WO2020085453A1

WO2020085453A1 - Machine tool

Info

Publication number: WO2020085453A1
Application number: PCT/JP2019/041780
Authority: WO
Inventors: 野口　賢次; 春彦御園; 敏之鈴木
Original assignee: シチズン時計株式会社; シチズンマシナリー株式会社
Priority date: 2018-10-26
Filing date: 2019-10-24
Publication date: 2020-04-30
Also published as: TW202015833A; JPWO2020085453A1; JP7312762B2

Abstract

Provided is a machine tool (1), which: comprises a first main shaft (10) and a second main shaft (20); and when a bar (W) becomes a length that is difficult to machine into a product (P), removes the bar (W) as a previous material (W1) from the first main shaft (10) and delivers the same to the second main shaft (20) while supplying a new bar (W) as a new material (W2) from a bar supply unit (50) to the first main shaft (10) and, after making the previous material (W1) and the new material (W2) into a single bar (W3) by joining the mutually facing ends of the previous material (W1) gripped by a second gripping means (22) and the new material (W2) gripped by a first gripping means (12), successively performs a prescribed machining using a tool (41) and cutoff of the bar (W3). The machine tool (1) is characterized in being configured so that when performing the initial machining of the bar (W3) gripped by the first gripping means (12), the first gripping means (12) grips the portion of the bar (W3) that comprises the previous material (W1).

Description

Machine Tools

The present invention relates to a machine tool.

Conventionally, a long bar material supplied from a bar material supply section to a first spindle is gripped by a gripping means of the first spindle, and predetermined processing and cut-off processing are sequentially performed on the bar material using a tool. Then, a machine tool is known in which a large number of products are continuously processed from a bar material.

Further, as such a machine tool, it is provided with a first spindle and a second spindle facing the first spindle, and when the length of the bar becomes difficult to process the product, the bar is As an old material, it is removed from the first spindle and delivered to the second spindle, and a new rod material is supplied as a new material from the rod material supply unit to the first spindle, and the old material is grasped by the grasping means of the second spindle. The opposite ends of the new material gripped by the gripping means of the first spindle are joined by means such as concavo-convex fitting or friction welding to form the old material and the new material into one bar, and then the bar. BACKGROUND ART A machine tool is known in which an old material is used without waste by sequentially performing a predetermined processing using a tool and a cut-off processing on the material (for example, refer to Patent Document 1).

JP, 2005-174179, A

However, in the conventional machine tool described in Patent Document 1, the old material and the new material are joined to form one rod, and the rod is pulled toward the first spindle, and then the holding means of the first spindle is held. By gripping the part made of the new bar material and starting the part of the bar made of the old material, at the start of the machining, the part to be machined and the first spindle are gripped by the tool. The joining portion between the old material and the new material, which is weak in strength, is located between the portion gripped by the means and the accuracy of the machining may deteriorate when processing the portion of the bar material made of the old material. There was a problem that there was.

The present invention has been made in view of the above problems, and an object thereof is to provide a machine tool capable of accurately processing a portion made of an old material of a rod material obtained by joining an old material and a new material. Especially.

A machine tool of the present invention includes a first spindle having a first gripping means, a second gripping means, a second spindle facing the first spindle, and a long bar material supplied to the first spindle. And a machining means provided with a tool for machining the bar, and the machining means continuously performs predetermined machining and cut-off machining on the bar grasped by the first grasping means. So as to obtain a plurality of products, product processing means for operating the first spindle, the second spindle, the bar material supply section and the processing means, and after the bar processing by the product processing means is completed, Old material transfer means for operating the first main spindle and the second main spindle so that the rod is removed from the first spindle as an old material and delivered to the second spindle, and the old material is removed. New bar material is supplied as new material from the bar material supply unit to the first spindle By the new material supply means for operating the first spindle and the bar material supply part so that the first gripping means grips the first material and the old material and the first gripping means gripped by the second gripping means. Joining means for joining the opposite ends of the gripped new material to each other to form the old material and the new material into one bar, and joining the old material and the new material by the joining means. Retraction for actuating the first main spindle, the second main spindle and the bar material supply unit so that the old material portion of the bar material that is formed is removed from the second main shaft and retracted to the first main shaft side. Means, and the predetermined machining and cut-off machining are continuously performed by the product machining means with respect to the bar material that is drawn into the first spindle by the drawing means and gripped by the first gripping means. A machine tool for performing, by the retracting means When the first processing is performed by the product processing means on the bar that is drawn into the first main shaft and gripped by the first gripping means, the first gripping means removes the old material from the old material of the bar. It is characterized in that the portion to be held is grasped.

In the machine tool of the present invention, in the above configuration, the first gripping means is movable in the axial direction of the first main shaft with respect to the bar material, and the predetermined machining of the bar material by the product machining means and A grip for moving the first gripping means so that the first gripping means grips a portion of the bar other than the joint between the old material and the new material when continuously performing the parting process. It is preferable to have a part moving means.

In the machine tool of the present invention, in the above-described configuration, a guide bush that movably supports the rod member in the axial direction of the first spindle is provided between the first spindle and the second spindle, and When the predetermined processing and the cut-off processing for the bar material by the means are continuously performed, when the joint between the old material and the new material is located in the guide bush, the product processing means, It is preferable to operate the first main spindle, the second main spindle, the bar material supply unit, and the processing means so as to perform a cut-off processing on the new material side with respect to the joining portion.

The machine tool of the present invention preferably has position recognition means for recognizing the axial position of the joint between the old material and the new material in the above configuration.

