JP3738764B2 - Lapping device and lapping method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lapping apparatus and a lapping process method for film lapping (hereinafter simply referred to as lapping) on a work surface of a workpiece by a lapping film with abrasive grains (hereinafter also simply referred to as film).
[0002]
[Prior art]
For example, when finishing a workpiece having a cross-sectional arc-shaped outer peripheral surface such as a pin portion or journal portion of a crankshaft or a cam lobe portion or journal portion of a camshaft, a lapping film having abrasive grains on one side recently. Wrapping process.
[0003]
In this lapping process, the work surface of the work is covered with a wrapping film, the film is pressed with a shoe from the back, and the work is processed on the abrasive surface of the film while rotating the work while the film is pressed against the work. In addition to a mechanism that presses a shoe against a workpiece through a film, the lapping machine is a mechanism that rotates the workpiece, and an oscillation that imparts oscillation along the axial direction of the workpiece to at least one of the workpiece and the wrapping film. It has a mechanism (for example, refer to Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-237116 (see FIGS. 1 and 2)
[0005]
[Problems to be solved by the invention]
Some workpieces have a machined surface with holes. For example, an oil hole as a hole is formed in a pin portion or a journal portion of the crankshaft so as to penetrate in the direction perpendicular to the axis. It is preferable that the corner of the mouth of the oil hole has a rounded cross-sectional shape so that such an oil hole does not damage the counterpart component (for example, a bearing metal).
[0006]
For this reason, conventionally, after the lapping film abrasive surface is pressed against the work surface of the workpiece with a so-called hard shoe, additional processing is performed to press the abrasive surface of the wrapping film against the mouth of the oil hole with a so-called soft shoe. The rounded part is formed at the corner of the mouth of the oil hole.
[0007]
However, since the processing using the hard shoe and the processing using the soft shoe are performed independently, a wrapping processing device including a hard shoe and a wrapping processing device including a soft shoe must be prepared, resulting in poor processing efficiency. The processing takes a relatively long time. As the number of equipment increases, equipment costs and processing costs also increase.
[0008]
In addition, after increasing the shape accuracy (roundness and straightness) of the processed surface by processing with a hard shoe, processing with a soft shoe is further performed, so there is a risk that the shape accuracy of the processed surface will be greatly destroyed by processing with a soft shoe. is there.
[0009]
Furthermore, the wrapping film may bite into the corners of the oil holes at the time of processing with a soft shoe, leading to the peeling of abrasive grains.
[0010]
The present invention has been made to solve the problems associated with the above-described conventional technology, and even a workpiece having a machining surface with a hole portion such as an oil hole can be machined quickly, resulting in an increase in machining cost. Another object of the present invention is to provide a lapping apparatus and a lapping method that can suppress a decrease in shape accuracy (roundness and straightness) as much as possible and reduce the peeling of abrasive grains of a lapping film.
[0011]
[Means for Solving the Problems]
The object of the present invention is achieved by the following means.
[0012]
The present invention is a lapping apparatus for performing a lapping process on a workpiece having a machining surface with a hole portion opened,
A wrapping film in which abrasive grains are provided on one surface of a thin substrate;
A first shoe that presses the abrasive surface of the wrapping film against the processed surface;
A second shoe that presses the abrasive surface of the wrapping film against the mouth of the hole;
Shoe driving means for driving the second shoe between an operating position pressed toward the mouth of the hole and a non-operating position separated from the mouth of the hole;
A rotation driving means for rotating the workpiece;
Detection means for detecting the position of the hole in the rotating workpiece;
Control means for controlling the operation of the shoe drive means according to the position of the hole during processing,
The lapping apparatus is characterized in that lapping performed by pressing the lapping film with the second shoe is limited to the mouth of the hole and the periphery thereof.
[0013]
The present invention also provides a lapping method for performing lapping while rotating the workpiece while the abrasive grain surface of the lapping film is pressed by a first shoe against a workpiece having a machining surface in which a hole is opened. Because
The position of the hole in the rotating workpiece is detected by a detecting means, and a second shoe that presses the abrasive grain surface of the wrapping film against the mouth of the hole according to the position of the hole during processing, Driving to an operating position pressed toward the mouth of the hole or a non-operating position away from the mouth of the hole, and wrapping applied by pressing the wrapping film with the second shoe, It is a lapping method characterized by being limited to the periphery of the mouth of the hole.
