JP6415224B2 - Rotary positioning device - Google Patents

Description

  The present invention relates to a rotational positioning device, and more particularly to a rotational positioning device used for rotational indexing of a machine tool or the like.

  Since this type of rotational positioning device is subjected to a large load from the tool during work, it is required to withstand the load and reliably hold the workpiece at a predetermined angular position. Therefore, in Patent Document 1, for example, a concavo-convex shape for increasing the friction coefficient with respect to the clamp mechanism is formed on both surfaces of the brake disc held by the clamp mechanism during positioning by shot peening, and the concavo-convex shape is formed on the surface. In order to maintain it for a long period of time, a material in which a friction holding force is improved by forming a hard metal plating layer such as chromium has been proposed.

JP 2009-208182 A

  However, the above-described conventional apparatus has a problem in that the process of forming the hard metal plating layer requires time and increases the cost.

  Therefore, the present invention solves such problems, and an object of the present invention is to provide a rotary positioning device that can perform sufficient positioning of a workpiece by exhibiting sufficient frictional holding force at low cost with a simple process. And

In order to achieve the above object, according to the first aspect of the present invention, a brake plate (51) integrally provided on an output member (4) connected to the drive motor (2) and rotated, and the brake plate (51) The brake piston is provided so as to be able to advance and retreat, and clamps the brake plate (51) between the inner wall surface (52) of the device housing (1) and positions the output member (4) by frictional resistance at the time of advancement. (53), and at least one of the inner wall surface (52), the plate surface of the brake plate (51), and the end surface of the brake piston (53) that come into contact with each other when sandwiched by the brake piston (53). Concavities and convexities are formed on the surfaces that have been hardened in advance by quenching .

  In the first invention, the surface roughness is increased by forming irregularities on at least one of the inner wall surface of the device housing, the plate surface of the brake plate, and the end surface of the brake piston that are in contact with each other when sandwiched by the brake piston. Therefore, a sufficiently large frictional force is generated when they come into contact with each other, and the rotation of the brake plate, that is, the output member integrated with the brake plate can be surely stopped against the external force, thereby positioning the workpiece. It can be done reliably. In addition, since the inner wall surfaces of the device housings that are in contact with each other have a high hardness, even when used for a long time, the unevenness is not worn and a sufficiently large frictional force is maintained. And since it is not necessary to form a hard metal plating layer like the past, the manufacturing process of an apparatus is simple and an apparatus can be implement | achieved cheaply.

In the second aspect of the present invention, the hydraulic piston (61) and the cylinder (62) that generates hydraulic pressure for operating the brake piston (53) when the hydraulic piston (61) enters from the opening are provided. ), A gap (621) is formed in the opening of the cylinder (62), and the inner space of the cylinder (62) communicates with the oil reservoir (18) through the gap (621). Yes.

In the second aspect of the present invention, even when the hydraulic oil temporarily flows from the oil reservoir into the cylinder having a negative pressure through the gap generated in the cylinder opening when the hydraulic piston returns to the retracted end, the surplus Since the hydraulic oil is returned from the cylinder to the oil reservoir through a gap again, it is possible to avoid the occurrence of residual hydraulic pressure in the hydraulic chamber behind the brake piston. As a result, the brake piston is reliably returned to the retracted end, and free rotation of the output member is ensured.

In the third invention, the outer diameter of the brake piston (53) is made substantially the same as the outer diameter of the brake plate (51), and the brake plate (51) is arranged on the outermost peripheral portion of the end surface of the brake piston (53). A contact portion (531) is provided.

In the third aspect of the invention, since the contact portion that contacts the brake plate is formed on the outermost peripheral portion of the end surface of the brake piston, the brake plate is narrowed at the outermost peripheral portion, particularly a booster mechanism or the like. It is possible to obtain a large brake torque with a relatively small narrow pressure without providing a. Thereby, simplification and compactness of the apparatus are realized.

In the fourth invention, a leaf spring (54) for urging the brake piston (53) away from the brake plate (51) in the hydraulic chamber (13) behind the brake piston (53). Arrange.

In the fourth aspect of the invention, the leaf spring that biases the brake piston away from the brake plate is housed in the hydraulic chamber behind the brake piston, so that the device can be simplified and made compact.

  The reference numerals in the parentheses indicate the correspondence with specific means described in the embodiments described later.

  As described above, according to the rotational positioning apparatus of the present invention, it is possible to perform reliable positioning of a workpiece by exhibiting sufficient friction holding force at low cost by a simple process.

It is a whole longitudinal section of a rotation positioning device. It is a cross-sectional view of the rotary positioning device along the line II-II in FIG. It is an expanded sectional view of the brake mechanism in the A section of FIG. It is a side view of a brake piston assembly. It is an expanded sectional view of the hydraulic operation mechanism in the B section of FIG.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

  FIG. 1 is an overall longitudinal sectional view of the rotary positioning device, and FIG. 2 is a transverse sectional view of the device along the line II-II in FIG. A servo motor 2 as a drive motor is horizontally disposed in the longitudinal half 11 of the apparatus housing 1, and its output shaft 21 is located in the other half 12 of the apparatus housing 1 via gears 22 and 23. It is connected to a rod-like cam member 3 disposed horizontally below. The cam member 3 is formed with a tooth profile 31 spirally at an intermediate position. A turret 4 as an output member is disposed above the cam member 3.

