JPH0115513Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a work holding device for holding a work by vacuum suction, and particularly to means for periodically cleaning its suction holes.

Background of the invention In a device that suctions a workpiece by vacuum suction, a vacuum air source is connected to the suction hole. As the workpiece becomes smaller, the diameter of the suction hole correspondingly decreases, so that dirt and the like tend to adhere to the opening surface and inside of the hole during suction, reducing the suction ability during use. For example, the diameter of the adsorption hole is 0.5
When the diameter is about mm, the inside of the hole becomes easily clogged by dust in the air. Therefore, maintaining adsorption capacity over a long period of time has always been a problem. Furthermore, when dust or the like adheres to the surface of the pores, the adsorption capacity decreases rapidly.

Purpose of the invention Therefore, the purpose of the present invention is to clean the suction hole when a workpiece is not being suctioned, thereby preventing the suction ability from decreasing.

Summary of the invention Therefore, the present invention blows air out of the suction hole when a workpiece is not being suctioned, thereby preventing the hole from clogging and maintaining its suction ability over a long period of time. ing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings.

First, FIGS. 1 and 2 show a workpiece holding device 1 of the present invention. The workpiece 2 is, for example, an annular rubber body, and is guided into the cylindrical guide 3 by a parts feeder (not shown) and transferred to a receiving surface on the workpiece receiver 4. A pusher 5 is provided on the upper surface of the workpiece receiver 4 so as to be able to move forward and backward, and a pusher 5 at the tip of the pusher 5 holds the lowest workpiece 2 on the receiving surface. Move it to the left in the drawing while sliding on the top surface of the machine, and stop at the supply position. This amount of movement corresponds to the stroke S of the pusher 5.

For example, 2
Two suction holes 7 are formed. This hole 7
is a top-opening type, and is connected to one connection port of the switching valve 10 by a connector 8 and piping 9. Moreover, the two connection ports of this switching valve 10 are
Each is connected to a vacuum pump 11 and an air pump 12, respectively. These vacuum pumps 11
and the air pump 12 constitute an air source 13.

The switching valve 10 is, for example, an electromagnetic self-resetting type, and is controlled by a controller 14. This controller 14 is connected to a photoreceptor 15 on the input end side. This photoreceptor 15
corresponds to the light emitting body 16, these are optically opposed to each other across the supply position of the workpiece 2, and constitute a detection means. Incidentally, above the workpiece receiver 4, a chuck 17 for automatic feeding is provided. The controller 14 also operates by receiving, for example, a signal from a limit switch 19 as an input. This limit switch 19 detects movement of the chuck 17.

Effect of the invention The workpieces 2 are sequentially fed into the cylindrical guide 3, and the lowest workpiece 2 is placed on the receiving surface of the workpiece receiver 4. Here, the pusher 5 moves forward in the range of stroke S from the retreat position, holds the lowest workpiece 2 with the pushing part 6 at its tip, and moves it to the supply position. Work 2
is fed into the supply position, the photoreceptor 15
detects the arrival of the workpiece 2 by blocking the light beam from the light emitter 16, and sends a signal to the controller 14.
Therefore, when the controller 14 receives the signal,
The switching valve 10 is switched to connect the adsorption hole 7 to the vacuum pump 11. For this reason, the workpiece 2 is vacuum-adsorbed at the position of the suction hole 7, and if the workpiece-receiving surface is simply flat, it is pneumatically held at that position. The pusher 5 then retreats, but since the workpiece 2 is held by the vacuum, it slips out of the pressing portion 6 of the pusher 5 and remains in that position. Therefore, it is possible to reliably prevent the workpiece from being taken back by the pusher 5, and the movement of the workpiece due to the vibration of the workpiece receiver 4 can also be suppressed.

Thereafter, the chuck 17 descends, for example from above, frictionally holds the workpiece 2 with its holding portion 18, rises again, changes direction by 90 degrees at the raised position, and horizontally moves the workpiece 2 to a predetermined position. Send it to the position. When the chuck 17 moves to the position of the workpiece 2 and grips it, the limit switch 1
9 turns on and generates a signal indicating the arrival of the chuck, the switching valve 10 switches the air pump 1 from that point on.
2 pressure air is sent to hole 7. This facilitates separation of the workpiece 2. This operation is effective when the receiving surface is made into a recess, or when the workpiece 2 is difficult to separate from the receiving surface due to dirt on the receiving surface, surface condition, or material of the workpiece 2. Of course, there is also a cleaning effect at this time.

