JPH10225845A - Main spindle device for machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a main spindle device in which tightness between a taper hole in a main spindle and a taper part of a tool holder can be recognized to prevent oscillation of the main spindle. SOLUTION: This main spindle device for a machine tool is provided a fluid supply hole 27 through an axial center L in a pull rod 12 axially slidably inserted into a through hole 11 in a main spindle 3. A pipe 28 through the axial center L is inserted into the fluid supply hole 27, so the fluid supply hole 27 is set as an axial center coolant flow passage, and the pipe 28 is set as a tightness recognizing air flow passage. Air is supplied from a tightness recognizing air jet hole 18 to a taper hole 8, and air pressure is detected by a pressure detection means 57, so tightness between a taper part and the taper hole 8 is recognized. Between the pipe 28 and the fluid supply hole 27, a coil spring through which axial center coolant can pass is provided, so the pipe 28 is held at the axial center L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device of a machine tool or the like having a tool holding confirmation device for confirming tool holding.

[0002]

2. Description of the Related Art As a spindle device of the machine tool, for example, a tool holding confirmation device for detecting that the spindle holds a tool holder is provided, and a coolant flow path of a shaft coolant discharged from a tool is provided in the spindle. There is known one provided on a pull rod for tool holding inserted in a freely slidable manner.
According to the technique disclosed in Japanese Patent Application Laid-Open No. H6-170619, a proximity sensor for detecting the advancing / retracting position of a flange body provided at a rear end of a tool pull-in drawbar (pull rod) provided in a main spindle is provided at an appropriate position at the rear end of a spindle head. It was provided. The pull stud of the tool holder is pulled in by the collet (holding portion) at the tip of the draw bar by the pulling force of the draw bar, and the tapered portion of the tool holder is fitted in the main shaft tapered hole.
At the time of fitting of the tool holder, the proximity sensor detects the flange body, thereby confirming a gripping error of the tool holder. The coolant communicates from a rotary joint provided at the rear end of the draw bar to a through hole (coolant passage) formed in the axis of the draw bar to a through hole formed in the main shaft, and reaches the tool holder. Was.

[0003]

In the above prior art,
The proximity sensor detects the mistake of holding the tool holder of the main spindle at the rear end of the drawbar by the proximity sensor, that is, by detecting the stroke of the pull rod.In this case, the response and mounting of the sensor should be at the ideal position. Is difficult and the detection variation is large and the reliability is lacking, so it is not possible to confirm the adhesion of the tapered portion to the tapered hole with high accuracy.
The accuracy was low such that the presence or absence of the tool holder was detected. For this reason, even if foreign matter such as a small amount of chips enters between the tapered portion and the tapered hole, or the tool holder is inserted with a slight inclination when the tool holder is mounted, it may be regarded as normal even if the insertion is poor. However, if the workpiece is processed in a state where the tapered portion and the tapered hole are not in close contact with each other, there is a problem that the machining accuracy of the workpiece is greatly reduced due to the runout of the tool. An object of the present application is to make it possible to detect the close contact between the tapered portion of the tool holder and the tapered hole of the spindle by supplying air for checking the contact between the tapered hole and the tapered portion with high accuracy. Further, as another problem of the present application, when supplying air for confirming contact with a coolant via a pull rod, that is, when passing a plurality of fluids having different specific gravities through the pull rod, an eccentric load is generated on the main shaft and the main shaft does not swing. The fluid supply hole and the pipe align the axis of the pull rod so that there is no need to provide a plurality of fluid supply holes so that machining is easy even if the shaft diameter of the pull rod is small and the shaft diameter of the pull rod is small. The object is to provide a spindle device which is adapted to pass through.

[0004]

In order to solve the above-mentioned problems,
A spindle device of a machine tool according to the present invention is a spindle device of a machine tool having a tool holding confirmation device that detects that a tool holder is held on a rotatably supported spindle. Tool holding that checks the close contact between the tool holder and the tool holder by detecting the air pressure of the close contact checking air by providing the close contact checking air injection hole and injecting the close contact checking air from the close contact checking air injection hole Has a confirmation device.

The tool contact portion is a tapered hole, and the taper hole of the tool holder is checked for close contact. Further, the spindle of the spindle device is provided with a coolant flow path for coolant that is communicated from the spindle to the tool holder when the tool holder is held on the spindle, and that is jetted from the tip of the tool. In addition, a fluid supply hole is provided in the axis of the pull rod inserted in the main shaft so as to be slidable in the axial direction, and a pipe for fluid passage through the axis of the pull rod is provided in the fluid supply hole provided in the pull rod. One of the holes or the pipe was used as an air flow path for checking adhesion, and the other was used as a flow path for coolant.

