JP2013029186A - Brake structure of rotary table device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly stop inertial rotation of a rotary table even if power supply is stopped, in a rotary table device having a direct drive motor.SOLUTION: In the rotary table device 10 including a direct drive motor 14 and a brake mechanism 15 for permitting or restricting rotation of a rotary table 11, the brake mechanism 15 is characteristically allowed to select any one state among three states of a first brake state where a braking member 31 is advanced by operation of operation parts 36, 37 and is pressed to a braked member 30, a brake release state where the braking member 31 is retracted by operation of the operation parts 36, 37 and is separated from the braked member 30, and a second brake state where the braking member 31 is brought into contact with the braked member 30 by a biasing means 33 while the operation parts 36, 37 are non-operational.

Description

  The present invention relates to a rotary table device including a direct drive motor, and more particularly to a brake structure of a rotary table device that clamps a rotary table so as not to rotate.

  Generally, the rotary table device includes a drive source such as a motor that drives the rotary table, and a gear reduction mechanism that reduces the rotational speed of the drive source with a gear reduction mechanism and transmits the reduced speed to the rotary table. In addition to this, there is no gear reduction mechanism, a rotor is provided on the rotary table, a stator is provided on the housing of the rotary table device, and a rotary drive is provided that directly drives the rotary table by rotating the rotor by energizing the stator. Table devices are also known. The rotary table is clamped so as not to rotate by the attached brake mechanism.

  For example, in the rotary indexing table device disclosed in Japanese Unexamined Patent Publication No. 2009-148840 (Patent Document 1), an inner rotor type direct drive having a motor rotor fixed to the back surface of the rotary table and a motor stator fixed to a fixed frame. A motor rotates the rotary table. Further, clamping means as a brake mechanism is provided on the inner diameter side of the motor rotor. The clamp means is supplied with pressure fluid such as hydraulic oil and clamps the rotary table so as not to rotate.

JP 2009-148840 A

  However, in the rotary indexing table device provided with the direct drive motor as described above, the following problems occur. In other words, if the power supply is interrupted due to a power failure, lightning strike, or unexpected circumstances while chucking the work on the rotary table and energizing the rotary indexing table device to rotate the rotary table, the rotary table rotates by inertia. Will continue to do. Such inertial rotation of the rotary table is not preferable, and it is desirable to stop the rotation quickly. However, without power supply, the clamping means cannot be operated and there is no way to brake inertial rotation of the rotary table.

  In view of the above-described circumstances, the present invention can not only rotate the rotary table at a specified index angle during normal operation where power is supplied, but also rotate even if the power supply is interrupted. It is an object of the present invention to provide a brake mechanism for a rotary table device capable of quickly stopping inertial rotation of a table.

  For this purpose, the present invention has a rotary table, a rotor provided on the rotary table, and a stator arranged to face the rotor, and a direct drive for rotating the rotor by electromagnetic action between the rotor and the stator. A motor, a brake member coupled to the rotary table, a brake member slidingly contacting the brake member, an urging means for urging the brake member toward the brake member, and a brake member moving forward and backward with respect to the brake member A rotary table device including a brake mechanism that has an operation unit and allows or restricts rotation of the rotary table is assumed.

  The brake mechanism includes a first brake state in which the braking member is advanced by the operation of the operation unit and pressed against the member to be braked, and a brake release state in which the braking member is retracted by the operation of the operation unit and separated from the member to be braked. One of the three states including the second brake state in which the braking member is brought into contact with the member to be braked by the urging means while the operation unit is not operating can be selected.

  According to the present invention, the brake mechanism is set to the first brake state or the brake released state by the operation of the operation unit, and is also set to the second brake state while the operation unit is not operated. Therefore, the rotary table can be clamped so as not to rotate during normal operation where power is supplied, or can be freely rotated. Even in the case of an emergency in which the power supply is interrupted, the inertial rotation of the rotating rotary table can be quickly stopped.

