JPH1043979A - Work clamp device in machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly clamp a work by providing a releasing member which makes contact with the work prior to the contact of a clamp member tip part to the work placed on a table to interrupt a clutch member. SOLUTION: The connection between a driving nut member 17 and a clutch board 23 is interrupted, the transmission of rotating farce from the driving nut member 17 to a driven nut member 19 is interrupted to stop the movement of a clamp member 15 on a second stud bolt 13 side. The driving nut member 17 is turned in this state, and the tip side of the clamp member 15 regulated in movement of the base and part is moved down and brought into contact with the upper surface of a work W. Thus, the clamp member 15 clamps the work W by the tip part pressed onto the upper surface of the work W in the state where a first stud bolt 11 side is slightly inclined down to the second stud bolt 13 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work clamping device for fixing a work to a table of various machine tools.

[0002]

For example, in a machine tool such as a milling machine, a stud bolt is turned around a dovetail groove provided on a table on which a work is placed or a dovetail groove provided on a fixed block fixed on the table. A counter block slightly higher than the work (about 1 to 2 mm) is placed between the table and the base end of the clamp bar where the intermediate part is inserted into the stud bolt and the clamp bar is mounted. The tip of the clamp bar is pressed against the work and clamped with the counter block as a fulcrum as the nut is engaged with the nut.

However, when the work is clamped using the counter block as described above, when turning the clamped part of the work, the work is performed according to the work whose height has been reduced by turning after releasing the clamp once. It is necessary to replace the counter block with the counter, but selecting a counter block according to the height of the work requires a high level of skill, and ordinary workers take a lot of time to replace. In addition, there has been a problem that the processing efficiency of the work is deteriorated and the processing cost is increased.

[0004] In particular, in the case of NC machine tools, although work processing is automated on the basis of NC data, work is required to perform work clamping work, so that work processing cannot be fully automated. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is to provide a machine tool capable of firmly clamping a workpiece without using a counter block. An object of the present invention is to provide a work clamping device.

Another object of the present invention is to provide a work clamping device for a machine tool which can efficiently perform a work for clamping a work and increase a work efficiency of the work.

Another object of the present invention is to provide a work clamping apparatus for a machine tool which can automate a work for clamping a work.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a first and second stud bolts having vertical axes which are fixed at predetermined intervals to a table of a machine tool corresponding to a work clamping point. , A drive nut member meshed with the first stud bolt, a driven nut member meshed with the second stud bolt, a drive nut member at the distal end side and a driven nut member at the base end side, respectively. In this state, a clamp member that is rotatably inserted, a clutch member that disconnects the clutch disk with respect to the drive nut member, a connecting unit that connects the clutch disk and the driven nut member, and a workpiece mounted on the table. A work clamping device in a machine tool is constituted by a release member that abuts against a work and disconnects a clutch member prior to abutment of a tip portion of a clamp member.

Then, the clamp member is moved integrally with the first and second stud bolts by the driven nut member which rotates integrally with the rotation of the drive nut member so as to approach the work, and the tip of the clamp member with respect to the work. Prior to contact of the parts, the drive nut member and the clutch disc are disconnected by the release member that comes into contact with the work to interrupt the transmission of the rotational power from the drive nut member to the driven nut member, and then continue to rotate. The movement of the distal end of the clamp member, the movement of the base end of which is regulated by the driven nut member, is moved to press against the work and clamped.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, a table 1 of a machine tool (not shown), such as a slicing machine, has a fixed block 7 in which two dovetail grooves 3.5 are formed at predetermined intervals in parallel. Has been fixed. The fixed block 7 may be fixed individually according to each clamping position of the work W on the table 1 or may be a long shape fixed along the edge of the work W on the table 1. When the dovetail grooves 3 and 5 formed on the table 1 are used, the fixing block 7 may not be provided.

At least a pair of work clamping devices 9 are mounted on the table 1 via a fixed block 7. That is, the first stud bolt 11 is attached to the dovetail groove 3 on the workpiece W side, and the second stud bolt 13 is attached to the other dovetail groove 5 in a state where it is prevented from rotating. These first stud bolt 11 and second stud bolt 1
Reference numeral 3 has an axis in the up-down direction, and screws 11a and 13a having a predetermined lead and a predetermined pitch are turned.

In order to attach the first stud bolt 11 and the second stud bolt 13 to the dovetail grooves 3 and 5 so as to prevent rotation, the heads of the first stud bolt 11 and the second stud bolt 13 are formed to have different diameters. Form and dovetail groove 3.
5 are formed so as to coincide with the head, and the first stud bolt 11 and the second stud bolt 13
The head may be fitted so as to prevent rotation by inserting the head.

