JPH0141445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a general-purpose chuck mainly used for metal processing lathes, and in particular, to provide a chuck whose gripping claws can be moved over a wide range with great ease.

Such conventional chucks include, for example, JP-A-52-
There is one described in Publication No. 150884. However, the movement of the grasping claw is a wide-area movement using a segment scroll (rotary motion converting means at the time of public announcement), and this segment scroll (rotary motion converting means) is structured to have a limited range of motion. However, this had the disadvantage that the amount of movement over a wide area was naturally restricted.

The present invention has been devised to remove such restrictions on the amount of wide-area movement of the grasping pawl, and its features include: a body and a grasping pawl that slides inward and outward in the radial direction of the body; a drive gear that meshes with the teeth on the back surface of the grasping claw; a drive claw that rotatably supports the drive gear and slides inward and outward in the radial direction of the body; The chuck consists of a drive shaft that moves forward and backward in the axial direction of the body as well as a chuck that can grasp a wide area as shown below. (A) The drive gear transmits the rotational force of the drive shaft. (a) The drive gear is configured to have a structure including a rotational force transmission means, and the grasping claw can be moved over a wide area via the rotational force transmission means; (a) The drive gear transmits axial force in the axial direction of the drive shaft. The grasping claw is formed in a structure provided with a means, and the grasping claw is moved within a narrow range via the axial force transmission means.

It is in.

That is, the features of the present invention include a grasping claw, a drive gear that meshes with the teeth on the back surface of the grasping claw, and a drive gear that rotatably supports the drive gear and slides inward and outward in the radial direction of the body. In addition to forming the gripping claw into a drive claw that moves over a wide area, the rotational force of the drive shaft is used to move the grasping claw over a wide area, and the axial force of the drive shaft is used to move the grasping claw over a narrow area. The point is that both are performed by the action of the same drive shaft. Moreover, since the wide-area movement is specifically carried out by a gear mechanism, it has the feature that it can be carried out over a wider area compared to a conventional segment scroll (rotary motion conversion means).

However, the chuck of the present invention is superior in that the grasping claws can move over a very wide range.

Hereinafter, specific examples will be described using the drawings.

Fig. 1 is a vertical cross section of a lathe with a chuck 2 and a cylinder 3 fixed to the main shaft 1. The main shaft 1 is driven by a motor (not shown) to rotate, and the chuck 2 is rotated by the rotational force of the main shaft 1. Rotate valve 4. Sleeve body 5 and motor 6 to be described later
The mounting base is fixed to the lathe body.
As shown in the figure, the grasping claw is composed of a child claw 7 and a master claw 8 that holds it, or it is made by integrating the child claw 7 and the master claw 8. The grasping claws are moved in a narrow area by the reciprocating movement of the drive shaft 9, and in a wide area by the rotating movement. The details of this operation will be described later, but the feature of this embodiment is that the narrow-area movement and wide-area movement of the grasping claws are performed only by operating the same drive shaft 9. That is, grasping of the workpiece is performed by reciprocating motion, while major positional changes of the grasping claws are performed by rotational motion.

FIG. 2 is a longitudinal sectional view showing the chuck in FIG. 1. In the figure, reference numeral 20 denotes a body, into which a plurality of grooves (three in the illustrated example) are cut into which grasping claws that move inward and outward in the radial direction are slidably inserted. There is. Furthermore, a drive gear 22 that rotates about the drive claw 21 as an axis of rotation is rotatably supported on a drive claw 21 that is arranged in parallel with the grasping claw and similarly moves inward and outward in the radial direction. The drive gear 22 meshes with the teeth on the back surface of the grasping pawl. The grasping pawl is configured to reciprocate inward and outward in the radial direction of the body 20 in conjunction with the rotation of the drive gear 22. Further, the drive gear 22 is driven and rotated by a ring gear 23 that meshes with the drive gear 22, and the rotational force of the ring gear 23 is received by the center gear 24 from the rotational force of the drive shaft 9 driven by a drive means to be described later. , the rotational force is transmitted through an intermediate gear 25 that meshes with the ring gear 23. Therefore, when the drive shaft 9 rotates in the forward direction, the grasping claws move outward in the radial direction to release. During the opposite rotation, the gripping pawls are operated to move radially inward toward closure. This movement via the rotational force transmission means is used to move the gripping claws over a large distance and change the gripping position of the gripping claws when changing the workpiece, so the amount of movement needs to be large, for example 50mm or 100mm. etc. On the other hand, when grasping the workpiece and attaching and detaching it, the amount of movement may be small and limited;
For example, the amount of movement may be about 5 mm. Of course, these amounts of movement are relative values depending on the size of the chuck.

