JP4687285B2 - Polishing processing method and polishing processing apparatus - Google Patents

Description

  The present invention relates to a polishing method and a polishing apparatus for polishing a processing surface of a workpiece having a circular arc cross section and having a processing surface having a predetermined width in the axial direction using a polishing tape.

  As a workpiece having a circular arc cross section and a machining surface having a predetermined width in the axial direction, for example, there is a crankshaft used for an internal combustion engine. In order to improve fuel efficiency in an internal combustion engine, it is necessary to reduce friction as a sliding surface of the pin portion and the journal portion that are processed surfaces of the crankshaft. The moving surface is polished (for example, see Patent Document 1 below).

The processing using the polishing tape is performed by sandwiching the processing surface consisting of the pin portion or journal portion of the crankshaft described above with a pair of clamp arms, and polishing between the clamping surface with respect to the processing surface of the clamp arm and the processing surface. The processing surface is polished by interposing the tape and moving the polishing tape relative to the processing surface.
JP 2000-108005 A

  By the way, in the polishing process using the conventional polishing tape described above, two types of workpieces having different diameters can be processed with one processing facility, but the width of the polishing tape is equal to the width of the processing surface of the workpiece. Correspondingly, the specifications are uniform for each product, so when processing various workpieces with different processing surface widths, measures such as preparing multiple types of polishing tapes and clamp arms with different widths are available. Is required, resulting in an increase in equipment costs.

  Accordingly, an object of the present invention is to enable various types of workpieces having different processing surface axial widths to be processed with a kind of polishing tape.

According to the present invention, the work surface of a workpiece having a circular arc cross section and having a work surface with a predetermined width in the axial direction is sandwiched between a pair of clamp arms, and the clamp arm is sandwiched between the work surface and the work surface. The polishing tape is made narrower than the width of the processing surface when the polishing tape is interposed between the processing surface and the polishing tape is moved relative to the processing surface along the longitudinal direction thereof. A polishing method for polishing the entire axial direction of the processing surface while moving the polishing tape in the axial direction with a swing width corresponding to the width of the processing surface , the polishing tape The axial relative movement speed of the machining surface with respect to the machining surface is made constant by driving a linear motor, and the linear motor is moved relative to the machining tape in the axial direction with a deflection width corresponding to the width of the machining surface. Driven The most important feature to us.

According to the present invention, the polishing tape having a width narrower than the width of the processing surface is polished while being relatively moved in the axial direction of the workpiece with a runout width corresponding to the width of the processing surface. Even various workpieces having different widths can be processed with a kind of polishing tape, and the equipment cost can be reduced.
Further, the axial relative movement speed of the polishing tape with respect to the processing surface is made constant by driving the linear motor, and the linear motor is moved relative to the processing direction of the polishing tape in the axial direction according to the width of the processing surface. Since the control unit is driven and controlled, the machining amount can be stabilized and uniform over the entire axial width of the machining surface, and such control that keeps the moving speed constant can be easily realized by a linear motor. Can do.

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

  FIG. 1 is a schematic front view of a polishing apparatus for a crankshaft as a workpiece, showing an embodiment of the present invention. This polishing apparatus is for polishing a processed surface comprising the journal portion 3 or the pin portion 5 of the crankshaft 1, and is a polishing tape provided with abrasive grains on one surface of a non-stretchable and deformable thin substrate. As a wrapping film 7, a shoe 9 (see FIG. 2) that is disposed on the back side of the wrapping film 7 and has a clamping surface with respect to the processing surface, and presses the shoe 9 against the processing surface to process the abrasive grain surface of the wrapping film 7 Shoe pressing means 11 (see FIG. 2) that presses against the surface, rotational driving means 13 (see FIG. 1) for rotationally driving the crankshaft 1, and driving means for relatively oscillating the crankshaft 1 and the wrapping film 7 As an oscillation means 15 (see FIG. 1), cooling is performed by supplying a cooling liquid around the crankshaft 1 and the wrapping film 7 A stage 17 (refer to FIG. 2), respectively, it is subjected to lapping (grinding) and presses it to the lapping film 7 while rotating the crankshaft 1.