  The form of the member to be braked and the braking member is not particularly limited. Further, the urging means may be an elastic member such as a spring, or may be another form such as urging using the weight of the braking member. As an embodiment, the rotary table has a table member and a central axis extending from the table member along the rotation axis, and the brake member of the brake mechanism is fixed to the central axis of the rotary table and rotates together with the table member. And the braking member of the brake mechanism faces the surface of the brake disc.

  According to this embodiment, a brake mechanism with excellent durability can be provided. The braking member may be pressed against one side of the brake disc, but may be pressed against both sides of the brake disc. For example, the brake member includes a first brake member and a second brake member, and the first and second brake members clamp the brake disc in the thickness direction. The operating part of the brake mechanism is not particularly limited as long as it moves at least one of the first braking member and the second braking member in the thickness direction of the brake disc.

  As one embodiment of the present invention, the braking member has a ring shape having a central hole, the central axis of the rotary table is passed through the central hole, and the operating portion of the brake mechanism is coupled to the inner peripheral surface of the ring-shaped braking member. Partition wall portion, an inner diameter side guide ring that is disposed between the partition wall portion and the brake disk and guides the inner peripheral surface of the braking member so as to be movable in the axial direction, and an axis line between the partition wall portion and the inner diameter side guide ring An unclamping chamber that is a directional gap, a clamping chamber that is on the opposite side of the inner diameter side guide ring from the partition wall, and a fluid supply means that selectively supplies fluid to the clamping chamber and the unclamping chamber.

  According to this embodiment, by supplying fluid to the clamp chamber, the partition wall portion approaches the brake disc and presses the braking member against the brake disc. Further, by supplying fluid to the unclamping chamber, the partition wall portion is separated from the brake disc, and the braking member releases the brake disc. The fluid supply means includes, for example, a fluid supply source such as a pump or a compressor for supplying hydraulic oil or air, a fluid discharge portion, and extends from the fluid supply source and the fluid discharge portion and is connected to the clamp chamber and the unclamp chamber. And a switching valve provided in the middle of the fluid passage to communicate either the clamp chamber or the unclamp chamber with the fluid supply source and the remaining fluid with the fluid discharge portion. Have.

  As a preferred embodiment, the partition wall portion is fixed to a housing side member of a rotary table device that rotatably supports the rotary table at its inner diameter portion, and its outer diameter portion is movable in the axial direction together with the braking member, Of the end face on one axial direction of the inner diameter side guide ring, the outer diameter side region defines an unclamping chamber, the inner diameter side region is fixed to the inner diameter portion of the partition wall portion, and the inner diameter side region includes the outer diameter side region. And a passage groove through which fluid passes is formed, and a ring-shaped seal member is interposed between the inner diameter side region of the inner diameter side guide ring end surface and the inner diameter portion of the partition wall portion. A portion near the passage groove is located closer to the inner diameter than the passage groove, and the remaining portion of the seal member is located relatively closer to the outer diameter.

  According to such an embodiment, since the ring-shaped seal member is interposed between the inner diameter side region of the inner diameter side guide ring and the inner diameter portion of the partition wall portion, the airtightness on the inner diameter side of the unclamp chamber is improved, Fluid does not leak from the unclamping chamber to the inner diameter side. In addition, since the portion near the passage groove in the seal member is located closer to the inner diameter than the passage groove, and the remaining portion of the seal member is located relatively closer to the outer diameter, the partition wall portion which is a movable portion is arranged. The radial dimension can be increased. Accordingly, it is possible to increase the stroke of the advancing / retreating of the braking member, and it is possible to efficiently advance / retreat the braking member and increase the clamping force.

