JP2001179514A - Boring work device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the working accuracy of a crankshaft bearing hole while preventing the increase of the cost as possible. SOLUTION: Crankshaft bearing holes 3a, 3b, 3c, 3d, 3e of a cylinder block 1 are finished by an intermediate finishing tool 11 and final finishing tools 13, 15 mounted on an outer peripheral part by axially moving an arbor 9 connected to a point of a spindle 5 while rotating the same. The arbor 9 is rotated integrally with rotary sleeves 35, 37, 39 in a point sleeve 17, a rear end sleeve 19 and an intermediate sleeve 21, and the hydrostatic fluid bearings 41, 43, 45 are formed between the arbor 9 and each of rotary sleeves 35, 37, 39.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a rotating rod provided with a tool, which is inserted into a hole to be processed while being inserted and supported by a support portion, while rotating and axially moving the rotating rod. The present invention relates to a boring apparatus and a processing method for cutting an inner surface of a workpiece with a tool.

[0002]

SUMMARY OF THE INVENTION An object of the present invention is to increase the machining accuracy of a hole to be machined while minimizing an increase in cost.

[0003]

According to a first aspect of the present invention, there is provided a rotary rod having a tool inserted into a hole to be processed while being inserted and supported by a support portion.
While the rotating rod is rotating and moving in the axial direction, in a boring apparatus that cuts the inner surface of the hole to be machined with the tool, between the rotating rod and a supporting portion,
The structure is provided with a fluid bearing.

[0004] According to the above configuration, when the rotary rod rotates to machine the hole to be processed by the tool, the rotary rod is supported by the fluid bearing in a floating state with respect to the support portion.

According to a second aspect of the present invention, in the configuration of the first aspect, the support portion includes a rotating sleeve rotatable integrally with the rotating rod, and a static pressure is provided between the rotating sleeve and the rotating rod. A fluid bearing is provided.

According to the above construction, when the rotary rod rotates to machine the hole to be machined by the tool, the rotary sleeve also rotates integrally with the rotary rod, and at this time, the rotary rod is moved with respect to the rotary sleeve. It is supported in a floating state by a hydrostatic bearing.

According to a third aspect of the present invention, in the configuration of the first aspect, the rotating rod is rotatable with respect to the supporting portion, and a hydrodynamic bearing is provided between the rotating rod and the supporting portion. Have been.

According to the above construction, when the rotary rod rotates to machine the hole to be machined by the tool, the rotary rod is supported by the hydrodynamic bearing on the supporting portion in a floating state. According to a fourth aspect of the present invention, in the configuration of any one of the first to third aspects, a volume portion for holding a working fluid used for a fluid bearing is provided between the rotary rod and the support portion.

According to the above configuration, when the rotating rod is supported by the support portion, the working fluid is held in the volume portion to form a fluid bearing.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the volume portion is formed between a concave portion provided on the outer peripheral surface of the rotating rod and the inner peripheral surface of the support portion.

According to the above configuration, when the rotating rod is supported by the support, the working fluid is stored in the volume formed between the concave portion provided on the outer peripheral surface of the rotating rod and the inner peripheral surface of the support. Are held to form a fluid bearing.

According to a sixth aspect of the present invention, in the configuration of the fourth aspect, the volume portion is formed between the concave portion provided on the inner peripheral surface of the support portion and the outer peripheral surface of the rotating rod.

According to the above construction, when the rotating rod is supported by the supporting portion, the working fluid is stored in the volume formed between the concave portion provided on the inner peripheral surface of the supporting portion and the outer peripheral surface of the rotating rod. Are held to form a fluid bearing.

According to a seventh aspect of the present invention, in the configuration of any one of the first to sixth aspects of the present invention, a flow path of a working fluid used for a fluid bearing is provided in the rotary rod, and the flow path is formed in the axial direction. A supply flow path that is extended, and a discharge flow path that communicates with the supply flow path and extends radially from a substantially central position of the rotating rod and opens to the surface of the rotating rod are provided.

According to the above configuration, the working fluid supplied to the supply flow path in the rotary rod is discharged from the approximate center of the rotary rod to the surface of the rotary rod via the discharge flow path, thereby forming a fluid bearing.

According to an eighth aspect of the present invention, in the configuration of the seventh aspect of the present invention, a throttle section is provided at an opening of the discharge flow passage on the surface of the rotating rod.