  Further, in this processing, the polishing apparatus appropriately detects the operating states of the shoe pressing means 11, the rotation driving means 13, the oscillation means 15 and the like by means of detection means (not shown), and each means based on this detection signal. A control unit 19 is provided for controlling the above.

  Although there are various types of wrapping film 7, in this embodiment, the base material is made of a non-stretchable material having a strip shape with a predetermined width, for example, a polyester having a thickness t of about 25 μm to 130 μm. Yes. In this way, if the wrapping film 7 is made of a non-stretchable and deformable thin base material, the wrapping process can be performed smoothly and the working efficiency is improved.

  A large number of abrasive grains (specifically, made of aluminum oxide, silicon carbide, diamond, etc.) are bonded to one surface of the thin base material constituting the wrapping film 7. It is attached by the agent. The abrasive grains may be bonded to the entire surface of the base material, or may be formed by intermittently forming non-abrasive grain regions having a predetermined width. A resistance material (not shown) made of rubber, synthetic resin, or the like is attached to the other surface of the base material.

  And as shown to Fig.3 (a), the width H1 of the above-mentioned wrapping film 7 is made narrower than the width | variety L of the axial direction (left-right direction in FIG. 3) of the pin part 5 which is a processed surface. Specifically, when the width L of the pin portion 3 is 18 mm, the width H1 of the wrapping film 7 is 10.5 mm. Further, the width H2 of the shoe 9 at this time is, for example, 10 mm, which is slightly narrower than the width H1 of the wrapping film 7.

  The width of the journal portion 1 which is another processed surface is also made wider than the width H1 of the wrapping film 7.

  Further, as shown in FIG. 4, corners at both ends in the width direction of the shoe 9 are R-shaped portions 9 a that are gradually separated from the processing surface from the center in the width direction toward the outside. In this case, the corner portion may be chamfered instead of the R-shaped portion 9a.

As shown in FIG. 2, the wrapping film 7 is pulled out from a supply reel 25 supported on a frame body of a polishing apparatus by rotating the take-up reel 21 with a motor 23 and pulling it. Guided by R _{1 to} R ₉ and taken up by the take-up reel 21.

In the vicinity of the supply reel 25 and the take-up reel 2 1 provided a locking device (not shown), a predetermined tension is applied to the entire lapping film 7 by the operation of the locking apparatus, and polishing in this state.

  The shoe 9 is made of rubber or synthetic resin and has relatively rigidity. As shown in FIG. 2, the inner surface is a concave arcuate surface along the processed surface of the crankshaft 1. A shoe case 27 holds the outer peripheral side.

  The shoe pressing means 11 is provided at pressing arms 29 and 31 as clamp arms with a shoe case 27 supporting the shoe 9 attached to the tip, and at the rear ends of these pressing arms 29 and 31, and both of them are pressed with a predetermined pressure. A fluid pressure cylinder 33 that presses the shoe 9 toward the machining surface of the crankshaft 1 and a pressing force adjusting means 35 that adjusts the pressing force of the shoe 9 are provided.

  In the shoe pressing means 11 described above, when the fluid pressure cylinder 33 is actuated, both the pressing arms 29 and 31 are opened and closed around the support pin 37, and the both pressing arms 29 and 31 are rotated together with the wrapping film 7. The shoe 9 presses the processed surface of the crankshaft 1 through the wrapping film 7 by the closing rotation, and the contact between the processing surface and the shoe 9 is released by the opening rotation.

  The pressing force adjusting means 35 adjusts the pressing force of the shoe 9 against the processed surface of the crankshaft 1 by adjusting the spring force pressing the shoe case 27 with the cam 39. However, not only this, but also the spring force may be adjusted using a screw member.

  In FIG. 1, the rotation driving means 13 includes a head stock 43 that rotatably supports the main shaft 41, a chuck 45 that is connected to the tip of the main shaft 41 and grips one end of the crankshaft 1, and a belt 47 connected to the main shaft 41. Each has a coupled main shaft motor 49 and a tailstock 51 that supports the other end of the crankshaft 1.

