JP6446638B2 - Machine tool table equipment - Google Patents

Description

  The present invention relates to a table device for a machine tool in which a rotary table on which a workpiece is mounted is rotationally driven and a predetermined cutting process is performed on the workpiece.

  In recent years, multi-task machines have been introduced that perform turning by rotating a rotary table, which has been conventionally only indexed, based on a machining center.

This type of rotary table is rotatably supported by a fixed housing via a bearing. In general, the outer ring of the bearing is fixed to the fixed housing, and the inner ring is fixed to the rotary shaft of the rotary table ( For example, see Patent Document 1).

  By the way, since the inner ring has a smaller heat capacity than the outer ring, the temperature easily rises. For this reason, when the inner ring is thermally expanded, the gap between the inner ring and the outer ring is reduced, and in some cases, the machining accuracy may be adversely affected.

  In order to prevent such deterioration of the processing accuracy, for example, in Patent Document 2, the lubricating oil introduction member is disposed on the inner ring fixed to the main shaft and fixed to the outer ring side, and is formed on the lubricating oil introduction member. A structure is disclosed in which cooling lubricant is supplied to a circumferential groove formed in the inner ring from an oil supply path and a nozzle to cool the inner ring.

JP 2004-314203 A JP 2008-240947 A

  By the way, when the cooling liquid is supplied to the rotating inner ring through the lubricating oil introducing member fixed to the outer ring side as in the conventional device, the inner ring can be cooled, but the cooling structure is There is a problem that the cost increases as the number of parts increases and the number of parts increases.

  The present invention has been made in view of the above-mentioned conventional situation, and it is a machine tool that can prevent deterioration of machining accuracy due to thermal expansion of the inner ring with a simple structure without causing problems of increase in the number of parts and cost. It is an object to provide a table device.

According to a first aspect of the present invention, there is provided a rotary table on which a work is mounted, a fixed housing that rotatably supports the rotary table, a bearing interposed between the fixed housing and the rotary table, and the rotary table. In a table device of a machine tool, comprising: a drive mechanism that rotationally drives the drive mechanism; and a cooling mechanism that cools the drive mechanism and the bearing.
The outer ring of the bearing is fixed to the rotary table, and the inner ring is fixed to the fixed housing,
The cooling mechanism is configured to supply a coolant to the inner ring through a cooling jacket formed in the fixed housing.

The invention of claim 2 is the table device of the machine tool according to claim 1,
The drive mechanism includes a rotor fixed to the rotary table, and a stator fixed to the fixed housing,
The cooling mechanism is configured to supply a cooling liquid to the rotor via a cooling jacket provided in an inner peripheral portion of the rotor of the rotary table.

The invention of claim 3 is the table device of the machine tool according to claim 1 or 2,
The cooling mechanism is configured to supply a coolant made of low-viscosity wear-resistant oil stored in one cooling tank to the inner ring and the rotor.

The invention of claim 4 is the machine tool table device according to any one of claims 1 to 3,
The drive mechanism is disposed on the opposite side of the rotary table across the bearing, and a brake mechanism that applies a braking force to the rotary table is disposed between the drive mechanism and the bearing. It is a feature.

  According to the table device of the first aspect, the outer ring of the bearing is fixed to the rotary table, the inner ring is fixed to the fixed housing, and the coolant is supplied to the inner ring via the cooling jacket formed on the fixed housing. As a result, the thermal expansion of the inner ring is suppressed, whereby the gap with the outer ring can be maintained at a predetermined value, and deterioration of the machining accuracy can be prevented.

  In the present invention, since the cooling jacket for cooling the inner ring is formed in the fixed housing to which the inner ring is fixed, it can be realized with a simple structure by simply forming the cooling jacket. The structure can be simplified as compared with the case where the coolant is supplied via the lubricating oil introduction member fixed to, and the number of parts can be reduced and the cost can be reduced.

In the invention of claim 2, since the coolant is supplied to the rotor via the cooling jacket provided on the inner peripheral portion of the rotor of the rotary table, it is possible to suppress the heat generated by the rotor from being transmitted to the rotary table. it can. As a result, thermal displacement of the rotary table can be prevented, and as a result, the torque of the drive mechanism can be increased and the duty time can be improved. That is, conventionally, since it is common to cool only the stator side, the heat generated by the rotor is easily transmitted to the rotary table.

