JPH0234724B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of operating a general-purpose chuck mainly used in lathes for metal processing, etc., and particularly to a device for operating a grasping claw by expanding the movement of the grasping claw over a wide range. be.

Such conventional chucks include, for example, JP-A-52-
There is one described in Publication No. 150884. However, the operation of the grasping claw involves wide-area movement using a segment scroll (rotational operation converting means at the time of public announcement), and this segment scroll (rotary movement converting means) structure has a limited range of motion. It had the drawback of being restricted in its operation over a wide area.

The present invention has been devised to remove and expand the operation of the grasping pawl over a wide range of movement, and its main features are as follows:
When operating the grasping claws using the book's drive shaft, there is a first movement step in which the grasping claws are moved relatively largely forward and backward in the radial direction by the rotational movement of the drive shaft, and a first movement step in which the grasping claws are moved in the radial direction by the reciprocating motion of the drive shaft. The grasping claw is operated by a second movement step in which the grasping claw is moved relatively small forward and backward.

That is, in the method of the present invention, the first movement (wide area movement) of the grasping claw is performed by the rotational power of the drive shaft, and the second movement (narrow area movement) is performed by the axial force generated by the reciprocating movement of the drive shaft. The process is performed in that both the first movement process and the second movement process are performed by one and the same drive shaft. Moreover, since the first movement step is specifically carried out by a gear mechanism, it can be carried out over a wider area and is more effective than the conventional segment scroll (rotary motion converting means). It is.

An example of implementing the method of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a usage diagram in which a chuck 2 and a cylinder device 3 are fixed to the main shaft 1 of a lathe, and the chuck 2 of the main shaft 1 and the cylinder 4 of the cylinder device 3 are rotated together by the drive of a motor (not shown). Reference numeral 5 designates a sleeve body of the cylinder device 3, and the sleeve body 5 and a mounting base for a drive shaft driving motor 6, which will be described below, are fixedly provided on the lathe main body side.
Reference numeral 7 denotes a raw jaw, and 8 a grasping jaw for holding the raw jaw, which is used to attach and detach the workpiece and to adjust the attachment position of the grasping jaw in the reciprocating second movement process and the rotational first movement process of the same single drive shaft 9. Changes are made, which will be explained in detail in the following figures.

FIG. 2A is a longitudinal sectional view showing an example of the chuck 2 used in the present invention, and FIG. 2B is a partial view of the drive pawl 21 and guide pawl 26 used within the chuck. In the drawing, 20 is a body, and a plurality of grooves (three in this example) cut on the front side of the body 20 have a set screw 1 with a raw claw 7 on the front side.
A grasping claw 8 fixed at 0 is inserted so as to be slidable in the radial direction. Here, a rack tooth 11 is carved on the rear surface of the grasping claw 8, and is supported by a drive claw 21, which will be described later.
The body 20 is screwed together with a drive gear 22 that rotates freely around the body 20 as an axis, and is configured to perform a relatively large first movement step of forward and backward movement of the body 20 in the radial direction in conjunction with the rotation of the drive gear 22. It will be done.

Therefore, the rotation of the drive gear 22 is driven by the ring gear 23 that meshes with the drive gear 22 in a spur gear structure, and the rotation of the ring gear 23 is driven by a drive shaft 9 driven by a drive means described below.
This is achieved by transmitting the rotational power through the center gear 24 and intermediate gear 25.

