JP2011056633A - Workpiece gripping method and workpiece gripping device in lathe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attach or detach a workpiece, whose base cannot be gripped by an outside diameter chuck because of a processed hole decentered from a center of the base, to or from a workpiece gripping device with an automatic operation. <P>SOLUTION: When a processed hole 15 of a workpiece 10 is processed by a lathe, the workpiece 10 is seated on a workpiece seating face 4. Under this condition, a positioning pin 5 is inserted in a first long hole 13<SB>-1</SB>, and an inside diameter chuck 3 decentered from a main shaft center of the lathe is inserted in a through hole 12 of the workpiece. The workpiece 10 is positioned to a position, at which rotation around the inside diameter chuck 3 is restrained by the positioning pin 5. Then, the workpiece 10 is gripped by the inside diameter chuck 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a workpiece gripping method and a workpiece gripping apparatus used when a workpiece having a hole to be processed, a through hole, and a long hole is processed on a lathe, and more specifically, a hole to be processed and one end surface of the workpiece are processed on the same lathe. The present invention relates to a work gripping method and a work gripping apparatus that are sometimes effective.

  An example of a workpiece to which the present invention is applied is shown in FIGS. The illustrated workpiece 10 is an L-shaped sintered link, and has a through-hole 12 having a round hole at the center of the base 11. In addition, two long holes 13 are provided at positions away from the through-holes 12, and a processed hole 15 is provided at the tip of the arm part 14 extending from one end of the base part.

  About this workpiece | work 10, the to-be-processed hole 15 is processed and provided with the lathe after sintering, and the to-be-processed hole is processed through the following processes.

1) As shown in FIGS. 9 and 10, the pins 21 are inserted into the two long holes 13, respectively.
2) The workpiece 10 is rotated to a position where the rotation restriction by the two pins 21 is made, and the hole 15 to be machined is positioned at the center of the lathe spindle.
3) The clamp plate 22 is applied to the end surface of the workpiece 10, and the clamp plate 22 is pulled by the draw bar 23 to sandwich the workpiece 10 between the workpiece seating surface 24.
4) The tool 15 is made to enter the workpiece from the opening provided in the clamp plate 22 to machine the hole 15 to be machined.

  The workpiece 10 is gripped by using the clamp plate 22 because the hole 15 to be machined is eccentric from the center of gravity of the base 11 (the center of the through hole 12 in the illustrated workpiece). This is because the hole 15 to be machined is displaced from the center of the main shaft and the hole cannot be machined by the method of gripping with the outer diameter chuck arranged at the center.

  Patent Document 1 below discloses a workpiece re-holding device and a processing method for processing a center hole and an outer periphery of a deformed workpiece by re-holding the workpiece with a clamp device. The processing of the outer periphery of the workpiece by the method of Patent Document 1 is performed by sandwiching the workpiece between a holding member drawn into the draw bar and a receiving surface (work seating surface).

JP 2002-307206 A

  The workpiece gripping method shown in FIGS. 9 and 10 is difficult to automate workpiece attachment / detachment. Although the operations 1) and 2) can be performed by a machine, for example, when a workpiece is carried in by a robot hand, the robot hand holding the workpiece becomes an obstacle and the clamp plate 22 cannot be mounted. For this reason, the actual situation is that the attachment / detachment of the work relies on manual work.

  Further, for the workpiece 10 shown in FIG. 7, it is required to process not only the hole 15 to be processed but also the one end surface 16. In the processing of the end face, the clamp plate 22 becomes an obstacle.

  Therefore, in order to remove the clamp plate 22, it is necessary to change the workpiece as disclosed in Patent Document 1. However, if the gripping is changed, a work loss occurs, which adversely affects productivity and processing cost. This method also complicates the structure of the gripping device.

  Accordingly, an object of the present invention is to make it possible to attach and detach a workpiece in which the base portion cannot be gripped by the outer diameter chuck because the work hole is eccentric from the center of the base portion with respect to the workpiece gripping device by an automatic operation. Yes.

