JP2887725B2 - Automatic sheet material feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic sheet material feeding apparatus for automatically feeding a sheet material into a press die of a press machine in a press line of an automobile or the like.

[0002]

2. Description of the Related Art For example, in a press line for an automobile or the like,
Sheet materials blanked to a certain size are stacked neatly on a lifter, for example, around 300 sheets, and are sequentially suctioned one by one from above using a vacuum lifter or the like, and automatically supplied into a press die of a press machine. I have. But,
Due to its own weight and good flatness of the flat surface of the sheet material, the laminated surface is in a state close to vacuum, and if liquid such as rust preventive oil adheres to the surface, the degree of vacuum and adhesion will be stronger. Become. For this reason, it is difficult to peel off and it is easy to be adsorbed in a state where a plurality of sheets are stuck together when adsorbing with a vacuum lifter, and if the plurality of sheets are conveyed to a press machine in a state where they are stuck together, there is a possibility that the press die or the press machine may be damaged at the time of pressing. is there.

For this reason, conventionally, there has been provided a sensor for detecting whether or not there is one sheet material to be sucked and supplied into the press die. A device has been proposed. In such a conventional apparatus, a sheet material conveyed by a conveyance device is received by a lifter of a positioning stage before conveying the sheet material into a press die, and is leveled by the lifter of the positioning stage. And supplied into the press mold. Then, when the sheet material, which has been made horizontal by the lifter of the positioning stage, is sucked by the vacuum lifter, the strength of the magnetic field transmitted at that time is detected by a sensor that is vertically arranged so as to sandwich the sheet material on the carrier side. To detect whether there is only one sheet material.

As described above, by detecting the number of sheets in a state in which the sheet is held in a horizontal state by the lifter, erroneous detection due to drooping around the sheet or a state in which the sheet is displaced from the sensor position and cannot be detected. I try to prevent that.

[0005]

However, in the detection method for detecting the cross-sectional thickness of the sheet material as in the above-mentioned conventional apparatus, the erroneous detection due to the deformation due to the bending of the sheet material is prevented. A device such as a lifter of a positioning stage for holding the sheet material in a horizontal state so as not to be deformed is indispensable. For this reason, there has been a problem that the manufacturing cost of the sheet material automatic supply apparatus is expensive, the installation area of the apparatus is too large, and the apparatus cannot be installed in a narrow place.

Further, since the size of the sheet material in the thickness direction is small, an allowable error range for judging one sheet is extremely narrow, and high detection accuracy is required. For example, since two sheets of 0.8 mm thick sheet material are 1.6 mm, even if the upper limit of the permissible error is, for example, 1.5 times, it is 1.2 mm, and the difference is only 0.4 mm (= 1.2−0.8 ), Which requires a sensor having high measurement accuracy.

The present invention has been made in view of the above circumstances, and requires only a low-cost and small installation space which does not require a sheet material horizontal holding mechanism and the like, and is high even without using a sensor having a high measurement accuracy. It is an object of the present invention to provide a sheet material automatic feeding device capable of obtaining detection accuracy.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a lifter on which a sheet material is placed, and a sheet material stacked and placed on the lifter, adsorbed by a vacuum cup, peeled off, and supplied into a press die. A weight sensor is interposed between the vacuum cup and a support fitting supporting the vacuum cup, while a lower limit and an upper limit are determined and set.
Storage means for storing a plurality of quasi-tolerance values, and
Specifying means for specifying the type of sheet material to be supplied;
From the plurality of reference tolerance values stored in the storage means.
Select the standard tolerance value corresponding to the sheet material specified by the
The selection means to select and set the standard tolerance value manually
Configurable manual input means and detection by the weight sensor
The detected value of the output sheet material and the set standard tolerance value
Comparison means for comparison and detection based on the comparison result of the comparison means
If the sheet material is one when the value is within the range of the standard tolerance value
Determining means for determining the number of copies to be stored in the storage means.
Supports multiple types of sheet materials for each of the standard tolerance values
The configuration was adopted.

