JPH10225842A - Rotation axis structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent warping and oscillation of a rotation axis for holding a pipe at an axial center. SOLUTION: This rotation shaft structure is provided with a fluid supply hole 27 through an axial center L in a pull rod 12 inserted into a through hole 11 in a main shaft 3 to be slidable in an axial direction, a pipe 28 through the axial center L is inserted into the fluid supply hole 27, the fluid supply hole 27 is set as an axial center coolant flow passage, and the pipe 28 is set as a tight adhesion checking air flow passage. Strength deterioration and oscillation of the pull rod 12 are thus prevented. Between the pipe 28 and the fluid supply hole 27, a coil spring which axial center coolant can pass is provided, theby the pipe 28 is held at the axial center L for preventing the pipe 28 from warping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary shaft structure in which a plurality of fluid flow paths are provided in a rotary shaft.

[0002]

2. Description of the Related Art Conventionally, when a flow path is provided for passing a plurality of different fluids through a rotating shaft, in order to prevent the rotation of the rotating shaft, the flow paths of the respective fluids are adjusted so that the rotating shaft can be dynamically balanced. A plurality of fluid supply holes are provided symmetrically with respect to the rotation axis. For example, when one fluid is air for an air sensor or an air blow, and the other fluid is oil for a cylinder, the specific gravities are different from each other. Therefore, as shown in FIG. Are provided symmetrically with respect to the axis of the rotary shaft 72, and oil is supplied to the oil passage 7.
A plurality of rotation shafts 72 are provided so as to be symmetrical about the axis with only three rotation shafts 72. In some cases, both ends of the pipe are supported through a pipe in a fluid supply hole passing through the axis of the rotating shaft, and flow paths are formed between the outer periphery of the pipe, the inner wall of the fluid supply hole, and the inside of the pipe.

[0003]

In the above prior art, a large number of fluid supply holes must be provided symmetrically in the rotating shaft so as to be balanced, and only two fluid flow paths having different specific gravities are required. In such a case, for example, when one is for a coolant liquid and the other is for an air blow, it is not reasonable to have twice as many channels for the two systems. In addition, when the rotating shaft is narrow, it is extremely difficult to provide a large number of fluid supply holes in such a well-balanced manner, and there is a problem that it cannot be adopted. In addition, in the case where a pipe is provided as a flow path for the other fluid in the fluid supply hole for one fluid, twice as many flow paths as the fluid supply holes to be formed on the rotating shaft can be obtained. In the shaft, the labor of drilling the fluid supply hole of half of the number of required flow paths is sufficient, and the labor for hole processing is less than that, and when two flow paths are required, the same amount of time is required. It is reasonable because it only has a flow path, but if the pipe is considerably long compared to its diameter or if it is thin, the pipe central part will bend and the center of the fluid supply hole will be bent. There was a problem that the pipe could not be reliably held, thereby breaking the dynamic balance of the rotating shaft. The object of the present application is to take advantage of the above advantages, and furthermore, to prevent the pipe from bending when the pipe is provided in the fluid supply hole,
An object of the present invention is to prevent the dynamic balance of the rotating shaft from being lost by securely holding the pipe center on the axis of the fluid supply hole.

[0004]

In order to solve the above-mentioned problems,
In the present application, in a rotating shaft structure having a flow path in the rotating shaft, a fluid supply hole is provided in the rotating shaft, a pipe is arranged inside the fluid supply hole, and a flow path is formed inside and outside the pipe. The pipe is held at the axial position of the fluid supply hole between the outer periphery of the pipe and the inner wall positioned outside and forming a flow path between the outer periphery of the pipe and does not hinder the passage of the fluid in the flow path. A pipe holding member was provided.

In particular, when only two channels are required, in order to solve the above-mentioned problems, in a rotary shaft structure having a channel in the rotary shaft, a fluid supply hole is provided in the axis of the rotary shaft, A pipe is arranged inside the fluid supply hole, a flow path is formed inside and outside the pipe, and between the pipe outer periphery and an inner wall which is located outside the pipe and forms a flow path between the pipe outer periphery. A pipe holding member that holds the pipe at the position of the axis of the rotating shaft and does not hinder the passage of fluid in the flow path is provided.

The pipe holding member is a helical wire and does not prevent passage of the fluid flowing through the fluid supply hole. Specifically, for example, a coil spring is preferable because it is easy to assemble. The rotating shaft is a small-diameter pull rod for pulling in a pull stud of a tool holder detachably mounted in a tapered hole at a tip of a main shaft of a machine tool.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a rotating shaft structure 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. A tapered hole 8 for mounting a tool holder 7 for holding a tool at the tip of the main shaft 3 is formed at the front end of the main shaft 3. A through hole 11 which is a large diameter hole 10 is formed. 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. The air blow passage 16 is formed at the tip of the spindle 3 and communicates with the flow passage 15.
The air blow is blown out toward the tapered hole 8 through the hole. 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. At the tip of the main spindle 3, there is provided a coolant flow path 19 for the coolant injected from the tip of the tool, and the tip end side of the coolant flow path 19 is urged by the urging member 20 in the tip direction to the tool holder 7. A communication member 21 is provided so as to be capable of separating the coolant flow path 7b communicating from the tool path to the tool tip and the coolant flow path 19 of the main shaft 3 so that the rear end side of the main shaft 3 opens toward the through hole 11. ing.

