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EP-4342608-B1 - TURRET DEVICE

EP4342608B1EP 4342608 B1EP4342608 B1EP 4342608B1EP-4342608-B1

Inventors

  • UEDA, TOSHIO
  • MATSUYAMA, HITOSHI

Dates

Publication Date
20260506
Application Date
20210526

Claims (6)

  1. A turret device (1) comprising: a shaft unit (10), the shaft unit (10) being non-rotatable and having at least one supporting part (11) having an outer peripheral surface of a cylindrical shape; and an outer cylinder unit (20) comprising a hollow polygonal prismatic body having openings at both ends thereof and each of the openings defining a respective opening side, the outer cylinder unit (20) having, at least on each planar surface of an outer periphery thereof, an attachment surface (21) for attaching a tool thereto, wherein: the outer cylinder unit (20) has at least one supported part (21') having an inner peripheral surface of a cylindrical shape and is rotatably supported by the shaft unit (10) with the supported part externally fitted on the supporting part (11) of the shaft unit (10) inserted through one of the openings; and the turret device (1) is configured to be able to index each of the attachment surfaces formed on an outer peripheral surface of the outer cylinder unit (20) to a predetermined machining position, wherein: the outer cylinder unit (20) has, on the other opening side, a housing space (24) having an inner peripheral surface of a cylindrical shape and has a coolant discharge flow path opened as a connection port (35) in the inner peripheral surface of the housing space (24); the connection port (35) being formed at a predetermined pitch interval in a circumferential direction in correspondence with the attachment surfaces; a coolant supply mechanism (25) arranged on an end of the other opening side of the shaft unit (10) is disposed in the housing space (24) of the outer cylinder unit (20) and the other opening of the outer cylinder unit (20) is closed by a lid (39); the coolant supply mechanism (25) includes: a reciprocating rod (30) disposed along a radial direction and configured to advance and retract with respect to the inner peripheral surface of the housing space (24); and a shaft receiving unit (26) supporting the reciprocating rod (30) in such a manner as to allow the reciprocating rod (30) to advance and retract and including a drive unit (45) configured to advance and retract the reciprocating rod (30); the reciprocating rod (30) has a supply hole (34) bored along an axis of the reciprocating rod (30) and opened in a distal end of the reciprocating rod (30) and has an annular elastic body arranged on the distal end of the reciprocating rod (30) to surround the supply hole (34); and when the reciprocating rod (30) is advanced, the elastic body comes into contact with the inner peripheral surface of the housing space (24) to surround the connection port (35) formed in the inner peripheral surface of the housing space (24).
  2. The turret device (1) according to claim 1, characterized in that : the drive unit (45) includes: a piston (46) externally fitted on the reciprocating rod (30); and a pressure chamber (47) formed in the shaft receiving unit (26) and having the piston (46) inserted therein; and the drive unit (45) is configured to advance the reciprocating rod (30) by supplying pressure fluid into the pressure chamber (47) on a rear side in an advancing and retracting direction of reciprocating rod (30) and retract the reciprocating rod (30) by supplying pressure fluid into the pressure chamber (47) on a front side in the advancing and retracting direction.
  3. The turret device (1) according to claim 1 or 2, characterized in that : the reciprocating rod (30) has a stepped portion (31) on an intermediate portion thereof so as to have a small diameter on a rear side in an advancing and retracting direction and a large diameter on a front side in the advancing and retracting direction; the shaft receiving unit (26) has an annular contact surface (27) configured to come into contact with an entire surface of a large diameter portion (32) of the reciprocating rod (30) and provide sealing in cooperation with the large diameter portion (32) when the reciprocating rod (30) is retracted and separate from the large diameter portion (32) when the reciprocating rod (30) is advanced; the shaft receiving unit (26) further has a coolant supply chamber (40) formed in a predetermined area including the contact surface (27) in the advancing and retracting direction; the reciprocating rod (30) has a connection port (35) formed in an outer peripheral surface thereof on the rear side of the stepped portion (31), the connection port (35) communicating with the supply hole (34); and a coolant supply flow path (12) formed in the shaft unit (10) and connected to a predetermined coolant supply source is opened in the coolant supply chamber (40) on the front side of the contact surface (27) in the shaft receiving unit (26).
  4. The turret device (1) according to any one of claims 1 to 3, characterized in that the elastic body is detachably mounted via a mounting member on the distal end of the reciprocating rod (30).
  5. The turret device (1) according to any one of claims 1 to 4, characterized in that a front end surface of the elastic body is formed in a convex curved surface having a predetermined curvature.
  6. The turret device (1) according to any one of claims 1 to 5, characterized in that the supporting part (11) of the shaft unit (10) and the supported part of the outer cylinder unit (20) externally fitted on the supporting part (11) are liquid-tightly sealed therebetween by a sealing member.