According to the above configuration, the working fluid is discharged to the surface of the rotary rod through the throttle portion of the discharge flow path,
The supply pressure is adjusted.

According to a ninth aspect of the present invention, in the configuration of the eighth aspect of the present invention, the throttle section is configured to be detachable.

According to the above configuration, the supply pressure of the working fluid in the fluid bearing can be set to an optimum condition by appropriately replacing the throttle portion.

According to a tenth aspect of the present invention, in the configuration according to any one of the seventh to ninth aspects, the flow path of the working fluid includes:
A cutting fluid discharge port for discharging a cutting fluid communicates with the working fluid, and the working fluid also serves as a cutting fluid used for machining.

According to the above configuration, the working fluid channel and working fluid dedicated to the fluid bearing are not required.

According to an eleventh aspect of the present invention, in the configuration of the tenth aspect, the cutting fluid discharge port is formed by a throttle.

According to the above configuration, the pressure drop of the working fluid in the working fluid flow path is prevented by the throttle section.

According to a twelfth aspect of the present invention, while the rotating rod provided with the tool is inserted into a hole to be processed while being supported by a support portion via a fluid bearing, the rotating rod rotates and moves in the axial direction. According to another aspect of the present invention, there is provided a method for cutting an inner surface of the hole to be processed by the tool.

According to the above-described processing method, when the rotary rod rotates to machine the hole to be machined by the tool, the rotary rod is supported by the fluid bearing in a floating state with respect to the support portion.

According to the first aspect of the present invention, when the rotating rod provided with the tool rotates to machine the hole to be machined, the rotating rod is supported by the fluid bearing with respect to the supporting portion in a floating state. Therefore, the coaxiality between the rotating rod and the support portion during processing is ensured, and processing accuracy is improved, and wear between the rotating rod and the support portion is avoided, so that
There is no need to maintain gaps between them. In this case, it is not necessary to increase the capital investment for the purpose of improving the processing accuracy by adding a process or the like, and the increase in the total cost is suppressed as much as possible.

According to the second aspect of the present invention, when the rotary rod provided with the tool rotates to machine a hole to be machined, the rotary sleeve also rotates integrally with the rotary rod. Since the rotating sleeve is supported by the hydrostatic bearing in a floating state, the coaxiality between the rotating rod and the rotating sleeve during processing is secured, processing accuracy is improved, and the rotating rod and the rotating sleeve are mutually worn. Therefore, it is not necessary to maintain the gap between them. In this case, there is no increase in capital investment due to additional processes and the like, and the rise in cost is kept to a minimum.

According to the third aspect of the present invention, when the rotating rod provided with the tool rotates to machine the hole to be machined, the rotating rod is rotatably supported by the supporting portion by the hydrodynamic bearing. Therefore, the coaxiality between the rotating rod and the support portion during processing is ensured, and processing accuracy is improved, and wear between the rotating rod and the support portion is avoided, so that
There is no need to maintain gaps between them. In this case, there is no increase in capital investment due to additional processes and the like, and the rise in cost is kept to a minimum.

According to the fourth aspect of the present invention, since the volume portion for holding the working fluid used for the hydrodynamic bearing is provided between the rotary rod and the support portion, the rotary rod is supported by the support portion. At this time, the working fluid is held in the volume, and the fluid bearing can be reliably formed.

According to the fifth aspect of the present invention, since the volume portion is formed between the concave portion provided on the outer peripheral surface of the rotating rod and the inner peripheral surface of the supporting portion, the rotating rod is provided on the supporting portion during processing. On the other hand, even if the recess moves in the axial direction, the axial length of the concave portion is set within the axial length of the support portion, whereby a fluid bearing can be configured.

According to the sixth aspect of the present invention, since the volume portion is formed between the concave portion provided on the inner peripheral surface of the support portion and the outer periphery of the rotating rod, the rotating rod moves in the axial direction during processing. Even so, the fluid bearing can be configured by securing the volume.

According to the seventh aspect of the present invention, with respect to the supply flow path extending in the axial direction within the rotary rod, a plurality of radially extending radially extending from substantially the center position of the rotary rod and opening to the surface of the rotary rod. Since the discharge flow paths are provided in communication, the flow resistance of each discharge flow path becomes uniform, and the supply pressure of the working fluid to the rotating rod surface is stabilized.

