JP2010005752A - Surface processing tool and surface processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface processing tool for repairing a cavity on a surface of a casting capable of removing an excessive thickness part accumulated on a tool surface. <P>SOLUTION: The surface processing tool 1 for processing an inner peripheral face C<SB>S</SB>of the casting C having a cylindrical part is provided with a body part 2 rotating around a rotational axis X and being advanced in an axis direction, a pressing projection 3 projecting from the body part 2 and having an ironing face 32a inclined with respect to the inner peripheral face C<SB>S</SB>and facing the forward face of a rotating direction and a pressing end part 3p positioned at an front end of the ironing face 32a to press the inner peripheral face C<SB>S</SB>, and a contact projection 4 projecting from the body part 2 in a back side in a forwarding direction more than the pressing projection 3 and having a cutting face 42a inclined more than the ironing face 32a, and a contact end part 4p positioned at a front end of the cutting face 42a and brought into contact with the inner peripheral face C<SB>S</SB>after the pass of the pressing projection 3. The rotating body part 2 is advanced in the axis direction in the cylindrical part and the excessive thickness part M accumulated on the ironing face 32a of the pressing projection 3 is cut by the contact projection 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to processing of an inner peripheral surface of a casting having a cylindrical portion obtained by die casting or the like.

  One of the casting products is a cylinder block of an automobile engine. The cylinder block includes a plurality of cylindrical portions (cylinder bores) that accommodate the pistons. The cylinder block is made of a light and inexpensive aluminum alloy and is often cast by die casting. In casting, a cast hole may be formed on the inner peripheral surface of the cylindrical portion. Since such a casting hole impairs the airtightness between the cylinder block and the piston, it is necessary to repair the casting hole.

  As a method of repairing the casting hole on the surface side of the casting, there is a method of crushing the casting hole by plastically deforming the surface layer of the casting by surface processing. For example, Patent Document 1 discloses a method of processing the inner peripheral surface of a cylindrical portion 81 of a casting using the cylindrical tool 1 shown in FIG. The cylindrical tool 1 has a plurality of concavo-convex processed portions 10 formed in a concavo-convex shape in which the pressing protrusions 11 and the groove portions 21 are alternately arranged in the circumferential direction in the direction of the axis C1. The arrangement positions of the pressing protrusions 11 of the uneven processing portion 10 adjacent in the axial direction are shifted from each other. By advancing the cylindrical tool 1 in the cylindrical portion 81 along the direction of the axis C1 without rotating, the inner peripheral surface of the cylindrical portion 81 is pressed by the pressing protrusions 11, so that the cast hole on the surface is crushed. This reduces casting defects.

In Patent Document 2, Patent Document 3 and Patent Document 4, the surface layer around the cast hole is plasticized by a tool attached to the rotating shaft and movable in the circumferential direction and the axial direction on the inner peripheral surface of the cylindrical casting. A method of repairing a cast hole by deforming is described. Specifically, as shown in FIGS. 1 to 8 of Patent Document 2, the tool 10 protrudes from the rotary shaft 30, is inclined with respect to the inner peripheral surface 52, and is a rake face 13 facing forward in the rotational direction, and the tool. A rake face 13 and a blade kill face 16 adjacent to each other at the tip end portion of 10. By rotating the tool 10 in the cylindrical portion and feeding it in the axial direction, the inner peripheral surface is locally pressed by the blade-killing surface 16 and plastically flows in the circumferential direction by the rake surface 13 (scoring processing). At this time, if there is a dent 55 (cast hole) on the inner peripheral surface, the surface layer 58a on the near side of the dent 55 moves and joins with the surface layer 58b on the other side of the dent 55, thereby closing a new structure 58c that closes the dent 55. Is formed.
JP 2003-191162 A JP 2003-205357 A Japanese Patent Laid-Open No. 2003-340566 JP 2004-202562 A

  According to the method for repairing a cast hole described in Patent Document 2 to Patent Document 4, the surface layer of the casting can be plastically deformed by an inexpensive tool with a simple configuration, and the cast hole is easily repaired. However, in order to repair a casting hole having a large opening on the surface, for example, it is necessary to increase the amount of tool reduction on the casting surface. As the amount of tool reduction increases, the cast hole tends to close. However, when the amount of reduction of the tool increases, the material (surplus) that is plastically flowed by the tool increases and accumulates in front of the tool in the moving direction, so that surplus material tends to aggregate on the tool surface. As a result, there is a problem that adhesion between the tool and the material is likely to occur, or the processing is not performed smoothly and the inner peripheral surface after processing is likely to be rough. In order to maintain the tool life and the appearance of the product, some countermeasures are necessary for these problems. However, at present, the countermeasures are limited to the lubrication method (for example, Patent Document 3), tool material, and surface treatment. is there.

