JP4632072B2 - Index table - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an index table having a table on a base so that turning indexing is possible.
[0002]
[Prior art]
As a conventional index table, for example, in (1) the one disclosed in Japanese Patent No. 2930889, a rotary table is rotatably supported on a table body via a thrust bearing and a roller bearing, and is opposed to the upper surface of the table body. The rotary table is rolled and supported on the table body by a thrust bearing provided between the rotary table and the lower surface of the rotary table. In addition, as disclosed in (2) No. 6-39864, etc., there are those in which the lower surface of the table is slidably supported on the upper surface of the opposing frame. Further, (3) In the one disclosed in Japanese Patent Laid-Open No. 5-23936, a concavity is formed concentrically on one of the opposing joint surfaces of the bed and the rotary table, and hydrostatic oil is supplied to the concavity, The rotary table is supported rotatably.
[0003]
[Problems to be solved by the invention]
In the conventional {circle around (1)}, the lower surface of the rotary table is rolled and supported by a thrust bearing provided on the upper surface portion of the table main body facing the lower surface, so that there is a problem that the structure becomes complicated and cannot be manufactured at low cost. Further, in the case where the lower surface of the table slides on the upper surface of the opposite frame as in (2), if the lubricating oil is supplied from the outside to the sliding contact surface between the lower surface of the table and the upper surface of the frame, the lubricating oil is supplied. For this reason, there is a problem that a dedicated pump or the like is required and the equipment becomes complicated and expensive. In addition, when lubricating oil is supplied to the contact surface from the outside, the lubricating oil and the lubricating oil inside the index table are mixed, so both lubricating oils must use a common lubricating oil. When the lubricating oil is supplied from, the lubricating oil in the index table increases. Further, in (3), there is no description about the method of supplying the hydrostatic oil, and it is considered that the lubricating oil is supplied from the outside. Therefore, there is a problem that the equipment for supplying the lubricating oil becomes complicated and expensive. .
[0004]
Although not an index table, Japanese Patent Application Laid-Open No. 11-277350 discloses a slip guide device. This slide guide device is made of a fluororesin such as affixing turkite (trade name) on the sliding surface of the table. In addition to the coating process, the sliding surface of the table is formed with a surface pressure reducing pocket. Lubricating oil is supplied to the surface pressure reducing pocket so that the sliding surface of the table is in contact with the guide surface of the bed. Guidance is supported. Since the lubricating oil supplied to the slide guide device is supplied by a pressure oil supply source such as a pump outside the slide guide device, the pressure oil supply source becomes complicated as described above, and space is also increased accordingly. There was a problem taking.
An object of the present invention is to lubricate the lubricating oil inside the index table between the contact surfaces of the table and the base, thereby preventing the supply of the lubricating oil from the outside and preventing mixing with the lubricating oil supplied from the outside. This is to prevent the lubricating oil inside the table from increasing. Another object of the present invention is to provide an inexpensive index table that eliminates the need for a lubricant supply source outside the index table, saves space, simplifies the configuration.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the present invention, in the index table that rotatably supports the table on the base, a clamp device for fluid pressure operation for clamping the table to the base is provided, and the clamp device is provided integrally with the table. The clamp member is configured with a clamp member attached along the inner peripheral surface of the base that clamps the rotation shaft. The clamp member includes a flexible clamp portion having a substantially U-shaped cross section formed in a thin portion, and has a base inner periphery. An annular fluid pressure chamber is formed with the surface, and the clamp part is deflected toward the rotating shaft by the pressure increase in the fluid pressure chamber due to the pressurized fluid supplied to the fluid pressure chamber, and the rotating shaft is pressed by the clamp part. While clamping the table in the clamping state, it is equipped with a clamp operation confirmation cylinder in which the piston moves in and out by supplying and discharging pressurized fluid to and from the clamp device. The cylinder as a lubricating pump, so as to circulate the lubricating oil by the operation of the clamping operation confirmation cylinder, between the contact surfaces of the base and the table, the internal base by circulating lubricating oil for lubricating it has to be lubricated It is characterized (claim 1). According to this, since the lubricating oil inside the index table is circulated to the contact surface, the lubricating oil inside the index table is not mixed with the lubricating oil from the outside, and the lubricating oil in the index table increases. There is no overflow. Further, since the clamp operation confirmation cylinder also serves as a lubrication pump, a separate facility for supplying lubricating oil such as a pump is not required, and the configuration can be simplified and inexpensive, and the space can be saved.
