bottom center of the recess 7a is smaller than the recess 7a and is substantially U in a plan view in FIG. A letter-shaped guide portion insertion hole 7b is provided. In other words, the concave portion 7a and the guide portion insertion hole 7b are open on the front side in FIG.

  The adhesion force measuring instrument 9 set on the jig 3 includes a guide part 11 as an adhesion force measuring tool and a pin 13 as a pressing tool that is movably inserted into the guide part 11. As shown in a front view in FIG. 2A and a bottom view in FIG. 2B, the guide portion 11 includes a boss portion 11a inserted into the recess portion 7a of the instrument mounting portion 7 and an upper portion of the boss portion 11a. An upper shaft portion 11b that protrudes upward from the end surface, a lower shaft portion 11c that protrudes downward from the lower end surface of the boss portion 11a and is inserted into the guide portion insertion hole 7b of the instrument mounting portion 7, and a lower end of the lower shaft portion 11c. An adhesive fixing part 11d that is continuous and has a larger diameter than the lower shaft part 11c is provided. The outer diameters of the upper shaft portion 11b and the lower shaft portion 11c are the same.

  The lower shaft portion 11c described above protrudes downward from the guide portion insertion hole 7b in a state where the boss portion 11a is placed on the bottom surface 7c of the concave portion 7a, and the adhesive fixing portion 11d provided at the distal end thereof is connected to the distal end adhesive surface 11e. Is a convex curved surface corresponding to the concave curved surface Wa which is the surface of the workpiece W.

  The workpiece W is a measurement test piece obtained by cutting a part of the cylinder bore 29 formed in the cylinder block 27 of the engine shown in FIG. 6, and the sprayed coating 15 is formed on the concave curved surface Wa. And the front-end | tip adhesion surface 11e of the adhesion fixing | fixed part 11d in the guide part 11 and the thermal spray coating 15 of the workpiece | work W are adhere-fixed by the sheet-like adhesive 17 shown in FIG.

  Further, as shown in FIG. 2, the guide portion 11 of the instrument 9 for measuring the adhesion force extends from the upper shaft portion 11b to the adhesive fixing portion 11d at the lower end, and a pin insertion hole 11f as a through hole penetrating the shaft center portion. Is forming. The pin insertion hole 11f includes a large diameter portion 11g from the upper shaft portion 11b to a substantially intermediate position of the lower shaft portion 11c, and a small diameter portion 11h from the intermediate position to the adhesive fixing portion 11d.

  As shown in FIG. 1, the upper shaft portion 11 b protrudes upward from the upper surface 7 d of the instrument mounting portion 7, and this protruding portion is inserted into the insertion hole 19 a of the fixing plate 19. The fixing plate 19 is fixed to the upper surface 7d of the instrument mounting portion 7 by a fixing tool 21 such as a bolt. At this time, the inner diameter of the insertion hole 19a described above is substantially equal to the outer diameter of the upper shaft portion 11b. The horizontal displacement of the guide part 11 set in the jig 3 is prevented.

  The pin 13 corresponds to the large diameter portion 11g and the small diameter portion 11h of the pin insertion hole 11f of the guide portion 11 as shown in the front view in FIG. 3A and the bottom view in FIG. A pin large-diameter portion 13a and a pin small-diameter portion 13b are provided, a taper portion 13c is provided between the pin large-diameter portion 13a and the pin small-diameter portion 13b, and a disk portion 13d is provided at the upper end of the pin large-diameter portion 13a. I have. However, the length of the pin small diameter portion 13b is formed longer than the length of the small diameter portion 11h of the pin insertion hole 11f.

  Further, as shown in FIG. 1, a pressure head 23 using hydraulic pressure is installed above the pin 13 in a state of being inserted into the pin insertion hole 11f. The disk portion 13d is configured to pressurize downward. By pressurizing the workpiece W through the pin 13 by the pressurizing head 23 described above, the thermal spray coating 15 is peeled off and the adhesion force thereof is measured.

  Here, when the distal end adhesive surface 11e of the adhesive fixing portion 11d in the guide portion 11 is adhesively fixed in a state of being pressed against the curved surface Wa of the workpiece W via the sheet adhesive 17, as shown in FIG. The part 17a of the adhesive 17 enters the pin insertion hole 11f so as to rise from one end opening 11i on the workpiece W side. Further, a part 17b of the adhesive protruding from the tip adhesive surface 11e can be seen around the adhesive fixing portion 11d.