  The surface of the brake disk may be a flat surface, or an uneven shape for increasing the frictional force with the braking member may be formed. Preferably, the brake disk has a base material and a hard surface treatment layer that covers the surface of the base material, and the surface of the brake disk covered with the hard surface treatment layer has an uneven shape for increasing the coefficient of friction with respect to the brake member. Is formed. According to this embodiment, since the uneven shape for increasing the coefficient of friction with respect to the braking member is formed on the surface of the brake disc, the clamping force can be increased. Further, since the base material of the brake disk is covered with the hard surface treatment layer, the wear resistance of the surface of the brake disk is improved. The uneven surface is formed of a hard surface treatment layer. Accordingly, the wear resistance of the concavo-convex shape is improved, and a high friction coefficient can be maintained over a long period of time even when the first brake state and the brake released state are repeated.

  As described above, the present invention can quickly stop the inertial rotation of the rotating rotary table even in an emergency where the power supply is interrupted. Therefore, it is possible to provide a rotary table device that is advantageous in terms of safety and reliability.

It is sectional drawing which shows the rotary table apparatus which becomes one Example of this invention. It is sectional drawing which expands and shows the brake mechanism of the Example. It is a top view of a brake disc. It is sectional drawing of the outer diameter part of a brake disc. It is a top view which takes out and shows the inner diameter side guide ring of the Example. It is explanatory drawing shown by contrasting the brake mechanism of the Example, and the brake mechanism of a comparative example.

  Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings. FIG. 1 is a sectional view showing a basic configuration of a rotary table device according to an embodiment of the present invention. The rotary table device 10 includes a rotary table 11, a housing 12, a bearing 13 provided between the rotary table 11 and the housing 12, a direct drive motor 14 provided across the rotary table 11 and the housing 12, and the rotary table 11. And a brake mechanism 15 provided across the housing 12.

  The rotary table 11 is for supporting a workpiece, and rotates about an axis O indicated by a one-dot chain line in FIG. The rotary table 11 has a disk-shaped table member 21 and a central shaft 22 extending along the axis O from the back surface of the table member 21. The table member 21 has a surface 21f orthogonal to the axis O, and chucks the workpiece indirectly or directly on the surface 21f side.

  The housing 12 forms an outline of the rotary table device 10 and supports the rotary table 11 via a bearing 13 so as to be rotatable. The bearing 13 is a cross roller bearing centering on the axis O, and supports axial and radial loads.

  The direct drive motor 14 includes a rotor 24 provided on the rotary table 11 and a stator 25 that is disposed so as to face the rotor 24 via a radial clearance. Specifically, the direct drive motor 14 is an inner rotor type motor, the rotor 24 is disposed on the inner diameter side, the stator 25 is disposed on the outer diameter side, and the rotor 24 is driven by electromagnetic action between the rotor 24 and the stator 25. Rotation drive. The rotor 24 has a ring shape and is fixedly attached to the outer periphery of the central shaft 22 by screws. The stator 25 is a coil that is mounted and fixed inside the housing 12, and is energized to exert a magnetic force on the rotor 24. As a result, the rotary table 11 rotates together with the rotor 24. The direct drive motor 14 is controlled by a control unit (not shown) to directly drive the rotary table 11 to a specified index angle.

  The brake mechanism 15 allows or restricts the rotation of the rotary table 11 and clamps the rotary table 11 so as not to rotate. As a specific configuration, the brake mechanism 15 includes a brake disk 30 as a member to be braked coupled to the rotary table 11, and a first clamp member 31 and a second clamp member 32 as brake members slidingly contacting the brake disk 30. The brake mechanism 15 includes an operation unit that moves the first clamp member 31 forward and backward toward the brake disk 30 as will be described in detail later.

  FIG. 2 is an enlarged sectional view showing the brake mechanism 15 of the rotary table device 10. FIG. 3 is a plan view of the brake disc 30. The brake disc 30 as a member to be braked has a disk shape having a central hole 30h, and the tip of the central shaft 22 is inserted into the central hole 30h. The brake disc 30 is fixed to the central shaft 22 with screws. As a result, the center of the brake disc 30 coincides with the axis O, and the brake disc 30 rotates together with the rotary table 11. The brake disc 30 has a thickness in the direction of the axis O.

