JP2000343301A - Supporting method and device for rod-shaped workpiece by turning machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rod-shaped workpiece supporting device of a turning machine tool capable of turning a rod-shaped workpiece in the condition that run-out is prevented using the effect of centrifugal force due to the rotation of a spindle. SOLUTION: A rod-shaped workpiece supporting device of a lathe 1 is to support a rod-shaped workpiece 3 in cooperation with a chuck 12 attached to the front part of a spindle 10, wherein the workpiece 3 is grasped by the chuck 12 and rotated in a single piece with the spindle 10. The spindle 10 is furnished with a supporting means 22 located a certain distance behind the chuck 12 and supporting the workpiece 3 by the effect of centrifugal force due to the rotation of the spindle 10, and rotation is generated while the center line of the workpiece 3 is positioned approx. identical to an axis CL of the spindle 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device and method for supporting a bar-shaped workpiece (hereinafter, referred to as a bar work) having an axial dimension at least several times longer than a radial dimension in a lathe or other turning machine tool. .

[0002]

2. Description of the Related Art Among turning machine tools, for example, a lathe is provided with a gripping means such as a collet chuck or a hollow chuck at a front end of a spindle, a bar work is inserted into a hole formed on the spindle, and the bar is inserted by a collet chuck or the like. Turning is performed by gripping the workpiece. In such a lathe, if there is a gap between the outer periphery of the bar work and the hole of the spindle, the following problem occurs. That is, when the bar work whose one end is grasped by the grasping means is rotated together with the main shaft, the bar work vibrates at the other end (the side opposite to the grasping position). The run-out tends to increase in amplitude when the rotation speed of the spindle increases, and causes problems such as causing the spindle or the like to vibrate so that machining cannot be performed, and reducing machining accuracy of a turned product. For this reason, an anti-sway member called a filler tube is inserted into the main shaft to prevent the runout of the bar work, and to reduce the generation of vibration of the main shaft and the like. However, in a lathe, since bar workpieces having different diameters are sometimes turned, it is necessary to replace the filler tube each time, and it takes a long time to perform a setup change operation. In addition, if this setup change operation takes time, the operation rate of the lathe decreases.

[0003] Therefore, various techniques for preventing the occurrence of runout of the bar work during rotation of the spindle have been conventionally proposed as techniques replacing the replacement of the filler tube. For example, Japanese Patent Application Laid-Open No. 7-164206 discloses a bag-like elastic body which can be expanded and contracted by supplying and discharging a pressure fluid, and is supported in a radial direction in order to prevent a runout of a bar-shaped workpiece (bar work). A bar-shaped workpiece steady rest support device for an automatic lathe is described. On the other hand, Japanese Utility Model Publication No. 3-44405 describes a support that supports a long material (bur work) from a radial direction by expanding and contracting a plate spring in a radial direction by elastically deforming a plate spring in an axial direction of a main shaft. ing.

[0004]

However, the technique described in Japanese Patent Application Laid-Open No. 7-164206 may cause a problem in the life of the bag-shaped elastic body. Meanwhile, actual fairness 3
The technology described in Japanese Patent No. 44405/44 requires a complicated setup adjustment operation of adjusting the amount of deflection of a leaf spring by a spring operating member every time the diameter of a bar work to be processed changes, and the operating rate of a machine tool is reduced. There was a risk of lowering.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and it is possible to perform turning by supporting a bar-shaped workpiece in a state where run-out of the bar-shaped workpiece is prevented by the action of centrifugal force caused by rotation of a main shaft. It is an object of the present invention to provide a supporting device and a supporting method for a rod-shaped workpiece in a turning machine tool. Another object of the present invention is to reduce the occurrence of run-out during rotation of a bar-shaped workpiece within a predetermined wide diameter range without performing a setup change operation of a support means for supporting the bar-shaped workpiece at the rear side of the spindle. Is to automatically support in a state where is prevented.

[0006]

In order to achieve the above-mentioned object, a supporting device for a bar-shaped workpiece in a turning machine tool according to the present invention is gripped by a gripping means on the front side of a spindle and rotated with the spindle. A bar-shaped workpiece support device in a turning machine tool for supporting a bar-shaped workpiece in cooperation with the gripping means, wherein the gripping means is attached to the spindle or a rotating body that rotates integrally with the spindle. Is provided at a rearward position away from the main shaft by a predetermined distance, and when the main shaft rotates, a supporting means for supporting the rod-shaped workpiece by the action of centrifugal force due to the rotation is provided, and a center line of the rod-shaped workpiece is a central axis of the main shaft. It is possible to rotate almost in line with. As a specific embodiment, the supporting means has at least three supporting moving members provided so as to be able to move forward and backward to abut and support the outer periphery of the bar-shaped workpiece from at least three directions, and the main shaft rotates. It is preferable that the bar-shaped workpiece is supported by moving the at least three supporting moving members in the supporting direction by the action of the centrifugal force when the bar-shaped workpiece is moved. For example, when the rotation speed of the main shaft is higher than a predetermined rotation speed, the support unit supports the rod-shaped workpiece by the action of the centrifugal force, and when the rotation speed of the main shaft is lower than the predetermined rotation speed, It is preferable that the support moving member is moved in the support release direction so as to be separated from the outer periphery of the bar-shaped workpiece, and the support of the bar-shaped workpiece is released.
Further, the support means is fixed to the main shaft or the rotating body and is rotatable integrally with the main shaft, and is provided on the main body so as to be swingable, and swings by the action of the centrifugal force. A weight member for supporting a rod-shaped workpiece, and a bias provided between the main body and the weight member, and constantly biased to swing the weight member in a direction opposite to the acting force due to the centrifugal force. And a member. Specifically, the support means includes a main body fixed to the main shaft or the rotating body and rotating integrally with the main shaft, and a main body provided at a position corresponding to the at least three supporting moving members. Swingably provided, at least three weight members that swing by the action of the centrifugal force to move the supporting moving member in the supporting direction, and are provided between the main body portion and the weight member, It is preferable that a biasing member that constantly biases the weight member to swing in a direction opposite to the acting force due to the centrifugal force is provided. Further, it is preferable that the supporting means is provided between the gripping means and a gripping means driving device for gripping / releasing the gripping means. Furthermore, it is preferable that the bar-shaped workpiece support device includes a workpiece guide member which is provided in the gripping means so as to be replaceable and which guides and supports the bar-shaped workpiece in an auxiliary manner.

