JPS59201738A - magnetic chuck - Google Patents

Abstract

PURPOSE:To prevent drop of attraction force at the end parts of a facial plate by dividing the portion of magnetic pole surface, which is situated outermost and has different polarity from that of the extension part, in the direction of extending this pole surface portion in the extended part. CONSTITUTION:A magnet chuck 10 includes a housing 14, which is to accommodate a magnetic force source 12 and open at one end, and a facial plate 16 to close this open end. The facial plate 16 consists of a magnet material, and a transverse groove 28 in a flat plate 24 is restricted at its No.1 magnetic pole surface portion 30a, and the outermost No.1 pole portion 30b is divided into several divisions by an aux. groove 28' in the direction extending. In this transverse groove 28, magnetic pole members 34a, 34b to restrict No.2 magnetic pole portions 32a, 32b are accommodated with spacers 36a, 36b consisting of non- magnetic material. As the extension part 32b' of the member 34b intersects the magnetic pole portion 30b situated outermost, it is divided in the extending direction of the transverse groove 28. The magnetic pole surfaces 30, 32 are magnetized with different polarities.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic chuck, and more particularly to a magnetic chuck suitable for use in connection with each other.

The magnetic chuck includes a housing with one end open, a magnetic force source housed within the housing, and a face plate fixed to the open end of the housing. Generally, the suction surface of the face plate has a plurality of first ones extending parallel to each other.
and second magnetic pole face portions are formed alternately, and the first and second magnetic pole face portions are magnetically isolated from each other by a nonmagnetic member. Since the first and second magnetic pole surface portions are magnetized to have different magnetic poles by the magnetic force of the magnetic force source, a magnetic body is attracted to the attracting surface including the magnetic pole surface portion.

The pair of magnetic pole portions located on the outer side when viewed in the width direction of the magnetic pole surface portions are magnetized so that they have the same magnetic pole, but due to the structure, the width dimension of the pair of outermost magnetic pole surface portions is larger than that of the magnetic pole face portion located therebetween. Therefore, a plurality of magnets are used to attract a magnetic body such as a long iron plate.

When the magnetic chucks are connected in series in the width direction of the magnetic pole surface portions, a wide magnetized region of the same magnetic pole having twice the area is formed by the adjacent outermost magnetic pole surface portions of each magnet chunk. That will happen. Since no strong magnetic potential difference occurs in this magnetized region, the area near the connection of each magnet chunk, that is, each magnet I
- The adsorption force near the end of the face plate of the chuck was reduced, making it difficult to securely hold the magnetic material. especially,
When attempting to adsorb a long thin iron plate with low rigidity and small thickness, the iron plate warps near the end of the face plate, which adversely affects machining accuracy.

If a magnet chunk corresponding to the size of the long magnetic body is used to hold the long magnetic body, the above-mentioned problem can be solved. However, in an electromagnetic chuck in which an electromagnet is used as the magnetic force source, the amount of heat generated by the electromagnet increases as the magnetic force source increases, causing problems such as thermal distortion of the face plate. Chunks are not suitable for high precision machining. For this reason, electromagnetic chucks are often used in conjunction with each other, and the above-mentioned reduction in the adsorption force at the end of the face plate regarding the outermost magnetic pole surface portion has been a major problem, especially in this electromagnetic chuck.

An object of the present invention is to provide a magnetic chuck that does not cause a decrease in suction force at the end of the face plate.

The present invention defines an attraction surface that includes a plurality of first and second magnetic pole face portions that are magnetically isolated from each other, extend parallel to each other, and are arranged in an alternating manner so as to be magnetized to different magnetic poles. In the face plate, on the magnetic pole face portion adjacent to the magnetic pole face portion located at the outermost position IC when viewed in the width direction of the magnetic pole face portion, a corresponding end of the face plate that crosses the outermost magnetic pole face portion is provided. The outermost magnetic pole face portion, which has a different magnetic pole from the extended portion, is divided by the extended portion in the extending direction of the magnetic pole face portion. It is characterized by preventing a decrease in the adsorption power of

The features of the invention will become more apparent from the following description of the illustrated embodiments.

As shown in FIG. 1, the magnet chunk lo according to the present invention includes a housing 14 with one end open for accommodating a magnetic force source 12, and a face plate fixed to the housing to close the open end of the housing. 16. The housing is made of the same magnetic material as in the conventional magnetic chuck, and has a flange provided at both ends of the bottom with a port groove 14a having a semicircular cross section for receiving an anchor pole (not shown). 14b. In the illustrated example, a pair of electromagnets 12 consisting of an iron core j8 and an exciting coil 2o are used as the magnetic force source, and the electromagnets are excited by power supplied from an electric wire 20' (see FIG. 2).

