JPH10249668A - Bar delivery mechanism and delivery method of bar feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a bar delivery mechanism to correspond to the promotion of more accelerating the spindle speed of an automatic lathe as well as the travel speed of a headstock. SOLUTION: A grasping member 20, being attached to the tip of a push rod 8 of a bar feeder 10 free of rotation, and stationarily grasping a rear end of a bar W, is installed there, and it is made into such a mechanism as installed with a tractive means pulling the push rod 8 to the opposite direction against an automatic lathe spindle 3 together with the bar W, and further, owing to this to this mechanism, the bar W is pulled to the opposite direction to the lathe spindle 3 during machining by this automatic lathe, whereby any flexure and saggingness of the bar W are prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar feeding mechanism and a bar feeding method of a bar feeding device for feeding a bar to be processed to a lathe, particularly to a main spindle of an automatic lathe.

[0002]

2. Description of the Related Art FIG. 5 is a plan view schematically showing a headstock moving type automatic lathe provided with a conventional bar feeder. A headstock 2 is provided so as to be movable in the Z-Z direction with respect to the bed 1, and the headstock 2 is provided with a spindle 3 having a collet chuck 4 for chucking the bar W and the like. There is a guide bush 5 for guiding the bar W in front of the main shaft 3,
A blade 6 for processing the bar W is provided in the vicinity thereof. Reference numeral 7 denotes a bar supply device provided behind the headstock 2.

The bar feeder 7 is provided with a feed guide (not shown) for guiding the bar W to be inserted into the main shaft 3, and a pusher for pushing the rear end of the bar W in the feed guide. A push rod 8, and a finger 9 rotatably attached to a tip of the push rod 8 and elastically fitted at a rear end of the rod W.
And a push rod driving device 10 for moving them. The push rod driving device 10 includes a chain 11 stretched along the moving direction of the push rod 8, sprockets 12A and 12B for hanging the chain 11, a motor 13 for driving one sprocket 12A, and a chain 11
And a chain connector 14 and the like.

Next, the operation of the conventional bar supply device 7 will be described. When supplying a new bar W to the main shaft 3, the new bar W is set on a delivery guide (not shown) behind the main shaft 3, and the rear end of the bar W is elastically moved by the finger 9. After clamping, the delivery motor 13 is operated. Thereby, the push rod 8 advances toward the headstock 2 (moves forward),
The bar W is inserted into the main shaft 3.

When the rod W passes through the spindle 3 and projects a predetermined length from the tip of the spindle 3, the spindle collet chuck 4
Clamps the bar W and starts the machining operation. That is, the spindle collet chuck 4 advances in the ZZ direction while rotating while clamping the bar W, and the tip end of the bar W is
Process by During this processing, the feed motor 13
Always exerts a pressing force on the push rod 8 via the chain in a direction toward the headstock 2 so that the rear end of the rod W does not come off from the finger 9 even when the rod W advances with the spindle 3. I have to.

[0006] After the predetermined processing on the tip of the bar W is completed, the tip is cut off, and then the clamp of the bar W by the collet chuck 4 is released. Next, push rod 8
The bar W is advanced from the tip of the spindle 3 by moving the spindle W backward with respect to the spindle 3 or by moving the spindle 3 backward with the tip of the bar W restrained so as not to advance with the blade 6. Protrude by a predetermined length. Thereafter, the bar W is clamped again by the collet chuck 4 and the next processing is started.

[0007] In recent headstock moving type automatic lathes, the speed of the spindle rotation during processing and the speed of the headstock moving speed have been increasing, and the bar feeder has been required to cope with them. First, it is required that the bar material supply device be compatible with the increase in spindle speed. Despite the backward movement of the headstock, since the push rod exerts a pressing force in the direction toward the headstock, a relative displacement occurs between the push rod and the rod, and a load is applied to the rod,
This results in deflection of the bar. In some cases, the problem of "run-out" or "randomness" of the bar during high-speed rotation due to sagging caused by the weight of the bar due to the clearance between the bar and the delivery guide may be solved. As a countermeasure, a steady rest device has been conventionally used.