A method for supporting a bar-shaped workpiece in a turning machine tool according to the present invention is provided on a front side of a spindle.
Gripping means for gripping the rod-shaped workpiece for rotating the rod-shaped workpiece together with the main spindle, and a rotating body which rotates integrally with the main spindle or the main spindle, provided at a rear position separated by a predetermined distance from the gripping means, A method of supporting a bar-shaped workpiece in a turning machine tool having a bar-shaped workpiece support device having a support means capable of supporting and releasing support from the bar-shaped workpiece, wherein the main spindle rotates at a predetermined rotation speed or more. At this time, the support means supports the rod-shaped workpiece by the action of the centrifugal force due to this rotation, and when the main shaft rotates at a lower rotation number than the predetermined rotation number, the support means releases the support to the rod-shaped workpiece. I am trying to do it.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front view of a lathe to which a bar feeder is attached, FIG. 2 is a front sectional view of the lathe provided with the bar-shaped workpiece support device of the present invention, and FIG.
FIG. 4 is an enlarged front sectional view showing a part of the lathe, and FIG. 4 is a sectional view taken along line IV-IV in FIG. In the present embodiment, a lathe is shown as the machine tool for turning. However, the bar-shaped workpiece (bar work) gripped by the gripping means at the spindle end is rotated, and the bar-shaped workpiece and the tool are separated by at least the spindle. For machine tools that perform turning by relatively moving in a direction parallel to the axis (Z-axis direction) and a direction perpendicular to the spindle axis (X-axis direction), other machine tools such as NC lathes, automatic lathes, turning centers, etc. Any type of machine tool for turning may be used.

As shown in FIG. 1, a lathe 1 is provided with a bar feeder 2 as a bar-shaped workpiece supply device. The bar feeder 2 lathes a bar-shaped workpiece (bar work) 3 such as a round bar or a square bar whose axial dimension is at least several times (for example, several to several tens times) longer than the radial dimension.
Are supplied sequentially for each predetermined dimension. The bar feeder 2 is disposed near the lathe 1. The bar feeder 2 is installed such that the center of the bar-shaped workpiece 3 to be supplied to the lathe 1 is located on the same or almost the same axis as the center axis CL of the main spindle (hereinafter referred to as the main spindle axis). Bar feeder 2
Is to move the unmachined bar-shaped workpiece 3 forward to the lathe 1 side, to insert it from the rear side Ba of the headstock 5 to the front side (processing area side) Bb through the inside of the main spindle, and to start a predetermined amount (predetermined An operation (forward feeding) of feeding forward by a length L (FIG. 2) so as to protrude from the chuck 12 is performed. The bar feeder 2 intermittently moves the bar-shaped workpiece 3 forward, so that the lathe 1 is gripped in a state where the bar-shaped workpiece 3 protrudes a predetermined length from a chuck 12 provided at the spindle end and rotates with the spindle. Turn.

The lathe 1 has a headstock 5 fixed on a bed 4 and a saddle 6a movably provided on the bed 4. On the bed 4, a Z guide surface 9 is formed in a Z-axis direction which is a direction parallel to the direction of the main axis CL. The saddle 6a is driven by a Z-axis servomotor (not shown), a ball screw, or the like, is guided by the Z guide surface 9, and moves in the Z-axis direction. The cross slide 6b has an X on the saddle 6a.
It is provided movably guided by the guide surface 6c. The main body 6d of the tool rest 6 is mounted on the cross slide 6b. That is, the cross slide 6b to which the tool rest 6 is attached is driven by an X-axis servomotor (not shown), a ball screw, or the like, and is movable in the X-axis direction orthogonal to the Z-axis direction. A turret 7 is provided on the tool rest main body 6d in a predetermined direction, for example, an axis CL parallel to the main axis CL.
It is provided so as to be able to rotate around 1. A plurality of tools 8 are radially mounted on the turret 7. The lathe 1 may be another type of machine tool for turning that moves relatively not only in the X-axis direction and the Z-axis direction but also in the Y-axis direction and the C-axis direction. In addition, a tailstock may be provided on a guide surface (not shown) on the bed 4. In this case, the center of the tailstock supports the tip of the bar-shaped workpiece 3 in a pressed state. The rod-shaped workpiece 3 can be firmly supported therein.

