JPS608180B2 - Workpiece feeding device for double-head grinding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for feeding a workpiece to a grinding wheel in a double-headed grinding machine.

A double-head grinder is a grinding machine that rotates a pair of grinding wheels with their grinding surfaces facing each other, and uses a workpiece conveyance guide rail (hereinafter simply referred to as a conveyance guide rail) between the grinding wheels.

) is a machine tool that processes the workpiece while passing it through the guide. Therefore, opposing surfaces of the workpiece can be simultaneously ground. In order to automatically sequentially process a large number of workpieces using such a double-headed grinder, a device for automatically feeding the workpieces between the grinding wheels, that is, a feeding device is required.

A conventional feeding device is configured to feed a conveyed object by sandwiching it between belt rollers that are provided opposite to each other on both the left and right sides of the extended conveyed object guide rail.

The conveyed object guide rail is provided to pass between the grindstones, so it is made thinner than the workpiece. Therefore, if the workpiece is thin, the belt rollers will not be sufficient to hold the workpiece in place, and since the belt rollers will flex as they rotate, problems such as the workpiece falling off the guide wheel may occur. Ta. In addition, with conventional feeding devices, it was very difficult to change the setup, and it was difficult to feed the workpiece at high speed. ．． However, according to such a method, it is necessary to control the posture of the workpiece so that the workpiece is held tightly by a chuck.
Furthermore, if the workpiece is small or thin and easily deformable, the chuck device needs to be more precise and smaller, which is disadvantageous in terms of manufacturing time and cost. Therefore, it is an object of the present invention to provide a feeding device that can feed workpieces automatically and continuously without the need for posture control and pushing devices, and furthermore, without the need to provide a particularly precise chuck device. purpose. The present invention will be described in detail below based on illustrated embodiments.

FIG. 1 is a schematic diagram showing the configuration of a feeding device according to the present invention. First, the general operation of this device will be explained.

In FIG. 1, a workpiece 2 guided and supplied by a workpiece supply guide rail (hereinafter simply referred to as a supply guide rail) 1 is sequentially received by a local attraction surface 9A on the attraction surface 4 of an electromagnetic chuck 3. 1 with weak adsorption force in part A
They are absorbed one by one. The attracted workpiece 2 is supplied to the feeding section C via the feeding section B as the electromagnetic chuck 3 rotates (in the direction of the arrow). In the feeding section B, the workpiece 2 is attracted with a strong attraction force, and in the feeding section C, the attraction force is weakened.
The workpiece 2 that has reached the feeding section C is successively peeled off from the suction surface 4 at the entrance of the conveyance guide wheel 5 and is fed between the grindstones 6 and 7. The force for feeding the workpiece 2 is generated by the pressing force when successive workpieces are placed on the entrance of the conveyance guide rail 5. The workpiece 2 is then ground between the grindstones 6 and 7 and sent out from the exit of the conveyance guide rail 5. Next, the configuration will be explained. The electromagnetic chuck 3 includes a rotary body 8 that is rotationally driven and a plurality of individually independent electromagnets 9 embedded in the rotary body 8 as basic components. The electromagnets 9 are embedded in the rotating body 8 at appropriate intervals in the circumferential direction. Further, each electromagnet 9 is provided so that its respective attraction surface is flush with the negative side surface of the rotating body 8, so that one side surface of the rotating body 8 has a local attraction surface corresponding to each electromagnet 9. 9A is formed. The above attraction surface 4 depends on the strength of the magnetic field generated by each electromagnet 9.
Apparently, it is roughly divided into a receiving section A, a forwarding section B, and a sending section C.

In other words, the receiving section A first places the supplied workpiece 2 on the suction surface 9.
This is the part for adsorption to A, and it is located in this part (
or passing through) the electromagnet 9 is weakly excited. The reason for weak excitation is that when strong excitation is used, it is rapidly attracted and the workpiece 2
This is because there is a risk that the suction surface 9A may be damaged, and the minimum suction force necessary to individually suction each workpiece 2 is generated. By doing this,
Workpieces 2 can be reliably fed one by one. The feeding section B is a section for transferring the workpiece 2 picked up by the receiving section A to the entrance of the conveyance guide rail 5.

Therefore, the electromagnet 9 located in this forwarding section B is strongly excited to prevent the workpiece 2 from detaching. The feeding section C is a section for transferring the workpiece 2 transferred through the feeding section B from the suction surface 4 to the entrance of the conveyance guide rail 5.

