JP3088125B2 - Magnetic chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic chuck having a plurality of fluid jetting means for floating a magnetic material from a work surface with a fluid such as compressed air.

[0002]

2. Description of the Related Art As one of magnetic chucks used in machine tools such as a cutting machine and a grinding machine, a plurality of fluid jetting means for jetting compressed air to a work surface are provided on a face plate, and a workpiece to a work surface, There is a magnetic chuck in which compressed air is ejected from a fluid ejection unit when a magnetic material is attached or detached, thereby floating the magnetic material from a work surface, thereby facilitating the work of attaching or detaching the magnetic material to or from the work surface.

In this type of magnetic chuck, a liquid such as a cutting oil or a polishing liquid used for machining enters into an air passage in the magnetic chuck from a fluid jetting means, and a liquid adhering to a work surface or the like. Prevents the magnetic substance from being scattered in the form of a mist due to the ejected fluid, thereby lowering the workability and work environment for attaching and detaching the magnetic body and the workability and work environment for machining without removing the magnetic body when attaching and detaching it. It is important to be able to lift off the work surface.

In order to solve the above problems, a valve seat having a hole through which fluid in a fluid supply passage flows toward a work surface, and a valve seat disposed on the work surface side of the valve seat, and a valve provided by the fluid in the fluid supply passage. A valve body that opens the hole of the seat, a pedestal that is arranged on the working surface side of the valve seat and has a space that houses the valve body, a speed reduction member mounted on the pedestal, and a speed reduction member. There has been proposed a magnetic chuck in which a plurality of fluid ejectors having a holding ring for pressing against a table are arranged in a recess formed in a face plate.

[0005] In this known magnetic chuck, after a valve seat is fitted from below into a portion below the recess (the side opposite to the working surface), a valve body, a pedestal, and a speed reduction member are arranged in that order. It is inserted into the recess from above (from the side of the face plate), and then a retaining ring is screwed into the recess, thereby preventing the valve element, the pedestal and the reduction member from falling out of the recess. .

[0006] However, the known magnetic chuck has a structure in which the fluid ejection means is directly assembled to the magnetic chuck by disposing the valve seat, the valve element, the pedestal, the deceleration member, and the holding ring in the magnetic chuck in the above procedure. Therefore, it takes a lot of time and effort to assemble and remove the fluid ejecting means with respect to the magnetic chuck, and therefore, it takes a lot of time and effort to replace the fluid ejecting means or its parts due to failure or the like.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic chuck which can reliably float a magnetic body without causing a decrease in workability and working environment for attaching and detaching a magnetic body and machining. The fluid ejection means is easy to assemble and remove the fluid ejection means.

[0008]

A magnetic chuck according to the present invention has a plurality of recesses which are open on the side of the work surface and communicate with the fluid supply path on the side opposite to the work surface, and are ejected to the work surface. Fluid ejection means is located in each recess.

Each of the fluid jetting means includes a first flow path communicated with the working surface side and the fluid supply path side and the first flow path.
A stepped portion in the middle of the flow path and facing the fluid supply path, a cylindrical member screwed into the recess, and a number of air passages for reducing the speed of the fluid; A speed reducing member disposed in the first flow path to reduce the speed of the fluid, and a second flow path for guiding fluid in the fluid supply path to the first flow path; A valve mechanism that is actuated by the fluid supplied to the path to open the second flow path.

The valve mechanism includes a valve seat having the second flow path and having a space communicating with the face plate side of the second flow path, and a valve element disposed in the space, The valve seat is screwed to the tubular member from the side of the fluid supply path, and the speed reduction member is disposed between the step portion and the valve seat.

The second flow path is normally closed by a valve mechanism, and is opened when the magnetic body is attached or detached. With this, even if a liquid such as a cutting oil or a polishing liquid is used during processing, the liquid does not enter the fluid supply path, so that the liquid does not scatter when the magnetic substance is attached or detached, and therefore, the workability of attaching and detaching the magnetic substance. And the working environment is not reduced.

When the magnetic body is attached or detached, the valve mechanism is actuated by the fluid supplied to the fluid supply passage to open the second flow passage. Thus, since the fluid in the fluid supply path is ejected from the fluid ejection means, the detachable magnetic body is reliably levitated, and the work of attaching and detaching the magnetic body is facilitated.

The fluid ejected to the working surface by the fluid ejection means is diffused by passing through the speed reducing member. As a result, even if the liquid is attached to the fluid ejection means, the work surface, the magnetic material, and the like, the liquid is prevented from being scattered by the ejected fluid, and therefore, the workability and working environment for machining the magnetic material are reduced. It does not drop.

The fluid jetting means is arranged such that the speed reducing member is disposed in the first flow path of the cylindrical member, and the valve body is disposed in the space of the valve seat. It can be assembled by screwing. Thus, the speed reduction member is pressed by the step portion of the tubular member by the valve seat to prevent the speed reduction member from falling off the tubular member, and the valve seat and the valve body are prevented from falling off from the tubular member. The assembled fluid jetting means can be assembled to the magnetic chuck by screwing the cylindrical member into the recess of the magnetic chuck, and can be removed from the magnetic chuck by untwisting the cylindrical member.

