JP3624413B2 - Rotating shaft structure - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a rotating shaft structure in which a plurality of fluid flow paths are provided in a rotating shaft.
[0002]
[Prior art]
Conventionally, (1) When a flow path is provided to allow a plurality of different fluids to pass through the rotating shaft, in order to prevent the rotating shaft from vibrating, the fluid that is the flow path of each fluid so that the rotating shaft can be dynamically balanced A plurality of supply holes are provided symmetrically with respect to the rotation axis. For example, when one fluid is air for an air sensor, an air blower, etc., and the other fluid is oil for a cylinder, the specific gravity is different from each other . Therefore, as shown in FIG. Thus, a plurality of oils are provided so as to be symmetric with respect to the axis of the rotating shaft 72, and a plurality of oils are provided on the rotating shaft 72 so as to be symmetric with respect to the axis only by the oil passage 73. (2) In some cases, both ends of the pipe are supported through the pipe in the fluid supply hole passing through the axis of the rotating shaft, and the flow path is between the pipe outer periphery and the fluid supply hole inner wall and inside the pipe.
[0003]
[Problems to be solved by the invention]
In the prior art (1), a large number of fluid supply holes must be provided symmetrically on the rotating shaft so as to be balanced, and when only two fluid flow paths with different specific gravities are required, When the coolant is for the coolant and the other is for the air blow, it is not reasonable to have twice as many flow paths for the two systems. Moreover, when the rotating shaft is thin, it is extremely difficult to provide a large number of fluid supply holes in such a balanced manner, and there is a problem that it cannot be adopted. Further, in the case of providing a pipe as a flow path for the other fluid in the fluid supply hole of one fluid as in (2), the flow path is twice as many as the fluid supply holes to be formed on the rotating shaft. Therefore, it is only necessary to make a fluid supply hole that is half the number of required flow paths on the rotating shaft. Therefore, compared with (1), there is less labor for drilling holes and two flow paths are required. Sometimes it is reasonable to have only the same number of channels, but if the pipe is considerably longer than its diameter, or if it is thin, the central part of the pipe will bend and fluid There was a problem that the pipe could not be reliably held at the hole center of the supply hole, thereby breaking the dynamic balance of the rotating shaft.
The problem of the present application is to prevent the pipe from being bent when the pipe is provided in the fluid supply hole, while keeping the advantage of the above (2), and to securely hold the axis of the pipe in the axis of the fluid supply hole. This is to prevent the dynamic balance of the rotating shaft from being lost.
[0004]
[Means for Solving the Problems]
In order to solve the above problem, in the present application, in a rotating shaft structure having a flow path for allowing a plurality of different fluids to pass through the rotating shaft , a fluid supply hole is provided in the axis of the rotating shaft , and the fluid supplying hole is disposed inside the fluid supplying hole. A pipe is disposed to form a flow path on the inside and outside of the pipe, and between the outer periphery of the pipe and the inner wall of the fluid supply hole that is positioned on the outer side and forms a flow path between the pipe outer periphery , A coil spring having a rough lead that holds the pipe at the axial center position of the rotating shaft and does not prevent passage of fluid in the flow path is inserted .
[0005]
In the present application, in the rotating shaft structure having a flow path for allowing a plurality of different fluids to pass through the rotating shaft, a fluid supply hole is provided in the center of the rotating shaft, and a pipe is disposed inside the fluid supplying hole. Another pipe is arranged inside the pipe to form a first flow path by the inner wall of the fluid supply hole and the outer periphery of the outer pipe, and the second inner periphery of the outer pipe and the outer periphery of the inner pipe. A flow path is formed, and the inner circumference of the inner pipe is the third flow path, and each pipe is rotated between the inner wall and the outer circumference of the outer pipe, and between the outer circumference of the outer pipe and the outer circumference of the inner pipe. A coil spring having a rough lead that is held at the axial center position of the shaft and does not prevent passage of fluid in the flow path is inserted .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the rotating shaft structure of the present application will be described with reference to FIGS. A main shaft 3 is rotatably supported by a main shaft head 2 of the main shaft device 1 via a plurality of bearings 4. A rotor 5 is integrally provided on the outer periphery of the substantially central portion of the main shaft 3, and an electric motor that rotates the main shaft 3 is constituted by a stator 6 provided in the main shaft head 2. A taper hole 8 for mounting a tool holder 7 for holding the tool at the tip is formed at the tip of the main shaft 3, and the front of the main shaft 3 is a small-diameter hole 9 and the rear is continuous with the taper hole 8. A through-hole 11 that is a large-diameter hole 10 is formed. A pull rod 12 is inserted into the through hole 11 so as to be slidable in the axial direction, and is urged rearward by a disc spring 13. An unclamp cylinder 14 that slides the pull rod 12 in the front-rear direction is integrally provided at the rear portion of the spindle head 2. As shown in FIGS. 1 and 2, the main shaft head 2 is provided with an air blow channel 15, and an air blow channel 16 is formed at the tip of the main shaft 3 and communicates with the flow channel 15. The air blow is blown out toward the taper hole 8 through. Further, as shown in FIG. 2, a contact confirmation air passage 17 of the tool holder 7 is formed at the tip of the spindle 3, and the tip 3 of the contact confirmation air passage 17 is arranged around the tapered hole 8. An air-injection hole 18 for contact confirmation that opens toward the inside of the tapered hole 8 on the surface, and the rear end side of the main shaft 3 opens toward the through-hole 11. Further, a coolant flow path 19 for coolant sprayed from the tool tip is provided at the tip of the spindle 3, and the tool holder 7 is biased toward the tip of the spindle 3 by a biasing member 20 in the tip direction. A communication member 21 is provided to connect the coolant channel 7b communicating from the tool tip to the tool tip so that the coolant channel 19 of the main shaft 3 can be separated, and the rear end side of the main shaft 3 opens toward the through hole 11. ing.