[0014]
【The invention's effect】
According to the lapping apparatus and the lapping method according to the present invention, even a workpiece having a machining surface in which a hole portion such as an oil hole is opened can be quickly machined, and an increase in machining cost and shape accuracy (roundness) Degree and straightness) can be suppressed as much as possible, and the abrasive grains of the wrapping film can be prevented from peeling off.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0016]
(First embodiment)
FIG. 1 is a schematic configuration diagram illustrating a lapping apparatus 1 according to a first embodiment of the present invention, and FIG. 2 illustrates a closed state of upper and lower arms 22 and 23 provided in the lapping apparatus 1 so as to be openable and closable. 3 is a schematic cross-sectional view showing the open state of the upper and lower arms 22 and 23, and FIGS. 4A and 4B are cross-sectional views showing the main part of the lapping apparatus 1, FIG. 4A shows a state in which the second shoe 72 constituting the soft shoe is driven to an operating position where the second shoe 72 is pressed toward the mouth 67 of the oil hole 66, and FIG. The state where it was driven to the non-operation position which leaves | separates from the mouth 67 is shown. FIGS. 5A to 5C and FIGS. 6A to 6C are views for explaining a range in which the soft shoe 72 is driven from the non-operation position to the operation position. 7A is a perspective view showing an example of a crankshaft 62 as a workpiece W to be lapped, and FIG. 7B is a partially cutaway view showing an oil hole 66 formed in the crankshaft 62. It is sectional drawing. For convenience of explanation, the axial direction (the left-right direction in FIG. 1) of the crankshaft 62 is defined as the X direction, and the horizontal direction orthogonal to the X direction (the direction orthogonal to the paper surface in FIG. 1) is defined as the Y direction. The vertical direction (vertical direction in FIG. 1) perpendicular to the X direction is defined as the Z direction.
[0017]
The lapping apparatus 1 of this embodiment will be outlined with reference to FIGS. 1 to 4. A lapping film 11 in which abrasive grains are provided on one surface of a non-stretchable and deformable thin substrate, and the lapping film 11. The first shoe 71 that presses the abrasive grain surface against the processing surface 65 of the workpiece W, and the second shoe 72 that presses the abrasive grain surface of the wrapping film 11 against the mouth 67 of the hole 66 opened in the processing surface 65. And the shoe drive unit 30 (corresponding to shoe drive means) that drives between the operating position where the second shoe 72 is pressed toward the mouth 67 of the hole 66 and the non-operating position separated from the mouth 67 of the hole 66. ), A rotational drive unit 40 (corresponding to rotational drive means) that rotationally drives the workpiece W, and at least one of the workpiece W and the wrapping film 11 along the axial direction of the workpiece W. It includes a oscillation unit 50 for imparting the oscillation, and pressing the lapping film 11 to the workpiece W rotating is subjected to lapping. The lapping apparatus 1 of the present embodiment is suitably used for lapping a workpiece W having a machining surface 65 with a hole 66 opened. As this type of workpiece W, a crankshaft 62 can be cited as shown in FIG. 7A, and the outer peripheral surfaces of the pin portion 63 and the journal portion 64 of the crankshaft 62 are processed surfaces 65 on which lapping is performed. It becomes. As shown in FIG. 7B, oil holes as holes 66 are formed in the pin portion 63 and the journal portion 64 of the crankshaft so as to penetrate in the direction perpendicular to the axis, and the oil holes 66 are formed on the processed surface 65. The mouth 67 is open. A plurality of pairs of upper arm 22 and lower arm 23 are arranged corresponding to the positions of the pin part 63 and the journal part 64 (see FIG. 1).
[0018]
Hereinafter, the lapping apparatus 1 will be described in detail.
[0019]
Referring to FIG. 1, the rotation drive unit 40 includes a head stock 42 that rotatably supports a main shaft 41, a chuck 43 that is connected to the tip of the main shaft 41 and grips one end of a crankshaft 62, and a belt attached to the main shaft 41. The main shaft motor M <b> 1 connected via the shaft 44, and a tail stock 46 including a center 45 that supports the other end of the crankshaft 62. The crankshaft 62 is rotationally driven by the rotation of the main shaft motor M1 being transmitted through the belt 44 and the main shaft 41. By changing the rotation speed of the spindle motor M1, the work rotation speed Vw is set to a desired speed. In order to detect the position of the oil hole 66 in the rotating crankshaft 62, a rotary encoder S1 (corresponding to detection means) for detecting the rotational position of the workpiece W during processing is attached to the main shaft 41. Each of the head stock 42 and the tail stock 46 is provided on tables 47 and 48 that are slidable along the Y direction, and these tables 47 and 48 are arranged on a table 49 that is slidable along the X direction. ing. In order to set the crankshaft 62 between the headstock 42 and the tailstock 46, or to move the crankshaft 62 to the processing position, the respective tables 47, 48, 49 are moved.
[0020]
The oscillation unit 50 includes an eccentric rotator 51 that contacts the end surface of the table 49, and an oscillation motor M <b> 2 that rotationally drives the eccentric rotator 51. The oscillation unit 50 includes an elastic means 52 such as a spring for biasing a resilient force that presses the table 49 toward the eccentric rotator 51 so that the end surface of the table 49 and the eccentric rotator 51 are always in contact with each other. Is provided. By changing the rotation speed of the oscillation motor M2, the oscillation speed Vo is set to a desired speed (for example, 10 Hz). The oscillation amplitude is determined based on the amount of eccentricity of the eccentric rotating body 51 with respect to the axis of the oscillation motor M2. The amount of eccentricity is about 1 mm, and the amplitude of oscillation is about 2 mm. The eccentric amount of the eccentric rotating body 51 can be adjusted by known means such as changing the number of inserted adjustment plates (not shown). A rotary encoder S <b> 2 that detects the rotational position of the eccentric rotator 51 is attached to the shaft of the eccentric rotator 51.
