JP3054001B2 - Work centering method for indexing chuck, work centering device for indexing chuck, and indexing chuck for machine tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for aligning a workpiece in an indexing chuck, a workpiece alignment apparatus for the indexing chuck, and an indexing chuck for a machine tool.

[0002]

BACKGROUND ART For example, as shown in FIG. 7, a central flange with holes, line l perpendicular to the center line l _1
When machining a workpiece such as a valve body with a side flange with holes formed bilaterally symmetrically at both ends in _two directions while chucking and indexing with the indexing chuck of the machine tool, use a two-dot chain line. Clamping is performed by the pair of upper and lower clamp claws at the three positions shown. Then, while performing indexing with the indexing chuck, the end face of each flange, the outer diameter of the flange, and the inner diameter of the hole are respectively turned or bored, and then the inner periphery of the outer end of each hole is chamfered.

[0003]

In processing such a work W, the work W is set on a lower clamp claw in the chuck body, and then the work W is clamped and fixed by a pair of upper and lower clamp claws. At this time, the claw portions 6 of the clamp claws clamp the inner narrow portions of the left and right side flanges 4 from both the upper and lower sides.

However, in the conventional indexing chuck, although the clamp claws are exchanged according to the shape of the work W to be processed, the work W is simply set on the lower clamp claws, and then the upper and lower clamp claws are used. Since the work is only clamped and fixed from both sides, when the work W is a cast valve body or the like, the following problem occurs.

That is, when the inner diameter of the left and right holes 3 is eccentric due to the displacement of the core with respect to the outer shape of the clamp portion of the work W, or when casting is performed using a plurality of divided molds. If the external dimensions vary, it is very difficult to center the work in a state where it is chucked by the indexing chuck.

Therefore, if machining is performed with the centering failure, problems such as black scales remaining on the inner surface of the hole 3 during machining of the inner diameter and chamfering defects such as uneven chamfering occur.
It is practically impossible to use an indexing chuck when processing a valve body or the like that is large in shape.

Therefore, when machining a workpiece W such as a large valve body, a machining method using an indexing chuck cannot be employed. Therefore, each machining of each part using a plurality of machining machines is required. At present, it is inevitable to adopt a processing method of attaching and detaching a workpiece and changing a processing portion.

The present invention has been made in view of such conventional problems,
Provided is a method of centering a work in an indexing chuck, a work centering device for the indexing chuck, and an indexing chuck of a machine tool, which can easily and surely center the work such as a valve body on the basis of the inner diameter. The purpose is to do.

[0009]

According to a first aspect of the present invention, a workpiece is clamped in a chuck body of an indexing chuck of a machine tool by a pair of upper and lower clamp claws on the chuck body side. When machining the work while indexing it with an indexing chuck, the work is held in an aligned state based on the inner diameter of the work on the lower clamp claw removed outside the machine tool, A plurality of lower pawls on the lower clamp pawl were brought into contact with the work in the set-out state from below to fix and support the work with the lower pawls, and then the work was set in the centered state. The lower clamp claw is inserted into the chuck body and mounted on the chuck body side.

According to a second aspect of the present invention, there is provided a base having a mounting portion on which a lower clamp claw detached from a chuck body side of an indexing chuck of a machine tool is removably mounted.
A pair of left and right supports disposed on the base on both the left and right sides of the mounting portion, and slidably supported in the left and right directions by the respective supports, and on the lower clamp claw of the mounting portion. A pair of right and left centering shafts which are removably fitted and centered from the left and right sides of the arranged work, and the lower clamp pawl is provided with a pair of left and right centering shafts on the lower clamp pawl. A plurality of lower pawls provided to be slidable in the perspective direction with respect to the work centered by a shaft and supporting the work in a centered state from below, and each of the lower pawls; And fixing means for fixing. According to a third aspect of the present invention, there is provided an indexing chuck for a machine tool, wherein the workpiece is machined while clamping and indexing the workpiece by a pair of upper and lower clamp claws in a chuck body. The work piece is detachably provided on the chuck body side, and is provided on the lower clamp claw so as to be slidable in the near and far directions with respect to the work in a centered state on the lower clamp claw, and the work is centered from below. A plurality of lower pawls for fixing and supporting in a state, and fixing means for fixing each of the lower pawls, and centering on the lower clamp pawls by the lower pawls outside the machine tool. The work in the state is supported from below, and a lower clamp claw in which the work is fixed in a centered state is mounted on the chuck body side.