Now, when the drive shaft 9 rotates in the forward direction, the grasping claws 8 move in the radial direction to open, and when the drive shaft 9 rotates in the reverse direction, they move inward in the radial direction to close. Since this movement is performed to change the mounting position, the initial movement distance is relatively large, such as 50 mm or 100 mm, but it can be quickly adjusted and activated. . On the other hand, once the workpiece has been grasped, the attachment/detachment may be limited to a small movement, for example, a movement amount of about 5 mm, and hereinafter, the second movement to grasp the workpiece with this relatively small movement amount is sufficient. The operation of the grasping claw 8 during the process will be explained. A through hole 12 is bored in the interior of the body 20 in the axial direction, and a guide pawl 26 that slides in the axial direction while being guided by the wall surface a of the through hole 12 is inserted. The guide pawl 26 is attached to the boss body 13 at the end of the drive shaft 9, and can rotate freely with respect to the boss body 13, but is prevented from moving in the axial direction by a protruding ring 27 and a nut 28. . On the other hand, the guide claw 26 has a T-shaped tapered groove d for engagement between the guide claw 26 and the drive claw 21.
is cut so that the taper direction approaches the axis toward the tip of the drive shaft 9, and when the drive shaft 9 is pushed into the body 20, the taper portion where the two engage The drive claw 21 moves outward in the radial direction due to the wedge action, and in conjunction with this movement, the grasping claw 8 that meshes with the drive tooth 22 with the drive claw 21 as the rotation axis opens in the radial direction. It is moved outward. On the other hand, when the drive shaft 9 is pulled out from the inside of the body 20, the drive pawl 21 moves radially inward to close the grasping pawl 8. In this operation, since the drive gear 22 is stationary, the amount of movement of the drive pawl 21 and the amount of movement of the grasping pawl 8 are the same.

FIG. 3 shows another example of the case previously disclosed in Japanese Patent Application No. 55-5137 by the present applicant, in which a drive claw (master jaw) 17 as shown in FIG. As an example, in this case it would be implemented as follows. At this time, a cavity F is bored in the main body of the drive pawl (master jaw) 17, and a hollow shaft drive gear 22 is fitted into the cavity. The support shaft 18 supporting the drive gear 22 is formed in a spline shaft structure, and the grasping pawl 8 can be freely moved in the radial direction by clockwise or counterclockwise rotation of the bevel gear 19 fixed to the lower end. This is done in such a way that a large amount of displacement occurs.

At this time, the rotational power from the drive shaft 9 is fixed at the end of the drive shaft, and is transmitted through the needle bar shaft 29 whose tip has a spline shaft structure with a certain length, and the bevel gear 30 which is pivotally supported on the body 20 side. It is transmitted. In this example, the needle bar shaft 29 has a spline shaft structure in order to allow the drive shaft 9 to move forward and backward while the bevel gear 30 is in a rotatable state. In this example, the guide claw 26 is threadedly attached to a collar 31 that is integrally fixed on the outer periphery of the drive shaft end, and a T-shaped taper is formed in the guide claw 26 by the reciprocating movement of the drive shaft 9. As in the previous example, the protruding wing g of the drive claw (master jaw) 17 that engages with the groove d slides in the radial direction of the body, allowing a relatively small amount of movement. .

FIG. 4 is a partial longitudinal cross-sectional view of a cylinder device for rotating the drive shaft 9 of each of the above examples in forward and reverse rotation within a reciprocating range of a certain distance. Cylinder 4 in the drawing
The cylindrical body P is fixed to the lathe main body, and passes through the sleep body 5 in a stationary state to form the cylinder 4.
is rotatably provided, and a piston 32 is provided in a sliding state inside the cylindrical body P of the cylinder 4. Here, the piston 32 is reciprocated in the directions of arrows A and B by external fluid pressure (not shown), and 14 is a guide pin, and 15a and 15b are guide holes. Therefore, the reciprocating movement of the drive shaft 9 caused by this causes the grasping pawl 8 to move in the radial direction via the guide pawl 26, as described above. On the other hand, a pawl clutch 36 is fixed to the rear end of the drive shaft 9, and on the opposite side, another pawl clutch 37 is rotatably supported on the bracket 16 on the lathe main body side. A certain gap h is provided between the pawl clutch 37 and the pawl clutch 37. The pawl clutch 37 is rotated by the drive of the motor 6 fixed to the bracket 16, and the rotational force is transmitted to the drive shaft 9 in the following manner.

Now, if the amount of movement necessary for the operation of the guide pawl 26 explained with reference to FIG. The amount of movement in the direction is used to attach and detach the workpiece. Incidentally, the piston 32 is designed to perform an auxiliary movement of an amount g in addition to the amount of movement f within the cylinder, and if the auxiliary movement amount g is increased, the convex teeth of the pawl clutch 36 are clawed. The concave teeth of the clutch 37 mesh with each other. The design is such that the relationship h≦g holds between the gap h between the two pawl clutches and the auxiliary movement amount g.

