JPH0152122B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention provides chuck attachment means driven by power such as hydraulic pressure on the main shaft of a lathe, so that various types of separate power chucks can be freely replaced and attached. This invention relates to an automatic chuck changing device.

[Conventional technology]

In the chuck of a lathe, a pawl driven by power such as hydraulic pressure is provided at the tip of the main shaft provided in the headstock, and various types of separate power chucks are removably fixed to the chuck attachment means by this pawl, and various workpieces can be attached to the chuck. An automatic chuck changing device in which the chuck is machined using a lathe is known.

[Problem that the invention seeks to solve]

In the case of the above-mentioned known automatic chuck changing device, two forward and backward shafts are required in the main shaft of the lathe: one for driving the pawl of the chuck mounting means, and the other for driving the power chuck fixed to the chuck mounting means. However, since each drive cylinder must be provided at the rear of the main shaft, the mechanism becomes extremely complicated.

[Means for solving problems]

In order to solve the above problems, the present invention provides chuck attachment means on the front part of the spindle provided in the headstock of a lathe, and allows a separate power chuck to be detachably fixed to the spindle using this attachment means. In the device, the chuck attaching means has a plurality of presser claws that move back and forth in the radial direction, and in conjunction with the presser claws, when the presser claws move inward and engage with the recess on the outer periphery of the adapter of the power chuck, the chuck attaching means moves outward. It is composed of a plurality of reciprocating members that move toward each other and a spring that pushes these retracting members outward, and the headstock is provided with an actuator that pushes the outer end of each stopped retracting member to retract each presser pawl, and a hollow main shaft. A joint member at the tip of the drawbar, which is moved forward and backward by a drive cylinder installed at the rear end, is installed in the front part of the main shaft.At the end of this joint member, there is a tightening tube that expands by its own elasticity when moving forward, and is attached to the main shaft when moving backward. A plurality of joint pieces are provided which are pushed inward by a plurality of joint pieces, and on the outer periphery of the rear end of the operating shaft of the chuck claw protruding from the rear of the power chuck, the tip of each joint piece is provided with the power chuck being fixed to the main shaft by the chuck attachment means. It is provided with an engaging portion that engages with the inner engaging claw.

[Effect]

Since this invention has the above-mentioned configuration, when the main shaft is stopped, when each actuator is operated to move each rod inwardly, each advancing/retracting member moves inwardly against the spring. Each interlocking presser claw moves outward.

On the other hand, each engaging pawl at the tip of the joint piece at the tip of the drawbar which is in the forward position by the drive cylinder is in an expanded state.

Under these conditions, put the rear part of the power chuck adapter carried by the automatic exchanger into each presser claw, and put the rear end of the operating shaft into each joint piece, and then operate each actuator to remove each rod. When the power chuck is retracted, each reciprocating member is retracted by a spring, and each presser pawl linked thereto moves inward to engage with each concave portion of the power chuck.

Next, when the joint member is moved backward together with the drawbar using the drive cylinder at the rear of the main shaft, each joint piece is contracted and moved backward by the tightening member, and the engaging pawl on the inside of the front part of each piece is connected to the engaging part of the operating shaft. to move the operating shaft backward.

This causes each chuck pawl of each power chuck to move and grip the workpiece. Furthermore, when removing the workpiece and power chuck, the drive cylinder and actuator are operated in the opposite manner to the above.

〔Example〕

In the figure, 1 is a headstock fixed on the head 2 of the lathe, 3 is a hollow main shaft, which is rotatably supported by bearings at the front and rear of the headstock 1, and this main shaft 3 is rotated in a predetermined direction by an appropriate drive means. let

Reference numeral 5 denotes a chuck attachment means provided at the tip of the main shaft 3, which has a presser pawl 7 and a reciprocating member 15 interlocked with the presser pawl 7.