In the machine tool of the present invention, in the above-mentioned configuration, the bar member is supplied to the bar member by the bar member supply unit while the bar member is released from being gripped by the first gripping unit and the second gripping unit. It is preferable that it is configured to be drawn from the side of the second main shaft to the side of the first main shaft.

According to the present invention, it is possible to provide a machine tool capable of accurately processing a part made of an old material of a bar material obtained by joining an old material and a new material.

It is an explanatory view showing roughly the composition of the machine tool which is one embodiment of the present invention. (A) is an explanatory view showing in a simplified manner a state where a bar material is subjected to predetermined processing, and (b) is an explanatory view showing in a simplified state a state where a product is processed from the bar material. (A) is an explanatory view showing a simplified state of the machining of the bar material, and (b) shows a state in which the old material is transferred from the front spindle to the back spindle and the new material is supplied to the front spindle. It is explanatory drawing simplified and shown. (A) is an explanatory view showing a simplified state of measuring the protrusion length of a new material from the front chuck, and (b) is a front spindle and a back spindle from the state shown in (a) of the same figure. FIG. 6 is an explanatory view showing in a simplified manner a state in which the end surfaces of the old material and the new material facing each other are brought into contact with each other by moving in a direction in which they approach each other. FIG. 4A is an explanatory view showing a simplified state in which the back surface spindle is moved to the front surface spindle side with the back surface chuck opened from the state shown in FIG. 4B, and FIG. From the state shown in (a), simplifying the state in which the rear spindle is moved in the direction away from the front spindle while the old material is gripped by the rear chuck, and the recess is formed in the end surface of the old material and the end surface of the new material. FIG. (A) is an explanatory view showing a simplified state in which an old material and a new material are frictionally welded to each other, and (b) is a deburring process for a joint portion between the frictionally welded old material and new material FIG. 6C is an explanatory diagram showing a simplified state of performing the step, and FIG. 13C is an explanatory diagram showing a simplified state of the bar after completion of the deburring process. (A) is an explanatory view showing a simplified state in which a bar, which is friction-welded between an old material and a new material, is pulled in to the front spindle side, and (b) is a friction-pressure contact between the old material and the new material. It is explanatory drawing which simplifies and shows the state which measures the protrusion length from the front chuck of the rod material which did. (A) is the explanatory view which simplifies and shows the state which is performing predetermined processing to the rod material which joined the old material and the new material, (b) is the rod which joined the old material and the new material It is explanatory drawing which simplifies and shows the state which processed the product from the material. (A) is explanatory drawing which simplifies and shows the state which the joining part of the rod material which joined the old material and the new material was located in the front chuck, (b) is moving a front main spindle to an axial direction, It is explanatory drawing which simplifies and shows the state which is performing predetermined processing in the state which hold | gripped parts other than the joining part of a bar material with the front chuck, (c) is the bar material which joined the old material and the new material. It is explanatory drawing which simplifies and shows the state which cut off. (A) is explanatory drawing which simplifies and shows the state which the joint part of the bar material which joined the old material and the new material was located in the guide bush, (b) is a new material rather than the joint part. It is explanatory drawing which simplifies and shows the state in which the parting process is carried out at the side. (A)-(c) is explanatory drawing which shows the other method of measuring the axial direction position of a joining part.

Hereinafter, a machine tool 1 according to an embodiment of the present invention will be described in detail with reference to the drawings.

The machine tool 1 shown in FIG. 1 is an automatic lathe (CNC lathe) that processes a long bar W as a work, and has a front spindle 10 as a first spindle and a back spindle 20 as a second spindle. is doing.

The front spindle 10 and the back spindle 20 are arranged so as to face each other such that the axis of the front spindle 10 and the axis of the back spindle 20 are parallel to each other. Hereinafter, the direction parallel to the axis of the front main shaft 10 and the back main shaft 20 is the Z-axis direction, the direction orthogonal to the Z-axis direction is the X-axis direction, and the direction orthogonal to the Z-axis direction and the X-axis direction is the Y-axis direction. To do.

A front headstock 11 is installed on the base 2 so as to be movable in the Z-axis direction by a front-side moving mechanism 3 such as a guide rail mechanism. The front main spindle 10 is rotatably supported by holding the rod W on the front main spindle stock 11 and is rotationally driven by a main spindle motor. As the spindle motor, for example, a built-in motor configured between the front spindle headstock 11 and the front spindle headstock 10 inside the front spindle headstock 11 can be adopted.

A rear headstock 21 is installed on the base 2 so as to be movable in the Z-axis direction by a rear-side moving mechanism 4 such as a guide rail mechanism. The back spindle 20 is rotatably supported by holding the rod W on the back spindle stock 21 and is rotationally driven by a spindle motor. As the spindle motor, for example, a built-in motor configured between the back spindle 21 and the back spindle 20 inside the back spindle 21 can be adopted.

An X-axis moving mechanism for moving the front spindle 10 relative to the rear spindle 20 in the X-axis direction is installed between the base 2 and the front spindle headstock 11 or between the base 2 and the rear spindle headstock 21. It Further, a Y-axis moving mechanism for relatively moving the front spindle 10 in the Y-axis direction with respect to the back spindle 20 is provided between the base 2 and the front spindle head 11 or between the base 2 and the back spindle 21. Is installed.