[0011]

The lower clamp claw 31 for the indexing chuck 20 is mounted on the mounting portion 57 on the base 56 of the work centering device 21. next,
A pair of right and left centering shafts 59 are fitted into the holes 3 of the work W from the left and right sides on the lower clamp claw 31, and the work W is positioned on the lower clamp claw 31 in a centered state based on the inner diameter thereof.
, And adjust the lower clamp pawl 31 with the adjusting screws 39 and 40.
Slide the lower pawls 37 and 38 toward the workpiece W,
The work W is supported from below by 37 and 38, and each centering shaft 59 is removed from the work W.

Then, with the work W set on the lower clamp pawl 31, the lower clamp pawl 31 is placed on the mounting portion of the base 56.
The work W is removed from the chuck 57 and inserted into the chuck body 22, and the work W is clamped and fixed by a pair of upper and lower clamp claws 30, 31.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 to 3 show an indexing chuck 20 of a machine tool that chucks a work W such as a valve body. FIGS. 4 to 6 show centering outside the machine tool before chucking the work W. 1 shows a work centering device 21 used in this case.

In the indexing chuck 20 shown in FIGS. 1 and 2, reference numeral 22 denotes a chuck body, which is mounted on a spindle head (not shown). 23 is a square frame, as shown in FIG.
At the lower part of the chuck body 22, four main plungers 70 and auxiliary plungers 71, which are rotatably supported around an axis perpendicular to the axis of the spindle, and which alternately move back and forth by switching hydraulic pressure, come into contact. Are formed on the outer periphery. Then, the corner piece 23 causes the main plunger 70 and the auxiliary plunger 71 to alternately move back and forth,
By sequentially contacting the tip with each of the contact surfaces A to D, the tip rotates intermittently around the axis at an index pitch of 90 degrees.

Numeral 24 denotes a claw receiving stand, which is placed on the upper surface of the square piece 23 with the engaging portion 25 engaged, and is detachably fixed by bolts 26. A key groove 26 is formed on the upper surface of the claw cradle 24, and a stopper 27 is provided on the rear end side of the key groove 26.
Is fixed. Reference numeral 28 denotes a clamp shaft, which is arranged on the upper side of the chuck body 22 on the axis of the square top 23. The clamp shaft 28 is rotatably mounted on a piston 29 fitted inside the chuck body 22, and the piston 29 is provided on the chuck body 22 so as to be able to slide up and down by switching hydraulic pressure.

Reference numeral 30 denotes an upper clamp pawl, 31 denotes a lower clamp pawl,
The workpiece W is provided on the clamp shaft 28 and the claw support 24 so as to be clamped and fixed from above and below. The upper clamp claw 30 has a pair of left and right upper claw portions 32 for pressing left and right constricted portions of the work W from the upper side, and a pair of left and right inclined upper claw portions 33 for pressing the center flange 2 of the work W from the upper left and right sides. The clamp shaft 28 is floatably mounted on the clamp shaft 28 by a bolt 72 via a spherical convex portion 30a slidably fitted in a spherical concave portion 28a at the lower end of the clamp shaft 28.

After the work W is centered on the work centering device 21 based on the inner diameter of the hole 3, the lower clamp claw 31 is placed on the claw receiving table 24 in the chuck body 22 while being set together with the work W. It is designed to be detachably attached to the. As shown in FIGS. 4 to 6, the lower clamp claw 31 includes a base plate 34 and a pair of left and right front sliding members 35 slidably disposed on the base plate 34 so as to be slidable in the front-rear direction. A rear sliding body 36, a pair of left and right front and rear lower claws 37 and 38 projecting from the front and rear sliding bodies 35 and 36 so as to face each other in the front-rear direction;
Front and rear adjustment screws 39, 40 for sliding the 37, 38 in the perspective direction (that is, the front-back direction) with respect to the workpiece W are provided. The fixing means are constituted by the adjusting screws 39 and 40.

