JPH0229574B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a magnetic attraction chuck that uses magnetic attraction, and includes a large number of magnetic thin plates made of a ferromagnetic material such as an iron-nickel alloy. It is used for picking up sheets one by one from a stack of sheets.

(Prior Art) A magnetic suction chuck, which uses a magnet to lift a magnetic thin plate made of a ferromagnetic material such as an iron-nickel alloy, has been proposed as one means for transporting the magnetic thin plate. FIG. 5 is a diagram showing a schematic structure of an automatic plating apparatus using this magnetic attraction chuck as a conveying means for a magnetic thin plate. This apparatus is an apparatus for plating a metal frame 10 for forming lead wires of an integrated circuit as illustrated in FIGS. 6a and 6b. Each metal frame 10 is made of a ferromagnetic material, and a large number of them are stacked in a stocker 11.
The sheets are picked up one by one by a magnetic attraction chuck 12, placed one by one on a conveying roller 13, and sent to a plating tank 14.

By the way, there are as many as 120 to 130 types of metal frames 10 that can be plated using the above-mentioned apparatus, in addition to those illustrated in FIGS. 6a and 6b.
Their lengths and widths vary widely, and each metal frame 10 has a complicated punching pattern for forming lead wires of integrated circuits, and each pattern is different, so the weight and magnetic attraction characteristics vary. The metal frames 10 are different from each other and are plated accordingly.
It is necessary to replace the magnetic attraction chuck 12 depending on the type of the magnetic attraction chuck, and replacing the chuck requires a lot of time and effort.

Therefore, as disclosed in Japanese Patent Publication No. 47-2900, it has been proposed that in a magnetic attraction chuck using an electromagnet, the distance between the attraction surface of the electromagnet and the magnetic thin plate to be lifted can be adjusted. ing.

[Problem that the invention seeks to solve]

However, in a magnetic attraction chuck using an electromagnet, when attracting a magnetic thin plate, it is necessary to maintain the exciting current of the electromagnet at a constant current in order to keep the attraction force constant. Therefore, there is a problem in that a constant current circuit is required to always keep the excitation current at a constant current even when the power supply fluctuates. In addition, when releasing the attraction of the magnetic thin plate, it is necessary to turn off the excitation current of the electromagnet, which is affected by the hysteresis characteristics of the electromagnet.Even if the excitation current is kept constant, the attraction force of the electromagnet The problem is that it is not always constant.

Therefore, if a permanent magnet is used instead of an electromagnet and the surface of the magnetic thin plate is struck with an ejector pin when releasing the magnetic thin plate, the above-mentioned problem will not occur. However, if the surface of the magnetic thin plate is struck with a small ejector pin, the surface of the magnetic thin plate may be damaged. Also, if an ejector pin is provided on the chuck body,
Another problem is that the structure becomes complicated.

(Means for Solving the Problems) In order to solve the above-mentioned problems in the magnetic attraction chuck of the present invention, as shown in FIG. 1, a large number of stacked magnetic thin plates 1 are used. A chuck body 2 that descends to the top surface; a permanent magnet 3 that is attached to the bottom side of the chuck body 2 and has a horizontal magnetic attraction surface; a plunger 7 that is movable up and down with respect to the chuck body 2; Connected to the lower end, magnetic thin plate 1
A holding plate 4 having a horizontal surface that comes into contact with the upper surface of the holding plate 4; A cylinder 6 fixed to the chuck body 2 and driving the plunger 7 up and down; When the plunger 7 moves upward, the horizontal surface of the holding plate 4 is magnetically attracted by the magnet 3 It has a fine movement device 5 that adjusts the vertical position slightly below the surface.

(Function) Using the magnetic attraction chuck of the present invention, the magnetic thin plate 1 is
When suctioning, the plunger 7 is moved upward as shown in FIG. When the chuck body 2 is lowered onto the upper surface of the magnetic thin plate 1, which is laminated with a large number of sheets, the horizontal surface of the presser plate 4 comes into contact with the upper surface of the magnetic thin plate 1, and the magnetic attraction surface of the magnet 3 directly contacts the upper surface of the magnetic thin plate 1. Never touch it. The level difference between the horizontal surface of the holding plate 4 and the magnetic attraction surface of the magnet 3 is adjusted by the fine movement device 5, and the magnetic attraction force acting on the magnetic thin plate 1 from the magnet 3 is made strong enough to lift one magnetic thin plate 1. When this setting is made, the uppermost one of the stacked magnetic thin plates 1 rises and is attracted to the magnetic attraction surface of the magnet 3. When the chuck main body 2 is pulled upward in this state, the magnetic thin plate 1 is lifted while being attracted to the magnetic attraction surface of the magnet 3.

