JPS6035526Y2 - Outer diameter floating diaphragm chuck - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a diaphragm chuck for gripping a flange workpiece.

Generally, when cylindrical grinding the end face of a flange workpiece, the gripping means is a collet chuck or the outer diameter is gripped by a diaphragm chuck, but the perpendicularity to the inner diameter or outer diameter is always stable at a high precision < 0.001. It was very difficult to process it.

Therefore, the present invention aims to provide a diaphragm chuck that can consistently obtain high accuracy in perpendicularity between the inner diameter and the end face.The present invention is particularly designed to provide a core bar that fits into the hole of the workpiece at the center of the end face of the chuck body. , Reference pins are provided at two spaced apart locations on the outer periphery of this core metal, parallel to and concentric with the axis, and floating claws are provided on the outer periphery of the workpiece that come into contact with the two reference pins from directly above. This chuck is characterized by a hole-based chuck in which a claw provided on a diaphragm acts on the back surface of a floating claw, and is gripped at three points using a reference pin as a base.

Embodiments of the present invention will be described below based on the drawings.

A hollow chuck base 3 fitted to the short tapered end portion 1a of the main shaft 1 has a hollow protrusion 4 at its center, and a cylinder for fluid pressure is formed between the protrusion 4 and the chuck base 3. A chuck frame 5 is tightly fitted and fastened to the chuck base 3 with bolts.

A piston 6 is fitted in the cylinder, and an air vent hole 7 communicating with the front chamber 5a of the cylinder and a pressurized air supply hole 8 communicating with the rear chamber 5b are open.

Also, between the piston 6 and the wall surface of the chuck frame 5, the piston 6
A return spring 9 is interposed.

A land 5c is provided on the outer peripheral edge of the front end of the chuck frame 5, and a diaphragm 10 is fixed to the land 5c via a presser ring 11.

On the other hand, a core metal 12 having a small diameter portion 12a that can be inserted into a hole in a workpiece W is concentrically fastened to the front end of the protruding portion 4 of the chuck table 3, and the outer circumference of the small diameter portion 12a is approximately 60° to 1500°.
2 parallel to the axial direction, preferably at a position of 120°.
A groove 12b having an arcuate cross section is concentrically cut into the book, into which a wear-resistant carbide needle 13 of the same diameter is fitted.

Then, the needle 13 is subjected to centering grinding in the assembled state.

A floating claw 14 is fastened to a notch 12c cut in one location of the boss portion of the core bar 12 parallel to a plane containing the axes of the two needles 13.

The tips of this floating claw 14 are two needles 13
The arm portion 14c has an arcuate gripping claw 14a that contacts the outer periphery of the working portion W directly above the handle member W, and a flat back surface 14b thereof, and the arm portion 14c is thin and can float.

When no force is applied to the back surface 14b, the gripping claw 14a
is adapted to be displaced outward.

A diaphragm 10 is provided on the flat back surface 14b of the gripping claw 14a.
The restoring force of the diaphragm is applied to the claw portion 15a of one upper claw 15, which is attached to the upper claw rest 16 by a bolt 17 so that its position can be adjusted in the radial direction.
As a result of the action of a, it joins the floating claw 14 and the workpiece W
is gripped at three points, the two needles 13 and the gripping claws 14a, with the hole as a reference.

A support bolt 18 for grinding the inner surface of the gripping claw 14a of the floating claw 14 in the assembled state is attached to the claw portion 15a.

Reference numeral 19 denotes a first balance weight of the upper claw 15, which is attached to the back side of the diaphragm 10 in correspondence with the upper claw base 16.

Reference numeral 20 denotes a second balance weight for the upper jaw 15, which is fixed to the presser ring 11 at a symmetrical position with respect to the chuck center axis.

Near the inner circumference of the central diaphragm 10 of the chuck frame 5, holes 5d are equally spaced in three locations in the axial direction, and pins 21 protruding from both sides are fitted into the holes 5d.
When pin 2 is moved toward the workpiece W by the action of pressure fluid, pin 2
The other end of the push pin pushes the diaphragm 10 and bends the center toward the workpiece, thereby opening the upper claw 15 and separating it from the floating claw 14 to release the workpiece.