In order to solve the above-described problems, in the present invention, the workpiece is gripped by the following method when machining the workpiece hole of the workpiece having the workpiece hole, the through hole, and the long hole with a lathe.
In this method, when the workpiece is seated on the workpiece seating surface, a positioning pin that protrudes in a direction parallel to the main shaft of the lathe from the workpiece seating surface is provided in the long hole, and an inner diameter chuck that is eccentric from the main shaft is provided in the through hole. insert. Next, the workpiece is positioned at a position where the rotation of the workpiece using the inner diameter chuck as a fulcrum is regulated by the positioning pin. Thereafter, the workpiece is gripped by the inner diameter chuck.

  The present invention also provides the following lathe work gripping apparatus for carrying out the above method.

The apparatus includes a face plate provided with a workpiece seating surface perpendicular to the spindle, which is mounted on the spindle of the lathe and rotated, an inner diameter chuck for gripping the inner surface of the through hole of the workpiece, and the elongated hole of the workpiece. A positioning pin to be inserted and biasing means for applying a rotational force to the workpiece seated on the workpiece seating surface are provided.
Further, the inner diameter chuck is provided at a position eccentric from the center of the lathe spindle, the inner diameter chuck is inserted into the through hole, and the rotation of the workpiece with the inner diameter chuck as a fulcrum is restricted by the positioning pin. The hole to be machined is positioned concentrically with the lathe spindle, and in this state, the workpiece is gripped by the inner diameter chuck.

Preferred forms of the workpiece gripping device are listed below.
(1) The urging means is constituted by a ball plunger.
(2) Provided with positioning detection means for detecting that the workpiece is positioned by the positioning pins.
(3) A device equipped with seating detection means for detecting that the workpiece is correctly seated on the workpiece seating surface.

  The positioning of the workpiece in the present invention can be performed using a ball plunger or the like that is simple, inexpensive and easily available. In addition, it is possible to automate clamping and unclamping of a workpiece by using a power-driven inner diameter chuck.

  Therefore, the work necessary for attaching and detaching the workpiece is only to insert and remove the workpiece with respect to the inner diameter chuck and the positioning pin, and the operation becomes simple. Therefore, it is possible to attach and detach workpieces in an automated operation using a robot hand or the like.

  Further, since the inner diameter chuck is provided at a position eccentric from the center of the lathe spindle and the workpiece is gripped by the inner diameter chuck, the hole to be machined can be positioned at the center of the lathe spindle and processed by a drill or the like.

  Further, by using the inner diameter chuck, the workpiece can be gripped without using the clamp plate. For this reason, it is not necessary to hold the workpiece, and processing with a so-called one chuck of the hole to be processed and one end surface becomes possible.

  Note that the rotational force applied to the workpiece by the ball plunger does not require a power source for obtaining the rotational force. In addition, the ball plunger inevitably wears the ball as the pressurizer, but even when the ball is worn, the ball can be regenerated by replacement.

Further, the apparatus provided with the positioning detection means and the seating detection means prevents the positioning failure and the seating failure of the workpiece, and eliminates the processing error of the product and the decrease in accuracy due to the positioning failure and the seating failure.

The front view which shows an example of the workpiece holding apparatus for lathes which enforces the method of this invention Sectional view of the workpiece gripping device of FIG. FIG. 1 is an enlarged cross-sectional view of a positioning pin provided in the workpiece gripping device of FIG. Enlarged sectional view of the urging means provided in the work gripping device of FIG. Sectional drawing which shows the other example of a biasing means The front view which simplifies and shows the state which hold | gripped the workpiece | work with the workpiece | work gripping apparatus of FIG. End view showing an example of a workpiece gripped by the method of the present invention Sectional drawing along the XX line of the work of FIG. FIG. 7 is a front view showing a gripping state of the workpiece of FIG. 7 according to the conventional method. FIG. 9 is a cross-sectional view of the grip state

  Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 show an example of a lathe work gripping apparatus (hereinafter, simply referred to as a work gripping apparatus) for carrying out the method of the present invention.