Reference numeral 9 denotes an annular receiving member fixed to the flange at the tip of the main shaft 3, and a guide ring 4 is attached near the outer periphery of the front surface of the annular receiving member.
is fixed, and the presser claws 7 are fitted into a plurality of holes provided radially in this ring so as to be able to move forward and backward.

Further, the receiving member 9 is also provided with holes 6 radially located behind the presser claws 7, and the reciprocating member 15 is fitted into the holes 6. A notch 1 is provided on the front side of the outer end of each hole 6.
1 is provided, and the center of the lever 12 is swingably supported by a pin 13 provided in this notch. engage.

Further, a main shaft 3 is provided on the front surface of the headstock 1.
An annular mounting base 16 concentric with the mounting base 1 is fixed, and this mounting base 1
6 is provided with an actuator 8 such as a hydraulic cylinder corresponding to each reciprocating member 15, and this actuator 8 is arranged radially so as to be coaxial with the axis of each retracting member 15 when the main shaft is stopped.
Moreover, it is fixed at a position equidistant from the axis of the main shaft 3.

Reference numeral 17 denotes a piston inside each actuator 8, and a rod 18 integrated with this piston protrudes from the inner end of the actuator 8 and faces the outer end of each reciprocating member 15. A spring 19 is installed in a compressed state between the bottoms of the rods 6 to bring the outer end of each reciprocating member 15 into contact with the inner end of each rod 18.

Each of the actuators 8 is of a double-acting type, and oil feed ports at both ends thereof are connected to a hydraulic unit (not shown) via a switching valve in a hydraulic circuit provided in the headstock 1.

Reference numeral 21 denotes an adapter, on the front of which a variety of power chucks 22 of arbitrary types are fixed by means such as bolting. Therefore, although there are many types of power chucks 22, there is only one type of adapter 21 with the same size. A small diameter rear portion of the adapter 21 is provided with a plurality of recesses 23 in which the inner ends of the presser claws 7 are removably engaged.

Further, on the inner side of the front surface of the annular receiving member 9,
An annular coupling ring 25 is fixed, and a coupling ring 26 is also fixed on the inner side of the rear surface of the adapter 21, so that radial irregularities that engage with each other are provided on the opposing surfaces of both coupling rings 25 and 26.

1 is a hydraulically actuated drive cylinder fixed to the rear end of the main shaft 3, and a piston rod 31 passing through its front end is loosely fitted into the rear end of the main shaft 3. In addition, there is a drawbar 3 inside the main shaft 3 that can freely move forward and backward.
2 is fitted and connected to the piston rod 31, and a joint member 33 is fixed to the tip of the drawbar 32.

The joint member 33 is cylindrical and has a plurality of cuts from its tip, and a plurality of elastic joint pieces 34 are formed between the cuts. Further, an engaging pawl 35 is provided on the inside of the tip of each piece 34, and the rear end of the convex portion 36 on the outside of the tip is formed as a front upward slope.

A tightening tube 40 is fixed to the front end of the inner circumference of the main shaft 3, and the joint piece 34 is retracted into this tightening tube 40. A tapered surface is provided on the inner periphery of the front end of the tightening tube 40, and when each joint piece 34 is pulled into this tightening tube 40, its convex portion 36 is tightened by the inner periphery of the tightening tube 40, and each piece 34 is It is pushed inward as shown in Figure 1,
When the front part of each joint piece 34 comes out in front of the tightening tube 40, it expands outward due to its own elasticity as shown in FIG. 3.

Reference numeral 45 in FIG. 1 denotes a plurality of chuck pawls provided at the front of the power chuck 22. This is just one example, and some chuck pawls have various shapes other than those shown. 4
Reference numeral 6 denotes an operating shaft protruding rearward from the rear center of the chuck 22, and this shaft 46 and each pawl 45 are interlocked by a link mechanism provided inside the power chuck 22.
As the operating shaft 46 moves forward and backward, the claws 45 move inward and outward all at once. Further, a groove-shaped engagement portion 47 extending over the entire circumference is provided at the rear end of the operating shaft 46, and the engagement claw 35 of the joint piece 34 engages and disengages from this engagement portion 47.