[0007]
In addition, a coating layer having high slidability is formed on at least one of the contact surfaces of the base and the table (claim 2 ). The coating layer is made of a fluororesin (Claim 3 ). According to these, the lubricity is maintained, the sliding resistance of the contact surface is reduced, and a smooth operation can be performed.
[0008]
Specifically, the cylinder for confirming the clamping operation is provided with a first cylinder chamber into which the working fluid of the clamping device flows by a piston in the cylinder tube, and a retracting spring for urging the piston rod in the pulling direction into the cylinder tube. The second cylinder chamber is a lubricating oil chamber that sucks and discharges the lubricating oil, and flows into the first cylinder chamber when the clamping device performs a clamping operation. The piston moves to the second cylinder chamber side, and the volume of the lubricating oil chamber is reduced by the movement, so that the lubricating oil is discharged toward the contact surface, and when the clamping device performs an unclamping operation, the piston is moved by the retracting spring. It moves to the 1st cylinder chamber side, and it attracts | sucks lubricating oil by the expansion of the volume of the lubricating oil chamber by the movement (Claim 4 ). . The clamp operation check cylinder is a single-acting cylinder. The second cylinder chamber, which is provided with a pull-in spring that returns the piston rod, is used as a supply / discharge chamber for supplying and discharging lubricating oil, which simplifies the structure and saves space. It is suitable without any problem.
[0009]
Further, between the rotary shaft and the clamp member, characterized in that the groove for returning the lubricating oil supplied to between the contact surfaces in the lubricating oil storage space in the base is formed (claim 5). According to this, the lubricating oil supplied between the contact surfaces can return to the lubricating oil storage space through the groove, which is preferable.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. The index table 1 includes a base 2 and a table 3. The base 2 has a central through hole 4 formed therein. Further, the base 2 is formed with a worm wheel insertion space 6 in which a worm wheel 5 described later is located. A worm disposition space 7 that is continuous with the worm wheel insertion space 6 is formed in the base 2, and a worm 9 that is driven by a motor 8 is rotatably disposed in the worm disposition space 7. The worm wheel insertion space 6 stores lubricating oil 69 that lubricates the index table 1 and is a lubricating oil storage space. A space between the central through hole 4 and the worm wheel insertion space 6 is defined by a substantially cylindrical cylindrical inner wall 10 standing from the bottom of the base 2. The cylindrical inner wall 10 has a hole that connects the central through hole 4 and the worm wheel insertion space 6. In addition, a plurality of empty, hydraulic fluid supply / discharge ports 11, an empty communicating with these, and a hydraulic passage 12 are provided on the side surface of the base 2. The lower opening of the central through hole 4 is closed by a closing member 13, and the closing member 13 is provided with a plurality of flow paths 14 whose one ends communicate with each of the empty and hydraulic passages 12. .