  The crankshaft 1 is set between the head stock 43 and the tail stock 51, and rotates via the belt 47, the main shaft 41 and the chuck 45 by the rotation of the main shaft motor 49.

    The head stock 43 and the tail stock 51 are provided on tables 53 and 55 that are slidable along the Y direction (the direction orthogonal to the paper surface in FIG. 1). The tables 53 and 55 are arranged in the X direction (FIG. 1). It is arranged on a table 57 that is slidable along the horizontal direction.

  As shown in FIG. 1, the oscillation means 15 moves the table 57 reciprocally at a constant speed in the left-right direction in FIG. 1 through a linear guide mechanism (not shown) by the linear motor 59. Oscillate the whole in the X direction.

  Next, the operation will be described.

  First, in a state where both pressing arms 29 and 31 are open, the locking device provided in the vicinity of the supply reel 25 is locked, and the motor 23 is operated to rotate the take-up reel 21. As a result, the wrapping film 7 moves by a predetermined amount in the longitudinal direction, and a new abrasive grain surface is set on the processed surface of the crankshaft 1 and a predetermined tension is applied to the wrapping film 7.

  Then, when the locking device in the vicinity of the take-up reel 21 is locked, the tension is applied and the wrapping film 7 is tightly stretched without any slack. In this state, the crankshaft 1 is set between the head stock 43 and the tail stock 51. After this setting, when the fluid pressure cylinder 33 is operated, both the pressing arms 29 and 31 are closed, and the wrapping film 7 is set on the processed surface of the crankshaft 1 (here, the pin portion 5). Pressed against the machining surface with a predetermined pressing force.

    If the crankshaft 1 has a plurality of processing surfaces such as the pin portion 5, the wrapping film 7 is set and pressed so as to correspond to each pin portion 5.

  Therefore, when the crankshaft 1 rotates, the processed surface is lapped by the abrasive surface of the wrapping film 7.

    The pin portion 5 rotates eccentrically with respect to the journal portion 3, but both pressing arms 29, 31 follow the same and swing by the usual method and are similarly lapped.

  In particular, in the present embodiment, as shown in FIG. 3A, the width H1 of the wrapping film 7 is set in the axial direction (left and right direction in FIG. 3) of the pin portion 5 and the journal portion 3 which are processed surfaces. It is narrower than the width L.

  In this state, the linear motor portion 59 in the oscillation means 15 is driven to reciprocate the table 57 together with the tables 53 and 55 in the left-right direction in FIG. 1 at a constant speed. Oscillate in the X direction.

  By reciprocating the entire crankshaft 1 in the X direction, the wrapping film 7 moves relative to the pin portion 5 in the axial direction, and the entire axial direction of each pin portion 5 is polished.

Further, as shown in FIG. 3B, the axial width M of the pin portion 50, which is the processed surface, is shown in FIG.
3), the reciprocating region (runout width) in the X direction of the crankshaft 1 driven by the linear motor portion 59 is determined from A in FIG. This is dealt with by reducing the size to be B in FIG.

  On the other hand, the reciprocating region (runout width) in the X direction of the crankshaft 1 driven by the linear motor portion 59 is applied to the machining surface having a width longer than the axial width of the pin portion 5 in FIG. ) Is further increased from A in FIG.

  As described above, in this embodiment, the width H1 of the wrapping film 7 is made narrower than the width L in the axial direction (left and right direction in FIG. 3) of the pin portion 5 and the journal portion 3 which are processed surfaces. Is polished while relatively moving in the axial direction with a runout width corresponding to the width of the machining surface, so even for various workpieces having different widths of the pin portion 5 and journal portion 3 of the crankshaft 1, It can be processed with a kind of wrapping film 7, and the equipment cost can be reduced.

  Further, by setting the moving speed when reciprocating the crankshaft 1 to a constant speed, the machining amount can be stabilized and made uniform over the entire axial width of the pin portion 5 and the journal portion 3.

  Such control that makes the moving speed constant can be easily realized by the linear motor unit 59.

Further, by making the width H1 of the shoe 9 smaller than the width H2 of the wrapping film 7 and making the corners at both ends in the width direction of the shoe 9 R-shaped portions 9a, the corners of the shoe 9 come into contact with the processed surface. It is possible to prevent damage to the processed surface due to the operation.