As described above, according to the present invention, the magnetic body can be reliably levitated at the time of attachment / detachment without deteriorating the workability and working environment for attaching / detaching the magnetic body and for machining. In addition, assembling and removing of the fluid jetting means with respect to the magnetic chuck becomes easy.

Preferably, at least a part of the valve mechanism is inserted into the first flow passage from the side of the fluid supply passage. At least a portion of the valve seat may be inserted into the first flow path from the side of the fluid supply path to press the deceleration member against the step. Thus, since the valve seat is screwed into the tubular member from the side of the fluid supply path, the valve mechanism does not hinder the mounting and removal of the tubular member with respect to the recess.

The cylindrical member is screwed into the recess from the work surface side, and a groove for engaging a tool for rotating the cylindrical member is formed in an end of the cylindrical member on the work surface side. Can be formed.

It is preferable that the cylindrical member is made of a synthetic resin. Thereby, the cylindrical member 42 can be manufactured in large quantities and at low cost by injection molding or the like. Further, since the tubular member does not corrode, the tubular member does not adhere to the recess, and therefore, the fluid ejecting means can be easily removed. Further, even if the tubular member is fixed in the recess, the tubular member is heated to such an extent that the synthetic resin as the material is softened, and the tubular member is taken out. Can be removed.

[0019]

In the following embodiments, the magnetic chuck uses compressed air as a fluid, but the present invention can be applied to a magnetic chuck using another gas as a fluid or a magnetic chuck using a liquid. .

Referring to FIGS. 1 and 2, the magnetic chuck 10 includes a case 12 containing an electromagnet. Case 1
2, a terminal box 16 for attaching a power cord 14 for an electromagnet to the case 12 is attached.
A face plate 20 that defines a rectangular work surface 18 for adsorbing the magnetic material is disposed so as to close the opening of the case 12.

The face plate 20 includes a plurality of pole pieces 24 arranged in the longitudinal direction of the work surface 18 with a non-magnetic material 22 therebetween.
A plurality of fluid ejectors 26 provided on the pole piece and a fluid supply path 30 for supplying compressed air supplied from an air source via a pipe 28 to the fluid ejectors 26 are provided. Magnetic pole piece 24
Are extended in parallel in the width direction of the work surface 18 and are excited by the electromagnet such that adjacent magnetic pole pieces become different magnetic poles when the magnetic material is attracted.

The present invention provides a magnetic chuck having a plurality of fluid ejectors on a work surface for adsorbing a magnetic material, not only a magnetic chuck using an electromagnet but also a magnetic chuck or an electromagnet using a permanent magnet. The present invention can also be applied to a magnetic chuck using a permanent magnet.

Each of the fluid ejectors 26 is received in a recess 34 having an internal thread 32, as shown in FIG. The recess 34 is formed in the pole piece 24,
It also opens to the work surface 18 side. The female screw 32 is formed at a position defining the recess 34 of the pole piece 24 and on the side of the work surface 18, that is, above the work surface 18. A female screw hole 38 is formed in the bottom wall of the pole piece 24 that defines the bottom of the recess 34, and the upper end of a communication member 40 that allows the fluid supply path 30 to communicate with the recess 34 is formed in the female screw hole. It is screwed.

Each fluid ejector 26 is provided with a female screw 3
2 is provided with a cylindrical member 42 screwed. The internal space of the cylindrical member 42, that is, the first flow path, extends in the vertical direction through the cylindrical member 42, and includes a lower screw hole 44a and an upper small diameter portion 44b having a smaller diameter than the screw hole. Become. For this reason, a step 46 facing the fluid supply path 30 is formed in the tubular member 42 in the middle of the first flow path 44. The cylindrical member 42 has a groove 48 at the upper end for engaging the tip of a tool such as a screwdriver for rotating the same.

Each fluid ejector 26 has a cylindrical member 42.
A speed reducing member 50 for reducing the velocity of the fluid passing through the first flow path. The deceleration member 50 is a disk-shaped member having a large number of fine air passages, such as a felt or a luffa, reinforced with a fine-meshed wire mesh, and is screwed so that the wire mesh is on the step 46 side. It is arranged in the hole 44.

Each fluid ejector 26 further includes a cylindrical member 4
A valve seat 52 screwed into the second screw hole 44b from below is provided, and a spherical valve element 54 housed in the valve seat. The valve seat 52 has a space 56 opened upward so as to receive the valve element 54 from above, and a hole that connects the space to the fluid flow path 58 of the communication member 40, that is, a second flow path 60.

In each fluid ejector 26, the speed reducing member 50 is disposed in the screw hole 44a of the cylindrical member 42, and then the valve 54
Can be assembled by screwing the valve seat 54 into the screw hole 44a in a state where is disposed in the space 56 of the valve seat 52. As a result, the deceleration member 50 is pressed by the step portion 46 of the tubular member 42 by the valve seat 52 and is prevented from dropping from the tubular member 42, and the valve seat 52 and the valve body 54 are dropped from the tubular member 42. Is prevented.