  In view of the above problems, an object of the present invention is to provide a surface processing tool and a surface processing apparatus capable of removing surplus flocculent aggregated on the tool surface.

The surface processing tool of the present invention is a surface processing tool for processing the inner peripheral surface of a casting having a cylindrical portion,
A main body that rotates about the rotation axis and is sent in the axial direction;
A pressing having a squeezing surface that protrudes from the main body part, is inclined with respect to the inner peripheral surface and faces forward in the rotation direction, and a pressing end portion that is located at a tip portion of the squeezing surface and presses the inner peripheral surface Protrusions,
A cutting surface that protrudes from the main body portion behind the pressing projection in the feeding direction, is inclined more than the ironing surface with respect to the inner circumferential surface and faces forward in the rotation direction, and is positioned at the tip of the cutting surface. A contact protrusion having a contact end that contacts the inner peripheral surface after the pressing protrusion has passed,
The rotating main body is sent in the axial direction within the cylindrical portion, so that the surplus material gathered on the ironing surface side of the pressing protrusion is cut and removed by the contact protrusion.

The surface processing apparatus of the present invention is a surface processing apparatus for processing the inner peripheral surface of a cylindrical casting,
The surface processing tool according to the present invention is characterized by comprising: a rotating means for rotating the surface processing tool around a rotation axis; and a feeding means for feeding the surface processing tool in the axial direction.

  The surface processing tool and the surface processing apparatus of the present invention include a contact protrusion as well as a pressing protrusion that processes the inner peripheral surface of the casting by ironing. The abutting protrusion has a cutting surface that is largely inclined with respect to the inner peripheral surface than the ironing surface of the pressing protrusion, and is disposed behind the pressing protrusion in the feed direction. When the inner peripheral surface of the casting is pressed by the pressing protrusion moving on the inner peripheral surface, the surface layer of the casting plastically flows in front of the moving direction of the pressing protrusion. At this time, if there is a concave portion such as a cast hole on the inner peripheral surface side of the casting, the fluidized material moves and is supplemented to close the concave portion. The surplus is accumulated sequentially in front of the movement of the pressing protrusion, but the surplus remaining in the rear in the feeding direction is cut by the contact protrusion having a cutting surface. As a result, adhesion between the surface of the pressing protrusion and the material is prevented, and the load on the tool is reduced. Moreover, since the contact protrusion moves in a state of being in contact with the inner peripheral surface after being ironed by the pressing protrusion, the inner peripheral surface of the cast after processing is very smooth and excellent in dimensional accuracy.

  It is preferable that the pressing protrusion of the surface processing tool of the present invention further has a flank that is adjacent to the ironing surface at the rear end portion of the ironing surface and is inclined more than the ironing surface with respect to the inner circumferential surface. Due to the flank, excessive excess material can be divided in the circumferential direction. Therefore, by using the surface processing tool of the present invention having both the contact protrusion and the pressing protrusion having the flank, agglomeration of surplus is effectively suppressed.

  That is, according to the surface processing tool and the surface processing apparatus of the present invention, even when the amount of reduction of the pressing projections against the inner peripheral surface of the casting is larger than that of normal ironing, the load applied to the tool is small and good. Surface processing becomes possible.

  Below, the best form for implementing the surface processing tool and surface processing apparatus of this invention is demonstrated.

[Surface machining tool]
The surface processing tool of the present invention is a surface processing tool for processing an inner peripheral surface of a casting having a cylindrical portion, and mainly includes a main body portion, a pressing protrusion, and a contact protrusion. Below, the structure of each part is demonstrated.