[0021]
Although there are various types of the wrapping film 11, in this embodiment, the base material is made of a highly non-stretchable material, for example, a polyester having a plate thickness of about 25 μm to 130 μm. A large number of abrasive grains (specifically, made of aluminum oxide, silicon carbide, diamond, etc.) having a particle diameter of several μm to 200 μm are attached by an adhesive. 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. On the other surface of the base material, a back coating for attaching a resistance material (not shown) made of rubber or synthetic resin to prevent the first and second shoes 71 and 72 from slipping, or in some cases, a slip-proofing process. Is given.
[0022]
2 and 3, the wrapping film 11 is pulled out from the supply reel 15, and a pair of first guide rollers R <b> 1 provided at the front end of the upper arm 22 and a pair provided at the front end of the lower arm 23. Is guided by the second guide roller R2 and the like, and is taken up by the take-up reel 16. A motor M3 is connected to the take-up reel 16. When the motor M3 is operated and the take-up reel 16 is rotated, the wrapping film 11 is sequentially fed out from the supply reel 15. In order to detect the feed amount of the wrapping film 11, a rotary encoder S3 for detecting the rotation amount is attached to the shaft of the take-up reel 16. A lock device (not shown) is provided in the vicinity of the supply reel 15 and the take-up reel 16, and a predetermined tension is applied to the entire film 11 by the operation of the lock device.
[0023]
The paired upper arm 22 and lower arm 23 are rotatable via a support pin 24 so that the distal end portions where the first and second shoes 71 and 72 are disposed can be opened and closed relatively in the Z direction. Is provided. One end of a fluid pressure cylinder 25 that is operated by hydraulic pressure or air pressure is pin-connected to the rear end portion of the upper arm 22, and the tip of a piston rod 26 is pin-connected to the rear end portion of the lower arm 23. When the piston rod 26 is extended from the contracted state, the upper and lower arms 22 and 23 are pivoted about the support pins 24 in the direction in which the tip ends are closed, and are in the closed state shown in FIG. On the other hand, when the piston rod 26 is contracted from the extended state, the upper and lower arms 22 and 23 are rotated in the direction in which the distal ends are opened, and are in the open state shown in FIG. The upper and lower arms 22, 23 are rotated together with the wrapping film 11, the first shoe 71 comes into contact with the processing surface 65 through the wrapping film 11 by closing rotation, and the processing surface 65 and the first surface are rotated by opening rotation. The contact with the shoe 71 is released.
[0024]
In the illustrated embodiment, the first shoe 71 is a hard shoe, and the second shoe 72 is a soft shoe. As is well known, the hard shoe 71 is made of a hard material such as a grindstone or steel. By backing up the wrapping film 11 with the hard shoe 71 and pressing the abrasive surface of the wrapping film 11 against the processed surface 65, the shape accuracy (roundness or straightness) of the processed surface 65, which is a cylindrical surface, is high. Finished. On the other hand, the soft shoe 72 is formed of, for example, a urethane resin material that is softer and elastically deformable than the hard shoe 71. The soft shoe 72 is elastically deformed and comes into contact with the processing surface 65 with a relatively large area through the film 11. The soft shoe 72 is a shoe excellent in the function of improving the surface roughness of the processed surface 65 although the function of correcting the workpiece shape is lower than that of the hard shoe 71. In the first embodiment, the soft shoe 72 is used to form the rounded portion 68 (see FIG. 7B) in the mouth corner portion 67a. In the present specification, the contact of the shoe indirectly with the outer peripheral surface of the workpiece W via the film 11 is abbreviated as “contact”.
[0025]
The shoe is classified into a concave shoe and a convex shoe according to the shape of its tip, but the hard shoe 71 is a concave shoe having a concave tip and the soft shoe 72 is formed as a convex shoe having a convex tip. ing. The soft shoe 72 of the present embodiment is preferably a shoe having a shape specialized for forming the rounded portion 68 at the mouth corner portion 67a, for example, a convex shoe having a spherical shape.
[0026]
A plurality of hard shoes 71 are attached to a shoe case 73 having an inner peripheral surface facing the processing surface 65. In the illustrated example, two pieces are attached to each of the upper and lower shoe cases 73. The shoe case 73 is housed in a recess 27 formed at the tip of the upper and lower arms 22 and 23 so as to be movable forward and backward with respect to the workpiece W. The shoe case 73 moves while its outer surface is guided by the inner surface of the recess 27. A work clamping spring 74 made of a compression coil spring is disposed on the back surface of the shoe case 73. The hard shoe 71 is pressed against the work surface 65 through the wrapping film 11 by the elastic force of the work clamping spring 74.
[0027]
As shown in FIGS. 4A and 4B, the soft shoe 72 is attached to the tip of the shoe holder 75 and is arranged in the + X direction (right side in the figure) with respect to the crankshaft 62. The shoe holder 75 is attached to the tip of a rod 76 that can move forward and backward along the X direction passing through the axis O (rotation center) of the crankshaft 62. The rod 76 has a forward limit position approaching the crankshaft 62 (the state shown in FIG. 4A) and a reverse travel limit position separating from the crankshaft 62 (the state shown in FIG. 4B). Move back and forth between.
