JP3916927B2 - Longitudinal positioning device for workpiece - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a longitudinal positioning device for positioning a workpiece in a longitudinal direction when the workpiece is inserted into a spindle hole of a machine tool from the chuck side and gripped by a chuck in a state in which a workpiece is projected from the chuck. It is about.
[0002]
[Prior art]
FIG. 3 shows a conventional workpiece longitudinal positioning apparatus used in a lathe. In FIG. 3, the conventional workpiece longitudinal positioning device is arranged at the rear end of a spindle 102 supported by a plurality of bearings (not shown) provided on a spindle stock 101 via a rotary cylinder 104 for opening / closing a claw of a hydraulic chuck 103. The adjustment nut 109 is attached concentrically, and has a stopper shaft 106 that is screwed with the adjustment nut 109. A lock nut 105 that restricts relative movement between the adjustment nut 109 and the stopper shaft 106 is provided behind the adjustment nut 105 of the stopper shaft 106. And provided in the center hole of the main shaft 102 via a draw pipe 107 so that the position in the axial direction can be adjusted. A stopper 108 is provided at the tip of the stopper shaft 106, and the workpiece is positioned by the workpiece contact surface 108a. A rotary joint 110 for supplying air or coolant to the cutting portion through the center hole of the stopper shaft 106 is connected to the rear end of the stopper shaft 106.
By changing the position of the contact metal in the axial direction of the adjustment nut 109 and the stopper shaft each time the workpiece lot changes, the adjustment range can be set to L100, and it is possible to handle the axial positioning of multiple types of workpieces W with different lengths. The workpiece W is gripped by the hydraulic chuck 103, and the portion protruding from the chuck is cut.
[0003]
[Problems to be solved by the invention]
As described in the prior art, according to the longitudinal positioning apparatus employed so far, the rotary joint 110 extends rearward from the lock nut 105 at a portion (projecting amount L200 in FIG. 3) that projects from the rear portion of the cylinder during processing of the workpiece. The stopper shaft connected to the projection protrudes and rotates. However, since the protrusion amount L200 cannot be increased due to the limitation based on the dangerous rotation speed, there is a problem that the width of the workpiece longitudinal position adjustment range L100 is narrow.
In addition, in order to increase the adjustment range L100, it is necessary to replace the stopper shaft or the stopper tip each time, and to manually adjust the stopper position, the master is attached to the hydraulic chuck during adjustment. In addition, the longitudinal position (fixed position) must be determined using a gauge or the like, and there is a problem that it takes time to change the setup.
[0004]
Therefore, the present invention has been made in view of such problems of the prior art, and the object of the present invention is to prevent the workpiece longitudinal positioning adjusting member from rotating while the workpiece is being processed. An object of the present invention is to provide a workpiece longitudinal positioning device that eliminates the protrusion of the stopper shaft so as not to be restricted by the rotational speed, expands the adjustment range in the longitudinal direction, and can automatically perform longitudinal positioning of the workpiece. To do.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is a longitudinal positioning apparatus for a workpiece in a spindle of a machine tool, comprising a guide sleeve fixed to a spindle base and having a female thread portion concentric with the spindle at the tip. A small-diameter shaft portion having a length determined by an adjustment amount in the workpiece longitudinal direction is formed following the shaft portion that is inserted into the guide sleeve and supported so as to be rotatable only, and a guide groove is formed in the outer peripheral shaft direction. An adjustment shaft and a key member fitted to the small-diameter shaft portion and slidably engaged with the guide groove are fixed and screwed with a female screw of the guide sleeve so that a longitudinal dimension range of the guide groove is defined as a key member. the advance and retreat in synchronization with the rotation of the adjusting shaft of the workpiece and the stopper shaft for positioning the longitudinal direction, of the workpiece that is configured to include a motor for driving said adjustment shaft but is engraved movable Nioneji is Longitudinal positioning amount adjustment Member is one that does not rotation during the machining of the workpiece.
[0006]
According to the first aspect of the present invention, the adjusting member related to the positioning of the workpiece in the longitudinal direction in the main shaft is prevented from rotating during processing of the workpiece. The members related to the positioning in the longitudinal direction are: a stopper shaft that is supported at the rear end of the stopper that rotates in contact with the workpiece and is mostly inserted in the spindle hole, an adjustment shaft that rotates synchronously with the stopper shaft, and an adjustment shaft And a driving member such as a motor that rotationally drives the adjustment shaft and feeds the axial movement forward and backward with a screw, both of which are fixed to the headstock.
Therefore, there is no rotating member that is provided on the main shaft axis and protrudes rearward from the rotary cylinder for opening and closing the chuck, and only the stopper that contacts the work in the main shaft rotates, and the protruding portion at the rear end of the main shaft has a high speed. It becomes possible to avoid the limitation of the dangerous speed due to the rotation.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional explanatory view of the workpiece longitudinal positioning apparatus of the present invention, and FIG. 2 is an enlarged explanatory view of the main part of FIG.