When the above claw clutches are engaged, the motor 6
is driven, the drive shaft 9 is rotated, and the center gear 24 is rotated within the body 20 described above.
rotates, which rotates the ring gear 23 via the intermediate gear 25, and the drive gear 22 rotates around the drive pawl 21 accordingly. The rotation of the drive gear 22 moves the gripping pawl 8 in the radial direction because the drive gear 22 meshes with the lock teeth 11 of the gripping pawl 8. The mounting position of the grasping claw 8 is changed by moving it in the direction of arrow C and in the direction of arrow D in the reverse direction. Since this amount of displacement is determined by the amount of drive of the motor 6, a position detector (such as a pulse coder) 3 is installed at the end of the drive shaft of the motor 6.
8, and checking the operation of the position detector 38, the desired amount is determined as appropriate. Note that 39 is a stroke detector such as a phototube or a proximity switch attached to the sleeve body 5 on the clutch side via a bracket, and is adapted to automatically regulate the amount of movement of the piston 32.

By the way, in order to prevent the drive shaft 9 from rotating as the cylinder device 3 rotates, a brake means is provided between the sleeve body 5 and the pawl clutch 36, and the brake means is connected to the sleeve. A sliding plate 40 is fixed to the side surface of the body 5, and a spring 4 is connected to the sliding plate 40.
The flanged sleeve 43 has a part 42 that is normally pressed into contact with the elastic force of 1, and when the flanged sleeve 43 is fitted onto the drive shaft 9, A pawl k formed on the inner peripheral surface of the tip of the mantle tube 43 is fitted into a spline groove 44 formed in a certain length range, so that the mantle tube 43 is slidably slidable in the axial direction. A flange tube 45 is screwed onto the top of the tube 43, and
A spring 41 is installed in the hollow V formed in the sliding plate 40.
By incorporating this into the flange tube 45 and elastically receiving it via the packing 6 and the ring 47, the part 42 of the flanged sleeve 43 and the sliding plate 40 are normally connected to each other. The brakes are designed to work by pressing into contact with each other. Note that 48 is a protruding ring fixed on the drive shaft 9, and when the drive shaft 9 is rotated, that is, when the drive shaft 9 moves backward and the pawl clutches 36 and 37 engage, At a slightly forward position, the protruding ring 49 connects to the flanged sleeve 43.
By making contact with the front edge m of the part 43 and similarly moving the pipe 43 backward against the resiliency of the spring 41, the contact between the part 42 and the sliding plate 40 is released and the braking action is performed. It prevents them from working.

Next, an example of actual operation of the present invention will be explained as follows.

At the work site, a robot picks up each workpiece that is neatly arranged in a pallet magazine and feeds it to the chuck in sequence, replacing it with a previously identified workpiece that has been processed and continues machining work. will be held. This process requires attachment/detachment operations such as attaching the workpiece to the grasping claws and detaching the already processed workpiece from the grasping claws. By the way, if the direction of fluid pressure supply to the piston in the cylinder is automatically selected and switched using a signal when a robot picks up a workpiece as an input signal, it is possible to either open or close the grasping claw in the desired direction of movement. It can be activated to

In the present invention, the command signal from the robot is used as an input signal to appropriately switch the fluid line valve for the piston 32 in the cylinder 4, and the drive shaft 9 is caused to reciprocate in conjunction with the operation of the piston 32 by fluid pressure. By this reciprocating motion, the grasping claws 8 are reciprocated in the radial direction of the body, thereby performing the work of attaching and detaching the workpiece. This command signal may be obtained not only from the operation of the robot but also from the operation of the pallet magazine, or from other sequences or programs.

When the gripping jaws are automatically activated in this way by an external signal, there is no problem even if there are workpieces with different gripping jaws, and this can be handled by a signal that instructs the gripping diameters to be different in advance. It is. Specifically, the change in grip diameter when the robot picks up the workpiece, or the change in the shape of the workpiece carried by the pallet magazine, is used as a command signal to control the motor 6.
is driven and the drive shaft is rotated as described above, so that the mounting position of the grasping claw can be changed as appropriate.