  In addition, if the casting by which the surface is processed with the surface processing tool of this invention is a shape which has a cylindrical part, there will be no limitation in particular in the dimension and material. The shape is, for example, a block shape having a hole or a cylindrical shape. Specifically, the cylinder block of an engine is mentioned. If the inner diameter of the inner peripheral surface of the casting is intentionally defined, it is preferably 30 to 200 mm, more preferably 50 to 150 mm, and the inner diameter of the inner peripheral surface should not change in the axial direction. In addition, the surface processing tool of the present invention is particularly suitable for an aluminum or aluminum alloy casting that easily forms a cast hole. If the cast hole is a recess opened in the inner peripheral surface, the opening is closed by being processed by the surface processing tool of the present invention. Further, the cast hole may be a cavity that exists on the inner peripheral surface side and does not open to the inner peripheral surface. The cavity existing on the inner peripheral surface side is processed and crushed by the surface processing tool of the present invention. However, the recess and the cavity are not limited to the cast hole.

  The main body rotates about the rotation axis and is sent in the axial direction. There is no particular limitation on the shape of the main body, but it is preferable to have an outer peripheral surface having an outer diameter smaller than the inner diameter of the casting that is the work surface. Specifically, the main body portion may have a columnar shape or a cylindrical shape. Even when a plurality of pressing protrusions and abutting protrusions are provided, it is possible to arrange them in a balanced manner on the outer peripheral surface of the main body.

  The pressing protrusion protrudes from the main body portion and has at least a squeezing surface and a pressing end portion. The ironing surface is inclined with respect to the inner peripheral surface of the casting and faces forward in the rotational direction. The pressing end is located at the tip of the ironing surface and presses the inner peripheral surface of the casting. Here, the “front end portion” and the later “rear end portion” are used in the direction in which the pressing protrusion (or contact protrusion) protrudes. In addition, the direction in which the pressing protrusion (or the contact protrusion) protrudes generally coincides with the radial direction.

  The ironing surface is preferably inclined by 5 ° to 45 °, more preferably 10 ° to 30 ° with respect to the tangent line of the inner peripheral surface at the contact position between the pressing end and the inner peripheral surface of the casting. This inclination angle is hereinafter referred to as “squeezing angle”. When the ironing angle is less than 5 °, the contact area when the inner peripheral surface of the casting is pressed with a desired reduction amount becomes large, and it becomes difficult to smoothly rotate the surface processing tool. If the ironing angle exceeds 45 °, it is not preferable because the material is more likely to be divided by cutting and the cast hole cannot be repaired well than the flow of the material on the surface portion by ironing on the inner peripheral surface.

The pressing end is located at the tip of the ironing surface and constitutes the tip of the pressing protrusion. The pressing end may have a first land surface adjacent to the ironing surface. The first land surface may be configured to draw a circle having a diameter slightly larger than the inner diameter of the inner peripheral surface of the casting. Note that the difference between the radius of the inner peripheral surface of the casting and the radius of the circle drawn by the first land surface corresponds to the amount of reduction during processing. The surface processing tool of the present invention can perform good surface processing even when the reduction amount is large, but the reduction amount is preferably 0.1 to 0.4 mm in the radial direction. The first land surface preferably has a circumferential width of 0.3 to 2 mm and an axial length of 1 to 5 mm from the viewpoint of reducing a sliding load with the inner peripheral surface of the casting. the contact area between the circumferential surface 10 mm ² or less still more preferably set to 0.3 to 5 mm ^2.

  The pressing projection has a squeezing surface, and since it only needs to have a pressing end at the tip of the squeezing surface, it may be a plate-like body projecting obliquely from the main body, but from the point of strength of the pressing projection, For example, the axial cross-sectional shape of the tip portion of the pressing protrusion may be a triangle or a trapezoid. In particular, an isosceles trapezoid allows processing under the same conditions regardless of the rotation direction of the main body. However, since the pressing end presses the inner peripheral surface of the cylindrical portion, the upper base of the trapezoid may be an arc.

