JP4831453B2 - Forming tools - Google Patents

Description

  The present invention relates to a forming tool used for forming a large number of fine recesses on the outer peripheral surface of a cylindrical part for a workpiece having a cylindrical part, and more specifically, an apparatus such as an automobile engine or a transmission. This invention relates to a forming tool used to form fine irregularities for reducing friction on the sliding surface of the sliding component constituting the.

  Fig.7 (a) is a figure explaining the apparatus which forms many fine recessed parts in the outer peripheral surface S of a cylindrical part with respect to the workpiece W which has a cylindrical part. One end of the workpiece W is held by the chucking device 102 of the headstock 101 in the processing machine. The forming device 105 has a shaft 107 that can reciprocate in the axial direction (Z direction) of the workpiece W held by the chucking device 102 and can move back and forth in the direction of the workpiece W (X direction). A forming tool 150 is attached to the tip of the shaft 107.

  The forming tool 150 includes a retainer 151 connected to the shaft 107, a rotating shaft 152 that is rotatably attached to the retainer 151, and a foam roller 153 that is attached to the rotating shaft 152. The foam roller 153 is arranged so that the rotation shaft 152 thereof is parallel to the rotation shaft of the workpiece W. As shown in FIG. 7B, a large number of fine convex portions 153a for forming concave portions are provided on the outer peripheral portion of the foam roller 153 at predetermined intervals in the circumferential direction and the axial direction.

The above apparatus rotates the workpiece W while pressing the foam roller 153 against the outer circumferential surface S of the workpiece W with a constant load, thereby causing the foam roller 153 to rotate and the outer circumferential surface S of the cylindrical portion. In this case, a large number of concave portions are formed on the entire outer peripheral surface S by moving the forming tool 150 in the axial direction of the workpiece W.
JP 2002-361351 A

  By the way, for example, as shown in FIG. 6, the workpiece is a crankshaft CS, and a large number of recesses are formed almost entirely on the outer peripheral surface of a cylindrical portion that is a journal J or a crankpin P. Since the counterweight CW protrudes in the radial direction in the vicinity of the cylindrical portion, it is difficult to move the foam roller in the axial direction of the rotation shaft. For this reason, in order to form concave portions on the outer peripheral surface of the cylindrical portion, a large number of convex portions are arranged in the circumferential direction and the axial direction as foam rollers that can form concave portions without moving the rotating shaft in the axial direction. The used foam roller (see FIG. 7) had to be used.

  However, in the conventional forming tool provided with the foam roller as described above, a plurality of convex portions arranged in the axial direction of the rotation axis of the foam roller simultaneously contact the workpiece. This increases the amount of pressing force, which increases the size of the entire forming device as well as the tool.In addition, the machining surface is tilted due to waviness of the machining surface of the workpiece, positioning error of the workpiece, etc. If it occurs, there is a problem that it is difficult to make the plurality of convex portions uniformly contact with the processed surface. Therefore, it has been a problem to solve these problems.

  The present invention has been made paying attention to the above-mentioned conventional problems, and in particular, in a forming tool for forming a large number of minute recesses on the outer peripheral surface of a cylindrical portion, on a workpiece having the cylindrical portion, Even when the workpiece has an interference portion in the vicinity of the cylindrical portion that prevents the axial movement of the forming tool, a large number of concave portions are formed with a small pressing load on the outer peripheral surface of the cylindrical portion of the workpiece. An object of the present invention is to provide a forming tool that can be formed with high accuracy.

The forming tool of the present invention is a forming tool for forming a large number of fine concave portions on the outer peripheral surface of a cylindrical portion with respect to a workpiece having a cylindrical portion, and a large number of convex portions for forming concave portions on the outer peripheral portion. comprises a foam roller which is arranged a number of protrusions, are positioned as Ru configuration tare at predetermined intervals along a helical continuous over only one round form roller, the outer circumference of the cylindrical portion of the form roller at a constant load By rotating the workpiece around the axis of the cylindrical portion in contact with the surface, the foam roller is rotated to form a fine recess on the outer peripheral surface of the cylindrical portion. And many recessed parts are formed in the substantially whole outer peripheral surface of a cylindrical part by rotating a to-be-processed object in multiple times.

