JPH07164086A - Method and device for hole piercing work - Google Patents

Abstract

PURPOSE:To finish the inside diameter, of which the diameter and cylindricity are hard to be machined, to high precision. CONSTITUTION:Balls 3 of plural kinds of diameter are placed on an upper stage 2 free to slide and rotate, the ball selected from among these so as to coincide with the diameter of a prepared hole is pushed into a bearing hole 1A by a pin 5B. By this method, when there is a variance in the diameter of the prepared hole, a variance for the finished hole is contained to a minimum, a high precision sleeve and high performance bearing is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hole of a work,
The present invention relates to a hole drilling apparatus and method for a workpiece, which punches an inner surface of the hole by pushing a working ball having the same outer diameter or a slightly larger outer diameter as the hole. In particular, in recent years, bearings used in office equipment, consumer equipment, etc. have become faster and more accurate, and there is an increasing need for hydrodynamic bearings and special plain bearings that have been specially processed with high precision. The present invention relates to a processing apparatus and a processing method capable of finishing the inner diameter of a sleeve of these highly accurate bearings.

[0002]

2. Description of the Related Art The structure of a conventional work hole drilling apparatus will be described below with reference to the drawings. 8 to 10, 11 is a sleeve of a bearing as an example of the work,
11A is a bearing hole, 12 is a dynamic pressure generating groove, 13 is a residual protrusion,
Reference numeral 14 is a processed ball made of a material such as hardened steel, and 15 is a pin.

The operation of the conventional work hole drilling apparatus will be described below with reference to the drawings. Conventionally, in the inner diameter processing process of precision bearings such as a hydrodynamic bearing with a groove, as shown in FIG. 9, first, the bearing hole 11A of the sleeve 11 is processed into a dimension of D1 in the drawing by cutting, and then shown. A plurality of dynamic pressure generating grooves 12 are machined by a machining tool (for example, a manufacturing apparatus disclosed in Japanese Patent Publication No. 3-68768). As shown in FIG. 9, the residual protrusion 13 raised during this processing is formed by quenching a ball 14 made of hardened steel or the like and having a certain diameter Db with a pin 15 so as to press it into place. Had been removed.

The hole inner diameter of the sleeve 11 by this ball burnishing is the inner diameter (prepared hole diameter) D1 after cutting.
The diameter D2 was slightly larger.
In FIG. 10, structural strength is weak in the vicinity of both ends of the inner diameter 11A of the sleeve 11, and as shown by D3 in the figure, the plastic change amount due to the ball burnishing is large, which deteriorates the cylindricity. It was

[0005]

However, in the above structure, as shown in FIG. 11, the prepared hole diameter D1 of the sleeve 11 varies by about 6 microns with respect to the reference diameter depending on the cutting conditions (for example, with respect to the reference diameter). -5 to +1 micron), but the finished diameter D2 also has a similar variation due to the variation of the prepared hole, and it is 1 to 3 microns (-1 to 1 in the specific example) required for the sleeve of the precision bearing. It was extremely difficult in mass production to machine the finished diameter D2 to a tolerance of about +1 micron.

Therefore, the object of the present invention is to perform highly precise finishing of the inner surface of a hole by a controlled special plastic working without using a cutting work or a polishing work, which has generally been difficult to obtain accuracy. An object of the present invention is to provide a work hole drilling apparatus and method.

[0007]

In order to solve the above problems, a hole drilling apparatus for a workpiece according to the present invention comprises a plurality of spheres slightly larger and slightly different in diameter depending on the hole inner diameter of the workpiece. A hole having a diameter selected from the above is pushed through a hole of a work to perform hole processing.

That is, a work hole drilling apparatus according to an aspect of the present invention is a work hole drilling apparatus that inserts a work ball into a hole of a work to machine the inner surface of the hole. When the inner diameter of the hole of the work is set to D1 from the processing sphere supply device provided with the processing sphere having the processing sphere and the processing sphere provided in the sphere supply device, the outer diameter is (1-1.02) × A machining sphere selecting device for selecting one machining sphere having a size within the range of D1, and a machining sphere pushing device for pushing the machining sphere selected by the selecting device from the machining sphere supplying device into the hole of the workpiece. To prepare for.

