JPH0236336B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a release control device in a feeding device for press working materials.

(Prior Art) In general, press working is rarely completed in one process, and a finished product is obtained through multiple processes. A progressive press type press machine is capable of performing multiple press processes at the same time, and processes material that is intermittently fed by a feeding device in the order of the processes.

By the way, since an error occurs in the feed amount during the above-mentioned intermittent feeding, high-precision press working cannot be performed as it is, and it is necessary to correct the position of the material. That is, pilot holes are formed in the press material at predetermined intervals (corresponding to the ideal feed amount) using a punch supported by the upper die. and,
The position of the material is corrected by inserting a pilot pin supported by the upper die at a predetermined distance from the punch into the pilot hole.

The position correction using the pilot pin is performed immediately before pressing by lowering the upper die, but before this position correction is performed, the holding of the material in the feeding device must be released. Furthermore, the material must be held again until the pilot pin is removed from the pilot hole after the press work is completed.

Conventionally, the holding release and holding of the material in the feeding device as described above has been controlled in the following manner. That is, a cam switch is provided that is linked to the crankshaft of the press, and is turned on and off as the crankshaft rotates. The feed device releases and re-holds the material based on ON and OFF signals from the cam switch, but in this case, there is an operational delay from when the feed device receives the signal until it actually releases or re-holds the material. Time exists. Therefore, the operating point of the cam switch must be determined in consideration of this activation delay time. Therefore, conventionally, the operating point of the cam switch has been determined by repeatedly operating the press machine and repeating trial and error without accurately measuring the activation delay time.

(Problems to be Solved by the Invention) In the above-described release control means, the operating point of the cam switch is determined by trial and error, which is very time consuming. Furthermore, when the number of presses per minute of the press machine is changed, in other words when the rotational speed of the crankshaft is changed, the operating point of the cam switch must be determined again by trial and error.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides the first
As shown in the figure, it is characterized by having the following constituent elements.

(a) Shaft rotation angle detection means 101 for detecting the rotation angle Θ of the drive shaft of the press machine.

This means 101 is usually based on top dead center (0°)
The rotation angle Θ is detected.

(b) Ideal holding release angle Θ ₁ and reholding angle Θ ₂
(that is, the rotation angle of the drive shaft at the time of release of holding and the rotation angle of the drive shaft at the time of re-holding when the delay time is not considered).

(c) Operation delay time _t1 of the feed device 103 from when the holding release command signal _S1 is issued until the holding is actually released, and from when the reholding command signal _S2 is issued to when the holding is actually performed again. Delay time input means 104 for inputting the operation delay time t ₂ of the feeding device 103 up to.

(d) Shaft rotational speed input means 105 for inputting the rotational speed ω of the drive shaft of the press machine.

(E) Depending on the rotational speed of the drive shaft input by this shaft rotational speed input means 105,
First calculation means 10 for calculating delay angles Θ _t1 and Θ _t2 corresponding to the above two types of delay times t ₁ and t ₂ , respectively.
6. The angle corresponding to the delay time varies depending on the rotational speed of the drive shaft. Therefore, this means 106 calculates the delay angles Θ _t1 and Θ _t2 corresponding to the delay times t ₁ and t ₂ according to the input value ω of the rotational speed of the drive shaft.

(f) Holding release angle Θ ₁ and reholding angle Θ ₂ input by the above-mentioned releasing angle setting means 102
A second calculation means 107 that subtracts the respective delay angles Θ _t1 and Θ _t2 outputted by the first calculation means 106 from , respectively, to obtain a holding release command angle Θ ₁ ' and a rehold command angle Θ ₂ '.

(g) When the angle Θ detected by the shaft rotation angle detection means 101 matches the hold release command angle Θ ₁ ' outputted by the second calculation means 107, a hold release command signal is outputted to the feeding device 103. , and when the detected angle Θ matches the re-holding command angle Θ ₂ ', the re-holding command signal S ₂ is sent to the feeder 1.
Release command signal output means 108 outputs toward 03.