A front chuck 12 as a first gripping means is provided at the tip of the front spindle 10 so as to be openable and closable. The front chuck 12 is housed inside the chuck sleeve 13. When the chuck sleeve 13 slides toward the tip side of the front spindle 10, the tapered surface of the front chuck 12 is pressed by the tapered surface of the chuck sleeve 13, and the front chuck 12 is closed. On the contrary, when the chuck sleeve 13 slides toward the base end side of the front spindle 10, the taper surface of the chuck sleeve 13 releases the pressure on the taper surface of the front chuck 12, and the front chuck 12 is opened. The front spindle 10 can hold the bar W by inserting the bar W with the front chuck 12 open and closing the front chuck 12.

A back chuck 22 as a second gripping means is provided at the tip of the back spindle 20 so as to be openable and closable. The back surface chuck 22 is housed inside the chuck sleeve 23. When the chuck sleeve 23 slides toward the tip side of the back spindle 20, the taper surface of the chuck sleeve 23 presses the taper surface of the back chuck 22, and the back chuck 22 is closed. On the contrary, when the chuck sleeve 23 slides toward the base end side of the back spindle 20, the pressing of the taper surface of the chuck sleeve 23 against the taper surface of the back chuck 22 is released, and the back chuck 22 is opened. The back spindle 20 can hold the bar W by inserting the bar W with the back chuck 22 open and closing the back chuck 22.

The slide driving mechanism of the

chuck sleeves

13 and 23 does not limit the present invention, and various structures can be adopted.

A guide bush 30 is provided between the front spindle 10 and the back spindle 20. The guide bush 30 is mounted on a guide bush support base 31 installed on the base 2 and arranged coaxially with the front main shaft 10. By adjusting the position of the guide bush 30 in the axial direction with respect to the guide bush supporting base 31, the guide bush 30 is adjusted to have an inner diameter corresponding to the outer diameter of the bar W. The guide bush 30 can guide the rod W so as to be movable in the Z-axis direction.

The machine tool 1 includes a processing unit 40 as a processing means. The processing section 40 includes a tool 41 that processes the bar W. The tool 41 is held by a tool rest 42. In the tool rest 42, the tool 41 is arranged in front of the guide bush 30 and is supported by the guide bush support base 31 so as to be movable in the X axis direction and the Y axis direction. The position of the tool rest 42 in the Z-axis direction is constant. As the tool 41, for example, an outer diameter cutting bite or a parting bite is mounted on the tool rest 42, and these can be appropriately switched according to the processing content by moving the tool rest 42, for example, in the X-axis direction.

Further, the machine tool 1 is provided with a back side fixed processing section 43 as a processing means. The back side fixed processing section 43 includes a plurality of (three) tools 44 for back side processing for processing the bar W. The tools 44 are each fixed to the base 2 via the back tool post 45, and can be appropriately switched according to the processing content by moving the back spindle 20 (back spindle head 21) in the Y-axis direction.

Further, the machine tool 1 is provided with a back side movement processing unit 46 as a processing means. The back side movement processing section 46 includes a tool 47 for processing the bar W. The tool 47 is held by a tool rest 48. The tool rest 48 is supported by the base 2 so as to be movable in the X-axis direction and the Y-axis direction. The position of the tool rest 48 in the Z-axis direction is constant. The tool rest 48 is equipped with, for example, an outer diameter cutting bite or a parting bite as the tool 47, which can be appropriately switched according to the processing content by moving the tool rest 48, for example, in the X-axis direction.

The machine tool 1 includes a bar material supply unit (bar feeder) 50 arranged behind the front main spindle 10. The bar material supply unit 50 includes a finger 51 that grips the rear end of the bar material W and a drive rod 52 that drives the finger 51 in the Z-axis direction. The bar material supply unit 50 can sequentially supply the bar material W to the front main shaft 10. Further, the bar material supply unit 50 can pull in the bar material W projecting from the front main shaft 10 to the rear main shaft 20 side to the front main shaft 10 side.

The machine tool 1 includes a control unit 60. The control unit 60 may be composed of, for example, a microcomputer including a storage unit such as a CPU (Central Processing Unit) and a memory. The control unit 60 includes a front spindle 10 (including the front spindle headstock 11 and the front chuck 12), a rear spindle 20 (including the rear spindle headstock 21, and a rear chuck 22), a machining unit 40, a backside fixed machining unit 43, a backside. The operations of the moving processing unit 46 and the bar material supply unit 50 can be integrally controlled.

More specifically, the control unit 60 uses the processing unit 40, the back side fixed processing unit 43, and the back side moving processing unit 46 to perform predetermined processing on the bar W held by the front chuck 12 and the back chuck 22. The front spindle 10, the back spindle 20, the bar material supply unit 50, the machining unit 40, the back side fixed machining unit 43, and the back side moving machining unit 46 are operated so as to continuously perform the cut-off processing to obtain a plurality of products. It has a function as a product processing means.

Further, the control unit 60 removes the bar W from the front main shaft 10 as the old material W1 and transfers it to the rear main shaft 20 after the completion of the processing of the bar W by the function as the product processing means. And has a function as an old material transfer means for operating the back main shaft 20.

Further, the control unit 60 supplies the new rod W as the new rod W2 from the rod feeding unit 50 to the front spindle 10 from which the old rod W1 has been removed, and causes the front chuck 12 to hold the new rod W. It also has a function as a new material supply means for operating the bar material supply unit 50.

Further, the control unit 60 joins the opposite ends of the old material W1 gripped by the back surface chuck 20 by the back surface chuck 22 and the new material W2 gripped by the front surface chuck 12 by the front surface spindle 10 to the old material W1. It has a function as a joining means for joining the new material W2 into one bar W3.

Further, the control unit 60 removes the portion of the old material W1 of the rod material W3, which is formed by joining the old material W1 and the new material W2, by the function of the joining means, and removes the portion of the old material W1 from the back spindle 20 to the front spindle 10 side. It has a function as a retracting means for actuating the front main shaft 10, the rear main shaft 20, and the bar material supply unit 50 so as to be retracted.