[0008] However, this steady rest device also requires: The finger has a diameter capable of grasping the maximum bar diameter that can be fed by the bar feeder (generally, the bar diameter + about 2 mm), and the clearance of the steady rest member is adjusted according to the bar diameter. Therefore, when the tip of the finger reaches the position of the steady rest device, the steady rest must be released so that the finger can pass through.Therefore, it is necessary to divide the steady rest device into several places. Increases cost. 2. In general, a steady rest device cannot be mounted in the main spindle of an automatic lathe, so that the steady rest becomes insufficient. 3. When the headstock of the automatic lathe retreats, the bar comes into contact with the steady rest, and this contact part becomes a resistance when the bar retreats, causing another deflection of the bar, and eventually the deflection of the bar Prevention cannot be performed. 4. During rotation, the rod material comes into rotational contact with the steady rest member, generating noise and vibration, and the steady rest member wears out, requiring replacement as a consumable. In particular, when the bar is a square bar such as a square bar or a hexagon bar, it is extremely large, and the life of the steadying device is shortened. There are problems such as. To cope with these problems, the steadying device becomes extremely expensive, but there is still a problem that the above measures cannot be taken sufficiently.

[0009] Next, as a problem due to the increase in the speed of the headstock moving speed, the rod is grasped by the headstock chuck and moves forward and backward by the movement of the headstock, but the drive device of the push rod cannot quickly follow. Sometimes.

The problem is described in detail as follows. The finger may come off from the rear end of the bar due to a delay in following the push bar when the headstock advances, and as a result, the rear end of the bar rotates while swinging largely. As a result, not only does the bar produce a so-called rampage, generating noise, the bar is damaged, but also the product accuracy is adversely affected. In particular, in the case of small-diameter rods, when the rear end of the rod rotates while swinging out of the fins, the rear end bends and violently hits the surrounding mechanical parts and peripheral equipment, damaging them. There is a danger that this could result in personal injury. 2. When the headstock is retracted, the driving force is applied to the push bar in the forward direction, so that the relative displacement between the push bar and the bar causes a load to be applied to the bar, causing deflection, and the bar being ramped up and generating noise. It may cause sticking, scratching the bar, and adversely affect product accuracy. This phenomenon appears more remarkably as the rod becomes smaller in diameter.

Conventionally, these problems have been dealt with by using a tracking control device of the type described below so that the push rod can follow the movement of the headstock as much as possible. There is a problem as follows.

In a system in which a detector for generating a pulse of the amount of movement of the headstock is mounted on the headstock, and the generated pulse is distributed to a driving device on the side of the bar feeder, and the following is performed, the following method is adopted. It is necessary to be able to attach a detector for generating a pulse to various automatic lathes. For this purpose, the automatic lathe must be attached to the automatic lathe side, which requires many man-hours. 2. A pulse generator and a control device on the bar feeder side are required so that the push rod can be driven by the pulse generated from the pulse generator, and the driving device becomes expensive.

Next, in a system in which the headstock and the push bar are connected via a connecting member such as a bar, and the push bar is moved in accordance with the movement of the head stock, a connecting member with the head stock is required. The connecting member is attached to the side, and a transmission member, a switching clutch, and the like are required.

In the method of detecting a delay of the movement of the push rod with respect to the movement of the headstock and correcting the following delay, the following methods are used. Since the tracking delay is detected and then corrected, even if the tracking delay is compensated for by a spring or the like, there is a tracking delay, especially when the headstock retreats. Not enough for prevention. 2. Since it is a method of detecting the follow-up delay from the amount of extension and contraction of the spring, a detector for exclusively detecting the amount of extension and contraction of the spring and a compensating device for the follow-up delay by the spring are required. Is complicated and expensive.

A method of simultaneously providing the movement amount and speed data of the headstock to the push rod driving device on the side of the bar feeder so as to follow the data.
That is, a method of performing a follow-up control between a servomotor of a headstock and a drive servomotor of a push rod of a bar feeder using two-axis synchronous control by CNC control is as follows. The CNC controller for automatic lathe control is dedicated to the axis that can be synchronized with the headstock movement for the bar feeder.
Since it has to be an NC control device, there is a problem in versatility. 2. The use of one CNC axis and the need for a synchronous control function make the equipment expensive.