A key 41 slidably fitted in the key groove 26 of the claw receiving base 24 is provided on the lower side of the base plate 34 in the front-rear direction at the center in the left and right direction. A pair of left and right portions 42 and 43 are provided, and a key 44 in the front-rear direction is fixed between the front and rear protrusions 42 and 43.

Each front / rear sliding member 35, 36 has a front / rear projection 4
The front and rear sliding members 35 and 36 are formed with key grooves 45 and 46 in which the keys 44 of the base plate 34 are slidably fitted. In addition, two long holes 47, 48 parallel to the key grooves 45, 46 are formed at the front and rear, respectively. The front and rear sliding bodies 35 and 36 are connected to the base plate 34 through long holes 47 and 48, respectively.
Bolts 49 and 50 to be screwed into and a disc spring 5 for applying preload
1, 52 attached to the base plate 34.

A pair of left and right front and rear lower claws 37 and 38 support left and right narrow portions of the work W from the front and rear on the lower side, and are integrally formed on the front and rear sliding bodies 35 and 36. I have. The pair of left and right front projections 42 has a central flange of the workpiece W.
Receiving bolt 53 for receiving 2 from the lower left and right is provided to be adjustable.

The adjusting screws 39 and 40 are screwed into female screw holes 54 and 55 formed in the front and rear protrusions 42 and 43 so as to be able to advance and retreat in the front-rear direction. It is connected only rotatably, and can be rotated by appropriately fitting a tool into the hexagonal hole on the outer end side.

In the work centering device 21 shown in FIGS. 4 to 6, reference numeral 56 denotes a rectangular base, and the base 56 has a chuck body.
A mounting section 57 for detachably mounting the lower clamp claw 31 removed from the mounting section 22 is provided at the center in the left and right direction, and a support body 58 is provided on both left and right sides of the mounting section 57.
Are provided, and a pair of right and left centering shafts 59 are slidably supported in the left and right directions by the respective support members 57.

When the lower clamp claw 31 is mounted on the mounting portion 57, the mounting portion 57 of the base 56 has the same key 41 as the key groove 26 of the claw receiving base 24. A key groove 60 is formed to slidably fit, and a stopper 61 with which the key 41 abuts is attached to the rear end.

A pair of left and right centering shafts 59 are slidably inserted in the left and right direction into the holding cylinder 62 of the support body 58, and the workpiece W disposed on the lower clamp claw 31 at the opposite end side.
It has a centering head 63 that is removably fitted in the hole 3 and a grip portion 64 for operation on the outer end side. Note that each centering shaft 59 is retained by a retaining bolt 65 screwed to the holding cylinder 62.

Each support 58 is provided with a key on the base 56 in a horizontal direction.
A slot 67 slidably provided along the key 66 and parallel to the key 66
A bolt 68 inserted through the nut and a nut 69 screwed into the bolt 68 are fixed at an appropriate position in the left-right direction so as to be adjustable. Note that each support 58 is provided with a stopper bolt 70 near the lower part of the centering shaft 59.

When machining the work W using the indexing chuck 20, the following is performed. First, the lower clamp claw 31 is mounted on the mounting portion 57 of the work centering device 21, and the work W is centered on the basis of the inner diameters of the holes 3 on the left and right sides.

That is, the lower clamp pawl 31 is used to align the work centering device.
It is mounted on the mounting portion 57 on the base 56 of 21. In this case, after placing the edge of the base plate 34 of the lower clamp claw 31 on the base 56 and aligning the lower key 41 with the key groove 60 of the base 56, the base plate 34 is When pressed in the direction indicated by the arrow, the base plate 34 slides on the base 56 in the direction indicated by the arrow a while being guided by the key 41 and the key groove 60. When the tip of the key 41 is slid to a position where it comes into contact with the stopper 61 of the base 56, the mounting of the lower clamp claw 31 is completed.

Next, the workpiece W is positioned between the pair of right and left centering shafts 59.
After aligning the holes 3 of the left and right side flanges 4 with the axes of the centering shafts 59, the centering heads 63 of the centering shafts 59 are fitted into the holes 3 from both left and right sides. .