[0011]
The base 2 is provided with a lubricating oil supply passage 15, which opens to the outer surface of the base 2, and is formed between the lubricating oil discharge hole 16 and the cylindrical outer wall 18 on the upper surface of the cylindrical inner wall 10. It communicates with the lubricating oil discharge hole 17 on the upper surface. The upper surface of the cylindrical outer wall 18 and the lower surface of the table 3 are contact surfaces 19 and 20 that are slidably in contact with each other, and a lubricating oil groove 21 is formed on the contact surface 19 of the cylindrical outer wall 18 by cutting. The lubricating oil discharge hole 17 is open. On the upper surface of the cylindrical outer wall 18, a seal member 22 is provided on the outer peripheral side of the lubricating oil groove 21 to prevent intrusion of oil from the outside and leakage of the internal lubricating oil 69. A bearing lubricating oil supply groove 23 is formed on the upper surface of the cylindrical inner wall 10, the lubricating oil discharge hole 16 is open, and a part of the bearing lubricating oil supply groove 23 is formed in the central through hole 4. A lubricating oil 69 is dropped toward the lower bearings 24 and 25, which will be described later. In addition, a lubricating oil suction passage 26 communicating with the lubricating oil storage space 6 is provided in the base 2 on the side of the lubricating oil supply passage 15 and opens on the outer surface of the base 2.
[0012]
A clamp member 29 constituting a clamp device 28 is attached to the inner peripheral surface 27 of the upper end portion of the cylindrical outer wall 18 of the base 2 along the inner peripheral surface 27. The clamp member 29 is formed in a thin portion and has a substantially U-shaped cross section including a clamp portion 30 that can be bent. An annular hydraulic chamber 31 is formed between the clamp member 29 and the inner peripheral surface 27 of the cylindrical outer wall 18. It is composed. A pressure oil supply / discharge port 32 provided in the base 2 communicates with the hydraulic chamber 31. Further, a pressure oil supply / discharge passage 33 is provided on the side opposite to the pressure oil supply / discharge port 32 of the base 2 and on the lubricating oil supply passage 15 side, and one end of the pressure oil supply / discharge passage 33 is connected to the hydraulic chamber 31. The other end is open to the outer peripheral surface of the base 2. The pressure oil supply / discharge port 32 is connected to a pressure oil supply source (not shown) that supplies pressure oil as a working fluid.
[0013]
The base 2 is provided with a clamp operation confirmation cylinder 34. As shown in FIGS. 3 and 4, a cylinder main body 35 is attached to the outer peripheral surface of the base 2 on the lubricating oil supply passage 15 side. The cylinder body 35 includes a pressure oil supply / discharge passage 36 that communicates with the pressure oil supply / discharge passage 33, a lubricant discharge passage 37 that communicates with the lubricant supply passage 15, and a lubricant intake passage that communicates with the lubricant intake passage 26. 38 is provided. In the middle of the lubricating oil discharge passage 37 and the lubricating oil suction passage 38, check valves 39a and 39b having a well-known structure are provided. The check valve 39a is connected to the second cylinder chamber 40 from the lubricating oil discharge passage 37 of the lubricating oil 69. The check valve 39b prevents the reverse flow of the lubricating oil 69 from the second cylinder chamber 40 to the lubricating oil suction passage 38. A cylinder cap 41 is attached to the cylinder body 35, and a cylinder tube 42 that is integral with the cylinder cap 41 is fitted in the fitting hole 43 of the cylinder body 35. A piston 44 is slidably provided in the cylinder tube 42. The cylinder tube 42 is divided into a first cylinder chamber 45 and a second cylinder chamber 40, and a piston rod integrated with the piston 44 is provided. 46 protrudes from the cylinder cap 41 to the outside. A pressure oil supply / discharge passage 36 communicates with the first cylinder chamber 45, and a retraction spring 47 is provided in the second cylinder chamber 40. The retraction spring 47 is interposed between the piston 44 and the cylinder cap 41. The piston rod 46 is always urged in the pulling direction in which the piston rod 46 is pulled into the cylinder tube 42.
[0014]
The second cylinder chamber 40 communicates with the lubricating oil storage space 6 via the lubricating oil suction passages 26, 38, and communicates with the lubricating oil discharge holes 16, 17 via the lubricating oil supply passage 15 and the lubricating oil discharge passage 37. is doing. The clamp operation confirmation cylinder 34 includes a clamp and unclamp detection dogs 48 and 49 provided on the piston rod 46, and a clamp and unclamp detection means (proximity switch) 50 provided on the cylinder body 35. Clamping and unclamping operations of the outer rotating shaft 51 of the table 3 to be described later by the clamping device 28 are detected.
