JPH04121346A - Two-sheet detecting device - Google Patents

Abstract

PURPOSE:To enhance measuring accuracy of displacement so as to improve accuracy of detecting a two-sheet doubled condition by providing a detecting piece pressing device for pressing a detecting piece to a reference contact piece and a measuring device for directly measuring displacement of the detecting piece. CONSTITUTION:A turning frame 13 is left as retracted at an angle of not interfering with lifting a plate material W, and when it is lifted to predetermined height, the turning frame 13 is turned to a side of the plate material W to hold it by a reference contact piece 18 and a detecting piece 19. Under this condition, displacement of the detecting piece 19 is measured by a measuring device 24. A holding thickness is detected by this displacement detection value to discriminate whether the plate material W is placed in a two-sheet doubled condition or not.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a two-sheet detection device that is applied to a board loader or the like that picks up and conveys stacked boards one by one.

(Conventional technology) Conventionally, in automatic production systems such as sheet metal processing lines,
A suction-type plate material loader is used when separating plate materials stacked at a stocking location one by one and transporting them to a plate processing machine. In this plate material loader, the topmost plate material is suctioned and lifted one by one using a suction pad, and then transported.

However, because the stacked plates have oil etc. attached to their surfaces due to surface treatment, or the plates are in close surface contact with each other, it is difficult to lift the top plate with a suction pad. In some cases, the board underneath may also be lifted up. Transferring a plurality of plates as they are to a plate processing machine not only causes processing problems, but also poses a danger because the lower plate may fall during transportation.

Therefore, conventionally, a two-sheet detection device shown in Fig. 4 was used,
Checking the number of planks lifted
Publication No. 1205).

This two-sheet detection device consists of a pair of rollers 51 that sandwich the plate material and the peg.
．． 52 is provided, and the roller 52 on the detection side is connected to the air cylinder 5.
The pinching thickness is detected by attaching it to a swinging link 54 driven by the eddy current displacement sensor 56 and detecting the amount of the swinging displacement. The swinging motion of the swinging link 54 is transmitted via a roller 58 to a lifting member 55 installed on a guide rod 57, converted into a linear motion, and detected by an eddy current displacement sensor 56.

The roller frame 59 that supported the rollers 51, 52, etc.
In order to allow the plate material Wa to be displaced vertically, it is supported in a floating state by a guide rod 61 and a support spring 62. Both rollers 51. ! l) The sandwiching of the plate material Wa between the two plates is carried out by moving the entire detection device, together with the advancing/retracting frame 60 provided with the guide rod 61, forward and backward with respect to the plate material -a (in the direction of the arrow a).

[Problem to be solved by the invention]

The two-sheet detection device shown in Fig. 4 has a structure in which the entire device moves forward and backward in order to sandwich the plate material-a, so it requires a space for movement and a guide device (not shown) to drive the movement forward and backward, making it difficult to make it more compact. The problem is that it cannot be planned.

Further, since the displacement of the roller 52 is detected through a link type motion transmission mechanism consisting of the swing link 54 and the elevating member 55, there is a problem that the accuracy is poor and the structure is complicated.

A second object of the invention is to provide a two-sheet detection device that can be made more compact and has improved detection accuracy.

[Means to solve the problem]

In the two-plate detection device of the present invention, a reference contact and a detector that sandwich a plate material between each other are provided on a rotating frame, the detector is movable forward and backward facing the reference contact, and the detection is performed by pressing the detector against the reference contact. A child pressing device is provided, and a measuring device for directly measuring the displacement of the detector is provided.

The rotating frame is capable of rotating around an axis perpendicular to the plate material to be detected. Detecting the displacement of the detector directly means
This is to detect it without using a motion transmission mechanism.

[For production]

The revolving frame is retracted at an angle that does not interfere with the lifting of the board, and when the board is lifted to a predetermined height,
The rotating frame is rotated toward the plate material, and the plate material is sandwiched between the reference contact and the detector. In this state, the displacement of the detector is detected by a measuring instrument. The pinching thickness is detected based on this displacement detection value, and it is determined whether or not the two plates are in an overlapping state.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 to 3.

In FIG. 3, the two-sheet detection device 1 is installed on a support 4 on a column 3 at a stocking location P where sheets W to be supplied to the sheet material loader 2 are loaded. The plate material W is loaded on a material cart 5. The plate material loader 2 runs along a rail 6- installed on a support column 3, and is provided with a large number of suction pads 7 for adsorbing the plate material W so as to be movable up and down via an elevating mechanism 8.

FIG. 1 shows a broken side view of the two-piece detection device 1, in which a guide shaft 10 is mounted on a base frame 9 and upper and lower bearings 11. ．． A linear bearing 14 provided at the base end of the rotating frame 13 is fitted to the guide shaft 10 so as to be movable up and down. The base frame 9 is fixed to the support base 4 shown in FIG. 3 via the mounting height adjustment member 28. The linear bearing 14 is elastically supported by a support spring 15 secured to the large diameter portion 10a of the guide shaft 10. The guide shaft 10 is connected to a rotation drive source 16 installed on the base frame 9 through a shaft coupling 17. Swing drive source 16
is composed of a pneumatic swing type actuator, etc., and together with the guide shaft 10, rotates the rotating frame 13 at an angle of 90'' in forward and reverse directions.