Next, the operation of the above embodiment will be explained. Now, when the main shaft 3 is stopped and each reciprocating member 15 provided on the annular receiving member 9 at the front thereof is facing the inner end of the rod 18 of each actuator 8, actuate the actuator 8 to move the rod. When the spring 18 is moved inward, the reciprocating member 15 compresses the spring 19 and moves inward as shown in FIG.

As described above, when each reciprocating member 15 moves inward, each presser claw 7 moves outward all at once due to the action of each lever 12.

Under these conditions, an automatic exchange device (not shown) operates to move the desired power chuck 22 to the front of the main shaft, align the centers of this chuck 22 with the main shaft 3, and move it straight toward the main shaft 3. The rear end of the operating shaft 46 protruding from the shaft 21 fits into each joint piece 34 as shown in FIG.
When the concave and convex portions of the coupling ring 26 on the second side are engaged and each concave portion 23 is in a state facing the inner end of each presser claw 7, each actuator 8 is operated to retract each rod 18 and the receiving member 9 If it is outside the rotation range of
Each advancing/retracting member 15 is moved outward by a spring 19,
The lever 12 rotates to move each presser pawl 7 inward so that its inner end engages with the recess 23 to fix the power chuck 22 to the main shaft 3.

With the chuck 22 fixed to the main shaft 3 as described above, the drive cylinder 30 shown in FIG. 1 is operated,
When the piston rod 31 is moved backward, the drawbar 32 and joint member 33 connected thereto are moved back.

When the joint member 33 retreats as described above, each joint piece 34 also retreats, and each convex portion 36 on the outside of the tip is pressed inward by the tapered portion on the inner periphery of the tip of the tightening tube 40 and engages inside. The mating claw 35 is fitted into the engaging portion 47 of the operating shaft 46. Next, when a desired workpiece 48 is applied to the front part of the power chuck 22 and the rod 31 is further retreated, each engaging claw 35 engages with the engaging portion 47 and moves the operating shaft 46 backward. is moved inward to grasp and hold the desired workpiece 48.

After gripping the workpiece 48 securely in this manner, the main spindle 3 is driven to perform a predetermined turning process on the workpiece 48. In order to stop the main spindle 3 and remove the workpiece 48, the piston rod of the drive cylinder 30 is 31 and the operating shaft 46 to open each chuck pawl 45 of the power chuck 22 to release the workpiece 4.
8, then move each joint piece 34 forward as shown in FIG.
0, each joint piece 34 expands and the engaging claw 35 at the inner end of the joint piece 34 is disengaged from the engaging portion 47 of the operating shaft 46.

Next, when each actuator 8 of the headstock 1 is operated to move each rod 18 inward, the inner end moves each reciprocating member 15 to the inner end, and each presser pawl 7 is retracted via the lever 12, so that the power chuck 22 Since the power chuck 22 is removed from each concave portion 23 of the power chuck 22, the power chuck 22 can be replaced using an automatic replacement device.

To perform the above action, when the main shaft 3 stops,
Each advancing/retracting member 15 must correctly oppose each rod 18, but this can be easily accomplished by providing a detection device for detecting the stop position of the main shaft 3 and controlling the driving device of the main shaft 3 with this device.

〔effect〕

As described above, this invention includes a plurality of presser claws that move forward and backward in the radial direction of the chuck attachment means provided on the headstock of the lathe, and a plurality of presser claws that move inward in conjunction with the presser claws to attach the chuck attachment means to the power chuck adapter. It is composed of a plurality of reciprocating members that move outward when engaged with the recesses on the outer periphery of the presser, and a spring that pushes the retracting members outward, and the headstock is provided with a presser foot that pushes the outer end of each of the stopped retractable members. Since the device is equipped with an actuator that retracts the claws, when the actuator is operated to move each rod inward, each reciprocating member moves inward against the spring, and each presser claw that is linked to this moves inwardly. When the rods are moved outward and the actuators are activated to move the rods backward, the springs move the reciprocating members backward, and the corresponding presser claws move inward to engage the recesses of the power chuck. It matches. Therefore, since the actuator for attaching and detaching the power chuck is provided on the non-rotating headstock, hydraulic piping to the actuator is extremely easy.