[0015]
Upper and lower bearings 24 and 25 are mounted on the inner peripheral portion of the cylindrical inner wall 10. The upper and lower bearings 24 and 25 have a cylindrical rotary shaft 52 inserted into the central through hole 4 from above. It is supported so as to be rotatable around a vertical axis. A table 3 on which a workpiece and a jig are placed is assembled to the flange portion 53 of the rotating shaft 52. A circular hole 54 is formed in the center of the table 3. A cylindrical outer rotary shaft 51 is integrally provided on the table 3 downward from the lower surface. The outer rotary shaft 51 has a slight gap between the clamp member 29 and the cylindrical inner wall 10. Inserted. A worm wheel 5 that meshes with the worm 9 is integrally screwed to the lower end portion of the outer rotating shaft 51, and the rotating shaft 52 and the table 3 are integrally rotated by the motor 8. The worm wheel 5 is located in the lubricating oil storage space 6 and is immersed in the lubricating oil 69. In addition, a spiral groove 56 is formed on the outer peripheral surface 55 that is clamped by the clamp member 29 of the outer rotating shaft 51, leading from the lower surface side of the table 3 to the lubricating oil storage space 6.
[0016]
The contact surface 20 of the table 3 is provided with a highly slidable coating layer made of a fluororesin. This coating layer is formed by attaching turkite 57 (trade name) made of a fluororesin material. The formation of the coating layer is not limited to the attachment of the turkeyite 57. By this turkite 57, when the table 3 rotates, the lubricity between the contact surfaces 19 and 20 is maintained, the sliding resistance is reduced, and the smooth operation is maintained. Further, by providing the turkite 57, the structure becomes simpler than that in which the conventional bearing is provided between the contact surface of the table and the base, and the manufacture can be performed at a low cost.
[0017]
A cylindrical distributor 58 is inserted into the central through hole 4 with a gap inside the rotating shaft 52, and a through bolt 59 is passed through the distributor 58 from above, and the through bolt 59 allows the distributor 58. The lower end is fastened to the closing member 13. A center shaft 60 is inserted into the distributor 58 so as to be relatively rotatable. A flange portion 61 is integrally formed at the upper end of the center shaft 60, and the circular hole 54 of the table 3 is closed by the flange portion 61. The flange portion 61 is screwed to the upper end of the rotating shaft 52, and the center shaft 60 rotates integrally with the rotating shaft 52 and the table 3.
[0018]
The distributor 58 is formed with a plurality of vertical holes 62 and an inner peripheral groove 63, and the lower ends of the vertical holes 62 are connected to the respective flow paths 14 of the closing member 13. Adjacent inner circumferential grooves 63 are sealed with O-rings 64. A plurality of vertical holes 65 communicating with the respective inner peripheral grooves 63 are formed in the center shaft 60, and the upper ends of the vertical holes 65 are opened toward the upper side of the table 3. The vertical hole 62, the inner peripheral groove 63 of the distributor 58 and the vertical hole 65 of the center shaft 60 constitute a rotary joint so that air and oil can be supplied from the base 2 side to the table 3 side. Reference numeral 66 denotes a lubricating oil supply passage for supplying the lubricating oil 69 to the lubricating oil storage space 6, 67 denotes an oil gauge, and 68 denotes a lid for closing the side of the base.