  Further, when measuring the adhesion of the above-described thermal spray coating 15, it is performed in a state in which a part 17a of the sheet-like adhesive 17 that has entered one end opening 11i of the pin insertion hole 11f is removed. For removing the part 17a of the sheet-like adhesive 17, a drill 25 whose part on the front end side is shown as a perspective view in FIG. 5 is used. The drill 25 has an outer diameter (diameter) of, for example, 4.5 mm, which is substantially the same diameter as the pin insertion hole 11f, and a tip 25 is ground with a grindstone or the like to provide a flat surface 25a. Further, a chamfer 25c is provided on the periphery of the flat surface 25a on the rake portion 25b side.

  Next, the operation will be described. The cylinder block 27 shown in FIG. 6 is made of an aluminum alloy, and the thermal spray coating 15 made of iron-based metal is formed on the curved surface Wa, which is the inner surface of the cylinder bore 29, by using a conventionally known thermal spraying device. It is an alternative to a cylinder block with a structure in which is cast.

  And in this embodiment, before setting the guide part 11 of the instrument 9 for contact | adhesion force measurement to the jig | tool 3, between the front-end | tip adhesion surface 11e of the adhesion fixing part 11d in the guide part 11, and the thermal spray coating 15 of the workpiece | work W. As shown in FIG. 7A, a circular sheet-like adhesive 17 having the same shape as the outer shape of the tip adhesive surface 11e is disposed, and the sheet-like adhesive 17 is melted by heating in this state and then solidified. Thus, the tip adhesive surface 11e and the thermal spray coating 15 are bonded and fixed.

  At this time, as shown in FIG. 4 described above, a part 17a of the sheet-like adhesive 17 enters the pin insertion hole 11f so as to rise.

  As shown in FIG. 7 (b), a portion 17 a of the sheet-like adhesive 17 that has entered is inserted into the pin insertion hole 11 f without rotating the drill 25, and the flat surface 25 a at the tip of the adhesive 17 is The portion 17a is pressed against the portion 17a, and by this pressing operation, a further portion 17c of the portion 17a is raised on the rake portion 25b of the drill 25 which is a space portion between the drill 25 and the inner peripheral surface of the pin insertion hole 11f. Get in.

  Subsequently, by rotating the drill 25 from this state, the cutting blade 25d starts cutting from the raised portion 17c, and further moves downward while rotating, whereby the portion 17a of the sheet-like adhesive 17 is gradually moved. Cutting is performed, and finally a part 17a of the sheet-like adhesive 17 is almost completely removed as shown in FIG.

  As shown in FIG. 7C, after the part 17a of the sheet-like adhesive 17 is almost completely removed, the flat surface 25a at the tip of the drill 25 comes into contact with the thermal spray coating 15, but this flat surface 25a is Since the tip of the drill 25 is simply ground so as to be flat and does not have a cutting edge like the end face of the end mill, the fine irregularities on the surface of the sprayed coating 15 are cut to provide a smooth surface. However, a situation in which the thermal spray coating 15 itself is cut is avoided.

  For example, the part 17a of the sheet-like adhesive 17 is removed by, for example, attaching a handle or the like to the base end portion of the drill 25 to form a hand drill, and the operator manually rotates the hand drill. Do.

  After the part 17a of the sheet-like adhesive 17 is almost completely removed, the drill 25 is pulled out from the guide part 11, and the pulled-out guide part 11 is set on the jig 3 as shown in FIG. At this time, the guide portion 11 is inserted into the concave portion 7a and the guide portion insertion hole 7b which are U-shaped in a plan view so as to be pushed from the open side on the front side of the drawing in FIG.

  Thereafter, the plate 19 is placed on the upper surface 7 d of the instrument mounting portion 7 while the upper shaft portion 11 b of the guide portion 11 is inserted into the insertion hole 19 a and is fixed by the fastener 21. At this time, the upper shaft portion 11 b protrudes upward from the plate 19.

  In this state, the pin 13 is inserted into the pin insertion hole 11f of the guide portion 11 as shown in FIG. 1, and at this time, as shown in FIG. 8, the distal end surface 13e of the pin small diameter portion 13b of the pin 13 is flat. Comes into contact with the thermal spray coating 15. In this contact state, the pressure head 23 is lowered to press the disk portion 13d of the pin 13 downward, and the workpiece W is pressed through the thermal spray coating 15 by the tip surface 13e of the pin 13 described above.

  At this time, since the guide portion 11 is placed on the bottom surface 7c of the concave portion 7a and the movement in the pressing direction is restricted, the guide portion 11 is held by the jig 3, and the curved surface Wa of the workpiece W and the thermal spray coating 15 In the meantime, forces in directions away from each other act.