Next, the operation of the grasping claws when strongly grasping a workpiece will be explained. A cylindrical hole opening in the axial direction is formed inside the body 20, and a plunger 26 that slides forward and backward in the axial direction while being guided by the wall surface a of the hole is inserted. . The plunger 26 is attached to the tip of the drive shaft 9 so that it can only rotate freely, and is blocked in the axial direction by a projection ring 27 and a nut 28. Furthermore, a T-shaped taper groove d is cut in the plunger 26, and the taper direction thereof is directed toward the tip of the drive shaft 9 and brought closer to the axis. On the other hand, the drive claw 21 is inserted through the tapered groove d.
is engaged with plunger 26. However, when applying a load to the drive shaft 9 toward the front in the axial direction of the body in the axial force transmission means configured as described above, the drive pawl 21 moves radially outward due to the wedge action of the wedge portion. Conversely, when the drive shaft 9 is directed rearward in the axial direction of the body and a load is applied, the drive pawls 21 are operated to move radially inward. In movement via this axial force transmission means,
Since the drive gear 22 is in a non-rotating state, the amount of movement of the drive pawl 21 and the amount of movement of the grasping pawl are exactly the same.

FIG. 3 is a longitudinal sectional view showing an example of a cylinder that can be suitably used in combination with the chuck described above. In the figure, a rotary valve 4 passes through a sleeve body 5 that is fixed to the lathe body and is in a stationary state.
is rotatable with the body 5 by a bearing (not shown), and has a piston 32 housed inside a rotating portion that projects outward from the sleeve body 5. The piston 32 is reciprocated by external fluid pressure (not shown), and the nut 3
3, the drive shaft 9 fixed to the piston 32 is moved together. The reciprocating motion of the drive shaft 9 is
This has the effect of moving the grasping claws radially inward and outward through the axial force transmission means as described above, thereby enabling powerful grasping of the workpiece. On the other hand, one piece 36 of a pawl clutch is fixed to the tip of the drive shaft 9, and is opposed to the other pawl clutch 37 with a certain gap h provided therebetween. Claw clutch piece 37
is rotated by the drive of a motor 6 fixed to the lathe body, 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 plunger 26 shown in FIG. This means that you will be able to put it on and take it off. However, since the piston 32 can move a distance of (f+g) as shown in FIG.
If the pawl clutch piece 36 is moved by an additional amount, the convex portion of the pawl clutch piece 36 will be inserted into the concave portion of the pawl clutch piece 37, and the clutch will be engaged. However, the gap h is conditioned on the condition that the relational expression h≦g holds true. When the motor 6 is driven with the clutch engaged, the drive shaft 9 is rotated, and the grasping claws are moved radially inward and outward via the rotational force transmission means such as the center gear 24 mentioned above. The grasping position of the grasping claw is changed and displaced. Since this amount of displacement is determined by the amount of drive of the motor 6, the desired amount is appropriately displaced while checking the operation of the position detector 38 (pulse coder, etc.) provided at the tip of the shaft of the transmission installed in the motor 6. I have made it possible. Further, a stroke detector 39 (phototube, proximity switch, etc.) is fixed to the sleeve body 5 on the clutch side so that the piston 32 operates within f. By the way, chuck 2 and cylinder 3
In order to prevent the drive shaft 9 from rotating along with the rotation of the sleeve body 5, a sliding surface i is provided on the sleeve body 5, and the brake is ON up to the range of the movement amount J (J<h) of the drive shaft 9. A brake device is provided in which a sliding part 40 that is spline-coupled or key-coupled to the shaft 9 and pressed against the sliding surface by a spring 41 is provided. When this part 40 is pressed and moved by the protruding ring 42 of the drive shaft 9, the pressing force overcomes the pressing force of the spring 41 and moves away from the sliding surface i, turning off the brake.