  The workpiece gripping device 1 includes a face plate 2, an inner diameter chuck 3, a workpiece seating surface 4, a positioning pin 5 projecting on the workpiece seating surface 4, a biasing means 6, and a workpiece by positioning pins 5. Positioning detecting means 7 for detecting whether or not the positioning of the workpiece is correctly performed, and seating detecting means 8 for detecting whether or not the workpiece is correctly seated on the workpiece seating surface 4 are provided. The face plate 2 is mounted on a main shaft (not shown) of the lathe and is rotationally driven by the main shaft.

  The inner diameter chuck 3 is provided at a position eccentric from the spindle center C of the lathe. L is the amount of eccentricity. The inner diameter chuck 3 includes a split collet 3a whose outer diameter in a free state is smaller than the inner diameter of the through hole 12 of the workpiece, a taper core 3b that is inserted into and removed from a taper inner diameter portion of the split collet 3a, and a drawbar for transmitting driving force. (Not shown. The drive source is also not shown).

  In the illustrated inner diameter chuck 3, the split collet 3a is connected to the movable body 3d by a bolt 3c, and further the movable body 3d is connected to the draw bar by a bolt 3e, and the split collet 3a is pulled by pulling back and pushing back. Clamp and unclamp by moving forward and backward in the direction parallel to the lathe spindle.

  The workpiece seating surface 4 is perpendicular to the main axis C of the lathe. The split collet 3a of the inner diameter chuck 3 protrudes from the workpiece seating surface 4 in a direction parallel to the main axis of the lathe.

The positioning pin 5 also protrudes from the workpiece seating surface 4 in the same direction as the split collet 3a. The positioning pin 5 is inserted into a long hole 13 provided in the workpiece. Here, for convenience of explanation, the long hole on the side where the positioning pin 5 is inserted with the first long hole 13 _-1, it referred to the other long hole and the second elongated hole 13 _-2.

The positioning pin 5 is a pin having a thickness that can be inserted into the first long hole _13-1 with play, and is fixed at a fixed position. Positioning of the workpiece 10 is performed by causing the positioning pin 5 abuts against the hole surface of the first elongated hole 13 _-1.

  The illustrated positioning pin 5 is provided with an air hole 7a (see FIG. 3) that opens to the outer periphery, and an air passage 7b that guides air from the air pressure source to the air hole 7a.

The biasing means 6 rotates the workpiece 10 to the positioning point. Positioning point here is the position where the positioning pin 5 rotation restricting of the work is made in contact with the hole surface of the first elongated hole 13 _-1.

  The illustrated urging means 6 is a ball plunger. As shown in FIG. 4, the ball plunger includes a ball (pressurizer) 6a that presses against the workpiece, a spring 6b that urges the ball 6a, and a sleeve 6c that incorporates them.

  The sleeve 6c is formed with a male screw on the outer periphery, and is screwed into a bracket 6d attached on the face board 2 to hold the ball plunger in a fixed position, and the ball 6a pushed out by the spring 6b contacts the workpiece 10. Then, a rotational force is applied to the workpiece 10.

  When the workpiece 10 is gripped by a transfer device such as a robot hand and set on the workpiece seating surface 4, the ball 6a is pushed by the workpiece 10 and is immersed. In this way, when the work is released, the spring 6b is elastically restored, and the work 10 is pressed by the ball 6a to apply a rotational force.

  The positioning detection means 7 includes an air hole 7a provided in the positioning pin 5, an air passage 7b, an air pressure source (not shown), and a sensor for detecting a change in air pressure supplied to the air hole 7a (also shown). Z)).

  The seating detection means 8 is also provided with a plurality of air holes 8a for ejecting air and a plurality of air passages 8b for leading the air supplied from the air pressure source via the air passage to the air holes 8a. Whether the workpiece is seated on the seating surface 4 is detected based on changes in air pressure.