  The first clamp member 31 and the second clamp member 32, which are brake members, form a pair and are disposed on one side and the other side in the axis O direction when viewed from the brake disk 30. The first clamp member 31 faces one surface of the brake disc 30. The second clamp member 32 is attached and fixed to the housing 12 via the housing side member 16 and faces the other surface of the brake disc 30.

  When the operating portion of the brake mechanism 15 moves the first clamp member 31 toward the brake disc 30, the first clamp member 31 is pressed against one surface of the brake disc. As a result, the first and second clamp members 31 and 32 clamp the brake disc 30 in the thickness direction. Conversely, when the operating portion of the brake mechanism 15 retracts the first clamp member 31 from the brake disc 30, the first clamp member 31 is separated from one surface of the brake disc 30. As a result, the first and second clamp members 31 and 32 release the brake disc 30.

  The first clamp member 31 is a ring-shaped member having an inner peripheral surface 31 i and an outer peripheral surface 31 o and is disposed coaxially with the brake disc 30. The first clamp member 31 has end faces on one side and the other side with respect to the axis O. The end surface closer to the brake disc 30 faces one surface of the brake disc 30.

  FIG. 4 is a cross-sectional view of the outer diameter portion of the brake disc. As shown in FIG. 4, the brake disc 30 includes a base material 30a and a hard surface treatment layer 30b that covers the surface of the base material 30a. On the surface of the brake disk 30 covered with the hard surface treatment layer 30b, a concave / convex shape 30e is formed for increasing the friction coefficient with a large number of concave portions 30c and convex portions 30d. The uneven shape 30e is formed on the outer diameter portion of the brake disc. The uneven shape is formed on one side and the other side of the brake disc, respectively.

  The uneven shape 30 e is formed on both surfaces of the brake disc 30. Thereby, the clamping force can be further increased as compared with the case where only one side is formed. Although not shown in the drawing, the uneven shape 30e may be formed on any one surface as a modification.

  As an example of the method for forming the concavo-convex shape, as an example, first, the base material 30a is shot peened to provide the base material 30a with a large number of concave portions and convex portions. Shot peening is a cold working method in which a large number of particles are projected onto the surface to be processed, and compressive stress remains when a large number of irregularities are formed on the surface to be processed, so that the fatigue life of the surface to be processed is improved.

  By forming an uneven shape on the surface of the outer diameter portion of the brake disc 30, the friction coefficient of the brake disc 30 with respect to the clamp members 31 and 32 increases, and the clamping force of the brake mechanism 15 increases, but the first clamp member 31 and If the pinching operation of the outer diameter portion by the second clamp member 32 is repeatedly performed, the surface of the outer diameter portion, more specifically, the convex portion of the concavo-convex shape is worn, and the friction coefficient is lowered. Therefore, in this embodiment, in order to maintain the uneven shape of the one surface and the other surface of the outer diameter portion of the brake disk 30 over a long period of time, the hard surface treatment is applied to the one surface and the other surface of the outer diameter portion of the brake disk 30. Layer 30b is formed. The hard surface treatment layer 30b is formed along the recesses and protrusions provided on the substrate 30a, and the recesses and protrusions provided on the substrate 30a appear on the surface of the hard surface treatment layer 30b.

  Various methods are conceivable as the hard surface treatment. In one embodiment, plating a hard metal such as chrome. If the hard surface treatment layer 30b is a hard chrome plating layer, excellent wear resistance is exhibited, so that the surface irregularity shape of the outer diameter portion of the brake disk 30 can be maintained over a long period of time.

  The processing method for imparting an uneven shape to the surface of the outer diameter portion of the brake disk is not limited to shot peening, and a general machining method or the like can also be employed. For example, a number of grooves extending radially may be formed on the surface of the outer diameter portion of the brake disk 30 by machining. Since these grooves do not penetrate the brake disk 30 in the thickness direction but have a groove bottom, the rigidity of the brake disk 30 is maintained well.

