Machining head

A machining head is provided with a turret on which multiple rotating tools are mounted, and this head is configured such that rotation of each of the multiple rotating tools during machining and rotation of the turret are performed by a single motor. A switchable turret rotation transmission mechanism is disposed to be capable of transmitting the rotation of the motor shaft to the turret as the rotation of the turret and releasing the transmission. The rotation of each of the multiple rotating tools during the machining and the rotation of the turret can be performed by the single motor.

TECHNICAL FIELD

The present disclosure relates to a machining head that holds a rotating tool in order to perform machining.

BACKGROUND ART

In the related art, PTL 1 discloses, as a technique relating to a lathe, a technique in which, in addition to a bite as a type of tool, a lathe has a rotating tool such as a drill as another type of tool mounted on a turret, and performs machining by rotating the rotating tool. According to this technique, rotation of the rotating tool during the machining by the rotating tool and rotation of the turret are performed by a single motor.

CITATION LIST

Patent Literature

SUMMARY

Problem to be Solved

The technique disclosed in PTL 1 is a technique for performing machining with a single rotating tool mounted on a turret; however, for improving machining variation, it is desirable that multiple rotating tools are mounted on the turret, such that one of the rotating tools to be used is able to be selected by the turret being rotated, so that machining is able to be performed by any one of the multiple rotating tools. The inventor of the present application has reached a conclusion that the practicality of a machining head which is provided with a turret holding multiple rotating tools can be improved by responding to these needs. The present disclosure is based on this knowledge, and an object thereof is to provide a machining head that has a high level of practicality.

Means for Solving the Problem

A machining head according to the present disclosure, which is to address the above-described problem, is a machining head that is provided with a turret on which multiple rotating tools are mounted; a single motor is configured to perform both rotation of each of the multiple rotating tools during machining and rotation of the turret.

Effects

The machining head according to the present disclosure can perform both the rotation of each of the multiple rotating tools during machining and the rotation of the turret with a single motor, and thus is highly practical.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a representative embodiment of the present disclosure will he described in detail with reference to the accompanying drawings. The present disclosure is not limited to the following embodiment and can be realized in various modified or improved forms based on the knowledge of those skilled in the art.

EXAMPLE

Hereinafter, an embodiment of a machining head according to the present disclosure will be described in the order of the overall configuration of a work system that is equipped with the machining head, the configuration of the machining head, and operation and so on of the machining head.

[A] Overall Configuration of Work System

The work system illustrated inFIG. 1is configured to include one system base10and four working machines12that are placed side by side on system base10.FIG. 1shows the work system with exterior panels attached.FIG. 2shows, from a viewpoint different to that ofFIG. 1, the work system with the exterior panels removed.

In this work system, each of the working machines12is able to be drawn out of system10in a longitudinal direction by wheels14rolling on a rail that is laid on system base10.FIG. 2shows a state where the third working machine12from the left (second working machine12from the right) is drawn out by a certain distance. Although not illustrated in detail in the drawing, two base units, on each of which are loaded two working machines12, are lined up next to each other and fixed to each other to constitute system base10.

Each of the four working machines12is a machine tool, a lathe to be specific, with substantially the same configuration. Broadly speaking, each of the working machines12is configured to include, as illustrated inFIG. 3, bed16where wheel14is disposed, pillar18that is erected on bed16, spindle20that is rotatably held by pillar18, motor22that rotates spindle20, turret-type machining head26that holds multiple bites24, head moving device28that is supported by pillar18and moves the machining head26forward, backward, upward, and downward, and control panel30that controls working machine12. Work W, which is a work object, is held by chuck32that is mounted on the front end of spindle20as illustrated in the drawing; lathing is performed on the work W, by one of the multiple bites24that are held by machining head26, by machining head26being moved while work W is rotated.