In this case, for example, after aligning the hole 3 of the left side flange 4 of the workpiece W with the centering head 63 of the centering shaft 59, the grip portion 64 is gripped to move the centering shaft 59 in FIG. b. Slide in the direction of the arrow to insert the centering head 63 into the hole 3. Similarly, the centering head 63 of the right centering shaft 59 is inserted into the right hole 3 of the work W.

Then, the work W is placed on a pair of right and left centering shafts 59.
Then, the work W is placed on the bolt 53 by receiving the center flange 2 of the work W. At this time, as the workpiece W is shown in two-dot chain line W _1, if the deviation in the lateral direction, by sliding the workpiece W in the horizontal direction on the axis of the centering shaft 59 is positioned in the center. Then, the central flange 2 of the work W rests on the pair of left and right receiving bolts 53, and the position of the work W in the left-right direction is determined.

[0031] Therefore, the workpiece W is when mounted on the nail cradle 24 of the chuck 20 indexing the lower clamp jaws 31 as it is, the center line l ₁ of the workpiece W coincides with the axis of the spindle shaft, Also, a line segment l ₂ connecting the centers of the left and right holes 3, that is, the axis of the centering shaft 59 is located at the intersection of the axis of the spindle shaft with the axes of the square top 23 and the clamp shaft 28, and The workpiece W is in a perpendicular orientation, and the workpiece W is in a centered state based on the inner diameter of the left and right holes 3.

Then, next, a pair of left and right front / rear adjustment screws 3 is provided.
Operate 9,40 around the axis with a tool.
The front and rear sliding members 35 and 36 are slid in the front-rear direction according to the amount of clearance between the workpiece W and the workpiece W, and the front and rear lower claws 37 and 38 are moved downward. The workpiece W is brought into contact with the work W from both front and rear sides.

When the front and rear receiving portions 37 and 38 come into contact with the work W, the grip portions 64 of the pair of right and left centering shafts 59 are gripped, and the centering shafts 59 are moved outward (counterclockwise). (In the direction of the arrow), and the centering head 63 is removed from the hole 3 of the work W. However, the work W has already been
The rear lower claws 37, 38 abut from below, and the front and rear lower claws
Therefore, even if the centering shafts 59 are removed, the posture of the work W does not change at all, and the centering state is maintained.

With this, the external centering operation is completed. Next, the lower clamp claw 31 is removed from the mounting portion 57 of the base 56 while the work W is mounted on the lower clamp claw 31. It is inserted into the chuck body 22 and mounted on the claw receiving stand 24. At the time of this mounting, with the edge of the base plate 34 of the lower clamp claw 31 placed on the claw cradle 24 and aligning the tip of the key 41 with the key groove 26 of the claw cradle 24, The base plate 34 is pushed in until it comes into contact with the stopper 27. And
When the key 41 hits the stopper 27, the clamp shaft 28 and the upper clamp claw 30 are lowered by the piston 29, and the workpiece W is clamped and fixed from above and below by the pair of upper and lower clamp claws 30, 31.

Next, the main plunger 70 and the auxiliary plunger 71 are alternately operated, and each part of the work W is machined while performing indexing at a predetermined indexing pitch by intermittent turning of the square piece 23. In this way, the work W in the chuck body 22 can be easily and reliably centered. Therefore, even the work W such as a large valve body can be chucked by the indexing chuck 20 in the centered state, and the work W can be efficiently processed using the indexing chuck 20.

In particular, since the workpiece W has the centering shaft 59 inserted from both sides into the left and right holes 3 and is centered on the basis of the inner diameter, black scale remains on the inner surface of the hole 3 when the inner diameter of the hole 3 is machined. Alternatively, when chamfering the inner periphery of the outer end of the hole 3, uneven chamfering may not be caused, resulting in high precision machining.

After the lower clamp claw 31 is taken out of the chuck main body 22 and the work W on the lower clamp claw 31 is centered outside, the work W is set on the lower clamp claw 31 and set. Insert it into the chuck body 22 and insert the claw support 24
If a plurality of lower clamp claws 31 are prepared for mounting on the upper side, the next work W can be centered during processing. For this reason, the setup at the time of processing the work W can be performed easily and quickly, and every time the processing of the work W is completed, the setup time is not wasted compared to the case of centering and chucking, and the movement efficiency is improved. Therefore, productivity is remarkably improved.