According to the eighth aspect of the present invention, since the throttle portion is provided at the opening of the discharge flow path to the surface of the rotary rod, the pressure of the working fluid discharged to the surface of the rotary rod can be adjusted.

According to the ninth aspect of the present invention, since the throttle portion is configured to be detachable, the pressure of the working fluid in the fluid bearing can be set to an optimum condition by appropriately replacing the throttle portion. In addition, the bearing performance can be improved.

According to the tenth aspect of the present invention, the cutting fluid discharge port for discharging the cutting fluid communicates with the working fluid flow path, and the working fluid also serves as the cutting fluid used for machining. A working fluid flow path and working fluid dedicated to the fluid bearing are not required, and an increase in equipment cost can be suppressed accordingly.

According to the eleventh aspect of the present invention, since the cutting fluid discharge port is formed by the throttle, the throttle prevents a decrease in the pressure of the working fluid in the working fluid flow path, and achieves desired bearing performance. Can be maintained or changed.

According to the twelfth aspect of the invention, when the rotary rod provided with the tool rotates to machine the hole to be machined, the rotary rod is supported by the fluid bearing in a floating state with respect to the support portion. Since the coaxiality between the rotating rod and the support during processing is ensured and the processing accuracy is improved, and since the rotating rod and the support are mutually abraded,
There is no need to maintain gaps between them. In this case, there is no increase in capital investment due to additional processes and the like, and the rise in cost is kept to a minimum.

[0037]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a boring hole processing apparatus showing an embodiment of the present invention. This processing equipment
Crankshaft bearing holes 3a, 3b as holes to be machined in the cylinder block 1 of the automobile engine
The inner surfaces of 3c, 3d, and 3e are subjected to finishing, and an arbor 9 as a rotating rod is connected to the tip of the main shaft 5 via an Oldham coupling 7.

The arbor 9 is inserted through the crankshaft bearing holes 3a, 3b, 3c, 3d, 3e.
With the medium finishing tool 11 and the final finishing tools 13 and 15 attached to the periphery, the processing is performed while rotating and retreating leftward in the drawing.

On the other hand, on the jig side on which the cylinder block 1 is positioned and fixed, three sleeves as support portions for supporting the arbor 9, that is, a front end sleeve 17, a rear end sleeve 19, and an intermediate sleeve 21 are respectively installed. ing. The distal sleeve 17 is located near the distal end protruding rightward from the crankshaft bearing hole 3e at the right end in the figure, and the rear end sleeve 19 is the proximal end leftward from the crankshaft bearing hole 3a at the left end in the figure. In the vicinity of the portion, the intermediate sleeve 21 supports between the crankshaft bearing holes 3c and 3d.

The above three sleeves 17, 19, 2
Reference numeral 1 denotes rotating sleeves 35, 3 via bearings 29, 31, 33 on sleeve bodies 23, 25, 27, respectively.
7, 39 are provided rotatably. Rotating sleeve 3
Grooves 35a, 37a, 39a
Are formed over the entire length in the axial direction. This groove 35a,
37a and 39a connect the arbor 9 to the rotating sleeves 37 and 3;
Upon insertion into 9, 35, the intermediate finishing tool 11 and the finishing tools 13, 15 pass.

Rotating sleeve 3 in intermediate sleeve 21
9, a groove 39b is also formed on the side facing the above-mentioned groove 39a. On the other hand, the groove 3
9b and connecting members 40 which enter the grooves 35a and 37a and serve as keys, respectively, are attached at three longitudinal positions of the arbor 9. The head of each connecting tool 40 protruding from the surface of the arbor 9 has grooves 35a, 37a, 39
b, the arbor 9 and the rotating sleeves 35, 3
7, 39 rotate integrally.

Distal sleeve 17 and proximal sleeve 19
Like the intermediate sleeve 21 in which the crankshaft bearing holes 3c and 3d are arranged on both sides, the mounting space is smaller than the intermediate sleeve 21 as a whole because the installation space is less restricted. The rotating sleeve 35,
37 is formed longer than the sleeve bodies 23 and 25 and protrudes left and right.
The axial length of the rotary sleeve 39 at is approximately the same as the length of the sleeve main body 27.