[0009]

[0010]

[0011] Further, the determination means may determine that the number of sheet materials is one.
It is preferable to provide a control unit for stopping the sheet material supply operation of the transport unit when it is determined that there is no sheet material supply operation. Also,
The transfer means has an arm rotatably supported on the front side of the press machine, and a vacuum lifter provided with the vacuum cup at the end of the arm. It is preferable that the sucked sheet material is supplied into the press die.

It is preferable that the sheet sensor is detected by the weight sensor during a period in which the sucked sheet material is horizontally conveyed.

[0013]

In this configuration, it is determined whether the number of sheet materials is one or not from the detection value based on the weight of the sheet material acting on the weight sensor via the vacuum cup. Therefore, at least one of the plurality of vacuum cups is provided. Since a weight sensor is interposed in the vacuum cup part and the determination can be made based on the detection value detected by one of the weight sensors, the weight and shape of the sheet material being conveyed, the conveyance posture, the conveyance trajectory of the conveyance means, etc., are restricted. In addition, a function of holding the sheet material separately from the conveying means is not required, the manufacturing cost of the apparatus is low, and the installation area of the apparatus is small, and it is possible to install the apparatus even in a narrow place.

Further, since the number of adsorbed sheet materials is determined based on the weight of the sheet material, the reference tolerance range (allowable error range) is wider than in the conventional determination based on the thickness of the sheet material in the cross-sectional direction. It is possible to set, and a weight sensor with high measurement accuracy is not required, and an inexpensive sensor can be used. Also, by storing a plurality of reference tolerance values corresponding to the type of sheet material in the storage means, specifying the type of sheet material to be supplied into the press die, and setting the corresponding reference tolerance value from the storage means, the sheet It can respond to changes in wood types.

Further, by detecting a plurality of types of sheet materials with one reference tolerance value, it is possible to determine many sheet materials with a small reference tolerance value. In addition, manually set reference tolerance values.
Specified manual input means is provided.
When the reference tolerance value corresponding to the sheet material is not stored
However, the number of sheet materials can be determined. Further, when the determination means determines that the number of the sheet materials absorbed is not one, the control means stops the sheet material supply operation of the conveyance means, thereby ensuring the safety of the worker and protecting the press machine. be able to.

[0016]

An embodiment of the present invention will be described below with reference to the drawings. A system configuration of an embodiment of an automatic sheet feeding apparatus according to the present invention will be described with reference to FIGS. In FIG. 1, a lifter 3 on which a large number of stacked sheet materials 2 are placed is arranged at a lower part on the front side of the press machine 1.
The lifter 3 has a support 6 that is supported on a support shaft 5 by crossing each other on a base 4. On the support 6, a roller conveyor 7 is provided on the upper surface, and the lifter 3 is transferred from a transfer device (not shown). A mounting table 8 on which the stacked sheet materials 2 are mounted is provided. Although not shown, an actuator such as an air cylinder or a hydraulic cylinder that raises the mounting table 8 is interposed between the base 4 and the mounting table 8. The lifter 3 intermittently raises the mounting table 8 by a predetermined distance by an actuator in synchronism with a suction operation of the sheet material 2 by a robot 9 as a conveying means described later, and moves the suction position of the sheet material 2 by the robot 9. Is always in a fixed position.

