JPH0426170Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a workpiece holding device, especially a workpiece in which a plurality of holes extending radially around one axis are formed in the same plane. This invention relates to a holding device for holding objects.

(Prior Art) When performing machining such as cutting or grinding on a workpiece, it is important to reliably hold the workpiece in a predetermined position in order to improve machining accuracy.
For this reason, various improvements have been made to holding devices for workpieces.
No. 45605 discloses a holding device that can hold workpieces of different sizes with high positional accuracy according to the size of the workpiece during setup changes. .

By the way, when a workpiece has multiple holes formed in a radial pattern and you want to perform grinding on each of these holes, first make sure that the hole to be ground is coaxial with the workpiece spindle. Set the workpiece, and then grind the workpiece using a grindstone or the like while rotating the workpiece around the axis of the hole to be ground using the work spindle, and after the grinding of the hole is completed. When grinding the next hole, set the workpiece again so that the next hole is coaxial with the work spindle, then grind in the same way as above, and repeat these operations for each hole. Grinding of the holes takes place.

In this case, conventionally, each time the workpiece is reset, the clamp on the workpiece in the holding device is released, the workpiece is rotated so that the next hole is coaxial with the work spindle, and then The work involved clamping the workpiece.

(Problem to be solved by the invention) However, in the case of conventional holding devices that require repeated clamping and unclamping of the workpiece each time each hole is ground, The time required for setup changes becomes extremely long, making it impossible to work efficiently.

The present invention was developed in view of these circumstances, and aims to shorten the time required for setup changes when grinding each hole of a workpiece in which a plurality of holes are formed radially. It is an object of the present invention to provide a workpiece holding device that can achieve this without causing problems such as abnormal wear.

(Means for Solving the Problems) The workpiece holding device according to the present invention uses an indexing rotation means to hold the workpiece at predetermined angles around its axis while the workpiece is clamped by the clamping means. By rotating the workpiece, each hole can be sequentially positioned at the workpiece position, that is, a position coaxial with the work spindle, while the workpiece is clamped. This eliminates the time required for clamping and unclamping the workpiece. In addition, an elastic member is provided as a part of the index rotation means, and this elastic member provides resistance to the rotation of the clamp means, thereby preventing sudden rotation of the clamp means. It was designed to do so. That is, it is a holding device for holding a workpiece in which a plurality of holes extending radially around one axis are formed in the same plane, and includes clamping means for clamping the workpiece from both sides in the axial direction. , an indexing rotation means for rotating the clamping means by a predetermined angle around the axis of the workpiece to sequentially position each hole of the workpiece at a processing position; the clamping means and the indexing rotation; holding and rotating means for holding the means and rotating both means about the axis of the hole in the workpiece in the workpiece position, the clamping means comprising an upper clamping member actuated by a drive cylinder; , a lower clamp member, and the index rotation means includes an index member fixed to the lower clamp member and having a notch, and a spring biased in a direction to engage with the notch of the index member. an engaging member that engages and disengages from the notch by rotation of the indexing member; a pinion member that is attached to the lower clamp member via a one-way transmission means; and a rack that engages with the pinion member. The device is characterized in that it comprises a member, a drive means for actuating the rack member, and an elastic member for providing resistance to rotation of the lower clamp member.

As long as the above-mentioned "multiple holes" are formed radially within the same plane, the angular spacing between the holes is arbitrary.

The above-mentioned "predetermined angle" may be a fixed angle or may be a different angle, and in short, a size that allows each hole formed in the workpiece to be sequentially positioned at the workpiece position. It is sufficient if the angle is . Therefore, for example, if the angular intervals between the holes of the workpiece are different, the "predetermined angle" can be set to different angles correspondingly, or the "predetermined angle" can be set to different angles. ” may be set at a constant angle and the clamping means may be rotated by a “predetermined angle” once or multiple times to correspond to the angular spacing between each hole of the workpiece. good.

The above-mentioned "machining position" means a position where the axis of the hole to be machined in the workpiece is coaxial with the rotation axis of the work spindle.