  It is preferable that the pressing protrusion further has a flank that is adjacent to the ironing surface at the rear end portion of the ironing surface and is inclined more than the ironing surface with respect to the inner peripheral surface. The flank is preferably inclined at 15 ° to 115 °, more preferably 20 ° to 110 ° with respect to the ironing surface. Further, if the flank is 60 ° or more with respect to the tangent line of the inner peripheral surface at the contact position between the pressing end and the inner peripheral surface of the casting, excessive surplus accumulated in the circumferential direction during processing is divided. And aggregation of the material on the ironing surface is suppressed. On the other hand, if it exceeds 120 °, the dimension of the connecting portion between the pressing protrusion and the main body is reduced, and the strength of the pressing protrusion is lowered, which is not preferable.

  The pressing protrusion may further include an axial introduction portion having a tapered surface adjacent to at least the ironing surface and the front in the feeding direction (axial direction). The tapered surface faces the inner peripheral surface of the casting and the front of the main body in the feed direction, and is preferably inclined by 1 ° to 10 °, more preferably 3 ° to 7 ° with respect to the rotation axis of the main body. If the angle is 1 ° or more, the axial direction introduction portion smoothly feeds the surface processing tool in the axial direction. However, if it exceeds 10 °, the length of the axial direction introduction portion is shortened, so that the progress of the processing accompanying the axial feed is abruptly generated, and the casting is likely to be cracked, which is not preferable.

  The contact protrusion protrudes from the main body portion behind the pressing protrusion in the feed direction, and has at least a cutting surface and a contact protrusion. The cutting surface is inclined more than the ironing surface with respect to the inner peripheral surface and faces forward in the rotational direction. The abutting end is located at the tip of the cutting surface, and the pressing projection abuts on the inner peripheral surface after passing.

  The cutting surface is preferably inclined by 60 ° to 120 °, more preferably 70 ° to 100 ° with respect to the tangent line of the inner peripheral surface at the contact position between the contact end portion and the inner peripheral surface of the casting. This inclination angle is hereinafter referred to as “cutting angle”. If the cutting angle is 60 ° or more, excess excess accumulated behind in the feed direction is satisfactorily cut by the contact protrusion. On the other hand, when the cutting angle exceeds 120 °, the size of the connecting portion between the contact protrusion and the main body is reduced, and the strength of the contact protrusion is lowered, which is not preferable.

The contact end is located at the tip of the cutting surface and constitutes the tip of the contact protrusion. The contact end portion may have a second land surface adjacent to the cutting surface. The second land surface may be configured so that the pressing protrusion draws a circle having the same diameter as the inner diameter of the inner peripheral surface after passing. In other words, the first land surface and the second land surface described above may be configured to draw a circle having the same size when rotated about the rotation axis. The second land surface reduces the sliding load with the inner peripheral surface of the casting to reduce the rotational force, and in terms of the load on the tool, the contact area with the inner peripheral surface is the first land of the pressing protrusion. It should be the same as the surface. That is, the circumferential width is preferably 0.3 to ² mm and the axial length is preferably 1 to 5 mm, and the contact area with the inner circumferential surface is 10 mm ² or less, and further 0.3 to 5 mm ² . Is preferred.

  Since the contact protrusion has a cutting surface and only needs to have a contact end at the tip of the cutting surface, the contact protrusion may be a plate-like body protruding obliquely from the main body. In view of this, for example, the axial cross-sectional shape of the tip portion of the contact protrusion may be a triangle or a trapezoid. In particular, an isosceles trapezoid allows processing under the same conditions regardless of the rotation direction of the main body. However, since the contact end portion presses the inner peripheral surface of the cylindrical portion, the upper base of the trapezoid may be an arc.

  The pressing protrusion, the contact protrusion, and the main body portion described above may be integrally formed, or the pressing protrusion and the contact protrusion may be detachable from the main body portion. Further, the pressing protrusion and the contact protrusion may be integrally formed, or may be separate from each other. The number of pressing protrusions and contact protrusions protruding from one main body is not particularly limited, and a plurality of pressing protrusions and contact protrusions may be arranged in the circumferential direction. At this time, if the contact protrusion is located behind the pressing protrusion in the feed direction, there may be a plurality of contact protrusions for one pressing protrusion. Furthermore, the pressing protrusion and the contact protrusion may rotate relative to each other.

