JP6014567B2 - Arrangement method of pad cylinder in trimming apparatus - Google Patents

Description

  The present invention relates to a method for determining an arrangement position for a plurality of pad cylinders used in a trimming apparatus.

  In the trimming device, a work placed on a die is pressed by a pad urged by a plurality of pad cylinders, and an unnecessary part of the work is cut off with a cutter.

When the workpiece is large, a plurality of cylinders are used for pressing, and a plurality of ejector pins are used for discharging. That is, the cylinders and ejector pins are dispersedly arranged so as not to apply a local force to the workpiece.
Several methods have been proposed for the arrangement of ejector pins (see, for example, Patent Document 1 (FIG. 2)).

  In FIG. 2 of Patent Document 1, the pressure applied to each ejector pin is calculated in S5, and it is confirmed in S6 that the maximum pressure is equal to or lower than the yield stress of the workpiece. By this confirmation, an appropriate arrangement position and shape of the ejector pins can be set.

When the technique of Patent Document 1 is applied to a pad cylinder arrangement method in a trimming apparatus, the following problem occurs.
Since the maximum pressure is used as a reference, it can be confirmed that all of the plurality of pad cylinders exceed the required pressure, and as a result, the workpiece can be pressed against the die without any shortage.
On the other hand, a pad cylinder placed at a certain part presses the workpiece with an unnecessarily large force, and the number and performance of the pad cylinder becomes so-called over-spec (excess performance), and the equipment cost of the trimming device increases. .

  While cost reduction of the trimming device is required, an arrangement method that can efficiently and efficiently arrange the pad cylinder is required.

JP 2001-71064 A

  An object of the present invention is to provide a method for arranging a pad cylinder in a trimming apparatus that can arrange the pad cylinder efficiently and without waste.

The invention according to claim 1 is directed to a trimming device for pressing a work placed on a die by a pad urged by a plurality of pad cylinders and cutting an unnecessary part of the work with a cutter. A pad cylinder arrangement method for determining
A data input means for inputting data related to the workpiece, a data storage section for storing the data, a calculation section for calculating using data stored in the data storage section, and an output means for outputting a calculation result are prepared. And
Storing the rated load per pad cylinder in the data storage unit by the data input means;
A step of calculating a total cutting length of the workpiece in the calculation unit based on data obtained from the data storage unit;
Based on the total cutting length and the data obtained from the data storage unit, in the calculation unit, a spring back pressing force for pressing the spring back that is expected to be generated, and a cut pressing force for pressing the workpiece against the die for cutting Calculating the total force of
Calculating the required number of the pad cylinders from the total force obtained and the cylinder rated load in the arithmetic unit;
Dividing the workpiece into virtual calculated dividing lines into the calculated number while making the cutting line length uniform;
For each of the divided pieces, a step of calculating the individual total force of the spring back pressing force and the cut pressing force in the calculation unit based on the cutting length of the divided piece;
In the calculation unit, comparing the individual total force and the rated load of the cylinder, and correcting the position of the dividing line so that the individual total force substantially matches the rated load of the cylinder;
For each piece excluding the first piece and the last remaining piece, calculating the individual total force and correcting the position of the dividing line;
Calculating the individual total force for the last remaining piece, and confirming that the individual total force does not exceed the cylinder rated load;
After being confirmed, the calculation unit calculates the center of gravity of the projection plane for each individual segment;
And outputting the information that the pad cylinder is arranged at the calculated center of gravity by the output means.

In the invention according to claim 1, the work is virtually divided so that the cutting line length is uniform, the individual total force is calculated for each divided piece, and the calculated individual total force is the rating of the pad cylinder. The dividing line is drawn again so that the load matches, and the pad cylinder is arranged at the center of gravity of the projection surface of the determined divided piece.
Conventionally, the arrangement of the pad cylinder, which has been determined based on feeling and experience, is reasonably determined. In the conventional method determined by calculation, the pad cylinder tends to be excessive. However, according to the present invention, the pad cylinder is efficiently and wasted. Can be arranged without.