Next, when releasing the attraction of the magnetic thin plate 1, the plunger 7 is moved downward by the cylinder 6, and the holding plate 4 is moved downward. As a result, the distance between the magnet 3 and the magnetic thin plate 1 increases, so the attraction force decreases and the attraction is released. That is, in the present invention, the holding plate 4 for adjusting the suction force also serves as an ejector pin, and the structure is simplified compared to the case where the ejector pin is provided separately. Moreover, since the horizontal surface of the holding plate 4 is in contact with the surface of the magnetic thin plate 1 from the beginning, the surface of the magnetic thin plate 1 is less likely to be scratched compared to when the surface of the magnetic thin plate 1 is hit with a small ejector pin.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of a magnetic attraction chuck according to an embodiment of the present invention. As shown in the figure, the magnetic attraction chuck of this embodiment has a metal chuck body 2.
It has a thin magnet 3 such as a rubber magnet, an adjustment screw 51 constituting the fine movement device 5, a presser plate 4, and a cylinder 6 that drives the presser plate 4 up and down. 2 to 4 are a plan view, a left side view, and a perspective view showing the shape of the chuck main body 2, which forms the framework of the magnetic attraction chuck. As shown in the above figures, the chuck main body 2 includes a substantially U-shaped fixing base 21 for mounting and fixing the cylinder 6, and a magnet extending horizontally from the bottom of one end of the fixing base 21. 3 is attached to the horizontal plate 23 and the horizontal plate 23
A pair of vertical plates 2 erected vertically from both ends of
4 and 25, a support plate 26 that extends upward from the center of the upper end of the vertical plate 24 on the side closer to the fixed base 21, and an adjustment plate that extends horizontally from the upper end of the support plate 26 in the same direction as the fixed base 21. It has a screw mounting plate 27. The fixing base 21 has a pair of screw holes 28a, 2.
8b is provided, and the cylinder 6 can be fixed through this screw hole. The cylinder 6 has a plunger 7 that is driven up and down. The lower end of the plunger 7 is connected to the holding plate 4 through the recess 22 of the fixed base 21, so that the holding plate 4 can be driven up and down by the vertical movement of the plunger 7. The upper end of the plunger 7 is
The upper return position is regulated by coming into contact with the lower end of the adjustment screw 51. The holding plate 4 is the fourth
As shown in the figure, the cross section is approximately U-shaped, and the fixing base 21
It is designed to be worn so as to hold both sides of the Each of the vertical plates 24 and 25 is provided with an insertion hole 29 through which a fixture for fixing the chuck body 2 to the chuck moving means is inserted. A screw hole 52 is provided in the adjustment screw mounting plate 27 at a location directly above the recess 22 of the fixing base 21, and the adjustment screw 51 is screwed into the screw hole 52. A hexagonal nut 53 is screwed onto the base of the adjustment screw 51, as shown in FIG. I try not to. As the cylinder 6, various types such as an air cylinder or an electromagnetic cylinder can be used.
The plunger 7 of the cylinder 6 is normally urged upward, but the upper end of the plunger 7 is attached to the adjustment screw 5.
1, the upper return position of the plunger 7, and hence the normal position of the presser plate 4, can be finely adjusted by the adjustment screw 51. When the chuck main body 2 is lowered onto the magnetic thin plate 1 with the plunger 7 returned upward, the horizontal surface of the holding plate 4 comes into contact with the upper surface of the magnetic thin plate 1, and the uppermost of the stacked magnetic thin plates 1 The object on the surface floats up and is attracted to the magnetic attraction surface of the magnet 3. When the chuck main body 2 is pulled upward in this state, the magnetic thin plate 1 is lifted while being attracted to the magnetic attraction surface of the magnet 3. Next, when the plunger 7 of the cylinder 6 is driven downward, the holding plate 4 is driven downward, so the magnet 3
The magnetic thin plate 1 attracted to the magnetic attraction surface is dropped downward.

By the way, in the present invention, even when the magnetic attraction chuck is lowered onto a large number of laminated magnetic thin plates 1, the holding plate 4 is in direct contact with the magnetic thin plate 1, and the magnetic attraction surface of the magnet 4 is Since the magnetic thin plate 1 is not directly placed on the magnetic thin plate 1, the attraction force of the magnet 3 is difficult to reach the second and subsequent magnetic thin plates 1, thereby reducing the possibility of picking up two or more magnetic thin plates 1 at the same time. This is something that can be reduced.
Furthermore, especially in the illustrated embodiment, since a rubber magnet is used as the magnet 3, the range of the magnetic lines of force is not very large, which also contributes to making it difficult to pick up the second and subsequent magnetic thin plates 1. I can say that.

In this embodiment, even when an electromagnetic cylinder is used as the cylinder 6, it is needless to say that the excitation current does not need to be a constant current, and it is sufficient to simply control whether or not the current is energized.

(Effects of the Invention) As described above, in the present invention, the holding plate for adjusting the attraction force of the magnetic attraction chuck is moved up and down by the cylinder and the plunger to separate the magnetic thin plate from the magnetic attraction chuck. Because it also serves as an ejector, the structure is simpler than when a separate ejector pin is provided, and there is no need to use an electromagnet as a magnet, so it is necessary to control the excitation current to a constant current. Since it is not affected by hysteresis characteristics, it has the effect that a stable adsorption force can always be obtained.

[Brief explanation of drawings]

FIG. 1 is a front view of a magnetic attraction chuck according to an embodiment of the present invention, FIGS. This figure is a schematic diagram of an automatic plating apparatus using the above magnetic attraction chuck as a conveyance means, and FIGS. 6a and 6b are front views of a metal frame to be plated in the above automatic plating apparatus. 1 is a magnetic thin plate, 2 is a chuck body, 3 is a magnet,
4 is a holding plate, and 5 is a fine movement device.

Claims (1)

[Scope of Claims] 1. A chuck body 2 that descends onto the upper surface of a large number of stacked magnetic thin plates 1; a permanent magnet 3 attached to the lower surface of the chuck body 2 and having a horizontal magnetic attraction surface; and a chuck body 2 A plunger 7 is movable up and down relative to the plunger 7, and a magnetic thin plate 1 is connected to the lower end of the plunger 7.
A holding plate 4 having a horizontal surface that comes into contact with the upper surface of the holding plate 4; A cylinder 6 fixed to the chuck body 2 and driving the plunger 7 up and down; When the plunger 7 moves upward, the horizontal surface of the holding plate 4 is magnetically attracted by the magnet 3 A magnetic attraction chuck comprising a fine movement device 5 for adjusting the vertical position slightly below the surface.