Further, the control unit 60 performs predetermined processing and cut-off processing on the bar material W3 drawn into the front spindle 10 by the function of the drawing means and gripped by the front chuck 12 by the function of the product processing means described above. In order to continuously perform the above, it has a function of controlling the operations of the front spindle 10, the back spindle 20, the bar material supply section 50, the processing section 40, the back side fixed processing section 43, and the back side moving processing section 46. .

Further, the control unit 60 pulls the rod W3, which is formed by joining the old member W1 and the new member W2, into the front spindle 10 by the function as the pulling-in means and grips the rod W3 with the front chuck 12, and then the rod W3. On the other hand, when the first machining is performed by the function as the product machining means, the front main shaft 10, the back main spindle 20, and the bar material supply unit are arranged so that the front chuck 12 grips the part made of the old material W1 of the bar material W3. It has a function of controlling the operation of 50.

Further, the control unit 60 has a function as a product processing unit, and the front chuck 12 is configured to continuously perform the predetermined processing and the cut-off processing on the bar W3 formed by joining the old material W1 and the new material W2. , And has a function as a gripper moving unit that moves the front spindle 10 (front chuck 12) so as to grip a portion of the rod W3 other than the joint 80 between the old material W1 and the new material W2.

Further, the control unit 60 has a function as a product processing means, and when performing the predetermined processing and the cut-off processing on the bar material W3 obtained by joining the old material W1 and the new material W2 continuously, the control part 60 and the new material W1 are not used. When the joint 80 with the material W2 is located in the guide bush 30, the front spindle 10, the rear spindle 20, the bar material are supplied so that the bar W3 is cut off on the new material W2 side of the joint 80. It has a function of controlling the operations of the section 50 and the processing section 40.

The machine tool 1 is shown in FIG. 7B in order that the front chuck 12 recognizes the axial position of the joining portion 80 between the old material W1 and the new material W2 of the bar material W3 when performing the above control. The measuring rod 61 as the position recognizing unit or the old material position measuring terminal 62 as the position recognizing unit shown in FIG. 11C may be provided.

Next, a procedure for continuously processing a large number of products P from a long bar W by the machine tool 1 having the above configuration will be described. As described above, the procedure is performed by the integrated control of each unit of the machine tool 1 by the control unit 60.

2 to 11, the front spindle 10 and the back spindle 20 are omitted and only the front chuck 12 and the back chuck 22 are shown. However, the movement of the front chuck 12 is performed together with the movement of the front spindle 10, and It is assumed that the movement is performed together with the movement of the back spindle 20.

As shown in FIG. 2A, when the bar material W is supplied from the base end side of the front main shaft 10 to the front main shaft 10 by the bar material supply unit 50, the front chuck 12 grips the bar material W. The bar W held by the front spindle 10 (front chuck 12) is in a state of protruding from the guide bush 30 toward the back spindle 20 by a predetermined length. In this state, the front spindle 10 is rotationally driven by the spindle motor to rotate the bar W. With respect to the rotating bar W, the selected tool 41 of the machining unit 40 is moved in the Y-axis direction (cutting direction) to cut into the bar W, and the front spindle 10 (front spindle headstock 11) is moved to the Z-axis. By moving in the direction (feeding direction), the bar W can be subjected to predetermined processing (cutting).

After subjecting the bar W held by the front main shaft 10 to a predetermined process, the rear main shaft 20 is arranged coaxially with the front main shaft 10, and the end of the bar W held by the front main shaft 10 is attached to the rear main shaft 20. The rod material W is gripped by the back chuck 22 and the rod material W is cut off by the tool 41 in this state, so that the cut rod material W can be transferred from the front main spindle 10 to the back main spindle 20.

As shown in FIG. 2 (b), it is possible to further process the bar W that has been passed from the front spindle 10 and held by the back chuck 22 on the back spindle 20. In this case, the rod material W can be processed (cut) by the selected tool 44 of the rear surface side fixed processing portion 43 by moving the rear surface main shaft 20 in the Y axis direction or the Z axis direction. Further, the bar material W can be processed by the tool 47 of the back side moving processing unit 46. By the processing, the bar W is made into the product P. The completed product P is taken out from the back spindle 20 and conveyed to the next step.

During the processing of the bar W by the back main shaft 20, the bar W is fed out by the bar supply unit 50 on the side of the front main shaft 10, and again, as described above, the predetermined processing and the cut-off of the bar W on the front main shaft 10. Processing is performed. Similarly, a plurality of products P having a predetermined shape can be obtained from one long bar W by feeding out the bar W and repeating predetermined processing and cut-off processing.

As shown in FIG. 3A, when a plurality of products P are processed from the bar material W and the bar material W has a length that cannot be processed in a state where the bar material W is gripped by the front chuck 12 of the front spindle 10, The processing of the material W is completed, and the bar material W becomes the old material W1 as the remaining material.

When the processing of the bar W is completed and the old material W1 is generated, the back spindle 20 moves so as to approach the front spindle 10. The gripping of the old material W1 by the front chuck 12 is released, and the old material W1 is gripped by the back surface chuck 22. Then, the old material W1 is passed from the front spindle 10 to the back spindle 20 by causing the back chuck 22 to grip the old material W1. The back main spindle 20 that has received the old material W1 moves in the Z-axis direction so as to separate from the front main spindle 10 while holding the old material W1. Next, a new bar material W is supplied as a new material W2 from the bar material supply unit 50 to the front spindle 10. The new material W2 is gripped by the front chuck 12 to be in the state shown in FIG. 3 (b).

