JP2001129753A - Honing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a honing unit capable of executing honing-finishing with a horning pressure constant. SOLUTION: In this honing unit, a hone 4 connected to a taper shank part 2 is formed with a cylinder housing space 38, a mandrel insertion hole 41 and a slot 42 penetrating to the mandrel insertion hole 41 from the periphery of a tip part. A piston 46 advanced by supply of a coolant to a cylinder chamber 44 of a cylinder 43 installed in the cylinder housing space 38 is installed into the cylinder chamber 44. A constant-pressure shaft 51 is installed into an insertion hole 50 of the piston 46, while elastic force of a disk spring 57 is applied to the constant-pressure shaft 51. A mandrel 59 is connected to the constant- pressure shaft 51, a taper surface 70 of a honing stick table 68 installed in the slot 42 is contacted with a taper guide surface 67 formed in the mandrel 59, and a honing stick 71 supported by the honing stick table 68 is contacted with a cylinder inner face c of a work W by the elastic force of the disk spring 57 to make the horning pressure constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a honing unit for honing a cylindrical inner surface of a hole formed in a work.

[0002]

2. Description of the Related Art A plurality of elongated grindstones supported by a horn are expanded radially outward to come into contact with a cylindrical inner surface of a hole formed in a work, and a work is applied to each grindstone in a state of applying an outward pressure. As a honing unit that performs a rotary motion and a reciprocating motion between it and a honing finish on the inner surface of the cylinder while pouring a large amount of grinding fluid, the grinding wheel is pressed against the inner surface of the cylinder formed on the workpiece using the coolant of the machining center. Conventional honing units are known.

[0003]

In a conventional honing unit using a coolant, the supply pressure of the coolant is used as the honing pressure. Therefore, pressure fluctuation occurs due to dirt or temperature change of the coolant or fluctuation of the supply amount. This has the disadvantage that the roundness, cylindricity, surface roughness, etc. of the finished surface are greatly affected and stable processing cannot be performed.

[0004] It is an object of the present invention to provide a honing unit in which the honing pressure is made constant, and the inner surface of the cylinder can be extremely stably and precisely finished.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a horn that rotates integrally with a shank portion is connected to a tip of a shank portion inserted into a shank insertion hole of a main shaft. In the horn, a cylinder housing space, an axial mandrel insertion hole communicating from the distal end surface to the cylinder housing space, and a plurality of axially elongated slots communicating from the outer periphery of the distal end portion to the mandrel insertion hole are formed, A cylinder is incorporated in the cylinder housing space, and a piston that moves forward by supply of coolant is slidably inserted into a cylinder chamber formed in the cylinder,
A constant-pressure shaft is inserted into an axial insertion hole formed in the piston, and between the constant-pressure shaft and the piston, the piston is axially engaged when the piston is retracted so that the constant-pressure shaft is retracted. An engagement means for releasing the engagement is provided, a spring means for pressing the constant pressure shaft in a direction in which the constant pressure shaft advances is provided, and a mandrel slidable in the mandrel insertion hole is connected to a distal end of the constant pressure shaft. An elastic means for slidably inserting a grindstone table supporting a grindstone into each of the slots and providing elastic means for pressing the grindstone table against the outer periphery of a mandrel is provided. Thus, a configuration is provided in which a tapered guide surface that comes into contact with is provided.

Here, as a spring means for pressing the constant pressure shaft in the axial direction, a disc spring or a coil spring can be used.

With the above construction, when the coolant is supplied to the cylinder chamber formed in the cylinder, the piston advances, and the engagement means provided between the piston and the constant pressure shaft is disengaged. Moves forward by the elastic force of the spring means. Since the mandrel is connected to the constant pressure shaft, the mandrel also advances together, and the advance of the mandrel causes the wheel head to move radially outward.

For this reason, by moving the grindstone head outward while the tip of the horn is inserted into the hole formed in the work, the grindstone supported by the grindstone head on the cylindrical inner surface of the hole is moved to the constant pressure shaft. The hole can be pressed against the inner surface of the cylinder by the elastic force of the pressing spring means, and the inner surface of the cylinder can be honed in a stable processing state in which the honing pressure is substantially constant.