  FIG. 5 shows the straightness of the processed surface after polishing in this way, and it can be seen that the processed surface is substantially uniformly polished over the entire width of the processed surface.

  The processing conditions during the polishing process described above are as follows.

Rotation speed of crankshaft 1: 80 rpm
Clamping pressure by pressing arms 29 and 31: 98kN
Diameter of pin part 5: 60 mm
Pin part 5 width (L): 18 mm
Abrasive grain size of lapping film 7: roughing 30 μm, finishing 15 μm
Wrapping film 7 width (H1): 10.5mm
Shoe 9 width (H2): 10 mm
Oscillation width (L-H2): 8mm
In addition, this invention is not limited only to embodiment mentioned above, A various change can be made. For example, in the above-described embodiment, the case where the pin portion 5 of the crankshaft 1 is mainly processed has been described. However, not only this but also the journal portion 3 of the crankshaft 1 may be used. It may have an arcuate machining surface with a non-circular cross section, such as a cam lobe part or a journal part, and can also be applied to those having other arcuate machining surfaces.

  Further, at the time of polishing, instead of reciprocating the crankshaft 1 side in the axial direction, the wrapping film 7 side may be reciprocated in the axial direction with respect to the crankshaft 1 together with the shoes 9 and the pressing arms 29 and 31.

1 is a schematic front view of a polishing apparatus showing an embodiment of the present invention. It is a cross-sectional equivalent view along the AA line of FIG. It is explanatory drawing which shows the relationship between the width | variety of the pin part of a crankshaft, and the width | variety of a wrapping film. It is explanatory drawing which expanded and showed the shape of the corner | angular part of the both ends of the width direction in a shoe. It is explanatory drawing which shows the straightness of the processed surface after grinding | polishing.

Explanation of symbols

1 Crankshaft 3 Journal part (machined surface)
5 Pin part (machined surface)
7 Wrapping film (polishing tape)
9 Shoe (clamping surface)
9a R shape part (corner part)
15 Oscillation means (drive means)
29, 31 Press arm (clamp arm)
59 Linear motor section

Claims (3)

The work surface of a work having an arc cross section and having a work surface with a predetermined width in the axial direction is sandwiched by a pair of clamp arms, and a polishing tape is interposed between the work surface and the clamping surface of the clamp arm with respect to the work surface the interposed, during the polishing by causing relative movement with respect to the working surface along the polishing tape in its longitudinal direction, the width of the abrasive tape is narrower than the width of the working surface, the polishing A polishing method for polishing the entire axial direction of the processing surface while relatively moving the tape in the axial direction with a runout width corresponding to the width of the processing surface ,
The relative movement speed in the axial direction of the polishing tape with respect to the processing surface is made constant by driving a linear motor, and the linear motor is relatively moved in the axial direction with a deflection width corresponding to the width of the processing surface. A polishing method characterized in that the control unit drives and controls so as to. The width of the clamping surface with respect to the processed surface of the clamp arm is made narrower than the width of the polishing tape, and the corners on both sides of the clamping surface in the width direction facing the polishing tape are centered in the width direction. The polishing method according to claim 1, wherein the polishing method is shaped so as to gradually move away from the processing surface from the outside toward the outside. The work surface of a work having an arc cross section and having a work surface with a predetermined width in the axial direction is sandwiched by a pair of clamp arms, and a polishing tape is interposed between the work surface and the clamping surface of the clamp arm with respect to the work surface the interposed, during the polishing by causing relative movement with respect to the working surface along the polishing tape in its longitudinal direction, the width of the abrasive tape is narrower than the width of the working surface, the polishing the use tape, while relatively moving in the axial direction in said working surface width depending shake width, a grinding device having a driving unit Ru is polished axial entire region of the processing surface,
The drive means includes a linear motor that maintains a constant axial relative movement speed of the polishing tape with respect to the processing surface, and the polishing tape has a swing width corresponding to the width of the processing surface. A polishing apparatus comprising a control unit that controls driving so as to relatively move in the axial direction .

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