(Function) The function of the apparatus having the above configuration will be explained with reference to FIG. 2. To operate this device, first, the ideal holding release angle Θ ₁ and ideal reholding angle Θ ₂ are determined by actual measurement, and these values are set by the releasing angle setting means 102. Additionally, there is a delay time t ₁ from when the hold release command signal S ₁ is issued until the hold is actually released, and a delay time t ₂ from when the re-hold command signal S ₂ is issued until the re-hold is actually performed.
and are obtained by actual measurement, and these values are inputted by the delay time input means 104. Since these holding release angle Θ ₁ , reholding angle Θ ₂ , and delay times t ₁ and t ₂ can be managed constant, they only need to be set once.

Furthermore, the rotational speed ω of the drive shaft in the current press operation is inputted by the shaft rotational speed input means 105.

Then, the first calculating means 106 calculates the delay angles Θ _{t1 and} Θ _t2 corresponding to the delay times t ₁ and t ₂ according to the shaft rotational speed ω. Next, the second calculation means 107 should subtract the delay angle Θ _t1 calculated by the first calculation means 106 from the hold release angle Θ ₁ inputted by the release angle setting means 102, and issue a hold release command. Calculate the angle (hold release command angle) Θ ₁ '. Further, the re-holding angle Θ ₂ set by the releasing angle setting means 102
The delay angle Θ _t2 calculated by the first calculation means 106 is subtracted from , to calculate the angle at which the re-hold command should be issued (re-hold command angle) Θ ₂ '.

In this state, when the rotation angle Θ of the drive shaft of the press matches Θ', the release signal output means 108 sends a signal to the feeder 103.
At this time, the holding release command signal S ₁ is outputted to start the releasing operation, and when a delay time t ₁ has elapsed from that point, the holding release is actually performed. The rotation angle of the drive shaft at this time is _Θ1 .

Further, when the rotation angle Θ of the drive shaft of the press matches Θ ₂ ', the release signal output means 1
A reholding command signal S ₂ is outputted to the sending device 103 from 08, and after a delay time t ₂ has elapsed from this point, reholding is actually performed. The rotation angle of the drive shaft at this time is _Θ2 .

Further, even when the rotational speed of the drive shaft, that is, the number of presses per unit time is changed, the release control is performed in anticipation of the delay time of the feeding device, similarly to the above.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 3 to FIG. 8.

In FIG. 7, 100 is a coil material (material for press working), and this coil material 100 is wound around a reel stand (not shown), and a leveler 1
It is pulled out and the curls are straightened,
A feeding device 2 located apart from this leveler 1
is sent to the press machine 3 by the feeding device 2.
It is now being sent to The coil material 100 is slack between the leveler 1 and the feeding device 2.

The press machine 3 is of a progressive press type, and is designed to perform multiple press processes simultaneously with one press machine. The press machine 3 has a lower mold 4 and an upper mold 5 that moves up and down with respect to the lower mold 4. The upper mold 5 has a punch (not shown) used in each pressing process, and the lower mold 4 has a die 6 (FIG. 8).

The press machine 3 has a position correction mechanism 7, as shown in FIG. The position correction mechanism 7
It has a punch 8 and a guide pin 9 supported by. The lower end of the punch 8 is at the same height as the lower end of other press punches, and the pilot pin 9 is
It protrudes downward from the lower end of the punch 8. The lower end 9a of the pilot pin 9 has a spherical shape, and the shank portion 9b has a cylindrical shape having the same diameter as the punch 8. Further, a stripper 10 is supported on the upper die 5 so as to be movable up and down. The die 6 and the stripper 10 are formed with holes 6a, 6b and holes 10a, 10b through which the punch 8 and pilot pin 9 pass.

As shown in FIG. 3, the feeding device 2 has two rollers 11 and 12 arranged one above the other.
The lower roller 11 is fixed to a shaft 13, and this shaft 13 is connected to a motor (not shown) to rotate it at a fixed position. The upper roller 12 is moved up and down by an air cylinder 21.

The cylinder section 22 of the air cylinder 21 is arranged above the upper roller 21, and the piston section 23 that slides inside the cylinder section 22 has a rod 2 that protrudes downward from the cylinder section 22.
4 are connected. A slider 25 is connected to the lower end of the rod 24.
is guided by a guide 26 to move up and down. The upper roller 12 is rotatably supported on the slider 25 by the shaft 14 . The air cylinder 21 is controlled by a solenoid valve 27.
It is adapted to be operated by compressed air pressure from a compressed air source 28.

