JPH11226679A - Pneumatic circuit of vacuum suction pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a mistaken suction of a pat by flowing the compressed air from an external pilot piping to each side of a spool of a solenoid valve to move the spool to right and left sides with the same as the main pressure. SOLUTION: An external pilot piping 71 in which the compressed air in an air supply pipe 51 supplied from an air pressure source 49 is branched, is connected to a pilot port 69 for operating a spool provided on a solenoid valve 53 to constitute a pneumatic circuit 47 of a vacuum suction pad 43. The spool movement of the solenoid valve 53 is smoothed to prevent a mistaken suction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic circuit for a vacuum suction pad for sucking and conveying a work.

[0002]

2. Description of the Related Art Conventionally, an origin pulling pad used in a turret punch press, for example, has applied a pad to a work and evacuated the pad to suck the work with the pad and convey the work. As a pneumatic circuit for evacuating the pad, a circuit using a three-position closed center type electromagnetic switching valve and an ejector is used.

More specifically, referring to FIG. 4, a pneumatic circuit 101 is connected from a pneumatic source 103 to a P port of a three-position closed center type electromagnetic switching valve 107 through a pneumatic supply pipe 105. I have. Outlet A of the electromagnetic switching valve 107
A discharge side pipeline 109 is connected to the port, and a discharge side pipeline 111 is connected to the outlet B port of the electromagnetic switching valve 107. The pneumatic circuit 101 is intended for an apparatus provided with two vacuum suction pads 113.

The discharge-side pipes 109 are connected to respective vacuum suction pads 113, and an ejector 115 is provided in the discharge-side pipes 109. The ejector 115 is formed by a throttle 117 and a silencer 119. It is configured. The discharge side pipes 111 are also connected to the respective vacuum suction pads 113, and the two discharge side pipes 109 and 111 join between the ejector 115 outlet side and the vacuum suction pad 113.

With the above configuration, air is sent from the pneumatic source 103 to the ejector 115 through the electromagnetic switching valve 107, and the air is released from the silencer 119. Here, the aperture 117
Since the internal pressure is reduced, the air in the vacuum suction pad 113 flows toward the throttle 117, and the inside of the vacuum suction pad 113 is evacuated, so that the work can be sucked.

[0006]

By the way, the pneumatic circuit 10 for operating the conventional vacuum suction pad 113 described above.
In 1, when air is sucked by the ejector 115, the end of the circuit becomes vacuum, so that there is no force for switching the spool of the electromagnetic switching valve 107. This causes a malfunction that the electromagnetic switching valve 107 does not switch, and the vacuum suction pad 113 does not suck the work.

More specifically, the discharge side pipelines 109 and 111
Is vacuumed, and the air is released when the electromagnetic switching valve 107 opens the pad suction (when the solenoid of the electromagnetic switching valve 107 is ON). As a result, a pressure loss occurs in the internal pilot of the electromagnetic switching valve 107, so that there is a problem that the spool operation of the electromagnetic switching valve 107 malfunctions.

An object of the present invention is to provide a pneumatic circuit for a vacuum suction pad which prevents a suction error of the vacuum suction pad.

[0009]

According to a first aspect of the present invention, there is provided a pneumatic circuit for a vacuum suction pad according to the present invention. The path is connected to a vacuum suction pad, and an ejector equipped with a throttle and a silencer is used as a pneumatic circuit of a vacuum suction pad provided in the discharge-side pipe line, to a spool operation pilot port provided in the electromagnetic switching valve. And an external pilot pipe branched from the pneumatic supply pipe.

Therefore, an external pilot line branched from a pneumatic supply pipe is connected to a pilot port of an electromagnetic switching valve provided in a pneumatic circuit for sucking and releasing a vacuum suction pad. Therefore, air pressure flows from the external pilot line to both sides of the spool of the electromagnetic switching valve, and the spool is moved to the left and right sides at the same pressure as the main pressure.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. Although the embodiment will be described with respect to a pneumatic circuit of an origin pulling pad used in a turret punch press, the present invention is not limited to this model, and can be generally applied to a device that conveys a workpiece by a vacuum suction pad. .

First, a schematic configuration of a turret punch press will be described. Referring to FIGS. 2 and 3, the turret punch press 1 includes an upper frame 3 and a lower frame 5.
The upper frame 3 and the lower frame 5 respectively support a rotatable upper turret 9 and a lower turret 11 by a drive device (not shown). Various pairs of punches 13 and dies 15 are mounted on the circumference of the upper turret 9 and the lower turret 11, respectively.

The upper frame 3 is provided with a hydraulically operated cylinder 17, and a striker 19 which is vertically movable by the cylinder 17 is provided. Reference numeral 21
Is a stamping part.

With the above structure, the upper turret 9 and the lower turret 11 are rotated and driven immediately below the striker 19 so that a desired pair of punches 13 and dies 15 are positioned. The workpiece is punched in cooperation with the die 15 by lowering the punch 13.

A fixed table 23 is provided surrounding the lower turret 11, and side tables 25A and 25B are provided on both sides of the fixed table 23. A carriage base 27 integrated with the side tables 25A and 25B is provided so as to extend in the X-axis direction (the horizontal direction in FIGS. 2 and 3). A feed screw (not shown) extending in the X-axis direction is provided in the carriage base 27, and a nut member (not shown) provided on the carriage 29 is screwed to the feed screw. A plurality of clampers 31 are attached.