The rotating frame 13 has a substantially U-shaped side surface, and a reference contact 18 and a detector 19 sandwiching a plate W therebetween are vertically opposed to each other. The reference contactor 18 is made up of a roller supported by a support shaft 20, and is able to roll freely in the rotating direction of the rotating frame 13. The detector 19 is boss-shaped and is provided on a piston rod 22 of a detector pressing device 21 consisting of an air cylinder installed on the rotating frame 13. The piston rod 22 has a protruding rod portion 22a'i) that protrudes downward from the cylinder body of the detector pressing device 21, and a detection piece 23 is integrally fixed to the lower end thereof. A measuring device 24 for detecting the displacement of the detected piece 23 is installed on the detector pressing device 21 via a mounting plate 25. The measuring device 24 consists of a distance sensor that performs analog detection through contact, for example, an eddy current displacement sensor.

A rotation stopper rod 26 is provided upright on the detected piece 23.
The tip thereof engages with the engagement hole 27 of the mounting plate 25 so as to be able to move up and down.

The operation of the above configuration will be explained. In FIG. 3, the plate material loader 2 picks up the plate material W on the material cart 5 with a suction pad 7 and lifts it. At this time, the two-sheet detection device 1 places the rotating frame 13 on standby at a sideways angle that does not interfere with the lifting path of the plate material W, as shown by the chain line in FIG. 2, and lowers the detector 19 as shown in FIG. and the reference contact 18.

When the plate material W rises to the height of the two-piece detection device 1, lifting of the plate material W by the plate material loader 2 is stopped.

In this state, the rotating frame 13 is rotated toward the plate material W side as shown by the solid line in FIG. 2 by driving the rotating drive source 16,
A plate material W is inserted between the reference contact 18 and the detector 19. Next, the detector 19 is raised by the detector pressing device 21, and the plate material W is sandwiched between the reference contact 18 and the detector 19. In this state, the displacement of the detected piece 23 integrated with the detector 19 is measured by a measuring device. Measured by 24.

This measured value is the thickness sandwiched between the reference contactor 1 and the detector 19, and by comparing the preset plate thickness data and the measured value using an appropriate signal processing means,
It is determined whether the two sheets are in an overlapping state or not. If two sheets overlap, the board loader 2 is stopped and a warning is given to the operator. If there is no overlap, plate loader 2
Continue the plate material conveyance operation.

In this two-piece detection device 1, the reference contact 18 and the detector 19 are moved to the interlocking position by the turning operation in this manner, so that the conventional forward/backward space and forward/backward drive guide mechanism can be omitted. Therefore, the whole can be formed compactly. Further, since the displacement of the detector 19 is directly detected without going through a motion transmission mechanism such as a link mechanism, the accuracy of displacement measurement is improved, and therefore the accuracy of determining the two-sheet overlap state is improved. Furthermore, since a motion transmission mechanism such as a link mechanism is not used, the structure is simple and the weight is reduced accordingly.

In the embodiment described above, the detector pressing device 21 is constructed of an air cylinder, but a spring member may be used to maintain the pressing state at all times.

Furthermore, in the embodiment described above, the reference contactor 18 is made up of a roller and the detector 19 is made into a boss shape, but the detector 19 may be made up of a roller or the reference contactor 18 may be made into a boss shape.

〔Effect of the invention〕

In the two-sheet detection device of the present invention, the reference contact and the detector that sandwich the plate material are provided on the rotating frame, and are moved to the sandwiching position by the rotating movement of the frame, so that the conventional forward/backward space and the guiding mechanism for forward/backward drive are not required. It can be omitted and the entire structure can be made compact. Furthermore, since the displacement of the detector is directly detected without going through the motion transmission mechanism of the link mechanism, there is an effect that the measurement accuracy of the displacement is improved and the detection accuracy of the two-sheet overlap state is improved.

[Brief explanation of drawings]

Fig. 1 is a cutaway side view of one embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a front view of a plate material supply facility using the two-sheet detection device, and Fig. 4 is a conventional example. FIG. 1... Two sheet detection device, 2... Plate material loader, 7...
Suction pad, 9... Base frame, lO... Guide shaft, 13
...Swivel frame, 14...Linear bearing, 1
5...Support spring, 16...Swivel drive source, 18...
Reference contact, 19...Detector, 21...Detector pressing device, 22...Piston rod, 23...Detected piece, 24...Measuring instrument, W...Plate material

Claims (1)

[Claims] A rotating frame capable of rotating around an axis perpendicular to the plate material to be detected is provided, and a reference contact that sandwiches the plate material between each other and a detector that can move forward and backward in opposition to the reference contact are provided on the rotating frame, A two-piece detection device including a detector pressing device that presses the detector against the reference contact and a measuring device that directly measures the displacement of the detector.