According to the forming tool of the present invention, even when the workpiece has an interference portion in the vicinity of the cylindrical portion that prevents the forming tool from moving in the axial direction, the foam roller is moved in the axial direction of the rotating shaft. without, it is possible to form a large number of concave portions to substantially the entire outer peripheral surface of the cylindrical portion, this time, only a small portion of the convex portion is in contact with one箇office of the outer peripheral surface of the cylindrical portion of the workpiece since, pressing it shall load is small, thereby the tool and it is possible to reduce the overall size of the forming apparatus, even if inclined working surface of the workpiece for example, a small portion to an箇office in working surface Therefore, the concave portions can be formed with high accuracy with almost no influence of the inclination of the processed surface, and all the concave portions can be formed uniformly with high accuracy.

  FIG. 1 is a view for explaining an embodiment of a forming tool according to the present invention. The workpiece to be processed by the forming tool is not particularly limited, but the workpiece having an interference portion that prevents the forming tool from moving in the axial direction in the vicinity of the cylindrical portion, that is, a workpiece shown in FIG. A crankshaft CS can be mentioned. In this case, the crankpin P and the journal J are cylindrical portions, and the counterweight CW corresponds to an interference portion.

  A forming tool 1 shown in FIGS. 1A and 1B is attached to a retainer 2 connected to a shaft 107 of a forming device 105, a rotary shaft 3 provided to be rotatable with respect to the retainer 2, and the rotary shaft 3. The foam roller 4 is provided, and is held so that the foam roller 4 can advance and retreat with respect to the crankshaft CS shown in FIG. At this time, the forming device 105 holds the forming tool 1 so that the rotating shaft 3 of the foam roller 4 and the rotating shaft of the crank pin P are parallel to each other.

  The material of the foam roller 4 is not particularly limited. For example, the material is made of carbide, high speed or other hard metal, ceramics such as alumina, silicon nitride, and the like, as shown in FIG. The crankshaft CS is inserted between the counterweight CW of the crankshaft CS together with the retainer 2 and has a width corresponding to the crankpin P.

In the foam roller 4, convex portions 4 a for forming concave portions are spirally arranged at predetermined intervals on the outer peripheral portion. In this embodiment, the convex portions 4 a of the foam roller 4 are continuous over one circumference of the roller 4. It is arranged along the spiral. This spiral extends from one end surface of the foam roller 4 to the other end surface. The height of the convex portion 4a is, for example, about 100 μm. Since these convex portions 4a are arranged so as to form continuous irregularities when viewed from the rotational axis direction of the foam roller 4, grinding or wire cutting from the rotational axis direction makes comparison even though it has a complicated shape. Can be formed easily .

  Further, as shown in FIG. 2, the foam roller 4 has a radius R that extends from the center of rotation to the tip of the convex portion 4a with respect to the distance r from the center of the crank pin P to the bottom surface of the concave portion formed on the surface. Further, the size is an integral multiple, and as shown in FIG. 3, the tip of the convex portion 4 a has an arc shape in a cross section including the rotation shaft 3 of the roller 4. The dimensional relationship between the foam roller 4 and the crank pin P is that the distance r from the center of the crank pin P to the bottom surface of the recess formed on the surface is a non-integer multiple of the radius R of the foam roller 4. It can happen.

  Here, the forming device 105 is configured to include a means for applying a load to the foam roller 4 in contact with the crankpin P and a means for detecting the load, and the load of the foam roller 4 on the crankpin P is always constant. It can control so that it may become constant, and can aim at the further uniformity of the depth of each recessed part.

  In order to form a large number of minute recesses on the outer peripheral surface of the crankpin P in the crankshaft CS using the forming tool having the above-described configuration, the crankshaft CS is rotatably held by holding means (not shown) At this time, the crankshaft CS is held so as to rotate around the axis of the rotation axis of the crankpin P. Then, the foam roller 4 is brought into contact with the outer peripheral surface of the crankpin P with a constant load, and the crankshaft CS is rotated, whereby the foam roller 4 is rotated to form a fine recess on the outer peripheral surface of the crankpin P. . The depth of the recess is, for example, about 1 μm.