As shown in FIGS. 1 and 2, a main shaft 10 is rotatably supported by a main bearing 11 on the headstock 5. The spindle 10 is rotated by a spindle motor provided inside (or outside) the headstock 5 directly or via a driving force transmission mechanism, and rotates at a desired rotation speed. A hollow hole 14 is formed in the center of the spindle 10 in the direction of the spindle axis CL, so that the bar-shaped workpiece 3 can be inserted between the rear side Ba and the front side Bb. A chuck 12 is provided at the front end of the spindle 10 as a gripping means on the front side of the spindle, and a collet 40 of the chuck 12 is formed with a grip 21 for inserting and gripping the bar-shaped workpiece 3. Have been. The chuck 12 has a spindle 10
Of the bar-shaped workpiece 3 inserted into the holding portion 21 through the hollow hole 14 of FIG. In the present embodiment, a collet chuck is used as the chuck 12, but another chuck such as a hollow chuck may be used as long as it has a function of inserting the bar-shaped workpiece 3 and holding / releasing the workpiece. Further, the collet chuck is described as a stationary type collet chuck, but may be another type of collet chuck such as an extrusion type or a retract type.

At the rear of the main shaft 10, there is provided a rear support means 22 for supporting and releasing the rod-shaped workpiece 3 at a predetermined position in cooperation with the chuck 12. A support device 23 is constituted by the front chuck 12 and the support means 22. The support means 22 is provided at a rear position away from the chuck 12 by a predetermined distance, and is for supporting the bar-shaped workpiece 3 by the action of centrifugal force due to the rotation of the main shaft 10 when the main shaft 10 rotates. The support means 22 may be provided on a rotating body that rotates integrally with the main shaft 10. Behind the spindle 10, a gripping means (chuck 12) is gripped.
A chuck cylinder device (hereinafter, referred to as a cylinder) 24 is provided as a driving device for gripping means for releasing gripping. The cylinder 24 is supplied with a pressure fluid such as pressure oil having a predetermined pressure. The chuck 12 is
By switching the direction of supply of the pressurized fluid to the cylinder 24, the piston 46 is driven by the piston 46 moving in the direction of the spindle axis CL, so that the front side of the bar-shaped workpiece 3 can be gripped and released. A rotary joint 27 is provided behind the cylinder 24. The rotary joint 27 is for connecting the pressure fluid supply source on the fixed side to each flow path of the cylinder 24 that rotates together with the main shaft 10. A stay 26 is fixed to the headstock 5 toward the rear. A rotating member (not shown) of the rotary joint 27 is attached to a cylinder 24 that rotates with the main shaft 10, and a fixed member (non-rotating member) 28 is restricted from rotating by a stay 26. .

The main body portions 20a and 20b of the chuck 12 are formed in an annular shape.
It is fixed by a fastening member such as 5b. Main unit 20b
, A cap 36 is detachably fixed by bolts (not shown). A sleeve 38 is fitted on the inner peripheral surface 37 of the main body 20b so as to be movable in the direction of the spindle axis CL. A distal end of a cylindrical draw tube 39 is screwed and fixed to a rear portion of the sleeve 38. The rear end of the draw tube 39 is connected to the piston 46 of the cylinder 24, and the draw tube 39 is movable in the hollow hole 14 of the main shaft 10 in the main shaft axis CL direction. Sleeve 3
A collet 40 is mounted inside 8, and the collet 40 is in contact with the sleeve 38 by the tapered portion 41 and is restricted from moving forward by the cap 36.
In the tapered portion 41, the tapered portion 41 of the collet 40 and the tapered hole 38a of the sleeve 38 are in sliding contact. The cap 36 has a function of a stopper so that the collet 40 does not slip forward. The sleeve 38 is attached to the cylinder 24
Driven by the main shaft axis CL through the draw tube 39
To the collet 40 in the tapered hole 38a.
By pressing the tapered portion 41, the grip portion 21 of the collet 40 is reduced in diameter. When the sleeve 38 moves rearward, the diameter of the grip portion 21 of the collet 40 is increased by the spring force of the collet 40, and the grip of the bar-shaped workpiece 3 is released.
Thus, the collet 40 grasps and releases the bar-shaped workpiece 3 inserted through the grasping portion 21.

The chuck 12 is provided with a guide member 43 as a work guide member. That is, at the rear end portion 42 of the collet 40, a replaceable guide member 43 for assisting and guiding the bar-shaped workpiece 3 is mounted so as to protrude rearward. The guide member 43 has a substantially cylindrical shape and is elongated in the direction of the main axis CL.
It is arranged inside the draw tube 39. The front end 44 of the guide member 43 is screwed and fixed to the rear end 42 of the collet. The inner diameter of the guide member 43 is the collet 4
The collet 40 and the guide member 43 correspond to a grippable diameter of the gripper 21 of 0. That is,
The inner diameter of the guide member 43 is larger than the outer diameter of the rod-shaped workpiece 3 by a predetermined amount so that the rod-shaped workpiece 3 having an outer diameter dimension that can be gripped and released by the collet 40 can be inserted.
The guide member 43 is provided to prevent the runout of the rod-shaped workpiece 3 shorter than the position of the support means 22 from occurring at the time of rotation.
The bar-shaped workpiece 3 can be auxiliary-guided and supported substantially at the position of the spindle axis CL. When the outer diameter of the bar-shaped workpiece 3 to be processed is changed, a setup operation for exchanging the collet 40 and the guide member 43 applicable to the changed outer diameter is performed. Since the collet 40 and the guide member 43 may be replaced as a unit by removing the cap 36, the replacement operation is easy, and there is no difference from the operation of replacing only the collet 40. Thus, the guide member 43
Does not increase the time required for the changeover of the lathe 1, and does not reduce the operating rate of the lathe 1.

