JPH0538658A - Work seating sensing device - Google Patents

Abstract

PURPOSE:To provide a work seating sensing device, which can sense that a work is seated certainly even when the seating area of a work is narrow. CONSTITUTION:On a work placing table 1 are installed a contact piece 6, which can protrude and imerge while the top is contacting the seating area S of a work W, and a contact sensing surface 1a which comes in tight contact with the undersurface of the contact piece 6 in the imerged condition. Air blowout devices 15, 18 are provided having an air jet 14 which is opening at this contact sensing surface 1a, while a sensor 22 is furnished which senses the back pressure of this air jet 14. The contact piece 6 is energized protrusive by a resilient member 9. When the work W is seated, the contact piece 6 contacted by its seating area is depressed, and the undersurface of the piece 6 blocks the air jet 14 opening at the sensing surface 1a. so that the back pressure of the air jet 14 is raised. The work W being seated can thus be checked by sensing this rise of back pressure with the sensor 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seating detection device for a work used in a machining center, a machine tool such as a milling machine, a drilling machine or the like.

[0002]

2. Description of the Related Art Conventionally, in a machining center or the like, when confirming that a work is seated on a work table or a surface plate on a pallet, an air blowing type seating detector shown in FIG. 4 is used. In the figure, the work W1 is placed on a seating surface forming portion 31 formed to project on the work mounting table 30. The seating surface forming portion 31 is provided with an air passage 33 in which the air ejection port 32 opens on the seating surface 31a.
33 is a back pressure detector including an air limiter and a pressure control valve 34
An air source 35 is connected via. Work W1 is seating surface 31
When seated on a, the back pressure of the air ejection port 32 becomes high, and when the back pressure reaches a set value, the back pressure detector 34 detects this, and the seating of the work W1 is detected from the detection signal. It is confirmed.

[0003]

However, in the case of the work W2 having a narrow seating surface S2 as shown in FIG. 5, even if the seating surface forming portion 31 is provided with the air ejection port 32, the work W is surely closed. Cannot be performed, and air leakage may occur,
Seating cannot be detected reliably.

An object of the present invention is to provide a work seating detection device capable of surely detecting the seating even when the seating surface of the work is narrow.

[0005]

SUMMARY OF THE INVENTION A seating detection device for a work according to the present invention comprises a contact element capable of projecting and retracting, a contact detection surface, and an air blowing device having an air ejection port opened on the contact detection surface.
A detector for detecting the back pressure of the air ejection port is provided. The contactor is provided on the work mounting table so that the upper end of the contactor comes into contact with the seating surface of the work and is set in the work mounting table. The contact detection surface is provided on the work mounting table, and is set so that the lower surface of the contactor comes into close contact with the contactor in the retracted state.

[0006]

When the work is seated, the contactor is retracted against the projecting biasing force of the elastic member, and the lower surface of the contactor closes the air ejection port of the air blowing device which opens to the contact detection surface. As a result, the back pressure at the air ejection port rises until it reaches the set value. The seating of the work is detected by the detector detecting the increase in the back pressure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. On a pallet 1 which is a work mounting table, a disk-shaped surface plate 2 is replaceably provided. The surface plate 2 is
The pallet 1 is pressed and fixed on the pallet 1 by the claw portion 3a of the chuck 3 which is urged downward by the return spring 5 engaged with the bolt 4.

A vertical hole 7 is pierced through a part of the surface plate 2 to accommodate a contactor 6 whose upper end is in contact with the seating surface S of the work W so as to be retractable. The contact 6 is provided with a return spring 9 interposed between a ring-shaped spring receiving member 8 screwed into the lower portion of the vertical hole 7 and a spring receiving portion 6a formed on the outer periphery of the upper portion of the contact 6. The upper end protrudes from the upper surface of the surface plate 2, and the contact 6
The lower surface of the pallet 1 is held in a state of being lifted from the contact detection surface 1a which is the upper surface of the pallet 1. Further, the lower surface of the surface plate 2 is formed with an external opening hole 2a for communicating the vertical hole 7 with the outside of the surface plate 2.

Another vertical hole 11 is provided at the other part of the surface plate 2 so as to accommodate the positioning pin 10 so as to be retractable. The positioning pin 10 is for inserting into the hole b formed in the flange a of the work W to position the work W when seated. A return spring 12 is attached to the cylinder 10a that constitutes the lower half of the positioning pin 10.
The positioning pin 10 is biased to project by being received by the spring receiving member 13 screwed to the lower portion of the vertical hole 11.