  It is desirable that the pressing protrusion and the contact protrusion are adjacent to each other in the axial direction, and the tip of the pressing end and the tip of the contact end are disposed on the same straight line in the axial direction. Since the surplus that has accumulated in the pressing projections and excessively accumulated in the axial direction is immediately divided, surface processing is performed smoothly. Alternatively, the pressing protrusion and the contact protrusion may be disposed so that they are adjacent to each other in the axial direction, and the contact end portion is positioned behind the pressing end portion in the rotation direction. At this time, the positions of the tip of the pressing projection and the tip of the abutting projection are exactly the same in the direction perpendicular to the axis, or are more perpendicular to the axis of the abutting projection than the dimension perpendicular to the axis of the pressing projection. The dimensions should be slightly reduced so that the tip of the abutment protrusion does not stick out. Note that this is not the case when both are rotated relative to each other.

  The material of the pressing protrusion and the contact protrusion is not particularly limited as long as it is made of a material suitable for the processing of the casting surface. If the casting is made of aluminum or an aluminum alloy, the pressing protrusion and the contact protrusion may be made of tool steel, high speed steel, cemented carbide, cermet or the like. In addition, the pressing protrusion and / or the contact protrusion may be subjected to various surface treatments on the surface. For example, a hard film such as a titanium nitride film (TiN film), a vanadium carbide film (VC film), or an amorphous carbon film (DLC film) is formed on at least a part of the surface of the pressing protrusion and / or the contact protrusion. Used. These films suppress the adhesion of the surplus. The surface treatment may be performed at least on the ironing surface and the inner peripheral surface of the casting if it is a pressing protrusion, and on the cutting surface and the inner surface of the casting if it is an abutting protrusion. .

  The surface processing tool of the present invention having the pressing protrusion and the contact protrusion described above is such that the surface layer of the inner peripheral surface of the casting first pressed by the pressing protrusion is plastic by feeding the rotating main body portion in the axial direction within the cylindrical portion. To flow. At this time, if there is a recess opening on the inner peripheral surface of the casting, the fluidized material moves and is supplemented by the recess, thereby closing the opening end of the recess. In the forward direction of the pressing protrusion, surplus material accumulates sequentially. If the surplus that collects on the ironing surface side of the pressing protrusions is excessively accumulated behind the feeding direction, it is cut by the contact protrusions and removed from the ironing surface, the vicinity of the ironing surface, and the inner peripheral surface of the casting.

[Surface processing equipment]
A surface processing apparatus of the present invention is a surface processing apparatus for processing an inner peripheral surface of a cylindrical casting, the surface processing tool, a rotating means for rotating the surface processing tool around a rotation axis, and a surface processing tool A feeding means for feeding in the axial direction.

  The rotating means and the feeding means may be any driving means that sends the main body portion in the axial direction while rotating. The rotation speed and feed speed may be appropriately selected according to the diameter of the inner peripheral surface, the amount of reduction, the size and shape of the pressing protrusion and the contact protrusion, and for example, the inner peripheral surface having a diameter of 50 to 150 mm. When processing, the reduction amount should be 0.1 to 0.4 mm, and the rotation speed should be 60 to 600 rpm. The feed speed V is the total number of pressing protrusions and contact protrusions, n rotations. When the speed is N, 0.05 × N × n ≦ V ≦ 0.3 × N × n. For example, the feed speed V is 6 to 360 mm / min when n = 2 and 12 to 720 mm / min when n = 4. If the amount of rolling reduction is too large or the rotational speed is too high, the load on the tool increases, and it is not desirable because it vibrates greatly during machining and the tool life is reduced.

  Further, the surface processing apparatus of the present invention may further include a lubricant supply means for supplying a lubricant between the contact surfaces of the surface of the surface processing tool and the inner peripheral surface of the casting.

  As mentioned above, although embodiment of the surface processing tool and surface processing apparatus of this invention was described, this invention is not limited to the said embodiment. The present invention can be implemented in various forms without departing from the gist of the present invention, with modifications and improvements that can be made by those skilled in the art.