[0006] The pipe is held at the axial center of the pull rod between the fluid supply hole provided in the pull rod and the pipe,
A pipe holding member that does not hinder the passage of the fluid in the fluid supply hole provided in the pull rod is provided. This pipe holding member is a spiral wire. Specifically, for example, a coil spring whose lead is rough enough to allow a fluid to pass through is used.

A rotary joint having a plurality of fluid supply ports is attached to a rear portion of the spindle of the spindle device of the machine tool.
The fluid supply hole and the pipe of the pull rod were respectively connected to corresponding fluid supply ports of the rotary joint.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a spindle device for a machine tool according to the present invention will be described with reference to FIGS. A spindle 3 is rotatably supported by a spindle head 2 of the spindle device 1 via a plurality of bearings 4. A rotor 5 is integrally provided on the outer periphery of a substantially central portion of the main shaft 3, and constitutes an electric motor that rotates the main shaft 3 together with a stator 6 provided in the main shaft head 2. The tip of the spindle 3 is a spindle tool holding portion, and a tapered hole (tool contact portion) 8 for mounting a tool holder 7 for holding a tool at the tip is formed. A through hole 11 having a small-diameter hole 9 at the front and a large-diameter hole 10 at the rear is formed in the axis of No. 3. A pull rod 12 is inserted through the through hole 11 slidably in the axial direction, and is urged rearward by a disc spring 13. An unclamping cylinder 14 that slides the pull rod 12 in the front-rear direction is integrally provided at a rear portion of the spindle head 2. As shown in FIGS. 1 and 2, an air blow passage 15 is provided in the spindle head 2, and an air blow passage 16 is formed at the tip of the spindle 3 and communicates with the flow passage 15. An air blow is blown out toward the tapered hole 8 through the air blower. As shown in FIG. 2, an air passage 17 for confirming the close contact of the tool holder 7 is formed at the distal end of the main shaft 3. An air injection hole 18 for confirming close contact is formed on the surface of the main shaft 3 and opens toward the inside of the tapered hole 8. The rear end side of the main shaft 3 opens toward the through hole 11. Also, at the tip of the spindle 3,
Coolant flow path 19 for coolant injected from the tool tip
The coolant flow path 7 is urged toward the tip end of the main shaft 3 of the coolant flow path 19 by the urging member 20 and communicates from the tool holder 7 to the tool tip.
A communication member 21 is provided so as to be capable of separating the b and the coolant flow path 19 of the main shaft 3 so as to be able to be separated from each other, and the rear end side of the main shaft 3 is open toward the through hole 11.

The rear end of the holding portion 22 is integrally screwed to the front end of the pull rod 12, and the front end of the rod 23 is integrally screwed to the rear end of the pull rod 12. The holding portion 22, the pull rod 12, and the rod 23 have through holes 24, respectively.
25, 26 are formed, and the through holes 24, 25, 26 constitute a fluid supply hole 27 which is a coolant flow passage through which the coolant passes through in a straight line.
Inside the axis of the pull rod 12 (also the axis of the main shaft) L
Is inserted. As shown in FIG. 2, the holding portion 22 has a plurality of steel balls 29 incorporated at its tip so as to be movable in the radial direction while equally dividing the circumferential direction. Pull stud 31 at the rear end of tool holder 7 in cooperation with cam surface 30 of
Are clamped and unclamped. The distal end side of the through hole 24 has a T-shape that opens in the radial direction of the holding portion 22, and communicates with the coolant channel 19 of the main shaft 3. A pin 32 is provided substantially at the center of the holding portion 22.
Is provided so as to be orthogonal to the through hole 24.

The pins 32 are formed in a large diameter portion 34 and a small diameter portion 35 as shown in FIGS. Also, the pin 32
Is provided with an air through hole 36 through which the air for checking the adhesion passes. A fitting hole 3 into which one end of the pipe 28 is radially inserted from the outer periphery of the small diameter portion 35 toward the air through hole 36.
7 are drilled. When the pin 32 is fitted into the fitting hole 33, the space between the outer periphery of the small diameter portion 35 and the fitting hole 33 becomes a part of the coolant flow path through which the coolant passes, and the air through hole 36 is used for confirming the close contact. The air passage 17 is continuous with the opening on the through hole 11 side through the arc groove 32a and the annular groove 3a.