A hole drilling apparatus for a work according to another aspect of the present invention is a hole drilling apparatus for a work, which inserts a working ball into a hole of a work to machine an inner surface of the hole.
Before inserting the processing sphere into the hole of the work, the outer diameter Db1 is D1 ≦ Db1 ≦ (1.003 × D1) when the inner diameter of the hole of the work is D1 with respect to the hole of the work. Push through the measuring sphere inside, and the measuring sphere insertion device that detects the magnitude of the load at the time of pushing through this measuring sphere, the processing sphere supply device equipped with a plurality of processing spheres having different diameter dimensions, and the above measuring sphere insertion device. Based on the detected load of the passed measurement sphere, the inner diameter of the hole of the workpiece is set to D1 and the outer diameter of the measurement sphere is set to Db1 from the processing spheres provided in the processing sphere supply device. When the outer diameter Db is
A machining sphere selecting device for selecting one machining sphere having a dimension within the range of 1 <Db ≦ (1.02 × D1), and a machining sphere selected by the selecting device from the machining sphere supplying device for the work. And a processing ball pushing device for pushing through the hole.

Further, a hole drilling method for a work according to still another aspect of the present invention is a method for drilling a hole in a work, wherein an inner surface of the hole is drilled by inserting a working ball into the hole.
Before inserting the processing sphere into the hole of the work, the outer diameter Db1 is D1 ≦ Db1 ≦ (1.003 × D1) when the inner diameter of the hole of the work is D1 with respect to the hole of the work. Pushing through the measuring sphere inside, the step of detecting the magnitude of the load at the time of pushing through this measuring sphere, the step of providing a processing sphere having a plurality of different diameter dimensions, of the measuring sphere pushed through by the measuring sphere insertion device When the inner diameter of the hole of the workpiece is D1 and the outer diameter of the measuring sphere is Db1 among the machining spheres provided in the machining sphere supply device based on the detected load, the outer diameter Db Is Db1 <Db ≦
1 machining sphere having a size within the range of (1.02 × D1)
And a step of pushing the machining sphere selected by the selecting device from the machining sphere supplying device into the hole of the work.

[0011]

According to the present invention, according to this structure, the best one type of sphere is selected from the plurality of spheres arranged on the stage so as to finish the prepared hole diameter of the work to the required size, and the pressing member is selected. By pushing through the hole inner diameter of the work, the inner surface of the hole is plastically deformed and the inner diameter is finished to a predetermined size.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A hole drilling apparatus for a workpiece and a hole drilling method carried out using the apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a work hole drilling apparatus according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 is a sleeve which has a bearing hole 1A which constitutes a dynamic pressure type fluid bearing as an example of a work and which is a non-processed object. The sleeve 1 is made of a plastically deformable material, for example, a metal such as a copper alloy, etc., and a dynamic pressure generating groove 1B is formed on the inner peripheral surface of the bearing hole 1A as needed as shown in FIG. ing. Reference numeral 2 is an upper stage that is slidable or rotatable in the direction A in the figure, and has a plurality of guide holes 2A and stoppers 23 in each of the guide holes 2A, and the guide holes 2A have a plurality of diameters for quenching. Processed balls 3 made of steel, etc., specifically 3B, 3C, 3D, 3E
Are arranged, and these processed spheres 3B, 3C, 3D, 3E are supplied by a processed sphere supply device 4 which is a chute-shaped or tube-shaped processed sphere supply means. 5B is a pin as a processing sphere pressing member that slides in the B direction in the figure, 6 moves integrally with the upper stage 2, and is arranged corresponding to the hole 2A of the upper stage 2 to remove the sleeve 1. A lower stage having holes 6A for receiving the processed balls 3B, 3C, 3D, 3E that have been removed, and each of the holes 6A has a processing ball 3B,
A chute 7 for collecting 3C, 3D and 3E is arranged. The processed balls 3B, 3 collected by the chute 7
C, 3D, and 3E are cleaned by a cleaning device (not shown), and then supplied again to the processing ball supply device 4 for reuse. Further, as shown in FIG. 3, the stopper 23 is constantly pressed into the hole 2A by the spring 24 in the recess 2B in the direction orthogonal to the axial direction of each hole 2A of the upper stage 2, and the stopper 23 is By being projected into the hole 2A, the processed balls 3B, 3C, 3D, 3E are held in the hole 2A without dropping. And the processing ball is the pin 5
When pressed downward by B, the stopper 23
The spheres 3B, 3C, 3D and 3E are pushed into the concave portion 2B against the urging force of, and the processing balls 3B, 3C, 3D and 3E are dropped from the hole 2A and supplied to the sleeve 1.