  The workpiece 10 is set on the workpiece seating surface 4 using the workpiece gripping device 1 configured as described above. The work is performed by gripping the workpiece 10 at a supply point (not shown) with a transfer device (also not shown) such as a robot hand, and setting the other end surface of the workpiece 10 to face the workpiece seating surface 4. The work is moved in the axial direction on the center of the lathe spindle until it is seated on the seating surface 4.

Then, as shown in FIG. 6, the split collet 3 a is inserted into the through hole 12 using the operation, and at the same time, the positioning pin 5 is inserted into the first long hole _13-1 .

  Further, the workpiece movement at this time is performed such that the ball 6a of the urging means 6 is pushed away while the workpiece 10 is moving, so that the ball 6a is immersed in the sleeve 6c.

  The spring 6b is compressed by the operation. Therefore, the spring 6b is elastically restored when the conveying device releases the workpiece, and the ball 6a receiving the force from the spring pushes and moves the workpiece 10. At this time, the split collet 3a is still contracted.

Therefore, the workpiece 10 rotates in the clockwise direction (clockwise in the figure) in FIG. 6 with the split collet 3a inserted into the through hole 12 as a fulcrum, and the rotation of the first elongated hole 13-1 _occurs . The hole surface hits the positioning pin 5, and the rotation of the workpiece stops at that position, and the positioning of the workpiece 10 is completed.

In this state, the outlet of the air hole 7a shown in FIG. 3 is closed by the hole surface of the first elongated hole 13 _-1, air pressure supplied to the air hole 7a is changed. The change in the air pressure is detected by the sensor, and the quality of positioning of the workpiece 10 is judged.

  Further, when the workpiece 10 is correctly seated on the workpiece seating surface 4, the outlet of the air hole 8a is blocked, and whether the seating is acceptable or not is determined by the change in the supply air pressure.

  Next, when both the positioning and the seating are judged to be good, the draw bar is driven and the split collet 3a is pulled. With this operation, the tapered core 3b is press-fitted and pulled back with respect to the split collet 3a, and the diameter of the split collet 3a is changed. The split collet 3a shown in the figure has its diameter expanded by the inner surface of the face plate 2, and the outer diameter surface of the split collet 3a is pressed against the inner surface of the through hole 12 before the diameter expansion is regulated. 10 is clamped.

  Thus, according to the present invention, the work can be attached and detached with a simple operation, and the work can be automated. For this reason, productivity in workpiece machining can be greatly improved.

  Further, in the state where the gripping of the workpiece is completed, the processing hole setting portion of the workpiece 10 is positioned at the center of the face plate 2 (center of the lathe spindle), and the processing hole 15 can be processed.

  Further, as can be seen from FIG. 2, the components of the workpiece gripping device are not arranged on the one end surface side of the workpiece 10, and therefore, the machining of the processed hole 15 and the one end surface 16 with one chuck becomes possible. It can also be expected to improve productivity.

  In addition, although the inside chuck | zipper 3 illustrated what employ | adopted the split collet, the chuck | zipper which compresses an elastic body to an axial direction and changes an outer diameter may be sufficient.

  The biasing means 6 is not limited to the illustrated one. FIG. 5 shows a modification of the biasing means 6. The urging means 6 in FIG. 5 includes an auxiliary pin 6e, a spring 6g that urges the auxiliary pin 6e in a direction protruding from the workpiece seating surface 4, and a presser that prevents the auxiliary pin 6e from coming out of the assembly hole 6f. It consists of a plate 6h.

Auxiliary pin 6e has a tapered surface on the tip outer periphery and on its tapered surface contacting the second elongated hole 13 _-2 hole edge 13a sets the workpiece 10 on the workpiece seating surface 4, press the workpiece The auxiliary pin 6e thus compressed compresses the spring 6g and is pushed into the assembly hole 6f. Therefore, the auxiliary pin 6e is pushed out by the force of the spring 6g when the conveying device releases the work, and a rotational force is applied to the work 10 by the action of the tapered surface of the auxiliary pin.