[0008]
The pull rod 12 is integrally threaded with the rear end of the holding portion 22 at the front end, and the front end of the rod 23 is integrally threaded with the rear end of the pull rod 12. The holding portion 22, the pull rod 12 and the rod 23 are provided with through holes 24, 25 and 26, respectively. The fluid supply is a coolant flow path through which the through holes 24, 25 and 26 communicate with each other in a straight line. A hole 28 is formed, and a pipe 28 passing through an axis L (also the axis of the main shaft) L of the pull rod 12 is inserted into the fluid supply hole 27. As shown in FIG. 2, the holding portion 22 incorporates a plurality of steel balls 29 at the tip thereof so as to be equally divided in the circumferential direction and movable in the radial direction. In cooperation with the cam surface 30, the pull stud 31 at the rear end of the tool holder 7 is clamped and unclamped. Further, the front 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 fitting hole 33 into which the pin 32 is fitted is provided substantially at the center of the holding portion 22 so as to be orthogonal to the through hole 24.
[0009]
The pin 32 is formed in the large diameter part 34 and the small diameter part 35 as shown in FIG. 2, FIG. The pin 32 is formed with an air through hole 36 through which the contact confirmation air passes. A fitting insertion hole 37 into which one end of the pipe 28 is fitted in the radial direction from the outer periphery of the small diameter portion 35 is formed toward the air through hole 36. When the pin 32 is fitted in 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 adhesion confirmation. It continues to the opening on the through hole 11 side of the air passage 17 via the arc groove 32a and the annular groove 3a.
[0010]
The rod 23 is loosely fitted in the center of the piston rod 38 of the unclamp cylinder 14, and is supported by a sleeve 14b rotatably supported by the cylinder body 14a so as to be movable in the axial direction. A jaw portion 23a with which the piston 38 of the unclamp cylinder 14 abuts is provided on the outer periphery of the tip portion, and is integrally screwed. The rotor 40 of the rotary joint 39 is integrally attached to the rear end portion of the rod 23. Has been. When the piston 38 of the unclamp cylinder 14 moves forward, the rod 23 is pushed by the piston 38 and moves forward in the axial direction, and the pull rod 12, the holding portion 22, and the rotary joint 39 also move together. When the piston 38 of the unclamp 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. Further, the rod 23 is provided with a fitting hole 42 in which the pin 41 is fitted substantially at the center so as to be orthogonal to the through hole 26, and an air passage 43 for contact confirmation air communicating with the fitting hole 42 is provided. It has been drilled.
[0011]
As shown in FIGS. 3 and 5, the pin 41 is formed of a large diameter portion 44 and a small diameter portion 45, and a protruding portion 47 is formed on a side surface 46 on one end side. Further, the pin 41 is provided with an air through hole 48 that opens from the end surface of the projecting portion 47 whose one end is closed to the side surface 46 and through which the contact confirmation air passes. A fitting insertion hole 49 into which the other end of the pipe 28 is fitted in the radial direction from the outer periphery of the small diameter portion 45 is formed toward the air through hole 48. When the pin 41 is fitted into the fitting hole 42, a portion 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 side surface 46 of the pin 41 and the fitting hole 42. The air through hole 48 and the air passage 43 communicate with each other through a portion surrounded by the vertical surface 50.