Here, by supporting the cylinder so that its position can be adjusted in the axial direction, the mandrel also moves in the axial direction by adjusting the position of the cylinder, so that the contact position with respect to the grindstone table is changed, and the position within the working range is changed. Adjustment of the grinding wheel diameter can be performed. Here, the range of use refers to the axial length of the tapered guide surface formed on the mandrel.

Further, by connecting the mandrel to the constant pressure shaft in a detachable manner, when the use range is deviated due to wear of the grindstone, the mandrel can be returned to the use range by replacing the mandrel with a mandrel having a larger diameter. it can.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the honing unit 1 has a tapered shank portion 2, and a flange 3 is integrally provided at a large diameter end of the tapered shank portion 2.

The tapered shank portion 2 has a shank insertion hole a formed of a tapered hole formed in the main shaft A of the machining center.
To the main shaft A in the mounted state.
A drive key (not shown) provided on the front end surface of the drive shaft engages with a key groove formed in the flange 3 to transmit the rotation of the main shaft A to the tapered shank portion 2.

A horn 4 is connected to the tip of the tapered shank 2. The horn 4 includes a drive shaft 5 and a revolving plate 6.
And a horn head 7. The drive shaft 5 is connected to the tapered shank 2 via a connecting bolt 8.

The revolving plate 6 is abutted against a flange 9 formed on the outer periphery of the drive shaft 5 and is fixed to the flange 9 by tightening a screw 10 which passes through the revolving plate 6 and is screwed into a screw hole of the flange 9. I have.

The horn head 7 has a flange 11 at the rear end and a small diameter shaft 12 at the front end. The flange 11 is abutted against the revolving plate 6 and is removably attached to the revolving plate 6 through means by tightening screws 13.

At the time of mounting the flange 11 of the horn head 7, a ring fitting groove 14 in which the inner surface of the outer peripheral wall is tapered is provided on the revolving plate 6, and the ring fitting groove 14 is provided.
A taper ring 15 having an inner periphery and an outer periphery inclined in opposite directions, and a wedge ring 16 having an outer peripheral surface tapered inside the taper ring 15 are fitted therein. Is screwed into a threaded hole formed in the tapered ring 15 so as to be tightened.

The drive shaft 5 is inserted inside the housing 18. A double-row bearing 19 rotatably supporting the drive shaft 5 between the housing 18 and the drive shaft 5;
A pair of seal rings 20 and a pair of seal rings 2
A guide ring 21 is incorporated between the zeros.

The rear end opening of the housing 18 is covered by an orientation ring 22. The orientation ring 22 has a bearing cylinder 23 fitted on the outer periphery of the end of the drive shaft 5 on the inner periphery. The bearing cylinder 23 is fixed to the drive shaft 5 by tightening a set screw 24.

A positioning bracket 25 is provided on the outer periphery of the housing 18. A sleeve insertion hole 26 is formed in the positioning bracket 25 in parallel with the center line of the tapered shank portion 2, and a sleeve 27 with a flange is inserted into the sleeve insertion hole 26.

An adjusting sleeve 28 is slidably fitted to the rear end of the flanged sleeve 27, and a positioning pin 29 is slidably inserted across the two sleeves 27,28. The positioning pin 29 is pressed outward by a spring 30, and a retaining ring 31 attached to the outer periphery of the rear end of the positioning pin 29 and an inward flange 28 provided at the rear end of the adjustment sleeve 28.
By the engagement of a, the positioning pin 29 is prevented from coming off with its end protruding outward.

When the taper shank 2 is inserted into the shank insertion hole a of the main shaft A, the positioning pin 29 is
The rear end of the housing 18 engages with the positioning groove 33 of the positioning block 32 attached to the end surface of the spindle cover B, and the housing 18 is prevented from rotating by the engagement.

The adjusting sleeve 28 has an external thread 28b on the outer periphery, and a positioning member 34 is screwed to the external thread 28b. The positioning member 34 is provided with a positioning piece 34a. On the other hand, on the outer periphery of the housing 18 and the orientation ring 22, the positioning pieces 34a
The guide grooves 18a and 22a into which are fitted are formed.