  The first and second clamp members 31 and 32 pinch the outer diameter portion of the brake disc 30 whose friction coefficient is increased by the uneven shape appearing on the surface of the brake disc 30 in the thickness direction. The rotation can be stopped quickly and the clamping force can be increased. Moreover, since the uneven surface is formed of the hard surface treatment layer 30b, the wear resistance is improved and the uneven shape is maintained over a long period of time.

  The first clamp member 31 is integrally coupled to the outer peripheral edge of the disk-shaped partition wall portion 33 on the inner peripheral surface 31i thereof. The thickness of the partition wall 33 in the direction of the axis O is made thinner than the thickness of the first clamp member 31 in the direction of the axis O. And the partition wall part 33 is smoothly connected to the end surface far from the brake disc 30 among the both end surfaces of the first clamp member 31 without any step. Thereby, a recessed space surrounded by the inner peripheral surface 31 i of the first clamp member 31 and the partition wall 33 is formed. The recessed space accommodates the inner diameter side guide ring 35.

  The partition wall 33 has a central hole 33h. The central shaft 22 is inserted through the central hole 33h. The inner diameter portion of the partition wall portion 33 surrounding the central hole 33h is slightly thicker than the outer diameter side, and is attached to the housing side member 16 by screws. The housing side member 16 is a wall member having a central hole 17 through which the central shaft 22 passes, and is a fixing member having one surface coupled to the housing 12 and the other surface facing the partition wall portion 33.

  As described above, the partition wall portion 33 has an inner diameter portion fixed to the housing side member 16 and an outer diameter portion formed thin. Then, the outer peripheral edge of the partition wall portion 33 is coupled to the first clamp member 31. The remaining outer diameter side portion of the partition wall portion 33 excluding the fixed inner diameter portion can be elastically deformed in the direction of the axis O. Further, the partition wall 33 urges the first clamp member 31 toward the brake disk 30. The first clamp member 31 is attached to the housing side member 16 via the partition wall portion 33.

  With reference to FIG. 2, an operation unit for moving the first clamp member 31 forward and backward toward the brake disk 30 will be described in detail.

  An inner diameter side guide ring 35 is disposed between the partition wall portion 33 and the brake disk 30. The outer peripheral surface 35 o of the inner diameter side guide ring 35 is in sliding contact with the inner peripheral surface 31 i of the first clamp member 31. Thereby, the inner diameter side guide ring 35 guides the first clamp member 31 so as to be movable back and forth in the direction of the axis O. The central shaft 22 is inserted into the central hole 35 h of the inner diameter side guide ring 35. An inner diameter portion of the inner diameter side guide ring 35 surrounding the central hole 35 h is fixed to the inner diameter portion of the partition wall portion 33 and the housing side member 16 by bolts.

  The partition wall 33 partitions the space between the housing side member 16 and the inner diameter side guide ring 35, and includes a clamp chamber 36 that is a space on the housing side member 16 side and an unclamp that is a space on the inner diameter side guide ring 35 side. The chamber 37 is divided into two.

  On the flat surface of the housing side member 16 which is a flat wall member, an outer diameter side guide portion 38 which is a protrusion extending in the circumferential direction is formed. The outer diameter side guide portion 38 is a cylinder, the first clamp member 31 is a piston that moves forward and backward in the direction of the axis O in the cylinder, and the outer peripheral surface 31 o of the first clamp member 31 is the inner periphery of the outer diameter side guide portion 38. It is in sliding contact with the surface 38i. The clamp chamber 36 and the unclamp chamber 37 are communicated with an air supply source and an air discharge portion through passages 52 and 49, a switching valve (not shown), and the like, respectively.