Accordingly, the conventional steady rest device, push rod drive device and follow-up control device cannot cope with the high speed of the headstock moving type automatic lathe.

[0017]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a rod material for a bar feeder which responds to an increase in the speed of a spindle of an automatic lathe and a speed of movement of a headstock. An object of the present invention is to provide a delivery mechanism and a delivery method.

[0018]

In order to achieve this object, a material feeding mechanism of a bar feeder according to the present invention includes a feed guide for guiding the bar to insert the bar into a spindle of an automatic lathe; In a bar supply device including a push bar for pushing a rear end of a bar in a delivery guide, and a push bar driving device for moving the push bar, a bar is rotatably attached to a tip of the push bar, and a It is characterized in that a grasping member for grasping the rear end in a fixed manner during use is provided, and traction means for pulling the push bar together with the bar in a direction opposite to the main axis of the automatic lathe is provided. And the grasping member is formed of a collet chuck.

Further, in the bar feeding method of the bar feeding apparatus according to the present invention, there is provided a feed guide for guiding the bar to insert the bar into the main spindle of the automatic lathe; In a bar feeder comprising a push rod for pushing an end into the main spindle of the automatic lathe and a push rod driving device for moving the push rod in the delivery guide, a tip of the push rod and a rear end of the rod are pivoted. In the automatic lathe processing, the bar is connected to the push bar in a direction opposite to the main axis of the automatic lathe in a state where the bar is connected to the push bar during processing by the automatic lathe.

[0020]

According to the present invention, the clamp between the bar and the push rod is grasped by the collet chuck from the fitting clamp system. Therefore, during the processing of the bar, the bar can be pulled in opposite directions by the spindle chuck and the collet chuck of the push bar. This eliminates sagging and warping of the bar, so that it is possible to prevent rotation and runaway of the bar. Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 3. Here, the same components as those of the conventional device of FIG. 5 are denoted by the same reference numerals.

Reference numeral 1 denotes a bed of an automatic lathe on which a headstock 2 is mounted so as to be movable in the ZZ direction. Headstock 2
The main shaft 3 is rotatably installed in the, and a main shaft collet chuck 4 composed of a collet chuck or the like is attached to the tip of the main shaft 3. A guide bush 5 for guiding the bar W is provided in front of the main shaft 3, and a blade 6 for processing the bar W is provided near the guide bush 5. Reference numeral 7 denotes a bar supply device provided behind the headstock 2.

The bar supply device 7 includes a delivery guide 15 for guiding the bar W, a push bar 8 for pushing the rear end of the bar W, a push bar driving device 10, and the like, as in the prior art. The feed guide 15 has, for example, an open upper portion and a substantially semicircular cross-section, in which a bar W and a push rod 8 are installed toward the main shaft 3. A collet chuck (a collet chuck for grasping the rear end of the bar, that is, a grasping member) 20 for clamping (gripping) the rear end of the bar W is rotatably attached to the tip of the push rod 8.

FIG. 2 shows a collet chuck 2 for grasping the rear end of a bar.
An example of 0 is shown. A joint 21 is screw-coupled to the screw 8a at the tip of the push rod 8, and the outer diameter thread portion 2 of the joint 21 is
The bearing case 22 is screwed to 1b. 23
Is a rotary shaft, and a conical recess 23a is opened at one end on the push rod 8 side.
1a and a steel ball 24 is interposed. The other end of the rotating shaft 23 is integrally connected to a collet 32 by a shaft pin 31. The rotating shaft 23 is rotatably supported by the bearing case 22 via the radial bearings 25, 25.

When the push rod 8 moves in the direction of arrow a, the movement is transmitted to the rotating shaft 23 via the thrust bearing 26. That is, when the push rod 8 moves in the direction a, the moving force is transmitted to the rotating shaft 23 via the joint 21, the outer diameter screw portion 21b, the bearing case 22, the radial bearing 25, the collar 27, and the thrust bearing 26, and 23 moves together with the collet 32 in the a direction. When the push rod 8 moves in the direction b (the direction opposite to the direction a), the moving force is transmitted to the rotating shaft 23 via the joint 21, the tip 21a of the joint 21, the steel ball 24, and the recess 23a of the rotating shaft. , The rotating shaft 23 moves together with the collet 32 in the direction b.