On the contact detection surface 1a of the pallet 1, an air ejection port 14 is opened at a position where the lower surfaces of the contacts 6 face each other. The air ejection port 14 communicates with the ventilation path 15, and is connected to the air source 18 via the air limiter 16 and the pressure control valve 17 by piping. The air limiter 16 has a pressure switch 19, a pressure gauge 20, and a variable throttle valve 21. The pressure switch
The back pressure detector 22 is constituted by 19 and the air ejection port 14.

A rod 24 which is driven up and down by a cylinder 23 arranged on the pallet 1 side is provided at the center of the surface plate 2, and an upper end portion of the rod 24 which protrudes above the surface plate 2 is provided. A push-up member 25 for pushing up the seated work W is attached.

FIG. 3 shows a clamp device 36 for clamping the work W on the pallet 1. The clamp device 36 presses the work W from the upper surface by the clamp arm 38 which is rockably driven by the cylinder device 37.

The operation of the above configuration will be described. The contact 6 is
When the work W is not seated, as shown in FIG.
The protrusion is urged by and the tip projects above the upper surface of the surface plate 2. At this time, the lower surface of the contactor 6 is at a position floating above the contact detection surface 1a of the pallet 1, and the air ejection port 14 is open to the outside through the vertical hole 7 and the external opening hole 2a.

As shown by the chain line in FIG. 1, the positioning pin 12 is inserted into the hole b of the flange a of the work W, and the work W is held by the upper end of the contact 6 while the work W is held on the surface plate 2. When properly seated on the top, the contact 6 is pushed down by the load of the work W, and the air ejection port 14 is closed by the lower surface of the contact 6. As a result, the back pressure rises, the pressure switch 19 is turned on, and it is detected that the seat is properly seated.

When the seating is incomplete, the contactor 6 does not descend sufficiently and the air ejection port 14 is not blocked by the lower surface of the contactor 6, so air leaks and the pressure switch 19 does not turn on, and the seating It is judged to be incomplete.

The surface plate 2 is exchanged according to the type of work W to be placed. The position of the contact 6 housed in each surface plate 2 is set to a position for receiving the seating surface S of the corresponding work W. As described above, since the positions of the contacts 6 on the surface plate 2 used according to the workpiece W to be placed are different from each other, the lower surface of the contacts 6 with respect to the position of the air ejection port 14 opening on the contact detection surface 1a of the pallet 1. However, by making the area of at least the lower surface of the contactor 6 on each surface plate 2 large to some extent, the air ejection port 14 is contacted even if the position of the contactor 6 is different. It can be closed by the lower surface of the child 6.

[0017]

In the work seating detection device of the present invention, the work mounting table is provided with the contacting element which is urged by the elastic member and has its upper end in contact with the seating surface of the work piece so as to be projected and retracted. A contact detection surface that is in close contact with the lower surface of the contactor when the contactor is in a retracted state is provided on the workpiece mounting table, and an air blowing device having an air ejection port is provided on this contact detection surface to detect the back pressure of the air ejection port. Since the detector that operates is provided, the seating of the work can be reliably detected even when the seating surface of the work is narrow.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the outline of a work seating detection device according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a main part of the seating detection device.

FIG. 3 is a cutaway side view showing a relationship between a work placement table and a work clamp device using the seating detection device.

FIG. 4 is a longitudinal sectional view showing a seating detection operation by a conventional seating detection device.

FIG. 5 is a vertical cross-sectional view showing a problem when the conventional seating detection device detects seating of a work having a narrow seating surface.

[Explanation of symbols]

1 ... Pallet, 1a ... Contact detection surface, 2 ... Surface plate, 2a ... External opening hole, 6 ... Contact element, 9 ... Return spring, 14 ... Air ejection port, 15 ... Ventilation passage, 18 ... Air source, 22 ... Back Pressure detector, W ... Work, S ... Seating surface

Claims (1)

[Claims] 1. A work mounting table is provided with a projecting and retractable contactor which is urged by an elastic member to project into the seating surface of the work and is made to immerse into the seating surface of the work. Providing a close contact detection surface on the work mounting table,
A seating detection device for a work, which is provided with an air blowing device having an air ejection port opened on the contact detection surface, and a detector for detecting a back pressure of the air ejection port.