The robot 9 has a robot body 10 mounted on the front of the crown 1A at the top of the press machine 1 and an arm 12 attached to the robot body 10 via a support shaft 11 so as to be freely rotatable in the front-rear direction of the press machine. Have been. A vacuum lifter 14 for rotatably adsorbing the sheet material 2 via a support shaft 13 is provided at a distal end of the arm 12.
As shown in FIGS. 2 and 3, the vacuum lifter 14 has a total of six vacuum cups 16 each of which is, for example, three each mounted on two columns 15 parallel to each other. One of the six vacuum cups 16 is attached to a support post 15 via a support member 17, and is provided between the support member 17 and the vacuum cup 16 when the sheet material 2 is sucked. A load cell 18 is interposed as a weight sensor for detecting the weight acting on the cup 16. The load cell 18 outputs an analog voltage signal corresponding to the detected weight value. Reference numeral 19 denotes a vacuum hose connecting each of the vacuum cups 16 to a vacuum pump (not shown) serving as a vacuum generation source, and reference numeral 20 denotes electric wiring connected to the load cell 19.

Then, as shown in FIG.
The sheet material 2 on the lifter 3 is sucked one by one, and the arm 12 is rotated around the support shaft 11 to supply the sheet material between the opposing upper die 1B and lower die 1C of the press machine 1 (in the press die). It is supposed to. Then, the sheet material will be described configuration you detect whether one based on the detection output from the weight sensor of the sheet-material automatic feeding device of the present embodiment with reference to FIG.

[0019] In FIG. 4, Control Unit 30
Has a built-in microcomputer, for example, and is configured as follows. That is, an A / D conversion unit 31 that converts an analog signal into a digital signal, and a storage unit 32 that stores a plurality of preset reference tolerance values as described later.
The reference tolerance value selector 33 selects a reference tolerance value corresponding to the sheet material 2 to be absorbed based on the vehicle type information from the storage unit 32, and the detection value detected by the load cell 18 and the selection by the selector 33. A comparison unit 34 for comparing the reference tolerance value
When the detected value is within the reference tolerance range, an OK (one sheet 2) judgment output is generated based on the comparison output of No. 34, and when the detected value is out of the reference tolerance range, NG (two sheets of sheet 2) is output. The above configuration includes a determination unit 35 that generates a determination output, and a robot interface board 36 that outputs the determination output of the determination unit 35 to the robot 9.

The A / D converter 31 converts an analog voltage signal corresponding to the detected value from the load cell 18 into a digital signal and outputs the digital signal to the comparator 34. The reference tolerance value stored in the storage unit 32 is a value in which a lower limit value and an upper limit value are determined in advance with respect to the detection value of the sheet material 2 to be detected, and the range is set as the reference tolerance value. The lower limit is set to a value slightly lower than the actually measured value when the number of sheet materials 2 is one, or an appropriate value less than twice the lower limit is set to the upper limit. Then, a plurality of reference tolerance values corresponding to the type of the sheet material 2 to be pressed are stored. Further, a plurality of types of sheet materials are associated with each of the plurality of reference tolerance values. For example, 10 standard tolerance values are set, and each standard tolerance value is assigned a group number such as 1 group, 2 group,. Are classified into one group, those belonging to one group are classified into two groups, and those belonging to two groups are classified into two groups. These groups of reference tolerance values are input by an input operation of the manual input unit 37 by an operator.

The upper limit value can be set within a range of less than twice the lower limit value. However, the closer to twice the value, the more difficult it is to determine that two sheets have been adsorbed, and the higher the value, the greater the value. The closer the distance is, the higher the measurement accuracy is required and the higher the accuracy of the load cell 18 is. Therefore, the vicinity of 1.5 times is preferable. The selection unit 33 transmits the setup information (for example, information on the type of sheet material to be subsequently conveyed to the lifter) by the vehicle type, which is input to the machine control panel 39 by the external microcomputer 38 via the robot interface panel 36. A group of reference tolerance values corresponding to information used for determination is selected from a plurality of groups of reference tolerance values that are input and stored in the storage unit 32. Here, when it is determined that there is no reference tolerance value to be selected, that is, when it is determined that the reference tolerance value group corresponding to the sheet material 2 to be detected has not been input, the operator inputs the manual input unit 37 at that time. It can be directly input to the selection unit 33.