Next, opening and closing of the collet 32 will be described. As is known, the collet 32 has a slot 32a (usually three slots) from the tip end, and has an outer diameter tapered 32b. An inner peripheral surface of the sleeve 30 has a similar taper 3 so as to fit into the taper 32b.
0c. And the sleeve 30 is the collet 3
The body 2 is fitted so as to be movable in the axial direction. An annular groove 30b is formed on the outer periphery of the sleeve 30, and the operating rod 33 can be inserted into and removed from the annular groove 30b. By moving the operation rod 33 upward in the figure of arrow c,
This is inserted into the annular groove 30b. After a while, the operation stick 33
Is moved in the direction of the arrow a or b so that the sleeve 30 is similarly moved in the direction of the arrow a or b. or,
A long groove 30a is formed in the outer periphery of the sleeve 30 over a range in which the sleeve 30 moves, so that the sleeve 30 does not interfere with the shaft pin 31 even when the sleeve 30 moves in the arrow a or b direction. 29 is a compression coil spring,
Interposed between the end face of the sleeve 30 and the spring receiver 28,
The sleeve 30 is constantly pushed in the direction of the arrow b.

Now, insert the operating rod 33 into the groove 30b,
When the sleeve 30 is moved in the direction of arrow b, the collet 3
Similarly, the body 2 moves in the direction of the arrow b, and the taper 30c at the tip rides on the taper 32b of the collet 32. Thereby, the collet 3 is formed through the slot 32a.
2 is reduced, and the rear end of the bar W can be firmly grasped by the collet 32. Since the spring 29 pushes the sleeve 30 forward, the sleeve 30 does not move in the direction of the arrow a even if the operating rod 33 is removed from the groove 30b, and the collet 32 holds the rear end of the bar W firmly. Becomes Next, when the operation rod 33 is inserted in the groove 30b and the spring 29 is moved in the direction of the arrow a while pressing and shrinking, the sleeve 30 is also moved. As a result, the restriction of the taper 32b of the collet 32 by the taper 30c is released, the diameter of the collet 32 returns to the original open size, and the grasp of the rear end of the bar W is released.

As shown in FIG. 1, a chain connector 14 is attached to the rear end of the push rod 8. The push rod driving device 10 includes a chain 1 stretched along the moving position of the push rod 8.
1 and a sprocket 1 for hanging the chain 11
2A and 12B, a motor 13 for driving one sprocket 12A, a chain connector 14 for connecting the push rod 8 to the chain 11, and the like.

As shown in FIG. 2, in the present invention, the push rod 8
Collet chuck (gripping member) 2 for grasping the rear end of the bar at the tip
Since 0 is attached, the rear end of the bar W can be firmly clamped. Therefore, when the push rod driving device 10 operates to move the push rod 8, the bar W moves together with the push rod 8 in accordance with this movement. When the motor 13 is driven to move the push rod 8 backward (to the right in the drawing) as shown by the arrow a through the sprockets 12A and 12B, the chain 11 and the chain connector 14, the push rod 8 pulls the bar W. For this reason, the wrinkles and sagging of the bar W are eliminated.

Next, a description will be given of a method of feeding material when processing is performed by the headstock moving type automatic lathe using the bar material supply device 7 of the present invention. FIGS. 3A to 3I show the first embodiment, and describe a method of feeding a material from the end of processing to the start of processing of the next product.

FIG. 3A shows that the bar W is grasped by the collet chuck 4 of the main shaft 3 (FIG. 1), the tip of which is supported by the guide bush 5, and the predetermined processing is completed by the blade 6, and the product W
It shows that it is cut off as 1. In this state, the motor 13 of the push rod driving device 10 is rotating forward,
The push rod 8 is moved in the direction of the arrow a (that is, backward). For this reason, the bar material W is
The bar W is pulled (pulled) in the direction a by being clamped at 0. At this time, since the bar W is clamped by the spindle collet chuck 4, the bar W and the collet chuck 20 for grasping the rear end of the bar do not retreat.