The arbor 9 and the rotary sleeves 35, 37, 3
9, the hydrostatic bearings 41, 43, 45 are formed respectively.
5, 37, and 39 are floated through a minute gap.

The front sleeve 17 and the rear sleeve 19
The hydrostatic bearings 41 and 43 in FIG. 2 are enlarged sectional views taken along the line AA in FIG.
Is omitted. ) And FIG.
(However, the sleeve body 25 is omitted.) As shown in the figure, a plurality of flat portions 47 and 49 as recesses are respectively formed at appropriate positions in the circumferential direction of the outer peripheral surface of the arbor 9.
The working fluid is supplied to pockets 51 and 53 as volume portions formed between the flat portions 47 and 49 and the rotating sleeves 35 and 37. Plane parts 47, 49
May be replaced by a concave curved surface portion.

As shown in FIG. 1, the plane portions 47 and 49
The axial length is set to about 1/2 or 1/3 of the same length of the rotating sleeves 35 and 37, and the arbor 9 is further advanced to the right from the final finishing processing start position in FIG. While moving backward from the middle finish processing start position indicated by the dashed line to the final finish processing end position illustrated in FIG.
It is located at a position facing the inner surfaces of the rotating sleeves 35 and 37.
In other words, while the finishing process is being performed, the flat portions 47 and 49
Pockets 51, 53 between the rotating sleeves 35, 37.
Are formed to form the hydrostatic bearings 41 and 43.

As shown in FIGS. 2 and 3, fluid escape grooves 9b and 9c are formed between the plane portions 47 and 49 between the left and right sides of the arbor 9, respectively. The left end of the fluid escape groove 9 b in the distal sleeve 17 is located substantially at the same position as the flat portion 47, and the right end is open to the tip of the arbor 9. The fluid escape groove 9c in the rear end sleeve 19 has the left end portion located at the same position as the flat portion 49, and the right end portion slightly projects from the right end portion of the rotary sleeve 37 at the end of the processing shown in FIG. It is in a state where it has been done.

Further, as shown in FIG. 2 and FIG.
A fluid escape groove 9d and a fluid escape plane portion 9e are also formed between each other. Fluid escape groove 9d
As shown in FIG. 1, the right end is open to the tip of the arbor 9, while the left end is located between the crankshaft bearing holes 3b and 3c in the state of FIG. In the intermediate sleeve 21, the connecting member 40 described above is attached to the fluid escape groove 9d, and the head thereof enters the groove 39b. Like the fluid escape groove 9c, the fluid escape plane portion 9e has the left end at the same position as the plane portion 49 as shown in FIG. 1 and the right end has the rotating sleeve 37 at the end of the machining shown in FIG. It is in a state of slightly projecting from the right end and opening to the outside.

On the other hand, the hydrostatic bearing 45 in the intermediate sleeve 21 is an enlarged sectional view taken on line CC of FIG.
(However, the sleeve main body 27 is omitted.) As shown in the figure, a plurality of concave curved surface portions 55 as concave portions are formed at appropriate positions in the circumferential direction of the inner peripheral surface of the rotary sleeve 39. The working fluid is supplied to a pocket 57 as a volume formed between the arbor 9.

Since the intermediate sleeve 21 has a short axial length due to the presence of the crankshaft bearing holes 3c and 3d on both sides as described above, a pocket for supplying a working fluid is provided on the arbor 9 side. So, Arbor 9
Therefore, as described above, the hydrodynamic bearing can be formed from the start of the finishing to the end of the final finishing in FIG. 4 by forming the concave curved surface portion 55 on the rotating sleeve 39 side as described above. Can be configured.

Further, as shown in FIG.
A fluid escape groove 39c is formed between the concave curved surface portions 55 on the left and right sides of the fluid passage 9 and a fluid escape groove 39d is formed further below the concave curved surface portion 55 on the lower side.
These fluid escape grooves 39c and 39d are open at both ends in the axial direction.