A clamp member 15 is attached to the first stud bolt 11 and the second stud bolt 13 so as to be vertically movable. That is, through holes 15a and 15b are formed in the distal end portion and the base end portion of the clamp member 15 so as to be opposed to the first and second stud bolts 11 and 13, respectively. The meshed drive nut member 17 is rotatable and is inserted in a state where it is prevented from falling off. A driven nut member 19 meshed with the second stud bolt 13 is rotatably inserted into the other through hole 15b in a state where the driven nut member 19 cannot be removed. A large-diameter flange portion 17a engaging with the upper surface of the clamp member 15 is integrally formed at an intermediate portion of the drive nut member 17 inserted into the through hole 15a, and is inserted into the through hole 15a from the lower surface of the clamp member 15. A C-ring 21 that is engaged with the lower surface of the clamp member 15 is attached to the outer periphery of the protruding cylindrical portion 17b, and prevents the drive nut member 17 from coming off from the clamp member 15. Also, the cylindrical portion 17b of the drive nut member 17
A large number of engaging projections 17c are formed on the lower surface at equal intervals in the circumferential direction. On the other hand, a large-diameter gear 19b is integrally formed below the cylindrical portion 19a of the driven nut member 19 inserted into the through hole 15b, and the large-diameter gear 19b is used to clamp the clamp member 15a.
The driven nut member 19 is prevented from coming off.

The first member located below the drive nut member 17
A clutch disc 23, which constitutes a part of a clutch member, is rotatably inserted through the stud bolt 11.
A large number of recesses 23a are formed on the upper surface of the third member 3 so as to be engageable with the engagement projections 17c, and a gear 23b is formed on the outer periphery thereof. Also, a first position located below the clutch disc 23
An operation panel 25 constituting a part of a clutch member is inserted through the stud bolt 11, and the operation panel 25 is
The clutch disc 23 is always driven by the elastic force of the compression spring 29 attached between the cover disc 27 and the cover 27 attached to the lower surface of the clutch disc 23.
To the driving nut member 17 to engage the engaging projection 17c with the recess 23a.

An intermediate gear 31 as a connecting member is provided on the clamp member 15 located between the large-diameter gear 19b of the driven nut member 19 and the gear 23b of the clutch disc 23 as a large-diameter gear 1.
It is supported rotatably so as to be able to mesh with both 9b and the gear 23b.

The distal end (work side) of the clamp member 15 is formed in a bifurcated shape with a gap in the middle, and a lever 33 as a release member is swingably supported in the distal end. The lever 33 is located in the gap at the tip,
One arm 3 that can contact the upper surface of the work W before the tip
3a and a bifurcated other arm portion 33b rotatably supported on the outer periphery of the operation panel 25, and the lever 33 swings with the contact of the one arm portion 33a with the upper surface of the work W. The pressing plate 25 is moved downward against the elastic force of the compression spring 29 by 33b to separate the clutch disk 23 from the drive nut member 17 and release the engagement of the engaging projection 17c with the concave portion 23a.

Next, a description will be given of the work clamping action by the work clamping device configured as described above.

After the work W is placed on the table 1 with the upper surface thereof and the pressing portion 15c of the clamp member 15 separated from each other, the drive nut member 17 is moved by a wrench (not shown).
Is rotated in a required direction, the clutch disc 23 is engaged with the engaging projection 17c in its concave portion 23a by the operating disc 25 urged by the elastic force of the compression spring 29, and is integrally formed with the drive nut member 17. The driving nut member 17 rotates and transmits a rotating power to the driven nut member 19 connected via the intermediate gear 31 to rotate the driving nut member 17 in the same direction.

As a result, the clamp member 15 moves with respect to the first and second stud bolts 11 and 13 as shown in FIG.
The table 1 is integrally moved downward so as to be parallel to the plane of the table 1, and its tip is brought close to the upper surface of the work W. Although the drive nut member 17 is manually rotated by a wrench, an electric motor (not shown) is connected to the drive nut member 17 and the drive of the electric motor is controlled to rotate the drive nut member 17. It may be configured to move.

The tip of the one arm 33a projecting from the lower surface of the tip with the movement of the clamp member 15 is
When the lever 33 swings at a required angle in the clockwise direction as shown in FIG. 3, the other arm portion 33 b of the lever 33 resists the elastic force of the compression spring 29 and pushes the pressing plate 25.
Is moved downward to move the clutch disc 23, thereby releasing the engagement of the engaging projection 17c with the recess 23a. As a result, the connection between the drive nut member 17 and the clutch disc 23 is disconnected, so that the transmission of the rotational driving force from the drive nut member 17 to the driven nut member 19 is interrupted, and the clamp member on the second stud bolt 13 side is interrupted. 1
5 is stopped.

When the drive nut member 17 is further rotated in this state, the distal end side of the clamp member 15 whose base end is restricted from moving by the drive nut member 17 which rotates as shown in FIG. Is moved downward to be pressed against the upper surface of the work W. As a result, the clamp member 15 is clamped by the distal end portion that presses against the upper surface of the work W in a state where the first stud bolt 11 is slightly inclined downward with respect to the second stud bolt 13.