As shown in FIG. 1 to FIG. 3, the draw tube 39 is driven by the cylinder 24 to
It moves freely in the L direction. Cylinder 2
In 4, the large diameter portion 47 of the piston 46 is fitted in the cylinder hole 45 so as to be movable in the direction of the spindle axis CL. A front-side small-diameter portion 48 and a rear-side small-diameter portion 49 are integrally formed on the front side and the rear side of the large-diameter portion 47, respectively. 5
0 is formed. A rear end portion 51 of the draw tube 39 is screwed and fixed inside the front side small diameter portion 48. By switching the supply path of the pressure fluid and supplying the pressure fluid to the front pressure chamber 52 or the rear pressure chamber 53 in the cylinder hole 45 partitioned by the large diameter portion 47, the piston 46
Moves in the direction of the spindle axis CL. Since the sleeve 38 moves in the direction of the main axis CL through the draw tube 39 by the movement of the piston 46, the collet 40 performs the operation of expanding and contracting the diameter of the gripping portion 21 through the tapered portion 41, and Gripping or releasing the front part of.

Next, the support means 22 will be described with reference to FIGS.
This will be described with reference to FIG. The support means 22 is preferably provided between the gripping means and the driving device for the gripping means. In this embodiment, as shown in FIGS. 2 to 4, the support means 22 is provided between the main shaft 10 and the cylinder 24, and is fixed to the rear end 65 of the main shaft 10 with a key and a nut 67. The connecting member 66 is fixed by bolts 69. The support means 22 is also connected to a front side of the cylinder body 54 of the cylinder 24 by a connecting member 57 via fastening members such as bolts 55 and 56. That is, the main shaft 10, the support means 22, the cylinder 24, the chuck 12 and the like rotate integrally. The support means 22
May be arranged on the rear side of the cylinder 24 to support the bar-shaped workpiece 3 at a predetermined position.

The supporting means 22 has at least three supporting moving members provided to be able to move forward and backward to abut and support the outer periphery of the bar-shaped workpiece 3 from at least three directions.
The support moving member is moved in the supporting direction by the action of the centrifugal force when the main shaft 10 rotates, to support the bar-shaped workpiece 3. Therefore, the support means 2 of the present embodiment
Reference numeral 2 denotes a clamper 60 as three supporting moving members which can move in the radial direction of the main shaft 10 and can be opened and closed.
When the main shaft 10 rotates at a high speed higher than a predetermined rotation speed, the three clampers 60 move in the closing direction (supporting direction) by the action of the centrifugal force due to this rotation.
The bar-shaped workpiece 3 is supported at the position of the axis CL of the spindle to enable turning. When the rotation speed of the main shaft 10 is lower than the predetermined rotation speed, the three clampers 60 move in the opening direction (support release direction) due to a decrease in centrifugal force, and are separated from the outer periphery of the bar-shaped workpiece 3. By doing so, the support of the bar-shaped workpiece 3 is released. When the support means 22 is in the support release state and the chuck 12 is in the grip release state, the bar-shaped workpiece 3 can be moved forward. This predetermined rotation speed of the main shaft 10 is preferably a rotation speed lower than the range of the rotation speed used during turning. The predetermined number of rotations may be 0 (zero) rotation or near zero rotation, but may include a predetermined numerical value and a numerical value within a certain range.

The support means 22 is fixed to the rear side of the main shaft 10 and rotates around the main shaft 10 integrally with the main body 61. The support means 22 is rotated around the main body 61 so as to swing as shown by the arrow E by the action of centrifugal force. At least three (three in the present embodiment) weight members 62 equally attached in the direction, and a main body 61
The weight member 6 is provided between the weight member 62 and the weight member 6.
There is provided a tension spring 63 as a biasing member which is constantly biased to swing the actuator 2 in the direction opposite to the acting force by the centrifugal force. The three weight members 62 are connected to the three clampers 60.
, And swings by the action of centrifugal force to move the clamper 60 in the supporting direction. Clamper 60
Are radially disposed on the main body portion 61 with respect to the center position C thereof, and are engaged with the weight member 62 so that the weight member 6
The swinging operation 2 allows the main shaft 10 to move in the radial direction. Further, the support means 22 includes an annular ring 64 as a rotating member. The ring 64 is rotatably attached to the main body 61, engages with the weight member 62, and holds the clamper 60 via the weight member 62 by one or a plurality of (three in this embodiment) tension springs 63. It is always urged in the opening direction (support release direction).