[0019]
In the index table 1 configured as described above, when the table 3 is changed from the clamped state to the unclamped state and the rotation indexing of the table 3 is performed, the pressure oil is supplied into the hydraulic chamber 31 of the clamp device 28. The pressure in the hydraulic chamber 31 is stopped and the clamping portion 30 is restored by its own elasticity, so that the pressing state of the outer rotary shaft 51 by the clamp member 29 is released, and the table 3 is in the unclamped state. It has become. When the pressure in the hydraulic chamber 31 decreases, the piston 44 of the clamp operation confirmation cylinder 34 is positioned on the left side as shown in FIG. 3 due to the elasticity of the retracting spring 47, and the pressure oil in the first cylinder chamber 45 is discharged. Then, the volume of the second cylinder chamber 40 is enlarged, and the lubricating oil 69 is sucked into the second cylinder chamber 40 from the lubricating oil storage space 6 through the lubricating oil suction passages 26 and 38. At this time, the piston rod 46 is pulled into the cylinder 34, the detection means 50 detects the unclamp detection dog 49, and the unclamped state of the index table 1 is detected.
[0020]
When the unclamped state is detected, the worm 9 is rotated by the motor 8, and the table 3 is rotationally indexed by the worm wheel 5 meshing with the worm 9. At this time, the lubricity is maintained between the contact surface 19 of the base 2 and the contact surface 20 of the table 3 by the turkite 57 and the lubricating oil 69 supplied to the lubricating oil groove 21 as described later. At the same time, the sliding resistance is lowered, and a smooth indexing operation is performed.
[0021]
When the turning index of the table 3 is completed, when the pressure oil is supplied from the pressure oil supply source into the hydraulic chamber 31 via the pressure oil supply / discharge port 32 and the pressure in the hydraulic chamber 31 increases, the clamp portion 30 is moved to the outside. The outer rotary shaft 51 is brought into a pressure-contacted and clamped state by the clamp member 29, and the table 3 is clamped. Further, the pressure oil from the pressure oil supply source is supplied to the first cylinder chamber 45 of the clamp operation confirmation cylinder 34 via the pressure oil supply / discharge port 32, the pressure oil supply / discharge passage 33, and the hydraulic chamber 31, and the retraction spring 47. The piston 44 is moved to the right in FIG. 3 against the urging force of the second cylinder chamber 40 to reduce the volume of the second cylinder chamber 40, and the lubricating oil 69 in the second cylinder chamber 40 is supplied to the lubricating oil supply passage 15 and the lubricating oil discharge passage. 37 is discharged from the lubricating oil discharge holes 16 and 17 to the bearing lubricating oil supply groove 23 and the lubricating oil groove 21, respectively. The lubricating oil 69 supplied to the bearing lubricating oil supply groove 23 flows out from the notch 23a of the bearing lubricating oil supply groove 23, drops (freely drops) toward the lower bearings 24 and 25, and Lubricate the lower bearings 24 and 25. Further, the lubricating oil 69 supplied to the lubricating oil groove 21 flows out between the contact surfaces 19, 20, lubricates between the contact surfaces 19, 20, and flows out toward the inside of the base 2, so that the outer rotating shaft of the table 3 It is returned to the lubricating oil storage space 6 through a spiral groove 56 provided in 51. At this time, the piston rod 46 protrudes, the detection means 50 detects the clamp detection dog 48, and the clamp state of the index table 1 is detected.
[0022]
By repeating the clamping and unclamping of the table 3 as described above, the clamping operation confirmation cylinder 34 functions as a lubricating pump for supplying the lubricating oil 69 to the lubricating oil groove 21. Therefore, a lubricating oil supply pump or the like is separately provided. There is no need, and space is saved and the configuration is simple and inexpensive. Further, since the lubricating oil 69 supplied from the lubricating oil storage space 6 to the contact surfaces 19 and 20 returns to the lubricating oil storage space 6 again, the lubricating oil 69 circulates in the index table 1 and supplies the lubricating oil from the outside. Therefore, the lubricating oil supplied from the outside of the index table 1 is not mixed with the lubricating oil 69 inside, and the lubricating oil 69 in the index table 1 can be prevented from increasing and overflowing.