In FIG. 1, a spindle 2 is supported by a spindle head 1 of a lathe by a plurality of bearings (not shown), and a hydraulic chuck 3 is fixed concentrically to the tip of the spindle 2. A rotary cylinder 5 for opening / closing the claw of the hydraulic chuck 3 is attached to the rear end of the main shaft 2 via a flange 4. A draw pipe 7 that connects the piston 6 of the rotating cylinder 5 and the chuck 3 is fitted into the center hole 2a of the main shaft 2 so as to be movable in the axial direction.
[0008]
The main part of the longitudinal positioning apparatus for the workpiece W according to the present invention is a stopper shaft 13 which is partially inserted into the pipe of the draw pipe 7 and whose tip is supported by a stopper 14 which comes into contact with the workpiece W and moves forward and backward integrally therewith. And an adjustment shaft 15 rotatably supported by a guide sleeve 12 fixed to the headstock 1 and a motor 11 as a driving means.
[0009]
In FIG. 2, a guide sleeve 12, an adjustment shaft 15 and a stopper shaft 13 are provided on a support frame 10 on a spindle axis 1 on the rear axis of the main shaft, and none of them rotate during workpiece machining.
One end of the adjustment shaft 15 is inserted into a guide sleeve 12 fixed to the headstock 1 and is rotatably supported. That is, the shaft is supported by a hole 12b formed in the rear end portion of the guide sleeve 12, one flange surface 15a abuts on the end surface 12a of the hole, and further formed in the rear end hole of the guide sleeve 12, so that the screw 12c and The end surface of the round nut 8 with a small screw for locking, which is threaded to the outer diameter to be screwed, is in contact with the other flange end surface 15f so that the clearance is adjusted and the end surface is rotatable.
Further, the adjusting shaft 15 is rotated from the output shaft of the motor 11 attached to the support frame 10 to the dimming pulley 18 attached to the shaft end of the adjusting shaft 15 via a conductive member such as the timing pulley 16 and the timing belt 17. It is transmitted and it is driven forward and reverse.
[0010]
On the other end side (the chuck 3 side of the main shaft 2) following the flange surface 15a of the adjustment shaft 15, a stepped small diameter shaft portion 15e is formed following the shaft portion in which the radial direction is supported by a predetermined width. The length of the small-diameter shaft portion 15e is determined by an adjustment amount L in the workpiece longitudinal direction, and one or more guide grooves 15c are engraved on the outer periphery of the small-diameter shaft portion 15e in the axial direction. The front end surface 12 e of the guide sleeve 12 is at a position slightly extended from the front end surface 15 d of the small diameter shaft portion of the adjustment shaft 15. A cylindrical stopper shaft 13 is fitted to the outer diameter of the small-diameter shaft portion 15e so as to be slidable in the axial direction, and the screw 13a is associated with the adjustment of the longitudinal position of the workpiece on the outer diameter of the cylindrical portion. Is provided.
[0011]
External thread 13a of the stopper shaft 13 into the female screw 12d which is Wataruri threaded to a predetermined length to the front end of the guide sleeve 12 is screwed. A key member 19 slidable in the longitudinal direction of the groove and fixed to the rear end of the stopper shaft 13 is engaged with the guide groove 15c of the small diameter shaft portion 15e so that the adjustment shaft 15 and the stopper shaft 13 rotate synchronously. . The key member 19 rotates the stopper shaft 13 in synchronization with the rotation of the adjustment shaft 15 and the stopper shaft 13 moves forward and backward, so that the stopper shaft 13 can be positioned in the longitudinal direction. The range of the screw 13a is designed so that the key member 19 can move over the entire range of the longitudinal dimension of the guide groove 15c.
[0012]
In FIG. 1, a cylindrical stopper shaft 13 having a length approximately halfway through the draw pipe 7 has a front end portion inserted into the main shaft hole and a rear end side fitted into a small diameter shaft portion of the adjustment shaft 15. For this reason, since the front end portion of the stopper shaft 13 is cantilevered, it must be supported by the inner diameter portion of the draw pipe 7 that rotates integrally with the main shaft 2. The stopper 14 inserted with a clearance that can slide in the axial direction at the inner diameter of the draw pipe 7 is composed of a metal pad 20 made of a material capable of abutting the workpiece W on the front end surface, and is cylindrical. The stopper shaft 13 has a small-diameter shaft 21 at the front end thereof and is supported by bearings 22 and 23 at the center of the stopper 14 that rotates in contact with the workpiece. Since the stopper 14 rotates integrally with the draw pipe 7, a groove 14 a is formed on the outer periphery of the stopper 14, an O-ring 24 is fitted, and a frictional resistance is applied so as to follow and rotate. The O-ring 24 is also provided to prevent coolant leakage.
[0013]
Air or coolant supplied to the workpiece W from the rear of the headstock 1 through the center hole of the stopper shaft 13 passes through the center hole of the fixed-length stopper 14 that rotates from the fixed small-diameter shaft 21. A check valve 25 is pressurized by a spring 26 so that air or coolant does not flow back to the bearings 22 and 23, and is brought into contact with the end surface of the small diameter shaft 21.
[0014]
Next, the operation of the longitudinal positioning device of the present invention will be described.