Description

Technical Field 0001 The present invention relates to a turret device that is provided in a machine tool, and more particularly, relates to a turret device including a coolant supply mechanism. Background Art 0002 A conventionally known turret device including a coolant supply mechanism (coolant supply device) is disclosed in Japanese Unexamined Patent Application Publication No. 2014-240104 (Patent Literature 1 listed below). In the coolant supply device of the disclosed turret device, a piston is put in a piston holder, which is attached to a tool rest body, in such a manner as to be able to protrude from and retract into the piston holder. This turret device is configured to join the piston to a coolant inflow port provided in a rear surface of a turret to supply coolant to a tool. 0003 The positional relationship between an inflow port of the piston holder and the piston is set such that the pressure of coolant supplied into the piston holder from the tool rest body acts on the rear end surface of the piston. The piston has a coolant flow path formed in the center thereof, which penetrates from the rear end surface to the front end surface of the piston. 0004 In this coolant supply device, the pressure of coolant supplied into the piston holder acts on the rear end surface of the piston, so that the piston protrudes toward the rear surface of the turret and the distal end of the piston is pressed against and joined to the coolant inflow port provided in the rear surface of the turret. Consequently, the coolant is supplied into the turret through the coolant flow path formed through the piston. 0005 On the other hand, when the supply of coolant into the piston holder is stopped, the piston is retracted by a biasing force of a compression coil spring arranged in the piston holder. Thereby, the joint between the distal end of the piston and the rear surface of the turret is released and the turret is allowed to rotate. 0006 If there is no liquid-tightness between the distal end of the piston and the rear surface of the turret, it is possible that coolant leaks from between the distal end of the piston and the rear surface of the turret and scatters into an undesirable place. In addition, in a machining area, chips generated in machining may scatter toward the rear surface of the turret. If these chips are caught between the distal end of the piston and the rear surface of the turret, a gap is formed between the distal end of the piston and the rear surface of the turret, which results in coolant leaking from this gap. 0007 As disclosed in Japanese Unexamined Patent Application Publication No. 2017-205861, this issue has been addressed by providing an elastic resin seal ring on the distal end of the piston to provide liquid-tight sealing between the distal end of the piston and the rear surface of the turret. In addition, DE 10 2015 004268 discloses a tool turret having a tool disk which can be brought into selective pivot positions with respect to a stand part and having a coolant supply which transfers coolant under pressure by means of a transfer device to a distributor system in the tool disk. Furthermore, the arrangement can be made in such a way that a sealing device is provided on the end face of the piston part, which sealing device seals the supply of the distributor system when the valve device is open due to the pressing contact of the piston part at the transfer point of the tool disk in order to avoid a leakage problem, namely that leakage points form on the rotary distributor at the transfer point between the surface regions of the fluid outlet and of the fluid inlet which move relative to one another. Citation List Patent Literature 0008 Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2014-240104Patent Literature 2: Japanese Unexamined Patent Application Publication No. 2017-205861Patent Literature 3: DE 10 2015 004268 A1 Summary of Invention Technical Problem 0009 However, as described above, chips generated in machining can scatter toward the rear surface of the turret in the machining area. Such chips may be caught between the seal ring provided on the distal end of the piston and the rear surface of the turret. The liquid-tightness between the distal end of the piston and the rear surface of the turret may not be immediately impaired by such catching. However, if the distal end of the piston is repeatedly pressed against and separated from the rear surface of the turret in the state where such catching occurs, the seal ring is gradually damaged and the sealing property thereof is impaired, which results in coolant leaking from the damaged portion of the seal ring. 0010 Further, the seal ring damaged as described above needs to be replaced. However, since the conventional coolant supply device is arranged behind the turret, it is difficult to perform the replacement; therefore, there is a problem that the machine tool has to be stopped for a long period of time.