Further, in the robot 9, when the NG determination output is input from the robot interface board 36 to the robot body 10, the suction and transport operations of the sheet material 2 are immediately stopped. Here, the control unit 30 has functions of a comparison unit, a determination unit, and a selection unit, and the storage unit 32 stores
Manual input unit 37
It has a function of an input means , and the robot body 10 has a function of a control means. The external microcomputer 38 and the machine control panel 39 constitute a designating means.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. First, before the operation is started, the sheet material 2 stacked on the lifter 3 is placed by the transport device in a state where the robot 9 is at the original position (Step 1 (indicated by S1 in the figure, the same applies hereinafter)). And robot 9
The supply operation of the sheet material 2 into the press die is started (step 2).

The vacuum lifter 14 of the robot 9 descends via the arm 12 as shown by the arrow in FIG. 6, and presses the vacuum cup 6 on the upper surface of the sheet material 2. In this state, a vacuum hose is inserted into the vacuum cup 6. The suction operation of the sheet material 2 is performed by introducing a negative pressure through 19 (step 3). After confirming the suction of the sheet material 2, the vacuum lifter 14 is raised via the arm 12 while holding the vacuum lifter 14 horizontally as indicated by an arrow in FIG. 6, and further moved horizontally in the press die to supply the sheet material. I do. During this horizontal transfer, the output voltage signal of the load cell 18 is read to perform weight measurement (step 4). Here, load cell 18
The measurement of the weight of the sheet material 2 is performed in the latter half of the horizontal transfer shown in FIG. Thereby, the reliability of the detected value of the load cell 18 can be improved.

Next, the vehicle type information input to the machine control panel 39 in advance is selected via the robot interface panel 36 by the selection unit.
33, the type of the sheet material 2 currently supplied is determined based on the input vehicle type information and the like (the sheet material to be used is predetermined according to the vehicle type, and the sheet supplied to the press machine 1 is determined based on the vehicle type information). The material 2 can be determined), and the group number of the reference tolerance value corresponding to the determined sheet material 2 is designated, and the reference tolerance value is selected from the storage unit 32 (step 5). If the storage unit 32 does not store the corresponding group of reference tolerance values, the worker is notified by, for example, a display to that effect, and based on this, the worker responds to the sheet material 2 to be supplied. By operating the manual input unit 37, the reference tolerance value to be input is directly input to the selection unit 33.

Next, the value detected by the load cell 18 and the selection unit
A comparison is made with the reference tolerance value selected in 33 (step 6). If the detected value is within the range of the reference tolerance value, it is determined that one sheet material 2 is sucked, and the robot 9 sets the sucked sheet material 2 in the press die (step 7). Next, based on information such as the number of sheets placed on the lifter 3, it is determined whether or not the supply of the sheet 2 should be continued (step 8), and it is determined that the supply of the sheet 2 should be continued. In this case, the process returns to step 2 and the above operation is repeated. If it is determined that the supply operation of the sheet material 2 is completed, the process returns to step 1 to return the robot 9 to the original position. If it is determined in step 6 that the detected value is outside the reference tolerance range, it is determined that the number of the sheet materials 2 absorbed is two or more, and the robot body 10 is determined by NG determination from the robot interface board 36. , The operation of the arm 12 is immediately stopped, the setting of the sheet material 2 in the press die by the robot 9 is stopped, and the routine ends (step 9).

Here, the reference tolerance value selected in step 5 will be further described with reference to FIG. 7. For example, it is assumed that the upper limit value of the group of reference tolerance values is set as shown in FIG. In this case, the group number of the reference tolerance value is selected based on the detection value of one sheet measured in advance. For example, when a sheet material having a previously measured detection value of one sheet of 3.0 is conveyed, a reference tolerance value of group number 8 having a range greater than 2.7 and less than 3.9 (upper limit) is selected and measured in advance. The detection value for one sheet is
When the sheet material of 2.5 is conveyed, the reference tolerance value of the group number 7 having a range greater than 1.9 and less than 2.7 (upper limit) is selected. In this manner, a plurality of reference tolerance values for determining the number of sheet materials 2 to be attracted according to the type (detection value) of the sheet material 2 to be pressed are stored and managed by the group number.