[0028]
As conceptually shown in FIGS. 4A and 4B, the shoe drive unit 30 includes a rotatable eccentric cam 31 that contacts the rear end of the rod 76, a motor M4 that rotationally drives the eccentric cam 31, And an elastic means (not shown) that maintains the rear end of the rod 76 and the eccentric cam 31 in a state where they are always in contact with each other. As shown in FIG. 4A, when the eccentric cam 31 rotates and the top portion of the eccentric cam 31 contacts the rear end of the rod 76, the rod 76 moves to the forward limit position. As a result, the soft shoe 72 reaches the operating position where it is pressed toward the mouth 67 of the oil hole 66, and the abrasive grain surface of the wrapping film 11 is pressed against the mouth 67. On the other hand, as shown in FIG. 4B, when the base portion of the eccentric cam 31 comes into contact with the rear end of the rod 76, the rod 76 moves to the backward limit position. As a result, the soft shoe 72 reaches the non-operating position that is separated from the mouth 67 of the oil hole 66, and the pressing of the wrapping film 11 to the mouth 67 is released. In order to detect the position (operating position or non-operating position) of the soft shoe 72, a rotary encoder S4 that detects the rotational position of the eccentric cam 31 is attached to the shaft of the eccentric cam 31.
[0029]
The cam lift and base circle diameter of the eccentric cam 31 are determined based on the movement amount of the rod 76, that is, the movement amount of the soft shoe 72, the pressing force of the soft shoe 72, and the like. In addition, the position of the rotation center of the eccentric cam 31 can be adjusted in the X direction, and even when the same eccentric cam 31 is used, the pressing force of the soft shoe 72 can be adjusted.
[0030]
With reference to FIGS. 5A to 5C and FIGS. 6A to 6C, the range in which the soft shoe 72 is driven from the non-actuated position to the actuated position will be described. In these drawings, it is assumed that the crankshaft 62 rotates in the clockwise direction as indicated by an arrow. Further, as shown in FIGS. 5B and 6B, when the angle θ between the axis of the oil hole 66 and the X direction is zero, that is, the position where the axis of the oil hole 66 is parallel to the X direction. Is a reference position of the crankshaft 62.
[0031]
Ideally, the timing of driving the soft shoe 72 from the non-operating position to the operating position is only the moment when the rotating crankshaft 62 reaches the reference position. However, since the crankshaft 62 is always driven to rotate, if the soft shoe 72 is driven to the operating position only at the moment when the crankshaft 62 reaches the reference position, the rotation of the crankshaft 62 and the movement of the soft shoe 72 There is a possibility that the entire circumference of the mouth 67 of the oil hole 66 cannot be processed uniformly even if the synchronization is slightly shifted. Therefore, it is desirable to drive the soft shoe 72 to the operating position before the crankshaft 62 reaches the reference position, and to maintain the soft shoe 72 in the operating position for a while after the crankshaft 62 reaches the reference position.
[0032]
The lapping process for the mouth 67 is performed while the soft shoe 72 is in contact with the mouth 67. As a result, the soft shoe 72 is driven to the operating position only in the rotational angle range of the crankshaft 62 in which any part of the mouth 67 can come into contact with the soft shoe 72 in the operating position. As shown in FIG. 5A, at the rotation angle of θ = −α degrees before the crankshaft 62 reaches the reference position (θ = 0 degrees), the front end portion in the rotational direction of the mouth 67 contacts the soft shoe 72. 5C, it is assumed that the rear end portion in the rotation direction of the mouth 67 is separated from the soft shoe 72 at a rotation angle of θ = + α degrees after reaching the reference position. In this case, the soft shoe 72 may be driven to the operating position within a range of 2α degrees where the rank shaft 62 rotates from θ = −α degrees to θ = + α degrees.
[0033]
The lapping process performed by pressing the lapping film 11 with the soft shoe 72 is preferably limited to the mouth 67 of the oil hole 66 and its periphery. This is to prevent the shape accuracy (roundness or straightness) of the processed surface 65 from being broken by the processing by the soft shoe 72. Therefore, it is more preferable to drive the soft shoe 72 to the operating position within a range smaller than the range (2α degrees). 6 (A) and 6 (C), the soft shoe 72 is driven to the operating position when θ = −β degrees (β before the crankshaft 62 reaches the reference position (θ = 0 degrees). A rotation angle of <α) to a rotation angle of θ = + β after reaching the reference position is preferably 2β degrees.
[0034]
In the lapping apparatus 1 of the present embodiment, the rotary encoder S1 detects the rotational position of the crankshaft 62, thereby detecting the position of the oil hole 66 in the rotating crankshaft 62, and the oil during processing. The lapping process is performed by controlling the operation of the shoe drive unit 30 so as to drive the soft shoe 72 to the operating position or the non-operating position in accordance with the position of the hole 66 and pressing the lapping film 11 with the soft shoe 72. Is limited to the periphery of the mouth 67 of the oil hole 66.