The rod 23 is loosely fitted to the center of the piston rod 38 of the unclamping cylinder 14, and
a is movably supported in the axial direction by a sleeve 14b which is rotatably supported by a. A jaw 23a with which the piston 38 of the unclamping cylinder 14 abuts is provided on the outer periphery of the distal end, and is screwed integrally. The rotor 40 of the rotary joint 39 is integrally mounted on the rear end of the rod 23. Have been. When the piston 38 of the unclamping cylinder 14 moves forward, the rod 23 is pushed by the piston 38 and moves forward in the axial direction. Accordingly, the pull rod 12, the holding portion 22, and the rotary joint 39 also move integrally. When the piston 38 of the unclamping cylinder 14 is retracted, the pull rod 12, the holding portion 22, the rotary joint 39, and the rod 23 are integrally retracted by the spring force of the disc spring 13. The rod 23 is provided with a fitting hole 42 for fitting the pin 41 at substantially the center thereof so as to be orthogonal to the through hole 26, and an air passage 43 of the air for confirming adhesion that communicates with the fitting hole 42. Has been drilled.

The pin 41 has a large diameter portion 44 and a small diameter portion 45 as shown in FIGS. 3 and 5, and a projection 47 is formed on a side surface 46 at one end. The pin 41 is provided with an air hole 48 which is open to the end face and the side surface 46 of the protruding part 47, one end of which is closed, and through which the air for checking the adhesion passes. The small-diameter portion 45 faces toward the air through hole 48.
A fitting insertion hole 49 into which the other end of the pipe 28 is fitted in the radial direction from the outer periphery is formed. When the pin 41 is fitted in the fitting hole 42, the space between the outer periphery of the small diameter portion 45 and the fitting hole 42 becomes a part of the coolant flow path through which the coolant passes, and the pin 4
The air through hole 48 and the air passage 43 communicate with each other via a portion surrounded by the side surface 46 of the first and the vertical surface 50 of the fitting hole 42.

The rotary joint 39 is a housing 5
1, a rotor 40 is rotatably provided, and a housing 51 has a coolant supply port 52 and an air supply port 53 for confirming adhesion, and the coolant supply port 52 and the air supply port 53 for confirmation of adhesion are respectively provided. A coolant passage 54 communicating with the through hole 26 of the rod 23 provided in the rotor 40 and an air passage 55 communicating with the air passage 43 of the rod 23.
And communicates with Further, the air supply port 53 for contact confirmation is provided with a compressed air source 56 such as a compressor for supplying air for contact confirmation.
A pressure detecting means (pressure switch) 57 for detecting the air pressure of the air for confirming the adhesion is connected in the middle thereof. The housing 51 is provided with a detection member 58, and constitutes an unclamping confirmation means 60 for confirming the unclamping of the tool holder 7 by the proximity switch 59 attached to the unclamping cylinder 14. A tool holding and checking device for the main shaft 3 is constituted by the pressure detecting means 57 and the above-described air passage 17 for ejecting the air for checking contact and the air flow path for checking contact which communicates with the pipe 28 and the like.

Both ends of a pipe 28 inserted into the fluid supply hole 27 are inserted into insertion holes 37 and 49 of pins 32 and 41, respectively. The inner side 28a of the pipe 28 is an air flow path for checking adhesion, and a coolant flow path through which the coolant passes is formed by the outer periphery 28b of the pipe 28 and the inner wall 27a of the fluid supply hole 27. In addition, pipe circumference 2
8b and the inner wall 27a of the fluid supply hole 27
A coil spring (spiral wire) 61 which is a pipe holding member for positioning and holding the position 8 at the axial center position of the pull rod 12 is inserted. The coil spring 61 is formed such that the leads are rough enough to allow the coolant to pass smoothly. The pipe holding member may have any shape as long as the pipe is fixed to the shaft center and does not hinder the passage of the fluid in the fluid supply hole, and may be provided integrally with the outer periphery of the pipe.