It is principal part sectional drawing and action figure of a trimming apparatus. It is an illustration of the force _{F 1.} It is an illustration of a force _{F 4.} It is explanatory drawing of cut pressing force. It is a control block diagram concerning the present invention. It is a flowchart from the process of preserve | saving data to the process of calculating the required number of pad cylinders. It is a top view of a workpiece | work. It is a graph which determines bending from length. It is a flowchart from the process which divides | segments a workpiece | work virtually to the process which confirms that the individual total force does not exceed a cylinder rated load about the division piece which remained at the end. It is a figure of the workpiece | work to which the dividing line was given. It is a flowchart from a gravity center calculation process to a pad cylinder arrangement process. It is an arrangement view of the center of gravity and the pad cylinder.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

With reference to FIG. 1, the structure and operation of the main part of the trimming apparatus 10 will be described.
As shown in FIG. 1A, the trimming apparatus 10 includes a die 11, a pad 12, and a cutter 13. A work 14 that has been subjected to drawing or bending by a press machine is placed on the die 11. When the work 14 is high-tensile steel, it floats up from the die 11 by a springback action.

As shown in FIG. 1B, the work 14 is moved along the die 11 by being pushed down by the pad 12.
As shown in FIG. 1C, the unnecessary portion 15 is cut off by the cutter 13.
Incidentally, in order to deform the workpiece 14 shown in FIG. 1A as shown in FIG. 1B, the following force (total force) is required.

First, the springback pressing force will be described.
As shown in FIG. 2, the falling portion 17 of the workpiece 14 is fixed at the base A _1, the distal end is considered to be free cantilever. If the length of the falling portion 17 is L ₁ , the external force applied perpendicularly to the tip is F ₂ , the tip deflection is υ ₁ , the Young's modulus is E, and the sectional moment of inertia is I, then the cantilever formula is υ ₁ = (F ₂ · L ₁ ³ ) / (3EI).

Incidentally, when the thickness of the falling portion 17 t, the width of the drawing the front and back direction B, moment of inertia of area I is given by ^{I = B · t 3/12} .

Force F2 is a force component of the force _{F 1} acting perpendicularly, if the angle of the force _{F 1} and force _{F 2} theta, the force _{F 1 is} given by F ₂ = F 1 · sinθ. The above formulas are listed.

By substituting equation (3) into equation (1), F ₂ can be eliminated. Then, By combining the _{F 1,} it can be obtained (4).

A flange 18 overhangs the tip of the falling portion 17.
As shown in FIG. 3, flange 18 is fixed at the base A _2, the tip is considered to be free cantilever. Assuming that the length of the flange 18 is L ₂ , the external force applied perpendicularly to the tip is F ₄ , and the deflection of the tip is υ ₂ , the following equation (6) is determined from the cantilever formula.

To hold the spring-back, it is necessary to both F ₄ shown in F ₁ and (6) shown in equation (4). The total force is referred to as springback pressing force P _1. The spring back pressing force _{P 1} is given by equation (7). Formula (8) is an arrangement of formula (7).

Next, the cut pressing force will be described.
For example, in a manual paper cutting machine, paper is placed on a base plate and cut with a cutter while holding the paper. If the pressing force is weak, the cut surface becomes dirty. Therefore, in the cutting step, a cutter pressing force P ₂ having a moderate magnitude is required in addition to the spring back pressing force P ₁ described above.

As shown in FIG. 4, the thickness of the flange 18 is t and the width is B. The force required for cutting increases as the cross-sectional area (B · t) increases. Moreover, it becomes large, so that the tensile stress (sigma) is large. Therefore, the cutter pressing force P ₂ is given by the following equation (9). Note that k is a coefficient and is empirically 0.05 to 0.15.

Next, a calculation unit and incidental means used for the arrangement method of the pad cylinder in the trimming apparatus will be described.
As shown in FIG. 5, a data input means 21 for inputting data relating to a workpiece, a data storage unit 22 for storing data, a calculation unit 23 for calculating using data stored in the data storage unit 22, An output means 24 for outputting the calculation result is prepared.