In the arbor 9, one end is opened to the main shaft 5 side, and the cutting fluid serving as two supply flow paths through which the water-soluble cutting oil serving as the cutting fluid and the working fluid is supplied via the Oldham coupling 7. A working fluid channel 59 is formed along the axial direction. As shown in FIGS. 2, 3 and 5, the cutting fluid / working fluid flow path 59 is located on the lower side of the arbor 9, and in the sleeves 17 and 19 on the front and rear ends (see FIG. 2, FIG. 3), a discharge channel 6 extending substantially in the radial direction
The respective pockets 51 and 53 communicate with the corresponding pockets 51 and 53 via the first and second pockets 62, respectively. The discharge flow path 6 on the pocket 51, 53 side from the intersection of the discharge flow paths 61, 62
One ends of the branch discharge channels 63 and 64 communicate with 1 and 62, and the other ends of the branch discharge channels 63 and 64 communicate with corresponding pockets 51 and 53, respectively. A diaphragm adjusting plug 65 as a diaphragm is detachably attached to the openings of the discharge channels 61 and 62 and the branch discharge channels 63 and 64 on the pocket 51 and 53 sides.

The two discharge passages 61 and the two discharge passages 62 intersect at a substantially central position of the arbor 9, so that the working fluid is supplied to the cutting fluid / working fluid passage 59. Is discharged radially from each of the intersecting substantially central positions to each of the pockets 51 and 53.

As shown in FIG. 5, in the intermediate sleeve 21, a horizontal discharge flow path 67 that connects the two cutting fluid and working fluid flow paths 59 to each other at both ends, and an upper part from both ends of the discharge flow path 67. Notch end face 9 to which medium finishing tool 11 and final finishing tools 13 and 15 are attached.
A discharge channel 69 opening to a is formed in the arbor 9. Two locations at both ends of the discharge channel 67 and the discharge channel 69
An aperture adjusting plug 71 as an aperture section for communicating with the pocket 57 is detachably attached to the vicinity of the upper end. The medium finishing tool 11 and the final finishing tools 13 and 15 are held by a tool holder 73 installed in a state embedded in the arbor 9.

A water supply pressure securing plug 75 is attached to the upper end opening of the left discharge passage 69 in FIG. 5, and a cutting fluid discharge port 77 is formed in the water supply pressure securing plug 75 as a throttle. ing. By providing the water supply pressure securing plug 75 having the cutting fluid discharge port 77 having a predetermined nozzle diameter, even if the cutting fluid is discharged from the cutting fluid discharge port 77, the pockets 51, 5 are formed.
The supply pressure to 3, 57 can be maintained at a predetermined value. On the other hand, the upper end opening of the discharge passage 69 on the right side in FIG.

Land portions 81, 83 and 85 are formed at both ends in the circumferential direction of the pockets 51, 53 and 57, respectively. The lands 81, 83, and 85 have pockets 5
This is a part for reducing the working fluid discharged to 1, 53, 57 to a predetermined pressure. The arbor 9 and the rotary sleeves 35, 3
7, 39 corresponds to the bearing gap. For example, D in FIG.
FIG. 6 is an enlarged view of the land portion 81 indicated by the part.
The land portion 81, a gap h ₀ is formed. The land portion 81 is in the fluid escape grooves 9b and 9d and the groove 35a, and the land portion 83 is in the fluid escape groove 9c and the fluid escape plane portion 9.
e and the groove 37a, the land portion 85 is provided with the fluid escape groove 39.
c, 39d and the groove 39a.

[0057] In order to ensure the performance of the hydrostatic bearing to a predetermined, the size of the gap _{h 0} of the land portions 81, 83 and 85 described above and, squeezing nozzle diameter d of the adjustment plug 65 and 71
A dimension of ₀ occupies an important factor.

FIGS. 7 to 9 show the eccentricity of the arbor 9 with respect to the rotating sleeves 35 and 37 in the front end sleeve 17 and the rear end sleeve 19 and the eccentricity of the arbor 9 when eccentric.
The relationship with the load capacity (N) corresponding to the force returning the center to
For the nozzle diameters d ₀ = 0.5 mm (FIG. 7), 0.6 mm (FIG. 8), and 0.7 mm (FIG. 9), the supply pressure Ps of the working fluid was 3.0 MPa, 2.0 MPa, 1.0 MPa, respectively.
MPa and varied, and the land portion gap _{h 0, 7μm,}
It is shown by changing to 10 μm and 13 μm. 10 to 12 are graphs similar to the above for the intermediate sleeve 21. FIG.