Work loader34, which, extends forward from bed16, attaches and detaches work W to and from chuck32. Work loader34is configured to include work holder36where two chucks are disposed on the backs of each other, holder rotating device38that rotates work holder36about an axis which extends to the left and right, and holder moving device40that moves work holder36forward and backward. At a delivery position that is set on the front side, work holder36grips, from above, work W that is conveyed by a conveyance device (described later); then, work holder36rotates work W, transports work W backward, and causes work W to be held by chuck32. In addition, work holder36receives work W from chuck32after machining is completed, and then transports the received work W to the delivery position, rotates work W, and passes work W on to the conveyance device. Work W that is illustrated in the drawing is the largest work W that can be machined by working machine12, and although not illustrated in the drawing, a relatively large chuck pawl is mounted on work holder36when the attachment and detachment of work W to and from chuck32are performed.

Conveyance device50, which conveys and passes work W on to the four working machines12, is arranged on the front side surface of system base10as illustrated inFIG. 2so as not to interfere with working machines12when working machines12are drawn forward. Two conveyance device units,52L and52R (hereinafter, referred to as left-side unit52L and right-side unit52R in some cases), which are lined up next to each other, constitute conveyance device50. More specifically, left-side unit52L, is attached to the left, one of the two above-described base units, and right-side unit52R is attached to the right one of the two above-described base units. This work system performs machining on one work W in order from the working machine12on the left side, and thus conveyance device50has the function of conveying and passing the one work W on to the four working machines12in this order from the left to right. In other words, work W, which is a conveyance target object for conveyance device50, is conveyed to the right.

In further detail, three work support units58, each with table54where work W is placed, are disposed in left-side unit52L, and two other work support units58are disposed in the right-side unit. These five work support units58simultaneously reciprocate to the left and right. Conveyance device50conveys work W based on the operation of the five work support units58. Tables54are raised during the delivery of work W involving work loader34described above. When large work W as illustrated inFIG. 2is conveyed, auxiliary tables are mounted on tables54so that the work W can be loaded.

[B] Configuration of Machining Head

The above-described working machine12is a lathe, however, the machining head according to the embodiment is used instead of machining head26in a case where working machine12functions as a drilling machine, a milling machine, a machine tool in which a drilling machine and a milling machine are combined with each other, or a machine tool in which at least one of a drilling machine and a milling machine are combined with a lathe.

FIG. 4is a diagram in which machining head100according to the embodiment is viewed from the front, that is, a front view of machining head100according to the embodiment. Broadly speaking, machining head100is configured to include base body102, turret104that is rotatably held by base body102, and tool attaching unit106that is mounted on turret104as illustrated in this drawing. According to the drawing, two types of tool attaching units,106A and106B, are mounted. Tool attaching unit106A is for rotating tool T to be mounted extending in a perpendicular direction, and tool attaching unit106B is for rotating tool T to be mounted extending in a horizontal direction. Hereinafter, these will be collectively referred to as tool attaching unit106in some cases. Cover108covers an upper portion of base body102.

Eight mounting stages are disposed in turret104in its circumferential direction, and four tool attaching units106can be mounted on four of the eight mounting stages at an angular pitch of90°. In other words, tool attaching unit106can be mounted on every other one of the eight mounting stages. In addition, a bite holder can also be mounted on each of the eight mounting stages, and a bite can be mounted on turret104via the bite holder.FIG. 5is a diagram in which machining head100is viewed from below. This drawing shows a state where four bite holders110, which hold four respective bites B, are mounted in addition to the two tool attaching units106A and the two tool attaching units106B.

FIG. 6is a vertical cross-sectional view illustrating machining head100from a front viewpoint with cover108removed.FIG. 7is a partial cross-sectional view in which machining head100is in a cross section different to that ofFIG. 6. As is apparent fromFIGS. 6 and 7, first base member112and second base member114constitute base body102, and first base member112and second base member114are fastened to each other in a vertical direction with each having a substantially tubular shape. Turret104has turret main body116that has an octagonal outer periphery and a circular recess at the center, and tubular body118that is fastened to turret main body116at a flange that is formed in a lower end portion and extends upward from turret main body116. This tubular body118functions as a tubular portion of turret104.