Next, the old material W1 and the new material W2 are joined together. At this time, a procedure for recognizing the axial position of the joined portion 80 in the rod material W3 after joining is also performed.

First, as shown in FIG. 4A, the tip of the new material W2 facing the back spindle 20 is end-face processed by the tool 41. Here, the tool 41 is supported by the guide bush support base 31 and the position in the Z-axis direction (Z1-0) is determined, and the Z-axis position (Z1-1) of the front chuck 12 also controls the position of the front chuck 12. Since it is recognized by the control unit 60, the control unit 60 can calculate the protruding length A of the new material W2 from the front chuck 12.

Next, the front main shaft 10 and the back main shaft 20 are moved in the Z-axis direction so as to approach each other, and as shown in FIG. 4 (b), the end surfaces of the old material W1 and the new material W2 facing each other are brought into contact with each other. At this time, the back spindle 20 is set to the torque skip state (the movement of the back spindle is stopped by detecting the torque change of the motor in the back side moving mechanism 4 when the end faces abut each other), whereby the old material W1 When the opposite end surfaces of the new material W2 and the new material W2 come into contact with each other, the displacement of the old material W1 or the new material W2 with respect to the back main spindle 20 or the front main spindle 10 or the movement of the front main spindle 10 in the Z-axis direction does not occur. There is.

Next, as shown in FIG. 5A, the rear surface chuck 22 is opened while the end surfaces are in contact with each other, and the rear surface spindle 20 is moved to the front surface spindle 10 side. The back side chuck 22 is made to grip the tip side portion near the material W2. Then, while the old material W1 is held by the back surface chuck 22, the back spindle 20 is moved in the Z-axis direction away from the front spindle 10, and the end surface of the old material W1 and the end surface of the new material W2 are separated from each other, respectively. The

recesses

70 and 71 are processed using the tools 41 to 44 and the like.

Next, the ends of the old material W1 gripped by the back surface chuck 22 and the new material W2 gripped by the front surface chuck 12 (end surfaces having the recesses 70, 71) facing each other are friction-welded. Friction welding can be performed by the following procedures, for example.

First, the rear main shaft 20 is moved in the Z-axis direction toward the front main shaft 10 in the torque skip state, and the end surface of the old material W1 and the end surface of the new material W2 are moved to each other as shown in FIG. 6 (a). Abut. Then, from the position where the end surface of the old material W1 and the end surface of the new material W2 are in contact with each other, the back spindle 20 is further moved in the Z-axis direction by a predetermined distance (for example, 0.3 mm) toward the front spindle 10. Then, the end surface of the old material W1 and the end surface of the new material W2 are brought into contact with each other at a predetermined pressure. Then, in this state, for example, by rotating only the rear surface spindle 20 at a predetermined speed while stopping the front surface spindle 10 without rotating it, frictional heat is generated between the end surface of the old material W1 and the end surface of the new material W2. Then, the end face is heated.

In the present embodiment, the front main spindle 10 and the rear main spindle 20 are rotated relative to each other by rotating only the rear main spindle 20 at a predetermined speed while stopping the front main spindle 10 without rotating the front main spindle 10 and the end surface of the old material W1. Friction heat is generated between the end surface of the new material W2 and the end surface of the old material W1 by rotating only the front main spindle 10 at a predetermined speed while stopping the rear main spindle 20 without rotating it. May generate frictional heat between the end surface of the old material W1 and the end surface of the new material W2 by rotating the front main shaft 10 and the back main shaft 20 in opposite directions. May be generated between the end faces of the old material W1 and the new material W2 by rotating the front spindle 10 and the back spindle 20 in the same direction at different speeds. May be generated.

When the end surface of the old material W1 and the end surface of the new material W2 reach a predetermined temperature due to frictional heat generated between the end surface of the old material W1 and the end surface of the new material W2, relative rotation of the front spindle 10 and the rear spindle 20 is performed. The front main shaft 10 and the rear main shaft 20 are relatively moved in a direction of approaching each other so that the end of the old material W1 and the end of the new material W2 are moved in the Z-axis direction at a predetermined pressure (upset pressure). Press down. As a result, as shown in FIG. 6B, the old material W1 and the new material W2 are joined together by the joining portion 80 having their axial end faces as joining surfaces to form one rod W3.

As shown in FIG. 6B, in the joint portion 80 of the bar material W3 that has been frictionally welded, the portions softened by the frictional heat of the old material W1 and the new material W2 are pushed outward in the radial direction during the pressure contact. Burr 90 is generated by After the friction welding of the old material W1 and the new material W2 is completed, the machine tool 1 uses the tool 41 to perform a cutting process for removing the burr 90 from the bar material W3. In the cutting process, the tool 41 is pressed against the burr 90 while the bar W3 is held by at least one of the front spindle 10 and the back spindle 20, while rotating the holding front spindle 10 or the back spindle 20. It can be easily done by applying.

By performing the cutting process for removing the burr 90, as shown in FIG. 6C, on both sides of the joint 80 of the outer peripheral surface of the rod W3, a diameter smaller than that of the outer peripheral surface of the rod W3 is provided. The reduced diameter portion 81 is generated.

In the present embodiment, the frictional pressure welding can be easily performed by processing the

recesses

70 and 71 on the end surface of the old material W1 and the end surface of the new material W2, but without processing the

recesses

70 and 71. Friction welding may be performed.