The housing 14 accommodates the electromagnet 12 in each of a pair of recesses 22 extending parallel to its longitudinal direction. Each electromagnet 12 is arranged in a recess 22 such that the lower surface of the iron core 18 having the same polarity is magnetically coupled to the bottom surface of the housing, and the upper surface of each iron core 18, which is the other magnetic pole surface, is placed in the recess. 2
exposed through the opening of 2.

The face plate 16 includes a generally rectangular flat plate member 24 made of a magnetic material and having a width sufficient to cover the open end of the housing 14, and has similar grooves corresponding to the port grooves 14a at both end portions of the flat plate member. A port groove 24a is formed. Lower surface 2 of flat plate member 24 facing housing 14
4b, a pair of longitudinal grooves 26 are formed in the longitudinal direction of the flat plate member in correspondence with the openings of the recesses 22.

Further, on the upper surface of the flat plate member 24, there are a number of lateral grooves 28 (28a) extending parallel to each other in the width direction of the flat plate member.

28b) is formed. The sum of the depth dimensions of both tM26 and tM28 is slightly larger than the plate thickness of the flat plate member, and the horizontal groove 28 communicates with the vertical groove 26 at the portion where it intersects with the vertical groove.

The lateral grooves 28 define, between the lateral grooves, a large number of first magnetic pole face portions 30a having widths approximately equal to the widths of the lateral grooves and extending parallel to each other on the same plane. Also, the lateral groove 28 closest to both end portions of the flat plate member
b is a first portion having a width dimension similar to the magnetic pole surface portion 30a, but larger than the width dimension of the magnetic pole surface portion 30a, at both end portions of the flat plate member, that is, at the outermost portion when viewed in the width direction of the lateral groove 28. defines a magnetic pole face portion 30b. A plurality of auxiliary grooves 28' extend from the side of the lateral groove 28b toward the end of the flat plate member 24 adjacent to the lateral groove 28b. Auxiliary groove 2
8'' has the same depth as the horizontal groove 28, extends parallel to each other in the longitudinal direction of the flat plate member 24, and is open to the end face of the flat plate member.Therefore, the magnetic pole face portion 30b of each outermost node 1 is divided into a plurality of portions in the extending direction of the first magnetic pole surface portion 30b, that is, in the width direction of the flat plate member 24, by an auxiliary groove 28' that crosses the magnetic pole surface portion.

Magnetic pole members 34a and 34b for defining second magnetic pole face portions 32a and 32b are accommodated in the lateral groove 28 together with spacer members 36a and 36b made of non-magnetic material, respectively. The magnetic pole member 34a disposed in the lateral grooves 28a between the lateral grooves 28b is made of a magnetic material and has a substantially rectangular shape corresponding to the lateral grooves 28a. A pair of legs 38 is provided on the lower surface of each magnetic pole member 34a. Each spacer member 36a has a U-shaped cross-section and receives the magnetic pole member 34a to cover both sides and the bottom surface of the magnetic pole member 34a.

A hole 40 is provided at the bottom of the spacer member 36a to allow the leg portion 38 to come into contact with the upper surface of the iron core 18. The magnetic pole member 34a is fixed in the horizontal groove 28a together with a spacer member 36a, and is magnetically isolated from the flat plate member 24 by the spacer member 36a.

The upper surface of the magnetic pole member 34a, that is, the upper surface of the magnetic pole surface portion 32a and the upper surface of the spacer member 36a, are on the same plane as the first magnetic pole surface portions 30a, 30b.

The magnetic pole member 34b disposed within the lateral groove 28b is made of a magnetic material and includes a main portion 42 having a rectangular shape corresponding to the lateral groove 28b, and a branch portion extending from the side of the portion along the auxiliary grooves 2 and 8°. 44, and a pair of legs 38 similar to those in the magnetic pole member 34a are provided on the lower surface of the main portion.
is provided. Each spacer member 36b includes a main portion 46 having a U-shaped cross section over the entirety that covers both side surfaces and a lower surface of the main portion 42, and an entirety that covers both side surfaces and the lower surface of the branched portion 44 from one side of the main portion. and a branch portion 48 having a U-shaped cross section. A hole 40 similar to that provided in the spacer member 36a is provided at the bottom of the spacer member 36b to allow the leg portion 38 to come into contact with the upper surface of the iron core 18.