Further, a feed screw (not shown) extending in the Y-axis direction is screwed into a substantially central portion of the carriage base 27.

With the above configuration, when the feed screw extending in the X-axis direction is rotated, the carriage 29 is moved in the X-axis direction, and the clamper 31 is attached to the carriage 29. It will be moved in the axial direction. When the feed screw extending in the Y-axis direction rotates, the carriage base 27 moves in the Y-axis direction (vertical direction in FIG. 2), so that the side tables 25A and 25B also move in the Y-axis direction at the same time.

The work gripped by the clamper 31 is moved in the X-axis and Y-axis directions, and the desired processing position of the work is positioned directly below the striker 19, and punching is performed by the cooperation of the punch 13 and the die 15. Will be applied.

The arm 3 is positioned on one side of the upper frame 3.
3 is provided extending in the X-axis direction, and a plurality (two in this embodiment) of hydraulically operated first cylinders 35 are provided near the tip of the arm 33. A second cylinder 39 which is operated by fluid pressure is provided at the tip of the piston rod 37. A vacuum suction pad 43 is attached to the lower end of the piston rod 41 of the second cylinder 39. Reference numeral 45 is a reference origin of the work.

With the above structure, the second cylinder 39 is operated to lower the vacuum suction pad 43 onto the work, and the vacuum suction pad 43 is vacuumed to suck the work.
The reference position of the work is set by contacting the work with the reference origin 45 by operating the cylinder 35.

Next, a pneumatic circuit for vacuuming the vacuum suction pad 43, which is a main part of the present invention, will be described in detail.

Referring to FIG. 1, a pneumatic circuit 47 is connected from a pneumatic source 49 to a P port of a three-position closed center type electromagnetic switching valve 53 through a pneumatic supply pipe 51.
The discharge side pipe 55 is connected to the outlet A port of the electromagnetic switching valve 53.
Is connected, and a discharge-side pipe line 57 is connected to the outlet-side B port of the electromagnetic switching valve 53. The pneumatic circuit 4
7 is intended for an apparatus provided with two vacuum suction pads 43, but the number of vacuum suction pads 43 is not limited.

The discharge side pipes 55 are connected to the respective vacuum suction pads 43, and the discharge side pipes 5
An ejector 59 is provided in the middle of 5, and this ejector 59 is composed of a throttle 61 and a silencer 63. The discharge-side pipes 57 are connected to the respective vacuum suction pads 43, and a check valve 65 is provided in the discharge-side pipes 57.

The electromagnetic switching valve 53 has an electromagnet 67 on both sides of the spool and a pilot port 69 through which air pressure flows into both sides of the spool. An external pilot pipe 71 branched from the pneumatic supply pipe 51 is connected to the pilot port 69.

With the above configuration, the ejector 59 sends air from the pneumatic source 49 through the electromagnetic switching valve 53, and discharges air from the silencer 63. Here, since the pressure in the throttle 61 is reduced, the air in the vacuum suction pad 43 flows toward the throttle 61, and the inside of the vacuum suction pad 43 is in a vacuum state, so that the work can be sucked.

The external pilot line 71 branched from the pneumatic supply pipe 51 is connected to the pilot port 69 of the electromagnetic switching valve 53, and flows to both sides of the spool of the electromagnetic switching valve 53. Move the spool left and right with. Therefore, the electric switching valve 53 receives the main pressure loss at the time of switching, but since the spool is moved at the same pressure as the main pressure, it is possible to prevent the vacuum suction pad 43 from malfunctioning by suction.

The present invention is not limited to the above-described embodiment of the invention, but can be embodied in other modes by making appropriate changes.

[0028]

As will be understood from the above description of the embodiments of the present invention, according to the present invention according to the first aspect, the electromagnetic switching provided in the pneumatic circuit for sucking and releasing the vacuum suction pad. An external pilot line branched from the pneumatic supply pipe was connected to the pilot port of the valve. Therefore, air pressure flows from the external pilot line to both sides of the spool of the electromagnetic switching valve, and the spool is moved to the left and right sides at the same pressure as the main pressure.

[Brief description of the drawings]

FIG. 1 shows a main part of the present invention and is a pneumatic circuit diagram of a vacuum suction pad.

FIG. 2 is a plan view of a turret punch press according to an embodiment of the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 shows a conventional example and is a pneumatic circuit diagram of a vacuum suction pad.

[Explanation of symbols]

 43 Vacuum suction pad 47 Pneumatic circuit 49 Pneumatic source 51 Pneumatic supply pipe 53 Solenoid switching valve 55, 57 Discharge side line 59 Ejector 61 Throttle 63 Silencer 69 Pilot port 71 External pilot line

Claims (1)

[Claims] A discharge-side pipe is connected to a vacuum suction pad from a pneumatic source via a pneumatic supply pipe and an electromagnetic switching valve, and an ejector having a throttle and a silencer is provided in the discharge-side pipe. To the pneumatic circuit of the suction pad, to the pilot port for spool operation provided in the electromagnetic switching valve,
An air pressure circuit for a vacuum suction pad, wherein an external pilot line branched from the air pressure supply pipe is connected.