[0035]
The above control will be described with reference to FIG. FIG. 8 is a schematic block diagram showing a control system of the lapping apparatus 1 according to the present invention.
[0036]
Referring to FIG. 8, rotary encoders S1, S2, S3, and S4 are connected to a controller 100 (corresponding to control means) mainly composed of a CPU and a memory, and the rotational position of the crankshaft 62 during processing, the soft shoe A detection signal relating to the rotational position of the eccentric cam 31 that changes the position 72 is input to the controller 100. A detection signal related to the rotation speed of the spindle motor M1 that determines the workpiece rotation speed Vw and the rotation speed of the oscillation motor M2 that determines the oscillation speed Vo are also input to the controller 100. The controller 100 determines the position of the oil hole 66 based on a signal related to the rotational position of the crankshaft 62 from the rotary encoder S1. Then, the controller 100 variably controls the position of the soft shoe 72 to the operating position or the non-operating position according to the position of the oil hole 66 during processing.
[0037]
The change control of the position of the soft shoe 72 is performed by controlling the operation of the shoe drive unit 30 including the eccentric cam 31 and the motor M4 so that the soft shoe 72 enters and exits the mouth 67 in synchronization with the position of the oil hole 66. Made.
[0038]
Specifically, the controller 100 rotates the motor M4 so that the top portion of the eccentric cam 31 contacts the rear end of the rod 76 when the rotating crankshaft 62 reaches the reference position (θ = 0 degrees). Is output to the motor M4. Thereby, the soft shoe 72 reaches the operating position, the abrasive grain surface of the wrapping film 11 is pressed against the mouth 67, and the rounded portion 68 is formed in the corner portion 67a. The radius of the rounded portion 68 is, for example, about 10 μm to 20 μm.
[0039]
Next, the operation of this embodiment will be described.
[0040]
First, the crankshaft 62 is supported between the head stock 42 and the tail stock 46, and the upper and lower arms 22 and 23 are moved to the positions of the pin portion 63 and the journal portion 64. At this time, the fluid pressure cylinder 25 contracts the piston rod 26 and holds the upper arm 22 and the lower arm 23 in the open position. Thereafter, the fluid pressure cylinder 25 is operated to extend the piston rod 26 and rotate in a direction to close the upper and lower arms 22 and 23. By this closing rotation, the wrapping film 11 is set on the processing surface 65.
[0041]
While the upper and lower arms 22 and 23 are opened and rotated, the motor M3 is operated to rotate the take-up reel 16. The wrapping film 11 moves by a predetermined amount, and a new abrasive grain surface is set on the processing surface 65. Thereafter, when a lock device provided in the vicinity of the supply reel 15 is locked and the take-up reel 16 is rotated, a predetermined tension is applied to the wrapping film 11. Next, when the locking device in the vicinity of the take-up reel 16 is locked, the wrapping film 11 is given a tension and is not loosened.
[0042]
When the crankshaft 62 is clamped, the hard shoe 71 is pressed toward the processing surface 65 by the elastic force of the work clamping spring 74.
[0043]
Then, when the rotation unit 40 is operated and the crankshaft 62 is rotated about the axis while the oscillation unit 50 is operated and the crankshaft 62 is given oscillation along the axial direction, the wrapping film 11 is rotated by the hard shoe 71. The abrasive grain surface is pressed against the processing surface 65, and the processing surface 65 is lapped over the entire surface. Since the processing of the entire processing surface 65 is performed by the hard shoe 71, the processing efficiency is high.
[0044]
During this processing, the controller 100 controls the operation of the shoe drive unit 30 to synchronize the rotation of the crankshaft 62 and the movement of the soft shoe 72. The rotary encoder S1 detects the rotational position of the crankshaft 62, and the controller 100 determines the position of the oil hole 66 from the rotational position of the crankshaft 62, and the soft shoe 72 according to the position of the oil hole 66 during processing. Is variably controlled to an operating position or a non-operating position. That is, the controller 100 controls the operation of the motor M4 so that the top portion of the eccentric cam 31 contacts the rear end of the rod 76 when the rotating crankshaft 62 reaches the reference position (θ = 0 degrees). The eccentric cam 31 is rotated.
[0045]
Thereby, the soft shoe 72 reaches the operating position, the abrasive grain surface of the wrapping film 11 is pressed against the mouth 67, and the rounded portion 68 is formed in the corner portion 67a.
[0046]
During the lapping process, the crankshaft 62 is rotated forward a set number of times (for example, 5 times) and then reversely rotated the same set number of times. By changing the rotation direction, clogging of the wrapping film 11 is eliminated and the performance is maintained, and the entire circumference of the mouth 67 is processed uniformly.
[0047]
As described above, since the processing on the entire circumference of the processing surface 65 by the hard shoe 71 and the processing on the mouth 67 by the soft shoe 72 are performed by one lapping processing apparatus, the processing efficiency is good and the time required for processing is shortened. Can do. Further, since there is no increase in the number of equipment, the increase in equipment costs and processing costs can be suppressed.