  In addition, the sheet-like adhesive 17 at this time is in a completely solidified state, and the adhesive force of the solidified sheet-like adhesive 17 is stronger than the adhesion force of the thermal spray coating 15 to the workpiece W.

  The pressure applied by the pressure head 23 is gradually increased, and in the process, as shown in FIG. 9, the portion of the sprayed coating 15 a bonded and fixed to the guide portion 11 is peeled off from the concave curved surface Wa of the workpiece W. It becomes a state. At that time, the tip of the pin 13 is in a state of slightly protruding toward the workpiece W so as to break through the portion of the thermal spray coating that was in contact with the pin 13 during pressing.

  Then, the pressure applied by the pressure head 23 at the time when the thermal spray coating 15a is peeled off is measured to obtain the adhesion of the thermal spray coating.

  FIG. 10 shows that n = 10 measurement test pieces (work W) are prepared for each of the six cylinder bores # 1 to # 6 in a six-cylinder engine, and the above-mentioned adhesion force is measured. The upper limit value (upper horizontal bar), the lower limit value (lower horizontal bar) and the average value (circle) of each of the ten adhesion forces in # 1 to # 6 are shown, and these six upper limit values and lower limit values The average of each of the average values is also shown.

  According to this, the width of the measurement variation between the upper limit value and the lower limit value is 4.4 MPa, which is extremely small compared to the variation width of the current measurement method shown as a reference is 10 MPa. I understand that.

  As described above, according to the present embodiment, the guide part 11 is bonded and fixed to the surface of the thermal spray coating 15 via the sheet-like adhesive 17, and the sheet-like adhesive 17 exposed from the pin insertion hole 11 f of the guide part 11. By pressing the sprayed coating 15 that is exposed after the removal of the part 17a, a force in the direction of separating from the curved surface Wa of the workpiece W and the sprayed coating 15 acts reliably, and the adhesion force Can be measured with high accuracy.

  In the present embodiment, a part 17a of the sheet-like adhesive 17 exposed from one end opening 11i on the thermal spray coating 15 side of the pin insertion hole 11f is transferred from the other end opening 11j to the pin insertion hole 11f. It can be easily removed by the inserted drill 25.

  Further, since the flat surface 25 a is provided at the tip of the drill 25, the flat surface 25 a is pressed against a part 17 a of the sheet adhesive 17, so that a part 17 a of the sheet adhesive 17 is moved to the drill 25. If the drill 25 is rotated in this state, the part 17a of the sheet-like adhesive 17 can be easily removed.

  At this time, since the flat surface 25a of the drill 25 is simply flattened by grinding the tip and is not provided with a cutting edge, the operator rotates the drill 25 manually, and the flat surface 25a is sprayed. Even if the thermal spray coating 15 is in contact with the thermal spray coating 15, the thermal spray coating 15 merely scrapes off the uneven portion of the surface as described above, and basically does not cut the thermal spray coating 15. Only a part 17a of the agent 17 can be removed.

  Further, by chamfering 25c on the peripheral edge of the flat surface 25a of the drill 25 on the side of the rake portion 25b, a part 17a of the sheet-like adhesive 17 easily enters the rake portion 25b from the chamfered portion, and the drill 25 thereafter The cutting work of the part 17a of the sheet-like adhesive 17 by rotation can be performed efficiently.

  The guide part 11 is bonded and fixed to the thermal spray coating 15 using the sheet-like adhesive 17, and the removal work of the part 17 a of the sheet-like adhesive 17 by the drill 25 is performed by using the guide part 11 as a jig. In this case, the concave portion 7a and the guide portion insertion hole 7b of the jig 3 can be made circular instead of being U-shaped in plan view.

  Further, in order to remove the part 17a of the sheet-like adhesive 17, an end mill used for milling may be used instead of the drill 25 described above. However, since the end mill has a cutting edge on the tip surface, it is necessary to avoid cutting the sprayed coating 15 after removing the part 17a of the sheet-like adhesive 17, so it is difficult to perform manually. For example, it is necessary to perform work by performing position control in the feed direction of the end mill.

  The tip of the drill 25 is a flat surface 25a, and a part 17a of the sheet adhesive 17 is removed by the flat surface 25a. At this time, the surface of the sprayed coating 15 is actually a curved surface. Since the diameter is extremely thin as 4.5 mm, even if it is a curved surface, the portion corresponding to the flat surface 25a can be regarded as a substantially flat surface. Therefore, as shown in FIG. It is possible to remove a part 17a of the part in a state almost completely.