[0059] Further, FIGS. 13 to 15, in the front-end sleeve 17 and the rear end sleeve 19, a bearing gap which corresponds to the land portion gap _{h 0} ([mu] m), the arbor 9 1 [mu] m
Static rigidity (N / μm) equivalent to the force required for eccentricity
With the nozzle diameter d ₀ = 0.5 mm (FIG. 13)
For 0.6 mm (FIG. 14) and 0.7 mm (FIG. 15), the supply pressure Ps of the working fluid was 3.0 MPa,
It is shown by changing to 2.0 MPa and 1.0 MPa. 16 to 18 are graphs similar to the above for the intermediate sleeve 21. FIG.

From these graphs, considering that both the load capacity and the static rigidity are satisfied and that the supply water pressure has no problem in normal use, the land gap h ₀ = 10 μm.
m, nozzle diameter d ₀ = 0.
It was determined that 6 mm and the water supply pressure Ps = 3.0 MPa were optimal.

The thus set hydrostatic bearing 41,
Finishing of the crankshaft bearing holes 3a, 3b, 3c, 3d, 3e is performed by a processing device provided with 43, 45. Here, in order to reduce the load of the backing force from the tool exerted on the bearings, the finishing process is performed. It is divided into medium finishing and final finishing. Further, in the final finishing step, three crankshaft bearing holes 3a, 3c, 3e are connected to the five crankshaft bearing holes 3a, 3b, 3c, 3d, 3e by the final finishing tool 13 and the final finishing tool 15 is used. The crankshaft bearing hole 3b,
3d are each processed.

In the machining operation, first, the arbor 9 is moved forward by moving the main shaft 5 rightward in FIG. 1 so that the arbor 9 is moved further to the position shown by the two-dot chain line in FIG. (A position corresponding to the right end of the sleeve 35). At this time, the arbor 9 and the rotating sleeves 35, 37,
39 means that the head of the connecting tool 40 has grooves 35a, 37a, 39
b can be integrally rotated.

When the arbor 9 is inserted into the crankshaft bearing holes 3a, 3b, 3c, 3d, 3e, the cylinder block 1 is slightly raised with respect to the arbor 9, so that the center of the arbor 9 and the crank are inserted. The centers of the shaft bearing holes 3a, 3b, 3c, 3d, 3e are shifted from each other. As a result, the arbor 9 with the medium finishing tool 11 and the final finishing tool 13 attached thereto is removed from the crankshaft bearing holes 3a, 3b, 3c, 3d, 3d.
3e can be inserted. After insertion, the cylinder block 1
Is lowered, and the arbor 9 and the crankshaft bearing holes 3a, 3b, 3c, 3d, 3e are positioned and fixed at regular positions where the centers thereof coincide with each other.

With the arbor 9 set at the position indicated by the two-dot chain line in FIG. 1 described above, the rotating sleeves 35, 37 and 39 rotate with the rotation of the arbor 9, and the arbor 9 is moved backward. As a result, the rotary sleeves 35, 37, and 39 are retracted leftward in FIG. As a result, first, five crankshaft bearing holes 3a, 3b, 3c, 3d, and 3e are simultaneously semi-finished by the five semi-finishing tools 11, respectively. FIG. 1 shows a state in which the intermediate finishing is completed and immediately before the start of the final finishing to be performed subsequently.

When the arbor 9 is further retracted while rotating from the state shown in FIG. 1, three crankshaft bearing holes 3a, 3c are formed by three final finishing tools 13.
3c and 3e are subjected to final finishing, and subsequently, two final finishing tools 15 are used to perform final finishing on the remaining two crankshaft bearing holes 3b and 3d.

When the arbor 9 is rotated to perform the above-described finishing, the water-soluble cutting oil supplied into the cutting fluid / working fluid channel 59 in the arbor 9 is supplied to the tip sleeve 17 and the rear end. In the end sleeve 19, the discharge flow path 61,
After passing through 63, 62 and 64, the ink is discharged from the aperture adjustment plug 65 to the pockets 51 and 53. On the other hand, in the intermediate sleeve 21, the water-soluble cutting oil
Through 69, the fluid is discharged from the throttle adjusting plug 71 to the pocket 57, and is discharged as cutting fluid from the cutting fluid discharge port 77 of the water supply pressure securing plug 75 to the vicinity of the tool.