[0048]
Further, since the lapping process performed by pressing the lapping film 11 with the soft shoe 72 is limited to the periphery of the mouth 67 of the oil hole 66, the shape accuracy (roundness and straightness) of the processed surface 65 is soft. There is no risk of collapse due to processing by the shoe 72. Furthermore, the processing by the hard shoe 71 that increases the shape accuracy (roundness and straightness) of the processed surface 65 and the processing by the soft shoe 72 that forms the rounded portion 68 in the mouth corner portion 67a are performed in the same process. Therefore, the function of correcting the work shape by the hard shoe 71 also works on the portion on the processing surface 65 that has been processed by the soft shoe 72. From this point of view as well, there is no possibility that the shape accuracy of the processed surface 65 is broken by the processing by the soft shoe 72.
[0049]
In the case of comparison with the additional processing of pressing the abrasive surface of the wrapping film against the mouth 67 with the soft shoe after processing with the hard shoe, the wrapping film bites into the mouth corner 67a too much during processing with the soft shoe. As a result, peeling of the abrasive grains occurs. FIG. 9 shows a failure example in which a part of the abrasive grain layer of the wrapping film 91 is peeled off. As shown in the figure, a peeling portion 92 extending in a strip shape along the film conveyance direction is generated at a substantially central portion in the width direction of the wrapping film 91.
[0050]
On the other hand, in this embodiment, since the lapping process by the soft shoe 72 is limited to the periphery of the mouth 67 of the oil hole 66, the lapping film 11 does not bite into the mouth corner portion 67a, and the lapping film 11 is ground. Grain peeling is reduced, and the number of places where peeling occurs is reduced.
[0051]
The crankshaft 62 has a large number of pin portions 63 and journal portions 64, and lapping is performed on these pin portions 63 and journal portions 64 all at once. When the lapping process is completed, the fluid pressure cylinder 25 is operated to contract the piston rod 26, and the upper and lower arms 22 and 23 are rotated in the opening direction so that the crankshaft 62 can be taken out. If another crankshaft 62 is set after taking out the crankshaft 62, the same lapping process can be started.
[0052]
As described above, according to the wrapping processing apparatus 1 of the first embodiment, the wrapping film 11, the first shoe 71 that presses the abrasive grain surface of the wrapping film 11 against the processing surface 65, and the wrapping film 11 A second shoe 72 that presses the abrasive surface against the mouth 67 of the oil hole 66 as a hole, an operating position where the second shoe 72 is pressed toward the mouth 67 of the oil hole 66, and the mouth 67 of the oil hole 66. The position of the oil hole 66 in the workpiece W that rotates by detecting the rotational position of the workpiece W, and the rotational drive unit 40 that drives the workpiece W to rotate between the non-actuated position that is separated from the workpiece W. The shoe drive unit 3 is configured to drive the second shoe 72 to the operating position or the non-operating position in accordance with the rotary encoder S1 to be detected and the position of the oil hole 66 during processing. And the controller 100 for controlling the operation of the oil hole 66, and the lapping process performed by pressing the lapping film 11 with the second shoe 72 is limited to the periphery of the mouth 67 of the oil hole 66. Even a workpiece W having an opened processing surface 65 can be processed quickly, suppressing an increase in processing costs and a decrease in shape accuracy (roundness and straightness) as much as possible. There is an effect that it is possible to reduce the peeling of the abrasive grains and the parts to be peeled off.
[0053]
Further, since the first shoe 71 is made of a hard shoe and the second shoe 72 is made of a soft shoe, processing by the hard shoe 71 for improving the shape accuracy (roundness and straightness) of the processing surface 65, and the corner of the mouth. The processing by the soft shoe 72 that forms the rounded portion 68 in the portion 67a is performed in the same process, and the work shape by the hard shoe 71 is also corrected at the portion on the processing surface 65 that has been processed by the soft shoe 72. Is working. Therefore, there is no possibility that the shape accuracy of the processed surface 65 is lost due to the processing by the soft shoe 72.
[0054]
Further, the hole portion is, for example, an oil hole 66, and the processing surface 65 of the pin portion 63 of the crankshaft 62 and the journal portion 64 having such an oil hole 66 can be suitably lapped.
[0055]
Further, since the wrapping film 11 is non-stretchable and deformable, a suitable wrapping process can be performed on the workpiece W.
[0056]
In addition, the lapping apparatus 1 of the present embodiment is configured so that the workpiece W is pressed against the workpiece W having the machining surface 65 with the oil hole 66 opened by the first shoe 71 against the abrasive surface of the wrapping film 11. A lapping method for performing lapping while rotating, wherein the position of the oil hole 66 in the rotating workpiece W is detected by the rotary encoder S1, and the lapping film 11 is ground according to the position of the oil hole 66 during processing. The second shoe 72 that presses the grain surface against the mouth 67 of the oil hole 66 is driven to an operating position that is pressed toward the mouth 67 of the oil hole 66 or a non-operating position that is separated from the mouth 67 of the oil hole 66, The wrapping process performed by pressing the wrapping film 11 with the two shoes 72 is limited to the periphery of the mouth 67 of the oil hole 66. As described above, even the workpiece W having the machining surface 65 with the oil hole 66 opened can be quickly machined, and the machining cost increases and the shape accuracy (roundness and It is possible to suppress the decrease in straightness) as much as possible and to reduce the peeling of the abrasive grains of the wrapping film 11 and the places where peeling occurs.