  Therefore, in order to more completely remove the part 17 a of the sheet-like adhesive 17, the flat surface 25 a may have a convex curved surface shape that matches the curved surface of the surface of the thermal spray coating 15.

It is a front view which shows the structure of the whole apparatus which implements the adhesive force measurement of a thermal spray coating which shows one Embodiment of this invention. (A) is a front view of the guide part used for the apparatus of FIG. 1, (b) is a bottom view of (a). (A) is a front view of the pin used for the apparatus of FIG. 1, (b) is a bottom view of (a). It is a fragmentary sectional view which shows the state which adhere | attached and fixed the guide part of FIG. 2 to the sprayed coating surface of the workpiece | work with the adhesive agent. It is a perspective view which shows a part of drill which removes an adhesive agent. It is sectional drawing of the cylinder block which formed the sprayed coating in the cylinder bore inner surface. (A) is a fragmentary sectional view which shows the state which apply | coated the adhesive agent to the front end surface of the adhesion fixing part of a guide part, (b), after adhering and fixing a guide part to the sprayed coating surface of a workpiece | work with an adhesive, a guide The partial sectional view which shows the state which removed the adhesive agent which entered the pin insertion hole of the part with a drill, (c) is the partial sectional view which shows the state which removed the adhesive agent of (b) almost completely with the drill is there. It is a fragmentary sectional view which shows the state which pulled out the drill from the state of FIG.7 (b), and inserted the pin in the pin insertion hole. It is a front view corresponding to FIG. 1 which shows the state after an adhesive force measurement test. It is explanatory drawing which shows the result of having measured contact | adhesion power with respect to 10 measurement test pieces in each of 6 cylinder bores of a 6-cylinder engine with the result of a reference example.

Explanation of symbols

W Workpiece Wa Work surface (work surface)
11 Guide (Adhesion measuring tool)
11f Pin insertion hole (through hole)
11i One end opening of pin insertion hole 11h Other end opening of pin insertion hole 13 Pin (pressing tool)
DESCRIPTION OF SYMBOLS 15 Thermal spray coating 15a Thermal spray coating peeled off from workpiece | work after a measurement test 17 Sheet-like adhesive 25 Drill 25a Drill flat surface 25b Drill rake part 25c The chamfering provided in the periphery of the rake part side of a flat surface

Claims (6)

  On the thermal spray coating formed on the surface of the workpiece, an adhesive force measuring tool is bonded and fixed using an adhesive, and a through hole provided in the adhesive force measuring tool to expose the adhesive from one end opening is provided. The exposed adhesive is removed from the other end opening of the through hole, and the surface of the workpiece is held through the thermal spray coating exposed by removing the adhesive while the adhesive force measuring tool is held. Adhesion force measurement of a thermal spray coating characterized in that the thermal spray coating is peeled off from the workpiece surface by pressing with a pressing tool inserted from the other end opening of the through hole to measure the adhesion force of the thermal spray coating to the workpiece surface Method.   The adhesive force measurement of the thermal spray coating according to claim 1, wherein the adhesive exposed from one end opening of the through hole is removed by a drill inserted into the through hole from the other end opening. Method.   A flat surface is provided at the tip of the drill, and the flat surface is pressed against the adhesive exposed from one end opening of the through hole so that a part of the adhesive enters the rake portion, and then the drill is rotated. The method for measuring the adhesion of a sprayed coating according to claim 2, wherein:   4. The adhesion strength measurement of a sprayed coating according to claim 3, wherein chamfering is performed on a peripheral edge of the flat surface of the drill on the side of the rake portion, and a part of the adhesive enters the rake portion from the chamfered portion. Method.   On the thermal spray coating formed on the surface of the workpiece, an adhesive force measuring tool is bonded and fixed using an adhesive, and a through hole provided in the adhesive force measuring tool to expose the adhesive from one end opening is provided. The exposed adhesive is removed from the other end opening of the through hole, and the surface of the workpiece is held through the thermal spray coating exposed by removing the adhesive while the adhesive force measuring tool is held. When measuring the adhesion of the thermal spray coating to the work surface by pressing with a pressing tool inserted from the other end opening of the through hole to peel off the thermal spray coating from the work surface, the other end opening of the through hole is measured. A drill that removes the exposed adhesive inserted from the top, provided with a flat surface at the tip, and presses the flat surface against the adhesive exposed from one end opening of the through-hole, and the adhesive Part of Drill for causing enter the scoop portion.   6. The drill according to claim 5, wherein chamfering is performed on a peripheral edge of the flat surface of the drill on the side of the rake portion, and a part of the adhesive enters the rake portion from the chamfered portion.

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