  In the invention of claim 3, since the cooling liquid made of low-viscosity wear-resistant oil stored in one cooling tank is supplied to the inner ring and the rotor, the stirring loss of the cooling liquid can be minimized. In addition, a large amount of coolant can be supplied to the inner ring and the rotor, and the heat generation of the inner ring and the rotor can be more reliably suppressed, and thereby the speed of the rotary table can be increased.

  In addition, since the coolant stored in one cooling tank is directly supplied to the inner ring and the rotor, the cooling efficiency can be increased and the cooling mechanism can be reduced in size and cost.

  In the invention of claim 4, since the drive mechanism is disposed on the opposite side of the rotary table with the bearing interposed therebetween, and the brake mechanism is disposed between the drive mechanism and the bearing, the brake mechanism is located near the rotary table. Therefore, the braking force of the rotary table can be increased without increasing the size and cost.

It is a side view of the horizontal type machining center provided with the table apparatus by Example 1 of this invention. It is sectional drawing of the said table apparatus. It is principal part sectional drawing of the said table apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 3 are diagrams for explaining a table device of a machine tool according to a first embodiment of the present invention. In the present embodiment, front, rear, left, and right mean front, rear, left, and right as viewed from the front of the machine.

  In the figure, reference numeral 1 denotes a horizontal machining center provided with the table device 2 of the present embodiment. This horizontal machining center 1 has a column 4 mounted on a bed 3 so as to be movable in the front-rear direction A when viewed from the front of the machine (in the direction of arrow a in FIG. 1), and the spindle head 5 is moved in the vertical direction B on the column 4. The main shaft 6 having the tool T mounted on the main shaft head 5 is disposed.

The table device 2 is disposed at the front end of the bed 3, and includes a rotary table 10 on which a chuck 9 that grips a workpiece W is mounted, and a fixed housing 11 that rotatably supports the rotary table 10. And a support base 12 that supports the fixed housing 11.

  The support base 12 is fixed to the bed 3 so that the rotary table 10 can be rotated between a vertical position where the rotation center C of the rotary table 10 forms a vertical direction and a horizontal position C ′ which forms a horizontal direction. I support it. This provides a lathe function.

  The rotary table 10 includes a table main body 14 having the chuck 9 fixed on the upper surface thereof, a generally cylindrical rotary member 15 disposed on the lower surface of the table main body 14, and a bolted outer peripheral surface of the rotary member 15. The rotating side sleeve 16 is fixed.

The rotating member 15 is disposed so as to be coaxial with the rotation center C of the table main body 14, and is fixed to the table main body 14 with bolts.

  The fixed housing 11 includes a substantially cylindrical housing main body 17 formed so as to surround the outer peripheral portion of the rotating member 15, a fixed side sleeve 18 bolted and fixed to an inner peripheral surface of the housing main body 17, A block member 19 having a generally ring shape fixed to the upper end surface of the housing main body 17 with bolts.

  The table device 2 includes a cross roller bearing 20 interposed between the fixed housing 11 and the rotary table 10, a built-in servo motor 21 that rotationally drives the rotary table 10, the built-in servo motor 21, and the And a cooling unit 22 for cooling the cross roller bearing 20.

  The built-in servo motor 21 is opposed to the rotor 21a on the inner peripheral surface of the fixed side sleeve 18 of the fixed housing 11 and the rotor 21a fixed by bolting to the outer peripheral surface of the rotary side sleeve 16 of the rotary table 10. And a stator 21b that is bolted to the stationary sleeve 18 and fixed thereto.

An outer recess 14 a and an inner recess 14 b that are concentric with the rotation center C are formed on the lower surface of the table body 14. A support member 25 fixed to the upper and outer end surfaces of the block member 19 is inserted and disposed in the outer concave portion 14a. In addition, a protruding portion 19a that is integrally formed on the upper inner end surface of the block member 19 is inserted and disposed at the inner peripheral end portion of the inner concave portion 14b.
The cross roller bearing 20 is disposed in the inner recess 14b. The cross roller bearing 20 has a structure in which a large number of rolling elements 20c are arranged in parallel between an outer ring 20a and an inner ring 20b.

  The outer ring 20a of the cross roller bearing 20 is fastened and fixed to the table body 14 of the rotary table 10 by a plurality of inner bolts 23, and the inner ring 20b is fixed to the block member 19 of the fixed housing 11 by a plurality of outer sides. The bolt 24 is fastened and fixed.

  The built-in servo motor 21 is disposed on the opposite side of the rotary table 10 with the cross roller bearing 20 interposed therebetween, and is disposed so as to face the cross roller bearing 20 in a substantially axial direction.

