JP4973904B2 - Fine recess processing apparatus and fine recess processing method - Google Patents

Description

  The present invention provides, for example, a fine recess processing apparatus used to form a fine recess (oil sump) for realizing low friction on the inner peripheral surface of a cylinder bore (circular hole) in a cylinder block of an automobile engine. It is about.

Conventionally, shot blasting is often used when forming a fine recess in the inner peripheral surface of the cylinder bore of the cylinder block as described above. In this shot blasting, a masking sheet having a predetermined shape of holes is affixed to the inner peripheral surface of the cylinder bore, and then small diameter particles such as ceramics are projected onto the inner peripheral surface of the cylinder bore together with compressed air, thereby A recess is formed in a portion exposed through the through hole of the surface.
Then, after the recess is formed, the masking sheet is removed and washed, and then honing is performed again to remove the swelled portion generated around the recess in the shot blasting process.
JP 2002-307310 A

  However, in the formation of fine recesses using shot blasting as described above, it is difficult to regularly arrange the fine recesses, and in addition, the masking sheet is attached to the inner peripheral surface of the circular hole. The process, the removal process, and the cleaning process are indispensable, and there is a problem that the processing cost is increased by the amount of such work, and it has been a conventional problem to solve these problems .

  The present invention has been made by paying attention to the above-described conventional problems, and can form fine concave portions with high accuracy with respect to the inner peripheral surface of the circular hole and realize reduction in processing cost. It is an object to provide a fine recess processing apparatus and a fine recess processing method that are possible.

  A fine recess processing apparatus according to the present invention forms a fine recess on the inner peripheral surface of a circular hole, and a main shaft, a holder that is coaxially mounted on the main shaft, rotates integrally, and is movable in the axial direction. A processing roller having fine irregularities on the outer periphery, a roller support provided on the holder for rotatably supporting the processing roller around a roller shaft that is parallel to the main shaft, and a diameter applied to the roller support. Load detecting means for detecting the load in the direction, load generating means for applying the radial load of the processing roller to the roller support portion, and moving the processing roller so as to approach and separate from the inner peripheral surface of the circular hole After moving the processing roller in contact with the inner peripheral surface of the circular hole, the operation of the moving mechanism is continued until the detected load of the load detecting means reaches the set value, and the detected load becomes the set value. When the movement mechanism The processing roller pressed against the inner peripheral surface of the circular hole by the load generating means is rotated on the inner peripheral surface while rotating the holder while pressing the inner peripheral surface of the circular hole with a predetermined load. In the state of rolling with rotation, the holder and the circular hole are relatively moved in the axial direction to form a fine recess on the inner peripheral surface of the circular hole.

  In the fine recess processing method according to the present invention, after aligning the rotation axis of the holder with the center axis of the circular hole, the processing roller is brought into contact with the inner peripheral surface of the circular hole, and the detected load of the load detecting means becomes the set value. The operation of the moving mechanism is continued until the detected load reaches the set value, and the operation of the moving mechanism is stopped to pressurize the inner peripheral surface of the circular hole with a predetermined load while rotating the holder. The processing roller pressed against the inner peripheral surface of the circular hole by the load generating means is rotated finely by rotating the holder and the circular hole in the axial direction with the processing roller being rotated along the inner peripheral surface. A concave portion is formed on the inner peripheral surface of the circular hole.