The operation of the work hole drilling apparatus configured as described above will be described with reference to FIGS.

FIG. 2 shows a bearing sleeve as an example of a workpiece machined by the workpiece hole machining apparatus according to the first embodiment. In FIG. 1, processed balls 3B, 3C, 3D,
3E has substantially the same diameter (3 millimeters in the concrete example), but is a machining sphere of 5 kinds of diameters which are different step by step from 1 to 3 microns (2 micrometer in the concrete example). Diameter Db3 of 3C, 3D, 3E from Db2,
The diameters are set to increase in order from Db4 to Db5. These balls 3B, 3C, 3D and 3E are respectively arranged in the guide holes 2A of the upper stage 2 which is a rapid processing supply device, and are lightly supported by the stoppers 23 that can freely move in and out of the holes 2A so that they do not fall naturally. . here,
The sleeve 1 is supplied between the upper stage 2 and the lower stage 6, and the inner diameter of the bearing hole 1A is predicted in advance. In the specific example, the prepared hole (hole after cutting) of this bearing hole 1A is cut within a tolerance of -6 to -5 to +1 micron with respect to the reference inner diameter. When the diameter is small within the tolerance, the upper stage 2 and the lower stage 6 are integrally slid, and for example, the ball 3B having a relatively small diameter is moved directly above the pin 5B and the sleeve 1 to be selected. , The ball 3B is moved downward by the pin 5B to overcome the urging force of the stopper 23, and the bearing hole 1 of the sleeve 1
The bearing hole 1A is pushed through A, and is sized to a predetermined inner diameter D2 (within a specific example, within a tolerance of 2 microns of a reference diameter of −1 to +1 micron), that is, finished to have an inner diameter D2. At this time, the diameter Db2 of the sphere 3B is set to be larger than the prepared hole inner diameter D1 of the bearing hole 1A by 3 to 60 microns (about 20 microns in the specific example). When the supplied bearing hole 1A of the sleeve 1 is large, the upper stage 2 and the lower stage 6 are slid, and, for example, a ball 3E having a relatively large diameter Db5 is selected, and the bearing is moved by the descending operation of the pin 5B. Pressed into the hole 1A, the hole 1A of the sleeve 1 is sized by plastic working to a predetermined inner diameter dimension D2. Further, the balls 3B and the like that have passed through the bearing hole 1A are collected by the plurality of chutes 7 of the lower stage 6 and supplied again from the ball supply means 4 to be used repeatedly. As shown in FIG. 2, the sleeve 1 after finishing is finished to have an inner diameter of D2 (-1 to +1 micron with respect to the reference diameter in the specific example), and a large deformation of both ends of the bearing hole 1A shown by D3 in the drawing. However, by selecting the sphere 3 having the optimum diameter, the number can be reduced as compared with the conventional case. Therefore, in this first embodiment, the sleeve 1
With respect to the inner diameter D1 of the bearing hole (prepared hole) 1A of (1 to 1.
02) × D1 outer diameter machining ball 3, in other words, prepared hole 1
An appropriate working sphere 3 is selected from the working spheres 3 having an outer diameter that is the same as the inner diameter D1 of A or larger by 2% at the maximum, and finish processing is performed.

FIG. 3 shows a work hole drilling apparatus according to a second embodiment of the present invention, and FIG. 4 is a flow chart of a work hole drilling method carried out using the apparatus. This second
In the embodiment, when the processing sphere 3 is selected, the measurement sphere 3A is first pushed through the bearing hole 1A of the sleeve to measure the necessary load at that time, and the processing sphere 3 is selected and finished based on the measurement data. It differs from the first embodiment in that it is processed. The measuring sphere 3A has such an outer diameter that does not cause finishing, that is, plastic working, on the inner surface of the bearing hole 1A of the sleeve 1, in other words, has an outer diameter dimension that causes only elastic deformation.