The main body 61 has a substantially circular shape and is fixed to the rear side of the connecting member 66 by a fixing member such as a bolt 69. Therefore, the main body 61 is attached to the main shaft 10 via the connecting member 66. ing. Inside the main body 61,
Three holes 70 are formed around the center position C at 120 degrees apart from each other and radially penetrate the center position C. In the hole 70, a clamper 60 is provided in the radial direction of the main shaft 10 (arrow D).
3), the three clampers 60 are evenly arranged around the center position C. 3
The individual clampers 60 can simultaneously move in the direction of the center position C (the closing direction, that is, the supporting direction) to support the bar-shaped workpiece 3 at the center position C. For this purpose, the draw tube 39 is formed with three long holes 71 for allowing the clampers 60 to pass therethrough corresponding to the positions of the respective clampers 60. The long hole portion 71 is a long hole long in the direction of the main axis CL so that the draw tube 39 can move in the direction of the main axis CL without being disturbed by the clamper 60. Inner peripheral surface 72 of main body 61 and draw tube 3
An annular cover 73 is attached between the outer peripheral surface of the body 9 and the cover 73, and the cover 73 is fixed to the main body 61 by a fastening member such as a bolt 74. The cover 73 has a long hole 7
1 and a cover 73 is formed with a fitting hole 75. The clamper 60 is movably fitted in the fitting hole 75. Since the cover 73 is provided, it is possible to prevent foreign substances such as chips from being scattered outside the draw tube 39 through the long hole portion 71.

The weight member 62 has a substantially arc shape.
It is supported by a support shaft 80 attached to the main body 61 and can swing around the support shaft 80. The support shaft 80 is disposed at a position shifted to one side from the position of the center of gravity of the entire weight member 62. That is, with respect to the support shaft 80, the center of gravity G1 on one side is located at a distance R1 from the support shaft 80, and the center of gravity G2 on the other side is located at a distance R2 from the support shaft 80. The center of gravity of the clamper 60 is located at a distance R3 from the support shaft 80. When the moment due to the centrifugal force acting around the support shaft 80 during the rotation of the supporting means 22 is compared, the moment acting due to the centrifugal force F1 generated at the center of gravity G1 on one side is larger than the moment at the center of gravity G2 on the other side. Is larger than the sum of the moment acting due to the centrifugal force F2 and the moment acting due to the centrifugal force occurring in the clamper 60. The other end 81 of the center of gravity G2 side is connected to the clamper 6 by a connecting pin 82.
0 is connected to the outer end portion 83 of the first base member so as to be relatively swingable. Hole 84 on the weight member 62 side with which the connecting pin 82 engages
Has a long hole so that the swinging operation of the weight member 62 and the moving operation of the clamper 60 can be smoothly interlocked.

Further, the weight member 62 is connected to the ring 64 by a connecting pin 85 attached to the ring 64. The connecting pin 85 is loosely engaged with a concave portion 87 having an oval cross section formed on a front surface 86 of the weight member 62. The ring 64 is rotatably (rotatably) engaged with an annular groove 89 formed on an outer peripheral surface 88 of the main body 61 in the forward and reverse directions. The main body 61 and the ring 64
Spring stoppers 76 and 77 are respectively attached. The hook 90 at one end of the tension spring 63 is engaged with the spring stopper 76 of the main body 61, and the hook 91 at the other end is engaged with the spring stopper 77 of the ring 64. The ring 64 is always urged by the tension spring 63 such that the weight member 62 always swings in the direction of arrow E in FIG. 4, that is, the weight member 62 swings counterclockwise and the clamper 60 moves in the support release direction. (Arrow H). The three tension springs 63 are attached to the main body 6.
1 and around the center position C of the ring 64 are evenly spaced apart by 120 degrees. The swing range of the weight member 62 in the counterclockwise direction in FIG. 4 is regulated by the curved inner peripheral surface 92 of the weight member 62 abutting the outer peripheral surface 93 of the main body 61. On the other hand, FIG.
When the bar-shaped workpiece 3 is inserted into the main shaft 10, the tip end portion 94 of the clamper 60 is restricted by contact with the bar-shaped workpiece 3.
When the bar-shaped workpiece 3 is not present, the protrusion 78 of the weight member 62 is regulated by contacting the stopper surface 79 of the main body 61.

Next, the operation of the above-structured support means 22 will be described with reference to FIGS. When the bar-shaped workpiece 3 is inserted into the spindle 10 by the bar feeder 2 and the front side of the bar-shaped workpiece 3 is gripped or released by the chuck 12, the support means 22 and the cylinder 24 are also rotated. Rotate with 10. The total acting force due to the centrifugal force acting around the support shaft 80 of the weight member 62 is calculated from the moment (F1 × R1) acting on the center of gravity G1 of one side (heavy side) by the centrifugal force F1 generated on the other side. Centrifugal force F2 generated at the center of gravity G2 on the side (light side)
(F2 × R2) acting on the clamper 6
A value obtained by subtracting the moment (F3 × R3) acting on the centrifugal force F3 generated at the center of gravity of 0 (F1 × R1−F2 × R2−)
F3 * R3). When the rotation speed of the main shaft 10 is lower than the predetermined rotation speed, the centrifugal force acting on the weight member 62 and the like during rotation is small. As a result, the weight member 62 is moved by the spring force S of the tension spring 63 via the ring member 64 and the connecting pin 85.
Around the support shaft 80 that rotates the counterclockwise direction (FIG. 4) overcomes the moment around the support shaft 80 due to the centrifugal force acting on the weight member 62 and the like, and the weight member 62 It swings in the rotation direction (FIG. 4).
That is, the ring 64 is pulled by the tension spring 63 and is relatively rotated with respect to the main body 61 in the counterclockwise direction (arrow H) in FIG. The weight member 62 is rotated counterclockwise about the support shaft 80 (FIG. 4).
And the inner peripheral surface 92 is in contact with the outer peripheral surface 93 of the main body 61. Thereby, the weight member 62
The clamper 60 connected with the connecting pin 82 is moved to the retreat position in the support release direction to release the support of the bar-shaped workpiece 3. Further, if the grip of the bar-shaped workpiece 3 by the chuck 12 is released by controlling the cylinder 24, the bar feeder 2
Can move the bar-shaped workpiece 3 forward.