[0023]
【The invention's effect】
As described above, in the present invention, since lubricating oil for lubricating the inside of the base is circulated between the base and the contact surface of the table, lubrication from the outside is prevented from mixing with the lubricating oil inside the base. In addition, the lubricating oil in the base does not increase and overflow. In addition, the structure is simpler and less expensive than the conventional rolling support of the lower surface of the table. In addition, since the clamping operation confirmation cylinder of the clamping device that clamps the table provided on the base by the fluid pressure operation circulates the lubricating oil as a lubricating pump, the configuration is simple and the space can be saved. In addition, since a coating layer having high slidability is provided on at least one of the contact surfaces, the lubricity between the contact surfaces is maintained, sliding resistance is reduced, and smooth operation can be performed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an index table.
FIG. 2 is a plan view showing a cross section of a part of the index table with the table removed.
FIG. 3 is a cross-sectional view of a main part of the present invention.
FIG. 4 is a view on IV in FIG. 3;
FIG. 5 is an explanatory view showing each channel of the base.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Index table 2 Base 3 Table 6 Lubricating oil storage space 19, 20 Contact surface 28 Clamp apparatus 29 Clamp member
30 Clamp part
31 Fluid pressure chamber (hydraulic chamber)
34 Cylinder operation check cylinder (lubrication pump)
40 Second cylinder chamber (lubricating oil chamber)
42 Cylinder tube 44 Piston 45 First cylinder chamber 46 Piston rod 47 Retraction spring 51 Outer rotating shaft 56 Spiral groove 57 Coating layer (turkite)
69 Lubricating oil

Claims (5)

In the index table that rotatably supports the table on the base,
A clamp device for fluid pressure operation for clamping the table to the base, and the clamp device is constituted by a clamp member attached along the inner peripheral surface of the base for clamping the rotating shaft provided integrally with the table; The clamp member includes a flexible clamp portion having a substantially U-shaped cross section formed in a thin portion, and forms an annular fluid pressure chamber with the inner peripheral surface of the base, and is supplied to the fluid pressure chamber. While increasing the pressure in the fluid pressure chamber due to the pressurized fluid, the clamp part is bent toward the rotation axis, and the clamp part clamps the table with the rotation axis in the press-contact state,
A clamp operation check cylinder in which a piston protrudes and retracts by supply and discharge of pressurized fluid to and from the clamp device is used, and the clamp operation check cylinder is used as a lubrication pump so that lubricating oil is circulated by the operation of the clamp operation check cylinder.
An index table characterized in that a lubricating oil for lubricating the inside of the base is circulated between the base and the contact surface of the table for lubrication. Base and table according to claim 1 Symbol placement of the index table, characterized in that by forming a high coating layer slidability on at least one of the contact surface. 3. The index table according to claim 2, wherein the coating layer is made of a fluororesin. The clamp operation confirmation cylinder is a second cylinder in which a cylinder tube is provided with a piston, and a first cylinder chamber into which a working fluid of the clamp device flows, and a retraction spring that biases the piston rod into the cylinder tube in the retraction direction. The second cylinder chamber is a lubricating oil chamber that sucks and discharges lubricating oil, and the piston is moved to the second cylinder by the inflow of the working fluid into the first cylinder chamber when the clamping device performs the clamping operation. It moves to the chamber side, and the lubricant is discharged toward the contact surface by reducing the volume of the lubricating oil chamber by the movement, and when the clamping device performs the unclamping operation, the piston is moved to the first cylinder chamber side by the retracting spring. Go to the lubricating oil chamber of one any of claims 1 3, characterized by sucking the lubricant oil by the enlargement of the volume Kouki by the movement Index table. The groove | channel for returning the lubricating oil supplied between the contact surfaces to the lubricating oil storage space in a base is formed between the said clamp member and a rotating shaft, The any one of Claim 1 to 4 characterized by the above-mentioned. Index table described in the section.

Images