In FIG. 5, 8 is a load cell which is provided at the base of the pin 5A and measures the load required when the measuring ball 3A is pushed through the bearing hole 1A of the sleeve 1, and 9 is the load detected by the load cell 8. Is provided as a driving means for integrally sliding or rotating the upper stage 2 and the lower stage 6 on the basis of the output of the computer 9, and the computer 10 has a control unit for performing a predetermined calculation. The drive roller 10A is fixed to the rotating shaft of the motor 10 and slides or rotates the stage 2. The motor 10 is driven and controlled by the control unit of the computer 9. This driving means can be applied to the first embodiment as well.

In the second embodiment, first, in step # 1, the prepared hole of the bearing hole 1A of the sleeve 1 which is a non-machined object is machined. Then, in step # 2, the sleeve 1 is supplied between the upper stage 2 and the lower stage 6. In step # 3, in order to measure the inner diameter D1 of the prepared hole of the bearing hole 1A of the sleeve 1, the outer diameter Db1 which does not cause plastic deformation but only elastic deformation, for example, the bearing hole 1A (prepared hole) is 5 m.
In the case of about m, a ball 3A having a diameter 1 to 10 μm larger than the bearing hole 1A (in the specific example, a diameter 1 μm larger than the reference diameter of the prepared hole) is fixed at a constant speed (for example, 5 mm by a pin 5A).
/ Sec.) And the axial resistance at this time is detected by the load cell 8 (step # 4). At this time, if the inner diameter D1 of the prepared hole 1A of the sleeve 1 is larger than the reference value by 1 micron and is the same as the sphere 3A, the axial resistance is zero or a minute load of several grams is detected. . If the prepared hole D1 is smaller than that, a load in the axial direction (1.1 kg for a diameter difference of 1 micron in the specific example) is detected according to the diameter difference. After the detection result is input to the control unit of the computer 9, the control unit of the computer 9 issues a drive control command to the motor 10 as a result of the desired arithmetic processing (step # 5). Based on this drive control command,
The upper stage 2 and the lower stage 5 are integrally slid or rotated by the motor 10, and the balls 3B, 3C, 3D, 3E
Among them, a sphere having an optimum diameter, for example, sphere 3D in FIG. 5 is selected (step # 6). And the selected sphere 3
D is pushed through the prepared hole 1A by the pin 5B (step #
7) As a result, the prepared hole 1A having a variation of, for example, 6 microns is automatically sized within the tolerance of microns, and the performance and precision desired as a precision bearing can be exhibited. The pins 5A and 5B may be configured separately or may be used as one pin. The contact surface of the pins 5A and 5B with the sphere 3 may be a flat surface, but it is preferable that the contact surface of the pin 5A and 5B is a dented spherical surface in the shape of a rib to make it easier to hold the sphere 3.

The outer diameter Db1 of the measuring sphere 3A is generally
For the inner diameter D1 of the bearing hole (prepared hole) 1A of the sleeve 1,
D1 ≦ Db1 ≦ (1.003 × D1), in other words, it is desirable to have the same outer diameter as the inner diameter D1 of the bearing hole or 0.3% larger than the inner diameter D1. Then, the outer diameters Db2 to Db of the processed balls 3B, 3C, 3D, 3E.
5 is Db1 <(Db2 to Db5) ≦ (1.02 × D
1), in other words, it is desirable that the outer diameter is the same as Db1 or is larger than the bearing inner diameter D1 by at most 2.0%.

FIG. 6 is a diagram of a processing apparatus according to the third embodiment of the present invention and a speed control graph by the processing apparatus. This third embodiment is different from the first and second embodiments in that when the ball 5 is pushed through the prepared hole 1A by the pin 5B, the descending speed of the pin 5B differs depending on the processed portion of the prepared hole 1A. .

