JP4288124B2 - Finger chuck - Google Patents

Description

  The present invention relates to a chuck for turning, and more particularly to a finger chuck suitable for machining a variety of workpieces (workpieces) having different outer diameters, such as automobile wheels.

Conventional finger chucks are movable in the radial direction of the body so as to be able to cope with workpieces having different outer diameters such as automobile wheels.
For example, according to Japanese Patent Application Laid-Open No. 8-141808, a clamp arm that grips a workpiece is adjusted to an adjustment piece that moves in a radial direction by meshing with a scroll plate, and an operating body that moves in a front-rear direction by a clamp cylinder. A pair of brackets are provided on both sides of the clamp arm in the circumferential direction so that the clamp arm can be slid in the engagement portion.
When gripping the workpiece, first, the scroll plate is rotated, the adjustment piece is moved in the radial direction, and the lever position is adjusted according to the outer diameter of the workpiece.
Next, when the operating body is moved backward by the clamp cylinder and the clamp arm is moved backward, the claws of the clamp arm grip the work and the work is fixed to the body.
With the above operation, the workpiece is gripped by the clamp arm.
JP-A-8-141808

However, the finger chuck configured as described above has the following problems.
The brackets provided on both sides of the clamp arm are provided radially outward, and a centrifugal force corresponding to the weight of the bracket is generated when the chuck rotates.
This centrifugal force acts radially outward on the gear meshing with the pin and scroll plate engaging the bracket with the adjusting piece and the operating body.
The members such as the pin member, the scroll plate, and the adjusting piece resist the centrifugal force applied thereto, so that it is necessary to increase the strength of the member, so that the entire device is enlarged, and it is difficult to reduce the size and weight of the device. It was.
Therefore, in view of the above problems, an object of the present invention is to provide a finger chuck having a structure that reduces the centrifugal force of these members generated during rotation.

  In order to solve the above-described problems, the present invention provides a body, a plurality of frame bases that are engaged with guide grooves provided in the body and are slidable in the radial direction of the body, and provided behind the body. And a clamp plate that moves in the front-rear direction, a lever that is provided radially outward of the body and has a claw that grips a workpiece at the front end, and a long hole provided in a substantially middle part of the lever in the front-rear direction. In a finger chuck having a guide pin that holds the lever slidably with respect to the frame base and a lever shaft that is provided behind the lever and transmits the acting force of the crank plate to the lever, the frame base is radially inward. A screw rod that has a screw shaft provided in the back and a guide shaft that protrudes backward, and a screw rod that is screwed into the screw hole and rotatably mounted on the body, and a plurality of frame bases are synchronized with each other by rotation of the screw rod. Drive means for sliding in the direction is provided, the clamp plate is engaged with a guide groove provided in the radial direction and includes a connecting member that can slide in the radial direction, and the connecting member inserts the tip of the guide shaft And engaging with the rear end of the lever through the lever shaft to the radially outer end.

According to the present invention, since the weight of the radially outer portion of the apparatus is reduced compared to the prior art and excessive centrifugal force does not act when the chuck rotates, it can be safely used even with a chuck with low body strength. The chuck can be made smaller and lighter.
In addition, since the screw rod, connecting member, and guide shaft that move the lever are arranged radially inward, the center of gravity of the entire device is arranged radially inward, which makes the body unbalanced when the chuck rotates. Since no load is applied, the deflection and distortion of the entire body are reduced, and the workpiece can be reliably gripped.
In addition, the brackets provided on both sides of the lever according to the conventional configuration are eliminated, the lever is engaged only with the lever shaft and the guide pin, and the engaging portion of the lever is made with a simple component configuration, so maintenance etc. When exchanging the lever, it is possible to easily remove and attach the lever, thereby shortening the man-hour for the exchange.
Furthermore, since the chuck can be made smaller and lighter and the workpiece can be securely gripped, it is possible to cope with the high-speed rotation of the chuck.

The best mode of the present invention will be described below with reference to the drawings.
FIG. 1 is an overall sectional view of an embodiment according to the present invention.
FIG. 2 is a partially enlarged cross-sectional view showing an operating state in which the lever is moved to the large diameter side of the workpiece in FIG.
FIG. 3 is a partially enlarged cross-sectional view showing an operating state in which the lever in FIG. 1 is moved to the small diameter side of the workpiece.
FIG. 4 is an enlarged sectional view of the lever portion.
FIG. 5 is an enlarged cross-sectional view of the workpiece gripping portion.
6 is a partial cross-sectional view taken along the line BB in FIG. 2, and FIG. 7 is a partial cross-sectional view taken along the line CC in FIG.
FIG. 8 is a partially enlarged sectional view showing a state in which the lever in FIG. 3 is opened.