  The clamp chamber 36 on the side opposite to the inner diameter side guide ring 35 when viewed from the partition wall portion 33 is an axial clearance between the partition wall portion 33 and the housing side member 16 that are separated from each other in the axis O direction. The outer periphery of the annular clamp chamber 36 is defined by an inner peripheral surface 38 i of the outer diameter side guide portion 38. The outer periphery of the clamp chamber 36 is hermetically sealed by packing provided on the outer peripheral surface 31o of the first clamp member and in sliding contact with the inner peripheral surface 38i. The inner periphery of the clamp chamber 36 is hermetically sealed by a ring-shaped seal member 42 interposed between the housing side member 16 and the inner diameter portion of the partition wall portion 33. The clamp chamber 36 is connected to one end of a passage 52 provided in the housing side member 16. Although not shown, the other end of the passage 52 is connected to an air supply source that supplies air.

  The unclamping chamber 37 is an axial gap between the partition wall 33 and the inner diameter side guide ring 35 that are separated from each other in the axis O direction. The outer periphery of the unclamp chamber 37 formed in an annular shape is partitioned by the inner peripheral surface 31 i of the first clamp member 31. The outer periphery of the unclamp chamber 37 is hermetically sealed by a packing provided on the outer peripheral surface 35o of the inner diameter side guide ring 35 and in sliding contact with the inner peripheral surface 31i. The inner circumference of the unclamp chamber 37 is hermetically sealed by a ring-shaped seal member 43 interposed between the inner diameter portion of the partition wall portion 33 and the inner diameter portion of the inner diameter side guide ring 35. The seal members 42 and 43 are O-rings.

  FIG. 5 is a plan view showing the inner diameter side guide ring. As shown in FIGS. 2 and 5, the end surface on one side in the axial direction of the inner diameter side guide ring 35 is formed so that the inner diameter side region 45 is higher than the outer diameter side region 44. Further, an annular step 46 that is a boundary between the outer diameter side region 44 and the inner diameter side region 45 and a passage groove 47 that extends from the annular step 46 in the inner diameter direction are formed on the end surface on one axial side of the inner diameter side guide ring. . The outer diameter side region 44 and the annular step 46 define an unclamping chamber 37. Further, the inner diameter side region 45 of the end face is fixed to the inner diameter portion of the partition wall portion 33. The passage groove 47 is formed in the inner diameter side region 45, and the passage groove 47 forms a passage when the inner diameter portion of the partition wall portion 33 covers the passage groove 47.

  The outer diameter side end of the passage groove 47 is connected to the unclamping chamber 37. An inner diameter side end of the passage groove 47 is connected to one end of a passage 49 formed in the housing side member 16 through a hole 48 formed in the inner diameter portion of the partition wall portion 33. Although not shown, the other end of the passage 49 is connected to an air supply source that supplies air.

  The operation of the brake mechanism 15 will be described.

  In a normal operation state, the brake mechanism 15 moves the first clamp member 31 forward by the operation of the operation portion and presses it against the brake disc 30, or retracts the first clamp member 31 by the operation of the operation portion. Thus, the brake is released from the brake disc 30.

  That is, in the first brake state, air is pressed into the clamp chamber 36 from the passage 52 and air is discharged from the unclamp chamber 37, so that the clamp chamber 36 is expanded and the partition wall 33 is elastically deformed to be radially inner. Approach the guide ring 35. Thereby, the 1st clamp member 31 is pressed on the surface of the brake disc 30, the rotation of the turntable 11 can be stopped quickly, and the stop rotary table 11 can be clamped so that rotation is impossible.

  In such a first brake state, the work chucked on the surface 21f of the table member 21 is reliably predetermined against pressure or vibration from a tool in cutting or grinding operations by various machine tools such as a milling machine and a machining center. The rotation angle position is maintained.

  In the brake released state, air is pressed into the unclamping chamber 37 from the passage 49 and air is discharged from the clamping chamber 36 to expand the unclamping chamber 37 and elastically deform the partition wall portion 33, so that the inner diameter side is increased. Move away from the guide ring 35. Thereby, the 1st clamp member 31 leaves | separates from the surface of the brake disc 30, and rotation table 11 is accept | permitted rotation. Then, the rotary table 11 is rotated to a specified index angle by the direct drive motor 14.