A plurality of sheet members correspond to each group number. For example, with respect to the reference tolerance value of the group number 8, when there is a sheet material having a detection value of 2.9 or 3.5 in addition to a sheet material having a detection value of 3.0,
The reference tolerance value of the group number 8 is selected. In this way, for example, determination of 30 types of sheet materials can be managed by using ten reference tolerance values. In other words, there is no need to provide a reference tolerance value for each sheet material, and the determination of the number of suctioned sheets of various types of sheet materials can be managed with a small reference tolerance value, and the function of selecting the reference tolerance value can be simplified. . In the case where a plurality of sheet materials are associated with each group of reference tolerance values and managed as described above, if the detection value of one sheet is too close to the upper limit of the group number, Since the allowable error up to the upper limit value is reduced and high measurement accuracy is required for the load cell 18, it is desirable to avoid this, and it is preferable to assign a value having a detection value close to the lower limit value of the reference tolerance value of each group number. That is, regarding the group number 8, for example, if the detection value is
In the case of a sheet material of 3.0, an upper limit of 1.3 times is allowed as the upper limit of the allowable error, but in the case of a sheet material of 3.7, the allowable error up to the upper limit is only allowed to a value of about 1.05 times. It is necessary to use a high-precision 18 as.

As described above, in this embodiment, it is determined whether or not the number of attracted sheets 2 is one based on the weight of the sheet 2. Compared to the case where the thickness is determined, the difference between the detection values when the number of the suction sheet materials is one and when the number of the suction sheet materials is two is large, so that the allowable error range can be set wider, and the detection error can be reduced. Thus, the reliability of detection is improved. Also, it is not necessary to use a high-precision sensor as a sensor for detecting the number of sheets,
Equipment costs can also be reduced.

Further, since the allowable error range can be set wide, it is possible to determine a plurality of types of sheet materials with one reference tolerance value. When applied to materials, it is not necessary to set a reference tolerance value for each sheet material, and it is only necessary to store and set a reference tolerance value smaller than the type of sheet material, and the storage capacity of the storage device for storing the reference tolerance value may be small. .

Since the detection is performed based on the weight of the sheet material, the shape and the conveying posture of the sheet material at the time of the detection are not restricted. Therefore, a mechanism for holding the sheet material horizontally at the time of the detection separately from the conveying device. Is unnecessary, the manufacturing cost of the automatic sheet material feeding device can be reduced, and the sheet material can be installed in a small space with a small installation area. Further, by providing the robot 9 on the front surface of the press machine to convey the sheet material into the press mold, the installation area can be further reduced.

Also, by detecting the weight of the sheet material 2 in the latter half of the horizontal transport of the sheet material 2 by the robot 9, the weight can be detected at a time when the shaking accompanying the transfer of the sheet material 2 is small. Reliability can be improved. In the present embodiment, the configuration in which the reference tolerance value is divided into groups of 10 has been described. However, the number of groups is not limited to this, and the number of types of sheet materials to be handled (the detection values unique to the sheet materials are also limited). Take into account)
The number of groups may be appropriately set to be less than 10 or more than 10. Although one weight sensor is provided, it may be provided for each vacuum cup or a plurality of vacuum cups selected as appropriate.

[0033]

As described above, according to the present invention, whether or not one sheet material is adsorbed is detected based on the weight of the sheet material. As compared with the case where the thickness is determined, the allowable error range for detecting the number of suction sheet materials can be set wider, and erroneous detection can be eliminated, and the reliability of detection can be improved. Also, by detecting based on the sheet material weight,
Since there is no restriction on the shape of the sheet material and the conveyance posture at the time of detection, a mechanism for holding the sheet material horizontally at the time of detection separately from the conveyance device is unnecessary, and the manufacturing cost of the automatic sheet material feeding device can be reduced. At the same time, it can be downsized and can be installed even in a place where the installation area is small and narrow. Furthermore, it is not necessary to use a high-precision weight sensor, and the sensor cost can be reduced.