The electromagnetic valve 27 is controlled by a releasing control device 30, which is a feature of the present invention. The releasing control device 30 includes, among the components shown in FIG. 1, a first calculation means 106, a second calculation means,
It has a microcomputer 31 that constitutes a releasing command signal output means 108. The microcomputer 31 sends a holding release command signal and a holding command signal to the output circuit 32, and the output circuit 32 energizes or de-energizes the solenoid 27a of the solenoid valve 27 based on these signals. The microcomputer 31 includes a setting device 33 for inputting angle information, etc. (this corresponds to the releasing angle setting means 102 and delay time setting means 104 in FIG. 1), and a display 34 for displaying the angle information, etc.
is connected. The setting device 33 consists of numerical keys or a digital switch.

On the other hand, a rotary encoder 35 (angle detector) is attached to the side surface of the frame of the press 3 by a bracket 35b, and its shaft 35a
and one end of the crankshaft 15 (drive shaft) of the press 3 are connected by sprockets 36, 37 and a chain 38. Rotary encoder (shaft rotation angle detection means) 3
5 generates an electric pulse every time its shaft 35a rotates by a minute angle. These pulses are counted by a counter 39, and the counting information (detection angle information) is sent to the microcomputer 31. The rotary encoder 35 is at the origin during one rotation (corresponding to the top dead center of the crankshaft 15)
The Z output is sent out and the count value of the counter 39 is set to zero. As a result, the rotation angle of the crankshaft 15 can always be accurately detected.

In the above configuration, the feeding device 2 uses the air cylinder 21 to move the upper roller 12 to the lower roller 1.
The coil material 100 is biased in one direction and held between these rollers 11 and 12. In this holding state, the lower roller 11 is rotated for a certain period of time to send a certain amount of the coil material 100 to the press machine 3. On the other hand, in the press machine 3, the upper die 5 is moved up and down by the rotation of the crankshaft 15, and when the coil material 100 is stopped, each process is simultaneously pressed by a punch (not shown). A finished product is obtained by repeating the above-mentioned feeding and pressing in each step.

When the upper die 5 is lowered, the coil material 100 is punched out by the punch 8 of the position correction mechanism 7 to form a pilot hole 100a. This pilot hole 100
a is formed at intervals corresponding to the ideal feed amount by the feed device 2 each time the press work is performed. The pilot pin 7 is used as a punch for each of the above steps and the punch 8 for forming the pilot hole 100a is used as the coil material 1.
00, the insertion into the pilot hole 100a is started. If there is an error in the amount of feed by the feed device 2, the axis of the shank portion 9b may not be aligned with the pilot hole 1.
Although the lower end 9a of the pilot pin 9 has a spherical shape and acts as a guide, the shank portion 9b can be inserted into the pilot hole 100a, and as a result, the shank portion 9b
The axis of the coil material 100 can be aligned with the center of the pilot hole 100a, and the position of the coil material 100 can be corrected. As a result, each pressing step can be performed with high precision, and the pilot hole 100a can be formed at an accurate position by the punch 8.

When the position is corrected by the position correction mechanism 7 as described above, it is necessary to move the coil material 100 by a small amount, so the feeding device 2 releases the holding of the coil material 100. Specifically, by energizing the solenoid 27a, the solenoid valve 27 is switched,
Compressed air from the compressed air source 28 is supplied to the lower cylinder chamber 21 a of the air cylinder 21 , and the upper cylinder chamber 21 b is communicated with the outside air, and the compressed air pressure of the air cylinder 21 moves the upper roller 12 upward and lowers the lower roller 11 . The holding state of the coil material 100 is released.

As shown in FIG.
The most preferable point is when the needle starts to be inserted into the pilot hole 100a. Shank portion 9b of pilot pin 9
By the time it reaches the pilot hole 100a, it is already too late. In addition, the lower end 9a of the pilot pin 9
It is too early before it reaches the pilot hole 100a. This is because if the holding is released at this point, the coil material 100 will be dragged by the weight of the slack part between the leveler 1 and the feeding device 2, and as shown in FIGS.
This is because it moves to the left in the figure. In addition,
If the lower end portion 9a is just before being inserted into the pilot hole 100a, the coil material 100 will hardly move due to its own weight, so it is possible to release the holding at this point.