  In an emergency in which power is not supplied to the rotary table device 10 due to a sudden power failure or lightning strike, air is not supplied from the air compressor and the operating unit does not operate. Therefore, the brake mechanism 15 is in the first brake state or the brake released state described above. It is not done. The brake mechanism 15 is set to the second brake state while the operation unit is not operated.

  That is, in the second brake state, the partition wall 33 that is the urging means causes the first clamp member 31 to contact the surface of the brake disc 30 with a light force. Thus, according to the present embodiment, even when a power failure occurs during operation of the rotary table device 10, the inertial rotation of the rotary table 11 can be quickly stopped and the stopped rotary table 11 can be kept unrotatable. it can. Therefore, in a type driven by a direct drive motor, safety and reliability are higher than those of a rotary table device having a conventional clamp mechanism.

  Since the urging force of the partition wall 33 is lighter than the force applied to the partition wall 33 by the unclamping chamber 37 expanding, the urging force of the partition wall 33 does not hinder the expansion of the unclamping chamber 37. .

  In the present embodiment, as shown in FIG. 5, the seal member 43 is not arranged so as to have a simple perfect circle shape, but a part 43g thereof is arranged closer to the inner diameter than the remaining part 43r.

  A ring-shaped seal member 43 interposed between the inner diameter side region 45 of the inner diameter side guide ring 35 and the inner diameter portion of the partition wall portion 33 extends in the circumferential direction and surrounds the central hole 35 h of the inner diameter side guide ring 35. An O-ring is used as the seal member 43. A portion 43g of the seal member 43 near the passage groove 47 is located closer to the inner diameter than the passage groove 47, and the remaining portion 43r of the seal member is relatively closer to the outer diameter. To position.

  According to the present embodiment, the ring-shaped seal member 43 is disposed closer to the inner diameter in the part 43g and closer to the outer diameter in the other part 43r, so that the radius of the annular partition wall part 33 is increased. The direction dimension can be increased, and the first clamp member 31 can be efficiently advanced and retracted. This point will be described in detail with reference to FIG.

  FIG. 6 is a longitudinal sectional view, and is an explanatory view showing a comparison between the brake mechanism of the present embodiment and the brake mechanism of the comparative example. The basic configuration of the comparative example is the same as that of the present embodiment, but the radial position of each member is partially different. Corresponding symbols are assigned to the corresponding members in the relationship between the present embodiment and the comparative example, such as 36 and 136, 37 and 137, 43 and 143, 47 and 147, and the like.

  In the present embodiment, the seal member 43 is not arranged in a perfect circle shape, but a part 43g in the vicinity of the passage groove 47 of the seal member 43 is arranged closer to the inner diameter than the other part 43r. On the other hand, the sealing member 143 of the comparative example is arranged in a perfect circle shape. For this reason, the passage groove 47 of the present embodiment is disposed closer to the inner diameter than the passage groove 147 of the comparative example.

  Thereby, the radial direction dimension D1 of the movable part of a present Example can be made longer than the radial direction dimension D2 of the movable part of a comparative example. Here, the movable portion refers to a portion from the thinned portion of the partition wall portion 33 to the outer peripheral surface 31o of the first clamp member 31, and can move in the direction of the axis O.

  Since the partition wall portion 33 of the present embodiment has a long radial dimension D1 of the movable portion, the forward / backward stroke in the direction of the axis O can be increased. Further, since the radial dimension D1 is long and the area of the annular partition wall 33 that divides the clamp chamber 36 is increased, a large force is applied to the partition wall 33 by the air supplied to the clamp chamber 36 as indicated by an arrow. Can be given. Therefore, according to the present embodiment, the clamping force can be increased.