(Function) With the above configuration, cutting of each hole of a workpiece in which a plurality of holes are radially formed in the same plane is performed according to the following procedure, that is,
The workpiece clamped by the clamping means is rotated by the holding and rotating means around the axis of the first hole located at the position to be machined, and the first hole is ground, and when this is completed, the workpiece is indexed. The rotating means rotates the workpiece around the axis of the workpiece until the next hole is located at the position to be machined, and the holding rotation means rotates the workpiece around the axis of the next hole. The grinding process is performed under pressure. In this manner, each hole is sequentially ground while the workpiece is being clamped.

The rotation of the workpiece is performed by rotating the pinion member via the rack member by the drive means and further rotating the lower clamp member via the one-way transmission means, and the lower clamp member is rotated by the drive means. The rotation is performed until the engagement member separates from the notch of the indexing member and engages again.
Since the elastic member provides resistance to the rotation of the lower clamp member, rapid rotation of the lower clamp member is prevented.

(Effect of the invention) Therefore, according to the invention, when grinding a plurality of holes formed radially in a workpiece, it is unnecessary to clamp and unclamp each hole each time. , it is possible to shorten the time required for setup changes, and it is possible to improve work efficiency. Additionally, once the workpiece is clamped, it will not be unclamped until the grinding of each hole is completed, making it possible to accurately position each hole in the workpiece at the position to be machined. .

Furthermore, according to the present invention, the elastic member that constitutes a part of the index rotation means provides resistance to the rotation of the clamp means, thereby preventing sudden rotation of the clamp means. , it is possible to prevent the indexing member and the engagement member that engage for indexing from causing abnormal wear due to rapid rotation from the engaged state, and thereby improve durability. .

(Example) An example of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a side sectional view showing a workpiece holding device according to this embodiment.

A workpiece 2 is held at the tip of a workpiece spindle 1 rotatably provided on a workhead (not shown) via a clamping means 3, and the workpiece 2 is held by the rotation of the workpiece spindle 1. A holding and rotating means 4 for rotation is fixed. The workpiece 2 has four holes 5 that extend radially around one axis and are formed in the same plane at 90° intervals, and the clamping means 3 holds the workpiece 2 on both sides in the axial direction. It has been adapted to be clamped. The clamping means 3 is
Consisting of an upper clamp member 6 and a lower clamp member 7, the upper clamp member 6 is lowered by a cylinder 8 (driving cylinder) with the workpiece 2 placed on the lower clamp member 7, and the lower end of the upper clamp member 6 The workpiece 2 is clamped by fitting a positioning pin 9 protruding from the workpiece 2 into a center hole 10 formed in the shaft of the workpiece 2.
As a result, four holes 5 formed in the workpiece 2
The workpiece 2 is positioned in the axial direction so that the rotation axis of the work spindle 1 is included in the plane formed by the axis of the workpiece 2, and the workpiece 2 is positioned within the plane.
It is also designed to help with positioning. Further, the clamping means 3 is attached to the holding and rotating means 4 so as to be rotatable only in one direction about the axis of the clamped workpiece 2, that is, an axis perpendicular to the rotational axis of the work spindle 1. .

The rotation of the clamping means 3 is caused by the rotation of the lower clamping member 7.
This is done by the indexing rotation means 11 which is provided in engagement with the. That is, this index rotation means 11 is
A pinion member 14 that meshes with a rack member 13 that moves parallel to the rotation axis of the work spindle 1 by a cylinder 12 (driving means) is attached to the lower clamp member 7 via a one-way clutch 15 (one-way transmission means). As a result, the clamping means 3 is rotated by a predetermined angle only in one direction with respect to the reciprocating movement of the rack member 13. Furthermore, this indexing rotation means 11 has notches 16 formed at four locations on the circumference at 90° intervals corresponding to the four holes 5 formed in the workpiece 2, and the center portion is formed with the lower clamp member 7. As shown in FIG.
6 and a detent member 18 (engaging member) which is spring biased so as to come into contact with the outer peripheral surface of the indexing member 17 in the "retracted" position, thereby preventing the movement of the rack member 13. Accompanied clamping means 3
By this rotation, the hole 5 formed in the workpiece 2 is accurately positioned at the workpiece position, that is, at a position coaxial with the work spindle 1.

The lower clamp member 7 also has a coil spring 19 provided at its lower end, as shown in FIG.
(elastic member) is constantly biased downward,
As a result, when the clamping means 3 rotates, the lower surface of the indexing member 17 fixed to the lower clamping member 7 is brought into sliding contact with the holding rotating member 4 with an appropriate frictional force, and the rotation of the clamping means 3 is prevented. The clamping means 3 is configured to apply a braking force to suppress rapid rotation of the clamping means 3.