  In this way, urging means other than the ball plunger can be considered, but the ball plunger is easy to obtain because there is an inexpensive general-purpose product, and the advantage that the rotational force can be applied to the workpiece further away from the rotation fulcrum. is there.

  The positioning detection means 7 and the seating detection means 8 may be those using an electrical sensor or an optical sensor. However, the example does not include a component arranged outside the face plate, and there is no concern that the processing may be hindered.

The workpiece gripping device 1 shown in FIGS. 1 and 2 is employed in an NC lathe equipped with a robot hand, and the dimensions shown in FIG. 7 grip the following workpiece to process a hole to be machined and one end surface. .
Workpiece dimension / dimension between both ends of base 11: approx. 20mm
-Small diameter inner diameter of the through hole 12: 12 mm
-Hole diameter of the long hole 13: R radius at both ends of the hole: 4.25mm
-Eccentric amount L of the processed hole 15 with respect to the through hole: about 29 mm
-Diameter of the hole 15 to be processed: 6.5 mm

  As a result, it has been possible to completely automate the attachment and detachment of workpieces, which was conventionally performed manually with a dedicated worker on a lathe. Moreover, the work hole and one end surface of the workpiece could be processed without changing the workpiece.

1 Lathe work gripping device 2 Face plate 3 Internal diameter chuck 3a Split collet 3b Taper core 3c, 3e Bolt 3d Movable body 4 Workpiece seating surface 5 Positioning pin 6 Biasing means 6a Ball 6b, 6g Spring 6c Sleeve 6d Bracket 6e Auxiliary pin 6f Assembly hole 6h pressing plate 7 positioned detector 7a air hole 7b air passage 8 seating detection means 8a air hole 8b air passage 10 work 11 base 12 through holes 13 slots _{13 -1} first long hole _{13 -2} second long hole 13a Hole edge 14 Arm 15 Work hole 16 One end face 21 Pin 22 Clamp plate 23 Draw bar 24 Work seating surface C Spindle center L Eccentricity

Claims (5)

A workpiece gripping method used when machining the machining hole (15) of a workpiece (10) having a machining hole (15), a through hole (12), and a long hole (13) with a lathe,
An inner diameter chuck (3) in which a positioning pin (5) protruding from the workpiece seating surface (4) in a direction parallel to the center axis (C) of the lathe is eccentric to the long hole (13) from the center axis of the lathe Are inserted into the through holes (12), and the workpiece (10) is seated on the workpiece seating surface (4).
Positioning the workpiece (10) at a position where the rotation of the workpiece with the inner diameter chuck (3) as a fulcrum is regulated by the positioning pin (5);
Thereafter, a workpiece gripping method on a lathe that grips the workpiece with the inner diameter chuck (3). A workpiece gripping device utilized when machining the machining hole (15) of a workpiece (10) having a machining hole (15), a through-hole (12), and a long hole (13) with a lathe,
A face plate (2) provided with a workpiece seating surface (4) perpendicular to the spindle and rotated on the lathe spindle, and an inner diameter chuck (3) for gripping the inner surface of the through hole (12) of the workpiece And a positioning pin (5) to be inserted into the long hole (13) of the workpiece, and a biasing means (6) for applying a rotational force to the workpiece (10) seated on the workpiece seating surface (4). And
A lathe work gripping device in which the inner diameter chuck (3) is provided at a position eccentric from the spindle center (C).   The lathe work gripping device according to claim 2, wherein the urging means (6) is constituted by a ball plunger.   The lathe work gripping device according to claim 2 or 3, further comprising positioning detection means (7) for detecting that the work (10) is positioned by the positioning pins.   The lathe work gripping device according to any one of claims 2 to 4, further comprising seating detection means (8) for detecting that the work (10) is correctly seated on the work seating surface.

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