In addition, a workpiece pushing button 22 is inserted into the center hole of the chuck table 3 and the protrusion 4, and a push rod 23, which is installed at the tip in the axial direction, is inserted into the hole 12d of the core bar 12 and is inserted into the reference end surface 12e. The boss part of the workpiece W can be pushed more protrudingly.

Reference numeral 24 denotes an O-ring fitted in the diaphragm 10 on the protrusion 4 to prevent grinding fluid from entering.

25 is a cap screw for the needle 13.

The operation of the present invention configured as described above will be explained.

In order to grip the workpiece W on the ground and centered chuck with the needle 13 and the gripping claws 14a of the diaphragm claws 14 attached, the pusher 22 is in the retracted position and the push rod 23 is pressed against the core metal 12. It is slightly set back from the reference end surface 12e, and when pressurized air is sent to the supply port 8 and the piston 6 is advanced, the pin 21 pushes the center side of the diaphragm 10 and does not bend outward, so that the claw portion of the upper claw 15 is is opened and the gripping claws 14a of the floating claws 14 are displaced outward.

In this state, the workpiece W in this example is transported by the loading device, and when it is fitted into the small diameter portion 12a of the core metal 12 and the end face of the gear is pressed against the reference end face 12e of the core metal 12, it is supplied to the supply port 8. The compressed air is cut off and the piston 6 is moved back by the force of the spring 9, and the diaphragm 10 pushes the pin 21 with its restoring force and returns to its natural stable state without displacement.

As a result, the claw portion 15a of the upper claw 15 pushes the flat back surface 14b of the floating claw 14 in the radial direction.
The two needles 13 of the core metal 12 whose surfaces press against the outer diameter of the gear
Grip the gear strongly with three points.

After gripping is completed, the end face of the gear is ground by cylindrical grinding.

When the grinding is finished, pressurized air is sent from the supply port 8 to the piston 6.
The gear can be taken out by advancing the diaphragm 10 via the pin 21 and opening the claw portion 15a of the upper claw.

As described in detail above, the present invention has a core metal part that is used as a hole reference, and two centered needles that serve as gripping surfaces are arranged in parallel and gripped at three points via floating claws. As a result, the axial movement of the diaphragm claw is eliminated, and the direction of the acting force during gripping is only in the radial direction.The inner diameter of the workpiece is used as proof by the axis regulation by the edge of the needle, so the workpiece can be easily moved. By grinding the end face, the perpendicularity of the end face to the inner diameter can be made accurate, and the machining accuracy, which was 10μ or more with conventional chucks, is now 5P, making it possible to achieve stable and high quality machining accuracy.

In addition, since the needle is based on the inner diameter of the workpiece, there is no need to worry about errors caused by scratches on the reference surface.

In addition, since the reference needle is gripped from the outside diameter, the rotational force of the workpiece becomes large and there is no risk of slipping.

[Brief explanation of the drawing]

Figure 1 shows the diaphragm chuck of this invention, and A- in Figure 2.
2 is a sectional view taken along line A, and FIG. 2 is a view taken along line BB in FIG. 1. 3... Chuck base, 5... Chuck frame, 6... Piston, 10... Diaphragm, 12... Core metal, 13. ...Needle, 14...Floating claw, 15...Upper claw.

Claims (1)

[Scope of utility model registration request] A diaphragm chuck configured to grip the outer diameter of a flange workpiece by claws supported by a diaphragm whose outer periphery is fixed to the chuck body, and a core bar protruding concentrically from the center of the end face of the chuck body; Two reference pins that are fixed concentrically in parallel in the axial direction with a circumferential gap in the small diameter part of the core metal that can be inserted into the inner diameter of the workpiece, and two reference pins that are fixed to the core metal or the chuck body and that are a floating claw having one gripping claw that abuts the outer diameter of the gripped workpiece directly above the center between the reference pins, and the claw supported by the diaphragm abuts the back surface of the gripping claw of the floating claw. 1. An outer diameter floating diaphragm chuck, characterized in that the workpiece is supported at three points on one side with the hole referenced so as to apply a gripping force to the floating jaws.