[0012]
In the rotary joint 39, the rotor 40 is rotatably provided in a housing 51. The housing 51 has a coolant supply port 52 and an adhesion confirmation air supply port 53, and the coolant supply port 52 and the adhesion confirmation air supply. The opening 53 communicates with a coolant passage 54 that communicates with the through hole 26 of the rod 23 provided in the rotor 40 and an air passage 55 that communicates with the air passage 43 of the rod 23. Further, the contact confirmation air supply port 53 communicates with a pressure air source 56 such as a compressor for supplying contact confirmation air, and a pressure detection means (pressure switch) 57 for detecting the air pressure of the contact confirmation air is connected to the middle. Has been. Further, the housing 51 is provided with a detection member 58, and constitutes an unclamp confirmation means 60 for confirming unclamping of the tool holder 7 by a proximity switch 59 attached to the unclamp cylinder 14. A tool holding confirmation device for the spindle 3 is constituted by the pressure detection means 57 and the above-described air passage 17 for injecting the adhesion confirmation air, the adhesion confirmation air flow path communicating with the pipe 28 and the like.
[0013]
Both ends of the pipe 28 inserted into the fluid supply hole 27 are inserted into the insertion holes 37 and 49 of the pins 32 and 41, respectively. An inner side 28 a of the pipe 28 is an air flow path for adhesion confirmation, and a coolant flow path through which the coolant passes is formed by the outer periphery 28 b of the pipe 28 and the inner wall 27 a of the fluid supply hole 27. A coil spring (spiral wire) 61 is inserted between the pipe outer periphery 28 b and the inner wall 27 a of the fluid supply hole 27 as a pipe holding member for positioning and holding the pipe 28 at the axial center position of the pull rod 12. The coil spring 61 is formed such that the lead is rough enough to allow the coolant to pass smoothly .
[0014]
Next, the operation will be described. When the machining of the workpiece is finished, the piston 38 of the unclamp cylinder 14 moves in the direction of the spindle end (tool holder unclamping direction), the jaw portion 23a is pushed, and the pull rod 12 resists the biasing force of the disc spring 13 to the spindle. The tool holder 7 moved in the distal direction and clamped to the main shaft 3 by the cooperation of the holding portion 22 and the cam surface 30 is unclamped. The tool holder 7 is taken out from the tip of the main spindle 3 by a tool changer (not shown) and replaced with another tool holder 7. Clean the lever part. When the piston 38 of the unclamp cylinder 14 is retracted at the timing when the tool holder 7 is fitted in the taper hole 8, the pull rod 12 is urged by the disc spring 13 in the rear end direction of the main spindle (tool holder clamping direction). The pull stud 31 is clamped while being pulled into 22, and the tapered portion 7 a comes into contact with the tapered hole 8. When the taper portion 7 a comes into close contact with the taper hole 8, the adhesion confirmation air that has been blown out from the adhesion confirmation air injection hole 18 cannot be blown out, the air pressure rises, and the pressure detection means 57 determines the predetermined adhesion confirmation air. When the set air pressure is detected, the contact of the pressure detecting means 57 is closed, and a contact signal is output from the pressure detecting means 57. As a result, it is confirmed that the taper portion 7a is in close contact with the taper hole 8, and the operation proceeds to the next operation, and the workpiece machining is resumed.
[0015]
In addition, when a foreign object bites due to intrusion of chips or the like between the taper portion 7a and the taper hole 8 or a tool holder is inserted incorrectly by the tool changer, air leaks from the gap between the taper hole 8 and the taper portion 7a. Therefore, a predetermined air pressure is not detected by the pressure detection means 57, and the contact of the pressure detection means 57 is not closed. In this state, since the close contact signal is not output from the pressure detecting means 57, it is detected that the tapered hole 8 and the tapered portion 7a are not in close contact, and the operation stops 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 notification means such as a lamp, and after the operator cleans the tapered hole 8 and the tapered portion 7a and reinserts the tool holder 7. Processing is resumed.
[0016]
When machining is started, the coolant passes through the fluid supply hole 27 and is ejected from the tool tip via the coolant flow path 7 b provided in the tool holder 7. The coolant passes through the outer periphery of the pipe 28 inserted into the fluid supply hole 27 during processing, and even if the pipe is bent, the coil spring 61 between the inner periphery 27a of the fluid supply hole and the outer periphery 28b of the pipe is used. Since the pipe 28 is fixed at the axial center position of the main shaft 3, it does not shake due to the rotation of the main shaft 3. In addition, you may comprise so that close_contact | adherence confirmation air may be passed through a fluid supply hole and a coolant may be passed through a pipe.