When the old material W1 and the new material W2 are joined to form the bar material W3, as shown in FIG. 7A, the gripping of the bar material W3 of the rear chuck 22 is released, and the new material W2 of the bar material W3 is released. The front chuck 12 gripping the portion of (1) is moved in the Z-axis direction so as to be separated from the back spindle 20 together with the front spindle 10. As a result, the rod W3 is pulled toward the front spindle 10 side and removed from the back spindle 20.

Next, as shown in FIG. 7B, the back spindle 20 is moved in the Z-axis direction and the Y-axis direction, and the tip of the measuring rod 61 fixed to the back spindle stock 21 of the back spindle 20 is replaced with the old material. The rear end face of W1 facing away from the front main shaft 10 is brought into contact with the rear end face in a torque skip state.

Here, since the measuring rod 61 is fixed to the back spindle 21 of the back spindle 20, the control unit 60 that controls the position of the back spindle 20 recognizes the position of the tip of the measuring rod 61 in the Z-axis direction. You can Further, as described above, the control unit 60 can also recognize the position of the front chuck 12 in the Z-axis direction. Therefore, by bringing the tip of the measuring rod 61 into contact with the rear end surface of the old material W1, the control unit 60 can calculate the protruding length B of the rod W3 from the front chuck 12.

The ends of the old material W1 and the new material W2, which form the rod material W3, are crushed at the joining portion during friction welding, and the crushing length α is Z between the front spindle 10 and the back spindle 20 during friction welding. It can be calculated from the relative amount of movement in the axial direction.

Therefore, the control unit 60 can calculate the length L of the portion made of the old material W1 in the bar material W3 by L = BA + α / 2. Since the length L corresponds to the distance from the tip of the rod W3 to the joint 80, the controller 60 can recognize the position of the joint 80 in the Z axis direction on the rod W3. Further, even if the bar W3 is repeatedly cut off, the control unit 60 can recognize the position where the cut off is performed. Therefore, the axial position of the joint 80 in the bar W3 after the cut off is performed. Can always be recognized.

When the calculation of the position of the joint portion 80 in the rod W3 in the Z-axis direction is completed, the end face of the rod W3 is processed by the tool 41, and the front spindle 10 is opened with the front chuck 12 opened while pressing the end face with the tool 41. It moves in the Z-axis direction so as to approach the back spindle 20. Then, as shown in FIG. 8A, the front chuck 12 grips the portion of the rod W3 made of the old material W1. Then, as shown in FIGS. 8A and 8B, in this state, the front spindle 10 is rotationally driven by the spindle motor to rotate the bar W3, and the selected tool 41 of the machining unit 40 is moved to Y. The bar W3 is moved in the axial direction (cutting direction) to cut into the bar W3, and the front spindle 10 (front headstock 11) is moved in the Z axis direction (feed direction) to perform a predetermined machining (cutting) on the bar W3. And the parting process is continuously performed to process a plurality of products P from the bar W3.

Here, in the machine tool 1 of the present embodiment, as shown in FIG. 8A, first, for forming the product P on the bar material W3 in which the old material W1 and the new material W2 are joined. At the time of performing the above-mentioned processing, the front chuck 12 grips the portion of the rod W3 made of the old material W1. Therefore, at the time of the processing, the weak joint portion 80 is prevented from being located between the portion processed by the tool 41 and the portion gripped by the front chuck 12, and the old material W1 of the rod W3 is removed from the old material W1. It is possible to perform the processing in a state in which the front portion is securely held by the front chuck 12. As a result, the portion of the rod W3 made of the old material W1 can be accurately processed.

On the other hand, when the bar material W3, in which the old material W1 and the new material W2 are joined, is continuously subjected to the predetermined processing and the cut-off processing for forming the product P, it is shown in FIG. 9 (a). As described above, the axial position of the front chuck 12 and the axial position of the joint portion 80 of the bar W may coincide with each other. When the axial position of the front chuck 12 and the axial position of the joint portion 80 of the bar W coincide with each other, the bar W3 cannot be reliably gripped by the front chuck 12, and the machining accuracy of the bar W3 is reduced. There is a risk. In particular, when the old material W1 and the new material W2 are joined by friction welding and then the burr 90 is cut off, the bar W3 is formed on both sides of the joint 80 on the outer peripheral surface of the bar W3. Since a reduced diameter portion 81 having a smaller diameter than the outer peripheral surface of the rod is generated, when the front chuck 12 grips the portion of the joint portion 80 of the bar W3, the front chuck 12 and the joint portion 80 or the reduced diameter portion 81 are separated from each other. There is a possibility that a gap may be generated in the rod W3 and rattling may occur in the rod W3, and the processing accuracy of the rod W3 may be significantly reduced.

On the other hand, in the machine tool 1 of the present embodiment, the control unit 60 continuously performs the predetermined machining and the cut-off machining on the rod W3 and the axial position of the front chuck 12 and the rod W3. When the axial position of the joining portion 80 of No. 1 is coincident with the axial position of the joining portion 80, the front main spindle 10 (front chuck 12) is moved in the Z-axis direction relative to the rod W3 or the tool 41, and then the rod is moved by the front chuck 12. The control for gripping the portion of the material W3 made of the new material W2 is performed. As a result, as shown in FIGS. 9B and 9C, a portion of the rod W3 other than the joining portion 80 between the old material W1 and the new material W2 is gripped by the front chuck 12, that is, the front surface. Predetermined processing and cut-off processing by the tool 41 can be performed while the bar material W3 is securely held by the chuck 12. Therefore, the bar W3 can be processed accurately.