Although the explanation is omitted in FIG. 4, the drive shaft 9 is separated at the piston 32 in the cylinder 4 as seen in the drawing, and the shaft passing through the sleeve body is separated from the shaft through the pin 35 at that point. Each tsuba body 3
If 1a and 31b are connected and fixed integrally from the front using a nut 33, the chuck and cylinder device can be easily separated by removing the nut 33, which is the same. This is very convenient when replacing and using chucks with different performance in the cylinder device. Further, in the illustrated example, the rotation of the drive shaft is performed by engagement with a pawl clutch, but a slipping clutch using friction plates or an electromagnetic clutch may also be used. Furthermore, in addition to the transmission mechanism of the embodiment, the rotational power of the drive shaft may be moved by a combination of bevel gears and splines to change the mounting position of the grasping pawl.

Further, in order to move the grasping claw slightly in the radial direction of the body by reciprocating the drive shaft 9, an L-shaped lever 50 may be used as shown in FIG. In this example, the L-shaped lever 50 is connected to the body 20.
Inside, the curved corner part is fixed in a swingable manner using a pin 51, and on the other hand, the drive gear 2
2 is formed with a recess Q due to a missing tooth in the middle, one end of the L-shaped lever 50 is fitted into the recess Q, and the other end is a convex part of the nut 28 fixed on the boss 13. This is a configuration that engages with the starting point R. At this time, the intermediate gear 25 of the second illustrated example is omitted for the rotation of the drive gear 22, and the rotation of the drive shaft 9 is performed via the center gear 24 and the ring gear 23. Note that in this example and in the second
In the illustrated example, another tooth profile y is carved on the tooth surface of the drive gear 22 in the axial direction perpendicular to the tooth surface to mesh with the tooth surface of the ring gear. be.

The effects of the present invention are superior in that the movement range is dramatically expanded compared to the radial inward and outward movement of the grasping claws in conventional chucks, and furthermore, it can be operated using a single drive shaft. This has the remarkable effect that the grasping claw can be moved in a wide range and in a narrow range simultaneously or independently.

This is an excellent proposal that can be used not only for solid chucks but also for hollow chucks, and since it has a single drive shaft structure, it is natural that the hollow hole can be used more easily than a double structure with two drive shafts. It is also excellent in that the diameter can be made large.

[Brief explanation of drawings]

The attached drawings show an example of carrying out the method of the present invention, and Fig. 1 is a usage diagram in which the chuck and cylinder device are attached to the main shaft of a lathe, Fig. 2 A is a longitudinal sectional view of the chuck, and Fig. 2 B is a diagram showing the drive pawl and guide. FIG. 3A is a longitudinal sectional view of another example of the chuck, FIG. 3B is a partial perspective view of a drive pawl (master jaw), and FIG. 4 is a diagram of a cylinder device used in combination with the chuck. A longitudinal sectional view, FIG. 5, shows yet another example of the chuck. 2...Chuck, 3...Cylinder device, 8...
Grasping claw, 9... Drive shaft, 11... Teeth (easy claw), 20... Body, 21... Drive claw,
22... Drive gear, 23... Ring gear, 2
6...Guide claw, 32...Piston.

Claims (1)

[Claims] 1. A body, a plurality of grasping claws that slide inward and outward in the radial direction of the body, a drive gear that meshes with teeth on the back surface of the grasping claws, and a drive gear that rotates the drive gear. When using a chuck consisting of a drive pawl that is freely supported and slides inward and outward in the radial direction of the body, and one drive shaft that engages with the drive pawl and the drive gear, the drive shaft is The grasping is achieved by a first movement step in which the grasping claws are moved relatively largely forward and backward in the radial direction by rotational motion, and a second movement step in which the grasping claws are moved relatively small forward and backward in the radial direction by the reciprocating motion of the drive shaft. A grasping claw operation method for a power chuck, characterized in that the claw is operated. 2. A method for operating a power chuck grasping claw according to claim 1, wherein the grasping claw is operated automatically by using an external command signal as an input signal.