  Between the built-in servo motor 21 and the cross roller bearing 20, a plurality of brake mechanisms 27 that apply a braking force to the rotary table 10 are arranged at predetermined intervals in the circumferential direction.

  Each brake mechanism 27 is formed with a cylinder hole 19b penetrating a recess 19c formed between the support member 25 and the protrusion 19 of the block member 19 at a predetermined interval, and a piston is formed in each cylinder hole 19b. 28 has a schematic structure in which a hydraulic chamber 19d is formed between the piston 28 and the cylinder hole 19b. A lid member 29 is bolted and fixed to the upper end portion of the cylinder hole 19b, and a leaf spring 32 is fixed to the lower end portion.

  A pressing plate 30 is bolted and fixed to a portion of the rotating member 15 facing each piston 28, and a clamping member 31 is fixed to a portion of the fixed side sleeve 18 of the fixed housing 11 facing the pressing plate 30. Is fixed. The piston 28 is lowered by the hydraulic pressure, and the pressing plate 30 is clamped between the piston 28 and the clamping member 31, whereby a braking force is applied to the rotary table 10. When the hydraulic pressure is released, the piston 28 is retracted by the leaf spring 32.

  As shown in FIG. 3, the cooling unit 22 supplies a coolant to the inner ring 20 b via a cooling / lubricating path provided in the fixed housing 11, and uses a cooling path provided in the rotary table 10. The coolant is supplied to the rotor 21a.

  In addition, the cooling unit 22 is configured to supply the inner ring 20b and the rotor 21a with a cooling liquid made of low-viscosity and high wear-resistant oil stored in one cooling tank 35. This low-viscosity, high-abrasion resistant oil has both cooling and lubrication functions.

  The cooling / lubricating path of the inner ring 20b is formed so as to face the inner ring 20b in the cooling liquid supply passage 19e formed in the block member 19 of the fixed housing 11 and the protruding portion 19a of the block member 19, and the cooling liquid A cooling jacket 19f communicating with the supply passage 19e; a pair of communication holes 20d, 20d formed in the inner ring 20b and communicating with the respective rolling elements 20c of the inner ring 20b and the cooling jacket 19f; A recovery passage 19g is formed subsequent to the recess 19c of the member 19 and returns the coolant supplied to the inner ring 20b to the cooling tank 35.

  Further, an inclined portion 19h for guiding the coolant to the recovery passage 19g is formed between the cylinder holes 19b in the recess 19c of the block member 19.

  The cooling path of the rotor 21a is formed so as to be opposed to the stator 21b in the cooling liquid supply passage 17a formed in the housing body 17 of the fixed housing 11 and in the stationary sleeve 18, and to the cooling liquid supply passage 17a. A stator cooling jacket 18a that communicates, a rotor cooling jacket 16a that is formed on the rotating sleeve 16 so as to face the rotor 21a, and a rotary joint (not shown) that connects the rotor cooling jacket 16a and the stator cooling jacket 18a in communication. And a recovery passageway 17b formed in the housing body 17 for returning the coolant supplied to the rotor cooling jacket 16a and the stator cooling jacket 18a to the cooling tank 35.

  The cooling liquid returned to the cooling tank 35 is cooled in the cooling tank 35, filtered by a filter 35a, pressurized by a pump 35b, and supplied to the cooling liquid supply passages 17a and 19e.

  The coolant supplied to the coolant supply passage 19e on the inner ring side is supplied from the cooling jacket 19f to each rolling element 20c through each communication path 20d, and cools and lubricates each rolling element 20c and the inner ring 20b, while the outer ring. 20a is cooled and lubricated, and flows into the recess 19c through the gap between the outer ring 20a and the inner ring 20b. The coolant that has flowed into the recess 19c flows down the inclined portion 19h to the recovery passage 19g and is returned to the cooling tank 35 from here.

  On the other hand, the coolant supplied to the rotor-side coolant supply passage 17a passes through the stator cooling jacket 18a and then flows into the rotor cooling jacket 16a, and cools the rotor 21a and the stator 21b while passing through the recovery passage 17b. Returned to the cooling tank 35. In this way, the coolant is circulated between the cooling tank 35, the inner ring 20b, and the rotor 21.