  At this time, in the forming tool 1, the convex portions 4a on the outer peripheral portion of the foam roller 4 are arranged in a line along one spiral extending around the circumference of the roller 4, and therefore, as shown in FIG. As described above, only a small part of the convex portion 4 a comes into contact with the outer peripheral surface of the crankpin P. As a result, the pressing load of the foam roller 4 is smaller than that of the conventional foam roller (see FIG. 7) in which a plurality of convex portions are arranged in the axial direction of the rotating shaft, thereby reducing the size of the tool and the forming device. Can be achieved. The number of convex portions 4a that come into contact with the outer peripheral surface of the crankpin P varies depending on the size of the foam roller 4 and the like, but is, for example, about 1 to 3, and is clearly smaller than the conventional foam roller.

  Further, in the forming tool 1, the radius R of the foam roller 4 is a non-integer multiple of the distance r from the center of the crank pin P to the bottom surface of the recess formed on the surface. At the time of one revolution or when the foam roller 4 makes one revolution, the convex part 4a does not correspond to the already formed concave part, and the concave part is sequentially formed in the unformed part by continuing the rotation of the crank pin P. To do. Further, the load or the like of the foam roller 4 is controlled to set the recess depth to a predetermined value, and the radius R of the foam roller 4 is not relative to the distance r from the center of the crank pin P to the bottom surface of the recess formed on the surface. A method of forming the concave portion so as to be an integral multiple is also possible.

  In this way, the forming tool 1 causes the foam roller 4 to rotate the rotating shaft 3 by rotating the crank pin P a plurality of times even when there are counterweights CW that hinder lateral movement on both sides of the crank pin P. A large number of fine recesses can be formed on substantially the entire outer peripheral surface of the crankpin P without being moved in the axial direction.

  Further, the forming tool 1 has only a part of the protrusions 4a on the outer peripheral surface of the crankpin P as described above even if the machining surface is inclined due to the undulation of the crankpin P or the positioning error of the crankshaft CS. Therefore, the concave portion can be formed with high accuracy with almost no influence of the inclination of the machining surface, and the convex portion 4a is perpendicular to the machining surface by making the tip of the convex portion 4a into an arc shape. It is possible to form the recesses with higher accuracy by being pressed against each other, and all the recesses can be formed uniformly.

  When the workpiece is the crankshaft CS as in the present embodiment, in addition to forming the recesses on the outer peripheral surface of the crankpin P, the recesses are similarly formed on the outer peripheral surface of the journal J. be able to. In addition, the small pressing load of the foam roller 4 can prevent the crankshaft CS being processed from being bent when the workpiece is a long object such as the crankshaft CS. Therefore, it is possible to realize further high accuracy of the concave portion. Further, by forming the tip of the convex portion 4a in an arc shape, the convex portion 4a is difficult to be chipped off, and the life of the forming tool can be extended.

FIG. 4 is a view for explaining another embodiment of the forming tool according to the present invention.
In the illustrated forming roller 14, convex portions 14 a are arranged along a plurality of spirals corresponding to the entire circumference of the roller 14 and discontinuous with each other. In this embodiment, convex portions 14a for forming concave portions are provided at predetermined intervals along one spiral provided on the half circumference of the foam roller 14 and the other spiral provided on the remaining half circumference of the roller 14. is there. Each spiral extends from one end surface of the foam roller 14 to the other end surface and is not continuous with each other.

  Even in the forming tool provided with the foam roller 14, the pressing load is reduced to prevent the workpiece from being bent during processing, and the tool and the forming device can be downsized, as in the previous embodiment. In addition, even when the machining surface is tilted, it is possible to form the recesses with high accuracy and to form all the recesses uniformly with almost no influence of the tilt.