The data input means is preferably a keyboard, mouse or equivalent attached to a personal computer (hereinafter referred to as a personal computer).
The data storage unit 22 is preferably a memory built in a personal computer or an equivalent product.
As the calculation unit 23, a central calculation unit (CPU) of a personal computer or an equivalent product is recommended.
As the output means, a display attached to a personal computer, a printer, or an equivalent product is recommended.

Next, a method for arranging the pad cylinder, which is performed using the above-described arithmetic unit 23 and the like, will be described.
As shown in ST01 of FIG. 6 (step 01, the same applies hereinafter), the rated load Pc of the pad cylinder is stored in the data storage unit by the data input means. The rated load is a value guaranteed by the cylinder supplier, and is a rounded value such as 50 tons, 75 tons, and 100 tons, and a margin generally called a safety factor is expected.

  Next, the workpiece shape data, the plate thickness t, the Young's modulus E, the tensile stress σ, and the coefficient k are stored in the data storage unit by the data input means (ST02). Information can be provided directly from the host computer or line computer to the data storage unit.

  The workpiece 14 is, for example, a press product having a shape shown in FIG. The calculation unit calculates the total length of the cutting line that approximates the circumferential length of the workpiece (FIG. 6, ST03). In ST04, the total length is given to B.

FIG. 8 shows the correlation between the length of the cantilever and the deflection. The deflection is proportional to the cube of the length.
A correlation is prepared between the length and the deflection when the Young's modulus is E and the plate thickness is t.
The calculation unit estimates the deflection υ ₁ corresponding to the length L ₁ of the falling portion from FIG. 8, and estimates υ ₂ corresponding to the length L _{2 of the} flange from FIG. 8 (FIG. 6, ST05).
FIG. 8 is merely an example, and it is possible to prepare the function in the calculation unit and estimate the deflections υ ₁ and υ ₂ using the function.

To hold the workpiece, it is necessary to sum force of the spring-back pressing force P ₁ and the cutter pressing force P _2. This total force (P ₁ + P ₂ ) is borne by a plurality of pad cylinders.
Therefore, the number m of pad cylinders is determined in ST07 of FIG. By rounding up the fraction, m is a natural number.

FIG. 9A is connected to FIG.
In ST08 of FIG. 9, m is given to n. In the next ST09, the workpiece is divided into n pieces so that the cutting line length is uniform. This division is a virtual division, that is, a division on the drawing, and as shown in FIG. 10, seven division pieces 31 to 37 are obtained by dividing the division lines d1 to d6.

  In order to generalize, the seventh is nth and the sixth is (n−1) th. For convenience, the n-th divided piece is referred to as the first divided piece, and the first divided piece is referred to as the last remaining divided piece.

  The cutting line length of the (n-1) th divided piece 36 is 36a + 36b, and the cutting line length of the nth divided piece 37 is 37a. Since it is divided uniformly, the length 37a is equal to the length (36a + 36b).

The calculation unit calculates an individual total force (P ₁ + P ₂ ) n for the nth divided piece.
That is, the nth divided piece has a unique falling length and flange length. Based on these unique lengths, the individual total force (P ₁ + P ₂ ) n is calculated by performing the same processing as ST04, ST05 and ST06 in FIG. 6 (FIG. 9, ST10).

It is confirmed whether or not the obtained individual total force (P ₁ + P ₂ ) n is the same as the rated load Pc of the pad cylinder (ST11). Note that “identical” does not mean perfect equality, and if (P ₁ + P ₂ ) n falls within the range of 0.98 to 1.03 times Pc, for example, it is determined that they are the same. May be.

If (P ₁ + P ₂ ) <Pc, (P ₁ + P ₂ ) can be increased, so the dividing line d6 shown in FIG. 10 is moved slightly to the d5 side and recalculated (ST12).
If (P ₁ + P ₂ )> Pc, it is necessary to reduce (P ₁ + P ₂ ), so the dividing line d6 shown in FIG. 10 is moved away from d5 and recalculated (ST13). ).