Next, the operation will be described. When the processing of the work is completed, the piston 3 of the unclamping cylinder 14
8 moves in the direction of the spindle tip (tool holder unclamping direction), the jaw 23a is pushed, and the pull rod 12
3 moves toward the tip of the spindle against the biasing force of
The tool holder 7 clamped on the main shaft 3 is unclamped by the cooperation of the tool holder 7 and the cam surface 30. The tool holder 7 is taken out from the tip of the spindle 3 by a tool changing device (not shown) and is replaced with another tool holder 7, and immediately before the tool holder 7 is fitted into the tapered hole 8, the air blow blows out from the air blow passage 16. Clean the leverage. When the piston 38 of the unclamping cylinder 14 is retracted at the timing when the tool holder 7 is fitted into the tapered hole 8, the pull rod 12 is urged toward the rear end of the main shaft (tool holder clamping direction) by the disc spring 13, and the holding portion The pull stud 31 is clamped while being pulled into the tube 22, and the tapered portion 7 a contacts the tapered hole 8. Tapered part 7 in tapered hole 8
When a is in close contact, the air for contact confirmation that has been blown out from the air ejection hole for contact confirmation 18 cannot be blown out, the air pressure rises, and the pressure detection means 57 sets a predetermined air pressure of the air for contact confirmation. Is detected, the contact point of the pressure detecting means 57 is closed, whereby the close contact signal is output from the pressure detecting means 57. As a result, it is confirmed that the tapered portion 7a is in close contact with the tapered hole 8, and the process proceeds to the next operation, and the work processing is restarted.

If foreign matter is caught by the intrusion of chips or the like between the tapered portion 7a and the tapered hole 8, or if a tool holder is not properly inserted due to a tool changer, air flows between the tapered hole 8 and the tapered portion 7a. Pressure detecting means 5
7, the predetermined air pressure is not detected, and the pressure detecting means 57
Contacts do not close. In this state, since the close contact signal is not output from the pressure detecting means 57, the tapered hole 8 and the tapered portion 7a
And stop without moving to the next operation. Further, when it is detected that the tool holder 7 is not in close contact, the operator is notified by a notifying means such as a lamp, and the operator cleans the tapered hole 8 and the tapered portion 7a.
After re-inserting the tool holder 7, the machining is resumed.

When the machining is started, the coolant passes through the fluid supply hole 27 and is ejected from the tip of the tool through a coolant channel 7b provided in the tool holder 7. Coolant passes through the outer periphery of the pipe 28 inserted into the fluid supply hole 27 during processing, and between the fluid supply hole inner periphery 27a and the pipe outer periphery 28b even if the pipe is long or thin. Since the pipe 28 is fixed at the axial center position of the main shaft 3 by the coil spring 61, the pipe 28 does not bend, preventing the collapse of the dynamic balance due to the bending of the pipe, and does not swing due to the rotation of the main shaft. In addition, it may be configured such that air for confirming close contact with the fluid supply hole and coolant through the pipe.

Next, another embodiment will be described with reference to FIG.
The same components as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. An air injection hole 18A for checking the closeness of the air passage 17 for checking the close contact of the main shaft 3 is opened at the front end surface 3b of the main shaft 3 so that the air for checking the close contact is jetted toward the front end of the main shaft 3. A plurality of steel balls 2 are inserted into the tapered hole 8 at the tip of the main shaft 3.
A steel ball holding member 62 in which the circumferential direction of the steel ball 9 is equally divided and movably mounted in the radial direction is integrally fitted and fixed. Further, the rear end of the clamper 63 is integrally connected to the front end of the holding portion 22A, the rear end of which is screwed integrally with the pull rod 12, and this clamper 63 is moved back and forth around the center of the steel ball holding member 62. It is inserted as possible. A cam portion 64 which is an inclined surface for pressing the steel ball 29 outward in the radial direction is formed at the tip of the clamper 63. In addition, the clamper 63
Is provided with a coolant passage 19 which communicates with the coolant passage through hole 24 and supplies coolant to the coolant passage 7b of the tool holder 7 when the tool holder 7 is mounted.
The spindle tool holding portion is configured as described above, and the tapered hole 8 and the spindle tip surface 3b form a tool contact portion. The tapered portion 7a of the tool holder 7 has a small diameter portion 62 of a steel ball holding member 62.
There is a fitting hole 7c into which a is fitted.

When the machining of the workpiece is completed, the tool holder 7 at the tip of the spindle 3 is replaced, as in the above embodiment. When a new tool holder 7 is mounted on the spindle 3, the disc spring 13
The pull rod 12 is urged rearward by the urging force, whereby the clamper 63 moves rearward, the cam portion 64 presses and moves the steel ball 29 radially outward, and the steel ball 29 is provided on the tapered portion 7a. Steel ball pressure contact surface 65 with inclined holding hole 65
is pressed backward, the tapered portion 7a comes into close contact with the tapered hole 8, and the rear end surface 66a of the grip portion 66 of the tool holder 7 comes into close contact with the spindle front end surface 3b.
Surface restricted. At this time, the air injection hole 1
8A, the air for checking the contact is ejected. When the air for checking the contact can no longer be blown out and a predetermined air pressure is detected, the rear end face 66a of the tool holder 7, the front end face 3b of the spindle, and the tapered portion 7a And the taper hole 8 are confirmed to be in close contact with each other, and the work processing is resumed. Needless to say, the air jet hole for confirming adhesion may be provided on the peripheral surface of the tapered hole, and the adhesion between the tapered hole and the tapered portion may be confirmed.