In the press machine 3, each pressing process is performed simultaneously, and in the process of the upper die 5 rising, the pilot pin 9 separates from the pilot hole 100a. In order to prevent the coil material 100 from moving due to its own weight, the feeding device 2 moves the coil material 100 again just before the pilot pin 9 leaves the pilot hole 100a.
hold. To be more specific, the solenoid 27a of the solenoid valve 27 is de-energized, the solenoid valve 27 is reset, and compressed air from the compressed air source 28 is supplied to the air cylinder 2.
1 to the upper cylinder chamber 21b,
The lower cylinder chamber 21a is communicated with the outside air, and the compressed air pressure moves the upper roller 12 downward. As a result, the upper roller 12 is lower than the lower roller 11.
The coil material 100 is held with the coil material 100 sandwiched therebetween. After this, the feeding operation of the coil material 100 is started again.

Next, regarding the timing of energization of the solenoid valve 27 to perform the above-mentioned releasing operation,
This will be explained based on the time charts shown in FIGS. 4 and 5. Incidentally, FIG. 4 shows a time chart when the piston section 23 starts to descend before reaching the upper limit position, and FIG. 5 shows a time chart when the piston section 23 starts to descend after reaching the upper limit position. In each figure, the point in time at which the descent begins is indicated by d. There is an operation delay time y from when the solenoid 27a starts being energized until the piston part 23 starts moving up or down. Hereinafter, this will be referred to as the start delay time. In order to simplify the discussion, it is assumed that the start delay times a to b during ascent and the start delay times c to d during descent are equal. The holding release is achieved by the piston portion 23 starting to rise. Therefore, the time point a when energization should start is determined by subtracting this start delay time y from the ideal holding release time point b.

a=b-y ...... In the case of re-holding, the operation delay time z required from when the piston part 23 starts descending until the upper roller 12 holds the coil material 100 together with the lower roller 11 is be. Hereinafter, this time will be referred to as a stroke delay time. Note that the times b to d during which the piston 23 rises and the times d to e during which the piston 23 descends, that is, the stroke delay time z, are made equal. Therefore, the time point c at which energization should be stopped is determined by subtracting the start delay time y and the stroke delay time z from the ideal re-holding time e.

c=e-(y+z) ...... When the air cylinder 21 operates as shown in the time chart of FIG. 4, the following equation holds true. However, x is the release time from the holding release point b to the reholding point e.

z=x/2…… Therefore, from and, we get the following equation.

c=e-(y+x/2) In the present invention, the releasing control device 30 can be used to start and stop energization at the above-mentioned time points a and c, respectively. More specifically, the microcomputer 31 determines the rotation angles Θa and Θc (however,
As shown in FIG. 6, the top dead center is assumed to be 0°) is calculated and stored as described later. On the other hand, in the rotary encoder 35, the crankshaft 15
Pulses are generated in accordance with the rotation, and the pulses are counted by a counter 39. This count value, that is, the detected rotation angle of the crankshaft 15 is sent to the microcomputer 31. Then, in the microcomputer 31, when this detected rotation angle matches the calculated rotation angle Θa, a holding release command signal is sent to the output circuit 32, and the output circuit 32 uses the solenoid 27a based on this signal. It is energized and energized, and the holding by the feeding device 2 is released after the start delay time y has elapsed as described above. Furthermore, when the detected rotation angle matches the calculated rotation angle Θc, the microcomputer 31 sends a holding command signal to the output circuit 32, and the output circuit 32 de-energizes the solenoid 27a based on this signal. state, and after the above-mentioned time y+z has elapsed, the feeding device 2 performs re-holding.

Next, calculation of angles Θa and Θc by the microcomputer 31 will be explained. Prior to this calculation, information such as the angle to be input to the microcomputer 31 is obtained.

The rotation angle Θb of the crankshaft 15 corresponding to ideal times b and e when the feeding device 2 should release and hold the coil material 100, respectively;
Find Θe. That is, the press machine 3 is set to the inching mode, and a motor (not shown) is driven in short periods by manual operation of a switch, thereby rotating the crankshaft 15 in small increments. Pulses from the rotary encoder 35 are counted by a counter 39 and sent to the microcomputer 31, and a display 34 displays this detected rotation angle. Then, the upper die 5 is lowered and the pilot pin 9 is inserted into the pilot hole 1 of the coil material 100 as shown in FIG.
00a, the angle Θb displayed on the display 34 is read.