[0057]
(Second Embodiment)
FIG. 10 is a schematic cross-sectional view showing a closed state of the upper and lower arms 22 and 23 provided to be openable and closable in the lapping apparatus 2 according to the second embodiment of the present invention. 11A is a cross-sectional view showing the shoe 80 and the shoe case 83 used in the second embodiment, and FIG. 11B is an arrow view of FIG. It is. 10, members that are the same as those shown in FIG. 2 are given the same reference numerals, and descriptions thereof are omitted.
[0058]
As shown in FIG. 10, the lapping apparatus 2 according to the second embodiment is similar to the first embodiment in that a crank as a workpiece W having a machining surface 65 in which a hole 66 such as an oil hole is opened. The lapping machine is suitable for lapping the shaft 62, and includes a lapping film 11 and a shoe 80 that presses the abrasive grain surface of the lapping film 11 against the machining surface 65. However, it differs from the first embodiment in the structure of the shoe 80 itself, and also differs from the first embodiment in that the second shoe 72 and the shoe drive unit 30 are not provided.
[0059]
As shown in FIGS. 11A and 11B, a shoe 80 according to the second embodiment includes a first shoe member 81 constituting a hard shoe and a second shoe member 82 constituting a soft shoe. Contains. The second shoe member 82 is disposed at a portion where the wrapping film is pressed against the mouth 67 of the hole 66, in other words, at a location where the hole 66 passes. The shoe at the left end in the figure includes only the first shoe member 81 including the portion through which the hole 66 passes.
[0060]
The first shoe member 81 is formed of a hard material such as a grindstone or steel in order to constitute a hard shoe. On the other hand, the second shoe member 82 is formed of, for example, a urethane resin material that is softer and more elastically deformable than the first shoe member 81 in order to form a soft shoe.
[0061]
The surface of the second shoe member 82 protrudes toward the workpiece W by a slight size (several μm) from the surface of the first shoe member 81. The optimal amount of protrusion of the second shoe member 82 is determined based on the hardness of the second shoe member 82 and the shoe pressing force.
[0062]
In the lapping apparatus 2 including the shoe 80 having such a configuration, when the crankshaft 62 is clamped, both the first shoe member 81 and the second shoe member 82 are urged by the elastic force of the work clamp spring 74. It is pressed toward the processing surface 65.
[0063]
Then, when the rotation drive unit 40 is operated and the crankshaft 62 is rotated about the axis while giving oscillation along the axial direction to the crankshaft 62, the wrapping film 11 is formed by the first shoe member 81 constituting the hard shoe. The abrasive grain surface is pressed against the processing surface 65, and the processing surface 65 is lapped over the entire surface. Furthermore, the abrasive grain surface of the wrapping film 11 is pressed against the mouth 67 by the second shoe member 82 constituting the soft shoe, and the rounded portion 68 is formed in the corner portion 67a.
[0064]
During the lapping process, the crankshaft 62 is rotated forward a set number of times (for example, 5 times) and then reversely rotated the same set number of times. By changing the rotation direction, the performance of the wrapping film 11 is maintained, and the entire circumference of the mouth 67 is processed uniformly.
[0065]
As described above, also in the second embodiment, the processing for the entire circumference of the processing surface 65 by the first shoe member 81, that is, the hard shoe, and the processing for the mouth 67 by the second shoe member 82, that is, the soft shoe are performed by one unit. Since it is performed by the lapping processing apparatus, the processing efficiency is good and the time required for processing can be shortened. Further, since there is no increase in the number of equipment, the increase in equipment costs and processing costs can be suppressed.
[0066]
Moreover, since the shoe in the existing lapping apparatus can be replaced with the shoe 80 of the second embodiment, an increase in equipment cost and processing cost can be further suppressed as compared with the first embodiment.
[0067]
Further, the left end shoe 80 is composed only of a hard shoe, processing with a hard shoe that increases the shape accuracy (roundness and straightness) of the processed surface 65, and software for forming a rounded portion 68 in the mouth corner portion 67a. Since the processing with the shoe is performed in the same process, the function of correcting the workpiece shape with the hard shoe at the left end works at the portion on the processing surface 65 that has been processed with the soft shoe. Thereby, there is no possibility that the shape accuracy of the processing surface 65 may be lost by processing with the soft shoe.
[0068]
Note that the second embodiment can be effectively applied to the workpiece W in which the rounding amount of the mouth corner portion 67a is relatively small as compared with the first embodiment.
[0069]
(Modification example)
The processing surface 65 of the workpiece W is not limited to the pin portion 63 or the journal portion 64 of the crankshaft 62, and can be applied to various other workpieces W as long as the hole 66 has the processing surface 65 opened. Needless to say.