Further, since the allowable error range can be set broadly, it is possible to determine a plurality of types of sheet materials with one reference tolerance value, and it is possible to use the same for many types of sheet materials. , From the type of sheet material
Therefore, a storage device with a small storage capacity can be used, and the cost of the storage device is also advantageous. I
The reference tolerance value corresponding to the specified sheet material is stored.
Even if it is not set, you can set
Therefore, the number of sheet materials can be determined.

Further, by providing a robot in front of the press machine to transport the sheet material into the press mold,
The installation area can be further reduced. Also, if the weight of the sheet material is detected in the latter half of the horizontal transport of the sheet material by the robot, the weight detection will be performed at a time when the shaking accompanying the transfer of the sheet material is small, so the detection reliability will be further improved. Can be enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an automatic sheet material feeding apparatus according to the present invention.

FIG. 2 is a perspective view of the vacuum lifter of the embodiment.

FIG. 3 is a perspective view showing a state in which a weight sensor is attached to the vacuum lifter shown in FIG. 2;

FIG. 4 is a block diagram showing a configuration of a control unit of the embodiment.

FIG. 5 is a flowchart illustrating a sheet material supply operation of the embodiment.

FIG. 6 is a diagram showing a sheet material conveyance locus by the robot according to the embodiment.

FIG. 7 is a diagram showing reference tolerance values and setting examples according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Press machine 2 Sheet material 3 Lifter 9 Robot 14 Vacuum lifter 16 Vacuum cup 17 Support bracket 18 Load sensor 30 Control unit 32 Storage unit 33 Selection unit 34 Comparison unit 35 Judgment unit 36 Robot interface board 37 Manual input unit 38 Microcomputer 39 Machine control panel

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B21D 43/24

Claims (4)

(57) [Claims] An automatic sheet material comprising a lifter on which a sheet material is placed, and conveying means for sucking and peeling the sheet material stacked and placed on the lifter and supplying the sheet material into a press die. In the supply device, a weight sensor is interposed between the vacuum cup and a support fitting supporting the vacuum cup, and a lower limit value and an upper limit value are defined.
Storage means for storing a plurality of reference tolerance values set in advance,
Finger for designating the type of sheet material to be supplied into the press die
And a plurality of reference tolerance values stored in the storage means.
Of the sheet materials specified by the specifying means
Selection means for selecting and setting a reference tolerance value to be set;
Manual input means that can be set manually
It is set as the detected value of the sheet material detected by the weight sensor.
Comparing means for comparing the calculated reference tolerance value, and a ratio of the comparing means.
Sheet when the detected value is within the range of the standard tolerance value
Determining means for determining that the number of materials is one;
Multiple types for each of the multiple reference tolerance values stored in the means
An automatic sheet material feeding apparatus characterized in that the sheet materials are made to correspond to each other . 2. The method according to claim 1, wherein the determining unit determines that the number of sheet materials is not one.
When the determination is made, the sheet supply operation of the conveying means is stopped.
2. An automatic sheet material feeding apparatus according to claim 1 , further comprising control means for causing the sheet material to be fed. 3. The conveying means is rotated to the front side of the press machine.
It has an arm that is freely rotatably supported, and
Supports a vacuum lifter with a vacuum cup
And the sheet adsorbed by the turning operation of the arm
3. The sheet material automatic feeding device according to claim 1 , wherein the sheet material is supplied into a press die . 4. The timing of detecting a sheet material by a weight sensor,
The sheet material automatic feeding apparatus according to any one of claims 1 to 3, wherein a period in which the sucked sheet material is horizontally conveyed is set .