  On the other hand, since the partition wall 133 of the comparative example has a short radial dimension D2 of the movable part, the advance / retreat stroke in the axis O direction is shortened. In addition, since the area of the partition wall 133 is reduced, the force applied to the annular partition wall 133 by the air supplied to the clamp chamber 136 is small, and a large clamping force is applied as in this embodiment. Can't get.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The brake structure of the rotary table device according to the present invention is advantageously used in the field of machine tools.

  DESCRIPTION OF SYMBOLS 10 Rotary table apparatus, 11 Rotary table, 12 Housing, 13 Bearing, 14 Direct drive motor, 15 Brake mechanism, 16 Housing side member, 17 Center hole, 21 Table member, 22 Center shaft, 24 Rotor, 25 Stator, 30 Brake disk , 30a base material, 30b hard surface layer, 30e uneven shape, 31 first clamp member, 32 second clamp member, 33 partition wall, 35 inner diameter side guide ring, 36 clamp chamber, 37 unclamp chamber, 38 outer diameter side Guide part, 42, 43 seal member, 44 outer diameter side region, 45 inner diameter side region, 46 annular step, 47 passage groove, 49, 52 passage.

Claims (5)

A rotating table,
A direct drive motor having a rotor provided on the rotary table, and a stator arranged to face the rotor, and rotating the rotor by electromagnetic action between the rotor and the stator;
A braked member coupled to the rotary table, a brake member slidably contacting the braked member, an urging means for urging the brake member toward the braked member, and the brake member moving forward and backward with respect to the braked member In a rotary table device comprising an operating part to be moved and a brake mechanism that allows or restricts rotation of the rotary table,
The brake mechanism includes a first brake state in which the brake member is moved forward by the operation of the operation unit and pressed against the member to be braked, and the brake member is retracted by the operation of the operation unit to release the brake member from the braked member. One state can be selected from three states: a separated brake release state and a second brake state in which the urging means abuts the braking member against the braked member during non-operation of the operating portion. A brake structure for a rotary table device. The rotary table has a table member and a central axis extending from the table member along a rotation axis.
The brake member of the brake mechanism is a brake disk that is fixed to the central axis of the rotary table and rotates together with the table member,
The brake structure of the rotary table device according to claim 1, wherein a braking member of the brake mechanism faces a surface of the brake disc. The braking member has a ring shape having a central hole, and a central axis of the rotary table is passed through the central hole,
The operating part of the brake mechanism is
A partition wall portion coupled to the inner peripheral surface of the ring-shaped braking member;
An inner diameter side guide ring that is disposed between the partition wall portion and the brake disc and guides the inner peripheral surface of the braking member so as to be movable in the axial direction;
An unclamping chamber which is an axial clearance between the partition wall and the inner diameter side guide ring;
A clamp chamber on the opposite side of the inner diameter side guide ring as seen from the partition wall,
The brake structure for a rotary table device according to claim 2, further comprising fluid supply means for selectively supplying fluid to the clamp chamber and the unclamp chamber. The partition wall portion is fixed to a housing side member of a rotary table device that rotatably supports the rotary table at an inner diameter portion thereof, and an outer diameter portion thereof is movable in an axial direction together with the braking member,
Of the end face on the one axial side of the inner diameter side guide ring, the outer diameter side region defines the unclamp chamber, the inner diameter side region is fixed to the inner diameter portion of the partition wall portion, and the inner diameter side region includes the A passage groove that is connected to the outer diameter side region and through which the fluid passes is formed,
A ring-shaped seal member is provided between the inner diameter side region of the inner diameter side guide ring end surface and the inner diameter portion of the partition wall,
The rotary table device according to claim 3, wherein a portion of the seal member near the passage groove is located closer to the inner diameter than the passage groove, and a remaining portion of the seal member is located relatively closer to the outer diameter. Brake structure.   The brake disc has a base material and a hard surface treatment layer covering the surface of the base material, and an uneven shape for increasing the coefficient of friction with respect to the brake member on the surface of the brake disc covered with the hard surface treatment layer The brake structure of the rotary table device according to any one of claims 2 to 4, wherein:

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