According to the present embodiment, the outer ring 20a of the cross roller bearing 20 is fixed to the rotary table 10 side, the inner ring 20b is fixed to the fixed housing 11 side, the coolant supply passage 19e formed in the fixed housing 11, the cooling jacket. Since the coolant is supplied to the inner ring 20b via 19f, thermal expansion due to an increase in the internal pressure of the inner ring 20b can be suppressed. As a result, the gap between the outer ring 20a and the inner ring 20b can be maintained at a predetermined value without reducing it, and as a result, deterioration of the machining accuracy can be prevented. In this case, there is a concern that cooling the inner ring 20b may cause the outer ring 20a to thermally expand and the gap to widen, but there is almost no effect on machining accuracy. In this embodiment, the inner ring 20b is fixed to the fixed housing 11 side. Since the inner ring 20b is cooled via the cooling jacket 19f formed in the block member 19 of the fixed housing 11, it is easy to simply form the communication path 20d in the coolant supply passage 19e, the cooling jacket 19f and the inner ring 20b. Compared to the conventional case where the coolant is supplied to the rotating inner ring through the lubricating oil introduction member fixed to the outer ring side, the structure can be simplified, the number of parts can be reduced, and the cost can be reduced. .

In this embodiment, since the coolant is supplied to the rotor 21a via the rotor cooling jacket 16a provided on the rotation side sleeve 16 of the rotary table 10, the heat generated by the rotor 21a is transmitted to the rotary table 10. Can be suppressed. As a result, thermal displacement of the rotary table 10 can be prevented, and as a result, the torque of the built-in servo motor 21 can be increased and the duty time can be improved. That is, conventionally, since it is common to cool only the stator side, the heat generated by the rotor is easily transmitted to the rotary table.

  In this embodiment, the cooling liquid made of low viscosity and high wear resistance oil stored in one cooling tank 35 is supplied to the inner ring 20b and the rotor 21a, so that the oil stirring loss is minimized. In addition, a large amount of coolant can be supplied to the inner ring 20b and the rotor 21a, and the heat generation of the inner ring 20b and the rotor 21a can be more reliably suppressed. This makes it possible to shorten the work machining time by increasing the speed of the rotary table 10 or to process a large work by increasing the diameter.

  Further, since the coolant in the cooling tank 35 is directly supplied to the inner ring 20b and the rotor 21a, the cooling efficiency can be increased and the cooling unit 22 can be reduced in size and cost.

  In this embodiment, the built-in servo motor 21 is disposed on the opposite side of the rotary table 10 with the cross roller bearing 20 interposed therebetween, and a brake mechanism 27 is disposed between the built-in servo motor 21 and the cross roller bearing 20. Therefore, the brake mechanism 27 can be disposed in the vicinity of the turntable 10, and the braking force of the turntable 10 can be increased without increasing the size and cost.

  In addition, although the said Example demonstrated the case where it applied to the table apparatus 2 of the horizontal machining center 1, this invention is applicable also to the vertical machining center and the table apparatus of a multi-tasking machine.

1 Horizontal machining center (machine tool)
2 Table device 10 Rotary table 11 Fixed housing 20 Cross roller bearing (bearing)
20a Outer ring 20b Inner ring 21 Built-in servo motor (drive mechanism)
21a Rotor 21b Stator 22 Cooling unit (cooling mechanism)
27 Brake mechanism 35 Cooling tank W Workpiece

Claims (4)

A rotary table on which the workpiece is mounted;
A fixed housing that rotatably supports the rotary table;
A bearing interposed between the fixed housing and the rotary table;
A drive mechanism for rotating the rotary table;
In a table device of a machine tool provided with the drive mechanism and a cooling mechanism for cooling the bearing,
The outer ring of the bearing is fixed to the rotary table, and the inner ring is fixed to the fixed housing,
A table device for a machine tool, wherein the cooling mechanism is configured to supply a coolant to the inner ring via a cooling jacket formed in the fixed housing. The machine tool table device according to claim 1,
The drive mechanism includes a rotor fixed to the rotary table, and a stator fixed to the fixed housing,
A table device for a machine tool, wherein the cooling mechanism is configured to supply a coolant to the rotor via a cooling jacket provided on an inner peripheral portion of the rotor of the rotary table. The machine tool table device according to claim 1 or 2,
A table device for a machine tool, wherein the cooling mechanism is configured to supply a coolant made of low-viscosity wear-resistant oil stored in one cooling tank to the inner ring and the rotor. The machine tool table device according to any one of claims 1 to 3,
The drive mechanism is disposed on the opposite side of the rotary table across the bearing,
A table device for a machine tool, wherein a brake mechanism for applying a braking force to the rotary table is disposed between the drive mechanism and the bearing.

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