Therefore, the electromagnet 9 located in the feeding section C is provided with the necessary power so that the workpiece 2 can easily separate from the suction surface 9A, and also to send the preceding workpiece placed on the conveyance guide rail 5 forward. A moderately weak magnetic field is present. In other words, the existence of a weak magnetic field may be due to the magnetic field generated by active weak excitation depending on the thickness of the workpiece 2, or due to the residual magnetism remaining on the attraction surface 9A when excitation is stopped. This means that a magnetic field exists. More than electromagnet 9
Excitation switching is performed using the following configuration. That is, the electrode plate 11 provided on the back of the electromagnetic chuck 3,
A plurality of electrodes 12A, 12B, 12C, and 12D are provided on the surface of the electrode plate 11 facing the electromagnetic chuck, and brushes 13 and 14 extend from each electromagnet 9 so as to be able to slide over these electrodes.
(See Figure 4).

In addition, in FIG. 4, in order to simplify the explanation, only the electromagnets 9 in the receiving section A, the forwarding section B, and the sending section C are shown. The electrode plate 11 is fixed while the electromagnetic chuck 3 rotates. Excitation voltages are supplied from the excitation power supply device 15 to each of the electrodes 12A to 12D, depending on the role of the receiving section A, the forwarding section B, and the sending section C.

That is, low voltage is applied to the receiving part electrode 12A, and low voltage is applied to the receiving part electrode 12A.
A high voltage is applied to the electrode 2B, and a low voltage or a drop voltage is applied to the feeding section electrode 12C. The outermost electrode 12D is a common electrode, and a voltage is applied between this electrode 12D and each of the electrodes 12A to 12C. Therefore, the brushes 13 and 14 of each electromagnet 9 are connected to the common electrode 12D and each electrode 12A to 12.
It is arranged so that it straddles between C and makes sliding contact. Next, the operation will be explained (see FIGS. 2 and 4).

The workpiece 2 supplied by the supply guide loop is attracted by the electromagnet 9 located in the receiving section A with weak excitation.
At this time, since the electromagnetic chuck 3 is rotating, the workpieces 2 are successively attracted one by one. Next, the suctioned workpiece 2 is sent to a transport B. At this time, since the brushes 13 and I4 of the electromagnet 9 come into contact between the electrodes 12B and 12D, the workpiece 2 is attracted by strong excitation and is securely held. Next, the workpiece 2 is sent to the feeding section C. At this time, since the brushes 13 and 14 are in contact between the electrodes 12C and 12D, the electromagnet 9 is switched to weak excitation or excitation stop. Then, the workpiece 2 comes into contact with the entrance of the transport guide rail 5, and since the electromagnetic chuck 3 continues to rotate, it is peeled off from the suction surface and transferred to the transport guide rail 5. Subsequent workpieces 2 are sequentially fed in the same way, so the workpieces on the conveyance guide rail 5 are sequentially pushed forward and enter between the grinding wheels 6 and 7. As described above, according to the present invention, this device sequentially feeds the workpiece to the conveyance guide rail while being attracted by electromagnetic force, so the workpiece is continuously and rapidly fed to the grinding wheel without providing a pushing device. can do.

In addition, the attraction is based on electromagnetic force, and the receiving part uses weak excitation to attract it, so even small or thin workpieces can be reliably fed without falling off the rails, unlike conventional methods. This contributes to improving product quality.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a schematic perspective view of an embodiment of the workpiece feeding device according to the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a plan view thereof.
FIG. 4 is a front view showing the configuration of the excitation switching device. 1... Supply guide rail, 2... Workpiece, 3...
...Electromagnetic chuck, 5...Transfer guide rail, 6,7... Grinding wheel, 8...Rotating body, 9.
...Electromagnet, 9A...Local adsorption surface, 1
1... Electrode plate, A... Receiving part, B...
...Forwarding section, C...Infeeding section. Figure 1 Figure 3 Figure 2 Figure 4

Claims (1)

[Claims] 1. In a double-head grinding machine equipped with a pair of grinding wheels arranged in parallel and a workpiece conveyance guide rail passing between the grinding wheels, a plurality of individually independent electromagnets are attached to the rotating body. By providing them at intervals in the circumferential direction, a suction surface capable of locally suctioning the workpiece is formed on one side of the rotating body, and the suction surface is roughly divided into a receiving section, a forwarding section, and a feeding section. an electromagnetic chuck, the electromagnetic chuck having an inlet of the workpiece conveyance guide rail along the feed section; and a workpiece supply disposed perpendicularly to the suction surface on the receiving section of the suction surface. A guide rail, and an excitation switching device that weakly excite each of the electromagnets in the attracting surface receiving part, strongly excite them in the forwarding part, and weakly excite or stop excitation in the sending part to change the respective attracting forces. Workpiece feeding device for double-headed grinding machine.