If ST11 becomes YES, the position of the dividing line d6 is determined (ST14).
Next, by giving (n-1) to n in ST16, the dividing line d5 is determined by performing ST10 to ST14 for the divided piece of the n-1th, in the embodiment, the 6th surface.
In ST15, the positions of all the dividing lines are determined by repeatedly calculating up to the second divided piece.

Based on the determination of the dividing line d1, the individual total force (P ₁ + P ₂ ) ₁ is calculated for the last remaining divided piece (ST17).
It is confirmed that the obtained (P ₁ + P ₂ ) ₁ is not more than the rated load Pc of the pad cylinder (ST18).

If (P ₁ + P ₂ ) ₁ is not less than the rated load Pc of the pad cylinder, m−1 is given to m (ST19). That is, the number of pad cylinders is increased by one. And ST08-ST18 are implemented.

FIG. 11B is connected to FIG. 9B.
When all the dividing lines are determined as described above, the center of gravity of the projection plane is calculated for each divided piece in ST20 of FIG. The center of gravity of the projection surface corresponds to the centroid.
Then, a pad cylinder is arranged at the center of gravity (ST21).

As shown in FIG. 12, the centers of gravity G <b> 1 to G <b> 7 are determined for each of the divided pieces 31 to 37.
The seven pad cylinders 39 are arranged so as to correspond to the gravity centers G1 to G7, respectively.

  In the embodiment, the first divided piece is the nth (seventh) divided piece, and the last remaining piece is the first divided piece. However, the first divided piece may be the first divided piece and the last remaining divided piece may be the nth (seventh) divided piece.

  The present invention is suitable for the layout design of the pad cylinder in the trimming apparatus.

  DESCRIPTION OF SYMBOLS 10 ... Trimming apparatus, 11 ... Die, 12 ... Pad, 13 ... Cutter, 14 ... Workpiece, 15 ... Unnecessary part, 21 ... Data input means, 22 ... Data storage part, 23 ... Calculation part, 24 ... Output means, 31- 37: Divided pieces, 39: Pad cylinders, d1 to d6: Virtual dividing lines, G1 to G7: Center of gravity.

Claims (1)

A pad cylinder arrangement method for determining the arrangement of the pad cylinder for a trimming device that holds a work placed on a die by a pad urged by a plurality of pad cylinders and cuts out an unnecessary portion of the work with a cutter. There,
A data input means for inputting data related to the workpiece, a data storage section for storing the data, a calculation section for calculating using data stored in the data storage section, and an output means for outputting a calculation result are prepared. And
Storing the rated load per pad cylinder in the data storage unit by the data input means;
A step of calculating a total cutting length of the workpiece in the calculation unit based on data obtained from the data storage unit;
Based on the total cutting length and the data obtained from the data storage unit, in the calculation unit, a spring back pressing force for pressing the spring back that is expected to be generated, and a cut pressing force for pressing the workpiece against the die for cutting Calculating the total force of
Calculating the required number of the pad cylinders from the total force obtained and the cylinder rated load in the arithmetic unit;
Dividing the workpiece into virtual calculated dividing lines into the calculated number while making the cutting line length uniform;
For each of the divided pieces, a step of calculating the individual total force of the spring back pressing force and the cut pressing force in the calculation unit based on the cutting length of the divided piece;
In the calculation unit, comparing the individual total force and the rated load of the cylinder, and correcting the position of the dividing line so that the individual total force substantially matches the rated load of the cylinder;
For each piece excluding the first piece and the last remaining piece, calculating the individual total force and correcting the position of the dividing line;
Calculating the individual total force for the last remaining piece, and confirming that the individual total force does not exceed the cylinder rated load;
After being confirmed, the calculation unit calculates the center of gravity of the projection plane for each individual segment;
A method for arranging a pad cylinder in a trimming apparatus, comprising: a step of outputting, by the output means, information indicating that the pad cylinder is arranged at the calculated center of gravity.

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