JP2528495Y2 - Anti-chatter clamp device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a clamp device for suppressing chatter of a workpiece during cutting.

(Prior art) In order to suppress chattering during cutting caused by the shape of the work or the structure of the cutting machine, etc., a device that clamps a part of the work at a position away from the support position is known from the Japanese Utility Model. It has already been proposed in US Pat.

Such a device, like other devices, has a movable part and a fixed part, that is, an inevitable gap exists between the clamp mechanism and a guide member that guides the same. As a result of transmission and resonance, it has the inconvenience of not being able to fully exhibit the chatter prevention effect, and the chuck mechanism at the tip has only the function of simply gripping the work,
If the thickness or the like of the work is offset, the work is gripped in a state where the chuck mechanism is bent, and as a result, inconvenience such as amplifying chatter occurs.

(Problems to be solved by the present invention) The present invention has been made in view of such a problem, and its purpose is to avoid chatter vibration.
In addition, it is an object of the present invention to provide a new device that can firmly grip a workpiece and reliably suppress chattering during the cutting process, even if the gripping position is offset.

(Means for Solving the Problems) In other words, the present invention provides a chatter-preventing clamp device for achieving the above-mentioned object, which is guided by a guide member and moves between a workpiece holding position and a retracted position. At the front end of the work piece, a clamp claw for gripping the work constantly urged in the expanding direction by the urging member is arranged,
At the rear end of the clamp claw, a piston rod driven and operated by fluid pressure to move forward and backward, a swingable pressing rod provided at the tip of the piston rod and provided with a dish-shaped portion at the tip, In order to close the clamp claw in the gripping direction by being pressed by the dish-shaped portion, there is provided a free-moving sphere that enters the rear end inner surface, while the clamp mechanism main body is orthogonal to the guide member toward the surface of the guide member. A pressing member for pressing in the direction is provided.

(Operation) Even when the axis of the work is deviated to one side, the sphere that is in point contact with the clamp claw and the deflection of the pressing rod that is in surface contact with this sphere are clamped by this configuration. The nail is made to follow the work, and it is securely held without difficulty. In addition, by holding the clamp mechanism main body against one surface of the guide member by the pressing member, even if chatter vibration occurs in the work in the cutting process, the clamp mechanism main body gripping the work receives this chatter vibration. And grip the work without any problem.

(Embodiment) Therefore, an embodiment illustrated below will be described.

 The drawings show an embodiment of the present invention.

In the drawing, reference numeral 1 denotes a guide fixed on a base 2,
A guide surface 3 for guiding a lower surface of a clamp mechanism main body 10 described later is formed in a front half portion of the guide body 1, and a cylinder 4 is integrally fixed to a rear half portion of the guide body 1. The clamp mechanism body 10 is configured to be able to advance and retreat by applying hydraulic pressure to a piston 11 provided in a part thereof.

On the other hand, the clamp mechanism body 10 has a pair of clamp claws 12, 12 for gripping the workpiece W at its tip, which are rotatably supported on support shafts 13, 13. Is configured as a hydraulic cylinder 15, and a piston 16 slidably mounted thereon has a clamp claw 12
A cylindrical piston rod 17 extending to the side is integrally provided, and a pressing rod 19 constantly urged outward by a spring 18 is movably inserted into the inside thereof, and a distal end thereof is provided. The tapered surface 12a provided inside the base end of the clamp claw 12 is pressed from the inside by a spherical body 21 pressed by the dish-shaped portion 20, so that the clamp claws 12, 12 can be closed.

On the other hand, reference numeral 25 denotes a pressing cylinder for pressing the clamp mechanism main body 10 onto the guide surface 3 described above. This pressing cylinder 25 is provided above the front half of the guide 1, that is, above the guide surface 3 so as to sandwich the clamp mechanism main body 10. A pressing element 27 provided integrally with the piston 26 is slidably positioned on the upper surface of the clamp mechanism body 10.

Reference numerals 5 and 6 in the figure denote limit switches for detecting a forward end and a retreat end of the clamp mechanism main body 10 by coming into contact with a detector 22 provided on a part of the clamp mechanism main body 10. Guide rods provided at the ends, 14 and 14 are clamp claws 1
Shown are springs that constantly urge the members 2 and 12 in the expanding direction.