[0070]
In the first embodiment, an example in which the eccentric cam 31 and the motor M4 are used as the shoe drive means 30 is illustrated, but the present invention is not limited to this and can be appropriately modified. For example, the second shoe 72 may be driven to the operating position or the non-operating position using an actuator such as a fluid pressure cylinder that is operated by a servo motor or air pressure.
[0071]
Further, although the case where the second shoe 72 is configured by a soft shoe has been shown, the second shoe 72 is configured by the same hard shoe as the first shoe 71, and the pressing force of the second shoe 72 is weaker than the pressing force of the first shoe 71. However, the same effect can be obtained. The shoe pressing force may be adjusted by adjusting the fluid pressure such as hydraulic pressure or air, or adjusting the spring force of the spring.
[0072]
Further, the soft shoe 72 may be oscillated in the axial direction of the workpiece.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a lapping apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view showing a closed state of upper and lower arms provided in a lapping apparatus so as to be freely opened and closed.
FIG. 3 is a schematic cross-sectional view showing an open state of upper and lower arms.
4 (A) and 4 (B) are cross-sectional views showing the main part of the lapping apparatus 1, and FIG. 4 (A) shows the second shoe constituting the soft shoe at the mouth of the oil hole. FIG. 4B shows a state where the soft shoe is driven to a non-operating position where the soft shoe is separated from the mouth of the oil hole.
FIGS. 5A to 5C are diagrams for explaining a range in which the soft shoe is driven from the non-operating position to the operating position.
FIGS. 6A to 6C are views for explaining a range in which the soft shoe is driven from the non-operating position to the operating position.
7A is a perspective view showing an example of a crankshaft as a workpiece to be lapped, and FIG. 7B is a partially cutaway sectional view showing an oil hole formed in the crankshaft. It is.
FIG. 8 is a schematic block diagram showing a control system of the lapping apparatus according to the present invention.
FIG. 9 is a view showing a defect example in which a part of an abrasive layer of a wrapping film is peeled off.
FIG. 10 is a schematic cross-sectional view showing a closed state of upper and lower arms provided to be opened and closed in a lapping apparatus according to a second embodiment of the present invention.
FIG. 11A is a cross-sectional view showing a shoe and a shoe case used in the second embodiment, and FIG. 11B is an arrow view of FIG. It is.
[Explanation of symbols]
1.2 ... Lapping device
11 ... Wrapping film
30 ... Shoe drive unit (shoe drive means)
40: Rotation drive unit (rotation drive means)
50 ... Oscillation unit
62 ... Crankshaft (workpiece)
63 ... pin part
64 ... Journal
65 ... Machining surface
66 ... oil hole (hole)
67 ... Mouth
67a ... Corner
68 ... Earl Club
71 ... first shoe, hard shoe
72. Second shoe, soft shoe
80 ... Shoe
81. First shoe member, hard shoe
82 ... Second shoe member, soft shoe
100: Controller (control means)
M1 ... Spindle motor
M4 ... motor
S1 ... Rotary encoder (detection means)
S2, S3, S4 ... Rotary encoder
W: Work having a machining surface with a hole

Claims (6)

A lapping machine for lapping a workpiece having a machining surface with an open hole,
A wrapping film in which abrasive grains are provided on one surface of a thin substrate;
A first shoe that presses the abrasive surface of the wrapping film against the processed surface;
A second shoe that presses the abrasive surface of the wrapping film against the mouth of the hole;
Shoe driving means for driving the second shoe between an operating position pressed toward the mouth of the hole and a non-operating position separated from the mouth of the hole;
A rotation driving means for rotating the workpiece;
Detection means for detecting the position of the hole in the rotating workpiece;
Control means for controlling the operation of the shoe driving means so as to drive the second shoe to the operating position or the non-operating position in accordance with the position of the hole during processing,
A lapping apparatus characterized in that lapping performed by pressing the lapping film with the second shoe is limited to the periphery of the mouth of the hole. The lapping apparatus according to claim 1, wherein the first shoe is a hard shoe, and the second shoe is a soft shoe. The lapping apparatus according to claim 1, wherein the hole is an oil hole. A lapping machine for lapping a workpiece having a machining surface with an open hole,
A wrapping film in which abrasive grains are provided on one surface of a thin substrate;
A shoe that presses the abrasive surface of the wrapping film against the processed surface,
The shoe includes a first shoe member constituting a hard shoe and a second shoe member constituting a soft shoe, and the second shoe member is pressed against the mouth of the hole portion with the wrapping film. A lapping apparatus characterized by being arranged at a part and a part of a part through which the hole part passes . The lapping processing apparatus according to claim 1, wherein the lapping film is non-stretchable and deformable. A lapping method for performing lapping while rotating the workpiece while pressing the abrasive surface of the lapping film with a first shoe against a workpiece having a machining surface in which a hole is opened,
The position of the hole in the rotating workpiece is detected by a detecting means, and a second shoe that presses the abrasive grain surface of the wrapping film against the mouth of the hole according to the position of the hole during processing, Driving to an operating position pressed toward the mouth of the hole or a non-operating position away from the mouth of the hole, and wrapping applied by pressing the wrapping film with the second shoe, A lapping method characterized by being limited to the periphery of the mouth of the hole.

Images