Next, the operation of this embodiment will be explained.

As shown in FIG. 1, the clamping means 3
A pair of holes 5 at opposing positions among the four holes 5
The workpiece 2, which is clamped at a position where its axis is coaxial with the work spindle 1, rotates as the work spindle 1 rotates. With respect to the workpiece 2 rotating in this way, a grindstone shaft 2 having a rotation axis parallel to the work spindle 1
0 from the right, insert the cylindrical grindstone 21 attached to the tip of the grindstone shaft 20 into the hole 5 in the workpiece 2 to be ground, and rotate the grindstone shaft 20 in the direction of rotation of the work spindle 1. The outer peripheral surface of the grindstone 21 is brought into contact with the inner peripheral surface of the hole 5 by rotating in the opposite direction, thereby grinding the hole 5. When the grinding of the first hole 5 is completed, the grindstone 21 is moved sufficiently to the right. Thereafter, the cylinder 12 is actuated to move the rack member 13 to the right, thereby rotating the pinion member 14. At this time, the one-way clutch 15 is in the "engaged" state, and as the pinion member 14 rotates, the clamping means 3 also rotates at the same time. During this rotation, the rack member 13 receives a moderate reaction force from the pinion member 14 due to friction between the lower surface of the indexing member 17 and the holding and rotating means 4, so that the movement of the rack member 13 causes the clamping means 3 to suddenly move. You can avoid this inconvenience by rotating it.
Note that when the rack member 13 moves to the left,
Along with this, the pinion member 14 also rotates in the opposite direction, but since the one-way clutch 15 is in the "disengaged" state, the clamping means 3 remains stationary.

On the other hand, as shown in FIG. 2, the detent member 18 that was engaged with the notch 16 of the index member 17
As the clamping means 3 rotates, it is disengaged from the notch 16 and rides on the outer peripheral surface of the indexing member 17. Then, it comes into sliding contact with the outer circumferential surface of the indexing member 17 and engages with the next notch 16 . As a result, even if the amount of rotation of the clamping means 3 due to the movement of the rack member 13 is somewhat rough, the notches 1 formed at 90° intervals
6 is engaged with the detent member 17, allowing accurate indexing of the rotation angle. Therefore, workpiece 2
It becomes possible to position each hole 5 one after another at the position to be machined with high precision. Then, the grinding process performed on the first hole 5 may be repeated for each of the second and subsequent holes 5.

As described in detail above, according to this embodiment, it is possible to efficiently and accurately grind each hole 5 formed radially.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an example of a workpiece holding device according to the present invention, and FIG. 2 is a view taken in the direction of the arrow in FIG. 2... Workpiece, 3... Clamping means, 4...
Holding rotation means, 5... Hole, 6... Upper clamp member, 7... Lower clamp member, 8... Cylinder (driving cylinder), 11... Index rotation means, 12...
...Cylinder (driving means), 13...Rack member,
14... Pinion member, 15... One-way clutch (one-way transmission means), 16... Notch, 17... Index member, 18... Detent member (engaging member),
19...Coil spring (elastic member).

Claims (1)

[Claims for Utility Model Registration] A holding device for holding a workpiece in which a plurality of holes extending radially around one axis are formed in the same plane, the workpiece being held on both sides in the axial direction. a clamping means for clamping from the workpiece; an indexing rotation means for rotating the clamping means by a predetermined angle around the axis of the workpiece to sequentially position each hole of the workpiece at a workpiece position; holding/rotating means for holding a clamping means and an indexing/rotating means and rotating these means around an axis of a hole in the workpiece at the workpiece position, the clamping means being a drive cylinder; The indexing rotation means includes an actuated upper clamp member and a lower clamp member, and the indexing rotation means includes an indexing member fixed to the lower clamping member and having a notch, and the indexing member engages with the notch member of the indexing member. an engaging member that is spring-biased in a direction to engage with and disengage from the notch member by rotation of the indexing member; a pinion member that is attached to the lower clamp member via a one-way transmission means; A workpiece holding device comprising: a rack member that engages with a pinion member; a drive means that operates the rack member; and an elastic member that provides resistance to rotation of the lower clamp member.