When the product W1 is separated, the rotation of the main shaft 3 is stopped (FIG. 3B). Next, when the rotation of the spindle 3 is stopped, the motor 13 of the push rod driving device 10 is rotated in the reverse direction to give the push rod 8 a driving force in the forward direction toward the headstock 2 as shown by an arrow b (FIG. 3C). Thereafter, the clamp of the bar W by the spindle collet chuck 4 is released. At this time, the bar W does not move forward because its tip is restrained by the blade 6 (FIG. 3D).

Next, the headstock 2 is retracted by a distance corresponding to a predetermined length required for processing the bar W. The clamp of the spindle collet chuck 4 is released and the motor 1
Since the driving force in the forward direction is given to the push rod 8 by 3, neither the bar W nor the push rod 8 retreat, and the state shown in FIG. When the headstock 2 is retracted by a predetermined amount, the bar W is clamped by the spindle collet chuck 4 at that position (FIG. 3).
(F)).

The motor 13 is again rotated in the normal direction to give the push rod 8 a driving force in the backward direction away from the headstock 2 as shown by an arrow a. As a result, the bar W is pulled again, and the wrinkles and sagging of the bar W are removed (FIG. 3 (G)).
In this state, the main shaft 3 starts rotating (FIG. 3 (H)). While the headstock 2 moves in the direction of the arrow Z-Z, the blade 6 is cut to perform predetermined processing on the bar W. As described above, since a force acts on the bar W in the pulling direction, no warping or sagging occurs. In this way, material feeding is performed according to the processing of the bar W (FIG. 3 (I)).

As can be seen from the above, the push rod driving device 10
Also constitutes traction means for removing deflection and sagging of the bar W. In addition, the gripping member 20 secures the rear end of the bar W and the front end of the push bar 8 without being separated in the axial direction during the machining operation of the automatic lathe. It can be processed at high speed without sagging.

As a second embodiment, a method for feeding out a material without stopping the rotation of the main shaft 3 each time the processing of a product is completed will be described with reference to FIGS. 4 (A) to 4 (I).

FIG. 4A also shows a bar W
This shows that the product W1 is grasped by the spindle collet chuck 4 of the spindle 3 (FIG. 1), the tip thereof is supported by the guide bush 5, the predetermined processing is completed by the blade 6, and the product W1 is cut off. Since the motor 13 of the push rod driving device 10 is rotating forward and the push rod 8 is moved in the direction of arrow a, the rod material W is grasped by the collet chucks 4 and 20, so that the rod material W Is pulled to prevent warping and dripping.

When the product W1 is separated, the push rod driving device 10 is stopped and the driving force of the push rod 8 is cut off. By doing this, there is an advantage that at the time of releasing the clamp in the next step, problems such as the retreat of the bar W do not occur (FIG. 4).
(B)). Next, the clamping of the bar W by the spindle collet chuck 4 is released (FIG. 4C). Next, the motor 13 of the push rod driving device 10 is rotated in the reverse direction to apply a forward force to the push head 8 toward the headstock 2 as shown by an arrow b. In this case, since the clamp of the bar W by the spindle collet chuck 4 is released, the bar W attempts to move forward, but does not move forward because its tip is restrained by the blade 6. In addition, since the clamp is released, the bar W does not rotate and stops even though the main shaft 3 rotates. Therefore, the bar W is rotated to rotate the blade 6.
(FIG. 4D).

Next, the headstock 2 is retracted by a distance corresponding to a predetermined length required for machining. Even in this state, since the clamp of the spindle collet chuck 4 is released and the force in the forward direction is applied to the push rod 8, the bar W does not retreat, and is in the state of FIG. When the headstock 2 retreats by a predetermined amount, the push rod driving device 10 is stopped at that position, and the driving force of the push rod 8 is cut off. By doing this, there is no problem that a force in the forward direction is applied to the bar W during rotation of the main shaft at the time of clamping in the next step, causing the bar W to buckle or sag (FIG. 4F). Next, the bar W is clamped by the spindle collet chuck 4 (FIG. 4G).