The water-soluble cutting fluid discharged into each of the pockets 51, 53, and 57 acts as a hydrostatic bearing 41, 43, and 45 so that the arbor 9 floats with respect to the rotary sleeves 35, 37, and 39. And At this time, especially in the front end sleeve 17 and the rear end sleeve 19, the water-soluble cutting oil is discharged from the discharge channels 61 and 63 and between the discharge channels 62 and 63.
64 are ejected radially from the approximate center of the arbor 9 into the pockets 51 and 53, where
The flow path resistance is made uniform and stably supplied to the plurality of pockets 51 and 53, and the bearing characteristics of the hydrostatic bearing are improved.

The water-soluble cutting fluid discharged into each of the pockets 51, 53, 57 passes through the throttle adjusting plugs 65, 71, so that the pressure in the pockets 51, 53, 57 is secured as desired. The aperture adjustment plugs 65 and 71 are
Since it is configured to be detachable, it can easily cope with condition changes as a hydrostatic bearing.

As described above, the arbor 9 is supported by the rotating sleeves 35, 37, and 39 in a floating state via the hydrostatic bearing during the working operation, so that the arbor 9 and the rotating sleeve 35 during the working operation are processed. , 37, and 39, the machining accuracy is improved, and the wear of the arbor 9 and the rotating sleeves 35, 37, and 39 is avoided, so that the maintenance of the gap between them becomes unnecessary. . In this case, there is no increase in capital investment due to additional processes, etc.
The rise in costs has been kept to a minimum.

Table 1 shows the roundness and coaxiality of the crankshaft bearing holes 3a, 3b, 3c, 3d, 3e after the machining was completed by using the present machining apparatus using a hydrostatic bearing and the same. However, this is compared with a processing apparatus in which the arbor is simply inserted into the rotating sleeve. The roundness is the amount of deflection in the radial direction with respect to the perfect circle, and the coaxiality is the center of three central crankshaft bearing holes 3b, 3c, 3d with respect to a straight line passing through the centers of the crankshaft bearing holes 3a, 3e at both ends. It shows the amount of deviation. Further, the roundness indicates a case where the machined surface is AL (aluminum alloy) on the entire circumference and a case where FC (cast iron) is cast on a half machined surface on the bearing cap side (the lower side in FIG. 1). ing.

[0071]

[Table 1] According to this, it can be seen that the present processing device using the hydrostatic bearing is superior in both roundness and coaxiality as compared with a processing device not using the bearing.

In the above embodiment, the arbor 9
Rotating sleeves 35, 37, 3 that rotate with the arbor 9
9, the support portion supporting the arbor 9 does not rotate, and the support portion side is a so-called fixed sleeve or bush, and the arbor 9 rotates relative to this support portion. In between, a hydrodynamic bearing may be configured. Also in this case, the same effect as in the case where the hydrostatic bearing is formed can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a boring apparatus showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken on line AA of FIG. 1;

FIG. 3 is an enlarged BB sectional view of FIG. 1;

FIG. 4 is a cross-sectional view after processing is completed in the processing apparatus of FIG. 1;

FIG. 5 is an enlarged sectional view taken along the line CC of FIG. 1;

FIG. 6 is an enlarged explanatory view showing details of a portion D in FIG. 2;

FIG. 7 is a diagram illustrating a nozzle diameter of a plug for adjusting a diaphragm at a front end sleeve and a rear end sleeve in the processing apparatus of FIG.
FIG. 7 is a correlation diagram between the eccentricity and the load capacity in the case of m.

FIG. 8 is a correlation diagram between the eccentricity and the load capacity when the nozzle diameter is 0.6 mm.

FIG. 9 is a correlation diagram between the eccentricity and the load capacity when the nozzle diameter is 0.7 mm.

10 is a correlation diagram between the eccentricity and the load capacity when the nozzle diameter of the throttle adjustment plug of the intermediate sleeve in the processing apparatus of FIG. 1 is 0.5 mm.

FIG. 11 is a correlation diagram between the eccentricity and the load capacity when the nozzle diameter is 0.6 mm.

FIG. 12 is a correlation diagram between the eccentricity and the load capacity when the nozzle diameter is 0.7 mm.