Tubular body118of turret104is held by base body102via holding tube120. Holding tube120is configured by upper tubular member122and lower tubular member124being fastened to each other. In base body102, holding tube120is held by base body102in a state where rotation is prohibited by detent pin126while movement in the vertical direction is allowed. In a state where tubular body118of turret104is inserted into holding tube120, holding tube120holds tubular body118immovably in the vertical direction, but allowing rotation. In this manner, turret104is held to be capable of moving in the vertical direction and rotating with respect to base body102,

Tubular body118of turret104holds main spindle130of machining head100rotatably but immovably in the vertical direction such that main spindle130passes through tubular body118. Main spindle130extends downward from tubular body118, and main gear132, which is a spur gear, is fitted into a lower end portion to be incapable of rotating or moving in the vertical direction. This main gear132is placed in a cavity that is formed between a bottom wall of turret main body116and a flange of tubular body118. In addition, main spindle130extends upward from tubular body118as well, and the extending part functions as an extending portion of main spindle130.

Motor140is fixed to the upper portion of base body102. Motor140has housing144that holds coil142and hollow motor shaft148that has an outer peripheral portion to which magnet146is attached. The part of main spindle130that extends upward from tubular body118further extends upward through hollow motor shaft148as well. Motor140is a so-called direct drive motor (DD motor)

In the above-described structure, the central axis of turret104, central axis of tubular body118of turret104, central axis of main spindle130, and central axis of motor shaft148correspond to one another without exception, as is apparent from the drawing; these central axes are axis O that is illustrated in the drawing. In other words, turret104, tubular body118, main spindle130, and motor shaft148are coaxially arranged, and each of turret104, tubular body118, main spindle130, and motor shaft148rotates with axis O at its center, that is, about axis O. Hereinafter, the direction in which axis O extends will be referred to as the axial direction in some cases.

Rotary tube150is fastened to a lower end portion of motor shaft148. This rotary tube150functions as a member for transmitting the rotation of motor shaft148to main spindle130and tubular body118of turret104by being rotated about axis O by the rotation of motor shaft148.FIG. 8is a perspective view of a part where the transmission of the rotation is performed. Referring to this drawing, splice tube154that has an outer peripheral portion where spline152is formed is externally fitted into tubular body118to be incapable of rotating with respect to tubular body118and incapable of moving in the axial direction, and spline tube154functions as an outer peripheral portion of tubular body118. Simply put, spline152is formed in the outer peripheral portion of tubular body118. Spline156is formed in an inner peripheral portion of rotary tube150as well, and rotary tube150that is externally fitted into tubular body118is in spline fitting with tubular body118via spline tube154. In other words, spline152that is formed in the outer peripheral portion of tubular body118and spline156that is formed in the inner peripheral portion of rotary tube150, a part on a lower side of spline156to be specific, constitute a spline mechanism158(hereinafter, referred to as “first spline mechanism158” in some cases)

The part of main spindle130that extends upward from tubular body118being called the extending portion, spline ring162that has an outer peripheral portion where spline160is formed is externally fitted into the extending portion to be incapable of rotating or moving in the axial direction. Spline ring162functions as an outer peripheral portion of the extending portion of main spindle130. Simply put, spline160is formed in the outer peripheral portion of the extending portion of main spindle130. This spline160meshes with spline156that is formed in the inner peripheral portion of rotary tube150. In other words, rotary tube150is in spline fitting with the main spindle130. In other words, a part of the inner peripheral portion of rotary tube150that faces the above-described extending portion being called a facing portion, spline160that is formed in spline ring162in the extending portion and an upper part of spline156formed in the facing portion of rotary tube150constitute another spline mechanism164(hereinafter, referred to as “second spline mechanism164” in some cases).