When further inching is performed, the upper mold 5 eventually starts to rise, and the lower end 9a of the pilot pin 9 separates from the pilot hole 100a. The rotation angle Θe of the crankshaft 15 on the verge of separation is read on the display 34 in the same manner as described above.

Furthermore, the start delay time y from when the solenoid 27a of the electromagnetic valve 27 is energized until the piston portion 23 of the air cylinder 21 starts moving is measured.
Further, the time z ₀ required for the piston portion 23 to start rising from the position where the coil material 100 is held and reach the upper limit position is measured. Note that this time z ₀ is referred to as a total stroke delay time. It is easy to keep the air pressure of the air cylinder 21 constant, and therefore the above-mentioned times y and z ₀ can be kept constant, and once these are input into the microcomputer 31, there is no need to change them thereafter. .

The angle information Θb, Θe displayed on the display 34 and the measured times y, z are input from the setting device 33 to the microcomputer 31.

Furthermore, the press machine 3 is set to normal operation mode,
The crankshaft 15 is rotated within a predetermined angle range, e.g.
Measure the time t required to rotate 4 degrees from 16 degrees to 20 degrees. This measurement is performed by the microcomputer 31.
This is done using the timer function. This measurement value is
It represents the rotational speed of the crankshaft (drive shaft), and this value is automatically stored in the microcomputer 31. Therefore, here, certain functions of the microcomputer 31, the rotary encoder 35, and the counter 39 are combined with the shaft rotational speed input means 1 of the components shown in FIG.
05.

The microcomputer 31 performs the following calculation based on the above information.

The angle of the crankshaft 15 corresponding to the releasing time x, that is, the releasing angle Θx is determined from the following equation.

Θx = Θe − Θb ...... Crankshaft 1 corresponding to start delay time y
5, that is, the start delay angle Θy, is determined from the following equation.

Θy=4°×y÷t ...... Also, the rotation angle of the crankshaft 15 corresponding to the total stroke delay time _z0 , that is, the total stroke delay angle _Θz0, is determined from the following equation.

Θz ₀ =4°×z ₀ ÷t ......Then, by comparing the magnitudes of Θx/2 and Θz ₀ , it is determined whether the air cylinder 21 is in the operating mode shown in FIG. 4 or in the operating state shown in FIG. That is, in the case of FIG. 4, Θx/2<Θz ₀ In the case of FIG _. The rotation angles Θa and Θc of the crankshaft 15 corresponding to the times a and c when the command should be output, in other words, when the energization should start and end, are calculated.

Regardless of whether the air cylinder 21 operates in the manner shown in FIG. 4 or FIG. 5, the angle Θa can be determined by the following equation.

Θa = Θb - Θy ...... The formula is derived from the equation because time and angle are in a proportional relationship.

The angle Θc is obtained from the following equation.

Θc＝Θe−(Θy＋Θz)
(See formula) In the above formula, Θz is the rotation angle corresponding to the stroke delay time z, and the way to obtain this angle Θz differs depending on the operating mode of the air cylinder 21. Fourth
In the operating mode shown in the figure, Θz = Θx/2 (see formula)
Therefore, Θc can be found by the following formula.

Θc=Θe−(Θy+Θx/2)
......' (Refer to the formula) In addition, in the case of the operating mode shown in Fig. 5, the stroke delay time z is equal to the total stroke delay time z ₀ , and Θz = Θz ₀ , so Θc is obtained by the following formula. .

Θc=Θe−(Θy+Θz ₀ ) ………″ As mentioned above, the angles Θa and Θc can be easily determined by the calculation of the microcomputer 31. Note that when changing the rotational speed of the crankshaft 15, the time It is sufficient to newly input only t and perform the calculation.

This invention is not limited to the above-mentioned embodiments, and various embodiments are possible. For example, as shown in FIG. 9, release of holding by the feeding device 2 and reholding may be detected by a limit switch 40 or the like. Specifically, the limit switch 40 is supported in a fixed position, and the upper roller 12 is lowered to release the coil material 10.
0 together with the lower roller 11, the slider 25 switches the limit switch 40.
Press the actuator 41 of the limit switch 40.
is turned ON, and when the upper roller 12 rises away from the position where it can be held, the limit switch 40 is turned on.
Turn it off. The microcomputer 31 calculates the rotation angle of the crankshaft 15 corresponding to these times f and g from the time when it receives the ON/OFF signal of the limit switch 40 (that is, the actual holding release time f and the actual re-holding time g). Θf,
Calculate Θg, and combine this with the ideal holding release point b,
The rotation angles Θb and Θe corresponding to the re-holding point e are compared, and depending on the deviation, the rotation angles Θa and Θc corresponding to the points a and c at which the energization of the solenoid valve 27 should be started and energized are stopped. Auto-correct. Then, release control is performed again based on this corrected calculated value. By repeating the above correction, the actual holding release and reholding times f and g can be made to coincide with the ideal times b and e.