1 and 2, by rotating the motor 11, the adjustment shaft 15 and the stopper shaft 13 engaged with the adjustment shaft 15 by the key member 19 are synchronously rotated through the pulley 16, the belt 17, and the pulley 18. A male screw 13 a on the outer periphery of the stopper shaft 13 is screwed with a female screw 12 d of a guide sleeve 12 fixed to a support frame 10 provided behind the headstock 1. The stopper shaft 13 rotates and can move forward and backward together with the key member 19 along a groove 15 c formed in the longitudinal direction of the outer periphery of the adjustment shaft 15 in the direction of the chuck 3.
[0015]
The stopper shaft 13 is positioned and fixed in the longitudinal direction by the brake function of the motor 11 in the draw pipe 7 that rotates integrally with the main shaft 2 by numerical control of the motor 11. A small-diameter shaft 21 fixed to the front end of the stopper shaft 13 supports a stopper 14 that rotates integrally with the main shaft via bearings 22 and 23. Therefore, even if the stopper shaft 13 is stationary, it does not come into contact with the inner diameter of the draw pipe 7. Since the stopper 14 is fitted to the draw pipe 7 by an O-ring 22 attached to a groove provided in the outer shape of the stopper 14 with a gap that is movable, no vibration is generated. Further, the O-ring 22 rotates integrally with the draw pipe 7 by frictional resistance generated between the O-ring 22 and the outer periphery. A wear-resistant pad 20 is fixed between the stopper 14 and the workpiece W, but can be exchanged at every predetermined rotation speed.
[0016]
Since the longitudinal positioning device of the present invention operates as described above, it has the following three functional features.
First, in adjusting the work longitudinal position, the position of the stopper shaft 13 can be accurately detected based on the output of the rotation detector of the motor 11, and an arbitrary position can be easily set within the adjustment shaft range.
Secondly, by registering the longitudinal position of the workpiece W in advance and confirming the longitudinal position in a state where the workpiece is grasped, the workpiece can be discriminated and a machining program can be automatically selected. If the motor 11 becomes overtorque for some reason during positioning, it can be avoided by using a torque skip function that is a torque management function of the motor 11.
Thirdly, the protrusion amount of the member related to the longitudinal positioning device from the rotary cylinder 5 to the rear is constant regardless of the longitudinal position of the stopper support shaft, so that the limitation due to the rotational speed is suppressed, and the adjustment range of the workpiece longitudinal position can be increased. .
[0017]
【The invention's effect】
Since the workpiece longitudinal positioning apparatus of the present invention is configured as described above, it has the following effects.
A special effect of the present invention is that the member including the stopper shaft related to the longitudinal positioning of the workpiece does not rotate except for the stopper abutting on the workpiece during machining of the workpiece. As a result, the following effects can be obtained.
[0018]
Since the stopper shaft for positioning the workpiece within the spindle hole is driven by the control motor via the adjustment shaft, the workpiece longitudinal positioning is accurate. Further, positioning data can be input in advance, and automatic setting of workpieces having different lengths is easy.
Further, since the amount of protrusion to the rear portion of the rotating cylinder that drives the chuck is constant and does not rotate during workpiece machining, it is not necessary to limit the rotational speed of the spindle.
In addition, since it is not necessary to manually move the stopper shaft back and forth for adjustment, there is an effect of improving work efficiency without requiring a setup change time when changing the longitudinal dimension of the workpiece.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a workpiece longitudinal positioning apparatus according to the present invention.
FIG. 2 is an enlarged view of a main part of FIG.
FIG. 3 is an explanatory diagram of a conventional workpiece longitudinal positioning device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main shaft stand 2 Main shaft 3 Hydraulic chuck 4 Flange 5 Rotating cylinder 6 Piston 7 Draw pipe 8 Split nut 10 Support frame 11 Motor 12 Guide sleeve 13 Stopper shaft 14 Stopper 15 Adjustment shaft 16 Timing pulley 17 Timing belt 18 Timing pulley 19 Key member 20 Latch 21 Small-diameter shaft 22, 23 Bearing 24 O-ring 25 Valve 26 Spring W Workpiece

Claims (1)

A longitudinal positioning device for a workpiece in a spindle of a machine tool, a guide sleeve fixed to a spindle head and having a female thread portion concentric with the spindle at a tip, and a shaft portion inserted into the guide sleeve and supported only for rotation Subsequently, a small-diameter shaft portion having a length determined by the adjustment amount in the longitudinal direction of the work is formed and a guide groove is engraved in the outer peripheral shaft direction, and the small-diameter shaft portion is fitted in the small-diameter shaft portion. A key member that is slidably engaged is fixed and screwed with a female screw of the guide sleeve so that the key member can be moved in the longitudinal dimension range of the guide groove, and the adjustment shaft is rotated. advance and retreat in synchronization with the stopper shaft for positioning the longitudinal direction of the work, that the longitudinal positioning amount adjusting member of the work that has been configured to include a motor for driving the adjusting shaft is not rotating during machining of the workpiece Features Longitudinal positioning device of a work.

Images