When the work 2 is sent out by the chuck 17, the light from the light emitting body 16 reaches the light receiving body 15 again, so the controller 14 switches the switching valve 10 to its original state and switches the air pump 12 to the suction hole. Connect to 7. As a result, when the workpiece 2 no longer exists at the supply position on the upper surface of the workpiece receiver 4, air is blown out from the hole 7, so that dirt on the upper surface of the workpiece receiver 4 and dust in the air enter the inside of the hole 7. Furthermore, dirt and the like that have entered the inside of the hole 7 are discharged to the outside by the blown air.

In this way, the suction hole 7 is periodically cleaned depending on the effectiveness of the workpiece 2. At the same time, the cleaning cycle of filters that may be installed in the middle of the piping and the cleaning of the piping itself becomes longer, making maintenance management easier.

Other Embodiments Although the above embodiment uses the vacuum pump 11 and the air pump 12, it is of course possible to use either one of the pumps. For example, negative pressure air can also be obtained by injecting pressurized air from a ventilator. Further, the presence or absence of the workpiece 2 can be detected using a magnetic sensor, a mechanical limit switch, or the like. Furthermore, if the presence or absence of the workpiece 2 directly corresponds to the movement of the pusher 5, the movement of the pusher 5 is detected by a limit switch, a dog, etc., and the controller 1
4 can also be controlled. Furthermore, the hole 7 for adsorption
The direction in which the air is blown out is not limited to the direction shown in the figure, but can be set in a horizontal direction, an inclined direction, or any other arbitrary direction.

Effects of the invention In this invention, when a workpiece is sent to the workpiece receiving surface by a pusher, it is held by vacuum suction from the hole, so there is no need to take the workpiece back by the pusher, and it is stable against vibrations. Furthermore, when transferring the workpiece, air is blown out from the hole, which facilitates the transfer of the workpiece.Furthermore, dirt does not adhere to the surface or inside of the hole, and even if it enters the cage, it will not flow out with the air. Since it is discharged, there is no decrease in the adsorption capacity of the adsorption holes, and stable operation can be expected over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of the work holding device of the present invention, and FIG. 2 is a plan view of the main parts. 1... Work holding device, 2... Work, 3...
Cylindrical guide, 4... Workpiece receiver, 5... Pusher, 6... Pressing part, 7... Adsorption hole, 8... Connection tool, 9... Piping, 10... Switching valve, 11... Vacuum Pump, 12...Air pump, 13...Air source, 14...Control unit, 15...Photoreceptor, 16...
Luminous body, 17...Chuck, 18...Holding part, 1
9...Limit switch.

Claims (1)

[Scope of utility model registration request] A work receiver 4 is arranged below the cylindrical guide 3 that supplies the work 2 and the chuck 17 that sends out the work 2, and a pusher 5 is placed on the upper surface of the work receiver 4.
is provided so as to be able to move forward and backward with a stroke from the workpiece receiving surface of the workpiece receiver 4 to the workpiece supply position, and a top-opening suction hole 7 is formed at the workpiece supply position of the workpiece receiver 4, and this hole 7 is connected to the switching valve 10. is connected to the air source 13, and the workpiece receiver 4 is connected to the air source 13.
Detection means 1 for detecting the presence or absence of a workpiece 2 at the supply position of
5, 16 and a limit switch 19 for detecting movement of the chuck 17.
6 and a limit switch 19 are connected to a controller 14, and this controller 14 is further connected to the switching valve 10.
When receiving a signal indicating the arrival of the work from the limit switch 19, the switching valve 10 is switched to the negative pressure air flow path of the air source 13, and when receiving a signal indicating the arrival of the chuck from the limit switch 19, the switching valve 10 is switched to the negative pressure air flow path from the air source 13. A workpiece holding device 1 characterized in that the flow path is switched to a pressure air source 13.