The magnetic pole member 34b has a main portion 42 and a branch portion 44.
are respectively received in the main portion 46 and the branch portion 48 of the spacer member 36b. The magnetic pole member 3
4b, the spacer member 36b receives the branched portion 4b.
8 is fixed within the 1+I'j 28 b and 28° together with the magnetic pole member 34b so as to be received in the corresponding auxiliary groove 28', and the spacer member 36
b magnetically isolates the magnetic pole member 34b from the flat plate member 24. The upper surface of the magnetic pole member 34b, that is, the upper surface of the main portion 42 and the branch portion 44, is the magnetic pole surface portion 32b and the upper surface of the spacer member 36b.
It is on the same plane as the first magnetic pole face portions 30a, 30b.

The magnetic pole members 34a are arranged parallel to each other.

34b, the branch portion 44 formed on the outermost magnetic pole member 34b is connected to the corresponding magnetic pole face portion 30.
b and terminates at the end face of the flat plate member. Therefore, the extension portion 32b' of the magnetic pole face portion 34b defined by the upper portion 1a1 of the branch portion 44 crosses the outermost magnetic pole face portion 30b and returns to the end face of the flat plate member. Therefore, the magnetic pole surface portion 30b located at the outermost side is in the extending direction of the magnetic pole surface portion, that is, the lateral groove 28
It is divided in the direction of elongation.

The flat plate member 24 is magnetically coupled to the housing 14 which is magnetically fitted R1 to the lower surface of the iron core 18, and the magnetic pole members 34 (34a, 34b) are connected to the leg portion 3.
8, the magnetic pole surface portions 30 (30a, 30b) and the magnetic pole surface portions 32 (32a, 32b) and are magnetized to have different magnetic poles.

In the magnetic chuck according to the present invention, as in the conventional magnetic chuck, the width dimension of the outermost magnetic pole face portion 30b is equal to the width of the other magnetic pole face portions 32a located between the magnetic pole face portions.

32b, this outermost magnetic pole surface portion 30b is divided by an extension portion 32b'' of the magnetic pole surface portion 32b of a different magnetic pole, and is subdivided in the extending direction of the magnetic pole surface portion 30b. ing.

Therefore, even if a relatively small magnetic body is placed near both ends of the face plate 16, the magnetic body will surely come into contact with both of the magnetic pole face portions of the different magnetic poles, and as a result, the magnetic body will be securely held. Ru.

Furthermore, as shown in FIG. 2, when a plurality of magnetic chucks 10 are used in series to hold a long magnetic plate, each magnetic chuck 1
Since the outermost magnetic pole surface portion 30b of the face plate 16 of No. 0 is divided in the extending direction, a large identical magnetic pole surface area is not formed at the connecting portion of the face plate 16 as in the conventional case, and the outermost magnetic pole surface portion 30b of the face plate 16 is The magnetic attraction force at the connecting portion does not decrease as in the conventional case.

Therefore, according to the present invention, it is possible to reliably hold the magnetic material at the end portions of the face plate without reducing the adsorption force at the end portions.

As described above, the magnetic force source is 1! Although an example in which a magnet is used has been described, it will be clear that the present invention can be applied to a magnetic magnet assembly that uses a permanent magnet assembly as the magnetic force source.

Further, the flat plate member can be constituted by a plurality of magnetic pole members as in the conventional magnet chunk.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of the magnetic chuck according to the present invention, and FIG. 2 is a plan view of the magnetic chunk shown in FIG. 1. 12: Magnetic source, 14: Howsink, 16: 1
rti board, 30 (30a, 30b), 32C
32a, 32 +1): magnetic pole surface portion, 32b: extension portion. Agent Patent Attorney Nobuyuki Matsunaga

Claims (1)

[Claims] A magnetic chuck including a face plate that closes the open end of the housing to define a suction surface for holding a magnetic material by the magnetic force of a magnetic source housed in a housing with one end open, the suction surfaces mutually magnetically is blocked by
a plurality of first and second magnetic pole face portions extending in parallel and arranged alternately so as to be magnetized to different magnetic poles by the magnetic force of the magnetic force source; The magnetic pole face portion adjacent to the outermost magnetic pole face portion has an extension portion that crosses the magnetic pole face portion to partition the outermost magnetic pole face portion in the extending direction of the magnetic pole face portion,
A magnetic chuck characterized in that the extension portion returns to a corresponding end surface of the face plate.