According to the fine recess processing apparatus according to the present invention, since it has the above-described configuration, not only a groove shape but also a dimple-like fine recess can be accurately and efficiently formed on the inner peripheral surface of the circular hole. In addition, since the fine irregularities of the processing roller can be pressed against the inner peripheral surface of the circular hole with a constant load, it is not necessary to finish the processed surface with high precision before processing the fine recesses. The step before processing the concave portion can be omitted, and as a result, a very excellent effect that a significant reduction in processing cost can be realized.
Since the load detecting means for detecting the radial load of the processing roller applied to the roller support portion is provided, the pressing load of the processing roller against the inner peripheral surface of the circular hole can be constantly monitored, so the accuracy is higher. Fine recesses are processed.
According to the fine recess processing method according to the present invention, after the processing roller is brought into contact with the inner peripheral surface of the circular hole, the operation of the moving mechanism is continued until the detected load of the load detecting means reaches a set value, and the detected load When the value of becomes the set value, the operation of the moving mechanism is stopped to pressurize the inner peripheral surface of the circular hole with a predetermined load, and after aligning the rotation axis of the holder with the central axis of the circular hole, the load is generated. By pressing the fine irregularities of the processing roller on the inner peripheral surface of the circular hole by means and rotating the holder, the holder and the circular hole are moved relatively in the axial direction in this state. By controlling the shape of the unevenness, the rotational speed of the holder, and the feed amount of the processing roller with respect to the circular hole, it is possible to form a fine concave portion having a free pattern on the inner peripheral surface of the circular hole that is the processing surface.

  In the fine recess processing apparatus of the present invention, a roller support portion, a processing roller supported by the roller support portion, and a load generating means for applying a load in the radial direction to the roller support portion are used as a rotating shaft of the holder The holder can be provided with a moving mechanism that moves integrally in the orthogonal direction. In this case, it is possible to cope with a change in the inner diameter of the circular hole to be processed.

  In the fine recess processing apparatus of the present invention, it is desirable to employ a compression coil spring as the load generating means in order to simplify the structure.

  Furthermore, in the fine recess processing apparatus of the present invention, it is desirable to provide a load detection means such as a load cell for detecting the radial load of the processing roller applied to the roller support, and in this case, the inner peripheral surface of the circular hole Since the pressing load of the processing roller against can be constantly monitored, a fine recess with higher accuracy is processed.

  On the other hand, in the fine recess processing method of the present invention, after aligning the rotation axis of the holder with the central axis of the circular hole, the load generating means presses the fine irregularities of the processing roller on the inner peripheral surface of the circular hole and rotates the holder. In this state, the holder and the circular hole are moved relative to each other in the axial direction, so that the fine irregularities of the processing roller, the rotation speed of the holder and the feed amount of the processing roller to the circular hole can be controlled. For example, a fine recess having a free pattern can be formed on the inner peripheral surface of the circular hole, which is the surface to be processed.

  Further, in the fine recess processing method of the present invention, the radial load applied to the support shaft that supports the processing roller from the load generating means may be changed during processing. In this case, the inner surface of the circular hole may be changed. In addition, the fine concave portions having different depths can be continuously formed, that is, the depth of the fine concave portions formed on the inner surface of one circular hole can be changed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

  As shown in FIG. 2, this fine recess processing apparatus 1 is an NC machine tool that forms fine recesses on the inner peripheral surface of a cylinder bore that is a circular hole of a cylinder block of an automobile engine, and is movable in the vertical direction. A spindle 3 supported in a state of protruding downward from the spindle head 2, a workpiece mounting table 4 that is movable below the spindle head 2 in two orthogonal directions within a horizontal plane, and coaxial with the spindle 3 And a holder 10 that rotates integrally with the holder 10. The holder 10 is attached to and detached from the main shaft 3 by an automatic tool changer (not shown).

  As shown in FIG. 1, the holder 10 has a shank portion 10A that is a portion to be attached to the main shaft 3, and a body portion 10B that is continuous below the shank portion. A processing roller 11 having fine irregularities on the part, an arm 12 as a roller support portion that rotatably supports the processing roller 11, and a housing 13 that holds the arm 12 are provided. The material of the processing roller 11 is not particularly limited. For example, the processing roller 11 is made of carbide, a hard metal other than carbide, ceramics such as alumina or silicon nitride, and is smaller than the diameter of the cylinder bore B. It has a diameter.

  The arm 12 that supports the processing roller 11 is provided in parallel with the main shaft 3, a support shaft 14 that fixes the processing roller 11, and a support member that rotatably supports the support shaft 14 via a double-row angular ball bearing 15. 16 is provided. On the other hand, the housing 13 has a hollow block shape connected to the body portion 10B via the adapter 10C, and a spline nut 17 is fitted and fixed to the lower end side hollow portion. The arm 12 can be moved in a direction orthogonal to the main shaft 3 by spline coupling with the spline shaft 18 connected to the support member 16.