  Hereinafter, the present invention will be specifically described with reference to examples of the surface processing tool and the surface processing apparatus of the present invention. 1 to 3 are schematic views showing an example of the surface processing tool of the present invention. FIG. 1 is a plan view, FIG. 2 is a side view, and FIG. 3 is a perspective view of a pressing protrusion and a contact protrusion. is there.

[Surface processing equipment]
The surface processing apparatus includes a surface processing tool 1, rotation means (not shown) for rotating the surface processing tool 1 around the rotation axis X, and feed means (not shown) for feeding the surface processing tool 1 in the axial direction. . The rotating means and the feeding means drive the drive shaft 9 to move the surface processing tool 1 attached to the tip portion of the drive shaft 9 in the axial direction while being rotated in the cylindrical portion of the casting C (FIG. 2). See arrow).

  The surface processing tool 1 is made of high-speed tool steel SKH51, and includes a main body 2, a pressing protrusion 3, and a contact protrusion 4. The main body 2 has a hole 2h for attaching the drive shaft 9 to the center of a cylinder having a height of 25 mm. The hole 2h has a recess on the inner peripheral surface side. The drive shaft 9 has a small-diameter portion 9h that is formed at the front end portion and has a convex portion that fits into the concave portion on the rear end portion side. By inserting the small-diameter portion 9h into the hole 2h, the concave portion of the hole portion 2h and the convex portion of the small-diameter portion 9h are fitted to serve as a detent, and the relative rotation between the main body portion 2 and the drive shaft 9 is prevented. Is prevented. The main body 2 and the drive shaft 9 are fixed by a tightening nut 91 via a spring washer 92 from the distal end side of the drive shaft 9.

  The protrusion 5 protruding from the main body 2 includes a pressing protrusion 3 and an abutting protrusion 4 that are adjacent to each other in the axial direction. The protrusions 5 are formed integrally with the main body 2 on the outer peripheral surface of the main body 2, and four protrusions 5 having the same shape and dimensions are arranged at equal intervals in the circumferential direction. The length of the projection 5 in the axial direction is 25 mm, of which the pressing projection 3 occupies 17 mm from the distal end side (forward in the feed direction) of the drive shaft 9 and the contact projection 4 occupies the remaining 8 mm.

  The pressing protrusion 3 has a first land surface 31, a squeezing surface 32a and a squeezing surface 32b adjacent to the first land, a flank 33a adjacent to the squeezing surface 32a, and a flank 33b adjacent to the squeezing surface 32b. The end face of the pressing end 3p, which is the tip of the pressing protrusion 3, is the first land surface 31, and the axial length is 3 mm and the circumferential length is 0.7 mm. The pressing projections 3 are arranged in the order of the ironing surface 32a and the relief surface 33a from one long side of the first land surface 31, and the ironing surface 32b and the relief surface 33b from the other long side of the first land surface 31 in this order. It has a shape connected to the end.

  Further, the pressing protrusion 3 has an axial direction introduction portion 3q. The axial direction introduction part 3q is located on the front side in the feed direction and has a tapered surface 34 adjacent to the first land surface 31 and the ironing surfaces 32a and 32b on the front side in the feed direction.

  The contact protrusion 4 is located on the rear side in the feed direction of the pressing protrusion 3. The contact protrusion 4 has a second land surface 41, a cutting surface 42a adjacent to the second land surface, and a cutting surface 42b. The end surface of the contact end 4p, which is the tip of the contact protrusion 4, is the second land surface 41, and the axial length is 3 mm and the circumferential length is 0.5 mm. The contact protrusion 4 has a shape in which a cutting surface 42a, a second land surface 41, and a cutting surface 42b are connected in this order. The second land surface 41 is configured to draw a circle having the same size as the first land surface 31 of the pressing protrusion 3 when the second land surface 41 is rotated about the rotation axis X. That is, the first land surface 31 and the second land surface 41 are formed as the same curved surface composed of curves having the same curvature radius. Further, the contact protrusion 4 has a tapered surface 44 that is located rearward in the feed direction and is adjacent to the second land surface 41 and the cutting surfaces 42a and 42b.