As described above, in the present embodiment, the distal end of the clamp member 15 is positioned slightly below the base end with the rotation operation of the drive nut member 17 without using the counter block. In this state, the workpiece W can be firmly clamped, and the workpiece clamping operation can be performed efficiently.

In particular, in the case of the NC machine tool, the work clamp device 9 is mounted on a slide table movable by an actuator such as an electric cylinder, and the position of the work clamp device 9 can be automatically set based on the NC data. At the same time, when cutting the clamped part of the work, the electric motor (servo motor) connected to the drive nut member 17 is driven in the direction opposite to the clamping direction based on the NC data to release the work clamp. After the portion of the work is cut in the state, the electric motor is driven in the clamping direction to clamp the work having a reduced height, so that the work clamping operation can be completely automated.

The above description has been made with reference to the gear 23b of the clutch disc 23.
And the large-diameter gear 19a of the driven nut member 19 is connected to the intermediate gear 31.
The drive nut member 17 and the driven nut member 1
9 is rotated in the same direction. However, as shown in FIG.
3 or a configuration in which they are connected by a toothed belt (not shown). In this case, the clutch disc 51 connected by the chain 53 or the toothed belt is
Since it is difficult to move the stud bolt 11 in the axial direction, a claw clutch structure in which the drive nut member 17 and the clutch disc 23 are connected to each other by the engaging projections 17c that engage with the concave portions 23a as in the above-described embodiment. Instead, a friction clutch structure in which the drive nut member 17 and the clutch disc 23 are connected by a frictional force may be used.

[0026]

According to the present invention, the work can be firmly clamped without using a counter block. Further, according to the present invention, the work of clamping the work can be efficiently performed, and the processing efficiency of the work can be increased. Furthermore,
The present invention can automate the work of clamping a work.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a work clamp device.

FIG. 2 is a central longitudinal sectional view of a work clamping device.

FIG. 3 is a longitudinal sectional view showing a state in which an operation panel is pushed down by a lever.

FIG. 4 is a longitudinal sectional view showing a clamped state of a work.

FIG. 5 is a longitudinal sectional view showing a modification.

[Explanation of symbols]

1 Table, 9 Work Clamping Device, 11 1st Stud Bolt, 13 2nd Stud Bolt, 15 Clamp Member, 17 Drive Nut Member, 19 Follower Nut Member, 23 Clutch Board Forming Part of Clutch Member,
25 Operation panel constituting a part of clutch member, 31 Intermediate gear as connecting member, 33 Lever as releasing member, W work

Claims (7)

[Claims] 1. A first and second stud bolt having an axis in a vertical direction fixed to a table of a machine tool at a predetermined interval in accordance with a work clamping location, and a drive engaged with the first stud bolt. A nut member, a driven nut member meshed with the second stud bolt, and a clamp member for rotatably inserting the driven nut member on the distal end side and the driven nut member on the base end side, respectively, in a state of being prevented from coming off. A clutch member for connecting and disconnecting the clutch disk to the drive nut member; connecting means for connecting the clutch disk and the driven nut member; and a work piece prior to abutment of the tip end of the clamp member against the work placed on the table. The first and second driven nut members rotate integrally with the rotation of the drive nut member. The clamp member is moved integrally with the tod bolt so as to come close to the work, and the connection of the clutch disc to the drive nut member is released by a release member that comes into contact before the front end of the clamp member comes into contact with the work, and the driven nut member After the transmission of the rotational power from the drive nut member to the workpiece is stopped, the distal end side of the clamp member, whose movement of the base end is restricted by the continuously rotated drive nut member, is pressed against the workpiece. Work clamp device in a machine tool that clamps a workpiece. 2. The work clamp device for a machine tool according to claim 1, wherein gear teeth are formed on the outer periphery of the clutch disk and the driven nut member, and the clutch disk and the driven nut member are connected via an intermediate gear. 3. The work clamp device according to claim 1, wherein the clutch disc and the driven nut member are connected by a chain. 4. The work clamp device according to claim 1, wherein the clutch board and the driven nut member are connected by a belt. 5. The machine tool according to claim 1, wherein the clutch member is inserted through the first stud bolt, and the clutch disk can be connected to the drive nut member via an operation panel urged by the elastic force of the elastic member. Work clamp device. 6. A work clamp device for a machine tool according to claim 5, wherein said clutch disc and said drive nut member have a claw clutch mechanism for connecting an engagement projection provided on one side to said other recess for connection. 7. A work clamping apparatus for a machine tool according to claim 5, wherein the release member comprises a lever member having one arm protruding from the tip of the clamp member and the other arm supported by the operation panel.