FIG. 5 is a view for explaining still another embodiment of the forming tool according to the present invention.
In the illustrated forming rollers 24 and 34, convex portions 24 a and 34 a are arranged along two spirals arranged in the axial direction of the rotary shaft 3. Each spiral is continuous over the circumference of the roller as shown in the figure. In the embodiment shown in FIG. 5 (a), the foam roller 24 has concave portions forming convex portions 24a arranged at predetermined intervals along two spirals having the same twisting direction . Further, in the embodiment shown in FIG. 5B, the foam roller 34 has a convex portion 34a for forming a concave portion along one spiral provided in the half in the axial direction and the other spiral provided in the other half. Are arranged at a predetermined interval, and the one and the other spirals are reversely threaded.

Even in the forming tool provided with the foam rollers 24 and 34, the same effects as those of the previous embodiments can be obtained. At this time, the convex portions 24a and 34a are arranged along the two spirals. As a result, the number of convex portions 24a and 34a that come into contact with the processed surface is increased as compared with the previous embodiments, but the number of the foam rollers 24 and 34 is still higher than that of the conventional foam roller (see FIG. 7). The pressing load can be made sufficiently small, and all the recesses can be formed in a short time by reducing the number of rotations of the workpiece.

The detailed configuration of the forming tool according to the present invention is not limited to the above embodiments. Furthermore, the forming tool is in the outer peripheral portion of the foam roller, since the arranged projections of recesses formed along the screw-handed continuous only over its circumference, a number around the circumference and axial form roller Compared to the conventional one in which the convex portions are arranged, the number of the convex portions is significantly reduced. This makes it easy to manufacture the foam roller, and it is possible to realize cost reduction.

  In addition to the crankshaft CS described in the embodiment, the workpiece to be processed by the forming tool can include various parts constituting an automobile engine and transmission. By forming a large number of fine recesses, an oil sump can be provided at a low cost, and the friction of the sliding portion can be reduced, thereby contributing to the improvement of the functions of automobile engines and transmissions.

It is the side view (a) explaining one Example of the forming tool concerning this invention, the front view (b), and the front view (c) which shows the state in process. It is explanatory drawing which shows the dimensional relationship between a form roller and a journal. It is sectional drawing explaining the front-end | tip of a convex part. It is the front view (a) and side view (b) explaining the foam roller in the other Example of the forming tool concerning this invention. It is each front view (a) (b) explaining two examples of the foam roller in the further another Example of the tool for forming concerning this invention. It is explanatory drawing which shows a crankshaft as a row of to-be-processed objects. It is explanatory drawing (a) which shows the conventional tool for forming, and the perspective view (b) of a foam roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Forming tool 4 Foam roller 4a Convex part 14 Foam roller 14a Convex part 24 Foam roller 24a Convex part 34 Foam roller 34a Convex part CS Crankshaft (workpiece)
J Journal (Cylindrical part)
P Crank pin (cylindrical part)

Claims (6)

A forming tool for forming a large number of fine concave portions on the outer peripheral surface of the cylindrical portion with respect to the workpiece having the cylindrical portion, comprising a foam roller in which a plurality of convex portions for forming concave portions are arranged on the outer peripheral portion, A forming tool characterized in that a large number of convex portions are arranged at predetermined intervals along a spiral that continues only over one circumference of a foam roller.   The forming tool according to claim 1, wherein the tip of the convex portion of the foam roller has an arc shape in a cross section including the rotation axis of the roller.   The radius of the foam roller is a non-integer multiple of the distance from the center of the cylindrical part of the workpiece to the bottom of the recess formed on the outer peripheral surface. Forming tool.   A vehicle engine or transmission component, wherein a recess is formed using the forming tool according to any one of claims 1 to 3.   A crankshaft in which a recess is formed using the forming tool according to any one of claims 1 to 3.   A recess forming method for forming a recess in a workpiece using the forming tool according to any one of claims 1 to 3, wherein the radius of the foam roller is from the center of the cylindrical portion of the workpiece. A method for forming a recess, comprising controlling the depth of the recess so as to be a non-integer multiple of the distance to the bottom of the recess formed on the surface.

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