[Surface processing method]
Using a surface processing apparatus described above, to process the inner peripheral surface C _S of the casting C of the aluminum alloy. Casting C is, 79.06Mm or 78.86mm diameter of the inner peripheral surface _{C S,} the outer diameter is 95 mm. In order to evaluate the repairing effect of blow holes, on the inner peripheral surface C _S, pre-processed artificial defect depth 2 mm. The diameter of the artificial defect _{C H} was 0.5 mm, 1 mm, and three types of 2 mm.

  Further, the surface machining tool 1 has an ironing angle α1 of 25 ° or 15 °, a cutting angle α2 of 70 °, an inclination angle α3 of the relief surface 33a with respect to the ironing surface 32a of 45 ° or 55 °, and a tapered surface 34 with respect to the rotation axis X. The inclination angle α4 is 7 °, and the inclination angle α5 of the tapered surface 44 with respect to the rotation axis X is 15 °. The radius of curvature of the first land surface and the second land surface was 39.63 mm, and the tool rotation speed was 60 rpm. During the processing, a lubricant was sprayed on the surface of the surface processing tool 1.

  The following six types of surface processing were performed by changing the ironing angle α1, the reduction amount, and the axial feed speed of the surface processing tool 1. Table 1 shows the processing conditions.

  Next, the surface processing method will be described with reference to FIGS. FIG. 4 is a side view (left view) of the protrusion 5 as viewed from the front end side of the protrusion 5 and a side view (right view) of the protrusion 5 as viewed from the front in the rotational direction. FIG. 5 is a plan view of the protrusion 5 as seen from the rear in the feed direction. FIG. 5 shows the inclination angles α1, α2, and α3 of the ironing surface 32b, the cutting surface 42b, and the flank 33b. The protrusion 5 passes through the centers of the first land surface 31 and the second land surface 41 and has a diameter. Since it is symmetrical with respect to the surface Y spreading in the direction, the inclination angles of the ironing surface 32a, the cutting surface 42a and the flank 33a are the same as α1 to α3.

The surface processing tool 1 is inserted into the cylindrical part of the casting C from the axial direction introduction part 3q side. When the surface machining tool 1 is fed in the axial direction in this state, the pressing end portion 3p presses the inner peripheral surface C _S. Then, when the pressing projection 3 moves the inner peripheral surface C _S in the circumferential direction and the axial direction, the surface layer of the inner peripheral surface C _S that is pressed to plastic flow by pressing projection 3. At this time, surplus meat M accumulates sequentially on the ironing surface 32a facing forward in the rotation direction. In the periphery of the artificial defect C _H, the excess thickness M _C which is a part of the excess metal M is compensated by moving the concave portion, the artificial defect C _H is closed. Of the remaining surplus M, surplus M _{3 that} has accumulated excessively in the circumferential direction is divided by the flank 33a. Further, the excess M ₄ accumulated excessively rearward in the feed direction is cut by the contact protrusion 4 having the cutting surface 42a. Further, the second land surface 41 of the abutment projection 4, the surface of the inner peripheral surface C _S is smooth.

[Evaluation]
After surface processing, as well as visually observed the inner peripheral surface C _S of the ironing surface 32a and casting C, and observed a cross-section of a prosthetic defect C _H diametrically cutting the castings C in the axial direction by an optical microscope . Each cross-sectional photograph is shown in FIGS.

In Examples 1 to 3 in which the inclination angle of the ironing surface 32a was 25 °, an artificial defect having a diameter of 1 mm could be completely blocked by setting the reduction amount to 0.2 mm. In this case, the casting C of any of Examples 1 to 3 also, rough on the inner peripheral surface C _S is not observed, a smooth surface was obtained. Moreover, in any of the examples, metal scraps that seemed to be surplus cut during processing were generated, and no material adhesion was observed on the ironing surface 32a after processing.

Further, in Examples 4 to 6 in which the inclination angle of the ironing surface 32a was 15 °, an artificial defect having a diameter of 2 mm could be completely blocked by setting the reduction amount to 0.2 mm. At this time, one of the casting C also rough on the inner peripheral surface C _S is not observed, a smooth surface was obtained. Moreover, in any of the examples, metal scraps that seemed to be surplus cut during processing were generated, and material adhesion slightly occurred on the ironing surface 32a after processing. This adhesion was suppressed by applying a surface treatment to form an amorphous carbon film or a VC film on the surface.