  The rotation shaft 41 of the turret 4 has a cylindrical shape (FIG. 2) and is disposed so as to be orthogonal to the cam member 3. A large number of roller members 42 are provided on the outer periphery of the turret 4 at equal intervals so as to be rotatable in parallel with the outer peripheral surface, and a plurality of roller members 42 located on the lower peripheral portion of the outer periphery of the turret 4 are formed in the tooth profile 31 of the cam member 3. Is engaged. The rotation shaft 41 is an output shaft of the rotation positioning device, and a workpiece is fixed via a mechanism (not shown). When a rotation command is given to the servo motor 2, the turret 4 is rotated to a predetermined angular position via the cam member 3, and the output shaft 41 integrated with the turret 4 is also rotated to the predetermined angular position.

  A brake mechanism 5 is provided to reliably position the turret 4 rotated to a predetermined angular position against an external force. The brake mechanism 5 includes an annular brake plate 51 whose inner peripheral portion is fixed to the side surface of the turret 4 (FIG. 3), and a partition wall of the device housing 1 adjacent to one surface of the brake plate 51 includes an inner wall surface thereof. An annular pressure receiving plate 52 having the same outer diameter as that of the brake plate 51 is fixed. A brake piston 53 is located close to the other surface of the brake plate 51, and the brake piston 53 forms an annular shape having substantially the same outer diameter as that of the brake plate 51, and with respect to the brake plate 51 in the device housing 1. It is held so that it can move forward and backward.

  The side surface (end surface) of the brake piston 53 facing the brake plate 51 is formed as an abutting portion 531 with the outermost peripheral portion protruding with a constant width. Here, the hardness of the pressure receiving plate 52 and the brake piston 53 is increased by quenching, and the plate surface of the pressure receiving plate 52 facing the brake plate 51 and the surface of the contact portion 531 of the brake piston 53 are shot. Unevenness is formed by blasting to increase the surface roughness. The quenching process and the formation of irregularities may be performed on one side or both sides of the brake plate 51, or may be performed only on the brake plate 51 in place of the pressure receiving plate 52 and the brake piston 53.

  An annular hydraulic chamber 13 is formed behind the brake piston 53 between the inner wall of the device housing 1. An oil supply path 14 communicating with a hydraulic operation mechanism 6 (FIG. 1), which will be described later, communicates with the hydraulic chamber 13. When the brake mechanism 5 is operated, pressure oil is supplied to the hydraulic chamber 13 and the brake piston 53 is connected to the brake plate 53. The brake plate 51 is advanced in the direction 51, and the brake plate 51 is narrowed between the contact portion 531 of the brake piston 53 and the pressure receiving plate 52. Since the contact part 531 is formed in the outermost peripheral part of the end surface of the brake piston 53, the brake plate 51 is narrowed by the outermost peripheral part. As a result, a large brake torque can be obtained with a relatively small narrow pressure without providing a booster mechanism or the like, and the brake mechanism 5 can be simplified and made compact.

  Since the surfaces of the abutting portion 531 and the pressure receiving plate 52 are uneven as described above to increase the surface roughness, a sufficiently large frictional force is generated when contacting the brake plate 51, resulting in an external force. Against this, the rotation of the turret 4 is surely stopped and positioned. Further, since both the brake piston 53 and the pressure receiving plate 52 have high hardness, even when used for a long time, the uneven wear is minimized and a sufficiently large frictional force is maintained.

  A ring-shaped leaf spring 54 is disposed in the hydraulic chamber 13 behind the brake piston 53 (FIG. 4). The leaf springs 54 are fixed to the brake piston 53 and the member 55 constituting the inner wall of the device housing 1 alternately by screwing at a plurality of positions of the ring, so that the brake piston 53 is always separated from the brake plate 51 in the backward direction. Energizing in the direction. Thereby, when the supply of the pressure oil to the hydraulic chamber 13 is stopped, the brake piston 53 is quickly separated from the brake plate 51, the narrow pressure state of the brake plate 51 is eliminated, and the turret 4 can be rotated. As described above, the biasing member for biasing the brake piston 53 backward is housed in the narrow hydraulic chamber 13 behind the brake piston 53 as a leaf spring 54. This also simplifies and compacts the brake mechanism 5. Realized.

  A hydraulic operating mechanism 6 is provided in an upper position near the turret 4 in the apparatus housing half 12. Details of the hydraulic operation mechanism 6 are shown in FIG. The hydraulic operation mechanism 6 includes a hydraulic piston 61 in which a small-diameter piston portion extends horizontally from a large-diameter base portion. The hydraulic operation mechanism 6 is partitioned into a base portion 611 and air chambers 15 and 16 are formed on the front and rear sides thereof. The tip of the piston portion 612 faces the opening of the cylinder 62 formed on the inner wall of the apparatus housing 1, and the space in the cylinder 62 communicates with the hydraulic chamber 13 behind the brake piston 53 (FIG. 3) via the oil supply path 14. doing.