Structural characteristics of this machining head100will be described; the above-described first spline mechanism158is not a simple spline mechanism. Spline152that is formed in spline tube154is shaped such that multiple toothless portions166with no tooth over the entire periphery and multiple toothed portions168with teeth over the entire periphery are alternately aligned at an equal pitch P in the axial direction; likewise, the part on the lower side of spline156that is formed in the inner peripheral portion of rotary tube150is shaped such that multiple toothless portions170with no tooth over the entire periphery and multiple toothed portions172with teeth over the entire periphery are alternately aligned at the equal pitch P in the axial direction. The multiple toothed portions168that are formed in spline152have the same length in the axial direction, and the multiple toothless portions166have the same length in the axial direction. The axial length of each of the multiple toothed portions168is slightly smaller than the axial length of each of the multiple toothless portions166. Likewise, the multiple toothed portions172that are formed at the part on the lower side of spline156have the same length in the axial direction, the multiple toothless portions170have the same length in the axial direction, and the axial length of each of the multiple toothed portions172is slightly smaller than the axial length of each of the multiple toothless portions170.

In the state illustrated inFIGS. 6 and 8, the multiple toothed portions168of spline152and the multiple toothless portions170of spline156are positioned at positions matching with each other in the axial direction and the multiple toothless portions166of the spline152and the multiple toothed portions172of the spline156are positioned at positions matching with each other in the axial direction. In a case where turret104moves downward by a distance equivalent to half of the above-described pitch P with respect to rotary tube150from this state, the multiple toothed portions168of spline152and the multiple toothed portions172of spline156are put into a state of being positioned at positions matching with each other in the axial direction. The axial position of turret104with respect to rotary tube150in this state being called a first position and the axial position of turret104with respect to rotary tube150in the previous state, that is, the state illustrated in the drawing being called a second position, spline152and spline156mesh with each other in a state where turret104is positioned at the first position, whereas spline152and spline156do not mesh with each other in a state where turret104is positioned at the second position. First spline mechanism158is a spline mechanism that has the above-described structure. The states where turret104is positioned at the first position and the second position with respect to base body102have the same meaning as the states where tubular body118of turret104is positioned at the first position and the second position with respect to rotary tube150, respectively.

Accordingly, in a case where turret104is positioned at the first position, the rotation of rotary tube150, that is, the rotation of motor shaft148is transmitted to tubular body118via the first spline mechanism and turret104is rotated by the motor140in a case where turret104is positioned at the second position, the rotation of motor shaft148is not transmitted to tubular body118and turret104does not rotate even if motor shaft148rotates.

As described above, main spindle130is held by tubular body118to be incapable of moving in the axial direction, and thus main spindle130is moved along with turret104in a case where turret104is moved in the axial direction. Unlike the transmission of the rotation from rotary tube150to tubular body118, the rotation of rotary tube150, that is, the rotation of motor shaft148, is transmitted to main spindle130via second spline mechanism164and main spindle130is rotated by motor140in a case where turret104is positioned at either the first position or the second position. However, in a state where turret104is positioned at the first position, turret104is also rotated by the rotation of motor shaft148as described above, and thus main spindle130is in a state of non-rotation with respect to turret104.

As described above, tubular body118is held by holding tube120to be incapable of moving in the axial direction. Multiple spring holding holes180, which are placed on the same circumference with each being open downward, are disposed in holding tube120, and compression coil spring182is arranged in each of the multiple spring holding holes180. Holding tube120is biased upward by an elastic reaction force of spring182. Holding tube that has flange184in an axial intermediate portion. By an upper surface of a peripheral end of the flange184being locked by locking surface186that is disposed in base body102as illustrated inFIG. 6, holding tube120is positioned at an upper end position within a range of axial movement thereof. Turret104is positioned at the second position described above by holding tube120being positioned at the upper end position.

Annular hydraulic chamber188, which is partitioned by the upper surface of flange184and a part of base body102, is disposed in machining head100. High-pressure hydraulic oil is supplied to this hydraulic chamber188via hydraulic oil port190. The hydraulic oil supply causes a force that depends on the pressure of the hydraulic oil in hydraulic chamber188to overcome the biasing force of compression coil spring182, thus causing holding tube120to move downward. This movement is stopped by a lower portion of holding tube120being locked by another locking surface192that is disposed in base body102. In this state, holding tube120is positioned at a lower end position within the axial range of movement thereof, and turret104is positioned at the first position described above. When the supply of high-pressure hydraulic oil is stopped, holding tube120is moved upward and turret104is returned to the second position by the elastic reaction force of compression coil spring182.