The rear end of the holding portion 22 is integrally screwed with the front end of the pull rod 12, and the front end of the rod 23 is integrally screwed with 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 pin 32 is 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 intrusion of cuttings or the like between the tapered portion 7a and the tapered hole 8 or a tool holder is not properly inserted due to a tool changing device, 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 jetted 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 the coil spring 61 between the inner periphery 27a of the fluid supply hole and the outer periphery 28b of the pipe even if the pipe bends. Since the pipe 28 is fixed at the axial position of the main shaft 3, it does not swing due to the rotation of the main shaft 3. still,
The air for confirming the close contact with the fluid supply hole may be configured to pass the coolant through the pipe.

Next, FIG. 7 shows another embodiment.
A fluid supply hole 81 is formed in the rotating shaft 80, a pipe 82 is disposed inside the fluid supply hole 81, and another pipe 83 is disposed inside the pipe 82, and an inner wall 81 of the fluid supply hole 81 is provided.
a and the outer periphery of the pipe 82 form a first flow path,
A second flow path is formed by the inner circumference of the pipe 82 and the outer circumference of the pipe 83, and the inner circumference of the pipe 83 is used as a third flow path.
a between the outer circumference of the pipe 82, the inner circumference of the pipe 82 and the pipe 83
The same coil spring 6 as in the first embodiment is provided between the outer periphery and the outer periphery.
1A, the coil spring 61B is inserted, and the pipe 82 and the pipe 83 are held at the axial center position of the fluid supply hole 81, thereby preventing the pipe from bending or swinging. With this configuration, it is possible to allow more fluid to pass therethrough and to reciprocate one of the fluids than in the first embodiment, and similarly, the pipes 82 and 83 can be moved to the axial center position of the rotary shaft 80 without swinging. Will be retained.

FIG. 8 shows another embodiment.
A plurality of (two in the present embodiment) fluid supply holes 85 are bored symmetrically with respect to the axis of the rotation shaft 84, and the same pipes 86 are inserted into the respective fluid supply holes 85. A coil spring 61C substantially similar to that of the first embodiment is inserted between the inner wall 85a of the fluid supply hole and the outer periphery of the pipe 86, and the pipe 86 is formed similarly to the first and second embodiments.
Is held at the axial center position of the fluid supply hole 85 to prevent the pipe from bending or swinging.

[0019]

As described above, according to the present invention, when different fluid flow paths are provided on the rotating shaft, one fluid flow path is provided so that each fluid flow path has the same axis. Since the pipe serving as the other flow path is provided in the supply hole and the pipe holding member is provided between the fluid supply hole and the pipe, it is not necessary to provide a large number of fluid supply holes, and the processing is easy. Holds the middle part of the pipe, so that it does not bend even if the pipe is long or thin. Further, since the pipe does not bend in this way, it is possible to prevent the dynamic balance from being lost due to the bending of the pipe, and to prevent the rotation of the rotating shaft. In addition, since the pipe holding member is a spiral wire, it can be wound around the pipe and inserted into the fluid supply hole, so that the assembly is easy and the cost is low.

[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.

FIG. 8 is another embodiment.

FIG. 9 shows a conventional rotating shaft structure.

[Explanation of symbols]

12 Pull rod (rotary shaft) 27, 81, 85 Fluid supply holes 27a, 81a, 85a Inner wall 28, 82, 83, 86 Pipe 28b Pipe outer periphery 61, 61A, 61B, 61C Coil spring (pipe holding member) L axis

Claims (4)

[Claims] In a rotary shaft structure having a flow path in a rotary shaft, a fluid supply hole is provided in the rotary shaft, a pipe is arranged inside the fluid supply hole, and a flow path is formed inside and outside the pipe. The pipe is held at the axial center position of the fluid supply hole between the outer periphery of the pipe and the inner wall positioned outside and forming a flow path between the outer periphery of the pipe and the passage of the fluid in the flow path. A rotating shaft structure provided with a pipe holding member that does not hinder the rotation. 2. A rotary shaft structure having a flow path in the rotary shaft, wherein a fluid supply hole is provided in the axis of the rotary shaft, a pipe is disposed inside the fluid supply hole, and a flow is provided inside and outside the pipe. A passage is formed, and the pipe is held at the axial center position of the rotating shaft between the outer periphery of the pipe and an inner wall which is located outside the outer periphery of the pipe and forms a flow passage between the outer periphery of the pipe and passage of fluid in the flow passage A rotating shaft structure provided with a pipe holding member that does not hinder the rotation. 3. The rotary shaft structure according to claim 2, wherein the pipe holding member is a spiral wire. 4. The rotary shaft structure according to claim 2, wherein the rotary shaft is a pull rod for detachably mounting a tool holder on the main shaft in a spindle device of a machine tool.