The controller 60 can always accurately recognize the axial position of the joint 80 on the rod W3 by the procedure using the measuring rod 61 described above. The control unit 60 grips the front chuck 12 on the portion other than the joining portion 80 between the old material W1 and the new material W2 of the rod material W3, based on the correctly recognized axial position of the joining portion 80 on the rod material W3. As described above, the movement of the front main spindle 10 in the Z-axis direction can be accurately controlled. Therefore, the front chuck 12 can hold the bar W3 more reliably, and the bar W3 can be processed more accurately.

The controller 60 joins the old material W1 and the new material W2 by friction welding and then performs a process of cutting off the burr 90, when the axial position of the front chuck 12 and the reduced diameter portion 81 of the bar material W3. It is preferable to move the front main spindle 10 in the Z-axis direction even when the position coincides with the axial position. This prevents the front chuck 12 from gripping not only the joint portion 80 of the rod W3 but also the portion of the reduced diameter portion 81, so that the rod W3 can be processed more reliably and accurately.

In the present embodiment, when the axial position of the front chuck 12 and the axial position of the joint portion 80 of the bar W match, the front spindle 10 (front chuck 12) is moved in a direction away from the back spindle 20. The front chuck 12 grips the portion of the bar W3 made of the new material W2. In this case, it is possible to move the front chuck 12 in the Z-axis direction by a desired distance by reducing restrictions on the moving space of the front main shaft 10 or the front chuck 12.

On the other hand, when the axial position of the front chuck 12 and the axial position of the joint portion 80 of the bar W coincide with each other, the front main spindle 10 (front chuck 12) is moved toward the rear main spindle 20, and then the front chuck is moved. Alternatively, the portion of the rod W3 made of the old material W1 may be gripped by the rod 12. In this case, the front chuck 12 can hold a position closer to the processed portion of the bar W3. As a result, the bar W3 can be held more reliably by the front chuck 12, and the bar W3 can be processed more accurately.

When the machine tool 1 is configured to include the guide bush 30, the control unit 60, as shown in FIG. 10 (a), continuously performs the predetermined processing and the cut-off processing on the bar W <b> 3. When the axial position of the joint portion 80 of the rod W is located on the guide bush 30, the predetermined processing for the rod W3 is completed and the rod W3 is joined as shown in FIG. 10 (b). It is possible to adopt a configuration in which the parting control is performed on the new material W2 side with respect to the part 80. As a result, it is possible to prevent the portion of the rod W3 having the joint portion 80 from being processed as the product P.

At this time, the control unit 60 processes the product P from the portion made of the old material W1 of the bar W in advance based on the axial position of the joint 80 so that the guide bush 30 does not support the joint 80. The number may be set.

Also in this case, when the reduced diameter portion 81 of the bar W is located in the guide bush 30, the predetermined processing for the bar W3 is completed, and the bar W3 is positioned closer to the new material W2 than the joint 80. You may make it control the parting off. As a result, it is possible to prevent the portion of the rod W3 having the reduced diameter portion 81 from being processed as the product P.

The method for causing the controller 60 to recognize the position of the joint 80 in the Z-axis direction is not limited to the method using the measuring rod 61 described above, and various methods or configurations can be adopted.

For example, as shown in FIG. 11A, after the old material W1 is transferred to the back main shaft 20, before the friction joining is performed, the amount of protrusion of the old material W1 from the back chuck 22 is adjusted by the back side positioning plate 72. The amount of protrusion of the new material W2 from the front chuck 12 is measured by the front side positioning plate 73, and the end surface of the old material W1 and the end surface of the new material W2 are, if necessary, measured as shown in FIG. 11B. 11C, the end surface of the old material W1 and the end surface of the new material W2 are brought into contact with each other, and the position of the rear end surface of the old material W1 is adjusted by the old material position measuring terminal 62, as shown in FIG. 11C. By measuring the positions of the front chuck 12 and the back chuck 22 in the Z-axis direction, the protruding amount of the old material W1 from the back chuck 22, the protruding amount of the new material W2 from the front chuck 12, and the old material position measuring terminal 62. May be calculated the position of the joint portion 80 on the basis of the position of the rear end face of the constant has been old wood W1.

The method for causing the control unit 60 to recognize the position of the joining portion 80 in the Z-axis direction is not limited to the above. For example, a bar material W3 obtained by joining the old material W1 and the new material W2 is photographed by a camera. A method of detecting the position of the joint 80 in the Z-axis direction by performing image recognition processing on the captured image, a method of detecting the position of the joint 80 in the Z-axis using an optical position detection sensor, and a controller Various methods such as a method of detecting the position of the joint 80 in the Z-axis direction based on the machining program of 60 and a method of calculating the position of the joint 80 in the Z-axis direction based on the machining length of the bar W are adopted. can do.

Needless to say, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

For example, in the above-described embodiment, the old material W1 and the new material W2 are joined by friction welding, but the invention is not limited to this. For example, a concave portion may be formed on one end of the old material W1 and the new material W2. Is provided, a convex portion is provided on the other of the old material W1 and the new material W2, and the old material W1 and the new material W2 are joined by fitting them, and the joining means can be variously changed. .

In the above-described embodiment, the machine tool 1 includes the guide bush 30, but the guide bush 30 may be omitted.

In the above-described embodiment, the old material W1 is held by the back surface chuck 22 of the back surface spindle 20, but a work clamp device having an axis parallel to the axis of the back surface spindle 20 and installed on the back surface spindle 20 is provided. It is also possible. It is also possible that the clamp device grips the old material W1 and the front chuck 12 of the front spindle 10 grips the new material W2 to bring their end surfaces into contact with each other to perform friction welding to form the bar material W3. Further, it is also possible to transfer a work obtained by processing the rod W3 by the front main spindle 10 from the front main spindle 10 to the back main spindle 20 and continue the processing on the back main spindle 20.