On the other hand, when the main shaft 10 rotates at a speed higher than a predetermined rotation speed while the chuck 12 grips the bar-shaped workpiece 3, the rotation around the support shaft 80 due to the centrifugal force acting on the rotating weight member 62. The moment is the tension spring 6
With the spring force S of 3, the moment around the support shaft 80 due to the spring force of rotating the weight member 62 counterclockwise (FIG. 4) via the ring member 64 and the connecting pin 85 becomes larger. Then, the weight member 62 moves the support shaft 8 by centrifugal force.
0, the tension spring 63
Of the weight member 62 in the counterclockwise direction (FIG. 4)
Against the moment around the support shaft 80 to be turned
It swings clockwise (FIG. 4) about the support shaft 80. The clamper 60 moves in the supporting direction from the retracted position via the connecting pin 82 connected to the weight member 62, so that the distal end 94 of the clamper 60 comes into contact with the bar-shaped workpiece 3. In this way, the three clampers 60 are simultaneously moved in the supporting direction (arrow D), so that the bar-shaped workpiece 3 is evenly supported at the position of the spindle axis CL from three directions. That is,
Since the bar-shaped workpiece 3 is cooperatively supported by the chuck 12 and the support means 22, the bar-shaped workpiece 3 can be rotated such that the center line thereof substantially coincides with the center axis CL of the main shaft 10. The bar-shaped workpiece 3 can be turned with the tool 8.

Next, a procedure for turning the bar-shaped workpiece 3 with the lathe 1 will be described. Collet 40 of chuck 12
Is a state in which the bar feeder 2 is driven so that the bar-shaped workpiece 3 is inserted through the spindle 10 from the rear side Ba to the front side Bb of the headstock 5 with the gripping released state and the clamper 60 of the support means 22 released. Let's start with the explanation. (1) The tip part (or processing part) of the bar-shaped workpiece 3 is
The bar is fed to a predetermined position in front by the bar feeder 2. That is, the tool rest 6 having a stopper (not shown) attached to one surface of the turret 7 is moved to a predetermined position,
The bar feeder 2 sends out the bar-shaped workpiece 3 until it comes into contact with the stopper. With the bar-shaped workpiece 3 in contact with the stopper, a pressure fluid is supplied to the pressure chamber 53 behind the cylinder 24. Then, the piston 46 moves forward and the piston 4
6 through the draw tube 39 connected to the sleeve 3
8 advances to reduce the diameter of the gripping portion 21 of the collet 40, so that the bar-shaped workpiece 3 is gripped by the collet 40 while projecting a predetermined amount L from the chuck 12. (2) With the chuck 12 holding the front part of the bar-shaped workpiece 3, the spindle motor is controlled to control the spindle 10 and the support means 2.
A rotating body such as 2 is rotated at a rotational speed for turning the bar-shaped workpiece 3. The number of revolutions for the turning process is equal to or higher than a predetermined number of revolutions. Then, in the support means 22, the moment due to the centrifugal force acting around the support shaft 80 of the weight member 62 causes the spring force S of the tension spring 63 to rotate the weight member 62 in the counterclockwise direction (FIG. 4). Overcoming the moment about axis 80, weight member 62 swings clockwise (FIG. 4). As a result, the three clampers 60 simultaneously move in the support direction, and support the bar-shaped workpiece 3 at the main shaft axis CL at a predetermined rear position. If the rotation speed of the rotating body such as the main shaft 10 exceeds a predetermined rotation speed and becomes higher, the centrifugal force acting around the support shaft 80 of the weight member 62 increases, and as a result, the moment due to the centrifugal force also increases. The weight member 62 firmly supports the bar-shaped workpiece 3 with the clamper 60.