In FIG. 1, a shaft body 9 integrally fixes a disc-shaped body 1 to the front surface (right side in FIG. 1) on the work mounting side, and a plurality of guide grooves are radially formed on the front surface of the body 1. Is provided. A plurality of frame bases 2 slidably embedded in the guide grooves are provided.
The frame base 2 has a screw hole 13 in which a female screw is provided on the inner surface at the radially inner end, a receiving base 16 for receiving the lever 3 for gripping the workpiece 24 is provided in the front, and a cylinder is provided in the rear. A guide shaft 8 is provided so as to protrude rearward.
A substantially intermediate portion in the front-rear direction of the lever 3 is slidably supported by a guide pin 6 that slidably holds the intermediate portion in the front-rear direction of the lever 3 at the radially outer end of the frame base 2. .
The frame base 2 is screwed into the screw rod 17 through the screw hole 13, and the screw stand 17 rotates so that the frame base 2 moves in the radial direction of the body.
The screw rod 17 is rotatably attached to the body 1 and has a rotation gear 27 at one end.
In order to rotate the screw rod 17, the body 1 has a transmission gear 19 that synchronously rotates a plurality of screw rods 17 as driving means, and a hexagonal engagement portion 25 that is engaged with the transmission gear 19 and is a connecting portion with a tool. A rotor 18 is provided.
A transmission gear 19 that meshes with the rotation gear 27 of the screw rod 17 is rotatably fixed to the body, and a rotor 18 that meshes with the transmission gear 19 is provided in the body 1. A hexagonal engagement portion 25 is formed by projecting from 1 to the front.
When the tool 26 is engaged with the hexagonal engagement portion 25 and rotated, the rotor 18 transmits the rotation of the tool 26 to the transmission gear 19, and the plurality of screw rods 17 rotate synchronously via the transmission gear 19. Are moved in synchronism with each other in the radial direction.

As shown in FIG. 7, the guide shaft 8 provided on the frame base 2 is inserted into an engagement hole 21 provided at the tip of the connecting member 4, and the connecting member 4 is guided by the guide shaft 8 to move forward and backward. It is made movable in the direction.
A shaft hole 20 is provided at the radially outer end of the connecting member 4, and the lever 3 is inserted through the lever shaft 7 and supported so as to be pivotable in the front-rear direction. Is engaged as.
The connecting member 4 is guided by a guide groove 22 provided in the clamp plate 5 and engaged so as to be slidable in the radial direction of the body 1.
The clamp plate 5 is fixed to the shaft body 9 and is movable in the front-rear direction as the shaft body 9 moves in the axial direction (front-rear direction).
An opening 23 is provided in the guide groove 22 portion of the clamp plate 5 in the front-rear direction so that the connecting member 4 is slidable in the radial direction while being engaged with the guide shaft 8.
The lever 3 that grips the workpiece 24 includes a claw 10 that sandwiches the workpiece 24 at the front end portion, and includes a shaft hole 12 through which the lever shaft 7 is inserted on the other end side. It is supported so as to be rotatable in the direction, and the acting force of the clamp plate 5 is transmitted.
A U-shaped elongated hole 11 is provided in a substantially middle portion of the lever 3 in the front-rear direction, and the guide pin 6 is inserted into the pin hole 29 of the frame base 2 so that the middle portion of the lever 3 is an end portion of the frame base 2. The long hole 11 is slidably engaged within the length range.

The operation of this embodiment will be described below.
FIG. 2 shows a state where the large-diameter workpiece 24 is gripped by the lever 3. When the workpiece is changed from the large-diameter workpiece 24 to the small-diameter workpiece 28, the position of the lever 3 needs to be changed.
After engaging the tool 26 with the hexagonal engagement portion 25 of the rotor 18, the tool 26 is rotated to rotate the rotor 18, whereby the plurality of screw rods 17 are rotated synchronously via the transmission member 19.
When the screw rod 17 rotates, the plurality of frame bases 2 screwed into the screw rod 17 are embedded in the guide groove, so that the rotation is prevented and the screw slides inward in the radial direction (Y direction in FIG. 2). Move.
When the top 2 moves inward in the radial direction, the connecting member 4 engaged with the guide shaft 8 provided in the top 2 is also guided by the guide groove 22 of the clamp plate 5 and moved inward in the radial direction. To do.
Similarly, the lever 3 engaged at the two positions of the connecting member 4 and the frame base 2 is moved in synchronism radially inward, and the lever 3 is moved to a position where the small-diameter workpiece 28 is gripped as shown in FIG. Moving.