The motor 13 is rotated forward again to apply a backward force to the push rod 8 away from the headstock 2 as shown by an arrow a. As a result, the bar W is towed, so that the bar W is not deformed or sagged (FIG. 4).
(H)). While the headstock 2 moves in the arrow Z-Z direction,
As in the first embodiment, the bar 6 is processed by the blade 6. At this time, since a force acts on the bar W in the pulling direction, no deflection or sagging occurs. Thus, the bar W
Material is fed out according to the processing of FIG.
(I)).

As described above, also in the second embodiment,
The gripping member 20 secures the rear end of the bar W and the front end of the push rod 8 without being separated in the axial direction during the machining operation of the automatic lathe. And can be processed at high speed.

[0041]

As described above, according to the bar feeding mechanism and the feeding method of the present invention, the following effects can be obtained. 1. By pulling the bar during processing, there is no warping or sagging of the bar, so there is no problem of tracking delay when the headstock retreats, and the bar is gripped by a collet chuck or other gripping member. Because of the coupling, the problem that the rod material comes off from the fitting clamp portion of the finger as in the related art due to a delay in following the push rod when the headstock advances is solved. As a result, no expensive follow-up control device is required, and
Without mounting parts on various automatic lathes,
It is possible to cope with an increase in the moving speed of the headstock. 2. Irrespective of the position of the push rod, there is a steady rest effect over the entire area, so that there is no need for a steady rest device.Therefore, there is no resistance to the bar material when the headstock retreats, and the steady rest member is replaced as a consumable. No need. Further, a bar material such as a square bar, a hexagon bar or the like can be provided with an anti-sway effect without suppressing the outer diameter, and noise generation is reduced. 3. Conventionally, when processing small-diameter rods, reduce the diameter of the push rods and feed guides, etc. to reduce the clearance between these and the rods, and take measures to prevent runout. To make them lighter,
This improved the followability and took measures to prevent the rod from being deformed due to the delay of the follow-up of the push rod when the headstock retracted. In addition, there is no need to replace the delivery guide and the like. Further, since the diameter of the push rod and the feed guide can be determined regardless of the diameter of the rod, the range of the diameter of the rod that can be fed by the rod feeder becomes wider than before.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a headstock moving type automatic lathe in which a bar feeder of the present invention is arranged.

FIG. 2 is a sectional view showing an example of a grasping member of the present invention.

FIGS. 3A to 3I are views showing a first embodiment of a bar feeder and a bar feeder using a bar feeder according to the present invention.

FIGS. 4A to 4I are views showing a second embodiment of a bar feeder and a bar feeder using a bar feeder according to the present invention.

FIG. 5 is a plan view schematically showing a headstock moving type automatic lathe in which a conventional bar feeder is arranged.

[Explanation of symbols]

Reference Signs List 1 bed 2 headstock 3 spindle 4 spindle collet chuck 5 guide bush 6 blade 7 bar feeder 8 push rod 10 push rod drive 11 chain 12A, 12B sprocket 13 motor 14 chain connector 15 delivery guide 16 groove 20 for grasping rod end of rod Collet chuck W Bar W1 Product

Claims (3)

[Claims] 1. A delivery guide for guiding a bar to insert the bar into a main spindle of an automatic lathe; a push bar for pushing a rear end of the bar in the delivery guide; and a moving bar for moving the push bar. And a push rod driving device, wherein the push rod drive device is rotatably attached to the tip of the push rod, and
A gripping member for gripping the rear end of the bar in use during use; and a pulling means for pulling the push bar together with the bar in a direction opposite to the main axis of the automatic lathe. Bar feeding mechanism. 2. A bar feeding mechanism according to claim 1, wherein said grasping member comprises a collet chuck. 3. A delivery guide for guiding the bar to insert the bar into the main spindle of the automatic lathe; a push bar for pushing a rear end of the bar in the delivery guide into the main spindle of the automatic lathe; In a bar feeder provided with a push bar driving device for moving the push bar in the delivery guide, a front end of the push bar and a rear end of the bar are fixedly connected in the axial direction and rotatably to each other, A bar feeding method of a bar feeder, wherein the bar is connected to the push bar together with the push bar during processing by an automatic lathe and is pulled in a direction opposite to the main axis of the automatic lathe.