As for the positioning piece 34a, the tip of the positioning pin 29 is fitted into the positioning groove 33 of the positioning block 32, and the tip of the adjusting sleeve 28 is
2 is fitted in a guide groove 18a formed in the housing 18 in a state of abutting against the end face of the orientation ring 22.
Is free to rotate.

On the other hand, the positioning piece 34a moves in the axial direction by the elastic force of the spring 35 pressing the positioning member 34 in a state where the honing unit for pulling out the taper shank portion 2 from the shank insertion hole a of the main shaft A is removed. Of the orientation ring 22 and the guide groove 22a of the orientation ring 22 to prevent the housing 18 and the orientation ring 22 from rotating relative to each other.

The positioning block 32 is provided with a coolant supply port 36. The coolant supply port 36 communicates with passages 29a and 27a formed in the positioning pin 29 and the flanged sleeve 27, respectively. Further, a passage 27 a formed in the sleeve 27 with the flange communicates with a communication passage 37 formed in the positioning bracket 25, the guide ring 21 and the housing 18,
The communication passage 37 communicates with a cylinder housing space 38 formed in the horn 4.

For this reason, when the coolant is supplied to the coolant supply port 36, the coolant is supplied to the cylinder housing space 38.

The flanged sleeve 27 has a passage 27
a pressure adjusting valve 39 for adjusting the pressure of the coolant in the nozzle a.
Is connected.

As shown in FIGS. 2 and 3, the horn head 7 has an axial mandrel insertion hole 41 communicating with the cylinder accommodating space 38 and an axial direction penetrating the mandrel insertion hole 41 from the outer periphery of the tip. A plurality of elongated slots 42 are provided.

A female screw 7a is formed on the inner circumference of the cylinder housing space 38 of the horn head 7, and a male screw 43a provided on the outer circumference of the cylinder 43 is screw-engaged with the female screw 7a so that the position can be adjusted in the axial direction. Have been.

The cylinder 43 has a cylinder chamber 44 opening at the front end surface and an inlet 4 penetrating the cylinder chamber 44 from the rear end.
5 are formed. The piston 4 is provided in the cylinder chamber 44.
6 is slidably assembled.

The piston 46 is connected to the cylinder chamber 4 through the inlet 45.
4. It moves forward by the supply pressure of the coolant supplied into 4,
A ring-shaped stopper 47 for limiting the sliding amount of the piston 46 is fitted in the opening of the cylinder chamber 44 and is prevented from falling off by a retaining ring 48.

The piston 46 is pressed toward the closed end of the cylinder chamber 44 by a spring 49 incorporated in the cylinder chamber 44.

An axial insertion hole 50 is formed in the piston 46, and a constant pressure shaft 51 is incorporated in the insertion hole 50. The constant pressure shaft 51 is engaged between the constant pressure shaft 51 and the piston 46 when the piston 46 is retracted.
Is retracted, and an engagement mechanism 52 is provided to release the engagement when the piston 46 advances.

The engagement mechanism 52 comprises a flange 53 formed on the inner periphery of the insertion hole 50 and a head 54 provided at the rear end of the constant pressure shaft 51.

The constant pressure shaft 51 has a screw shaft 51a at the tip, and an adjusting nut 55 and a lock nut 56 are screwed to the screw shaft 51a. A disc spring 57 as a spring means is incorporated between the adjusting nut 55 and the flange 53, and the constant pressure shaft 51 is pressed by the disc spring 57 in the forward moving direction.

It should be noted that a coil spring may be used in place of the disc spring 57.

A shaft-shaped mandrel 59 is detachably connected to the distal end of the constant pressure shaft 51 via a joint 58. As shown in FIG. 4, the joint 58 fits the distal end of the holding cylinder 60 screwed to the screw shaft 51 a to the rear end of the mandrel 59, and has a plurality of pockets 61 at the distal end of the holding cylinder 60. The ball 62 is incorporated in each pocket 61 at intervals in the circumferential direction, and an engagement groove 63 with which the ball 62 can be engaged is provided at the rear end of the mandrel 59.