The thus-assembled fluid ejector 26
Can be assembled to the magnetic chuck 10 by screwing the cylindrical member 42 into the recess 34 of the magnetic chuck 10, and can be removed from the magnetic chuck 10 by untwisting the cylindrical member 42.

When the fluid ejector 26 is disposed in each of the recesses 34, the valve body 54 is moved by its own weight to the second position of the valve seat 52.
Is closed. For this reason, even if a liquid such as a cutting oil or a polishing liquid is used during processing, the liquid does not enter the fluid supply path 30, and therefore, even if compressed air is subsequently supplied to the fluid supply path 30, the liquid such as the cutting oil The liquid does not scatter, and the workability and work environment for attaching and detaching the magnetic body are not reduced.

When the compressed air is supplied to the fluid supply passage 30, the valve body 54 is floated by the compressed air and the valve seat 52 is lifted.
The second flow path 60 is opened. As a result, the compressed air flows from the second flow path 60 through the reduction member 50 to the work surface 18.
It is gushing. Therefore, the magnetic body can be reliably levitated, and the work of attaching and detaching the magnetic body becomes easy.

The compressed air jetted to the work surface 18 is diffused by passing through the speed reduction member 50. As a result, even if a liquid such as cutting oil adheres to the fluid ejector 26, the work surface 18, the magnetic material, or the like, the liquid is prevented from being scattered by the jetted compressed air. Workability and work environment are not degraded.

When the fluid ejector 26 fails, the fluid ejector is removed from the magnetic chuck 10 by untwisting the tubular member 42, and a new fluid ejector is attached to the magnetic chuck 10 instead. Therefore,
Attaching and detaching the fluid ejector to and from the recess 34 becomes easier as compared with a conventional magnetic chuck which is detached from the magnetic chuck for each component constituting the fluid ejector and attached to the magnetic chuck.

The cylindrical member 42 is preferably made of a synthetic resin, especially a thermoplastic synthetic resin. Thereby, the cylindrical member 42 can be manufactured in large quantities and at low cost by injection molding or the like. Also, since the cylindrical member does not corrode, the cylindrical member does not adhere to the recess, and even if it does, heat the cylindrical member to such an extent that the synthetic resin as the material is softened and take out the cylindrical member. Thereby, the fluid ejector 26 can be removed without damaging the female screw 32.

Instead of directly forming the recess 34 in the pole piece 24, a bush having the recess 34 and the female screw hole 38 is prepared, and a hole for fitting the bush is formed in the pole piece 24. The bush may be fitted into the bush.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a magnetic chuck according to the present invention.

FIG. 2 is a front view of the magnetic chuck shown in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Magnetic chuck 18 Working surface 26 Fluid ejector 30 Fluid supply path 32 Female screw 34 Depression 42 Cylindrical member 44a Screw hole part (first flow path) 44b Small diameter part (first flow path) 46 Step part 48 Groove 50 Reduction member 52 Valve seat 54 Valve element 60 Second flow path

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23Q 3/154

Claims (5)

(57) [Claims] 1. A magnetic chuck having a plurality of fluid ejection means for ejecting a fluid to a work surface, the magnetic chuck being disposed in a recess opened to a work surface and communicated with a fluid supply passage on a side opposite to the work surface. The fluid ejecting means includes a first flow path that is communicated with the working surface side and the fluid supply path side, and a halfway side of the first flow path that is closer to the fluid supply path. A cylindrical member screwed into the recess, having a number of air passages for reducing the velocity of the fluid, and having a plurality of air passages in the first flow path to reduce the velocity of the fluid. A second decelerating member arranged to guide the fluid in the fluid supply path to the first flow path;
A valve mechanism that is actuated by a fluid supplied to the fluid supply path to open the second flow path, wherein the valve mechanism has the second flow path and Second
A valve seat having a space communicating with the face plate side of the flow path,
A valve body disposed in the space, wherein the valve seat is screwed to the tubular member from a side of the fluid supply path, and the deceleration member is disposed between the step portion and the valve seat. Has been a magnetic chuck. 2. The apparatus according to claim 1, wherein at least a part of the valve mechanism is provided with the first
The magnetic chuck according to claim 1, wherein the magnetic chuck is inserted into the flow path from the side of the fluid supply path. 3. The valve according to claim 1, wherein at least a part of the valve seat is inserted into the first flow passage from a side of the fluid supply passage, and presses the deceleration member against the step portion. The described magnetic chuck. 4. The cylindrical member is screwed into the recess from the side of the work surface, and has a groove on the side of the work surface for engaging a tool for rotating the cylindrical member. The magnetic chuck according to claim 1, wherein the magnetic chuck has: 5. The magnetic chuck according to claim 1, wherein the cylindrical member is formed of a synthetic resin material.