The chuck mechanism described above is operated as follows.

The robot grasps each of the unprocessed items that are neatly arranged in the pallet magazine and feeds them to the chuck in sequence, replacing them with the already-processed items that have already been grasped in advance, and continuously performs processing operations. continue. This process requires attachment/detachment operations such as attaching the unprocessed workpiece to the grasping claws and detaching the finished 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 the robot grasps a workpiece as an input signal, the grasping jaw can be moved in either the open or closed direction of the desired movement. It can be activated. However, in this embodiment, the robot switches to the commanded position and causes the drive shaft to reciprocate in conjunction with the operation of the piston due to the pressing force of the fluid, and the reciprocating movement opens and closes the grasping claws to perform the work of attaching and detaching the workpiece. Do it. 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. In this way, when automatically operating the gripping jaws using an external signal, it does not matter even if there are workpieces with different gripping diameters, the difference in gripping diameter is detected in advance, and the detection signal is used to command the gripping claws. It can be activated by For example, a change in the grasp diameter when a robot grasps a workpiece, or a change in the shape of a workpiece carried by a pallet magazine is used as a command signal to control the motor 6.
When the gripper is driven and the drive shaft is rotated, the mounting position of the grasping claw is changed and displaced.

Although the explanation is omitted, the drive shaft connecting the chuck and the cylinder has a flange joint structure with a flange 34 and a shear pin 35, and the chuck and cylinder can be easily separated by removing the nut 33. This is very convenient when using the same cylinder interchangeably with chucks of different performance.

Further, although the embodiment shows a drive shaft having a solid shaft, a hollow shaft may also function. Furthermore, although not shown, the clutch has pawl clutch pieces 36 and 37.
In addition to the transmission mechanism of the embodiment, the rotational force of the drive shaft rotated by the operation of the clutch may be a slipping clutch using friction plates. The grasping position of the grasping claw may be displaced and moved.

An advantage of the present invention is that even with a simple structure, the grasping claw can be moved over a wide range and within a narrow range simultaneously or independently. Furthermore, it is an excellent product that can be used as a drive shaft with a hollow shaft structure to improve functionality.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing a chuck and cylinder fixed to the main shaft of a lathe, Fig. 2 is a longitudinal sectional view showing an example of the chuck, and Fig. 3 is a longitudinal sectional view showing an example of the cylinder. . 2...chuck, 3...cylinder, 4...rotary valve, 6...motor, {7...child claw, 8...main claw} grasping claw, 9...drive shaft, 20...body, 21... ...Drive pawl, 24...Center gear,
26...plunger, 32...piston, 38...
...Position detector, 39...Stroke detector.

Claims (1)

[Scope of Claims] 1. A body, a grasping claw that slides inward and outward in the radial direction of the body, a drive gear that meshes with teeth on the back surface of the grasping claw, and a drive gear that is rotatable. A chuck consisting of a drive pawl that is supported by the body and slides inward and outward in the radial direction of the body, and a drive shaft that engages with the drive pawl and moves forward and backward in the axial direction of the body, A chuck capable of grasping over a wide area configured as follows (A) The drive gear is formed in a structure including a rotational force transmission means for transmitting the rotational force of the drive shaft, and the grasping claw is connected to the gripping claw via the rotational force transmission means. (a) The drive gear is formed in a structure including an axial force transmitting means for transmitting axial force in the axial direction of the drive shaft, and the grasping claw is moved over a narrow area through the axial force transmitting means. To move. 2. The drive shaft in the rotational force transmission means is
A chuck capable of grasping a wide area according to claim 1, which is formed in a structure that is supported by a plunger that slides forward and backward in the axial direction of the body. 3. The rotational force transmission means is formed in a structure including a gear mechanism that meshes with the teeth of the drive shaft through the teeth of the drive gear, and is capable of rotation of 360 degrees or more in both forward and reverse directions. A chuck that can be grasped over a wide area according to claim 1. 4. The chuck capable of gripping over a wide area according to claim 1, wherein the axial force transmitting means is formed in a structure including a wedge-shaped mechanism that engages with the wedge portion of the drive shaft via the wedge portion of the drive pawl. 5. A chuck capable of grasping a wide area according to claim 1, wherein the drive shaft is formed as a hollow shaft.