Furthermore, since the power chuck is fixed by the pressure of a spring that has nothing to do with the actuator, there is no risk of the power chuck coming off the main shaft even if the oil pressure that operates the actuator drops due to a power outage or the like.

In addition, when the advancing/retracting member moves outward by the spring, the power chuck is fixed, so when the advancing/retracting member starts rotating, both the centrifugal force generated in this member and the spring force act on the outward movement of the advancing/retracting member. encourage However, although centrifugal force acts on the presser claw, an outward force from a spring acts on the retractable member, so even if the mass of the retractable member is approximately equal to the mass of the presser claw, the presser claw can be held. If the mass of the reciprocating member is further increased, the centrifugal force will further increase, and the holding force of the presser claw can be increased.

Furthermore, in the case of this invention, the joint member at the tip of the drawbar, which is provided in the hollow main shaft so as to be freely advanced and retractable, is moved forward and backward by the drive cylinder at the rear of the main shaft.
The tip of this joint member is provided with a plurality of joint pieces that expand due to their own elasticity when moving forward and are pushed inward by a tightening tube provided on the main shaft when moving forward or backward, and are attached to a chuck pawl that protrudes from the rear of the power chuck. An engaging portion is provided on the outer periphery of the rear end of the operation shaft, which engages with the engaging pawl inside the tip of each joint piece when the power chuck is fixed to the main shaft by the chuck attaching means. When the presser claw is fixed to the main shaft, moving the joint member forward and backward using the drive cylinder at the rear end of the main shaft will operate the operating shaft, allowing the chuck claw of the power chuck to be freely operated, and the operating shaft and drawbar can be freely connected and separated. can be done. Therefore, compared to conventional devices of this type, the operating mechanism is extremely simple.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal side view showing an embodiment of the device of the present invention, FIG. 2 is a partially longitudinal front view of the same, and FIG.
The figure is an enlarged longitudinal sectional side view of the main part. DESCRIPTION OF SYMBOLS 1...Headstock, 3...Main shaft, 5...Chuck attachment means, 7...Press claw, 8...Actuator, 12...Lever, 13...Pin, 15...
...Advancing/retracting member, 18... Rod, 19... Spring, 2
2...power chuck, 23...recess, 30...
Drive cylinder, 32... drawbar, 33... joint member, 34... joint piece, 40...
Tightening tube, 45...chuck claw, 46...operating shaft,
47...Engagement part.

Claims (1)

[Claims] 1. In a device in which a chuck attachment means is provided in the front part of the main spindle provided on the headstock of a lathe, and a separate power chuck can be detachably fixed to the main spindle by this attachment means, the chuck attachment means is installed in the radial direction. A plurality of presser pawls that move forward and backward, a plurality of reciprocating members that move inward in conjunction with the presser pawls and move outward when the presser pawls engage a recess on the outer periphery of the adapter of the power chuck; The head stock is equipped with an actuator that pushes the outer end of each stopped advancing/retracting member to retract each presser pawl, and a drawbar that is advanced or retracted by a drive cylinder provided at the rear end of a hollow main shaft. A joint member at the tip is provided in the front part of the main shaft, and at the end of this joint member there are multiple joint pieces that expand due to their own elasticity when moving forward and are pushed inward by a tightening tube provided on the main shaft when retreating. , on the outer periphery of the rear end of the operating shaft of the chuck pawl protruding from the rear of the power chuck, there is an engaging portion that engages with the engaging pawl inside the tip of each joint piece when the power chuck is fixed to the main shaft by the chuck attachment means. An automatic chuck exchange device equipped with