[0020]

As described above, according to the present invention, air for confirming close contact is supplied to the tapered hole of the main shaft, and by detecting the air pressure of this air, the tapered hole when the tool holder is held on the main shaft is formed. Since the close contact with the tapered portion is checked, there is a very slight gap between the tapered hole and the tapered portion due to a small amount of foreign matter entering between the tapered hole and the tapered portion or due to poor insertion of the tool holder. This can be reliably detected even when it is not present. Thereby, it is possible to prevent a reduction in the processing accuracy of the work due to the runout of the tool holder due to the taper hole and the tapered portion not being in close contact during the processing of the work, and to perform the processing with high precision. Also, a fluid supply hole passing through the axis is provided in the pull rod, and a pipe passing through the axis is provided in the fluid supply hole,
One is used as an air flow path for confirming adhesion, and the other is used as a flow path for coolant. Since it is not necessary to provide a plurality of flow paths in the device, processing is easy. In addition, since the pipe holding member is provided between the fluid supply hole and the pipe, even if the pipe is long or thin, the pipe is positioned at the axis without bending and the collapse of the dynamic balance due to the bending of the pipe can be prevented. . If the pipe holding member uses a spiral wire, it is easy to assemble and inexpensive.

[Brief description of the drawings]

FIG. 1 is a sectional view of a spindle device.

FIG. 2 is an enlarged view of a tip side of a spindle device.

FIG. 3 is an enlarged view of a rear end side of the spindle device.

FIG. 4 is a view of a pin fitted to a holding unit.

FIG. 5 is a view of a pin fitted on a rod.

FIG. 6 is a sectional view of a pull rod of the spindle device.

FIG. 7 is another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spindle device 3 Spindle 3b Spindle tip surface (tool contact part) 7 Tool holder 7a Taper part 8 Taper hole (tool contact part) 12 Pull rod 27 Fluid supply hole 28 Pipe 39 Rotary joint 54 Coolant passage 55 Air passage 61 Coil spring ( Pipe holding member) L axis

Claims (7)

[Claims] In a spindle device of a machine tool having a tool holding confirming device for detecting that a tool holder is held on a spindle rotatably supported, air for checking contact with a tool contact portion of a spindle tool holding portion is provided. A tool holding and checking device is provided that has an injection hole, injects air for checking adhesion from the air injection hole for checking adhesion, and detects the air pressure of the air for checking adhesion to check the close contact between the tool contact portion and the tool holder. A spindle device for a machine tool, comprising: 2. The main spindle device for a machine tool according to claim 1, wherein the tool contact portion is a tapered hole, and the taper hole and the taper portion of the tool holder are checked for close contact. 3. The spindle according to claim 1, wherein when the tool holder is held by the spindle, the spindle is connected to the tool holder, and a coolant flow path for the coolant injected from the tip of the tool is provided on the spindle. Spindle device for machine tools. 4. A fluid supply hole is provided in the axis of a pull rod inserted in the main shaft so as to be slidable in the axial direction, and a pipe for fluid passage passing through the axis of the pull rod is provided in the fluid supply hole provided in the pull rod. 4. A spindle device for a machine tool according to claim 3, wherein one of the fluid supply hole and the pipe is used as an air flow path for confirming close contact, and the other is used as a flow path for coolant. 5. A pipe holding member is provided between the pipe and a fluid supply hole provided in the pull rod, the pipe being held at an axial center position of the pull rod, and a pipe holding member not obstructing passage of fluid in the fluid supply hole provided in the pull rod. The spindle device for a machine tool according to claim 4, wherein: 6. The spindle device for a machine tool according to claim 5, wherein the pipe holding member is a spiral wire. 7. A rotary joint having a plurality of fluid supply ports is attached to a rear portion of the main shaft, and a fluid supply hole of a pull rod and a pipe are respectively connected to corresponding fluid supply ports of the rotary joint. Item 6
A spindle device for a machine tool according to any one of the preceding claims.