The structure of the upper and lower clamp claws 30, 31 is as follows.
What is necessary is just to change suitably according to the outer shape of the workpiece | work W to be processed, and it is not limited to the shape and structure of an Example. For example, it is sufficient that each of the lower claws 37, 38 can be adjusted in the direction toward and away from the workpiece W.
In addition to sliding back and forth with 39 and 40, sliding bodies 35 and 36 may be vertically slid with adjusting screws 39 and 40, or may be slid in a radial direction on a plane. good.

A key groove may be provided below the lower clamp claw 31, and a corresponding key may be provided on the claw receiving base 24 and the base 56. Further, the claw clamp claws 30 and 31 may be mechanically moved in and out or replaced between the chuck body 22 and the work centering device 21.

[0040]

According to the method of the present invention described in claim 1,
In the chuck body of the indexing chuck of the machine tool, the workpiece is clamped by a pair of upper and lower clamp claws on the chuck body side, and when the workpiece is machined while being indexed by the indexing chuck, it is removed outside the machine tool. The work is held in a centered state based on the inner diameter of the work on the lower clamp claw, and a plurality of lower claw portions on the lower clamp claw are brought into contact with the work in the centered state from below. The work is fixedly supported by the lower claw portion, and then the lower clamp claw in which the work is set in the centered state is inserted into the chuck body and attached to the chuck body side, so that even a work such as a valve body can be used. The work can be easily and reliably centered on the basis of the inner diameter. Therefore, even a work such as a large valve body can be chucked by the indexing chuck in the centered state, and the work can be processed with high accuracy and efficiency using the indexing chuck.

Also, since the work is centered on the basis of the inner diameter, there is a possibility that black scales remain on the inner surface during the inner diameter processing, or uneven chamfering occurs when the inner periphery of the inner end is chamfered unevenly. And can be processed with high precision. In addition, the lower clamp pawl is taken out of the chuck body, the work is centered on the lower clamp pawl outside the machine tool, and then the lower clamp pawl is inserted into the chuck body for mounting. If a plurality of clamp claws are prepared, the next work can be centered during processing. For this reason, the setup at the time of processing the work can be performed easily and quickly, and every time the processing of the work is completed, the setup time is not wasted and productivity is remarkably improved as compared with the case of centering and chucking.

According to the second aspect of the present invention, there is provided a base having a mounting portion on which the lower clamp pawl detached from the chuck body side of the indexing chuck of the machine tool is removably mounted. A pair of left and right supports arranged on the base on both the left and right sides of the unit, and a hole in the workpiece that is slidably supported in the left and right direction by each support and that is arranged on the lower clamp claw of the mounting unit A pair of left and right centering shafts that are fitted and removably fitted from both left and right sides and are aligned with the lower clamp claw, for a work centered by the pair of left and right centering shafts on the lower clamp claw. A plurality of lower claws provided slidably in the perspective direction and for supporting the work in a centered state from below,
Since a fixing means for fixing each lower claw portion is provided, the lower clamp claw removed from the chuck body is placed on the mounting portion of the base outside the machine tool, and the lower clamp claw is removed. The work can be centered on the claws, and then the lower clamp claws can be inserted and mounted on the chuck body 22 side. Therefore, even for a work such as a large valve body,
The work can be easily and reliably centered on the basis of the inner diameter of the hole, and the work can be processed with high accuracy and efficiency using the indexing chuck 20. Moreover, since the lower clamp pawl is taken out of the chuck main body and the work on the lower clamp pawl is centered outside the machine tool, the lower clamp pawl can be inserted into the chuck main body 22 for mounting.
By preparing a plurality of lower clamp claws, the centering of the next work can be performed during processing, the setup for processing the work can be performed easily and quickly, and there is no waste of setup time and productivity. Is significantly improved. Furthermore, since the workpiece can be centered on the basis of the inner diameter of the hole, black scales may remain on the inner surface during the inner diameter processing, or uneven chamfering may occur when chamfering the inner periphery of the outer end of the inner diameter. And can be processed with high accuracy. If the lower clamp claw removed from the chuck body side is placed on the mounting portion of the base, and the centering axes of the supports on both sides are fitted into the holes of the work, It can be easily held in the centering state based on the inner diameter. In addition, if the lower pawl is adjusted and fixed by the fixing means, the work can be easily fixed and supported from below by the lower pawl, and when the lower clamp pawl is inserted into the chuck body and mounted, the lower pawl can be used. The misalignment of the work due to the movement of the part can be prevented. According to the third aspect of the present invention, in an indexing chuck of a machine tool in which a workpiece is machined while clamping and indexing the workpiece by a pair of upper and lower clamp claws in the chuck body, On the lower clamp pawl so as to be slidable in the near and far directions with respect to the work in the centered state on the lower clamp pawl, and to fix and support the work in the centered state from below. A plurality of lower pawls and fixing means for fixing each lower pawl, and a work in a centered state is supported from below by a lower pawl on the lower clamp pawl outside the machine tool. Since the lower clamp pawl with the work fixed in the centered state is mounted on the chuck body side, the work on the lower clamp pawl is centered outside the machine tool, and then the lower clamp pawl is chucked. On the body 22 side It can be mounted by entering. In addition, if a plurality of lower clamp claws are prepared, the centering of the next work can be performed during processing, and the work can be set up easily and quickly during the processing of the work without wasting the set-up time. Productivity is significantly improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional front view of an indexing chuck in a chuck state showing one embodiment of the present invention.