[0017]
Next, another embodiment is shown in FIG. A fluid supply hole 81 is formed in the rotary shaft 80, a pipe 82 is arranged inside the fluid supply hole 81, and another pipe 83 is arranged inside the pipe 82, and the inner wall 81 a of the fluid supply hole 81 and the pipe 82 forms the first flow path, the inner periphery of the pipe 82 and the outer periphery of the pipe 83 form a second flow path, the inner periphery of the pipe 83 is the third flow path, The same coil spring 61A and coil spring 61B as those in the first embodiment are inserted between the inner wall 81a and the outer periphery of the pipe 82, and between the inner periphery of the pipe 82 and the outer periphery of the pipe 83, respectively. It is held at the axial center position 81 to prevent the pipe from being bent or shaken. With this configuration, it is possible to pass more fluid than in the first embodiment or to reciprocate one of the fluids, and similarly, the pipes 82 and 83 are not shaken and are positioned at the axial center of the rotary shaft 80. Retained.
[0019]
【The invention's effect】
As described above, according to the present invention, in a rotary shaft structure having a flow path for allowing a plurality of different fluids to pass through the rotary shaft, a fluid supply hole is provided in the axis of the rotary shaft, and the fluid supply hole is formed inside the fluid supply hole. A pipe is arranged to form a flow path on the inside and outside of the pipe, and the pipe is formed between the pipe outer periphery and the inner wall of the fluid supply hole that is located outside the pipe and forms a flow path between the pipe outer periphery and the pipe. was held in the axial position of the rotating shaft, since the inserts rough lead of the coil spring which does not interfere with the passage of the fluid in the flow path, is easy to process is not necessary to provide a plurality of fluid supply holes, also, by the coil spring Since the middle part of the pipe is held, it will not bend even if the pipe is long or thin. Further, since the pipe does not bend in such a manner, the dynamic balance can be prevented from being lost due to the deflection of the pipe, and the rotation shaft can be prevented from shaking. Further, the coil spring can be inserted into the fluid supply hole so as to be wound around the outer periphery of the pipe, so that assembly is easy and inexpensive.
Further, in a rotating shaft structure having a flow path for allowing a plurality of different fluids to pass through the rotating shaft, a fluid supply hole is provided in the shaft center of the rotating shaft, and a pipe is arranged inside the fluid supply hole. Another pipe is arranged to form a first flow path by the inner wall of the fluid supply hole and the outer periphery of the outer pipe, and the second flow path is formed by the inner periphery of the outer pipe and the outer periphery of the inner pipe. The inner circumference of the inner pipe is formed as a third flow path, and each pipe is arranged between the inner wall and the outer circumference of the outer pipe, and between the outer circumference of the outer pipe and the outer circumference of the inner pipe. Since the coil spring having a rough lead that is held at the center position and does not hinder the passage of the fluid in the flow path is inserted, more fluid can be passed by holding the two pipes at the axial center position.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a spindle device.
FIG. 2 is an enlarged view of the distal end side of the 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 in a holding part.
FIG. 5 is a view of a pin fitted to a rod.
FIG. 6 is a cross-sectional view of a pull rod of the spindle device.
FIG. 7 is another embodiment.
FIG. 8 shows a conventional rotating shaft structure.
[Explanation of symbols]
12 Pull rod (rotating shaft)
27, 81 Fluid supply holes 27a, 81a Inner walls 28, 82 , 83 Pipe 28b Pipe outer periphery 61, 61A, 61B Coil spring (pipe holding member)
L axis

Claims (2)

In a rotating shaft structure having a flow path for allowing a plurality of different fluids to pass through the rotating shaft , a fluid supply hole is provided in the axial center of the rotating shaft , and a pipe is arranged inside the fluid supply hole. passage is formed outward, held between the pipe outer circumference and an inner wall of the fluid supply hole to a flow path between the pipe outer periphery is located on the outer side, the axial center position of the rotation axis of the pipe A rotating shaft structure characterized by inserting a coil spring having a rough lead that does not obstruct the passage of fluid in the flow path. In a rotating shaft structure having a flow path for allowing a plurality of different fluids to pass through the rotating shaft, a fluid supply hole is provided in the axis of the rotating shaft, a pipe is arranged inside the fluid supply hole, and a separate pipe is provided inside the pipe. The first flow path is formed by the inner wall of the fluid supply hole and the outer periphery of the outer pipe, and the second flow path is formed by the inner periphery of the outer pipe and the outer periphery of the inner pipe. The inner circumference of the inner pipe is the third flow path, and each pipe is positioned between the inner wall and the outer circumference of the outer pipe and between the outer circumference of the outer pipe and the outer circumference of the inner pipe. A rotating shaft structure characterized in that a coil spring having a rough lead that is held in the flow path and does not prevent passage of fluid in the flow path is inserted .

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