In Examples 1 to 6, even when the tool rotation speed is set to 300 rpm, the artificial defect can be blocked in the same manner as described above, and material adhesion to the ironing surface 32a and casting C roughening of the inner peripheral surface C _S was observed.

It is a schematic diagram which shows the surface processing tool used for each Example, Comprising: It is the top view seen from the feed direction back. It is a side view which shows typically the surface processing tool used for each Example. It is a perspective view which shows the press protrusion and contact protrusion which comprise the surface processing tool shown in FIG. 1 and FIG. It is a side view which shows the press protrusion and contact protrusion which comprise the surface processing tool used for each Example. It is a top view which shows the press protrusion and contact protrusion which comprise the surface processing tool used for each Example. 2 is a drawing-substituting photograph showing a cross section of a casting processed in Example 1. FIG. 6 is a drawing-substituting photograph showing a cross section of a casting processed in Example 2. FIG. 4 is a drawing-substituting photograph showing a cross section of a casting processed in Example 3. FIG. 6 is a drawing-substituting photograph showing a cross section of a casting processed in Example 4. FIG. 6 is a drawing-substituting photograph showing a cross section of a casting machined in Example 5. FIG. 10 is a drawing-substituting photograph showing a cross section of a casting machined in Example 6. FIG.

Explanation of symbols

1: Surface processing tool 2: Main body part 3: Pressing protrusion 3p: Pressing end part 31: First land surface 32a, 32b: Ironing surface 33a, 33b: Relief surface 4: Contacting protrusion 4p: Contacting end part 41: First Two land surfaces 42a, 42b: Cutting surfaces

Claims (9)

A surface processing tool for processing an inner peripheral surface of a casting having a cylindrical portion,
A main body that rotates about the rotation axis and is sent in the axial direction;
A pressing having a squeezing surface that protrudes from the main body part, is inclined with respect to the inner peripheral surface and faces forward in the rotation direction, and a pressing end portion that is located at a tip portion of the squeezing surface and presses the inner peripheral surface Protrusions,
A cutting surface that protrudes from the main body portion behind the pressing projection in the feeding direction, is inclined more than the ironing surface with respect to the inner circumferential surface and faces forward in the rotation direction, and is positioned at the tip of the cutting surface. A contact protrusion having a contact end that contacts the inner peripheral surface after the pressing protrusion has passed,
The surplus body that collects on the ironing surface side of the pressing protrusion is cut and removed by the contact protrusion by feeding the rotating main body section in the axial direction within the cylindrical section. tool.   2. The pressing protrusion and the abutting protrusion are adjacent to each other in the axial direction, and the tip of the pressing end and the tip of the abutting end are arranged on the same straight line in the axial direction. Surface processing tools.   The surface processing according to claim 1, wherein the pressing protrusion and the contact protrusion are adjacent to each other in the axial direction, and the contact end portion is disposed behind the pressing end portion in the rotation direction. tool.   2. The surface processing tool according to claim 1, wherein the pressing protrusion further has a flank that is adjacent to the ironing surface at a rear end portion of the ironing surface and is inclined more than the ironing surface with respect to the inner peripheral surface.   The surface processing tool according to claim 1, wherein the pressing protrusion and / or the abutting protrusion is subjected to a surface treatment on at least a part of a surface thereof.   The surface processing tool according to claim 1, wherein the ironing surface is inclined by 5 ° to 45 ° with respect to a tangent line of the inner peripheral surface at a contact position between the pressing end portion and the inner peripheral surface.   The surface processing tool according to claim 1, wherein the cutting surface is inclined by 60 ° to 120 ° with respect to a tangent line of the inner peripheral surface at a contact position between the contact end portion and the inner peripheral surface. A surface processing apparatus for processing an inner peripheral surface of a cylindrical casting,
A surface processing apparatus comprising: the surface processing tool according to claim 1; a rotating unit that rotates the surface processing tool around a rotation axis; and a feeding unit that sends the surface processing tool in an axial direction. .   The surface processing apparatus according to claim 8, further comprising a lubricant supply unit configured to supply a lubricant between contact surfaces of the surface of the surface processing tool and the inner peripheral surface.