  In the state shown in FIG. 5 in which the hydraulic piston 61 is retracted, the space in the cylinder 62 passes through the gap 621 formed between the tip of the piston portion 612 and the opening peripheral edge of the cylinder 62 and the oil flow passage 17, and the apparatus housing 1. Leading to an oil reservoir 18 formed in the top of the tank. The oil reservoir 18 stores hydraulic oil and communicates with the atmosphere. In addition, seal members 613 and 614 that are in contact with the outer periphery of the piston portion 612 are disposed at two locations in the longitudinal direction on the inner periphery of the opening of the partition wall through which the piston portion 612 passes.

  When operating the brake mechanism 5, compressed air is supplied to the air chamber 15. As a result, the hydraulic piston 61 is advanced to enter the cylinder 62, the opening of the cylinder 62 is closed, the hydraulic pressure in the cylinder 62 increases, and the pressurized oil is supplied into the hydraulic chamber 13 (FIG. 3). As a result, the brake piston 53 is advanced in the direction of the brake plate 51, the brake mechanism 5 is operated as described above, and the rotation of the turret 4 is stopped.

  When releasing the operation of the brake mechanism 5, the supply of compressed air is switched from the air chamber 15 to the air chamber 16. As a result, the hydraulic piston 61 is retracted, and the supply of pressure oil into the hydraulic chamber 13 is stopped. As a result, the brake piston 53 is retracted by the spring force of the leaf spring 54, the operation of the brake mechanism 5 is released, and the turret 4 can be rotated. When the hydraulic piston 61 reaches the retracted end shown in FIG. 5, a gap 621 is formed between the tip of the piston portion 612 and the opening edge of the cylinder 62, and the space in the cylinder 62 passes through the gap 621 to the oil reservoir 18. The inside of the cylinder 62 is returned to the atmosphere through communication.

  According to such a structure, when the hydraulic piston 61 returns to the retracted end, the hydraulic oil temporarily becomes negative pressure from the oil reservoir 18 through the gap 621 generated between the opening edge of the cylinder 62. Even if it flows into the cylinder 62, the excess hydraulic oil is returned to the oil reservoir 18 through the gap again from the cylinder 62 that has returned to the atmospheric pressure. As a result, the remaining hydraulic pressure is prevented from occurring in the hydraulic chamber 13 behind the brake piston 53, the brake piston 53 is reliably returned to the retracted end, and the operation of the brake mechanism 5 is completely released. In addition, leakage of hydraulic fluid is reliably prevented by the seal members 613 and 614 provided at two locations in the longitudinal direction in contact with the outer periphery of the piston portion 612.

  The method of forming irregularities on the pressure receiving plate or the like is not limited to the shot blasting process, and can be formed by a machining process such as grinding or a chemical process such as corrosion. The quenching treatment for increasing the hardness may be any method such as salt bath treatment, high-frequency heat treatment, vacuum heat treatment, carburizing, and nitriding. Alternatively, a pressure receiving plate or the like may be formed from a material having a high hardness such as a super hard material, and irregularities may be formed on the pressure receiving plate. Furthermore, the rotation transmission of the drive motor may be transmitted by the tooth profile of the worm wheel which is the output member meshing with the worm member in addition to the cam member and the roller member on the outer periphery of the turret as the output member as in the above embodiment.

DESCRIPTION OF SYMBOLS 1 ... Device housing, 13 ... Hydraulic chamber, 18 ... Oil reservoir, 2 ... Servo motor (drive motor), 3 ... Cam member, 4 ... Turret (output member), 5 ... Brake mechanism, 51 ... Brake plate, 52 ... Pressure receiving Plate (inner wall surface), 53 ... brake piston, 531 ... contact portion, 54 ... plate spring, 6 ... hydraulic operating mechanism, 61 ... hydraulic piston, 62 ... cylinder, 621 ... gap.

Claims (4)

A brake plate that is integrally provided on an output member that is connected to a drive motor and is rotated, and is provided so as to be able to advance and retreat relative to the brake plate, and clamps the brake plate between the inner wall surface of the device housing when advanced. A brake piston for positioning the output member by frictional resistance, and at least one of the inner wall surface, the plate surface of the brake plate, and the end surface of the brake piston that come into contact with each other when sandwiched by the brake piston. Rotational positioning device in which irregularities are formed on the surface hardened in advance by quenching . A hydraulic piston, and a cylinder that generates hydraulic pressure for operating the brake piston when the hydraulic piston enters from the opening. The rotary positioning device according to claim 1, wherein an inner space of the cylinder communicates with the oil reservoir . The outer diameter of the said brake piston is made substantially the same as the outer diameter of the said brake plate, The contact part which contacts the said brake plate is provided in the outermost periphery part among the end surfaces of the said brake piston . Rotary positioning device. The rotary positioning device according to any one of claims 1 to 3 , wherein a leaf spring that urges the brake piston in a direction of separating the brake piston from the brake plate is disposed in a hydraulic chamber behind the brake piston .

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