In the processing apparatus according to the third embodiment, the pinion 25 fixed to the rotation shaft of the pulse motor 26 whose rotation speed is variable is engaged with the rack portion 5C of the pin 5B. The motor 26 is drive-controlled by a drive circuit 27, and the drive circuit 27 is connected to, for example, a memory 28 in which the data of the speed control graph of FIG. 6 is stored, and the drive circuit is based on the data stored in the memory 28. A drive pulse is sent from 27 to the motor 26, and the motor 26 is drive-controlled at a desired timing. Therefore, the forward / reverse rotation of the motor 26 changes the feed speed of the pin 5B at a desired timing to move the pin 5B up and down. The drive circuit 27 and the memory 28 can be controlled by the computer 9 by being built in or connected to the computer 9 of the processing apparatus of FIG.

An example of this drive control will be described below. That is, any one type of ball 3 in the bearing hole 1A of the sleeve 1
When C is pushed through by the pin 5B, the balls are slowly moved at a low speed as shown by S2 (for example, 1 mm / sec) in FIG. 6 at both ends 1D near the opening of the bearing hole 1A so as not to give much stress to the sleeve 1. 3C is pushed through, while at the intermediate portion other than both end portions 1D, even if stress is applied, it does not hinder as much as the above both end portions D1, so the ball 3C at a medium speed of S3 (for example, 10 mm / sec)
Is pushed through and the sleeve 1 is plastically processed. Speed S1
(For example, 20 mm / sec) indicates the speed of fast-forwarding in the portion 1C of the intermediate portion that is not plastically worked. In addition, a portion 1E in the vicinity of a portion 1C which is not plastically worked except for both end portions 1D
Then, the speed is between S2 and S3.

The graph of FIG. 7 shows the relationship between the speed of pushing the ball 3C (vanishing speed) and the amount of change in the inner diameter of the bearing hole 1A of the sleeve 1 in which the diameter Db of the ball and the diameter D1 of the prepared hole are constant. It is the figure showing about the case. As shown in the figure, when the feed rate is high, the change in inner diameter becomes slightly large. It is presumed that this is because the higher the feed rate, the higher the processing stress applied to the sleeve 1, and the plastic working amount increases accordingly. In this way, by slowing the feed speed of the ball 3C at both ends 1D of the bearing hole 1A,
The cylindricity of the bearing hole 1A after processing can be improved.

The same applies even if the dynamic pressure generating groove 1B is not provided on the inner peripheral surface of the bearing hole 1A. The hole of the workpiece to which the present invention is applied is not limited to the bearing hole 1A of the sleeve 1 and may be a hole of a plate member.

As described above, in this embodiment, the ball 3 of the selected diameter is selected from the plurality of balls of the diameter 3 in the bearing hole 1A of the precision bearing.
By pushing through, it is possible to suppress variations in the inner diameter of the bearing hole 1A, and it is possible to obtain a high-performance precision bearing.

[0026]

INDUSTRIAL APPLICABILITY As described above, the device and method for drilling a hole of a workpiece according to the present invention are capable of forming a hole by pushing a ball selected from a plurality of balls having a plurality of diameters prepared in advance into the hole of the workpiece. It is possible to perform sizing processing with high accuracy by suppressing variations in inner diameter to several microns, and it is possible to perform highly accurate work processing.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a work hole drilling apparatus according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the sleeve after being processed by the processing device according to the first embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a stopper portion of the processing apparatus according to the first embodiment.

FIG. 4 is a flowchart of a processing method according to the first embodiment.

FIG. 5 is a partial cross-sectional view of a work hole drilling apparatus according to a second embodiment of the present invention.

FIG. 6 is an explanatory view of a processing apparatus according to a third embodiment of the present invention and its speed control graph.

FIG. 7 is a graph showing the relationship between the amount of change in the inner diameter of the bearing hole of the sleeve and the vanishing speed in the processing apparatus according to the third embodiment of the present invention.

[Figure 8] Explanatory drawing of the hole drilling process for hydrodynamic bearings

FIG. 9 is an explanatory diagram of drilling by a conventional drilling device for bearings.

FIG. 10 is a sectional view of a conventional sleeve after processing.

FIG. 11 is a graph showing the relationship between the finished diameter and the prepared hole diameter in the conventional processing apparatus.