(3) The bar-shaped workpiece 3 is gripped by the chuck 12 at the front of the headstock 5 and supported by the support means 22 at the rear of the headstock 5.
In a state where the bar-shaped workpiece 3 is rotated at high speed together with the main shaft 10 in a state where the tool is supported by the guide member 43 and the guide member 43, the moving operation of the tool rest 6 is controlled to control the turret 7, and a desired tool is controlled. Find 8. Then, by relatively moving the tool 8 in the Z-axis and X-axis directions with respect to the bar-shaped workpiece 3, the machined portion of the bar-shaped workpiece 3 protruding forward from the chuck 12 is turned by the tool 8. During the turning, the bar-shaped workpiece 3 is firmly supported by the chuck 12 and the clamper 60 at the position of the spindle axis CL. As a result, high-precision turning can be performed. (4) When the predetermined turning is completed, the tool post 6 is moved and the turret 7 is turned to index another tool (for example, a parting tool) for cutting the workpiece, thereby machining the bar-shaped workpiece 3. And cut off the part. (5) After cutting, the spindle motor is controlled to reduce the rotation speed of the spindle 10 to a predetermined value or less. Then, the tension spring 6
3, the moment around the support shaft 80 rotated by the spring force S overcomes the moment due to the centrifugal force acting around the support shaft 80, so that the weight member 6 by the spring force S
The weight member 62 swings in the counterclockwise direction (FIG. 4) by the action of the moment for rotating the rod-shaped workpiece 2 in the counterclockwise direction (FIG. 4), and the clamper 60 moves in the support release direction to move the rod-shaped workpiece 3 from the rod-shaped workpiece 3. Leave. (6) The supply path of the pressure fluid supplied to the cylinder 24 is switched to supply the pressure fluid to the front pressure chamber 52.
Then, since the piston 46 retreats, the sleeve 38 retreats via the draw tube 39 connected to the piston 46, and the grip portion 21 of the collet 40 expands in diameter. As a result, the bar-shaped workpiece 3 can be moved in the direction of the spindle axis CL without being supported by either the chuck 12 or the clamper 60, so that the procedure returns to the procedure (1) and the same operation is repeated.

In this manner, the turning and cutting of the bar-shaped workpiece 3 can be automatically performed by sequentially repeating the steps (1) to (6). When the turning of one bar-shaped workpiece 3 is completed, the next unprocessed bar-shaped workpiece 3 is received by the bar feeder 2, and the bar-feeder 2 moves the new bar-shaped workpiece 3 forward to the lathe 1 to move the spindle. The operation starting from the procedure (1) is repeated by inserting the rear side Ba of the base 5 through the inside of the main shaft 10 to the front side Bb. The bar-shaped workpiece 3 is normally supported by a front collet 40 and a support means 22 behind the collet 40, and is assisted and guided by a guide member 43. However, when the turning and cutting of the bar-shaped workpiece 3 progress and the bar-shaped workpiece 3 is shortened, the rear end of the bar-shaped workpiece 3 is out of the position of the clamper 60 of the support means 22. Even in this case, since the guide member 43 protrudes rearward from the chuck 12, the bar-shaped workpiece 3 continues to be substantially supported by the collet 40 and the rear guide member 43 at the position of the main axis CL. Therefore, there is no danger that the bar-shaped workpiece 3 will run out during rotation.

FIG. 5 is a schematic configuration diagram showing a modification of the present embodiment. In the support means 22a shown in FIG. 5, at least three weight members 62a are mounted so as to swing by the action of centrifugal force generated around the support shaft 96. At least three clampers (supporting moving members) 60a that support the bar-shaped workpiece 3 include a support shaft 96 attached to the main body.
It swings freely around as indicated by arrow J. The clamper 60a is provided with a weight member 62a on one side 97 with respect to the support shaft 96, extends the other side 98 as long as possible toward the front side (that is, the chuck 12 side), and supports the bar-shaped workpiece 3 on the other side 98. Like that. If the bar-shaped workpiece 3 is supported at a position closer to the chuck 12 by the support means 22a having such a simple configuration, the bar-shaped workpiece 3 can be moved even if the turning progresses and the bar-shaped workpiece 3 is shortened. It can be supported by the chuck 12 and the clamper 60a. Also in this case, the chuck 12 has the bar-shaped workpiece 3
Guide member 4 for assisting and guiding the support
Preferably, 3 is provided.

As described above, according to the present invention, the spindle 10
During high-speed rotation, the support shaft 8 of the weight members 62, 62a
By the action of centrifugal force generated around 0, 96, the bar-shaped workpiece 3 is supported in a state where occurrence of run-out is prevented and can be turned. When the rotation speed of the spindle 10 is low, the bar-shaped workpiece 3 is intermittently rotated. Can be moved forward. Also,
The rod-shaped workpiece 3 within a predetermined wide diameter range can be shaken without changing the support means (support means 22, 22a in the present invention) for supporting the rod-shaped workpiece 3 on the rear side of the spindle 10. Can be automatically supported so as not to cause the lathe 1, so that the operation rate of the lathe 1 can be improved. Since the present invention utilizes the centrifugal force acting around the support shafts 80 and 96, the higher the rotation speed of the rod-shaped workpiece 3 at which the rod-shaped workpiece 3 tends to run, the greater the centrifugal force acting around the support shafts 80 and 96. Since the clampers 60 and 60a press the bar-shaped workpiece 3 more strongly, the bar-shaped workpiece 3 is turned while being supported more firmly. Further, since the bar-shaped workpiece 3 is uniformly supported from three directions by the three clampers 60, 60a, the bar-shaped workpiece 3 is supported by the spindle axis CL.
It is supported in a state where it is precisely centered at the position. Weight members 62, 62a, clampers 60, 60a, tension spring 6
Since 3 and the like are evenly arranged around the center position C, the balance during rotation is good. Therefore, the bar-shaped workpiece 3 can be turned by the lathe 1 with high accuracy. By controlling the spindle motor to increase or decrease the number of revolutions of the spindle 10, the rod-shaped workpiece 3 can be freely supported and released by the clampers 60, 60a.
The bar-shaped workpiece 3 having a wide diameter range can be continuously turned by the automatic operation without performing the setup change work of the workpieces 2 and 22a. The bar feeder is not necessarily required if the operator performs the attachment / detachment of the bar-shaped workpiece 3 and the opening / closing operation of the chuck when the rotation of the main shaft 10 is stopped. In addition,
The same reference numerals in the drawings indicate the same or corresponding parts.