An operation cylinder 64 is provided outside the holding cylinder 60. The operation cylinder 64 has a large-diameter hole 64a that allows the ball 62 to move outward, a tapered hole 64b, and a ball 62.
Are formed in order from the front end with a small-diameter hole 64c that holds the engagement state with the engagement groove 63, and the large-diameter end of the tapered hole 64b is brought into contact with a flange 60a formed at the front end of the holding cylinder 60. The holding cylinder 60 is pressed by the spring 65 so that the small-diameter hole 64c is located outside the ball 62.

In the joint 58 having the above structure, the mandrel 59 is pulled out from the holding cylinder 60 by retracting the operating cylinder 64 against the elasticity of the spring 65 and positioning the large-diameter hole 64a outside the ball 62. The mandrel 59 can be replaced with a mandrel 59 having a different outer diameter.
It can be exchanged for.

As shown in FIG. 2, the tip of the mandrel 59 is inserted into the mandrel insertion hole 41 formed in the horn head 7. An axially long guide groove 66 is formed in the mandrel 59 at a position corresponding to each slot 42 provided in the horn head 7.
6 is provided with a tapered guide surface 67 that is inclined toward the tip of the mandrel 59 with a downward gradient.

An elongated grindstone table 68 is slidably fitted in each of the slots 42, and each grindstone table 48 is connected to the horn head 7 by an elastic ring 69 as elastic means.
The tapered surface 70 formed on the inner surface by being pressed inward in the radial direction is pressed against the tapered guide surface 67 of the mandrel 59.

On the outer surface of the grindstone table 68, an elongated grindstone 71 for grinding the cylindrical inner surface c of the work W is fixed.

The honing unit 1 shown in the embodiment has the above configuration, and has a cylindrical inner surface c formed on the workpiece W.
At the time of grinding finishing, first, as shown in FIG. 1, the tapered shank portion 2 is inserted into the shank insertion hole a of the main shaft A, and the distal end of the positioning pin 29 is placed in the positioning block 32.
And the honing unit 1 is attached to the tip of the main shaft A. In the attached state, the main shaft A is moved in the axial direction, and the small diameter shaft portion 12 of the horn head 7 is moved.
Is inserted into the hole b formed in the work W, the coolant is supplied to the coolant supply port 36 of the positioning block 32, and the spindle A is reciprocated in the axial direction while rotating in the supply state.

FIG. 5 shows a state in which the small diameter shaft portion 12 of the horn head 7 is inserted into the hole b formed in the work W, and the surface of the grindstone 71 is not in contact with the cylindrical inner surface c of the hole b of the work W. It is in.

When the coolant is supplied to the coolant supply port 36 of the positioning block 32 shown in FIG. 1 in the state shown in FIG. 5, the coolant flows as shown by the arrow in FIG. An inlet 45 of the cylinder 43 shown in FIG.
And flows into the cylinder chamber 44.

The supply of coolant into the cylinder chamber 44 of the cylinder 43 causes the piston 46 to
9 against the elasticity of 9 and comes into contact with the stopper 47 and stops. As the piston 46 advances, the flange 53 separates from the head 54 of the constant pressure shaft 51 and the constant pressure shaft 5
1 moves forward by the elastic force of the disc spring 57, and the mandrel 59 connected to the constant pressure shaft 51 also moves forward.

At this time, the guide groove 66 of the mandrel 59
Since the tapered surface 70 of the grindstone table 68 is in contact with the tapered guide surface 67 formed in the above, the advancement of the mandrel 59 causes the grindstone table 68 to move outward and the grindstone 71 to the cylindrical inner surface c of the hole b. Crimp.

For this reason, by rotating the main shaft A in the axial direction while rotating, the honing of the cylindrical inner surface c can be performed by the grindstone 71, and the grindstone 71 is brought into contact with the cylindrical inner surface c by the elastic force of the disc spring 57. Due to the pressing, the inner surface c of the cylinder can be efficiently honed with the honing pressure kept constant.

As in the embodiment, the female screw 7a is formed on the inner periphery of the cylinder housing space 38 provided in the horn head 7, and the male screw 43a provided on the outer periphery of the cylinder 43 is engaged with the female screw 7a. By loosening the screw 13 and rotating the horn head 7, the cylinder 4
3 can be axially adjusted.