Further, in the present invention, a hydraulic cylinder may be used instead of the air cylinder for releasing.

In the feeding device, instead of feeding the coil material by rotationally driving a roller, the coil material may be sent by having a pair of upper and lower pressing members and moving the pressing members.

The feeding device may also serve as a leveler for correcting curls in the coil material. Furthermore, the feeding device is the seventh
It may be placed on the right side of the press in the figure.

(Effect of the invention) As explained above, in this invention, the releasing angle (holding release angle and reholding angle)
By setting , inputting the operation delay time of the feeder, and further inputting the rotational speed of the drive shaft, calculate the angle at which the holding release command should be issued and the angle at which the reholding command should be issued, taking into account the delay time. do. Then, when the rotation angle of the drive shaft matches the calculated angle, a holding release command and a reholding command are output to the feeding device. Therefore,
Release control can be performed accurately without mechanical adjustment by trial and error.

Further, according to the present invention, even when the rotational speed of the drive shaft is changed, the delay angle corresponding to the operation delay time of the feeder is automatically calculated, and the holding release command angle is automatically calculated based on the result. and calculate the re-holding angle. Therefore, even if the number of presses of the press per unit time is changed, there is no need for any mechanical adjustment.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a releasing control device of the present invention, and FIG. 2 is a diagram for explaining the operation of the device. 3 to 8 show an embodiment of the present invention, FIG. 3 is a schematic diagram of a feeding device and a releasing control device, and FIGS. 4 and 5 show different operations of the air cylinder. Fig. 6 is a diagram showing the rotation angle of the crankshaft of the press machine, Fig. 7 is a schematic side view showing a device for guiding the coil material to the press machine, and Fig. 8 is a diagram showing the time chart for each embodiment. FIG. 2 is an enlarged vertical cross-sectional view showing a position correction mechanism of the press. Furthermore, Figure 9,
FIG. 10 shows another embodiment, FIG. 9 is a schematic diagram of the feeding device, and FIG. 10 is a time chart. 2,103...Feeding device, 3...Press machine, 7
... Position correction mechanism, 15 ... Crankshaft (drive shaft), 30 ... Releasing control device, 31 ... Microcomputer, 35 ... Rotary encoder (shaft rotation angle detection means), 100 ... Coil material ( press processing materials),
101...Shaft rotation angle detection means, 102...
...Release angle setting means, 104...Delay time input means, 105...Shaft rotation speed input means, 106...First calculation means, 107...Second calculation means, 108...Release command signal output means.

Claims (1)

[Claims] 1. A device that holds a material for press processing and sends it to a press machine, releases the holding state when the press machine corrects the position of the material and presses it, and then holds and sends the material again. A releasing control device for controlling the above-mentioned holding release and reholding in,
The above-mentioned holding release and re-holding timing is related to the rotation angle of the drive shaft of the press machine, which includes: (a) shaft rotation angle detection means for detecting the rotation angle of the drive shaft of the press machine; ) a releasing angle setting means for setting the holding release angle and the reholding angle; (d) a shaft rotational speed inputting means for inputting the rotational speed of the drive shaft of the press; (e) a shaft rotational speed inputting means for inputting the rotational speed of the drive shaft of the press; (f) first calculating means for calculating delay angles corresponding to the two types of delay times, respectively, according to the rotational speed of the drive shaft inputted from the rotational speed inputting means; (g) a second calculation means for obtaining a holding release command angle and a reholding command angle by subtracting each delay angle output from the first calculation means from the holding release angle and reholding angle; When the angle detected by the rotation angle detection means matches the holding release command angle outputted by the second calculation means, a holding release command signal is output to the feeding device, and the detected angle matches the reholding command angle. 1. A releasing control device for a feeding device for press working materials, comprising: a releasing command signal output means for outputting a re-holding command signal to the feeding device when the re-holding command signal is released.