  A compression coil spring 20 as a load generating means is interposed between the support member 16 of the arm 12 and a cap 19 fitted into the upper end side hollow portion of the housing 13, and the support member 16 of the arm 12. By applying a load in a direction perpendicular to the main shaft 3 (the radial direction of the processing roller 11) to the processing roller 11 on the inner peripheral surface Ba of the cylinder bore B whose center axis is aligned with the rotation axis L of the holder 10. The fine irregularities are pressed. In this case, a piezoelectric load cell 21 as a load detecting means is provided between the cap 19 and the compression coil spring 20.

  Further, a stopper 22 made of a soft material such as urethane resin having a diameter larger than the diameter of the spline shaft 18 and on the side opposite to the support member 16 of the spline shaft 18 that is spline-coupled with the spline nut 17 in the housing 13. The stopper 22 suppresses the expansion of the compression coil spring 20, reduces the impact when the compression coil spring 20 is fully extended, and prevents the arm 12 from falling off the housing 13. It is supposed to be.

  Further, an adjustment piece 23 for applying a preload to the compression coil spring 20 is provided between the compression coil spring 20 and the load cell 21, and the length of the adjustment piece 23 (the length of the compression coil spring 20 in the expansion / contraction direction) is set. The preload can be adjusted by selecting. The load cell 21 has a spherical protrusion at the contact portion 21a with the adjustment piece 23, so that the collapse of the compression coil spring 20 in the expansion / contraction direction can be absorbed.

  The adapter 10C connected to the housing 13 has a built-in moving mechanism having a stepping motor (not shown). By operating the moving mechanism, the processing roller 11 held by the housing 13 is moved against the inner peripheral surface Ba of the cylinder bore B. Can be separated from each other.

  In the fine recess processing apparatus 1 described above, when forming the fine recess on the inner peripheral surface Ba of the cylinder bore B, first, the main shaft 1 and the center axis of the cylinder bore B are positioned so as to substantially coincide with each other. The holder 10 is lowered and the processing roller 11 is inserted into the cylinder bore B.

  Next, the moving mechanism in the adapter 10C is operated to bring the processing roller 11 into contact with the inner peripheral surface Ba of the cylinder bore B, and the movement in the adapter 10C is performed until the load detected by the load cell 21 reaches a preset value. Continue operating the mechanism.

  That is, when the processing roller 11 comes into contact with the inner peripheral surface Ba of the cylinder bore B and the operation of the moving mechanism in the adapter 10C is continued, the compression coil spring 20 is compressed between the arm 12 and the housing 13, and the repulsion thereof. Since force is applied to the processing roller 11 as a load and this load is detected by the load cell 21, if the operation of the moving mechanism in the adapter 10C is continued until the detected load of the load cell 21 reaches a set value. The inner peripheral surface Ba of the cylinder bore B can be pressurized with a predetermined load.

  As described above, when the set value of the load is detected, when the operation of the moving mechanism in the adapter 10C is stopped and the holder 10 is rotated together with the main shaft 1, it is pressed against the inner peripheral surface Ba of the cylinder bore B. The processing roller 11 is rotated, and a minute recess is formed on the inner peripheral surface Ba of the cylinder bore B by the rolling of the processing roller 11.

  At this time, if the rotation of the main shaft 1 and the lowering speed are synchronized, a fine recess can be formed in a wide region of the inner peripheral surface Ba of the cylinder bore B.

  As described above, in the fine recess processing apparatus according to this embodiment, since the fine recess can be formed with high accuracy, the pre-processing applied to the inner peripheral surface Ba of the cylinder bore B can be omitted, and the number of processes can be reduced. In addition, cost reduction can be realized.

  Moreover, by selecting the tip shape of the outer peripheral portion of the processing roller 11, it is possible to form recesses of various shapes, and it is possible to form recesses that are continuous in a groove shape or discontinuous recesses that are dotted. In this case, it is possible to change the depth and width of the recess by appropriately changing the load applied to the processing roller 11. In any case, the recess is continuously formed by rolling of the processing roller 11. Therefore, the processing efficiency is also good.