The contact position of the tapered surface 70 of the grindstone table 68 with the tapered guide surface 67 of the mandrel 59 changes due to the axial position adjustment of the cylinder 43 as described above. Can be adjusted. Here, the range of use refers to the axial length of the tapered guide surface 67.

Further, by connecting the mandrel 59 to the constant pressure shaft 51 via a joint 58 so as to be detachable, the mandrel 59 can be converted to a mandrel 59 having a larger diameter when the grinding wheel 71 is worn out of the range of use. Can be returned to the use range.

After the honing, the pressure adjusting valve 3
9 is released, the coolant is discharged from the nozzle 40, the pressure in the cylinder chamber 44 is reduced, the piston 46 is retracted by the elastic force of the spring 49, and the constant pressure shaft 51 and the mandrel 59 are engaged by the engagement of the flange 53 and the head 54. Are retracted together to release the pressing of the grindstone 71, and then the main shaft A is moved backward to pull out the tip of the horn head 7 from the hole b of the work W.

[0053]

As described above, according to the present invention, the elasticity of the spring means for pressing the constant-pressure shaft is set to the honing pressure, so that the inner surface of the cylinder can be honed at a substantially constant honing pressure. For this reason, a stable processing state is obtained, and a finished surface with high roundness and cylindricity and excellent surface accuracy can be obtained.

Further, the contact position of the tapered surface of the grindstone table with the tapered guide surface of the mandrel is changed by adjusting the position of the cylinder in the axial direction, so that it is possible to adjust the processing diameter of the grindstone in the range of use.

Further, since the mandrel is detachably connected to the constant pressure shaft, when the use range is deviated due to wear of the grindstone, the mandrel can be returned to the use range by replacing the mandrel.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a honing unit according to the present invention.

FIG. 2 is an enlarged sectional view showing a horn of the honing unit shown in FIG. 1;

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is an enlarged sectional view showing a joint portion of FIG. 2;

5 is a cross-sectional view of the honing unit shown in FIG. 1 in a state where the pressing of the grindstone table is released.

[Explanation of symbols]

 A main shaft a shank insertion hole 2 taper shank portion 4 horn 38 cylinder housing space 41 mandrel insertion hole 42 slot 43 cylinder 44 cylinder chamber 50 insertion hole 51 constant pressure shaft 52 engagement mechanism 57 disk spring 59 mandrel 67 taper guide surface 68 grinding wheel base 69 Elastic ring 70 Tapered surface 71 Whetstone

Claims (3)

[Claims] 1. A horn that rotates integrally with a shank portion is connected to a tip of a shank portion inserted into a shank insertion hole of a main shaft, and the horn communicates with a cylinder housing space and a cylinder housing space from a tip end surface. An axially extending mandrel insertion hole, and a plurality of axially elongated slots communicating with the mandrel insertion hole from the outer periphery of the distal end are formed, and a cylinder is assembled in the cylinder housing space, and a cylinder chamber formed in the cylinder is formed. Slidably insert a piston that moves forward by the supply of coolant, and inserts a constant-pressure shaft into an axial insertion hole formed in the piston,
An engagement means is provided between the constant pressure shaft and the piston to engage the axial direction when the piston retreats to retreat the constant pressure shaft, and to release the engagement when the piston advances, in the direction in which the constant pressure shaft advances. A spring means for pressing the constant pressure shaft is provided, a mandrel slidable in the mandrel insertion hole is connected to the tip of the constant pressure shaft, and a grindstone table supporting a grindstone is slidably inserted into each of the slots. A honing unit provided with elastic means for pressing the grinding wheel head against the outer periphery of the mandrel, and a tapered guide surface provided on the outer circumference of the mandrel to be in contact with a tapered surface formed on the inner surface of the grinding wheel head. 2. The honing unit according to claim 1, wherein the cylinder is supported so that its position can be adjusted in the axial direction. 3. The honing unit according to claim 1, wherein the mandrel is detachably connected to a constant pressure shaft.