[0029]

According to the present invention, the bar-shaped workpiece is supported by the centrifugal force generated by the rotation of the main shaft in a state where the run-out is prevented from occurring, and the turning can be performed. When the spindle rotation speed is high, the rod-shaped workpiece can be prevented from oscillating.When the spindle rotation speed is low, the support of the rod-shaped workpiece is released. An object can be moved forward. In addition, the rod-shaped workpieces within a predetermined wide diameter range can be automatically rotated in a state where run-out is prevented without rotating the support means for supporting the rod-shaped workpiece at the rear side of the spindle without performing a setup operation. Can be supported.

[Brief description of the drawings]

FIGS. 1 to 5 show an example of an embodiment of the present invention, and FIG. 1 is a front view of a lathe to which a bar feeder is attached.

FIG. 2 is a front sectional view of the lathe provided with the bar-shaped workpiece support device of the present invention.

FIG. 3 is an enlarged front sectional view showing a part of the lathe.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a schematic configuration diagram showing a modification of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lathe (machine tool for turning) 3 Bar-shaped workpiece 10 Spindle 12 Chuck (gripping means) 22, 22a Support means 24 Chuck cylinder device (driving device for gripping means) 43 Guide member (workpiece guiding member) 60, 60a Clamper (Supporting moving member) 61 Main body 62, 62a Weight member 63 Tension spring (biasing member) CL Center axis of main shaft

Claims (8)

[Claims] A bar-shaped workpiece support device in a turning machine tool for supporting a bar-shaped workpiece gripped by a gripping means on the front side of a spindle and rotating together with the spindle in cooperation with the gripping means. The main shaft or a rotating body that rotates integrally with the main shaft is provided at a rear position separated by a predetermined distance from the gripping means, and when the main shaft rotates, the bar-shaped workpiece is moved by centrifugal force caused by the rotation. A bar-like workpiece support device for a turning machine tool, comprising: a support means for supporting the bar-like workpiece so that the center line of the bar-like workpiece can be rotated substantially coincident with the center axis of the main spindle. 2. The supporting means has at least three supporting moving members provided to be able to advance and retreat to abut and support the outer periphery of the bar-shaped workpiece from at least three directions, and the main shaft is rotated. The turning machine tool according to claim 1, wherein the centrifugal force acts to move the at least three supporting moving members in a supporting direction to support the bar-shaped workpiece. Rod-shaped workpiece support device in. 3. The support means, when the rotation speed of the main shaft is higher than a predetermined rotation speed, supports the rod-shaped workpiece by the action of the centrifugal force, and the rotation speed of the main shaft is higher than the predetermined rotation speed. 3. The support member, when lower, moves the support moving member in a support release direction to separate from the outer periphery of the bar-shaped workpiece to release the support of the bar-shaped workpiece. 4. Bar-shaped workpiece support device in machine tools for turning. 4. The support means includes: a main body fixed to the main shaft or the rotating body and rotating integrally with the main shaft; and a swingably provided on the main body, and oscillating by the action of the centrifugal force. And a weight member for supporting the rod-shaped workpiece, and provided between the main body and the weight member, and constantly biased to swing the weight member in a direction opposite to the acting force due to the centrifugal force. The bar-shaped workpiece support device in a turning machine tool according to claim 1, further comprising a biasing member. 5. The main body, the main body being fixed to the main shaft or the rotating body and rotating integrally with the main shaft, wherein the main body has a position corresponding to the at least three supporting moving members. Swingably provided, at least three weight members that swing by the action of the centrifugal force to move the supporting moving member in the supporting direction, and are provided between the main body portion and the weight member, 4. The turning process according to claim 2, further comprising an urging member that constantly urges the weight member to swing in a direction opposite to the acting force due to the centrifugal force. Work support device for industrial machine tools. 6. The gripping means according to claim 1, wherein said supporting means is provided between said gripping means and a driving device for gripping means for gripping / releasing the gripping means. A bar-shaped workpiece support device for a turning machine tool according to any one of the preceding claims. 7. A workpiece guide member according to claim 1, further comprising a work guide member which is replaceably provided on said gripping means and which guides and supports the rod-shaped work in an auxiliary manner. Bar-shaped workpiece support device in machine tools for turning. 8. A gripping means provided on a front side of a main spindle for gripping the rod-shaped workpiece for rotating the rod-shaped workpiece together with the main spindle, and a rotating body which rotates integrally with the main spindle or the main spindle. A method of supporting a bar-shaped workpiece in a turning machine tool having a bar-shaped workpiece supporting device provided at a rear position at a predetermined distance from the gripping means and capable of supporting and releasing the bar-shaped workpiece. When the main shaft rotates at a predetermined rotation speed or more, the support means supports the rod-shaped workpiece by the action of centrifugal force due to this rotation, and the main shaft rotates at a rotation speed lower than the predetermined rotation speed. A method of supporting a bar-shaped workpiece in a turning machine tool, wherein the supporting means releases the support to the bar-shaped workpiece.