From this state, the movement for opening the lever 3 will be described.
When the shaft body 9 is moved forward in the axial direction (X direction in FIG. 2), the clamp plate 5 is moved forward along with the shaft body 9, and the connecting member 4 engaged with the clamp plate 5 is moved to the guide shaft 8. The lever 3 is guided forward and moved forward, and the lever 3 is moved forward in the axial direction via the lever shaft 7.
When the lever 3 moves forward, it is guided to the elongated hole 11 through the guide pin 6, and the lever 3 rotates rearward in the front-rear direction around the lever shaft 7, and the lever 3 is opened as shown in FIG. It becomes a state.

When gripping the workpiece 28, when the shaft body 9 is moved rearward (in the opposite direction to X in FIG. 2), the clamp plate 5 is moved rearward, and the coupling member 4 engaged with the clamp plate 5 is guided. It is guided by the shaft 8 and moves rearward, and the lever 3 is moved rearward in the axial direction via the lever shaft 7.
When the lever 3 moves rearward, it is guided to the elongated hole 11 through the guide pin 6, and the lever 3 rotates forward and backward about the lever shaft 7, and the lever 3 is closed as shown in FIG. The workpiece is sandwiched between the claw 10 and the cradle 16 of the stand 2 and the workpiece 28 is gripped and fixed to the chuck. At this time, since the plurality of frame bases 2 are synchronized and moved in the radial direction, a grasping force is equally applied to the plurality of levers 3 so that the stable work 28 is grasped.

To open the lever 3 again from this state and release the grip of the workpiece 28, when the shaft body 9 is moved forward in the axial direction, the clamp plate 5 moves forward along with the shaft body 9, and the clamp plate 5 The connecting member 4 engaged with the guide member 8 is guided by the guide shaft 8 and moved forward to move the lever 3 forward in the axial direction via the lever shaft 7.
When the lever 3 moves forward, it is guided to the elongated hole 11 through the guide pin 6, and the lever 3 rotates rearward in the front-rear direction around the lever shaft 7, and the lever 3 is opened as shown in FIG. The workpiece 28 sandwiched between the claw 10 and the cradle 16 of the stand 2 is released, and the gripping of the workpiece 28 is released.

The present invention is provided with a screw rod 17 screwed inward of the piece base 2 as a moving means for moving the piece stand 2 in the radial direction. Therefore, a guide shaft 8 that guides the sliding of the lever 3 in the front-rear direction can be provided behind the frame base 2.
Therefore, in the present invention, since the guide shaft 8 guides the movement of the lever 3 in the front-rear direction, the conventional apparatus does not require a pair of brackets provided on both sides of the lever radially outward, and the radius of the apparatus. The weight of the outer part in the direction can be reduced, the generation of the centrifugal force acting on the outer part in the radial direction of the apparatus during rotation of the chuck is suppressed, and the moment of inertia acting on the body is reduced. .
Further, in the present invention, since the lever 3 is inserted through the connecting member 4 by the lever shaft 7, the movement of the lever 3 in the front-rear direction and the radial direction is performed integrally with the movement of the connecting member 4, and the lever 3 moves back and forth. The operation is performed in a stable state in which the direction is guided by the guide shaft 8 and the radial direction is guided by the guide groove 22.

The whole sectional view of the example by the present invention. The partial expanded sectional view which shows the operation state which moved the lever in FIG. 1 to the large diameter side of the workpiece | work. The partial expanded sectional view which shows the operation state which moved the lever in FIG. 1 to the small diameter side of the workpiece | work. The expanded sectional view of a lever part. The expanded sectional view of a work holding part. The fragmentary sectional view by the BB arrow in FIG. The fragmentary sectional view by CC arrow in FIG. FIG. 4 is a partial enlarged cross-sectional view showing a state where the lever is opened in FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Body 2 Block base 3 Lever 4 Connecting member 5 Clamp plate 6 Guide pin 7 Lever shaft 8 Guide shaft 9 Shaft body 17 Screw rod

Claims (1)

A body, a plurality of frame bases that engage with a guide groove provided in the body and are slidable in a radial direction of the body, a clamp plate that is provided behind the body and moves in the front-rear direction, and the body A lever that has a claw that grips the workpiece toward the front tip, and is inserted in a long hole in the middle of the lever in the front-rear direction. The lever is slidably held with respect to the stand. A finger chuck provided with a guide pin and a lever shaft provided rearward of the lever for transmitting the acting force of the crank plate to the lever;
The frame has a screw hole provided radially inward and a guide shaft protruding rearward, a screw rod screwed into the screw hole and rotatably mounted on the body, and by rotation of the screw rod Drive means for synchronizing and sliding a plurality of tops in the radial direction is provided, and the clamp plate is engaged with a guide groove provided in the radial direction and includes a connecting member that can slide in the radial direction. The finger chuck has an engagement hole for inserting the tip end of the guide shaft and engages the rear end of the lever through the lever shaft to the radially outer end portion.

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