FIG. 2 is a cross-sectional side view of the indexing chuck in a chuck state, showing one embodiment of the present invention.

FIG. 3 is a plan sectional view of a corner piece of the indexing chuck showing one embodiment of the present invention.

FIG. 4 is a partially cutaway front view of a work centering device showing one embodiment of the present invention.

FIG. 5 is a plan view of a work centering device showing one embodiment of the present invention.

FIG. 6 is a partially cutaway side view of a work centering device showing one embodiment of the present invention.

FIG. 7 is a sectional view of a work.

[Explanation of symbols]

 20 Indexing chuck 21 Work centering device 22 Chuck body 30 Upper clamp pawl 31 Lower clamp pawl 37 Front lower pawl 38 Rear lower pawl 39 Front adjustment screw 40 Rear adjustment screw 56 Base 57 Mounting part 58 Supporting body 59 core Extension shaft W Work

Claims (3)

(57) [Claims] In a chuck body of an indexing chuck of a machine tool, a workpiece is clamped by a pair of upper and lower clamp claws on a side of the chuck body, and when the workpiece is machined while being indexed by the indexing chuck, The work is held in a centered state based on the inner diameter of the work on the lower clamp claw removed outside the machine tool, and a plurality of work pieces on the lower clamp claw are attached to the work in the centered state. The lower claws are brought into contact with the lower side to fix and support the work by the lower claws, and then the lower clamp claws in which the work is set in a centered state are inserted into the chuck main body. Workpiece centering method in indexing chuck, which is mounted on chuck body side 2. A base having a mounting portion on which a lower clamp claw removed from a chuck body side of an indexing chuck of a machine tool is removably mounted, and said base on both left and right sides of said mounting portion. A pair of left and right supports arranged on the upper side, and slidably supported in the left and right directions by the respective supports, and from both left and right sides of the hole of the work arranged on the lower clamp claw of the mounting portion. A pair of right and left centering shafts which are fitted and detachably fitted to each other, and wherein the lower clamp claw is provided with respect to the work centered by the pair of left and right centering shafts on the lower clamp claw. A plurality of lower pawls provided to be slidable in the perspective direction and supporting the work in a centered state from below, and fixing means for fixing the lower pawls. A work centering device for an indexing chuck. 3. An indexing chuck for a machine tool wherein a workpiece is machined while clamping and indexing the workpiece by a pair of upper and lower clamp claws in a chuck body. The lower clamp pawl is provided on the lower clamp pawl so as to be slidable in the near and far directions with respect to the work in a centered state on the lower clamp pawl, and fixedly supports the work in a centered state from below. A plurality of lower claws for fixing the lower claws, and a fixing means for fixing each of the lower claws, the work being in a centered state on the lower clamp claws by the lower claws outside the machine tool. An indexing chuck for a machine tool, wherein a lower clamp pawl supported from below and having the workpiece fixed in a centered state is mounted on the chuck body side.