In the above-described structure, machining head100is provided with relative moving device194that moves the turret104, which is configured to include hydraulic chamber188, port190, locking surface186, locking surface192, and the like, between the first position and the second position described above. In addition, mentioning the transmission of the rotation to turret104of machining head100with reference to the above-described configuration, this machining head100has a mechanism that is configured to include rotary tube150, first spline mechanism158, and relative moving device194, that is, a switchable turret rotation transmission mechanism that is capable of transmitting the rotation of motor shaft148to turret104as the rotation thereof and releasing the transmission.

Furthermore, in machining head100, coupling rings200and202that have multiple radially-formed teeth are fixed respectively to a lower surface of base body102and the upper surface of the flange of tubular body118of turret104such that the multiple teeth formed on coupling rings200and202face each other. The coupling ring202that is fixed to turret104moves in the axial direction, that is, the vertical direction along with turret104. As illustrated inFIG. 6, coupling rings200and202mesh with each other in a case where turret104is positioned at the second position described above. The rotation of turret104with respect to base body102is prohibited by this meshing. In a case where turret104is positioned at the first position described above, coupling rings200and202are separated from each other in the vertical direction and do not mesh with each other, and the rotation of turret104with respect to base body102is allowed. As is apparent from the structure described above, machining head100is provided with a mechanism that is configured to include coupling rings200and202, that is, switchable connection mechanism204that allows the rotation of turret104with respect to base body102in a state where turret104is positioned at the first position and prohibits the rotation of turret104with respect to base body102in a state where turret104is positioned at the second position.

Tool attaching unit106A is configured to include casing210, intermediate shaft212that is rotatably held by casing210extending in the axial direction, and tool holding shaft214that is rotatably held by casing210extending in the axial direction and holds the rotating tool T. A collet is disposed at a tip of tool holding shaft214, and rotating tool T is fixedly held by tool holding shaft214by this collet. Pinion216, which is a spur gear with a small diameter, is externally fitted in a fixed manner into an upper end portion of the intermediate shaft212. In a state where tool attaching unit106A is mounted on turret104, pinion216meshes with main gear132described above. In addition, an intermediate gear218, which is a spur gear, is externally fitted in a non-rotatable manner into an axial intermediate portion of intermediate shaft212, and an end gear220, which is a spur gear, is externally fitted in a non-rotatable manner into an axial intermediate portion of tool holding shaft214. Intermediate gear218and end gear220mesh with each other. Accordingly, when main gear132is rotated by the rotation of main spindle130, the rotation of main gear132is transmitted to tool holding shaft214via pinion216, intermediate shaft212, intermediate gear218, and end gear220, such that rotating tool T is rotated. This machining head100has the above-described rotation transmission mechanism, that is, first tool rotation transmission mechanism222that transmits the rotation of main spindle130to tool holding shaft214as the rotation of tool holding shaft214.

Likewise, tool attaching unit106B is configured to include casing230, intermediate shaft232that is rotatably held by casing230extending in the axial direction, and tool holding shaft234that is rotatably held by casing230extending in the horizontal direction and holds rotating tool T. Likewise, a collet is disposed at a tip of tool holding shaft234, and rotating tool T is fixedly held by tool holding shaft234by this collet. Pinion236, which is a spur gear with a small diameter, is externally fitted in a fixed manner into an upper end portion of intermediate shaft232as in tool attaching unit106A. In a state where tool attaching unit106B is mounted on turret104, pinion236also meshes with the main gear132. In tool attaching unit106B, intermediate gear238, which is a bevel gear, is externally fitted in a non-rotatable manner into a lower end portion of intermediate shaft232, and end gear240, which is a bevel gear, is externally fitted in a non-rotatable manner into an axial intermediate portion of tool holding shaft234. Intermediate gear238and end gear240mesh with each other. Accordingly, when main gear132is rotated by the rotation of main spindle130, the rotation of main gear132is transmitted to tool holding shaft234via pinion236, intermediate shaft232, intermediate gear238, and end gear240, such that rotating tool T is rotated as in the tool attaching unit106A. This machining head100has the above-described rotation transmission mechanism, that is, a second tool rotation transmission mechanism242that transmits the rotation of main spindle130to tool holding shaft234as the rotation of tool holding shaft234.