[Explanation of symbols]

 1 sleeve 1A bearing hole 1B dynamic pressure generating groove 2 upper stage 3,3B, 3C, 3D, 3E processing sphere 3A measuring sphere 4 processing sphere supply device 5A pin 5B pin 6 lower stage 7 chute 8 load cell 9 computer 10 stage driving means 23 Stopper 24 Spring 25 Pinion 26 Pulse motor 27 Drive circuit 28 Memory

Claims (6)

[Claims] 1. A hole drilling device for a work, which inserts a working ball (3) into a hole (1A) of a work (1) to machine the inner surface of the hole, and is provided with a plurality of working balls having different diameters. Out of the machining sphere feeder (4) and the machining sphere provided in the sphere feeder, the outer diameter is (1 to 1.0) when the inner diameter of the hole of the workpiece is D1.
2) A machining sphere selecting device (2, 9, 10) for selecting one machining sphere having a size within the range of D1 and a machining sphere selected by the selecting device from the machining sphere supplying device to the workpiece. A workpiece hole punching device having a punching ball pushing device (5B, 25, 26, 27) for pushing through a hole. 2. The processing ball pushing device pushes the selected ball with a pressing member (5B) to push it into the hole of the work, and to push both the holes of the work rather than near the opening of the hole of the work. The hole drilling device for a workpiece according to claim 1, wherein a machining ball passing speed at an intermediate portion near the hole opening is increased. 3. A work ball (3) is provided in a hole (1A) of a work (1).
B, 3C, 3D, 3E), the hole drilling apparatus for a workpiece for machining the inner surface of the hole, before inserting the machining ball into the hole of the workpiece, When the inner diameter of the hole of the workpiece is D1, the outer diameter Db1 is pushed through the measuring sphere (3A) within the range of D1 ≦ Db1 ≦ (1.003 × D1), and the magnitude of the load when the measuring sphere is pushed through is detected. Measuring ball insertion device (8, 5
A, 9) and processing spheres (3B, 3C, 3) having a plurality of different diameter dimensions.
D, 3E) provided with the processing sphere supply device (4) and the processing sphere provided in the processing sphere supply device based on the detected load of the measurement sphere pushed by the measurement sphere insertion device. Therefore, when the inner diameter of the hole of the work is D1 and the outer diameter of the measuring sphere is Db1, the outer diameter Db
Is a machining ball selection device (2, 9 ,, which selects one machining sphere having a dimension within the range of Db1 <Db ≦ (1.02 × D1).
10) and a work ball pushing device (5B, 25, 26, 27) for pushing the work ball selected by the selection device from the work ball supply device into the work hole. Processing equipment. 4. The processing sphere pushing device pushes the selected sphere with a pressing member (5B) to push the sphere into the hole of the work, and to press both of the holes of the work rather than the vicinity of the opening of the hole of the work. The hole drilling device for a workpiece according to claim 3, wherein a machining ball passing speed at an intermediate portion near the hole opening is increased. 5. A processing ball (3) is provided in a hole (1A) of a work (1).
B, 3C, 3D, 3E), the inner surface of the hole is machined by inserting the inner surface of the hole into the hole of the workpiece before inserting the machining ball into the hole of the workpiece. When the inner diameter of the hole of the workpiece is D1, the outer diameter Db1 is pushed through the measuring sphere (3A) within the range of D1 ≦ Db1 ≦ (1.003 × D1), and the magnitude of the load when the measuring sphere is pushed through is detected. Based on the step and the detected load of the pushed measuring sphere, the inner diameter of the hole of the work is defined as D1 from the machining spheres (3B, 3C, 3D, 3E) having a plurality of different diameter dimensions. When the outer diameter of the measuring sphere is Db1, the outer diameter Db is Db1 <D
of the work, the step of selecting one machining sphere having a dimension within the range of b ≦ (1.02 × D1), and the step of pushing the selected machining sphere into the hole of the work. Hole processing method. 6. The step of pushing the processed sphere through the step of pushing the selected sphere by a pressing member (5B) to push it into the hole of the work, and The hole boring method for a workpiece according to claim 5, wherein a passing speed of a boring ball at an intermediate portion near the openings of both holes is increased.