  Furthermore, since the fine recess is formed as the processing roller 11 rolls, the tool wear is very little, and as a result, the tool life can be extended.

  The present invention is not limited to the above-described examples, but can be applied to various other embodiments. For example, the processing roller 11 may be configured to have a plurality of rows of fine irregularities, or the compression coil spring 20 may be replaceable in order to change the load of the load generating means. Moreover, although the compression coil spring 20 was mentioned as an example as a load generation means, the other thing is applicable if it is an elastic body which provides a fixed load.

  When the fine concave portion is formed on the inner peripheral surface of the circular hole using the fine concave portion processing apparatus 1 described above, the cost of the member having the circular hole can be reduced, and as described above, the fine concave portion processing apparatus 1 is provided. When a fine recess is formed in the inner peripheral surface Ba of an automotive part, for example, a cylinder bore B of a cylinder block, the cost of the part can be reduced and the friction can be reduced and the engine performance can be improved. .

It is sectional explanatory drawing of the tool holder which shows one Example of the fine recessed part processing apparatus of this invention. Example 1 It is a whole perspective explanatory drawing of the fine recessed part processing apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fine recessed part processing apparatus 3 Main shaft 10 Holder 11 Processing roller 12 Arm (roller support part)
20 Compression coil spring (load generating means)
21 Load cell (load detection means)
B Cylinder bore (circular hole)
Ba Inner circumferential surface of cylinder bore L Rotating shaft of holder

Claims (6)

In a fine recess processing apparatus for forming a fine recess on the inner peripheral surface of a circular hole,
A main shaft, a holder that is coaxially mounted on the main shaft, rotates integrally with the main shaft, and is movable in the axial direction, a processing roller having fine irregularities on the outer periphery, and a roller that is provided on the holder and is parallel to the main shaft A roller support portion that rotatably supports the processing roller around the shaft, a load detection means that detects a radial load applied to the roller support portion, and a radial load of the processing roller is applied to the roller support portion. Load generating means for moving, and a moving mechanism for moving the processing roller so as to approach and separate from the inner peripheral surface of the circular hole,
After bringing the processing roller into contact with the inner peripheral surface of the circular hole, the operation of the moving mechanism is continued until the detected load of the load detecting means reaches the set value, and when the detected load reaches the set value, the moving mechanism is operated. While pressing the inner peripheral surface of the circular hole with a predetermined load by stopping
The holder and the circular hole are relatively axially moved in a state where the holder is rotated, and the processing roller pressed against the inner peripheral surface of the circular hole by the load generating means is rotated along the inner peripheral surface. A fine recess processing apparatus characterized in that a fine recess is formed on an inner peripheral surface of a circular hole by being moved.   The fine recess processing apparatus according to claim 1, wherein the moving mechanism integrally moves the roller support portion, the processing roller supported by the roller support portion, and the load generating means in a direction orthogonal to the rotation axis of the holder.   The fine recess processing apparatus according to claim 1 or 2, wherein the load generating means is a compression coil spring.    The fine recessed part processing apparatus of any one of Claims 1-3 which used the load detection means as the load cell. A fine recess processing method for forming a fine recess on an inner peripheral surface of a circular hole using the micro recess processing apparatus according to any one of claims 1 to 4,
After matching the rotation axis of the holder with the center axis of the circular hole, the processing roller is brought into contact with the inner peripheral surface of the circular hole,
The operation of the moving mechanism is continued until the detected load of the load detecting means reaches the set value, and when the detected load reaches the set value, the operation of the moving mechanism is stopped, so that the inner peripheral surface of the circular hole has a predetermined load. The holder and the circular hole are moved relative to each other while the processing roller pressed against the inner peripheral surface of the circular hole by the load generating means is rotated with the inner peripheral surface. A fine recess processing method characterized in that the fine recess is formed on the inner peripheral surface of the circular hole by moving it in the axial direction.   The fine recess processing method according to claim 5, wherein a radial load applied to the roller support portion that supports the processing roller from the load generating means is changed during processing.

Images