In view of the functions of first tool rotation transmission mechanism222and second tool rotation transmission mechanism242described above, it is conceivable that this machining head100is configured to have a single tool rotation transmission mechanism that transmits the rotation of main spindle130to each of the multiple tool holding shafts214and234as the rotation of each by using first tool rotation transmission mechanism222and second tool rotation transmission mechanism242. In a case where a tool attaching unit other than tool attaching units106A and106B is mounted, a tool rotation transmission mechanism that is similar to first tool rotation transmission mechanism222and the tool rotation transmission mechanism242of the tool attaching units106A and106B may be disposed in the tool attaching unit.

[C] Operation and so on of the Machining Head

In a case where cutting is performed by one of the multiple rotating tools T, turret104is in a state of being positioned at the second position as illustrated inFIG. 6. In this state, as described above, the transmission of the rotation from motor shaft148to turret104by first spline mechanism158is not performed with the rotation of turret104with respect to base body102being prohibited by switchable connection mechanism204. Accordingly, turret104does not rotate even if motor shaft148rotates. An operation of motor140in this state causes the rotation of motor shaft148to be transmitted to tool holding shafts214and234by main spindle130, second spline mechanism164, first tool rotation transmission mechanism222, and second tool rotation transmission mechanism242, thus causing rotating tool T to rotate. Drilling and milling can be performed on work W by any one of the multiple rotating tools T as machining head100is moved in a state where the rotating tool T has been rotated.

When one rotating tool T that is scheduled to perform machining is positioned at a specific position, turret104is lowered by the distance equivalent to half of the pitch P by the above-described relative moving device194as partly illustrated with a two-dot chain line inFIG. 6. When motor140is operated in this state, the rotation of motor shaft148is transmitted to tubular body118of turret104by first spline mechanism158such that turret104is rotated. In this case, as described above, a state is achieved where the rotation of motor shaft148is transmitted to main spindle130by second spline mechanism164, but none of the rotating tools T rotates since turret104and main spindle130rotate integrally with each other.

In machining head100, as described above, the transmission of the rotation from motor shaft148to turret104and the release of the transmission are selectively performed by the switchable turret rotation transmission mechanism that is configured to include rotary tube150, first spline mechanism158, and relative moving device194. Relative moving device194moves turret104by only half of the pitch P in the axial direction for this selection. The first spline mechanism158is configured such that the multiple toothless portions166and170and the multiple toothed portions168and172are alternately aligned at equal pitches in the respective spline152and spline156constituting first spline mechanism158, and thus can release the transmission of the rotation from motor shaft148to turret104by merely moving turret104by such a short distance while ensuring the transmission of sufficient rotation torque from motor shaft148to turret104.

In machining head100, motor shaft148, main spindle130, tubular body118of turret104, and rotary tube150are coaxially arranged, and thus machining head100can be compact in size. In other words, the machining head has a compact configuration so that, for example, motor140is prevented from being disproportionately placed in a direction intersecting with the axial direction.

In this machining head100, relative moving device194releases the transmission of the rotation from motor shaft148to tubular body118by moving turret104, that is, tubular body118of turret104with respect to rotary tube150. However, different configurations may be adopted in place of this configuration. For example, a relative moving device that moves rotary tube150with respect to tubular body118of turret104may be adopted and the transmission of the rotation from motor shaft148to tubular body118may be released by rotary tube150being moved.

In this machining head100, bite B can also be held extending in the horizontal direction with another type of bite holder250that differs from the above-described bite holder110mounted in place of tool attaching unit106as illustrated inFIGS. 9 and 10.FIG. 10shows a state where four bite holders250are mounted in place of all the four tool attaching units106.

REFERENCE SIGNS LIST