13 is a diagram illustrating a state in which the nozzle diameter of the aperture adjustment plug at the leading end sleeve and the trailing end sleeve in the processing apparatus of FIG. 1 is 0.5.
FIG. 6 is a correlation diagram between a bearing gap and static rigidity in the case of mm.

FIG. 14 is a correlation diagram between a bearing gap and static rigidity when the nozzle diameter is 0.6 mm.

FIG. 15 is a correlation diagram between a bearing gap and static rigidity when the nozzle diameter is 0.7 mm.

16 is a correlation diagram between a bearing gap and static rigidity when the nozzle diameter of the throttle adjusting plug in the intermediate sleeve in the processing apparatus of FIG. 1 is 0.5 mm.

FIG. 17 is a correlation diagram between a bearing gap and static rigidity when the nozzle diameter is 0.6 mm.

FIG. 18 is a correlation diagram between a bearing gap and static rigidity when the nozzle diameter is 0.7 mm.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder block 3a, 3b, 3c, 3d, 3e Crankshaft bearing hole (hole to be processed) 9 Arbor (rotating rod) 11 Medium finishing tool (tool) 13, 15 Final finishing tool (tool) 17 Tip sleeve (Supporting part) 19 Rear end sleeve (Supporting part) 21 Intermediate sleeve (Supporting part) 35, 37, 39 Rotating sleeve 41, 43, 45 Hydrostatic bearing (Fluid bearing) 47, 49 Flat part (Recess) 51, 53 57, pocket (volume part) 55 concave curved surface part (recess) 59 cutting fluid / working fluid flow path (supply flow path, working fluid flow path) 61, 62 discharge flow path (working fluid flow path) 63, 64 branch Discharge flow path (flow path of working fluid) 65, 71 Throttle adjustment plug (throttle section) 77 Cutting fluid discharge port (throttle section)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Narika Yoshimoto 1-3 of Kagurazaka, Shinjuku-ku, Tokyo Tokyo University of Science (72) Inventor Takashi Iniya F-term in Nissan Motor Co., Ltd. 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Reference) 3C036 AA11 AA16

Claims (12)

[Claims] In a state in which a rotary rod provided with a tool is inserted into a hole to be processed while being inserted and supported by a support portion, the rotary rod rotates and moves in the axial direction to move the inner surface of the hole to be processed. In a boring apparatus for cutting with a tool, a fluid bearing is provided between the rotary rod and a support. 2. The device according to claim 1, wherein the supporting portion includes a rotating sleeve rotatable integrally with the rotating rod, and a hydrostatic bearing is provided between the rotating sleeve and the rotating rod. The boring device according to 1. 3. The boring according to claim 1, wherein the rotary rod is rotatable with respect to the support, and a hydrodynamic bearing is provided between the rotary rod and the support. Processing equipment. 4. The boring process according to claim 1, further comprising a volume between the rotary rod and the support for holding a working fluid used for a fluid bearing. apparatus. 5. The boring apparatus according to claim 4, wherein the capacity portion is formed between a concave portion provided on an outer peripheral surface of the rotary rod and an inner peripheral surface of the support portion. 6. The boring apparatus according to claim 4, wherein the volume portion is formed between a concave portion provided on an inner peripheral surface of the support portion and an outer peripheral surface of the rotating rod. 7. A rotary fluid passage for a working fluid to be used for a fluid bearing is provided in the rotary rod. The flow passage includes an axially-extending supply flow path, and a flow path substantially connected to the supply rod. The boring apparatus according to any one of claims 1 to 6, further comprising a plurality of discharge passages extending radially from the center position and opening on the surface of the rotating rod. 8. The boring apparatus according to claim 7, wherein a throttle section is provided at an opening of the discharge flow path to the surface of the rotating rod. 9. The boring apparatus according to claim 8, wherein the drawing portion is configured to be detachable. 10. A cutting fluid discharge port for discharging a cutting fluid communicates with a flow path of the working fluid, and the working fluid also serves as a cutting fluid used for machining. The boring apparatus according to any one of claims 9 to 13. 11. The boring apparatus according to claim 10, wherein the cutting fluid discharge port comprises a throttle. 12. A rotary rod provided with a tool is inserted into a hole to be processed while being supported by a supporting portion via a fluid bearing, and the hole to be processed is rotated and axially moved while the rotary rod is being moved. A boring method, wherein the inner surface of the boring is cut by the tool.