In the apparatus configured as described above, in order to operate to clamp the work W from the standby state in FIG. 1, first, the first switching valve V ₁ is switched, and the hydraulic pressure is applied to the back surface of the piston 11. The clamp mechanism main body 10, which is integral with the main body, is advanced to the position indicated by the two-dot chain line in FIG. In this state, the pair of clamp claws 12, 12 are urged by the springs 14, 14, which act on the rear ends thereof, and are expanded, so that when these clamp claws 12, 12 come to the position where the work W is clamped. , then switches the second switching valve V _2, by the action of hydraulic pressure to the back of the pressure piston 16 protrudes a cylindrical piston rod 17. As a result, the pressing rod 19 in the piston rod 17 is also extruded, and the spherical body 21 is pressed by the dish-shaped portion 20 at the tip of the pressing rod 19, and this is a tapered surface provided inside the rear end of the clamp claw 12.
By acting on 12a, the work W is clamped as shown in FIG.

By the way, at this time, assuming that the axis of the workpiece W is slightly displaced downward by a small amount δ as shown in FIG. 3, the upper and lower clamp claws 12, 12 which clamp this are tapered at the rear end. The spherical body 21 that is in contact with the surface 12a is slightly displaced upward, and the pressing rod that is in surface contact with the spherical body 21
The workpiece 19 is displaced and swung upward to rotate counterclockwise in the figure from a regular position, and is displaced following the workpiece W which has been displaced and is securely gripped.

When the above operation is completed, the third operation (not shown) is performed.
The switching valve is operated to slide the piston 26 in the pressing cylinder 25 downward, and the clamp mechanism main body 1 is pressed onto the guide surface 3 from above by the pressing element 27 at the lower end thereof, and the gap existing between the two. To eliminate

For this reason, when a cutting process is performed on the clamped work W next, even if chatter vibration occurs between the work W and the cutting tool in the cutting process, the clamp mechanism main body 10 that holds the work W is pressed by the pressing cylinder 25. Guide surface 3 on guide body 1
The work W is securely held during machining without receiving chatter vibration from the work W.

Then, when the above processing is completed, the above-mentioned operation is performed in reverse to return the clamp mechanism body 1 to the non-clamp position again and return to the standby state shown in FIG.

(Effects) As described above, according to the present invention, the front end of the clamp mechanism main body which is guided by the guide member to move forward and backward is supported by the clamp claws for the workpiece gripping constantly biased in the expanding direction, This clamp claw is closed by a free-moving sphere that comes into surface contact with the swingable pressing rod provided at the tip of the piston rod, so that even if the axis of the work is deviated to one side, point contact with the clamp claw Due to the respective spheres and the swinging pressing rods that are in surface contact with the sphere,
The clamp claws can be grasped without difficulty while following the work.

Moreover, since the clamp mechanism body is pressed in a direction perpendicular to the surface of the guide member, even if chattering vibration occurs in the work during the cutting process, the clamp mechanism body is firmly fixed by the clamp mechanism body which is firmly fixed. The work can be firmly gripped via the claws and can be subjected to normal processing.

[Brief description of the drawings]

FIG. 1 is a side view of an apparatus showing an embodiment of the present invention, FIG. 2 is a side view of the apparatus showing a state where a work is clamped, and FIG. 3 is a state where a work in an eccentric state is gripped. FIG. 4 is a front view of the same device. DESCRIPTION OF SYMBOLS 1 ... Guide body, 3 ... Guide surface 4 ... Cylinder, 10 ... Clamp mechanism main body 12 ... Clamp claw, 15 ... Pressing cylinder 17 ... Piston rod, 19 ... Swinging rod 21 ... Spherical body , 25 …… Pressing cylinder

Claims (1)

(57) [Scope of request for utility model registration] 1. A clamping claw for gripping a workpiece constantly biased in an expanding direction by a biasing member at a front end of a clamp mechanism main body which is guided by a guide member and moves between a gripping position and a retracted position of the workpiece. And a piston rod which is driven and operated by fluid pressure to move forward and backward, and a swingable free end which is disposed at the tip of the piston rod and has a dish-shaped portion at the tip. A pressing rod and a free-moving sphere pressed by the dish-shaped portion of the pressing rod and entering the inner surface at the rear end thereof to close the clamp claw in the gripping direction are arranged, while the guide member is provided with the clamp mechanism main body. Characterized in that a pressing member for pressing the pressing member in a direction orthogonal to the surface of the guide member is provided.