In the above-described embodiment, after the old material W1 and the new material W2 are joined to form one bar W3, the front chuck (first gripping means) 12 holds the bar W3 while the back chuck (second grip) is held. The gripping of the bar W3 by the means 22 is released, and the front chuck 12 for gripping the bar W3 is moved in the Z-axis direction away from the back main shaft (second main shaft) 20 together with the front main shaft (first main shaft) 10. By moving the rod W3, the rod W3 is pulled toward the front spindle 10 side and pulled out from the back spindle 20, but the invention is not limited to this, and the old rod W1 and the new rod W2 are joined together to form one rod W3. After that, without moving the front chuck 12 together with the front spindle 10 in the Z-axis direction, the rod material supply unit 50 pulls the rod material W3 from the back spindle 20 side to the front spindle 10 side and pulls it out from the back spindle 20. It may be formed. In this case, the front main shaft 10 may not move in the Z-axis direction with respect to the base 2. The control unit 60 as a retracting means pulls out the portion of the old material W1 of the bar material W3 from the rear surface main shaft 20 by the bar material supply unit 50 and retracts it to the side of the front main shaft 10, so that the front main shaft 10 and the rear main shaft 20 are connected. Also, the operation of the bar material supply unit 50 is controlled.

More specifically, when the old material W1 and the new material W2 are joined to form the bar material W3, both the gripping of the bar material W3 of the front chuck 12 and the gripping of the bar material W3 of the rear chuck 22 are released. At the same time, the rear end of the bar W3 is gripped by the fingers 51 of the bar supply unit 50, and in this state, the fingers 51 are driven by the drive rod 52 to move the fingers 51 in the Z-axis direction in the backward direction away from the rear main shaft 20. To do. As a result, the rod material W3 can be drawn into the front spindle 10 side by the rod supply portion 50 and can be removed from the back spindle 20.

1 machine tool 2 base 3 front side moving mechanism 4 back side moving mechanism 10 front side spindle (first spindle)
11 front headstock 12 front chuck (first gripping means)
13 Chuck sleeve 20 Back spindle (second spindle)
21 Rear Headstock 22 Rear Chuck (Second Grip Means)
23 Chuck Sleeve 30 Guide Bush 31 Guide Bush Support 40 Processing Section (Processing Means)
41 tool 42 turret 43 rear side fixed processing section (processing means)
44 tool 45 rear tool post 46 rear side moving processing section (processing means)
47 tool 48 turret 50 bar material supply unit 51 finger 52 drive rod 60 control unit 61 measuring rod (position recognition means)
62 Old material position measurement terminal (position recognition means)
70 recessed part 71 recessed part 72 rear side positioning plate 73 front side positioning plate 80 joint part 81 reduced diameter part 90 burr W bar material W1 old material W2 new material W3 bar material P product A protruding length B protruding length α collapsed length L length

Claims

A first spindle having a first gripping means,
A second spindle including a second gripping means and facing the first spindle;
A bar material supply unit for supplying a long bar material to the first main shaft,
A processing means provided with a tool for processing the bar,
The first main spindle, the second main spindle, the second main spindle, the second main spindle, A product processing means for operating the rod supply part and the processing means,
After the bar processing by the product processing means is completed, the first main shaft and the second main shaft are operated so that the bar is removed from the first main spindle as an old material and transferred to the second main spindle. Old material transfer means
The first main spindle and the bar material supply so that a new bar material is supplied as a new material from the bar material supply unit to the first main shaft from which the old material has been removed so that the first gripping means grips it. New material supply means to operate the section,
The opposite ends of the old material gripped by the second gripping means and the new material gripped by the first gripping means are joined together to form the old material and the new material into one bar. Joining means,
The first spindle so that the portion of the old material of the rod formed by joining the old material and the new material by the joining means is removed from the second spindle and pulled toward the first spindle. A retracting means for operating the second main shaft and the bar material supply part,
A machine tool for continuously performing predetermined processing and cut-off processing by the product processing means on the bar material drawn into the first spindle by the drawing means and gripped by the first gripping means,
When the product processing means performs the first processing on the bar material that is drawn into the first spindle by the drawing means and is gripped by the first gripping means, the first gripping means is A machine tool characterized in that it grips a portion made of the old material.
The first gripping means is movable in the axial direction of the first main shaft with respect to the bar material,
The first gripping means grips a portion of the bar other than the joint between the old material and the new material when continuously performing the predetermined processing and the cut-off processing on the bar by the product processing means. The machine tool according to claim 1, further comprising a gripper moving unit that moves the first gripping unit.
A guide bush for movably supporting the rod in the axial direction of the first main shaft is provided between the first main shaft and the second main shaft,
When the predetermined processing and the cut-off processing for the bar material by the product processing means are continuously performed, when the joint between the old material and the new material is located in the guide bush, the product processing means, The first spindle, the second spindle, the rod supply unit, and the processing means are operated so as to cut off a rod on the side of the new material with respect to the joining portion. Machine tool described.
The machine tool according to any one of claims 1 to 3, further comprising position recognition means for recognizing an axial position of a joint portion between the old material and the new material.
With the drawing means releasing the grip of the bar by the first gripping means and the second gripping means, the bar is fed from the side of the second spindle to the first spindle by the bar feeding part. The machine tool according to any one of claims 1 to 4, wherein the machine tool is configured to be retracted to the side.